The mismatched pair is bitter; acids such as those in toxins or poisons. Ligands (stimulating agent) for bitter receptors are molecules like cycloheximide, denatonium, or β-glucopyranosides. Bitterness is the most sensitive of the tastes and it often has unpleasant taste. The most often used bittering agent is caffeine. Bitter foods and beverages include coffee, unsweetened cocoa, olives, citrus peel, beer…
