열수 및 효소적 가수분해로 제조된 틸라피아 비늘 젤라틴 가수분해물의 ACE 저해 활성

Abstract

Fish scales have potential in functional food preparation due to their antioxidant and antihypertensive properties. We investigated the angiotensin I converting enzyme (ACE) inhibitory activity of Tilapia mossambica scale extracts. Hydrolysates of tilapia scales were prepared by enzymatic extraction using five proteases (<TEX>${\alpha}$</TEX>-chymotrypsin, Alcalase, Kojizyme, Protamex and trypsin) after scales were treated with hot water for 3 hr. Scale enzymatic hydrolysates prepared using both hot water and enzyme treatments exhibited elevated hydrolysis (about 25%-55%) compared to only enzyme treatment (about 15%-45%). Enzymatic hydrolysates (1 mg/mL) prepared by both hot water and enzyme treatments also showed significantly increased ACE inhibitory activities from about 20%-75%. The pattern of ACE inhibitory activities was similar to the degree of hydrolysis. Alcalase and <TEX>${\alpha}$</TEX>-chymotrypsin hydrolysates displayed the highest ACE inhibitory activities (<TEX>$IC_{50}$</TEX> = 0.83 mg/mL and 0.68 mg/mL, respectively). In addition, the ACE inhibitory effects of <TEX>$IC_{50}$</TEX>-chymotrypsin hydrolysates increased with decreasing molecular weight (5 kDa>, 10 kDa> and 30 kDa>), with the 5 kDa> fraction displaying the highest ACE inhibitory activity (about 89.9% and <TEX>$IC_{50}$</TEX> = 0.1 mg/mL). We suggest that the peptide compounds of enzymatic hydrolysates prepared from tilapia scale enhances ACE inhibitory activity and might be useful as an antihypertensive material.