Abstract: In this study, routine biochemical assays were used to evaluate the nutritional composition and quality of farmed Silurus meridionalis Chen muscle from a farm in Shuangliu region, Sichuan. The contents of crude protein, crude fat, crude ash and water in fresh fish muscles were (18.06 ± 0.49)%, (2.47 ± 1.08)%, (1.17 ± 0.06)% and (78.49 ± 0.45)%, respectively. Eighteen amino acids were found in the muscle of farmed Silurus meridionalis Chen, including all 8 essential amino acids (EAA), all 2 half-essential amino acids (histidine and arginine), 8 nonessential amino acids (NEAA, namely glutamic acid, aspartic acid, glycin, alanine, serine, cystine, tyrosine and proline). In dry samples, the total content of amino acids (TAA) was (83.59 ± 2.30)%, and the contents of EAA, was (34.43 ± 1.45)%, respectively. Four delicious amino acids (DAA) accounted for (31.52 ± 1.20)% in dry sample. The ratio of DAA to TAA was 37.71%. The essential amino acids index (EAAI) was 74.82. The ratio of EAA to TAA was 41.19%, and the ratio of TAA to NEAA was 70.04%. These data suggest that the EAA profile of the muscle of farmed Silurus meridionalis Chen can meet completely the FAO/WHO Standard. In terms of amino acids score (AAS) and chemical score (CS), the first and second limiting amino acids were identified as valine and (methionine + cystine), respectively. Eight saturated fatty acids (SFA), 8 mono-unsaturated fatty acids (MUFA) and 10 polyunsaturated fatty acids (PUFA) were found in the muscle of Silurus meridionalis Chen. The relative contents of PUFA, EPA and DHA in total fatty acids were (41.05 ± 0.77)%, (4.00 ± 0.21)% and (7.80 ± 1.42)%, respectively, which were much higher than those of Ictalurus punctatus and P.vachelli muscles. The index of atherogenicity (IA) and index of thrombogenicity (IT) of fatty acids were 0.42 and 0.35, respectively. Farmed Silurus meridionalis Chen muscle was rich in minerals, such as K, Zn and Fe and had a reasonable Zn/Fe ratio. Our study demonstrates that farmed Silurus meridionalis Chen muscle tastes delicious, and is rich in amino acids with an even balance and also abundant in PUFAs, EPA and DHA, thus having great nutritional and edible value and being worthy of further processing and utilization.

Key words: farmed Silurus meridionalis Chen, muscle, nutritional component, nutritional quality, amino acids, fatty acids