Wasabi’s not just for sushi
Laila Benkrima, PhD
That green blob on your sushi plate called “wasabi” is likely a pale imitation of the real thing. Most real wasabi (along with its associated health benefits) is found primarily in Japan. The good news is you may soon taste the real wasabi, thanks to new cultivation techniques in BC.
Because of the rising popularity of sushi restaurants around the world, everybody is familiar with wasabi. For thousands of years, wasabi has been incorporated into Japanese cuisine to enhance flavour and add pungency to many traditional dishes. But wasabi can also provide some amazing health benefits.
Wasabi (Eutrema japonica), also called Japanese horseradish, is a plant originating in Japan that belongs to the cruciferous or Brassica family. What used to be the most underrated of vegetables, such as cabbage, broccoli, kale, cauliflower—and wasabi—are now becoming superstars of functional food.
We all know that we should be eating our daily portion of these health-giving brassicas as part of a balanced diet. Packed with fibre, vitamins, and minerals, cruciferous vegetables also contain glucosinolates, which are the precursors of the cancer-preventing compounds isothiocyanates.
On top of being one of the most appreciated and flavourful condiments of Japanese cuisine, wasabi also has a remarkable history. Native to Japan, it has been used as a spice and in traditional medicine for more than a thousand years.
Wasabi’s fleshy stem was purportedly used to increase appetite, for stomach disorders, and as a topical treatment against rheumatism and neuralgia. It is also said to have been consumed for detoxification purposes and for its antimicrobial properties.
Historical records indicate that wasabi cultivation started during the 10th century, but it really became popular a few centuries later in Japan, when it was served as a ground condiment with raw fish preparations and other traditional dishes.
The word wasabi is usually associated with the pungent green paste served with our sushi rolls, but most of us have probably never eaten real wasabi. The green spicy paste served in most Western sushi bars doesn’t contain any authentic wasabi; what’s almost universally served is a mixture of horseradish, mustard, and artificial green food colouring.
Due to its high cost, real Japanese horseradish—wasabi—is rarely served in restaurants. Prices for a “handsome” fresh wasabi rhizome can be as high as $160 a kilogram, wholesale.
In an interview with Dr. Zamir K. Punja, professor of plant pathology and biotechnology at Simon Fraser University, BC, I asked him about Canadian-grown wasabi.
[Q]: Why does wasabi have a reputation as one of the most difficult crops to cultivate?
[A]: In its natural range of distribution in Japan, wasabi can be found growing near river beds and in valleys that are cool, moist, and foggy. Therefore, commercial production of wasabi in BC requires these conditions be provided for best growth. In addition, the rhizome is slow growing, requiring as much as 18 months to reach a marketable size.
[Q]: What are the main challenges faced by growers?
[A]: The cool, moist conditions optimal for wasabi growth can encourage the development of fungal diseases that can dramatically reduce the quality of the crop. Sustainable and environmentally acceptable methods for managing these diseases are currently being researched.
So, in the near future, when you spread that dab of green paste on your sushi, you might just get to taste the real thing—Canadian-grown wasabi.
In 2011, an Ig Nobel Prize for Chemistry was awarded to the Japanese inventors of a wasabi fire alarm that sprays a synthesized wasabi compound (allyl isothiocyanate) responsible for the “somatosensation” that the nervous system perceives—even during sleep—as a painful, stinging feeling. The inventors went on to patent the system they described as an “Odor Generation Alarm and Method for Informing Unusual Situation.” The Ig Nobels are awarded for scientific achievements that “first make people laugh, then make them think.”
Got a hankering for wasabi? Check out this recipe: Salmon-Avocado Burgers with Wasabi Yogurt Sauce