Slaughter yield and fatty acid profiles of fillets of pike (Esox lucius L.) caught before and after spawning

Abstract The aim of the study was to determine the impact pike fishing season (before spawning in fall (group A) and after spawning in spring (group B)) had on the slaughter yield and fillet fatty acid profile. The slaughter yield of fillets with skin and skinned fillets from the group B fish was significantly lower (by approximately 7.5% of body weight). The fatty acid profile of the fish meat from the groups examined differed significantly. The fillets of pike caught before spawning were dominated by unsaturated fatty acids (UFA), while those from fish caught after spawning had mainly saturated fatty acids (SFA). The share of polyunsaturated fatty acids (PUFA) in the fillets of fish that had spawned was sixfold lower, and the n-3 PUFA differences were nearly ninefold. The content of eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids in fillets of fish that had spawned was ninefold lower than in those that had not yet done so. Consequently, the ratio of n-3 PUFA/n-6 PUFA in pike from group A was over three times higher than that in the fish that had spawned (2.61 vs 0.82). Fillets from pike that have spawned are a significantly poorer source of valuable fatty acids for consumers.