Table Of ContentSHELL COLOR AND OTHER QUALITY ATTRIBUTES OF BROWN EGGS AS
AFFECTED BY THE HENS' AGE AND VANADIUM IN THEIR DIET
By
ASLI ZEYNEP ODABA§I
A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
2003
Dedicated to you, dear reader...
ACKNOWLEDGMENTS
I would like to thank my advisor Dr. Murat Balaban for his
guidance throughout my graduate studies. He has made it possible
for me to obtain a Ph.D. at the University of Florida. My
appreciation is also extended to Dr. Richard Miles who was
considerate enough to stand up for my research when the Poultry
Science Unit at the university was closed right in the middle of
my studies due to the abolishment of the poultry program by the
university administration. My special thanks to Dr. Kenneth
Portier for sharing his expertise and providing insight during
the analysis of my data. Dr. Charles Sims' contributions to my
graduate studies are also very much appreciated.
I want to express my gratitude for Dr. C.W. Comer and Verne
Sampath, for their much-needed help in the hen house.
Finally, my best, sincere regards to Dr. Serdar Kirli, my
dear husband for the one-of-a-kind support he has given, through
all stages of my doctoral work.
iii
TABLE OF CONTENTS
page
ACKNOWLEDGMENTS iii
LIST OF TABLES
LIST OF FIGURES ix
ABSTRACT xii
CHAPTER
1 INTRODUCTION 1
Shell Eggs in the United States and the World 1
Brown Eggs and the Importance of Eggshell Color 1
Vanadium: Its Occurrence in Feed and Its Effects on Egg
Quality 3
Machine Vision as an Alternative Tool in Color Analysis 3
Objectives 5
2 LITERATURE REVIEW 6
Food Color, Its Importance and Measurement 6
Representation of Color 7
Measurement of Color 12
Structure, Composition and Formation of the Egg 18
Structure 18
Composition 20
Egg Formation 22
Albumen Thinning 25
Foaming Properties of Egg White 27
Shell Pigmentation 29
The Effect of Hens' Age on Egg Quality 31
Vanadiiom and Its Route into the Hens' Feed 32
3 CHANGES IN THE BROWN SHELL COLOR AS THE HEN AGES 46
Materials and Methods 47
Chickens and Egg Collection 47
Color Analysis 48
Measurement of color 48
Calibration and extraction of color data 50
Statistical Analyses 51
IV
Analysis of color block data 51
Analysis of the L*, a*, b* data 52
Results and Discussion 53
Conclusion
4 QUALITY OF BROWN EGGS AS AFFECTED BY VANADIUM IN THE HENS'
DIET "^9
Materials and Methods 82
Experiment 1 and Experiment 2 82
Experiment 3 85
Statistical Analyses 86
Results and Discussion 87
Eggshell Color 87
Experiment 1: Higher levels of vanadium 87
Experiment 2a: Lower levels of vanadium 95
Experiment 2b: Lower levels of vanadium supplemented
with vitamins 98
Experiment 3, Supplementation of the 15 ppm vanadium
diets with vitamins for prevention 103
Albumen Quality and Foaming Properties 106
Experiment 1 106
Experiments 2a and 2b 110
Experiment 3 118
Conclusion 118
5 GENERAL CONCLUSIONS 120
APPENDIX LOCATION OF THE IMAGES USED FOR COLOR ANALYSIS 125
LIST OF REFERENCES 128
BIOGRAPHICAL SKETCH 134
V
LIST OF TABLES
T2a-ble
23--1. Relation between perceptual attributes and CIE L* a* b*
coordinates* 12
2-2. Relation between hue angle and chromacity coordinates of the
CIE L*a*b* system 12
3. Composition of the hen's egg 20
1. Covariance parameter estimates obtained with AR (1)
covariance structure 55
3-2. Solution for fixed Effects (L*) 56
3-3. Covariance parameter estimates obtained with AR (1)
covariance structure (a*) 58
3-4. Solution for fixed effects (a*) 59
3-5. Covariance parameter estimates obtained with AR (1)
covariance structure (b*) 60
3-6. Solution for fixed effects (b*) 61
3-7. Covariance parameter estimates obtained with AR (1)
covariance structure (egg weight) 63
3-8. Solution for fixed effects (egg weight) 63
3-9. Covariance parameter estimates obtained with AR (1)
covariance structure (shell weight) 65
3-10. Solution for fixed effects (shell weight) 65
3-11. Pearson correlation coefficients of L* a* b* values across
months 68
3-12. Canonical correlation coefficients, r, for color data from
a given month and the last month's color data 69
3-13. Multiple linear regression equations estimating the last
months L*a*b* values based on those in the indicated month71
VI
3-
4-14. Sample sizes required to estimate the L*a*b* of eggshells75
1. Corn/soybean meal based diet used to feed commercial egg-
type laying hens 84
4-2. P values of the tests for fixed effects on L*, a*, b*.... 87
4-3. Linear and quadratic effects of time (day) and their
interaction with the other fixed effects (P value of tests
for the effects are shown) 88
4-4. Covariance parameter estimates and their standard errors
obtained with AR (1) covariance structure 89
4-5. Change in L*value of the eggshells during Experiment 1.. 91
4-6. Change in a* value of the eggshells during Experiment 1. 92
4-7. Change in b* value of the eggshells during Experiment 1. 94
4-8. Change in L* values of the eggshells during Experiment 2a.96
4-9. Change in a* value of the eggshells during Experiment 2a..97
4-10. Change in b* value of the eggshells during Experiment 2a.99
4-11. Results of the tests for fixed effects on L*, a*, b*.
Experiment 2b (P-values are shown) 100
4-12. Comparison of the least square means of vanadium groups
pooled over vitamins and days. Experiment 2b 100
4-13. Comparison of the least squared means of vitamins pooled
over vanadium groups and days. Experiment 2b 101
4-14. Comparison of the least squared means (L*) of vanadium by
vitamins interaction pooled over days. Experiment 2b 101
4-15. Comparison of the least squares means (a*) of vanadium by
vitamins interaction pooled over days. Experiment 2b 103
4-16. Effects of vanadium diets supplemented with various
vitamins on the eggshell color. Experiment 3 106
4-17. Change in the HU of the eggs during Experiment 1 107
4-18. Change in the HU of the eggs during Experiment 2a Ill
4-19. Change in the HU of the eggs during Experiment 2b 112
4-20. Comparison of the least squared means (HU) of vanadium by
vitamins interaction pooled over days. Experiment 2b^ 113
Vll
4-21. Change in % foam stability. Experiment 2a 1
4-22. Comparison of the least squared means (FS) of vanadium by
vitamins interaction pooled over days. Experiment 2b 1
LIST OF FIGURES
Figure
H
22--1. The L, a, b color space
23--2. Components of a machine vision system 15
2-3. Spectral power distributions of standard illuminants A, C
and D65
2-4. Parts of an egg 19
5. Reproductive system of the hen 24
1. Color Machine Vision System with eggs and color tile 51
3-2. Correlation between two responses of the same chicken at
different time points 55
3-3. Fixed effects estimates (L*) 56
3-4. Distribution of random effects estimates (L*) 57
3-5. Fixed effects estimate (a*) 59
3-6. Distribution of random effects estimates (a*) 60
3-7. Fixed effects estimates (b*) 61
3-8. Distribution of random effects estimates (b*) 62
3-9. Fixed effects estimates (egg weight) 64
3-10. Distribution of random effects estimates (egg weight). ...65
3-11. Fixed effects estimates (shell weight) 66
3-12. Distribution of random effects estimates (shell weight) ..66
3-13. Change in shell color after the correction for the change
in egg size ^2
3-14. Eggs with L*a*b* values representative of the mean L*a*b*
values recorded in each month 73
IX
4-1. Changes in L* value of eggshells over time with different
levels of V in the hens' diets (LS meanslSE) 90
4-2. Significant shade effect, day effect and their non-
significant interaction
4-3. Changes in a* value of eggshells over time with different
levels of V in the hens' diets
4-4. Significant shade effect, day effect and their interaction
significant at an a level of 0.0357
4-5. Changes in b* value of eggshells over time with different
levels of V in the hens' diets
4-6. Significant shade effect, day effect and their significant
interaction
4-7. Changes in L* value of eggshells over time with lower levels
of V in the hens' diets. Experiment 2a 97
4-8. Changes in a* value of eggshells over time with different
levels of V in the hens' diets. Experiment 2a 98
4-9. Changes in b* value of eggshells over time with different
levels of V in the hens' diets. Experiment 2a 99
4-10. Change in L* with vanadium concentration for different
vitamin supplementations. Experiment 2b 103
4-11. Change in a* with vanadium concentration for different
vitamin supplementations. Experiment 2b 104
4-12. Changes in the color of eggshells when hens are fed various
diets. Experiment 3 105
4-13. Changes in HU of eggshells over time with different levels
of V in the hens' diets. Experiment 1 108
4-14. Change in the percent foam stability of eggs from hens fed
vanadiimi diets. Experiment 1 109
4-15. Change in the percent foam capacity of eggs from hens fed
vanadium diets. Experiment 1 110
4-16. Changes in HU of eggs over time with different levels of V
in the hens' diets. Experiment 2a Ill
4-17. Change in the percent foam stability of eggs from hens on
vanadium diets Experiment 2a 114
,
X
