Content of 6-methylsulfinylhexyl isothiocyanate in wasabi and processed wasabi products

Abstract

In wasabi (Wasabia japonica, Japanese domestic horseradish), 6-methylsulfinylhexyl isothiocyanate (6-MSITC), one of its components, has been found to have activities to inhibit metastasis of cancer, to induce phase II enzymes, and to inhibit platelet aggregation. To establish a guideline for effective intake of 6-MSITC from daily diet, we have analyzed the 6-MSITC content in various species of wasabi and processed wasabi products. The 6-MSITC content in different parts of five species of wasabi was analyzed. The result showed that in all species analyzed the 6-MSITC content was the highest in rhizome and then in the order of root, stem and leaf. Among the five species tested, the 6-MSITC content in rhizome was the highest in "Mitsuki", a high yield species. In Horseradish, however, the 6-MSITC content was below one-tenth of that in wasabi rhizomes. Furthermore, the 6-MSITC content in 25 types of processed wasabi products was analyzed. The result showed that there were great differences among manufacturers and types of products. The 6-MSITC content in processed wasabi products were related to the percentage of wasabi rhizome in the material. In conclusion, for effective intake of 6-MSITC from daily diet, it is most desirable to take the rhizome part of wasabi or choose processed wasabi products with a high percentage of rhizomes of wasabi.