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 1:5 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.
ABSTRACT
A Vitis hybrid-Vitis coignetiae red wine was vinified by fermentation of a mixture of a Vitis hybrid-Vitis coignetiae must with Saccharomyces cerevisiae KCTC 7904 at 25degrees C for 10 days. The Vitis hybrid-Vitis coignetiae red wine showed high antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity (67.8%) and antioxidant activity (76.7%). The antihypertensive ACE inhibitor in the Vitis hybrid-Vitis coignetiae red wine was partially purified by solid phase extraction chromatography, and its ACE inhibitory activity yielded an IC50 of 1.8 mg/mL. Six kinds of oligopeptides, including five new kinds, were contained in the partially purified ACE inhibitor fraction from the red wine after 10 days of fermentation. Antioxidant activity decreased significantly from 76.7% to 40.5% when the post-fermentation period was prolonged to 30 days.
Subject(s)
Angiotensins , Chromatography , Fermentation , Inhibitory Concentration 50 , Oligopeptides , Peptidyl-Dipeptidase A , Saccharomyces , Saccharomyces cerevisiae , Solid Phase Extraction , Vitis , WineABSTRACT
To produce bioactive compound enriched yeast using medicinal Gugiga (Lycium chinensis Mill), several edible Saccharomyces species were cultured in Gugija extracts added yeast extract, peptone and dextrose medium (GE - YEPD medium) at 30degrees C for 24 hr, and their growth were determined. Growth of Saccharomyces cerevisiae K-7 and Sacchromyces cerevisiae ACTC 7904 were better than those of the other yeasts. Two yeasts were selected and then determined their some physiological functionalities after cultivated the yeasts in the GE - YEPD medium and compared those grown on YEPD medium. Antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity of S. cerevisiae K-7 grown on GE - YEPD medium was about 20% higher than that grown on YEPD medium. Superoxide dismutase-like activity of S. cerevisiae ACTC 7904 was also about 12% more high. However, the other physiological functionalities were almost same or lower. Optimal addition concentration of Gugija extract was 10%, and maximally growth and ACE inhibitory activity of S. cerevisiae K-7 were shown when the strain was cultured in 10% Gugija extracts containing YEPD medium at 30degrees C for 12 hr.