Optimization on Hydrolysis Conditions of Coix Prolamin and Angiotensin-converting Enzyme Inhibitory Activity of Hydrolysates / 世界科学技术-中医药现代化

ABSTRACT

This study was aimed to optimize the hydrolysis conditions of Coix prolamin, which occupied the highest content in total protein of it, and then evaluate the angiotensin-converting enzyme (ACE) inhibitory activity of the corresponding hydrolysates. Pepsin was used to hydrolyze prolamin and OPA method was applied to determine the degree of hydrolysis. The optimum conditions of hydrolyzing prolamin were obtained by orthogonal design subse-quently. The ACE inhibitory activity of small molecular weight (less than 3 kD) peptides gained by ultrafiltration of the hydrolysates was assayed by RP-HPLC method. The result showed that the optimized hydrolysis conditions were substrate concentration of 1%, enzyme-to-substrate ratio of 15 and hydrolysis duration for 48 h. The hydrolysates exhibited an ACE inhibitory ratio of (83.40 ± 0.93)% at the concentration of 0.1 mg·mL-1. It was concluded that prolamin hydrolysates displayed a high ACE inhibitory activity in vitro, which provided guidance for further research of antihypertensive component and development of functional food from Coix.