In silico approaches towards the exploration of rice bran proteins-derived angiotensin-I-converting enzyme inhibitory peptides

Rice bran is an important underutilized by-product of rice-processing industries, and a huge amount of bran is released during rice processing. It can be used as a prime source of bioactive peptides towards the development of functional food ingredients. The aim of the study was to evaluate the potential of rice bran proteins such as glutelin, globulin, and prolamin as a precursor of bioactive peptides using various in silico approaches (BLAST, BIOPEP, PeptideRanker, PepDraw, Pepcalc, and ToxinPred). Rice bran proteins majorly release angiotensin-I-converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) inhibitory peptides. Papain protease can cleave the rice bran proteins effectively compared with other proteases to release ACE-inhibitory peptides. Physicochemical studies have shown that ACE-inhibitory peptides have low molecular weight profiles. These peptides have been classified as bitter peptides with a non-toxic profile. The result of this study demonstrates the usefulness of in silico approaches and provides a theoretical basis for the development of rice bran proteins as a source of bioactive peptides. The predicted prominent ACE-inhibitory peptides could be used for the development of functional food products or nutraceuticals.