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This is to certify that the

thesis entitled

Chemical and Physical Factors Producing

a Green Color in Pickles.

presented by

Robert Donald Wheaton

has been accepted towards fulfillment
of the requirements for

L8. " degree in Bacteriology and
Public Health

£mw

Major professor

 

 

Date

 

——- —-—- .

 

113 CIE ICAL AiD PHYSICAL FACTDRS TICDficIIG
GRIZZLY COLOR IL? PICECLES

 

A THESIS

Submitted to the School of Graduate Studies of'"ichigan
tote College of Aériculture and Aoplied Science
in partial fulfilment of the requirements
for the degree of

MASTER OF SCIENCE

Department of EacteriolOQy did Puolic I Zeal h

1952

 

ACKITO WLEDGIZEIT

The author wishes to express his sincere appre-
ciation to Dr. F. W. Fabian, Professor of Bacteriology
and Public Health, Without whose patient guidance the

completion of this work would have been impossible.

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EFFECT OF ELATCHIHG . . . . . . .

L3)

11:
IIEBIIODS USED TO COLOR P10231138 . . . .
Chlorophyllin . . . . . . . .'. . .
Certified I‘ood Dyes . . . . . . . .
DISCUSSION . . . . . . . . . . . . . .
SUIJIARY . . . . . . . . . . . . . . .

LITERATURE CITED . . . . . . . . . . .

e on to l4

(O

TABLE

1. List oflietellic

2. Amount of Copper
Green Color in

3. count of Sodium

Pickles . . .

LIST OF TAL'LES

Salts sea to Treat Pickles

Chloride Required to Produce

FAQ

1:?

A4

C0

INTRODUCTION

The color of commercially packed pickle products is
subject to wide variation. Not only is there varietal dif-
ference in color, but also in the sane variety of pickle put
up by the same packer. Color is important in the sales ap-
peal of pickles pa ked in glass since a good color attracts
a potential cust mer tothe product. Color also may be an
index to the quality of the product. A product that shows
bleached areas or varies a great deal in color usually in-
dicates a low quality product. Therefore, care should be
taken in color grading of the product. Some factors that
affect the color of pickles are uncontrollable such as cli-
matic and soil conditions.

The packaging of pickles in an acid medium helps to
destroy the green color by conversion of the chlorophyll to
pheophytin.. This cannot be helped because the acetic acid
is essential in the flavor as well as in the keeping quality
of the product. It was the purpose of this work to study
all of the factors that are involved in pickle manufacture,
which would affect the green color of the finished product
and, if possible, to restore the green color either wholly

or in part by chemical or physical treatments.

LITERATURE REVIEW

The preservation of the green color of pickles is a
problem of the relative stability of the chlorophyll mole-
cule. Willstater in 1915 (1) states that the retention of
the magnesium.metal in the chloro_hyll molecule is correlat-
ed with greenness. This;metal is readily replaced with hy-
drogen ions contained in dilute acid solutions. The result-
ing magnesium-free compound is called pheophytin which is
responsible for the olive green color.

Blair and Aynes (2) state that the first attempt to
protect the greenness in canned vegetables was done by
Blassneck in 1910. This was done by blanching the vegetables
in an alkaline solution before canning. These authors also
outline the process that is now used to can peas to preserve
the natural green color. This process consists of (a) a
preheat treatment by immersion of the peas at room tempera-
tures in a 2-percent sodium carbonate solution, (b) blanch-
ing in a 0.005 molar calcium hydroxide solution, (c) canning
in a salt-sugar brine to which is added a 0.020 to 0.025-
percent suspension of magnesium hydroxide.

Eisenstat (3) studied the destruction of color in
pickles by light. He found that light in the infrared range
was the:most effective in producing bleaching.

Jones (4) stated that sodium benzoate was capable of
producing a green color in pickles. Jones also stated (5)

that steaming of the pickles in certain spice oil vapors

produced greenness in pickles. He was of the opinion that
this greenness was not due to changes in the chlorophyll,
but to the production of a new color compound.
a? "-.f 'l _ Pr. 1 f l
hagnus,.maoee, and Reynard (0) give several ormu as
for using the certified food dyes in the coloring of

pickles.

1.33.1 BEEIENTAL ME‘ IO DS

Commercial practices were followed in these experi-
ments as closely as possible. In all cases, unless other—
wise indicated, the pickles were packed in l-pintlhason
jars. One hundred grams of pickles were added to each jar
and 400 ml of finishing liquor added. The pickles used were
cured salt stock obtained from theifiichigan Pickle Company,
Lakeview,1i‘dhigan. The pickles were desalted before use by
freshening in running lukewanm tap water for 24 hours fol-
lowed by soaking for 4 hours each in 4 changes of distilled
water. The pickles were divided into 2 batches and l batch
was made into standard sweet pickles by the usual dry sugar
method and when finished tested 57-percent sucrose, 2-per—
cent acid as acetic, and 2-percent salt. The other batch
was made into processed dill pickles by the addition of a
brine consisting of the proper amounts of salt and vinegar
so that the finished product tested 0.8-percent acid and 2-
percent salt. In the latter case pasteurization was accom-

plished by immersion of the closed jars in a hot water bath

4
until an internal jar temperature of l65°F had been reached
and held 15 minutes at this temperature. The jars were
cooled hmnediately.

All salt and acid determinations were made by titra-
tion. In the case of salt, 0.1711 N silver nitrate was used
with dichlorofluorescein as an indicator. The acid titra-
tions were carried out using 0.1666 N sodium hydroxide with
phendphthalein as the indicator. Sugar concentrations were
measured by an Abbe refractometer.

The pickles used were the 6000 size and were careful-
ly inspected before use. They were all of essentially the

same color with no bleached areas nor physical defects.

THE EFFECT OFIfiETALS

To determine the effect of various chemicals on the
greening of different kinds of pickles, metals were given
first consideration since it is well known that the salts of
copper cause a green color to develop in the pickle. The
metals were first screened to decide which ones might come
in contact with the pickles at any time during their manu-
facture. Some metals such as bismuth were not used because
of the relative insoluhility of their salts. Others such as
gallium, cerium, etc., were considered to be of too rare oc-
currence to be commonly found in the manufacturing opera-

tions.

Various salts of the metals were used to prepare a
stock solution of each metal so that the concentration of
the metallic ion was present in a 1:1000 dilution of metal
to water. Chloride salts were used wherever possible. Howe
ever, when these were not available or relatively insoluble
other salts such as sulfates were used. The metallic salts
“were first dried in an electric oven at 100°C a 2°C for 24
hours, after which they were weighed and placed in a liter
volumetric flask and filled to the mark with distilled wa-
ter. The amount of1netallic salt used to obtain the desired
concentrations of metal are given in table 1. This stock
solution was then used to prepare 3 different solutions con-
taining l, 10, or 100 ppm of the metallic salt, which were
the concentrations used in these experiments. Proper
amounts of C.P. sodium chloride were added to each of these
solutions to make a final concentration of 2-percent sodium
chloride. Each.eolution of the metallic salt was then di-
vided into 4 equal lots. The first was untreated. The sec-
ond lot was.acidified with glacial acetic acid to 0.8-
percent. The third lot was acidified to 2-percent with gla-
cial acetic acid. The fourth lot in addition to acidifica-
tion to 2-percent contained enough sucrose so that the final
sugar concentration was 57-percent.

Prior to the addition of the above solutions, the
freshened and desalted pickles were also divided into a lots
and treated as follows: Lot 1 was untreated; lot 2 was

acidified with glacial acetic acid to 0.8-percent acid and

Table 1

Lists of ketallic Salts Used to Treat Pickles

 

 

 

”w“

holecular Chemical"mmfi61ecuIEETMIEEEfifoTTEEHHT"

 

‘Metal weight of Formula of Weight of 'Used to Give

Iietal Salt Used Salt 1:1000
Aluminum 26.97 A1013 _l55.54 4.944
Antimony 121.76 313013 228.15 1.875
Barimn 157.56 BaClg 208.72 1.519
Beryllium 9.01 BeClg 79.95 8.871
Cadmium ll2.4l CdClg 185.52 1.650
Calcium. 40.08 CaClg 110.99 2.769
Cerium 140.15 CeClS 246.5 1.759
Chromium 52.01 CrClz 122.92 2.565
Cobalt 58.94 00804 155.00 2.629
Copper 65.57 CuClZ 154.48 2.115
Iron 55.84 Fe013-6H20 270.51 4.840
Lead 207.21 PbC12 278.12 1.542
Lithium 6.94 LiCl 42.40 6.109
Magnesium 24.52 ngClg 95.25 5.915
manganese 54.95 MnClZ 125.84 2.290
Mercury 200.61 Hg012 271.52 1.555
Nickel 58.69 HiClZ 129.60 2.208
Potassium 59.10 KCl 74.55 1.906
Silver 107.88 AgN05 169.89 1.574
Strontium 87.6 Sr012 158.54 1.809
Thallium 204.59 TlCl 259.85 1.175
Tin 118.70 SnSO4 214.76 1.809
Zinc 65.58 ZnClZ 156.29 2.084

-..- N 0—...-

 

sufficient NaCl added to give a final concentration of 2-
percent; and lots 5 and 4 were acidified with glacial acetic
acid to 2—percent acid and sufficient NaCl added to give a
final concentration of 2—percent. In addition the fourth
lot had been sweetened with sucrose so that the sugar con-
centration was 57-percent. The above treatment of the 4
lots of pickles was necessary so that they'nnuld have the
same acid and salt content as the liquors which were then
added to them.

The pickles were placed in pintiiason jars and the
respective liquors poured over them. These liquors had the
same acid and salt content as the pickles and also contained
the various metallic salts shown in table 1 in concentra-
tions of l, 10, and 100 ppm. Proper controls were prepared
for comparison which contained no metallic salts. The jars
were then closed and heated in a hot water bath until they
reached an internal temperature of 18OOF and were then held
at this temperature for 15 minutes. The jars were imme-
diately cooled and stored in their original cases. In these
experiments there was a total of 276 jars treated with the
various metals and 24 control jars. Observations wereznade

at the end of 1 day, 2 weeks, 1 month, and 5 months.

Results
At the end of 5 months the pickles were removed from
the jars and placed beside a control for comparison. The

pickles to which the metallic salts had been added in con-

 

 

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WE IIIFLUEE-TCE OF SO DIUH ~E'ITZOATE

Pickles which had been freshened as previously de-
scribed were added to pintIMason jars. Tb 10 sets of jars
in duplicate were added solutions containing from 1 to 10-
percent sodium benzoate at 1-percent increments. To one set
of the duplicates of each increnent, glacial acetic acid was
added to give a final concentration of l-percent acid. A

white precipitate formed in the ac dified solutions, vnich
doubtless was insoluble benzoic acid. The 20 jars were

‘closed and stored for 5 months.

Results
Observations made at time intervals of 1 week, 1
month,_ and 5 months showed that a green color appeared in
the pickles at the end of 1 week in the concentrations in-
dicated in the accompanying tabulation and did not increase

in intensity thereafter.

Table 5

Amount of Sodium Benzoate Required
to Green Pickles

 

Percent of deium Benzoate

SOlutlon 1 2 3 4 5 6 7 s 9 10

Distilled water - - - - + 2 + + + +

l-percent acetic acid

m

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# = Green Color - I No Green Color

10
Discussion of Results

In distilled water sodium benzoate produced a green
color in pickles within a week in the 5—percent concentra-
tion. The green color produced was a deeper and more in-
tense green than was produced in an acid solution. In the
solution which was acidified to 1-percent with glacial ace-
tic acid, the green color was produced at a 4-percent con-
centration of sodium benzoate. IEowever, the green color
produced was not as intense a green as that produced in the

’ckles when they were treated with different percentaees of
sodium benzoate dissolved in distilled water. The precipi-
tate which formed in a 1-percent acetic acid solution was
tested according to the official preliminary and also the
ferric chloride quantitative tests of ANO.AJC., p. 455 (7),
which showed the white ppt.to be benzoic acid. This would
indicate that the sodium benzoate in the l-percent acetic
acid solution formed benzoic acid and sodium acetate. Since
benzoic acid in water is soluble to the extent of only 0.27
grams per 100 ml. of water at 180C, the excess regained
the insoluble preci Mi ate.

Additional e} :periments seemed to verify Jones' state-
ment (4) that the green color produced was a new color com-
pound and not due to the ch10 mlrll. The greened pickles
were washed in running lukewarm tap water overnight, soaked
in distilled water 12 hours, and then placed in an acidzne

dium. These pickles Iere then placed in the direct sunliilit

11
for several days. They held their color much better than

ordinary pickles did under the same conditions.

The effect of spice oils on the color of pickles was
first studied by using a 21—percent emulsion of the follow;
ing oils: Cloves, ginger, celery seed, nu meg, mace, or-
ange, lemon, cassia, coriander, cardamon, mustard, pimento
(allspice), garlic, black pepper, and dill. The normal con-
centration of spice oils used for spicing pickles is usually
about 1:5000, that is, 1 part spice oils to 5000 parts of
pickles and liquor. However, to speed up the reactions a
1:1000 concentration was used in all spicing reported here.

Processed dill pickles were used to test the influ-
ence of spice oils alone and in combination on the color of
dill pickles. The spice oils tested for the dill pickle —x-
periments were: dill, garlic, mustard, black pepper, and a
combination of these in a commercial spice oil formula. The
spiced dill brine used was divided into two portions. One
portion was first heated, as is sometimes done in commercial
practice, before it was poured over the pickles in the jars;
while the other portion was poured over the jars cold, the
jars sealed, and then placed in a hot water bath and pas-
teurized at an internal jar temperature of 1650F for 15 min-
utes. In both experiments the jars were cooled immediately

and stored for 1 month.

12
Standard sweet pickles were tested by adding hot and
cold sweet spiced liquor containing the various spices pre-
viously listed, as well as combinations of these oils as
found in several commercial formulas. Controls for these
experiments consisted of pickles from the same lot treated

with unspiced brine and sweet liquor.

R—sults

The controls, processed dills and sweet pickles, were
stored at room temperature for one month after which they
were examined for any color changes. A comparison of the
processed dills and sweet pickles with the controls at the
end of 50 days showed only two instances of color change. A
deeper green color was noted in the jars of sweet pickles to
which the sweet liquor containing oil of pimento had been
added, but no Change in color was observed in the pickles to
which the cold sweet liquor containing oil of pimento had
been added. The other change was noted in tne case of gar-
lic oil which caused bleaching of the standard sweet pickles
in the case where sweet liquor containing garlic oil in a
l:lOOO concentration had been used. No bleaching was ob—
served in standard sweet pickles treated with cold sweet
liquor containing this same concentration of garlic oil nor
in processed dill pickles treated in the two ways as previ-

ously described.

15
Discussion of Results

It was concluded from this that heat was necessary to
produce a noticeable color change within a 50 da; period.
Ib confirm the above results additional experiments were set
up as follows: Standard sweet pickles were cut in half and
one half of the pickle was suspended over a beaker contain-
ing 5 ml of each of the spice oils previously listed. The
beaker was then heated for 50 minutes under a hood during
vmich time the pickle was subjected to the hot oil vapor
given off by the oils. With this drastic treatment oil of
pimento was the only spice oil which produced any color
change when compared to the other half of the standard sweet
pickle not subjected to this treatment which vas used as a

control in comparing color changes. From these results t

H.

was concluded that of all the spice oils tested, oil of p -
mento was the only one which produced any noticeable color
change in standard sweet pickles. This change has not be-
lieved due to the heat to which the half of the pickle was
subjected,since no difference in color could be noticed when
other spice oils were used. To further check this,other
pickles from the same lot were cut in half and one half was
subjected to steam for 50 minutes and the other half left
unheated as a control. No color change was noted in the
heated half of the pickle.

The only other conclusion which can be deduced from
these eXperiments is that garlic oil causes bleaching in 50

days time only in the presence of hot sweet liquor. This

14
does not preclude the possibility that garlic oil cannot
cause bleaching in either standard sweet pic} :les nor in
processed dill piclzles in a longer length of time nor under
different circumstances. The interes ti n~ thinks, is that
there is present in garlic oil a pr nciple which under cer-
tain conditions can cause bleaching of the color from

pickles. This was true of no other spice oil tested.

WnE “FECT OF DIFFEREZTT SUGARS

To determine the influence of sugars on the color of
pickles, 3 different sugars were used as sweetening agents,
viz., d—glucose, d-fructose, and sucrose. tandard sweet
pickles were prepared by the commonly used dry sugar method
using these 3 sugars. When the sweetenina process was com-
pleted, the pickles sweetened with each sugar were divided
into 4 lots. The first lot sweetened with eacli suaar wa
left untreated. The second lot was treated as follows: The
sweet liquor was poured off the pickles and heated to the
boiling point, poured back over the pickles izrlediately, and
the pickles and liquor cooled at once.

The third lot was treated the sane as lot No. 1, ex-
cept that a :3000 concentration of spice oils ‘es anCed to
the respective sweet liquors. The composition of the spicing
mixture was 60 parts oil of cloves, 20 parts oil of cassia,

and 20 parts oil of pimento. The fourth lot w'as the sane as

15
lot No. 2, except that the same spice mixture as in lot No.
3 was added in a 1:5000 concentration.

As controls for the 4 lots of pickles sweetened with
three different sugars, another set of 4 lots of pickles was
prepared which contained the sane amount of salt and acid,
but no sugar. These were given the same treatment as re-
pards heat and spices as just described for the 4 lots of
sweetened pickles. This made a total of 16 different lots
of pickles, 12 sweetened and 4 un weetened, for this series
of eXperiments. All jars of pickles in the 16 lots beflmre
any observations were made for color chanres were stored for

50 days.

Results
From the standpoint of color all pickles that had

been treated with any of the three different sugars showed a
deeper green color than the unsweetened samples at the end of
30 days. No color differences could be discerned between the
pickles sweetened with the three sugars. This was true ir-
respective of the heat and spice treatments which they re-
ceived. It must be concluded from these results that sucar

does change pickles to a deeper green color in the presence

or absence of heat or spices.

16

THE “FECT OF BLAHCEING

Blanching has been used in the canning industry for a
great many years. One of the several reasons for blanching
is to set the color in the vegetable. Pickles as made today
do not go through a process of blanching. Therefore, exper—
rnents were done to see whether blanching would have any ef-
fect on the color of finished pickles. Fresh cucumbers of
the long greaiproduce variety were used, since the pickling
variety was not available at this time of year. Four dif-
ferent blanching procedures were used, viz., boiling rater,
steam, boiling 0.0051i calcium hydroxide solution, and a
boiling 0.0052M calcium hydroxide solution preceeded by a 2
hour immersion in a 2-percent sodium carbonate solution at
room temperature. The time intervals used were 1 to 5 min-
utes at 1 minute intervals, followed by inmediate cooling in
cold water. The pickles were sliced into l/4 inch slices,
one slice of each of 6 pickles or a total of 6 slices were
blanched according to the procedure just outlined. Controls
were unblanched slices from the same pickles. Four separate
lots of pickle slices were prepared. Each of the lots con-
sisted of separate batches of pickle slices that were treat-
ed at the various time intervals indicated above in the 4
blanching procedures together with the proper controls. The
first of the 4 lots was truersed in a cold 7.9—percent salt
brine for 2 hours immediately after the blanchinfi process.

The second lot, immediately after the blanching process, was

17
hmaersed in a 7.9-percent brine solution which was kept at a
temperature of lBOOF for 30 minutes. The third and fourth
lots were the same as the first and second respectively ex-
cept that the immersion of the pickle slices in the brine
solution preceded the blanching process. The slices were
then made into fresh pasteurized dill slices by placing in
hot jars and covering with a finishing brine consisting of
the proper amounts of vinegar, salt, and spice emulsion.
The closed jars were then pasteurized at 1650F for 15 min-
utes. They were cooled immediately by immersion in cold
water. A total of 80 jars of blanched pickle slices were
prepared along with 8 control jars of unblanched pickles.

The slices tested when finished 0.69-percent acid and 2.1-

percent salt.

Results

Observations were made one day after the pickles
were made and pasteurized. The pickle slices were removed
from the jars and placed beside each other in glass trays
for camparison. The pickle slices that received any of the
4 different blanching treatments previously described had a
much better retention of green color than those that received
no blanching treatment. There was no great difference in
color retention whether the blanching treatment preceded or
followed the immersion in the salt brine or whether the
pickle slices were treated in a hot or cold brine. There

was no treat difference in the texture of the pickle slices

18
treated by any of the above methods. The conclusion that
may be drawn from these ekperiments is that any of the above
blanching methods helps in the green color retention of

pickles.

IHETHODS USED TO COLOR PICKLES

Chlorophyllin

It has long been known that the greenness of vege-
tables is destroyed by an acid medium and exposure to light
which completely destroys the chlorophyll. Therefore, at-
tempts were made to color pickles with water soluble chloro-
phyll products. Two types of water soluble chlorophylls
were used in this experiment. They were potassium.magnesium
chlorophyllin and sodium.potassium copper chlorophyllin.
SinCe these compounds were insoluble in an acid medrni,
freshened salt stock pickles were placed in distilled water
which had been adjusted with sodium hydroxide to a pH of
7.5. One ml of each of the chlorophyllins was added to du-
plicate 52 ounce jars of pickles and liquor, the ratio of
pickles to liquor being 2 to 1. Observations a ter 1 week's
time showed the pickles were definitely colored with the
chlorophyllins. However, there was no uniformity of color;
the worts on the pickle were almost black in color. At-
tempts to remove this dark color from parts of the pickle

and obtain a uniforn colored product were unsuccessful. The

19
pickles still retained uneven color after they were made in-

to processed dills.

Certified Food Dyes

A stock solution of each of the dyes used was pre-
pared by dissolving 1 ounce of the powdered dye in 1 pint of
hot distilled water. These stock solutions were blended in
various ways and the blends used in this experiment to color
pickles. Coloring was done by adding l'ml of the blends to
16 ounces of pickles and liquor. The ratio of pickles to
liquor vas 2 parts pickles to 1 part liquor. The follonang

blends have been found to color pickles satisfactorily.

 

 

Blend A Blend B
Yellow #5 Tartrazine 50 parts 46 parts
Blue #2 Indigo Carmine 55 parts 29 parts
Orange #1 Orange I 15 parts 25 parts

Blend A produced a green color in the pickles typical
of the color found in sweet pickles. However, blend A did
not give a uniform color if there was a great variation in
the color of the pickle before dyeing. If the pickle was
not of uniform color due to chlorosis, a disease such as mo-
saic, or ahere it had come in contact with the ground, the
color added by this dye did not overcome the color differ-
ence. The lighter colored portion of the pickle was still
much lighter than the darker portion. Blend B produced a
much darker color and was much better suited than blend A in

coloring pickles that had bleached areas. The best results

20
were obtained with blend B when the color in the pickles was
fixed during the presouring process by heating the colored
pickles in 0.2-percent aluminum sulfate (Alg(804)3°181'120)
solution for 5 minutes at 165°F. When this was done, the
sweet liquor on the pickles was only slightly colored at the
end of 5 months storage time, indicating a good retention of

the dye in the pickle.

DISCUSSION

A study of the color changes in pickles presents many
difficulties. There are many variables to be considered
which may have a definite influence on the final color of
the product. The greatest care possible was used to keep
the number of variables at a minimum throughout these exper-
iments so that each of then could be studied by itself.

It has long been known in the pickles industry that
the salts of copper will cause a greenness in pickles. This
was confinned since it was the only metal studied in these
experiments that would bring about this reaction.

Spice oils may have a definite effect on color, es-
pecially when long storage life is a factor. In a thirty
day storage period oil of pimento was shown to cause a def-
inite greening action on the pickles. The concentration
used here, however, was 15 times greater than that which
would be used ordinarily. Garlic oil was shown to have just

the opposite action, since it caused bleaching. However,

21
the concentration of garlic oil in sweet pickles is very
small and the amount used here was probably more than 100
times greater than the concentration ordinarily used.

The three sugars used in these experiments all pro-
duced a darkening of the green pigment of the pickles. No
difference could be noted in the depth of color caused by
the three different sugars. This would indicate that the
chemical structure of the sugar 23; se'was1not responsible
for the change since d-glucose is an aldehyde sugar, d-
fructose is a ketone sugar, and sucrose is a disaccharide in
which the d—glucose and d-fructose are combined andtnndlhasno
free reducing group. The color change must, therefore, be
due to some other action of the sugars on the pickle.

Sodium benzoate caused a definite greening in the
pickles when used in concentrations greater than those al-
lowed by law. In a neutral solution there was no greening
noted in concentrations up to 5-percent. However, in an
acid solution beginning at 4-percent a definite green color
was produced. This color remained and was stable when the
pickles were washed in running warm tap water overnight;
soaked in distilled water for 12 hours; and packed in an
acid medium. Furthermore, the color did not fade when the
'pickles were subjected to direct sunlight for a week. This
would indicate that the color formed was very stable and
may, as Jones (4) suggests, be a new color compound.

Blanching, as done in these experiments, had a defii

nite preserving action on the green color of pickles. The

22
cucumbers used here were not of the pickling variety, since
they were out of season at the time of these experiments.
Crispness and storage life must be considered in connection
with blanching. In these experiments these factors were not
given sufficient consideration since the observations were
made immediately after pasteurizing. However, none of the
pickle slices were soft because of the blanching and pas-
teurizing treatments which they received; so it is believed
that the storage life and crispness would not be seriously
impaired by blanching. In fact, with the thick skin produce
variety of cucumber, blanching would actually improve the
edibility since it would tenderize the skin. It has been
found, since heat treatment has become more general in
pickle manufacture, that cucumbers will withstand a great
deal more heat than formerly was believed when the old meth-
ods of making pickles were used.

These experiments have also demonstrated that certain
combinations of certified food colors may be used in produc-
ing a satisfactory green color in pickles under the condi-
tions employed.here. Certain combinations were much better
than others in this respect. By increasina or decreasing
the amount of yellow or blue, different shades of green may
be produced. Attempts to color pickles with two water sol-
uble chlorophyll products, viz., potassium magnesium chloro-
phyllin and sodium potassium copper chlorophyllin, were un-

successful. The pickles were colored; but it was impossible

23

under the conditions used to obtain a uniformly colored prod-

uct.

Under

1.

SGILARY

the conditions of these experiments:

Copper was the only metal tested which produced
a greenness in pickles. It produced a green-
ness in pickles in a concentration of 1 ppm in
a neutral solution and Sppm in an acid solu-
tion.

Sodium benzoate produced a greenness in pickles
in a concentration of 5-percent in a neutral
solution and of d-percent in an acid solution.
Oil of pimento produced a greenness in standard
sweet pickles in a concentration of 1:1000 in
heated sweet liquor. Oil of garlic was found
to cause a loss in green color of pickles under
the sane conditions.

D—glucose, d-fructose, and sucrose all produced
a darkening of the color of pickles when used
to weeten pickles. No color differences could
be discerned between pickles sweetened with the
5 sugars, irrespective of the heat and spice
treatments thich they received.

Blanching of pickles had a definite preserving

action on the green color of pickles.

24
Attempts to color pickles with 2 water soluble
chlorophyll products, viz., potassium macnesium
chlorophyllin and sodium potassium copper chlo-
rophyllin were unsuccessful. These compounds
would readily color the pickles in a basic but
not in an acid medium. A uniformly colored
product was not obtained in the basic solution.
Certain combinations of certified food colors
were used in producing a satisfactory green
color in pickles. Different shades of green
color in pickles could be obtained by increas-
ing or decreasing the proportions of the con-

stituents of the dye.

25

LI1AAA1anE CITED

 

weilstatter and Stall, Investigations on Chlorophyll,
do1d__erz, Sc1ence Press

(1)
translated by Schertz
Printinv 00., Lancaster, Penn., 1923
Blair, J. S., and Ayres, T. B. "Protection of Natural
Green Pigment in the Canning of Peas. Industrial
and En3ineerin3 Chemistry, Vol. 55, pp. 85-95, Jan-

uary, 1945.
"Factors 1&1ich Produce Bleachin3 of
S.,Ijichigan State College.

Eisenstat, Leon.
ThesisII.

Pickles."
195‘ o
(4) Jones, A” H. "Studies on the Curina,
Finishing 01 Cucumbers for Sweet r1ckles." Paper
presented at the Technical School for Pickle and
ulCthQn State College, February 19,

(2)

A
(51

Freshening, and

 

 

 

 

Kraut Packers,
20, 21, 1952.
(5) Jones, AniH. Personal communicat1or to F. W. Fabian,
April 24, 1952.
(6) "Pickle Flavor Facts by.nn1R,"'a3nus, Habee, and Hey-
nard Ir 0., NeW'York, New lork, 1951.
(7) Official}. ethods of Analysis of the Associat1on of Of-
ficial A ricrlt11ol Crew‘str, Associa tionfl of Offi-
Cherie ts, 7 edition, 1950.

 

cial Agriculturfl