The impact of dietary oil source and frozen storage on the physical, chemical and sensorial quality of fillets from market-size red hybrid tilapia, Oreochromis sp.

Abstract

Red hybrid tilapia ( Oreochromis sp.) were fed one of four diets containing either fish oil, crude palm oil, palm fatty acid distillates or refined palm olein as the only added oil. Post-harvest fillet quality was then evaluated at 1, 10 and 30 weeks of frozen storage. Dietary oil source did not significantly ( p > 0.05) influence the liquid holding capacity and texture of fillets but both these parameters were increased by frozen storage. Fillets from fish fed palm oil-based diets exhibited significantly higher oxidative stability during frozen storage, compared to fish fed the fish oil diet. Dietary oil source and frozen storage had little impact on sensory attributes. Unlike fillet proximate composition, fillet fatty acid composition was significantly affected by both diet and frozen storage. Total n-3 polyunsaturated fatty acids decreased significantly in the fillet lipids of all fish after 30 weeks of frozen storage.