Wasabi

The true wasabi rhizome (Eutrema japonicum) is a marvel of defensive biochemistry. Grated raw on a very fine surface (shark skin), the cellular rupture mixes two isolated compounds to form allyl isothiocyanate. This gas is so volatile that it instantly shoots up the nasal passages, but loses all its power in less than 15 minutes in the open air. It traditionally serves as a natural antimicrobial agent for raw fish while "cleansing" the palate between fatty bites.