Quality of table eggs in relation to shell colour

Abstract

The present study evaluated the quality of table eggs in relation to shell colour. The study was conducted on 60 table eggs with shells coloured white, green, blue and brown (15 eggs per colour) obtained from laying hens from the same backyard farm. The following external quality traits of table eggs were measured: egg weight, percentage of dirty and cracked eggs, egg width and length, egg shape index, eggshell colour, eggshell weight and percentage, and eggshell thickness. The following internal quality indicators of table eggs were determined: albumen weight and percentage, albumen pH value, albumen width, length and height, Haugh index, albumen index, yolk weight and percentage, yolk pH value, yolk width and height, yolk index and yolk colour. Green eggs had the lowest weight, as well as the lowest width and length. White eggs had the highest eggshell dirtiness scores and egg shape index, while brown eggs had the highest eggshell thickness and weight. Green and brown eggs had the highest albumen index and Haugh index. In addition, green eggs had the lowest yolk width and the highest yolk index. White eggs had the highest albumen and yolk width, the greatest albumen length and the lowest albumen height. Yolks of white and blue eggs had a higher sensory colour score, as well as lower L* and b* values compared to the yolks of green and brown eggs. Based on the results of this study, it can be concluded that green and brown table eggs are of better overall quality compared to white and blue table eggs.