Optimizing preparation conditions for Angiotensin-I-converting enzyme inhibitory peptides derived from enzymatic hydrolysates of ovalbumin

Angiotensin-I-converting enzyme (ACE) inhibitory peptides were prepared from ovalbumin using enzyme hydrolysis with pepsin as an enzyme source. Effects of pH, enzyme dosage, substrate concentration, hydrolysis temperature, and time on the degree of hydrolysis and the ACE inhibition rate were investigated using single factor experiments. Preparation conditions for ACE inhibitory peptides were optimized using a response surface design on the base of single factor experiments. Optimum preparation conditions were a substrate concentration of 5.2 g/100 mL of D.W with a pH value of 2.5, an enzyme dosage of 14,000 U/g, and a hydrolysis time of 250 min at 30°C. The ACE inhibition rate was up to 70.55±1.13% under these conditions.