Organoleptic and volatile aroma compounds comparison of wild and cultured gilthead sea bream ( Sparus aurata): sensory differences and possible chemical basis

Abstract

The aim of this study was to determine whether there are organoleptic differences among wild and cultured gilthead sea bream ( Sparus aurata) and to find their possible chemical basis. Wild and cage-cultured fish of the same average weight (400 g) were compared. Cultured fish diet consisted of a commercial extruded feed (45% crude protein, 21% fat). An expanded forced-choice triangular test was conducted on cooked fillets according to the British Standards [BS 5929, 1986. British Standard Methods For Sensory Analysis, British Standard Methods For Sensory Analysis, Milton, Keynes, UK]. Fifteen assessors, regular consumers of this fish species, were used. The proportion of people who made the correct choice was 0.8 and thus the alternative hypothesis was proved valid ( P≤0.001). The degree of discrimination (calculated proportion of people who can really distinguish) was 0.7 ( P≤0.01). These results show a strong organoleptic difference between wild and cultured fish. The test also showed a preference on wild fish, while most common descriptors given for wild fish were “more pleasant taste” (four answers), “more firm texture” (four answers) and for cultured fish were “poorer taste” (four answers). From these answers, a superiority of wild fish is strongly indicated. A volatile aroma compound analysis by GC-MS took place for wild and cultured gilthead sea bream. The volatile aroma compounds profile of the wild fish was found different than that of the cultured counterparts, containing a higher number of taste-contributing compounds. Organoleptic differences can be related to proximate analysis, volatile aroma compounds and fatty acid profile differences of the fish muscle.