Horseradish

The natural chemical weapon. Intact horseradish has almost no odor. It is the mechanical action of grating that brings sinigrin and the enzyme myrosinase into contact, producing allyl isothiocyanate, a volatile gas that directly attacks sinus receptors. Because this molecule is thermolabile (destroyed by heat), horseradish must never be cooked. It is used raw, grated à la minute (ideally on a sharkskin Oroshigane grater) to preserve its explosive effect, and bound with a thick fat (whipped cream, bone marrow) to encapsulate and prolong its heat.