So Whatsup with Wasabi?

So, you finally get that date with “Miss brown eyes” and in hopes of impressing her with your worldly knowledge of cuisine you take her to enjoy sushi. Unfortunately, you can’t resist the temptation to tell her that the wasabi you are using as a condiment to your sushi is not really wasabi from the ground rhizomes of the Japanese plant ‘Eutrema japonicum’, but rather is actually made from the vulgar, all too common, western plant, the horseradish root (Amoracia rusticana). As you proceed to wax eloquently regarding the subtle differences that your refined palate can detect between real wasabi and the horseradish imposter, you note that she is focused instead on her cell phone, has ordered an Uber via whatsup, and is on her way home. What went wrong? Another example of “pompopus vegetarious” or focusing too much on the differences and overlooking the similarities. Although their origins are geographically diverse: wasabi is native to river valleys in japan and horseradish is native to southeastern Europe and Asia, both are members of the Brassicaceae family, and more importantly, both share very similar chemistry. “Western wasabi’ based on horseradish was developed because the Japanese wasabi is very difficult to grow commercially, and hence is simply too expensive.

The shared chemistry of these two plants helps us understand why the similarities outweigh the differences. Like all members of the Brassicaceae family, including cole crops, mustards, Chinese cabbage, turnips and radishes the defense against herbivory is based on repellent pungency. Both wasabi and horseradish and all Brassicaceae produce stable sulfur-based compounds called glucosinolates. When bites into a leaf or tissue and crushes the plant cells, the substrate glucosinolates is put in contact with an enzyme, myrosinase, which cleaves off the glucose sugar from the glucosinolates and produces less stable more volatile isothiocyanates which repel the insect or critter. Variation in the glucosinolates and resulting isothiocyanates contributes to the unique favors and pungency of different vegetables in the Brassicaceae family. The isothiocyanates produced from freshly grated wasabi or horseradish are quickly dissipated, thus, it is best served fresh. The addition of wine or vinegar produces a longer lasting paste that can be packaged like toothpaste. The dried roots or rhizomes can be stored as a ground powder as the reaction to produce isothiocyanates requires the addition of water. Commercial wasabi powder contains food coloring to make it bright green.

Thus, the plants may be different, but the chemistry is almost the same – so in wasabi made from wasabi or horseradish, focus on the similarities, not the differences.

The “heat” of wasabi and mustard is due to the isothiocyanates activation of TRPV1 channels in human tissue sends a FAKE message to the brain indicating that something physically hot is touching your skin or tongue, thus, our bodies react by flushing the region with blood, producing sweating. This is similar to the effect of hot peppers, but not as long lasting.