Amaranth proteins as potential source of bioactive peptides with enhanced inhibition of enzymatic markers linked with hypertension and diabetes

Abstract The health and environmental concerns are provoking changes in human diets and plant-based proteins are being considered as sustainable source of proteins compared to animal-derived proteins. In line with this, the current study investigated amaranth protein isolate (API) and hydrolysates (APHs) for in-vitro angiotensin-I converting enzyme (ACE), dipeptidyl peptidase-IV (DPP-IV), and α-glucosidase (AG) inhibitory activities. Amaranth protein hydrolysates (APHs) were generated by bromelain, chymotrypsin, and pronase E for 2, 4, and 6 h. All APHs, especially bromelain-4 h hydrolysate (B4) displayed enhanced ACE, DPP-IV, and AG inhibition compared to API and other APHs. About 116 peptides were identified in B4 by LC-MS-QToF and 17 peptides were predicted to be bioactive. Six of these peptides were predicted to possess high ACE inhibiting potential, while peptides FPFPPTLGY and FPFPR were found to bind to the highest number of active hotspots of DPP-IV and AG, respectively. Overall, this study demonstrated that APHs could be a potential source of antidiabetic and antihypertensive peptides for functional food formulation.