Formation of Sulforaphane and Iberin Products from Thai Cabbage Fermented by Myrosinase-Positive Bacteria.
Level 5 - mechanism / opinion, no new human data
Bench food chemistry and microbial fermentation study with no human data
PubMed 29671807 · doi:10.3390/molecules23040955
What was done
Researchers isolated 17 myrosinase-positive bacterial strains from Thai fermented foods and evaluated their ability to convert glucosinolates into isothiocyanates (ITCs). The two highest-producing strains—Enterobacter xiangfangensis (EX) and Enterococcus casseliflavus (EC)—were used to ferment Thai cabbage (Brassica oleracea L. var. capitata) containing glucoiberin (430.5 µmol/100 g DW), glucoraphanin (615.1 µmol/100 g DW), and 4-hydroxyglucobrassicin (108.5 µmol/100 g DW) for 3 days at 25 °C. Fermentations were evaluated against spontaneous fermentation for ITC/nitrile yields and antioxidant capacity.
What was found
Bacterial inoculation produced significantly higher ITC concentrations (p < 0.01) with increased antioxidant activities compared to spontaneous fermentation. Peak yields occurred on day 2: - EX-induced cabbage produced 117.4 µmol/100 g DW iberin and 294.1 µmol/100 g DW sulforaphane. - EC-induced cabbage produced 51.7 µmol/100 g DW iberin (significantly lower than EX) and 242.6 µmol/100 g DW sulforaphane (not significantly different from EX).
Why it matters
Using selected myrosinase-positive starter cultures in brassica vegetable fermentation can substantially enhance the formation of health-promoting isothiocyanates like sulforaphane and iberin from their precursor glucosinolates.
Limits
This is an in vitro food chemistry and microbial bench study with no human or animal intake, bioavailability, or clinical outcome data. The safety profile, potential toxicity, and sensory acceptability of these bacterial strains were not reported in the abstract.
Cited by
- supports Strains of Enterococcus, Lactobacillus, and Bifidobacterium species possess myrosinase activity.