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

Summary 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 °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.