Abstract: This study aimed to evaluate the changes in nutritional quality during the processing of giant salamander soup. At five different lengths of cooking times (30, 60, 90, 120, and 150 min), the nutritional indexes including soluble solids content, soluble protein content, crude fat content, inosine monophosphate content, fatty acid and amino acid composition were analyzed. The results showed that the contents of soluble solids and soluble protein in giant salamander soup increased significantly from 30 to 60 min, tended to be stable during the following 60 min, and then significantly increased again from 120 min onward; inosine monophosphate content was increased during the whole cooking period of 150 min. A total of 16 fatty acid were detected from giant salamander soup, the predominant ones being palmitic, palmitoleate, oleic acid, linoleate acid, cis-5,8,11,14-eicosatetraenoic and nervonate; the ratio of saturated fatty acids to polyunsaturated fatty acids (SFA/PUFA) decreased at first and then increased, and desired contents of crude fat and fatty acids were obtained at 60 min, together with the lowest SFA/PUFA ratio (1.37). The contents of total amino acids, essential amino acids and umami amino acids and the ratio of essential to non-essential amino acids first increased with cooking time until reaching a peak at 60 min (239.529 mg/100 g total amino acid content, 0.858 EAA/NEAA ratio), and then decreased. In conclusion, giant salamander soup cooked for 60 min under atmospheric pressure condition had a better nutritional quality as indicated by the highest amino acid content, the best SFA/PUFA ratio and a desired fat content.

Key words: giant salamander soup, nutritional quality, fatty acid composition, amino acid composition