Temperature-modulated microbial succession governs sulforaphane bioconversion during natural enriched fermentation of...

Sulforaphane, a potent anti-cancer isothiocyanate from broccoli, shows limited bioavailability in raw vegetables, restricting functional food applications. This study suggests for the first time that native lactic acid bacteria fermentation systematically enhances sulforaphane bioconversion through controlled temperature and matrix optimization. Broccoli inflorescences were fermented at 20-35 °C with different pretreatments (raw, blanched, sterilized), followed by HPLC-DAD quantification, 16S rRNA gene amplicon sequencing, and biochemical characterization including myrosinase activity and glucosinolate-isothiocyanate conversion efficiency. Fermentation at 35 °C with blanching achieved high sulforaphane concentrations of 84,000 μg/kg d.w. a 44-fold increase over unfermented raw broccoli values. Pearson correlation analysis revealed a strong positive association (r = 0.93, p < 0.01) between sulforaphane accumulation and microbial succession from Lactococcus to Lactiplantibacillus plantarum dominance across three distinct fermentation phases. This work supports the potential of natural fermentation biotransforms cruciferous vegetables into sulforaphane-enriched functional foods without chemical extraction, enabling sustainable microbiome-driven bioprocessing strategies for nutraceutical development and cancer chemoprevention applications.