Production of ACE inhibitory peptides from corn germ meal by an enzymatic membrane reactor with a novel gradient diafiltration feeding working-mode and in vivo evaluation of antihypertensive effect

Abstract This study investigated the performance of an enzymatic membrane reactor (EMR) with a new gradient diafiltration feeding (GDF) working-mode on the production of peptide with potent angiotensin-converting enzyme (ACE) inhibitory activity from corn germ meal (CGM) under the selected conditions. The antihypertensive effect of the released peptide was evaluated in vivo. Results showed that the protein conversion rate and the peptide yield were 81.94% and 80.20%, respectively, when the EMR-GDF worked for 660 min, and the corresponding IC50 value of the released peptide was 0.83 mg/mL. In vivo experimental results indicated that the high-dose corn germ peptide significantly reduced the systolic blood pressure (SBP) by 18.22 and 28.6 mmHg in acute oral and long-term intragastric administration tests, respectively. The corn germ peptide could also inhibit the ACE activities in kidney, lung, and heart of rats and regulate the level of endothelium-derived vasoconstrictor and relaxing factors in serum.