Sweet, Sour, Salty and Bitter Flavors

Food has various flavors, and the perception of flavors is called the sense of taste. The human sense of taste includes being sweet, sour, bitter and salty. The flavor of food is commonly recognized by the sense of smell and sense of taste. The flavorous chemicals in food must dissolve in water first, or we can’t taste them out. If the mouth is very dry, no flavor is able to be tasted out.

Fig.1:Map in cooperation with the tongue taste distribution
Fig.1:Map in cooperation with the tongue taste distribution
Source:Made by the project

There are taste buds on the tongue, and these taste buds (there are about 10,000 taste buds in the human body) are classified in to four types, each one of which is made up of 50 to 150 receptor cells. The receptor cells have only a lifespan of one to tow weeks and will be replaced by new cells later. Receptors of the taste buds can make the best response to a give basic flavor. One receptor is able to sense a lot of flavors but only most sensitive to a certain flavor. Depending on different taste buds, the tongue also has areas especially sensitive to a certain sense of taste, e.g. the tip of the tongue is the sweet taste area, and the root of the tongue is sensitive to the bitter flavor. Each taste bud is made up of gustatory cells. Gustatory cells have taste hairs and the taste which gustatory cells sense is sent into the brain via the sensory nerve. After integrating the temperature, quality and various signals sensed by other receptors, the brain can judge which flavor it is.

【Map in Cooperation with the Tongue Taste Distributionn】

  1. The origin of the bitter flavor is alkaloids and the position of perception is the root of the tongue.
  2. The origin of the salty flavor is the salt and the position of perception is the bilateral sides of the tongue and the tip of the tongue.
  3. The origin of the sour flavor is the acid and the position of perception is the bilateral sides of the tongue.
  4. The origin of the sweet flavor is the sugar and the position of perception is the tip of the tongue.

When the flavorous components in food contact the taste buds, this stimulus turns into a chemical signal and forms the sense of taste after processed by the brain. There are a lot of taste buds in one’s childhood but taste buds will change to some extent with age. Hence, the sense of taste is well-developed in one’s youth and any kind of food is very delicious. However, the number of the taste buds decrease with age such that the sense of taste becomes blunt and the diet amount also reduces.

Reviewed by:Zhang, Yong-Ta、Huang, Mei-Chuan professor

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