Comparison of the Effect of Caspian kutum trypsin (Rutilus frisii kutum) with commercial enzymes on the functional and antioxidant properties of soy protein hydrolysates

Nowadays, modifying of the functional properties of proteins by proteolytic enzymes is a novel way in order to use the hydrolysates as a natural antioxidant, emulsifier or foaming agent. In this study, TSP was hydrolyzed by commercial trypsin (porcine), trypsin extracted from Caspian Kutum, pepsin, alcalase and papain. The results showed that the highest degree of hydrolysis (DH%) was related to commercial trypsin (19.34 %), Alcalase (16.04%) and Kutum trypsin (14.29%), respectively. The highest emulsifying capacity was obtained by commercial and Kutum trypsin, compared to non-hydrolyzed protein, and Alcalase hydrolysates had the highest emulsion stability (p <0.05). Higher foaming capacity was observed in hydrolysates by commercial trypsin, followed by Kutum trypsin, compared to non-hydrolyzed protein. However, the lowest value was related to Alcalase. In the case of foam stability, the commercial trypsin hydrolysate had the most stable foam, while Kutum trypsin, despite its lower efficiency compared to commercial trypsin, had the second place. Hydrolysates prepared with Kutum trypsin had the highest DPPH-scavenging ability and reducing power but the lowest OH-radical scavenging power. The results of this study show that kutum trypsin can produce soy protein hydrolysates with good functional and antioxidant properties, which are comparable to commercial enzymes.