Jack Bean (Canavalia ensiformis) Tempeh: ACE-Inhibitory Peptide Formation during Absorption in the Small Intestine

Abstract

Research background. High blood pressure is the most significant cause of mortality globally. Some fermented foods include ACE inhibitor peptides that help fight this disease. The ability of fermented jack bean (tempeh) to inhibit ACE during consumption has not been demonstrated. This study identified and characterised ACE inhibitor peptides from jack bean tempehh produced by small intestine absorption using the everted intestinal sacs model. Experimental approach. Sequentially, the protein extract of jack bean tempehh and unfermented jack bean was hydrolysed using pepsin-pancreatin for 240 min. The hydrolysed samples were then evaluated for the peptide absorption using three-segmented everted intestinal sacs (duodenum, jejunum, and ileum). The peptides absorbed from all intestine segments were mixed as the mixtures of peptides absorbed in the small intestine. Results and conclusion. The data showed that both jack bean tempehh and unfermented jack bean possessed the same peptide absorption pattern, with the highest percentage of peptide absorption in the jejunum, followed by the duodenum and ileum. The absorbed peptides of jack bean tempeh exhibited the same strong ACE inhibition activity in all intestine segments, while the unfermented jack bean showed strong activity only in the jejunum. The mixture of peptides that absorbed in the small intestine from jack bean tempeh possessed higher ACE inhibitory activity (81.09 %) than the unfermented jack bean (72.22 %). The peptides produced from jack bean tempeh were identified as pro-drug ACE inhibitors and possessed the mixed inhibition pattern. The mixture peptides consisted of seven types of the peptide with a molecular weight of 826,86 – 978,20 Da (DLGKAPIN, GKGRFVYG, PFMRWR, DKDHAEI, LAHLYEPS, KIKHPEVK and LLRDTCK). Novelty and scientific contribution. This study discovered that consuming jack bean tempeh generated more potent ACE inhibitory peptides during small intestine absorption than boiling jack beans. Absorbed tempeh peptides provide seven peptides with high ACE inhibitory action.

Old and new technological strategies to improve Jack beans quality and promote its utilization

“…Several microorganisms, such as bacteria, yeast, and fungi, and different fermentation types and conditions are used to ferment the beans. Fermentation can improve the nutritional quality of food such as increasing nutrient bioaccessibility [130], decreasing antinutritional components [131], improving nutrients digestibility [132], and generating bioactive compounds [133]. The fermentations resulted in modifications of chemical compositions as presented in Table 1.3.…”