It turns out that spiciness is not a taste, but a pain!

Science Fiction Network, December 30 (Jin Kaiyi) We often talk about the five tastes of "sour, sweet, bitter, spicy and salty", but in fact, the human taste buds can only distinguish four basic types of tastes: sweet, sour, bitter and salty, and spicy is a pain sensation, not a taste sensation.

The spicy feeling is produced by capsaicin and other substances acting on the receptors on the pain fibers of the tongue. This pathway is actually a pain pathway, not a taste pathway. Therefore, from the perspective of neuroscience, spiciness is actually a kind of pain. To explain it in more popular terms, capsaicin stimulates the pain nerves of the taste buds and makes us feel a burning pain, which is the source of the spicy feeling.

In addition, because the sensor that can sense capsaicin is also a receptor that senses temperature, when it is activated, it will produce a burning sensation almost like touching boiling water, so there will be a "spicy and hot" feeling. In this sense, the feeling of "spicy" is more like an illusion of "hotness", and then the brain directs the body to make a series of stress reactions, such as sweating, blushing, runny nose, tears, etc.

Since spiciness is a painful sensation, why is eating spicy food addictive? After capsaicin enters the human body, it stimulates the oral mucosa and nerve endings, and the brain continuously releases endorphins, which make people feel relaxed and excited, so that they feel a sense of pleasure after eating chili peppers. In addition, eating spicy food promotes increased saliva secretion and gastrointestinal motility, which greatly increases appetite, and the more you eat, the more you can't stop.

In addition to the spiciness, the numbing taste of Sichuan pepper is a vibration produced by the hydroxysanshool it contains stimulating the vibration receptors. Astringency is a sense of astringency caused by the stimulation of tactile nerve endings when food ingredients cause oral proteins to coagulate. These are not taste sensations felt by taste buds.