User:Plantdrew/Wasabi

Wasabi (わさび（山葵）) is a condiment used in Japanese cuisine. Wasabi was traditionally prepared from the rhizomes of the wasabi plant (Eutrema japonicum), but currently is usually prepared from horseradish to which green food coloring has been added. Wasabi has an extremely strong, hot flavor. Its hotness is more akin to that of a hot mustard than that of the capsaicin in a chili pepper, producing vapours that stimulate the nasal passages more than the tongue. Both horseradish and rhizomes of the wasabi plant contain the compound allyl isothiocyanate which is responsible for this effect.

True wasabi and western wasabi
Wasabi is difficult to cultivate (see below), and that makes it quite expensive. Due to its high cost, a common substitute is a mixture of horseradish, mustard, starch and green food coloring. Outside of Japan, it is rare to find real wasabi plants. Often packages are labeled as wasabi, but the ingredients do not actually include wasabi plant. Although the taste is similar between wasabi and horseradish, they are easily distinguished. In Japan, horseradish is referred to as "western wasabi" (西洋わさび). In the United States, true wasabi is generally found only at specialty grocers and high-end restaurants.

Etymology
The two kanji characters "山" and "葵" do not correspond to their pronunciation: as such it is an example of gikun (meaning, not sound). The two characters actually refer to the mountain Asarum, as the wasabi plant's leaves resemble those of a member of Asarum species, in addition to its ability to grow on shady hillsides. The word, in the form 和佐比, appeared in 918 in The Japanese Names of Medical Herbs (本草和名 Honzō Wamyō). Spelled in this way, the particular kanji are used for their phonetic values only, known as ateji (sound, not meaning — opposite of gikun).

Uses
Wasabi is generally sold as a dried powder in large quantities, or as a ready-to-use paste in tubes similar to travel toothpaste tubes. . The dried powder and ready-to-use paste are prepared from horseradish rather than the root of the wasabi plant. When the root is served in restaurants, a paste is prepared when the customer orders, and is made using a grater to grate the root; once the paste is prepared, it loses flavor in 15 minutes. In sushi preparation, sushi chefs usually put the wasabi between the fish and the rice because covering wasabi until served preserves its flavor.

Because the burning sensations of wasabi are not oil-based, they are short-lived compared to the effects of chili peppers, and are washed away with more food or liquid. The sensation is felt primarily in the nasal passage and can be quite painful depending on amount taken.

Legumes (peanuts, soybeans, or peas) may be roasted or fried, then coated with wasabi powder mixed with sugar, salt, or oil and eaten as a crunchy snack. Inhaling or sniffing wasabi vapor has an effect like smelling salts, a property exploited by researchers attempting to create a smoke alarm for the deaf. One deaf subject participating in a test of the prototype awoke within 10 seconds of wasabi vapor being sprayed into his sleeping chamber. This was "rewarded" with the 2011 Ig Nobel Prize in Chemistry to Makoto Imai, Naoki Urushihata, Hideki Tanemura, Yukinobu Tajima, Hideaki Goto, Koichiro Mizoguchi and Junichi Murakami for determining the ideal density of airborne wasabi (pungent horseradish) to wake people in event of an emergency.

The wasabi plant


Eutrema japonicum (synonym Wasabia japonica often misspelled as Eutrema japonica), is a member of the Brassicaceae family, which includes cabbages, horseradish, and mustard. It is also called Japanese horseradish, although it is not actually from the horseradish species of plants. Its root is used as a condiment and has an extremely strong flavor. The plant grows naturally along stream beds in mountain river valleys in Japan. There are also other species used, such as W. koreana, and W. tetsuigi. The two main cultivars in the marketplace are W. japonica 'Daruma' and 'Mazuma', but there are many others.

Fresh wasabi leaves can be eaten, having the spicy flavor of wasabi roots.

Cultivation


Few places are suitable for large-scale wasabi cultivation, and cultivation is difficult even in ideal conditions. In Japan, wasabi is cultivated mainly in these regions:


 * Izu peninsula, located in Shizuoka prefecture
 * Nagano prefecture
 * Iwate prefecture

There are also numerous artificially cultivated facilities as far north as Hokkaidō and as far south as Kyūshū. As the demand for real wasabi is very high, Japan has to import a large amount of it from China, Ali Mountain of Taiwan, and New Zealand.

In North America, a handful of companies and small farmers are successfully pursuing the trend by cultivating Wasabia japonica.

Preparation
Wasabi root is often grated with a metal oroshigane, but some prefer to use a more traditional tool made of dried sharkskin with fine skin on one side and coarse skin on the other. A hand-made grater with irregular teeth can also be used. If a shark-skin grater is unavailable, ceramic is usually preferred.

Nutritional information
100g of wasabi root contains:
 * Calories : 109
 * Fat: 0.63 g
 * Carbohydrates: 23 g
 * Fibre: 7.8 g
 * Protein: 4.8 g

Chemistry
The chemical in wasabi that provides for its initial pungency is the volatile allyl isothiocyanate, which is produced by hydrolysis of natural rhizome 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's rhizome.

The unique flavor of wasabi root is a result of complex chemical mixtures from the broken cells of the rhizome, including those resulting from the hydrolysis of thioglucosides into glucose and methylthioalkyl isothiocyanates:


 * 6-methylthiohexyl isothiocyanate,
 * 7-methylthioheptyl isothiocyanate, and
 * 8-methylthiooctyl isothiocyanate.

Research has shown that such isothiocyanates inhibit microbe growth, perhaps with implications for preserving food against spoilage and suppressing oral bacterial growth.