CHARACTERISTICS AND ANTIOXIDATIVE ACTIVITY OF GELATIN HYDROLYSATES FROM UNICORN LEATHERJACKET SKIN AS AFFECTED BY AUTOLYSIS-ASSISTED PROCESS

Autolysis-assisted process mediated by indigenous protease in combination with thermal hydrolysis and hydrolysis using papain was used for production of gelatin hydrolysate from skin of unicorn leatherjacket. Prior autolysis could enhance the yield and antioxidative activity of gelatin hydrolysates, especially when subsequent hydrolysis by 2% papain was implemented (AU + HP2.0). Hydrolysates possessed ABTS (2,2'-azinobis-[3-ethylbenzothiazoline-6-sulfonic acid]) radical and H2O2 scavenging activities as well as metal chelating activity. AU + HP2.0 and gelatin hydrolysate prepared using papain without prior autolysis (HP2.0) could retard oxidation in lecithin liposome system, and antioxidative activity of hydrolysates at 10.0 g/L was comparable to that of 0.1 g/L Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), in which the oxidation was almost completely inhibited. On the basis of size exclusion chromatography, antioxidative peptide in AU+ HP2.0 had molecular weight of 2200 Da. Therefore, autolysis-assisted process showed the potential for the production of gelatin hydrolysates with enhanced antioxidative activity.