Enhancement of isoflavone aglycones, GABA, and mineral bioavailability in <i>Apios americana</i> Medikus by co-fermentation with <i>Lactiplantibacillus plantarum</i> LAB02 and <i>Levilactobacillus brevis</i> BMK484.

Abstract

This study evaluated metabolic and functional changes in <i>Apios americana</i> Medikus (AAM) during lactic acid bacteria fermentation using <i>Lactiplantibacillus plantarum</i> LAB02 and <i>Levilactobacillus brevis</i> BMK484 at different strain ratios and fermentation times. A 1:1 mixed culture fermented for 36 h was optimal. Isoflavone glycosides decreased (1.837 → 0.006 mg/g), while aglycones increased (0.097 → 0.604 mg/g), including genistein (0.194 mg/g) and 2'-hydroxygenistein (0.184 mg/g). Fermentation increased γ-aminobutyric acid (52.6 mg/100 g), aspartic acid, and extractable minerals (P, K, Ca, Mg) under the applied extraction conditions, with key unsaturated fatty acids retained. Antioxidant activity improved, with DPPH and ABTS IC₅₀ values reduced by 26.7% and 21.5%, respectively. PCA and heatmap clustering confirmed distinct shifts among dried, sterilized, and fermented AAM, supporting its use as a functional food ingredient.