Contents
What is this Wasabi Radish?
Japanese horseradish (Eutrema japonicum), commonly known as wasabi radish, is a perennial plant of the Brassicaceae family native to Japan, Korea, and the Eastern parts of Russia. The economically vital part of the plant is its rhizome which is made into a paste after grinding. The wasabi paste is pungent and spicy and is served as a condiment with sushi and sashimi.
Wasabi radish Cultivation
But this isn’t easy to cultivate and requires unique environmental conditions to thrive. However, due to its high demand and market price, the commercial cultivation of wasabi has expanded to include New Zealand, Taiwan, Korea, Israel, Brazil, Thailand, and some parts of Canada and the United States. Although wasabi paste can be found in plenty of grocery stores and Western restaurants, it is not authentic wasabi. Instead, it is made from the more common horseradish, another plant from the same family, mixed with mustard and food coloring.
Planting
Wasabi is found growing freely in cool, shady stream beds in the Japanese mountains. The plant prefers a temperature of 8°C to 20°C and a soil pH of 6 to 7.5. They are grown in semi-aquatic, greenhouse or field conditions.
Under semi-aquatic conditions, specialized hydroponic systems are used. Wasabi grown in fields are irrigated to maintain soil moisture and humidity and to cool the plant. Microirrigation systems, including sprinkler irrigation, are ideal as they are able to manage soil moisture and keep the canopy moist. When grown under semi-aquatic conditions are, slowly releasing, N-P-K fertilizer is added to circulating irrigation water. For field conditions, compost is incorporated into the soil prior to planting.
Wasabi is propagated by tissue culture, stem cuttings and seeds. The seeds or growing material should be acclimatized in a nursery before planting. Seedlings should be planted so that the plant’s crown is around half an inch above the soil surface. The plant requires a lot of shade and does not tolerate direct sunlight. Thus, they are commonly grown under shade trees or a shade net. Harvesting is done by pulling up the plant.
Wasabi is highly susceptible to pests and diseases, which deteriorate the stem quality and yield. Additionally, chemical pesticides are not recommended for wasabi as they may damage the delicate stem. Some common diseases associated with wasabi are; internal black rot, vascular wilt, black leg, white blister rust, downy mildew, damping off, white mold and club root.
Wasabi Paste
The wasabi paste is prepared by grating the fresh rhizome against a rough surface. “Oroshigane” or sharkskin graters are traditionally used for this in Japan. The grated root is then mixed with water to form the paste. As mentioned, it is often served alongside Japanese seafood dishes such as sushi and sashimi. Wasabi adds a unique flavor to Japanese cuisine. Although it is considered spicy, it is pretty different from chillis. The wasabi flavor quickly disappears, leaving a sweet aftertaste with no burning. The compounds in wasabi stimulate the nasal passage more than the tongue.
Health Benefits
A group of naturally occurring sulfur compounds called isothiocyanates (ITCs) gives the characteristic pungent flavor of wasabi. They evolve from glucosinolates by the action of the enzyme myrosinase when the tissue is damaged.
The medicinal value of wasabi and its chemicals are well documented and are at the forefront of research in functional foods. ITCs are known to have anti-carcinogenic, anticoagulant, -inflammatory, and anti-biotic effects. Several studies have found that consuming cruciferous vegetables, including wasabi, can reduce the risk of lung, breast, colon, prostate, liver, and pancreatic cancer.
ITCs have the potential to prevent inflammatory conditions such as asthma by inhibiting the production of inflammatory molecules. Wasabi could also contribute to healthy teeth and gums by inhibiting the growth of bacteria. They have also been effective against H. pylori, which causes stomach ulcers, and Escherichia coli and Staphylococcus aureus, which commonly cause food poisoning.
Apart from this, it is believed that wasabi helps improve digestion, boost the immune system, assist in fat loss, and lower the risk of heart disease and stroke.
End Note:
Wasabi is a unique ingredient that adds a myriad of tastes and benefits to your food. Due to its versatility in cuisine and very specific growing requirements, authentic wasabi is quite expensive and rare. However, it is starting to become popular in Western markets along with other Japanese cuisines such as sushi. If you have not tried wasabi yet, it is definitely worth seeking out. Whether you enjoy fresh, grated, or prepared paste, the pungent and spicy flavor of wasabi will surely add a new dimension to your culinary experiences.
