Volatile compounds and organoleptic qualities of gilthead sea bream (Sparus aurata) fed commercial diets containing different lipid sources

Gilthead sea bream were fed in triplicate four extruded diets containing different lipid sources. All diets contained a low level of fish meal (15%) and plant protein inclusion; the control diet contained fish oil (FO), whereas the other three experimental diets contained soya oil (SO), palm oil (PO) and rapeseed oil (RO) at a 68.7% substitution level. The volatile profiles of the diets and of the raw fish fillets produced were evaluated. Isolation of volatiles took place by purge and trap directly on the tissue and volatile analysis was by GC–MS analysis. A comparison of the volatiles resulting from the respective diets found that fish contained volatiles that were not related to the diets. The fish volatile profiles were mostly characterized by hydrocarbons, aromatics and carbonyls. Minor differences were observed in the volatiles of fish fed the different diets. The most characteristic one was d-limonene contained in the FO-fed fish. However, a taste panel evaluation of steam-cooked fillets did not detect any difference among the dietary groups.