描述
Wasabi (ワサビ or わさび（山葵）, earlier 和佐比; Eutrema japonicum or Wasabia japonica) is a plant of the Brassicaceae family, which includes cabbages, horseradish, and mustard. It is also called Japanese horseradish, although horseradish is a different plant (which is generally used as a substitute for wasabi, due to the scarcity of the wasabi plant). Its stem is used as a condiment and has an extremely strong pungency more akin to hot mustard than the capsaicin in a chili pepper, producing vapours that stimulate the nasal passages more than the tongue. The plant grows naturally along stream beds in mountain river valleys in Japan. The two main cultivars in the marketplace are E. japonicum 'Daruma' and 'Mazuma', but there are many others. The origin of wasabi cuisine has been clarified from the oldest historical records; it takes its rise in Nara prefecture, and more recently has seen a surge in popularity from the early 1990s to mid 2000s. The plant grows naturally along stream beds in mountain river valleys in Japan. The two main cultivars in the marketplace are W. japonica 'Daruma' and 'Mazuma', but there are many others. The chemical in wasabi that provides for its initial pungency is the volatile allyl isothiocyanate, which is produced by hydrolysis of natural thioglucosides (conjugates of the sugar glucose, and sulfur-containing organic compounds); the hydrolysis reaction is catalyzed by myrosinase and occurs when the enzyme is released on cell rupture caused by maceration – e.g., grating – of the plant. The same compound is responsible for the pungency of horseradish and mustard. Allyl isothiocyanate can also be released when the wasabi plants have been damaged, because it is being used as a defense mechanism. Research has shown that such isothiocyanates inhibit microbe growth, perhaps with implications for preserving food against spoilage and suppressing oral bacterial growth. [Wikipedia]