The ACE-inhibitory activity of alcalase, papain and pepsin lupin protein hydrolysates

Abstract

Recently, Lupinus angustifolius proteins revealed their high potential to liberate bioactive peptides after hydrolysis. In our study, we examined the release of angiotensin I-converting enzyme inhibitory peptides from extracted lupin proteins after digestion by alcalase, papain, and pepsin. Three enzyme-to-substrate ratios were evaluated with three hydrolysis duration times. First, the degree of hydrolysis was determined using the ortho-phthalaldehyde aldehyde (OPA) method and then, the HPLC-DAD method was applied to measure the ACE-inhibitory activity. According to our results, all hydrolysates possessed ACE inhibitory properties. The calculated IC50 concentrations varied from 0.26 ± 0.59 to 2.19 ± 0.23 μg.ml-1. The peptides with the lowest IC50 values were produced by pepsin (ΔIC50 = 0.33 ± 0.40 μg.ml-1), followed by papain (ΔIC50 = 0.67 ± 0.61 μg.ml-1), and alcalase (ΔIC50 = 1.78 ± 0.92 μg.ml-1). Further research on bioavailability is required to demonstrate the beneficial effects of bioactive peptides on human health, since they have to resist digestive processing pass the intestinal barrier, and reach the bloodstream and intended organs.