Antioxidant Activity of Gelatin Hydrolysate Produced from Fish Skin Gelatin Using Extracellular Protease from Bacillus amyloliquefaciensH11

Antioxidant activities of gelatin hydrolysates (GHs) from unicorn leatherjacket skin prepared using extracellular protease from Bacillus amyloliquefaciensH11 (GH-H11) with different degrees of hydrolysis (DHs) were comparatively studied with those of hydrolysate produced using Alcalase (GH-Al). Antioxidative activities of hydrolysates produced by both proteases increased with increasing DH (P<0.05). With DHs of 20-40%, GH-H11 showed higher 2,2-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical-scavenging activity and ferric-reducing antioxidant power than GH-Al (P<0.05), but no differences in chelating activity were found (P>0.05). Both hydrolysates (100 and 1,000ppm) could inhibit lipid peroxidation in lecithin liposome system in a dose-dependent manner. In vitro simulated gastrointestinal digestion study indicated that the antioxidative activity of GH was not affected by pepsin, while further hydrolysis by pancreatin enhanced the antioxidative activity. The dominant antioxidative peptides in GH-H11 and GH-Al had molecular weights of approximately 750 and 3,600Da, respectively. Practical ApplicationsBacillus amyloliquefaciensH11 protease could hydrolyze gelatin more effectively than Alcalase. Gelatin hydrolysate using B.amyloliquefaciensH11 protease had high antioxidant activity than that prepared by Alcalase. Antioxidative peptide could be useful for the food industry owing to process specificity and the economic value of producing bioactive peptide for commercial use.