Protein, Essential Amino Acid, and Fatty Acid Composition of Five Target Fishery Species of Central Mediterranean Sea.

The protein, essential amino acid, and fatty acid composition of European pilchard ( Sardina pilchardus ), European hake ( Merluccius merluccius ), surmullet ( Mullus surmuletus ), red mullet ( Mullus barbatus ), and deep water rose shrimp ( Parapenaeus longirostris ) from the central Mediterranean Sea were investigated. All the species showed an essential amino acid content of about 50% of total amino acids, while the protein and total fatty acids content varied from 19.9 to 24.8% and from 1.4 to 5.1%, respectively. The fatty acid profile mainly followed the order SFA (39.1-52.6%) > PUFA (21.0-39.3%) > MUFA (15.6-24.3%). Palmitic and stearic acids were predominant among saturated fatty acids (38-52% and 21-25%, respectively), while palmitoleic and oleic acids were the most represented of the total monounsaturated acids (10-21% and 55-68%, respectively). All the species, as expected, showed a more significant proportion of n-3 PUFA (EPA + DHA) of about 81-93% of the total PUFA, with the highest values was found in European pilchard. Also, several fat quality index values, such as n-6/n-3 ratio, PUFA/SFA, the index of atherogenicity (IA), the index of thrombogenicity (IT), the hypocholesterolemic/hypercholesterolemic ratio (HH), and fish lipid quality/flesh lipid quality (FLQ) were calculated to assess the nutritional quality. All the obtained results, along with the fat quality indexes, indicated the excellent nutritional values of the selected species.