DYEENG CE‘SARACTERESTECS Q? WWBSOR
AND NM’C‘LEGEY SWEEY CHERREE$
UNDER SELECTED CONDWGNS

Thesis for the Degree of M. S.
MECHEGM STATE UNWERSTY
CHARLES WESLEY KRAUT
1972

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ABSTRACT

DYEING CHARACTERISTICS OF WINDSOR AND
NAPOLEON SWEET CHERRIES UNDER

SELECTED CONDITIONS

BY

Charles Wesley Kraut

Windsor and Napoleon varieties of sweet cherries

(Prunus avium L.) were dyed using FD&C Red #3 and FD&C

 

Red #4. A linear relationship was observed between dye
uptake of the cherries and dye concentration in the dyeing
solution. Secondary bleaching of the cherries using

sodium chlorite greatly reduced the dye uptake capabilities
of the cherries even after two weeks storage in sulfur
dioxide-calcium brine. Treatment of the cherries with
Alar prior to harvest caused a lower dye uptake than that
observed in untreated cherries.

Secondary bleaching improved the appearance of.
dyed cherries by providing a brighter, stronger colored
product. Significant differences in appearance were found
between SO

bleached and dyed cherries and NaClO bleached

2 2

and dyed cherries. Chlorite bleached cherries were

Charles Wesley Kraut

significantly brighter in appearance with more intense red
color. Dye uptake for these cherries, however, was less
than that of the 802 bleached cherries.

Textural changes caused by secondary bleaching
were corrected after two weeks storage in sulfur dioxide-
calcium brine. The 1969 harvested cherries were found to
be significantly firmer than the 1970 harvested cherries.

Bleaching action of sodium chlorite was slightly

reduced under nitrogen. Bleaching under air showed slight

differences under different conditions.

DYEING CHARACTERISTICS OF WINDSOR AND
NAPOLEON SWEET CHERRIES UNDER

SELECTED CONDITIONS

BY

Charles Wesley Kraut

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE

Department of Food Science and Human Nutrition

1972

ACKNOWLEDGMENTS

The author would like to thank his major professor,
Dr. Clifford L. Bedford, for his assistance and helpful
suggestions throughout the course of this work and during
the preparation of this manuscript.

The author would also like to thank Dr. R. F.
McFeeters and Dr. A. L. Kenworthy for their suggestions
in the preparation of this manuscript and for their ser-
vice on the examining committee.

Appreciation is extended to the author's friends
for their suggestions and time at various stages of this
study, and to his wife, Linda, for her encouragement and

help.

ii

TABLE OF

LIST OF TABLES . . . . .
LIST OF FIGURES . . . . .
INTRODUCTION . . . . . .
MATERIALS AND METHODS . .
Dyeing Procedure . . .
Bleaching Procedure .
Analytical Methods . .

RESULTS AND DISCUSSION .

Dyeing of Cherries Using

Dyeing of Cherries Using

Color . . . . . . . .

Texture

CONTENTS

FD&C Red #3

FD&C Red #4

Effect of Air on Bleaching

SUMMARY AND CONCLUSIONS .

REFERENCES 0 O C O C O 0

APPENDIX 0 O I O O O O 0

iii

Page

iv

vi

10
12
l6
16
24
30
38
43
45
47

51

Table

10.

ll.

12.

13.

LIST OF TABLES

Data and Mathematical Formulas for Calculating
Dye Concentration . . . . . . . . . . . . . .

FD&C Red #3 Absorption of Windsor and
Napoleon Cherries . . . . . . . . . . . . . .

FD&C Red #3 Concentration Required for 150 ppm
Uptake, Windsors . . . . . . . . . . . . . . .

FD&C Red #3 Concentration Required for 150 ppm
Uptake, Napoleons . . . . . . . . . . . . . .

Effect of Secondary Bleaching on Dyeing with
FD&C Red #3, Windsor and Napoleon . . . . . .

FD&C Red #4 Absorption of Windsor and
Napoleon Cherries . . . . . . . . . . . . . .

FD&C Red #4 Dye Concentration Required for 150
ppm Uptake, Windsor . . . . . . . . . . . . .

FD&C Red #4 Dye Concentration Required for 150
ppm Uptake, Napoleon . . . . . . . . . . . . .

Effect of Secondary Bleaching on Dyeing with
FD&C Red #4, Windsor and Napoleon . . . . . .

Hunter Color Values Before and After
Secondary Bleaching . . . . . . . . . . . . .

Statistical Significance of Hunter Color
Values Before and After Secondary Bleaching .

Hunter Color Values, Windsor and Napoleon,
Dyed With FD&C Red #3 O O O O O O O O O O O 0

Statistical Significance of Hunter Values,
Windsor and Napoleon Dyed with FD&C Red #3 . .

iv

Page

15

17

21

22

23

25

29

29

3O

32

33

34

35

Table Page
14. Hunter Color Values, Windsor and Napoleon
Dyed with FD&C Red #4 . . . . . . . . . . . . . 37

15. Statistical Significance of Hunter Values,
Windsor and Napoleon Dyed with FD&C Red #4 . . . 38

16. Windsor and Napoleon Texture, 1970 Sample . . . 39

17. Statistical Significance, Windsor Texture,
1970 sample 0 O O O O I O O O O O O O O O O O O 39

18. Statistical Significance, Napoleon Texture,
1970 sample 0 O O I O O I O O O O O O O O O O O 4O

19. Texture of Non-Alar and Alar Treated
Cherries, 1969 Sample . . . . . . . . . . . . . 41

20. Texture of Windsor and Napoleon, 1969 and
1970 O O O O O I O I I I O O O O O O O O O I O O 42

21. Hunter Values, Effect of Air on Bleaching . . . 43

22. Consumption of Chlorite and pH Changes Under
Different Bleaching Conditions . . . . . . . . . 44

23. Sulfur Dioxide and pH Level of Brines Prior
to use 0 O O O O I O O O O O O O O O O O O O O O 51

24. Consumption of Chlorite and pH of Bleaching
SOlution O O O O O O O I O O O O O O O O O O O O 51

25. Hunter Color Values, Before and After
Bleaching (Direct Averages) . . . . . . . . . . 52

26. Hunter Color Values, Windsor Dyed Using FD&C
Red #3 (Direct Averages) . . . . . . . . . . . . 52

27. Hunter Color Values, Napoleon Dyed Using FD&C
Red #3 (Direct Averages) . . . . . . . . . . . . 53

28. Hunter Color Values, Windsor Dyed Using FD&C
Red #4 (Direct Averages) . . . . . . . . . . . . 53

29. Hunter Color Values, Napoleon Dyed Using FD&C
Red #4 (Direct Averages) . . . . . . . . . . . . 54

30. Hunter Color Values, Effect of Air on Bleach-
ing (Direct Averages) . . . . . . . . . . . . . 54

Figure

1. Regression
2. Regression
3. Regression
4. Regression

Lines,
Lines,
Lines,

Lines,

LIST OF FIGURES

Page

Windsor FD&C Red #3 . . . . . . l9
Napoleon FD&C Red #3 . . . . . 20
Windsor FD&C Red #4 . . . . . . 26

Napoleon FD&C Red #4 . . . . . 27

vi

INTRODUCTION

The 1969 harvest of sweet cherries in the United
States amounted to 126,800 tons with a value of about 42.8
million dollars. Of this harvest, 57,780 tons were sulfur
brined for later processing into maraschino and candied
cherries. (National Cherry Growers & Industries Founda-
tion, Inc., 1970 Report.)

Sulfur dioxide has long been known as an effective
and quick method for preserving fruit. Its primary advan-
tages include low cost, fast handling of large amounts of
fruit, bulk handling of preserved fruit, easy removal of
sulfur dioxide for processing, and extended storage capa-
bilitity. In addition, in the case of cherries, the fruit
is bleached to insure even dyeing in later processing.
(Atkinson and Strachan, 1963.)

In the past decade there has been an increase in
information reported in the literature on the characteri-
zation, bleaching, and preservation properties of sulfur
dioxide brines. (Van Buren, 1965; Van Buren, 1967;

Van Buren, gt_al., 1967; Watters, gt_§1., 1961; Whitten-
berger, gt_al., 1969; Wiegand, §E_al., 1939.)
Jurd (1964) reported that bleaching of the antho-

cyanin pigment is a reversible reaction of (anthocyanin)

flavylium carbonium ion and bisulfite. The reaction is
influenced by pH, thus decoloration is dependent on the
carbonium ion, bisulfite ion, and hydrogen ion concentra-
tions.

Payne and his coworkers (1969) report that preser-
vation is primarily dependent on the presence of molecular
sulfur dioxide gas (802) and sulfurous acid (H2803).
Hydrogen ion concentration plays a critical role in deter-
mining the amounts of these substances that are present.
The pH of the brine must be carefully controlled to main-
tain preservative properties.

Brining serves to bleach the anthocyanin pdgment
and to preserve the fruit. Brining, however, does not
remove the brown spots of scarred or bruised fruit.
Cherries to be brined must be handled carefully prior to
brining or they must be brined quickly to maintain quality
as high as possible (Whittenberger, gt_21,, 1968.) Damage
to cherries due to limb rub, wind whip, or other environ-
mental factors is unavoidable and, if sufficiently bad,
serves to decrease the quality of the brined cherry.
Dyeing of damaged fruit to maraschino or candied cherries
merely darkens the damaged portions, emphasizing their
presence, and thereby decreasing acceptance of the product.
Thus, damaged fruit can only be separated and discarded
from final processing to avoid reducing quality and price

of the final product.

Thienes, gt_al. (1969) found for the harvest years
1967-1968 that an average of 19 per cent of a representa-
tive harvest of Napoleon and Windsor sweet cherries in
Michigan were lost due to all causes. If this is assumed
to be an average loss for all years, it would represent a
loss of 10,978 tons from the 1969 brined harvest. Such a
loss would be valued at approximately 3.5 million dollars
or approximately 8 per cent of the total value of the 1969
brined harvest. This loss is more than the total combined
imports (7,303 tons) of sulfur brined and maraschino and
candied cherries in 1969. (National Cherry Growers and
Industries Foundation, Inc., 1970 Report.)

Because of the unacceptability of dyed blemished
fruit and the corresponding lower price paid for such pro-
duct, several investigations were undertaken to determine
if a secondary bleaching of sulfur dioxide bleached cher-
ries would remove the blemishes and yield an acceptable
product. Some of the methods produced unacceptable pro-
ducts unless special care was taken in the bleaching
process.

Hypochlorite solutions were used by Tucker (1935)
(Wagenknecht and Van Buren, 1965), and were found to pro-
duce snow white cherries under proper concentration and pH
conditions. However, poor texture, off flavors, and brown
color reversions occurred frequently making this method

undesirable.

Hydrogen peroxide was used by Wagenknecht and
Van Buren (1965). A 1% solution of hydrogen peroxide at
pH 11.5 produced evenly bleached, bright yellow cherries
with no off flavor. The major problem encountered with
this method was softening of cherry texture.

Wagenknecht and Van Buren (1965) also explored
several other peroxygen compounds for their suitability as
secondary bleaching agents but found that the performance
of hydrogen peroxide was best of those studied.

Beavers and Payne (1968a, 1968b, 1969) successfully
bleached cherries using sodium chlorite. The bleached
product was snow white in appearance, free from off flavors,
and had a firm texture. A sodium chlorite solution of
0.75% concentration was used. This level is "generally
recognized as safe" by the United States Food and Drug
Administration.

These investigators found a 0.75% solution of
sodium chlorite acidified to pH of 4.0 to 6.0 and held at
temperature below 110 F produced the best bleaching action.
The majority of sulfur dioxide from the brine must be re-
moved from the cherries prior to bleaching since sulfur
dioxide chemically reduces sodium chlorite according to

the equation:

C10; + 250;" ——-> c1" + 250;" .

Following bleaching, the cherries were leached in
running water and returned to sulfur dioxide-calcium brine
for at least two weeks prior to use. This served to re—
move residual chlorite according to the above equation.

Cherries bleached according to the above process
were successfully dyed with FD&C Red #3 and FD&C Red #4.
(Beavers and Payne, 1969.)

Although there are reports in the literature of
work accomplished on brining of cherries, preparation of
brines, and secondary bleaching of cherries, and although
there are references made to successful dyeing of brined
and bleached fruit, there is a notable absence in the
literature of dyeing procedures, with only a few exceptions:
Bullis and Wiegand, 1931; Jeffrey and Cruess, 1929; Weast,
1941. There are no standard dyeing procedures in the
literature. Each investigator determines his own pro-
cedure. Evaluation of a successful dyeing operation is
left up to the investigator. Companies that supply the
dyes are generally available for technical assistance but
the actual dyeing procedure is usually worked out by the
individual. It would be helpful, however, to have some
knowledge of how the fruit will react to dyeing procedures.

It was the purpose of this study to observe dyeing
characteristics of Windsor and Napoleon sweet cherries

under selected conditions.

MATERIALS AND METHODS

Raw Material

 

Windsor and Napoleon varieties of sweet cherry

(Prunus avium L.) were used in this study. The cherries

 

were obtained from the Hart-Shelby area of Western Michi-
gan. Two harvest years, 1969 and 1970, were used. The
1969 samples were harvested on 10 July, 1969 and consisted
of two treatments. Cherries treated with 2000 ppm Alar*
(Succinic acid, 2,2-Dimethyl hydrazide) are referred to as
Alar. Cherries not treated with Alar are referred to as
NonuAlar. The 1970 samples were harvested on 8 July, 1970
and consisted only of untreated cherries.

The samples were brined in the orchard as soon
after harvest as possible in 10,000 ppm sulfur dioxide,
0.5% calcium, pH 3.3 brine. The containers were agitated
each 24 hours of the first week to insure homogeniety of
the brine. All samples were stored at room temperature.

The 1970 samples were later divided into two lots
consisting of unblemished and blemished cherries. Unblem-
ished cherries were defined as being those cherries free

from any defects such as cracks, limb rub, bruises, or

 

*Tradename of Uniroyal, Inc.

other blemishes. Blemished cherries were defined as those
cherries which possessed such defects.

Fresh 5000 ppm sulfur dioxide, 0.5% calcium, pH
3.3 brine was placed on the 1969 samples on 27 July, 1971.
The 1970 samples were held in the original brine until

used.

Pitting

All samples used in this study were pitted using

a Dunkley Cherry Pitter (Dunkley Co., Kalamazoo, Michigan).

Dyes

The dyes used in this study were pure dyes, FD&C
Red #3 (Erythrosine) and FD&C Red #4 (Ponceau SX) obtained

from the. Stange Company, Chicago, Illinois.

Dye Solutions

 

Standard dye solutions were made up containing 10
mg dye per ml of solution. Appropriate amounts of this
solution were used to attain the desired dye concentration.
All dye concentrations are expressed as milligrams dye per

100 g fruit.

Dyeinngrocedures

 

All dyeing was accomplished using water of approximately
100 ppm hardness as CaCO3 determined by EDTA titration.

(American Public Health Association, 1961.)

FD&C Red #3

A modified method of Stange Co. (1968a) was used

for dyeing the cherries with FD&C Red #3.

Leaching

The brine was drained from the cherries and the
cherries were washed once with water. The cherries were
then covered with water, brought to a boil, and boiled
for 10 minutes. pH was determined after each boil using
pH test paper. This process was repeated until a pH of
4-5 was established. While leaching to pH 4-5, the sulfur
dioxide content was also reduced to a safe level for use

of FD&C Red #3.
Coloring

When prOper pH was attained, the cherries were
covered with water, dye was added, and the solution brought
to a boil. The cherries were then simmered in the solution
for 30 minutes, drained and rinsed. The ratio of fruit to
dyeing solution was, initially, 0.5:1 (w/v) prior to dye

addition.
Forced Bleeding

The dyed cherries were covered with water and
boiled for 5 minutes. 2 m1 of 5% citric acid per 100 g of
cherries was added and boiling continued for an additional

5 minutes, after which the solution was drained.

The cherries were again covered with water, 2 ml
5% citric acid per 100 9 fruit added, boiled for 10 minutes
and drained. ‘

The cherries were again covered with water, 6 ml
5% citric acid per 100 g fruit added, boiled for 10 minutes,
and drained. This step was repeated once more.

The cherries were covered with water, 8 ml 5%
citric acid per 100 9 fruit added, and the solution was
brought to a boil. The cherries were allowed to set in

this acidified solution for several hours before analysis.
FD&C Red #4

A modified method of Stange Co. (1968b) was used

to color the cherries with FD&C Red #4.

Leaching

The cherries were removed from brine, rinsed,
covered with water, and boiled for 10 minutes. Three
10 minute boils were used which were sufficient to remove

the SO to a residual 200-300 ppm.

2

Coloring

The cherries were covered with 20 Brix sirup such
that the ratio of fruit to sirup was 0.7:1 (w/w). The ap-
propriate amount of dye was added from the standard dye
solution. The solution was brought to a boil, cooled, and

allowed to stand. After each 24 hours the sirup was raised

10

by 10 B by adding sugar until 40 B was reached. Thus,
after the first 24 hours the sirup was raised to 30 B,

and after the second 24 hours the sirup was raised to 40 B.
The solution was brought to a boil with each addition of
sugar. After the final addition of sugar raising the sirup
to 40 B the solution was allowed to stand an additional 24'
hours after which the cherries were analyzed. Total dye-
ing time was 72 hours. The final °B at the time of analy-

sis ranged from 37 to 39 in the sirup.

Bleaching Procedure

 

Bleaching of cherries was accomplished using the
method of Beavers and Payne (1969).

Cherries to be bleached were first leached to a
residual 50-100 ppm of sulfur dioxide in several 10-
minute boils of water.

The leached fruit was drained and placed in 0.75%
sodium chlorite solution acidified to a pH 5.0 with acetic
acid (1:2 fruit/solution, w/w). Bleaching was allowed to
proceed at room temperature until complete. When bleach-
ing was complete, the fruit was leached in cold running
water for 36 hours and returned to 5000 ppm 802, 0.5%
calcium, pH 3.3 brine until used.

A commercial grade of sodium chlorite was used

which was approximately 80% pure.

11

Texture

Texture of the cherries was determined using the
Allo—Kramer shear press. Triplicate 100 9 samples were

used for each analysis.

Color

Color of Cherry samples was determined using a
Hunter Lab Model D25 Color and Color Difference Meter.
The sample to be read was placed randomly in the sample
dish such that the maximum surface area of the bottom of'
the dish was covered. The dish was then filled to capaC*
ity with the remainder of the sample.

The dish was placed on the aperature and covered
to exclude any room light from striking the photo cells.
L, a, and b values were recorded and the dish was rotated
90° before additional values were read. L, a, and b
values were thus recorded at 90° intervals through the
360° rotation of the dish. Each L, a, and b value re-
ported, then, is an average of four values: 0, 90, 180,
270 degrees.

Color was determined on triplicate samples.

12
Analytical Methods
Sulfur Dioxide Determination

Sulfur dioxide content of the brines was determined
using a modified method of the Association of Official
Agricultural Chemists (AOAC, 1965) as outlined by Payne,

et al. (1969).

Sodium Chlorite Determination

Determination of sodium chlorite in the bleaching
solution was accomplished using the modified method of
Haller (1948) as described by Beavers and Payne (1969).

Five ml of bleaching solution was pipetted into a
250 ml Erlenmeyer flask containing 100 ml distilled water.
Fifteen ml 1N potassium iodide and 5 m1 of 6N sulfuric
acid were added. The solution was titrated to a colorless
endpoint with 0.1N sodium thiosulfate. Starch indicator
(1%) was added just preceding complete destruction of
iodine. This thiosulfate titer is designated as titration
B.

Another 5 ml of bleaching solution was pipetted
into a 250 ml Erlenmeyer flask containing 100 ml distilled
water. This solution was made alkaline with 15 ml 1N
sodium hydroxide, stoppered, and allowed to stand undis—
turbed for 30 minutes. After this period, 15 ml of 1N

potassium iodide were added followed by 10 ml of 6N

13

sulfuric acid. The solution was titrated to a colorless
endpoint with 0.1N sodium thiosulfate solution. Starch
indicator solution was again added just prior to complete
destruction of iodine. This thiosulfate titer is designated

titration A.

C = (B titer - A titer) 5/3

% NaClO

2 (B — C) (0.04523)

Dye Extraction

 

Color was extracted from the dyed cherries using
a modification of the Stange Co. (1966) method. The
cherries were drained of excess sirup for 2 to 5 minutes
and 1010.1 9 samples were weighed. The cherries were
placed in a Waring blender jar along with 80 m1 of aqueous
acetone (1 + 1) solution. The jar was capped and the mix—
ture was ground at high speed for two minutes.

The slurry was transferred quantitatively to a
250 ml round bottom centrifuge tube. The mixture was
centrifuged for 30 minutes at 2000 rpm in an International
Model U Centrifuge (International Equipment Co., Boston,
Mass.). After centrifuging, the supernatent was filtered
into a flask through Whatman No. 1 filter paper. The
cherry pulp was washed back into the blender jar with an
80 ml aliquot of aqueous acetone solution. The second
and all subsequent extractions were blended for 1 1/2

minutes at high speed. A fresh filter paper was used for

14

each filtration after centrifuging. The filter paper ab-
sorbed a small amount of dye which was assumed to be con-
stant for each paper. The error thus introduced was kept
constant by treating each sample identically. The extrac-
tion was repeated until no color was left in the supernatent
and/or cherry pulp.

The combined extracts were filtered through a
fresh Whatman No. 1 filter paper into a volumetric flask
the size of which was the nearest volume easily divisible
into 1000. Before diluting to volume, for each 100 m1 of
final dilution, 1 m1 of 4N ammonium acetate was added.
Spectrophotometric absorption was determined on each
diluted extract using a 1 cm cell in a Bausch and Lomb
Spectronic 70 (Bausch & Lomb, Rochester, New York).

Table 1 shows the wave lengths, extinction values, and
mathematical formulas used for calculating dye concentra-

tion.

15

Table 1. Data and Mathematical Formulas for Calculating
Dye Concentration.

 

 

Wave length Extinction value
Color at maximum for 1 cm cell
absorption (A/mg/L)
FD&C Red #3 527 nm 0.109
FD&C Red #4 502 nm 0.054

A (of sample solution) x ml final dilution

M9 0f pure due = 1000 X Extinction Value

mg of pure dye x 100
sample wt in mg x 0.9

 

% color =

ppm = % color x 104

Triplicate samples were extracted for each dye

analysis. Results are expressed as ppm dye concentration.

6

FD&C Red #3: ppm = 1.13 x 10- moles/Kg

6

FD&C Red #4: ppm = 2.08 x 10- moles/Kg

 

RESULTS AND DISCUSSION
Dyeing of Cherries Using FD&C Red #3

Results of cherry dyeing using FD&C Red #3 are
summarized on Tables 2 through 5 and on Figures 1 and 2.

Windsor and Napoleon dye uptake data is contained
on Table 2. Single 50 9 samples of cherries were dyed
directly out of sulfur dioxide-calcium brine and again
after they had been bleached and returned to brine for
two weeks. (Beavers and Payne, 1969.) Triplicate samples
were analyzed from this single lot.

Plots were made of this data (ppm dye in fruit
versus dye concentration) which indicated that a linear
relationship existed between dye uptake and dye concen-
tration in the solution. Regression analysis was carried
out using the Method of Least Squares to determine the
line of best fit (Mendenhall, 1968a). Correlation was
generally very good between dye uptake and dye concentra-
tion as evidenced by the correlation coefficients. The
correlation coefficients with one exception, showed high
significance when tested using a standard t-test (Menden-
hall, 1968b). The r = .69 value showed a significance at

the 10% level.

16

 

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18

Perfect correlation, r = 1.0, cannot be realistic-
ally expected due to the inherent variation in the product
under study. However, at the same time, a reasonably good
correlation must be expected if the relationship is, in
fact, to be considered as a linear one. The generally high
r values provide good evidence that the relationship is
linear, and thus, the one relatively low r value (r = .69)
must be considered as being due to less than optimum ex-
perimental procedure. The FD&C Red #3 dye, since it is
precipitated in the cherry pulp through the dyeing process,
proved to be somewhat difficult to extract. This also
contributed to variation between samples, and within sam-
ples.

Figures 1 and 2 show plots of the regression func-
tions for each of the conditions of Table 2. Statistical
significance between slopes was determined using the t-
test. Tests for significance were carried out between
pairs of slopes independently within the Windsor and
within the Napoleon data. Tests were then carried out
between Windsor and Napoleon data within each of the
columns of Table 2.

Results for the Windsor variety showed so signifi-
cant difference between the slopes of the Non-Alar, $02
and Unblemished lines. All other combinations using Non-

Alar, SO showed significant differences. Generally, the

2

80

70

60

U1
0

ppm Dye in Fruit
.b
o

30

2O

10

Figure l.

 

l9

     
 
  
 

Non-Alar
502

Unblemished

802

802

 
 
 

Cl Non-Alar,
after bleaching .

D>O

 

Alar, after
A bleaching

8 10 12 14 16 18
Dye Concentration, mg/100 9 fruit

Regression Lines, Windsor FD&C Red #3.

20

  
   
  
    

 

 

80 r
70 -
Non—Alar, SO 0
Unblemished
60 r
.p
'3 50-
H
[u
c
-r-1
0
w
0 404
E
m
m
30 r
I3
20 -
o
Non-Alar,
after bleaching
£3
Alar, after
10 bleaching
r A
8 10 12 l4 16 18

Dye Concentration, mg/100 g Fruit

Figure 2. Regression Lines, Napoleon FD&C Red #3.

21

slopes of the 502 bleached lines were significantly dif-
ferent from the NaClO2 bleached lines. (Table 2.)

Results for the Napoleon variety showed signifi-
cant differences between the SO2 bleached and NaClO2
bleached data only. No significant differences were found
within the 802 bleached data or within the NaClO2 bleached
data. (Table 2.)

When Windsor was compared to Napoleon under each
of the conditions of Table 2, no significant differences
were found.

Using the regression equations, the concentration
of dye required to provide 150 ppm dye uptake in each of
the conditions was calculated (Tables 3 and 4). The dye
uptake level of 150 ppm was chosen as a base due to the
Food and Drug Administration restrictions limiting FD&C
Red #4 to the 150 ppm level in maraschino cherries.

Table 3. FD&C Red #3 Dye Concentration Required for 150
ppm Uptake, Windsor.

 

 

 

Sample Rggression Dye Conc.
quation mg/100 g
Non-Alar, 802 y = 4.25x+ 8.05 33.4
Alar, 502 y = 2.32x+ 4.61 62.7
Unblemished, 802 y = 3.24x+10.94 42.9
N235A§ggi0202 y = 0.83x+ 6.18 173.3
Alar, 802 & NaClO2 y = 0.68x+ 4.55 213.9

 

22

Table 4. FD&C Red #3 Concentration Required for 150 ppm
Uptake, Napoleon.

 

 

Regression Dye Conc.
Sample Equation mg/100 g
Non-Alar, SO2 y = 3.64x + 1.61 40.8
Alar, 802 y = 3.3lx + 0.30 45.2
Unblemished, 802 y = 3.54x — 3.75 43.4
Non-Alar, SO _
and NaC102 2 y — 0.98x + 0.33 152.7
Alar, 802 & NaClO2 y = 0.95x - 1.25 159.2

 

There is a great increase in dye concentration re-
quired after secondary bleaching has been performed.
Although the cherries can be successfully dyed, the amount
of dye needed is substantially increased. Alar treatment
of the cherries seemed to have a detrimental effect on
dye uptake capability. Amount of dye uptake (slope) was
consistently less in the Alar treated cherries than in
the Non-Alar cherries (Tables 3 and 4). The Alar treat-
ment had less of an effect in the Napoleon variety than
in the Windsor variety before secondary bleaching.

The effects of secondary bleaching and cherry dye
uptake recovery are shown on Table 5. These samples were
dyed directly from sulfur dioxide brine, immediately after
sodium chlorite bleaching, 1 week in brine after bleach-
ing, and two weeks in brine after bleaching. The dye up-
take immediately following sodium chlorite treatment is
greatly reduced which indicates that chlorite residues

still remained in the cherry pulp after the 36 hour water

23

Table 5. Effect of Secondary Bleaching on Dyeing with
FD&C Red #3, Windsor and Napoleon.*

 

 

 

 

Treatment Unblemished Blemiere-:=====3
Wind. Nap. Wind. Nap.

$02 bleached 61.5 51.5 65.8 47.3

NaClO2 bleached 19.2 11.5 20.6 12.5

1 wk brine 31.2 33.2 28.6 28.4

2 wk brine 34.6 24.9 53.6 19.0

 

*Dye concentration = 15.6 mg/100 g for all samples.

wash. Gradual recovery of dye uptake capability occurred
in sulfur dioxide brine as the chlorite is chemically re-
duced by the sulfur dioxide. Full recovery of dye uptake
capability did not occur after the two week brining period.

There appeared to be a loss of dye retention capa-
bility of the Napoleon cherries during the second week in
brine. This decrease in dye uptake was caused by precipi-
tation of calcium sulfite in the cherry pulp, blocking
pores in the skin, retarding dye diffusion. Formation of
insoluble calcium sulfite in sulfur dioxide brine is a
natural and unavoidable occurance (Payne, gt_al., 1969).
Calcium sulfite initially occurs as a supersaturated
solution in the brine. When a crystal nucleus is intro-
duced, precipitation of the calcium sulfite begins.

Sodium chlorite is a strong oxidizing agent
(Beavers and Payne, 1968b; Taylor, g£_gl., 1940) which
hydrolyzes cellulose in the cherry to some extent during
the bleaching operation. The combination of pitting and

bleaching provided adequate entry of crystal nucleii into

24

the cherry for the formation of calcium sulfite precipi-
tates within the pulp. Removal of the precipitate from
the cherry pulp could not be accomplished, even after

extensive boiling water treatments.

Dyeing of Cherries Using FD&C Red #4

Results of cherry dyeing using FD&C Red #4 are sum-
marized on Tables 6 through 9 and on Figures 3 and 4.

Table 6 shows results of dyeing Windsor and Napo-
leon cherries directly out of sulfur dioxide brine and
after they had been bleached with sodium chlorite and
returned to brine for two weeks. Plots of this data in-
dicated a linear relationship so regression equations
were determined. Correlation between dye uptake and dye
concentration was excellent as shown by the correlation
coefficients. Statistical tests of the r values showed
them to be highly significant.

Plots of the regression equations were made and
are represented in Figures 3 and 4. As was the case with
the FD&C Red #3 dye, Alar treatment showed a detrimental
effect on dye uptake capability of the cherries. Second—
ary bleaching also decreased the rate of dye uptake in
the cherries. However, recovery of the dye uptake charac-
teristics was much better after brine storage with FD&C
Red #4 than it was for FD&C Red #3.

Statistical significance between slopes was deter-

mined using the t-test as with the FD&C Red #3 data.

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140

130

120

110

100

90

80

ppm Dye in Fruit

70

6O

50

40

Figure 3.

 

26

o
Non-Alar,
802
o
+ +
Unblemished
802
O
. C) Alar, $02

 
    
  

Non-Alar, after
bleaching

 

Alar,
after bleach-
ing
[x’
8 10 12 14 16 18

Dye Concentration, mg/100 g Fruit

Regression Lines, Windsor FD&C Red #4.

27

    
 
  
 

  

   

 

 

130 r

120 _

110 _ Unblemished,

SO -+
100 F Non-Alar,
SO
2
4.)
-a
5 Alar,
; 90 .
2

c
-a
R
Q 80 -
E. Non-Alar,
g after bleach-

70 _

Alar, after

60 r bleaching

50 L

40 _

J_ J l 1 L _J
8 10 12 l4 16 18

Dye Concentration, mg/100 g fruit

Figure 4. Regression Lines, Napoleon FD&C Red #4.

28

Within the Windsor variety data, significant dif-

ferences were noted between the SO2 bleached non-Alar and

Alar samples. Significant differences were also noted be-
tween these two samples after NaClO2 bleaching. No

significant difference was found between the SO2 bleached

samples of non-Alar and unblemished. Consistent signifi-

cant differences were not found between the 502 bleached

samples and the 802 and NaClO2 bleached samples. This

indicated that recovery of dyeing characteristics was
better using FD&C Red #4 than it was using FD&C Red #3.
(Table 6.)

Results of Napoleon data comparisons showed only
5% significance between Alar treated NaClO bleached

2

cherries and the samples of SO bleached non-Alar, SO

2 2
bleached unblemished, and NaClO2 bleached non-Alar. Other
comparisons showed no significant differences. (Table 6.)

Comparing Windsor to Napoleon under the columns of
Table 2 showed significant differences under SO2 bleached
non-Alar and SO2 bleached unblemished. The other condi-
tions showed no significant differences. (Table 6.)

The regression equations were used to calculate
the dye concentrations required to provide 150 ppm uptake
in each of the conditions of Table 6. These results are
shown in Tables 7 and 8.

Dye concentration requirements were observed to

increase after secondary bleaching. The amount of increase

29

Table 7. FD&C Red #4 Dye Concentration Required for 150
ppm Uptake, Windsor.

 

 

sample Ream? 313183“;
Non-Alar, 802 y = 6.4 x + 21.1 20.1
Alar, 802 y = 3.79x + 43.15 28.2
Unblemished, SO2 y = 5.51x + 26.45 22.2
Ngngiéig; SO2 y = 4.24x + 26.45 29.1
Alar, $02 & NaClO2 y = 2.74x + 31.36 43.3

 

Table 8. FD&C Red #4 Dye Concentration Required for 150
ppm uptake, Napoleon.

 

 

sample Regiziiisn 32:31:33“;-
-Non-Alar, SO2 y = 4.11x + 29.95 29.2
Alar, 802 y = 2.77x + 47.96 36.8
Unblemished, SO2 y = 3.98x + 41.58 27.2
NinQQéig; SO2 y = 3.55x + 12.88 35.6
Alar, 802 & NaClO2 y = 2.94x + 17.23 45.2

 

was much less than that observed for the FD&C Red #3 re-
sults (Tables 3 and 4).

The effect of secondary bleaching on FD&C Red #4
dyeing characteristics of Windsor and Napoleons was in-

vestigated (Table 9). Recovery of dyeing characteristics

30

was slow and not complete after two weeks in brine
storage.

Table 9. Effect of Secondary Bleaching on Dyeing with
FD&C Red #4, Windsor and Napoleon.*

 

 

 

Unblemished Blemished
Treatment Wind. Nap. Wind. Nap.
SO2 Bleached 113.6 103.7 115.8 100.7
NaClO2 Bleached 48.0 44.8 57.0 45.7
1 wk brine 52.4 44.8 51.8 45.7
2 wk brine 52.8 44.2 53.8 46.5

 

*Dye concentration: 15.6 mg/100 g for all samples.

The occurrence of calcium sulfite precipitation in
the cherries slowed their full recovery of dye retention

capability as was seen in the FD&C Red #3 data.
Color

Color of various treatments was analyzed using the

Hunter Color and Color Difference Meter. L values repre-
sent lightness of color, the higher the better in this
case. Positive 3 values represent redness, negative 3
values indicate greenness. Positive g values represent
yellowness, negative Q values represent blueness. a/b
values show redness, yellowness, greenness: high values
for redness, low values yellowness, 0 or negative values

greenness. ‘Jaz + b2 shows strength or hue of the color;

31

high values indicating a strong color, low values a weak
color. (Wagenknecht and Van Buren, 1965).

Standardization of the instrument was accomplished
using either the Standard Yellow Tile 2814 (L 83.0, a -3.5,
b 26.5) or the Standard White Tile 2810 (L 94.8, a -0.7,

b 2.7). Which tile was used was determined by the range
of color to be read.

The Hunter Color values shown in the tables are
average values for all readings. The direct Hunter values
will be found in the Appendix.

Secondary bleaching greatly improved lightness (L)
and substantially reduced yellowness (b). The strength of
the color ( /§§_:_B§-) was also greatly reduced by secon-
dary bleaching (Table 10). Bleaching increased the pre-
sence of greenness as evidenced by the increase of
negativity of a after bleaching. The a/b value for
Windsor, unblemished, after bleaching indicates a redness
in the bleached cherry. This value was caused by rust in
the wash water which affected the cherry color. The red-
ness was removed by placing the cherries into brine,
acidified with citric acid, for a short time prior to
reading Hunter values (Wagenknecht and Van Buren, 1965).

Statistical significance was determined between
pairs of Hunter values from Table 10 (Table 11). The
Tukey Range Test, One Factor, was used to determine

significant differences. (Tukey, 1953.)

32

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Table 11.

33

Statistical Significance of Hunter Color Values
Before and After Secondary Bleaching.

 

 

 

 

Sample L values 1%* Values 1%* b values 1%*
WaB 66.7 a -2.2 a 0 ac
NaB 64.4 b -2.8 1.5 b
NaU 64.3 b -2.8 1.0 bc
WaU 64.2 b -2.0 ab -0.2 a
WbU 55.7 c -l.0 be 31.4 e
NbU 55.4 c -0.4 c 31.8 e
NbB 52.1 d 1.1 d 30.1 d
WbB .51.2 d 1.6 d 29.9 d
Code: N:Napoleon a: NaClO2 bleached B: Blemished
W:Windsor b: SO2 bleached U: Unblemished

*Like letters denote no significance.

Secondary bleaching significantly changed the
Hunter values of the samples by raising the L values and
reducing the gland 2 values. This indicates a significant
increase in lightness with loss of yellowness.

Table 12 shows the effects of bleaching on dyed
appearance of the fruit using FD&C Red #3. The bleached
fruit was held in sulfur dioxide brine for two weeks
prior to dyeing. Bleaching increased the lightness (L)
of the dyed product. Redness (a/b) was greatly increased
due to the removal of the yellow background (b). The

bleached product was much brighter and appeared more red.

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34

 

 

 

 

 

 

 

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35

Statistical significance was determined between

pairs of Hunter values from Table 12. (Table 13.)

Table 13. Statistical Significance of Hunter Values,
Windsor and Napoleon Dyed with FD&C Red #3.

 

 

 

 

 

 

Sample L values 1%* a values 1%* b values 1%*
NaN 45.9 a 29.5 a 2.5 a
NaA 45.6 a 29.2 a 0.5 b
WaN 44.9 a 33.3 b 3.2 c
WbN 30.4 b 33.3 b 14.4 d
WbA 29.7 b 31.4 c 13.1 e
NbA 29.4 b 30.6 c 12.6 e
NbN 28.9 b 32.0 b 12.9 e
Code: N:Napoleon azNaClO2 bleached N:Non-Alar
W:Windsor b:SO2 bleached A:Alar

*Like letters denote no significance.

There was a significant difference seen in the L,
a, b values between $02 bleached and NaClO2 bleached for
both Windsor and Napoleon. There was generally no signi-
ficant difference between Non-Alar and Alar cherries when
L values were compared. When the a values (redness) were
compared, significant differences were found. While
lightness of the cherries differed only slightly, the
redness was more intense in the non-Alar cherries. (Table
13.)

Comparison of Windsor and Napoleon showed signifi-

cant differences between the non-Alar cherries 802

36

bleached and NaClO2 bleached L values. The Alar cherries
showed no significant differences between Windsor and
Napoleon SO2 bleached but significant differences for the

NaClO2 bleached. The Windsor cherries showed more red

than the Napoleon cherries (a values) after NaClO2 bleach—
ing (Tables 12, 13).

Table 14 shows the results of dyeing 502 bleached
and NaClO2 bleached fruit with FD&C Red #4.

In dyeing with FD&C Red #4, there was a slight in-
crease in redness (a) after bleaching. a/b, indicating
redness, increased only slightly after bleaching. Yellow-
ness (b) tended to increase slightly after bleaching which
indicates that the dye completely covers the background
color of the cherry. The major changes caused by bleach-
ing were observed to be increased lightness and greater
strength of color.

Statistical significance was determined between
Hunter values from Table 14 (Table 15).

For the Windsor and for the Napoleon cherries
significance was found for all pairs tested except the

non-Alar vs Alar after NaClO bleaching. Chlorite bleach-

2
ing significantly improved lightness and redness with a
slight increase in yellowness. Differences in appearance

between non-Alar and Alar cherries were erased by chlorite

bleaching. (Table 15.)

37

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38

Table 15. Statistical Significance of Hunter Values,
Windsor and Napoleon Dyed with FD&C Red #4.

 

 

 

 

 

 

Sample L values 1%* a values 1%* b values 1%*
WaN 33.5 a 36.0 a 16.2

WaA 33.4 a 36.0 a 16.5

NaN 32.8 ab 33.0 bd 14.8 bc
NaA 32.4 b 33.6 b 15.3 b
NbA 26.9 c 29.5 ce 14.5 bc
WbA 26.7 c 31.3 cd 15.3 b
NbN 25.8 cd 31.0 c 15.2

WbN 25.3 d 28.4 e 14.1 c

 

Code: N:Napoleon a:NaClO2 bleached N:Non-Alar

W:Windsor b:SO2 bleached A:Alar

*Like letters denote no significance.

No differences were noted between 802 bleached
Windsors and Napoleons when L values were compared. There
were significant differences in L values after NaClO2
bleaching. The a and b_values showed significant differ-

ences between Windsors and Napoleons for all pairs tested.

(Table 15.)
Texture

Textural changes caused by secondary bleaching
were observed to recover very well when stored in sulfur

dioxide-calcium brine after bleaching. (Tables l6, l7,

18.)

39

the Tukey Range Test, One Factor (Tukey, 1953).

Texture values were tested for significance using

 

 

 

 

 

 

 

 

 

 

Table 16. Windsor and Napoleon Texture, 1970 Sample.
Undyed FD&C Red #3 FD&C Red #4
Unblem. Blem. Unblem. Blem. Unblem. Blem.
SO2 W: .0994 .0998 .0533 .0582 .0896 .0952
bleached N: .1280 .1300 .1838 .1752 .1467 .1424
NaClO2 W: -- -- .0218 .0198 .0498 .0596
bleached N: —- -- .0290 .0290 .0322 .0666
1 wk W: -- —- .0455 .0483 .0870 .0902
brine N: -- -- .0790 .0671 .1284 .1234
2 wk W: -- -- .0594 .0747 .0925 .0947
brine N: -- —— .0788 .0743 .1348 .1267
Units: lb force/g product.
Code: W:Windsor N:Napoleon.
Table 17. Statistical Significance, Windsor Texture, 1970
Sample.
FD&C Red FD&C Red
* 'k 'k
802 Bleached 1% #3 1% #4 1%
U .0994 a U .0533 b .0896 a
undyed B .0998 a SO2 B .0582 b .0952 a
U .0896 a U .0594 b .0925 a
Red #4 B .0952 a 2 Wk B .0747 a .0947 a
U .0533 b U .0455 b .0870 a
Red #3 B .0582 b 1 Wk B .0483 b .0902 a
U .0218 c .0498 b
C102 B .0198 c .0596 c
Units: 1b force/g product.
Code: U:Unblemished BzBlemished

*Like letters

denote no significance.

40

Table 18. Statistical Significance, Napoleon Texture,
1970 Sample.

 

 

 

FD&C Red FD&C Red

* * ‘k

SO2 Bleached 1% #3 1% #4 1%

U .1838 a U .1838 a U .1467 a

Red #3 B .1752 a SO2 B .1752 a B .1424 a
U .1467 b U .0788 b U .1348 ab

Red #4 B .1424 b 2 Wk B .0743 b B .1267 b
U .1300 b U .0790 b U .1284 b

undyed B .1280 b 1 Wk B .0671 b B .1234 b
_ U .0290 c U .0666 c

Clo2 B .0322 c B .0692 c

 

Units: 1b force/g product.
Code: U:Unblemished B:Blemished.
*Like letters denote no significance.

Napoleon cherries had a firmer texture than did
the Windsor cherries initially. Windsor, however, were
observed to recover firm texture slightly better than
Napoleon after secondary bleaching. (Tables l7, 18.)

The effect of secondary bleaching on texture was
investigated using the Alar treated cherries (Table 19).
Generally, significant differences were noted between the
varieties of Windsor and Napoleon but no significance with-
in either variety between non-Alar and Alar cherries.

Textural comparisons between the years of harvest
were made (Table 20).

There was a significant difference in texture be-

tween the 1969 harvest and the 1970 harvest. The prolonged

41

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43

storage in sulfur dioxide—calcium brine of the 1969 har-
vest served to firm the cherry tissue more than that of

the 1970 harvest.

Effects of Air on Bleaching

 

Samples of cherries were placed in sodium chlorite
bleaching solution under different conditions to observe
the effect of air on the bleaching action. Samples were
bleached for the standard time of 180 hours under nitrogen,
closed under air, open, and open with periodic agitation.
Evaluation of bleaching action was made using Hunter color
values (Table 21). Statistical comparisons of the values

were made using the Tukey Range Test, One Factor.

Table 21. Hunter Values, Effect of Air on Bleaching.

 

 

 

Sample L l%* a . 1%* b 1%* a/b yh§+b2
Nitrogen 65.5 b -5.0 a 7.9 a -0.6 9.3

Air, closed 66.2 a —4.9 ab 6.5 b -0.8 8.1

Open 66.3 a -4.7 b 6.4 b -0.7 7.9
Open _ _
Agitated 65.5 b 4.8 b 6.4 b 0.8 8.0

 

Standardization: White tile
*Like letters denote no significance.

L, a, b, tested independently.

44

The sample that was merely left open was observed
to have slightly better bleaching action than the other
samples.' The sample bleached under nitrogen was generally
poorer in appearance than the other bleached samples.
Samples bleached under air were generally not signifi-
cantly different in appearance.

The sample which had the slightly better bleach-
ing action (Open) also consumed slightly more chlorite
(Table 22). The pH of the solutions dropped during
bleaching but the final pH was within the optimum range
of 4.0-6.0 except for the nitrogen sample. (Beavers and
Payne, 1969.) The lower pH of the nitrogen sample did not
affect the bleaching action.

Table 22. Consumption of Chlorite and pH Changes under
Different Bleaching Conditions.

W
% C102 pH

Initial Final Consum. Initial Final

 

 

Nitrogen .573 .060 .513 5.0 3.9
Air, closed .573 .060 .513 5.0 4.0
Open .573 .046 .527 5.0 4.0

Open, agitated .573 .051 .522 5.0 4.0

 

SUMMARY AND CONCLUS IONS

Dyeing of sweet cherries was observed to possess
a linear relationship between dye absorbed into the cherry
and the dye concentration in the dyeing solution. To ob-
tain consistent results in dyeing operations the ratio of
fruit to dyeing solution was kept constant. Change in
this ratio lead to varying dye uptakes.

No predictable correlation can be made between dye
uptake and dye concentration for any treatment, other than
that the relationship is a linear one. Each treatment
studied showed different amounts of dye uptake. Secondary
bleaching using sodium chlorite markedly reduced the
amount of dye uptake in all conditions studied. Treat-
ment of cherries with Alar was observed to decrease dye
uptake capability of the fruit. Linear correlation be-
tween dye uptake and dye concentration was generally
excellent.

Secondary bleaching increased lightness and vir-
tually eliminated the yellow color of sulfur brined
cherries. Bleached cherries were snow white in appearance
with very little of any other color present as shown by
Hunter Color readings. Dyeing of bleached cherries pro-

vided a product which was brighter in appearance. Redness

45

46

increased when the fruit was dyed using FD&C Red #3, due

to removal of the yellow background of sulfur brined fruit.
Fruit dyed using FD&C Red #4 showed increased lightness
and greater color strength after bleaching with only
slight change in yellowness and redness. Secondary bleach-
ing significantly improved the appearance of the dyed pro-
duct as shown by Hunter values. As was shown previously,
secondary bleaching also caused a lower amount of dye
uptake. Thus, at the dye concentration used in this

study, cherries of significantly better appearance were
produced with much lower dye uptake.

Textural changes caused by sodium chlorite bleach-
ing were observed to be corrected by brining for two weeks
after bleaching was completed. During this period the
hydrolyzed cellulose materials complex with the calcium
of the brine to provide a firm texture. Significant dif-
ferences were found when cherry texture of the two harvest
years was compared. The 1969 cherries had a firmer tex-
ture due to prolonged brine storage.

Bleaching action of chlorite was slightly reduced
when bleaching was carried out under nitrogen. Various
conditions of bleaching under air showed slight variations
in bleaching action of chlorite. Consumption of chlorite

was similar for all conditions.

LIST OF REFERENCES

REFERENCES

American Public Health Association, American Water Works
Association, and Water Pollution Control Federa-
tion. 1961. Standard Methods for the Examination
of Water and Wastewater. Puplished by American
Public Health Association, Inc., New York, N. Y.
p. 133.

Amerine, M. A., R. M. Pangborn and E. B. Roessler. 1965.
Principles of SensoryfiEvaluation of Food. Acade-
mic Press, New York. Chap. 10.

AOAC. 1965. Official Methods of Analysis, 10th Edition.
Association of Official Agricultural Chemists,
Washington, D. C.

Atkinson, F. E. and C. C. Strachan. 1963. Sulfur dioxide
preservation of fruits. Canada Department of Agri-
culture, Publication 1176.

Beavers, D. V. and C. H. Payne. 1968a. Bleaching fruits
and vegetables. U. S. Patent Pending #700,389.

Beavers, D. V. and C. H. Payne. 1968b. Upgrades brined
cherries; Bleaching with sodium chlorite imparts
better color, flavor, and texture to the processed
fruit. Food Engineering, 40(7):84.

Beavers, D. V. and C. H. Payne. 1969. Secondary bleach-
ing of brined cherries with sodium chlorite. Food
Tech. 23(4):175.

Brekke, J. E. and M. M. Sandomire. 1961. Simple objective
method of determining firmness of brined cherries.
Food Tech., 15:335.

Bullis, D. E. and E. H. Wiegand. 1931. Bleaching and
dyeing Royal Ann cherries for maraschino or fruit
salad use. Oregon Agr. Exp. Station Bulletin No.
275.

Francis, F. J. 1963. Color control. Food Tech., 17:546.

47

48

Haller, J. F. and S. S. Listek. 1948. Determination of
chlorine dioxide and other active chlorine com—
pounds in water. Anal. Chem., 20:639.

Jeffrey, R. N. and W. V. Cruess. 1929. Effect of hydro-
gen ion concentration in the dyeing of cherries.
Industrial and Engineering Chemistry, 21:1268.

Jurd, L. 1964. Reactions involved in sulfite bleaching
of anthocyanins. Journal of Food Science, 29:16.

Kretlow, W. H. 1970. Manual of Certified Food Colors.
Stange Co., Chicago, Illinois. Private Publica-
tion.

LaBelle, R. L. and J. P. Van Buren. 1966. Maraschino and
candied cherries...some aSpects of their produc-
tion. Farm Research, Jan.-March, p. 2.

Lewis, J. C., C. F. Pierson, and M. J. Powers. 1963.
Fungi associated with softening of bisulfite
brined cherries. Applied Microbiology, ll(2):93.

Levin, J. H., R. T. Whittenberger and H. P. Gaston. 1969.
When to harvest sweet cherries mechanically.
Michigan State Univer. Agri. Exp. Station, East
Lansing, Mich. Research Report 87.

Mendenhall, W. 1968a. Introduction to Probability and
Statistics. 2nd ed. Wadsworth Publishing Co.,
Inc., pp. 227, 239.

 

Mendenhall, W. 1968b. Introduction to Probability and
Statistics. 2nd ed. Wadsworth Publishing Co.,
Inc., p. 189.

 

Murphy, D. H. 1965. How do you color maraschinos without
FD&C Red #4. Canner/Packer, 134(8):25.

National Cherry Growers and Industries Foundation, Inc.
302 NW 29th St., Corvallis, Oregon. Statistical
Compilation of Production, Utilization, Average
Prices, and Imports of Sweet Cherries. 1970
Report.

 

Payne, C. H., D. V. Beavers and R. F. Cain. 1969. The
chemical and preservative properties of sulfur
dioxide solution for brining fruit. Oregon Agr.
Exp. Station Circular of Information 629.

49

Robson, H. L., L. D. Taylor and R. R. Heinze, 1961.
Bleaching composition and method. U.S. Patent
2,988,514.

Sokal, R. R. and F. J. Rohlf. 1969. Biometry. W. H.
Freeman and Company, San Francisco. Chap. 14.

 

Stange C0. Technical Data Sheet. 1966. General procedure
for quantitative analysis of FD&C color additives
in maraschino cherries. Stange Co., Chicago, Ill.
Private Publication.

Stange Co. Technical Data Sheet. 1968a. Procedure for
coloring maraschino cherries with 150 ppm of Red
#4. Stange Co., Chicago, Ill. Private Publica-
tion.

Stange C0. Technical Data Sheet. 1968b. Recommended pro-
cedure for coloring brined cherries for fruit salad
or fruit cocktail with FD&C Red #3. Stange Co.,
Chicago, Ill. Private Publication.

Strachan, C. C. and F. E. Atkinson. 1955. Effect of
sucrose-invert and high conversion glucose sirups
in the preparation of candied cherries. Food
Tech., 9:518.

Taylor, M. C., J. F. White, G. P. Vincent and G. L. Cun-
ningham. 1940a. Sodium chlorite: properties and
reactions. Ind. and Eng. Chemistry, 32:899.

Thienes, J., R. P. Larsen and C. Kesner. 1969. Fruit re-
moval and quality of mechanically harvested sweet
cherries. Mich. State Univer. Agr. Exp. Station,
East Lansing, Mich. Research Report 88.

Tukey, J. W. 1953. Some selected quick and easy methods
of statistical analysis. Trans. N. Y. Acad. Sci.
Ser. 11, 16, 88-97.

United States Department of Agriculture. 1967. A revi-
sion of the United States standards for grades of
sulfur brined cherries and proposed visual aid for
defects and color. A study draft prepared by
Standardization Section, Processed Products Stand—
ardization and Inspection Branch, Consumer and
Marketing Service, U.S.D.A., Washington, D.C.

Van Buren, J. P. 1965. The effect of Windsor cherry
maturity on the quality and yield of brined
cherries. Food Tech., 19:98.

50

Van Buren, J. P. 1967. Pectic substances of sweet cher—
ries and their alteration during 502 brining.
Journal of Food Science, 32:435.

Van Buren, J. P., R. L. LaBelle, and D. F. Splittstoesser.
1967. The influence of 802 levels, pH, and salts
on brined Windsor cherries. Food Tech., 21:1028.

Wagenknecht, A. C. and J. P. Van Buren. 1965. Preliminary
observations on secondary oxidative bleaching of
sulfited cherries. Food Tech., l9(4):658.

Watters, G. G., J. E. Brekke, M. J. Powers and H. Y. Yang.
1961. Brined Cherries, analytical and quality
control methods. Agricultural Research Service
Publication, 74-23.

Weast, C. A. 1941. Dyeing maraschino cherries with
erythrosine. Fruit Products Journal, 20:332.

Whittenberger, J. H., J. H. Levin and H. P. Gaston. 1968.
Maintaining quality by brining sweet cherries after
harvest. Mich. State Univ. Agr. Exp. Station,

East Lansing, Mich. Research Report 73.

Whittenberger, R. T., J. H. Levin and B. F. Cargill. 1969.
Weight to volume relationship of sweet cherries in
brine. Mich. State Univer. Agr. Exp. Station,

East Lansing, Mich. Research Report 89.

Wiegand, E. H., C. E. Norton and D. J. Pentzer. 1939.
Investigations of the cracking problem in brining
of sweet cherries. Food Research, 4:93.

APPENDIX

APPENDIX

 

 

 

 

 

 

 

Table 23. Sulfur Dioxide and pH Levels of Brines Prior
to Use.
Sample Container ppm 802 pH
Windsor 1 4168 3.16
2 3840 2.88
3 3557 2.90
4 6534 2.90
avg. 4528 2.96
Napoleon 1 4031 3.10
4231 3.10
4333 3.00
7087 2.90
avg. 4929 3.03
Table 24. Consumption of Chlorite and pH of Bleaching
Solution.
%C102 pH
Sample initial final consumption initial final
Windsor, Alar .600 .343 .257 5.0 4.0
Windsor,
Non-Alar .599 .339 .260 5.0 4 0
Napoleon, __
Non-Alar .570 .002 .568 5.0
Napoleon, Alar .560 .173 .387 5.0 --

 

51

52

 

 

 

 

 

 

 

 

 

 

Table 25. Hunter Color Values Before and After Bleaching
(Direct average).
==—__._.—__—==
Unblemished Blemished
Sample L a b L a b
Windsor, 55.9 -1.2 31.3 51.6 1.1 30.2
unbleached 55.4 -0.8 31.2 51.3 1.4 29.8
55.9 -0.9 31.7 50.7 2.2 29.7
Windsor, 63.0 -2.0 -0.3 66.8 -2.4 0.0
bleached 64.9 -2.0 -0.2 66.6 -2.2 0.1
64.6 -1.9 0.0 66.8 -2.1 0.0
Napoleon, 56.0 -O.5 32.0 50.0 2.2 28.5
unbleached 54.8 -0.4 31.7 53.4 0.5 30.7
55.3 -0.3 31.7 52.9 0.6 30.2
Napoleon, 63.9 -2.8 0.8 64.4 -2.9 1.6
bleached 64.3 -2.9 1.1 64.3 -2.8 1.4
64.7 -2.6 1.1 64.4 -2.6 1.6
Standardization: Unbleached - Yellow Tile
Bleached - White Tile
Table 26. Hunter Color Values, Windsor Dyed using FD&C
Red #3 (Direct averages).
Non-Alar Alar
Sample L a b L a b
Unbleached, 30.2 33.4 14.3 29.9 32.1 13.0
dyed 30.5 33.3 14.6 29.7 31.1 13.2
30.6 33.1 14.3 29.4 31.1 13.0
Bleached, 63.9 -4.3 6.8 65.2 -4.4 7.3
undyed 65.4 -4.3 6.9 64.8 -4.3 7.1
65.2 -4.3 7.0 64.8 -4.3 7.7
Bleached, 43.5 35.6 3.2 44.4 33.4 3.2
dyed 43.8 34.7 3.4 45.6 33.2 3.0
43.0 35.1 3.4 44.7 33.4 3.4

 

Standardization:

Dye Concentration:

White Tile
16 mg/100 g

53

Table 27. Hunter Color Values, Napoleon Dyed Using FD&C

Red #3 (Direct Averages).

 

 

 

 

 

 

 

 

 

 

Non-Alar Alar
Sample L a b L a b
Unbleached, 28.9 32.7 12.9 29.7 30.6 12.7
dyed 28.8 32.9 12.9 29.0 30.2 12.4
29.0 33.1 12.8 29.6 31.0 12.6
Bleached, 65.7 -4.8 5 9 65.3 -4.3 4.2
undyed 65.6 -4.8 5.9 65.6 -4.1 3.6
66.1 -4.9 5.7 65.0 -4.2 3.8
Bleached, 45.8 29.8 2.6 45.4 29.7 0.7
dyed 46.2 29.1 2.8 45.6 28.9 0.6
45.8 29.7 2.2 45.9 28.9 0.3
Standardization: White Tile
Dye Concentration: 16 mg/100 9
Table 28. Hunter Color Values, Windsor Dyed Using FD&C
Red #4 (Direct Averages).
Non-Alar Alar
Sample L a b L a b
Unbleached, 25.8 29.0 14.3 27.0 32.2 15.7
dyed 25.2 28.4 14.0 26.4 30.9 15.1
25.0 27.8 13.9 26.6 30.7 15.1
Bleached, 63.9 -4.3 6.8 65.2 -4.4 7.3
undyed 65.4 -4.3 6.9 64.8 -4.3 7.1
65.2 -4.3 ,7.0 64.8 -4.3 7.7
Bleached, 33.2 36.9 16.6 33.7 36.0 16.4
dyed 33.7 35.5 16.0 33.3 36.1 16.6
33.6 35.6 16.1 33.3 35.8 16.5

 

Standardization: White Tile

Dye Concentration: 16 mg/100 g

54

 

 

 

 

 

 

 

Table 29. Hunter Color Values, Napoleon Dyed Using FD&C
Red #4 (Direct Average).
Non-Alar Alar
Sample L a b L a b
Unbleached, 25.8 31.4 15.4 26.8 30.0 14.8
dyed 25.8 30.9 15.1 27.0 29.4 14.5
25.9 30.8 15.1 26.8 29.0 14.3
Bleached, 65.7 -4.8 65.3 -4.3 4.
undyed 65.6 -4.8 65.6 -4.1 3.
66.1 -4.9 65.0 -4.2 3.
Bleached, 32.6 33.9 32.3 33.9 15.
dyed 32.5 33.3 32.5 33.5 15.
33.2 31.8 32.4 33.5 15.
Standardization: White Tile
Dye Concentration: 16 mg/100 9

Table 30. Hunter Color Values, Effect of Air on Bleaching

(Direct Averages).

m

 

 

Sample L a b
Under Nitrogen 65.4 -5.0 7.5
65.8 -5.1 8.2
65.4 -5.0 7.9
Closed under air 66.3 -4.9 6.8
66.3 -4.8 6.0
66.1 -5.0 6.6
Open, unagitated 66.2 -4.7 6.7
66.2 -4.7 6.0
66.4 -4.8 6.5
Open, agitated 65.5 -4.7 6.4
65.5 -4.8 6.4
65.5 —4.8 6.4
Standardization: White Tile