Process for the preparation of angiotensis converting enzyme (ACE) inhibitors and its use

A process for the preparation of Angiotensin Converting Enzyme (ACE) inhibitory peptides from glycinin, said process comprising the steps of:

• (a) isolating glycinin from defatted soy flour;
• (b) dispersing a 10–25% solution of glycinin in a buffer;
• (c) hydrolyzing the mixture of glycinin and buffer with 2–4% w/v of one or more proteolytic enzymes;
• (d) incubating the mixture at 37–50° C. for a period of 16–18 hours;
• (e) arresting the hydrolysis reaction by adding trichloroacetic acid to the mixture;
• (f) centrifuging the mixture at 15–20,000 rpm for 30–40 minutes, at a temperature of about 4–8° C.;
• (g) obtaining from the centrifugation supernatant a mixture of protein hydrolysates containing polypeptides;
• and
• (h) separating and purifying from the mixture of protein hydrolysates peptide fractions having ACE inhibitory activity of 66%, 81% and 75%.