Metabolomic dynamics and health-related properties of red radish (Raphanus sativus var. sativus) through lactic acid fermentation and storage.

Untargeted UHPLC-HRMS metabolomics coupled with HPTLC/HPLC bioautography revealed that lactic fermentation and subsequent storage profoundly remodelled the metabolome of red radish (Raphanus sativus var. sativus) and shifted bioactivity-relevant compound pools. Fermentation induced pronounced class-specific changes: organic acids increased approximately 10-fold, phenolic compounds 8-fold and flavonoids 4-fold, whereas glucosinolates decreased to 16% of their initial levels. Discriminant biomarkers of fermentation included phenyllactic acid, hydroxyphenyllactic acid, chlorogenic acid isomers and isorhamnetin derivatives. Antioxidants profiling showed a restructuring of the antioxidant pool - shifting from anthocyanins toward flavonols and phenolic acids, with kaempferol-3-O-rhamnoside, quercetin, and oxygenated lipids emerging as novel antioxidant contributors. α-Amylase inhibitory activity increased throughout fermentation and storage, peaking at 4.08 ± 0.08 mg acarbose equivalents/g DW after storage at 18 °C and correlating with increased flavonoid availability, supporting fermented red radish as a promising functional ingredient with antioxidant and antidiabetic potential.