Antibacterial activity of heated cabbage juice, S-methyl-L-cysteine sulfoxide and methyl methanethiosulfonate

Autoclaved cabbage juice was inhibitory to growth of Staphylococcus aureus. S-Methyl-L-cysteine sulfoxide (SMCSO), autoclaved either together with or separately from nutrient broth, also inhibited the growth of S. aureus, but inhibition was greater when SMCSO was autoclaved separately. Methyl methanethiosulfonate (MMTSO2), a thermal breakdown product of SMCSO, completely inhibited growth of S. aureus at 10 ppm. MMTSO2 was formed in both autoclaved samples of cabbage juice and aqueous solution of SMCSO. Thus, evidence indicates that the bacterial inhibitory activity in autoclaved cabbage juice was due to heat-induced formation of MMTSO2 from SMCSO.