Angiotensin-converting enzyme inhibitory effects of whey protein hydrolyzate prepared using Protamex.

摘要

Enzymic hydrolysates prepared from whey protein concentrate (WPC) were investigated for in vitro inhibition of angiotensin I-converting enzyme (ACE). Alcalase, trypsin, Protamex, Neutrase and Flavozyme were used to hydrolyse the WPC. The ACE inhibitory efficiency ratio (IER; percentage ACE inhibition/protein content) of the WPC was 79.25% (mg/ml)--1. All of the whey protein hydrolysates (WPH) tested showed greater ACE inhibitory activity than the WPC; highest inhibition was achieved by the WPH prepared using trypsin or Protamex (IER of 461.58 and 443.885 (mg/ml)--1, respectively). Due to economic considerations, however, the WPH prepared using Protamex was employed in further experiments. This WPH showed max. ACE inhibition after 5 h of hydrolysis (55.50%), and recovery was 70.15%. Kinetics studies of the Protamex WPH showed mixed-type inhibition. Furthermore, ACE inhibitory peptides from this WPH were purified using RP-HPLC with a C₁₈ column. The purified ACE inhibitory peptides had an IER value of 6303.34% (mg/ml)--1. From these results it is suggested that WPH made using Protamex may have antihypertensive effects and be of use for prevention or treatment of cardiovascular disease.