Abstract: Peanut protein isolates hydrolysates were prepared by enzymatic hydrolysis with Alcalase and Neutrase, and the angiotensin I-converting enzyme (ACE) inhibitory activities of the enzymatic hydrolysates were investigated at different hydrolysis times. The unhydrolysed protein showed no inhibitory activity. Hydrolysates generated with Neutrase displayed very low ACE inhibitory activity, while those obtained with Alcalase exhibited high inhibitory activity. The highest ACE inhibitory activity with the IC value of 0.56 mg protein/ml was found in the hydrolysate obtained with Alcalase at 30 min of 50 hydrolysis time. These results indicated that the peanut protein was a good protein source of ACE inhibitory peptides when hydrolyzed with the protease Alcalase. The peanut protein hydrolysates prepared with Alcalase might be utilized for physi- ologically functional foods with antihypertensive activity.

Key words: angiotensin I-converting enzyme inhibition, bioactive peptides, peanut protein hydrolysates, Alcalase