Enzymatic Modification of Fish Frame Protein Isolate

Abstract

ABSTRACT Protein isolate was hydrolyzed with pepsin yielding an approximate degree of hydrolysis of 80%. Frame protein hydrolysates were then employed for plastein synthesis. Enzyme induced plastein was optimized at: (1) pH 5 for pepsin and pH 7 for alpha‐chymotrypsin; (2) substrate concentration, 40% w/v; (3) time of incubation, 24 hr; (4) enzyme/substrate ratio, 1:100 w/w. Percent plastein yields of 33.8 and 27.3 were found for pepsin and alpha‐chymotrypsin, respectively, when trichloracetic acid was used as the precipitating agent. However, when plastein was precipitated by ethanol, the percent yield was found to be 46 and 40.5 for pepsin and alpha‐chymotrypsin, respectively.