Principle of taste

It is generally agrees that there are only four basic or true, tastes: sweet, bitter, sour, and salty. The tongue is the antenna that receives the taste of food and drink by which the physical body is sustained. The sensitivity to taste is located in taste buds on the tongue.

However, region responsive to taste are also found in the palate, in the pharynx and larynx on the tonsils and epiglottis, and in some people at least, on the mucosa of the lips and cheeks, the underside of the tongue and in the floor of the mouth.

The taste buds are grouped in papillae, which appear to be sensitive to more than one taste. There is undoubtedly a regional distribution of the four kinds of receptors at the tongue, creating areas of sensitivity – the sweet taste at the tip of the tongue bitter at the back, sour at the edges and salty at both edges and tip.

There is an area in the middle of the tongue which has no taste receptors. A number of factors influence the sense of taste. Taste is affected by temperature. Thus, a sugared drink appears sweeter when hot than when cold.

Similarly, a lemon drink tastes more sour when it is hot than when cold. Coffee and tea appear to be more bitter when cold than when hot. These effects are due to the variations on the sensitivity of tastes buds to temperature.
Principle of taste