Taste (or, more formally, gustation) is a form of direct chemoreception and is one of the traditional five senses. It refers to the ability to detect the flavor of substances such as food and poisons. In humans and many other vertebrate animals the sense of taste partners with the less direct sense of smell, in the brain's perception of flavor. In the West, experts traditionally identified four taste sensations: sweet, salty, sour, and bitter. Eastern experts traditionally identified a fifth, called umami (savory). More recently, psychophysicists and neuroscientists have suggested other taste categories (umami and fatty acid taste most prominently, as well as the sensation of metallic and water tastes, although the latter is commonly disregarded due to the phenomenon of taste adaptation.Fact: date=May 2008) Taste is a sensory function of the central nervous system. The receptor cells for taste in humans are found on the surface of the tongue, along the soft palate, and in the epithelium of the pharynx and epiglottis.

Basic taste

Psychophysicists have long suggested the existence of four taste 'primaries', referred to as the basic tastes: sweetness, bitterness, sourness, and saltiness. Umami is now accepted as the fifth basic taste, exemplified by the non-salty sensations evoked by some free amino acids such as monosodium glutamate.

Other possible categories have been suggested, such as a taste exemplified by certain fatty acids such as linoleic acid. Some researchers still argue against the notion of primaries at all and instead favor a continuum of percepts , similar to color vision.

All of these taste sensations arise from all regions of the oral cavity, despite the common misconception of a "taste map" of sensitivity to different tastes thought to correspond to specific areas of the tongue. This myth is generally attributed to the mis-translation of a German text, and perpetuated in North American schools since the early twentieth century . Very slight regional differences in sensitivity to compounds exist, though these regional differences are subtle and do not conform exactly to the mythical tongue map. Individual taste buds (which contain approximately 100 taste receptor cells), in fact, typically respond to compounds evoking each of the five basic tastes.

The basic tastes are those commonly recognized types of taste sensed by humans. Humans receive tastes through sensory organs called taste buds or gustatory calyculi, concentrated on the upper surface of the tongue, but a few are also found on the roof of one's mouth, furthering the taste sensations we can receive. Scientists describe five basic tastes: bitter, salty, sour, sweet, and umami (described as savory, meaty, or brothy). The basic tastes are only one component that contributes to the sensation of food in the mouth—other factors include the food's smell, detected by the olfactory epithelium of the nose, its texture, detected by mechanoreceptors, and its temperature, detected by thermoreceptors. Taste and smell are subsumed under the term flavor.