This paper investigates the physical and chemical quality indicators of table eggs available on the Croatian market. The research was carried out on eggs produced by two manufacturers, marked as A and B, on the 7th and 28th day of egg storing. According to the Regulations on egg quality (OJ 115/06, Art. 9), eggs are classified as class A or fresh eggs and class B or eggs for industrial processing. Referring to the weight of the eggs, the eggs of class A are divided into four grades: XL, L, M and S. Our research focused on the M weight grade eggs, because they are the most represented ones in our conditions. The following external indicators of egg quality were analyzed: shape index (%), egg weight (g), shell weight (g), shell strength (kg/cm2) and thickness (mm). Furthermore, the following indicators of inner egg quality were tested: weight of albumen and yolk (g), yolk colour, Haugh units (HU), albumen height (mm), pH of albumen and pH of yolk. Results of our research provided the following conclusions: based on evaluation of energy and protein value, eggs of the manufacturer B had better nutritive value than eggs of the manufacturer A. The results of research into quality of eggs on the 7th day of storage proved that there was statistically significant difference (P<0.001) between the A and B egg manufacturer if referring to the egg weight, shape index, shell thickness, shell weight and strength, as well as albumen weight. After the 28th day of egg storage, there was statistically significant difference (P<0.001) determined for albumen height, HU, pH values of albumen and yolk, and yolk colour (P=0.003). Based on the analysis of nutritive values and physical and chemical properties of eggs during storage, it was confirmed that eggs produced by the manufacturer B were of better quality than eggs of the manufacturer A. Eggs of both manufacturers met the requirements defined by the Croatian Regulations on egg quality.
Zlata Kralik, Josip Juraj Strossmayer University of Osijek, Faculty of Agriculture in Osijek, Department of Zootechnique, Chair of General and Special Zootechnique, V. Preloga 1, 31000 Osijek, firstname.lastname@example.org