Comparative study on structural, biological and functional activities of hydrolysates from Adzuki bean (Vigna angularis) and mung bean (Vigna radiata) protein concentrates using Alcalase and Flavourzyme

The physicochemical features of mung bean protein (MBP) and adzuki bean protein (ABP) hydrolysates derived from Alcalase (MBPHA, ABPHA) and Flavourzyme (MBPHF, ABPHF) were assessed using FTIR, hydrophobicity, emulsion activity, zeta potential, and health-promoting activities. The results proved that the choice of peptidase and substrate both have a significant effect on the hydrolysates in different physicochemical, structural and functional properties. Size exclusion-HPLC was used to fractionate the MBP and ABP hydrolysates. The results demonstrated that Alcalase hydrolysates included smaller peptides than Flavourzyme hydrolysates, and the chromatogram patterns of the two peptidases were similar. The peptides with the most potent antioxidant and ACE-inhibitory properties were identified using MALDI-TOF-MS. The fraction (F4) of MBPHA exhibited the highest levels of metal chelating activity. The Flavourzyme hydrolysates fraction (F2) and the ABPHA fraction (F2) showed the highest ABTS radical scavenging activity and ACE-inhibitory activity, respectively. Pro-Pro was identified in peptide sequences with ABTS radical scavenging activity as an active component while Pro-Gln was identified in peptide sequences with ACE-inhibitory activity. As a result, Pro-Pro and Pro-Gln, respectively, are likely-one of the characteristics of antioxidant and ACE-inhibitory peptides from MBP and ABP. Compared to mung bean and adzuki bean protein as substrate, Alcalase and Flavourzyme as peptidases significant impacted the development of distinct functionalities and biological activities.