Sodium Caseinate 가수분해물의 Angiotensin-I Converting Enzyme 저해효과에 관한 연구

Abstract

This study was carried out to identify the ACE (Angiotensin converting enzyme) inhibitory activity of casein hydrolysates for development of anti-hypertensive hydrolysates. Sodium caseinate was treated with six kinds of commercial proteases such as Flavourzyme, Protamex, Neutrase 1.5, Alcalase, Protease M, and Protease S for 8 h individually, and was then treated with the enzyme combination for 4 h at 45 o C. The hydrolysate which had the highest ACE inhibitory effect was then hydrolysed successively with three digestive enzymes: pepsin, trypsin, and α-chymotrypsin, at 37 o C for 4 h under conditions mimicking those of the gastrointestinal tract. UF (ultra filtration) treatment was applied to one of the secondary hydrolysates to determine ACE inhibitory activity. When sodium caseinate was hydrolysed by commercial proteases, the degree of hydrolysis (DH) showed 2.54 to 4.25% and after secondary hydrolysis, DH showed 4.30 to 5.22%. ACE inhibitory activity and IC50 values decreased, and inhibition rates increased during hydrolysis. Protamex treatment showed the lowest IC50 value (516 µg/mL) and Flavourzyme hydrolysate showed the highest IC50 value (866 µg/mL). As the first hydrolysate was treated with Flavourzyme, the ACE inhibitory activity increased. Neutrase hydrolysate had the highest activity with an IC50 value (282 µg/mL). When Neutrase plus Flavourzyme treatment was hydrolyzed by digestive enzymes, the IC50 value (597 µg/mL) was decreased statistically (p<0.05). As Neutrase plus Flavourzyme hydrolysate is treated by UF with MW cut-off 10,000, permeate showed 273 µg/mL of IC50 value, showed no difference, but retentate which has over MW 10,000 showed statistically different IC50 value, 635 µg/mL (p<0.05).