Preparation of Angiotensin I-Converting Enzyme Inhibiting Peptides from Soybean Protein by Enzymatic Hydrolysis

Abstract

Soybean protein isolate was hydrolyzed using two proteases (Protease M and Orientase 90N), and the inhibitory activity of angiotensin I-converting enzyme (ACE) and bitterness of the hydrolysates were investigated. The ACE inhibitory activity of the hydrolysates increased with increasing hydrolysis time. Hydrolysates obtained using Protease M for 4 to 10 h and Orientase 90N for 6 to 10 h showed a high ACE inhibitory activity, and the bitterness was negligible. The ACE inhibitory peptides were shown to be oligopeptides composed of 2-5 amino acid residues. These peptides might be useful for therapeutic applications based on the consumption of an anti-hypertensive food.