Somatic indexes, chemical-nutritive characteristics and metal content in caught and reared sharpsnout seabream (Diplodus puntazzo)

Abstract

The aim of this study was to compare some somatic indexes, chemical-nutritive characteristics and the contents of some metals (Pb, Cu, Cr and Zn) in the whole body and fillet from caught and reared sharpsnout seabream (Diplodus puntazzo). The fish came from three different conditions: reared in marine cages (R), captured in a natural lagoon (L) and in the Mediterranean sea (S). Thirty fish per group, divided into three weight categories (100±15.3, 200±18.7 and 300±20.4g), were used for the trial. Reared sharpsnout seabream showed higher amounts of celomatic fat (3.41%, 2.43%, 0.21%, respectively for R, L and S) and total lipid (13.86%, 11.23% and 5.06% respectively for R, L and S), and lower moisture (64.14%, 65.54%, 71.53%) and protein (17.73, 19.03 and 19.17%) than those caught in the lagoon and sea. The whole body of reared fish contained lower amounts of lead (0.70, 0.75 and 0.97mg/kg, respectively for R, L and S), copper (0.15, 0.38, 0.25mg/kg) chrome (2.19, 3.52, 3.77mg/kg) and higher zinc contents (63.47, 53.42, 47.31mg/kg) than caught fish. Fatty acids from sharpsnout seabream fillets showed a high lipid quality as confirmed also by low values of Thrombogenic index (0.36, 0.30 and 0.22, respectively for L, S, R) and Atherogenic index (0.47, 0.42 and 0.33, respectively for L, S, R). Reared sharpsnout seabream showed lower saturated fatty acid values (26.44%, 32.21%, 34.85%, respectively for R, S, L) and higher oleic acid amount (21.61%, 19.15%, 11.99%, respectively for R, L and S). The subjects captured in the sea had a higher arachidonic acid content (5.44%, 1.76%, 0.59%, respectively for S, L, R). In the weight categories, the 100g subjects, showed higher incidence of viscera (VSI: 4.32%, 3.12% and 2.92%, respectively for 100, 200 and 300g) and liver (HIS: 2.20%, 1.97%, and 1.77%, respectively for 100, 200 and 300g), higher moisture (69.49%, 67.03%, 64.69%) and lower lipid rate (7.64%, 10.18%, 12.32%).