Quality of eggs from different laying hen production systems, from indigenous breeds and specialty eggs

Abstract

Consumers are concerned about the quality of commercially available eggs. Eggs used in this study were marketed in Portugal and originated from laying hens raised in cages, barns, free-range, organic eggs, and eggs enriched with n-3 polyunsaturated fatty acids (PUFA), and from native Portuguese breeds. The eggs were analyzed for chemical and physical properties. Results indicated that yolk color was lighter in organic eggs and darker in n-3 PUFA enriched eggs. Eggs from caged hens had lower Haugh units in contrast with organic eggs. Caged hens produced eggs with a higher protein content while organic eggs had the lowest level of protein in the albumen. As might be expected, eggs enriched in n-3 PUFA had the highest n-3 PUFA content. Choosing an egg by its production system or labeling specificities may not be a guarantee of superior product quality. The layer genotype, age, diet, and the quality of the range also may affect egg properties. Due to a different layer diet, enriched eggs seem to be of superior quality.

Keywords: egg labeling; egg quality; polyunsaturated fatty acid; production system.