Lactiplantibacillus plantarum-mediated bioconversion of blue honeysuckle juice amplifies phenolics to inhibit xanthine oxidase and reshapes volatile metabolome.

Fermentation-mediated biotransformation represents an effective strategy to enhance the bioactivity of functional juices. This study examined the inhibitory effects of blue honeysuckle juice fermented with eight Lactiplantibacillus plantarum strains on xanthine oxidase (XO) activity. Fermentation significantly enhances the XO inhibition capacity of blue honeysuckle juice. LC-MS analysis revealed substantial increases in six key phenolic compounds with XO inhibitory activity: C3G (IC50 = 115.28 μmol/L), cyanidin-3,5-diglucoside (IC50 = 116.34 μmol/L), peonidin-3-glucoside (IC50 = 105.34 μmol/L), 3-caffeoylquinic acid (IC50 = 250.35 μmol/L), quercetin (IC50 = 88.75 μmol/L), and catechin (IC50 = 110 μmol/L). Molecular simulations elucidated the inhibitory mechanism through stabilized ligand-XO interactions involving hydrogen bonding, van der Waals forces, and π-σ interactions over 100 ns trajectories. Notably, fermentation also reduced the aldehyde content, correlating with improved sensory profile. These findings demonstrate that Lactiplantibacillus plantarum fermentation enhances the biological activity and organoleptic properties of blue honeysuckle juice, providing mechanistic insights and practical strategies for developing functional beverages.