Antioxidant activities of tilapia (Oreochromis niloticus) protein and component proteins hydrolysates

Pepsin, neutral protease, Alcalase2.4L were used to hydrolyse the tilapia protein, respectively. The effect of hydrolysis and antioxidant activities including 1, 1-diphenyl-2-picrylhydrazine (DPPH·) and hydroxyl radical (·OH) of hydrolysates hydrolysed by different proteases for 1, 2, 4, 6, 8h were studied and compared, the results showed that the hydrolysates of three proteases all had antioxidant activities, the hydrolysate of neutral protease had the highest degree of hydrolysis (DH) and the recovery rate of protein, the hydrolysate of pepsin had the minimum IC50 value of DPPH· and ·OH scavenging ability. Neutral protease was selected to hydrolyse sarcoplasmic protein, myofibrillar protein and stroma protein for 4h, the effect of hydrolysis and antioxidant activities of hydrolysates were studied and compared. The results indicated that the hydrolysate of stroma protein had the highest recovery rate of protein that was 89.8%, the hydrolysate of myofibrillar protein had the highest DH that was 10.1%, the hydrolysate of sarcoplasmic protein had the minimum IC50 value of ·OH and DPPH· scavenging ability that were 12.352mg/m L and 3.554mg/m L.