Assessment of the DPP‐IV inhibitory potential of mung bean and adzuki bean protein hydrolysates using enzymatic hydrolysis process: specificity of peptidases and novel peptides

Summary Mung bean and adzuki bean protein concentrates were hydrolysed to the same degree of hydrolysis by two peptidases: Flavourzyme and Alcalase. Peptide fractions were analysed using MALDI‐TOF MS to investigate the differences in enzyme cleavage specificity and the inhibition activity of Dipeptidyl peptidase‐IV (DPP‐IV), using bioinformatics tools. It was shown that each peptidase showed specific selectivity in cleaving the designated substrate at a specific site. Alcalase main cutting sites on mung bean and adzuki bean proteins were identified as hydrophobic amino acid residues, particularly between Leu‐X (X‐Leu) or Phe‐X (X‐Phe) while Flavourzyme cleavage occurred between peptide bonds between Gln‐X (X‐Gln) or Pro‐X (X‐Pro). The findings demonstrated that Flavourzyme had a higher capacity for generating active peptides from both mung bean and adzuki bean protein concentrates with higher levels of DPP‐IV inhibitory activity. Proteomics and bioinformatics methodologies provided the essential knowledge required to explore novel peptides with DPP‐IV inhibitor potential from mung bean and adzuki bean hydrolysates.