Scavenging peptides, antioxidant activity, and hypoglycemic activity of a germinated amaranth (Amaranthus hypochondriacus L.) beverage fermented by Lactiplantibacillus plantarum

Amaranthus hypochondriacus L. is a pseudocereal with nutritional properties. Some bioactive peptides have been identified from amaranth protein isolates. The metabolic reactions developed during seed germination have produced different functional foods. The present research aimed to develop a non-dairy germinated amaranth-based functional beverage fermented by Lactiplantibacillus plantarum (LP) strain using Lacticaseibacillus casei Shirota (LCS) as control. The content of betalains (BT), total phenolic compounds (TFC), antioxidant capacity (DPPH, ABTS, FRAP), color changes, and scavenging bioactive peptides were determined. BT in the original base was significantly increased after fermentation by LP and LCS (from 1.276 ± 0.030 to 2.732 ± 0.196 and 1.904 ± 0.760 mg/100 ml, respectively). TFC increased after fermentation; however, no significant differences were found between the two strains (p >.05). The fermentation did not decrease the antioxidant content of the germinated amaranth base. However, a slight increase in the antioxidant capacity was found by DPPH, ABTS, and FRAP in the beverage fermented by LP compared with the LCS one. Moreover, the peptidomic approach suggested 18 peptides with scavenging activity. Thus, a bioactive food product with antioxidant properties was obtained by germination of A. hypochondriacus and its subsequent fermentation by LP. Practical applications: Non-dairy fermented beverages are novel carriers for probiotics and beneficial metabolites. This research evaluated the antioxidant and hypoglycemic activity of a fermented drink made with amaranth (Amaranthus hypochondriacus) and a potential probiotic strain (Lactiplantibacillus plantarum). The results led to conclude that it is possible to develop functional drinks with potential antioxidant and hypoglycemic activities and provide the biochemical basis for further research and development.