Quality of reared gilthead sea bream (Sparus aurata) during ice storage, as affected by dietary fish oil substitution; an instrumental and sensory designation approach

The fillet fatty acids (FAs) and volatile compounds (VCs) of gilthead sea bream, fed either fish oil-based diet (FO) or plant oils (PO), were studied in dorsal and ventral fillet parts over a 12-day ice storage. Fillet FA reflected the FA composition of the respective diets. Monounsaturated FAs were reduced with storage, while no FA differentiations occurred between fillet parts. VCs varied between diet treatments, with food chain-transported compounds (α-pinene and dimethylsulphide) showing higher abundance in the FO group. VCs proposed as fish spoilage indicators (trimethylamine, pentanal, propanal, 3-methylbutanal and 1-penten-3-ol) increased with storage, while concentration of carbon disulphide associated with fresh fish aroma decreased during the same period. VCs varied between fillet parts, with ventral part exhibiting higher concentrations in fat-soluble (terpenes, aromatic hydrocarbons) and spoilage-associated VCs. Sensory analysis revealed no significant differences between diet groups with the exception of fattiness, which was found significantly higher in the plant oil group.