Capsaicin and the Heat in Chilies

The fiery heat of chili peppers is due to several chemical compounds, especially the alkaloid capsaicin which is co-concentrated in the seeds and pulp. Capsaicin and related capsaicinoids account for the various levels of heat experienced when you taste different chili peppers.

This is a searingly hot salsa of habenero, onions, lime and salt popular in the Yucatan. It's super spicy and incredibly delicious!

The interesting part is that chili peppers are not actually chemically hot. They do not cause a physical burn. Instead, they activate heat receptors on the tongue or skin, which causes the sensation of a temperature increase and even of the sensation of a burn. But it is a short-lived sensation, lasting about fifteen minutes. During this time it also locally increases inflammation in the mouth, making the tongue and mouth more sensitive to temperature, touch, taste, etc.

Other herbs and spices that contain capsaicin, though in much smaller amounts, include cinnamon, oregano, and coriander. It insoluble in water and acidic beverages. It is soluble in fatty and sugary substances as well as alcohol. Alcohol can mildly reduce the sensation of heat, while carbonation increases the burning sensation.

When capsaicin activates the heat receptors and causes a painful burning sensation, a nerve signal is sent to the brain to release endorphins in response to the pain. The endorphins in turn act as a mild temporary mood elevator, providing a slight high. That’s why some individuals love their spicy food! [Resource: François Chartier, Taste Buds and Molecules: The Art and Science of Food, Wine, and Flavor (2012).