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Issued May 10, 1912.

U.S. DEPARTMENT OF AGRICULTURE,
BUREAU OF CHEMISTRY—BULLETIN No, 155,

H. W. WILEY, Chief of Bureau.

LARGE SCALE EXPERIMENTS ON THE
PROCESSING OF JAPANESE
PERSIMMONS;

WITH NOTES ON

THE PREPARATION OF DRIED PERSIMMONS, ©

BY

H. ©. GORE,

Assistant Chemist, Division of Foods.

WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1912.

ORGANIZATION OF BUREAU CF CHEMISTRY.
R. E. DoouittLe, Acting Chief of Bureau.
F. L. Dunuap, Associate Chemist. :
W. D. eee Assistant Chief of. Bureau.
F. B. Linton, Chief Clerk.
JG: ae Supervisory Clerk, Interstate and Import Records.
A. L. Pierce, Editor.
A. E. Draper, Librarian.
Division of Foods, W. D. Brertow, Chief. :
Food Inspection Laboratory, L. M. Touman, Chief.
Food Technology Laboratory, EK. M. Cuace, Chief, and Asiaing Chief of Division.
Oil, Fat, and Wax Laboratory, HS. BAILEY, “Nnefe 2s
Division of Drugs, L. F. Kresurr, Chief.

Drug Inspection Laboratory, G. W. Hoover, Chief.
Synthetic Products Laboratory, W.O. EMERY, Chief.
Kssential Oils Laboratory, E. K. NELSON, Chief.
Pharmacological Laboratory, WILLIAM SALANT, Chief.

Chief Food and Drug Inspector, W. G. CampBELL.
Miscellaneous Division, J. K. Haywoop, Chief.

Water Laboratory, W. W. Skinner, Chief.

Cattle-Food and Grain Laboratory, Ger Bipwett, Acting.
Insecticide and Fungicide Laboratory, C. C. McDoNnNeELL, Chief.
Trade Wastes Laboratory, under Chief of Division.

Contracts Laboratory, P. H. WaLKer, Chief.

_ Dairy Laboratory, G. E. Patrick, Chief.

Food Research Laboratory, M. E. PENNINGTON, Chief.
Leather and Paper Laboratory, F. P. Veitcn, Chief.
Microchemical Laboratory, B. J. Howarp, Chicf.
Physical Chemistry Laboratory, C. S. Hupson, Chief.
Sugar Laboratory, A. H. BRYAN, Chief.

Sections:

Animal Physiological Chemistry, F.C. WEBER, in Charge. °
Bacteriological Chemistry, G. W. STILEs, in Charge.
Enological Chemistry, W. B. ALwoop, in Charge.
Nitrogen, T. C. Trescot, in Charge.

Plant Physiological Chemistry, J. A. LECitERc, Chief.
Food Technologist, A. W. Brrrina.

Food and Drug Inspection Laboratories:

' Boston, B. H. Smiru, Chief.

Buffalo, WwW. L. Dvxois, Chief.
Chicago, A.L _ WINTON, Chief.
Cincinnati, B. Rz Hart, Chief.
Denver, RS. HintNer, Chief.
Detroit, H.L. Scuvutz, Chief.
Galveston, G. M. BARTLETT, Acting.

- Honolulu, Hawaii; A. W. HANSON, Acting.
Kansas City, Mo., F. W. LIEPSNER, Chief.
Nashville, R. W. "BaLcom, Chief. : Sees
New Orleans, Wed. McGex, Chief
New York, A. W. OGDEN, Acting.
Omaha, 8. H. Ross, Chief.

Philadelphia, C.8. BRINTON, Chief.
Pittsburgh, M. C. ALBRECH, Chief
Portland, Oreg. vege KNISELY, Chief.
St. Louis, D. B. BisBez, Chief.

St. Paul, A. S. MircHext, Chief.

San Francisco, R.A. GouLp, Chief.

- San Juan, P. R., A. E, TAYLOR, Acting.
Savannah, Ww. C. BURNET, Chief.

Seattle, H. M, Loomis, Chief.

Issued May 10, 1912.

LS DEPARTMENT OF AGRICULTURE,
BUREAU OF CHEMISTRY—BULLETIN No, 155.

H. W. WILEY, Chief of Bureau.

LARGE SCALE EXPERIMENTS ON THE
PROCESSING OF JAPANESE
PERSIM MONS;

WITH NOTES ON

THE PREPARATION OF DRIED PERSIMMONS.

BY

H. GC. GORE,

Assistant Chemist, Division of Foods.

WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1912.

LETTER OF TRANSMITTAL.

U.S. DEPARTMENT OF AGRICULTURE,
BUREAU OF CHEMISTRY,
Washington, D. C., March 14, 1912.
Sm: I have the honor to submit for your approval an account of
certain experiments which have been conducted during the past
year by H. C. Gore, of this bureau, on the processing of Japanese
persimmons on a large scale and on the preparation of the dried
fruit. Mr. A. V. Stubenrauch, of the Bureau of Plant Industry, has
cooperated with Mr. Gore throughout the course of the work, giving
advice as to the general scope and conduct of the experiments. From
the data herein recorded explicit directions for processing persim-
mons on a large scale may be formulated and an idea obtained of the
probable place that processing may hold in the persimmon industry.
The preparation of dried persimmons on a laboratory scale indicates
that a product of excellent quality may be obtained by the use of
simple methods.
I recommend that this manuscript be printed as Bulletin 155 of
the Bureau of Chemistry.
Respectfully, Tes Wis Waray

| Chief of Bureau.
Hon. JAMES WILSON,

Secretary of Agriculture.

CON Es:

Page
MEROCIICELOM re cece ete ere en Senha yee tM le eis ata ISNT SM 5
Apparatus and methods used in processing...........------ yep Ou teraiere at cea 5
HxperimentsjatMacclemmny Hla ce yee Face fay seein ee Pe ee in aaa a 9
Haspenments atiGlenoti Many lass a aac. a9 EY an Bete aioe, aotebainl Cae evel 12
PxpemimentsjacowWasmino tons Wi C2. cece ep ati s to uke she Se Ss ae betes oe 12
DISCUSS ONEOUreSUNtseaec Aten eas yee a ses tie a wild ccc eee peutne ge 18
EFeparavion OL (ried persimaMOonget 6 set ceem sew asc.' ae jae cece oe ses ess 19
SSUDIOUU TTD ENA ee SS ake OS AES aS I ah ae ee ae a eer A Sane 20
PE Ske DON, S
Page
Fic. 1. Apparatus used in processing Japanese persimmons...............-.... i
2. Rate of softening of processed and unprocessed Tane-nashi persimmons
keptat ditierent temperatures, sean tse. chao rete sae een 15
3. Rate of softening of processed and unprocessed Zengi persimmons kept
ac Gitzeremt GOMUpeTACURES cc sae soe Seyi) Wels cette ols a iegc toe wcities ook 17

LARGE SCALE EXPERIMENTS ON THE PROCESSING OF
JAPANESE PERSIMMONS; WITH NOTES ON THE PREPARA-
TION OF DRIED PERSIMMONS.

INTRODUCTION.

During the seasons of 1907 to 1910, inclusive, experiments on
Japanese persimmons were carried on in cooperation with Mr. Taylor
and Mr. Fairchild, of the Bureau of Plant Industry.1. It was found
that upon, keeping the fruit for several days in an inert gas such as
carbon dioxid it becomes nonastringent while remaining firm. Dur-
ing the season of 1911 experiments on processing in carbon dioxid
were extended to a semicommercial scale in order to determine the
value of the method when applied to the commonly grown varieties
of Japanese persimmons.

In the experiments described herein, except when otherwise noted,
the persimmons to be processed were placed in large containers of
galvanized iron, which were then tightly closed. The air was then
displaced by carbon dioxid. When the fruits had become non-
astringent they were removed and kept under observation in com-
parison with check lots consisting of unprocessed fruits of the same
picking, to determine the effect of the treatment on their keeping
and shipping qualities. Each variety so treated in Florida was sub-
jected to a shipping test, while the persimmons processed by keeping
in carbon dioxid at Washington were used in studies on keeping at
different temperatures.

APPARATUS AND METHODS USED IN PROCESSING.

The apparatus used in processing is shown in figure 1. It con-
sisted of tanks of galvanized iron (A), in which the fruit was
processed on a large scale, glass desiccators (B), in which a few per-
simmons could be treated at a time, and liquefied carbon dioxid in
steel cylinders (C). Each of the galvanized iron boxes was 25 inches
square and 24 inches high. It was large enough to hold four of the
six-basket carriers commonly used in shipping persimmons. The
upper edge and cover were so constructed that the box could be
closed air-tight by means of clamps. This construction, shown in de-
tail at (D), was designed by Mr. S. J. Dennis, of the Bureau of Plant

i1U.S. Dept. Agr., Bureau of Chemistry Bul. 141. 5

6 PROCESSING OF JAPANESE PERSIMMONS.

Industry, and proved entirely satisfactory. The cost per box, with
accessories, was as follows:

Por boxand: cover. ssss25e¢ae eit eae Se ee eee $18. 00
One dozen:Clamips: sae youre ee ie aren re eee tener oer 3. 00
Three brass:stopcocks, at 27 cents each.........-.--.-...-- . 81

One and one-fourth pounds of white rubber tubing, at 79
CONS! POUNGL Eee was eee eke ek Ree ae ees 1.00
Xo) Fe rte ee a gram oe ween nie we Ge AM rt Se ees oa Ee 2208

It is recognized, however, that some changes would be desirable
if tanks for processing persimmons were to be made in quantity. In
such a design the rims of the tanks and covers should be made of cast
iron hinged together and fitted with eyebolts and slots. The adja-
cent surfaces should be planed and a solid rubber gasket used. The
design shown in figure 1 does not require special castings.

In processing persimmons these tanks are filled with the fruit,
which may be packed, if desired, in the standard six-basket carriers,
and may or may not be wrapped. The cover is clamped in position,
and the box tested for tightness by use of the water gauge (KE). It
should be entirely free from leaks on the bottom or sides, and so tight
that the rate of equalization of small differences in pressure, indi-
cated by the gauge, is slow. Carbon dioxid is then passed in through
the lower stopcock, while the displaced air flows out at the upper
stopcock on the opposite side. The water gauge is useful here in
cuarding against too high pressures, which might easily cause per-
manent distortion in shape, or bursting. The flow of carbon dioxid
is continued until the stream of displaced air tastes strongly of car-
bon dioxid. After such a taste is noted, the flow is continued for a
few minutes longer; the stopcocks are then closed and the box left
undisturbed for the time required in processing.

The necessity of opening the tanks to ascertain the progress of the
processing should be avoided by placing a few persimmons in process
in smaller containers. The most convenient apparatus for this pur-
pose is the tubulated glass desiccator of the pattern shown in (B),
which may be obtained from dealers in scientific apparatus. It
should be kept at the same temperature as that of the tanks, on
account of the influence of temperature on the rate of processing. (See
p. 14.) As shown in (B), it is fitted with a rubber stopper carrying
necessary delivery tubes. These may be of glass, or preferably of
copper or other metal. The stopper should be well lubricated before
forcing it into place, so that it will fit air-tight, and then be tied in
position. The ground-glass surfaces must be plane. They are coated
with vaseline. In displacing the air the carbon dioxid is passed in
through the delivery tube, which reaches to the bottom of the desic-
cator. It is well to fasten the cover in place with cord or small
clamps, because increases in pressure in the desiccator occasioned by
the formation of carbon dioxid in the fruit may cause it to pop off

APPARATUS AND METHODS USED IN PROCESSING. 7

suddenly. The fruits in the desiccator are examined from time to
time to determine when processing is completed, taking care to close
at once after opening and to renew the supply of carbon dioxid quickly.

Carbon dioxid may be purchased from dealers in soda-water sup-
plies in liquefied form in steel cylinders holding 10 or 20 pounds at
about 10 cents per pound. ‘This is equal to a cost of about 1.1 cents

7g D

—
olan:

Fic. 1.—Apparatus used in processing Japanese persimmons. A. Tank of galvanized iron. B. Desic-
cator. C. Cylinder of liquefied carbon dioxid with reducing valve’ D. Detail showing construc-
tion of edges of the tank and cover. E. Water gauge.

per cubic foot of the gas when expanded to atmospheric pressure.

These cylinders of liquefied carbon dioxid are under very high pres-

sure and must not be handled roughly; neither is it safe to allow them

to become heated by the direct rays of the sun. The reducing valve,
which is shown attached to the cylinder in figure 1, is very useful in
regulating the flow of carbon dioxid, and may usually be obtained of

8 PROCESSING OF JAPANESE PERSIMMONS.
the dealer supplying the gas. If no reducing valve is used, sudden
stoppages will usually occur during the outflow due to the choking
of the orifice in the needle valve with solid carbon dioxid. Such
stoppage is usually followed by a sudden rush of gas, and very close
watching is necessary if annoying accidents are to be avoided.

Processing experiments were conducted at the nurseries of the
Griffing Bros. Co. at Macclenny, and at the Glen St. Mary nurseries
at Glen St. Mary, using in all cases fruit freshly picked from the trees.
Two of the iron tanks were used at each locality. At the outset it
was supposed that the control of the humidity was an important
feature in processing, and so the treatment of the persimmons was
conducted in one of the tanks at each locality, with no attempt made
to lessen the very humid conditions which occur during processing,
while in the other the humidity was somewhat lessened by dis-
tributing about 50 pounds of dry starch among the persimmons.
Perceptible differences in the amounts of moisture which collected at
the top of the boxes during the processing period were noticeable in
the experiments at each locality, but as no injury traceable to exces-
sive humidity was observed at any time, the measures taken to lessen
it are without importance.

The experiments in Florida were started September 19 and com-
pleted September 27. During this period the diurnal changes in
temperature were quite uniform, as shown by recording thermome-
ters operated at each locality. The experiments at Macclenny were
conducted in a carriage shed, the doors of which were usually kept
closed. Here the temperature ranged from 70° to 86° F., with an
average of about 77° F. At Glen St. Mary experinents were carried
on in an open shed, and the temperature variation was from 73° to
99° F., with an average of about 80° F.

The number of fruits used in process and in check lots and the
time required in processing are shown in Table I.

TABLE I.—Time required in processing different varieties of Japanese persimmons.

Number of fruits— |

Time re-

FASVETAGE | ala hc a ee ee : ‘
Variety. Where processed. Date. tempera- qenedan

ture. In In con- dioxid

process. trol :

————— |

1911. ie | Days.
Tumphs.=---)) Macclenny, wia---a5-- sere Sept. 19-22... 77 395 118 23
Do kee | Sisese oe eee Sept. 22-24. ._| 77 196 117 12
Imperial......- [Saves ea ec peeps a Ti eh Reema Sept. 19-22...| 77 219 100 43
Wachivasse2-- bo GO Serene eae Sake Sept. 19-26... 77 144 & 7
Dor. ones Washington) D.C) Oct. 5-15..... 69 9 9 10
Okames sf ck Macclenny, HLA Fae voc Eee re Sept. 19-24... 77 49 25 AR
Tane-nashi.....]..... Oe en ed eae Sept. 19-26... 77 By ay 18 7
Dore 222522 Gien St: Marys @la.2 2-2 Sept. 20-27... 80 431 1 200 7
DO. hee Washington, ie Candee Sees Oct, 119. 69 474 100 12

VAS Slt Ae eae Macclenny, #a..- 22. ...25.5-- Sept. 25-27... 77 447 253 2
Doe Se Washington yD Crone ee OGia2s—2ie ee 69 540 100 =
Hyakume.....- Macclenny; Pla. - 2222 2:522226- Bel: is eta 77 3 0 13
TWEMON 2 eee GOT re CRE SDs eye aivoe ee 77 2 0 13
Cosiataz<-oes-e Glen St. Mary, Fla........---- See 30.34 cae 80) P2222 ee =
Taber’s 23.....- Washinston, ()) Clseste ae OG 51a. eee 69 68 71 2

1 Approximately.

EXPERIMENTS AT MACCLENNY, FLA. 9

The various lots of persimmons were quite evenly ripened and of
the degree of maturity at which they are usually picked for ship-
ment to northern markets, with the exception of Okame (see p. 10).

EXPERIMENTS AT MACCLENNY, FLA.

At Macclenny the following varieties were processed: Triumph,
Imperial, Hachiya, Okame, Tane-nashi, Zengi, Hyakume, and Yemon.

Trvumph.—Two experiments were made with this variety. Two
and one-half days and one and two-thirds days in carbon dioxid,
respectively, were required before the persimmons were nonastrin-
gent. In the first experiment 513 fruits were used, of which 395
were processed, while 118 constituted the control. On the comple
tion of the processing all of the persimmons in the tanks, with the
exception of one specimen which softened, were as hard as when
placed in process. Of the control 90 were firm, and 28, or 24 per cent,
were softening. Three days later the processed fruits were noticed
to be rapidly deepening in color, many possessing the beautiful deep
red shade characteristic of this variety when ripe. This color change
distinguished them sharply from the check lots, which were still
yellow. Several of the processed reddened fruits were tasted at
this time in contrast with normally ripened specimens. The flavor
of the former was slightly but distinctly less agreeable than that of
the latter, the fruits lacking freshness. On the following day the
firm persimmons of the experiment, both processed and controls,
were packed in earriers and sent to Washington, D. C., by express.
They arrived at the department promptly and were kept at about
60° F. until they were examined on October 2. The processed fruits
were found to have softened greatly and were utterly ruined for com-
mercial purposes, but the controls, as a whole, were firm and in good
condition.

On September 22 a second lot of Triumph persimmons was placed
in process at 6 o’clock p.m. These fruits were found to be non-
astringent two days later at 10 a. m., an interval of 40 hours. The
processed fruits showed the reddening conspicuously on September
26 but had not softened. The firm fruits of the experiment were
then sent to Washington in the same shipment with those of the
first experiment. Upon inspection on October 2 the processed per-
simmons were found to be in very poor condition, resembling closely
the first lot of processed Triumph, though they were not so badly
softened, whereas the controls were in excellent condition.

From these two experiments it is evident that the variety processes
readily in from 40 to 60 hours at Florida temperatures and that
after removal from the carbon dioxid it may be kept for four days
at these temperatures before deterioration, except a slight loss in

37998°—Bull. 155—12——2

10 PROCESSING OF JAPANESE PERSIMMONS.

flavor, occurs. It would therefore be practicable to process this
variety for local use, since it is no more perishable when removed
from the carbon dioxid than are most small fruits or peaches. It is
clearly shown, however, that processing greatly injures the naturally
excellent carrying qualities of this variety.

Imperial—This variety resembles Costata in size and shape. A

total period in carbon dioxid of four and one-half days was required.
During keeping for two days after processing 24 per cent softened,
while 8 per cent of the controls softened. The firm processed and
contro! fruits were sent to Washington in the same shipment with
Triumph. When examined, on October 2, the processed specimens
were found to be softening, while the control fruit was in good con-
dition. As in the case of Triumph, it is clear that while this variety
may be processed for marketing locally it is not advisable to process
with a view to shipping long distances.
- Hachiya.—This fruit required seven days in which to become non-
astringent. On shipment to Washington all of the processed fruits
softened, while the controls remained firm. These softened speci-
mens were delicious in eating quality when examined on October 2,
although they were not quite so palatable as normally ripened fruits.
The difference was at first noticeable only by careful comparison with
softened specimens among thecontrols. The processed fruit rapidly
lost in eating quality on keeping in the laboratory, the flesh darkening
noticeably from day to day. It is evident that it is impracticable to
process this variety except for local use.

Okame.—But relatively few of these fruits were available, and they
were as a whole very unevenly ripened, the color ranging from green
to orange yellow. Care was taken to include in the processed and
control lots equal proportions of specimens of the different degrees of
ripeness. They processed in four and one-half days. No difference
in time of processing the fruits of different degrees of maturity was
evident, the immature fruit becoming nonastringent about as rapidly
as the more highly colored persimmons. During the two days’ keep-
ing at Florida temperatures following the removal of the processed
fruit from the container a large proportion (35 per cent) of the treated
fruit softened, while all of the control remained firm. On shipping
to Washington all of the processed fruits had softened by October
2, the controls remaining firm. In this case, therefore, as with the
three varieties just mentioned, processing injures the shipping quality
very seriously. : 3

Tane-nashi.—Seven days were required in carbon dioxid. During
this period 56 per cent of the controls softened, while all of the speci-
mens in process remained firm. The examination of the fruits at
Washington on October 2 showed both processed and control fruits
to be softening. No deterioration in flavor or color such as was

EXPERIMENTS AT MACCLENNY, FLA. ll

noted in the case of Triumph and Hachiya occurred with the proc-
essed fruits of the Tane-nashi variety. When soft the processed
specimens could not be distinguished from those that had softened
normally.

Zengi.—Two groves of persimmons at the Griffing Bros.’ nurs-
eries at Macclenny bear fruit resembling Zengi but differing from it
as ordinarily described in:‘that most of the fruit is yellow-fleshed and
seedless as well as much larger in size. It closely resembles in habit
of tree, lateness, and size and shape the variety known as Taber’s
23, and indeed the fruits of the two varieties can not be distinguished.

A large number of these Zengi persimmons were gathered and
placed in process on September 25. Two days later the fruit was
found to have become sweet. The processed specimens, together with
the controls, were expressed to Washington, D. C., on September 27
and were examined on October 2. In marked contrast to all the other
lots experimented with in Florida, the processed fruit as well as the
controls endured the shipment without softening. From this time
on counts were made of the firm and softened fruits at intervals until
October 20, when the fruit had dried out to such an extent that the
counts became uncertain. The figures are shown in the following
table: ;

TaBLE I1.—Rate of softening of processed and unprocessed Zengr persimmons shapped
to Washington from Macclenny and kept at a temperature of about 69° F.

Percentage of softened fruit.

Watel Interval after
picking. Processed (447 | Control (253
specimens). specimens).
1911 Days.
OCtiee sro 13 28 30
NO Senseo ne 15 39 44
LS eee ieeae roe 19 46 50
ORs sae ee 22 63 55
I feta eae 5 24 69 57
PANES Greener 26 72 60

It is evident that although processing perceptibly accelerates soft-
ening, the effect is but slight and not apparent until 22 days after
picking. The natural excellent shipping qualities of the variety
were therefore uninjured. No deterioration in flavor or color occurred.
The processed persimmons were excellent in flavor at all times before
and after softening.

Hyakume and Yemon.—But three and two specimens, respectively,
of these varieties were available for study. They were processed in
desiccators, becoming nonastringent in 36 hours. It is regretted that
it was not possible to secure more specimens so as to determine the
effect of processing on the rate of softening. Both varieties are of
distinct promise in view of the fact that they become nonastringent
very readily.

a? PROCESSING OF JAPANESE PERSIMMONS.
EXPERIMENTS AT GLEN ST. MARY, FLA.

At Glen St. Mary the processing tanks were filled on September 20
with Costata and Tane-nashi. Costata required four days, while Tane-
nashi processed slowly, requiring seven days before the fruit became
edible. During this time at least one-third of the contro] Tane-nashi
had softened. For several reasons an exact count of the controls was
not made. The processed Costata and Tane-nashi were sent to
Washington, D. C., by express on September 27, together with the
firm specimens of their controls. The fruit was kept at about 60° F.
after its arrival in Washington until October 3, when it was examined.

Costata.—The processed fruits had softened much more than the
controls and had darkened somewhat, so that they were hardly mar-
ketable. The controls shipped successfully.

Tane-nashi.—The processed fruit was found to be in good condition

‘on examination in Washington and the unprocessed fruit also stood
the transportation excellently. In the following table are shown the
percentages of softened fruits when first examined, and two and four
days later.

TaBLe II1.—Rate of softening of processed Tane-nashi persimmons shipped to Washing-
ton after processing at Glen St. Mary and kept at a temperature of about 69° F.

|

¢ | Percentage oi softened fruit.
| |
| Interval after
Date. Sere |
picking. | Processed (431 , Control (125
specimens). | specimens).
1911. | Days. |
fPeOct Ser cootee.e 13 | 38 33
Sess Aaa ae 15 81 | 57
| 7 aaah wa | 17 99 | 77

In this instance it will be noted that the processed fruit is not com-
pared with the original control, but with the fruits of the control which
were firm on September 27. A distinct effect of the processing in
hastening the rate of softening of the persimmons is evident.

EXPERIMENTS AT WASHINGTON, D. C.

Four varieties were processed at Washington. These were Hachiya
and Paber’s 23, from Mr. Macklin at Dinsmore, Fla.; Zengi, from the
Griffing Bros. Co. at Macclenny; and Tane-nashi, from the Glen St.
Mary Nurseries Co.

Hachiya.—Eighteen large, evenly ripened fruits were received on
October 5. Nine were placed in carbon dioxid in desiccators, while
the remainder served as checks. Ten days were required for process-
ing at an average laboratory temperature of about 69° F. Six days
later all of the processed fruits were softening, while three of the con-
trols still remained firm. The processed fruits gradually darkened

EXPERIMENTS AT WASHINGTON, D. C. 13

and lost flavor. This result confirms the experience with Hachiya
processed in Florida.

Taber’s 23.—This variety, which so greatly resembles the Zengi
grown at Macclenny (see p. 11), was received on October 5. The fruits
placed in carbon dioxid became nonastringent at laboratory tempera-
tures averaging 69° F. in two days. All of the 68 fruits so processed
remained firm, while of 71 control specimens 8, or 11 per cent, were
softening at the end of the two days. The data on the subsequent
rate of softening are given in the following table:

TaBLe LV.—Rate of softening of processed and unprocessed Taber’s 23 persimmons.

Percentage of softened fruit.
Interval after
Date. placing in
carbon dioxid. | Processed (68 Control (71
specimens). specimens).
1911 Days
OCR eee eee 0 11
Da ae eee Ue Bt © 9 25 18
LZAiss ene ae 12 25 34
Di eeepc ky ok V2 20 45 48
BOR Sener 25 63 63

The rate of softening is thus shown to be practically unaffected by
the processing. No darkening of the flesh or deterioration in flavor
occurred at any time, either before or after softening.

Tane-nashi.—A large shipment of Tane-nashi was received by
express on October 7 and placed at once under observation. One
carrier of fruit was held in the laboratory at a temperature averaging
69° F., another was kept in a refrigerator at about 52° F., and a third
was held in cold storage at 35° F. These average temperatures are
estimated from the record sheets of thermometers kept beside the
respective samples. These lots were used as controls of fruit which
was processed at room temperature and then stored at these three
temperatures. Four hundred and seventy-four persimmons were
placed in process. These became nonastringent after an interval of
12 days, and all remained firm except 17, or 4 per cent, which were
softening from decay. During the same interval, of the controls at
room temperature, 82 per cent became soft, and of the fruits held at
refrigerator and cold-storage temperatures, 42 per cent and 6 per
cent, respectively, softened. Three lots of 100 specimens each of
the firm processed persimmons were selected for keeping at the three
temperatures mentioned. All of the fruits were wrapped. ‘The rates
of softening of each of these three lots and their controls were deter-
mined by counting at intervals. The results are shown in Table V
and are given graphically in figure 2.

14 PROCESSING OF JAPANESE PERSIMMONS.,

TaBLe V.—Rate of softening of processed and unprocessed Tane-nashi persimmons kept
at three different temperatures.

Room temperature. er ecrater, tempera- Cole sirens tempera-

| interval. SSS See
Processed | Control Processed Control | Processed | Control
(100). (90). (100). (88). (100). (73).
Days | Per cent Per cent Per cent Per cent. Percent. | Percent
ye Rae) [a aS es See SHE | Hee Pte ah od ADIN acerca he sae
iy eee 7 91 4 | 61 = 6
72 eae Se 97 | 98 4 | 73 4 7
7 eg ee 99 | 71 i ene Oe (eas SS 2 tb ee | Sasso oae
S05:oa5-e2 100 99 10 95 5 7
See ee (Se es Cae aU i Pee Da BSS ese [ae Ie ie | he SL ti
SSeS sees Gece eee hese ree 38 100 6 10
ro RE ik Sk |e een ea Sea ee Gio aaa aoe 7 15
52 Ee Sob oo] See Eee oe |e ce Sete O48 eS ace eee 7 15
Ue See (es eee nee (Ee eee LOOSE eee ee. 10 | 16
rae ener pes Pee Beg errue lee ee = Se ee eee 16 | 21
if eee Mee ae oo See Re ita ee A | ied Reh ee 43 | 26
RE eis ibe hea ell Fosiereah oe ss Ee api el Omi abe 63 | 40

1 The total number of fruits used in each lot is given at the top of each column.

The persimmons softened after removing from the process decidedly
more rapidly at room temperature than did the controls. The refrig-
erator temperature delayed the softening of the processed fruit
markedly, but as soon as rapid softening began the rate was about
the same as that of the control; the curves are practically parallel.
In cold storage the processed fruit at first softened less and then more
rapidly than the control. In no case was conspicuous injury to the
fruit caused by the keeping in carbon dioxid. It must be kept in
mind, however, that the data are incomplete, as studies on the
behavior of the fruit on withdrawal from cool temperatures are lack-
ing. Certain abnormalities, such as darkening of the flesh at bruised
places and blackening of the flesh near the calyx, occurred after 29
days in refrigerator storage, and it is probable that the persimmons
would not have held up well if withdrawn at this time and kept under
market conditions. The abnormalities were more frequent among
the processed fruits than among the controls. The results of this
experiment show that processing is fairly successful with this variety.
The fact that a longer time was required for the persimmons to become
nonastringent in Washington than in Florida is probably due to differ-
ences in temperature.

Zengi.—A large number of the yellow-fleshed Zengi were received
late in the afternoon of October 23, and were placed in process on
the following morning. About 1,100 fruits were received, and of these
840 perfectly sound and firm specimens were selected for the experi-
ments in processing. They were divided into several lots, the plan of
the experiment being identical with that just described for Tane-nashi.
Three lots of 100 fruits each were placed in common, refrigerator, and
cold storage, respectively, and the remainder placed in process at room
temperatures. The average temperatures were practically the same as

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8

EXPERIMENTS AT WASHINGTON, D. C.

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PROCESSING OF JAPANESE PERSIMMONS.

16

in the preceding experiment with Tane-nashi. Four days were required
in processing. All fruits but one remained firm, while of the controls at
room temperature 16 per cent had softened. Three lots of 100 speci-
mens each of the processed fruits were kept at the three temperatures
and counts of all lots were made at intervals, all fruits being kept. _
wrapped. The rate of softening of the various lots of persimmons
is shown in Table VI and graphically in figure 3.

TasiE VI.—Rate of softening after processing of Zengi persimmons kept at three different

temperatures.
| : : | cota
Room temperature. Sees EL tempera- | Col BOs: eh tempera-
Interval. SARE
Processed. | Control. | Processed. | Control. | Processed.| Control.
Days Per cent Per cent. Per cent. Per cent. Per cent. Per cent.
A nape alabaa eh EL a at eee N Re ea a ICR a
Greene 2 29 0 1 0 1
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a US ave A S 71 (as a fae Mae eke ee a aA el ON! bo AB a
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Die nemesis 92 73 6 14 0 2
FHS MO ase 3 100 87 17 33 0 2
DAO TA RAINS || SO aa RG AEN pares iI a ei Wee ord lhe eee ee aed
SL 53 Se Reps Se poe ese 98 91 64 0 2
A) Nile pice rage AW Re nT ICT cee trees DUNN Neps. gE cn ey 100 100 0 3
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(SB Se eee ee DN Se UE ge ee UE NCare | Ler aera bee Cha PR ay Deca a 17 36
TT pees 6s eps || eae Pen nee | US Ae Cen yea Be mates [an an Oe Hi 36 71

In many respects the curves resemble those obtained with Tane-
nashi. The processing period, however, is very much shorter. The
rate of softening of this variety was even better controlled by cooling
to refrigerator temperature than in the case of Tane-nashi. The
processed persimmons softened slightly more rapidly than the con-
trols at room and refrigerator temperatures, respectively, but the
differences are too small to be of practical importance. The processed
fruit in cold storage softened somewhat less rapidly than the controls.
No abnormalities among the firm or softened Zengi persimmons
occurred on keeping either at room, refrigerator, or cold storage
temperatures.

Lots of from 6 to 12 specimens of the processed Zengi fruit were
mailed on October 27 to 12 retail fruit dealers in various cities and to
5 growers of persimmons in the South. Of the fruit dealers, 8 ex-
pressed the opinion that a demand would have to be created for proc-
essed fruit before it could be expected to sell. Only 3 commented on
the excellent quality of the persimmons, while 2 expressed a preference
for the normally softened fruit. On the whole, the comments of the
fruit dealers were less favorable than was expected. This probably
indicates that less difficulty is now being had in selling the astringent
Japanese persimmons in their natural state than was the case a few

17

EXPERIMENTS AT WASHINGTON, D. C.

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18 PROCESSING OF JAPANESE PERSIMMONS.

years ago. That the astringency of the Japanese persimmon will
continue to retard greatly its wide introduction seems, however,
probable. All of the 5 growers pronounced the samples of most
excellent eating quality.

DISCUSSION OF RESULTS.

From the experiments just described some idea is given of the value
of persimmon processing when applied to the varieties of Japanese
persimmons commonly grown in this country. It can be recom-
mended generally for treating the fruit for local distribution, as none
of the varieties when processed were more perishable than are the
small fruits or peaches. It can not be recommended, however, if the
fruit is to be subsequently shipped for long distances except in the case
of the seedless yellow-fleshed Zengi and Taber’s 23, as the naturally
fine shipping qualities of the persimmons are greatly injured. Zengi
and Taber’s 23 are not unfavorably affected. Possibly the fruit
could be successfully shipped for long distances after precooling, as
cool temperatures retard the rate of softening considerably, but this
is a subject for further study, Processing may be successfully em-
ployed after shipment, and it would seem to be particularly useful in
so treating those varieties which, when ripened naturally, must
become extremely soft before they are edible. The most conspicuous
example of persimmons of this type is Hachiya, the most beautiful as
well as one of the largest of all varieties. If placed in carbon dioxid
when it is highly colored but firm it may be rendered nonastringent in
a much shorter time than when the fruit is more immature, and when
so processed is of most delicious eating quality.

It is hoped that the ease by which the remarkable change in the
fruit may be brought about will induce others to experiment with it,
as it is probable that it must be repeatedly tried by a number before
its place in the persimmon industry is definitely established.

Col. Watrous'in his report on persimmon processing by the Japa-
nese method notes that it is expert work requiring skill and judgment;
this is true also of processing in carbon dioxid. The maturity of the
fruit and the temperature must be considered by the operator, while
the time required in processing, the acceleration in rate of softening,
and effect on flavor must be determined before it is possible properly
to draw conclusions as to the application of the process to any par-
ticular variety. The operator is especially cautioned not to use
apparatus of a makeshift nature; for example, the employment of
wooden containers for the fruit, which though apparently air-tight
may allow diffusion of gases through the wood. The air must be
displaced and kept away from the main lot of fruit in process for the
time indicated by the small lots in the desiccators. If the air is not

1U.S. Dept. Agr., Bureau of Chemistry Bul. 141, p.6.

PREPARATION OF DRIED PERSIMMONS. 19

so excluded delays in processing may be expected, while the fruit may
soften rapidly both in process and afterwards and misleading results
be obtained.

A number of important varieties remain to be tested to determine
how rapidly they become nonastringent when placed in carbon
dioxid and the effect of the treatment on the rate of softening and on
the flavor. Among these are Yemon, Hyakume, Taber’s 129, and
the newly introduced Chinese and Japanese varieties which are not
yet fruiting in sufficient quantity for such experiments.

PREPARATION OF DRIED PERSIMMONS.

From time to time during the past few years persimmons have been
dried in a steam-heated evaporator at the Bureau of Chemistry.
Until the present season such experiments were purely of a prelimi-
nary nature. It was developed, however, that certain precautions
must be taken to insure satisfactory results. It was found necessary
to peel before drying, as otherwise the skin becomes very tough and
the shape of the fruit is distorted. It was desirable to peel and slice
in such a way that the fruit is not stained by contact with iron knife
blades, which quickly become coated with the blue-black iron-tannin
salts. Nickel-plated knives were found useful. To secure the best
appearance of the dried fruit it should be sliced at right angles to the
axis, and spread on trays of galvanized or tinned wire netting in such
a way that every part of each slice is well aerated, as darkening
occurs wherever the aeration is not sufficient. It was found best to
dry at temperatures not exceeding 122° F. The variety Tane-nashi
is most suitable for drying. It is of large size and the trees are pro-
ductive. As there are no seeds circular disks showing the beautiful
star-shaped centers can be cut easily and the fruit dries practically
without change in color.

A large quantity of Tane-nashi grown at Glen St. Mary, Fla., was
dried at Washington, D. C., during the season of 1911, using the pre-
cautions just mentioned. It became nonastringent soon after plac-
ing in the drier. When removed, the dried slices were kept in a closed
container for several days so that they became equalized in moisture
content and were pliable. They were then pressed into small bricks
and distributed to a number of persons interested in persimmons.
The comment on the whole was very favorable. Many likened them
to dried figs or dates. Samples have been kept under observation
in the laboratory in tin boxes held in closed glass jars for three months.
The color darkened slightly during thisinterval, but the fruit remained
perfectly sound and the flavor excellent. The drying of the seedless
variety Tane-nashi is of much promise in view of the ease with which
a very attractive product may be prepared.

20 PROCESSING OF JAPANESE PERSIMMONS.
SUMMARY.

A method of processing persimmons on a large scale by keeping in
carbon dioxid is described and an account is given of experiments in
the application of the method to persimmons in Florida and at
Washington, D. C. 3

(1) All of the varieties tried became nonastringent when kept in
carbon dioxid. The intervals in days necessary for processing at
Florida temperatures are given in parentheses following the name of
each variety: Triumph (12 to 24); Imperial (44); Hachiya (7);
Okame (44); Tane-nashi (7); Zengi (2); Costata (4); Hyakume (14),
and Yemon (14).

(2) All of these varieties were processed on a large scale in Florida
and subjected to a shipping test with the exception of Hyakume and
Yemon. With one exception (yellow-fleshed Zengi) processing
greatly injured the naturally excellent shipping qualities of the fruit.
~Tane-nashi was less seriously affected than many of the others.
Zengi was practically unaffected in shipping quality by the treatment.
Processing, therefore, can not be recommended for persimmons which
are to be shipped long distances with the exception of Zengi and
Taber’s 23 (with which the yellow-fleshed Zengi is possibly identical),
but it is practicable to process all of the varieties mentioned for
marketing locally.

(3) No undesirable effects were produced by high humidity while
in process.

(4) Processing in carbon dioxid at Washington required more time
than in Florida, probably on account of the lower temperatures.

(5) Keeping at refrigerator or cold storage temperatures consider-
ably retarded the softening of the persimmons.

(6) An excellent product in appearance and flavor was obtained
by drying Tane-nashi persimmons.

pee COPIES ofthis publication
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