Optimization of enzymatic hydrolysis of visceral waste proteins of beluga Huso huso using Protamex

Fish protein hydrolysate (FPH) was produced from the viscera of beluga (Huso huso). Hydrolysis conditions (enzyme activity, temperature, and time) were optimized using response surface methodology (RSM). Lack-of-fit test revealed a non-significant value for the model, indicating that the regression equation was adequate for predicting the degree of hydrolysis under any combination of the variables (P < 0.05). The optimum conditions to reach the highest degree of hydrolysis were: 39.21 °C, 114.2 min, and a protease (Protamex) activity of 27.41 AU/kg protein. The amino acid composition of protein hydrolysates of beluga in optimum conditions showed a high nutritional value of protein hydrolysates from beluga viscera.