Exploring the healthy potential of goat milk fermented by novel isolated lactic acid bacteria: Genetic identification, bioactive peptides, nutritional mechanism and sensory evaluation.

Lactic acid bacteria (LAB) ferment milk to produce bioactive peptides to benefit human health. In this study, a total of 74 LAB strains were used to ferment goat milk, and two novel strains, Lactobacillus delbrueckii MF55 and Lacticaseibacillus paracasei MF48, were identified with strong angiotensin-converting enzyme (ACE) inhibitory activity 70.73 % and antioxidant activity 63.33 %, respectively. Following ultrafiltration, QExactive identification, in silico simulations, and in vitro assay, five peptides (MPFPK, EMPFPK, FFDDK, GPFPILV, TTMPLW) were collected. Among them, peptide TTMPLW exhibited the strongest ACE inhibitory (IC50 115.55 μM) and antioxidant (IC50 2.57 mM) activities, followed by GPFPILV (232.96 μM and 10.27 mM). Molecular docking simulation suggested that peptides TTMPLW and GPFPILV were dual-target ligands for ACE and Keap1. Goat milk fermented by MF55 maintained stable bioactivity and favorable sensory properties during 28 days of cold storage. Our study provided two novel LAB strains with excellent dual-functional activity to help the development of functional dairy products.