The effect of enzymatic hydrolysis time and temperature on the properties of protein hydrolysates from Persian sturgeon (Acipenser persicus) viscera

Protein hydrolysate was prepared from the viscera of Persian sturgeon (Acipenser persicus), a major sturgeon species in the Caspian Sea. Hydrolysis was performed at three different temperatures (35, 45 and 55 °C), pH 8.5, using commercially available Alcalase® and an enzyme to substrate ratio of 0.1 AU/g viscera protein over a 205 min incubation period. Protein and lipid content of the hydrolysate were 65.82%, and 0.18%, respectively. Protein recovery and degree of hydrolysis ranged from 34.97% to 61.96% and 13.32% to 46.13%, respectively. The highest degree of hydrolysis was observed at 55 °C after 205 min (p < 0.05). The amino acid score of the hydrolysates was similar to that of the FAO/WHO reference protein. It is revealed that Persian sturgeon visceral protein hydrolysate amino acid fulfils adult human requirements. Based on National Research Council guidelines, phenylalanine is the first limiting amino acid in the hydrolysate. However, the hydrolysate has the potential for application as an ingredient in formulated diets.