Effect of simulated gastrointestinal digestion on the ACE inhibitory activity of peptides AHEPVK and GPSMR. Control: The peptide solutions (0.1 mg/ml) were incubated in buffer solutions (HCl and potassium phosphate buffer). P: The peptide solutions were incubated with 0.05% pepsin solution for 2.5 hrs at 37°C. P + T + C: The peptide solutions were successively digested with pepsin for 2.5 hrs. They were further incubated in pancreatin solution for another 2.5 hrs at 37°C. The ACE inhibitory activity are expressed as mean ± standard deviation (n = 3).