Legume proteins : ACE-inhibitory activity of enzymatic hydrolysates

The enzymatic hydrolysis of legume proteins produce peptide mixtures able to inhibit angiotensin-converting enzyme (ACE), that is involved in the renin-angiotensin system for the regulation of blood pressure [1]. In this work ACE-inhibitory activity of hydrolysates obtained by pepsin digestion of proteins of some legumes, such as chickpea, common bean, lentil, lupin, pea, and soybean were investigated, by using the tripeptide hippuryl-histidyl-leucine (HHL), as model peptide, and HPLC-DAD, as analytical method. Soybean and lupin resulted the most promising ones, with IC50 values of 224 and 226 µg/ml, respectively [2]. Moreover three different lupin species (Lupinus albus, L. angustifolius, L. luteus) were studied with the final goal of selecting the best enzyme/species combination for an efficient production of ACE-inhibitory peptide mixtures. Different enzymes were tested: trypsin, chymotrypsin, corolase PP, umamizyme, and flavourzyme. Pepsin gave peptides with the best activity followed by pepsin + trypsin, chymotrypsin, trypsin, corolase PP, umamizyme, and flavourzyme [3]. This investigation confirms that lupin proteins may be a source of ACE-inhibitory peptides, and foresee the application of lupin proteins into functional foods or dietary supplements. [1] F. Roy, J.I. Boye, and B.K. Simpson, B. K. Food Res. Int. 2010, 43, 432-442. [2] G. Boschin, G.M. Scigliuolo, D. Resta and A. Arnoldi Food Chem., 2014, 145, 34-40. [3] G. Boschin, G.M. Scigliuolo, D. Resta and A. Arnoldi J. Agric. Food Chem. 2014, 62, 1846-1851.