Effects of dietary enrichment with alpha-tocopherol acetate and post-harvest filleting on lipid oxidation and flesh quality of tropical farmed barramundi (Lates calcarifer)

Pre-harvest dietary enrichment with α-tocopherol acetate in combination with different post-harvest processing techniques was investigated with regard to quality degradation of farmed barramundi (Lates calcarifer), during chilled storage. Fish were fed commercial rearing diets supplemented with two levels of α-tocopherol acetate (standard level 192 mg kg^-1 and enriched level 628 mg kg^-1). During 5months of feeding, α-tocopherol content of fish fed the enriched diet increased significantly from an initial concentration of 13.67 to 24.18 mg kg^-1 after 56days. After this period fish were harvested and subjected to 14day chilled (2°C) storage as either fillets or whole ungutted fish. Dietary α-tocopherol enrichment in combination with storing fish whole and ungutted constrained lipid oxidation over 14days of storage, in comparison lipid oxidation was significantly higher in fish fed the standard diet and filleted prior to storage. Filleting also resulted in significant colour changes with reddening and yellowing of the flesh in conjunction with significantly lower flesh pH compared to barramundi stored whole and ungutted. These results indicate that dietary enrichment with α-tocopherol acetate in combination with storing fish whole and ungutted is the most effective strategy in constraining lipid oxidation and colour fluctuations in barramundi flesh during chilled storage. Statement of relevance: Our findings show that dietary enrichment with α-tocopherol acetate, combined with whole ungutted storage, is effective in preventing lipid oxidation and associated deteriorations in product quality in farmed barramundi flesh during chilled storage. These findings can be used to optimise shelf life of tropical farmed fish. © 2015 Elsevier B.V.