LIBRARY
OF THE
UNIVERSITY OF CALIFORNIA.
GIFT OK
Class
.
U. S. DEPARTMENT OF AGRICULTURE.
DIVISION OF CHEMISTRY.
BULLETIN No. 13.
FOODS
FOOD ADTTLTEKANTS.
INVESTIGATIONS MAKE FNDEli DIRECTION OF
H. W. WILEY,
ClIIKF C'UKMIST.
PART SEVENTH.
TEA, COFFEE, AND COCOA PREPARATIONS.
BY
GUILFORD L. SPENCER, Assistant Chemist,
WITH THE COLLAP,' NATION OF MK. ERVIN E. EWELL.
PUBLISHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE.
WASHINGTON:
G < > V 1 ; U N ^I E N ']' PRIX ri I X Cr O F F I ( ' E ,
1 S «,t L' .
U. S. DEPARTMENT OF AGRICULTURE.
DIVISION OF CHEMISTRY.
BULLETIN No. 13.
FOODS
AND
FOOD ADULTERANTS.
INVESTIGATIONS MADE UNDER DIRECTION Or
H. W. WILEY,
CHIEF CHKMIST.
PART SEVENTH.
TEA, COFFEE, AND COCOA PREPARATIONS,
35Y
GUILFORD L. SPENCER, Assistant Chemist,
WITH THE COLLABORATION OF MR. ERVIN E. EWELL.
PUBLISHED BY AUTHORITY OP THE SECRETARY OP AGRICULTURE..
WASHINGTON:
GOVERNMENT PRINTING OFFICE,
1892,
TABLE OF CONTENTS.
Page.
Letter of transmitted v
Letter of submittal vii
Tea : 875
Statistics of tea consumption 875
General classification 875
Methods of manufacture 876
Black teas 876
Green tea , 878
Adulteration — definition 879
Adulteration — methods 880
Detection of facing 881
Spent or exhausted leaves 882
Foreign leaves 883
Foreign astringents 885
Added mineral matter 885
. Lie tea 886
General remarks on tea adultcran ts 886
General statements concerning the constituents of teas 887
Analytical methods 889
General remarks to analysts 892
Report of the examination of teas bought in the open market 892
Conclusion 898
Coffee 899
Statistics of consumption 899
General statements 900
Chemical composition 901
Methods of analysis 907
Adulteration — definition 908
Adulterants and their detection 909
Substitutes for coffee 914
Imitation coffees 915
Detection of imitation coffees 920
Report of examination of samples bought in the open market ..' 921
Roasted coffees 926
Green coffees 927
Ground coffees 927
Extracts 929
Substitutes 932
Conclusion 932
Cocoa preparations 933
Nature, source, commercial importance, etc., of the cocoa, bean 933
Chemical constituents 935
The commercial preparations of the cocoa bean, their nature, methods
of preparation, and adulteration , 941
Microscopical examination 946
III
IV
CONTENTS ILLUSTRATIONS.
Cocoa preparations — Continued. . Page.
Methods of analyses reported by various chemists 949
Summary of results obtained by various chemists 959
Analyses of cocoa beans made by various chemists 960
Analyses of the husks from cocoa beans reported by various chemists.. 962
Analyses of commercial preparations of cocoa beans reported by various
chemists 963
Ash analyses reported by various chemists 969
Results of the examination of cocoa preparations in the laboratory of
the U. S. Department of Agriculture 970
Description of samples of cocoa preparations examined in the laboratory
of the U. S. Department of Agriculture 971
Analyses of cocoa preparations made in the laboratory of the U. S. De-
partment of Agriculture • 980
Discussion of results obtained 987
Appendix A. — Bibliography of the literature of tea, coffee, and cocoa prepa-
rations 991
Appendix B. — United States tea adulteration law 1011
Appendix C. — Abstracts from the Italian law relating to the adulteration of
foods 1013
List of leaves, illustrated by Plates XXXIX-XL 1014
LIST OF ILLUSTRATIONS.
Plate XXXIX. Genuine tea leaves and possible adulterants ................
XL. Genuine tea leaves and possible adulterants ................
XLI. Tea leaf, upper and lower surface of epidermis ..............
XLII. Stone cell of tea leaf; seed coat of coffee ....................
XLIII. Raw coffee ; wheat bran, outer layer .................... ...
XL1V. Wheat bran, second and gluten layers ......................
XLV. Roasted chicory: parenchyma and milk vessels; pitted cells.
XLVI. Cocoa, epidermis of husk; cocoa husks, thick Availed cells..
XL VII. Cocoa husk, thin membrane ; section of cotyledon of cocoa..
Page.
1014
1014
1014
1014
1014
1014
1014
1014
1014
LETTER OF TRANSMITTAL
IT. S. DEPARTMENT OF AGRICULTURE,
DIVISION OF CHEMISTRY,
Washington, 7). <7., March 1, 1892.
SIR: I beg to transmit herewith for your inspection and approval the
manuscript of Part Seventh of Bulletin No 13, relating* to the adultera-
tion of coffee, tea, and chocolate.
Respectfully,
H. W. WILEY,
Chemist.
Hon. J. M. RUSK,
Secretary of Agriculture.
LETTER OF SUBMITTAL
IT. S. DEPARTMENT OF AGRICULTURE,
DIVISION OF CHEMISTRY,
Washington, J). C., February 39, 1892.
SIR : I herewith submit to you the report which has been prepared
by Mr. E. E. Ewell and myself upon investigations of tea, coffee, and
cocoa preparations. That part of the report and bibliographic, work
upon cocoa preparations is entirely due to Mr. Ewell, who has also
assisted in the general analytical work. I also acknowledge the assist-
ance of Messrs. McElroy, Trescot, Krug, and Sanborn.
This report has been unavoidably and materially delayed in its prepa-
ration, but this time has not been lost, since much of the foreign and
other work on artificial coffees has been accomplished since it was
begun.
Respectfully,
. Gr. L. SPENCER,
Assistant Chemist.
Dr. H. W. WILEY,
Chief Chemist.
VII
FOODS AND FOOD ADULTERANTS.
PART VII— TEA, COFFEE, AND COCOA PREPARATIONS.
TEA.
Tea is prepared from the various species of Thca. This plant is a
hardy evergreen shrub.
STATISTICS OF TEA CONSUMPTION.
The extent of the consumption of teas is shown by the following State-
ments obtained from the United States Treasury:
Imports of lea lex* tlic amount exported.
1890.
1889.
1888.
1887.
Pounds.
round*.
rounds.
I'ounth.
83, 494, 95G
79, 192, 253
83, 944, 547
87,481,186
The present per capita consumption of tea. in the United Stales is
approximately 1.3.3 pounds.
We derive about 51 per cent of our tea from China, 42 per cent from
Japan, and all but a small fraction of a per cent of the remainder from
the British possessions.
GENERAL CLASSIFICATION.
Teas are usually designated as black or green, the name depending
upon the color of the prepared leaf, due to the methods of curing and
not, as formerly supposed, to differences in species.
Col. Money,1 in his work on tea cultivation, gives an illustration, from
which the following is taken, indicating the leaves which constitute
JTea cultivation, 3d eel., page 102 et xeq., Lieut. Col. Money; London, \\. B. Whiting-
hani & Co.
875
FOODS AND FOOD ADULTERANTS.
each of the different kinds of tea as classified according to the age of
the leaf.
WSCHOLL
FIG. 27. — a, Flowery Pekoe; 6, Orange Pekoe; c, Pekoe; d, Souchong 1st; e, Sou-
chong 2nd; /, Congou. — a, 1> (when mixed together), Pekoe; «, b, c, d, c (when
mixed together), Pekoe Souchong.
If there be another leaf below /, and it be taken, it is named and would make
Bohea.
Each of these leaves was first a flowery Pekoe leaf (a), it then became /*, then c,
and so on.
At the base of the, leaves c, d, c, f, exist buds 1, 2, 3, 4, from which new shoots
spring.
METHODS OF MANUFACTURE.
The methods of preparing teas differ in the different countries in
which this commodity is grown. In India the manufacturing processes
are very much simplified, and the greater portion, if not all the work,
is accomplished by machinery; thus the leaves only come in contact
witli the hands of the laborers in picking.
1U.ACK TKAS.
1 The methods of the manufacture of black teas in Japan is essen-
tially as follows:
The leaves are withered by exposure to the sun, fire being used only
1 Abstracted from Hnlletin Xo. 7, Iin)icri:il < 'iillc-jv ul Agriculture, Tok\ <>. Ki>mal>a.
Japan. V. Ko/ai.
TEAS METHODS OF MANUFACTURE. 877
in cloudy or rainy weather. An hour's sunning is usually sufficient.
After withering, the leaves are rolled and twisted. Black teas are
usually rolled in an apparatus made especially for this purpose. The
rolled leaves are now subjected to a fermentation. This is a very im-
portant operation since its influence on the quality of the tea is consid-
erable. During this operation the leaves lose their disagreeable raw
odor and acquire a fine flavor and the desired tint. One method of
fermenting the leaves is to make them up into small balls, which are
placed in shallow bamboo trays, covered with a white cloth, and set
aside in a sunny place. A second method is to spread the leaves in a
tray, press them together, cover and place them in a sunny place as
above. The progress of the fermentation is determined by the appear-
ance of the leaves, the full time required being about an hour. After
fermentation the leaves are exposed in a thin layer to the sun. During
this sunning the green color of the leaves gradually changes to a black.
The next process is termed the "firing." The leaves are placed in a
tray over a charcoal fire. The temperature gradually increases as the
moisture is driven off. The leaves are constantly turned to insure uni-
form drying. The leaves are transferred to another tray carefully
mixed, and the drying repeated until they are dry. The final operation
consists in passing the leaves through sieves of different meshes and
packing. The tea is divided into three classes depending upon the size
of the leaves, viz, Pekoe (the leaf buds), Souchong, and Bohea.
As already stated, these manipulations are very much simplified in
India. According to Col. Money J the operations practiced in the older
tea countries have been reduced from twelve to five. Col. Money states
that the brokers in India judge of the quality of the teas by the fol-
lowing examination:
They judge from three things, (1) the tea (t. c., the prepared leaf), (2) the liquor,
(3) the out-turn.2
The tea. — The color should be black, but not a dead black, rather a grayish black
with a gloss on it. No red leaf should be mixed with it, it should be all one color.
The tea should be regular : that is, each leaf should be about the same length, and
should have a uniform twist, in all but " broken teas." (These latter are called
" broken," because the leaf is more or less open and broken.) The tea should also be
regular of its kind, that is, if Pekoe all Pekoe, if Congou all Congou; for any stray
leaves in a tea, even if of a better class, will reduce its value. In the high class of'
teas, viz, Pekoe and broken Pekoes, the more Pekoe tips that are present the higher,
in consequence, will its price be.
The liquor. — In taste this should be strong, rasping, and pungent, in case of Pekoes
a "Pekoe flavor." There are other words used in the trade to particularize certain
tastes, but the words themselves would teach nothing. Tea-tasting can not be
learned from books. If the liquor is well flavored, as a rule, the darker it is in the
cup the better. But to judge of teas by the color of the liquor alone is impossible,
for some high-class teas have naturally a very pale liquor.
1 Tea cultivation, Lieut Col. Edward Money. W. B. Whittingham & Co., Lon-
don.
*The out-turn consists of the tea leaves after infusion.
878 FOODS AND FOOD ADULTERANTS.
The out-turn. — A good out-tnrn is generally indicative of a good tea. It should
he all, or nearly all, one color. No black (burned) leaves should appear in it. A
greenish tinge ill some of the leaves is not objectionable, and is generally indica-
tive of pungent liquor, but the prevailing color should be that of a bright new
penny.
GREEN TEA.
The leaves are first steamed until they lose their elasticity. The
operations of rolling' and drying follow the steaming. The leaves are
finally ported by means of a series of sieves. In China, instead of
steaming the leaves as practiced in Japan, they are heated in a pan
over a charcoal fire.
The Japanese sometimes prepare a tea which they term " flat tea."
In this tea the leaves, as the name indicates, are not rolled. They are
obtained from plants which are kept in darkness for a week or two
before picking; keeping the plants in darkness is said to produce a fine
aroma.
The operations of tea manufacture require considerable skill and ex-
perience. At certain stages of the work an error may ruin the quality
of the product.
In general the quality of a tea depends upon the age of the leaf, also
upon the time of picking. The leaves gathered after the first and second
picking (as high as twenty-five pickings are made in India) gradually
become tougher and less juicy as the season advances.
The India teas are usually very much stronger than those from
China and Japan, one part giving an infusion as strong as three parts
of that from the latter countries. To those persons who have acquired
a taste for the Chinese and Japanese teas, those from India at first
seem too strong and the flavor is not as agreeable as would be expected
from the high price of these teas. It is an excellent plan to add a cer-
tain proportion of India tea to the Chinese or Japanese product, the
strength and usually the flavor of the latter being considerably im-
proved by this mixture.
As has been stated the leaves of the India teas only come in contact
with the hands of the workmen at the time of picking; this may also be
said to a certain extent in regard to the Japanese teas, whereas those
of Chinese origin are manipulated almost entirely by hand, and even the
feet are sometimes used in rolling some of the cheaper grades.
The black teas have grown in favor to such an extent in England that
now but a small proportion of the teas consumed are green. This is
largely due to the supposition that the black teas contain less astrin-
gent matter and also act to a less extent upon the nerves. The fol-
lowing analyses from the valuable bulletin of Mr. Y. Koxai (/or. r/7., p.
24) show in parallel columns the percentage composition of black and
green teas made from the same leaves. In this experiment Mr. Ko/ai
took special precautions in sampling the leaves in order that the teas
might have identically the same composition provided the chemical
TEA ANALYSES ADULTERATION DEFINED.
879
changes were the same and of the same extent. These analyses are of
especial value on account of Mr. Kozai's knowledge of tea manufacture
and his residence in a tea-producing country. The percentages are
referred to the dry matter.
Original
leaves.1
Green
tea.
Black
tea.
37 33
37 4ij
38 90
Crude fiber
do .
10.44
10 06
10 07
do
6 49
5 52
5 82
do
27 86
31 43
35 39
Ash
do
4.97
•1 92
4 93
do .
3 30
3 20
3 30
Tannin 2
do ....
12. 91
10 61
4 89
do
50.97
53 74
47 ''3
do . ..
5. 97
5 99
6 22
Albuminoid nitrogen
do....
4.11
3.94
4 11
do
0.96
0 93
0 96
Amide-nitrogen
....• do....
0.91
1.13
1.16
1 Portion of original sample of leaves dried at 85° C.
2 Calculated as gallotanic acid.
This table shows the marked difference between the composition of the
green and the black .teas. In the black tea there is a very considerable
increase in the " other nitrogen-free extract." This increase has evi-
dently taken place at the expense of the tannin, a part of which has been
decomposed during the fermentation. This reduction in the tannin is
probably one of the reasons why black is considered more wholesome
than green tea by the English, but the change in the tanniu alone will
not account for this preference. There are not sufficient data concerning
the " other nitrogen-free extract" and other constituents for a further
discussion of this question or for a statement as to whether this pref-
erence for black tea by the English is not merely a prejudice.
ADULTEKATION — DEFINITION.
The law of th<* State of New York (see Part 2, Bulletin 13, p. 239)
defines adulteration of food as follows :
The term " food," as used in this act, shall include every article used for food or
drink by man. The term " drug," as used in this act, shall include all medicines for
internal and external use.
b. In the case of food or drink.
(1) If any substance or substances has or have been mixed with it so as to
reduce or lower or injuriously affect its quality or strength.
(2) If any inferior or cheaper substance or substances have been substituted
wholly or in part for the article.
(3) If any valuable constituent of the article has been wholly or in part
abstracted.
(4) If it be an imitation of, or be sold under the name of, another article.
(5) If it consists wholly or in part of a diseased, or decomposed, or putrid, or
rotten animal or vegetable substance, whether manufactured or not, or,
in the case of milk, if it is the produce of a diseased animal.
880 FOODS AND FOOD ADULTERANTS.
ft. In the case of food or drink. — Continued.
(6) If it be colored, or coated, or polished, or powdered, whereby damage is
concealed or it is made to appear better than it really is or of greater
value.
(7) If it contain any added poisonous ingredient or any ingredient which
may render such article injurious to the health of the person consuming
it: Provided, That the State board of health may, with the approval of
the governor, from time to time declare certain articles or preparations
to be exempt from the provisions of this act: And provided further, That
the provisions of this act shall not apply to mixtures or compounds rec-
ognized as ordinary articles of food, provided that the same are not
injurious to health and that the articles are distinctly labeled as a mix-
ture, stating the components of the mixture.
Under this definition the following may be classed as the adultera-
tions of teas :
(1) Facing (6).
(2) The addition of spent or partially exhausted leaves (3).
(3) The addition of foreign leaves (1).
(4) The addition of foreign astringents and substances designed to
affect the apparent quality or strength (1).
ADULTERATION — METHODS.
Facing. — The treatment of teas with various coloring matters, a
process termed facing, comes properly under the head of adulterants.
Facing consists in treating the prepared leaves with mixtures contain-
ing Prussian blue, turmeric, indigo, or plumbago to impart some favorite
color or gloss to the leaf and always has a fraudulent intent. Leaves
which have been damaged in the manufacture or which from their age
or certain imperfection are inferior are faced to improve their appear-
ance and price. The teas consumed by the Chinese and Japanese them-
selves are not faced, while those for export seldom escape this treatment.
The Chinese and Japanese black teas are usually treated with plumbago
(black lead). There is no evidence that these facing agents are delete-
rious to the health in the quantities in Avhich they are employed, but in-
asmuch as they add a useless foreign matter to the teas for the pur-
pose of deception their use should be discouraged. "Prussian blue is
insoluble in water and alcohol. * * * It is deemed a tonic, febrifuge,
and alterative, but is at present rarely used. * * * The dose is
from 0.2 to 0.33 gram repeated several times per day and gradually in-
creased until some effect is produced."1
In order to take the amount of Prussian bine stated above as a single
dose in the form of tea-facing, one would have to consume nearly a
pound of tea. It would require a long time under these conditions for
even an inveterate tea-drinker to consume this amount of Prussian
blue.
llassall2 includes Prussian bine in his list of substance •- more or less
injurious."
1 Sr,- T. S. Hispcnsatui v. Mill ••.!., p. 1171.
Food, by A. II. Hassall, p. 254.
TEAS METHODS OF ADULTERATION. 881
The remarks on Prussian blue apply to other facing materials, espe-
cially in regard to the large quantity of tea that must be consumed in
order to take even the smallest medicinal dose of the coloring matter.
The amount of coloring and inert matter (the latter often soapstone)
usually amounts to a very small percentage of the weight of the tea,
though statements have been made that the facing sometimes amounts
to as much as from 1 to 3 per cent.1 According to Y. Kozai2 the
maximum amount of facing in the green teas of Japan is about 0.4 per
cent. Excessive facing is evidently a fraud, as it increases the weight
and price of tea without giving the purchaser a fair return for his money.
DETECTION OF FACING.
Facing is usually easily detected by the microscope. A portion of the
leaf is mounted as an opaque object, the coloring matter appearing in
small dots.
Prussian blue. — This substance is easily detected by means of the
microscope. Shake the leaves in a glass cylinder with water and exam-
ine the detached particles with the microscope. If the coloring matter
sought is present, transparent particles of a brilliant blue may be seen.
Prussian blue may often be identified by the microscope on the leaf
mounted as an opaque object. The particles detached as above may be
examined chemically as follows : Treat with hot sodium hydroxide solu-
tion, acidulate with acetic acid, and add ferric chloride. If Prussian
blue was present in the facing the characteristic blue precipitate will be
formed. The powdered tea leaf may be examined by the chemical
method, but it is advisable to remove the tannin by precipitation with
gelatiir solution and filtration through powdered kaolin, after acidulat-
ing with acetic acid. The color of Prussian blue is discharged by
sodium or potassium hydroxide.
Indigo. — Under the microscope indigo appears of a greenish blue.
Its color is not discharged by sodium hydroxide, a distinction from
Prussian blue. Indigo forms a deep blue solution with sulphuric acid.
Turmeric. — Turmeric is identified by means of the microscope.
According to Hassell (op. c//., 143) turmeric consists of characteristic
yellow cells of a rounded form which are filled with peculiar shaped
starch granules. On the addition of an alkali the cells turn brown,
swell up, and the outlines of the starch granules become visible.
Plumbago. — The microscope is employed in the detection of plumbago.
A thin slice of the tea leaf will exhibit numerous bright particles if
plumbago facing has been used.
Gypsum j soapstone, etc. — These substances, employed with the color-
ing matter in facing teas, may be separated by shaking the leaves in a
cylinder with water. The sediment is examined by the usual qualita-
tive, methods for these substances.
1 Food, A. H. Hassall, pp. 122 to. 129.
8 Bulletin No. 7, Imperial College of Agriculture, p. 28.
3 See method for estimation of tanniu, p. 890,
882
FOODS AND FOOD ADULTERANTS.
SPENT OR EXHAUSTED LEAVES.
The detection of spent or partially exhausted leaves in teas is not a
simple problem. The chemical methods all depend upon the proportion
of certain of the soluble > constituents which remains in the tea leaves.
A large number of analyses of genuine teas made by different chemists
show a very wide range in the percentage composition of teas 5 hence
the difficulty in obtaining a basis for comparison. A genuine tea may
contain as little as 10 per cent tannin or even less, and as high as 25
per cent. It is evident from this that the percentage of tannin can not
be depended upon for the detection of the admixture of spent leaves.
A large quantity of such exhausted leaves would be required to reduce
a tea containing a high percentage of tannin to the average percentage.
The same may be said, in a measure, of each of the soluble constituents
of the leaves. Hence, we see the difficulty in securing data of value on
this point from a determination of the soluble matters. The only
estimation of this kind that is of value, and its value it must be said is
but relative, is the percentage of extract matter. A large number of
analyses by different authorities shows a range in the extract matter
of from 26 to 50 per cent of the air-dried tea. This extract is not the
total soluble matter of the prepared leaf, bat is the soluble matter
extracted under certain conditions which are fully described on page 892.
One of the most valuable series of analyses of genuine teas that have
been made is that of Mr. Joseph F. Geisler.1 This chemist obtained
the following averages of extract matter:
Moist-
ure.
Extract-
half hour
boiling
in 100 parts
water.
Total
extract.
Indian tea:
Per cent.
6.19
Per cent.
39.66
Per cent.
45.64
5.50
37.80
41.32
5.81
38.77
42.04
V veraire for tea dried at 100° C
41.13
45.58
Oolong tea :
G. 88
44.02
48.87
5.00
34.10
40.60
5.89
37.88
43.32
Average for tea dried at 100° C. . .
40.22
46.03
Congou tea:
9.15
:»2. 14
37.06
7.65
23.48
•11. 48
Average , ,
9.^7
28.40
::i.:;r.
Average for tea <lr}e(] at 100° C . .
30.98
:i7.4*
Formula' have been given, notably by Allen, lor the calculation «»!'
the proportion of spent leaves from t lie a mount of extract matter. Little
'.Josuph V. (icislcr in AIM. (Jror.-r, O«-t«>l>rr L'li. 1SSI; :i|s,, in 1'ivsrot f« O
Analysis, |ip. r>()f» (<> fill.'.
TEAS ADULTERATED WITH FOREIGN LEAVES.
883
reliance can be placed on the results of such calculations, owing to the
sources of error already named. If a tea contains less extract matter
than the minima given by G-eisler, the kind of tea being taken into
account, it may be placed on the doubtful list, and if all other conditions
agree it may be considered to have been adulterated by the addition of
spent leaves. In investigating this form of adulteration the appear-
ance of the leaf must largely determine the chemist's decision. If the
leaves are very much broken, frayed, or partly unrolled, there is evi-
dence of spent tea. For the examination, the suspected sample is
soaked in water and the softened leaves are unrolled and examined on
a glass plate. The following averages of the soluble constituents of
genuine teas are given for comparative purposes. The analyses of
Geisler are given above, so far as they relate to the extract.
Table nhowiny the maxima, minium, and mean percentages of the principal soluble con-
stituents of tea.
Indian
teas,
Jos F.
Geisler.
Indian
and Cey-
lon teas,
David
Hooper.
Black
teas,
A. H.
Hassall.
Oolong
teas,
Jos. P.
Geisler.
Congou
teas,
Jos. F.
Geisler.
Green
teas,
A. H.
Hassall.
Oolong
teas,
Jesse P.
Batter-
shall.
Japan
teas,
Jesse P.
Batter-
shall.
("Maxima . .
18.80
21.22
20.07
13.89
Tannin. < Minima- . .
13.01
10.14
11.93
8.44
[Mean
14.87
16.62
16.38
11.54
1 Maxima . .
3.30
3.04
3.50
2.87
2 79
Minima . . .
1.80
1.36
1 '5
1 70
1 08
Mean
2.70
2.08
2.32
2.37
2 17
[Maxima ..
3. 68
3.17
3.52
Solu,1)ltl Minima...
3. 2t
2.60
2.28
(Mean
3.52
3.20
3.06
3 44
3 60
The differences between the highest and lowest percentages of each
constituent are so marked that little possibility of detecting other than
exceedingly gross adulteration, by the admixture of spent leaves, is
afforded by these analytical data.
The total ash of genuine teas, according to various authorities, ranges
from a little below 5 to nearly 7 per cent, the iron from .08 to .17 per
cent, and the silica from .14 to .80.
FOREIGN LEAVES.
The addition of foreign leaves is best detected by means of the micro-
scope. The leaf of the tea plant is quite characteristic in its venation,
serration, and stomata. The veins recurve before reaching the border
of the leaf and each forms a loop with its neighbor. The serrations are
almost lacking in very delicate leaf buds, but are very distinct in the
older leaves. Plates xxxiv and XL have been prepared to illustrate
the leaf of the tea plant and other leaves which are said to have been
20393— :NO. 13 2
884 FOODS AND FOOD ADULTERANTS.
used in the adulteration of teas. These illustrations were prepared
from photographic prints made by the following simple method. The
natural leaf was used in making an ordinary silver print, precisely as
the photographer would employ a negative. The finished print was
copied by a photoengraving process. Many of these illustrations show
even the delicate veins of the leaves; the tea leaf, however, is quite
fleshy, and did not yield a photographic print as distinct as those from
the other plants. The lower epidermis of the leaf contains most o£ the
stomata, which are surrounded by curved cells. There are few stomata
in the upper epidermis. The stomata are shown in Plate XLI.
Hairs are very numerous on the younger tea leaves, but sometimes
entirely wanting in old leaves. They always contain theine. Dr.
Thomas Taylor,1 in a report to the Department, mentions the presence
of stone cells in tea leaves and states that his observations confirm
those of Blyth in regard to the absence of these formations in certain
leaves, viz, those of the willow, sloe, beech, Paraguay tea, ash, black
currants, two species of hawthorn, and raspberry. Dr. Taylor also
reports th e presence of stone cells in the leaves of the Camellia Japonica,
a plant related to the tea. Dr. Taylor prepares the sample of the leaf
for examination by boiling three minutes with a strong caustic soda or
potash solution. After the boiling a fragment of the leaf is placed on
a slide under a cover glass and the latter is pressed down firmly with a
sliding motion until the specimen is thin enough for microscopic exam-
ination. The stone cells appear as shown in Plate XLII.
In the general study of the serration and venation of a tea leaf the
specimen should be steeped in hot water, and, after softening, the leaves
should be unrolled and spread upon a glass plate for examination by
transmitted light. Even small fragments of tea leaves will usually show
some distinctive characteristic. In general in may be stated that a
microscopic examination is only necessary in exceptional cases. In
doubtful samples the stomata should be examined, and a search should
be made for stone cells; the epidermis of both the upper and lower leaf
should be examined. Even in the case of dust the microscope will fur-
nish conclusive evidence as to whether it is from tea or some other
plant.
According to Blyth2 every part of a theine-producing plant, even the
minute hairs, contain this alkaloid. The writer cited employs the fol-
lowing method in examining a leaf fragment for theine:
The leaf or fragment of a leaf is boiled for a minute in a watch glass with a very
little water, a portion of burnt magnesia of equal bulk is added, and the whole
heated to boiling and rapidly evaporated down to a large-sized drop. This drop is
transferred to a subliming cell, * * * and, if no crystalline sublimate be
obtained when heated to 110° (a temperature I'm above the subliming poiut of
theine), the fragment can not be that of a tea leaf. On the other hand, if a subli-
mate of theino in obtained it is not conclusive evidence of the presence of a tea leaf,
since other plants of the camellia tribe contain the alkaloid.
1 Annual Report of the Secretary, 1889, p. 192.
2 Foods: Their Composition and Analysis, A. W. Blyth, p. Hi'i'.
MINERAL MATTER IN TEAS. 885
Theine is detected under the microscope by the appearance of the
crystals.
The ash of suspected leaves should be examined for manganese and
potassium, since both these substances are always present in the tea
leaf.
A low proportion of soluble ash is an indication of foreign leaves,
since the ash of leaves suitable for use as an adulterant usually con-
tains a low percentage of soluble matter as compared with that from
tea. Facing renders dependence upon the proportion of insoluble ash
rather uncertain, as this form of adulteration, if excessive, may increase
the amount of insoluble mineral matter to a considerable extent.
A careful review of the methods of detecting foreign leaves shows
the microscopic to be the only methods to be relied upon in all cases.
FOREIGN ASTRINGENTS.
Catechu. — Teas are sometimes treated with this substance to increase
their astringency and indicate a greater strength than they naturally
possess.1 Hager's method for the detection of catechu gave very satis-
factory results in the Department's investigations. Small quantities of
the substance can not be detected with certainty. The following is a
general description of Hager's method :
Boil an extract of tea (1 gram per 100 cc. water) with an excess of
litharge ; filter ; the nitrate should be clear. To a portion of the nitrate
add a solution of nitrate of silver. In the presence of catechu a yellow
flocculent precipitate is formed, which rapidly becomes dark. Under the
same conditions pure tea gives a slight grayish percipitate of metallic
silver. The writer prefers a modification of this test, using ferric
chloride instead of the silver. Einse a small porcelain dish with a
dilute solution of ferric chloride; a sufficient quantity of the reagent
will adhere to the dish. Add the suspected solution, prepared accord-
ing to Hager. If catechu is present a characteristic green precipitate
is formed.
ADDED MINERAL MATTER.
Soapstone, gypsum, etc. — These substances, as has been stated, are
detected by the ordinary methods of qualitative analysis, the particles
to be examined being separated from the leaves by shaking in a cylinder
with water.
Iron salts. — Sulphate of iron is said to be occasionally added to a tea
to deepen the color of the infusion. Iron salts may be separated from
the leaves or powder by cold dilute acetic acid. This solution is tested
for iron by the usual qualitative methods.
Iron. — Metallic iron has been reported as sometimes present as an
adulterant of teas. Iron may be separated from the finely powdered
'Pharm. Centralhalle, 1879, p. 258.
886 FOODS AND FOOD ADULTEKANTS.
sample by a magnet. It may be distinguished from magnetic iron oxide
by the separation of metallic copper from cupric salts.
Magnetic oxide of iron. — Blyth1 states that ferruginous particles are
sometimes found as adulterants of teas. These particles may be sepa-
rated by a magnet. The author quoted (loc. cit.) states that he has
found over 1 per cent of this ferruginous sand in teas, and that it must
have been an adulterant.
Sand, particles of brick, etc. — A small amount of sand in a tea may
be due to accidental causes while gathering the leaves, but any consid-
erable quantity and particles of brick and similar matter can only be
considered as having been added with fraudulent intent. These sub-
stances may be separated by shaking the leaves with water and collect-
ing the sediment.
Copper. — The green color of some teas is popularly attributed to cop-
per. There is little evidence to prove that copper has ever been em-
ployed for this purpose. Hassall2 made a large number of examinations
of teas without detecting copper in a single sample. If copper is pres-
ent in a tea a portion of the powdered sample added to ammonia water
will impart a blue tint to the latter, the depth of the tint depending
upon the amount of copper present.
LIE TEA.
This substance, as its name implies, is an imitation of tea, usually
containing fragments or dust of the genuine leaves, foreign leaves, and
mineral matters, held together by means of a starch solution and col-
ored by one of the facing preparations. It is stated that gunpowder
and imperial teas are more subject to this form of adulteration. Of the
samples examined by the Department of Agriculture all were free from
lie tea.
According to Hassall3 the percentage of ash in lie tea ranges from
13.05 to 52.92 for black teas and 13.13 to 56.34 for green teas. The
same authority also found black teas containing from 6 to 17.7 per cent lie
tea, and green teas containing 1.38 to 48.46 per cent of this adulterant.
To detect lie tea treat the suspected sample with boiling water; if it
contain this adulterant portioMS will break up into dust and leaf
fragments.
GENERAL REMARKS ON TEA ADULTERANTS.
The adulterants of teas, as a rule, are not such as may be consid-
ered prejudicial to the health. The mineral matters employed in fac-
ing, etc., with the exception of salts of iron or copper, are insoluble in
water, hence would not be present in the infusion. Copper, which is
'Foods: Their Composition and Analyst*, A. W. Blyth, ',W2.
* Food, Its Adulteration!* and the Methods for Their Detection, A. II. Hassall, j». 131,
a Hassall, vjj. cit., 117.
CONSTITUENTS OF TEAS. 887
probably very rarely present, would be very objectionable even in very
small quantities. Sulphate of iron is a powerful astringent. In the
small quantities which would be used in increasing the astringency of
teas it would possibly not be seriously objectionable. It may also be
said of sulphate of iron that this substance was not detected in a very
large number of samples examined by Hassall nor in the Department's
samples.
Facing, if excessive, increases the weight of the tea, but there is no
evidence of its being prejudicial to the health.
From these statements we see that the adulterations of teas are in-
tended more especially to enhance the value of inferior grades, except
in the case of lie tea or the addition of foreign or exhausted leaves. In
the latter cases a spurious article, which is not justilied by any quality
or principle Avhich it contains, is foisted upon the market.
The evidence of authorities upon food adulteration con firms the state-
ment that the addition of foreign leaves is now but little practiced.
The general freedom of the teas of the markets of the United States
from adulteration is largely due to the enforcement of the United States
tea-adulteration law. Dr. Jesse P. Battershall,1 under whose direc-
tion a very large number of samples of teas were examined in con-
nection with this law, notes a very perceptible improvement in the
quality of teas imported under its provisions.
GENERAL STATEMENTS CONCERNING THE CONSTITUENTS OF TEAS.
The analyses of teas give little or no evidence bearing upon the mar-
ket value of this commodity. A tea may be very rich in theine or tan-
nin, and yet bring the same price as one poor in these substances. The
same may be said in a general way of the other constituents. This is
largely due, undoubtedly, to differences in soil, climate, the age of the
leaf, and methods of manufacture. The flavor, strength, and appear-
ance of a tea in general determine its market value. The flavor is due
to the volatile oil developed during the manufacture, the strength to
the proportion of tannin, and the appearance of the leaf to its age and
the care taken in the rolling and other manipulations. A tea may be
deficient in tannin and still bring a high price on account of the delicacy
of its flavor, or, by the admixture of leaves rich in tannin, an operation
termed blending, its strength may be increased to meet the demands
of the market. In genuine unfaced teas the value is usually in a direct
ratio with the soluble matter in the ash. According to Geisler, the
finer the quality of the tea the more theine, soluble ash, and extractive
matter it will contain, though this is not uniformly true. It has been
stated that the relatively high price of Indian teas is largely due to
their percentage of tannin. This permits the use of a very much smaller
quantity of tea in preparing the infusion for the table. The writer found,
' Food Adulteration and Its Detection, K. & F. Spon, New York, p. 20.
888
FOODS AND FOOD ADULTERANTS.
among the samples which he submitted to analysis, 50-eent teas (retail
price) containing as much tannin as many of those whose selling price
was nearly double this amount.
An attempt was made in classifying teas to utilize the property which
high grades have of quickly giving up a portion of their soluble matter
when steeped in water. These experiments were carefully made, the
conditions being the same in each case, but unfortunately the results
were far from satisfactory. This problem must be left until more
thorough studies of the chemistry of teas have been made, and until
then we must continue as heretofore to depend upon the skill of the
professional tea-taster and the honesty of the dealers in regulating the
relative prices.
Since the above and other remarks on the valuation of teas were
written, a Russian chemist1 has made an interesting series of investi-
gations bearing upon this question.
According to this chemist the quality of the tea depends upon the
care with which the fermentation is conducted. The fermentation of
the leaves destroys a portion of the tannin, thus decreasing the astrin-
gent action of the tea. Mr. Doorkovitch has devised a process for the
estimation of the products of the fermentation. In the article cited he
presents the table of analyses given below, and on a basis of these
analyses makes the following deductions:
The greater the ratio of theiue to the total amount of tannin and products of fer-
mentation, the dearer the tea. The more regular the fermentation, the better
the tea.
The regularity of the fermentation is recognized by the relative amount of prod-
ucts of fermentation in tea.
Analyses of first-crop China leas of Ihe neaxon of 1890.
* [Tea dried at 100° C.]
Num-
ber of
tea.
Water.
Theine.
Tannin.
Products
of fermen-
tation.
Extract-
ive sub-
stances.
Total
amount of
tlieine. tan-
nin, and
products of
fermenta-
tion.*
Theine,
per cent
A."
Tannin,
per cent
A.*
Products
olTcrmcn-
tatiou,
per cent
A.*
1
7.44
2.14
9.44
1.80
33.43
13.38
16.00
T.I. :.:.
13.45
2
7.79
2.50
9.87
1.61
33.33
13.98
17.89
70.60
11.51
3
4
8.29
2.53
2.68
9.27
10. 05
1.68
1.44
32.11
37.26
13. 48
14.17
18.78
18.92
68.76
70.92
12.46
10.16
5
7.97
2.66
!i.77
1.55
34.55
13.98
19.03
69.89
11. (W
6
8.16
2.65
9.76
1.45
31.20
13.86
19.13
78,41
10.46
7
g
7.66
7 90
2.72
2 73
9.59
1.78
30.70
14.09
lit. 21
68.06
12.63
9
7 91
2 86
10
2 itl
10 38
1.52
34.88
14.81
19.65
70.09
10.26
11
7.60
3.00
10.55
1.67
34.00
15.22
19.79
69.31
10.90
'Total amount of tlii-me. tannin, and products of fermentation is represented by \ for Invvity.
• K \arni nat ion of China Teas. 1'. Doorkovitch, Jour. anal, and ajipl. Chrin., 5. ti, ;<15.
METHODS OF DETERMINING ADULTERANTS 889
Analyses of first-crop China lean of the ncason of 1800 — Continued.
Num-
ber of
tea.
Water.
Theine.
Tannin.
Products
of fermen-
tation.
Extract-
ive sub-
stances.
Total
amount of
theine, tan-
nin, and
products of
fermenta-
tion.*
Tlieine,
per cent
A.*
Tannin,
per cent
A.*
Products
offermen-
tation,
per cent
A . ''
12
2.87
10.05
1.74
33.90
14.66
19. 92
68. 50
11.68
13
2.83
10.07
1.35
33.15
14.25
19.87
70.66
9.47
14
15
8.07
2.88
2.82
9.65
9.36
1.65
1.59
30.92
33.00
14.17
13.77
2i). 33
20.55
68.10
67.90
11.57
1 1 . 55
• 16
3.11
10.03
1.70
32. 21
14.84
20.96
67.59
11.45
17
18
8.10
3.00
3.10
9.30
10.00
1.88
1.50
34.12
34.10
14.24
U.60
20.02
21.23
65.73
68.50
13.25
10. 27
19
3.16
9.80
1. 75
33.66
14.71
21.48
06.62
11.90
20
3.02
9.37
1.50
32.40
13.89
21. 74
67.46
10 8,)
21
9.08
3.00
9.45
1.18
33.80
13.63
22.02
69. 33
8. 65
22
7.84
3.00
8.84
1.18
32.20
13. 02
23.05
67.89
9. OG
23
8.85
3.02
9. 05
.90
33.00
12.97
23.29
69.77
6.94
24
8.20
3.27
9.21
1.44
34.95
1J.92
23.50
66.16
10.34
25
26
8.24
9.13
3.25
3.41
9.14
9.32
1.25
1.44
32. 93
33.26
13.64
14.17
23. 84
24.07
67.00
65.77
9.16
10.16
27
9.78
3.33
9.22
1.27
32.03
13.82
24.11
66.71
9.18
28
29
8.42
7.83
3.45
3.21
9.42
9.00
1.38
1.17
34.80
33.46
14.25
13.38
24. 22
24.52
66.10
67.26
9.68
8.22
* Total amount of theine, tannin, and products <>f fermentation is represented by A for brevity.
ANALYTICAL METHODS.
In the following' paragraphs are presented the methods adopted for
the estimation of the various constituents of teas.
Caffeine or theine, C8H|0N4O2.— After experiments with a number of methods for
the estimation of caffeine, the following was adopted on account of its simplicity and
the accuracy of the results :
'Transfer 3 gs of powered tea into a 300 cc flask, add about 250 cc of water; heat
gradually to the boiling point, using a small fragment of tallow to prevent frothing;
boil gently 30 minutes, washing down any particles of tea which may collect on the
flask above the liquid. After the liquid begins to boil the flask should be filled al-
most to the neck and water should bo occasionally added to keep its level at this
point. Several samples may easily be extracted in this way at the same time, since
they require but little attention after regulating the flame of the lamp. After boil-
ing 30 minutes, cool, add a strong solution of basic acetate of lead in sufficient quan-
tity for the removal of precipitable substances; usually about 3 cc are required; com-
plete the volume to 300 cc, mix thoroughly, and filter, rejecting the precipitate un-
washed. Treat 50 cc of the filtrate with H2S for the removal of the lead ; boil off the
excess of HjS ; filter into a separately funnel, washing the precipitate with hot water,
or an aliquot part of the filtrate may be taken and washing of the precipitate may
thus be avoided. The error from the volume of the precipitate is very slight.
Extract the water solution in the separatory funnel seven times with chloroform;
collect the chloroform solution of caffeine in a small tared flask, and remove the
solvent by distillation; dry the caffeine at 75° C. two hours, weigh, and calculate
the percentage.
Jour. nnal. Chem. 4, 4, p. 390.
890 FOODS AND FOOD ADULTERANTS.
Nitrogen. — Tea contains a very liigli proportion of nitrogen. The analyses of Mr.
Ko/ai, tabulated on page 879, will show how this nitrogen is distributed in the pre-
pared leaf.
The nitrogen of teas should be determined by the absolute method, or Kjeldaht
method, modified for alkaloids. These methods are fully described in the text-books
on quantitative analysis, and in Bulletin 24, page 217, of the Chemical Division of
this Department.
Albuminoid nitrogen. — Stuizer'*1 method. — Prepare cupric hydrate as follows: Dis-
solve 100 grams of pure cupric sulphate in 5 liters of water, and add 2.5 cubic centi-
meters of glycerin; add dilute solution of sodium hydrate until the liquid is alka-
line; filter; rub the precipitate up with water containing 5 cubic centimeters of
glycerin per liter, and then Avash by decantatiou or filtration until the washings
are no longer alkaline. Rub the precipitate up again in a mortar with water con-
taining 10 per cent of glycerin, thus preparing a uniform gelatinous mass that can
be measured out with a pipette. Determine the quantity of cupric hydrate per
cubic centimeter of this mixture. To 1 gram of this substance add 100 cubic centi-
meters of water in a beaker ; heat to boiling, or, in the case of substances rich in
starch, heat on the water bath ten minutes ; add a quantity of cupric hydrate mixture
containing 0.7 to 0.8 grams of the 'lydrate; stir thoroughly; filter when cold; wash
with cold water, and put the filter and its contents into the concentrated sulphuric
acid for the determination of nitrogen after Kjeldahl. For the above filtration use
Schleicher and Schiill's No. 589 paper, or Swedish paper, either of which contains
so little nitrogen that it can be left out of account.
Tuinrin. — Liitrenthfil'*- method an improved 1>y Councler and Shroeder, and Procter. — In
the estimation, of tannin by this method the following standard solutions and re-
agents are required:
(1) Potassium permanganate solution containing, approximately, 1.33 grams of the
salt per liter.
(2) Tenth-normal ( ~ ) oxalic, acid solution, for use in standardizing the perman-
ganate solution.
(3) Indigo-carmine solution, containing fi grams of this indicator and 50 cc concen-
trated, sulphuric acid per liter.
(4) Gelatin solution, prepared by swelling 25 grams of gelatin for one hour in a
saturated solution of common salt, then heating until the solution is complete, and
finally, after cooling, making up to one liter (W. H. Krug's method of preparing this
solution).
(5) Salt-acid solution, prepared by mixing 975 cc saturated common salt solution
and 25 cc concentrated sulphuric acid.
(6) Powdered kaolin.
The potassium permanganate solution is standardized in the usual manner by ox-
alic acid. It is obvious, in the analytical manipulations which follow, that the end
reaction (golden yellow or pink tinge) which is adopted in the first process must also
be employed in the second. The indigo-carmine should be very pure and especially
free from indigo-blue.
(a) Five grams of finely powdered tea are placed in a flask of approximately 500 cc
capacity and boiled thirty minutes with 4<K) cc distilled water. The water should be
cold when added to the sample. After the completion of the boiling, the flask is
cooled and the solution and residue are transferred to a half-liter flask and the vol-
ume made up to 500 cc. The solution required for analysis is tillered on" if neces-
sary. To 10 cc of the tea infusion, 25 cc indigo-carmine solution are added, and
1 Bulletin 31, Div. Chem., U. S. Dept. Agric., p. 189.
" Counclrr and Sell roe, I cr, /tscli. anal. ('hem. 25, 121. Procter, .lourn. Sue. ('hem.
!'•!., 3, 82.
METHODS OF DETERMINING ADULTERANTS. 891
approximately 750 <•<• distilled water. The permanganate solution is now added, a
onbic centimeter at a time, the liqaid being vigorously stirred after each addition,
until the color changes to a light green; the addition of permanganate is continued
more slowly, drop by drop, until the whole liquid takes on a bright golden-yellow
color (Councler and Schi'oeder), or, if preferred, until the pure yellow liquid shows a
faint pinkish rim (Procter). The burette reading is now taken, and furnishes the
value (a) of the formula. It is absolutely necessary to vigorously stir the liquid
during the whole operation. It is best to repeat this titration, as well as that
which follows in the next step of the analysis, and take a mean of several readings.
(/>) 100 cc of the tea-infusion (filtered if not sufficiently clear after decantation) are
mixed with 50 cc of the gelatine solution in an Erlenmeyer flask, then 100 cc of
the salt-acid solution and 10 grams of kaolin are added, and the whole vigorously
shaken in the Avell-corked flask. Several minutes' shaking is necessary. If these
directions are carefully followed the precipitate will settle very rapidly, leaving a
clear, supernateut liquid which filters with great case. The use of kaolin, as recom-
mended by Procter, is an important modification of the original method, without
which it is often impossible to separate the precipitate. The whole liquid is filtered
and 25 cc of the filtrate (=10 cc of the original infusion) are mixed with 25 cc
of indigo-carmine solution and about 750 cc water, and a titration made as under (a).
The burette reading gives the value b of the formula.
The value a is the amount of permanganate solution necessary to oxidize all oxidi-
zable substances present; b, the amount required to oxidize the substances other
than tannin; hence a — 1) = c = permanganate solution required by the tannin. Ac-
cording to Xeubauer, .04157 grams of gallo-taunic acid is equivalent to .063 grams
oxalic acid; therefore, knowing the amount of oxalic acid equivalent to the perman-
ganate required to oxidize the tannin, we can easily calculate the amount of this
latter substance present.
The above method for tannin was selected after experiments with several other
methods. The general advocacy of its use by a number of very able analysts and
the satisfactory results obtained in this Department led to its adoption for this work.
Unfortunately, owing to the great variations in the results obtained by different
methods and the acknowledged inaccuracy of many of these methods, the A-alue of
a large number of tannin determinations, by various authorities, is doubtful. For
work of this kind the method of analysis should be clearly stated, and as far as pos-
sible, for the sake of uniformity, analysts should all adopt the same method in order
that their work may be comparable with that of others.
Waler. — The moisture may be determined in the usual manner by drying 1 or 2
grams of the powdered tea three hours at 100° C. in a flat dish, and calculating the
water from the loss in weight. This method probably entails a slight loss of theine,
which is credited to the moisture, but the error is very small and is negligeable.
Ash, total. — Two grams of the powdered tea are incinerated, at as low a temperature
as practicable, and the percentage calculated as usual.
Ash, soluble and insoluble. — The total ash is treated on a filter with hot water until
all the soluble matter is dissolved; the solution is evaporated to dryness, and the
residue ignited at a moderate temperature. The per cent soluble ash is calculated
from the weight of this residue; the insoluble ash is determined by difference.
Ash insoluble in acid. — The water insoluble residue from the soluble ash determina-
tion is treated with hydrochloric; acid. The undissolved portion is washed with
water, dried and weighed, and its percentage calculated.
Ash, alkalinity. — The soluble matter obtained in determining the soluble ash is dis-
solved in a little water and titrated with A acid. The alkalinity is calculated as
potassic oxide (K2O.).
Extract, total, and insoluble leaf. — Two grams of finely powdered tea are successively
extracted with seven portions of 50 cc each of boiling water. The extract is
892
FOODS AND FOOD ADULTERANTS.
decanted each time and the fractious united. The decanted solution is now boiled
and passed through a tared filter. The insoluble residue is finally transferred to
this filter, thoroughly washed with boiling wat«-r, dried, and weighed. The total
weight, less the tare of the filter, is the insoluble residue from which the per cent
insoluble leaf is calculated. The total extract is determined by difference, deducting
the per cent of insoluble leaf from 100.
A weighing tube should be used in weighing filters and residues on filters.
Half-hour extracts. — This extract is of doubtful value for comparative purposes
unless certain conditions are adopted and strictly adhered to. Slight variations may
cause very perceptible errors in the results. I have followed essentially the condi-
tions indicated by Geisler, which are evidently based on Wanklyu's method.
Place 1 gram of leaf tea in a 300 cc flask, add 100 cc cold distilled water and a small
fragment of paraffin, to prevent foaming. Immerse the flask a minute or two in
water heated to 90°C. in order to raise the temperature of its contents quickly to
within a few degrees of the boiling point. Having dried the outside of the flask,
boil the mixture thirty minutes. The flask must be fitted Avith a reflux condenser.
After boiling, cool quickly in a stream of water and filter off the extract. Transfer
an aliquot part of the extract to a tarred dish aud dry. Calculate the per cent of
matter from the weight of the residue.
GENERAL, REMARKS TO ANALYSTS.
The analyst must be guided almost entirely by comparisons of his
work on the suspected teas with the records of analyses of pure sam-
ples. The microscopic are almost the sole methods of detecting many
of the adulterants of teas. Questions in regard to quality, where this
depends upon aroma only, must be answered by a professional tea-
taster.
REPORT OF THE EXAMINATION OF SAMPLES OF TEAS BOUGHT IN
THE OPEN MARKET.
The samples examined in the course of the investigations were pur-
chased in stores of all grades. The analyses of these teas and general
statements concerning them are given in the following tables:
Description of samples.
Date
of i>ur-
cll.l-.l-.
Serial
number
Retail dealer.
Solii iw--
Retail
price
per
pound.
1887.
Feb 15
4850
$0.50
4851
streets,
do
50
4852
G G Cornwall &. Sons
1.30
4853
do
.88
Jan 18
4860
B. W. Reed's Sons
do
.CO
4863
PiU'itic Tea Store Seventh street \ \V
.50
4864
do
.50
4865
Apr 8
I'.'l"
ewj.
1.00
4941
4942
do
Formosa ( )oloii<;
.75
.80
street.
DESCRIPTION OF SAMPLES OF TEAS.
893
Description of H(t»q>l<',ts — Continued.
Date
•f pur-
chase.
1887.
Apr. 8
July 27
Aug. 19
Aug. 23
1881.
June 1
Serial
number
4943
4944
5139
5140
5141
5142
5143
5144
5145
5146
5147
5152
5153
5154
5155
5157
5158
5159
5160
5161
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
•r>179
5180
5181
Uetail dealer.
Sold as —
Atlantic and Pacific Tea 'Co., Seventh I English breakfast,
street.
.do
X. M. Burchell, 1325 F street
...do ...
.do
527 Tenth street NW
Jas. Rutherford, 906 D street NW ....
"W. H. Combs, 920Pennsylvaniaavenue
do
Win. Ornie & Son, 1013 Pennsylvania
avenue.
M. Goddard, 620 Twelfth streets N W.
1200 Thirteenth street NW
1 130 Thirteenth street
700 Thirteenth street
Corner New York avenue and Thir-
teenth streets NW.
F. N. Lanckton, 209 Four-aud-a-half
street.
J. H. Grimes, 235 Pennsylvania avenue
B. Maranghi, 101 B street SE
M. McCormack, 227 Pennsylvania
avenue.
G. Riani, 135 B SE
Enterprise Tea Co., Fourth street and
Pennsylvania avenue SE.
Pekin Tea and Coffee Co., 1308 Seventh
street.
Great Atlantic and Pacific Tea Co.,
1620 Fourteenth street.
United States Tea Co., 628 Pennsyl-
vania avenue.
Chicago Grocery Co., 806 Seventh
street.
China and Japan Tea Co. ,714 Seventh
street.
1500 Seventh street
J. C. Ergood, 915 Louisiana avenue
212 Thirteenth street SW
Geo. E. Kennedy, 1209 F street
Jackson & Co., 626 Pennsylvania
avenue.
F. Bell Tea Co., 824 Seventh street . . .
F. Hell Tea Co., 824 Seventh street
i:i(J7 C street SW
301 fourteenth street N W
G.G.Cornwall & Son, 1416 Pennsyl-
vania avenue.
Russian tea (black).
English breakfast . .
Gunpowder
Black tea.
...do ...
Gunpowder
Uncolored Japan .
English breakfast
Uncolored Japan
Oolong
Japan
Gunpowder
Oolong
Retail
price
per
pound.
Fine imperial.
Basket fired
Black tea
Japan
Black tea
Mixed . . .
Old Hyson tea.
...do ...
do
Young Hyson tea
. . .do . . .
Moyune Gunpowder
Moyune Gunpowder, third picking
Cheap Moyune Gunpowder
Gunpowder
...do ...
Japan Basket
Mixed teas
Oolong
Black, cheap. .
Pekoe
5940 j Park & Tilford, Broadway, New York. 1 Best Formosa Oolong...
5944 i do ' Best English Breakfast.
5945 I do Best Oolong
5946 I do Best Japan
894
FOODS AND FOOD ADULTERANTS.
])<'xcripti<m of xamplex — Continued.
Date
of pur-
chase.
Serial
number
Retail dealer.
Sold as-
Retail
price
per
pound.
1881.
June 1
5947
Park & Tilford, Broadway New York
$1 00
5948
do
1 00
5949
Not known. New York
47
5960
Martin, Gillet & Co. Baltimore Md
13
5961
Presented by the Chinese minister to
19
5963
the ladies' committee, Garfleld Hos-
pital.
Abbott Branch Store, H and Eleventh
.50
1890.
Feb. 3
6659
streets NW.
1.00
6660
do
Best English Break Cist
1.00
Mar. 8
6679
.:>o
10
Apr. 26
6680
6803
Ninth streets NW.
Redstrake, New York avenue and
Sixth streets.
The Boston Store
Johnson's Spring Leaf Blended Tea2
Tetlev s India and Cevlon Tea No. 1 .
.55
.70
6804
do
Tetlev's India and Cevlon Tea No. 2.
.50
1 Sold only iu 5-pound packages.
2 Sold in 5-cent packages; 11 packages ~15J ounces.
Analyses of tens.
Date
of pur-
chase.
Serial
num-
ber.
Mois-
ture.
Total
ash.
Soluble
ash.
Insolu-
ble ash.
Soluble
ash, per
cent
total ash.
Total
extract.
Half-
liour
extract.
Tannin.
Nitro-
gen.
Theine.
1887.
Per ct.
Per ct.
Per et.
Per ct.
Per ct.
Per ct.
Per ct.
Per ct.
Per ct.
Feb. 15
4850
5. 52
5.86
3.93
2.03
65.36
52. 75
3.83
2.50
4851
5 38
6.00
3.54
2.46
59. 00
48.98
13.17
3.60
1.09
4852
5.72
6.21
4.01
2.20
64.58
50.11
44.02
14.11
4.58
3.01
4853
5.40
6.63
3.31
3.32
49.92
49.47
12.30
4.06
1.50
Jan. 18
48fiO
3. 90
5.88
3.37
2.51
57. 31
51.06
15.41
4.12
2.13
4863
5.65
5.76
2.57
3.19
44.62
46.84
11. 17
3.46
2.69
4864
5.31
7.40
2.87
4.53
38.78
47.27
34.92
10.74
3.27
1.12
4865
7.05
5.69
3.24
2. 45
56.94
31.72
4.01
Apr. 8
4940
6.99
5. 76
3.67
2.09
63.72
48.28
36.58
12.57
4.03
2.13
4941
6.45
6.83
3.47
3. 36
50.81
48.22
35.88
7.44
4.00
1.92
4942
7.05
6.48
4.19
2.29
64.66
44.60
32. 12
5.07
3.98
3.11
4943
8.43
6.13
3.21
2.92
52. 37
44. 50
31.56
9.88
3.70
1.58
4944
7.76
6.66
3.79
2.87
56.91
42.84
30.08
5. 29
3.99
2.89
July 27
5139
7-78
5.83
3.65
2.18
62.61
51.26
39.70
10.71
4.09
3.43
5140
8.79
ft. 85
3.55
2.30
60.61
47. 73
22.00
7.63
4.39
3.43
5141
6.39
5.93
3.54
2.39
59.70
48.28
28.26
6.93
4.37
2.60
5142
6.67
6.41
3.04
3.37
47.41
46. 75
34.20
8.13
:i. •<.-.
2.42
5143
8.24
5.83
2.78
3.05
47.69
48. 33
32. 40
8.51
:i. -jit
1.06
5144
6.35
6.87
3.29
3.58
47.89
48.25
34.50
9.05
3.36
1.62
5145
7.89
6.46
3.16
3.30
48.92
47.83
38.10
8.25
:t. it:
2.07
5140
8.57
6. 45
•J .V.I
:s. si;
40.16
47.86
36.12
11.02
3. 93
2.53
5147
7.18
7. ir.
:t. 55
3.60
49.66
50. 91
40. 56
12. 51
1.00
Aug. 19
5152
H.74
6.08
3. Ml
2.49
.V.I. I.',
47. '.1:1
3!l. 04
8.00
3. 12
1.61
5153
8.12
7.69
2.87
4.82
B7.8J
46.18
34. 14
7.03
:i. tin
•J.20
ANALYSES OF TEAS.
895
Analyses of teas — Continued.
Date
of pur-
chase.
Serial
num-
ber.
Mois-
ture,
Total
ash.
Soluble
ash.
Insolu-
ble ash.
Soluble
ash, per
cent
total ash.
Total
extract.
Half-
hour
extract.
Tannin.
Nitro-
gen.
Theine.
1887.
Perct.
Per ct.
Per ct.
Per ct.
Perct.
Per ct.
Per ct.
Per ct.
Per ct.
Aug. 19
5154
6.32
6.69
3.41
3.28
50.87
53. 76
42.68
8.61
3.24
1.87
5)55
7.40
6.13
2.99
3.14
48.85
49.09
39.42
9.92
3.34
1.55
5156
6.59
5.99
3.28
2.71
54.67
50.40
39.60
9.79
3.83
1.55
5157
4.91
6.55
4.34
2.21
66.26
49.31
39.24
8.65
3.86
1.49
5158
8.58
6.11
3.21
2.90
52.87
48.98
31.66
10.10
3.25
1.04
5159
9.58
5.89
3.50
2.39
59.42
49.27
37.54
7.61
4.11
2.31
5160
8.46
5.92
1.78
4.14
30.03
45.44
34.44
8.76
3.16
2.14
5161
7.82
6.83
2.61
4.22
38.21
48.26
38.42
7.70
3.30
1.57
23
5167
8.71
6.21
3.24
2.97
52.18
43.40
33.98
6.71
3.18
1.93
5168
9.90
6.05
2.58
3.47
42.58
47.08
34. 52
8.25
3.33
2.00
5169
8.61
5.93
2.67
3.26
45.01
48.40
29.78
4.77
3.19
2.53
5170
9.72
5.36
1.66
3.70
31.02
46.44
36.12
10.75
2.91
1.98
5171
8.75
6.43
4.21
2.18
66.10
48. 98
39.06
11. 62
3.53
2.27
5172
8.28
6.02
2.78
3.24
46.14
50.52
39.30
14.09
3.80
2.01
5173
8.40
6.45
4.25
2.20
65.89
50.76
40.96
11.48
4.15
2.00
5174
9.64
6.65
1.99
4.66
34.37
47.70
36.68
7.23
3.33
1.26
5175
5.05
6.09
4.41
2.68
55.95
52.93
43.54
12. 60
4.16
2.22
5176
7.54
6.65
4.40
2.25
66.09
47.56
38.30
8.26
3.93
2.29
5177
8.70
5.59
3.04
2.55
55.35
49.97
38.74
14.76
3.76
2.05
5178
9.15
6.20
2.41
3.79
38.91
47.88
34.84
6.13
3.37
2.98
5179
8.64
5.98
3.09
2.89
51.67
48.51
37.02
10.06
3.38
2.09
5180
8.60
5.66
2.88
2.78
50.87
49.65
37.98
12.39
3.32
1.43
5181
8.49
5.38
2.71
2.67
50.39
53.32
39. 98
15.51
3.82
2.06
1888.
June 1
5943
5.82
6.53
4. 18
2.40
63.53
52. 07
39. 90
14.58
2.17
5944
5945
8.22
4.95
6.36
6.33
4.22
3.83
2.14
2.50
66.36
60.51
48.79
50. 16
39.82
38.55
5. 87
12.34
2.73
1.34
5946
4.87
6.17
3.63
2.54
58. 39
51.19
45.28
8.38
2.54
5947
5.54
6. 10
4.22
1.88
69. 18
49.53
41.98
11.48
1.73
5948
5.32
6.50
4.61
1.89
70.92
54.36
40.94
12.01
1.64
5949
6.03
6.75
4.23
2.52
62.67
50.41
38.32
10.19
1.03
June 13
5960
4.85
6.40
3.84
2.56
60.00
42.68
40.24
11.08
2.15
5961
3.59
6.98
3.86
3.12
55.30
48.03
38.31
14.76
1.93
June 19
5963
4.61
6.00
3.66
2.34
61.00
41.38
39.20
9.01
1.28
.1890.
Feb. 3
6659
5.08
6.21
3.45
2.76
55. 55
50.11
41.00
12.85
3.09
666U
3 65
5.29
3.24
2.05
61.06
49.46
40.40
15.21
2.66
Mar. 8
6679
4.14
7.40
3.00
4.40
40.54
47.38
35. 18
8.91
1.49
Mar. 10
6680
3.70
7.12
2.87
4.25
40.31
47.86
32.70
12.35
1.43
Apr. 26
6803
4.84
5.61
3.48
2. 13
62.03
47.26
13.67
2.15
6804
4.50
5.90
3.51
2.39
59.48
45.56
11.99
1.92
896 FOODS AND FOOD ADULTERANTS.
Table showing the condition of the leaves and the fwiyn wallers present.
Serial
No.
Color, etc.
Retail
>riceper
pound.
Qualitative examination.
4850
Green
$0.50
Largely composed of broken leaves. Faced.
4851
Black
.50
Leaves large.
4852
do
1.30
Leaves medium size, very much broken. Faced with black lead.
4853
....do
.88
Leaves very much broken.
4860
do ...
.60
Composed entirely of broken leaves. Faced.
4863
....do
.50
Leaves small, mostly broken.
4864
Green
.50
Largely composed of fragments. Faced.
4865
Black
Do.
4940
Green
1.00
Large leaves, very much broken. Faced.
4941
Black
.75
Fragments of medium and small sized leaves,
4942
do
.80
Largely composed of fragments of medium leaves.
4943
.do .
.60
Do.
4844
....do
.40
Consists largely of fragments and frayed leaves. Black lead facing; con-
tains magnetic iron oxide.
5139
....do
1.25
Largely composed of fragments.
5140
do
1.00
Do.
5141
Green
.75
Composed of large leaves. Faced.
5142
Black
.60
Largely composed of fragments.
5143
.T-.do
.50
Leaves large.
5144
Green
.50
Leaves frayed and largely fragments . Faced.
5145
Uncolored
.50
Fragments of large and small leaves ; frayed. Faced.
Japan.
5146
Black ....
.90
Fragments of medium sized leaves; frayed. Black lead facing.
5147
Uncolored
.75
Medium and small leaves, and a large proportion of stems.
Japan.
5152
Black ....
.60
Medium and small leaves.
5153
Uncolored
.50
Composed of fragments of leaves. Faced.
Japan.
5154
Green
.90
Fragments. Faced.
5155
Black ....
.50
Fragments. Contains paddy husks and rice seed. Black lead facing.
Contains magnetic iron oxide.
5156
Green
.50
Medium and small leaves. Faced.
5157
Black ....
.60
Large leaves, frayed. Contains paddy husks. Black lead facing. Con-
tains catechu.
5158
....do
.45
Largo leaves, frayed. Contained paddy husks.
5159
....do
.50
Largo leaves, frayed. Black lead facing.
6160
....do
.50
Fragments. Contains paddy husks. Black load facing.
5161
Black and
.40
Fragments of large leaves. Black lead and Prussian bliie facing
green.
5167
Green
.60
Largely composed of fragments. Indigo facing.
5168
....do
.50
Fragments of large leaves. Faced.
5169
Black ....
.50
Fragments of leaves. Contained pieces of gypsum, wood, and frag-
ments apparently nut shells.
5170
Green
.50
Fragments. Faced.
5171
....do
.60
Fragments. Faced.
5172
do
.80
Large leaves. Faced.
5173
....do
.75
Large leaves. Faced.
6174
....do
.50
Large leaves. Faced.
6175
....do
1.00
Leaves small. Many fragments. Faced.
6176
....do
.75
Leaves large. About 20 per cent tea-dust. Faced.
6177
Japan bas-
.50
Leaves small. Fragments few. Contains paddy husks.
ket.
1 Facing unless othe r wise stated is a mixture containing 1'nissian blue.
TEA ADULTERATED WITH LEAVES. 897
Table showing the condition of the leaves and the, foreign matters present — Continued.
Serial
No.
Color, etc.
Ketail
price per
pound.
Qualitative examination.
5178
Black and
$0.50
Fragments of largo leaves. Prussian blue and black
lead facing. Con-
green.
tains magnetic iron oxide.
5179
Black
.50
Fragments of medium-sized leaves. Black-lead facinj
; contains magnetic
iron oxide.
5180
5181
do
do ....
.50
.85
Fragments of large leaves. Contains paddy husks.
Small leaves and fragments. Black-lead facing.
5943
do
.75
Small leavus and fragments. Contains paddy busks.
Black-lead facing.
5944
... .do
.90
Small leaf fragments.
5945
....do
.80
Small leaf fragments. Black-lead facing.
5946
Japan
1.00
Small leaves, fragments, and pekoe tips.
5947
Green
1.00
Small leaves. Indigo facing.
5948
....do
1.00
Small leaves ;md fragments. Indigo facing.
*5949
5960
Black.....
Black and
.47
Small leaf fragments.
All fragments. Contains paddy husks.
5961
green.
Green
All stems and leaf buds.
5903
....do
.50
A large proportion of fragments of leaves.
6659
Black
1.00
Very few fragments.
6660
...do
1.00
Largely composed of fragments.
6679
Green
.30
Fragments of leaves. Contains fragments of brick
and lead. Faced.
6680
Green and
.55
Fragments of leaves. Contains paddy busks and a
few grains of rice.
black.
Black lead and Prussian blue facing.
* Sold in $5 packages only.
The prices of a few samples are omitted, since these teas were not
purchased by the Department. As nearly as possible all the grades of
teas on the market are represented in this work.
Many of these samples are of very inferior quality, but neither the
analytical nor microscopical data give positive evidence of the addition
of spent or foreign leaves. That this latter form of adulteration is still
practiced is evidenced by the work of a Canadian official chemist who
found two samples containing foreign leaves.1 Dr. Jesse P. Battershall2
examined nearly 2,000 suspected samples of teas under the United
States tea adulteration act, and states that he found foreign leaves
present in only a few instances.
Some of the higher-priced teas contained frayed and unrolled leaves,
but not in sufficient quantities to justify considering the sample to have
been adulterated with spent leaves, especially as the relative propor-
tions of the soluble constituents of the teas varied little from the aver-
age for genuine, unadulterated samples.
A large number of the samples examined by the writer were faced.
With the present ideas in regard to this practice, it can not be consid-
ered a form of adulteration, but facing should be condemned on account
of its use in making inferior teas appear to be of a superior quality. This
1 Report on adulteration of food. Supplement in to the report of the Department
of Inland Revenue, 1886. Ottawa.
2 Food adulteration. Jesse P. Batterskall, page 20.
898 FOODS AND FOOD ADULTERANTS.
practice also enables the admixture of spent leaves with little fear of
detection. Faced teas can not be excluded from this country under the
United States tea adulteration act, since this law specifies that the
addition of chemical and other deleterious substances must be in suffi-
cient quantities to render the tea unfit for use. This wording admits
of excessive facing, since it has never been shown that the substances
usually employed for this purpose are prejudicial to health, even when
taken in greater quantities than could be employed in treating teas.
A few of the samples examined contained magnetic-iron oxide, prob-
ably derived from the black-lead facing. Serial number 6079 contained
a few fragments of brick and lead. These substances were probably
added to increase the weight of the tea and were not accidental.
A general qualitative examination was made of each sample. The
foreign matters detected are given in the table, p. 896. Very few objec-
tionable substances were found. A statement of the condition of the
leaves is also given in this table. The teas of all grades were largely
composed of fragments of leaves.
CONCLUSION.
The analytical and other work in connection with this report indi-
cates that there are few if any spurious teas on the market. The range
in quality is undoubtedly very great, many samples deserving to be
termed "tea" simply because they are composed of the leaves of the
Thea, and not through the many pleasant qualities which we usually
associate with the beverage of this name.
With the strict enforcement of the United States adulteration act,
the consumer is reasonably well protected, so far as securing the genu-
ine leaf is concerned, but of course has no protection from the sale of
inferior teas.
COFFEE.
The seeds of the Coffca arabica, after roasting at a temperature
approximating 200° C., are ground and employed in preparing the popular
beverage termed coffee. Various substitutes have been prepared by
manufacturers for the purpose of cheapening the cost of this beverage
and defrauding the consumers. In the manufacture of these so-called
substitutes and in the adulteration of genuine coffees, chicory, cereals,
etc., occupy a prominent place. These substances have little, if any thing,
in common with coffee and possess none of the latter's valuable prop-
erties. It is the purpose of this report to deal with methods for the
detection of these substances in considerable detail, but first certain
statistical and other data will be considered.
STATISTICS OF COFFEE CONSUMPTION.
The following statistical statements are based on the Report of the
United States Treasury Department: '
Imports of coffees, less the amount exported.
Pounds.
1887 500, 819, 587
1888 408, 562, 775
1889 561, 132, 100
1890 490, 181, 755
The per capita consumption is approximately 7.8 pounds.
In addition to the consumption of pure coffee, there is a very large
quantity of so-called substitutes, chicory, etc., sold and consumed as
coffee. It is impossible to obtain statistics in regard to these substitutes
and adulterants. The high prices of coffee prevailing the past year or
more have induced certain unscrupulous dealers to impose spurious
coffee beans upon the public and to adulterate ground and other coffees
to such an extent that often samples may be purchased having little in
common with the genuine.
The fluctuations in the prices of coffees are shown in the accompany-
ing table. The values of the coffees are those which they bore in the
markets of the countries from which imported. This does not include
the cost of transportation, etc.
1 Commerce and Navigation of the United States.
899
20393— No. 13 3
900
FOODS AND FOOD ADULTERANTS.
Average price of coffee from 7,v;,v /<> IW,
Year.
Value
per
pound.
Ye;ir.
Value
per
pound.
1878
$0. 108
1885
$0 08"
1879 '.
. 1 IT.
1886
070
1880
. lit")
1887
107
1881
.125
1888
1882
1(10
1X89
129
1883
. 082
1890
160
1884
093
The coffee consumed in the United States is principally supplied by
Brazil, Venezuela, the Central American States, Mexico, and Colombia.
The quantities supplied by these countries are respectively 03, 12, (>.},
4, and 3£ per cent of the total imported. Very little coffee is imported
directly from Africa.
GENERAL STATEMENTS.
Of the following- statements those in quotation marks are from the
observations of Lascelles r1
"West India coffee is for the most part even-sized, pale, and yellow-
ish, firm and heavy, with fine aroma, losing little in weight by the
roasting process."
"Brazil coffee is larger, less solid, greenish or white, usually styled
by the brokers 'low' or 'low middling.'"
"Java coffee is smaller, slightly elongated, pale in color, 'deficient in
aroina and essential oil, and light."
"Ceylon produces coffee of all descriptions, but the ordinary planta-
tion coffees are even-colored, slightly canoe-shaped, strong in aroma
and flavor, of considerable gravity, and admit better of adulteration
than most other kinds."
Mocha is usually considered the best coffee of commerce. It is stated
that East India coffees are sometimes shipped to Arabia and exported
from this latter country as genuine Mocha coffee. The seeds of the
Mocha are small and dark yellow.
Java coffee when new is a pale yellow and is then cheaper than when
old and brown. This color is partly a result of the method of curing
in addition to the effects of age.
The high price of Java has led to the coloring <>l cheaper grades
with mineral pigments or otherwise, in imitation of this favorite coffee.
It may be well to state that this practice can not be general, since no
foreign coloring matters were found in the Javas examined iu the course
of the investigations treated of in this work, though it is probable that
coffees colored by exposure to a high, moist heat may have escaped
detection.
1 The Nature ami Cultivation of Coffee, Arthur R. W. Lascelles. London: Samp-
8on Low, Son & Marston.
SIZE OF COFFEE BEANS. 901
The following table, by Thorpe, ' indicates the variations in the size
of coffee beans:
Number of seeds in a measure holdiiiy 50 yramu of water.
Fine brown Java 187
Fine Mysore
Fine Neilgherry 203
CostaRica '-- - 203
Good ordinary Guatemala 207
Good La Guayra - 210
Good average Santos ". 213
Fine long-berry Mocha - - 217
Good ordinary Java 223
Fine Ceylon plantation - , 225
Good average Rio 236
Medium plantation (Ceylon)
Manilla 248
Ordinary Mocha 270
West African 313
llio Coffees form a very large proportion of those consumed in the
United States. Judging from the above table, the Bio coffee bean is
considerably smaller than the Java and is approximately the size of
the Mocha.
CHEMICAL COMPOSITION.
Iii preparing the tables on the following pages, showing the compo-
sition of Coffees, the better known authorities have been consulted and
analyses have been selected which give the principal constituents of
the grades usually found in our markets.
The estimation of the sucrose in sample No. 8712 was accidentally
omitted. Judging from other analyses made in the Division of Chemistry
the average per cent sugars given by Kouig is rather high. Consider-
able quantities of pure sucrose have been separated from coffees in the
course of these investigations. It has been definitely determined that
the soluble carbohydrates of coffee consist very largely of sucrose.
The caffetannic acid in No. 8712 was estimated by a method described
on page 908. Many of the statements in regard to this constituent are
very indefinite; no description of the methods for its estimation could
be found in the literature accessible.
1 Dictionary of Applied Chemistry, p. 578,
902
FOODS AND 'FOOD ADULTERANTS.
t
1
^
Remarks.
U. S. Department of Agri-
culture.
Calculated to dry matter.
Church.1
Ludwig.2
s
Hassall.4
James Bell.7
3
AV. Kisch.3
Konig's averages. '
pi
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w
§
a g'S
ug«
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iri
8
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its Detect
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"I
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Descriptio
Java coffee, serial
•
Brazil coffee (old)
f£
Brazil coffee (new
a
B
'So 5
« o
i? a
East India
Java coffee
I
i1^
"Loo.cit.
3 Includes cara
COMPOSITION OF COFFEE^
The chemical composition of roasted coffees^
903
1 *e
•a
aj
~ r.
i
OS
.^
•O
p<£l
^J-
9
Description
s
A
•§
CB
^a
£ * h
s.2
o
a
Remarks.
•B
<o
•
B
•
1
•M « *;
a">5
S
'S
*8
g
o
a
£
5"« S
w§
H
^
fc
O
H
O
^
o
02
0
Per ct.
Per ct.
Per ct.
Perct.
Perct.
7'er ct.
Perct.
Perct.
Perct.
Not given .
.36
8.30
44.96
5.17
1.06
12.03
26.28
'1.84
Hassall.2
Do
16.14
25.07
3.87
1.42
12.31
39.84
1.35
Blyth. To dry
substance.3
Do
3.19
15. 63
24.27
3.75
1.38
12.05
38.41
1.32
Blyth. To orig-
inal substance.3
Mochn
.63
13.59
48.62
4.56
.82
11.23
.43
1.24
James Bell.^
East India.
1. 13
13.41
47.42
4.88
1.05
13.13
.41
1 38
Do.
Javii
1.92
16.51
18.42
4.91
1.44
17.18
38.61
2.45
W. Kisch.5
1.15
14.48
19.89
4.75
1.24
13.98
45.09
.66
Konig's averages.^
1 Reported as cane sngar.
* Hassall, op cit., 146.
3 Foods, their composition and analysis, A. W. Blyth, 346.
4 Konig, op cit., 1002.
6 Loc. cit.
Composition of some pure coffees.
[A. Smetham, Analyst, 1882. 73.1
1.
2.
3.
4.
5.
6.
7.
Water per cent .
3 89
3.49
1.84
3 54
1.59
Fat . ... do
12 13
11.40
10 13
10 63
10 13
11 75
10 80
Cellulose do . .
26.33
27.50
34.40
30.26
27.90
Ash do..
4.63
4.29
4.40
4.08
4 19
4.25
4 20
3.34
3.50
3.60
3 14
3.40
3 25
3 35
No. 1, Ceylon coffee ; No. 2, Costa Rica; No. 3, Ceylon; No. 4, East Indian coffee; No. 5, Jamaica;
Nos. 6 and 7, best and purest kinds of coffee bought from a wholesale dealer.
Analyses of various coffees.
[O. Levesie, Arch. Pharin. (3) H 294.]
1.
2.
3.
4.
5.
6.
7.
Caffeine per cent
1.43
.64
1.53
1.14
1.18
.88
1.01
Fat do
14 76
21 79
14 87
15 95
21. 12
18.80
17.00
25 30
22 60
23 80
27 40
20.60
25 80
24 40
Caffeicand tannicacid.do. .
Cellulose do..
Ash do..
Potash do
22.70
33.80
3.80
1.87
23.10
29.90
4.10
2.13
20.90
36.00
4.00
20.90
32.50
4.50
21.10
33.00
4.90
20.70
31.90
4.30
19.50
36.40
.31
42
.27
.51
.46
.60
No. 1, best Jamaica; No. 2, best green Mocha; No. 3, pearl Ceylon; No. 4, washed Rio; No. 5, Coata.
Rica; No. 6, Malabar; No. 7, East Indian coffee.
904
FOODS AND FOOD ADULTERANTS.
TJ>e anii »f cnff<
Constituents.
Serial
No. 8874,
Mocha, 38
c. per Ib.
Serial
No. 8875,
Maracai-
bo 33 c.
per 11).
Serial
No. 8876,
Java 38
c. per Ib.
Serial
So. 8877,
Kio, 30 c.
per Ib.
Sand
1 44
0 72
0 74
1 34
Silica (SiO*) J . .
0 88
0 88
0 QI
0 6')
Ferric Oxide (Fc2O3)
do
0 89
0 89
1 ](•,
1 77
IJine (CaO)
do
7 18
5 00
4 >>4
4 94
Magnesia (MgO)
do
10 68
11 30
11 '!r>
10 CO
Potash (KSO)
59 84
Cl 82
62 08
63 60
Soda (NasO)
0.48
0 44
0 17
Phosphoric acid (P2O5)
.. . do
12 93
13 20
14 09
11 53
Sulphuric acid (SO3)
do
4 43
5 10
4 10
4 88
Chlorine (Cl) .....
do
1 25
0 59
0 73
0 48
100. 00
100.00
100.00
100. 00
* The descriptions of samples are based on the dealer's statements.
t Numbers given are parts in 100 of mineral matter after deduction of carbon dioxide. Oxygen
equivalent to chlorine is not deducted.
{ Soluble in solution of sodium carbonate.
One of the most important constituents of coffee is the alkaloid caf-
feine. This alkaloid is identical, chemically and physiologically, with
that present in tea and termed "theine." Coffee contains a much
smaller proportion of this alkaloid than is found in tea leaves. Caf-
feine was discovered in 1820 by Bunge,1 and was isolated some time
afterwards by Pelletier,2 Robiquet,3 Caventon, and Garrot. This alka-
loid is also found in the leaves of the coffee tree. According to Payen4
caffeine is present as a caffetaunate. Caffeine may readily be obtained
from coffee by extraction with chloroform. The alkaloid separated in
this way, after purification, is obtained on evaporating the solvent in
beautiful white silky, librous crystals. Unroasted coffees contain from
a little less than 1 per cent to approximately 2 per cent of caffeine.
Payen5 reports from 3.5 to 5 per cent caffeine plus caffetannate of
potassium, the free alkaloid amounting to .8 per cent. Caffeine" melts
at 224° to 228° C., sublimes at 187° C., is soluble in 58 parts of wafer
at 20° C., in 9.5 parts of water at 100° C., in 21 parts alcohol, in 545
parts of ether and in 9 parts of chloroform at 20° C. According to
Lapean7 the solubility of caffeine in alcohol at 15.5° C. is 1 part in 150
of the solvent. "Blyth cautions the analyst against drying this alka
1 Schweigg. Jour. Cheni. Phys. 31, 3()8.
8 Jour. Pharin. [2], 12, 229.
:<0/,. ,-it., 234.
••Ann. diim. phys. [3] 16, 108; Jahrosl). ii. <1. Fortsoh. d. Clicni. 1SI!>. IX<1.
*Ann. cliiin. phys. [3] 26, 108; Juluvsl.. ii. d. FortsHi. d. ('linn. ISI'l. ISii.
•Vierteljahreschr. ]>r. I'lumu 16, 167.
M'luiriii. .1. Trans. |3], 11, 902; Jalnvsl.. d.Clinn. 1SS1, 902.
"Foods: Their coinjHwition and analysis. A. W. Hlyth.
CONSTITUENTS OF COFFEES. 905
loid at 100° C. as is usual, and claims tliat it commences to sublime at
79° C. The specific gravity ' of caffeine at 10° C. is 1.23. The follow-
ing reactions are given by Luchini:2 Weuzell's reagent (solution of 1
part KMnO4 in 200 parts of hot H2SO4), gives an amethyst color with
caffeine, which changes to a dark violet, then becomes blood red and
after twenty-four hours a brown precipitate forms : 1 part caffeine in
10,000 can be detected by this reagent. With Luchini's reagent (a
hot solution of KsCr2O7 in concentrated H.,SO4 there is no change on
standing twenty-four hours. According to Bottiger3 caffeine may be
detected by evaporating an alcoholic extract of the substance to dry-
ness, treating with hydrochloric acid, again drying, then adding water.
The presence of the alkaloid is shown by a purple-red color. Schwar-
zenbach4 employs chlorine water instead of hydrochloric acid in the
above test. The purple residue becomes yellow on heating and red
when treated with ammonia.
Kornauth5 evidently overestimates the percentage of caffeine in
coffees. He states that a percentage of caffeine below 1.97 is an indi-
cation of an adulterated sample'. The writer's analyses and those quoted
in the table (p. 902) all show percentages of caffeine considerably below
the limit given by Kornauth.
The fat is a prominent constituent of coffee. Husemann6 separated
a white, odorless fat on cooling an alcoholic extract of coffee. The
melting point of the fat was 37.5° 0.; it consists7 of the glycerides of
palmitic acid and of an acid (Ci2H24O2). The percentage of fat in raw
coffee is approximately 13.
The caffetannic acid of coffee has been isolated by Pfaff B and by
Kochleder.9 The latter chemist also reported the presence of traces of
citric acid. Caffetannic acid as isolated by W. H. Krug in connection
with this Department's investigations agrees with the description given
by Beilstein.10 It is a light yellow, sticky mass, with a slightly acid and
astringent taste. According to Illasiwetz11 it is a yellow bitter mass
of the formula Cj5II]8O8.
Boussingault12 found in a sample of coffee 2.21 per cent mannite,8.73
per cent invert sugar, and 2.37 per cent sucrose.
The carbohydrates of the coffee berry have received very little
1 Ann. Chem. Pharin., 1, 17.
2 Arch d.Pharm. [3 E.], 23, 684; Ztschr. anal. Chem. 25, 565.
3 Pol. Notizblatter, 1873, 257; Ztschr. anal. Chern. 1873, 442.
<Chem. Centrhl., 1861, 989; Ztschr. anal. Chem. 1, 229.
"Mittl. a. (1. Pharm. Inst. n. Lab. f. angew. Chem., Erlangen, Heft, 3, 1-56.
fi Pflanzenstoffe, p. 1367.
7 Wien. Akad. 15er., 24, 10.
"Schweigg. Journ., 62, 31.
9 Wien. Acad. Ber., 7, 815.
loOrganische Chemie, Beilstein, 3, 343.
11 Hlasiwetz, Ann. Chem. Pharm., 149, 219.
12Corapt. rend., 91, 639.
906 FOODS AND FOOD ADULTERANTS.
thorough study until quite recently. The recent investigations and
discoveries in this line by Dr. Schulze at Zurich, and Dr. Tollens at
Gottingen, and their collaborators, have brought about a more careful
study of the carbohydrates of coffee among a host of other vegetable
materials. Thanks to their labors, the percentages of compounds in-
cluded in the term "other non-nitrogenous substances" have already
been materially lessened in a great many cases.
Rather indefinite statements about sugar, gum, and dextrin, make
up the existing literature of the carbohydrates of coftee which are
soluble in water. The coffee berry contains no starch. Mr. Walter
Maxwell1 has demonstrated the presence of an insoluble carbohydrate
which yields galactose by hydrolysis, and has succeeded in obtaining a
considerable portion of very pure and well crystallized galactose. R.
Iteiss2 has reported mannose as an hydrolysis product of an insoluble
carbohydrate of coffee.
By investigations made in this laboratory, cane sugar has been shown
to be the principal soluble carbohydrate present. It is accompanied
by a small percentage of a substance closely resembling dextrin and some
reducing sugar. The latter may be due to the inversion of a small
amount of the cane sugar before or during the process of extraction.
A considerable amount of cane sugar was obtained in pure, well-defined
crystals. For the purpose of isolating it from other soluble substances
of the berry, the extract obtained by the use of 60 to 70 per cent alcohol
is treated with a slight excess of lead acetate and the excess of the
latter removed from the filtrate by means of hydrogen sulphide. The
sugar is now converted into strontium saccharate by treatment with
strontium hydroxide at the boiling point of the liquid. The precipitate
of saccharate is separated by filtration, suspended in water, and de-
composed by a current of carbon dioxide. The filtrate from the stron-
tium carbonate thus formed is evaporated to a heavy sirup. This sirup
is purified by repeated solution in alcohol, ree'vaporation and resolu-
tion, gradually increasing the strength of the alcohol. The final solu-
tion in very strong alcohol is left to crystalize. For this method we
are indebted to Schulze, Steiger, and Maxwell.3
Just as satisfactory a preparation of cane sugar was obtained by the
evaporation of the filtrate from the precipitated lead sulphide and by
direct treatment of the residue with alcohol without the use of str<m
tium hydroxide. A preparation is now in progress without the use of
either strontium hydroxide or lead acetate, and promises .very good re-
sults, the separation being made by use of alcohol alone.
The portion of coffee insoluble in water is also being made the sub-
ject of detailed study. By distillation with hydrochloric acid an abun
1 Unpublished notes.
*Ber. <1. a. chem. Gvsell.. 1889, 22. 609.
3 Untersnchunjj iiber tlie cho.inisrhi' /iisammi-nsct/iinjj
Laiulwirt, Verauchs-Stat., 1891, 39, 269.
METHODS OF COFFEE ANALYSES. 907
dance of furfuraldehyde was obtained, which indicates the presence of
some pentose yielding substance. By treatment of a considerable por-
tion of the water-insoluble material with a 5 per cent solution of sodium
hydroxide, and by precipitation of the extract thus obtained with alco-
hol,1 a gummy substance was obtained. This gum yielded niucic acid
by oxidation with nitric acid, an indication of the presence of a galac-
tose yielding carbohydrate; by distillation with hydrochloric acid iur-
furaldehyde was also obtained, showing the presence of a pentose yield-
ing substance in the gum. A galactose and pentose yielding gum has
been separated from barley.2 Whether the gum obtained from coffee is
a mixture of galactose and pentose yielding substances, or is a single
substance yielding both, has not been determined.
The residue obtained by evaporation of the sulphuric acid extract of
the insoluble material yields an abundance of mucic acid when oxydized
with nitric acid, showing the presence of galactose, as stated by Maxwell.
Satisfactory evidence of the presence of any considerable amount of
mannose in the sample of coffee used in the investigation has not yet
been obtained. Parallel experiments with coffee and vegetable ivory
dust were made. With the latter, an abundant precipitate of mannose
hydrazon was obtained; with coffee, the precipitate was not of sum"
cient amount for a satisfactory determination of its properties.
Dierbach3 isolated the coloring matter of coffee and termed it "coffee-
green."
Coffee also contains traces of volatile oils and about 4 per cent of
mineral matter. Potassium salts form a considerable proportion of the
mineral matter. Silica, when present, amounts to little more than a trace.
Kornauth4 states that in the ash of pure coffees the potash amounts
to from 50 to 200 times the soda.
According to Bernheimer,5 the products obtained on roasting coffees
are palmitic acid, caffeine, caffeol, acetic acid, carbonic acid, hydrochinon,
methylamine, pyrol, and acetone. Caffeol is an oil, of the formula
CsH,oO2, boiling at a temperature of from 195° to 197° C.
A large number of analyses of coffees have been made, references to
which are given in the bibliography accompanying this report.
METHODS OF ANALYSIS.
In the detection of adulterants but little chemical work is necessary,
hence methods will only be given for the estimation of the principal
constituents of coffee.
Moisture. — Dry in a flat dish to constant weight and calculate the moisture as
usual.
Caffeine. — The method of estimating this alkaloid in tea (p. 889) may be employed.
1 A rneteod used for the separation of xylan from wood.
2Lintner and Dull, Chem. Ztg., 1891, 266.
3 Ann. d. Chem. u. Pharm., 14, 236.
4 Mittl. a. d. Pharm. lust. u. Lab. f. angew. Chem., Erlangen. Heft 3, 1-56.
6 Wien. Akad. Ber. (2 Abth.), 81, 1,032; Jahresb. d. Chern. 1880, 1069.
908 FOODS AND FOOD ADULTERANTS.
Fat. — Extract 2 grains of the finely powdered oofleein Soxlet's apparatus, or in one
of the various modifications of this apparatus, with anhydrous alcohol-free ether.
Remove the other from the extract by distillation and weigh the residue. Estimate
the caffeine in this residue and deduct. The caffeine will probably amount to a small
fraction of a per cent.
The sample of whole coffee beans may be prepared for analysis by means of a file
or rasp. Particles of iron in the raspings should be removed by means of a magnet.
Albuminoid nitrogen, — (Seep. 890.)
Crude fiber.1 — A quantity (6 to 8 grams) of the finely ground material is weighed
into a flask, and treated several times with very dilute caustic potash (0.2 per cent),
in order to remove the greater part of the albuminoids, lloil several times witli a
somewhat stronger solution of caustic potash (1.25 per cent), and after total removal
of the alkali boil repeatedly with acetic acid. The, residue after thorough washing
with water is dried at 105° C. and weighed.
Caffetannic add. — Owing to the lack of a method for the estimation of caffetannic
acid, the following was devised by Mr. W. H. Krug, of the Chemical Division, for
this report:
Weigh out duplicates of 2 grams each. Add 10 cc. of water and digest for 36 hours.
Then add 25 cc 90 per cent alcohol, and digest for 24 hours more. Filter, washing
the residue on the filter with 90 per cent alcohol. The filtrate contains tannin, caf-
feine, and traces of coloring matter and fat. . Heat it to the boiling point and add a
boiling concentrated solution of lead acetate. If this is carefully done a canVtan-
nate of lead containing 49 per cent lead will be precipitated. As soon as the pre-
cipitate has become flocculeut it is collected on a filter, washed with 90 per cent
alcohol until the washings show no lead with ammonium sulphide, washed with ether
to remove traces of fat, dried and weighed. The composition of the precipitate is
Pb:3 (Cift Hi5 Ota). Therefore weight of precipitate: weight of caffetannic acid
:: 1263.63: 652.
Total soluble and insoluble ask. — Refer to page 891 under the analy-
sis of teas for methods of asli determinations.
The color of the ash should be noted. A red ash is indicative of the
use of Venetian red or other iron compounds in coloring the sample.
ADULTERATION — DEFINITION.
Referring to the law of the State of New York (p. 879), the adul-
teration of coffees may be denned as follows: The addition of foreign
matter of any kind to reduce the strength or affect the quality; the sub-
stitution of cheaper substances in part or wholly for the genuine coffee;
facing or coloring in imitation of better grades or to conceal damage.
The use of cereals in so-called " blending " should be considered an
adulteration. The cereals act simply as a diluent, increasing the
weight and bulk without corresponding benefit to the purchaser.
These remarks might also well be applied to chicory, were it not that
many persons show a- decided preference for coffee containing this sub-
stance. Notwithstanding this preference, chicory is and should be con-
sidered an adulterant, except when the package containing the mixture
is distinctly branded and the proportions of pure coffee and chicory
indicated. It is stated that chicory possesses medicinal properties of a
diuretic and laxative character which render its excessive use objec-
1 Unpublished work of Mr. W. Maxwell, IT. S. Department of Agriculture.
DETECTION OF ADULTERATED COFFEE. 909
tionable. There is not sufficient evidence against chicory to warrant
placing it in the list of objectionable substances. Obvious adulterants
of coffees are the so-called substitutes molded in imitation of the genuine
beans.
ADULTERANTS AND THEIR DETECTION.
Facing or coloring. — It is not an uncommon practice to treat inferior
or damaged coffees by some process for the improvement of their
appearance and in imitation of superior grades. Java seems to have
been especially subject to this treatment, or rather other coffees are
colored in imitation of Java. E. Waller states ] that South American
coffees are often exposed to a high, moist heat, which changes their color
from green to brown, thus forming imitation Java. Waller also men-
tions the use of pigments in coloring coffees. This chemist found one
twenty-fourth grain of Scheele's green per one-half ounce of coffee. He
also reports the use in the Brooklyn mills of yellow ocher, silesian blue,
chrome yellow, burnt umber, Venetian red, drop black, charcoal, and
French black. Coffee is polished by rotation in cylinders with soap-
stone.
The following 2 is another method of preparing imitation Javas. Raw
coffee, which has been damaged by sea water, is washed, decolorized
with lime water, again washed, rapidly dried, and colored by a slight
roasting or by means of azo-orange. By this method Santos coffees
are converted into imitation Javas. The weight lost is regained by
steaming, and then coating the beans with glycerine, palm oil, or vase-
line to prevent evaporation.
Coffees are sometimes faced with Prussian blue or indigo, lead chro-
mate, etc. The following list of facing mixtures is from the published
investigations of K. Sykora.3
(1) Mixture of indigo, lead chromate, coal, and clay.
(2) (Approximately) 5 parts indigo, 10 parts coal, 4.5 parts lead chro-
mate, 05. 5 parts clay, and 15 parts ultramarine.
(3) (Approximately) 5 parts indigo with some yellow dye, 3 parts
coal, 8 parts lead chromate, 82 parts clay, 2 parts ultramarine.
(4) (Approximately) 12 parts indigo and some yellow dye, 5.5 parts
coal, 4.5 parts lead chromate, C.6 parts clay, and 12 parts ultramarine.
A mixture examined by G. C. Wittstein 4 was composed of 15 parts
Prussian blue (or indigo), 35 parts lead chromate, 35 parts clay and
gypsum, and 15 parts water. According to Nanning, coffee beans are
colored blue by shaking with finely powered iron.
Indigo and Prussian blue may be detected by the microscope or
chemically (see page 881 for methods). Lead chromate should be ex-
1 Analyst, 9, 128.
* Bull, cle la Soc. Chim. tie Paris, 47, 7; Chem. News, 56, 24.
3 Chem. Centrbl., 1887, No. 47; Rep. f. aual. Chem., 1887, 765.
4 Chem. News, 33, 194.
910 FOODS AND FOOD ADULTERANTS.
ainined for in the ash by the usual qualitative methods tor the de-
tection of lead and chromium. The asli should also be examined for
copper, and in the ease of moist preparations of coffee preserved in tin
cans, both tin and copper should be searched for. Azo-colors are de-
tected as follows:
Azo-colors are detected l>y treating the beans with strong alcohol, evaporating the
solution to dryness, and treating the residue, with water. This solution will give
the characteristic reactions of these dyes.
It is preferable, when possible, to detach the facing by shaking- the
coffee with cold water. The sediment may be examined chemically or
microscopically. Lead, tin, copper, and arsenic are the only objection-
able metals liable to be present in coffee or its preparations. The ash
should be examined for these metals.
Chicory. — One of the common adulterants of coffee is the prepared
root of the chicory plant, Cychorium intybus. There are .several chem-
ical methods for the detection of chicory, depending upon positive and
negative tests. Ground chicory when thrown on cold water sinks
quickly, coloring the water, and is soon softened, whereas ground
roasted coffee floats, imparting no color. Chicory is easily bleached by
chlorinated soda (labarraque solution); coffee is but slowly affected by
this bleaching agent. The coloring 1 matter of chicory is not precipi-
tated by iron salts, while that of coffee is colored green and is partially
precipitated. G. C. Wittstein2 employs the following method:
Boil 30 drops of the coffee infusion in a test tube with 2 drops of con-
centrated hydrochloric acid; add 15 drops potassium ferrocyanide solu-
tion (1 part of the salt to 8 of water), and again boil until the liquid
becomes a dark green ; add 6 drops of potassium hydroxide solution and
boil ; if chicory is present the liquid will become brown and murky,
v otherwise a precipitate will separate and settle to the bottom of the
tube, leaving the supernatant solution of a light-yellow color.
A. Franz3 states that copper acetate gives a greenish- brown precipi-
tate with coffee infusions and a dark-red brown precipitate with chicory.
With coffee the supernatant liquid is greenish and with chicory red
brown.
Hiepe1 tests for chicory as follows: Ignite 25 grams of the sample
and determine the amount of chlorine present in the ash. Coffee con-
tains 0.03 per cent chlorine, and chicory as high as 0.28 per cent. Kor-
nauth5 gives the maximum and minimum chlorine content of cotl'ee as
respectively 0.00 per cent and 0.15 per cent.
Chicory can be most readily and certainly identified in mixtures by
means of the microscope. The microscopic appearances of coffee, and
chicory are shown in Plates XLII, XLIII, and XLV.
'Ding. Polyt. Jonrn., 211,78; Jahresl.. d. ('hem., 1X71. IOC!.
2 Ding. I'olyt. Journ., 215, 81 ; Am. Chemist. 6, L'L'O.
'Arch. Pharni. [3], 8,2!»K; Jahresb. d. Cheni., 1S7IJ. 1021.
'Monit. -in- Scientific [3], 10, 1331); Jahresl,. .1. ( 'hem., isso, 1±>0.
f'Mitt. a. d. 1'liarm. lust. 11. Lal>. f. Angew. Cheni. Krlangrn. Heft 15, 1 to .M!.
CHICORY IN COFFEE. 911
The quantitative estimation of chicory or of the amount of coffee in
mixtures can not be made with certainty, and in all such estimations
only an approximate percentage content can be stated. The proportion
of chicory in a mixture is usually calculated from the specific gravity
of an extract made under definite conditions, comparison being made
with a coffee extract prepared under the same conditions. In other
methods a comparison is made of the depth of color of infusions under
certain standard conditions.
According to A. H. Allen1 the following method gives fairly good
results :
A weighed portion of the finely ground sample is boiled with water, filtered, and
the residue washed with hot water until the filtrate amounts to 10 cc. per gram of
the sample taken. The specific gravity of this extract is then determined and the
chicory calculated by the formula.
c = (1.023— d) 100
14.5.
in which c is the per cent of coffee, d the density of the extract. Allen found the
mean density of the 10 per cent decoction of a large number of coffees to be 1.0085,
and of chicory under the same conditions, 1.023.
The presence of cereals or other foreign matter would of course render this method
unreliable.
Prenier 2 states that —
Chicory may bo estimated by sifting a definite weight, approximately 2 grams
of the ground mixture ; the powder which passes the sieve is always coffee. The
larger grains are macerated with cold water for some hours, then thrown on a piece
of stretched cloth and rubbed with a pestle. The chicory will pass through the
cloth. The residue left on the cloth is now dried and weighed with the powder.
This is evidently a very rough method.
Another method for the estimation of chicory, and as rough as the above, is that
of C. Draper.3 In this method a glass similar in shape to a percolator is employed.
The stem is graduated and is sealed at the lower end. This apparatus is partly
filled with cold water, and a definite volume of the ground sample is slowly dis-
tributed upon its surface. The chicory sinks to the bottom of the water and its
depth is noted in the graduated tube.
The writer has found pure coffee, evidently overroasted, that would
sink in water. Other writers have also found coffee that would sink,
after a few minutes, in water. In case the adulterant has been treated
with a fat, it would be liable to float instead of falling to the bottom of
the apparatus. Chicory is often so treated.
The cells, milk vessels, etc., are well illustrated in the Plate XLV. The
milk vessels, vasa lacticentia, should be carefully studied, since their
peculiarities will usually serve to distinguish chicory from other roots
liable to be employed as adulterants.
Mangoldwurzel. — This is a root much used abroad for cattle feeding.
1 Chemical examination of coffee.— Chem. News, 29, 129, 140, 167, 189, 221. Op. cit.
30, 2.
2 Journ. Pharm. Chim. [5] 1, 222-224; Jouru. of the Chem. Soc. 1880, 514.
3Philos. Mag. 38, No. 228, 104; Zeitsch. f. anal. Chem. 7, 388.
912
FOODS AND FOOD ADULTERANTS.
According to Hassall,1 the large size of the cells and the absence of
milk vessels distinguish this root from chicory.
Cereals, leguminous seeds, and acorns. — Judging from those investiga-
tions the adulteration of coftees in this country with chicory is not as
common as with cereals, pease, beans, etc. These latter substances, in
general, are detected by the presence of starch and are finally identi-
fied by their structures as shown by the microscope.
The following method of A. H. Allen is probably the best for the
detection of starches, chemically, in adulterated coftees :
Boil a portiou of the powdered sample with water and lilter; cool the. filtrate,
acidulate with sulphuric acid; add a strong .solution of permanganate of potassium,
small quantities at a time, until the coloring matter of the original extract is dis-
charged; test for starch as usual with iodine.
Starch may be easily detected in the finely powdered sample, mounted
in Canada balsam, on examination by the microscope, with polarized
light. Starch, when examined as above, shows a dark cross on a white
field.
In Part II of this bulletin (Plates xm to xxvm), a number of
starches are illustrated as shown by the microscope with polarized
light and plain illumination. In the identification of starches it is well
to have a series of freshly-prepared slides of the materials from known
sources for purposes of comparison.
Sufficient of the original structures of the cereals or leguminous
seeds will usually remain for their identification with the microscope.
In this work it is well to have a series of slides prepared from the raw
and roasted materials for comparison.
The following statement of the percentage of ash in cereals is given
for comparison with that of coftees. The mean ash of the cereals given
is considerably lower than that of coft'ee.
Ash'2 of cvreala — (Aim-rivun).
Cereals.
Mean.
Highest.
Lowest.
Wheat
Per cent.
1.9
Per cent.
3 C
Per cent.
0.8
1 5
:t i
1.0
2.9
4 4
1.5
Oats
3.2
2 9
.9
KM-
2 1
"3.7
1.3
Canna seed, etc. — M. Mansfeld3 reported the presence of canna seed in
a coft'ee, and in an examination made in Austria, sawdust, oak bark,
baked liver, etc. Hassall4 mentions the use of 'sawdust, etc., in the adnl
1 Food, Arthur H. Hassall, Longmans, Green & Co., London, p. 167.
'J Dictionary of Applied Chemistry, Thorpe, 1, 490. Analyses by Cliflurd llich-
imhon, TJ. 8. Department, of Agriculture.
:1 l.Yv. Int. Scien. el I'nji. des Falsification, 4, 10.
4 Habball, Food, p. 159.
FOREIGN SUBSTANCES IN COFFEE. 913
' teration of coffees. None of these substances, except sawdust, have
been detected in the investigations in connection with this report.
Chemical tests are not applicable. On the detection of a foreign matter,
which is not among those described, evidently the only course to pursue
is to prepare slides for microscopic comparisons with others of known
composition.
TMoydad coffee. — This adulterant or substitute consists of the seeds of
the Cassia occidentalis. l E. Geissler 2 examined Mogdad coffee by 1 I ager's
method and found that it sinks very rapidly in water and colors sodium
chloride solution more intensely than coffee does; its infusion is not
indifferent to ferric chloride or tannic acid; it contains no starch.
Janecek 3 analyzed Mogdad coffee and found a different tannin from that
in the seed of Coffea Arabiea, but no caffeine.
JfiitiMtvn.da coffee. — This4 substance was supposed to be, seeds derived
from Mussaenda borbonica, but later investigations made at Kew Gar-
dens show these seeds to be from Gaertnera vaginata. It is stated that
Mussaenda coffee contains no caffeine.
Cocoa husks. — Cocoa husks may be identified by the methods given
under cocoa preparations.
Sugar and sirup. — Coffees are sometimes treated with sugar or sirup,
then roasted. When the caramel formed on roasting amounts to an
appreciable weight, it shoud be considered an adulterant. Stutzer5
and Eeitnair recommend the following method for the examination of
coffees supposed to have received this treatment: 20 grams of whole
coffee beans are transferred to a litre flask, covered with 500 cc. water
and the flask is then violently shaken for five minutes. After shaking
complete the volume to 1,000 cc., mix and filter off 50 cc. of the solution
into a tarred dish; evaporate to dryness on a water -bath, then transfer
to an oven heated to 95°-99° and dry two hours; weigh the residue,
incinerate, and deduct the ash before calculating the organic matter
extracted. Pure roasted coffee treated by this method gave from 0.44
to 0.72 per cent organic matter, and colored the water only slightly,
while coffees which had been roasted with sugar colored the water more
or less strongly and gave from 1.81 to 8.18 per cent organic extract.
The glazing of coffees, according to Konig,6 is objectionable, not that
the glazing material is unwholesome, but because coffees so treated
retain an excess of moisture in the roasting process. The following
comparative analyses quoted by Konig show the effect of roasting with
and without sugar. The sirup employed for glazing was simply a
solution of starch sugar.
1 J.Moeller, Pharm. Centralhalle, 22, 133; Zeitsck. f. anal. Chein., 21, 438.
•2Op. cit., 22, 134.
3 Chem. Ztg., 1880, 442; Jahresb. d. Chein., 1880, 1070.
4 Pharm. J.Trans., Nov. 16, 1889, 381; Am. J. Pharm,, 20, 4, 174.
5Zeitsch. f. angew. Chem., 1888, 701, also op. cit., 1890, 706.
eZcitsch. f, angew. Chem., 1888, 631.
,914
FOODS AND FOOD ADULTERANTS.
A. — Coffees roaxtal with
I.
II.
III.
Moisture
Per cent.
9 91
Per cent.
l'>-i t-i nl.
Calculated on the dry substance :
Soluble matter adhering to the beans
7 72
7 59
Reducing sugar, calculated as dextrose.
1 49
1 49
Total water soluble matter
°8 12
07 71
•>g 07
Fat ( volatile oil, ether extract)
12 62
I9 34
() 4-,
B. — Coffeeti rotwted without miflur.
I.
II.
III.
Moisture
Per cent.
3 14
Per cent.
" ~i",
Per cent.
•> 79
Calculated on the dry substance :
Soluble matter adhering to the beana
4 77
4 15
Reducing sugar present calculated as dextrose. . . .
44
34
19
Total water soluble matter
24 09
°1 81
""> ''7
Fat (volatile oil, ether extract)
16. 2l»
13. 44
'2. oo
The large percentage of moisture retained by tbe glazed coffee and the
decided increase in the soluble matters adhering to Mie beans must cer-
tainly prove of considerable profit to the roaster without advantage to
the consumer.
SUBSTITUTES FOR COFFEE.
A liumber of substitutes for coffee have been proposed. Many of
these have little claim to be entitled substitutes, since they simply fur-
nish a decoction more or less bitter and of a coffee color.
Substitutes, no matter how nutritious, should never be sold in mix-
tures with genuine coffee, except in properly labeled packages. The
package should be distinctly branded in such a way as to avoid mislead-
ing the purchaser and should indicate from what raw material the sub-
stitute has been prepared.
Besides chicory, Mogdad, and Mussaenda coffee, acorns, figs, legumi-
nous seeds, and cereals have been employed as coffee substitutes.
In this connection it maybe well to call attention to the fart that
the bogus coffee, known in Germany as "Kuust Kaffee," is largely
imported into this country. That this product is a fraud is evident from
the fact that it is molded in imitation of genuine coffee and in mixtures
is sold as such.
Koruauth1 examined chicory and figs, and considers them <>!' eonsid
erable nutritive value for the poorer classes.
1 KV\ . Internet. Scient. ct. Pop. dcs Falsifications <lcs I iccivcc's Aliuu-nl, 3, S; <Yn-
tralbl. 1890, 605.
IMITATION COFFEES.
915
1 The fruit of the wax palm ( Gorypha, cerifera L., or Gopernicia ceri
fera, Mart.), which yields camauba wax, is used in Brazil for the prep-
aration of a coffee substitute, for which purpose it is roasted in the
usual way. Chemical investigation of samples of this fruit procured
from Brazil, by Konig, gave: —
Raw.
Boasted.
Water
J'er cent.
9 37
Per cent.
3 76
6 54
6 90
5.82
6. 14
10 57
14 00
Sugar and dextrine
1.67
1.25
Starch
2.47
5.46
23 01
27 78
Fiber
44.31
38.45
Ash
2.06
2 24
Mean K2O
.63
.69
.42
45
.41
,43
12 17
18.50
Iii the raw state the fruits have a stony consistency. Starch could
not be detected and, if present, was in very slight quantity. The sub.
stance presented in the table as starch was obtained by treating the
mass, after extraction with water, Avith diastase, then heating three
hours in a Soxhlet pressure steam oven. The mixture was then fil-
tered, the filtrate inverted with HC1 and precipitated with Fehling's
solution. The fat from the fruit has apparently a different constitu-
tion from the wax from leaves (carnauba wax).
Only a slight amount of water soluble substances are found in the
roasted fruit, as is the case* with acorns.
IMITATION COFFEES.
Within two or three years the coffee markets have been flooded with
imitation coffees. The first official action toward suppressing this fraud
in this country was probably that of the New Jersey officers. It is
claimed that these fraudulent coffees are no longer to be found in the
markets of that State. Reports from dealers in various parts of the
country indicate that the sale of imitation coffees has been very general.
On the the following page is a list of the imitation coffees examined in
connection with this report, together with a description and statement
of their probable composition.
1 . 1. Konig, Central-Organ, f. Waarenkunde und Technologie, 1891, 2, 1; Chern-
Ztg., 15, 19, Aug., 1891.
20393— No. 13 4
916 FOODS AND FOOD ADULTERANTS.
Serial No.
6872. Imitation coffee beans, roasted; probably the same composition and manu-
facture as 8957.
8766. Coffee, bran, and molasses ; roasted ; not molded.
8767. Bran and molasses; roasted; not molded; samples 8766 and 8767 were obtained
through the courtesy of Dr. J. N. Hurty, chemist, Indianapolis, Ind.
8491. Imitation coffee beans, roasted. Composition: Wheat flour. Manufacturer
not known, but probably same as 8957.
8859. Imitation coffee beans, roasted. Composition: Wheat Hour, coffee, and chicory.
8883. A rather poor imitation of roasted whole coffee beans. Imported as a coffee
substitute under the name "Kunst Kaffee." Imported by M. Kliemand, 159
Front street, New York City; manufactured by Erhorn &. Dierchs, 1 linn-
burg, Germany. Price, 11 cents per pound. Composition: Wheat Hour,
coffee, and chicory. A German analysis of an imitation coffee termed " Kunst
Kaffee" is given on p. 919, by K. Portele.
8884. Imitation roasted coffee beans. Composition : AVheat flour, coffee, and chicory.
Manufacturer not known.
8885. Imitation green coffee. This sample contains two kinds of berries, one com-
posed of whetit flour and the other of wheat flour and coffee. Sample was
obtained in Philadelphia. Manufacturer not known.
8950. Imitation coffee beans, roasted. Composition : Wheat flour, chicory, and coffee.
Manufacturer not known.
8951. Coffee pellets, molded, but not in the form of coffee beans. When mixed with
ground coffee would escape the notice of the purchaser ; also probably in
mixture with whole coffee. Composition: Wheat flour aud,l*ran, rye also
probably present. Manufactured by the Clark Coffee Company, office 1">0
State street, Boston; factory, Roxbury, Mass. Price, 6 cents per pound, or
&k cents in 10-barrel lots. The manufacturers claim that an addition of 33
per cent of these "pellets" to genuine coffee Avill make "an equal drink to
the straight goods." The manufacturers, after making extravagant claims
for their product, state, with evident intention to further a fraud, that "it
is uniform in color, and can be furnished with any desired color of roast."
8952. Coffee pellets, same manufacture and composition as 8951. Grains lighter
color and longer than 8951.
8953. Cracked coffee pellets, same manufacture and composition 8951.
8954. Ground imitation coffee. Contains a small amount of chicory, a considerable
proportion of leguminuous seeds (peas or beans), and barley, wheat, oats.
and fragments of buckwheat. Manufactured by the Swedish Coffee Co., of
New York.
8955. Imitation coffee beans. Composed of wheat flour; light roast. Manufactured
by the Swedish Coffee Co., New York.
8956. Similar to 8955 and of the same manufacture. Composition: Wheat Hour and
probably saw dust. Dark roast. Two kinds of berries.
8957. Imitation coffee beans. Composition: Wheat Hour. Manufactured by L. II.
Hall, 1017 Chestnut street, Philadelphia. Pa.
8958. Granular imitation coffee. Composed of the hulls of leguminous seeds, probably
pease, formed into granules with molasses and roasted; source not known.
8963. Imitation roasted coffee beans. Composition: AVheat Hour. Probably of the
same manufacture as 6872, 8491. and 8957.
8996. Sample package, marked " Coffee Substitute, Columbia AAA." Composed of
bran and molasses, formed info small lumps and roasted. Manufactured by
E. A. Sibell, 19 and 20 AVabash avenue, Chicago. 111.
104H3. Imitation roasted coffee beans. Composition: Wheat or rye Hour and corn.
Manufacturer not known.
101X1. Imitation green coffee. The same composition and manufacture as 10483.
DEALERS IN SPURIOUS COFFEES. 917
Serial No.
10515. Granular imitation coffee. Composition: Pea hulls and bran. Maufactured by
the Powell Manufacturing Company, 120 Front street, New York." See cir-
cular letter, p. 918.
Abstracts and 'copies of a number of the circular letters sent out to
dealers by the manufacturers of spurious coffees may be of interest and
value. The following are copied in full with the exception of the address :
DEAH Siu: I send you by this mail a sample of "imitation coftee."
This is a manufactured beau, and composed of Hour; you can easily mix 15 per
cent of this substitute in with genuine coffee that ranges in price from 20 to 22£
cents, and it will improve the flavor of the same; it granulates the same as coffee.
If you deal with us it will be in the most strict confidence. .
This S. S. Coffee (Superior Substitute) is packed in barrels, weight about 170
pounds to barrel. By the use of our bean you can increase your profits to 1£ cents
per pound and improve the flavor. Try a sample barrel. Price 11£ cents per pound
net, ten days. No attention paid to postal cards.
Yours,
L. II. HALL,
Sole Agent.
I would not show samples even to employds.
GENTLEMEN: We desire to call your attention to our improved grade of coffee pel-
lets, which we mail you sample of to-night. The bulk of the goods has been in-
creased, and the drinking merit still further enhanced, as a test of the g jods will
demonstrate. To exhibit the value of our goods, and show the extent they can be
used with good results, wo mail you sample of a compound coffee made as follows:
7"> per cent pellets, 15 per cent coffee, 10 per cent chicory.
This makes a very desirable cup of coffee, equal to any low grade straight coffee,
and costs, on basis of 5 cents per pound for pellets, 7 cents per pound. By the use
of 33 per cent of our new pellets in fine goods, the same result is obtained as from
the straight goods alone.
We believe a thorough test of the coftee pellets will convince you that the goods
are the most valuable adjunct of the coftee business on the market.
We will be pleased to quote prices on quantities.
Yours, respectfully,
CLARK COFFEE COMPANY.
GENTLEMEN : We desire to make a proposition to you, which will be for your inter-
est to consider.
We are manufacturing a coftee substitute which is unquestionably far ahead of
anything in its line, which we term " coffee pellets." The merit of these we will not
dilate upon, but simply ask that you give them a fair trial. They are put out in
size used for crushed coffees, and are the best for that purpose upon the market. We
understand you are using peas extensively, and wo propose, if we can get your atten-
tion on the goods, to compete with that article on a basis of uniform price. Our
goods are 4 ounces lighter in bulk to the pound than pease, and double the quantity
can be used, with better results. As far as appearance is concerned, of course our
goods have considerably the best of it. We mail you sample to-night, and our Mr.
Clark will be in your city the first of next week, and we would ask that you see if it
is not for your advantage to use our goods.
Hoping you will give it your attention, we remain,
- Yours, respectfully,
CLARK COFFEE COMPANY.
918 FOODS AND FOOD ADULTERANTS.
"TIIK SUCCESS OF THK SKASON."
Java coffee compound, 1-pound packages, whole bean, 60 pounds in case ; cost, 10
cents per pound ; retail it for 15, and give better value than you now do for 24. Send
us your order at once. Draft or post-office order must accompany it. If for any rea-
son you wish to return Java coffee compound within thirty days of its receipt, do
so at our expense and we refund money. You won't return it, but will order more.
Very truly yours,
THK DOWLING MFG. Co.
Reference, Produce National Hank.
GENTLEMEN : We have sent you by mail a sample of our " coftee substitute," which
is being used by the trade very generally in this city. We claim for our goods that,
unlike any other mixture in the market, it is positively neutral in character and can
be used in larger quantities and to better advantage than any other, while the style
is always uniform both in color and grain. Those goods are put up in barrels of
about 200 pounds net, and are sold "F. O. B." at 5 cents, less 10 per cent, ten days.
We would be pleased to ship you any quantity for a trial, should you desire it.
Very respectfully,
POWELL MANUFACTURING Co.,
Per J. D. M.
(See p. 916, serial No. 10515.)
Abstract from letter of M. Kliemand,1 327 Degraw street, Brooklyn.
I beg to mail you a sample of a coffee substitute, "Kunst-Kaffee," manufactured by
Messrs. Erhorn & Dierchs, Hamburg, who appointed me general agent for the United
States.
Advantages. — It is animating, but not exciting, and very nutritious and whole-
some, softening the taste of the inferior coffees; quality unimpaired for twelve months
or longer.
Price. — Eleven cents per pound, New York, net, per Pennsylvania Railroad.
The above so-called coffee substitute (Department serial No. 8883) is
admitted at the pdrt of New York as a " substitute for coffee" at the
rate of 1^ cents per pound.
Dr. Van Hamel Roos calls attention to the following novel scheme for
the sophistication of coffee berries : 2
The microscopical examination of a sample, rendered suspicious by
its dark color, showed the structure of genuine coffee, but the fat glob-
ules, which are always abundant in pure coffee, were almost entirely
absent. The ether extract from pure coffee is 13 to 14 per cent. In
this sample it was less than 1 per cent. It is evident that the roasted
coffee had been treated for the manufacture of coffee extract, after
which the grains were roasted a second time with the addition of a little
sugar to cover the berries with a deceptive gla/ing. Tbe dark color
of the beans was due to the second roasting.
Owing to lack of time no chemical analyses of artificial coffees were
made in connection with this report. A large number of analyses have
given by the customs authorities is 159 Front street, Nc\v York, Cii> .
'Revue Intern. des Falsifications, 4, 10, 166, May 15, 1891.
IMITATION COFFEE BEANS.
919
been published in the journals, from which those given in the following-
table have been taken:
' Imitation coffee beans.
Sub-
stances
forming
Analyst.
Wa-
ter.
Protein
matter.
Fat.
Cellu-
lose.
Su-
gar.
Extract
matter.
Ash.
Caf-
feine.
Water
extract.
glucose
witb
dilute
sul-
phuric
acid.
Artificial coffee beans • '
P.ct.
r. ot.
P.ct.
P.ct.
P.ct.
V
P.ct.
/'. ct.
P.ct.
P.ct.
P. ct.
W. Kisch
5.14
10.75
2. 19
3.96
76.66
1.20
29.88
E Fricke 2
17.90
2.03
10.83
1.99
64.04
2.27
.94
24.85
8 30
1.10
iu :u
2 26
11 46
2 78
1 94
1 77
55
27 58
K. Portele 3
1.4G
13.93
3.80
15.83
.71
63.30
2.53
.071
21. 5:i
50.02
Barley coffee :
c3. 45
9.38
3.25
4.25
6.18
70.13
3.36
31.20
69.28
<0.41
10.56
1.04
10.56
68.36
3.04
34.37
67. 19
1 From a tabulation by C.Kornauth, Eev. Internat. Scient. et Pop. des. Falsifications des LKJrivees
Aliment., 3,195-196.
2 Zeit. f. angew. cbem., 1889, 310-311 ; Chein. centralbl., 1889, 154.
3 Original article, Zeit. f. Nahrungsmitteluntersuch. u. Hygiene, 3, 221-222 ; Chem. Centralbl., 1890, 135.
Kornauth (loc. tit.) states that he has analyzed artificial coffee beans
which were very similar to the genuine, having a specific gravity of
1.26. Specific-gravity determinations of the samples examined in con-
nection with this report gave the following numbers: Serial No. 8491,
1.195; No. 8933, 1.073; No. 8859, 1.198; No. 8883, 1.111; No. 8951, 1.119;
No. 8952, 1.183; No. 8953, 1.194; No. 8955, 1.211; No. 895G, 1.174 (light-
colored grains) and 1.131 (dark-colored grains), and No. 8957, 1.118. In
making these determinations a solution of sodium chloride was employed.
Twenty imitation coffee beans were immersed in this solution, the dens-
ity of which "was then gradually changed until ten beans floated near
the surface and ten at the bottom of the solution. The specific gravity
of the modified solution was then taken and recorded as the specific
gravity of the imitation coffee.
These specific gravities are only an approximation, owing to varia-
tions in the density of artificial coffees even from the same sample.
Kornauth, in the article cited, states that he supposes the imitation
coffee to be composed of grape sugar and dextrin, which are mixed with
fat and sugar and the mass pressed in forms, roasted, and glazed. He
states that imitation coffee beans sink in 40 per cent (by volume) alco-
hol, while the genuine beans float.
Stutzer and Keitnair suppose that the imitation coffee beans are com-
posed of roasted sugar; Konig, of wheat bran; Frike, of sugar and
lupine flour; Hanausek, of wheat bran and the refuse from white pep-
pers; Pavlicek, of sugared bran, and Portele supposes them to be com-
posed of sugar, cereals, and legumes. Fricke considers lupine seeds
920 FOODS AND FOOD ADULTERANTS.
harmful. These opinions are from Kornauth's article cited above. The
observations of Portele agree more closely with the results of the inves-
tigations of this laboratory.
A recent journal1 reports the following as tne composition of an imi-
tation coffee seized by the Government of Roumania: Coffee grounds
(spent coffee), chicory, and pease. The mixture had been molded in a
special machine in imitation of coffee beans.
A factory for the manufacture of imitation coffee was recently seized
at Lille, France, by the French Government.2 The capacity of this fac-
tory was 40 to 50 kilos of imitation coffee per day. The composition of
the product, as shown by the testimony at the trial of the manufactur-
ers, was as follows: chicory, 15 kilos; flour, 35 kilos, and sulphate of
iron, 500 grams.
L. Jammes3 examined a sample of imitation coffee and found it to be
composed of acorns and cereals.
DETECTION OF IMITATION COFFEES.
Roasted imitation coffees may usually be very easily detected. As a
rule, genuine roasted coffee will float on water, and the artificial prod-
uct, roasted, will sink; there are, however, exceptions to this. Coffee
that has been "overroasted" will sometimes sink in water. The arti-
ficial coffees examined in connection with this report, with one excep-
tion, sank in water. These remarks apply to whole coffee. Kornauth4
states that imitation coffee beans sink in 40 per cent (by volume) .alco-
hol. Certain coffees will also sink in alcohol of this density; hence
this alone is not a sure test.
In examining roasted coffee for the imitation product a portion of the
sample should be thrown on 40 per cent (by volume) alcohol, and those
beans which sink should be subjected to a further examination. The
genuine coffee bean always has a portion of the fine membrane with
which it was originally invested still adhering in the cleft. This test
alone will distinguish the genuine from the imitation coffee beans. On
the examination of a section of an imitation coffee bean it may l>e seen
that the structure is uniform, while that of the genuine bean is not.
The imitation coffee generally contains starch, a substance which is
never present in the genuine beans. If starch is absent the sample
should be examined microscopically for chicory or similar roots.
In the examination of aground sample tests should be made for starch
and chicory. A portion should be thrown on cold water. Chicory, if
present, will quickly color the water, while- cereals will sink, often
imparting little, if any, color to the water. It should be noted that
coffee, deprived of its oil, will sink in water ami that cereals or chicory
1 Rcvnc Intern. <!«>« F:ils. I' Ann6e, N. 11, iss.
'Revnn Inlcrn. <Ics Fills., I'1 Aimrfe, No. 11, 1S5.
sClM-iii. (Vntralbl., 185)1, 1, 0:tr>.
•• Kev. Internal. Scieu. et Pop. des Fiilsifiratimis. 3, 195.
COFFEE BOUGHT IN THE OPEN MARKET.
921
treated with oil will float. The cold-water test should always be made,
since valuable indications as to the purity of the samples may usually
be obtained. A low percentage of ash indicates an adulterated sample.
The microscope must be employed for the final identifications of the
constituents of the sample.
REPORT OF EXAMINATION OF SAMPLES BOUGHT IN THE OPEN MARKET.
The samples included in the following report were purchased in stores
ranging from the best class to the poorest. The grades of coffee fairly
represent the market:
Description of samples examined.
Serial
num-
ber.
Name and address of retail
dealer.
l;. -Mil
price
per
round.
Name under
which sold.
Descrip-
tion.1
Remarks.
>0
685;!
685 1
C855
6856
G857
6858
0X5!)
6860
C8G1
6862
G863
6864
G865
6866
G867
68G8
6869
6870
6871
6872
6873
Cents.
25
, 3£,
25
30
30
35
25
25
30
28
35
22
25
40
30
25
35
25
35
coft'ees
Rio
Roasted . .
Ground . .
Green. - . .
Dealer says con-
tains chicory.
No. 6868, roasted.
No. 6869, roasted.
W. R. Brown, 20tli and Penn-
sylvania avenue NW.
I'. H. Ward, 21st and Penn-
sylvania avenue NW.
W. H. & B. Reynolds, 2919
M .street NW.
M. Cropley, 3101 M street
NW.
'Atlantic and Pacific Tea Co.,
. 30th and M streets NW.
do
Oppert &Bros.,32d and M
streets NW.
Reck ert, 3232 M street NW.
Lowe, Potomac and M
streets NW.
W. T. Dyer, 3418 M street
NW.
Goddard, 30th and M streets
NW.
P. J. Mclntyre, 2534 K street
NW.
do
Podung Java . -
Johnson's Oof-
fee.
Rio
*
Roasted..
Ground - -
Flavored Java.
8 o'clock Break-
fast.
Rio
do
...do ....
G reen .
do
Ground . .
do
do
Mocha and Rio.
Rio
Roasted . .
Green .
do
Ground . .
Roasted . .
....do ....
Green
....do ....
Roasted . .
. . . .do
do
do
C. D. Kenny, 7th and I streets
NW.
do
Maracaiho
Java
Second quality
Java.
Java
Second quality
Java.
Rio
do
do
C. I. Kellogg, Masonic Tem-
ple.
Carl Mueller, 8th and II
streets NW.
1 "Roasted" indicates
Java
•ousted but not gi
Ground ..
ipiiml
Date.
1890.
June 20
922
FOODS AND FOOD ADULTERANTS.
Description of samples examined.
Date.
Serial
num-
ber.
Name and address of retail
dealer.
Retail
price
per
pound.
Name under
which sold.
Descrip-
tion.1
Remarks.
1890.
Juno 20
June 21
Juno 23
1891.
Feb. 26
Apr. !•
Apr. 11
Apr. 13
Apr. 15
C874
C875
0878
6879
6880
C884
6885
£886
6887
6888
6889
6X90
6895
G897
6904
8712
8770
8771
8772
8773
8775
8776
8777
Burchard, 4J street and
Pennsylvania avenue.
do
Cents.
40
4
25
25
35
38
35
* 28
22
40
28
35
50
50
27
32
25
25
30
20
25
'_'o
25
Mocha
Hummers Es-
sence of coffee.
Rio
Mocha and Java
Java
Roasted . .
Price given is that
of small package.
Dealer states prob-
ably contains
chicory.
Package price.
Do.
Do.
Sold in packages.
Dwinell, Hayward
&, Co., Boston.
I'arkagcs.
— Stentz, 639 Pennsylva-
nia avenue SE.
J. T. Earushaw, 8th and G
streets SE.
— Tolson, 701 7th street
B&Bi
Geo. E. Kennedy, 1209 F
street NW.
Bryan, New York ave-
nue, near 15th street N W.
Great Atlantic and Pacific .
Tea Co., 503 7th street N W.
Great China and Japan Tea
Corral 7th street NW.
Corn well & Sons, Penn-
sylvania avenue, near 15th
street NW.
Metzgers, 417 7th street
NW.
Goddard, ISthstreetand
New York avenue NW.
J. H. Magruder, New York
avenue N W.
G. G. Cornwell, Pennsylva-
nia avenue, near 15th
street NW.
— Burchard, 4 J street and
Pennsylvaniaavenue N W.
— Burchell, 1325 7th street
NW.
Chas. I. Kellogg, Masonic
Temple.
Alexander Clark, 7th street
and Florida avenue NW.
Arbuckle Bros., Pittsburg,
Pa., and Now York.
Alexander Clark, 7th street
and Florida avenue NW.
A. Orison, Mainea venue and
4J street SW.
\V. A. l:arnes,212 4J street
S\V.
Jno. B. Prout, 411 4J street
SW.
Ground. .
....do ....
do
Mocha (best) . .
Java (best) .
Itoasted. .
do
Java (very best)
Yellow Rio
....do....
do
Java and Mocha
Rio . .
....do....
do ...
Javaand Mocha
....do....
. . . .do ....
of coll'ee.
Borden's Ex-
tract of coffee.
Rio
Roasted . .
Green
KciM.sted
....do ....
Kio
do
do
do
Ground
Johnson's
Breakfast.
....do ....
Kiiasti-d
Ground
Blended coffee,
Java :m<l <•<•
reals.
1 " Roasted " indicates coffees roasU-d hut not ground.
SAMPLES OF COFFEE EXAMINED. 92d
Description of samples examined.
J)ai<-.
Serial
num-
ber.
Name and address of it-tail
dealer.
Retail
price
per
>ound.
Name under
which sold.
Descrip-
tion.1
Remarks.
1891.
Apr. 15
8778
8779
8780
8781
8782
8783
8784
8785
8786
8787
8788
8789
8790
8791
8792
8793
8794
8795
879G
8797
8798
8799
8800
Smith & Razen, 601 4£ street
SW.
Newman, (1 and 4J
streets SW.
Wm. A. L. Huntt & Co., 801
4J street SW.
Lacky, corner M and
4J streets SW.
Tolson, 1345 4J street
SW.
Tyno, corner L and 6th
streets SW.
B. F. De Atley, C and 3d
streets SW.
T. T. Keane, 429 3d street
SW.
Curtis & Bros., 217 Virginia
avenue.
C. A. Hammer, corner Vir-
ginia avenue and 2d street
SAV.
C. L. Callis, Virginia avenue
and ] st street SW.
P. A.Cudmore,101 B street
SE.
T. F.McCauley,209 Pennsyl-
vania avenue SE.
Cents.
25
25
iSO
30
30
25
25
30
25
25
28
25
25
''5
Maracaibo
Rio
Roasted..
...do
Sold in packages.
Sold in packages.
do ...
Brazil
Ground . .
do
Rio
Roasted . .
Ground . .
. . . .do . . . .
do*
do
Mochaand Java
Rio and Ar-
buckles.
do
do
do
Rio
Roasted . .
..do ..
do
O'Donnell, prop., Penn-
sylvania avenue and 4th
street SE.
D. E. Baldwin, 637 Pennsyl-
vania avenue SE.
Henry Kuhn, corner Penn-
sylvania avenue and llth
street SE.
Jno. Hessell, 326 llth street
SE.
K. C. Smallwo'xl, corner
South Carolina avenue
and llth street SE.
Wm. F. McAllister, corner
6th and C streets NE.
Thos. A. Rover, 714 North
Capitol street.
J. E. Connelly, 1st and K
streets NW.
— Murphy, O and 4th
streets NW.
E. Kleps, R and New Jersey
avenue NW.
1 "Roasted " indicate
28
28
28
25
25
25
20
25
coffee
Rio
do ...
do
do . . -
do
Ground .
Roasted .
Ground .
Roasted .
do...
Rio
Sunrise,blended
Rio
Rio
Ground .
Roasted .
•ouiid.
do
roasted but not g
FOODS AND FOOD ADULTERANTS.
Description of samples examined — Continued.
Date.
Serial
num-
ber.
Name and address of retail
draler.
Retail
price
per
pound.
Name under
which sold.
Descrip-
tion.'
Remarks.
1891.
Apr. 15
Mny 2
8801
8802
880.1
KS04
8805
8824
8825
. 8826
8827
8828
8829
8830
8831
8832
8833
8834
8835
8830
8837
8x:w
Mrs. Emma, 7th and Pome-
roy.
Grocery and variety store,
t2128 7th street NW.
M. P. Sullivan, 2222 7th
street NW.
Quilter, 2226 7th street
NW.
Goldman & Rubin, 1720 7th
street NW.
K. V. H. Lawson, 515 North
Clark street, Baltimore,
lid.
Atlantic and Pacific Tea
Co., 213 North Eutaw
street, Baltimore, Md.
N. T. Baker, Pearl and Lcx-
. ington streets, Baltimore,,
Md.
United States Tea Co., Pearl
and Lexington streets,
Baltimore, Md.
Bryant & Clarvoe, 128 North
Paca street, Baltimore, Md.
Great China Tea Co., 425
Lexington street, Balti-
more, Md.
M. J. Fadgen. corner Balti-
ini 11 1- :i nd Harrison streets,
Baltimore, Md.
.T. N. Anderson, 213 East
Pratt street, Baltimore,
Md.
N. Kciter, 709 East Haiti-
more street, Baltimore,
Md.
A.D. Landin, 707 East Bal-
timore street, Baltimore,
Md.
n. S. Potts, 327 High Hired,
Baltimore, Md.
W. M. Maynadier,404 \orlb
Culvert street. Baltimore,
Md.
Holler, McGav &. Co., 222
North Charles street.
Baltimore, Md.
Thou. M. Keese A- Sons, ,'U7
North Charles street,
Baltimore. Md.
li ('. l::illel.33l> I':|I k st reet,
Baltimore, Mel.
1 " Boasted " indicates
Cents.
30
25
20
30
23
20
26
21
28
22
20
30
23
M
28
26
24
( oilers
Maracaibo
Ground . .
do .
Rio
do
Kio and Mara
eailio.
Kio
... .do ....
do
do
do
1
... do
. . .do
do .
Rio
. . do
do
do . .
do
Rio
. ..do .
do
do
do
Rio
.In
Rio
do .'...
do ....
do
. . ,lo
roasted lint not
i round.
SAMPLES OF COFFEE EXAMINED.
Description of samples examined — Continued.
925
Date.
Serial
num-
ber.
Name and address of retail
dealer.
Retail
price
per
>ound.
Name under
which sold.
Descrip-
tion.1
Remarks.
1891.
May 2
8839
8840
Reitz Bros., 206 North Eu-
taw street, Baltimore, Md.
W. B. Bealmar & Co., 216
North Eutaw street, Balti-
Cents.
2C
26
Rio
do
...do
do
more, Md.
8841
A. Katzenberg, 222 North
26
...do
....do ....
Eutaw .street, Baltimore,
8812
Md.
Meyers, corner Pearl
and Chestnut streets,
»
. . do
do
8843
Baltimore, Md.
Acombo, corner Pearl
and Mulberry streets, Bal-
.
do
...do
8844
8845
timore, Md.
Schooly, 205 North Pearl
street, Baltimore, Md.
N. T. Baker, northeast cor-
ner Pearl and Lexington
— 1
26
do
do
do
..do
88»(i
streets, Baltimore, Md.
Hickmen, 037 West
Fayetto street, Baltimore,
27
do
do
.
8847
Md.
James, corner Fayetto
and Arch streets, Balti-
35
Java
...do
8848
8849
more, Md.
Win. Lutzer, 2C Harrison
street, Baltimore, Md.
Atlantic and Pacific Tea
Co., 613 East Baltimore
27
24
...do
do
. .do
street, Baltimore, Md.
8850
Frey & Co., 1000 East Fay-
25
....do
....do ....
ette street, Baltimore, Md.
8851
Franklin & (Jane, corner
26
Levering's cof-
....do ...
High and Gay streets, I'.al
fee.
tiniore, Md.
8852
Groat China Tea Co., 615
East Baltimore street,
12
Coffee substi-
tute.
8S53
Baltimore, Md.
do
16
Japan coffee . . .
Ground..
50 per cent coffee
50 per cent chic-
ory.
8854
H. Kettenboch, 18 Harrison
20
Golden, blender
....do ...
street, Baltimore, Md.
8S60
88fil
8862
C. C. Bryan, 1413 Now York
avenue, Washington. D. C.
do
35
35
Java
Roasted.
....do ...
do
G. G. Corn wall &Sons, Penn-
38
Mocha and Java
do . . .
sylvania avenue near 15th
street.
June IT
8950
On sale in Kansas
Aromatic Au-
....do ...
Sold in packages.
rora coffee.
1 " Roasted" iiidtcates coffees roasted but not ground.
92G
FOODS AND FOOD ADULTERANTS.
Description of samples examined— Coutiiuu-d.
Date.
Serial
11 um-
ber.
Name and address of retail
dealer.
Ketail
price
per
pound.
Name under
which sold.
Descrip-
tion.
Ki-in.irk-.
1891
June 19
8961
John Hockmeyer, Center
Cento.
28
Rio
8902
Market.
John H. O'Donnell, Center
28
do
do
8963
Market.
Capital Tea Co., Center
25
do
do
Market.
Juno 26
8987
C. C. Bryan, 1413 New York
40
Pulverized Java
....do....
Chase & Sauborn
avenue.
Boston, Mass.,
8988
Great Atlantic and Pacific
28
Eio
do
packages.
Tea Co. .market 21st and
K Streets.
Number
of sam-
ples.
30 \
60
3
18
1
112
1 Roasted indicates coffees roasted but not ground.
ROASTED COFFEES.
But three of the samples of whole roasted coffees were adulterated.
Knowing the large amount of imitation coffee that is on the markets
this result was unexpected. The adulterated samples were Nos.
6872, 8950, and 8963; each of these contained imitation coffee, The;
composition of the imitation coffee is given on page 916 under these
numbers. No. 6872 contained a small percentage of imitation coffee;
No. 8950 contained 50 per cent, and No. 8963 contained 1£ per cent.
The imitation coffee in the case of No. 6872 was introduced by the
roaster. No. 8950 is a package coffee, sold largely in Kansas. Its
origin is not known. It is very probable that roast <M! coffees are adulter-
ated to a very much greater extent for sale in packages in districts not
readily accessible to a roaster. Large quantities of package coffees
are sold in Kansas. Samples Nos. 8840 and 8849 contained an excessive
proportion of coffee screenings. While coffee screenings consist largely
of fragments of pure coffee beans, they should, notwithstanding this, be
considered adulterants. One, sample No. 8772, was roasted with a large
amount of a glazing material. According to Ko'nig (see page 9 13) this is
objectionable, since it would increase the weight of the roasted coffee
Without corresponding advantage to the consumer.
GREEN AND GROUND COFFEES.
927
It is not unusual for roasters to employ a small amount of glazing
material, as they claim, to protect the coffee.
The accompanying table gives the results of a few examinations of
coffees by Stutzer and Reitnair's method (see page 913) for the deter-
mination of the cold-water extract:
Serial No.
Extract.
Serial No.
Extract.
C853
I'd' rent.
0.9!!
6885
I'cr cent.
0.63
6856
87
6886
.85
6863
70
6887
1.12
6870
.40
6888
.35
6871
37
C889
.92
087''
.92
6890 '
.54
6873
.70
8772
1.76
6884
.57
Stutzer and Keitnair give from .44 per cent to .72 per cent as the
range of the organic extract as determined by their method.
Seven of the samples included in the above table gave a higher
extract than the upper limit given by these chemists, hence it is fair to
presume that these coffees were roasted with a glazing material. No.
08714 contains imitation coffee, which may account for the high organic
extract.
It is probable that the retail dealer is not usually directly to blame
in foisting imitation coffee upon the market, though he must in many
cases know that he can not obtain a good merchantable coffee for the
price he is paying. In most cases the imitation coffee is probable intro-
duced by the roaster. The price paid for roasting coffees is usually
very small and the competition is very sharp. A dishonest roaster can
so easily increase his profits by the addition of imitation coffee, and
with so little fear of detection, that he is often tempted and probably as
often yields to temptation.
GREEN COFFEES.
A large number of green coffees, bought on the open market, were
examined, all of which were genuine. It was impossible to detect
cases where coffee of one grade was sold for that of another. There
were undoubtedly many such samples.
GROUND COFFEES.
Ground coffees afford a very wide' field for adulterations. This class
of coffees is sold largely by the smaller dealers. The large stores
Usually grind the coffee to order, but in the latter case the presence of
the purchaser does not always insure pure coffee.
928
FOODS AND FOOD ADULTERANTS.
Ground coffees.
Serial.
Water test.
Coloration in
livo minutes.
Water test.
Proportion
sinking in
water in five
minutes.
Microscopic examination.
Approximate
coffee.
Adulterants.
0854
0857
6858
(5859
6801
68G2
6805
6874
6878
6879
6880
87715
8775
8777
8781
8782
8784
8785
8786
8787
8788,
H794
8796
8799
8801
8802
8803
8804
8853
8854
Slight
Per cent.
100
75 to 90
100
75
100
100
2fi
Nearly 100
75
Less than 25
90
100
50
;><>
50
50 to 75
50
5D to 75
25 to 50
Nearly H'O
25 to 50
100
50 to 75
No coffee
25 to 50
50
25 to 50
25 to 50
I'M.. 40
25 to 50
Imitation coll'ee.
Chicory and wheat. Dealer admitted presence,
of chicory.
do
Highly colored
do
Highly colored
Slight
probably (iraham bread crumbs; rest in
fragments.
Chicory.
Chicory and jiea.se.
Chicory, pea hulls, and wheat.
Imitation coffee.
Sample consists of collee screenings.
Much peas (especially the testa), wheat bran
and chicory.
Wheat and chicory.
Wheat, chicory, and pease, and a little corn.
Pease and chicory, with a little corn.
Chicory ami barley, witli small amount of jiea.se
anil coi n.
Chicory and jiease.
Small amount • chicory, wheat bran, buckwheat
bran, and pea hulls, and fragments of j>easc.
Small amount whe.it, pease, and chicory.
Chicory and barley, with occasional fragments
corn.
Chicory and pease.
...do
No color
do
Highly colored
do
two-thirds - . .
One-half
do
One-half
Slight
Highly colored
Slight
One-fourth
One-third
Highly colored
Slight
Two-thirds . . .
.Highly colored
Sli"ht
One-half
( )nc-fourth.
Highly colored
....do
do
Threr-foiirllm
Nearly ;ill
Three-fourths
Ono fifth
and ]>ea hulls mashed together.
No color
Slight
and small per cenl chicory.
Wheat, probably (iraham bread.
Chicory and \\ heal.
Tea hull. «ilh small per cent wheat ami chic-
ory.
About .">ii per cent chicory; rest pease ami
wheat. '
Wheat, chicor\ . and jiease.
....do
Highly cnlorcd
Oiif-half
1 Dealer stated that this sample contains 50 JHT cent cotl'ee and ."•(' per cent chicon .
The results of the examinat ion of thirty samples are liiven in the table
of ground coffees. Twenty six samples, or S(i^ per cent of the samples
examined, were adulterated, or it' we include serial No. 8773, this per-
centage is increased to !>0. One sample, sold as •••round Rio, contained
no coffee at all. In fifteen samples the purchaser obtained hall, or less
COFFEE EXTRACTS.
929
than half, the coffee he paid for. The price paid for samples Nos. 6874
and 6880 was certainly high enough to have insured a pure coffee.
The following table gives a comparative statement of the adulterated
coffees, showing the price and the quality; the latter only so far as the
percentage of pure coffee is concerned:
Table, showing name under which adultc.nitnl (/round coffees were sold, and tin- price per
pound.
Serial
No.
Name under which
sold.
Price
per.
pound.
Approximate |>rr cent.
pure cofl'ee.
Remarks.
6857
Rio
Cents.
30
75 to 90
6859
25
75
6865
Rio
25
25
6874
40
92
Ten per cent infusion indicated from
6878
Rio
25
75
7.7 to 8.7 per cent chicory.
6879
25
6880
35
90
8773
20
Coffee screenings
A sample of coffee screenings exam-
8775
25
50
ined contained 10 per cent sand;
also sticks and beans.
8777
Blended coffee, Java
25
50
8781
and cereals.
25
50
8782
Java
30
50' to 75
8784
Rio . .
25
50
8785
30
50 to 75
8786
25
25 to 50
8787
25
Nearly 100
8788
28
25 to 50
8796
25
50 to 75
8799
Rio
20
8801
Maracaibo (?)
30
25 to 50
8802
25
50
8803
Rio
20
25 to 50
8804
Rio and Maracaibo
30
25 to 50
8853
16
25 to 4'J
Dealer states that sample contains 50
8854
Golden blended-..
20
25 to 50
per cent chicory.
EXTRACTS.
Three samples of coffee extracts were examined, viz : Serial Nos. 6875,
6805 and 6897. No. 6875 contained no caffeine. On further examina-
tion it was found to contain cereals or other starchy bodies and no
coffee. This sample contained tin and traces of copper. The former
amounted to 0.248 grams per 1,000 grams of the extract.
Sample No. 6895 contained 1.19 per cent caffeine. This is about
Konig's mean (see p. 903) for roasted coffees ; hence pound for pound this
is about equal to average coffee. This sample contained considerable
dextrose.
930 FOODS AND FOOD ADULTERANTS.
Sample No. 6,897 is a preparation of coffee with milk and sugar. This
sample contains .72 per cent caffeine. On the basis of Konig's mean
percentage of caffeine two-thirds of a pound of average coffee is equal
to about 1 pound of this preparation. This sample contains both tin
and copper in the, following proportions per kilogram of the prepara-
tion :
(irillllH.
Compounds of till (calculated as metallic tin) 0. 338
Compounds of copper (calculated as metallic copper) 0. 023
Judging from the observations of Dr. Van Hamel Boos the amount
of tin in these samples is excessive and the risk of poisoning is great.
The article quoted by Dr. Van Hamel Eoos is well worth reproducing.
TIN POISONING BY PRESERVES IN TIN CANS.1
It seems to me that sufficient attention has not been paid to the impurities of pre-
serves and to poisoning by compounds of tin. It is only during recent years that
chemists and hygienists have given this subject serious consideration. It is the pur-
pose of these pages to make known the facts heretofore proved and to point out cer-
tain means for the prevention of like impurities.
Messrs. Nuger and Bodliinder were first to call attention to tbe presence of rela-
tively large amounts of tin in preserved asparagus. Sadie found 70 milligrams of
tin in 29 pieces of asparagus (see this Revue, 1, 91.) Likewise, Messrs. A. Menlho
(Chein. News, July, 1871) and Schuer (The Analyst, 1880, p. 318) proved the presence
of more or less important quantities of tin, not only in preserved fruit, but in other
food materials, liquids, meat, and other preserved foods.
Sedgwick cites for the first time a case of food poisoning which must be unques-
tionably attributed to tin (Archives dePharinacie, 1888). The poisoning was caused
by pears prepared in a tinned stewpan. [A member of the congress, present session,
informs me that a patient died from chronic metallic poisoning, resulting from the
prolonged use of metalliferous preserved vegetables.] He afterwards examined sev-
eral fruits preserved in tin cans and found very pronounced reactions for tin in all
of them.
Prof. Bockurts presented some very important data concerning the presence of tin
in foods preserved in tin cans, at the session of the congress of German physicians
held at Heidelberg, September 25, 1889. He emphasizes the importance of the sul-
phide of tin, which is formed by the action ot the albuminous matter of vegetables,
meat, etc., on the tin of cans. At the current session, Dr. Nehring stated that he had
proved the presence of 0.186 grams, 0.3146 grams, and 0.2269 grams, respectively
of tin in three tin cans containing asparagus; whence the congress decided that
the use of tin cans for the preservation of foods must be interdicted.
During the preceding year Prof. Blare/ comninmnicated to the Journ. de Pharm.
et de Chimie that he had found a considerable amount of tin in pears in tin cans. I
am not able to confirm this result, as by repeated trials I only obtained traces of tin.
I presume that the presence of a considerable quantity of salt has favored the solu-
tion of tin in the sample examined by M. Blarez.
Capitaine-Intendant Winckel reported to the Congress of Industrial Hygiene, held
at Amsterdam, September 1890 (see No. 3 of this Rrvucl, that 270 soldiers became ill
after having oaten lettuce and meat preserved in tins. According to the determina-
tions of Prof. Wefers Bettink, of Utrecht, the amount of tin present was from 19 to
72 milligrams per kilogram.
1 Dr. Van Hamel Roos, Rev. Intern, dee Falislications, 4, 10, 179, translated I>\ Mr,
fi. E. Ewell for this report.
POISONING BY TIN. 931
Prof. Kayser, of Nuremberg, reported in this Eevue (4, p. 29), that he had tound a
considerable amount of tin, about 0.19 per cent, in preserved eels. Several persons
had become very ill after eating them.
These facts move me to point out the necessity of coating the interior of tin cans
with a varnish or substance capable of resisting the action of a weak acid or of
organic substances. I am pleased that I am able to say that a Holland manufacturer,
C. Verwer, of Krommeiue, has succeeded in preparing a varnish which, according
to my investigations, answers the purpose perfectly, especially in regard to the man-
ner of its application to the tinned surface (an important consideration, since the
application of this useful invention rests not only upon the composition of the var-
nish, but in the first place upon the process for making the varnish perfectly adher-
ent to the inner tinned surface).
It is evident that time plays a great role in the question of the solubility of the in-
terior tinned surface. Evident proof of this is furnished by a can of asparagus pre-
served since 1860, a period of thirty-one years. (This box was opened and its con-
tents were exhibited at the current session.) The tin of this can having entirely dis-
appeared, was dissolved in the liquid.
I will now give the results of my own investigations.
A can containing beef, preserved eight years and weighing 976 grams (beef and
liquid), contained 77 milligrams of oxide of tin ; a can of asparagus, preserved six years,
contained 56 milligrams of oxide of tin, while another can of asparagus which had
been keptonly four months contained 11 milligrams. Another can of asparagus, pre-
served two years and having a net weight of 635 grams, contained 36 milligrams of
oxide of tin and 6 milligrams of copper. Some appricots contained 20 milligrams per
can, and some fine apples, imported from Singapore, a considerable quantity of tin, about
178 milligrams per kilogram. Fortunately the taste of this last sample was so disagreea-
ble that its consumption, if not its sale, was impossible. Several other preserved fruits
and vegetables, such as purslane, sauerkraut, pears, carrots, etc., as well as meat
and soup, all contained more or less tin, depending, in the case of vegetable and fruits,
on the quantity and kind of organic acids. I am perfectly confident of the correct-
ness of the opinion of Prof. H. Wefers Bettiuk, of Utrecht, as communicated to the
Congress, that malic acid is the principal solvent in the case of fruits and vegetables.
In order to determine whether the above-mentioned varnish was capable of pre-
venting the solvent action of acids on tin, some of the most acid foods, such as sauer-
kraut, buttermilk, and pears in wine, after four to nine months' preservation in
varnished tin cans, were subjected to examination. Only imponderable traces of tin
were found. The same results were obtained with a sample of beans coming from
France, and examined after being preserved twelve years in a varnished can. This
latter example is of less importance, since beans and pease free from salt dissolve al-
most no tin. I have been unable to procure acid foods which have been preserved
for as long a time, but in my opinion the experience acquired after four to nine
months suffices to heartily recommend the varnishing process, in consideration of
the strong reactions which occur in unvarnished cans. In accordance with experience
thus far gained, sorrel is the only vegetable whose action the varnish is unable to
resist. After a lew months the varnish was already detached and a considerable
amount of tin dissolved.
The writer closes his paper by recommending that varnished cans alone be used,
especially for acid foods, and deems it important that the various governments give
the matter consideration. Several manufacturers have already adopted the process
for acid foods and beverages.
The amouiit of copper in sample No. 6897 is quite large, and is suffi-
cient to condemn the preparation.
20o93— No. 13 5
932 FOODS AND FOOD ADULTERANTS.
SUBSTITUTES.
The number of coffee substitutes on the market is large. Many of
these are sold under this name and others are simply designated as
substitutes. Sample No. 8852 was sold as a coffee substitute. It is
composed largely of chicory (50 to 75 per cent), with wheat, and peas
or beans.
There is no objection to the so-called coffee substitutes, provided they
are sold as such and do not contain harmful ingredients. All substi-
tutes should be sold in packages, bearing labels distinctly stating their
composition.
CONCLUSION.
The examination of the coffees and coffee preparations on our markets
shows that the consumers, and especially the poor, are being grossly
deceived. Very little pure ground coffee is sold, and even whole coffee
does not escape sophistication. The purchase of green coffee for home
roasting does not insure a pure product, since even the green coffee is
imitated. Stringent laws are certainly needed to suppress these frauds.
That there is a large demand for imitation coffee is evidenced by the
fact of its importation from Germany. The manufacture of these cof-
fees in imitation of the form of the genuine bean should be interdicted,
even if the product is to be sold as a substitute.
COCOA PREPARATIONS.
By ERVIN E. EWELL.
THE NATURE, SOURCE, COMMERCIAL IMPORTANCE, ETC., OF THE
COCOA BEAN.1
The raw material from which the cocoas and chocolates of commerce
are manufactured is the "cocoa bean," the seed of the cocoa, or cacao,
tree (Theobroma cacao). While this tree has been successfully intro-
duced into various warm countries, tropical America, its native land,
still furnishes the larger and more highly valued portion of the world's
supply of cocoa. From Mexico to Peru on the west coast, Mexico to
Bahia, Brazil, on the east coast, and on the West India Islands, the most
favorable conditions for its cultivation are met.
The tree, 6 to 12 meters in height, blooms continuously and yields two
crops a year. The lemon yellow, fleshy fruit, 10 to 15 centimeters long,
5 to 7 centimeters in diameter, resembles in general appearance a cucum-
ber, constricted at the upper end, tapered to a point at the lower end,
and having ten longitudinal ridges. Twenty-five to forty, sometimes
more, seeds are arranged in the fleshy pulp in five longitudinal rows.
When first removed the seeds are colorless, fleshy, and covered with
mucilage. On drying, with exposure to air and light, they become
golden yellow to red or brown in color, and hard and brittle. They are
egg-shaped, somewhat compressed, 1.2 to 2 centimeters long, and 0.6 to
1 centimeter broad.
1 For more detailed information concerning cultivation, preparation for market,
manufacture, etc., of cocoa, see the following works: Cultivation, harvesting, etc. : An
anonymous article on the cultivation of the cocoa tree in Colombia, Phar. Jour.
Trans., [3] 970, 591; Boussiugault, Compt. Rend., 96, 1395; Jour. Chem. Soc., 1883,
44, 933; Boussingault, Ann. Chim. Phys., [5] 28, 433; Jour. Chem. Soc., 1884, 46,
202; Chem. Ztg., 1883, 203 and 902; Holm, American Chem., 5, 320; Jahresb. d.
Chem., 1875, 1121; Smith, Dictionary of Economic Plants. Manufacture: Bern-
hardt, Chein. Ztg., 1889, 32; Saldau, Die Chokolade Fabrikation, 1881; Trcscn, Les
Mondes, July 22, 1869. General description of tree, cultivation, harvcnli»{/, manufacture,
etc.: Blyth, Foods: their Composition and Analysis; Hassall, Food: its Adultera-
tion and the Methods for their Detection; Konig, Die ineiisi-lichen Nahrungs- und
Genussmittel, ihre Herstellung, Zusammensetzung und Beschaffenheit, ihre Verfal-
schungen und deren Nachweisung; Mace", Les substances alimeutaires e"tudie"es au
microscope ; Moeller, Mikroskopie der Nahrungs uud Genussmittel aus dem Pflanzen-
reiche; Schaedler, Die Technologie der Fette und Oeledes Pflanzen- und Tliierreichs.
933
934
FOODS AND FOOD ADULTERANTS.
After removal from the fruit two processes are used for the prepara-
tion of the seeds for market. For the production of " unfermented
cocoa," they are freed from adhering fruit pulp and at once dried in
the sun. For the production of " fermented cocoa," the beans are placed
in piles in sheds or are buried in trenches and allowed to ferment for
a time before being completely dried in the sun. When buried the
beans are now placed in casks or other coverings ; hence, the earthy
coating is no longer a mark for determining the process of preparation.
Much of the acridity and bitterness disappears in this process of fer-
mentation ; the beans so prepared have a mildly oleaginous, pleasant,
slightly bitter taste, and are more or less aromatic. The value of the
product therefore greatly depends upon the care bestowed upon this
operation.
Bernhardt ' has made a careful study of the losses occurring in the
preliminary processes of manufacture. He notes four main operations :
(1) The sifting of the raw cocoa to remove sand, dust, small stones,
etc.
(2) The separation by hand of the larger stones, empty beans, grass,
wood, etc.
(3) The roasting.
(4) The breaking up and cleaning to remove the husks.
He gives the results of thirty determinations, made in actual factory
work, of the losses in each of these processes. The means, maxima,
and minima of these determinations will be found in the table given
below. In this table the term " beans " is used to denote both the good
broken pieces and the small particles, which, of less value and consti-
tuting 9 to 15 per cent of the whole bean, are used for the preparation
of cheaper chocolates.
Losses in preliminary preparation for manufacture.
Means.
Maxima.
Minima.
Sifting
Per cent.
2.80
Per cent.
5.49
Per cent.
1.10
.80
2.09
.25
5.51
7.05
4.61
13.00
16.04
10.08
Total loss
22.11
"25 78
16.76
Total beans
77.89
74.22
83. 24
The following table, from the Annual Report of the Bureau of Statis-
tics of the United States Treasury Department for 1890, is given to
show something of the commercial importance of this commodity and
the extent of the use of its preparation in the United States.
1 Chem. Ztg., 1«89, 32.
CHEMICAL CONSTITUENTS OF COCOA BEAN.
935
Importation of cocoa or cacao, crude, and the leaves and shells of, for the year ending June
30, 1890.
Countries from which imported,
Pounds.
Value.
Brazil
2, 125, 614
$192, 866
1,000
125
3 036
412
Nicaragua
48, 750
8,424
769
157
China
52,304
10, 227
401, 759
83, 294
1 260 191
150 156
France
40, 181
6,358
86 160
16 334
England
1, 607, 821
335, 337
British West Indies
5, 382 498
674 165
12 084
1 286
East Indies
153 101
29 944
Haiti
1 303 114
101 396
468
149
191 970
25 361
Dutch Guiana
4, 128, 374
460 282
Peru . -
81 051
13 0^6
Portugal
54,103
5,730
54, 276
6 202
1 277 547
191 550
Total
18 266 177
2 312 781
During the same period, 634,551 pounds of chocolate, valued at
$140,476, and 993,402 poundsof manufactured or prepared cocoa, valued
at $400,385, were imported.
The Shipping and Commercial List and New York Price Current
for October 7, 1891, gave the following quotations for cocoa:
Cents per pound.
Caracas 14 to 15
Trinidad 13£ to 14
Guyaquil 13 to 14i
Baliia 13
St. Domingo 8 to 8£
CHEMICAL CONSTITUENTS.
On account of 'the peculiar properties of the cocoa bean, its prepara-
tions merit a place on our tables for two reasons: In addition to being
like tea and coifee, the material for the preparation of a pleasant and
exhilarating beverage, it is a valuable food material. Not only is it
much richer in nutritive substances than tea or coifee, but both the sol-
uble and insoluble portions become a part of the beverage, while only
the constituents soluble in hot water are obtained in the beverages
prepared from tea and coffee. The investigations of Stutzer (see below,
under head of nitrogenous constituents) and others clearly prove, how-
936 FOODS AND FOOD ADULTERANTS.
ever, that the food value of cocoa preparations has been greatly overes-
timated and that many of the present modes of preparation do not de-
velop in the highest possible degree the pleasing aroma and flavor. The
inventive energy of many manufacturers seems to be spent on the pro-
duction of a highly nutritive and easily digestible preparation; the
valuable fat is removed and the delicious aroma and flavor destroyed
by chemicals for the ostensible purpose of rendering more digestible a
residue of doubtful food value.
The more important constituents of the husked cocoa bean are fat,
theobromine, the nonalkaloidal nitrogenous substances, starch, the color-
ing matter called cocoa red, and the mineral matter.
The fat, cocoa or cacao butter, in consequence of its quantity and
peculiar excellence, is unquestionably the constituent of the cocoa
bean possessing highest food value. It usually forms 45 to 55 per cent
of the husked bean, rarely falls below 45 per cent, and only one recent
analysis shows as low as 36 per cent. At ordinary temperatures it is a
white, or slightly yellowish, brittle solid, having a pleasing taste and
odor, and showing but little tendency to become rancid. Its melting
point being below the temperature of the body, insures its being pre-
sented in liquid form to the action of the digestive juices. Chemically,
it is a mixture of the glycerides of stearic, palmitic, oleic, and arachidic
acids.1 It is readily soluble in ether, acetic ether, chloroform, oil of
turpentine, and hot absolute alcohol, but only £ per cent remains in
solution when the alcohol becomes cold;2 fully soluble at ordinary
temperatures in 2 parts ether, £ part of benzol, 100 parts of cold and 20
parts of hot alcohol.3
The physical and chemical constants of value in investigations for
identity and purity have been arranged in tabular form in the table
given on page 938. In addition to numbers there given, Yaleuta 4 has
found the temperature at which the solution in hot glacial acetic acid
becomes turbid to be 105° C.
The low melting point, the little tendency to become rancid, and other
properties render cocoa butter peculiarly suitable for the basis of many
pharmaceutical preparations. This by-product of the manufacture of
cocoa preparations has, therefore, a well-established place in commerce.
The Shipping and Commercial Lint and New York Price Current for
October 7, 1891, quotes foreign cocoa butter at 31 to 37 cents per pound
and domestic at 40 to 42 cents per pound.
Schaedler 2 thus describes the process of extraction on the large
scale:
In earlier times the ground and roasted beans were boiled with ten parts of water,
1 Benedikt, Analyse der Fette und Wachsarten. Schaedler, Die Technologie der
Fette und Oele des Pflanzen- nnd Thierrciclis.
2 Schaedler, Die Technologic der Fette und Oele des Pflanzen- und Thierreiehs.
3 Blyth, Foods: their Composition and Analysis.
* Dingler's polyt. Jour., 252, 296; Zeitsch. f. anal. Chem., 24. L'iC,.
THE ALKALOID OF COCOA. 937
the fat skimmed off, and the residue pressed out. The beans are now roasted,
husked, and very finely ground. The mass is heated to 70°-80° C., packed in sacks
of ticking, and submitted to pressure between previously warmed or steam-heated
plates. The fat expressed, about 30-35 per cent, is filtered through dry filters. The
pure residue, containing 10-15 per cent of oil, is made into chocolate. For the prep-
aration of an entirely fat-free cocoa powder, the roasted and ground beans are ex-
hausted with benzine or ether.
Theobromine, the alkaloid of cocoa, is very closely related chemically
(it is dimethyl xanthine, C5H2(CH3)2lSr4O2, while caffeine is trimethyl
xanthine, CsH^CHs^l^C^) to caffeine, the alkaloid of tea and coffee,
and has similar effects on the system; the power possessed by the bev-
erages prepared from these substances, " to cheer and not to inebriate,"
being largely due to the presence of these alkaloids.
Separated from the bean, it is a white powder, permanent in the air,
crystallizable in microscopic rhombic needles, and having a very bitter
taste. While neutral in reaction, it acts as a weak base, uniting with
acids to form crystallizable salts, which become basic on treatment with
water; its salts of volatile acids give up their acids on heating, at or
below 100° C. According to Blyth,1 it begins to sublime at 134° C.,
and yields distinct crystals at 170° 0. and above; Keller, 18542, reports
the subliming point as 290"-295° C. ; other writers note it as about 290°
C. Treuuiann3 has reported its solubility in water to be 1 in 148.5 at
100° C., and 1 in 1,600 at 17° C.; in absolute alcohol, 1 in 422.5 at the
boiling point, and 1 in 4,284 at 17° C.; in boiling chloroform, 1 in 105.
Husemann4 states its solubility in water to be 1 in 55 at 100° C., 1 in
G60 at 20° C., and 1 in 1,600 at 0° C.; in cold alcohol, 1 in 1,460, and in
boiling alcohol, 1 in 47; in .cold ether, 1 in 17,000, and in boiling ether,
1 in 600 ; more soluble in chloroform and warm amyl alcohol than in
water, less soluble in benzol, and insoluble in petroleum ether.
1 Op. cit., note 3, p. 936 of this work.
2 Op. Git., note 3, p. 938 of this work.
3 Archiv. d. Pharm., [3] 13, 5; Jahresb. d. Chern., 1878, 872.
4 Husemann's Pflanzenstoife.
938
FOODS AND FOOD ADULTERANTS.
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MoWtfl^OW SxSSofi <
Weisrniann
NITROGENOUS CONSTITUENTS OF COCOA. 039
For percentages of theobromine in cocoa and cocoa preparations, see
tables of analyses given below ; for methods of quantitative determina-
tion, see methods of analysis given below.
The commercial importance of theobromine at present offers no temp,
tation to remove it from cocoa preparations before placing them on the
market.
Small percentages of caffeine have been found in cocoa beans, espe-
cially in the shells. It is separated from the theobromine by solution in
cold benzol, in which the theobromine is practically insoluble. Weig-
mann1 reports 0.17 per cent in cocoa mass and 0.113 to 0.190 per cent in
cocoa shells ; Bell,2 traces to 0.25 per cent in the bean and 0.33 per cent
in the shells.
Nonalkaloidal nitrogenous substances. — Stutzer3 classifies the nitroge-
nous constituents of cocoa, as follows :
(1) Nonproteids, substances soluble in neutral water solution in presence of
Cu(OH)i (theobromine, ammonia, and amido compounds).
(2) Digestible albu:nen, insoluble in neutral water solution in presence of
Cu(OH)2, but soluble when treated successively with acid gastric juice and alkaline
pancreas extract.
(3) Insoluble and indigestible nitrogenous substances.
In the same article he writes as follows in regard to the food value of
the nitrogenous constituents of cocoa :
The group of nitrogenous constituents is of great importance in all foods, espe-
cially their content of digestible albumen. Among the general public the opinion
is very widely extended that cocoa belongs to the very easily digestible foods. The
extremely favorable mechanical treatment is certainly such that the digestive fluids
have no considerable mechanical resistance to overcome in the assimilation of the
nutritive constituents of cocoa. On the contrary, the chemical reaction between
the solvent constituents of the digestive juices and the nitrogenous nutritive con-
stituents of cocoa can not be called an especially strong one. A large proportion of
these constituents, in spite of apparently favorable conditions, remain entirely in-
digestible, entirely worthless. I have already called attention to the slight digesti-
bility of the albuminous substances of cocoa,5 and once illustrated their difficult di-
gestibility graphically in the Berliner Hygiene- Ausstellung. In the meantime, these
observations have been confirmed by investigations of H. Weigmann, which he un-
dertook on his own account. Weigmann found only 42 per cent of the nitrogenous
substances in cocoa to be digestible.
1 Op. cit., note 8, p. 938 of this work.
2 Bell, Analysis and Adulteration of Food.
3 Zeitsch. f. angew. Chem., 1891, 368.
940
FOODS AND FOOD ADULTERANTS.
The results of Stutzer's own investigations, referred to above,1 were
obtained with three samples of cocoa powder, and are given as follows:
Of the total nitrogen present, there was found-
Sample
No.l.
Sample
No. 2.
Sample
No. 3.
Nitrogen in form of soluble nitrogenous compounds,
Per cent.
31 43
Per cent.
26 95
Per cent.
°9 79
33 34
40 61
29 62
Nitrogen in the form of indigestible substances
35 33
32 44
47 83
100.00
100.00
100.00
For quantitative data concerning the nitrogenous constituents, see
tables on page 960 et seq.
Starch. — Cocoa contains 5.78 per cent to 15.13 per cent of starch.
/See tables of analyses.) A more detailed description of this stal'ch will
be found in paragraphs devoted to the microscopy of cocoa.
Cocoa red, the coloring matter of the bean, seems to be related to the
tannins, but authorities differ as to whether it is a decomposition pro-
duct of a tannin, or whether a tannin is the result of its decomposition.
It is obtained from the aqueous 'or alcoholic decoction by precipita-
tion with lead acetate and decomposition of the washed precipitate
with hydrogen sulphide. The solution thus prepared has a bitter
taste; according to Watts, gives a dark green or brown precipitate with
ferric and a green or sometimes violet precipitate with ferrous salts ;
absorbs oxygen, becoming acid, the coloring matter being converted
into a kind of taunic acid, which is precipitated by gelatin — cocoa red
in its unaltered state not being thus thrown down (Hassall).2
It is colored blue by iron salts and dissolved out by caustic potash
with a green color, by sulphuric acid with a red color, and by acetic
acid and alcohol with a violet color. Cold water dissolves the pigment
with difficulty, while warm water dissolves it entirely. Since the fresh
seeds are colorless, Mitscherhch presumes that cocoa red is formed by
a process of oxidation from a body related to the tannins (Moeller).3
It is changed to tannin by oxidation and colored green by iron salts
(Tuchen).4
Concerning the astringent principle of cocoa and cocoa red, Thorpe5
writes as follows :
The astringent principle is of the nature of tannin, but is different from the tan-
nin of tea and coffee. It rapidly changes during analysis to cocoa-red, which ren-
ders its quantitative estimation difficult. It is precipitated by subacetate of lead
and may be obtained from this precipitate by decomposition with hydrogen sulphide ;
1 Rep. f. anal, chem., 1882, 88 and 165 ; Hygiene-Bericht, 1882-'83, 1, 217 ; also op. cit.,
note 8, p. 938 of this work.
2 Hassall, Food: its Adulteration and the Methods for their Detection.
3 Moeller, Mikroskopic dor Nahrnngs- mid Genussinittrl aus dcin I'flau/enreiche.
*Tucheu, Dissertation liber d. organ. Bestandthi-ilt' der Cacao.
6Thorpe, Dictionary of Applied Chemistry.
COMMERCIAL PREPARATIONS OF THE COCOA BEAN. 941
gives a green precipitate with ferric chloride, not unlike that given by caffeic acid
under similar treatment (Bell).
Cocoa-red is not present in the fresh beans, but is the product of the oxidation of
the natural tannin of the seed. It consequently appears in different quantities in
different cocoas. It has the characters of a resin and exhibits variable degrees of
solubility, probably coinciding with the extent of oxidation \vhich it has under-
gone.
Bell1 reports 2.20 per cent of cocoa red in raw beans; Muter, 3.96 per
cent.
Gum. — It is precipitated from the aqueous solution of the fat-free
beans by alcohol. After drying it resembles gum arabic; by treatment
with nitric acid, yields mucic acid; and, when ignited, leaves an ash con-
sisting of basic phosphate of magnesium. Its specific rotatory power
is [a] j = + 68.6 (Boussingault2).
The beans contain 2.17 per cent of gum according to an analysis by
Bell,1 and 2.5 per cent according to Boussingault.2
Tartaric acid. — Weigmann 3 estimates tartaric acid by precipitation
of the aqueous extract, after neutralization with ammonia, with calcium
chloride, redissolving in hydrochloric acid and reprecipitating with
sodium hydrate. The amount of tartaric acid is calculated from the
amount of calcium oxide contained in this precipitate. By this method
he found 4.34 per cent to 5.82 per cent of tartaric acid in the raw,
whole beans. Boussingault2 reports 3.4 per cent and 3.7 per cent.
The aroma of cocoa is considered to be due to the presence of minute
quantities of an aromatic volatile oil. Boussiugault2 proves its pres-
ence by distillation of the roasted grains with water.
THE COMMERCIAL PREPARATIONS OF THE COCOA BEAN, THEIR
NATURE, METHODS OF PREPARATION, AND ADULTERATION.
The preparations of cocoa are so numerous that more or less confu-
sion of terms naturally arises. Most American manufacturers prepare
a plain chocolate (known in Europe as cacao-masse), made by reducing
the roasted and husked beans to a paste and pressing into the form
of cakes. When this is combined with much or little sugar (generally
much), vanilla and spices, the various "sweet," "vanilla sweet,"
" vanilla, " " spiced," etc., chocolates are produced. These are also usually
met in the form of cakes, but are sometimes pulverized and sold as "pow-
dered chocolates." The high percentage of fat renders a permanent pow-
der impossible without its partial removal or the addition of some
diluent, as sugar, starch, or flour. The preparations in powder, known
as "cocoas," "bromas," etc., are prepared in accordance with one or
the other, or a combination of these methods.
1 Op. cit., note 1, p. 939 of this work.
2 Ann. Chim. Phys. [5], 28, 433; Jour. Chem. Soc., 1884,46, 202; Chem. Ztg., 1883, 203
and 902.
3 Op. cit., note 8, p. 938 of this work.
942 FOODS AND FOOD ADULTERANTS.
Cocao shells are offered on the market in bulk and in packages, but
their use seems to be quite limited at present.
For more detailed information in regard to the preparations found in
American markets, see tabulated results of investigations given below.
Blyth1 says:
The commercial varieties of cocoa are very numerous: Cocoa nibs are simply the
bruised, roasted seeds deprived of their coverings, nmljlake cocoa is composed of the
nibs ground in a particular form of mill. The soluble cocoas are ground cocoa,
diluted with sugar and starches.
In the manufacture of chocolate, the cocoa nibs are ground in a mill, the rollers
of which are usually heated by steam, so as to soften the cocoa butter ; and in this
way a paste is formed which is mixed with refined sugar, and very often other sub-
stance, and pressed into molds.
The Association of Swiss Analytical Chemists2 has adopted the fol
lowing definitions of terms:
(1) Cacao-masse (pure pate). The beans are roasted, husked, ground,
and pressed into forms.
(2) Cacao deprived of its fat is prepared by heating cacao-masse,
removing about one-half of itsoil by pressure, and pulverizing the residue.
(3) Soluble cacao-powder is prepared by treating the cacao deprived
of its fat with ammonia, alkaline carbonates, or steam, so as to destroy
the cellular structure and convert the album en oid constituents into a
soluble modification.
(4) Cacao-powder is cacao-masse, wholly or partially deprived of fat
and flavored with spices (vanilla, cinnamon, cloves, allspice, etc.).
(5) Chocolate is pure cacao-masse mixed with sugar and pressed into
forms or powdered. Other admixtures, such as spices, flour, etc., must
be designated on the package.
(6) Couverture,
(7) Chocolat a la noisette, etc., are prepared from the above by adding
almonds, hazelnuts, etc.
Moeller3, writing in Germany, notes the following preparations:
The cocoa preparations of commerce and consumption are cocoa flour or cocoa
deprived of fat, cocoa butter, Holland cocoa, cocoa tea, and, most important of all,
chocolate.
Cocoa seeds contain 35 per cent to 54 per cent of fat, which renders them difficultly
digestible for children and convalescents, to whom a nourishing and stimulating
food must be given. Therefore, the greater part of the fat is removed by pressure
and the press residue designated as cocoa deprived of fat. -
If the fat is not entirely removed by the pressure and the residue is still plastic,
from it is prepared "Gesundhcits ScLokoladi'," under which name are also found
shameful adulterations.
The desire to make an easily digestible cocoa preparation without removing the
fat, led to the preparation of the so-called Holland cocoa. (It is, however, not cer-
tain that this object is in reality accomplished. By many it is stated that the
alkalis directly hinder the digestion by neutralization of the acid of the stomach;
'Op. tit., note 3, p. 936 of this work.
- <>i>. ril.. note 3, p. 949 of this work.
*f>l>. <•//., uoti- :t, p. it 10 of Mils work.
EXAMINATION OF COCOA POWDERS.
943
and besides, by saponification of the fat, because experience shows that the soap is
notagreeable to the stomach. Contrary opinions are asserted from the standpoint of
sanitary police. By application of alkalis, the ash content is considerably raised
[to over 9 per cent against 4 per cent in cocoa], which, according to the Deutschen
Reichs-Gesundheitsamtes, is to be considered an adulteration. Recently, May 24,
1884, a process for making cocoa preparations soluble was patented by Lobeck & Co.
In this process the material is heated, with or without water, in a closed vessel for
thirty minutes at 150° C.) The cocoa beans are soaked several hours in water in
which potassium or sodium hydrate (2 per cent to 4 per cent) and magnesia are dis-
solved, then dried and pulverized.
All good cocoa preparations should be made from the cotyledons only. For this
purpose the seeds are always husked and the husks, under the name of "cocoa tea,"
constitute an independent article of commerce. The husks serve for the preparation
of cheaper kinds of chocolate and for adulteration ; when, in consequence of the
small amount of theobromiue contained therein, the addition of husfes is usually
considered unallowable.
The most general preparation of cocoa is chocolate. For its preparation the husked
seeds, with the addition of sugar (50 per cent or more) and spices, are ground to a
paste at an elevated temperature and pressed into forms.
Results of the . examination of four cocoa powders by Stutzer1 for the purpose of determin-
ing the effect of the process of manufacture on the chemical constituents.
[I is composed of 40 per oeiit Ariba, 40 per cent Machala, and 20 per cent Bahia cocoa, and was made
in Wittekop & Co.'s factory in Braunschweig, without the use of chemicals. II is a sample of Hol-
land cocoa. Ill and IV are German cocoas, and, in Stutzer's opinion, were prepared by use of am-
monia.]
I.
II.
III.
IV.
Theobromine
Per cent.
1 92
Per cent.
1.73
Per cent.
1.98
Per cent.
1.80
0 06
0.03
0.46
0 33
Amido compounds
1.43
1.25
0.31
1.31
Albumen, digestible
10. 25
7.68
10.50
7.81
7 18
9 19
7 68
8.00
20.84
19.88
20.93
19.25
Fat
27.83
30.51
27.34
33.85
Fiber
3.36
38 62
£ 37. 48
39.99
36.06
Water . . . .
4.30
3.83
6.56
5.41
Ash... .
5.05
8.30
5.18
5.43
Total amount of P2O5
1.85
2.52
2.14
2.05
3 76
4.76
2.82
2.76
Amount of PjjOs soluble in water
1.43
0.50
0.74
0.77
Water-soluble ash, per cent total ash
74.
57.
54.
*49.
P.^Osin water-soluble ash, percent total I'jOs-
77.
19.
34.
37.
3 68
3 30
3.95
3.57
Nitrogen in form of theobromine
0.61
0.55
0.63
0.57
Nitrogen in form of ammonia
0.05
0.03
0.36
0.26
Nitrogen in form of ar.iido compounds
0.23
0.02
0.05
0.21
1.64
1.23
1.68
1.25
Nitrogen in form of indigestible nitrogenous
1.15
1.47
1.23
1.28
Nitrogen in form of indigestible nitrogenous
31.2
44 5
31.2
35. &
1 Op. cit., note 3, p. 939 of this work.
944 FOODS AND FOOD ADULTERANTS.
Konig and Wesener1 report a cocoa sweetened with saccharine, of
•which it contained 0.40 per cent. Another analysis is reported show-
ing 0.76 per cent of saccharine (Chem. Ztg., 1888, 106; also Konig).1
Stutzer2 has made a careful study of the effect of different processes
of manufacture on the chemical constituents of cocoa, the quality of
the product, etc. From the results of these investigations, which are
given in the table on page 943, he draws the following conclusions :
(1) The roasting processes hitherto used are faulty. The duration of the roasting
is too long. The temperature at which the process is carried on can not be accu-
rately regulated in most apparatus in use. Empyremuatic substances having
unpleasant odors are imperfectly removed; hence it occurs that the aroma of the
cocoa, in contrast with previous opinion, is only developed to be destroyed by the
formation of empyreumatic substances.
(2) The faults mentioned disappear when the new, double, centrifugal roasting
apparatus is used. This apparatus is much more suited to the purpose than appa-
ratus now in use, and insures a marked economy of time and fuel. The duration of
the roasting is short, the temperature of the inner part of the apparatus can be
accurately regulated during the roasting and the empyreumatic gases are removed.
The husks are more easily removed from the seed after the roasting and the losses of
cocoa mass are smaller in consequence of this better separation. The natural aroma
of the cocoa is better developed and, consequently, the poorer grades of cocoa can
be more profitably marketed than was hitherto possible.
(3) The addition of potash, soda, or ammonia for the opening of cocoa is unnec-
essary, if the beans are roasted with the new apparatus. The additions at present
in use (including ammonia) can be detected with certainty by the analysis of the
cocoa powder.
(4) It is for the interest of the public and of the manufacturers that the artificial
perfuming of cocoas be abandoned in future, and that only such preparations be
brought into the market as contain the natural cocoa aroma in pure unadulterated
condition. The technical arrangement of roasting apparatus and the methods of
preparation heretofore in use seem to render this artificial perfuming necessary.
This, as well as the addition of alkalis or ammonia, becomes unnecessary when Sal-
omon's apparatus is used.
(5) The value of cocoa as a mere pleasant addition to the table depends entirely
upon the content of the natural aroma. The finer it is the higher the price that will
be paid for the product. The manner of preparation, especially the manner of roast-
ing, in a marked degree influences the development and maintaining of the aroma.
The quantity of the physiologically important constituent appears to vary only
slightly with the different kinds of cocoa and different methods of preparation.
(6) The value of cocoa as a nutritive material is essentially dependent on the con-
tent of the cocoa powder in digestible albumen. The amount of cocoa butter should
not exceed.30 per cent as a rule. The digestible albumen can easily be rendered in-
digestible by too high a temperature in roasting. By examination of a well-prepared
cocoa powder, we found the relation of the quantity of digestfbh- albumen to the
quantity of indigestible nitrogenous substances to bo nearly 4 : 3. If too high a tem-
perature be used, this relation rises to 4 : 4, or even to 4 : 5, In the four samples inves-
tigated, No. 1, which was roasted in C. Salomon's apparatus, shows in this regard the
most favorable and the Holland cocoa the most unfavorable relation.
In the same article he gives the following results to show the effect
of roasting on the digestible albumen. The figures given are for the
1 Op. tit., note 8, p. 938 of this work.
» Op. tit., note 3, p. 939 of this work.
COCOA PREPARATIONS.
945
per cent of the total nitrogen existing in the form of indigestible nitro-
genous substances:
Raw.
Roasted.
Percent.
K! 2
Percent.
39 7
22 8
40 3
ir» :t
40 3
A discussion of Stutzer's method for the detection of the use of fixed
alkalis and ammonia will be found under the head of methods of analysis
and under the head of judgment of samples.
Adulterations of cocoa preparations. — Perhaps no food material offers
conditions so favorable for profitable adulteration and so well utilized
by its manufacturers as do cocoa preparations. While a discussion of
the adulteration of preparations sold in American markets is presented
in the tabulated results of investigations given below and in the text
accompanying them, a brief review of the favorite substances and
methods for adulteration is not considered out of place here.
There is probably no more misleading or more abused term in the
English language than the term "soluble cocoa." No cocoa in the
market contains a very considerable percentage of matter soluble in
water, unless the material so dissolved is foreign soluble material that
has been added during the process of preparation'. The term seems to
be used to denote a preparation that allows none of the insoluble mat-
ter to deposit from the beverage prepared from it. This purpose may
be accomplished in two ways, — the material may be so finely divided
that a very long time will be required for its deposition, or foreign
substances (as starch or sugar) may be added to render the liquid of
so high a specific gravity, or so pasty, that the insoluble matter will
not deposit. The first method is decidedly to be preferred ; it accom-
plishes the object in view and puts the preparation in better condition
for the action of the digestive juices — all this without the addition of
a cheap diluent that is always at hand in every kitchen, should its use
be desired. Any additions of this kind should be considered adulter-
ations unless their nature and quantity are accurately stated.
Attempts at the preparation of easily digestible cocoas (preparations
to which pepsin or other digestive ferments have been added do not
come in question here, since the favorable condition of the preparation
is not involved, but the supplying of a deficiency in the strength of the
digestive juices) seem to fail in purpose and to be attended with the
introduction of objectionable substances. The use of alkalis for this pur-
pose is quite generally regarded as injurious, and the investigations of
Stutzer1 show that the effect is opposite to that desired. He also states
Op. cit.y note 3, p. 939 of this work.
946 FOODS AND FOOD ADULTERANTS.
that these substances are used to aid the opening (aufschliessen) of the
beans and not for the purpose of increasing the digestibility of the
preparation.
The removal of the fat is not considered to be an adulteration when
it is acknowledged. It seems important, however, that the public have a
means of accurately knowing to what extent it has been removed. Con-
cerning the removal of the fat Mace ! writes :
The most frequent adulteration of cocoa powder consists in depriving it of a part
of its fatty matter, cocoa butter. " The best means of detecting this is to estimate the
fat by means of ether. Cocoa thus adulterated has lost a great part of its nutritive
power, and manufacturers often make great claims for their fraudulent practice, pre-
tending to furnish a product which is more easily digested.
The adulterants added are reported to be, besides sugar and starches,
other substances of organic and inorganic origin, to increase the weight
and bulk; ferruginous and other pigments to restore the color of highly
diluted preparations; and foreign fats to restore the normal percentage
of fat or to give the preparation the plasticity required for molding.
As examples of the nature of adulterants reported, the following list
of H. W. Warren2 may be cited : Sand, ferric oxide, clay, potassium
chromate, copper sulphate, and nickel sulphate are used as coloring
materials. Finely powdered tin is sometimes added to give the choco-
late a metallic luster.
The husk, because of its coarse nature and consequent tendency to
act as an irritating substance in the alimentary canal, and in conse-
quence of its poverty in the constituents that render cocoa valuable, is
regarded as an adulterant when not removed or when added to increase
the weight or bulk of the preparation.
MICROSCOPICAL EXAMINATION.
For a thorough study of cocoa preparations, ;a microscopical exam-
ination is indispensable. An accurate knowledge of the structure of
the cocoa bean and of the substances used as adulterants is necessary
for the successful carrying out of this investigation. While this infor-
mation is only to be gained by actual study of the materials in ques-
tion, its acquirement is greatly facilitated by the use of descriptions and
illustrations.
The literature of the subject will be found somewhat contradictory
(even with comparatively recent writers) in some details, but nothing
of importance in investigations for detection of adulteration seems to
be subject for debate at the present time. The works of Moeller and
Mace will be found to furnish valuable assistance in investigations of
this kind. The microscopical characteristics of the starches and other
materials used for adulteration have been so well described in various
works and in previous bulletins of this Department that any detailed
description of them seems unnecessary here.
1 Mac6, Los substances alimentaires e'tudie'es an microscope.
» Chem. News, 62, 99.
THE COCOA BEAN VIEWED MICROSCOPICALLY. 947
The cocoa beau is inclosed in a thin, brittle, reddish brown seed coat,
called the husk or shell. On the surface of the husk are often Found
numerous delicate, tubular cells, which come from the pulp of the fruit.
The important structures of the husk proper are the following:
(1) The epidermal layer.
(2) The loose parenchyma.
(3) The fiber bundles with small spiral cells.
(4) The layer of characteristic thick- walled cells.
After softening the husk by soaking the beau in water, a portion of
the epidermal layer is readily torn away with the forceps, freed from
adhering fragments of the adjacent tissue, and placed on the slide for
examination. It is found to consist of a layer of moderately thick-
walled, somewhat elongated, irregularly polygonal cells (see Plate
XLVI). By careful dissection and careful manipulation of the light
and the micrometer screw, a layer of exceedingly delicate, transversely
elongated cells can be seen to lie directly under the layer just described,
but it is so very delicate that it is rarely seen in the examinations of
preparations of cocoa for adulterants, and is consequently of almost no
importance in such investigations. If some of the underlying tissue
exposed by the removal of the epidermis be transferred to a slide and
dissected apart, it will appear as a mass of loosely aggregated, rather
large, thin-walled, slightly elongated cells, those constituting the inner
layers containing a large amount of mucilaginous matter that swells
up in contact with water and ruptures them. This parenchymatous
tissue, which makes up the greater part of the husk, is pierced in all
directions by small, ramifying fiber bundles inclosing small spiral cells
and stone cells; near the inner surface of the husk it is interrupted by
a single layer of small, very thick- walled cells (see Plate XLVI), which
are very characteristic and withstand the disintegrating processes
of manufacture better than any other part of the husk. In fact, these
processes are often carried so far that it is only by very diligent search
that one is able to find any recognizable structures besides these cells
and the starch grains of the cotyledons. For the detection of the
presence of husks in cocoa preparations, these thick-walled cells are
first sought for; and after these the epidermal and parenchymal struc-
tures. The fiber bundles, with inclosed spiral cells, are not readily
distinguished from those of the cotyledon.
If the brown husk be entirely removed from the remaining part of
the bean, a thin, transparent membrane will be observed, which partly
comes away with the husk and partly remains adherent to the bean
proper, dipping into all the clefts and plications of the latter. When
a portion of this membrane is examined with the microscope, it appears
as a single layer of small polygonal cells which are filled with granular
matter (see Plate XLVII). By careful manipulation one or more layers
of parenchymatous cells can be found underneath the layer just de-
scribed. Adherent to this membrane, especially to the folds entering
the clefts of the cotyledons, are numerous yellow, club-shaped masses
20393— No. 13 6
948 FOODS AND FOOD ADULTERANTS.
of cells, known as " Mitsclierlich bodies." They are now considered to
be epidermal hairs, but it is not decided as to whether they belong to
the membrane j ust described or to the surface of the cotyledon. Neither
the settlement of this question nor the membrane and hairs, are of any
great importance for our purpose, since both of these structures are
very rarely met in recognizable form in the commercial preparations.
After the removal of the husk and the membrane just described, the
two fleshy, much-folded cotyledons, or seed leaves, remain, inclosing
the radicle (the embryo stem of the undeveloped plant) at the larger
end of the bean in a manner not a little suggestive of the retracted
head of a turtle. Examination of a thin section shows the cotyledon to
be made up of comparatively thin-walled, closely packed, polygonal
cells (see Plate XL.VII). The most of these cells are filled with starch
grains, fat, and albuminous material; isolated or small groups of cells
are homogeneously filled with the reddish brown to violet pigment,
cocoa red. Fiber bundles with spiral cells, similar to those of the husk,
occur in the veins.
The starch grains are spherical, or nearly so, have a very indistinct
nucleus, react only feebly with polarized light, rapidly lose the blue
coloration imparted by iodine, and show only a slight tendency to
unite in the form of compound grains; three or four is usually the
maximum number so united. The size of the grains of cocoa starch is
usually stated to be 0.003-0.010 mm. The following measurements
were made in this laboratory :
Measurements of starch (/rains from a sample of unprepared cocoa beans.
Millimeters.
5 grains measured ............................................. 0. 003
11 grains measured ..................................... ........ 0. 004
14 grains measured ............................................. 0. 005
6 grains measured ............................................. 0. 006
11 grains measured ............................................. 0. 007
2 grains measured ............................................. 0. 008
1 grain measured .............................................. 0. 009
1 grain measured .............................................. 0.010
51 Average of 51 grains ................................... 0. 0054
Measurements of starch grains from Waltei1 Baker <f Go's. "o-ackwl cocoa."
Millimeters.
3 grains measured ................................ ~ ............ 0. 002
9 grains measured ............................................. 0. 003
12 grains measured ............................................. 0. 004
14 grains measured ................................. ........... 0. 005
14 grains measured ............................................. 0. 006
28 grains measured ............................................. 0. 007
7 grains measured ............................................. 0. 008
3 grains measured ............................................. 0. 009
8 grains measured ............................................. 0. 010
2 grains measured ............................................. 0. 012
100 Average of 100 grains .................................. 0.0062
METHODS OF COCOA ANALYSES. 949
For the preparation of the sample for microscopical examination, a
convenient portion is washed with ether by decantation in a small test
tube ; when the ether has evaporated from the residue, a portion is
triturated in a small mortar with a small quantity of solution of chlori-
nated soda until nearly or just decolorized ; the mixture is then washed
into a large test tube, or conical glass, diluted with much water, and
set aside to settle. The sediment thus obtained is removed with a
pipette for the microscopical examination. If both color and form are
found necessary for the identification of any structures, the reserved
portion of unbleached and fat-free material is used for this purpose.
A knowledge of the structures of the spices used for flavoring cocoa
preparations, sufficiently accurate to enable one to readily distinguish
them from substances added as adulterants, is very important; to
identify the individual spices when several have been used in the same
preparation is a very difficult and generally a highly unimportant prob-
lem. The ordinary flavoring materials are vanilla and cinnamon ; cloves,
nutmeg, mace, cardamom, Peruvian balsam, and artificial vanillin are
also reported as flavoring materials.
Starch, flour, and husks are the more ordinary adulterants to be
detected with the microscope ; Moeller } reports the materials most
commonly used to be wheat and potato starches, next rice and arrow-
root, and finally wheat, acorn, and rye flours, ground peanuts, and in
malted preparations raw malt as a substitute for malt extract; to these
Mace2 adds almond cake and sawdust. As the collecting of valueless
waste products and the converting them into suitable materials for the
adulteration of commodities of value has become a well-established
industry, every investigator must be prepared to find many new sub-
stances used for this purpose, and must not be disappointed if he finds
none of those that have recently been reported. To know what to
expect to find, he should consider the current prices, abundance, and
suitability of available materials, as well as the results of previous
investigations.
METHODS OF ANALYSIS REPORTED BY VARIOUS CHEMISTS.
A brief review of the methods that have been used or recommended
for the analysis of cocoa and its preparation is here given. If any im-
portant recently reported methods have been omitted, it is due to a
greatly regretted and unintentional oversight.
Preparation of the sample. — The method of analysis adopted by the Association of
Swiss Analytical Chemists3 directs that the substance should always be finely pow-
dered or rasped, and kept in well-stoppered bottles. Bensemann4 prepares the
beans by grinding in a porcelain mortar, separates the husk by use of a knife, and
1 Op. cit., note 3, p. 940 of this work.
2 Mace", Les substances alimeutaires 6tudi6es au microscope.
3 Vierteljahresschrift ii. d. Fortschritte auf d. Gebiete d. Chem. d. Nahr. u. Genusa-
mittel, 1890, 2, 171.
< Rep. f. anal. Chem., 1884, 4, 213.
950 FOODS AND FOOD ADULTERANTS.
scrapes chocolate with a knife to prepare it for analysis. Mansfeld1 recommends
that the material be finely rasped or powdered .
Determination of moisture. — The Association of Swiss Analytical Chemists 2 makes this
determination in cocoa powder. Two grams are spread in a thin layer on a watch
glass and dried to constant weight at 105° C. Beusemann3 dries 2 grams to a con-
stant weight at 100° C. ; Herbst,4 a weighed quantity, mixed with twice its weight
of sand, at 60° to 80° C. ; Mansfeld,1 5 grams to constant weight at 100° C.
Quantitative and qualitative examination of the ash. — For quantitative determination,
the method of the Association Swiss Analytical Chemists2 directs that the material
be incinerated in a platinum dish, carefully burned at a low red heat until the ash
is white, and after moistening with (NH4).2CO3, gently reignited. The ash is also
examined qualitatively for mineral substances and pigments; asocher, bolus, excess
of alkaline carbonates used in making the cocoa soluble, etc.
Benseniann.3 — Two grams of material are carbonized, extracted with water, and
the residue washed and incinerated. The aqueous extract is added to the ash and the
whole evaporated to dryness. The residue is dried at 100° C., weighed, and the result
taken as ash. All ashes were of a light gray, almost white, color, so that the addi-
tion of ocher, bolus, etc., could be easily detected by a red color of the ash.
Maiisfeld1 burns 5 grains at a low temperature and tests the ash for mineral addi-
tions; as ocher, excess of alkaline carbonates, etc.
Stutzer6 mixes 2 grams with sand, incinerates at a moderate heat, adds NH4NO3,
and ignites again until the ash is white and free from CO.j and nitrates. In a recent
article6 this writer has called attention to the value of the additional determinations
of ash soluble in water, total P2OS and P2O5 soluble in water, as a means of detect-
ing the use of fixed alkalis and ammonia in the process of manufacture. His results
are given in the table on page 943.
Quantitatived etermination of fat. — Association of Swiss Analytical Chemists.2 — The
sample is mixed with sand, extracted with absolute ether in a Soxhlet apparatus for
six to eight hours; the ether is removed by careful evaporation, and the fat dried at
100° C.
Bensemann.3 — Two grams of the substance are rubbed to a powder in a mortar
warmed to 60° C., some gypsum being added to facilitate the pulverizing. The mass
is extracted with ether in a Soxhlet apparatus and the extract is dried at 100° C.
Blyth.7 — The best method of extracting the fat is to exhaust the nibs with ether in
a Soxhlet apparatus.
Boussingault.8 mixes the material with sand and extracts with carbon disulphide.
Hassall.9 — Three grams of cocoa are dried in the water bath and exhausted with
ether; the ether is evaporated off, and the residue dried and weighed. This residue
contains some or all of the theobromine, the amount of which must be determined
and subtracted from the ether extract.
Herbst.4 — The residue from the moisture determination "is extracted with ether and
the extract dried at 100° C.
1 Zeitschr. d. allgem. osterr. Apotek. Ver., 44, 329.
'Vierteljahresschrift ii. d. Fortschritte auf d. Gebiete d.-Chem. d. Nahr. u. Genus-
smittel, 1890, 2, 171.
3 Rep. f. anal. Chern., 1884, 4, 213.
••Rundschau, 1882, 443; Rep. d. anal. Chem., 2, 236; Zoitsch. f. anal. Chem., 22, 278.
6Rep. f. anal. Chem., 1882, 88 and 165; Hygiene-Bericht, 1882-'3, 1, 217.
•» Op. cit., note 3, p. 939 of this work.
7 Op. tit., note 3, p. 936 of this work.
8 Ann. Chem. Phys., [5], 28, 433; Jour. Chem. Soc,, 1884, 46, 202; Chem. Ztg., 1883,
203, and 902.
"Op. tit., note 2, p. 940 of this work.
METHODS OF COCOA ANALYSES. 951
Mausfeld.1 — Five grams of cocoa, or 10 grains of chocolate, are mixed with au equal
weight of sand and extracted in a Soxhlet apparatus with petroleum ether.
Wolfram 2 uses petroleum ether for the extraction of the fat.
Qualitative examination of the fat.* — The Association of Swiss Analytical Chemists4
recommends the determination of the melting point by Riihdorfs method, Hiibls'
iodine number, and Kottstorfer's sapouification number. Bjorklund's ether test and
Filsinger'a ether-alcohol test are also stated to be of value.
Bjorklund5 covers about 3 grams of the fat in a test tube with double its weight of
ether, closes with a cork, and tries to bring the mass in solution by shaking at
18° C. When wax is present, a cloudy solution results, which is not changed by
warming. If the solution is clear, the tube is placed in water at 0° C. and the time
observed after which the solution begins to become milky or to deposit white flakes ;
then the temperature is noted at which the mixture becomes clear on removing from
the water. When the solution becomes cloudy after ten to fifteen minutes and at 19°
to 20° C. is again clear, the cocoa butter is pure. For a cocoa butter containing 5 per
cent of beef tallow, these numbers are eight minutes and 22° C. ; 10 per cent tallow,
7 minutes and 25° C., etc.
Dieterich.6 — Equal parts of the fat and paraffin are melted together, a drop of the
mixture placed on a slide and covered with a cover glass. After twelve hours this
is examined with a power of 20 diameters and polarized light, at a temperature not
exceeding 5° C. Pure cocoa butter shows palm-leaved crystals ; 10 per cent of tallow,
circular group of crystals.
Filsinger.7 — The iodine and Kottstorfer's numbers are determined in the dried fat.
If these leave any doubt, Bjorkluud's ether test or Filsinger's ether-alcohol test may
be applied. This writer has modified the ether test as follows : 2 grins, of fat are
melted in a graduated tube with 6 cc. ot a mixture of 4 volumes of ether (sp. gr. 0.725)
and 2 volumes of alcohol (sp. gr. 0.810), shaken and set aside. The pure fat gives a
solution that remains clear.
Hager's anilin test8 is conducted as follows: About 1 gram of cocoa butter is
warmed with 2 to 8 grams of anilin until dissolved ; the mixture is allowed to stand
1 hour at 15° C., or !•£ to 2 hours, when temperature is 17° to 20° C. Pure cocoa butter
floats as a liquid layer on the auilin. If the cocoa contains tallow, stearic acid, or
a little paraffine, cloddy particles, which remain hanging ou the upper wall, on
gentle agitation are deposited in the oil layer ; if wax or much paraffin is present,
the oil layer solidifies; if much stearic acid is present, there will be no separation
into two layers, but the whole solidifies to a hard crystalline mass; with pure cocoa
butter, the oil layer hardens only after many hours. A parallel test should be made
with pure cocoa butter.
Hassall.9 — Melting point is determined. Foreign fats become rancid and tallowy
in a few days.
Herbst. 10 — Melting point determination and Bjorklund's ether test are recommended.
1 Op. cit., note 1, p. 950 of this work.
2 Jahresbericht d. k. chein. Centralstelle f. off. Gesundheitspflege in Dresden,
1878; Zeitsch. f. anal. Chein., 18, 346.
3 See table on page 938 for the chemical and physical constants for cocoa butter.
4 Op. tit., note 3, p. 949 of this work.
s Zeitsch. f. anal. Chem., 3, 233; see also op. tit., note 2, p. 938 of this work.
6Geschafts-Ber. d. Papier- u. chem. Fabrik in Helfenberg, 1883; Zeitsch. f. anal.
Chem., 23, 567.
'Zeitsch. f. anal. Chem., 19, 247 ; Chem. Ztg., 1889, 13, 309 ; see also op. tit., note 2, p.
938 of this work.
8Zeitsch. f. anal. Chem., 19, 246; see also op. cit., note 2, p. 938 of this work.
9 Op. cit., note 2, p. 940 of this work.
10 Op. cit., note 4, p. 950 of this work.
952 FOODS AND FOOD ADULTERANTS.
The small quantity of sesame oil, added to give the broken surface of chocolate a
smooth appearance, can not be detected with certainty.
Mansfeld.1 — The purity of the fat is determined according to Filsinger. The
melting point is determined according to Pohl.
Schaedler.2 — The comparatively high commercial value of cocoa butter brings adul-
teration with waxes, stearin, paraffin, and beef tallow. The taste, odor, melting point,
and ether test are mentioned as means of detecting foreign fats. Paraffin gives cocoa
butter a soapy feel and lowers the specific gravity. An addition of stearic acid is
made known by the high melting point and by boiling with dilute NBOH, when the
stearic acid goes into solution as stearate of sodium and is reprecipitated by H.2SO.|.
Determination of theobromine. — Blyth.3 — This author outlines the methods of Wosk-
ressnsky, Mitscherlich, and Wolfram. He also gives the following "speedy method of
determining, with fair exactitude, the per cent of theobromine in cocoa " : Weigh out
a definite portion and exhaust it with petroleum ether. Mix the residue with a
little burnt magnesia and water, evaporate to dryness at 60° to 70° C., and exhaust the
residue with boiling 80 per cent alcohol, which dissolves out the theobromine. After
driving off the alcohol, the residue may be purified for weighing by washing with
petroleum ether.
Boussingault.4 — Extract the sample with boiling water and precipitate the decoc-
tion obtained with basic acetate of lead. After removing the excess of lead with
H.2S, evaporate to dryness and exhaust the residue with boiling alcohol. On cool-
ing this solution the alkaloid separates out as a crystalline powder.
HassalP uses the method devised by Hehner for the estimation of caffeine in tea,
which is conducted as follows : Twenty grams of material are boiled with about a
liter of water, cooled, and the solution made up to the mark and filtered. Five hun-
dred cc of the clear filtrate are evaporated on the water bath with the addition
of a little MgO. The dry residue is extracted with boiling alcohol. The united
extract is evaporated nearly to dryness, taken up with ether, filtered, and evapo-
rated to dryness for weight.
Legler'1 gives the following modification of Wolfram's method: 20 to 25 grams of
cocoa, or 50 grams of chocolate, deprived of fat, are digested several hours with 4
per cent H2SO4. The solution is filtered and the theobromine precipitated with
sodium phosphomolybdate. After standing twenty-four hours, filter, wash with 6 to
8 per cent H.2SO4, and dissolve the precipitate in NaOH or Na^COs. Add sufficient
H2SO4 to the solution to leave it slightly alkaline, evaporate with sand, dry at 110°
C., and extract at 70 to 90° C., with aniyl. alcohol. Evaporate the extract to dry-
ness in a platinum dish, dry, and weigh. Ignite the residue and weigh again. The
difference is the weight of the theobromine.
Mansfeld.1 — Another portion of 50 cc of the alcoholic extract, obtained by the
author's method for the determination of sugar (see methods for determination of
sugar on page 954), is evaporated to dryness with MgO and the finely powered residue
extracted in a Soxhlet's apparatus with CHC13. The extract is evaporated to dry-
ness and the residue dissolved in boiling water. The solution is filtered, evaporated
to dryuess, and the residue of theobromine weighed ; the alkaloid thus obtained is
pure.
Mulder.7 — Ten grams of cocoa are rubbed to a paste with water and boiled for fifteen
minutes; some MgO is uowaddedand the mixture evaporated to dryness on the water
1 Op. cit., note 1, p. 950 of this work.
2 Op. cit., note 2, p. 936 of this work.
" Op. cit., note 3, p. 936 of this work.
4 Op. cit., note 2, p. 941 of this work.
6 Op. cit., note 2, p. 940 of this work.
fi Ber. d. Chem. Ges., 15, 2938 ; Zeitsch. f. anal. Chem., 23, 89.
7 Op. cit., not* 8, p. 938 of this work.
DETERMINATION OF THEOBROMINE. 953
bath with continual stirring. The residue is extracted with CHC13 and the chloro-
form distilled off. The residue is dissolved in hot water, the solution filtered, evap-
orated to dryness, and the residue of theobromine dried and weighed. This method
includes the traces of caffeine which are present in cocoa. This may be isolated by
extracting the residue of theobromine with cold benzol, which dissolves only the
caffeine. The benzol is distilled off, the residue shaken with water, and the solution
filtered and evaporated.
Weigrnann.1 — Twenty grams of the material are rubbed up into a soft paste with hot
water; more water is then added and the mixture is boiled for fifteen to thirty min-
utes. The decoction is then made up to one liter, allowed to settle, and 500 cc
filtered off. This is brought to a boil and precipitated with ferric acetate. The pre-
cipitate is filtered off, the filtrate concentrated on the water bath, strongly acidulated
with H.2SO4 (the liquid should contain at least 6 per cent H2SO4), and precipitated
with sodium phosphomolybdate. After standing two to three hours the precipitate
is filtered off, washed with acidified water, and its content of nitrogen determined
after drying. The results thus obtained are somewhat lower than Wolfram's.
Wolfram.2 — If the bean deprived of husks is to be examined, it is first rubbed to a
paste in a hot mortar. Ten grams of this mass, or 20 to 30 grams of chocolate, are
treated for some time with boiling water, ammoniacal lead acetate added, the solution
filtered hot, and the precipitate washed lentil a drop of the filrate after cooling gives
no precipitate with sodium phosphomolybdate. A volume of 700 to 800 cc is gen-
erally necessary. After the addition of NaOH, the filtrate is evaporated to 50 ce. It
is then strongly acidulated with H.2SO4 and the lead sulphate separated by filtration.
The filtrate is mixed with a large excess of sodium phosphomolybdate (this reagent is
prepared by dissolving 100 grams of sodium molybdate and 60 to 80 grams of sodium
phosphate in 500 cc of water acidulated with about 6 per cent of nitric acid). Heating
and stirring facilitates the settling of the precipitate. After standing several hours
the liquid is filtered and the precipitate washed with 6 to 8 per cent H2SO4. The
filter and precipitate are placed in a beaker and Ba(OH)2 added until the reaction is
alkaline. Heating renders the decomposition more rapid. The excess of Ba(OH)2 is
neutralized with H.jSO4, and any possible excess of the latter with BaCO3. The
whole is filtered and washed hot; the filtrate is evaporated in a platinum dish and
the theobromine dried and weighed. As barium salts may be present, it is best to
ignite, moisten with (NH4)iCO3, reignite and weigh. The difference is theobromine.
Zipperer.3 — The substance is extracted with petroleum ether and then three times
extracted with 80 per cent alcohol. The alcoholic extracts are evaporated to dry-
ness on the water bath with 15 grams of Ca (OH).2. The dry residue is extracted with
CHCL, the latter distilled off, the residue dissolved in hot water, the solution
filtered and evaporated to dryness. The resulting theobromine is dried and weighed.
The results are regarded as unreliable, since the extraction is very questionable.
Determination of sugar by polarization. — Filsinger.4 — 13.024 grams are mixed with
water in a 100 cc flask. The solution is clarified with basic lead acetate, made up to
the mark, filtered, and polarized in a 200 mm tube.
Mansfeld5. — Ten grams of chocolate are heated with 100 cc water in a 250 cc flask
to 35° C., well mixed, clarified with lead acetate and alum, and made up to the mark.
The clear filtrate is polarized.
Determination of sugar by inversion. — Ass. Swiss Anal. Chem.5 — The substance is
1 Op. cit., note 8, p. 938 of this work.
3 Op. cit., note 2, p. 951 of this work.
3 Zipperer, Untersuch, u. Cacao u. dessen Priiparate, 1887 ; see also op. cit., note 8,
p. 938 of this work.
4 Op. cit., note 7, p. 938 of this work.
6 Op. cit., note 1, p. 950 of this work.
954 FOODS AND FOOD ADULTERANTS.
extracted with water; the extract is evaporated to a sirupy consistency, treated
with alcohol, decolorized by means of lead acetate, the excess of which is removed
with H.jSO.». The sugar thus prepared is inverted and the invert sugar determined
with Fehling's solution.
Hassall.1 — The sugar is dissolved out of the sample with cold water, inverted by .
boiling with dilute H..SO4, and then estimated with copper solution.
Mansfeld.2 — The residue from the fat determination is extracted for three hours
with 100 cc of 80 per cent alcohol, and the extract made up to 150 cc. Fifty cc are
evaporated to dryness. After weighing, the residue is dissolved in water, made up
N
to 100 cc, heated one-half hour on the water bath with 10 cc T^HCl, neutralized
with NaOH, and diluted to 250 cc. The invert sugar is then gravimetrically deter-
mined with Fehling's solution.
Determination of sugar 1)y direct weighing. — Hassall.1 — Dissolve a weighed quan-
tity of cocoa containing sugar in cold water and collect the residue on a filter. This
residue is dried on the water bath and weighed.
100 — per cent of insoluble matter=per cent of soluble matter.
Per cent of soluble matter — (per cent of moisture -f- the approximate
per cent of soluble matter in cocoa) = per cent of sugar.
Herbst.3 — The residue from the fat determination is extracted with boiling 50 per
cent alcohol as long as the extract is colored. This extract is evaporated to drynrss
and treated with cold water, which dissolves the sugar. This solution .is evaporated
to dryuess, the residue dried in hydrogen and weighed.
Determination of commercial glucose in chocolates. — In regard to the determination of
the sugars used for sweetening chocolates, M. Schrojder ' writes as follows:
"The detection and estimation of less than 5 per cent of commercial glucose in
presence of cane sugar by means of copper solution is uncertain, because commercial
cane sugar often contains an equivalent amount of reducing sugars. The optical
determination by Clerget's method is more satisfactory, since only a small percent-
age of commercial glucose is necessary to appreciably lessen the degree to which the
inverted solution rotates to the left. The evidence obtained by Clerget's method
can be strengthened by determining the dextrin which would be present in the
residue after fermentation, if commercial glucose were present in the original
material."
Determination of starch. — Asborth5 has published a method, according to wliirli lie
adds Ba(OH)2 to the boiled starch, with which it forms a compound Avlucli is insol-
uble in dilute alcohol. Dr. Mansfeld's modification of this method is given helow.
Ass. Swiss Anal. Chem.K — The sample, free from fat and sugar, is boiled with water
for four hours and the resulting starch solution is inverted with sulphuric acid ; the
excess of acid is removed by basic acetate of lead; the filtrate is freed from lead with
H2S and the reducing sugars determined by means of Fehling's solution. The
starch may also be determined by treating the powder in a Reischauer's pressure-
flask, inverting, etc.
Beusemaun.7 — Two grams of the substance, after extraction and washing with cold
water, and while still moist, are mixed with 200 cc of water and 20 cc HC1, sp. gr. 1 . 12.
The mixture is heated for at least three hours on the water bath, cooled, and filtered.
After making the filtrate alkaline with NaOH, a freshly prepared solution of 4 grams
of copper tartrate, 2 grams of tartaric acid, 30 cc of soda lye, sp. gr. 1.13, and 100
1 Op. cit., note 2, p. 940 of this work.
* Op. cit., note 1, p. 950 of this work.
3 Op. cit., note 4, p. 950 of this work.
•Zeitsch. f. angew. Chern., 1892, 173.
6 Rep. anal. Chem., 8, 20.
fi Op. cit., note 3, p. 949 of this work.
7 Op. cit., note 4, p. 949 of this work.
DETERMINATION OF FIBER. 955
cc water are added. The mixture is slowly heated to 70 to 80° C. and kept at that
temperature for one-half hour. After completely cooling the Cu3O is collected on a
filter, washed cold, dried at 100 to 110° C., and weighed.
1 gram Cu2O = 0.45315 grams of starch.
Hassall ' gives a method similar to that of the Ass. Swiss. Anal. Chem. given above.
Mansfeld.2 — Two portions of 25 grams of cocoa, or 5 grams of chocolate, are
weighed out and placed in 250 cc flasks with 100 cc of water in each. One sample is
heated ou the water bath; the other is placed in. water at 30 to .40° C., and shaken
to emulsify the fat. After thirty minutes the cooled samples are shaken with 50 cc
of a standard solution of Ba(OH)2 and 45 per cent alcohol added until the liquid
reaches the mark. Cool and make up with similar alcohol if necessary. The
Ba(OH)^ solution is titrated by mixing 50 cc with 100 cc of water and making up
to 250 cc with 45 per cent alcohol, using N/|0 HC1 with phenolphthalein for an indi-
cator, and titrating 50 cc. The sample is allowed to settle, and 50 cc of the yellow
supernatant liquid titrated. The difference between these two titrations for pure
chocolate is 1.25 cc. The general increase for each per cent of flour is 0.3 cc. Hence :
X - 10 — Q- — . D = number of cubic centimeters difference between the amounts of
o
N/io HC1 required. X = per cent of foreign starch in the sample.
Mansfeld.3 — The residue left after the removal of petroleum ether and alcohol
extracts is dried and mixed with 500 cc of water; the mixture is heated for
one-half hour, on the water bath, diluted to 1,000 cc, cooled to 55° C., and mixed
with 0.1 gram of Liutner's diastase, which has been previously rubbed up with a
little water. Keep at 55° to 60° C. until iodine gives no reaction for starch, decant
into a 1,500 cc flask and make up to the mark. Heat 100 cc of the clear liquid
with 10 cc HC1, sp. gr. 1.125 for three hours on the water bath, cool, neutralize,
dilute to 500 cc and determine the dextrose gravimetrically.
Schroeder.4 — For the inversion of the starch, 3 grms. of the material with 50 cc of
water and 1 cc HC1 (38.8 per cent) are heated for 1 hour under a pressure of one atmos-
phere. Results of experiments are also reported to show that this treatment does
not convert an appreciable amount of cellulose into dextrose.
Weigmaun 5 uses diastase solution prepared as directed by Stutzer. Ten grams of
cocoa, deprived of fat. are boiled one quarter hour with water and made up to 500 cc;
250 cc are removed after shaking, treated with 2 cc of diastase solution for four
hours at 60° C., inverted with 20 cc HC1, neutralized and precipitated with lead
acetate. After removal of the excess of lead with H.jSO,, the nitrate is made up to
500 cc and the reducing sugar determined gravimetrically.
Detection of Jtour in cocoa preparations. — Reinsch.6 — Boil one part of the material
with ten parts of water, cool and filter. If the sample is pure it will filter rapidly,
give a clear filtrate, having a light reddish color, and leave a residue that is not
gummy. If flour has been added, it filters murky and slowly, and a gummy mass
remains on the filter.
Determination of fiber. — Ass. Swiss Anal. Chem.7 used Henneberg and Stohmau's
method. This, as well as a method given by Mansfeld, does not differ materially
from the official method of the Association of Official Agricultural Chemists, an out-
line of which is given on page 958.
1 Op. cit., note 2, p. 940 of this work.
-Zeitsch. f. Nahrungsmittel-untersuchung ii. Hygiene, 1888, 1, 2; Deutsch. Chem.
Ztg., 3, 91.
3 Op. cit., note 1, p. 950 of this work.
4 Zeitsch. f. augen. Chem., 1892, 173.
5 Op. cit., note 8, p. 938 of this work.
6 Further Gewerbe Ztg., 1868, 63; Zeit. f. anal. Chem., 8, 514.
7 Op. cit., note 3, p. 949 of this work.
956 FOODS AND FOOD ADULTERANTS.
Determination of water-in sol idle organic matter. — Beusemann.1 — Two grams of the
substance are covered with cold water and allowed to stand twelve hours, with
occasional stirring. The insoluble residue is collected, washed cold, dried at 100°
C., weighed, incinerated, and weighed again. Difference^ weight of water-insoluble
organic matter.
Determination of gum. — Boussingault.2 — An aqueous infusion of the fat-free material
is precipitated with alcohol.
Determination of nitrogen. — Mansfeld3 used Kjeldahl's method, starting with 3
grams of material.
Determination of coloring matter and tannin. — Mansfeld.3 — The residue from the fat
determination (see page 951) is extracted with 80 per cent alcohol. In this extract
sugar, theobromine, and total residue are determined. Total residue — (sugar +
theobromine) = coloring matter and tannin.
Detection of the use of fixed alkalis and ammonia in the process of manufacture of
cocoas. — Stutzer.4 — The total ash, ash soluble in water, total PaO5 and PiOfi soluble
in water are determined. The relative proportions of these constituents in the ash
of a normal cocoa and in the ash of cocoas treated with fixed alkalis and ammonia
are given in the table on page 943. Additional evidence of the use of ammonia is
obtained by distillation of the sample with magnesia and determination of the am-
monia in the distillate. If this process yields more than 0.1 per cent of nitrogen in
the form of ammonia, this writer considers the result certain evidence of the use of
ammonia, or ammonia salts, in the process of manufacture.
METHODS BY WHICH THE RESULTS GIVEN IN THE TABLE ON PAGE
980 WERE OBTAINED.
The methods outlined below were chosen as best suited for the pur-
pose. While some are only approximate methods, they are sufficiently
accurate for the purpose and are much more rapid than some of the
methods previously employed.
Microscopical examination. — The method used for the preparation of the sample for
the microscopical examination has been outlined on page 949.
Determination of moisture, ash, and of the amount of acid required to neutralize the ash
from two grams of material. — Two grams of material are distributed over the bot-
tom of a flat platinum dish and dried to constant weight at 100 to 105° C. The
loss = moisture. The residue is carefully ignited in a muffle and weighed for the
amount of ash. The ash is then washed into a beaker, dissolved, with gentle boiling,
N N
in — H2SO4, and the excess of acid determined by titration with NaOH. Cc of
N N
— H2SO4 — cc of —NaOH = the number given in the table on page 980 as "acid
equivalent."
Determination of fat. — Three grams of the substance are placed in a 300 cc flask
and covered with 200 to 250 cc of redistilled petroleum ether ; after standing 4 to
5 hours with occasional shaking, the flask is filled nearly to the mark with petroleum
ether, shaken, and allowed to stand over night. After making up to the mark and
thorough shaking, the insoluble portion is allowed to deposit; the supernatant liquid
is then quickly decanted into a 100 oc flask until, the latter is just filled to the
mark, using every precaution to avoid raising the temperature of either flask. This
portion of 100 cc is filtered through a Gooch crucible, and the slight residue washed
1 Op. cit., note 4, p. 949 of this work.
8 Op. cit., note 2, p. 941 of this work.
3 Op. cit., note 1, p. 950 of this work.
*Op. cit., note 3, p. 939 of this work.
DETERMINATION OF SUGAR AND STARCH.
95?
with petroleum ether until free from fat. The filtrate and washings are received in
a weighed flask, in which the fat is weighed, after recovering the petroleum ether
by distillation and drying the residue to constant weight at 100° C. in a water oven.
The fat obtained is clear, of slightly yellowish color, and undergoes appreciable
oxidation only on prolonged heating under the conditions mentioned above. An
ordinary air bath is usually too small for the proper heating of a vessel of the size
required. Taking the density of the insoluble portion as 1.000, and ignoring the
small amount of residue decanted with the 100 cc portion, the following table of
corrections is applicable to the per cent of fat obtained by the above method:
When the sample contains
approximately
60 ~
0.24]
55
0.25
50
0.25
45
0.25
40
0.24
35
30
25
per cent of fat,
subtract
0.23
0.21
0.19
20
0.16
15
0.13
10
0.09
5
0.05
1
0.01
per cent from the result
obtained.
Determinations of fat are very quickly made by this method, and the results are
sufficiently accurate for ordinary purposes.
Determination of sugar. — A determination of the amount of sugar added in the
process of manufacture is readily made, by means of the polariscope, to within one
or two per cent of the truth; a closer determination is neither very easy nor very
important. The gum (see page 941) gives the aqueous solution of normal cocoa a
slight rotatory power, equivalent to 0.3 to 2.0 per cent of sugar in the bean in sev-
eral samples tested; the presence of starch necessitates the use of cold water, of
which 500 cc or more are necessary for the complete removal of the sugar from
13.024 grams of material. Considering these facts, the following method will be
found satisfactory for most purposes: 13.024 grams of material are placed in a small
mortar and triturated with alcohol until .1 smooth paste is obtained; this is trans-
ferred to a 500 cc flask, diluted with 400 to 450 cc water and shaken occasionally for
three to four hours ; 10 cc of a saturated solution of normal acetate of lead are added
and the volume brought to 500 cc. After standing for about one hour, with occa-
sional shaking, the solution is filtered and polarized in a 400 mm tube. The per
cent of sugar is then obtained by the following formula, in which R = the polari-
scopic reading, when the normal quantity for the polariscope used is 26.048 grams:
11
I 500-
( 13.024—
5 R X 13.024
Too"
100
: % sucrose.
A portion of the solution, as prepared for polarization, was freed from lead and
tested with Fehling's solution for reducing sugar, the result being taken as an indi-
cation of the quality of the sugar used in the manufacture of the sample.
For a more exact determination of the sugar, a gravimetric determination of the
reducing sugars in the aqueous extract, before and after inversion, is recommended.
(Weight of copper obtained after inversion) — (weight of copper obtained before in-
version)=weight of copper equivalent to cane sugar present.
Determination of starch. — Mr. K. P. McElroy devised the following method for the
determination of starch :
Five grams of chocolate were weighed into an Erlenmeyer flask, wet with alcohol,
and 30 to 40 cc of water added. The flask was then shaken at intervals until all
sugar present had gone into solution. Fifteen cc of a saturated solution of neutral
"958
FOODS AND FOOD ADULTERANTS.
lead acetate were then added and the mixture again shaken. After allowing it to
settle, the clear liquid was decanted through an asbestos filter and water added to
supply its place. This was in turn decanted, and so on until the filter began to clog,
when just enough acetic acid was added to the material in the flask to turn it red.
Decantation and filtration were then continued till the filtrate came through color-
.less. Under these conditions nitrations were rapid and filtrate extremely clear.
The asbestos filter and contents were then placed in the flask, water enough added
to bring the whole to about 100 cc, and the flask placed on the steam bath for
three hours. At the end of this time 10 cc of concentrated HC1 were added, and
the heating continued three hours more. After cooling, Na^COs was added until the
contents of the flask became blackish. The whole was now washed into a 250 cc
flask and made up to the mark. Dextrose was oxidized by Allihn's method, 25 cc
of solution being used, and the resulting Cu.2O collected on a Gooch crucible, redis-
solved in HNO:i, converted into CuSO4. and the Cu determined electrolytically.
Five samples of commercial starchy materials were examined for the purpose of
determining the amount of starch converted to dextrose by the method employed.
Three grams of material were heated on the steam bath for three hours with 200 cc
of water; 20 cc of HC1. (sp. gr. 1.125) were then added and the heating continued
three hours longer. After neutralization with Na^COa dilution to a definite volume,
and filtration from the slight residue, the dextrose was determined by Allihn's
method, the amount of Cu.^O being determined electrolytically. Duplicate samples
were inverted and duplicate weighings made from each inverted solution. The
results were as follows :
9
Percentage of starch in commercial starchy materials used in manufacture of cocoa prepara-
tions, i. e.,per cent of dextrose obtained by inversion X 0.9.
[All samples were air-dried.]
( 'liaractf r of sample.
Solution No. 1.
Solution No. 2.
Mean.
A.
B.
A.
B.
"Wheat flour ...
71.3
82.3
83.8
81.7
71.6
81.9
84.2
79.3
84.5
71.8
81.7
83.8
79.2
71.6
82.1
83.8
80.5
x». 1
82.5
83.6
81.9
83.7
Corn tarch
Potato tloui
Prepared cassava starch
Starch determinations are only reliable when the conditions are held
rigidly exact. In order that this may be made more certain each set
of determinations should be accompanied by a check determination with
material of known dextrose-yielding power.
Determination of fiber. — The official method of the Association of Official Agricul-
tural Chemists' was adapted to (his work, :is follows: Two grams of material were
placed in a long narrow test tube with a lip, washed with" several portions of ether,
deeaiiting through a Gooch crucible. After evaporation of the ether, the muterial in
the- tube and crucible was washed into an Erlenmeyer flask with 200 cc of 1.25 per
cent HiSO4. After boiling a half hour with a reflux condensing tube, the solution was
filtered through a linen filter, and the residue thoroughly washed with hot \\aier;
while still hot, the filtrate was refiltered through a Gooch crucible, and the slight
residue again thoroughly washed with hot water. The material on the linen and in
the crucible was rinsed back into the flask with 200 cc of !.!'."> per cent NaOH, and
the boiling and filtration repeated. The material on the linen was then washed into
1 r.nlletin No. 31, Cheiii. Div., U. S. Dept. of Agriculture.
SUMMARY OF RESULTS OF ANALYSES. 959
a beaker with alcohol and transferred to the crucible through which the alkali ex-
tract had beeu refiltered. After displacing the alcohol with ether, the residue was
dried at 110° C., weighed, ignited, and weighed again. The difference = the weight
of crude fiber.
SUMMARY OF RESULTS OBTAINED BY VARIOUS ANALYSTS.
A summary of the results of analyses by various chemists is presented
in the tables given below. These analyses were obtained, for the most
part, from Ko'nig's Chemie der menschlichen Nahrungs- und Genuss-
mittel, 3 Aufl., Band I. The tables of analyses given by Kb'nig are
abridged here, by giving only the means, maxima, and minima of the
results reported by each analyst on the same class of .samples. It is
believed that the tables, with appended notes, will be found self-explan-
atory.
As will be seen by reference to the tables, most analysts have reported
the percentage of total nitrogenous matter, including theobromine.
This figure is obtained by multiplying the per cent of total nitrogen by
6.25. This factor assumes the per cent of nitrogen in albuminous mat-
ter to be 16 per cent. Theobromine contains 31.1 per cent of nitrogen.
The per cent of nitrogenous matter, including theobromine, can, there-
fore, be changed to the approximate per cent of nitrogenous matter,
not including theobromine, by subtracting twice the percentage of
theobromine from the number given as nitrogenous matter, including
theobromine.
The percentages of theobromine, reported by Zipperer are considered
too low by many authorities. This seems to be due to imperfect ex-
traction of the theobromine by the method he used. (For the details of
the method see page 953.)
The tables given on pages 967 and 968 will be found to contain inter-
esting data concerning the quantitative relations of the constituents of
the cocoa bean and its preparations. Bensemann also reported analyses
of the ashes of the same samples, the results of which are given on page
969.
960
FOODS AND FOOD ADULTERANTS.
^
. § cs . g cs . * a . g a . j: a . g a . 2 ss
a K '2 5 X '2 2 x '- s x '2 2 S 'a c: "x °S 5 'x '- ?
Q • «9 9 fll w w fll •£« 9 40 IM w w <9 • 4B JZ w •! M 4
" cs . 2 a
x | 1 1 1
es .2 i ^ -3
•
. pi m oo
32«
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Ha*
•d
• PI P) PI CM P-l CM • PJ PJ *-H PJ PI PI
•
as
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^ . • O PI O O — O • '.-000
w oo eg co PJ
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•fli 0) n -* co
B
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01
£ *^ c ^2 o
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.
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S3 i
a
«
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o O S
OO OO t^ t^ t~ CM l> t^
o
Character of
sample.
' IS! '.
^a -o
9s «
cj ri ,
• 3 •« •si
2s® a
1 -s *
fr3 fl ^ D ^
S <B ^3 S
-1" 0 "S u 0 » «
« •c 5*1 <* •* S •=
3 a o a o
W « « M K
i
,M
S
M
1
o ^ S 3 S S S
S5
1
Analyst.
: pq : :
: -e « "B i • "SJ
i § t i silt
1 11 j 111
j 51 1 , 1 { 1 1
o 6 td ti (5 H P.
G. "Wolfram '»
•HPJW^lOWt-Ot
e>
ANALYSES OF COCOA BEANS.
961
E
I
J
1
•o S a p M
tj c 5 « ns
2 - ~ ** P
I li M
•e - a - *
•g . PS
1 1 p *^
-
g 2 § g1"
5 .,ȣ !l
1 II3! li
w s s S -g 2
s s s s* § i
g i^S JES
ijjiii ii
r s ^ a a .. *
^°M -g i 7. ^ M
N r S, c "S S3
ilEl8 II
e«t«l 1^
§
«
n
CJ
n. Chim. et Phys., 1883, 443;
ahrungs- und Genussmittel,
le amount of theobromine is <
ire albumen was determined
lllowing results: Mean, 9.97
06 per cent,
hresbericht d. k. chem. Cen
378 ; Konig, Chem. d. nieusch
aterial dried at 100° C.
p. f. anal. Chem., 1884, 4,. 345
—
-
—
0 ^ E £ * OS S rH ^ %
^ t-i H "i i*l W
irt . tc
P M
g ns •«
if .S
w> M g
i i; *
^ « .a»
>
—
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3 a
8 § . 1 M.
i 1 ! 51!
S -2 1 2M »
T3 P p, a r &,
3
d
9
1
1
1
1
1
1
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1 a, * s ^ •*
5 1 1 1 5 1
•» 1 ,; i ^ i i
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W HJ •! | | § 3 |
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JS^jJp1^®® pjcfic
a llili .-I5i
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ao:o^,!gs~pa§
9
962
FOODS AND FOOD ADULTERANTS.
'c
c8 c* ^ ci
a -5 S 2 .- 3 £
? s< *2 s x *s 5s
60 Maxima.
11 Minima.
10 Means.
= =
2 C3 - S B 53
ogsaa^ss
•^ .2 P "-< 2 fl •« B
31 1 a 1 1 1 1
s^s^sass
•ssen I'riiparate, 1887; Konig, Chemic dor mcnsch-
asmittel, 3 Ann., Band I.
entralstflle f. off. Gestindheitsptlesre in Dresden,
enschlieheD Xahrungs- nnd Genussinittd, :! Ann.,
345.
5 to
'H
1
•a
m
1
c
CO
CM
r~ cs r-i 10
CO •— <M OS
1^ CO O I-i
^H in in
CM CM
CO 0
o
ja
Per cent.
7.:
CD
" 3 " 2 S § 1
t~ cc co' t-'
§ 2 S
. OS CD
2 ^ t- c- co
^
i
|8
"-1.
CN Ml IO CS O Cl O
00 CM O CO O t> i-l
MI in oj
O C"l l>>
Mi in CM
O 00 CO
2 8
vm
-f
CC MI O Mi 00 <M CO
t~ m co
00 M- ?
£
'Centrbl. f. Agriknlturcheni., l«7n. :(u4: Kiinig, Cheinie der nieimehliehen Xah'r- ° Pure ash.
lings- nnd Gcniissmittel. 3 Anil.. Hand I. 7 Untersnchung ii. Cacao u. d
'Dietrich mid Ktinig. Znsammensctzmij; der Futtermittel : Kiinig, Chcmir der lichen Nahrnngs nnd Gem
menschlii lien Xahrungs- mid Genussmittel. :: Ann1.. Band I. " Jahresbencht d. k. chem. f
1 Total nitrogen r,. •_•:,. 18T8; Konig, Chemie der n
1 Ki'iing. f'liemie ill i- mi nsclilicheii Nahrnnjis- nnd (lenussniittel, .'i A nil.. Hand I. Band I.
8 Weiginann reports the results of determinations of pure protein in these sain- ° Rep. f. anal. Chem., 1884, 4,
pies by Stnt/.er's method: Mean, 12.48 per cent; maximum, 13.00 per cent;
minimum. 11.80 per cent.
% ^^ S
5 H S g
osga
- = *
|3
S
IO t- Ml OS r-l CS in
t- ff< Ml CO O (M t-
OO CO *~
O t—l
"3
-
-t
$ S S 3 3 & %
3 § g
cc m
fi
SW
OS
S S § c? £ S S
3 S S
? 0
1-1
CO CN Ml
li
2S
H
S
00 00 Ml
t~ 10 CO
0 0 CO rt C^j
t
Nitroge-
nous sub-
stancea.
is i
i S 3 51 S S i
s s s
§ M d
Is
e
O 7^ 00 -^t Cl *— " »C
CD CO f-.
M1 CO O
r^
I
P«r cent.
11.13
CO
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O^COCltH-*fCSCC'"*&OOCi *"
3,-H^~ rtrtrtr-
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tH i-H Mi 00 M
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oc
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Analyst.
C
1
C.
i
h
:
3 L. Grandeau2
4 G. Laube and B. Aldendorff4
I
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S
|X
: 1
^,
1
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1
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> <c
I- 00
ANALYSES OF COCOA PREPARATIONS.
963
1
•
Means.
Maxima.
Minima.
5
01
g
ID
M
o
H'3&
~ CO CO
« c-< in
£ oi IN
SJ
IM M t-
iH O O1
W CO CM
ct S §
C1^ C4 ^
cn co ^
•8
•tt
a
ce
OB
| 3 S
S :
0
• • a
i ; M
• h-i
05
tj « t~
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^i in IT
00 l> "5
l~ ". g
co m w
B
f
•8 S §
^ CO CO
8
«
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i^ 3 *^ M CO c"
O"3^ +•*
B v4 M
*> oo m
i~
00
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M
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s
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s
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1-1 "* i
ci oi ti.
a
1
•kS CO -*
'S co m'
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to in a
oo m -^
m 1-1 '2
OS CO ,™
o ci ^
co co H
ai
gl|
^J to in
S "
2 :
| u
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m
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tJD M , i) ^ ' y •
IS-lipgs
•t« a a- & £ •" v G*
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m i-i c
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co 06 a
co a a
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co to' tc
all . ! i
m in g jg
to to WQ
•soeX[BUT5 jo -o^j;
t-
rt rt 4} :o
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5
CS
p
in
3°
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C<l (N 'S f~
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I-H 1— f '^
§ 1
Description of sample.
Cocoa moss.
Cocoa powdert.
Lobeck & Co.'s, Dresden:
Cocoa deprived of fat
...do ..
Gerb. Stollwerck's, Cologne :
Cocoa deprived of fat, No. 1 .
Cocoa deprived of fat, No. 2 .
chlichen Nahrungs- und Genus*
161; Hygiene-Bericht, 1882-'83,
ports the following :
a
;
S w *
a oo *i
C 00 o
: 3 "1 S
| M q ^
i JB: S -8
I
a
H. Weigma
ii
o
g
Si
4
: a • 5
M'1*
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• -3 • -2
.a p, cs
W OJ CD
MOqiuux
PH
IM PS
So
*; •* to co
co m' to'
^j (M to 10 o
— t- CO r-( t-
S so' to t-^ i-i
= -
So
•« in co
S <N !•-
S to m'
£ o
a ~
g •§
20393— No. 13-
FOODS AND FOOD ADULTERANTS.
Means.
Maxima.
Minima.
|| g
»i O 00 t~ t- CO T-I t~ 01
» co i- o -H o m i-c c-
i g S
§
CO -*
o •
00 •
s
0
t
<N
CM CM
|
1
«5
A
01
|
S3 .3 14
• 00 O t; i* CM CO O
§8 e
^i in
CO O
CO §5
IS
CM
in in ir
} m m if
S t- 0
m a
t- i>
~ -
co in
1
£
i
•* CO C
CO t~ -^
i t~ m o
f CO O C!
> ao i-
• 00 '
§ el
rH. CM
OS 00
00 1-
00 CM
•* -* m -t co eo -* co m ; co -* o co — m
|i{li|
|
-H M m o> in c<
t» t^- m t- ^ c£
3 •* 00 CO •
> CM rH •* ,
a
CO 00
Si-<
in
•
O 00 (M CM 0 T
CM .-1 CM CM CM i-
HO f
•< CM i-
> 00
CO
CM
§ s
8 "
s
••JO CO -!< O •* CM 00 If
« CM CM CO CO 00 00 CO Ol
00 '•
o
O C!
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CM
O
j
1?
m -* t-
CO CO CC
CO i-
in |
a s
;
CO
|
M
9
ftj
CM CO
s °
CO O!
CM CO
o
8
H
OS COOOCMCOOCM cr
!S S
l> CO
CM CM
CM CO
§in
CM
B
« rH CO" — CO i-< 00 O CM 00 i-l
gK CM CM CM CM CM, CM CM CO CM CO
co" 06
CO CM
— —
— CM
rH CO
ill
I
CM m
•- CM
•* m oo
CO Cfe CM •
•^1 00
OS
O
CM (M
rl 0 ^ • ~ r-l •
CM
ti
1
O CM r-
m co c-
< rH 00 « t- O CM O
s §
t-l ITS
m CM
m o
CM in
§
in
S3 S3 ?
i o in *-
1 S {?
CM 2
•«• t-
co in
•-C O
I
•g
S.
^H r- o CM o o
00 CO i-l tO — -J
» CM t- rH O
< •* CM OO CO
t^ o
00 O
CO O
co in
l-H CO
O CN
00
CM
co comt— t--cDin ^co^
CO 00
in t~
•H" t-
•88s£l«tre jo -oj{
•s
r-r
-1
1
n
-* ^ a
00 CC O
oo oo oc
00 00 OC 00 CO CO O
00 00 00 00 00 00 00
00 00 00 00 00 00 OC
oo a
oo oo
00 00
a
m
00
00
1
1
"S.
•g
Q
Cocoo poivders— Continued.
Gerb. Stollwerck's, Cologne-
Continued.
. ( Acorn cocoas
- Saccharine cocoa
Chocolatet.
i, Sweet chocolate
4 marks per half kilo
2.40 marks per half kilo. .
. Lobeck &. Co. 's, Dresden
. P. W. Gaedtke's, Hamburg .
. C. S. Van Honten & Zoon's
Amsterdam.
...do.. ...:...
. P. W. Gaedtke's, Hamburg .
8 Holland cocoa powder
. Van Hpnten's
. " Nahr-salz-cocao, " Hewel £
Veithen, Cologne.
I
a
^
a ;
i S :
! .a
1 n
See not*)7
1. Kiinigand M. \V«?H
J. Konig, C. Krauc
J. Cosack and H
Weigmann. •
21 :
: 3
....do
h'riihling & Sc
lelohoubcrk s-
:. iii.s.-iuoff«-
«> !> S
iSH<§f9. <S<8£ie e
M •g -•:.. i'.. :.:.:: a
^ a i ; i ; ; : *
• I-'MIUM V
V t- 00 O =•
ci « t m
•- i.
00
rH
*
ANALYSES OF COCOA PREPARATIONS.
965
00 O IO
I-H o m
no _S ,2 OS
CM rH TO 00
in i- •*
in r-i in
TO co ^r
o in o
CM in cd
CO OS
CD Tf
O O
t- "* t-
oo os a
CO 00
•* •« ^
< CO CO
r
OS rH O
CS TO C
1 0 00 "
m co
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tilo.
5 marks per one
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966
FOODS AND FOOD ADULTERANTS.
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"Nahrsalz-cliocolatc, " I
. Veithen, Cologne.
French chocolate
do
do
Spanish chocolate
do
do
Chemie der menschlicbei
him. d. Phys., 1883,443;
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COCOA BEANS, HUSXS, AND CHOCOLATES.
987
J.a'gg
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8 8 §'8 i
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968
FOODS AND FOOD ADULTERANTS.
Table showing the quantlialirc relation* between ihe constituents of the cocoa bean (calcu-
lated by Bensemann from the analytics given in the table on page. 967).
[S = starch, F = fat, U = total organic matter insoluble in water.]
S
F
S
F
S
U-F.
U-S.
U.
U.
F.
Air-dried, husked beans :
0. 4289
0. 7395
0. 1636
0. 6185
0 2645
0. 4074
0. 7273
0 1578
0 6125
0 2577
Trinidad
0 3452
0 7297
0 1247
0 6387
0 1953
Machala-Guayaquil
0. 3583
0. 7330
0. T297
0. 0379
0 2033
Portoplata
0. 3660
0.7734
0.1481
0. 6589
0 2247
0 3946
0 7406
0 1446
0 6335
0 2283
Air-dried husks :
0. 1390
0.0412
0. 1341
0 0357
3 7564
0 1595
0. 0356
0 1479
0 0304
4 8674
Trinidad
0 1515
0. 0467
0 1455
0 0399
3 6413
0. 1272
0. 0402
0. 1227
0. 0352
3 4827
0. 1850
0. 0797
0.1728
0. 0660
2 6202
Means
0.1508
0.0484
0.1446
0. 0414
3. 4920
Chocolate in cakes, German manufac-
ture, and composed of the hiiaketl
bean and sugar only :
0. 3838
0. 7303,
0. 1438
0. 6253
0 2300
0 2476
0. 7161
0 1314
0. 6220
0 2112
1.60 marks per one-half kilo
0. 3310
•0.7226
0. 1207
0.6354
0. 1899
0.3029
0. 7035
0. 1141
0. 6232
0. 1831
1.00 marks per one-half kilo
0. 3729
0.7490
0.1298
0. 6517
0.1992
0 3480
0 7245
0 1282
0 6317
0 2029
ANALYSES OF COCOA ASH.
969
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Means (of 6-10
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Maracaibo
Caracas
Trinidad
Machala-Guayaq
Portoplata
Jahresb, 1851 : Wolff, A
LandwirtlischafT, 2. 2.
Fahresb., 18(50, 549; We
itsch., 7,311; Chera. C
Bl. d. Vereins anal. Ch
Analyst.
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970 FOODS AND FOOD ADULTERANTS.
RESULTS OF THE EXAMINATION OF COCOA PREPARATIONS IN THE
LABORATORY OF THE U. S. DEPARTMENT OF AGRICULTURE.
As cocoa preparations are always sold in the original packages of
the manufacturer, the purchase of samples does not need to be con-
ducted with the care and precautions that are necessary in the case of
many other food materials. The samples examined were all purchased
in Washington, D. C., and represented very nearly all the brands
obtainable at the time the purchases were made.
In accordance with the law that provides for these investigations, a
full description of each sample is given in the table on page 971. Each
description is accompanied by the laboratory index number and a con-
secutive number for use in reference to the table of results of analyses
that is given on page 980.
In the column headed "Weight of package and cost" the size and
nature of the package and the purchase price paid in the retail market
are given. The price per pound as given in the next column is calcu-
lated from these data. In a few cases where the weight was not given
on the package the price per pound is only approximate and is placed
in parenthesis with an interrogation mark.
The rather extended quotation of the manufacturer's descriptions of
the samples is necessary to do justice to the manufacturers of both
adulterated and unadulterated preparations. In several cases the addi-
tion of material that should otherwise be considered adulterants is duly
acknowledged on the package; in other cases no mention of the fact is
made or the statement implies that the sample is pure.
The variety of preparations offered to American consumers is certainly
very great; so great, in fact, that a satisfactory classification of them is
hardly possible. In the following tables no classification was attempted,
further than a separation of plain and sweet chocolates into groups by
themselves :
SAMPLES OF COCOA TREPARATIONS.
971
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C.
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pq
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st cocoa
id
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Where and by whom manufac-
tured.
Walter Baker & Co., Dorches-
ter, Mass.
S
m'
a
TJI
3
6
W
delphia, Pa.
H. Maillard, 1097 Broadway,
Rockwood & Co., Xew York ..
Ti
o
s
c
o
o
tcenth street and Irving
Place, Xew York.
Runkel Brothers, Xew York..
Stephen F. Whitman & Son,
ci
fc
2
^ft
T
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S
E. G. Whitman, 812 Chestnut
£
~
|
3
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|
Schilling, Stollwerck & Co.,
Cologne.
H. I. Rowntree & Co., York,
3
c'
W
W. Baker & Co., Dorchester,
Mass.
gfi
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53
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etail dealer fro
chased— all W
C., XW.
urchard, corne
Half street an
ilia avenue.
...do
. G. Cornwell
sylvania aveni
^
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9
W
F street,
reat Atlantic
lea Company,
. G. Cornwell .
sylvania aveni
. E. Kennedy
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972
FOODS AND FOOD ADULTERANTS.
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S pound in paper, 25c.
t pound in paper, lOc.
pound in paper, 60c.
pound in paper, 75c.
pound in paper, 'Me.
Far, 50c
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Label on package, together with statem
regarding ingredients, etc.
Maillard's Vanilla Chocolate
Caracas Chocolate, vanilla flavored
Double Vanilla Chocolate
Triple Vanilla Chocolate
Chocolate- Menicr, fine vanilla quality ..
Peerless Vanilla Chocolate
cS
I
«
q
Chocolate a la Vanille
Zoete Vanilie Chocolade
Maillard's Sweet Chocolate
Panama Sweet Chocolate
Fry's Diamond Sweet Chocolate
Frv's. Siv-PPt rimenlntft
Unrli uiioil iV t.'n.'s Sweet Chocolate
German Sweet Chocolate
Where and by whom manu-
factured.
H. Maillard, 1097 Broadway,
New Tork.
...do .
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r£
N
do
Menier, Xoisiel, France
Hawley <fe Hoops, Xew Tork .
Fullie <fc Co., Caracas, Venez-
uela.
(Xo name given on package) . .
Bensdorf & Co., Amsterdam,
Holland.
H. Maillard, 1097 Broadway,
M '•
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Rockwood & Co., New York..
S. German, Dorchester, Mass .
Retail dealer from whom pur-
chased — all Washington, D.
C., NW.
L G. G. Cornwell <fc Son, Penn-
sylvania avenue.
. S. R. Waters, 1342 Seventh
street.
L G. G. Cornwell <fc Son, Penn-
sylvania avenue.
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. S. I. Bradley, 1315 Fourteenth
street.
. S. R. Waters, 1342 Seventh
street.
. John S. Cissel. 1014 Seventh
street.
. P. R. Wilson, corner Seventh
and K streets.
. A. O. Wright, 1632 Fourteenth
street.
. H. H. Elliott, 1520 Fourteenth
street.
. G. E. Kennedy & Sons, 1209
F street.
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SAMPLES OF COCOA PREPARATIONS.
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Paris Sweet Chocolate . . .
Vienna Sweet Chocolate .
French Sweet Chocolate.
Gerhard Schmitz's Sweel
Chocolate.
Crown Sweet Chocolate..
Broadway Sweet Chocola
Wilbur's Vanilla Sweet C
Rock wood ft Co.'s Dutch
Tlotov'a Prwnn
Breakfast Cocoa. "This
hy a peculiar process i:
which preserves the tin
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Atlantic and Pacific Tei
pany, 501 Seventh sti
E. Schweitzer, 1308 S<
street.
......do
Ninth and Q streets.
D. Mazzochi, 1504 Four
strcrt.
J. W. Ruppert & Br<
Win. R. Brown, corner
sylvauia avenue and
tieth streets.
Philip H. Ward, corner
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important dietary properties as cocoa.
While acting on the nerves as a gentle
stimulant, it provides the "body with some
of the purest elements of nutrition, and at
the same time corrects and invigorates
the action of the digestive organs."
"Medical men of all shades of opinion have
agreed in recommending it as the safest
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"The excess of oil having been removed,
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of this preparation."
Breakfast cocoa: " Wilbur's cocoa is manu-
factured from the choicest cocoa bean,
with the excess of oil removed."
"Van Houten's Pure Soluble Cocoa is not
raw cocoa, but a greatly improved and
highly concentrated cocoa, in which the
proportion of natural fat is properly ad-
justed, and in which important constitu-
ents are rendered more soluble and useful.
while the flavor and aroma are most highly
developed."
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975
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London Cocoa: "Caracas and other cocoas,
scientifically blended with sugar and ar-
rowroot. It is guaranteed free from other
substances, and being deprived of all in-
digestible matter, by a process peculiar to
this manufactory, is a perfect nutrient for
the sick, aged, and children."
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Walter Baker & Co.'s Premium Cracked
Cocoa.
Maillard's Breakfast Cocoa
Maillard's Dietetic Cocoa : •' This cocoa is
made on the homeopathic principle by ex-
tracting a large percentage of the oil or
butter, and is especially adapted for the
use of invalids and persons whose condi-
tion requires such nourishment as will not
interfere with digestion."
Fry's Cocoa Extract: "We guarantee the
absolute genuineness of this pure and de-
licious cocoa, which consists of choice co-
'3
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a
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has beeii extracted."
Fry's Malted Cocoa. "A combination of
Fry's pure cocoa extract (cocoa deprived
of the superfluous oil) with Allen & Han-
bury's Extract of Malt."
Eockwood & Co.'s Breakfast Cocoa
Eockwood & Co. 'a Table Cocoa
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hillips' Digestible Cocoa. " Cocoas and
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(cocoa butter) in the pre]>aration of the co-
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value of the cocoa as a nourishing drink.
i this preparation the fat is wholly re-
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couditian for easy assimilation— by means
of ]iancreatine (nature's digester of fats).
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while it is being made iip for the cup — and
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acontinued useof this preparation will not
distress the most sensitive stomach, nor
cause headaches ; and no grease will be seen
coming to the surface, as with the ordinary
cocoas or chocolates. All the nutriment of
i-!
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SAMPLES OF COCOA PREPARATIONS.
977
hest cocoa may therefore be had by
stdelicate and without disagreement.
proportion of the soluble phos-
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d Cocoa. ' ' Cocoa contains a bland
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necessary that the imported seeds
Trinidad and Caracas should be
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eparation of the cocoa contained in
in we guarantee that no other in-
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regarding ingredients, el
Bensdorp's Pure Soluble Cocoa. .
i Brook's Prepared Cocoa
Huyler's Cocoa
Walter Baker & Co.'s Broma.
is a combination of tho cocoi
other ingredients, invigorating
able, both to invalids and to ]
health."
Henry Maillard's Broma . • • Bron
composed of the nutritious pr
rived from the cocoa bean, by e
the butyrous matter."
Wilbur's Cocoa-theta. '• Invigon
dyspeptic, powdered ehoco]
ranted strictly pure, * * *
all the nutritive properties of
bean, while eliminating the tr
qualities."
Racahout des Arabes
Schweitzer's Cocoatina. "Ant
cocoa or chocolate powser. Tl
preparation is the highest cla
ble cocoa or chocolate, being
•all cocoa,' with thu .
tracted.''
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Bensdorp & Co., Amst<
Holland.
C. D. Brooks, Dedham, "
Huyler, 18th street and '.
Place, New York.
Walter Baker & Co., DC
ter, Mass.
H. Maillard, 1097 Bros
New York.
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Walter Baker & Co., Dt
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H. Schweitzer & Co., L
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,a
2 S
§1
o
a
=
~~z
cc
t,
S 2
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£ *
o
o
o
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Ei
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1 1
S a
delicate.'
reakfast
De Jong
e in cold
P- *"*
-^ c;
-*j
W
-
>
<l *
ca
s natural
so treated
if the inos
es Arabes
o
1
1
c
will disso
Alketbrept
chocolate
nutritiou
which is ;
stomach (
Racahout d
a
a
o
ca
'W
""Windmill
ble cocoa
6
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,M
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ill
cj
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cj
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3
CO CO iH
20393— Ko, 13^— §
980
FOODS AND FOOD ADULTERANTS.
•jaquinu [ri.i.i^
i
r-
i-
S
OS O
00 00
to c-i
oc S
IN
i
o o
IN CO
00 OO
00
ill
oo oo oo
jaqiuuu OAi^naasuor)
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-T l.t tO
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r^ ^«
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5
55
1C t-
to -*
CO CO
2
m to
IN
K OS ?1
1C CO O
co m oo
CO 1C CO
ci
<N
IN IN
CN (N
CO
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CN
IM IN IN
IM IN IN
8
S
1< 1i
9 3!
IN
t-
c5 §
§
00 to M
3 S 5
•a -BAiuba ppv
a
- BAinbe ppv
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8
o in
in -t
iA o
CO O
in ic
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a
IN
Sin
00
in
it in o
•M tO O
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o o in
1C 00 O
IN • <N <>;
o
1
•qeu ]B}OX
"S 00
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X
3 2
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§
£ i"i
to
to
IN i-l IN
o oo in
to 00 1C
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•aaqu opiug
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S S
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co o: o
CO CO r-c
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£ S u i o n p 9 j£
£
a a
a
ill
O C IB
a s a
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to m
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»n »— c t>-
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co -r
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CO O OS
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2
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t- m
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m
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.71 (7*1 Cl
•ajnjsiOK
» §
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oo r~
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t- in
00
00
r-l H
o
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oo es in
00 OS tO
tn in oo
in in oo
it; «
CO
CO CO
IN 1<
rt
rt rH
IN
00
' 9
! ! '3
a
h
i
a
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^2
: : n
• ' —
a • ; ;
c f
~a
a
H
g
S
t>
•B
r3 rs S
i i^
5 •=,£.£
B cl ; |
Microscopical exan
Foreign starches.2
Much wheat starch
Much wheat flour
0
Much wheat starch
0
Much arrowroot
o
o o
Very small amount of
arrowroot.
o o o
- - i
,-eneuH
«
IN
-1
e-> .-i
M
C-l ^ IN
IN IN 0
*
1
i
"S
•
S 7!
1 §
5 A
o y
C
i
ll 1
1 :
B
: R
3
a
M
•« *
•
"o
!
5
2 S -a
3gl
00
o
t
n
Plain choeol
Baker's Chocolate
Wilbur's Chocolate
Maillard's Chocolate
Rockwood'o Chocolate . . .
IIu vler's Chocolate
Runkel Brothers' Chotola
Sweet chocola
S. F. Whitman & Son's
Chocolate.
K. (1. Whitman's Powder
Stollwerck Brothers' Prii
Rowntree' s Powdered Ch(
IJaker's Vanilla Chocolat*
Maillard's Vauilla (,'hocol.
do
Maillard's Double Vanillf
Maillard'rt Triple Vanilla
( inn iilat-Menier (with va
Mc|Miini ;>Aiin;»t)HUO3
-1
IN
CO 1C
lA CD
*•
00 OS
o
S 2 S
-t it •-;
i ic|iiinii p:i.i,.s;
B
£
3 1
to ri
-. M
Cl
e>
;• a
i
j S !r!
o Q
ANALYSES OF COCOA PREPARATIONS.
981
00
oo
00
00
00
00
00
00
00
•
00
00
00
1 In the column headed "husks" the following signs are used: 0 signifies that no characteristic husk tissue could be found ; 1 signifies that the husk has probal
been mostly removed ; 2 signifies that the husk has possibly been partly removed ; 3 signifies that the husk is probably all present ; 4 signifies that the husk that belongs
•the seed is present and probably more.
2 A zero (0) is used to indicate those sanvples that contained no foreign starch. The distinction between wheat starch and wheat flour is neither close nor importa
When bran structures occur somewhat abundantly, it is put down as wheat rtour; otherwise, as wheat starch.
1 All ashes were white or grayish white.
4 The acid equivalent is the number of cc of decinormal acid required to neutralize the ash from 2 grams of material.
8 The numbers in this column are obtained bv the following formula : acid ecmivalent +- ner cent ash— facld eQulvalent X .0053 X W0\_th Ilumber rnven.
t-
00
OS
s
s
§3
8
CM
m
S
s
CO
<M
s
i
00
s
s
00
o
to
00
•-i
O
§
CM
;
CO
is
•ri
•ri
s
CO
•*
s
8
§j
*
i-H
3
O
s
r-i
c-.
2
i
s
o
t-
c4
m
t-
CM
§
1-H
m
*
00
m
55
CM
0
-r
o
1-
i
t-
OS
00
00
CO
to
t-
to
I-H
8
00
CO
S
S
to
00
i
os
CM
2
co
CO
T-H
00
OO
*
CO
r-t
s
o
1-1
s
Much.
to
fl
o
a>
o
ft
o
i
fl
o
to
i
IS
i
cc
®
1
fe
5
H
Much.
<D
O
2
H
CM
I—
OS
m
s
s
m
m
8
*
s
S
5
OS
m
3
t-
os
Os'
£
CO
CO
m
C)
§
o
CM
S
oo'
s
CO
to
0
-M
00
S
00
:
*
CM'
OS
00
CO
o
00
CO
OS
-d
O
g
H
0
c-i
No vanilla tissue
could be found.
Vanilla and cin-
namou.
No vanilla tis-
sue.
Cinnamon and
a very small
i
Vanilla
1
1
5 ^
i
i
o
o
Mnch wheat flour
0
Small amount wheat
starch.
Considerable amount
wheat starch.
Much wheat starch with
some arrowroot.
Some wheat flour (not
as nr;ch as No. 24)
and arrowroot.
Much wheat flour
»
o
Much wheat flour
Much rice starch
CO
<M
^
"*
CM
„
CM
CM
CM
O
CM
TH
CO
Hawley & Hoop's Peerless Vanilla Chocolate .
2
1
'C
-
"3
CS
_CS
a
t— i
ci
."2
Chocolate.
Chocolate a la vanille (no name on jiackage,
bought of S. B. Taylor, 1610 7th street,
Washington, D. 0.).
Bensdorp's Sweet Vanilla Chocolate
Maillard's Sweet Chocolate
Maillard's Panama Sweet Chocolate
1
5
4>
B
(s
BQ
•O
c
3
P
1
>>
«2
hi
J. S. Fry & Son's Sweet Chocolate
Rockwood's Genuan Sweet Chocolate
S. German's German Sweet Chocolate
Mexican Sweet Chocolate (no name on pack-
age, bought of G. E. Kennedy & Sons. 1209
F street, Washington, D. C.).
28 Wilbur's Paris Sweot Chocolate
29 Runkel Brothers' Vienna Sweet Chocolate. .
S
00
OS
o
CM
CM
CM
8
•j
CM
?,
C-l
i
OS
00
i
OP
i
-f
OS
00
op
m
OS
00
cc
rH
CM
00
OS
00
r-
c;
o?
oo
CS
05
c:
a.
DQ
c-.
982
FOODS AND FOOD ADULTERANTS.
.1,11(1111111 |i:j.|.is!
ill III Hi ii II
•MH mini oAi^iuasuof)
co co co - — ' ~ fc °o co 0 -1 CT ec
3
V
1
a
H
5
«
•ij o^oa iooj sat;
go i~ to to in — i to •HI t- tooo oco
ci c^J ci cir-ico ri t i ? i co'ci coci
-BAtnba PPV
30 in i-osoo csmoo tooo o m
to -<t mc^in -*-*co ooco osm
WiTW
.0 o o oininminm
<- to i- O<MO et n f'l oos »os
CO C*i r4 icir-ic-l J 1 - 'J tOCO to'-*
•qWX
uo r~ ^t-o oin-ti ~r s-i ao t~
.CM to r-( COOSCO CNOin COOC ,-VrH
(^ S* r-i r-i rH O r-i •<)• irf -^i OO CJ OO C
-,«,»»,-.,
t)CS C CO IO-*QO C-JCOOS OOCO Ifl •?
.OS CM r-4 OSl^r^ O(NI> COr- -^CS
ft, *1 rH -*CO-*M-*M
i
3
OB
SnTotp'W
1 1 ,i 1 S 1 i
'A A fa -Ji H ^ -7.
^Stla
^-* co o riinoo M
™
"S i- •* m -t in in m oo t- oo rn m oc
(^ C-I rH Cl rH M Cl CO (M CO ci rH <N S
•^OK
•g m -* — — . : : : : : : : :
£ r-i rt r4 C-J I
Microscopical examination.
J3
i
i
§ :•:::::::::
S | j
<c
rO
E
a
1
I
£
® O
3 "^ -*3
<§ i «
r^ CO K r>
,-«[snH
•* 0 -* IM H Cl CO -H Cl rH SO CI
•
"3.
1
tc
t—
o
d
_o
D.
•C
o
1
,« 5 =• -: ri ~ : : : : i * '•
|s 1^ |3 i : ;;• x ;
oco ola a 2! z - III
Sfflpos S ^ . "3 S "S t> 9
c p N •£ £ s •=' 032- : -y =
-s-s~go 2 - . r. ^ •= ~ : ^
isiol'gsl5-l5i ; -5 «
9 f"f d -a * Saxl0"23 «« ® r t5
I 4 * rf 1 * S 3 ° r» f 1 1 §0 t* 2C!
OBM o«o M ^ - «• £ Z V fi u.-> ^r
ll«11l-ilrflt|*l 5 « go «§
!|rifr!ir?l^f Hl< ll IS 'f:
iilill^niliiLii 2 5 1 1 1
I!:
1$ J**J^*|fl iif jJ^SI
.!•!' 1 Illll II . l.\ 1 | II .I.IM H ', )
g S 8 Sg^SSg35!93
•j.jqmmi i«uos
i I i III iii if ii
ANALYSES OF COCOA PREPARATIONS.
983
CC t^ PI -*
{: § S S
32 1
IH
•- o
&| I
03 ^ T*
CMrH PJPJOpirHCM
PI PI PI
•*> a pjoscooocoot-o-i"-*
•«pi •oiTji^cioooeo'McoiOin
rHrH rHrHOrHOrHrHrHrHrH
IO 10 IO
c-COlOCOCOrHOOCOPICO
COCOrHOJpirHCOCOPj'-*
22
•S
OS CO O IO PI
*# T-I CO CO — _ — — - -
PICS l^PJPJOrHCSO
II
a -s
wtj
5
= I
-55°
«» a Bi
B
io *a cc o co
CO
rt
CO CO
,,COrHCOrHCOP»^rHPI rH £ „ jg X S =.
•
o
o
s
®o •§ ® 8 *> o S - § S "*
§ § a § I § *| 1 J •§ •§
^ ^ E & H fc -8 * .., « JS £
CO
§
r- o 10 10 10 oo 2*3 g ,j^ « »
COPJ CMPJ1OIO d>,' «^ 00 3
83 '« "ct-S 1 S
S
§
OS O
PlCOPIOO'rllOOOOi-IPIOS OOO
rHt-l-TKOSOSI-COCOt- rH-r* «2^ " 3*2
CO
PI
O OS
CO rH
^ J2 a * * §J^ g 2^
1 II
.2 *r|
:::::::::: 2-^® §«§a^S^^
:::::::::: ,23^ ^S-SS^ffel
III!
: •
MMMMM iiiifilill II
Considerable amountof ..
wheat flour with
some arrowroot.
Considerable amount E
of arrowroot.
0
Very small amount of . .
arrowroot.
::::::-.::: ° «„ H= =3 g 1 »
rd ... . — rH '3 r» 10
j N if ilPllW
i i i i !<i Ha|?i»
"riTn i ^t^f! i!
t* 3 t* S^fc* gaoa£go«g
^a -a -a ^a-SK^o saa^r-^at,^
§ § § § 1 -s § •§ el ll 1 1 Sla
»-,»»» 5 a »£ 1? II Ss-s
T)— ' 5 - § ^ B 412
PI
PI
-H rH
CMCOCOOCOCMCMPJrHPI COd y,'S 3 * *•• "3 ^ +* ®
. "So " -g ^o §.a2
1 0
: : |~ jg "g ^ §|Aj.
8
"S 6
1*1 1 "|si|^ 1 s|g
Maillard's Breakfast Coc
5
B
®
3
'S
J. S. Fry & Sons' Cocoa 1
J. S. Fry & Sons' Malted
0 § 1 j -g § ^ |5lc|ti § -:'"
ill I ill ii lltil&llllJ
HISJ^ i H! ;Hl !:i5ll.
«H |i||| !i| || l-s-alliis-fH
il^llPiS ^1 'ill lIlS -15*
ina>-^AH£<0!!'S K d®2-?>-'Hr3S-— 3
11 II III 111 H
«MDH«WMSW»3 ^S o^^H-S? 2 S S-sJ5
. . .S-S'KE; =; 5 5 a 8« §•'
00 CS O rH
rH rH PJ C?
•J M>
t 05
984
FOODS AND POOD ADULTERANTS.
•aaquiun rBuag
•H \n m cs m
r* r-l OO 00 OO
OS OS OS OS ••*
00 00 00 00 O
stic husk tissue could, be found; 1 signifles that the husk has probably been
e husk is probably all present; 4 signifles that the husk that belongs to the
ction between wheat starch and wheat flour is neither close nor important,
wheat starch.
rom 2 grams of material.
.,,„* ...i, /'acid equivalent X .0053 X K>0^_f1lr> T,,lmlwr irtvm
V 2 J
Formula for the preparation of racahout (Pharmaceutical Record, 1892, 13, 305): Powdered chocolate, 1 pound; corn starch, IJ pounds; powdered salep, J pound; sugar,
ands. Vanilla to flavor.
•jaqomu aAtjnaaetiog
0 .-i IM rt •*
•9 9^OU !}OOJ S»9g
•* 1O CO -f -t
•^1 t- 07 O! O
e-i CM ci r-i co
t'qSB (JU93
„ J9d -j- !jnai
-j -BAinba ptoy
o •?
OO O CO 00 CO
•* 05 -* (N 00
f-1 »-! ^ r-H rH
,-ve»\
3 -WAinba ppy
s
»-» <N 0 0 ^
°oS ci rt to 3
§
g -qsi: IBJOX
•a
^s? ss s § s
£«e i-5 d •* t^
•Jtaqg apiuo
£
'a o «o c-i o
.t- !M in OS
j^CO r-i CO
•sjBSns
g Snionpoy;
fan
03 §
9 *
o G
^ H
cc -adonsuBiod
A"q 'jBftllB OUBQ
1
">BJ
^•co to n t?
y i-H rH TJ CS
i* 1-1 O t-^ O
£JCO <M C-
'9jn}8lOJ^[
^ !
•
1
— p
O
Pd
3
cS
'3
1
ins are used : 0 signifles that no character
[y been partly removed ; 3 signifies that tli
it contained no foreign starch. The distil
t is put down as wheat Hour ; otherwise, as
normal acid required to neutralize the ash
I
H
® °*.
•a |
0 A
'Si h
O c3
0 •£
00 00
o fce
^ 1
1-H
c •
i! ^
'E p
•s 1 s
i : «
0 « 2 - S 0
a cs » o
§ = -S B
S ft p *
JS JS cj' — -g
§ § « 1 2
« S 1
,-8j[8nH
-H W rH W O
Description of sample.
Schweitzer's Cocoatina
Smith Manufacturing Company's Alke-
threjita.
DeLangrenier's Racahout des Aralies G. .
Hawley <fc Hoop's Breakfast Cocoa
De Jong's Cocoa
In the columu headed "husks" the following si
,ly removed; 2 signifles that the husk has possib
is present and probably more.
A zero (0) is used to indicate those samples th
sn bran structures occur somewhat abundantly, i
All ashes were white or grayish white.
The acid equivalent is the number of cc. of deci
Tl,.. i,ni.,l...r< in tin* , olii.ni, an- ni.t :i i n.-il l,v til
•JOqwnn .> \ i IID.IHIKI, )
g s @ SS 3
i »|iii ini |i-i i >-,•
r1
s"2 •*
ii *
a
*
SUMMARY OF RESULTS OF ANALYSES.
985
Summary of the results of analyses made in the laboratory cf the U. S. Department of
Agriculture.
M
a m
s-S
Samples containing sugar.
q §
•
00 ."S -•
0! 0
Ml
tc
M
tii
"g,
-2^ a
t1^
r^ G
PH=« o5
Is
G+J
s?,
8 <J
is
a ^
11
• eta
*>a
Character of samples.
Ifs
<w OS _a
0— "o
« t*2
O'tJDcS
s »
8ft
11
It
III
o "-1
« 0
ii
3 «
1
t, st£
3 H «
|'S|
||
I!
I!
,3 O
a
S'S<M
SIO
a o
a o
9
W
^
*
^^
£
^^
4
30
11
8
22
8
12
6
7
i
3
Total
64
27
14
7
i
25
8
Determinations made toshoiv the soluMUti/ of cocoa and certain of its constituents in water.
b
J3
a
1
In tbo air-dry sample.
J3® J2
f' ^ ^,
01 «
Portion soluble in water
a
o
?
o
p
Total ash.
Total
r,oc.
Total mat-
lei' soluble
in water.
contains —
Il|
*4|
£
D
BD
Ash.
PA-
"s -I--2
"a^^
^o
fc'" Pl°
8^4 WW
38
40
42
43
0899
6893
G901
8889
Per cent.
5. 05
8.64
8.48
3.17
Per cent.
Per cent.
18.27
19.84
Per cent.
3.87
5.77
Per cent.
1.27
1.02
0.87
0.80
77
67
1.99
1.71
0.94
51
51
85
11.28
2.70
85
51
8909
G.OG
1.72
17. 92
2.27
1.27
37
74
53
64
8913
10485
6.95
7.89
1.94
19.17
19. 70
4.21
5.36
0.77
0. 95
Gl
68
40
Before proceeding- with a discussion of the results obtained in tins
laboratory, a brief review of the methods proposed by various analysts
for the judgment of samples and the interpretation of analyses is not
considered out of place.
The Association of Swiss Analytical Chemists' regards the following
determinations as absolutely necessary:
(a) Microscopical examination for foreign starches, cocoa hunks, Hour, etc.
(1>) Quantitative estimation of inoistnro (in cocoa powder), ash, fat, sugar (in
chocolate), and liber.
(r) Taste, odor, and color of the aqueous infusion, as well as the appearance of
the surface of fracture in cake chocolate and cacao-masse.
It is sometimes of value to determine —
(a) Quantitatively: Theobromiue, tauuic acid, and starch.
(b) Qualitatively: Fat and ash (for alkaline carbonates, mineral pigments, etc.).
Not more than 2 per cent of alkaline carbonates iu soluble cocoas is considered
allowable by this association. The ash in normal samples of cacao-masse may vary
from 2 to 5 per cent ; the fat, from 48 to 54.5 per cent.
1 Op. cit., note 3, p. 949 of this work.
986
FOODS AND FOOD ADULTERANTS.
Mansfield1 states the average amount of starch to be 5 per cent in
chocolate and 10 per cent in cocoa. He also gives the maximum amount
of cellulose as 2.5 per cent for chocolate and 5 per cent for cocoa.
Bensemann2 proposes the determination of water-insoluble organic
matter (=TJ), fat (== F) and starch (=S), as a means of judging the per-
centage of cocoa and flour in chocolate. He calculates these percent-
S
ages from S and the coefficient which he calls the starch coefficient.
U-b,
The following results were obtained by Bensemaim:3
I.
II.
III.
IV.
V.
VI.
Per cent insoluble organic bodies dried at 100 to
110° C — U
69.0
35.5
36.0
37.0
:i7 o
30.0
Per cent fat, extracted with ether, dried at 100 to
110° — F
28 0
22 5
21 0
17 5
19.0
6.5
Per cent starch, estimated aa starch sugar by amount
CuO, — S
13.0
4.5
8.5
12.0
11.5
17.0
0
Starch coefficient —
0.317
0.340
0.567
0. 615
0.639
0.723
U— F
I. Was so-called soluble Dutch cacao.
II. Table chocolate (about 60 parts sugar, 40 parts cacao).
III. Crumb chocolate (about 60 parts sugar, 25 parts cacao, and 15 parts flour).
IV and V. Table chocolate (about 60 parts sugar, 20 parts cacao, and 20 parts Hour).
VI. Chocolate flour (about 60 parts sugar, 10 parts cacao, and 30 parts flour).
Filsinger 4 makes the following recommendations:
Quantitative determination of ash (qualitative examination, if asli runs above 5 per
cent in cocoa and 2.5 to 3 per cent in chocolate), fat and sugar. The fat is also
examined qualitatively. The microscopic examination is considered very important.
Herbst 5 determines in chocolate: Moisture, fat (quantitatively and
qualitatively), ash, and sugar; and makes a microscopical examination.
The ash should not exceed 2 per cent.
The following is abridged from Bernhardt:6
In many cases chocolates, to which a large amount of flour and starch has been
added, must be colored. The author found a Spanish chocolate, which contained
3.2 per cent ash, to be colored with 1.5 per cent ocher. As these additions are only
assimilated by the chocolate in proportion to the amount of fat present, the addition
of coloring matter necessitates the adulteration with foreign fats, so that we may
obtain a chocolate that contains no cocoa whatever. The author has in reality found
chocolates which consisted of cocoa-remnants, fat, sugar, spices, and coloring matter.
As cocoa butter is quite expensive, other fats are often added, and this writer there-
fore considers the examination of the fat as the most important test. The following
fats are mostly used as substitutes; cocoanut butter, rasped eocoanut, liaxelnuts.
almonds, animal fats, margarin, cotton and sesame oils, etc.
1 Op. cit., note 1, p. 950 of this work.
* Rep. f. anal, chum., 1883, 119.
3 See also tables on pp. %7 and !»(>S.
4 Op. cit., note 7, p. 938 of this work.
' <>i>. <•'<>., note I, p. !>50 of this work.
•Z.Nalmiiigsm. llyg., 1 «!»(>, I. 1J1.
DISCUSSION OF RESULTS OBTAINED. 987
Vanilla, and vanillin are often replaced by balsam Pern, storax, toln, and gum ben-
zoin.
The melting and. congealing points of the fats and of the free fatty acids are no
indication whatever, as pnre cocoa butter shows great variations.
Legler1 regards the cellulose determination as an uncertain means of
detecting husks, because the results vary with the method used.
DISCUSSION OF THE RESULTS OBTAINED.
While the time at our disposal has not permitted as thorough an
investigation in some details of the work as seemed desirable, sufficient
data have been obtained to show the general character and extent of
the adulteration of the cocoa preparations sold on our markets.
The determination of the ash serves as a means of determining the
extent of dilution with foreign materials (the nature of these materials
being known) of organic or inorganic origin. The per cent of ash
decreases with the addition of substances low in ash, as starch, flour,
etc. ; increases with the removal of fat, the addition of mineral matter
for weight or color, or the addition of alkaline carbonates in the process
of manufacture. The percentages of ash, fat, sugar, and starch must
be considered with reference to each other in order to determine whether
any one is abnormal. Any addition of mineral matter that could pos-
sibly be of value for increasing the weight or color of the preparation
would certainly render the ash conspicuously abnormal in amount or
color.
For the detection of the use of fixed alkalis in the process of manu-
facture, the number of cubic centimeters of decinormal acid necessary
to neutralize the ash from 2 grams of material was determined. The
number thus obtained is put down in the table of results as acid equiva-
lent. By use of this number and the number expressing the per cent
of ash in the sample, the following additional numbers were calculated :
A = acid equivalent — per cent ash.
B = acid equivalent — per cent ash — the per cent of alkali in the ash (calculated
/acid equivalent X .0053 X 100. \
as Na.2CO3) = acid equivalent — per cent ash — \ — — ^ — — I
In the samples yielding a normal ash, A varies from 1.20 to 1.72 and
exceeds 1.50 in eleven cases; B varies from 1.07 to 3.15 and exceeds
2.80 in three cases.
The determinations proposed by Stutzer were made in only six
samples. It is greatly regretted that time did permit more of these
determinations, since the method seems to be of considerable value,
although the differences in the results are not as marked as are those
obtained by Stutzer (see pp. 943 and 985).
The only decidedly abnormal ashes were those from samples Nos. 40,
42, and 04 which were unquestionably prepared by use of alkalis (see
table of results). The ash figures obtained for samples 51 and 53, while
!Rep. f. anal, chem., 1884, 4, 345.
988 FOODS AND FOOD ADULTERANTS.
not so pronounced, are sufficiently high to cause suspicion of the use of
alkalis.
A determination of the fat shows the amount of this important food
material in the preparation, and is of value in determining the extent
of adulteration with other substances. The amount of fat was not suf-
ficiently inconsistent with the amount of the other ingredients to
attract suspicion to any one of the samples. Time did not permit a
qualitative examination of the fat from each sample.
Sugar and starch are used to a most deplorable extent, as the results
in the table show. The quality of the sugar used is generally good,
however, as is shown by the somewhat rare occurrence of reducing
sugars.
A determination of theobromine is of very little value, since it has no
commercial importance to tempt its removal, as is the case writh cocoa
butter. Its determination can, therefore, only be of value for judging
the extent of adulteration with other substances, for which purpose a
nitrogen determination would serve just as well (in the absence of nitrog-
genous adulterants), and is much more easily made.
A fiber determination is of value for the detection of the presence of
husks and other substances rich in cellulose, and for judging the extent
to which these substances have been added. The value of the deter-
mination is greatly reduced, however, by the variation in the result
that follows the degree of fineness of the powder. It is very difficult
indeed to produce a sample by laboratory means that will give results
that are comparable with those obtained with samples ground in choco-
late works. Our comparisons must be, therefore, between commercial
samples of known purity and those of questionable purity.
In adding "phosphates as found in wheat," the manufacturers of sam-
ple No. 50 seem to have overlooked the fact that the husked cocoa
bean is fully as rich in phosphoric acid as is wheat.
Beef tea was once considered to be a very concentrated and easily
digestible food, and was given to invalids in small quantities with full
confidence in its great, almost miraculous, nourishing power. It has
long since been degraded very nearly to the rank of a. mere stimulant
and is never intelligently administered except when accompanied by
an ample amount of nourishing food. As a concentrated and easily
digestible food for invalids cocoa preparations are already Beginning
to share the same fate; as material for the preparation of pleasant, ex-
hilerating, and slightly nutritive beverages for both weak and strong, the
career of cocoa preparations is only just begun. Moreover, their progress
in popular favor will keep paee with the manufacturers' appreciation of
this fact.
For a study of the nutritive value of cocoa, the following data can be
taken as fairly representative of cocoas from which a part of the fat has
been removed, and to which no foreign substances have been added:
COMPOSITION OF PURE COCOAS. 989
Approximate average composition of pure cocoas, partially deprived of fat.
Nutritive constituents.
Per cent.
Nitrogenous substances
Fat
Carbohydrates ("nitrogen-free extract," including starch, etc.)
20
30
30
It must be remembered, however, that only about 01 e-half of these
nitrogenous substances are digestible protein, and the carbohydrate
figure given includes several substances of doubtful nutritive value.
Amount of nutritive materials required per day by a man doing moderate manual labor.1
Nutrients.
Authority.
Voit.
Atwater.
Protein . .
Grams.
118
50
5(10
(rVrtHfS.
125
125
450
Fat
1 W-O. Atwater and Charles I). Woods, Fourth Annual Report of the Storm School Agricultural
Experiment Station, Storrs, Conn., 1891.
The amount of cocoa used for the preparation of a cup of the beverage
is generally less than 2.5 grams. From these data, the weights of the
principal nutrients in a cup of cocoa and the equivalent parts of an
average daily ration, given in the following table, were calculated :
Nutrients in a cup of cocoa, made from 2.5 grams of material.
Nutrients.
Weight
in grams.
Part of an
average
daily ration.
Protein v
0 5
-I t,O „'„
Fat
0 G
Carbohydrates
0 G
!„ tfl ,i
In these calculations the variable additions of milk and sugar are
disregarded.
The results of these investigations emphasize in many ways the many
ideas that have been made for the establishment of standards of purity,
strength, and quality for foods — for some certain means of enabling
the public to know the strength, quality, and degree of purity of the
food materials on the markets. The question of economy alone is suf-
ficiently important to justify serious consideration of this need, for no
question can be of more importance to a great part of our nation than
questions of economy in food, drink, and clothing.
APPENDIX A.
BIBLIOGRAPHY OF THE LITERATURE OF TEA, COFFEE, AND COCOA
PREPARATIONS.
GENERAL WORKS.
BATTKRSHALL. Adulteration of food. 1887.
BELL. Analysis and adulteration of food.
BLYTH. Foods: Their composition and analysis. London, 1882.
CHEVALLIER. Dictionnaire. des alterations et falsifications des substances alimen-
taires, me"dic<amenteuses et commerciales, avec 1'indication des nioyeus pour
les reconuaitre. Paris, 1878.
COSTER, HOORN and MAZURE. The adulteration of tea, coffee, and chocolate in Hol-
land. Rev. internat. scient. etpop. d. falsifications d. denr6es aliment., 4, 7.
DAMMER. Illustrirtes Lexicon der Verfalschuugeu und Verunrciuigungen der Nah-
rungs- und Genussmittel. Leipzig, 1886.
DIETRICH und KONIG. Zusammensetzuug der Futtermittel.
DIETZSCH. Die wichtigsten Nahrungsmittel und Getriinke, deren Verunreiniguugen
und Verfalschungen, u. s. w. Ziirich, 1884.
ELSXER. Die Praxis des Nahrungsmittel-ChemikerH. Hamburg — Leipzig, 1882.
FRANCAISE RKPUBLIQUK, PREFECTURE DE POLICE. Documents sur les falsificati(»ns
des mati«-.res alimentaires et sur les travaux du laboratoire municipal.
HANAUSEK. Die Nahrungs- und Genussmittel aus dem Pflanzenreiche. Kassel,
1884.
HASSALL. Food: Its adulterations and the methods for their detection. London,
1876.
HUSEMANN. Pflanzenstoffe.
KONIG. Die menschlichen Nahrungs- und Genussmittel, ihre Herstellung, Zusam-
mensetzung und Beschaffenheit, ihre Verfalschungen und ihre Nachweisung.
Berlin, 1882.
K6NIG. Chemie der menschlichen Nahrungs- und Genussmittel, 3. Ann., Band I.
Berlin, 1889.
MACE. Les substances alimentaires etudie'es an microscope. Paris, 1891.
MOELLER. Mikroskopie der Nahrungs- und Genussmittel aus dem Pflanzenreiche.
Berlin, 1886.
PRESCOTT. Organic analysis. New York, 1887.
SCHIMPER. Anleitung zur mikroscopischen Untersuchung der Nahrungs- und Ge-
nussmittel. Jena, 1886.
SMITH. Dictionary of economic plants.
SOUBEIRAN. Nouveau dictionnaire des falsifications et des alterations des aliments,
etc. Paris, 1874.
THORPE. Dictionary of applied chemistry. London, 1890.
992 FOODS AND FOOD ADULTERANTS.
WALCHNER. Die Nahrungsuiittel der Menschen, ihre Verfiilschungen uncl Verun-
reiniguug. Berlin, 1875.
WANKLYN. Tea, coffee, and cocoa.
ZIPPEKKR. Microcbeinie ties Cacaos mid Thees. Bericbt. siebenten Vers. bayer.
Fertreter d. a. Chemie, 64.
BIBLIOGRAPHY OF THE LITERATURE OF TEAS.
ALLEN, A. H. Tea, adulterations of. Cbeui. News, 29, 167, 189, 221 ; 30, 2.
ANONYMOUS.— Bataliu, a substitute for tea. Chem. Centrbl., 1, 52.
ANONYMOUS. TEA, Brick. Chem. Ztg., 1889, No. 11; Zeitscb. f. Nabr.-Unters. u.
Hyg., 1889, 25.
Teas. Phariu. Jour., Nov. 19, 1887; Journal do Pbarin. ft do Chiin., Feb. 15,
1888, p. 196; Revue Agricole de Maurice, 3""-' aunee, 4, 92; Pbarm. Jour.,
6, 1875, 261, 263, 281, 282, 402, 404.
Tea ash. Analyst, 7, 1882, 7.
Tea, Brush. Pharm. Jour., 1853, 172.
Tea, Green. Pharm. Journ., [3], 6, (1876), 746.
Tea, Japanese. Pharm. Jour., [2], 9, (1868), 343.
BALL, SAMUEL. Tea : Its cultivation and manufacture. London, 1848.
BAILDON, SAMUEL. Tea in Assam. Calcutta, 1877.
BELL, J. C. Tea, Ash of. Analyst, 1882, 7 ; Jsb. d. Chem., 1882, 1451.
BiNG, I. Teas and coffees, nitrates in. Jour. pr. Chem. [2] 22, 348.
BLYTH, A. W. Tea, India. Chern. News, 30, 212.
CAMPBELL-BROWN, J. Tea plant, agricultural chemistry of. J. Chem. Soc. [2] 13,
1217.
DRAGENDORF. Tea, adulterations of. (Seven samples contained exhausted leaves;
16 adulterated with foreign leaves.) Chem. Centrbl., 2, 492.
EDER. Catechu and logwood, detection of in teas. Zeitsch. f. anal. Chem. 19, 372.
EDER, J. M. Teas, analysis of. Dingl. polyt. Jour., 231, 445, 526.
GUISLEH, J. F. Teas, Analyses of. Analyst, 9, 220; orig. American Grocer, Oct. 23,
1884.
GRIFFITH, WILLIAM. Tea Plant of Assam. London, about 1834.
HAGKR, H. Teas, Analysis of. Zeitscb. f. anal. Chem., 1880, 371.
KILL, A. Tea, Analyses of. Analyst 6, 232.
HODGES. Teas, cachar. Chem. News, 3O, 114.
HORSFORD. Tea, composition of ash. Sill. Am. J. [2], 11, 249. Jsb. d. Chem.,
(1851), 717.
HUSSON, C. Tea and coffee, examination of. Ann. chim. phys. [5] 16, 419.
INDIA, GOVERNMENT OF. (Home department.) Tea cultivation in the northwest
provinces and in the Punjab. Report en the present condition and future
prospects. Calcutta,, 1857.
KOSSEL, A. The'ophylline, a new alkaloid in tea. Journ. de Pbann. ft de Chim.,
March, 1889,297; Zeitsch. f. phys. Chem., 13 (1888), 298.
KOZAI, Y. Tea leaves, comparison between the composition of unprepared given
and black. Journ. Tokyo Chem. Soc., 1889, 10, No. 8; Rep. 12, 109.
Tea. Researches on the manufacture of. Imp. College Agric. Tokyo, KOJIM l>a,
Japan, Bull. No. 7.
KRAUS, C. Tea, percentage of extract. Neues Rep. Pharm., 21, 327; Jsb. d. Chem.,
(1872), 805.
LEHMANN, J. Tea and coffee, analysis of. Liebig's diem. Bride, :\ anil., 611; Jsb.
d. Chem., 1851, 717.
LEEDS, A. R. Tea, substitutes and adulterations. Chem. News, 44,244; Am.
J. Chom. Soc., 3 (1881).
BIBLIOGRAPHY OF LITERATURE. 993
LEES, NASSAU W. Tea districts of Eastern Bengal, a memorandum written after a
tour through tin-,, in 1864-'65. Calcutta, 1866.
LEES, NASSAU W. Tea cultivation, cotton, etc., in India. London, 1863.
McGowAN, A. T. Tea planting in the outer Himalaya. London, 1861.
McPiiERSON, JAMES. Tea planter, the Neilgherry. Madras, 1870.
MONEY, EDWARD. Tea, the cultivation and manufacture of. London, 1878.
MIUSTADT. Tea, adulteration of. Rev. Intern. Scien. et Pop. des Falsif. des Den-
ree"s aliment., 4, 39.
SUMNER, JOHN. Tea, a popular treatise on; its qualities and effects. Birmingham,
1863.
STOKER, T. G. Tea plant, notes on the management of the. Calcutta, 1874.
WIGNER, G. W. Teas, analyses of. Chem. N,ews, 32, 166, 189, 235. Phar. J. Trans.
[3], 6, 261, 281, 402.
Tea, composition of. Phar. J. Trans. [3], 4, 909.
WILSON, A. S. Teas, analyses of. Chern. News, 28, 307.
WINN^CKI. Tea, adulteration of. Pharm. Ceiitr, in Diugl. polyt. Jour., 217, 256.
ZIPPERER, PAUL. Teas and cocoas, microchemistry of. Ber. d. 7ten Vers. d. F. Vere-
iuigung bay. Vertreter d. ang. Chem., Speier., 10, 11, 12 Sept., 1888, 64.
ZOLLER, PH. Tea leaves, ash of. Ann. Chem. Pharin., 158, 180; Neues Rep. Pharm.,
20, 457; Pharm. J. Trans., 1871 [3], 2, 161.
BIBLIOGRAPHY OF THE LITERATURE OF COFFEES.
ALLEN, A. H. Coffee, examination of. Chem. News, 29, 129, 140, 167.
ANONYMOUS. Coffee, acorn. Pharm. Jour., 1876, 772.
Coffee, colored. Jour, de Pharm. et de Chim., 15 Feb., 1888, 198.
Coffee, extract of. The Jour. Soc. Chem. Industry, 1887, p. 377-577.
Coffee and its adulterations. Pharm. Jour., 10 (1851), 394-396.
BIBKA. Coffee, adulteration of. Abhandl. d. uaturwiss.-tcchn. Commission d. k.
bayr. Akad. d. Wissenschaft., 2, 219; Jsb. d. Chem., 1858, 659.
BOUSSINGAULT. Coffee, sugars in. Compt. Rend., 91, 639; Jsb. d. Chem., 1880,
1069.
BERNHEIMER. Coffee, products of roasting. Wieii. Akad. Ber. (2 Abth.) 81, 1032;
Jsb. d. Chem., 1880, 1069.
BouTKRON-CiiARLARD et RoBiQUET. Coffee, analysis of. Ann. de Chem. et de
Pharm., 23, 93.
CECH, C. O. Coffee oil. J. pr. Chem. [2], 22, 395; Jsb. d. Chem., 1880, 1082.
COMMAILLE, A. Coffee, analysis of. Mouit. sclent. [3], 6, 779.
DIEKBACH. Coffee, green. Ann. Chein. Pharm., 14, 234.
DRAPER, J. C. Coffee adulterations, detection of. Phil. Mag. [4], 34, 104; Zeitsch.
f. anal. Chem., 7, 388.
DUNSTAN. Coffee, Mussaenda. Phar. J. Trans., Nov. 16, 1889, 381; Am. J. Pharm.,
20, 4, 174.
EDDY, C. E. Coffee, analysis of. Am. Chem. J., 7, 45; Jsb. d. Chem., 1876,1149-50.
EDSON. C. Coffee, imitation Java. Analyst, 9, 128.
FRICKE, E. Coffee, imitation. Zeit. f. angew. Chem., 1889, 310-311; Chem. Cen-
trbl., 1889, 639.
FERRARI. Coffee syrup. Ann. Chem. Pharm., 9, 246.
GEISSLER, E. Coffee, Mogdad. Pharm. Centralhalle, 22, 134; Zeitsch. f. anal
Chem., 21, 438.
GRAHAM, STENHOUSE and CAMPBELL. Coffee, ash analysis of. J. Chem. Soc., 9, 33.
GRAHAM, STENHOUSE and CAMPBELL. Coffee adulterations. Phar. J. Trans., 26,
228, 521 ; Jsb. d. Chem., 1856, 814.
HAGER, H. Coffee substitutes. Chem. Centrbl., 1880, 398 ; Jsb. d. Chem., 1880., 1070.
HEHNER. Coffee leaves, examination of. Analyst, 1879, 84.
994 FOODS AND FOOD ADULTERANTS.
HEHNEU, O. Coffees, roasted and um ousted, analyses of. Analyst, 1879, 84.
HLASIWETZ. Caffetannic acid, formula of. Ann. de Cheni. et de Pharm., 142, 219.
HLASIWETZ, H. Hydrocoffeic acid. Wien Acad. Ber., 55, 337; J. prakt. Chom.,
103,41; Cheiu. Centrbl., 1867, 1893.
HUSEMANN. Fat of coffee. Pflanzenstoffe, p. 1367.
JANECEK. Coffee, Mogdad. Chem. Ztg., 1880, 442 ; Jsb. d. Chem., 1880, 1070.
JANKE, L. Coffeo, analysis of. Veroff. d. Reichsgesundheitsamtes, 1880, 157,175,
Jsb. d. Cbem., 1880, 1343.
KONIG, J. Coffee beans, coating of. Cbem. Centrbl., 1889, 20, 1, 51.
KONIG, J. Coffee, imitation. Cbem. Centrbl., (1889), 20, 1, 51.
KORNAUTH, C. Coffee beans, imitation. Rev. internat. scient. et popul. des falsifi-
cations des denre~es aliment., 3, 195-496.
KORXAUTH, C. Coffee and coffee substitutes. Mitt. a. d. pharrn. Ins. und Lab. f.
angew. Cbem., Erlangeu, Heft 3, 1-56.
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popul. des falsifications des denr6es aliment., 3, 8; Cbem. Centrbl., 1890,
605.
KORNAUTH, C. Coffee substitutes. Zeitscb. f. angew. Chem., 1891, 645.
LUDWIG, H. Coffee tree, ash of various parts of. Arch. Pharm. [3], 1, 482; Jsb.
d. Chem., 1872, 804.
LEHMAN, J. Coffee, ash of aqueous extract of. Liebig's Chom. Briefe, 3 Aufl., 611;
Jsb. d. Chem., 1851, 717.
LEVI. Coffee, ash, analysis of. Ann. de Chem. et de Pharm,, 50, 424.
LEVESIR, O. Coffee, analysis of. Arch. Pharm. [3], 8, 294; Jsb. d. Chein., 1876, 888.
MANSFELD, M. Coffee, adulteration of. Rev. internat. scient. et popul. des falsif.
des denrdes aliment., 4, 40.
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21, 438.
MULDER. Javas, yellow and blue. Jsb. d. Chem., 1858, 659.
NANNING. Coffee coloring. Weekblad vor Pharm., Nov., 1883; Rep. d. anal. Chem.,
1884, 12.
PAUL and COWXLEY. Coffeo, caffein in, roasted and unroasted. Phar. J. Trans.,
1887, 17, 821.
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26, 108.
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PFAFF. Caffetannic acid, isolation of. Schweigg. Journ., 62, 31.
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News, 56, 24.
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Pharm., 50, 224; 59, 300; 63, 193; 66, 35; 82, 194.
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BIBLIOGRAPHY OF LITERATURE. 995
SYKORA, T. Coffee colorings. Chem. Centrbl., 1887, No. 47; Rep. f. anal. Cbem.,
1887, 765.
THIEL, C. Coffee substitutes. Zeitscb. f. tinge \v. Cheiu., 1892, 75.
TIEMANN and NAGAI. Caffeic acid, relation of to ferulic acid. Bericbte, 1878, 646 ;
Jsb., 1878, 799.
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719.
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8, 193; Dingl. polyt. Jour. 147, 395; Chem. Centrbl., 1858, 367.
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WEYRICH. Coffees, roasted and unroasted. Analysis of; Phariu. Z. Russl. 12, 362.
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WOLFFENSTEIN. Coffee substitutes, analysis of. Zeitsch. f. angew. Chem., 90, 84;
Chem. Centrbl., 1890, 606.
COCOA AND COCOA PREPARATIONS.
ANONYMOUS. Adulteration of chocolate. Ann. Chem. Pharm., 16, 80.
Cacao und dessen Prtiparate. Chem. Ztg., 1889, 32.
Coloring matter for chocolate. Analyst, 1888, 13, 96.
Cultivation of cocoa in Colombia. Phar. Jour. Trans. [3], 970, 591.
ANTHON. Preparation of cocoa butter. Ann. Chem. Pharm., 24. 251.
ASBORTH. Estimation of starch in cocoa and chocolate. Rep. anal. Chem., 7, 99.
ASSOCIATION OF Swiss ANALYTICAL CHEMISTS. Directions for the examination
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Fortschr. auf dem Gebiete der Chemie d. Nahr.- u. Genussmittel, 1890, 2, 171.
BELL. Caffeine in cocoa. Analysis and adulteration of food, p. 85.
BELOHOUBECK. An analysis of Van Houten's cocoa. Casopsis cesk6ho le"karnictva,
1888, 7, 311; Rep. d. Chem. Ztg., 1888, 270.
BELOHOUBECK. Soluble Dutch cocoa. Bohm. pharm. Zeitsch , 7, 311; Chem. Cen-
trbl., 1890, 131.
BENEDIKT. Analyse der Fette uud Wachsarten. Berlin, 1886.
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4, 213; Ibid., 5, 178; Zeitsch. f. anal. Chem., 24, 464.
BENSEMANN. Estimation of cocoa in chocolate. Ber. d. chem. Ges., 6, 856, ; Chem.,
News, 48, 305.
BENSEMANN. Properties of cocoa butter. Rep. f. anal. Chem., 4, 165; Zeitsch. f. anal.
Chem., 24, 628.
BERNHARDT. Examination of cocoa and chocolate. Zeitsch. Nabrnngsm. u. Hyg.,
1890, 4, 121,
BERNHARDT. Losses in the preliminary preparation of the bean for manufacture.
Chem. Ztg., 1889, 32.
BOUDETAND PELOUZE. Examination of cocoa butter. Ann. Chem. Pharm., 29, 41.
BJORKLUND. Ether.test for cocoa butter. Zeitsch. f. anal. Chem., 3, 233; Benedikt,
Analyse der Fette und Wachsarten.
BOUSSINGAULT. Constituents of cocoa. Compt. Rend., 1883, 96, 1395.
BOUSSINGAULT. Cultivation of the cocoa tree. Compt. Rend., 96, 1395 ; Jour. Chem.
Soc., 1883, 44,933. A second article. Ann. Chim. Phys. [5] , 28, 433 ; Jour.
Chem. Soc,, 46,202.
BOUSSINGAULT. Examination of cocoa and chocolate. Ann. Chim. Phys. [5], 28,433.
BOUSSINGAULT. Properties of cocoa butter. Ann. Cbem. Pharm., 21,200.
BOUSSINGAULT. Percentage of theobromine in cocoa beans. Vortrage ii. Agricultur~
Chemie, 1872, 451. A second article, Ann, Chitn, Phys, [5], 28, 433 ; Chen).
Ztg., 1883, 902.
-tf P, 13 9
996 FOODS AND FOOD ADULTERANTS.
DELCHKR. Historical and chemical researches on cocoa.
DIETERICH. Specific gravity of cocoa butter. Geschaftsber. d. Papier- n. chem. Fab.
rik zu Helfenberg, 1883; Zeitsch. f. anal. Chem., 23, 567.
DIETEKICH. Chemical properties of cocoa butter. Zeitsch. f. anal. Chem., 25,431.
DUCLAUX. Copper in cocoa ash. Bull. Soc. Chim. de Paris, 1871, 16, .33.
ELSNER. Microscopical examination of cocoa. Rep. anal. Chem., 1885, 5, 128;
Chem. Ztg., 1885, 781.
FILSINGER. Examination of chocolate. Chem. Ztg. Rep., 13, 309; Chem. Centrbl.,
1890, 130.
FILSINGER. Modification of the ether test for cocoa butter. Zeitsch. f. anal. Chem.,
19, 247; Chem. Ztg., 1889, 13, 309; Benedikt, Analyse der Fette und W;n-hs-
arten.
FISCHER. Constitution of theobromine. Ann. Chem. Pharm., 215, 253.
FRTJHLIXG UND SCHULZ. An analysis of cocoa powder. Correspondenz-Bl. d.
Vereins analyt.Chem., 1880, 17.
GALIPPE. Copper in cocoa ash. Jour, de Pharm. et de Chim. [5], 1, 505.
GLASSON. Formula of theobromine. Ann. Chem. Pharm., 61, 335.
G5SSMANN and SPECHT. Cocoa butter. Ann. Chem. Pharm., 90, 126.
GRANDEAU. Analyses of cocoa husks. Dietrich u. Konig, Zusainmensetzung der
Futtermittel, p. 264.
HAGER. Anilin test for the purity of cocoa butter. Zeitsch. f. anal. Chem., 19, 246;
Benedikt, Analyse der Fette und Wachsarten.
HANAUSEK. Commercial varieties of cocoa beans. Hanausek's Die Nahruugs- und
Genussmittel aus dem Pflanzenreiche.
HARTWICH. Determination of starch in chocolate. Jour. Chem. Soc., 1889, 192 ; Chem.
Ztg., 12,375.
HEISCH. Analysis of cocoa. Analyst, 1, 142.
HEISCH. Analyses of cocoa beans. American Chem., 1876, 76, 930.
HERBST. Examination of chocolate. Rundschau, 1882, 443; Rep. d. anal. Chem., 2,
236; Zeitsch. f. anal. Chem., 22, 278.
HOLM. The harvesting and preparation of cocoa beans. American Chem. ,5, 330;
Jsb. d. Chem., 1875, 1121.
HUSEMANN. Solubility of theobromine. Husemann's Pflanzenstoffe, p. 822.
JURGENSEN. Adulteration of cocoa and chocolate in Denmark. Chem. Ceutralblatt-
1890 [2], 21, 890.
KELLER AND STRICKER. Solubility of theobromiue. Ann. Chem. Pharm., 118, 151.
KINGZETT. Composition of cocoa butter. Phar. Jour. Trans., 8, 412.
LEGLER. A modification of Wolfram's method for the determination of theobromine.
Ber. d. chem. Ges., 15, 2938; Zeitsch. f. anal. Chem., 23, 89.
LEGLER. Microscopical examination of cocoa. Rep. d. anal. Chem., 4, 345; Chem.
Ztg., 1885, 105. A second article. Ref. d. anal. Chem., 5, 95 ; Chem. Ztg., 1885,
679.
MANSFELD. A modification of Asborth's method for the determination of starch in
cocoa and chocolate. Zeitsch. f. Nahrnngsmitteluntersuch. u. Hygiene,1888, 1,
2; Chem. Ztg., 3, 91.
MANSFELD. Examination of cocoa preparations. Zeitsch. d. allg. cisterr. Apotek.^
Ver., 44, 329.
MOSER. Analyses of cocoa husks. Dietrich uud Konig, Zusammensetzung der Fut-
termittel.
MULDER. Estimation of theobromine. Kouig, Clu-mie <ler Menschliclu-n Nahrungs-
und Genussmittel, 3 Aufl., Band I, p. 1019.
MUNCH. Analysis of cocoa. N. Jahrb. Pharm.. 25, X; /.. -itsrh. chem.. 1866, 191.
MUTER. Analysis of cocoa. Analyst, 1879, 65.
PAYKN. Detection of foreign starches in chocolate. Jour, de Pharm. et de Chim.,
41, 367; Zeitsch. f. anal. Chem., 2, 444.
BIBLIOGRAPHY OF LITERATURE. 997
PENNETIER. Estimation of starch in chocolate. Jour. Pharm. Chiru. [5], 1887,
15, No. 3.
POHL. A method for the determination of melting points. Wiener Academie, Be-
richte, 6, 587 ; Benedikt, Analyse der Fette nnd Wachsarten.
PORTKLE. Analysis of cocoa husks. Centrbl. f. Agrikulturchem., 1870, 304.
REINSCH. Detection of flour in chocolate. Further Gewerbe Ztg., 1868, 63; Zeitsch.
f. anal. Cheni., 8, 514.
ROST VAN TONNINGEN. Analyses of the ash from various parts of the cocoa tree.
Rep. Chim. Applique", 2, 261; Jadsb. d. Chem., 1859, 548.
RUDORFF. A method for the determination of melting points. Jsb. d. Chem., 1872,
32.
SALDAU. Die Chokolade-Fabrikation, 1881.
SAMELSON. Adulteration of cocoa powder. Chem. Ztg., 1888, 44, 722.
SALTSIEN. The action of iodine on the starch of cocoa. Zeitsch. f. anal. Chem., 28, 1.
SCHAEDLER. Die Technologie der Fette und Oele der Pflanzen- und Thierreichs.
Berlin, 1883.
SCHMIDT. Caffeine in cocoa. Arch. d. Pharm., 221, 675; Zeitsch. f. anal. Chem.-
23, 89.
SCHROEDER. Untersuchuugen iiber die Bestimmungen des Zuckers in den Cacao,
waaren. Zeitsch. f. angew. Chem., 1892, 173.
SKALWEIT. Refractive index of cocoa butter. Rep. d. anal. Chem., 6, 181 ; Zeitsch.
f. anal. Chem., 28 386.
STENHOUSE. Cocoa butter. Ann. Chem. Pharm., 36, 56.
STUTZER. Analysis of cocoa. Rnss. Zeitsch. f. Pharm., 21, 724.
STUTZER. Analysis of cocoa, partially deprived of fat. Rep. f. anal. Chem., 1882,
88 and 161; Hygiene-Bericht, 1882-'83, 1, 217.
STUTZER. Neues aus der Rost-, Darr- und Trocknungs-Industrie. Zeitsch. f. angew.
Chem., 1891, 368.
STUTZER, FASSBINDER, AND KLINKENBERG. Determination of nitrogen in cocoa.
Chem. Centrbl., 1882, 538; Jsb. d. Chem., 1882, 1438.
TRAUB. Composition of cocoa butter. Arch. Pharm. [3], 21, 19.
TRESCA. Manufacture of chocolate. Les Mondes, July 22, 1869.
TREUMANN. Solubility of theobromine. Arch. Pharm. [3], 13, 5; Jsb. d. Chem.,
1878, 872.
TUCHEN. Dissertation iiber d. organ. Bestandtheile der Cacao. Gottiugen, 1857.
VALENTA. Solubility of cocoa butter in glacial acetic acid. Dingl. polyt. Jour., 252,
296; Zeitsch. f. anal. Chem., 24, 295.
WARREN. Adulteration of chocolate. Chem. News, 62, 99.
WEIGMANN. Estimation of theobromine. Konig, Chemie d. mensch. Nahrungs- u.
Genussmittel. 3 Aufl.. Baud i, S. 1019.
WEIGMANN. Microscopical examination of cocoa beans. Rep. d. anal. Chem., 1885,
182.
WIGNER. Nitrogenous constituents of cocoa beans. Analyst, 4, 8.
WOSKRESENSKY. Discovery of theobromine. Ann. Chem. Pharm., 41, 125.
WOLFRAM. Determination of theobromine. Jsb. d. k. chem. Centralstelle f. off.
Gesuudheitspflege zu Dresden, 1878; Zeitsch. f. anal. Chem., 18, 346.
ZEDELER. Analysis of the ash of husked cocoa beans. Ann. Chem. Pharm., 78, 348;
Pharm. Ceutrbl., 1851, 716.
ZIPPERER. Untersuch. ii. Cacao u. dessen Praparate, 1887.
ZIPPERER. Estimation of theobromine. Konig, Chemie der menschlichen Nahrungs-
und Genussmittel, 3 Aufl.. Band I, S. 1020.
BIBLIOGRAPHY OF METHODS FOB THE ESTIMATION OF TANNIN.
,ALLEN, A. H. Nearly all the methods worthy of detailed description are based on
the precipitation of tannin by gelatin or its absorption by a gelatinous sub-
998 FOODS AND FOOD ADULTERANTS.
stance. Many of the methods appear very simple, but in practice offer very
considerable difficulties, especially when gallic acid is present.
Commercial Organic Analysis, vol. in, Pt. 1, 109.
ALLEN, A. H. This writer states that a German commission recommends, in per-
manganate titrations, the addition of the solution 1 cc at a time instead of
drop by drop. The results of the "1 cc method" differ considerably from
those obtained by the "drop method." The latter method was employed by
Neubauer and Oser in determining the reduction coefficients ; hence Allen
recommends it. At the reference cited, Procter points out the source of error
in the " 1 cc method."
Op. cit., page 116.
ALLEN, A. H. A method for tea assay based on the precipitation of Tannin from a
hot solution by a standard solution of lead acetate, employing ammouiacal
ferricyanide in ascertaining the end reaction.
Chem. News, 29, 189; also Allen's Commercial Organic Analysis, vol. in, Pt.
i, 123.
BARBIERI, J. Essentially the method of Carpen4 (vide Carpene", A., Ding, polytec.
Journ., 216, 452) ; Ber. d. chem. Ges., 9, 78; also Zeitsch. f. anal. Chem., 16, 123.
BECKER. A volumetric method in which a solution of tannin is run into a hot
solution of methyl-violet until the color is discharged. Zeitsch. f. anal.
Chem., 25, 133.
BECKMA.N, E. A volumetric method employing a solution of anmionio-ferrous sul-
phate, crystallized sodium acetate, and acetic acid for the removal of the
tannin. The usual permanganate titrations are made before and after the
removal of the tannin. Zeitsch. f. anal. Chem., 25, 527.
CARPENE, A. A volumetric method employing an ammoniacal solution of zinc acetate
for the precipitation of the tannin. The precipitate is collected, Avashed,
dissolved in dilute sulphuric acid, and titrated with permanganate of potas-
sium. Ding, polytec. Journ., 216, 452; Zeitsch. f. anal. Chem., 15, 112.
CASALI, ADOLPHO. A volumetric method employing a standard nickel solution. A
paper soaked in ferric chloride solution containing ferrous sulphate is em-
ployed as an indicator. Annali di Chimi., 79, 65; also Chem. Ztg., 8, 1767;
also Zeitsch. f. anal. Chem., 24, 272.
CECH. This author states that the presence of acetic acid, citric acid, tartaric acid,
malic acid, cane sugar, dextrin, gum, fat, caffeine, or urea does not interfere
in the estimation of tannin by permanganate, provided the solution is prop-
erly diluted. Zeitsch. f. anal. Chem., 7, 134.
COLLJN AND BENOIST. A volumetric method based on the precipitation of tannin
by gelatin. A derivative of aniline added to the gelatin solution is used as
an indicator. The taimate absorbs the coloring matter and the solution be-
comes colorless when the precipitation is complete. A standard tannin solu-
tion is employed in making up the gelatin solution. Mon. Scien., March, 1888,
364 ; Journ. Soc. of Dyers, 4, 62.
COMMAILLE. A volumetric method employing a standard -solution of iodic acid in
the presence of hydrocyanic acid. Zeitsch. f. anal. Chem., 3. 488.
CONNCLER AND VON ScHKOEDER. An official report on the estimation of tannins,
containing recommendations in regard to methods of analysis, strength of
solutions, etc. Zeitsch. f. aiial. Chem., 25, 121.
DARTON, N. H. Darton employed an amiuoiiio-.sulphate of copper solution for the
precipitation of tannin. Extract the tea first with cold, then with boiling
water. Treat the infusion with 'S< cc dilute sulphuric acid (1 part acid to 10
parts water ^ filter, render filtrate slightly alkaline with ammonia, and a.yain
filter. Treat 100 cc this solution with an equal volume of unimoiiiu sulphate
of -copper solution (1± per cent copper Hall ), collect the pn-ci|.jt;ite. Titrate
A knpwn volume of f.ho filtrate with purmttWganate for uow-t/aunins. Wash
BIBLIOGRAPHY OF LITERATURE. 999
the precipitate with ammonium carbonate solution, dry and weigh or ignite,
moisten with nitric acid and again ignite and weigh. Weight, CuOx 1.034=
gallotannin. Journ. Am. Chem. Soc., 1882, 4.
DAVY, SIR H. This is the first method devised for the estimation of tannin, and con-
sisted in titrating with a standard gelatin or glue solution. Phil. Trans.,
1803,268.
DURIEU, F. A method employing a standard calcium hypochlorite solution, under
certain conditions, after the addition of ferric chloride. Arch. d. Pharin., 22,
523; Zeitsch. f. anal. Chern., 24, 273.
EDER, J. M. A method for tannin of teas based on that of Fleck (vide Wagner's
Jsb., 1860, 531, or abstract in this bibliograpy). The tannin is precipitated
from water solution, with copper acetate solution ; the precipitate is collected,
washed, and ignited, then moistened with nitric acid and again ignited. 1
gram CuO=1.3061 grams tannin. Zeitsch. f. anal. Chem., 19, 106; Ding,
poly. Jour., 228, 81.
FEHLJNG. An improvement of Davy's method, consisting in the addition of alum to
the glue solution. Jsb., Liebig and Kopp, 1853, 683; Ding. poly. Joum.,130,
53.
FLECK. A method based on the precipitation of tannin by copper acetate. Wag-
ner's Jsb., 1860, 531.
GAUTIER, A. A method employing carbonate of copper for the estimation of tannin
in wines. Zeit. f. anal. Chem., 1878, 222 ; Jsb. d. Chem., 1878, 1088.
GANTTER, F. A permanganate method. Ten cc of the bark solution are saturated
with dilute sulphuric acid, heated to boiling point, then permanganate solu-
tion is added (3.988 grains permanganate of potassium per 1,000 cc) 1 cc at a
time until the color disappears slowly ; boil and then add the permanganate
drop by drop. When a precipitate, not dissolved by hard boiling, forms,
add 1 cc permanganate and boil until the color disappears. Add oxalic acid
(7.951 grams per liter) until the precipitate dissolves and the solution becomes
clear, then complete the titration with permanganate. From the total per-
manganate, less that required by the oxalic acid, calculate the tannin.
Zeitsch. f. angew. Chem., 1889, 57, 577; Jour. Anal. Chem., 4, 83.
GERLAND. A method based upon the precipitation of tannin by tartrate of antimony
and potassium, in the presence of ammonium chloride. Chem. News, 1863,
54 ; Zeitsch. f. anal. Chem., 2, 419.
GINTL, W. This chemist rejected Pribram's method on account of great variations
in the results. Zeit. Chem., 1868, 144; Jsb. d. Chem., 21, 888.
GRASSI, E. A modification of Maumend's method. The tannin is precipitated by
barium hydrate; the precipitate is washed with ammonium chloride or
nitrate solution, neither of which dissolves the tannate of barium. This
latter is dissolved in dilute sulphuric acid and titrated with standard per-
raaganate. Ber. chem. Ges., 1875, 257; Jsb. d. Chem., 1875, 989.
GUENEZ, E. A volumetric method employing a standard tartar emetic solution, with
Poirier's green, 4 J. E., as an indicator. The tannin solution is kept at the
boiling point during the titration. It is claimed that gallic acid offers no
resistance in this method. Compt. Rend., 1890, 532.
HAMMER. This method employs a piece of animal skin to abstract the tannin
from solution. Dr. A. B. Prescott (Organic Analysis, 473) says Hammer's
method gives untrustworthy results, Journ. f. prakt. Chem., 81, 159; notes
on this method, by Muntz and Ramspacher, Compt. Rend., 79, 380; also,
Zeitsch. f. anal. Chem., 13, 462.
HANDTKE. A method based on the reaction of ferric acetate with tannin. Stand-
ardize the iron solution by means of a tannin solution of known strength.
In practice add the iron solution to the tannin solution until the precipitate
settles and the liquid becomes clear. Method not applicable to coffees and
teas. Journ, f. prakt. Chem., 82, 345; Zeitsch. f. anal. Chem., 1, 104.
1000 FOODS AND FOOD ADULTERANTS.
JOHANSON, E. A modification of Davy's method, employing 5 to 8 drops of a solu-
tion of chromic sulphate (one part in twenty-five parts water) per 100 cc of
the glue solution. Chem. News, 50, 176.
JACKSON, E. This method employs lead carbonate as a precipitant of tannin. The
percentage of tannin is calculated from the density of the solution before
and after the precipitation. An error is possible from the partial solution of
the lead by a free organic acid. Chem. News, 50, 179; Zeitsch. f. anal.
Chem., 24, 271.
JEAN, F. A volumetric method based upon the fact that tannic and gallic acids
combine with iodine, in the presence of sodium carbonate, in definite propor-
tions. Filter paper covered with starch powder is used in testing for excess
of iodine. The presence of gallic acid necessitates a second titration after
the removal of the tannin by an appropriate precipitant. Ber. d. cheui.
Ges., 9, 730; Zeitsch. f. anal. Chem., 16, 123.
JEAN, F. A colorimetric method, in which a tannin solution of known strength (1
per cent) is added to a ferric chloride solution containing free hydrochloric
acid, until a piece of white paper placed under the beaker on black cloth is
no longer visible. A similar titration is made with a solution of the sample
to be assayed. Two titrations are necessary, one before and one after the
removal of the tannin by gelatin. Bui. Soc. chim. de Paris., 44, 183;
Zeitsch. f. anal. Chem., 28, 108.
KATREINER. This chemist objects to the methods of Carpene and Barbieri, and
states that the probabilities of error are great. Zeitsch. f. anal. Chem., 18,
112.
LOWE. In this method the infusion is evaporated with a few drops of acetic acid,
and residue is then exhausted with alcohol, which dissolves the tannin only.
The tannin is then estimated in the alcoholic solution. Jsb. d. Chem.,
18, 743.
LEHMAN. Titration with a glue solution containing ammonium chloride. Jahres-
ber. d. Chem., 1881, 1206; Russ. Zeit. Pharm., 1881, 321.
L.OWENTHAL, J. This method is one of the most important yet devised for tannin.
It is given in considerable detail, since a modification of this method is usu-
ally employed in modern practice. See method as modified by Procter,
Conncler, and Schroeder, page 890, this report.
The method devised by Lowenthal is based upon the oxidation of tannin by per-
manganate of potassium. Four solutions are employed: (a) permanganate of potas-
sium, standard solution; (J>) 6 grams indigo, with 50 cc concentrated sulphuric acid
per liter; (c) 25 grams white glue, dissolved in water and the solution saturated
with sodium chloride, then made up to 1 liter; (d) a saturated solution of sodium
chloride, with 25 cc sulphuric acid per liter. The sample is extracted in boiling
water, the solution is cooled and made up to 1 liter. (1) 10 cc of this extract are
diluted to 800 or 1,000 cc, 25 cc indigo solution added, and a titration is made with
the permanganate. (2) 25 cc indigo solution are diluted to 800 or 1,000 cc. and
titrated with permanganate. This burette reading is subtracted from that under (1)
to obtain the net reading, i. e., the permanganate required for the tannin and gallic
acid and other oxidizable matter in 10 cc of the extract. (3) 100 cc of the extract
are now treated with 50 cc glue solution, and, after shaking, 100 cc salt solution
are added. After several hours the solution is filtered. To 50 cc of the filtrate 25
cc indigo are added and another titration is made. I'mler these conditions, again
determine the permanganate required for the indigo and deduct tlie burette, reading
ftg before. In the titration under (3) a volume of the solution equal to 20 cc of the
extract was taken; hence divide the net burette rending by 2. This yives the per-
manganate required to oxidi/e the substances other than tannin in 10 cc of the ex-
tract. Deducting this last amount <if penn:mg:m:ite from that required for all the
oxidizable matter in the extract, and the remainder is that required for the tannin
in 10 cc extract.
BIBLIOGRAPHY OF LITERATURE. 1001
The permanganate is standardized with oxalic acid. According to Neubauer, 63
grams crystallized oxalic acid correspond to 41.57 grams purified gallotannic acid.
Zeitsch. f. anal. Chem., 16,33; 20, 91.
MACAGNO. A method based on the use of mercuric nitrate as a precipitant. Ber. d
chern. Ges., 7, 1, 360.
MAUMENE. A method for the estimation of tannin in wines. The tannin is precip-
itated by barium hydrate, and the precipitate after washing is dissolved in
dilute sulphuric acid and titrated with permanganate. Bui. Soc. Chim. [2],
22, 41;* Jsb. d. Chem., 1874, 1046.
MITTENZWEY. A method depending upon the absorption of oxygen by tannin. A
portion of the substance is shaken in a graduated tube with a 30 per cent
solution of potassium hydroxide. After standing twenty-four hours the tube
is opened under water and the absorption noted. Journ. f. prakt. Chem., 91,
81.
MONIER E. Monier was the first to propose the use of permanganate of potassium
in tannin estimations. He did not publish a definite method. Compt. Rend.,
46, 577 ; Ding. poly. Journ., 118, 209.
MOULLADE, A. A modification of Jean's method for the estimation of tannin, em-
ploying iodine with sodium bicarbonate. Carbon bisulphide is used as an
indicator. Journ. de Pharm. et de Chim. [5], 22, 153.
MILLER, G. An improvement in Davy's method similar to that of Lehman. Wag-
ner's Jsb., 1858, 510; Zeitsch. f. anal. Chem., 5, 5.
OSTERMAYER. This chemist substitutes magenta for the rose aniline in Wagner's
method. Chem. News, 40, 181.
PA VESI and ROTONDI. A modification of Fleck's method, employing a solution of cop-
per acetate with ammonium carbonate. The authors consider the precipitate
to have the formula CHtt.Cu^NH.OiOa + Hs O. Gazz. Chim. Ital., 1874, 194 ;
also Ber. d. chem. Ges., 1874, 590.
PERSOZ, J. Persoz estimated the tannin, employing stannous chloride, by comparing
the volume of the precipitate after setting aside from ten to twelve hours,
with that obtained under the same conditions as to volume and time with a
standard tannin solution. Trait6 de 1' Impression des Tissus, I, 282.
PERRET, M. Perret employs an albumin solution as a precipitant of tannin, then
removes the excess of albumin. The tannin is calculated from weight of the
dried precipitate. Bui. Soc. Chim. de Paris, 41, 32; Zeitsch. f. anal. Chem.,
24, 273.
PRIBRAM. Based on the precipitation of tannin by lead acetate. The organic mat-
ter contained in the precipitate is termed "total astringent matter." Jsb.
d. Chem., (1866) 17, 821; Vierteljahresber. f. Chem., 15, 520.
PROCTER, H. R. A modification of Lowenthal's method (see page 890, this report). A
valuable improvement comprised in this modification is the use of powdered
kaolin to facilitate the filtration after the addition of the gelatin. Journ.
Soc. Chem. Ind., 3, 82.
PROCTER, H. R. The same as Hammer's method, except that hide powder is used in-
stead of the animal skin. Allen's Commercial Organic Analysis, Vol. HI, Pt.
1, 119.
PROCTER, H. R. A criticism of Gantter's method. Procter finds that the amount
of permanganate consumed is materially influenced by the excess in which
it is added and by the time of boiling. He concludes that by a rigid scheme
of operation the new method might give concordant results, but at best such
results could have but a comparative value. Journ. Soc. Chem. Ind., 9, 260;
Journ. Franklin Inst., 129, 421.
PRUD'HOMME. A volumetric method employing a standard solution of calcium hypo-
chlorite with an aniline color (methyl-orange) as an indicator. The color is
discharged in the presence of unprecipitated tannin. Bui. Soc. Chem. [2],
21, 169; Jsb. d. Chem., 1874. 1034.
1002 FOODS AND FOOD ADULTERANTS.
RICHAEDS and PALMEK. A volumetric method based upon the work of Gerland. A
standard solution of tartrate of antimony and potassium is employed for the
titration. A solution of acetate of ammonium is prepared for use as de-
scribed below. In preparing this solution, saturate glacial acetic acid with
stronger water of ammonia. Exhaust a weighed portion of the sample as usual
with water, using such proportions to give approximately 0.3 to 0.9 gram
tannin per 150 to 300 cc. Divide this solution into three or four aliquot
parts. To one portion add the standard tartar emetic solution in slight ex-
cess, and to a second add less of the solution than is required to precipitate
the tannin. To each portion add 1 cc ammonium acetate solution per 25 cc
taken. After allowing time for the precipitate to settle, test a drop of the
clear liquid on a porcelain plate with a drop of sodium thiosulphate. An
excess of antimony is indicated by an orange-yellow precipitate. The tests
of the first two aliquot parts, more tartar emetic being added to the second
if necessary, indicate approximately the volume of the antimony solution
required to precipitate the tannin, and the remaining aliquot part or parts
serve to determine this volume with accuracy. The volume of the standard
solution taken X .01 == tannin as digallic acid. Ammonium acetate acts
similarly to the chloride in Gerland's method and prevents the precipita-
tion of the gallic acid. Arn. Jour. Sci., 16, 196 and 361; Allen's Commercial
Organic Analysis, Vol. in, Pt. 1, 123; Prescott's Organic Analysis, 471.
RISLER-BEUNAT, H. A method based on the precipitation with stannous chloride.
Extract 10 grams of tea thirty minutes with 500 cc water; wash the residue
with about 500 cc boiling water; cool and complete the volume to 1 liter.
Precipitate 100 cc 'of this extract with 100 cc staunous chloride solution
containing 18 grams of this salt and 2 grams ammonium chloride per liter.
Collect, wash, dry, and weigh the precipitate, then ignite with ammonium
nitrate and again weigh. Calculate the resulting SnO; to SnO, and deduct
this from the weight of the precipitate ; the remainder is the weight of the
tannin, /eitsch. f. anal. Chem., 2, 287.
SCHREINER, L. An apparatus for the absorption of tannin by hide powder. This
apparatus is so arranged that the first portions of the solution, which always
dissolve some albumin from the powder, collect in a small bulb placed below
by reason of their greater density. Der Gerber, 14, 244.
SCHULZE, F. A volumetric method employing a gelatin solution standardized by
means of pure tannin disolved in a concentrated solution of chloride of am-
monium. The gelatine is also dissolved in a concentrated solution of chlo-
ride of ammonium. In the titration, the standard solution is added until
the precipitate formed will settle within half a minute, leaving the super-
natant liquid clear. Zeitsch. f. anal. Chem., 5, 455.
SCHMIDT, E. A method employing a standard solution of lead acetate in dilute al-
cohol. A measured volume of the solution to be assayed is warmed to 60° C.
and titrated with the lead solution, using potassium iodide as an indica-
tor. Bui. Soc. Chem. [2], 21, 256; also, Jsb. d. Chem., 1874, 1035.
SACKNER. Sackner commenting on various methods for tannin considers that of
Lowenthal the most accurate. Wagner's .Jsb., 1861, 625.
SIMPKIN, S. J. A volumetric method based on the oxidation of tannin by perman-
ganate, and its precipitation by ammonium sulphate of copper. Chem.
News, 32, 11 ; also Jsb. d. Chem.
TERREIL. An improvement of Mittenzwey's method. Terreil states that 0.1 gram
pure tannic acid will absorb 20 cc oxygen in twenty-four hours. Ber. d.
chem. Ges., 5, 362; also, Compt. Rend., 78, (!'.K); also, Zeitsch. f. anal. Chem.,
13, 243.
VILLON, M. A method involving extensive calculations based on the specific gravi-
ties of the original solution, the precipitant, and the solution after filtering
off the precipitate. Lead acetate with sodium acetate is the precipitant ein-
BIBLIOGRAPHY OF LITERATURE. 1003
ployed. In the original article several of the constants for diiferent tannins
are given. Chem. News, 55, 168.
WAGNER. A volumetric method, employing a standard solution of cinchonine col-
ored with rosanaline and acidulated with sulphuric acid. Zeitsch. f. anal.
Chem., 5, 1.
WARRINGTON. A volumetric method depending upon the direct precipitation of
tannin by gelatin. A filter tube for testing is prepared by loosely introduc-
ing a piece of sponge into the end of a small tube. In filtering off a test
sample immerse the sponge in the solution, and the clear liquid will rise into
the tube. Test this filtrate with gelatin. Phil. Mag., 31, 150; also Journ.
Sci., 1848, 6, 112.
WEISS. Illustrations of apparatus for the continuous extraction of barks, etc.
Zeitsch. f. anal. Chem., 28, 114.
WILDENSTEIN, R. A coloriiuetrio method, employing strips of filter paper of vari-
ous shades and comparing them with strips of similar paper after dipping
them into the infusion which had been previously treated with an iron salt.
Zeitsch. f. anal. Chem., 2, 137.
WOLFF, E. A method for the estimation of tannin in teas, employing copper acetate
as a precipitant. The precipitate, after washing with boiling water, is dried
and ignited, moistening with nitric acid. Weight obtained X 1.304 — gallo-
tannin. Krit. Blaett., 44, 167; Zeitsch. f. anal. Chem., 1, 103.
ADDITIONAL REFERENCES TO THE LITERATURE OF TANNINS.
BtiCHNER. Tannin estimations, criticisms on. Jsb. d. Chem., 18, 862 (1867) ; Dingl.
polyt. Jour., 184, 250, 330.
CARLES, P. Tannin, gelatin solution for estimating. Chem. News, 51, 297; Zeitsch f_
anal. Chem., 24, 272 (1885).
ETTI, C. Tannic acid, composition of. Chem. Ceutrbl., 1880,204; Jsb. d. Chem.,
1880, 898.
FRANK. Tannins, estimation of. Pogg. Ann., 43, 161.
FRAAS. Tannin, improvement on Miiller's method. Zeitsch. f. anal. Chem., 5, 5;
Ergebnisse landwirthsch. und agri. chem. Versuche, Munich, (1861), 3, 41.
FREDA, P. Tannic acid, constitution of. Gazz. Chim. ital. 8, 9.
GAUHE, F. Tannin, comparison of various methods. Zeitsch. f. anal. Chem., 3, 122.
GRIESSMAYER, V. Tannin, detection of. Zeitsch. f. anal. Chem., 1872, 43; Jsb. d.
Chem., 1872, 903.
HALLWACHS, W. Tannin, criticisms on methods. Zeitsch. f. anal. Chem., 5, 231; N.
Jhrb. f. Pharm., Bd. 25, 2, 68.
HILL, ALFRED. Tannin, estimation of, in tea. Analyst, 6, 95.
HINSDALE, S. J. Tannin, colorimetric method for. Chem. News, 62, 19.
HLASIWETZ and MALIN. Tannin, note on error in estimating. Dingl. polyt. Jour.,
229, 87; Wien. Akad. Ber., 1867, 55, 19.
HOOPER, DAVID. Tannin in Indian and Ceylon teas, on the. Chem. News, 60
(1870), 311.
JAHODA, RUDOFF. The variability of the percentage of tannin in some tanning ma-
terials. Zeitsch. f. angew. Chem. (1891), 4, 104.
KOKOSINSKI, E. Tannin, determination of in hops. Ztschr. f. d. ges. Brauw. (1890),
13, 571; Chem. Ztg. Rep., 15, 3, 27.
MUNTZ and RAMSPACHER. Tannin, estimation of. Zeitsch. f. anal. Chem., 13, 462;
Compt. Rend., 79, 380.
RENISCH, H. Tannin of the sumach. N. Jhrb. d. Pharm., 25, 82 ; Zeitsch. Chem., 1866,
220; Jsb. d. Chem., 1866, 695.
SCHIFF, H. Tannic acid, constitution of. Ber. d. chem. Ges., 1871, 231, 967; Bull.
soc.chim. [2], 16,198.
1004 FOODS AND FOOD ADULTERANTS.
SCHIFF. Tannic acid, constitution and formula of. Ber. d. chem. Ges., 1872, 291, 438;
Bull. soc. chim. [2], 18, 23.
SCHIFF, H. Taunic acid, constitution of. Berichte, 1882,2588; Jsb. d. Chem., 1882,
915.
SCHMIDT, E. Tannin, modification of Pribram's method. Jsb. d. Chem., 1874, 1035 ;
Bull. soc. chim. [2], 21, 256.
HENHOUSE. Tannin, kinds of. Dingler's polyt. Jour., 165, 150.
SONNENSCHEIN. Tannin, action of, on Fehling's solution. Analyst., 10, 205.
SIMAND, F. Gelatin, substitute for, in Lowenthal's process. Analyst., 3, 125.
TRIMBLE, HENRY. Tannins, the. J. B. Lippincott Company, Philadelphia.
ULBRICHT, R. Tannin, notes on Lowenthal's method. Zeitsch. f. anal. Chem., 25,
252; Ber. d. chem. Gesell. zu Berlin, 18, 1116.
VOGL, A. Tannin in the roots of plants. Wien. Acad. Ber., 53, 156; Jsb., d. chem.
1866, 690.
WATTS. Tannin, criticisms on Fleck's method. Jsb. d. Cheni. 19, 887 (1868) ; Pharm.
J.Trans. [2], 10. 223.
CAFFETANNIC ACID.
HLASIWETZ. Caffetannic acid, derivatives of. Ann. Chem. Pharm., 142, 219; Bull.
soc. chim. [2], 9, 122; J. pr. Chem., 101, 97.
KRUG, W. H. The separation and estimation of caff'etannic acid. Original article
in this report, page 908.
LIEBICH. Caffetannic acid, action of KOH on. Jsb. d. Chem., 1849, 324; Ann.
Chera. Pharm., LXXI, 57; Pharm. Centralhalle, 1849, 855.
BIBLIOGRAPHY OF METHODS FOR THE ESTIMATION OF CAFFEINE.
ALLEN, A. H. A thin dough is made of the powdered tea, caustic lime, and water
and the whole allowed to stand several hours. It is now dried on the water-
bath, extracted with benzole, the benzole evaporated and the caffeine re-
crystallized from water. Chem. News, 29, 129, 140, 167, 189, 221; 30, 2.
BEEKMAN. The material is extracted with water containing a little sodium carbon-
ate. The aqueous extract is mixed with an alum solution, the excess of
alum precipitated by sodium carbonate and the precipitate filtered off. The
filtrate and washings are evaporated to a syrupy consistence, made alkaline
with sodium carbonate, and the caffeine extracted with ether. Zeitsch. f.
anal. Chem., 4, 206.
BLYTH, A. W. This method is based on the ease with which caffeine sublimes.
The author proceeds as follows : From one to two grams of finely powdered
tea are boiled with water for an hour in a flask connected with an upright
condenser. The whole is transferred to a porcelain dish, about its weight of
magnesia added, and the mass evaporated nearly to dryness. It is now trans-
ferred to an iron subliming plate and covered with a tarred glass funnel, the
edge of Avhich i.s accurately ground and which has a neck several inches
long. The mixture is first heated to 110° C., then slowly raised to 200° C. and
finally to 220° C. The caffeine sublimate is collected and weighed. Ana-
lyst, 2, 39 ; also in Foods : Their Composition and Analysis, A. W. Bly th.
CANADA, DOMINION OF. Ten grains of the finely ground sample are exhausted by
repeated boiling with water, filtered, the filtrate made up to a definite vol"
lime, and an aliquot part precipitated with basic acetate of lead. The filtrate
without any concentration is shaken with successive portions of chloroform.
The chloroform is removed by distillation and the caffeine is weighed. Re-
port on Adulteration of Food, Supplement III, Report of the Dept. of Inland
Revenue, 1886.
CAZENEUYE-CAILI.OL. Add to the tea four times its weight of boiling water and when
the leaves become soft add an equal weight of slaked lime. Dry and extract
BIBLIOGRAPHY OF LITERATURE. 1005
with chloroform. Distill off the chloroform and dissolve the residue in boil-
ing water. Filter and wash with boiling water. Evaporate the filtrate and
washings carefully 011 the water bath to obtain the caffeine. Zeitsch. f. anal.
Chem., 17, 221.
GLAUS, C. The material is extracted Avith ether and the extract evaporated to one-
third its original volume. This is now mixed with one-tenth of its volume of
very dilute sulphuric acid, shaken in a separator, and the acid solution run
off, successive portions of dilute acid being added until the ether is no longer
bitter. To the united acid solutions magnesium oxide in excess is added, its
whole mass dried, pulverized, and extracted with ether. The ethereal solu-
tion is evaporated and the resulting caffeine weighed. Zeitsch. f. anal.
Chem., 4, 205.
COMMAILLE, A. Five grams of the powdered tea are mixed with 1 gram of calcined
magnesia, dried twenty -four hours, and the caffeine extracted with three suc-
cessive portions of chloroform. The chloroform extract is evaporated three
times with boiling water. The aqueous extract is evaporated and the caf-
feine dried and weighed. Ber. d. chem. Ges., 8, 2, 1590.
EDER, J. M. Ten grams of tea are dried, powered, and mixed with 3 grams anhy-
drous sodium carbonate and 3 grains lead oxide. The mixture is moistened
with 10 grams of water, dried, powdered, and extracted with chloroform.
The chloroform is distilled off and the caffeine weighed. Zeitsch. f. anal.
Chem., 19, 371.
HEIJNSIUS, H. Separate the caffeine from tea by means of a subliming apparatus
similar to that employed for benzoic acid. J. f. prakt. Chem., 49, 317 ; Jsb. d.
Chem., 1849, 382; Pharm. Centralhalle, 1850, 73.
IWANOW. Extract with dilute sulphuric acid; add an excess of magnesia to the acid
extract ; evaporate and extract with ether. This method gives results uni-
formly lower than any other method. Zeitsch. f. anal. Chern., 4, 207.
KKK.MKI., A. Estimation of caffeine in guaraua. Ten grams of guarana are mixed
with 100 cc 25 per cent alcohol in a flask and the whole weighed. After digest-
ing for one to two hours on the waterbath, the loss in weight is made up
with similar alcohol and 50 cc of the solution is (= 5 grams guarana) filtered
off, mixed with calcium hydrate and dried. The finely powdered residue is
extracted with chloroform, the chloroform distilled off, and the caffeine
dried at 100° and weighed. Arch. Pharm. [3], 26, 318; Pharm. Post, 21, 101.
LIEVENTHAL, E. Extract the powdered tea with chloroform, filter, wash the residue
with chloroform. Distill off the chloroform, extract the residue several times
with boiling water, filter, and evaporate. The residue consists of caffeine.
Zeitsch f. anal. Chem., 12, 104 (orig. Pharm. Zeit. f. Russland, 11, 369).
L58CH, A. Ten to 20 grams of tea are boiled twice with water, filtered, and the residue
washed with boiling water until the filtrate runs colorless. The filtrate is
mixed with magnesia equal to 1| times the weight of tea taken, and then
evaporated to dryness on the waterbath. The residue is finely powdered and
extracted with boiling chloroform. The chloroform is evaporated in a tared
beaker, and the caffeine obtained dried at 100° and weighed. Arch. Pharm.
[3], 25, 497; Jour. Chem. Soc., October, 1887, 1002.
MARKOWNIKOFF, W. Ten grams of tea are extracted with 500 cc of water, after
having been mixed with 30 grams of magnesia. The extract is filtered, the
filter being washed with hot water and the filtrate and washings mixed with
a little magnesia and sand, then evaporated to dryness. The residue is ex-
tracted with hot benzole, the benzole distilled off, and the caffeine weighed.
Ber. d. chem. Ges., 9. G1313.
PAUL, B. H. Author states that he has proved by experiment that chloroform can
not be substituted for alcohol in determining caffeine in tea. By chloroform
1006 FOODS AND FOOD ADULTERANTS.
he obtained 1.3 per cent caffeine from a tea known to contain 3.78 per cent.
Boiling alcohol was then used and the rest of the caffeine was obtained. Ex-
periments were made to determine whether caustic lime decomposed caf-
feine. By experiment he determined that caustic lime does not decompose
caffeine under the conditions obtaining in analysis, but that lime exerts a
restraining influence on the extractive power with chloroform. Complete
extraction of caffeine was obtained with boiling chloroform when magnesia
was used. Pharm. J. Trans., March 1891, 882.
PAUL and COWNLEY. Five grams of powdered tea are moistened with hot water,
well mixed with 1 gram of calcicum hydrate, and the whole dried on the
water bath. The dry residue is then transferred to a small percolating appa-
ratus and extracted with strong alcohol. The clear liquor is evaporated to
remove the alcohol and the remaining water solution, which amounts to about
50 cc, is mixed with dilute sulphuric acid which separates traces of lime and
partially decolorizes the liquid. After filtering it is transferred to a sepa-
rator and well shaken with chloroform, about 200 cc, in five to six successive
portions. The united chloroform solutions are then placed in a separator
and shaken with very dilute sodium hydrate. This renders the caffeine quite
colorless. The chloroform is then distilled off and the caffeine weighed.
Phar. J. Trans., [3], 908, 417.
PATROUILLARD, C. Fifteen grams tea are extracted with boiling water until com-
pletely exhausted. The liquid is filtered, evaporated to the consistence of
an extract, mixed with 2 grams calcined magnesia and 5 grams powdered
glass, and dried, The residue is ground to powder, extracted three or four
times with 60 cc of ether and this solvent then distilled oft". The crystals
of caffeine obtained are redissolved in chloroform and recrystallized. Chem.
Ztg. No. 9, Feb. 26, 1880; Chem. News, 42, 259.
PELIGOT. Make an aqueous extract of the tea, precipitate with lead acetate, add
ammonium hydrate, andheat. Filter, pass hydrogen sulphide into the liquid,
and filter again. Evaporate to a proper consistency and allow the caffeine
to crystallize. This chemist determined the caffeine in exhausted tea leaves
by means of a standard tannin solution, but does not give the details of his
method. Zeitsch f. anal. Chem., 4, 207.
SCHWAKZ, M. H. Exhaust the tea with boiling acidulated water, neutralize with
lime, evaporate to dryness, and exhaust the residue with ether. Evaporate
collect, and weigh the caffeine. Bull. Soc. Chim. de Paris Aug. 5, 1876, 3;
Chem. News, 34, 94.
SMITH, E. D. Coarsely powdered coffee (0.65 gram) is mixed with 0.13 gram mag-
nesia, boiled 15 minutes with 150 cc water, filtered, and the filtrate made up
to 300 cc by percolation. The filtrate is evaporated to 20 cc and the residue
treated with 120 cc strong alcohol, transferred to a filter, and washed with
alcohol. The alcohol is then drawn off and the residue dissolved by gradual
addition of small quantities of water. This water solution is extracted three
times with 25 cc chloroform. The chloroform is distilled off and the caffeine
dried and weighed. Chem. Centrbl. 1887, 1270, 1271 ; Zeit. oesterreich. Apoth.,
Ver., 41, 359.
SNYDER, HAKUY. Author states that the albuminoids of tea are almost entirely in-
soluble in hot water. He extracts the powdered sample with four or five
portions of hot water, collects the residue on a filter (S. & S. No. 589), and
transfers filter and contents to a digestion flask, and determines the nitrogen
by the Kjeldahl method. Total nitrogen in the sample (as determined by
Kjeldahl method for alkaloids), less nitrogen of the insoluble portion, gives
the alkaloidal nitrogen from which the caffeine may be determined. See
Kozai's article on teas, which gives the distribution of the nitrogen, page
879, Journ. Anal. Chem., 4, 443.
BIBLIOGRAPHY OF LITERATURE. 1007
STAHLSCHMIDT. Extract the tea six hours with water; precipitate with basic lead
acetate ; decant and wash the precipitate by decantation. Remove excess
of lead by H2S ; filter off the PbS and evaporate the filtrate to a sirup. Ex-
tract this with hot benzole, which on evaporation will yield the caffeine.
Poggendorf 's Annalen, 112, 441; Cheiu. centrbl., 1861,396.
THOMPSON. Exhaust the tea by boiling with water, remove the tannin by means of
lead acetate, and free the filtrate from lead by means of hydrogen sulphide.
The lead sulphide is filtered off and the caffeine precipitated in the filtrate
by means of potassium carbonate. The caffeine is crystallized from an alco-
holic solutiou to purify it. Zeitsch. f. anal. Chem., 1872, 203; Jsb. d. Chem.,
1872, 924.
VITE, F. The author has made a critical study of the methods for the estimation of
caffeine in teas. He adopted a modification of Hilger's method. Extract 5
grams tea, 3 times, one hour each, with successive portions water of about
300 cc. ; evaporate the united extracts to one-fourth the original volume, and
while still hot add fresh lead hydrate and coarse sand. Dry on water bath
and extract with ehloroform. Collect the caffeine as usual and dry at a
temperature not exceeding 100° C. — Mitth. Lab. ang. Chem. Erlaugen, 3, 131;
Chem. Centrbl. (1890), 2, 274; Journ. Chem. Soc. 140, 372.
WAAGE. This chemist prefers Mulder's method modified as follows : Ten grams tea
are exhausted by boiling four times with water, the exhaustion requiring
about three hours. The decoction should amount to about two liters. It is
evaporated to a syrupy consistence after filtering. The residue is mixed with
2 grams magnesia and 5 grams pure sand, dried, extracted in a Soxhlet appa-
ratus with anhydrous chloroform, and this extract carefully evaporated. The
caffeine is purified by dissolving in water, filtering, evaporating to dryness,
drying two hours at 100C C., and weighing. — Archivd. Pharm, 225, 443 ; Zeitsch.
f. anal. Chem., 28, 257.
WEYKICH. This author has examined various methods of caffeine estimation and
reports as follows :
Peligot's method is very unreliable and must be rejected, as the titration
Avith tannin must of course be very uncertain and the tannin besides precipi-
tates many other substances.
Zoller's method gives a very impure caffeine, and the long heating with a
concentrated acid may cause decomposition of caffein. The method is also
quite complicated.
Loewenthal's method is uncertain, as the chloroform is unable to penetrate
the tea sufficiently to dissolve all the thein. Besides it dissolves other sub-
stances.
The author finally recommends Mulder's method as being simple and accu-
rate. The magnesia in this method must be very finely pulverized, as the ether
extraction may otherwise be incomplete. The mass previous to extraction
must be pulverized in a warm mortar. Zeitsch f. anal. Chem., 12, 104.
ZOLLER. Extract the powdered leaves with quite concentrated sulphuric acidt
dilute the extract with water, neutralize with lead hydrate, and evaporate
to dryness. Extract the residue with 85 per cent alcohol, filter, and evapo-
rate to dryness. Extract the caffeine from the residue by means of ether,
distill off the ether, and weigh the caffeine. Zeitsch f. anal. Chem., 12,106.
ADDITIONAL REFERENCES TO THE LITERATURE OP CAFFEINE.
AUBERT. Caffein, per cent of in coffee. Dingl. Polyt. Jour., 206, 500; Jsb. d. Chem.,
1872, 805.
ATTKIELD, J. Caffeine in cola nuts. Jsb. d. Chem., 1865, 632. Pharm. J. Trans.
[2]) 6, 457.
BOTTGER, R. Caffeine;deteptionpf. Zeitsch. f. anal, Chein.; 1873, 442 j Jsb, d, Chem,;
1873, 960,
1008 FOODS AND FOOD ADULTERANTS.
BOTTGER, R. Caffein, reaction of. Pol. Notizblatter, 1873, 257; Zeitsch. f. anal.
Chem. (1873), 12, 442.
Caffeine, influence of, on digestion. Journ. Chem. Soc., 1889, 534.
Caffeine oxalate. Jourri. Chem. Soc., 1889, 1018.
Caffeine, oxidation of, with ozone. Journ. Chem. SOP., 1889, 1017.
Caffeine in coffee. Pharm. Transactions, 1887, 565.
Caffeine, synthesis of. Chem. News, 1889, June 28, 305.
COMMAILLE, A. Caffeine, estimation of in coffee. Compt. Rend., 81, 817-819.
FISHER, E. Caffeine, derivatives of. Jsb. d. Chem., 1881, 902; Ber. d. chem. Ges.,
1881, 637, 1905.
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Monit. scien. [3], 12, 381,433.
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[2], 128, 206.
HECKEL and SCHLAGDENHAUFFEN. Caffeine in cola nuts. Jsb. d. Chem., 1882, 1162;
Compt. Rend., 94, 802.
HILGER. Caffeine, determination of. Zeitsch. f. anal Chem., 28, 257 (orig. Arch. d.
Pharm., 223,828).
HINTEKBERGER. Caffeine, compound of, with mercuric chloride. Aim. Ch. Pharm.,
78, 201; Jsb., 1851, 474.
KOHL and SWOBODA. Caffeine, compound, with mercuric cyanide. Wien. Acad. Ber.,
9, 252; Ann. Chem. Pharm., 83, 339; Jsb. d. Chem., 1852, 549.
LAFEAN, A. H. Caffeine, solubility in alcohol. Phar. J. Trans. [3], 11, 902; Jsb. d.
Chem., 1881, 902.
LEHMANN, J. Caffein, physiological action of. Jsb. d. Cheni., 1853, 751 ; Ann. Chem.
Pharm., 87, 205,275; J. pr. Chem., 62, 104.
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sch. f. anal. Chem., 25, 565.
MALYAXD HINTEREGGER. Caffeine, constitution and derivatives. Monatsh. f. Chem.,
1882, 85.
PAUL andCowNLEY. Caffeine, content of, in teas. Centrbl., 1890, 2, 491.
PAUL and COWNLEY. Caffeine, estimation of, in tea. Journ. Chem. Soc., 106, 540.
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ROCHLEDER. Caffeine, decomposition of. Ann. Chem. Pharm., 69, 120 ; Jsb. d. Chem.,
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SCHMIDT, E. Caffeine, literature of. Ber. d. chem. Ges., 14, 814.
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BIBLIOGRAPHY OF LITERATURE. 1009
SCHWARZENBACH. Caffeine, reaction of. Chem. Centralbl., 1861, 989; Zeitsch. f.
anal. Chem. 1, 229.
SPENCKK, G. L. Estimation of caffeine. Jour. Anal. Chem. ,4, October, 1890. See
this report, page 889.
STUAUCH, A. Caffeine, properties of. Jsb. d. Chem., 1867, 808, 770. Zeitsch. f. anal.
Chem., 6, 503.
STRECKKK. Caffeine, preparation of, from Theobromine. Ann. Chem. Phar., 108,
151; Compt. Rend., 52, 1210. 1268.
TIEMANN, F. Caffeic and hydrocaffeic acids. Ber. d. chem. Ges., 1878, 659.
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Soc. Jour. [2], 3, 99; Jour. pr. Chem., 96, 371; 98, 245.
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Pharm. Centrbl., 1851, 889; Jsb. d. Chem., 1851, 474.
BIBLIOGRAPHY OF THE LITERATURE OF CHICORY.
ANDERSON, Th. Chicory, analysis of ash of. Pharm. Centrbl., 1853, 525.
CHEVALLIER. Chicory, method of detecting adulterations of. J. Pharm. [3], 16,
50; Dingl. polyt. Journ., 102, 387.
DRAPER, C. Chicory, detection of. Philos. Magaz., 38 (No. 228), 104; Zeitsch. f.
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1222.
HrssoN, C. Chicory, detection of. Ann. Chim. Phys. [5], 21, 419-426; Jour, of the
Chem. Soc., 36, 558.
KRAUCH, C. Chicory and cereals, detection of. Ber. d. chem. Ges., 1878, 277; Jsb.
d. Chem., 1878, 1163.
KRAUCH, C. Chicory, detection of. Biedermann's Centrbl., July, 1878.
LEEBODY, J. R. Chicory, detection of. Chem. News, 30, 243.
LKEBODY, J. R. Chicory, colorimetric determination. Chem. News, 30, 243.
MAYER, A. Chicory, analyses of. Biedermann's Centrbl., 1885, 828; J. Chem. Soc.,
1886, 50, 388.
MARQUIS. Chicory, adulteration of. J. Pharm. [3], 24,210; Jsb. ii. d. Fort, der Chem.,
1853, 752.
FADE, L. Chicory, detection of. Bull. Soc. Chim. de Paris, 1887, 47, 501; Jsb.
d. Chem., 1887, 258.
PETERMANN, A. Chicory, analyses of. Biedermann's Centrbl. 1883, 843 ; Jour. Chem.
Soc. 46, 648.
POLYTECHXISCIIE GES. zu BERLIN. Chicory, detection of. Dingl. polyt. Jour.,
211, 78; Jsb. d. Chem., 1874, 1043.
PRUNIER. Chicory, detection of. J. Pharm. Chem. [5], 1, 222; Jonr. Chem. Soc.,
1880, 514.
RIMMINGTON, F. M. Chicory, detection of, in coffee. Analyst, 6, 2. Pharm. J.
Trans. [3], 11, 529; Jsb. d. Chem., 1881, 1215.
SMITH, ALBERT. Chicory, detection of. Chem. News, 34, 283.
SCHULZ, HUGO. Chicory, ash of, analysis of, Z. des Ver. f. Riibenzuckerindus-
trie, 1866, 435.
\\MTTSTEIX, G. C, Chicory, detection of, Am. Chemist, 6, 220.
APPENDIX B.
UXITED STATES TEA ADULTERATION J.AW.
Be it enaoted by the Senate and House of Representatives of the United States of Amer-
ica in Congress assembled, That from and after the passage of this act it shall be un-
lawful for any person or persons or corporation to import or bring into the United
States any merchandise for sale as tea, adulterated with spurious leaf or with ex-
hausted leaves, or which contains so great an admixture of chemicals or other dele-
terious substances as to make it unfit for use ; and the importation of all such merchan-
dise is hereby prohibited.
SEC. 2. That on making entry at the custom-house of all tea or merchandise de-
cribed as tea imported into the United States, the importer or consignee shall givee
a bond to the collector of the port that such merchandise shall not be removed from
warehouse until released by the custom-house authorities, who shall examine it with
reference to its purity and fitness for consumption; and that for the purpose of such
examination samples of each line in every invoice shall be submitted by the importer
or consignee to the examiner, with his written statement that such samples represent
the true quality of each and every part of the invoice, and accord with the specifi-
cation therein contained ; and in case the examiner has reason to believe that such
samples do not represent the true quality of the invoice, he shall make such further
examination of the tea represented by the invoice, or any part thereof, as shall
be necessary : Provided, That such further examination of such tea shall be made
within three days after entry thereof has been made at the custom-house: And pro-
vided further, That the bond above required shall also be conditioned for the payment
of all custom-house charges which may attach to such merchandise prior to being
released or destroyed (as the case may be) under the provisions of this act.
SEC. 3. That if, after an examination, as provided in section 2, the tea is found by
the examiner not to come within the prohibition of this act, a permit shall at once
be granted to the importer or consignee declaring the tea free from the control of the
custom authorities; but if on examination such tea, or merchandise described as tea,
is found, in the opinion of the examiner, to come within the prohibitions of this act,
the importer or consignee shall be immediately notified, and the tea, or merchandise
described as tea, so returned shall not be released by the custom-house, unless on
reexaminatoin called for by the importer or consignee the return of the examiner
shall be found erroneous : Provided, That should a portion of the invoice be passed by
the examiner, a permit shall be granted for that portion, and the remainder held
for further examination, as provided in section 4.
SEC. 4. That in case of any dispute between the importer or consignee and the ex-
aminer, the matter in dispute shall be referred for arbitration to a committee of three
experts, one to be appointed by the collector, one by the importer, and the two to
choose a third, and their decision shall be final ; and if, upon such final reexamina-
tioii, the tea shall be found to come within the prohibitions of this act, the importer
or consiguee shall give a bond, with securities satisfactory to the collector, to export
such tea, or merchandise described as tea, out of the limits of the United States
1011
20393— No. 13 10
1012 TEA ADULTERATION LAW.
within a period of six months after, such final reexamination ; but if the same shall
not have been exported within the time specified, the collector, at the expiration of
that time, shall cause the same to be destroyed.
SEC. 5. That the examination and appraisement herein provided for shall be made
by a duly qualified appraiser of the port at which said tea is entered, and when
entered at ports where there are no appraisers, such examination and appraisement
shall be made by the revenue officers to whom is committed the collection of duties,
unless the Secretary of the Treasury shall otherwise direct.
SEC. 6. That leaves to which the term "exhausted" is applied in this act shall
mean and include any tea which has been deprived of its proper quality, strength, or
virtue by steeping, infusion, decoction, or other means.
SEC. 7. That teas actually on shipboard for shipment to the United States at the
time of the passage of this act shall not be subject to the prohibition thereof.
SEC. 8. That the Secretary of the Treasury shall have the power to enforce the
provisions of this act by appropriate regulations.
Approved, March 2, 1883.
APPENDIX C.
ABSTRACTS FROM THE ITALIAN LAW (AUGUST, 1890) RELATING TO THE
ADULTERATION OF FOODS.
[Translated from Revue Internationale de Falsifications, 15 Juin, 1891.]
XXI. — COFFEE.
ART. 155. It is forbidden to apply the name "coffee," or to sell under this name
any substance, whether in the form of grains or powder, which does not consist ex-
clusively of the product of the plant Coffea AraMca.
ART. 156. Under the following conditions, it is forbidden to sell genuine coffee
beans :
(a) When colored by means of objectionable or injurious substances;
(6) When roasted and ground with spent coffee ("coffee grounds") or with foreign
substances.
ART. 157. Coffee substitutes and mixtures must not contain any harmful sub-
stance, and can only be sold under a name indicating the nature and name of the
substances entering into the preparation, and must never be sold under the name of
genuine coffee. These brands or marks must be entered on the books of the dealer
and upon the invoices, bills of lading, etc.
XXII.— TEA.
ART. 158. The sale is forbidden of tea (leaves of Thea Chinensis) artificially colored
or sophisticated by means of the addition of foreign leaves or mineral matters ; also
the sale of exhausted or damaged tea leaves ; and further, the sale is forbidden under
the name "tea" of leaves coming from any other plant.
XXIII. — CHOCOLATE.
It is forbidden to sell chocolate (powder or the preparations of Theobroma cacoa
and sugar) sophisticated with lime,, ocher, or other substances, mineral or vegetable,
which are indigestible or harmful.
1013
LIST OF LEAVES ILLUSTRATED BY PLATES XXXIX AND XL.
1. Tea.
2. Mate", or Paraguay tea (Ilex Paraguayaensia).
3. Camellia (Camellia Japonica).
4. Hawthorn.
5. Box Elder.
6. Horse Chestnut.
7. Sycamore.
8. Rose.
9. Plum.
10. Elm.
11. Ash.
12 and 13. Willow.
14. Beech.
15. Oak.
16. Missouri, or Golden Currant.
17. Ash.
18. Common Red Currant.
19. Birch.
20. Poplar.
21. Raspberry.
22. Jersey Tea (Ceanathw Americanus).
1014
BULL. NO. 13, DIV. OF CHEMISTRY.
GENUINE TEA LEAVES AND POSSIBLE ADULTERANTS
BULL.N9I3 DIV.OF CHEMISTRY.
XLJ
r%r>'~
*! ~- ft""^ •»
TEA LEAF x 115
Upper surface of epidermis.
TEA LEAF xl!5
Lower surface of epidermis.
A.H nen I Co. Heliocauslic .Bahimare
BULL.N9I3 DIV.OFCHEMISTBY.
xr.n
STONE CELL OF TEA LEAF x 115
SEED COAT OF COFFEE x55
"Coffee Flights."
A.HnEn & Cn.Helincaustic .Baltimore ,
BULL.N9I3 DIV.OF CHEMISTRY.
PLATE XLJIT
EAW COFFEE x55
Cross section.
WHEAT BRAN x!15
Outer or longitudinal layer.
HElincauslic,BahimnrE.
BULL.N°I3 DIV.OFCHEMISTBY.
WHEAT BRAN xl!5
Second or transverse layer.
WHEAT BRAN x55
Gluten layer.
A.HDEH I Co.Heliacaustic ,Balt i mare .
BULL.N9I3 DIV.OF CHEMISTRY.
CHICORY (ROASTED) x95
Parenchyma cells and milk vessels.
CHICORY (ROASTED) x95
Pitted cells.
A.Hnen X CD.HEliDcaustic .Bahimnre.
BULL.N<?I3 DIV.OF CHEMISTRY.
PLATE XLYI
COCOA X75
Epidermis of Husk.
COCOA HUSK xl!5
Characteristic thick-walled cells.
A.HnEnXCD.HElincauslic,BahimnrE.
BULL.N°I3 DIV.OF CHEMISTRY.
PLATE XLVII
COCOA HUSK x!15
Thin inner membrane.
COCOA xl!5
Section of cotyledon.
A.HnEnXCD.Helincaustic.Ballininre.
INDEX.
A.
Page.
Acid, caffetannic 1004
Acorns, detection of 912
Adulteration of coffees, definition of the 908
foods, definition of 879
Italian law relating to 1013
Adulterations of teas - 880
Albuminoid nitrogen, estimation of 908
Albuminoids of cocoa, food value of : 939
Ammonia, detection of the use of, in the manufacture of cocoas 956
Analyses of cocoa beans, summary of, by various chemists 960
husks by various chemists 962
preparations by various chemists 959
summary of, by the Department of Agriculture 985
Analysts, general remarks to .' 892
Analytical methods for cocoa preparations 949
the constituents of teas 889
Ash, acid required to neutralize, from 2 grams of cocoa preparations 956
alkalinity of, in teas 891
determination of, in cocoas 956
insoluble in acid, estimation of, in teas 891
of cocoa beans and preparations, analysis of . 969
cocoas/, quantitative and qualitative examination of 950
soluble and insoluble , estimation of, in teas' 891
maxima, minima, and mean percentage of, in teas 883
total, estimation of, in teas 891
soluble and insoluble of coffees 908
Association Swiss Analytical Chemists, report of 985
Astringents, foreign, in teas 884
Azo-colors, detection of 910
B.
Bibliography of the literature of tea, coffee, and cocoa 991
Black teas 876
Brazil coffee ~-, 900
Brick, particles of, detection of, in teas 886
C.
Cacao-masse 941
definition of.. 942
Caffeine, bibliography of methods for the estimation of 1004
detection of __.,-_,--..--_---.--. 905
I
II INDEX.
Page.
Caffeine, estimation of 889
in coffees _ ._ 907
in coffees 904
presence of, in cocoa beans 939
Caffetannic acid 905,1004
estimation of 908
Carbohydrates of coffee 905
Catechu, examination of teas for 885
Canna seed 912
Cereals, ash of 912
detection of „ 912
Ceylon coffee 900
Chicory, bibliography of the literature of , 1009
detection of 910
Draper's method for the estimation of 911
formula for the quantitative estimation of, in coffees 911
milk vessels of 911
Premier's method for the estimation of 911
Chocolate a la noisette, definition of : 942
Chocolate, definition of 942
Chocolates, preparation of 941
Cocoas and chocolates, recommendations in regard to the examination of _ 986
Cocoa, aroma of 941
astringent principle of 940
beans and preparations, analysis of, by Bensemann 967
analyses of, by various chemists 960
analyses of commercial preparations of „ 963
commercial preparations of 941
chemical constituents of 935
nonalkaloidal nitrogenous substances of 939
relations between the constituents of , 968
butter, commercial value of ,-.„„-, _.. ,-._____ 936
extraction of , , ---r- 936
properties of . 936
effect of different processes of manufacture on the chemical constit-
uents of 944
fat, physical and chemical constants for 933
properties of 936
fate, variations in the melting and congealing points of 987
food value of 989
gum, properties of 941
manufacture, losses in.. . 934
microscopical examination of 956
powders, examination of, by Stutzer 943
soluble, definition of 942
preliminary processes of manufacturing 934
preparation of, for analysis - 949
preparations 933
adulterations of 945
analyses of, by various chemists - 962
in the Department of Agriculture 980
analytical methods for 949
bibliography of the literature of 991, 99§
INDEX. m
Page.
Cocoa preparations, definition of, Swiss Association of Analytical Chem-
ists 942
description of samples of- 971
discussion of results of examination of - 987
examination of, in the Department of Agriculture,--. 970
microscopic examination of 946
red - 940
solubility of, in water 985
starch, measurements of the grains of 948
starch of 940
statistics of 935
Summary of analyses of, by the Department of Agriculture 985
tree, description of 933
Coffee . - 899
ash of - - - 904
average price of, from 1878 to 1890 . .... 900
beans, imitation, analyses of - . 919
seized by the French Government, composition of. 920
Roumanian Government, composi-
tion of 920
specific gravity of 919
size of 901
berries, sophisticated 918
bibliography of the literature of - . - 991, 993
bought in the open market, description of 921
Brazil - 900
Ceylon - 900
chemical composition of 901
consumption, statistics of 900
extracts - 929
presence of tin and copper in 929
facing of 909
fat 905
glazing of . ...,. 913
imitation 915
Java 900
presence of pentose-yielding substances in 907
roasted, composition of 903
with sugar 914
without sugar 914
substitutes 914,932
unroasted, composition of •__ 902
West India 900
Coloring matter of cocoas 940
cocoa preparations, determination of 956
Copper, detection of, in teas. 886
presence of, in coffee extracts ' 929
Crude fiber, estimation of, in coffees 908
E.
Exhausted leaves, detection of, in teas ___ 882
Extyact, half hour, Geissler's averages for 882
total. Geissler's averages for 882
of teas.. 891
IV INDEX.
Page.
Extracts of coffee 929
Ewell, Ervin E.; report of , on cocoa preparations 933
F.
Facing mixtures for coffees 909
of coffees 909
teas 880
detection of 881
objections to •_ 887
Pat, cocoa, estimation of 950
qualitative examination of 951
determination of, in cocoa preparations 956
estimation of, in coffees . 908
Fiber, determination of 958
in cocoa preparations 955
Fixed alkalis, detection of the use of, in the manufacture of cocoa prepa-
rations 956
Flour, detection of, in cocoa preparations 955
G.
Geissler , Joseph F. , analyses of genuine teas by 882
Glazing of coffees, objections to the 914
Glucose, commercial, determination of, in chocolates 954
Green coffees ... 927
teas . . 878
Ground coffees 927
adulterated 929
results of the examination of . _ 928
Gum, determination of, in cocoa preparations .- 956
of cocoas, properties of • 941
Gypsum, detection of, in tea facing 881, 885
I.
Imitation coffee beans, analyses of 919
seized by the French Government, com position of- 920
seized by the Roumanian Government, composi-
tion of 920
specific gravity of 919
coffees 915
composition of _ 916
circulars of dealers in regard to 917
detection of 920
India teas 878
Indigo, detection of. in facing 881
Iron, magnetic oxide of, detection of, in teas 886
metallic, said to be sometimes present in adulterated teas 885
salts, examination of teas for 885
Italian law relating to the adulteration of foods 1013
J.
Java coffee 900
coloring of *. 900
K.
KunstKaffee.. 914
INDEX. V
L. Page.
Leguminous seeds — 912
Lie tea. .'. 886
detection of 886
M.
Mangoldwurzel, detection of 911
Mannite, presence of, in coffees 905
Microscopic examination of cocoa preparations 946
Mogdad coffee 913
Moisture, determination of, in cocoas 950-956
coffees . 907
in teas, Geissler's averages for 882
Mussaenda coffee - 913
N.
Nitrogen, albuminoid, Stutzer's method for 890
determination of, in cocoa preparations 956
estimation of .' 890
O.
Organic matter, water-insoluble, determination of 956
P.
Plumbago, detection of, in facing 881
Prussian blue, detection of, in facing 881
R.
Rio coffee 900
Roasted coffees 926
adulterants of 926
S.
Sand, detection of, in teas 886
Sawdust - 912
Soapstone, detection of, in tea facing 881, 885
Soluble cocoa . 945
Sophisticated coffee beans 1 918
Spent leaves, detection of, in teas 882
Starch, Allen's method for the detection of 912
average amount of, in cocoa and chocolate 986
determination of, in cocoa preparations , 954
McElroy's method for the determination of 957
of cocoas 940
precentage of, in materials used in cocoa manufacture 958
Starches used as adulterants of cocoa 949
Stone cells, presence of, in tea leaves 884
Substitutes for coffee . 914
Sugar and sirup, treatment of coffee with 913
determination of . 957
estimation of, in cocoa preparations 954
Swiss Analytical Chemists' Association, report of 985
T.
Tannin, bibliography of the methods for.-- _ 99.7
determination of, in cocoa preparations 956
VI INDEX.
Page.
Tannin, estimation of 890
maxima, minima, and mean percentages of, in tea 883
Tartaric acid, estimation of, in cocoas , ^ 941
Taylor, Dr. Thomas, method of, for preparing leaves for microscopic ex-
amination 884
Tea . . ... 875
adulterants, general remarks on * 886
adulteration law, United States ^ _it *^.. 1011
bibliography of the literature of . :........ 991, 992
general classification of , • „ _ 875
green . ;. . 878
half-hour extract of »k j . A . . . . <. 892
leaf, general examination of ^ . 884
leaves, stomata of , ^ 884
maxima, minima, and mean percentages of tannin in 883
theinein 883
statistics of the consumption of 875
Teas, adulterations of 880
analyses of 894
analytical methods for the constituents of 889
black 876
China, analyses of .. . 888
classification of . 888
description of samples of 892
estimation of insoluble-leaf of 891
foreign astringents in 885
leaves in 883
general statements concerning the constituents of 887
green and black, comparative analyses of 879
India 878
Japanese flat 878
method of judging the quality of 877
methods of manufacturing » 876
proposed chemical method for estimating value of 888
qualitative examination of 896
table showing the condition of the leaves and foreign matters pres-
ent 896
remarks on qualitative examination of 897
Theine, estimation of 889
maxima, minima, and mean percentages of, in tea 883
presence of, in every part of a theine-producing plant- - - - 884
sublimation test for. . 884
Theobroma cacao 933
Theobromine, proprieties of — 937
Tin poisoning 930
presence of, in coffee extracts 929
Turmeric, detection of. in facing 881
W.
Water, estimation of, in teas 891
insoluble organic matter of cocoas 985
Wax palm, fruit of, as a coffee substitute 915
West India coffee . . 900
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