Capsaicin, a alkaloid containing vanilla amide, can be combined with the vanilla receptor subtype 1 (vanilloid receptor subtype1, VR1) of sensory neurons. As the VR1 receptor activates, it transmits a searing sensation (it is also activated when stimulated), so when eating chili peppers, it feels like a burning sensation. This searing sensation allows the brain to create an erroneous concept of bodily injury and begin releasing the body's own analgesic substance, endorphins, so that people have a euphoric feeling that the more they eat, the more they want to eat.
Capsaicin is partial alkalinity after the ph value is tested. The advantage of edible chili peppers, first of all, is to reduce the acid content of human body. Because the human diet like sour food, so the body of the high acid content, so that toxins in the body can not effectively discharge in vitro. In order to make the acid and alkali food chain in the body to achieve a balanced state, usually also eat a small amount of spicy food and vegetables, to ensure that the ph value of body fluids are basically in a balanced state. If you eat spicy vegetables, you can add acidic substances when cooking spicy vegetables to reduce the content of capsaicin.
American scientist (Wilbur L. Scoville) in 1912, for the first time to establish the evaluation of chili spicy units, that is, after grinding the pepper, diluted with sugar syrup, until the detection of spicy, then the dilution of a multiple represents the spicy pepper. To commemorate the Scoville, so the standard is named the Scoville Index, and the "History of the High Dimension" (SHU, Scoville Heat unit) has become a spicy units.
Scoville Tasting method of judging the degree of hotness has been replaced by instrumental quantitative analysis, but his unit system has been retained. On the hot pepper, just look at their Scoville index on the line.