Effect of cooking temperatures on protein hydrolysates and sensory quality in crucian carp (Carassius auratus) soup.

Cooking methods have a significant impact on flavour compounds in fish soup. The effects of cooking temperatures (55, 65, 75, 85, 95, and 100 °C) on sensory properties and protein hydrolysates were studied in crucian carp (Carassius auratus) soup. The results showed that the soup prepared at 85 °C had the best sensory quality in color, flavour, amour, and soup pattern. Cooking temperature had significant influence on the hydrolysis of proteins in the soup showed by SDS-PAGE result. The contents of water soluble nitrogen (WSN) and non-protein nitrogen (NPN) increased with the cooking temperature, but the highest contents of total peptides and total free amino acids (FAA) were obtained at the cooking temperature of 85 °C. The highest contents of umami-taste active amino acid and branched-chain amino acids were also observed in the 85 °C sample. In conclusion, a cooking temperature of 85 °C was preferred for more excellent flavor and higher nutritional value of crucian carp soup.