capsaicin definition
Capsaicin (pronounced cap-SAY-a-sin) is the chemical in chili peppers that makes them spicy. Specifically, capsaicin occurs in the fruits of plants in the Capsicum family, including bell peppers, jalapeÃ±o peppers, cayenne peppers and other chili peppers. Capsaicin in chili peppers is measured on the Scoville Scale and expressed in terms of Scoville Heat Units. Bell peppers are the only member of the capsicum family that don't contain capsaicin, and thus register zero Scoville units.