Food function is nowadays not merely limited to nourishment supplying; consumers' interest is oriented to food healthiness and nutritional value, animal welfare, environmental impact of animal productions, and products' traceability. The objective of the present work is to compare physical parameters and fatty acids profiles of market eggs produced from hens housed in four different systems. In addition, the effects of the presence of an outdoor space allowance (IND = no outdoor space allowance, OUT = outdoor space allowance) on the same parameters have been investigated. Sixty-nine market eggs from four different production systems labelled as Alternative (ALT), Enriched Cage (ECA), Litter Floor (LIF), and Organic (ORG) have been analysed. Physical parameters and fatty acid concentrations were measured. An ANOVA analysis was performed with production system and outdoor space allowance as sources of variation, two Principal Component Analyses (PCA) were carried out with physical parameters and fatty acid parameters as variables. The effects of the complex interactions occurring among production system, hen welfare, and eggs quality have been analysed in marketed eggs leading to the conclusion that eggs from different production systems available on the market are characterized by differences in fatty acid profile and physical parameters. In physical parameters the differences among systems were influenced by the whole egg weight, albumen weight and yolk weight. In fatty acids parameters the determining variables are the content in polyunsatured fatty acids (PUFA), linoleic acid concentration, and n6/n3 ratio.
Keywords: eggs; fatty acids; production system; quality; welfare.