Stabilization of 6-methylthiohexyl isothiocyanate in wasabi by addition of antioxidants

The stabilization of 6-methylthiohexyl isothiocyanate in Wasabi (Wasabia japonica Matsum.) by addition of antioxidants and some other compounds was studied. Addition of 1% each of sodium thiosulphate, methionine, acetic acid, and ethanol did not show any effects on stabilization of 6-methylthiohexyl isothiocyanate in wasabi, whereas addition of 1% of α-tocopherol or a rosemary extract resulted in significant stabilization of it. Addition of α-tocopherol together with ascorbic acid induced a synergistic effect on stabilizing not only 6-methylthiohexyl isothiocyanate but also the allyl isothiocyanate.