Antioxidant and ACE-Inhibition Activities After In Vitro Digestion of a Non-Fermented Dairy Beverage Enriched with Postbiotics of <i>Lactobacillus</i> spp.

Postbiotics are recently gaining consumer attention for their potential health benefits. This study aimed to examine the effects of supplementation of a non-fermented dairy beverage with postbiotics derived from <i>Lactobacillus acidophilus</i> and <i>Lactobacillus helveticus</i> on antioxidant (DPPH, ABTS, FRAP, and ORAC), antimicrobial, and ACE-inhibition activities before and after in vitro digestion. Three dairy beverages were elaborated: without the addition of postbiotics (T0), with <i>Lactobacillus acidophilus</i> postbiotics (T1), and with <i>Lactobacillus helveticus</i> postbiotics (T2). Before in vitro digestion, T2 presented higher antioxidant activity (<i>p</i> < 0.05). And, after in vitro digestion, except by the ABTS method, T1 and T2 presented the highest antioxidant activities (<i>p</i> < 0.05) and bioaccessibility indexes (<i>p</i> < 0.05). Regarding ACE-inhibition activity, before in vitro digestion, there were no differences among treatments (<i>p</i> > 0.05), but after in vitro digestion, T1 and T2 presented the highest ACE-inhibition activities (<i>p</i> < 0.05) and bioaccessibility indexes (<i>p</i> < 0.05). An antimicrobial effect against <i>Bacillus</i> spp. and <i>S. aureus</i> was observed in <i>Lactobacillus acidophilus</i> and <i>Lactobacillus helveticus</i> postbiotics. However, <i>L. acidophilus</i> postbiotics did not present an antibacterial effect against <i>E. coli</i>. Such findings highlight the potential of postbiotics as functional ingredients to enhance the antioxidant and ACE-inhibition activities of non-fermented dairy beverages, further adding to their appeal as health-promoting dairy food.