Effect of processing and storage on the fatty acid composition of n-3 or n-6 fatty acid-enriched eggs

Abstract

Fresh eggs from hens fed diets supplemented with 4% linseed oil (LO) or sunflower oil (SO) were either directly submitted to pasteurisation, hard-boiling or scrambling processing, or first submitted to refrigerated storage at 4 degrees C for 60 day and then to processing. Fresh LO eggs showed higher (P = 0.05) proportions of monounsaturated fatty acids (MUFAs) and n-3 polyunsaturated fatty acids (PUFAs), but lower (P = 0.05) proportions of saturated fatty acids (SFAs), PUFAs and n-6 PUFAs than the SO eggs. Storage decreased (P = 0.05) the proportion of PUFAs and increased (P = 0.05) that of MUFAs in egg yolks from both treatments. The pasteurisation process had no effect on the fatty acid composition of fresh eggs from both treatments, but increased (P = 0.05) n-6 PUFAs and decreased (P = 0.05) n-3 PUFAs in stored LO eggs. Hard-boiling and scrambling modified the fatty acid composition of fresh and stored eggs from both treatments by decreasing (P = 0.05) the proportion of PUFAs, particularly of the very long-chain n-3 eicosapentaenoic, docosapentaenoic and docosahexaenoic PUFAs. LO eggs showed a higher susceptibility to fatty acid modification upon processing as compared to the SO eggs.