Tasting - How Do We Taste?

The sense of taste, or gustation, is part of the central nervous system. It allows us to detect the flavour of foods and other substances.

Being able to taste protects us from eating unsafe foods. It also helps us to balance our diets with different nutritional requirements.

The sense of taste is greatly enhanced by the sense of smell, and by feeling the texture and physical/chemical temperature of foods. In fact, the experience of flavour is really a combination of a number of senses besides taste.

Inside the mouth there are approximately ten thousand taste buds (also called gustatory calyculi). These are found mainly on the tongue, on or around small lumps called papillae, as well as on the soft palate, epiglottis and pharynx. Each of these taste buds is able detect five basic taste sensations. These are sweet, sour, salty, bitter and unami (savoury). (Scientists are now considering that fat may be a sixth basic taste.)

Each taste bud contains about fifty to one hundred receptor cells. Each of these cells has a long, hair-like protrusion that extends from a small opening where it comes into contact with food chemicals it finds dissolved in saliva. Each receptor will respond best to one of the five basic tastes. Once stimulated, these cells send nerve impulses containing the taste information to the brain, where the signals are interpreted in several areas of the cerebral cortex.

It is often thought, and was even taught in schools for many years, that certain areas of the tongue specifically detect certain tastes. This has been found to be incorrect. While there are apparently some tiny differences in sensitivity in certain areas of the tongue, they are only very slight and are barely significant.  In general, taste buds in all areas of the tongue can uniformly distinguish the basic tastes.