• Peptide release methods influence its bioactivity by generating different sequences. • The absorption, toxicity and taste of peptides is influenced by the production method. • The most used methods are enzymatic hydrolysis and microbial fermentation. • The most used methods are biotechnological and differ in their process.

Protein hydrolysates are a promising source of bioactive peptides. One strategy by which they can be obtained is fermentation. This method uses the proteolytic system of microorganisms to hydrolyze the parental protein. Fermentation is a little-explored method for obtaining protein hydrolysates from amaranth. Different strains of lactic acid bacteria (LAB) and Bacillus species isolated from goat milk, broccoli, aguamiel, and amaranth flour were used in this work. First, the total protein degradation (%TPD) of amaranth demonstrated by the strains was determined. The results ranged from 0 to 95.95%, the strains that produced a higher %TPD were selected. These strains were identified by molecular biology and were found to correspond to the genera Enterococcus, Lactobacillus, Bacillus, and Leuconostoc. Fermentation was carried out with amaranth flour and the selected strains. After this process, water/salt extracts (WSE) containing the released protein hydrolysates were obtained from amaranth doughs. The peptide concentration was measured by the OPA method. The antioxidant, antihypertensive and antimicrobial activity of the WSE was evaluated. In the FRAP test, the best WSE was LR9 with a concentration of 1.99 μMTE/L ± 0.07. In ABTS, 18C6 obtained the highest concentration with 19.18 μMTE/L ± 0.96. In the DPPH test, there was no significant difference. In terms of antihypertensive activity, inhibition percentages ranging from 0 to 80.65% were obtained. Some WSE were found to have antimicrobial properties against Salmonella enterica and Listeria monocytogenes. Fermentation of amaranth with LAB and Bacillus spp. allowed the release of protein hydrolysates with antioxidant, antihypertensive, and antimicrobial activity.

Protein hydrolysates containing bioactive peptides have emerged as therapeutic agents. However, these peptides may lose this bioactivity under gastrointestinal conditions. Encapsulation in edible biopolymers is a solution to this problem. Protein hydrolysates with ACE-I inhibitory activity, obtained previously, were encapsulated. A 1% solution of the biopolymers alginate (AG) and pectin (PC) in various ratios was prepared. The beads formed were evaluated in both wet and dry states for size, roundness, thermal gravimetric analysis (TGA), encapsulation efficiency, and ACE-I inhibitory activity. Selected samples underwent in vitro digestion, after which peptide release and ACE-I inhibitory activity were determined. Size analysis revealed that increasing the PC content increased the bead size, with 100% PC beads showing total deformation and reduced roundness. TGA indicated that wet beads had lower thermal stability compared to dry beads. The highest encapsulation efficiency (95.57% ± 0.49) was observed with 100% AG beads. The 75% AG 25% PC beads exhibited the highest ACE-I inhibitory activity (97.97% ± 1.01). Encapsulated protein hydrolysates retained their ACE-I inhibitory activity after simulated digestion, whereas non-encapsulated hydrolysates lost their bioactivity. Encapsulation of amaranth protein hydrolysates with AG and PC thus preserves antihypertensive activity even after in vitro digestion.

Currently, microwaves, ultrasound, and ultrasound‐microwaves are technologies with several applications, one of which is their use as a method of pasteurization. So far, these techniques have not been used for the pasteurization of a functional aguamiel beverage. This beverage was pasteurized and enriched with probiotic LAB to generate an antihypertensive effect. The physicochemical characteristics (pH, total soluble solids, and color) of the aguamiel beverage were evaluated. Microbiological analysis of the product was also carried out. The probiotic LAB were added to the beverage with the selected pasteurization technique. The growth of LAB in the aguamiel beverage and the prebiotic effects that this product as well as the antihypertensive activity of the beverage were evaluated. It was shown that there is no significant effect of the techniques used on the physicochemical characteristics of the product. However, the storage time may be affected. Compared to traditional pasteurization, microwave, ultrasound, and ultrasound‐microwave techniques were found to reduce the concentration of some pathogenic microorganisms. The microwave technique was selected as the most effective for pasteurization. The probiotic LAB were able to grow in the pasteurized aguamiel beverage and produce an antihypertensive effect. In summary, a functional microwavable pasteurized aguamiel beverage with antihypertensive activity was produced.