Formation of dipeptidyl peptidase-IV (DPP-IV) inhibitory peptides from Jack Bean (Canavalia ensiformis (L.) DC.) sprout in simulated digestion

Abstract

Bean sprouts are potential plant proteins that produce DPP-IV inhibitory peptides. These peptides must be stable and active in the brush border membrane of the small intestine to inhibit DPP-IV. The purpose of this research is to evaluate the DPP-IV inhibitory activity of jack bean sprouts using pepsin-pancreatin during simulated digestion, as well as the absorption of these peptides through the everted gut sac method. The results showed that after 180 min of digestion simulation, the Mw < 1 kDa peptide fraction of jack bean hydrolysate, which germinated for 60 h (HG60), had the highest inhibitory activity. The duodenum absorbs most of the peptides with inhibitory activity of 61.77%, which is slightly lower than activity after digestion (62.19%). These outcomes suggest that the DPP-IV inhibitory activity of HG60 can be maintained after digestion and absorption. Two novel peptides KAVGDPI and QGVVLRP identified after absorption contain crucial amino acids confirming as DPP-IV inhibitor.

Supplementary information: The online version contains supplementary material available at 10.1007/s10068-023-01343-9.

Keywords: DPP-IV inhibitor; Digestion simulation; Jack bean sprout; Peptide absorption.

Fig. 1

Degree of hydrolysis (A), peptide concentration (B), and DPP-IV inhibitory activity (C) of jack bean during 240 min of digestion simulation with pepsin-pancreatin. Mean values (± SD of three replications). Different letters show significant differences (Duncan’s test, p < 0.05). HG0 is ungerminated seed hydrolysate; HG60 is 60 h germinated seed hydrolysate

Fig. 2

The interaction of DPP-IV and KAVGDPI (A) and QGVVLRP (B). Grey ribbon was the visualization of DPP-IV, while green and blue were KAVGDPI and QGVVLRP respectively