• TABLE OF CONTENTS
HIDE
 Title Page
 Credits
 Introduction
 Description of the varieties
 Utilization of grapes
 Holding fresh fruit
 Conclusion














Group Title: Bulletin - University of Florida Agricultural Experiment Station ; 329
Title: Utilization and storage of Florida grapes
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Permanent Link: http://ufdc.ufl.edu/UF00027674/00001
 Material Information
Title: Utilization and storage of Florida grapes
Series Title: Bulletin - University of Florida Agricultural Experiment Station ; 329
Physical Description: Book
Language: English
Creator: Abbott, Ouida Davis
Loucks, K. W.
Publisher: University of Florida Agricultural Experiment Station
Publication Date: 1938
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Bibliographic ID: UF00027674
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Table of Contents
    Title Page
        Page 1
    Credits
        Page 2
    Introduction
        Page 3
    Description of the varieties
        Page 4
        Page 5
    Utilization of grapes
        Page 6
        Page 7
        Page 8
    Holding fresh fruit
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
    Conclusion
        Page 14
Full Text


December, 1938


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA
WILMON NEWELL, Director









UTILIZATION AND STORAGE


OF FLORIDA GRAPES


By
OUIDA DAVIS ABBOTT and K. W. LOUCKS


Bulletins will be sent free to Florida residents upon request to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA


Bulletin 329







EXECUTIVE STAFF

John J. Tigert, M.A., LL.D., President of
the University
Wilmon Newell, D.Sc., Director
Harold Mowry, M.S.A., Asst. Dir., Research
V. V. Bowman, M.S.A., Asst. to the Director
J. Francis Cooper, M.S.A., Editor
Jefferson Thomas, Assistant Editor
Clyde Beale, A.B.J., Assistant Editor
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Manager
K. H. Graham, Business Manager
Rachel McQuarrie, Accountant

MAIN STATION, GAINESVILLE
AGRONOMY
W. E. Stokes, M.S.., Agronomist'
W. A. Leukel, Ph.D., Agronomist
G. E. Ritchey, M.S., Associate2
Fred H. Hull, Ph.D., Associate
W. A. Carver, Ph.D., Associate
John P. Camp, M.S., Assistant
Roy E. Blaser, M.S., Assistant

ANIMAL HUSBANDRY
A. L. Shealy, D.V.M., Animal Husbandman'
R. B. Becker, Ph.D., Dairy Husbandman
L. M. Thurston, Ph.D., Dairy Technologist
W. M. Neal, Ph.D., Asso. in Dairy Nutrition
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian
N. R. Mehrhof, M.Agr., Poultry Husbandman
O. W. Anderson, M.S., Asst. Poultry Husb.
W. G. Kirk, Ph.D., Asst, An. Husbandman
R. M. Crown, B.S.A., Asst. An. Husbandman
P. T. Dix Arnold, M.S.A., Assistant Dairy
Husbandman
L. L. Rusoff, M.S., Asst. in An. Nutrition'

CHEMISTRY AND SOILS
R. V. Allison, Ph.D., Chemist'
R. M. Barnette, Ph.D., Chemist
F. B. Smith, Ph.D., Soil Microbiologist
C. E. Bell, Ph.D., Associate
R. B. French, Ph.D., Associate
H. W. Winsor, B.S.A., Assistant
J. Russell Henderson, M.S.A., Assistant
L. W. Gaddum, Ph.D., Biochemist
L. H. Rogers, M.A., Spectroscopic Analysts
Richard A. Carrigan, B.S., Asst. Chemist

ECONOMICS, AGRICULTURAL
C. V. Noble, Ph.D., Agricultural Economist'
Bruce McKinley, A.B., B.S.A., Associate
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Assistant

ECONOMICS, HOME
Ouida Davis Abbott, Ph.D., Specialist'
Ruth Overstreet, R.N., Assistant

ENTOMOLOGY
J. R. Watson, A.M., Entomologist'
A. N. Tissot, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant

HORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist'
A. L. Stahl, Ph.D., Associate
F. S. Jamison, Ph.D., Truck Horticulturist
R. J. Wilmot, M.S.A., Spec. Fumigation Res.
R. D. Dickey, B.S.A., Assistant Horticulturist
J. Carlton Cain, B.S.A., Asst. Horticulturist
Victor F. Nettles, M.S.A., Asst. Hort.

PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist'
George F. Weber, Ph. D., Plant Pathologist
R. K. Voorhees, M.S., Assistant3
Erdman West, M.S., Mycologist
Lillian E. Arnold, M.S., Assistant Botanist


BOARD OF CONTROL

R. P. Terry, Chairman, Miami
Thomas W. Bryant, Lakeland
W. M. Palmer, Ocala
H. P. Adair, Jacksonville
Chas. P. Helfenstein, Live Oak
J. T. Diamond, Secretary, Tallahassee

BRANCH STATIONS

NORTH FLORIDA STATION, QUINCY
L. O. Gratz, Ph.D., Plant Path. in Charge
R. R. Kincaid, Ph.D., Asso. Plant Pathologist
J. D. Warner, M.S., Agronomist
Jesse Reeves, Farm Superintendent

CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Horticulturist in Charge
John H. Jefferies, Superintendent
Michael Peech, Ph.D., Soils Chemist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Asst. Entomologist
W. W. Lawless, B.S., Asst. Horticulturist

EVERGLADES STATION, BELLE GLADE
J. R. Neller, Ph.D., Biochemist in Charge
J. W. Wilson, Sc.D., Entomologist
F. D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane
Physiologist
Jos. R. Beckenbach, Ph.D., Asso. Horticul.
Frederick Boyd, Ph.D., Asst. Agronomist
G. R. Townsend, Ph.D., Asso. Plant Path.
R. W. Kidder, B.S., Animal Husbandman
W. T. Foresee, Ph.D., Asst. Chemist
B. S. Clayton, B.S.C.E., Drainage Engineers

SUB-TROPICAL STATION, HOMESTEAD
W. M. Fifield, M.S., Asst. Horticulturist
S. J. Lynch, B.S.A., Asst. Horticulturist
Geo. D. Ruehle, Ph.D., Asso. Plant Pathologist

W. CENTRAL FLA. STA., BROOKSVILLE
W. F. Ward, M.S., Asst. An. Husbandman
in Charge2

FIELD STATIONS

Leesburg
M. N. Walker, Ph.D., Plant Pathologist in
Charge
K. W. Loucks, M.S., Asst. Plant Pathologist
C. C. Goff, M.S., Assistant Entomologist
Plant City
A. N. Brooks, Ph.D., Plant Pathologist
R. N. Lobdell, M.S., Asst. Entomologist
Cocoa
A. S. Rhoads, Ph.D., Plant Pathologist
Hastings
A. H. Eddins, Ph.D., Plant Pathologist
Monticello
Samuel O. Hill, B.S., Asst. Entomologist2
Bradenton
David G. Kelbert, Asst. Plant Pathologist
Sanford
R. W. Ruprecht, Ph.D., Chemist in Charge,
Celery Investigations
W. B. Shippy, Ph.D., Asso. Plant Pathologist
Lakeland
E. S. Ellison, Meteorologist2
B. H. Moore, A.B., Asst. Meteorologists

'Head of Department.
'In cooperation with U.S.D.A.
"On leave.








UTILIZATION AND STORAGE

OF FLORIDA GRAPES

By OUIDA DAVIS ABBOTT and K. W. LOUCKS

CONTENTS
PAGE
DESCRIPTION OF VARIETIES ... 4
UTILIZATION OF GRAPES ........... .. ... .. 6
Preparation for Table Use ... ..... 6
Preparation of Jelly ................ 6
Preparation of Sweet Juice... --
Results and Discussion ...... .. -
HOLDING FRESH FRUIT ............ .. .. ..... 9
Cold Storage .................... 9
Chemical Treatment and Cold Storage .. 10
Chemical Treatment ...................... 10
Observations and Results ..... ---- 10
CONCLUSIONS ............. .. 14

Commercial grape growing is an industry of recent origin in
Florida. While grapes have been grown in the state for many
years it is only within the past few years that grape growing
has assumed a place of economic importance. Scattered grape
plantings are found throughout the state, but for the most
part the commercial vineyards are located in the central parts
of the state. Many varieties of grapes have been tested in
Florida, but Munson hybrids, Muscadine varieties and a few
well known Northern varieties make up the greater part of
the commercial plantings. Early attempts at grape growing
in this state ran into several difficulties of which two were
outstanding. Little was known concerning the adaptation of
varieties to soil and climatic conditions and many failed because
they did not fit into the environment. Diseases also took heavy
toll of plants and fruit. Even as late as seasons from 1929 to
1931, for instance, diseases caused such ravages to the industry
that large acreages were abandoned. However, during the next
few years control methods were improved to the extent that
in 1935 the yield per acre in Lake County had increased 46
percent although the number of bearing vines had increased
only 14 percent.
It is probable that increased plantings and better cultural
practices will further increase the yield within the next few
years, and that disposition of the crop will become an important
problem. At present a portion of the grape crop is shipped






Florida Agricultural Experiment Station


to Northern markets but the greater part of it is sold locally
from roadside stands and fruit and grocery stores. Some of
the fruits are used fresh and others in the preparation of jellies
and juices.
When the vineyards were set it was thought that early grapes
would find a ready sale in Northern markets, but when the
vines came into bearing it was found that during the three to
five weeks in early summer when Florida grapes were ripe
and in a marketable condition there was comparatively little
demand in those markets for grapes, especially blue varieties.
Until 1936 the growers had no comprehensive organization
for advertising and disposing of the crop. Local markets often
became flooded, prices fell and the growers lost. It is evident
that if the grape industry is to continue and expand, some
profitable disposition must be made of the surplus. The surplus
usually consists of grapes of good quality in prime condition
for which there is no ready market and those which for various
reasons are of inferior quality. Grapes ripen during the rainy
season and frequent rains sometimes cause the fruits to become
so soft that they are unsuited for even short-distance shipping.
The best use for these fruits appears to be in the preparation
of jellies and similar products. For the better fruits cold storage
is a logical solution, for by this means the marketing period
may be spread over a much longer time. However, considerable
loss has been incurred by growers in the storage of grapes at
certain temperatures, as the fruit sometimes goes down in
storage and deteriorates rapidly after removal from storage.
The objects of this investigation were (1) to test the suit-
ability of several of the most promising varieties of grapes
for table use and in the preparation of jelly and sweet juice
and (2) to determine the storage conditions best adapted to
Florida grapes.

DESCRIPTION OF THE VARIETIES
In these experiments one variety of grapes, the Beacon, was
used in storage experiments and 10 were tested for table use
and suitability for the preparation of jelly and sweet juice. A
description of these varieties follows:







Utilization and Storage of Florida Grapes


Variety


Berries


Wapanuka Rich yellowish
(early)* white, translucent
skin, thin and
delicate


Loc


Yield per
Use acre in
tonsf

cal 1 to 11/


market
Only


Resistance to
disease

* Susceptible to ripe
Srot


Carman i Black with stem All
(late) bloom, skin heavy, markets
tough, pulp meaty,
firm but tender

Bailey I Large black, skin i All


!tough, thin, pulp
meaty but not
tough

SBlack without
bloom, skin never
cracks, pulp tender


Lomanto Dark purple to
(early) black, pulp
melting, excellent
quality

3 G 2 Dark purple to
(early) black, pulp tender,
good quality


23 G 3
Chuchu
(mid-
season)

Fredonia
(early)





Extra
(Beacon)
(mid-
season)


Unknown
(mid-
season)


Dark grey to pur-
ple with moderate
bloom, skin tough
and thin


markets



Local
market
only


Local
market
only


Local
market
only

All
markets


Black, with heavy Local
bloom, skin thick, market
medium in tough- only
ness, pigments red,
flesh greenish
white, translucent,
juicy, tender

SDark purple to All
black, with mod- markets
rate bloom, skin
tough, thin, pulp
tender

SDark red, dull, skin Local
thin without pig- market
ment, flesh juicy, only
tender, sprightly


1/ to 1%/2 Resistant to black
and ripe rots



1 to 11 Susceptible to black
and ripe rots
Resistant to
anthracnose

% to 3 Susceptible to black
and ripe rots
Resistant to
anthracnose

1 to 11/2 Susceptible to black
I and ripe rots



to 114 Susceptible to black
Sand ripe rots and to
anthracnose

1 to 1 Somewhat resistant
Ito black and ripe
rots. Resistant to
anthracnose


% to 11/






1 to 112




4 to z


F Susceptible to black
and ripe rots
Resistant to
anthracnose




Very susceptible to
I black and bitter rots
Resistant to
anthracnose


SSusceptible to black
Sand ripe rots
Resistant to
anthracnose


(mid-
season)


R. W.
Munson
(early)


*The time of ripening depends on the season: early varieties ripen from the last of May
to the last of June; mid-season varieties from the middle of June to the middle of July,
and late varieties from the last of June to the last of July. During any one season,
however, the ripening period for the combined groups will scarcely exceed seven weeks.
tThe reported yields are not taken from actual records, but represent the combined
observations of various individual growers.






Florida Agricultural Experiment Station


UTILIZATION OF GRAPES
Preparation for Table Use.-During the growing season grapes
are sprayed repeatedly with Bordeaux mixture. Four to six
weeks before maturity they are sprayed with copper acetate
or some other copper spray that is as near stainless as possible.
As a result of these treatments considerable spray residue fre-
quently remains on the fruits which is not removed from the
more compact bunches by washing in water. In preparing grapes
for use in this experiment dilute solutions of citric and acetic
acids were found very effective in removing spray residues.
These acids were prepared by mixing one part of citric acid
with 20 parts of water, or one part of acetic acid with two
parts of water. The grapes after picking were spread on a
table and sprayed with the acid solution. After an interval
of 10 minutes they were sprayed with water until drenched.
A dilute solution of grapefruit juice also was found very effec-
tive in removing spray residues. It was prepared by mixing
one part of grapefruit juice with four parts of water. The
grapes were immersed for 10 minutes in the juice solution and
then sprayed with water.
Preparation of Jelly.-Partially green or hard ripe grapes were
picked from the stems, washed, crushed, and boiled from 2 to
10 minutes in their own juice. The hot juice was filtered through
a flannel jelly bag and cleared of argol and other sediment by
placing it in shallow pans and allowing it to set for 24 hours
at 50 degrees F. The juice was decanted or siphoned off from
the sediment directly into the cooking kettle. The amount of
pectin present in the juice and the amount of sugar to be added
were determined by the use of Baker's Jellmeter. The direc-
tions for making the test with this apparatus were followed
in detail.
The pH of the juice was determined and if it were found to
be much higher than pH 3 citric acid was added until this
value was reached. Tarr' found that hydrogen-ion concentra-
tion and not total acidity is the important factor in jelly making.
He found that there is a minimum hydrogen-ion concentration
below which no juice will jell, regardless of the quantity of pectin
and sugar present. The optimum expressed as a pH value was
about 3, which is approximately that of the juice extracted from
guavas and mayhaws and other good jelly making fruits.
1Tarr, Lester W. Fruit Jellies, I. The role of acids. Del. Agr. Exp.
Sta. Bul. 134, 38 pp. 1923.






Utilization and Storage of Florida Grapes


The cooking was then done as rapidly as possible until the
jell point was reached. This point was determined by the
sheeting-off test or by the thermometer (219-221 degrees F.).
Preparation of Sweet Juice.-Clean, sound, well ripened but
not over-ripe grapes were gathered and allowed to stand for
several hours as this seemed to mellow the juice. They were
then crushed and heated from 140 to 158 degrees F. in enamel
kettles. The heated grapes were put into well washed muslin
bags which were twisted until the greater part of the juice was
expressed. After this the residue was run through a fruit
press. The juice was poured immediately into glass jars and
allowed to settle for 24 hours; then siphoned from the sediment
and run through several thicknesses of flannel. It was then
heated in a double boiler to 176-188 F., stirred constantly with
a wooden spoon and poured into hot, clean jars or bottles. In
filling the containers sufficient juice was added to force the
foam formed during filling over the top and out of the con-
tainers. The bottles were capped immediately and stored.
Results and Discussion.-The composition of the juices of
several varieties of grapes and the characteristics of the result-
ing jelly and sweet juice are given in Tables 1 and 2.
TABLE 1.-COMPOSITION OF JELLY STOCK FROM SEVERAL VARIETIES OF
GRAPES, AND CHARACTERISTICS OF THE RESULTING JELLY.
I Jellmeter reading,
Varity of Grapes pH of Juice time of flow Character of
in seconds resulting jelly
Wapanuka 5.5 30 Did not jell
3 G 2 ..................... 3.56 30 Did not jell
Unknown .... ....... 3.44 30 Did not jell
Lomanto ........ 3.67 30 Soft
Bailey ... .................... 3.62 45 Soft
Carman .. .. 3.57 45 Soft
Munson .... ..... ........ 3.48 45 Soft
23 G 3 .......... ............. 3.67 30 Did not jell
Fredonia ...- .................. 3.44 60 Fair quality
Beacon ..... ......... ...... 3.62 45 Soft


The data show that of the 10 varieties of grapes tested no
one produced an excellent jelly. As shown in Table 1, pectin






Florida Agricultural Experiment Station


was the limiting factor since all the juices were high in acid
but, as measured by the jellmeter, low in pectin. The jelly made
from the Fredonia was best, while juices from the other grapes
produced soft jellies or did not jell at all. These soft jellies
were unsuited for shipping but were well suited for home use.
All the grapes were too low in pectin to make acceptable com-
mercial jellies. When small amounts of apple or citrus pectins
were added the jellies were improved in texture but some of
them were lacking in flavor.
TABLE 2.-COMPOSITION AND CHARACTERISTICS OF JUICE FROM SEVERAL
VARIETIES OF GRAPES.
Total acids as
Variety Brix anhydrous Properties of the resulting juice
of Grapes Reading citric acid,
percent Color Flavor

Munson ....... 25.2 1.01 Reddish purple Tart, slightly
I astringent
Carman -...... 19.6 0.45 Dark reddish Sweet
3 G 2 ......... 22.7 0.86 Dingy claret red Tart, slightly
astringent
Bailey ......... 19.2 1.32 Dark purplish red Pungent, sweet
Fredonia ..... 24.2 0.97 Dark purplish red Sweet, smooth
Unknown ... 11.9 0.57 Dingy pink Sweet
Lomanto .._ 14.1 1.00 Dark claret red Tart, slightly
astringent
Wapanuka .. 23.6 0.45 Pale yellow Musky, delicate
sweet
Beacon ...... 23.9 0.49 Dark purplish red Pungent, sweet


All the grapes produced from 40 to 50 percent of juice and,
as shown by the Brix reading, were relatively high in total
solids. These solids consisted for the most part of sugars, pig-
ments and tannins, there being little pectin present. The juices
varied from a tart, slightly astringent juice to a sweet, smooth
musky one. The most delicious and fragrant juice was obtained
from the Wapanuka variety. This grape also was found to be
the most desirable one for table use. The varieties especially
suited for sweet juice were Wapanuka, Lomanto, Munson, Bea-
con, Carman and Fredonia, while those most desirable for table
use were Wapanuka, Fredonia, Beacon and Carman.
From this study of the characteristics of fresh grapes and
juices, it appears that the use of the fruit in the fresh state
and in the preparation of sweet juices offers the most promising






Utilization and Storage of Florida Grapes


possibilities. The wide range of flavors and colors of the juices
suggested that highly desirable results might be obtained by
blending certain juices. Some of the juices were tart and
slightly astringent but were lacking in color; these were im-
proved by blending with sweet insipid juices of high color.

HOLDING FRESH FRUIT
In an effort to extend the marketing period of fresh grapes,
three different methods of preventing deterioration and decay
were tried. The first of these was cold storage, the second,
chemical treatment before storage, and the third, chemical treat-
ment alone.
Grapes were obtained from commercial vineyards in Lake
County. Some time was consumed in transporting the fruit
from the vineyard to storage, but an effort was made to get
the fruit into storage as soon as possible. At no time was the
interval between picking and storing more than 24 hours.
Grapes were stored in two different cold storage plants. One
was the experimental refrigeration plant at the Agricultural
Experiment Station at Gainesville, and the other a commercial
storage plant. In the former the temperatures were maintained
within 1 degree of those desired. Humidity varied slightly, but
was held approximately between 85% to 90% except in the
room kept at 32 F. In this room the humidity was much
lower (80%) as much of the moisture froze out on the pipes.
In the commercial storage plant the fruit was placed in the ice
storage room. The recording thermometer in this room showed
that the minimum temperature was 300 F. and the maximum
330 F. No effort was made to control the humidity, but from
the general appearance of foods stored in this room it was
evident that the humidity was high, as very little shrinkage
occurred.
Cold Storage.-Storage experiments were conducted on Bea-
con grapes during 1936 and 1937. They were picked and packed
in lugs the same day. The next morning they were placed in
storage at the following temperatures: 320 F., 37 F., 42 F.,
650 F. and 75 to 850 F. Results during the first year showed
that temperatures higher than 450 F. were useless; consequently
during 1937 tests were made only at the lower temperatures
and observations were made at more frequent intervals. Addi-
tional grapes were packed in baskets and placed in a commercial
ice storage room.






Florida Agricultural Experiment Station


Chemical Treatment and Cold Storage.-(1) Grapes picked in
the afternoon were packed in lugs the following morning. In
the late afternoon they were treated for 30 minutes with sulfur
dioxide gas at the rate of 2 grams to a hundred cubic feet. The
next morning the fruit was placed in storage at the following
temperatures: 5 lugs at 32 F., 5 at 420 F., 4 at 650 F. and
one at room temperature. Results from these tests were so
unsatisfactory that the experiment was not repeated during
1937.
(2) Seven baskets of Beacon grapes were dipped into a solu-
tion of sulfocide2 1 to 200, and soap 1 pound to 50 gallons of
water. After this treatment they were spread and allowed
to dry. These grapes and the untreated checks were placed
in a commercial ice storage room.
At weekly intervals grapes were taken from storage and obser-
vations made on the amount of fruit lost through decay, shelling
and shriveling.
Chemical Treatment. Duplicate baskets of sound, ripe,
freshly picked Beacon grapes were treated as follows: (1) sul-
fur dioxide gas at the rate of one ounce per 100 cu. ft.; (2)
sodium bisulphite dip, 1 oz. to 2 gallons of water; (3) sulfur
dioxide gas at the rate of 2 oz. per 100 cu. ft.; (4) borax dip,
1 oz. to 2 gallons of water; (5) untreated checks. The sulfur
dioxide was supplied in closed chambers for 30 minutes, after
which the fruit was removed and placed in storage. The dips
were applied for 30 minutes, the fruit was then removed, dried
under a current of air and placed in storage. The storage
simulated as nearly as possible the conditions in a store window
during the latter part of July-hot and dry during the day and
cooler at night. Daily observations were made on the effective-
ness of these treatments.
Observations and Results.-During 1936 the effect of storage
temperatures on the keeping of Beacon grapes was studied. The
results are given in Table 3. When the grapes were stored for
28 days at 32 F. no diseases developed but when they were
stored for the same length of time at 370 F. a slight fungous
infection was noted. Even after storage for 56 days the deter-
ioration of both lots was due almost entirely to shriveling.
Experiments on storage of grapes repeated in 1937 (Table 3)
show that the loss was somewhat greater than during the previ-
ous year. During the first five weeks of storage at 320 F. the
'Sodium polysulphid, 38-40 percent. Sodium thiosulphate, 1-2 percent.







Utilization and Storage of Florida Grapes


grapes showed practically no rot but began to shrivel and shell
from the bunches. The fruit stored at 37' and at 42' developed
more rot and shelling than those stored at the lowest tempera-
ture. At the end of six weeks approximately 50 percent of all
the fruit had been discarded and the remainder was not in a
saleable condition. It is shown in the same table that when
grapes were kept in the ice storage room in the commercial
cold storage plant they were in a marketable condition for
84 days. The grapes stored in this room showed practically
no rot and little shelling or shriveling.
TABLE 3.-PERCENTAGE OF FRUIT DISCARDED FROM UNTREATED LOTS OF
BEACON GRAPES HELD AT VARIOUS STORAGE CONDITIONS.
1937
No. days 30- 1936 1937 1936 1937 1936 1937 1936 1936
in 33oF.t 32-33F. 37F. 42F. 65F. Room
storage un- 55%* Vari-
|known 80%* 82%* *1889%* 86%* 88%* 86,%*, able*

7 0 T | 3 5 100
14 0 5 6 5 8 6 11 100
21 12 15 21
28 10 21 11 26 13 36
35 26 34 45
42 29 32 21 45 30 62
45 0
49 41 58 75
56 53 66 44
60 0
66 59 95
70 T
84 4

*Humidity.
tThis lot was held in a commercial ice storage room where the humidity was unknown
but relatively high.
$T indicates less than three percent.

In Table 4 data are given on the effect of storage tempera-
tures on grapes which had been chemically treated. Among the
lots treated with sulfur dioxide at the end of 28 days there
was apparently little loss in those stored at 320 F. and 37 F.
but after 45 days more than 70 percent of fruit was discarded.






Florida Agricultural Experiment Station


The loss of fruit stored at 32 F. and 37 F. was due almost
entirely to shriveling while the loss at 42 F. was caused by
fungous infection.
TABLE 4.-PERCENTAGE OF FRUIT DISCARDED FROM CHEMICALLY TREATED
LOTS OF BEACON GRAPES HELD AT VARIOUS STORAGE CONDITIONS.
30-33F. I I
No. of unknown* I 32-33F. 37F. 42F. 65oF. Room
days in t 80%* 88%* 88%* 55%* Variable*
storage sulfocide SO, SO2 S02 I SO 2 SO2

7 0 50
14 0 TT T T 1 50
21 T T T 100
28 4 6 9
45 9 73 74
49 74
60 0
70 4
84 5

*Humidity.
tThis lot was held in a commercial ice storage room where the humidity was unknown
but relatively high.
$T indicates less than three percent.

Beacon grapes untreated and treated with sulfocide stored
in a commercial cold storage room showed practically no loss
from rot or shriveling, for the first 70 days (Tables 3 and 4,
respectively). After that soft rot became evident and some
of the stems shriveled.
In Table 5 is shown the marketability of the fruit used in
these experiments when they were exposed to room conditions
for the indicated number of days. When the grapes were
removed from the commercial ice storage room at the end of
84 days and placed at room temperature it was noted that in
4 days the sulfocide treated grapes became so soft that they
were entirely unsaleable. Every bunch shattered when it was
touched. Of the untreated fruit, 40 percent was still saleable.
Juice extracted from these grapes was sweet, high in total solids
and dark purple in color. The sugar content had apparently
increased and the flavor and odor intensified so that the juice
had the musky flavor and sweetness of juice from Concord
grapes.







Utilization and Storage of Florida Grapes


TABLE 5.-MARKETABILITY OF BEACON GRAPES WHEN MOVED TO ROOM
TEMPERATURE FROM VARIOUS STORAGE CONDITIONS.


No. days
Treatment in
storage


None 28
28
28

None 42
42
42

None 49
49
49

None 56
56
56

None 84
84

Sulfocide 84
84


Subs
da;
ro
temp


equent Total percent marketable from fruit
ys at I stored at:
oom 1300-330F.
erature unknown* 32F. 37F. 42F.
S t 80%* 88%* 88%*

0 89 90 89
5 47 59 47
8 29 34 25

0 62 81 67
3 43 62 43
7 31 44 31

0 59 74 62
4 47 43 49
7 28 27 42

0 64 55
3 37 43
6 29 28

0 96
4 40

0 93
4 0


*Humidity.
fThese were held in
but relatively high.


a commercial ice storage room where the humidity was unknown


Observations on untreated grapes and grapes treated with
sulfur dioxide, sodium bisulfite and borax and kept at room
temperature showed that these materials in concentration used
were ineffective in improving the keeping qualities of the grapes,
as the untreated checks were in better condition throughout
the experimental period (7 days) than any of the treated ones.
The untreated grapes were also in a saleable condition for a
longer period than any of the treated ones.
As previously shown (Table 3) grapes can be stored with
little loss at 32' and 37 F. for approximately one month, but
data presented in Table 5 show that after removal from storage
grapes deteriorate rapidly. For this reason storage fruit should
be utilized immediately after removal.





Florida Agricultural Experiment Station


CONCLUSIONS
The varieties of grapes tested in this study did not contain
sufficient pectin for use in commercial jelly making but can be
used advantageously in the preparation of jellies and jams for
home use. The best use found for these grapes was in the
preparation of sweet juices. Some of these juices were of ex-
cellent quality. It should be mentioned, however, that these
grapes do not produce the purplish-blue juice characteristic of
commercial grape juice usually prepared from Concord grapes,
but the excellent quality of some of these juices should soon
overcome any prejudice against the color.
At a storage temperature of 32 F. very few grapes were
discarded because of fungous infection, but shelling and shrivel-
ing occurred. Storage of grapes at 370 F. for about 30 days
gave satisfactory results. From the data presented it appears
that cold storage of grapes in a commercial ice storage room
for as much as 60 days will be economically possible, if the
fruit can be used quickly after removal.
Treatment of grapes with sulfur dioxide before storage de-
layed deterioration in storage for about 30 days, but after that
treated fruits showed greater loss from fungous infection than
the untreated.
Of the two chemical treatments tested neither was effective
in improving the keeping qualities of grapes.

Grapefruit juice (1 part to 4 of water) was effective in re-
moving spray residues from grapes.




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