SHELL 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