Optimization of Conditions for Enzymatic Production of ACE Inhibitory Peptides from Collagen

Enzymatic condition for producing angiotensin I-converting enzyme (ACE) inhibitory peptides from collagen was optimized with the aid of response surface methodology, which also derived a statistical model for experimental validation. The results showed that the optimal condition for the hydrolysis by pepsin was at pH 2, temperature 37 °C, and in enzyme to substrate ratio (E/S) of 2 when 8.23% collagen (w/v) and 3.82 h of hydrolysis time were applied. Through the single-enzyme hydrolysis, the ACE inhibitory activity could reach an average of 78.06%. In contrast, when a combination of pepsin and trypsin was used for a multiple-proteases hydrolysis, the ACE inhibitory activity could be significantly improved to an average of 88.25%. Furthermore, the IC₅₀ (μg/mL) value of the enzyme combination by pepsin and trypsin (141.64 ± 22.11) was significantly lower than that of the combinations of pepsin and papain (438.59 ± 84.37) or pepsin and protease M (336.76 ± 87.88; p<0.05). Our results have shown that collagen can be used for enzyme-mediated production of ACE inhibitory peptides.