Stabilization of 6-methylthiohexyl isothiocyanate in wasabi by addition and inhibition of enzymes

The finding of hydrogen peroxide (947 nmol/100 g) in the paste of wasabi (W asabia japonica Matsum) stems led us to restrain oxidation of 6-methylthioh exyl isothiocyanate by eliminating hydrogen peroxide. The effects of additi on of catalase or peroxidase and sodium ascorbate were examined. When we ad ded catalase or peroxidase and sodium ascorbate, this substance remained a twice and quadruple amount, respectively. Some enzymatic inhibitors were te sted for inhibiting 6-methylthiohexyl isothiocyanate oxidation, When EDTA w as added, about twice as much 6-methylthiohexyl isothiocyanate as that in t he control remained. In the addition of EGCG, 6-methylthiohexyl isothiocyan ate was not reduced. But the addition of EDTA or EGCG had no effect on the stabilization of allyl isothiocyanate.