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This is to certify that the
thesis entitled

EFFECTS OF PROCESSING, STORAGE TEMPERATURE AND
STORAGE DURATION ON PHYSICO-CHEMICAL, SENSORY
QUALITY, AND ANTIOXIDANT PROPERTIES OF MICHIGAN

MONTMORENCY CHERRY JUICE CONCENTRATE

presented by
Claudia Jean Place

has been accepted towards fulfillment
of the requirements for the

MS. degree in Food Science

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5/08 KzlProleocatPresIClRC/DateDm.indd

EFFECTS OF PROCESSING, STORAGE TEMPERATURE AND STORAGE
DURATION ON PHYSICO—CHEMICAL, SENSORY QUALITY, AND
ANTIOXIDANT PROPERTIES OF MICHIGAN MONTMORENCY CHERRY
JUICE CONCENTRATE

By

Claudia Jean Place

A THESIS
Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE
Food Science

2009

ABSTRACT
EFFECTS OF PROCESSING, STORAGE TEMPERATURE AND STORAGE
DURATION ON PHYSICO-CHEMICAL, SENSORY QUALITY, AND
ANTIOXIDANT PROPERTIES OF MICHIGAN MONTMORENCY CHERRY
JUICE CONCENTRATE
By
Claudia Jean Place

Unpasteurized and pasteurized tart cherry juice concentrate was stored
for 48 weeks at 4, 21 and 38°C. Microbial activity, total soluble solids, pH,
titratable acidity, Hunter color, and turbidity were measured over time.
Concentrate was analyzed for total antioxidant capacity (Oxygen Radical
Absorbance Capacity) total anthocyanins (pH-differential) and total phenolic
content (Folin-Ciocalteu). Sensory quality was measured by trained and
consumer panels. Results for yeast and mold were found negative.
Pasteurization had minimal to no significant effect on all attributes tested.
Storage temperature and duration had minimal to no effect on Hunter “L” and
“b” values, pH and total phenolics. Total soluble solids and titratable acidity
showed significant decrease for ambient and elevated storage conditions.
Hunter “a” value, turbidity and anthocyanin content showed significant change
over time, showing a significantly higher decrease at ambient and elevated
temperature conditions. Storage duration decreased ORAC values
significantly; however, no differences were seen among storage conditions.
Analytical analysis and sensory panels showed most overall stable concentrate

quality for refrigerated temperatures while ambient storage condition showed

poor quality after week 12 and elevated storage conditions after week 2.

DEDICATION

To my family and friends for all their love and support.

iii

ACKNOWLEDGEMENTS

First and foremost I would like to thank my advisor Dr. Kirk Dolan. Dr.
Dolan has been an outstanding mentor and has given me valuable guidance on
my research and education. With him my graduate education was possible and
for that I am very thankful. I would also like to thank my committee members
Dr. Janice Harte and Dr. Maurice Bennink and my professor Dr. Muhammad
Siddiq for contributing all their help and knowledge to my research. Thank you
to all of my lab mates and fellow food science graduate students. I have made
lifetime friends within the Food Science department and your friendship and
support means a great deal to me. Special thanks to Korey Hodges for both
her friendship and her assistance in the lab. Your help was so greatly
appreciated and you made long days in the lab much more fun. Thank you to
all who participated in my trained sensory panel. Your time and dedication to
the project made for valuable data, which I could not have produced without
your help. Thank you to Shoreline Fruit (Traverse City, Michigan) for the
donation of the cherry juice concentrate. Finally, thank you Michigan Cherry
Research Committee for the grant and support which made this research

possible.

iv

TABLE OF CONTENTS

LIST OF TABLES ............................................................................................. viii
LIST OF FIGURES ............................................................................................ xi

1. EFFECTS OF PROCESSING, STORAGE TEMPERATURE AND STORAGE
DURATION ON PHYSCIO—CHEMICAL PROPERTIES AND SENSORY

QUALITY OF MONTMORENCY CHERRY JUICE CONCENTRATE ................. 4
1.1 Literature Review ...................................................................................... 4
1.1.1 Background of Tart Cherries and Tart Cherry Concentrate ............... 4
1.1.2 Microbiological Content ..................................................................... 5
1.1.3. Sensory Attributes ............................................................................ 5
1.1.4 Hypothesis ........................................................................................ 6
1.2 Materials and Methods ............................................................................. 6
1.2.1 Chen'y Juice Concentrate Samples ................................................... 6
1.2.2 Pasteurization of Concentrate ........................................................... 7
1.2.3 Packaging and Storage of Concentrate ............................................. 7
1.2.4 Shelf Life Schedule ........................................................................... 8
1.2.5 Physico-Chemical Analysis ............................................................... 9
1.2.5.1 Total Soluble Solids ................................................................... 9
1.2.5.2 pH and Titratable Acidity ............................................................ 9
1.2.5.3 Turbidity ................................................................................... 10
1.2.5.4 Hunter Color ............................................................................. 10
1.2.6. Microbial Content ........................................................................... 1 1
1.2.6.1 Plate Preparation and Dilution Buffer ....................................... 11
1.2.6.2 Sample Preparation ................................................................. 12
1.2.7 Sensory Analysis ............................................................................. 12
1.2.7.1 Environmental Condition .......................................................... 12
1.2.7.2 Trained Panel ........................................................................... 12
1.2.7.2.1 Panelist Training ............................................................... 12
1.2.7.2.2 Sensory Analysis Test Method ......................................... 13
1.2.7.2.3 Sample Preparation and Presentation .............................. 14

1.2.7.3 Consumer Panel ...................................................................... 15
1.2.7.3.1 Sensory Analysis Test Method ......................................... 15
1.2.7.3.2 Sample Preparation and Presentation .............................. 15

1.2.8 Statistical Analysis ........................................................................... 16
1.3 Results and Discussion .......................................................................... 16
1.3.1 Microbial Analysis ........................................................................... 16
1.3.2 Physico-Chemical ........................................................................... 16
1.3.2.1 Total Soluble Solids ................................................................. 16
1.3.2.2 pH ............................................................................................ 19
1.3.2.3 Titratable Acidity ...................................................................... 21
1.3.2.4 Turbidity ................................................................................... 23

V

1.3.2.5 Hunter Color ............................................................................. 25

1.3.3 Trained Sensory Panel .................................................................... 33
1.3.3.1 Processing and Storage Condition Effect ................................. 33
1.3.3.2 Effect of Storage Duration ........................................................ 41

1.3.4 Consumer Sensory Panel ............................................................... 52
1.3.4.1 Processing and Storage Condition Effect ................................. 52
1.3.4.2 Storage Duration Effect ............................................................ 56

1.4 Conclusion .............................................................................................. 57

2. EFFECTS OF PROCESSING, STORAGE TEMPERATURE AND STORAGE
DURATION ON ANTIOXIDANT PROPERTIES OF MONTMORENCY CHERRY

JUICE CONCENTRATE ................................................................................... 60
2.1 Literature Review .................................................................................... 60
2.1.1 Antioxidants ..................................................................................... 60
2.1.1.1 Background of Antioxidants ..................................................... 60
2.1.1.2. Anthocyanins .......................................................................... 61
2.1.1.3 Phenolics ................................................................................. 63
2.1.1.4 Health Benefits ......................................................................... 64
2.1.2 Analysis of Antioxidant Capacity ..................................................... 64
2.1.2.1 Oxygen Radical Absorbance Capacity ..................................... 64
2.1.2.2 Total Anthocyanins - pH Differential Method ............................ 66
2.1.2.3 Total Phenolics - Folin-Ciocalteu Assay ................................... 68
2.1.3 Hypothesis ...................................................................................... 69
2.2 Materials and Methods ........................................................................... 69
2.2.1 Cherry Juice Concentrate Samples ................................................. 69
2.2.2 Pasteurization of Concentrate ......................................................... 70
2.2.3 Packaging and Storage of Concentrate ........................................... 70
2.2.4 Shelf Life Schedule ......................................................................... 71
2.2.5 Oxygen Radical Absorbance Capacity ............................................ 71
2.2.5.1 Reagent and Sample Preparation ............................................ 71
2.2.5.2 Experimental Procedure .......................................................... 73
2.2.6 Total Anthocyanins- pH Differential Assay ...................................... 74
2.2.6.1 Reagent Preparation ................................................................ 74
2.2.6.2 Experimental Procedure .......................................................... 75
2.2.7 Total Phenolics- Folin-Ciocalteu Assay ........................................... 76
2.2.7.1 Reagent and Sample Preparation ............................................ 76
2.2.7.2 Experimental Procedure .......................................................... 77
2.2.8 Statistical Analysis ........................................................................... 78
2.3 Results and Discussion .......................................................................... 78
2.3.1 Oxygen Radical Absorbance Capacity ............................................ 78
2.3.2.1 Interaction Effect ...................................................................... 78
2.3.2.2 Storage Duration Effect ............................................................ 79
2.3.2 Total Anthocyanins .......................................................................... 82
2.3.2.1 Interaction Effects .................................................................... 82

vi

2.3.2.2 Pasteurization Effect ................................................................ 82

2.3.2.3 Storage Temperature Effect ..................................................... 84

2.3.2.4 Storage Duration Effect ............................................................ 87

2.3.3 Total Phenolics ................................................................................ 89
2.3.3.1 Interaction Effects .................................................................... 89

2.3.3.2 Pasteurization Effect ................................................................ 90

2.3.3.3 Storage Condition Effect .......................................................... 91

2.3.3.4 Storage Duration Effect ............................................................ 93

2.4 Conclusion .............................................................................................. 95

3. OVERALL CONCUSIONS AND FUTURE RECOMMENDATIONS .............. 95
APPENDIX 1 RAW PHYSClO-CHEMICAL DATA ............................................ 97
APPENDIX 2 RAW ANTIOXIDANT DATA ...................................................... 101
REFERENCES ............................................................................................... 125

vii

LIST OF TABLES

Table 1.1: Schedule which analysis was performed on cherry juice concentrate9

Table 1.2: Linear regression results for total soluble solids (°Brix) ................... 17
Table 1.3: Linear regression results for pH ....................................................... 19
Table 1.4: Linear regression results for titratable acidity (% malic acid) ........... 21
Table 1.5: Linear regression results for turbidity (% transmittance) .................. 23
Table 1.6: Linear regression results for Hunter Color L Value .......................... 26
Table 1.7: Linear regression results for Hunter Color b Value .......................... 30

Table 1.8: Initial trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice .................................................................. 34

Table 1.9: Trained panel average sensory ratings for tart cherry concentrate
and reconstituted juice stored 2 weeks 4, 21 and 38°C .................................... 34

Table 1.10: Trained panel average sensory ratings for tart cherry concentrate
and reconstituted juice stored 4 weeks at 4, 21 and 38°C ................................ 36

Table 1.11: Trained panel average sensory ratings for tart cherry concentrate
and reconstituted juice stored 8 weeks at 4, 21 and 38°C ................................ 37

Table 1.12: Trained panel average sensory ratings for tart cherry concentrate
and reconstituted juice stored 12 weeks at 4, 21 and 38°C .............................. 38

Table 1.13: Trained panel average sensory ratings for tart cherry concentrate
and reconstituted juice stored 16 weeks at 4, 21 and 38°C .............................. 39

Table 1.14: Trained panel average sensory ratings for tart cherry concentrate
and reconstituted juice stored 20 weeks at 4, 21 and 38°C .............................. 40

Table 1.15: Trained panel average sensory ratings for tart cherry concentrate
and reconstituted juice stored 24 weeks at 4, 21 and 38°C .............................. 40

Table 1.16: Trained panel average sensory ratings for tart cherry concentrate
and reconstituted juice stored 36 weeks at 4, and 21 °C ................................... 41

Table 1.17: Trained panel average sensory ratings for tart cherry concentrate
and reconstituted juice stored 48 weeks at 4, and 21°C ................................... 41

Table 1.18: The average trained panel acceptance ratings and Tukey’s HSD
test comparison results for storage duration (21 °C unpasteurized) .................. 47

viii

Table 1.19: The average trained panel acceptance ratings and Tukey’s HSD
test comparison results for storage duration (21°C pasteurized) ...................... 47

Table 1.20: The average trained panel acceptance ratings and Tukey’s HSD
test comparison results for storage duration (38°C unpasteurized) .................. 51

Table 1.21: The average trained panel acceptance ratings and Tukey’s HSD
test comparison results for storage duration (38°C pasteurized) ...................... 51

Table 1.22: Average consumer acceptance ratings and Tukey’s HSD test
comparison at week 16 of storage (unpasteurized and pasteun'zed) ................ 53

Table 1.23: Average consumer acceptance ratings and Tukey’s HSD test
comparison at week 24 of storage (unpasteurized and pasteurized) ................ 53

Table 1.24: Average consumer acceptance ratings and Tukey’s HSD test
comparison at week 36 of storage (unpasteurized and pasteurized) ................ 54

Table 1.25: Average consumer acceptance ratings and Tukey’s HSD test
comparison at week 48 of storage (Fresh vs. Stored) ...................................... 55

Table 1.26: Tukey’s HSD p-values for consumer panel evaluation over storage
duration of 36 weeks ......................................................................................... 57

Table 2.1: Summary of p-values of variables and interactions for ORAC values
(micromole TE/g tart cherry juice concentrate) ................................................. 79

Table 2.2: The average ORAC values (micromole TE/g tart cherry juice
concentrate) and Tukey’s HSD test comparison results for storage duration ...80

Table 2.3: Summary of p-values of variables and interactions for total
anthocyanin values (mg cyn-3-glu/liter tart cherry juice concentrate) ............... 82

Table 2.4: Summary of p-values of variables and interactions for total phenolic
(grams GAE/liter tart cherry juice concentrate) ................................................. 89

Table 2.5: The average total phenolic (g GAE/liter liter tart cherry juice
concentrate) results for storage conditions (unpasteurized) ............................. 91

Table 2.6: The average total phenolic (g GAE/liter liter tart cherry juice
concentrate) results for storage conditions (pasteurized batch 1) ..................... 92

Table 2.7: The average total phenolic (g GAE/liter liter tart cherry juice
concentrate) results for storage conditions (pasteurized batch 2) ..................... 92

Table 2.8: The average total phenolic (g GAE/liter liter tart cherry juice
concentrate) results for storage conditions (pasteurized batch 3) ..................... 92

ix

Table A.1.1 Raw data for total soluble solids (°Brix) ......................................... 97

Table A.1.2 Raw data for pH ............................................................................. 97
Table A.1.3 Raw data for titratable acidity (% malic acid) ................................. 98
Table A.1.4 Raw data for turbidity (% transmittance) ........................................ 98
Table A.1.5 Raw data for Hunter Color L value ................................................ 99
Table A.1.6 Raw data for Hunter Color a value ................................................ 99
Table A.1.7 Raw data for Hunter Color b value .............................................. 100

Table A.2.1 Raw data for Oxygen Radical Absorbance Capacity (ORACFL) for
tart cherry juice concentrate ............................................................................ 108

Table A.2.2 Raw data for total anthocyanins for tart cherry juice concentrate 115

Table A.2.3 Raw data for total phenolics for tart cherry juice concentrate ...... 120

LIST OF FIGURES

Figure 1.1: Effects of storage time and temperature on the total soluble solids
(°Brix) values of unpasteurized cherry juice concentrate .................................. 18

Figure 1.2: Effects of storage time and temperature on the total soluble solids
(°Brix) values of pasteurized cherry juice concentrate ...................................... 18

Figure 1.3: Effects of storage time and temperature on the pH values of
unpasteurized cherry juice concentrate ............................................................ 20

Figure 1.4: Effects of storage time and temperature on the pH values of
pasteurized cherry juice concentrate ................................................................ 20

Figure 1.5: Effects of storage time and temperature on the titratable acidity
(% malic acid) values of unpasteurized cherry juice concentrate ...................... 22

Figure 1.6: Effects of storage time and temperature on the titratable acidity
(% malic acid) values of pasteurized cherry juice concentrate ......................... 22

Figure 1.7: Effects of storage time and temperature on the turbidity
(% transmittance) values of unpasteurized reconstituted cherry juice .............. 24

Figure 1.8: Effects of storage time and temperature on the turbidity
(% transmittance) values of pasteurized reconstituted cherry juice .................. 24

Figure 1.9: Effects of storage time and temperature on the Hunter color L value
of unpasteurized cherry juice concentrate ........................................................ 26

Figure 1.10: Effects of storage time and temperature on the Hunter color L
value of pasteurized cherry juice concentrate ................................................... 27

Figure 1.11: Effects of storage time and temperature on the Hunter color a
value of unpasteurized cherry juice concentrate ............................................... 28

Figure 1.12: Effects of storage time and temperature on the Hunter color a
value of pasteurized cherry juice concentrate ................................................... 29

Figure 1.13: Effects of storage time and temperature on the Hunter color b
value of unpasteurized cherry juice concentrate ............................................... 30

Figure 1.14: Effects of storage time and temperature on the Hunter color b
value of pasteurized cherry juice concentrate ................................................... 31

Figure 1.15: Effects of storage time and temperature on the Hunter color Delta
E value of unpasteurized cherry juice concentrate ........................................... 32

Figure 1.16: Effects of storage time and temperature on the Hunter color Delta
E value of pasteurized cherry juice concentrate ............................................... 32

xi

Figure 1.17: Effects of storage duration at 4°C on trained sensory quality for
unpasteurized cherry juice concentrate ............................................................ 42

Figure 1.18: Effects of storage duration at 4°C on trained sensory quality for
pasteurized cherry juice concentrate ................................................................ 43

Figure 1.19: Effects of storage duration at 21 °C on trained sensory quality for
unpasteurized cherry juice concentrate ............................................................ 46

Figure 1.20: Effects of storage duration at 21 °C on trained sensory quality for
pasteurized cherry juice concentrate ................................................................ 46

Figure 1.21: Effects of storage duration at 38°C on trained sensory quality for
unpasteurized cherry juice concentrate ............................................................ 49

Figure 1.22: Effects of storage duration at 38°C on trained sensory quality for

pasteurized cherry juice concentrate ................................................................ 50
Figure 2.1: Six common anthocyanins found in plants ...................................... 62
Figure 2.2: Structural changes of an anthocyanin at pH 1.0 and pH 4.0 ........... 67

Figure 2.3: Effects of storage duration on the average of all storage temperature
and processing types ORAC values (micromole TE/g tart cherry juice
concentrate) for cherry juice concentrate .......................................................... 80

Figure 2.4: Effects of storage time and temperature on the average total
anthocyanin values (mg cyn-3—glu/liter tart cherry juice concentrate) for
unpasteurized cherry juice concentrate ............................................................ 85

Figure 2.5: Effects of storage time and temperature on the average total
anthocyanin values (mg cyn-3-glu/liter tart cherry juice concentrate) for
pasteurized (batch 1) cherry juice concentrate ................................................. 86

Figure 2.6: Effects of storage time and temperature on the average total
anthocyanin values (mg cyn-3-glu/liter tart cherry juice concentrate) for
pasteurized (batch 2) cheny juice concentrate ................................................. 86

Figure 2.7: Effects of storage time and temperature on the average total
anthocyanin values (mg cyn-3—glu/liter tart cherry juice concentrate) for
pasteurized (batch 3) cherry juice concentrate ................................................. 87

Figure 2.8: Effects of storage time and temperature on the average total
phenolic values (9 GAE/liter liter tart cherry juice concentrate) for pasteurized
(batch 2) cherry juice concentrate ..................................................................... 93

xii

Figure A.2.1: Effects of storage time and temperature on the average ORAC
values (micromole TE/g tart cherry juice concentrate) for unpasteurized cherry
juice concentrate ............................................................................................. 101

Figure A.2.2: Effects of storage time and temperature on the average ORAC
values (micromole TE/g tart cherry juice concentrate) for pasteurized (batch 1)
cherry juice concentrate .................................................................................. 102

Figure A.2.3: Effects of storage time and temperature on the average ORAC
values (micromole TE/g tart cherry juice concentrate) for pasteurized (batch 2)
cherry juice concentrate .................................................................................. 103

Figure A.2.4: Effects of storage time and temperature on the average ORAC
values (micromole TE/g tart cherry juice concentrate) of pasteurized (batch 3)
cherry juice concentrate .................................................................................. 104

Figure A.2.5: Effects of storage time and temperature on the average total
phenolic values (9 GAE/liter liter tart cherry juice concentrate) for unpasteurized
cherry juice concentrate .................................................................................. 105

Figure A.2.6: Effects of storage time and temperature on the average total
anthocyanin values (9 GAE/liter liter tart cherry juice concentrate) for
pasteurized (batch 1) cherry juice concentrate ............................................... 106

Figure A.2.7: Effects of storage time and temperature on the average total
anthocyanin values (9 GAE/liter liter tart cherry juice concentrate) for
pasteurized (batch 3) cherry juice concentrate ............................................... 107

xiii

INTRODUCTION

In 2008 the United States total tart cherry production was 213 million
pounds. Michigan is the United State’s leading producer of tart cherries,
producing approximately 75% of the overall yield per year. In 2008 Michigan
produced 165 million pounds of cherries, valued at 64.7 million dollars (Boriss
and others 2009). Though Michigan produces both sweet and tart cherry
varieties, in 2007 94.8% of all cherries produced in Michigan were of the tart
Montmorency van'ety (USDA 2007). In 2008 Michigan used 10 million pounds
of tart cherries to produce cherry juice and cherry juice concentrate
(Schwannecke 2009).

Currently during the concentration processing of 68°Brix cherry juice
concentrate, producers do not pasteurize the concentrate due to the product’s
high acidity, and high Brix. When removing water during the concentration
process the product is heated to temperatures as high as 190°F (~88°C).
Though the product goes through high heating temperatures when being
concentrated it is undetermined if the process of later pasteurization has an
effect on the physio-chemical, sensory quality or antioxidant content of the
cherry juice concentrate.

Recently tart cherry juice concentrate, along with other tart cherry
products, have been gaining support among consumers as a functional food
owing to its nutraceutical potential. The high levels of antioxidants and
anthocyanins found in tart cherries have been shown to have anti-inflammatory,

anti-carcinogenic, and anti-aging properties (Blando and others 2004;

Kirakosyan and others 2009). Food products having high antioxidant activity
have been shown to reduce stress (Kirakosyan and others 2009), lower the risk
of heart disease (Solway 2009) and have a number of other health benefiting
properties. I

During storage or long-distance shipment these beneficial compounds of
tart cherry juice concentrate are susceptible to deterioration and may not be
stable under all conditions. Currently processors do not have sufficient shelf life
information to account for these negative changes. Properly researched shelf
life data are important to preserve both the nutraceutical and sensory quality of
the concentrate. The results from this study will help to provide guidance, not
currently available, to the tart cherry industry to improve or lengthen tart cheny

juice concentrate shelf life.

Therefore, the objectives of this research were to:
1) Determine the effect of pasteurization, storage temperature and
storage duration on the physico-chemical (total soluble solids, pH,
titratable acidity, color, and turbidity), microbial, and sensory quality of

Michigan tart Montmorency cherry juice concentrate.

2) Determine the effect of pasteurization, storage temperature and
storage duration on the antioxidant properties (total antioxidant, total
anthocyanins, and total phenolics) of Michigan tart Montmorency

cherry juice concentrate.

This thesis presents the results of one shelf life study in the format of two
separate chapters. Each chapter contains a literature review, materials and
methods section and a conclusion pertaining to the chapter’s topic. Chapter 1

directly addressed objective 1 while chapter 2 directly addresses objective 2.

1. EFFECTS OF PROCESSING, STORAGE TEMPERATURE AND STORAGE
DURATION ON PHYSCIO-CHEMICAL PROPERTIES AND SENSORY
QUALITY OF MONTMORENCY CHERRY JUICE CONCENTRATE

1.1 Literature Review
1.1.1 Background of Tart Cherries and Tart Cherry Concentrate

The state of Michigan is the leading producer of tart cherries (Prunus
cerasus) within the United States producing over 75% of the country’s total
output. In 2008 the United States produced 214.4 million pound of tart cherries.
It is projected that the 2009 total will be 283.6 million pounds (NASS 2009).
Following Michigan in top production is New York, Oregon, Pennsylvania, Utah,
Washington, and Wisconsin. The state of Michigan uses approximately 10
million pounds of tart cherries each year to produce cherry juice and Icherry
juice concentrate (Schwannecke 2009). The majority of the tart cherries grown
in Michigan are of the Montmorency variety.

During concentration process cherry juice is pressed to a product with
total soluble solid content of 68°Brix and a pH between 3.2 and 3.8 (Cherry
Marketing Institute 2007a). In order to achieve this high Brix level the cherry
juice goes through a number of heating and filtering steps, where it is heated up
to temperatures of 190°F to remove water for concentration. Currently during
the processing of the concentrate producers do not pasteurize the product

before being packaged and sold.

1 .1 .2 Microbiological Content

The microbiological content of food is very important for food safety,
shelf life and food quality. Fruits have the ability to support the growth of
bacteria, mold and yeast. Fruit concentrates such as tart cherry juice
concentrate are known for not being a successful medium for bacterial growth.
This is due to the concentrate’s low acidic pH and its high concentration (Brix)
level. However, processors of tart cherry juice concentrate have had problems
with mold growth on their product.

There are some varieties of fungi that have the ability to grow and
survive in acidic environments. A Fliamentour fungus is highly tolerant to high
acidity. Also fungi such as Penicillium, Aspergillus, Cladosporium and
Byssochlamys spp. have been found to grow as surface colonies on fruit juices
and purees (Garza and Sanchis 1998). The heat resistant mold, Byssochlamys
type spp. B. fulva is common in fruits such as cherries, apples, grapes, and
strawberries. This mold type has been known to survive 1 minute at 200°F
(Murdock and Hatcher 1976). It is also reported that Zygosaccharomyces rouxii
and Z. bailii are the principle yeasts to cause spoilage in fruit concentrates

(Garza and Sanchis 1998).

1.1.3. Sensory Attributes

Fresh tart cherry juice concentrate is known for its highly tart flavor, fresh
cherry flavor and aroma, and its bright red color. The concentrate’s fresh cherry
flavor is characterized by the compound benzaldehyde (McGorrin 2007).

Benzaldehyde has been determined to be one of the most important

5

compounds in tart cherries due to the aroma and flavor profile it gives the
product. Research has shown that benzaldehyde decreases over storage
duration, especially at high storage temperatures (Petersen and Poll 1999).
The decrease in benzaldehyde is caused by oxidation in the concentrate
(Petersen and Poll 1999). In a study of tart cherries it was determined that at
high storage temperatures the ethanol and acetic acid concentration increased
over time (Petersen and Poll 1999). The development of these compounds can
produce off flavors and off aroma within the product. In a shetf life study of tart
cherry juice, conducted by (Gonzalez-Mulet 2008), a trained panel concluded
that the tart flavor of the product began to diminish over a 24 week storage
duration. Over storage as the tart flavors decreased, an increasing sweet flavor

became apparent.

1.1.4 Hypothesis

The independent variables of processing, storage temperature and
storage duration have a degradative effect on the dependent variables physico-

chemical, microbial, and sensory quality of tart cherry juice concentrate.

1.2 Materials and Methods
1.2.1 Cherry Juice Concentrate Samples

Montmorency tart cherry concentrate was received in five 5-gallon
containers from Shoreline Fruit LLC (Traverse City, Michigan). Shoreline Fruit
LLC processed the product (crop year: 2007) to a concentration of 68° Brix.
The concentrate was stored in 5-gallon buckets in a Michigan State University

6

Food Science freezer at -15° C until the concentrate was further processed,

packaged and stored.

1.2.2 Pasteurization of Concentrate

Approximately two 5-gallon containers of concentrate were pasteurized
at 85°C for 5 seconds. The pasteurization took place in Michigan State
University Food Science's pilot plant. The concentrate was pumped through a
spiral stainless steel tube that was submerged in water heated in a steam-

jacketed kettle.

1.2.3 Packaging and Storage of Concentrate

All samples were stored in clear, square 8, or 16 oz. glass jars. The
bottles were acquired from Qorpak (Bridgeville, Pennsylvania). Bottles of
concentrate were all labeled indicating if they were unpasteurized or
pasteurized. Containers were also labeled with the week number to indicate
when the sample would be removed from storage for analysis. All concentrate
samples were stored in conditions absent of light. Samples were stored at 4°C
in a VWR Scientific Model 2005 Low Temperature Incubator (West Chester,
Pennsylvania). Concentrate samples stored at 21 °C were stored in a laboratory
cupboard with minimal temperature changes and finally samples at 38°C were
stored in a Fisher lsotemp® Oven 200 Series Model (Pittsburgh, Pennsylvania).
Temperatures were monitored every 2 to 3 days to confirm consistent storage

temperatures. After samples were removed from storage they were kept frozen

in an upright Frigidaire freezer (Martinez, Georgia) at approximately ~15°C until
analysis could be completed. The only exceptions were the samples analyzed
for yeast and mold. They were tested immediately after being removed from

storage and not frozen.

1.2.4 Shelf Life Schedule

The shelf life study was conducted over the course of 48 weeks. The
samples stored at 4°C and 21°C were tested up to 48 weeks while the samples
stored at 38°C were tested only up to 24 weeks. The cherry juice concentrate
stored at elevated conditions was no longer stored after 24 weeks because they
were no longer of consumable quality. Table 1.1 shows the schedule at which
the cherry juice concentrate was analyzed for a particular attribute over the

course of the study.

Table 1.1: Schedule which analysis was performed on cherry juice
concentrate

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3 a) 3'5 g o .3; ES.
3 1’ I 5 $3 'é t-
3 I .3 I-tn 8m
0 X X X X X X X

2 X X X X X

4 X X X X X X X

6 X X X X X

8 X X X X X X X

10

12 X X X X X X X

14

16 X X X X X X X X
18

20 X X X X X X X

22

24 X X X X X X X X
36 X X X X X X X X
48 X X X X X X X X

 

 

 

 

 

 

 

 

 

1.2.5 Physico-Chemical Analysis
1.2.5.1 Total Soluble Solids

Total soluble solids were read in °Brix using a Thermo Fisher Scientific

(Waltham, Massachusetts) Abbe-3L refractometer with the sensitivity of 0.1%.

1.2.5.2 pH and Titratable Acidity

The pH and titratable acidity of the cherry juice concentrate was
measured according to the guidelines of AOAC Official Method 942.15 (AOAC
2000) using a Corning (Corning, New York) 430 pH meter and a Pinnacle
combination electrode (Wobum, Massachusetts). When measuring titratable

acidity 100 mL of distilled water was added to 10 grams of cherry juice

 

concentrate. Samples were neutralized using a 0.1N sodium hydroxide
(Mallinckrodt Baker, Phillipsburg, New Jersey) solution to a pH of 8.1 :l: 0.2.
Titratable acidity results were expressed in percent malic acid and calculated
using equation 1.1.
% malic acid =mL 0.1 N NaOH x N NaOH x 0.067 meq x (100/wt. of sample)
Eq. 1.1

1.2.5.3 Turbidity

The turbidity (lack of clarity) of the concentrate was measured using the
method of (Krop and Pilnik 1974) and (Ough and others 1975). A sample
amount of 10mL was centrifuged at the speed, 11000 rev/minute for 10
minutes. The centrifuge process removed any coarse particles contained within
the sample. The absorbance value was read using a Milton Roy (lvyland,
Pennsylvania) Spectronic 21 D spectrophotometer at the wavelength of 660nm.
This value was then converted to %Transmittance using formula 1.2:

Percent Transmittance =antilog (2-absorbance). Eq. 1.2
The turbidity was measured for the reconstituted juice (14°Brix). This
reconstituted juice was analyzed because the high Brix of the concentrate did

not allow for measurement on the spectrophotometer.

1.2.5.4 Hunter Color

Hunter Lab was analyzed by measurement of the L, a, b and AE values.
Analysis was done using a LabScan® XE Spectrophotometer (Reston, Virginia)
and EasyMatch® QC software. Color measurements were taken when

samples were at room temperature. Using the LabScan glass sample cup

10

(diameter 1.75 inches) samples were analyzed in 25mL volumes. Data was
collected using an Illuminant value of D65 and an Observers value of 10. The
spectrophotometer was calibrated using a black tile and a white tile #LX17582
(X=80.37, Y=85.26, 2:89.86). Values a and b are measured in positive and
negative values where —a represents green and +a represents red. The -b
values represents blue and +b represents yellow. The value “L” is represented
by a value between 0 and 100 where the value 0 equals black and 100 equals
white. The value AE is a single value representing total color difference which

takes the Hunter L, a, and b values all into account.

1.2.6. Microbial Content
1.2.6.1 Plate Preparation and Dilution Buffer

The total plate count for yeast and mold was tested using a Potato
Dextrose Agar (Becton, Dickinson and Company, Sparks, Maryland) media.
The amount of 39.0 grams of Potato Dextrose Agar (PDA) was added to
1000mL of distilled water. The solution was thoroughly mixed and heated to a
boil for 1 minute to completely dissolve all powder. The solution was then
autoclaved on the liquid cycle for 15 minutes at 121°C. The agar solution was
not acidified due to the high acidity of the cherry juice concentrate. A
phosphate buffer, of pH 7.4 was used to dilute the samples prior to plating the

samples.

11

1.2.6.2 Sample Preparation

Three dilutions of the each sample were plated in duplicate. The

dilutions included the original concentration (100) and also 10'1 and 10'2 of the

original concentration. A sample size of 100uL was added to each plate. The
plates sat covered for 3 days at room temperature before being analyzed for

yeast and mold growth.

1.2.7 Sensory Analysis
1.2.7.1 Environmental Condition

All sensory panels were performed in the Michigan State Food Science
and Human Nutrition sensory evaluation laboratory under controlled sensory
conditions. All sensory evaluations were done under full spectrum light.
Institutional Review Board approved sensory analysis (IRB Log Number X07-

722).

1.2.7.2 Trained Panel
1.2.7.2.1 Panelist Training

Panelists ages 18 years and older were recruited by flyers from the
Michigan State University campus. Also people who had participated on past
panels were contacted for this panel. All panelists were screened where
contact information was collected and participants were also asked to complete
two triangle tests dealing with the taste and color of cherry juice concentrate.

The screening resulted in 15 panelists who were then trained in five, one-hour

12

training sessions over several weeks. The panelists were taught to rate the
cherry juice concentrate and cherry juice using a 15 cm scale on the qualities of
color, aroma, off aromas/flavors and overall quality for both the concentrate and
the reconstituted juice. Panelists were introduced to reference samples and
were also given time to learn, practice, and be tested on. Panelists were also

taught all proper sampling methods.

1.2.7.2.2 Sensory Analysis Test Method

Trained sensory panelists completed descriptive sensory tests rating the
concentrate’s attributes of color and fresh cherry aroma. The reconstituted
juice (14°Brix) was evaluated for color and fresh cherry flavor. A rating was
then given for the product’s overall quality. Comments on any perceived off-
flavors or off-aromas in the juice were also recorded. Both the color of the
concentrate and the juice were rated with 15 representing a very good, bright
red color and 0 representing a very poor, dull brown color. The concentrate’s
aroma was evaluated using a score of 15 that represented a good, fresh cherry
aroma. Decreasing ratings showed a loss of cherry aroma and development of
off-aromas. The juice was evaluated for its flavor using a score of 15 that
represented a good, fresh tart cherry flavor. Decreasing flavor ratings indicated
a loss of freshness and development of a sweet flavor compared to the desired

tart flavor.

13

1.2.7.2.3 Sample Preparation and Presentation

Trained panelists were required to read and sign a consent form prior to
their participation in the shelf life study. For each training session or sensory
panel the panelists were compensated for their time with an ice cream coupon
good at the Michigan State University Dairy Store. During each panel,
participants received their samples both as a concentrate and as a
reconstituted juice. Three mL of the concentrate was presented at room
temperature in clear 20 mL scintillation vials from Research Products
lntemational Corp (Mount Prospect, Illinois). Alongside the concentrate
samples was the reconstituted juice in 25 to 30 mL amounts presented in clear
Sweetheart 50 oz. plastic cups (Solo, Highland Park, Illinois). The juice was
served at refrigerated temperatures of approximately 4-5°C. Trained panelists
were presented with a sample of fresh reconstituted cherry juice made from the
concentrate that had not undergone processing or storage to use as a
reference. The panelists also received five cherry juice concentrate references
that correspond with the quality ratings of 15, 13, 9, 5, and 0 on the 15 cm
scale. Panelists were provided distilled water and unsalted saltine crackers and
were trained to use them to cleanse their palate prior to tasting and in-between
samples. Panelists were given a Styrofoam cup, if they wished to expectorate

the samples after tasting.

14

1.2.7.3 Consumer Panel
1.2.7.3.1 Sensory Analysis Test Method

A consumer sensory panel of approximately 100 panelists was recruited
from faculty, staff and students at Michigan State University. Panelists rated
the cherry juice (14°Brix) color, aroma appearance, flavor and overall quality.
The sensory panel was conducted using a 9-point hedonic scale where
1=dislike extremely, 2=dislike very much, 3=dislike moderately, 4=dislike
slightly, 5=neither like nor dislike, 6=like slightly, 7=like moderately, 8=|ike very
much, 9=Iike extremely. Consumers were also asked questions about their

age, gender and personal juice preferences.

1.2.7.3.2 Sample Preparation and Presentation

Panelists were required to read and sign a consent form prior to
participation and were compensated for their time with an ice cream coupon
good at Michigan State University Dairy Store. All samples were served to the
participants at refrigerated temperatures at ~4-5°C. Each panelist received
between 25 and 30 mL of juice per sample served in a clear Sweetheart 50 oz.
plastic cup (Solo, Highland Park, Illinois). Panelists were also provided distilled
water and unsalted saltine crackers and encouraged to use them to cleanse
their palate between samples. Panelists were allowed to consume all samples
however they received a Styrofoam cup if they wished to expectorate the

sample.

15

1.2.8 Statistical Analysis

Physico-chemical attributes were analyzed using linear regression to
determine if significant differences occurred over storage duration. To
determine if the variables of processing and storage temperature significantly
effected physico-chemical data, F tests were used. For the analysis of sensory
data, ANOVA analysis was used, using the Turkey HSD test to compare

multiple means.

1.3 Results and Discussion
1.3.1 Microbial Analysis

Over the storage period of 48 weeks all counts for yeast and mold
resulted in negative results. In addition, no growth was found on the surface of
the concentrate prior to plating the samples. These results were expected
since tart cherry juice concentrate is a high acid product having a pH lower than

4.6. Having an acidic pH inhibits the growth of mold and yeast in the product.

1.3.2 Physico-Chemical
1.3.2.1 Total Soluble Solids

Figures 1.1 and 1.2 display the total soluble solids values for both
unpasteurized and pasteurized concentrate at all storage conditions over the
duration of storage. Using linear regression, the concentrate stored at 4°C and
21 °C showed no significant change over a year of storage for both
unpasteurized and pasteurized concentrate (Table 1.2). F tests showed no

significant difference between the total soluble solids values among 4°C and

16

21°C for both unpasteurized (p=0.4436) and pasteurized (p=0.7632)
concentrate. Processing did not affect the results among these storage
conditions.

The total soluble solids content for concentrate stored at the elevated
38°C was found to significantly decrease over time (Table 1.2). F tests showed
pasteurized concentrate had a significantly higher decreasing slope compared
to unpasteurized product (p=0.0197). For the unpasteurized concentrate the
total soluble solids decreased from its initial value of 69.1 to 67.4°Brix (Figure
1.1), while the pasteurized concentrate decreased from the initial value of 68.8
to 669°an (Figure 1.2). Cherry juice concentrate is produced to be 68°Brix. If
storage at elevated conditions decreases the Brix level below 68° this attribute
could limit its shelf life. However, the total soluble solid values do not fall below
68°Brix until week 8 of storage. By this time the trained panelist had already

determined the concentrate to be of poor and inconsumable quality (See

 

 

 

 

1.3.3.2).
Table 1.2: Linear regression results for total soluble solids (°Brix)
. P- . P-
Unpasteurized value Slope Pasteurized value Slope
No No
4°C 0.1225 significant 4°C 0.2891 significant
difference difference
No No
21°c 00942 significant 21°C 0.1106 significant
difference difference
38°C 0.001 9 -0.0824 38°C 0.0001 -0. 1 029

 

 

 

 

 

 

 

 

17

TSS (°Brix)

 

 

'1'

36404448

66.0 + , , i .
0 4 8 12 16 20 24 28 32
Storage Duration (Weeks)

Figure 1.1: Effects of storage time and temperature on the total soluble
solids (°Brix) values of unpasteurized cherry juice concentrate

70.0 -; ------------------------------------------------------------------------------
‘ —I-— 21 C + 380
Pasteurized

TSS (°Brix)

 

66.0 . - , - ,
0 4 8 12 16 20 24 28 32 36 40 44 48
Storage Duration (Weeks)

Figure 1.2: Effects of storage time and temperature on the total soluble
solids (°Brix) values of pasteurized cherry juice concentrate

18

1.3.2.2 pH

Shown in Figures 1.3 and 1.4 are the unpasteurized and pasteurized pH
values for each storage condition over 48 weeks of storage. Using linear
regression it was concluded that the pH of the concentrate did not significantly
change over the storage period for all storage temperatures, and both
processing types (Table 1.3). Using the F test to compare the intercepts of
each processing/storage condition it was concluded that pH was not
significantly affected by processing or storage temperature (Table 1.3).

The pH for all unpasteurized samples ranged from 3.29 to 3.46;
pasteurized samples had a very similar pH range of 3.28 to 3.45. The pH of tart
cherry juice concentrate is reported to range from as low as 3.2 to 3.8 (Cherry
Marketing Institute 2007a). All pH values from this study fell within this reported
pH range.

Table 1.3: Linear regression results for pH

 

 

 

 

 

 

 

 

 

Unpasteurized v 5;. e Slope Pasteurized “FL-m Slope

No No
4°C 0.5134 significant 4°C 0.6614 significant
difference difference

No No
21 °C 0.5290 significant 21 °C 0.9864 significant
difference difference

No No
38°C 0.1815 significant 38°C 0.2718 significant
difference difference

 

 

 

19

3.60 - -------------------------------------------------------------------------------
+ 4c + 21 c + 380

3.50 4 -------------------------------------------------------------------------------
Unpasteurized

 

3.20 - ~ E. -%q. , ~ ~ r ,
0 4 8 12 16 20 24 28 32 36 40 44 48
Storage Duration (Weeks)

 

 

fir

Figure 1.3: Effects of storage time and temperature on the pH values of
unpasteurized cherry juice concentrate

+4C +21C +386

13.40
Q.

3.30

 

3.20 ‘ , i—w .. n . ~77 .. ._, . , .
0 4 8 12 16 20 24 28 32 36 40 44 48
Storage Duration (Weeks)

Figure 1.4: Effects of storage time and temperature on the pH values of
pasteurized cherry juice concentrate

20

1.3.2.3 Titratable Acidity

Figures 1.5 and 1.6 display the titratable acidity values for all storage
temperatures and processing types over the duration of storage. Concentrate
stored at 4°C had no significant changes over storage (Table 1.4). The F test
showed that pasteurization did not have an effect on concentrate at this storage
condition (p=0.7177).

Concentrate held at 21°C had a slight, but significant decrease in
titratable acidity over the storage period of 48 weeks (Table 1.4). Analysis of
the first 24 weeks of data for 21°C showed no significant difference
(unpasteurized p=0.6981, and pasteurized p=0.5599). This indicates that the
decrease in titratable acidity occurred after week 24 of storage. No analysis
was completed on 38°C concentrate after week 24 due to the low inconsumable
quality. Linear regression results showed no significant change in storage
temperature 38°C during the 24 weeks, however it is predicted that if analysis
continued a significant decrease would have occurred. Though significant
decrease occurred in the concentrate’s titratable acidity over the duration of 48
weeks, the titratable acidity values for all samples stayed within close range of
one another. All samples ranged with 4.70 to 5.27% malic acid.

Table 1.4: Linear regression results for titratable acidity (% malic acid)

 

 

 

 

 

Unpasteurized vaFIUe Slope Pasteurized vaFIue Slope
No No
4°C 0.2175 significant 4°C 0.2438 significant
difference difference
21 °C 0.0410 —0.0055 21 °C 0.0099 -0.0055
No No
38°C 0.1 160 significant 38°C 0.8152 significant
difference difference

 

 

 

 

 

 

 

21

5.50 T, """"""""""""""""""""""""""""""""""""""""""""

 

 

+ 4C + 21 C + 38C
5.30
3 a
3 T, 5.10
< I!
2 £52
3 g 4.90
E 5:
i:
4.70
4.50 “I"—' _' ’ 'l‘ " ——"_I l l i I l 'T f l l l

 

 

0 4 8 12162024283236404448
Storage Duration (Weeks)

Figure 1.5: Effects of storage time and temperature on the titratable
acidity (% malic acid) values of unpasteurized cherry juice concentrate

5.50 7 ---------------------------------------------------------------------------
—e— 4C + 21 C + 38C

9'
w
o

oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo

   
    

Pasteurized

I
.3
O

 

P
o
o

Titratable Acidity
(% malic acid)

 

 

T‘ _“*”—" f r l l r l l

0 4 812162024283236404448
Storage Duration (Weeks)

Figure 1.6: Effects of storage time and temperature on the titratable
acidity (% malic acid) values of pasteurized cherry juice concentrate

22

1.3.2.4 Turbidity

Figures 1.7 and 1.8 display the turbidity (% transmittance) values for all
storage temperatures and processing types over the duration of storage. A
significant decrease over the duration of storage was seen for all cherry juice
concentrate samples (Table 1.5).

Using the F test, statistical difference was shown among all storage
conditions (Table 1.5). Results showed that an increase in storage temperature
increased the rate at which the concentrate lost clarity. Concentrate stored at
38°C lost clarity the fastest, losing about half of its percent transmittance over
24 weeks of storage. Concentrate at 4°C lost clarity the slowest, with the
percent transmittance decreasing less than 10% transmittance over the year
storage period. No statistical differences were seen among unpasteurized and
pasteurized concentrate (Table 1.5). Little information is known about the
substances that are responsible for the development of haze and turbidity of
cherry juice concentrate. However, with research done on apple juice and other
beverages the development of the haze may result from proteins, polyphenols,

oxidized phenols and insoluble tannins (Meyer and others 2001 ).

Table 1.5: Linear regression results for turbidity (% transmittance)

 

 

 

 

 

 

 

 

 

 

Unpasteurized P-value Slope Pasteurized P-value Slope
4°C 0.0305 -0.1042 4°C 0.0482 -0.0804
21°C <0.0001 -0.5814 21°C <0.0001 -0.5564
38°C 0.0030 -1.3102 38°C 0.0063 -1.2892

 

23

 

% Transmittance

100.0 — -----------------------------------------------------------------------------

 

 

 

20.0 - -----------------------------------------------------------------------------

0.0% i .
04812162024283236404448

 

Unpasteurized

 

 

_ T— i I I l l l 1

Storage Duration (Weeks)

Figure 1.7: Effects of storage time and temperature on the turbidity
(% transmittance) values of unpasteurized reconstituted cherry juice

% Transmittance

 

100.0 1 ...........................................................................
l +4c +21c +38C

80.0 ........................................................................
’ A

60.0 . ...................................................................
40.0 - ---------------------------------------------------------------------
20.0 ~ ............................................................................

Pasteurized
0.0+~~—-1- . i . , . ,. , f p. ,

 

 

0 4 812162024283236404448
Storage Duration (Weeks)

Figure 1.8: Effects of storage time and temperature on the turbidity
(% transmittance) values of pasteurized reconstituted cherry juice

24

1.3.2.5 Hunter Color

Figures 1.9 and 1.10 display the Hunter color L values for all storage
temperatures and processing types over the duration of storage. Using linear
regression it was concluded that for the majority of conditions, storage
temperature and pasteurization did not have an affect on L values over the
duration of storage (Figure 1.6). The only exception was seen for the
unpasteurized concentrate stored at 4°C (p=0.0234). At week 6 a high peak
measurement is seen, which is the likely reason for the small p-value (Figure
1.9).

With F test analysis no significant difference was seen between
unpasteurized and pasteurized concentrate for all storage conditions (4°C:
p=0.1147, 21 °C: p=0.0538, 38°C: p=0.0820). F test showed storage condition,
21 °C, to have a significantly higher Hunter L value (or lighter color) compared to
38°C for unpasteurized concentrate (p=0.0116). For pasteurized concentrate,
the storage condition 4°C had a significantly higher Hunter L value over 38°C
(p=0.0445). Though these trends are slight, it was confirmed through sensory
testing (Section 1.3.3.2) that storage of concentrate at higher storage
temperatures yields a dark brown color over storage duration. This dark color
that is developed is likely to be correlated with the sample’s increased turbidity

and decreasing anthocyanins content.

25

Table 1.6: Linear regression results for Hunter Color L Value

 

 

 

 

 

 

 

 

 

 

 

 

 

. P- . P-
Unpasteunzed value Slope Pasteurized value Slope
No
04°C 0.0234 -0.0159 4°C 0.0790 significant
difference
No No
21 °C 0.1151 significant 21°C 0.0883 significant
difference difference
No No
38°C 0.0569 significant 38°C 0.4006 significant
difference difference
5.00 i -----------------------------------------------------------------------------
+ 4C + 21 C + 380
4.00
a 3.00
3
E
_, 2.00

 

 

 

 

1.00 f -----------------------------------------------------------------------------
I Unpasteurized
0,004. . r—————————— . . . 4
0 4 8 12 16 20 24 28 32 36 404448

Storage Duration (Weeks)

Figure 1.9: Effects of storage time and temperature on the Hunter color L
value of unpasteurized cherry juice concentrate

26

5.00 T -----------------------------------------------------------------------------

 

 

 

 

 

 

+4C +21C +380
4.00 - ------------------------------------------------------------------------------
3.00 . ................................................
o ,1
a -
:3 :!‘_\_.'
42.00 i --------------------------------------------------------------------------
1.00 4 ..............................................................................
Pasteurized
0.00 i l I I r l l l r . l
04812162024283236404448

Storage Duration (Weeks)

Figure 1.10: Effects of storage time and temperature on the Hunter color L
value of pasteurized cherry juice concentrate

Figures 1.11 and 1.12 display the Hunter color a values for all storage
temperatures and processing types over the duration of storage. The Hunter a
value was the most affected Hunter value during the shelf life study. A positive
a value represents a red color in the product. Over the course of storage as the
concentrate’s red color was lost and oxidized, the Hunter a value began to
decay. Since the red pigment of cherry juice concentrate is a result of
anthocyanin compounds, the decay trends were very comparable to the total
anthocyanin decay (Section 2.3.3).

Initial a values were 4.46 for unpasteurized concentrate and 3.95 for
pasteurized concentrate. Concentrate stored at 4°C showed a significant
decrease over the duration of 48 weeks for both unpasteurized (p=0.0002) and

pasteurized (p=0.0007) concentrate. Among all storage condition refrigerated

27

temperatures showed the slowest rate of red color loss. Unpasteurized
concentrate show a significantly larger decreasing slope over the 48 weeks of
storage (p=0.0827) however values were found to be very similar after the
storage year (1.51 and 1.89 for unpasteurized and pasteurized concentrate
respectively).

The storage temperature of 38°C showed the very steep rate of decay
losing 95% of its value within the first 4 weeks of storage. After 4 weeks of
storage values were not significantly different throughout the rest of storage for
both unpasteurized (p=0.5552) and pasteurized (p=0.9377) concentrate.
Concentrate stored at 21 °C showed a slowly significant decreasing exponential
decay curve (p<0.0001). After 16 weeks of storage the concentrate had lost the
majority of its value and no large change occurred throughout the rest of the

storage period.

 

 

 

 

 

5.50 - .............................................................................
+38C

Unpasteurized

_ """"""""""" + """""""""" :.

-0.500 ----- 4----8----12----16---20---24—---28---32—---36---40---44—---48

Storage Duration (Weeks)

Figure 1.11: Effects of storage time and temperature on the Hunter color a
value of unpasteurized cherry juice concentrate

28

5.50 ~ .............................................................................
+ 4C -—I— 21C + 38C

 

 

 

4,50T .............................................................................
3.50 ..........................................................................
,x, I Pasteurized
3
7' 2.50 — -----------------------------------------------------------------------
>
II
1.50 ~ .............................................................................
0.50 - ......................................................................
-0.500 ----- 4----8----12----16---20----24---28----32----36---40--“~48

Storage Duration (Weeks)

Figure 1.12: Effects of storage time and temperature on the Hunter color a
value of pasteurized cherry juice concentrate

Shown in Figures 1.13 and 1.14 are the Hunter b values over the
duration of storage. Linear regression showed that there was no significant
change in the Hunter b values over storage duration (Table 1.7). Using the F
test it was determined pasteurization does not affect the b value (yellow/blue
color) over duration of time by showing no significant difference among the
unpasteurized and pasteurized concentrate (Table 1.7).

All Hunter D values were shown to range with the 0 to 1 values. Though
all values were found within a small range, F tests showed concentrate stored
at 4°C were significantly different than concentrate stored at 38°C. Concentrate
at 4°C had a significantly higher Hunter b value for both unpasteurized
(p=0.0154) and pasteurized (p=0.0187) concentrate. Pasteurized concentrate

at 4°C also had a significantly higher Hunter b value compared to the storage

29

condition of 21°C. Based on results the lower the storage temperature
concentrate is stored at the higher the Hunter b value. These higher Hunter b
values represent a concentrate with a more yellow color than concentrate
stored at elevated conditions.

Table 1.7: Linear regression results for Hunter Color b Value

 

 

 

 

 

 

 

 

 

 

 

 

Unpasteurized P-value Slope Pasteurized P-value Slope

4°C 0.7019 No 4°C 0.5211 No
significant significant
difference difference

21 °C 0.8675 No 21 °C 0.0932 No
significant significant
difference difference

38°C 0.1059 No 38°C 0.0635 No
significant significant
difference difference

4.00 . -------------------------------------------------------------------------------

+4C +21C +38C

 

 

 

 

 

0 4 8 121620242832 36404448
Storage Duration (Weeks)

Figure 1.13: Effects of storage time and temperature on the Hunter color b
value of unpasteurized cherry juice concentrate

3O

4.00 i ------------------------------------------------------------------------------

+ 4C + 21 C + 38C
3.00 --------------------------------------------------------------------------------

Pasteurized

 

 

 

 

0.00 T r r r r r r r r l l

0 4 8 121620 24283236404448
Storage Duration (Weeks)

Figure 1.14: Effects of storage time and temperature on the Hunter color b
value of pasteurized cherry juice concentrate

Shown in Figures 1.15 and 1.16 are the Hunter AE values over the
duration of storage. The value AE is a single value representing total color
difference which takes the Hunter L, a, and b values all into account. Since it
was determined that only Hunter a change significantly over time the trend the
AE represent are very similar to the Hunter a values. The concentrate stored at
the _4°C showed to have the most stable color over storage duration.
Concentrate stored at the elevated 38°C had the most drastic and rapid change
in overall color. This color change occurred mostly during the first 2 weeks of

analysis.

31

600~ -------------------------------------------------------------------------------

    

Unpasteurized

 

 

 

2.00 ! 7 "T ' l l l l i l i l
0 4 8 12 16 20 24 28 32 36 40 44 48
Storage Duration (Weeks)

Figure 1.15: Effects of storage time and temperature on the Hunter color
Delta E value of unpasteurized cherry juice concentrate

6.00 T ..............................................................................
' —e— 40 —I— 21 C + 380

   
 
   

Pasteurized

 

 

AN

1
|

200+—~eeewmfi~» ~ ev—e~

0 4 8 12162024283236404448
Storage Duration (Weeks)

 

 

Figure 1.16: Effects of storage time and temperature on the Hunter color
Delta E value of pasteurized cherry juice concentrate

32

1.3.3 Trained Sensory Panel
1.3.3.1 Processing and Storage Condition Effect

Over the duration of the shelf life study the trained sensory panel
evaluated the cherry juice concentrates to have slight to no significant
difference between the attributes of the unpasteurized and pasteurized
samples. However, at the initial analysis (Table 1.8), and week 4 (Table 1.10)
and 8 (Table 1.11) panelists found slight significant differences among the
samples. These differences were mainly seen in the color attribute. After 8
weeks of storage, no significant difference was seen between unpasteurized
and pasteurized concentrate. After 8 weeks, the storage duration had a higher
effect on the concentrate than did the processing variable.

Table 1.8 presents the average sensory results and the Tukey’s HSD
test comparison results for processing of the concentrate. At the initial analysis,
the trained panel found that the concentrate’s attributes were not significantly
different among the unpasteurized and pasteurized samples. The only
exception was the fresh cherry flavor of the unpasteurized samples (14.50 i
0.97), which was found to be significantly higher (p=0.0197) than the
pasteurized concentrate (13.56 :I: 1.55). The average overall quality of the
unpasteurized and pasteurized samples was 14.44 t 1.09 and 14.19 i 1.05,

respectively (p=0.2997).

33

Table 1.8: Initial trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice

 

 

 

 

 

 

 

Attribute Unpasteurized Pasteurized P-value
Concentrate Color 14.75 i 0.58 14.56 i 0.89 0.4230
Concentrate Cherry Aroma 14.13 1- 1.71 13.88 i 1.78 0.3332
Juice Color « 14.63 i 0.89 14.13 i 1.31 0.1194

Juice Fresh Cherry Flavor 14.50 i 0.97 A 13.56 i 1.55 B 0.0197
Overall Quality 14.44 t 1.09 14.19 i 1.05 0.2997

 

 

 

 

 

n=16, 15 cm line scale, Values within each attribute not connected by the same letter are
significantly different

After 2 weeks of storage only the concentrate stored at 38°C was
analyzed by panelists. The additional analysis was held due to the predicted
and observed high rate of quality decline. Table 1.9 presents the average
values and the Tukey’s HSD test comparison results for the unpasteurized and
pasteurized concentrate stored at 38°C for 2 weeks. All attributes for the
unpasteurized and pasteurized samples were not significantly different. The
overall quality ratings of the unpasteurized and pasteurized samples were found
to be 9.13 i 1.73 and 8.47 i 2.39, respectively. The quality of this concentrate
decreased at a very rapid rate over the 2 weeks of storage. The product’s initial
bright red color had has begun to diminish and become darker and duller. Also
over these 2 weeks of storage, the juice fresh flavor and concentrate aroma had
also decreased.

Table 1.9: Trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice stored 2 weeks 4, 21 and 38°C

 

 

 

 

 

 

 

Attribute UP 38°C P 38°C P-value
Concentrate Color 9.93 i 1.44 10.00 1 1.77 0.8430
Concentrate Cherry Aroma 8.87 i 2.72 8.67 i 2.69 0.8142
Juice Color 9.53 i 1.81 9.53 i 1.85 1.0000
Juice Fresh Cherry Flavor 8.87 i 1.60 8.53 i 2.80 0.6050
Overall Quality 9.13 i 1.73 8.47 i 2.39 0.3535

 

 

 

 

 

n=15, 15 cm line scale, Values within each attribute not connected by the same letter are
significantly different, UP= unpasteurized, P= pasteurized

34

Table 1.10 presents the average ratings and the Tukey’s HSD test
comparison results for the processing and storage of the unpasteurized and
pasteurized samples at 4 weeks of storage. All p-values were found to be
0.0001 for each attribute. After 4 weeks of storage the sensory ratings for
samples stored at 38°C were shown to be significantly lower than those of
samples stored at 4°C and 21°C for all attributes analyzed. The concentrate
stored at 38° C was evaluated with an average rating of 5.27 i 0.80 and 5.67 t
1.11 for the unpasteurized and pasteurized samples. These low sensory
ratings represented a concentrate of poor quality with a dull brown color, low
cherry aroma and flavor with developing off flavors and aromas. Panelists
described off aromas as fermented, and medicine like. They described the
samples as having both cooked and prune like flavors.

For concentrate held a 4°C, the overall quality ratings were 14.13 :I: 1.06
for unpasteurized, and 14.47 :I: 0.64 for pasteurized concentrate while the
concentrate stored at 21°C were found to be 13.60 i 1.40 for unpasteurized
and 12.93 i 1.58 for the pasteurized. The concentrate stored at 4°C and 21°C
were not found to be significantly different in the attribute of cherry aroma. For
the attributes of color, taste and overall quality it was shown that the
pasteurized sample stored at 21°C had a significantly lower rating than the

unpasteurized sample (21°C) and the concentrate stored at 4°C.

35

Table 1.10: Trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice stored 4 weeks at 4, 21 and 38°C

 

 

 

 

 

 

 

 

. 21°c 38°C
“mm“ UP P UP P UP P

Concentrate 14.80 1 14.87 1 14.53 1 14.07 :I: 6.00 i- 6.00 1
Color 0.041AB 0.35 A 0.52 AB 0.59 B 1.36 c 1.00 c
Concentrate 13.40 1 13.73 1 13.60 1 12.60 1 5.53 1 5.47 1
Cherry Aroma 1.64 A 2.12 A 2.23 A 2.64 A 1.77 B 0.99 B
. 14.60 1 14.53 1 14.20 1 13.27 1 4.93 1 5.60 1
Ju'“ °°'°' 0.74 A 0.64 A 0.86 A 1.22 B 1.16 c 0.83 c
Juice Fresh 14.07 1 14.40 1 13.47 1 12.80 1 5.07 1 5.73 1
Cherry Flavor 1.03 A 0.91 A 1.36 AB 1.47 B 1.39 C 1.75 C
. 14.13 1 14.47 1 13.60 1 12.93 1 5.27 1 5.67 1
0""3" QM“ 1.06 A 0.64 A 1.40 AB 1.58 B 0.80 c 1.11 c

 

 

 

 

 

 

 

n=15, 15 cm line scale, Values within each attribute not connected by the same letter are
significantly different, UP= unpasteurized, P= pasteurized

Table 1.11 presents the average scores and the Tukey’s HSD test
comparison results for processing and storage of the samples after _8 weeks of
storage. All p—values for each attribute were 0.0001. The pattern of quality
deterioration continued where the samples stored at the elevated temperature
(38°C) were significantly lower than samples stored at refrigerated (4°C) and
ambient (21°C) temperatures. The cherry concentrate stored at refrigerated
and room temperature was found not to be significantly different in the attribute
of cherry aroma. This relationship between samples also occurred the previous
evaluation (Table 1.10). For the 4°C stored samples, the overall quality ratings
were 14.20 :I: 1.82 and 13.80 i 1.47, for unpasteurized and pasteurized
samples, respectively. The samples that were stored at 21°C had an overall
quality rating of 11.60 for both unpasteurized and pasteurized samples. These
ratings represented a good quality sample with slight loss of bright red color,
cherry aroma, and fresh cherry flavor. Finally samples at 38°C had an average

quality rating of 0.73 1 1.39 for unpasteurized and 1.67 i 2.35 for pasteurized.

36

 

Concentrate stored at 38°C were not evaluated for its juice’s color and flavor
because the concentrate was no longer of a consumable quality.

Table 1.11: Trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice stored 8 weeks at 4, 21 and 38°C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. 4°C 21°C 38°C
“mute UP P UP P UP P
Concentrate 14.60 1 14.67 1 12.73 1 12.60 1 1.67 1 1.33 1

Color 0.83 A 0.62 A 1.03 B 0.83 B 1.95 c 1.68 c
Concentrate 13.20 1 13.53 1 11.73 1 12.53 1 1.47 1 1.20 1
Cherry Aroma 3.73 A 2.03 A 2.37 A 1.41 A 1.60 B 1.52 B
. 14.53 1 14.27 1 12.00 1 12.00 1
Ju'“ °°'°' 0.74 A 0.96 AB 1.51 B 1.36 B ”la ”la
Juice Fresh 14.20 1 13.53 1 11.67 1 11.40 1 n la n la
Cherry Flavor 1.82 A 1.64 AB 1.80 AB 2.23 B
Overall 14.20 1 13.80 1 11.60 1 11.60 1 0.73 1 1.67 1
Quality 1.82 A 1.47 A 1.72 B 1.88 B 1.39 c 2.35 c

 

 

n=15, 15 cm line scale, Values within each attribute not connected by the same letter are
significantly different, UP= unpasteurized, P = pasteurized

The average ratings and the Tukey’s HSD test comparison results for
processing and storage for the concentrate samples after 12 weeks of storage
are presented in Table 1.12. The p-values for each attribute were 0.0001. At
12 weeks, the concentrate’s attributes at each storage condition were
significantly different among one another. Concentration stored at 4°C had the
highest ratings while those held at 38°C had the lowest ratings for all attributes
evaluated. The average overall quality ratings for unpasteurized and
pasteurized concentrate stored at 4°C were 14.33 1 0.90 and 14.07 1 1.16,
respectively. Concentrate stored at 21°C had ratings that were significantly
lower than the concentrate stored under refrigerated conditions. However, the
overall quality ratings for the products at 21 °C were still were of acceptable

quality and very similar to ratings after 8 weeks of storage (11.67 1 1.92 and

11.27 1 1.62 for unpasteurized and pasteurized respectively). Unpasteurized

37

samples stored at 38°C were unacceptable and were given a 0.80 1 2.15 and
0.93 1 2.63 rating for unpasteurized and pasteurized, respectively. Concentrate
of these low ratings were of very poor and inconsumable quality due to the
development brown/oxidized color, poor taste and aroma profile and the
development of aged and off-flavors and aromas.

Table 1.12: Trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice stored 12 weeks at 4, 21 and 38°C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. 4°C 21°C 38°C
Ammute UP P UP P UP P
Concentrate 14.73 1 14.67 1 12.20 1 11.53 1 0.47 1 0.53 1

Color 0.46 A 0.49 A 1.61 B 1.85 B 0.92 c 0.99 c
Concentrate 13.80 13.53 1 11.60 1 11.80 0.67 1 0.33 1
Cherry Aroma 11 .94A 2.33 A 2.10 B 12.76 B 1.45 c 0.62 c
. 14.53 1 14.33 1 11.47 1 11.07 1
Ju'“ C°'°' 0.52 A 0.90 A 1.73 B 1.67 a "la "la
Juice Fresh 14.33 1 13.93 1 11.87 1 11.20 1 n la n la
Cherry Flavor 1.29 A 1.58 A 2.07 B 2.08 B
. 14.33 1 14.07 1 11.67 1 11.27 1 0.80 1 0.93 1
°"°'a" Guam 0.90 A 1.16 A 1.92 B 1.62 B 2.15 c 2.63 c

 

 

n=15, 15 cm scale, Values within each attribute not connected by the same letter are
significantly different, UP= unpasteurized, P = pasteurized

Table 1.13 displays the trained panel average ratings and the Tukey’s
HSD test comparison results for processing and storage for the concentrate
samples after 16 weeks of storage. The p-values for each attribute were
0.0001. The samples held at 4°C continued to have the highest overall quality
ratings for the unpasteurized (14.40 1 0.91) and pasteurized samples (13.47 1
1.92). The ratings for the samples held at 21°C continued to decrease with the
additional 4 weeks of storage. The average overall quality rating for the
unpasteurized 21°C temperature sample was 9.33 1 1.95 while the pasteurized
samples were significantly similar at 8.87 1 2.03.

These ratings were

approximately 35% lower than those of the refrigerated samples stored for 16

38

weeks. A concentrate with this overall quality rating had lost most of its bright
red color and had turned a dull dark red color. Also, the product’s cherry aroma
became much weaker. Though the product at 21°C ratings reflected a product
that was no longer a high quality concentrate, it was not considered poor and
inconsumable. A rating of 5.0 or lower was considered the lowest score for
consumable product. The quality ratings for the samples held at 38°C were too
low to be considered acceptable for consumption (Table 1.13).

Table 1.13: Trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice stored 16 weeks at 4, 21 and 38°C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. 4°C 21°C 38°C
“mute UP P UP P UP P
Concentrate 14.67 1 14.67 1 9.60 1 9.00 1 0.27 1 0.20 1
Color 0.62 A 0.49 A 1.81 B 0.76 B 0.59 c 0.56 c
Concentrate 13.87 1 14.07 1 10.00 1 9.27 1 0.40 1 0.73 1
Cherry Aroma 1.89 A 1.44 A 2.24 B 1.83 B 0.63 c 1.22 c
. 14.40 1 13.80 1 9.33 1 8.53 1
Ju'“ °°'°' 1.06 A 1.15 A 1.95 B 1.85 B "’a "’a
Juice Fresh 14.20 1 13.47 1 9.20 1 8.80 1 n / a n la
Cherry Flavor 0.94 A 2.17 A 2.01 B 2.27 B
. 14.40 1 13.47 1 9.40 1 8.87 1 0.27 1 0.60 1
°"°’a" Guamy 0.91 A 1.92 A 1.68 B 2.03 B 0.59 c 1.30 c

 

 

n=15, 15 cm line scale, Values within each attribute not connected by the same letter are
significantly different, UP= unpasteurized, P = pasteurized

The trained panel average ratings and the Tukey’s HSD test comparison
results for processing and storage for the concentrate samples for week 20 and
week 24 of storage are shown in Tables 1.14 and 1.15. The p-values for each
attribute were 0.0001. Trained panels at week 20 and 24 of storage were very
similar to one another. Concentrate at 4°C continued to have the highest

acceptance ratings, while concentrate stored at 21°C was approximately 45%

lower.

39

Table 1.14: Trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice stored 20 weeks at 4, 21 and 38°C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. 4°C 21°C 38°C
“mm“ UP P UP P UP P
Concentrate 14.67 1 14.40 1 8.00 1 8.30 1 1.07 1 0.07 1
Color 0.49 A 0.51 A 1.13 B 1.15 B 3.62 c 0.26 c
Concentrate 14.07 1 13.13 1 8.47 1 8.00 1 1.20 1 0.40 1
ChernLAroma 1.28 A 2.00 A 1.46 B 2.10 B 3.61 c 1.06 c
. 14.40 1 14.20 1 7.87 1 7.80 1
Ju'“ c°'°' 0.74 A 0.78 A 1.25 B 1.15 B ”la "’3
Juice Fresh 14.00 1 13.67 1 8.33 1 7.73 1 n/a n/a
Cherry Flavor 1.41 A 1.50 A 1.54 B 1.83 B
. 14.07 1 13.60 1 8.00 1 7.67 1 1.07 1 0.27
(”mm Guam 1.34 A 1.60 A 1.25 B 1.63 B 3.35 c 10.80 c

 

 

n=15, 15 cm scale, Values within each attribute not connected by the same letter are
significantly different, UP= unpasteurized, P = pasteurized

Table 1.15: Trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice stored 24 weeks at 4, 21 and 38°C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. 4°C 21°C 38°C
“mute UP P UP P UP P
Concentrate 14.50 1 14.50 1 8.21 1 7.86 1 0.07 1 1.14 1

Color 0.65 A 0.52 A 0.98 B 1.17 B 0.27 c 4.00 c
Concentrate 14.07 1 13.36 1 7.29 1 7.43 1 0.43 1 0.21 1
Cherry Aroma 1.90 A 2.71 A 1.20 B 1.56 B 0.94 c 0.58 c
. 14.50 1 14.21 1 7.71 1 7.21 1
Ju'ce c°'°' 0.52 A 0.80 A 1.49 B 1.72 B "/3 "’3
Juice Fresh 14.14 1 13.64 1 8.21 1 7.07 1 ”la “la
Cherry Flavor 1.10 A 2.06 A 1.76 B 1.82 B
. 14.36 1 13.71 1 7.93 1 7.50 1 0.14 1 0.07 1
own" qua'm' 1.80 A 2.30 A 1.33 B 1.83 B 0.36 c 0.27 c

 

 

n=14, 15 cm line scale, Values within each attribute not connected by the same letter are
significantly different, UP= unpasteurized, P = pasteurized

At week 36 and 48 of storage, the concentrate at 38°C was no longer
evaluated. All sensory and analytical tests were no longer continued due to the
concentrate’s poor and unacceptable quality. The trained panel average ratings
and the Tukey’s HSD test comparison results for processing and storage for the
concentrate samples for week 36 and week 48 of storage are shown in Tables

1.16 and 1.17. The p-values for each attribute were 0.0001. At week 36 and

40

48 the concentrate stored at 21°C had a quality rating 65 to 75% lower than
concentrate stored at 4°C.

Table 1.16: Trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice stored 36 weeks at 4, and 21 °C

 

 

 

 

 

 

 

. 4°C 21°C
Attrlbute UP P UP P
Concentrate 14.70 1 14.20 1 5.40 1 4.90 1

Color 0.48 A 0.63 A 1.35 B 1.60 B
Concentrate 13.70 1 12.80 1 4.10 1 3.60 1
Cherry Aroma 2.06 A 2.97 A 1.73 B 2.37 B
Juice Color 14.40 1 14.00 1 4.20 1 4.10 1
0.97A 1.33A 1.873 2.13 B

Juice Fresh 13.40 1 13.20 1 3.70 1 4.50 1
Cherry Flavor 2.07 A 2.66 A 2.16 B 1.84 B
. 13.80 1 13.10 1 3.60 1 4.50 1

overa" °“a"ty 1.55 A 2.56 A 1.84 B 2.12 B

 

 

 

 

 

 

 

n=10, 15 cm line scale, Values within each attribute not connected by the same letter are
significantly different, UP= unpasteurized, P = pasteurized

Table 1.17: Trained panel average sensory ratings for tart cherry
concentrate and reconstituted juice stored 48 weeks at 4, and 21°C

 

 

 

 

 

 

 

 

 

 

 

. 4°C 21°C
Attrlbute UP P UP P
Concentrate 14.45 1 14.09 1 4.45 1 4.55 1

Color 0.69 A 1.45 A 1.37 B 1.37 B
Concentrate 13.64 1 13.82 1 3.64 1 3.91 1
Cherry Aroma 1.50 A 1.72 A 2.73 B 2.30 B
Juice Color 13.91 1 13.64 1 3.91 1 3.18 1
1.51 A 2.34 A 1.97 B 2.23 B

Juice Fresh 13.82 1 12.91 1 3.09 1 4.18 1
Cherry Flavor 1.66 A 3.45 A 2.02 B 2.86 B
Overall Quality 13.55 1 13.36 1 3.36 1 4.00 1
2.07 A 2.87 A 1.80 B 2.57 B

 

 

 

n=11, 15 cm line scale, Values within each attribute not connected by the same letter are
significantly different, UP= unpasteurized, P = pasteurized

1.3.3.2 Effect of Storage Duration

Figures 1.17 and 1.18 display the average attribute ratings for the
unpasteurized and pasteurized concentrate stored at 4°C over storage duration.

Using the Tukey’s HSD statistical analysis test, the concentrate stored at 4°C

41

showed no statistical change in its five rated attributes over 48 weeks of
storage. These results were concluded for both unpasteurized and pasteurized
concentrate (p>0.05). All average attributes ratings ranged within the values,
12 to 15. Showing no statistical difference over 48 weeks of storage
demonstrates the benefits of storing tart cherry juice concentrate under,
refrigerated conditions to best preserve its color, aroma, flavor and overall

quality.

+ Concentrate Color

+ Concentrate Cherry Aroma
+ Juice Color

—>l<—Juice Fresh Cherry Flavor
+ Overall Quality

 

 

.h
00

Average Rating

Unpasteurized (4 C)

 

 

12

 

0 4 812162024283236404448
Storage Duration (Weeks)

Figure 1.17: Effects of storage duration at 4°C on trained sensory quality
for unpasteurized cherry juice concentrate

42

+ Concentrate Color

+ Concentrate Cherry Aroma
+ Juice Color

+Juice Fresh Cherry Flavor
+ Overall Quality

 

 

Average Rating

 

 

Pasteurized (4 C)
12 t » l i l T l l l

0 4 812162024283236404448
Storage Duration (Weeks)

 

Figure 1.18: Effects of storage duration at 4°C on trained sensory quality
for pasteurized cherry juice concentrate

Figures 1.19 and 1.20 present the unpasteurized and pasteurized
concentrate’s average ratings over the storage period at 21°C. Concentrate
stored at 21°C showed a significant decrease in quality over the 48 week
storage period (p<0.0001). The largest significant decrease in the
concentrate’s attributes ratings occurred after weeks 4, 12, and 24. The
average concentrate ratings for unpasteurized and pasteurized concentrate are
displayed in Table 1.18 and 1.19, along with the Tukey’s HSD test comparison
over storage duration. After 4 weeks of storage the trained sensory ratings
decreased from the 13 to 14 value range to the 10 to 12 value range. Trained
panelists commented that at weeks 8 and 12 the concentrate’s color was

becoming a deeper red and not as bright as it was initially. Though the color

43

was losing brightness, no browning was detected during these weeks. The
concentrate did not have any off-aromas; however, the cherry aroma was
beginning to diminish, and had become very light. The reconstituted juice had a
good flavor however panelists commented that the product lost some of its tart
flavor, and was becoming sweeter in taste. This developing sweet flavor was
also seen in a storage study of cherry juice (Gonzalez-Mulet 2008). Even with
the change in the concentrate’s color, aroma and taste profile, the concentrate
at 12 weeks still represented a good quality product.

After 12 weeks of storage (Figures 1.19 and 1.20), there was a constant
decrease in quality up to week 20. From weeks 20 to 24 there was small
significant difference seen in the concentrate’s color and aroma, however, the
overall quality of the concentrate was constant. Over weeks 18, 20, and 24 of
storage the attribute ratings decreased to rating values 7 to 9. Panelists
reported that the concentrate now had a color of a weak, less vibrated red, also
showing slight brown pigments. Much of the fresh aroma had diminished and
the concentrate no longer processed a fresh cherry aroma. Slight off aromas
were becoming present including ones of cooked, aged, and prune-like odors.
The trained panel believed that for a consumer familiar with tart cherry juice
concentrate this product was no longer of quality to be sold.

After week 24 the concentrate’s attribute ratings showed a significant
decrease at week 26. After week 36, attributes were not significantly different
with the additional 12 weeks of storage at week 48. At weeks 36 and 48

attribute values had decreased to a rating within the 3 to 5 value range.

44

Panelists described these samples with very brown, muddy color which
contained no red pigment. The aroma was no longer fresh, and gave off
cooked, aged, and medicine-like off-aromas. Panelists reported a majority loss
of the juice's tartness. The reconstituted juice was now a very sweet, bland
product lacking freshness. A product of these low ratings and poor quality
descriptors would definitely not meet quality standards to be of a quality product
to be sold to consumers.

A correlation was shown between the trained panel ratings for color
results and the Hunter a values. Both the trained panelists and colorimeter
measured a constant decrease in red color over storage. However, panelists
were not able to view the decreasing color as fast as the instrument. Also, the
trained panel saw a decrease in the color attribute throughout the whole 48
weeks while the Hunter a value showed the majority of all red color loss by

week 16.

45

+ Concentrate Color

+ Concentrate Cherry Aroma
+ Juice Color

+Juice Fresh Cherry Flavor
+ Overall Quality

 

 

Average Rating

 

Unpasteurized (21 C) I
o T i I T l I i l f l T l

04812162024283236404448
Storage Duration (Weeks)

Figure 1.19: Effects of storage duration at 21°C on trained sensory quality
for unpasteurized cherry juice concentrate

 

 

+ Concentrate Color

+ Concentrate Cherry Aroma
+ Juice Color

—>l<— Juice Fresh Cherry Flavor
+ Overall Quality

 

15

 
 
  

...........................................................

-l
O
l

 

0|

 

Average Rating

 

Pasteurized (21 C)
OI T F T l l i i ' I T
O 4 8 12162024283236404448
Storage Duration (Weeks)

Figure 1.20: Effects of storage duration at 21°C on trained sensory quality
for pasteurized cherry juice concentrate

 

46

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Figures 1.21 and 1.22 present the unpasteurized and pasteurized
concentrate’s average ratings over the 24 week storage duration at the storage
condition of 38°C. Using the Tukey’s HSD test for statistical analysis, the
samples stored at 38°C showed a significant decrease in quality over the year
storage period (p<0.0001). Average sensory ratings for all concentrate are
displayed in Table 1.20 and 1.21, along with the Tukey’s HSD test comparison
over storage duration. The concentrate’s quality attributes significantly
decreased at 2 weeks, and week 4 and 8. After week 8 of storage the
concentrate’s attributes were no longer significantly different. There was no
significant decrease after week 8 because the concentrate had then already lost
all quality and no longer able to decrease in acceptance ratings.

At week 2 of storage the concentrate’s ratings had decreased to an 8 to
10 range. Panelists commented that these samples were on the verge of no
longer being acceptable for sale. At week 2 the color of the concentrate had
lost a majority of its bright red pigment, while brown pigments began to develop.
The concentrate had developed a slightly aged, cooked aroma, and became
much sweeter in taste. The overall freshness of the sample had slightly
decreased; however the cherry flavor was still present.

At week 4 the quality of the concentrate decreased to the acceptance
range 5 to 6. These ratings were given for the concentrate's poor brown color
and for having only small amount of red pigments. Trained panelists
commented that the aroma of the concentrate was very poor, and the fresh

cherry aroma had completely diminished. Off aromas and flavors were

48

beginning to become present giving the concentrate a fermented, aged aroma,
and an aged, cooked taste. After 4 weeks of storage the reconstituted juice had
lost the majority of its tartness and was very sweet, with only a slight cherry
flavor.

From week 8 throughout the rest of the storage period the reconstituted
juice was no longer evaluated due to its very low quality. At week 8 through 24
the concentrate’s color had become a dark, dull muddy brown. The
concentrate’s aroma lacked freshness, cherry aroma, and contained off-aromas

including those fermented, cooked, and medicine-like aromas.

+ Conc.Cherry Aroma

+ Conc.Cherry Aroma

+ Juice Color

—)l(— Juice Fresh Cherry Flavor
+ Overall Quality

 

15

 

........................................................................................

A
N
1

....................................................................

CD
1

Average Rating
03

U
j

 

 

 

0 2 4 6 8 1012141618202224
Storage Duration (Weeks)

Figure 1.21: Effects of storage duration at 38°C on trained sensory quality
for unpasteurized cherry juice concentrate

49

+ Concentrate Color

—I— Concentrate Cherry Aroma
+ Juice Color

+Juice Fresh Cherry Flavor
+ Overall Quality

 

Pasteurized (38 C)

Average Rating

 
 

 

 

 

o T r T T T T l .
0 2 4 6 8 10 12 14 16 18 20 22 24
Storage Duration (Weeks)

Figure 1.22: Effects of storage duration at 38°C on trained sensory quality
for pasteurized cherry juice concentrate

50

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1 .3.4 Consumer Sensory Panel
1.3.4.1 Processing and Storage Condition Effect

After 16 weeks of storage, an acceptance consumer panel was
conducted to evaluate both the unpasteurized and pasteurized concentrate
stored at 4 and 21°C. The samples stored at 38°C were not evaluated because
the trained panel determined that they were not fit for consumption after 4
weeks of storage. Average acceptance ratings of each attribute rated are
displayed in Table 1.22. Also shown is the Tukey HSD statistical analysis on
each rated attribute. Consumers found that the color among the reconstituted
juice stored at 4 and 21°C were significantly different. Concentrate stored at
21°C had significantly poorer acceptance ratings than samples held at 4°C.
Concentrate stored at 4°C had average color ratings of 7.58 :t 1.10 and 7.32 i
1.16 for unpasteurized and pasteurized concentrate respectively. These ratings
represent a color that is moderately liked by the consumer. Concentrate stored
at 21°C had average color ratings of 5.89 i 1.77 and 5.89 i 1.78 for the
unpasteurized and pasteurized concentrate respectively. Ratings represented
a color of a product that was neither liked or disliked by the consumer. The
aroma and flavor among the four samples were found to have no significant
difference in acceptance. Similar to color, the overall acceptability of the juice
was significantly different among the concentrate stored at 4°C and 21°C.
Concentrate stored at 4°C were found to have a greater degree of acceptability

in overall acceptance.

52

Table 1.22: Average consumer acceptance ratings and Tukey’s HSD test
comparison at week 16 of storage (unpasteurized and pasteurized)

 

 

 

 

 

 

 

 

 

 

 

 

 

. 4°C 21°C P-

Ammte UP P UP P value
7.58 1 7.32 :t 5.87 :1: 5.89 1
c°'°' 1.10 A 1.16 A 1.77 B 1.78 B 00001
Aroma 6.51 11.49 6.46 11.33 6.43 11.61 6.54 11.49 0.9019
Flavor 6.87 11.70 6.78 11.61 6.50 11.66 6.57 21:1 .63 0.2518
Overall 6.90 1 6.88 1 6.42 1 6.51 1 0 0153
Acceptability 1.58 A 1.33 A 1.67 B 1.59 B '

 

n=91, 9 point hedonic scale, Values within each attribute connected by different letters
are significantly different, UP= unpasteurized, P = pasteurized

The consumer panel average acceptance ratings and Tukey HSD
statistical analysis for storage week 24 are shown in Table 1.23. The ratings for
aroma and flavor attributes were found to be significantly the same for all
samples evaluated by consumers. The concentrate stored at 4°C had
significantly higher color ratings and overall acceptability over concentrate
stored at 21°C. The overall acceptability for concentrate stored at 4°C was 6.90
1 1.46 and 6.89 1 1.25 while concentrate stored at 21°C had an acceptance
rating of 6.24 1 1.62 and 6.13 1 1.73. Though both storage temperatures had
significantly different overall acceptability ratings all concentrate’s ratings fell
within the “like slightly" definition.

Table 1.23: Average consumer acceptance ratings and Tukey’s HSD test
comparison at week 24 of storage (unpasteurized and pasteurized)

 

 

 

. 4°c 21°C P-
Ammte UP P UP P value
7.67 1 7.55 i 4.96 1 5.10 1:
c°'°' 1.07 A 0.94 A 1.91 B 2.02 B 00001

 

Aroma 6.56 1 1.26 6.55 1 1.31 6.35 1 1.46 6.72 1 1.37 0.1826
Flavor 6.71 1 1.81 6.86 1 1.42 6.49 1 1.69 6.38 1 1.90 0.1067
Overall 6.90 1 6.89 1 6.24 1 6.13 1 0 0001
Acceptability 1.46 A 1.25 A 1.62 B 1.73 B '

n=100, 9 point hedonic scale, Values not connected by the same letter are significantly
different, UP=unpasteurized, P=pasteurized

 

 

 

 

 

 

 

 

 

 

53

In Table 1.24 are the consumer panel average acceptance ratings and
Tukey HSD statistical analysis for storage week 36. Unlike the consumer
panels at week 16 and 24, week 36 is the first consumer panel that participants
significantly saw a difference in flavor between the two storage conditions.
Consumers saw no significant difference among the unpasteurized and
pasteurized concentrate, but they did see a significant difference between color,
flavor and overall acceptability. The concentrate’s color played a large factor in
the consumer’s perception of overall quality. Concentrate stored at 4°C
received an average hedonic rating of “like moderately” while concentrate at
21°C received an average “dislike slightly" ratings. Concentrate stored at
refrigerated conditions received higher overall acceptability with acceptance
ratings of 6.88 1 1.46 and 6.95 1 1.48, while concentrate stored at ambient

temperatures received ratings of 5.52 1 1.72 and 5.40 1 1.84.

Table 1.24: Average consumer acceptance ratings and Tukey’s HSD test
comparison at week 36 of storage (unpasteurized and pasteurized)

 

 

 

 

 

 

 

 

 

 

 

 

. 4°C 21°C P.

“mute UP P UP P value
7.60 :l: 7.67 1 4.22 1 4.17 1

C°'°' 1.35 A 1.07 A 1.86 B 1.97 B 00001
6.32 1 6.48 i 6.16 1 6.18 1

”ma 1.41 1.32 1.55 1.63 02374
6.76 1 6.70 1 6.09 1 5.84 1

”3"" 1.58 A 1.58 A 1.79 B 2.00 B 00001

Overall 6.88 1 6.95 1 5.52 1 5.40 1 0 0001

Acceptability 1.46 A 1.48 A 1.72 B 1.84 B '

 

n=101, 9 point hedonic scale, Values not connected by the same letter are significantly

 

different, UP=unpasteurized, P=pasteurized
For the final consumer panel, panelists evaluated the unpasteurized
concentrate which was held at 4°C for 48 weeks and “fresh” unpasteurized

concentrate which was held at frozen temperatures since production. These

54

products were chosen for the 24 week consumer panel because the
concentrate stored at 21°C at 48 weeks received very low ratings by the trained
panel. These low ratings represented a product, which was poor quality and
would not be sold to consumers. Pasteurized concentrate was not analyzed
because it was already determine that the average consumer does not see a
significant difference among these samples.

Table 1.25 displays the consumer panel’s average acceptance ratings
and Tukey HSD statistical analysis for storage week 48. The consumer panel
showed that after 48 weeks, concentrate stored at refrigerated conditions had a
significantly lower acceptance rating for color than fresh concentrate. However,
both concentrates were shown to not be significantly difference in the attributes
of aroma and flavor and the overall acceptability of the products.

Table 1.25: Average consumer acceptance ratings and Tukey’s HSD test
comparison at week 48 of storage (Fresh vs. Stored)

 

 

 

 

 

 

 

 

 

 

Attribute Fresh (UP) 4°C (UP) P- value
Color 7.55 1 1.14 A 6.75 1 1.43 B 0.0001
Aroma 6.57 1 1.39 6.41 1 1.38 0.3021
Flavor 6.55 1 1.70 6.92 1 1.43 0.0735
Overall Acceptability 6.73 1 1.52 6.88 1 1.36 0.4106

 

n=96, 9 point hedonic scale, Values not connected by the same letter are significantly
different, UP=unpasteurized, P=pasteurized

From analyzing the effects of pasteurization and storage condition on the
consumer’s acceptance of cherry juice concentrate it can be concluded that
consumers do not detect a significant difference between unpasteurized and
pasteurized concentrate. Consumers saw no significant difference in the aroma
profile among the 4°C and 21°C storage conditions. This was also true for
flavor, however at week 36 a taste difference between 4°C and 21°C became

present. The attribute that was most influential on the overall acceptance of the

55

concentrate was the color attribute. In all consumer panels concentrate stored
at 4°C had the higher acceptance ratings over concentrate stored at ambient
temperatures.

Dun'ng each consumer panel, panelists were also asked marketing
questions to better understand their likeness of the product and purchasing
habits. Of the consumers who participated in the panels approximately 75 to
80% of them were consumers of juice made from concentrate. Panelists were
asked if they were likely to purchase their favorite juice sample. On a 5-point
scale ranging from “definitely not likely" to “definitely likely" only a small
percentage of ranging from 7 to 17% answered that they would “probably" or
“definitely" purchase the product. 22 to 33% of the panelists were unsure of
their purchasing decisions. A number of the panelists commented that the
product was too tart or sour for their taste, however since tart cherry juice
concentrate is known for being a tart product, it can be assumed that a number
of consumers are not familiar with the product. Even with the low number of
consumers reporting that they would purchase their favorite sample, a quite
high percentage (91%) said that they would more willing to purchase the

product for its health benefiting attributes.

1.3.4.2 Storage Duration Effect

When analyzing consumer sensory data over storage duration (week 16,
24, and 36) using Tukey HSD statistical analysis test it was determined that
consumers saw no statistical difference in color, aroma, flavor and overall

quality for concentrate stored at 4°C.

56

Tukey’s HSD p—values are shown in Table 1.26 for each sample
evaluated. For concentrate stored at 21°C consumers saw a significant
decrease in color acceptance at weeks 24 and 36. For the aroma and flavor
attributes of concentrate stored at 21°C consumer panels saw no statistical
difference for the unpasteurized concentrate. For pasteurized concentrate
there was a statistical difference between weeks 24 and 36 for aroma and a
statistical differenCe between week 16 and 36 for flavor. For the overall quality
of the samples stored at 21°C, consumers did not see a statistical decrease
until week 36.

Table 1.26: Tukey’s HSD p-values for consumer panel evaluation over
storage duration of 36 weeks

 

 

 

 

 

 

Attnbute Unpagtglrized Pasttlfi'ized Unpaflefirized Pasfe'ufized
Color 0.8563 0.0798 <0.0001 <0.0001
Aroma 04226 0.8715 0.4437 0.0347
Flavor 0.8133 0.7701 0.1601 0.0194
832:3: 0.9948 0.9226 0.0005 <0.0001

 

 

 

 

 

 

1.4 Conclusion

A significant decrease in total soluble solids was only seen at elevated
conditions. Processing, storage temperature and storage duration had no
statistical affect on the pH of the product. Titratable acidity was only affected by
storage conditions 21°C or higher and after storage duration of 24 weeks. The
clarity of the product was greatly impacted by both storage temperature and
duration, showing the most rapid rate of decay at high storage temperatures.

Hunter color a values were shown to have the largest significant effect caused

57

by storage duration and storage temperature of all color measurements. All
storage temperatures showed a significant decrease in a values over time, with
higher temperature showing the largest rate of degradation.

The trained panel found a slight significant difference between the
unpasteurized and pasteurized concentrate during the early stages of storage.
The untrained panel of consumers did not see significant effect of
pasteurization. Due to the minimal effect pasteurization has on sensory
acceptance it is likely that any of sensory quality loss caused by heat occurs
during concentration process.

Trained panelists were able to distinguish significant flavor and aroma
difference among samples earlier than consumer panelists. Consumers only
saw a significant difference in the samples’ color, which affected the overall
acceptance of the juice at weeks 16 and 24. It was only at week 36 that
consumers saw a significantly higher flavor acceptance of 4°C over 21 °C.

The manner at which the storage duration affected the sensory quality of
the concentrate depended highly on the concentrate’s storage temperature. It
is shown that storing concentrate at refrigerated (4°C) conditions for 48 weeks
does not significantly affect the sensory properties and only minimally affects
the physico-chemical properties of the product.

Trained and consumer panels were able to see a steady decreasing
trend in the sensory attributes of concentrate stored at 21°C. Consumers were
not able to pick up on flavor and aroma differences until week 36; however, the

trained panel that was familiar with the product saw a decrease in aroma and

58

flavor quality after only 4 weeks. Consumer evaluation concluded that the color
of the product highly affects the overall acceptance. Though concentrate stored
at ambient temperatures (21°C) are shown to be accepted equally in flavor and
aroma as refrigerated (4°C) concentrate until week 36, the color is the first
quality attribute to noticeably decrease, limiting the shelf life of the concentrate
at ambient storage condition. Based on the trained and consumer panel results
it is not recommended to store concentrate at ambient temperature longer than
12 weeks.

High storage temperatures greatly reduced the quality of cherry juice
concentrate in a short period of time. Based on data collected it not
recommended exposing concentrate to elevated temperatures as its sensory
attributes, especially color, are greatly affected. If the product is exposed to

elevated conditions, maximum exposure should not be greater than 2 weeks

59

2. EFFECTS OF PROCESSING, STORAGE TEMPERATURE AND STORAGE
DURATION ON ANTIOXIDANT PROPERTIES OF MONTMORENCY CHERRY
JUICE CONCENTRATE

2.1 Literature Review
2.1.1 Antioxidants
2.1.1.1 Background of Antioxidants

Research has shown that tart Montmorency cherries contain a high
number of compounds that convey health benefits. These compounds,
including anthocyanins and phenolics, act as antioxidants within the body. An
antioxidant is “a substance that opposes oxidation or inhibits reaction promoted
by oxygen or peroxides” (Huang 2005). Preventing oxidation within the body is
very important because oxidative damage, caused by free radicals, can cause
harm to the body in a number of ways.

There are a number of types of free radicals including reactive nitrogen
species (RNS), reactive chlorine species (ROS), reactive oxygen species (ROS)
and reactive bromine species (ROS) (Halliweil and Gutteridge 2007). These
reactive species, or free radicals, are formed in a variety of ways within the
body and its surrounding environment. Free radicals can results from smog,
ozone, drugs, chemicals, radiation and physiological processes (Gropper and
others 2005). A free radical is defined as one or more unpaired electrons,
which are in an orbit and can cause oxidation of DNA, proteins, lipids, and uric
acid (Halliweil and Gutteridge 2007). The natural antioxidants found in tart
cherries quench free radicals within the body to form a stable compound.

Antioxidants form this stable compound through the donation of a hydrogen

60

atom to the reactive free radical. Eating foods that contain high levels of
antioxidants reduces the overall level of free radicals in the body, which prevent
oxidative stress and oxidative damage from occurring in the body.

There are a number of commonly used assays used to measure total
antioxidant content of foodstuffs such as Total Radical-Trapping Antioxidant
Parameter (TRAP), Trolox Equivalent Antioxidant Capacity (TEAC), and Ferric
Reducing/Antioxidant Power (FRAP) (Mermelstein 2008). However, the oxygen
radical absorbance capacity (ORAC) assay was chosen for the shelf life study
to measure the total antioxidant capacity.

Cherry juice concentrate has one of the highest ORAC values among
other fruit and fruit products. The high levels are partly due the highly
concentrated product. In 3 Cherry Nutritional Report (Reiter) tart cherry
concentrate was found to yield an ORAC value of 128 (micromole TE/g).
Though tart cherry juice concentrate is always known for its high ORAC values,

these levels can vary from season to season.

2.1.1.2. Anthocyanins

Anthocyanins are the pigment that gives an orange, red, blue or purple
color to a number of plants, flowers and fruits in nature. For tart cherries, in
particular, anthocyanins give the fruit their deep red color. Anthocyanins are
one of the major group of pigments found in nature and belong to the secondary
metabolite group of flavonoids (Blando et al. 2004). in Figure 2.1 are the
chemical structures of the six most common anthocyanins found in nature,

including pelargonidin, cyanidin, peonidin delphinidin, petunidin and malvidin.

61

  
 

Pelargonidin Peondin
OCH3
O OH
+
O\ OCH3
/
Delphinidin Petunidin Malvidin

Figure 2.1: Six common anthocyanins found in plants

Anthocyanin structures are unique from one another by the number of
hydroxyl groups within the molecule, the degree of methylation of the hydroxyl
groups, the nature, number and position of sugars attached to the molecule and
the nature and number of aliphatic or aromatic acids attached to the sugars
within the molecule (Mazza and Miniati 1993). Tart cherries are known to
contain a variety of anthocyanins including cyanidin 3—sophoroside, cyanidin 3-
glucosylrutinoside, cyanidin 3-glucoside, cyanidin 3-arabinosylrutinoside,
perlargonidin 3-glucoside and peonidin 3-rutinoside (Kim and others 2005).

The stability of the anthocyanin structure can be affected in various
ways. Anthocyanins are most stable in an acidic solutions and lose their
pigment, due to structural changes as the pH becomes more alkaline (Mazza

and Miniati 1993). Other affecting factors include light, oxygen, acetaldehyde,

62

ascorbic acids, sugars, and others (Mazza and Miniati 1993). It has also been
shown that the by-products of degradation products, such as ascorbic acid can
accelerate the anthocyanin degradation (Mazza and Miniati 1993) and
(Alighourchi and Barzegar 2009). As temperature storage or processing
temperature rises the degradation rate of the anthocyanins increase (Ma 2007).
Beny fruit products and beverages from these fruits can provide the consumer
10’s to 100’s of milligrams of anthocyanins in a single serving (McGhie and
Walton 2007). It is common for fruit and vegetable juices to contain an total

anthocyanin content to from 50 to 500 mg/liter (Giusti and Wrolstad 2005).

2.1.1.3 Phenolics

Phenolics are a diverse group of aromatic compounds with at least one
hydroxyl group (Kim and others 2005). They are known for being beneficial to
one’s health due to their various biological activities (Kim and others 2005).
Foodstuffs and plants contain a large array of phenolic derivatives including
simple phenols, phenylpropanoids, benzoic acid derivaties, flavonoids,
stilbenes, tannins, lignans and lingins (Shahidi and Naczk 2004).

Tart Montmorency cherries have one of the highest total phenolic
contents of all tart cherry varieties (Kim and others 2005). It is reported fresh
Montmorency cherries contain 4.07 mg GAE/g of fresh weight (Chaovanalkit
and Wrolstad 2004) and Montmorency cherry juice concentrate contain 4013 1
578 pg GAE/g dry weight (Kirakosyan and others 2009). However the most
comparable total phenolic value is found in a study on dark fruit juices. Total

phenolic content for a sour cherry nectar juice (including sour cherry and apple

63

juice) showed a total phenolic content ranging from approximately 1043 to 1604

mg GAE/L (Piljac-Zegarac and others 2009).

2.1.1.4 Health Benefits

The antioxidant-acting compounds, anthocyanins and phenolics, have a
wide range of potential benefits for the body. These compounds have been
shown to inhibit the growth of cancer cells and protect against other chronic
diseases such as heart disease (Kim and others 2005; Piccolella and others
2008). Phenolic compounds in particular have been shown to have the
potential to decrease the risk of certain types of Alzheimer’s disease (Kim and
others 2005) and to defend against infection (Piccolella and others 2008). In
mice studies it has been shown that anthocyanins from tart cherries inhibited
the growth of a developing tumor (Blando and others 2004). The anthocyanins
found in tart cherries have the potential to slow cardiovascular disease
(Piccolella and others 2008; Zafra-Stone and others 2007) and retard the aging
process (Piccolella and others 2008) and to improve neuronal and cognitive
brain functions (Zafra-Stone and others 2007). Anthocyanins and phenolics
have the ability to reduce oxidative stress and inflammation in the body

(Kirakosyan and others 2009; Kim and others 2005).

2.1.2 Analysis of Antioxidant Capacity
2.1.2.1 Oxygen Radical Absorbance Capacity

The oxygen radical absorbance capacity (ORAC) allows for the
measurement of all antioxidant activity within a sample. The measurement

64

includes anthocyanins, and phenolic compounds along with all other
compounds with antioxidant potential. The ORAC assay has come to be a very
common and widely used method. The ORAC method has been used in many
research areas including nutraceutical, pharmaceutical and food industries
(Huang and others 2002).

The assay quantitatively determines antioxidant activity by measuring the
ability of the antioxidants contained in the samples to inhibit peroxyl radical
induced oxidation. The antioxidants inhibit the oxidation by quenching free
radicals by the donation of hydrogen atoms. This type of reaction is classified
as a hydrogen atom transfer (HAT). The ORAC method uses a fluorescent
probe that when oxidized by peroxyl radicals, yields an unfluorescent product.
The oxidation reaction is initiated by a 2,2’-azobis(2-amidinopropane)
dihydrochloride (AAPH) solution.

The ORAC assay has been credited and developed by (Ghiselli and
others 1995), (Glazer 1990) and (Cao and others 1993). Originally the reaction
was performed using B-phycoerythrin (B-PE), a fluorescent protein that is
isolated from Porphyridium cruentum. Eventually the method was changed to
use fluorescein (FL; 3',6'-dihydroxy- spiro[isobenzofuran-1[3H],9'[9H]-xanthen]-
3-one), a synthetic, non-protein probe. The change was done because
fluorescein overcomes some of the disadvantages that B-PE has. Fluorescein
is photostable unlike B-PE, which loses roughly 50% of its fluorescence after 35

minutes of exposure to excitation light (Huang and others 2002). Also B-PE

65

has shown to have lot-to-lot variability, which affects the overall assay results
(Huang and others 2005).

During the ORAC procedure, loss of fluorescence is measured over time
and decay curves for both sample and blank sample are built. With the decay
curves the net area under the curve (AUC) is calculated using the trapezoidal
rule and the equation Net AUC = AUC Sample— AUC Blank. A standard curve is
built using the antioxidant Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-
carboxylic acid), a water soluble vitamin E analog (Prior and others 2005). Like
with the sample and blanks, decay curves for five Trolox concentrations are
made. The net area under the curve is found and the Trolox concentrations are
plotted against the AUC to build the standard curve. The net AUC for the
samples is compared against that of the standard curve to obtain a value
expressed in micromoles of Trolox equivalents per gram or liter of sample (pmol

TE/g or pmol TE/L).

2.1.2.2 Total Anthocyanins - pH Differential Method

The pH differential method quantitatively measures total monomeric
anthocyanins within a variety of food products. This assay was originally
designed by Sondheimer and Kertesz in 1948 to determine the anthocyanin
content in strawberry jams. Later on in 1968 Fuleki and Francis adjusted the
pH buffers from 2.0 and 3.4 to 1.0 and 4.5 so the assay could be applied to
cranberries and also a wider variety of food products (Giusti and Wrolstad

2005)

66

The pH differential method is a rapid and easy assay that works
effectively even when in the presence of a number of obstructive compounds.
Among the few materials that do cause interference within this method are the
red pigments FD&C Red No. 40, FD&C Red No. 3, cochineal and beet powder
(Giusti and Wrolstad 2005). Using optical spectroscopy the assay measures
the structural transformation of the anthocyanin compounds dependent upon
different pH environments. Anthocyanin pigments can range in colors from red,
blue and purple. At a pH lower than 2 the anthocyanins form flavylium cations
which produce a red or yellow color. If the pH of the system is raised to a pH
between 4 and 6 the anthocyanin structure changes to a colorless hemiketal
form due to the hydration of the flavylium cation (Mazza and Miniati 1993).
Figure 2.2 shows the structural change between the colored structure flacylium

cation and the colorless hemiketal form that takes place during this assay.

   

-H
+H20
O-g|y O'gly
Flavylium cation: orange to purple Hemiketal form: colorless
pH= 1.0 pH= 4.0

Figure 2.2: Structural changes of an anthocyanin at pH 1.0 and pH 4.0

67

The pH differential method measures the absorbance of both the

flavylium cation (pH 1.0) and hemiketal (pH 4.5) anthocyanin structures. The

absorbance is measured at Avis-max (nm) and at 700 nm. No absorbance

occurs at the wavelength of 700 nm however the measurement is taken to

correct any absorbance readings that occur due to haze or sediment within the

sample. The Avis-max (nm) is determined based off the anthocyanin compound

being measured within the sample. For cheny juice concentrate the
anthocyanin cyanidin-3-glucoside (520 nm) is chosen as it is a common

anthocyanin found within tart cherries (Blando and others 2004).

2.1.2.3 Total Phenolics - Folin-Ciocalteu Assay

Folin and Ciocalteu first developed the Folin-Ciocalteau method in 1927
for the analysis of tyrosine and tryptopane in proteins. (Folin and Ciocateu
1927) Singleton and Rossi first used the Folin-Ciocalteau method in a food
application for wine analysis in 1965 (Waterhouse 2005). Since then it has
been adopted as the official procedure for determining total phenolic content in
wine and tea. The procedure is used for a number of food products and is one
of the most popular procedures for total phenolic analysis in foods due to being
fast and simple. It is also commonly used because results can be compared
directly to other results reported in literature (Bravo and Mateos 2008). The
assay uses gallic acid as a standard and reports all results in gallic acid

equivalents. There are a number of standards that can be used however, gallic

68

acid is used most commonly because it is inexpensive in its pure form and it is
stable in its dry form (Waterhouse 2005).

The chemistry of the procedure involves the oxidation of the phenolate
ion within the foodstuff and the reduction of the phosphotungstic-
phosphomolybadic, also called the Folin-Ciocalteau reagent (Bravo and Mateos
2008). The metal oxide reduction produces a blue phosphotungstic-
phosphomolybdic complex. This blue complex can be measured
spectroscopically because it exhibits a broad light absorption at a maximum of
765 nm. The intensity of light the sample absorbs at 765 nm is proportional to

the total phenolic concentration of the sample (Waterhouse 2005).

2.1.3 Hypothesis

The independent variables of processing, storage temperature and
storage duration have a degradative effect on the dependent variables physico-

chemical, microbial, and sensory quality of tart cherry juice concentrate.

2.2 Materials and Methods
2.2.1 Cherry Juice Concentrate Samples

Montmorency tart cherry concentrate was received in five 5-gallon
containers from Shoreline Fruit LLC (Traverse City, Michigan). Shoreline Fruit
LLC processed the product (crop year: 2007) to a concentration of 68° Brix.
The concentrate was stored in the 5-gallon buckets in a Michigan State
University Food Science freezer at approximately -15°C until the concentrate
was further processed, packaged and stored.

69

2.2.2 Pasteurization of Concentrate

Pasteurization took place in the Michigan State University Food
Science’s pilot plant. The concentrate was pumped through a spiral stainless
steel tube that was submerged in water heated in a steam-jacketed kettle.
Approximately two 5-gallon containers of concentrate were pasteurized at 85°C
for 5 seconds. Three pasteurized samples were collected and stored to
represent different times during the pasteurization of the concentrate (beginning
of the run, middle, and end of the run). These pasteurized samples were
represented as pasteurized batch 1: beginning of run, pasteurized batch 2:

middle of run and pasteurized batch 3= end of run.

2.2.3 Packaging and Storage of Concentrate

All samples were stored in clear, square 1 oz. glass jars. The bottles
were acquired from Qorpak (Bridgeville, Pennsylvania). Bottles of concentrate
were all labeled indicating if they were unpasteurized or pasteurized.
Containers were also labeled with the week number to indicate when the
sample would be removed from storage for analysis. All concentrate samples
were stored in conditions absent of light. Samples were stored at 4°C in a VWR
Scientific Model 2005 Low Temperature Incubator (West Chester,
Pennsylvania). Concentrate samples stored at 21°C were stored in a laboratory
cupboard with minimal temperature changes and finally samples at 38°C were
stored in 3 Fisher lsotemp® Oven 200 Series Model (Pittsburgh, Pennsylvania).

Temperatures were monitored every 2 to 3 days to confirm consistent storage

70

temperatures. After samples were removed from storage they were kept frozen
in an upright Frigidaire freezer (Martinez, Georgia) at approximately -15°C until

analysis could be completed.

2.2.4 Shelf Life Schedule

The shelf life was conducted over the course of one year. The samples
stored at 4°C and 21 °C were tested up to the one year while the samples stored
at 38°C were only tested Up to 24 weeks. The cherry juice concentrate stored
at elevated conditions was no longer stored after 24 weeks because it was no
longer of consumable quality. Total antioxidants, total anthocyanins, and total
phenolics were measured every 6 weeks for 24 weeks. They were analyzed

again at week 36 and week 48.

2.2.5 Oxygen Radical Absorbance Capacity
2.2.5.1 Reagent and Sample Preparation

The oxygen radical absorbance capacity (ORACFL) assay was based off

of (Huang and others 2005). The ORACFL assay used the chemical solutions;

sodium phosphate buffer pH 7.4 (75mM), 6-hydroxy-2,5,7,8-

tetramethylchroman-Z-carboxylic acid (Trolox®) stock solution (2.0mM),

fluorescein sodium salt stock solution (4 x 10'3 mM) and also an 153 mM 22’-

Azobis(2-amidinopropane) dihydrochloride (AAPH) solution. The sodium

phosphate buffer solution was prepared by adding 11.741 grams of dibasic

7]

sodium phosphate (Sigma-Aldrich, St. Louis, Missouri) and 4.306 grams of
monobasic monohydrate sodium phosphate (Mallinckrodt Baker Phillipsburg,
New Jersey) to 1000 mL of distilled water and adjusting the pH to 7.4 with 1M
sodium hydroxide (Mallinckrodt Baker Phillipsburg, New Jersey) and 1M
hydrochloric acid (Columbus Chemical Industries, Columbus, Wisconsin). The
2.0 mM trolox solution was prepared by adding 0.25 grams of trolox (Sigma-
Aldrich, St. Louis, Missouri) to 500 mL of 75 mM sodium phosphate (buffer pH
7.4). The trolox stock solution was stored in the refrigerator between uses and

also wrapped in foil to prevent light from reaching the solution.

A fluorescein stock solution at a concentration of 4 x 10'3 mM was

prepared by dissolving 0.1 grams of fluorescein sodium salt (Sigma-Aldrich, St.

Louis, Missouri) in 50 mL of sodium phosphate buffer (75 mM, pH 7.4). This

created a 5.3153 x 10'3 M solution. Finally 0.752 mL of the 5.3153 x 10‘3 M

fluorescein solution was added to a 1 L volumetric flask and the volume as
brought to 1 L with sodium phosphate buffer (75 mM, pH 7.4). The stock
solution was stored at refrigerated conditions, wrapped in aluminum foil for up
to three months. During each ORAC analysis a working solution was prepared
by diluting the fluorescein stock solution (1:1000) in sodium phosphate buffer
(75 mM, pH 7.4). A fresh 153 mM 2,2’-Azobis(2-amidinopropane)
dihydrochloride (AAPH) solution was made for each ORAC analysis. This
solution was prepared by adding 0.414 grams of AAPH to 10 mL of sodium

phosphate buffer (75 mM, pH 7.4).

72

Trolox samples were prepared in five concentrations to build a standard
curve. The concentrations (6.25, 12.5, 25, 50, 100 pL) were prepared using
sodium phosphate buffer (75 mM, pH 7.4). All cherry juice concentrate samples
were diluted using sodium phosphate buffer (75 mM, pH 7.4) with a dilution
factor of 11. This sample was then diluted into four more dilutions adding 100,
75, 50, and 25 pL of the sample to 10 mL of sodium phosphate buffer (75 mM,

pH 7.4).

2.2.5.2 Experimental Procedure
The ORAC procedure was performed using an FLx800 Multi-Detection

Microplate Reader (Biotek Instruments, Winooski, Vermont) and the Biotek
software Gen 5. The microplate reader was set at the detection parameters of
528 nm, 20 nm bandpass, emission filter and 485 nm, 20 nm bandpass
excitation filter. Black polystyrene 96-well, round bottom microplates (Corning,
Corning, New York) were used. The exterior wells of the plated were left

empty, while the interior wells were used for the analysis. To all wells that

would be used for analysis, 150 uL of the diluted Fluorescein solution (4 x 10'6

mM) was added. Twenty-five uL of sodium phosphate buffer (75 mM, pH 7.4)
was added to the wells that would represent a blank sample. The remaining
wells contained 25 pL of the diluted Trolox samples for the standard curve and
25 pL of the diluted cherry juice concentrate samples. The microplate was then
incubated for 30 minutes at 37°C in the Biotek reader. After the incubation

period 25 pL of the 153 mM AAPH solution was added to all experimental wells.

73

After the addition of the AAPH solution the Biotek microplate reader measured
the relative fluorescence intensity every two minutes for up to five hours.

Decay curves for the blank, standards and samples were built by plotting
the fluorescence intensity versus the time. The normalized area under the
curve (AUC) for each decay curve was calculated using the trapezoidal rule

(Eq. 2.1).

AUC = E1-+R2+R3+...+Rn.1+—Rfl E Eq. 2.1
2 2 R1
Where R1 represents the fluorescence reading at the initial time of the reaction,

Rn represents the final fluorescence reading and At is the change in time

between readings equaling two minutes. The blank and the sample’s AUC was

then used to calculate the Net AUC where Net AUC= AUCSample-AUCBIank. A

standard curve was built using the AUC of the standards versus the

concentration of the standards. The sample’s Net AUC was then compared to

the standard curve in order to determine the sample’s ORACFL of micromole of

Trolox equivalent per gram of liter of sample (pM TE/g or (M TE/L).

2.2.6 Total Anthocyanins- pH Differential Assay
2.2.6.1 Reagent Preparation

The total anthopcyanins— pH differential assay was followed according to
them method of Giusti and Wrolstad (2005). A 0.025 M potassium chloride
buffer pH 1.0 and 0.4 M sodium acetate buffer pH 4.5 solutions were prepared

for the total anthocyanin assay. To prepare the potassium chloride buffer, 1.86

74

grams of KCI (Mallinckrodt Baker Phillipsburg, New Jersey) was mixed with 980
mL of distilled water. The pH was adjusted to 1.0 using concentrate
hydrochloric acid (Columbus Chemical Industries, Columbus, Wisconsin). The
solution was transferred to a 1 L volumetric glass and the volume was brought
up to 1 L. The sodium acetate buffer was prepared by mixing 54.43 grams of
CH3COZNa - 3 H20 (Mallinckrodt Baker Phillipsburg, New Jersey) with ~960
mL of distilled water. The pH was adjusted to 4.5 using concentrate
hydrochloric acid. The solution was transferred to a 1 L volumetric flask and the

volume was brought up to 1 L.

2.2.6.2 Experimental Procedure

The appropriate dilution factor was determined to be 40. This value was
found by diluting the cherry juice concentrate sample with the potassium

chloride buffer until it was confirmed that the absorbance reading was within

linear range of the spectrophotometer at the wavelength Avis-max (510 nm). It

was advised that the sample volume not exceed the total sample volume by
20% so as not to exceed the buffer’s capacity.

Two solutions were prepared for each sample, one with potassium
chloride buffer, pH 1.0 and the other with the sodium acetate buffer pH 4.5.
The dilutions were allowed to equilibrate for 15 minutes prior to absorbance
reading. Distilled water was used as a blank to calibrate the
spectrophotometer. The absorbance value for each sample was read using a

Milton Roy Spectronic 21D spectrophotometer (lvyland, Pennsylvania) at both

75

the Avismax (510 nm) and 700 nm. The absorbance (A) of the samples were
calculated using equation 2.2.
A = (A). vis-max - A700)pH 1.0 - (A). vis-max - A700)pH 4.5 EQ- 2-2

Using the absorbance value the monomeric anthocyanin pigment (mg/L) was

calculated using equation 2.3:
Monomeric anthocyanin pigment (mg/liter): (A x MW x DF x 1000)/(£ x 1)

Eq. 2.3
In equation 2.3 the MW is the molecular weight of Cyanidin-S-glucoside (449.2
g/mole), DF is the dilution factor (40) and e is the molar absorptivity of Cyanidin-

3-glucoside (26,900).

2.2.7 Total Phenolics- Folin-Ciocalteu Assay
2.2.7.1 Reagent and Sample Preparation

The total phenolics- Folin-Ciocalteu’s assay was performed according to
the Waterhouse’s method (Waterhouse 2005). A gallic acid stock solution and
sodium carbonate solution was prepared for the total phenolic assay. To
prepare the gallic acid solution 0.5 grams of gallic acid (Sigma-Aldrich, St.
Louis, Missouri) was added to 10 mL of ethanol (EMD Chemicals, Gibbstown,
New Jersey) and then diluted to 100 mL of distilled water. The gallic acid stock
solution was stored in an amber glass container at refrigerated temperatures for
up to 2 weeks. Five gallic acid standard dilutions were prepared using the
premade gallic acid stock solution and distilled water. The dilutions included

the concentrations of 50, 100, 200, 300, and 400 mg/L.

76

The saturated sodium carbonate solution was prepared by dissolving
200 grams of anhydrous sodium carbonate (Mallinckrodt Baker, Phillipsburg,
New Jersey) into 800mL of water. The solution was brought to a boil and then
allowed to cool. After cooling a few crystals of sodium carbonate was added to
the solution and then it was allowed to sit for 24 hours at room temperature.
The solution was filtered through Whatman No. 1 paper (Whatman Inc., Clifton,
New Jersey). The volume was brought up to 1 L with distilled water and was
stored at room temperature.

Cherry juice concentrate samples were prepared by diluting the sample

with distilled water with the dilution factor of 41.

2.2.7.2 Experimental Procedure

For each five gallic acid concentrates and diluted cherry juice
concentrate samples the amount of 0.5 mL was added to separate glass test
tubes. For a blank sample 0.5 mL of distilled water was added to an empty test
tube. The amount of 7.5 mL of distilled water was added to all tests tubes
(blank, standards, samples) followed by 0.5 mL of the Folin- Ciocalteu reagent
(Sigma-Aldrich, St. Louis, Missouri). All test tubes were mixed using 3 Fisher
Scientific vortex mixer (Pittsburg, Pennsylvania). The test tubes were allowed
to incubate at room temperature for one to eight minutes. Following by the
incubation 1.5 mL of the saturated sodium carbonate solution was added to
each test tube. All samples were mixed using the vortex mixer for the second
time. The test tubes were covered and then allowed to incubate for two hours

at room temperature. After the incubation period the samples’ absorbance was

77

read at a wavelength of 765nm using a Spectronic 21D Milton Roy
spectrophotometer (lvyland, Pennsylvania). The blank sample prepared was
used to calibrate the spectrophotometer prior to reading the standard curve and
cherry juice concentrate samples.

The absorbencies of the five gallic acid concentrations were used to
create a standard curve of absorbance values versus the gallic acid
concentrations. Using the absorbance readings of the cherry juice concentrate
samples and the standard curve, total phenolic values were calculated and
expressed in gallic acid equivalents (GAE). The values were also corrected

using the sample’s dilution factor.

2.2.8 Statistical Analysis

Antioxidant properties were analyzed using a three-way factorial design
using the GLIMMIX procedure in the statistical software SAS 9.1 (Raleigh,

North Carolina).

2.3 Results and Discussion
2.3.1 Oxygen Radical Absorbance Capacity
2.3.2.1 Interaction Effect

Using a three-way factorial design it was concluded that the interactions
among the variables of processing, storage temperature and storage duration
did not significantly affect the concentrate’s ORAC values (p>0.05). Analysis of

the effect of each individual variable showed that only the storage duration had

78

a significant affect (p<0.0001). P-values for all variables and variable
interactions are presented in Table 2.1.

Table 2.1: Summary of p-values of variables and interactions for ORAC
values (micromole TELg tart cherry juice concentrate)

 

 

 

 

 

 

 

 

 

 

Variable and Interactions p-value
Pasteurization 0.2034
Storage Temperature 0.0627
Storage Duration <0.0001
Storage Duration*Storage Temperature 0.5006
Storage Duration*Pasteurization 0.1870
Storage Temperature*Pasteurization 0.8368
Storage Duration *Storage Temperature*PasteUrization 0.9659

 

 

2.3.2.2 Storage Duration Effect

Since it was determined that storage duration was the only variable
significantly affecting the ORAC value, the main effects of storage duration
were analyzed, while excluding the effects of the processing (pasteurization)
and storage temperature variables. This analysis was completed using the
Tukey Honest Significant Difference test. In Table 2.2 are the results of the
Tukey HSD test showing the average ORAC values at each 6 week analysis.
Each week includes all storage condition data. Figure 2.3 displays the same
results in a graph format. Graphs for each individual processing type and

storage temperature are found in Appendix 2.

79

Table 2.2: The average ORAC values (micromole TEIg tart cherry juice
concentrate) and Tukey’s HSD test comparison results for storage
duration

 

 

 

 

 

 

 

 

($113233; ””3"“ ORAC Values
0 670 1 102 A
6 260 1 50 co
12 285 1 107 c
18 203 1 50 E
24 340 1 114 B
36 198 1 34 E
48 216 1 35 DE

 

 

 

 

*Values not connected by the same letter are significantly different

 

 

A
A 700 ..................................................................................................
a, 8
E g 600 3 ..................................................................................................
8
g g 500 ..................................................... B .........................................
E u C
g 3 400 ~ »»»»»»»»» co ------- - ----- - ------- - -------------- .— -------------------------------------------
E E- t E 3 DE
5' a 300 ---------- I ----------------------- ; ------------- -.- ---------------------- E ----------------
< E i ! . e .
g o 200 --------------------------------------- ! --------------------------------- g ---------------------- .
E .
100 ................................... __ ...........................................................
01.--.... . , . - . H
0 6 12 18 24 30 36 42 48
Storage Duration (Weeks)

Figure 2.3: Effects of storage duration on the average of all storage
temperature and processing types ORAC values (micromole TEIg tart
cherry juice concentrate) for cherry juice concentrate

*Values not connected by the same letter are significantly different

80

Analysis of the ORAC content over the one year storage period showed
that the ORAC value at the initial day 0 measurement was statistically greatest.
Average ORAC values at the initial analysis were 670 1 102 micromole TE/g
tart cherry juice concentrate. At week 6 the ORAC value significantly
decreased to between approximately 40% of its initial ORAC content. It is likely
that the reason for the large ORAC value decay within the first 6 weeks was
due to the loss of the concentrate’s most abundant antioxidant. Research is not
available on what antioxidant is the most abundant in tart cherries, however it is
know that they contain a variety of anthocyanins, phenolics and high levels
other antioxidant compounds such as the melatonin (Burkhardt and others
2001). After week 6, the concentrate’s ORAC values significantly increased
and decreased throughout the rest of the year storage period. Though
significant changes were occurring, average ORAC values stayed within the
range of 198 1 34 to 340 1 114 micromole TE/g tart cherry juice concentrate. It
is likely that biological variation within the cherry juice concentrate samples was
the cause for some of the ORAC value fluctuation.

In a Cherry Nutritional Report (Reiter; Cherry Marketing Institute 2007b)
tart cherry concentrate was found to yield an ORAC value of 128 (micromole
TE/g). The fresh tart cherry concentrate in this study yielded an ORAC value 5
times that amount. After storage of the concentrate, the ORAC value yielded
approximately twice the amount as reported in the Cherry Nutritional Report. It
must be noted that little information is known about the cherry juice concentrate

reported in the Cherry Nutritional Report, including the age and the storage

81

conditions of the concentrate. The total antioxidant capacity of tart cherry juice

concentrate is also dependent on the growing season.

2.3.2 Total Anthocyanins
2.3.2.1 Interaction Effects

With the analysis of a three-way factorial design it was concluded all
variables and the interactions of these variables had a significant affect on the
total anthocyanin content of the tart cherry juice concentrate (p<0.05). The p-
values of each individual variable and the variable interactions are presented in
Table 2.3.

Table 2.3: Summary of p-values of variables and interactions for total
anthocyanin values (mg cyn-3-glu/Iiter tart cherry juice concentrate)

 

 

 

 

 

 

 

 

Variable and Interactions p-value
Pasteurization <0.0001
Storage Temperature <0.0001
Storage Duration <0.0001
Storage Duration*Storage Temperature <0.0001
Storage Duration*Pasteurization <0.0001
Storage Temperature*Pasteurization <0.0001
Storage Duration *Storage Temperature*Pasteurization 0.0362

 

 

 

 

2.3.2.2 Pasteurization Effect

The effects of each interaction were shown through the simple effects
comparison of the interaction, storage duration*storage temperature*processing
least squares means sliced by that particular interaction. The effects of
processing with the interaction of storage duration*storage temperature showed

the majority of significant difference among processing types occurring during

82

the initial analysis at day 0. No significant difference occurred among the three
pasteurization batches (p>0.05) at the initial analysis. However, significantly
higher total anthocyanin values were seen for the unpasteurized concentrate
(p<0.05), with an average total anthocyanin value of 538.37 1 28.44 mg cyn-3-
qu/liter tart cherry juice concentrate.

For the storage condition 38°C no significant difference was seen among
processing types during the 24 weeks of storage (p>0.05). This was also seen
for the storage condition 21°C. However, there was one exception, which
occurred early in the study at week 6. At this condition a significant difference
was observed among the concentrate pasteurized at the beginning of
processing and at the end of processing (p=0.0390).

The remaining effects of processing occurred throughout the duration of
the storage study within the storage temperature, 4°C. Significant differences
occurred at weeks 6, 18, and 48 of analysis. At week 6, the unpasteurized
concentrate had a significantly higher total anthocyanin value over pasteurized
batch 1 (p=0.0006). At week 18 of storage unpasteurized concentrate had a
significantly higher value over all three pasteurized batches (p<0.05). Finally, at
week 48, unpasteurized concentrate had a significantly higher total anthocyanin
content over pasteurized batch 1 (p=0.0178), while pasteurized batch 1 being
significantly large compared to batch 3 (p<0.0001).

Based on analysis of total anthocyanin content it can be concluded that
any minimal temperature fluctuations that occur during the pasteurization

process have minimal to no affect on the total anthocyanin content. Results

83

show that the interactions of storage temperature and storage duration have a
greater effect on total anthocyanin content than the variable of processing.
However, for concentrate stored at 4°C the interaction effect of storage
temperature and storage duration are minimal, giving the variable of processing

a greater effect on total anthocyanin content.

2.3.2.3 Storage Temperature Effect

The effects of storage temperature with the interaction of storage
duration*processing showed a high significant difference among the three
storage conditions (p<0.05). At each 6 week analysis, the concentrate stored at
the 4°C contained the highest total anthocyanin content. The concentrate
stored at the 21°C yielded the second highest, with the concentrate stored at
38°C yielding the lowest total anthocyanin values. The only exceptions seen
were during week 18 and 24 of analysis. At week 18, pasteurized batch 2
showed no significant difference among the 21 and 38°C storage conditions
(p=1.000). At week 24 of analysis pasteurized batch 1 and 2 also showed no
significant difference among storage conditions 21 and 38°C (p>0.05). The
cause for these non significant values was due to the very low total anthocyanin
content seen for both storage temperature 21 and 38°C after week 12 of
storage (Figures 2.4, 2.5, 2.6 and 2.7).

The trend seen in this anthocyanin analysis is similar to those seen in a
number of other analyses of other fruit products. In a study with reconstituted
pomegranate juice, a fruit that also contains high levels of anthocyanins, the

juice was stored at storage temperatures of 4, 20, and 38°C for 220 days. The

84

anthocyanin degradation was found to be very similar to the results found within
the cheny concentrate. The study found that the pomegranate juice stored at
4°C had the smallest anthocyanin degradation over time while the juice stored
at 38°C had the highest degradation on anthocyanins (Alighourchi and
Barzegar 2009). This trend was also seen in a study looking at the total
anthocyanin content of raspberry pulp. Over the storage of 55 days at the
storage temperatures of 4, 20, and 37°C there was a significant decrease in all
storage conditions, however the higher storage temperature greatly increased

the rate of total anthocyanin decay (Ochoa and others 1999).

 

Total Anthocyanins (mg cyn-3-
glulliter cherry juice concentrate)

 

 

 

0.00 .11 -—— ,1 . . a— -— . . H .

O 6 12 18 24 30 36 42 48
Storage Duration (Weeks)

Figure 2.4: Effects of storage time and temperature on the average total
anthocyanin values (mg cyn-3-glulliter tart cherry juice concentrate) for
unpasteurized cherry juice concentrate

85

500.00 ; ....................................................................................
Pasteurized 1

    

400.00 4

 

 

Total Anthocyanlns (mg cyn-3-
glulliter cherry juice concentrate)

 

 

O 6 12 18 24 30 36 42 48
Storage Duration (Weeks)

Figure 2.5: Effects of storage time and temperature on the average total
anthocyanin values (mg cyn-3-glulliter tart cherry juice concentrate) for
pasteurized (batch 1) cherryjuice concentrate

600.00 7 ..................................................................................

300.00

200.00

Total Anthocyanlns (mg syn-3-
glulllter cherry juice concentrate)

100.00 ‘

0.00 *

 

Storage Duration (Weeks)

Figure 2.6: Effects of storage time and temperature on the average total
anthocyanin values (mg cyn-3-glulliter tart cherry juice concentrate) for
pasteurized (batch 2) cherry juice concentrate

86

Total Anthocyanins (mg cyn-3-
glulliter cherry juice concentrate)

 

Storage Duration (Weeks)

Figure 2.7: Effects of storage time and temperature on the average total
anthocyanin values (mg cyn-3-glulliter tart cherryjuice concentrate) for
pasteurized (batch 3) cherry juice concentrate

2.3.2.4 Storage Duration Effect

The effects of storage over a 1 year duration with the interaction of
storage temperature*processing showed a significant decrease over the year of
storage for all simple effect levels. The concentrate at the storage condition
38°C had the largest decay rate of anthocyanins while the storage condition,
4°C had the smallest.

The concentrate stored at the 4°C showed a slow rate of decay
becoming significantly smaller at most 6-week intervals. Significant decay in
total anthocyanins were seen as early as week 6 of storage for the

unpasteurized and pasteurized concentrate (p<0.05) and as late as week 12 for

87

pasteurized batches 2, and 3 (p<0.05). Initial total anthocyanin values ranged
from 238.85 1 9.63 to 538.37 1 28.44 mg cyn-3—qu/liter tart cherry juice
concentrate. Sample held at the 4°C lost 27 to 45% of their overall total
anthocyanin content over the year of storage, resulting in final values ranging
from 254.71 1 10.65 to 321.95 1 24.24 mg cyn-3—glu/liter tart cherry juice
concentrate.

Concentrate stored at 21°C had a moderately steep total anthocyanin
decay. At weeks 6 and 12 a significant loss in total anthocyanins occurred for
each processing type (p<0.05). At week 6 the unpasteurized and pasteurized
batches had already lost 48 to 59% of its overall anthocyanin content, and by
week 12, the samples had lost 75 to 76% of their overall anthocyanin content.
After week 12 the decay of the anthocyanin began to decrease to a slow rate.
Significant loss was seen between weeks 12 and 36 (p<0.05), however
anthocyanin content was not significantly different between analysis at week 36
and 48 (p>0.05). By week 36 the concentrate had lost the majority of its
anthocyanins, losing over 89% of the concentrate’s initial value. The final total
anthocyanin content after a year of storage ranged from 34.96 1 9.73 to 47.42 1
26.12 mg cyn-3-glU/Iiter tart cherry juice concentrate.

Concentrate stored at the elevated temperature of 38°C lost the majority
of its anthocyanin value after only the first 6 weeks of storage. After week 6
until the end of storage no significant change occurred in total anthocyanin
content (p>0.05). In the storage study of raspberry pulp the majority of the total

anthocyanin lost occurred around day 40 (approximately 6 weeks) for the

88

sample stored at 37°C (Ochoa et al. 1999). From week 12 to week 24 the
anthocyanin content stayed significantly the same due to losing most of the
value within the first 6 weeks of storage. At week 6 the concentrates had
already lost from 87 to 94% of its original anthocyanin content. At week 24 the
values had decreased to a measurement of 11.80 1 7.14 to 31.84 1 23.86 mg

cyn-3-gIU/liter tart cherry juice concentrate.

2.3.3 Total Phenolics
2.3.3.1 Interaction Effects

Three-way factorial design results showed that all variables and the
interactions of these variables had a significant effect on the total phenolic
content of the tart cherry juice concentrate (p<0.05). The p-values of each
individual variable and the variable interactions are presented in Table 2.4.

Table 2.4: Summary of p-values of variables and interactions for total
phenoligggms GAE/liter tart cherry juice concentrate)

 

 

 

 

 

 

 

 

 

 

Variable and Interactions p-value
Pasteurization <0.0004
Storage Temperature <0.0001
Storage Duration <0.0001
Storage Duration*Storage Temperature <0.0001
Storage Duration*Pasteurization <0.0001
Storage Temperature*Pasteurization <0.0001
Storage Duration *Storage Temperature*Pasteurization <0.0001

 

 

89

2.3.3.2 Pasteurization Effect

The effects that each interaction had on the total phenolic content were
shown through the simple effects comparison of the interaction, storage
duration*storage temperature*processing least squares means spliced by that
particular interaction. The effects of processing with the interaction of storage
duration*storage temperature did not show a consistently clear trends
throughout the study. Statistical differences among processing types occurred
in samples at week 0, 6, 12, 18, 24 and 48 within all storage temperature
conditions. At the initial analysis at day 0 the unpasteurized concentrate had a
significantly higher total phenolic content over the three pasteurized batches
(p<0.05). This same occurrence appeared again at week 24/storage condition
4°C (p<0.05). However, at week 12/storage condition 38°C the unpasteurized
concentrate had a significantly lower total phenolic content compared to the
pasteurized batches, with pasteurized batch 1 having the significantly highest
values (p<0.05). Unpasteurized concentrate once again had a significantly
lower total phenolic content at week 18/storage condition 38°C and week
24/storage condition 38°C.

A storage durations of 6, 12, 18, 24, and 48 weeks significant difference
was seen among the three pasteurized batches (p<0.05), however no
pasteurized batches was shown to consistently have the significantly higher or

lower totally phenolic content among the rest of the batches.

90

Though a number of statistical differences were seen among processing
types throughout the storage study, no results occur consistently to draw a

conclusion from the data.

2.3.3.3 Storage Condition Effect

For the unpasteurized concentrate (see Table 2.5) there were no clear
trends or storage conditions, which consistently showed the highest or lowest
total phenolic content over the year of storage. For the pasteurized concentrate
(Table 2.6, 2.7 and 2.8) during the first 12 weeks of storage no clear trends
were present in the relationship among the three storage conditions. At week
18 and forward a trend became clear. In most cases the concentrate stored at
21°C had a significantly higher total phenolic content over 4°C (p<0.05). Also
the concentrate stored at 38°C had a significantly higher total phenolic content
over the 4 and 21°C (p<0.05).

Table 2.5: The average total phenolic (g GAE/liter liter tart cherry juice
concentrate) results for stora e conditions (unpasteurized)

 

 

 

 

 

 

 

 

 

 

 

Storage

Period 4°C 21°C 38°C

(Weeks)
6 11.451024 10.861015 11.081011
12 10.591018 10.401015 11.441019
18 12.03 :I: 0.11 13.00 :I: 0.23 12.45 1 0.13
24 10.97 1 0.18 10.94 1 0.05 13.63 :I: 0.71
36 11.101017 11.40:l:0.12 n/a
48 11.20 1 0.05 11.52 i 0.13 n/a

 

*Highest Total Phenolic content is bolded

91

 

Table 2.6: The average total phenolic (g GAE/liter liter tart cherry juice
concentrate) results for storage conditions (pasteurized batch 1)

 

 

 

 

 

 

 

 

 

 

 

Storage
Period 4°C 21 °C 38°C

(Weeks)
6 11.02 1 0.18 10.99 1 0.32 11.42 1 0.0
12 10.42 1 0.21 10.971 0.21 12.54 1 0.10
18 12.43 1 0.21 13.67 1 0.22 13.61 1 0.30
24 10.34 1 0.14 10.94 1 0.04 14.58 1 0.32
36 11.40 1 0.13 11.66 1 0.07 Na
48 11.151018 11.93101 n/a

 

*Highest Total Phenolic content is bolded

Table 2.7: The average total phenolic (g GAE/liter liter tart cherry juice
concentrateLresults for storage conditions (pasteurized batch 2)

 

 

 

 

 

 

 

 

 

 

 

Storage

Period 4°C 21 °C 38°C

(Weeks)
6 11.051015 109910.11 11.161024
12 10.22 1 0.09 10.20 1 0.22 12.82 1 0.45
18 12.43 1 0.23 12.88 1 0.05 13.32 1 0.18
24 108310.13 11.38 10.11 14.61 10.10
36 11.191011 11.591015 n/a
48 11.46 1 0.05 11.79 1 0.10 n/a

 

*Highest Total Phenolic content is bolded

Table 2.8: The average total phenolic (g GAE/liter liter tart cherry juice
concentrate) results for stora e conditions (pasteurized batch 3)

 

 

 

 

 

 

 

 

 

 

 

 

 

Storage
Period 4°C 21 °C 38°C

(Weeks)
6 11.25 1 0.20 10.58 1 0.20 10.95 1 0.33
12 10.45 1 0.07 10.36 1 0.15 12.22 1 0.31
18 12.26 1 0.30 13.43 1 0.31 13.73 1 0.22
24 10.46 1 0.11 11.45 1 0.31 14.07 1 0.26
36 11.35 1 0.30 11.61 1 0.19 n/a
48 10.93 1 0.24 11.74 1 0.12 Na

 

*Highest Total Phenolic content is bolded

92

 

2.3.3.4 Storage Duration Effect

Figure 2.8 presents the average total phenolic values (GAE gram/liter
tart cherry juice concentrate) for pasteurized batch 2 of cherry juice

concentrate. Figures for all other storage conditions are found in Appendix 1.

 

 

 

 

 

 

8
g - 10 00
a. 2 -
m g
< r:
9 8
O o
c o
g a 5.00 1 ---------------------------------------------------------------------------------------
5 o +C4 +C 21 +C 38
o .c
l- o
Pasteurized2
0.00 ”VF ' I Y “*"—_T*"'_‘___"fil———‘ _~_—_ 7 T I
0 6 12 18 24 30 36 42 48

Storage Duration (Weeks)

Figure 2.8: Effects of storage time and temperature on the average total
phenolic values (9 GAE/liter liter tart cherry juice concentrate) for
pasteurized (batch 2) cherry juice concentrate

For the analysis of total phenolics there was no constant significant
increase or decrease of values for the storage conditions of 4°C and 21°C. In
both these storage conditions the total phenolic value decreased up to week 12,
increased at week 18 and then decreased again until week 36 of storage. No

significant difference was seen between week 36 and week 48 (p>0.05). In all

93

processing conditions a spike of values can be seen at week 18 (Figure 2.13).
This spike could be the cause of instrumental or human error. However it is
also noted that the total phenolic values through the year of storage have a
small distribution of values ranging from approximately 10 to 14 GAE gram/liter
tart cherry juice concentrate. Due to this small range any slight peak is
considerably more noticeable.

At the elevated storage of 38°C the total phenolic content steadily
increased over the 24 weeks of storage. At week 24 the total phenolic value
was significantly the highest of all weeks of analysis. However, it is not likely
that the phenolic content of this product will increase with time. Because of this
it can be concluded that over the storage period there was the development of
interfering compounds. These compounds reacted within the total phenolic
method, and caused an overestimation of the measurement.

Through the analysis of these results it can be concluded that the total
phenolic content of cherry juice concentrate goes through a number of
significant fluctuations over storage duration. Though these fluctuations are
significant it is observed that all values are within a fairly small range. This
conclusion was also made in a study done on the fluctuations of total phenolic
content of dark fruit juices in refrigerated conditions. The study had a much
shorter storage period of 29 days; however, it was concluded that even with
significant increasing and decreasing fluctuations in the total phenolic content

values remain stable during storage (Piljac-Zegarac and others 2009). Due to

94

interference caused by developing compounds in concentrate stored at 38°C no

definite conclusion can be made for high temperature storage.

2.4 Conclusion

Based on the results of this research it can be concluded that
pasteurization will not greatly affect the health-benefiting properties of the tart
cherry juice concentrate. However, a significant difference was seen among
unpasteurized and pasteurized concentrate during the early stages of storage,
at low storage conditions for total anthocyanins. Storage temperature of
concentrate can have harmful effects on the total anthocyanin content;
however, storage temperature has minimal effect on total phenolic content and
total antioxidant capacity. Concentrate stored at 4°C yields higher and most
stable anthocyanin content over a year of storage; however, total antioxidant
decay is shown to be unavoidable for concentrate stored over 6 weeks at any
storage temperature 4°C and higher. Concentrate stored at 21 °C was shown to
lose the majority of its total anthocyanin content by week 12 while concentrate
stored at 38°C lost the majority of its total anthocyanin content by week 6.
Though fluctuations were seen in the total phenolic content over the year of

storage, the storage duration had only minimal affect on its content.

3. OVERALL CONCUSIONS AND FUTURE RECOMMENDATIONS

Through the analysis of physico-chemical, sensory quality and antioxidant

content it was determined that the pasteurization process has little to no effect

95

during storage duration at all storage conditions. Refrigerated storage
conditions had the best and most stable quality concentrate over the one year
storage period. However, concentrate stored over time at any storage condition,
experienced significant decline total antioxidants by week 6. If concentrate
were to be marketed as having high antioxidant properties the shelf life of this
product would be significantly shorter. Ambient storage temperature was
possible for short-tenn storage; however, continual storage at 21°C would
greatly affect sensory quality and anthocyanin content. Taking into account
both these properties concentrate should not be stored at ambient temperatures
longer than 12 weeks. Elevated storage temperatures had harmful and rapid
effects on the concentrate’s sensory quality and antioxidant properties, reducing

the shelf life to no more than 2 weeks.

Future recommendations for continued research of this topic include:

1. A repeated study on the analysis of different crop seasons to show
repeatability of attribute results.

2. A more in-depth, detailed sensory analysis of the first two weeks of
storage for the elevated (38°C) storage condition.

3. Further ORAC analysis determining the changes in total antioxidant
capacity during the first six weeks of storage.

4. Investigation into packaging alternatives to better protect the

antioxidant properties of the product.

96

APPENDICES

APPENDIX 1 RAW PHYSCIO—CHEMICAL DATA

Table A.1.1 Raw data for total soluble solidg°Brix)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unpasteurized Pasteurized
4°C 21 °C 38°C 4°C 21 °C 38°C
0 69.1 69.1 69.1 68.8 68.8 68.8
2 68.7 68.7 68.8 69.2 69.1 69.0
4 68.9 68.5 68.1 69.0 69.0 68.9
6 68.7 68.8 68.2 69.2 69.2 68.5
8 68.9 68.7 67.9 69.1 69.1 68.2
12 68.6 68.5 67.7 68.9 69.1 68.3
16 68.5 68.0 66.8 68.8 68.7 67.3
20 68.4 68.2 66.8 68.7 68.7 66.7
24 68.0 67.7 67.4 68.3 68.1 66.9
36 68.6 68.2 n/a 68.7 68.9 n/a
48 68.6 68.3 n/a 69.0 68.6 n/a
Table A.1.2 Raw data for pH
Unpasteurized Pasteurized
4°C 21°C 38°C 4°C 21 °C 38°C
0 3.29 3.29 3.29 3.31 3.31 3.31
2 3.36 3.37 3.33 3.32 3.36 3.41
4 3.36 3.33 3.38 3.35 3.34 3.34
6 3.31 3.35 3.42 3.30 3.35 3.36
8 3.30 3.37 3.39 3.34 3.39 3.41
12 3.31 3.32 3.39 ‘ 3.29 3.33 3.38
16 3.32 3.41 3.39 3.32 3.38 3.40
20 3.44 3.44 3.46 3.39 3.43 3.45
24 3.34 3.38 3.35 3.33 3.38 3.35
36 3.36 3.38 n/a 3.33 3.38 n/a
48 3.33 3.33 n/a 3.28 3.30 n/a

 

 

 

 

 

 

 

 

97

 

 

Table A.1.3 Raw data for titratable acidi

(% malic acid)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unpasteurized Pasteurized
4°C 21°C 38°C 4°C 21°C 38°C
0 5.01 5.01 5.01 5.03 5.03 5.03
2 4.97 4.96 4.85 5.01 4.99 4.91
4 5.03 4.92 4.82 5.07 4.96 4.81
6 5.03 4.93 4.77 5.07 4.95 4.82
8 4.99 4.80 4.78 5.00 4.88 4.83
12 4.99 4.82 4.79 5.03 4.86 4.85
16 4.95 4.70 4.79 4.99 4.81 4.87
20 5.19 4.99 4.88 5.27 5.05 4.90
24 4.94 4.97 4.70 4.79 4.94 4.98
36 4.91 4.63 n/a 4.90 4.73 n/a
48 4.91 4.71 n/a 4.94 4.72 n/a
Table A.1.4 Raw data for turbidity (% transmittance)
Unpasteurized Pasteurized
4°C 21°C 38°C 4°C 21°C 38°C
0 76.9 76.9 76.9 76.3 76.3 76.3
2 79.4 76.7 67.5 78.0 75.4 67.9
4 79.6 75.1 57.1 77.9 73.8 56.5
6 79.0 73.2 52.4 78.1 72.3 50.6
8 79.2 70.8 49.4 77.6 68.2 44.9
12 76.2 65.3 43.7 74.7 64.8 43.4
16 72.3 59.5 40.8 72.1 60.9 39.1
20 76.7 59.1 45.9 75.1 59.3 42.4
24 74.8 57.1 38.9 74.2 57.8 41.3
36 75.8 55.9 n/a 75.4 55.3 n/a
48 74.0 50.9 n/a 73.8 50.5 n/a

 

 

 

 

 

 

 

 

98

 

 

Table A.1.5 Raw data for Hunter Color L value

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unpasteurized Pasteurized
4°C 21°C 38°C 4°C 21°C 38°C
0 2.73 2.73 2.73 2.68 2.68 2.68
2 2.96 2.37 2.28 2.60 2.76 2.63
4 2.54 2.55 2.54 2.39 2.48 2.73
6 3.38 2.70 2.55 3.02 2.85 2.82
8 2.93 2.75 2.89 3.06 2.93 2.64
12 2.91 2.49 2.85 2.45 2.92 3.33
16 2.46 2.49 2.86 2.88 2.62 2.82
20 3.03 2.65 2.61 2.78 3.06 2.70
24 2.60 2.45 3.19 2.28 2.52 2.89
36 2.44 2.40 n/a 2.31 2.48 n/a
48 2.08 2.43 n/a 2.26 2.32 n/a
Table A.1.6 Raw data for Hunter Color a value
Unpasteurized Pasteurized
4°C 21°C 38°C 4°C 21°C 38°C
0 4.46 1 4.46 4.46 3.95 3.95 3.95
2 4.07 3.95 0.80 3.89 2.67 0.69
4 3.55 2.57 0.15 3.85 2.06 0.10
6 3.33 1.76 0.09 2.94 1.19 0.09
8 3.82 1.18 0.02 2.73 0.97 0.13
12 3.41 0.64 -0.02 3.50 0.61 —0.02
16 3.68 0.43 -0.03 2.46 0.36 0.04
20 3.01 0.41 0.04 2.89 0.31 0.01
24 1.70 0.32 0.28 2.45 0.44 0.19
36 2.18 0.22 n/a 2.18 0.13 n/a
48 1.51 0.15 n/a 1.89 0.13 n/a

 

 

 

 

 

 

 

 

99

 

 

Table A.1.7 Raw data for Hunter Color b value

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unpasteurized Pasteurized
4°C 21°C 38°C 4°C 21 °C 38°C
0 0.81 0.81 0.81 0.63 0.63 0.63
2 0.62 0.85 0.47 0.92 0.50 0.48
4 0.73 0.59 0.41 0.85 0.44 0.39
6 0.55 0.45 0.34 0.38 0.40 0.19
8 0.72 0.37 0.35 0.53 0.20 0.42
12 0.76 0.38 0.45 0.84 0.32 0.41
16 0.92 0.16 0.61 0.43 0.26 0.62
20 0.33 0.26 0.81 0.42 0.30 0.62
24 0.42 0.57 1.01 0.61 0.54 1.02
36 0.50 0.68 n/a 0.64 0.68 n/a
48 0.45 0.74 n/a 0.60 0.79 n/a

 

100

 

APPENDIX 2 RAW ANTIOXIDANT DATA

ORAC (micromole TElg tart
cherry juice concentrate)

 

 

 

 

 

0 6 12 18 24 30 36 42 48
Storage Duration (Weeks)

Figure A.2.1: Effects of storage time and temperature on the average
ORAC values (micromole TEIg tart cherry juice concentrate) for
unpasteurized cherry juice concentrate

101

ORAC (micromole TEIg tart
cherry juice concentrate)

 

 

 

0 6 1 2 1 8 24 30 36 42 48
Storage Duration (Weeks)

Figure A.2.2: Effects of storage time and temperature on the average
ORAC values (micromole TEIg tart cherry juice concentrate) for
pasteurized (batch 1) cherry juice concentrate

102

+4C +21C +38C

Pasteurized 2

 

 

ORAC (micromole TEIg tart
cherry juice concentrate)

 

 

 

Storage Duration (Weeks)

Figure A.2.3: Effects of storage time and temperature on the average
ORAC values (micromole TEIg tart cherry juice concentrate) for
pasteurized (batch 2) cherry juice concentrate

103

 

ORAC (micromole TEIg tart
cherry juice concentrate)

 

 

 

O 6 12 1 8 24 30 36 42 48
Storage Duration (Weeks)

Figure A.2.4: Effects of storage time and temperature on the average
ORAC values (micromole TEIg tart cherry juice concentrate) of
pasteurized (batch 3) cherry juice concentrate

104

 

 

 

 

 

8
=
g 1
a, 3
In 8
< c
9. 8
0 o
c o
is E
l- '5
Unpasteurized
0.00 “f * ' Y 3 r t I I j
0 6 12 18 24 30 36 42 48

Storage Duration (Weeks)

Figure A.2.5: Effects of storage time and temperature on the average total
phenolic values (9 GAE/liter liter tart cherry juice concentrate) for
unpasteurized cherry juice concentrate

105

 

 

 

 

Total Phenolics (GAE gram/liter

cherry juice concentrate)

Pasteurized 1

 

 

T-— T j T T l l

l

l

,

0 6 1 2 18 24 30 36 42 48
Storage Duration (Weeks)

Figure A.2.6: Effects of storage time and temperature on the average total
anthocyanin values (9 GAE/liter liter tart cherry juice concentrate) for
pasteurized (batch 1) cherry juice concentrate

106

 

 

 

8
=
g 1
a 3,, .
ID a j
< r:
9 8 l

C
3 s 1

9 I
E .2 ., ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
g .2 5.00 l
O. z, j '
73 :5 I +4C +21C +38C
o 1 l
r- o ,

Pasteurized 3
0,00 +‘-————.~——— ~-1——--—-—.———--—.—————1— 1 a H
0 6 12 18 24 30 36 42 48
Storage Duration (Weeks)

Figure A.2.7: Effects of storage time and temperature on the average total
anthocyanin values (9 GAE/liter liter tart cherry juice concentrate) for
pasteurized (batch 3) cherry juice concentrate

107

Table A.2.1 Raw data for Oxygen Radical Absorbance Capacity (ORACFL)
for tart cherry juice concentrate

 

Total
Antioxidants
(micromole
TEIg tart
cherry juice
concentrate)

Storage Storage
Period Temperature Processing
(WeekS) (°C)

Standard

Average Deviation

 

569
. 571
0 n/a Unpasteurized 717 655 100

764

 

613
Pasteurized 615

(1 ) 651
836

679 106

 

583
Pasteurized 653
643
857

 

582
Pasteurized 662
558
837

 

224
. 224
6 4 Unpasteurized 293 268 53

332

 

226
Pasteurized 290
31 5
403

 

212
Pasteurized 260
227
253

 

261
Pasteurized 272
310
319

290 29

 

273
312

284 303 32

6 21 Unpasteurized

 

292
Pasteurized 351
281
255

 

 

 

 

 

 

 

 

108

Table A.2.1

l Continued

 

Storage
Period
(Weeks)

Storage
Temperature
(°C)

Processing

Total
Antioxidants
(micromole
TEIg tart
cherry juice
concentrate

Average

Standard
Deviation

 

21

Pasteurized

198
226
262
327

253

56

 

21

Pasteurized

191
230
227
246

224

23

 

38

Unpasteurized

185
223
214
228

212

19

 

38

Pasteurized

193
207
290
318

252

61

 

38

Pasteurized

(2)

202
238
227
295

240

39

 

38

Pasteurized

(3)

201
235
201
235

218

20

 

12

Unpasteurized

207
266
322
352

287

64

 

Pasteurized

225
285
381
460

338

104

 

12

Pasteurized

1 98
243
242
624

327

199

 

12

 

 

 

Pasteurized

 

224
243
308
419

 

 

88

 

109

 

Table A.2.1 Continued

 

Storage
Period

(Weeks)

Storage
Temperature
(°C)

Processing

Total
Antioxidants
(micromole
TElg tart
cherry juice
concentrate

Average

Standard
Deviation

 

12

21

Unpasteurized

216
276
343
385

305

74

 

12

21

Pasteurized

(1)

21 1
261
335
449

314

104

 

12

21

Pasteurized

(2)

163
254
230
534

295

164

 

12

21

Pasteurized

(3)

228
246
290
441

301

97

 

12

38

Unpasteurized

181
210
259
370

255

83

 

12

38

Pasteurized

(1)

191
208
230
365

248

79

 

12

38

Pasteurized

(2)

1 51
168
99
449

217

158

 

12

38

Pasteurized

(3)

1 94
204
1 86
348

233

77

 

18

Unpasteurized

183
236
128
342

222

91

 

18

 

 

 

Pasteurized

(1)

 

184
201
213
222

 

205

 

16

 

110

 

Table A.2.1 Continued

 

Storage
Period

(Weeks)

Storage
Temperature
(°C)

Processing

Total
Antioxidants
(micromole
TEIg tart
cherry juice
concentrate

Average

Standard
Deviation

 

18

Pasteurized

(2)

155
210
227
173

191

33

 

18

Pasteurized

(3)

192
177
186
132

172

27

 

18

21

Unpasteurized

155
164
173
144

159

12

 

18

21

Pasteurized

(1)

151
154
138
102

136

24

 

18

21

Pasteurized

(2)

221
256
263
263

251

20

 

18

21

Pasteurized

(3)

206
271
247
354

270

62

 

18

38

Unpasteurized

191
213
202
210

204

10

 

18

38

Pasteurized

(1)

192
175
236
276

220

46

 

18

38

Pasteurized

(2)

172
210
213
273

217

42

 

18

 

 

38

 

Pasteurized

(3)

 

182
196
183
193

 

188

 

 

111

 

Table A.2.1 Continued

 

Storage
Period

(Weeks)

Storage
Temperature
(°C)

Processing

Total
Antioxidants
(micromole
TE/g tart
cherry juice
concentrate

Average

Standard
Deviation

 

24

Unpasteurized

211
261
279
316

267

43

 

24

Pasteurized

338
400
441
567

436

97

 

24

Pasteurized
(2)

269
349
320
393

333

52

 

24

Pasteurized

21 7
262
347
496

331

123

 

24

21

Unpasteurized

193
255
308
365

280

74

 

24

21

Pasteurized

(1)

369
384
400
533

421

76

 

24

21

Pasteurized

284
323
338
325

317

23

 

24

21

Pasteurized

197
239
401
499

334

141

 

24

38

Unpasteurized

167
206
245
322

235

66

 

24

 

 

38

 

Pasteurized
(1 )

 

31 2
383
392
542

 

407

 

97

 

112

 

Table A.2.1 Continued

 

Storage
Period
(Weeks)

Storage
Temperature
(°C)

Processing

Total
Antioxidants
(micromole
TEIg tart
cherry juice
concentrate

Average

Standard
Deviation

 

24

38

Pasteurized
(2)

230
249
418
640

385

191

 

24

38

Pasteurized

1 94
1 93
342
588

329

186

 

36

Unpasteurized

135
171
235
262

201

58

 

36

Pasteurized

162
176
210
240

35

 

36

Pasteurized

136
170
164
233

176

41

 

36

Pasteurized
(3)

176
216
261
201

333

52

 

36

21

Unpasteurized

151
178
232
248

213

36

 

36

21

Pasteurized

167
199
219
182

202

45

 

36

21

Pasteurized

188
198
225
231

192

22

 

36

 

 

21

 

Pasteurized
(3)

 

167
202
209
192

 

211

 

21

 

113

 

Table A.2.1 Continued

 

Storage
Period
(Weeks)

Storage
Temperature
(°C)

Processing

Total
Antioxidants
(micromole
TEIg tart
cherry juice
concentrate

Average

Standard
Deviation

 

48

Unpasteurized

173
213
236
281

 

48

Pasteurized

218
223
253
260

226

45

 

48

Pasteurized

191
176
132
259

238

21

 

48

Pasteurized

200
258
267
214

189

53

 

48

21

Unpasteurized

179
225
231
218

235

33

 

48

21

Pasteurized

189
219
239
273

213

23

 

48

21

Pasteurized

(2)

179
203
176
189

230

36

 

48

 

 

21

 

Pasteurized

(3)

 

175
198
240
232

 

187

 

 

114

 

Table A.2.2 Raw data for total anthocyanins for tart cherry juice
concentrate

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Total
Storage Storage Angiogyzngs Standard
Period Temperature Processing 9. y Average . .
(Weeks) (0 C) glulllter tart Devnatlon
cherry juice
concentrate)
569.77
0 n/a Unpasteurized 531.02 538.37 28.44
514.33
. 463.56
0 n/a Fatwa“ 448.87 455.77 7.39
454.88
. 476.92
0 n/a Pas‘g‘zed 468.90 463.12 17.44
443.52
Pasteurized 428'16
0 n/a (3) 441.52 438.85 9.63
446.86
422.82
6 4 Unpasteurized 464.23 456.66 30.76
482.93
Pasteurized 394'09
6 4 (1) 393.43 398.77 8.68
408.79
Pasteurized 405'45
6 4 (2) 409.46 419.03 20.15
442.1 9
. 391 .42
6 4 Pas‘?;)r'zed 414.13 422.15 35.42
460.89
197.05
6 21 Unpasteurized 204.39 212.41 20.58
235.79
6 21 PaSteU’ized 158.2,? 186 80 29 43
(1 ) . . .
185.02
. 1 76.34
6 21 Pas‘g'md 199.05 192.15 13.73
201 .05
Pasteurized 21 1 '74
6 21 (3) 227.10 226.66 14.70
241 .1 3
42.08
6 38 Unpasteurized 40.75 48.76 12.74
63.46
6 38 Pasteurized 29'39
33.40 36.96 9.85
48.09

 

 

 

 

 

 

 

 

115

Table A.2.2 Continued

 

Storage
Period

(Weeks)

Storage
Temperature
(°C)

Processing

Total
Anthocyanins
(mg cyn-3-
glulliter tart
cherry juice
concentrate)

Average

Standard
Deviation

 

38

Pasteun’zed

(2)

14.70
39.41
32.73

28.94

12.78

 

38

Pasteurized

36.07
58.78
80.82

58.56

22.38

 

Unpasteurized

428.16
406.78
400.11

411.68

14.65

 

Pasteurized

361.36
384.07
398.10

381.18

18.54

 

Pasteurized

377.39
379.40
402.78

386.52

14.11

 

Pasteurized

(3)

401.44
386.75
371.38

386.52

15.03

 

21

Unpasteurized

138.93
120.23
122.24

127.13

10.27

 

21

Pasteurized

112.22
104.87
109.54

108.88

3.72

 

21

Pasteurized

114.89
122.24
104.20

113.78

9.07

 

21

Pasteurized
(3)

99.53
104.87
116.22

106.87

8.53

 

38

Unpasteurized

30.73
22.04
7.35

20.04

11.82

 

38

Pasteurized

(1)

40.75
24.05
30.06

31.62

8.46

 

38

Pasteurized

(2)

32.06
39.41
37.41

36.29

3.80

 

 

 

38

 

Pasteurized
(3)

 

70.80
49.43
32.06

 

50.76

 

19.41

 

116

 

Table A.2.2 Continued

 

Storage
Period

(Weeks)

Storage
Temperature
(°C)

Processing

Total
Anthocyanins
(mg cyn-3-
glulliter tart
cherry juice
concentrate)

Average

Standard
Deviation

 

18

Unpasteurized

405.45
458.22
433.50

432.39

26.40

 

18

Pasteurized

350.01
366.04
375.39

363.81

12.84

 

18

Pasteurized

(2)

344.66
366.71
360.03

357.13

11.30

 

18

Pasteurized

356.02
363.37
370.05

363.15

7.02

 

18

21

Unpasteurized

93.51
71.47
94.18

86.39

12.92

 

18

21

Pasteurized

105.54
82.83
84.18

94.18

11.36

 

18

21

Pasteurized

86.17
78.15
88.17

84.16

5.30

 

18

21

Pasteurized
(3)

78.82
80.82
97.52

85.72

10.27

 

18

38

Unpasteurized

96.19
24.71
30.06

50.32

39.81

 

18

38

Pasteurized

78.15
28.05
22.71

42.97

30.58

 

18

38

Pasteurized
(2)

100.19
66.80
60.12

75.70

21.47

 

18

38

Pasteurized

25.38
53.44
63.46

47.42

19.74

 

24

Unpasteurized

344.00
335.98
342.66

340.88

4.29

 

24

 

 

 

Pasteurized

(1)

 

324.63
317.95
307.26

 

316.61

 

8.76

 

117

 

Table A.2.2 Continued

 

Storage
Period
(Weeks)

Storage
Temperature
(°C)

Processing

Total
Anthocyanins
(mg cyn-3-
glulliter tart
cherry juice
concentrate)

Average

Standard
Deviation

 

24

Pasteurized

350.68
331.31
346.67

342.88

10.23

 

24

Pasteurized

(3)

343.33
338.65
331.97

337.99

5.71

 

24

21

Unpasteurized

74.14
72.14
63.46

69.91

5.68

 

24

21

Pasteurized

50.76
71.14
52.10

59.00

13.13

 

24

21

Pasteurized

76.15
96.19
90.17

87.50

10.28

 

24

21

Pasteurized

51.43
42.75
82.83

59.00

21.08

 

24

38

Unpasteurized

41.41
49.43
4.68

31.84

23.86

 

24

38

Pasteurized

30.39
29.39
15.36

25.05

8.40

 

24

38

Pasteurized

8.02
20.04
7.35

11.80

7.14

 

24

38

Pasteurized

0.67
46.09
40.08

28.94

24.67

 

36

Unpasteurized

360.70
325.96
360.70

349.12

20.05

 

36

Pasteurized

323.96
304.59
310.60

313.05

9.91

 

36

Pasteurized

310.60
310.60
348.67

323.29

21.98

 

36

 

 

 

Pasteurized

 

335.31
321.29
331.31

 

329.30

 

7.23

 

118

 

Table A.2.2 Continued

 

Storage
Period
(Weeks)

Storage
Temperature
(°C)

Processing

Total
Anthocyanins
(mg cyn-3-
glulliter tart
cherry juice
concentrate)

Average

Standard
Deviation

 

21

Unpasteurized

65.46
38.74
40.08

48.09

15.05

 

21

Pasteurized

(1)

42.08
50.10
45.42

45.87

4.03

 

36

21

Pasteurized
(2)

40.75
9.35
32.06

27.39

16.21

 

36

21

Pasteurized

58.11
54.10
27.39

46.53

16.70

 

48

Unpasteurized

267.18
301.92
325.96

298.35

29.55

 

48

Pasteurized

259.83
261 .84
242.47

254.71

10.65

 

48

Pasteurized
(2)

287.22
279.21
293.23

286.55

7.04

 

48

Pasteurized

349.34
303.25
313.27

321.95

24.24

 

48

21

Unpasteurized

42.75
38.07
24.05

34.96

9.73

 

48

21

Pasteurized

38.07
14.03
83.49

45.20

35.28

 

48

21

Pasteurized

22.71
44.75
74.81

47.42

26.15

 

48

 

 

21

 

Pasteurized

 

36.07
55.44
30.73

 

40.75

 

13.00

 

119

 

Table A.2.3 Raw data for total phenolics for tart cherry juice concentrate

 

Storage
Period
(Weeks)

Storage
Temperature
_ (°C)

Processing

Total

Phenolics
(GAE glliter
tart cherry

juice

concentrate)

Average

Standard
Deviation

 

n/a

Unpasteurized

11.22
11.36
12.30

11.96

0.52

 

n/a

Pasteurized

(1)

11.19
11.36
11.15

11.23

0.11

 

n/a

Pasteurized

(2)

11.15
11.36
11.28

11.26

0.11

 

n/a

Pasteurized

(3)

11.06
11.45
11.28

11.26

0.19

 

Unpasteurized

11.22
11.70
11.44

11.45

0.24

 

Pasteurized

(1)

10.87
11.22
10.96

11.02

0.18

 

Pasteurized

(2)

10.96
10.96
11.22

11.04

0.15

 

Pasteurized

(3)

11.04
11.44
11.26

11.25

0.20

 

21

Unpasteurized

10.69
10.95
10.95

10.87

0.15

 

21

Pasteurized

(1)

10.69
10.95
11.33

10.99

0.32

 

21

Pasteurized

(2)

10.91
10.95
11.12

10.99

0.11

 

21

Pasteurized

(3)

10.35
10.74
10.65

10.58

0.20

 

38

Unpasteurized

10.95
11.12
11.16

11.08

0.11

 

 

 

38

 

Pasteurized

(1)

 

11.42
11.42
11.42

 

11.42

 

0.00

 

120

 

Table A.2.3 Continued

 

Storage
Period

(Weeks)

Storage
Temperature
(°C)

Processing

Total
Phenolics
(GAE glliter
tart cherry
juice
concentrate)

Average

Standard
Deviation

 

38

Pasteurized

(2)

10.95
11.12
11.42

11.16

0.24

 

38

Pasteurized

(3)

11.33
10.74
10.78

10.95

0.33

 

12

Unpasteurized

10.73
10.64
10.39

10.59

0.18

 

12

Pasteurized

(1)

10.52
10.17
10.56

10.42

0.21

 

12

Pasteurized

(2)

10.13
10.22
10.30

10.22

0.09

 

12

Pasteurized

(3)

10.39
10.52
10.43

10.44

0.07

 

12

21

Unpasteurized

10.26
10.56
10.39

10.40

0.15

 

12

21

Pasteurized

(1)

10.77
10.94
11.20

10.97

0.21

 

12

21

Pasteurized

(2)

9.96
10.26
10.39

10.20

0.22

 

12

21

Pasteurized

(3)

10.34
10.22
10.52

10.36

0.15

 

12

38

Unpasteurized

11.24
11.63
11.46

11.44

0.19

 

12

38

Pasteurized

(1)

12.48
12.48
12.65

12.54

0.10

 

12

38

Pasteurized

(2)

12.31
13.16
12.99

12.82

0.45

 

12

 

 

38

 

Pasteurized

 

(3)

11.88
12.31
12.48

 

12.22

 

0.31

 

121

 

Table A.2.3 Continued

 

Storage
Period

(Weeks)

Storage
Temperature
(°C)

Processing

Total

Phenolics
(GAE glliter
tart cherry

juice

concentrate)

Average

Standard
Deviation

 

18

Unpasteurized

12.09
12.09
11.91

12.03

0.11

 

18

Pasteurized

(1)

12.55
12.55
12.18

12.43

0.21

 

18

Pasteurized

(2)

12.46
12.18
12.64

12.43

0.23

 

18

Pasteurized

(3)

11.96
12.28
12.55

12.26

0.30

 

18

21

Unpasteurized

12.74
13.09
13.17

13.00

0.23

 

18

21

Pasteurized

(1)

13.43
13.70
13.87

13.67

0.22

 

18

21

Pasteurized

(2)

12.82
12.91
12.91

12.88

0.05

 

18

21

Pasteurized

(3)

13.78
13.35
13.17

13.43

0.31

 

18

38

Unpasteurized

12.48
12.30
12.56

12.45

0.13

 

18

38

Pasteurized

(1)

13.96
13.43
13.43

13.61

0.30

 

18

38

Pasteurized

(2)

13.26
13.52
13.17

13.32

0.18

 

18

38

Pasteurized

(3)

13.96
13.70
13.52

13.73

0.22

 

24

Unpasteurized

10.79
11.14
10.97

10.97

0.18

 

24

 

 

 

Pasteurized

(1)

 

11.06
10.97
10.79

 

10.94

 

0.14

 

122

 

Table A.2.i

1 Continued

 

Storage
Period

(Weeks)

Storage
Temperature
(°C)

Processing

Total
Phenolics
(GAE glliter
tart cherry
juice
concentrate)

Average

Standard
Deviation

 

24

Pasteurized

(2)

10.83
10.97
10.70

10.83

0.13

 

24

Pasteurized

(3)

10.48
10.57
10.34

10.46

0.11

 

24

21

Unpasteurized

10.88
10.97
10.97

10.94

0.05

 

24

21

Pasteurized

(1)

10.30
10.39
10.34

10.34

0.04

 

24

21

Pasteurized

11.28
11.50
11.37

11.38

0.11

 

24

21

Pasteurized
(3)

11.81
11.23
11.32

11.46

0.31

 

24

38

Unpasteurized

13.69
12.88
14.31

13.63

0.71

 

24

38

Pasteurized

(1)

14.22
14.84
14.67

14.58

0.32

 

24

38

Pasteurized

14.67
14.67
14.49

14.61

0.10

 

24

38

Pasteurized
(3)

14.22
14.22
.13.77

14.07

0.26

 

36

Unpasteurized

10.92
11.13
11.26

11.10

0.17

 

36

Pasteurized

(1)

11.26
11.52
11.43

11.40

0.13

 

36

Pasteurized

11.09
11.17
11.30

11.19

0.11

 

36

 

 

 

Pasteurized
(3)

 

11.05
11.35
11.64

 

11.35

 

0.30

 

123

 

Table A.2.3 Continued

 

Total
Phenolics
16:33:36 Processing (GAE glliter
(°C) tart cherry
juice
concentrate)

Storage
Period

(Weeks)

Standard

Average Deviation

 

36

21

Unpasteurized

11.26
11.47
11.47

11.40

0.12

 

36

21

Pasteurized (1)

11.60
11.64
11.73

11.66

0.07

 

36

21

Pasteurized (2)

11.43
11.73
11.60

11.59

0.15

 

36

21

Pasteurized (3)

11.43
11.81
11.60

11.62

0.19

 

48

Unpasteurized

11.17
11.26
11.17

11.20

0.05

 

48

Pasteurized (1)

11.00
11.35
11.09

11.15

0.18

 

48

Pasteurized (2)

11.43
11.43
11.52

11.46

0.05

 

48

Pasteurized (3)

10.92
11.17
10.70

10.93

0.24

 

48

21

Unpasteurized

11.39
11.52
11.64

11.52

0.13

 

48

21

Pasteurized (1)

11.81
11.99
11.99

11.93

0.10

 

48

21

Pasteurized (2)

11.73
11.73
11.90

11.79

0.10

 

48

 

 

21

 

Pasteurized (3)

 

11.60
11.81
11.81

 

11.74

 

0.12

 

124

 

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