''This article refers to the sensory system. For the social and aesthetic aspects of taste, consult taste (sociology). For other uses, see taste (disambiguation).

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. Classical taste sensations include sweet, salty, sour, and bitter. More recently, psychophysicists and neuroscientists have suggested other taste categories (umami and fatty acid taste most prominently.)

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 classification of tastes

Main article: Basic taste

Psychophysicists have long suggested the existence of four taste 'primaries', referred to as the basic tastes: sweetness, sourness, bitterness, and saltiness. Umami, or savoriness, has been suggested as a fifth basic taste, exemplified by the non-salty sensations evoked by Monosodium glutamate.^[1][2]

Other possible categories have been suggested, such as a taste exemplified by certain fatty acids such as linoleic acid (see [1], [2], [3]). Some researchers still argue against the notion of primaries at all and instead favor a continuum of percepts, in sharp contrast to color vision.

All of these taste sensations arise from all regions of the oral cavity, despite the common misperception of a "taste map" of sensitivity to different tastes thought to correspond to specific areas of the tongue [4]. The "mouth map" is a myth, generally attributed to the mis-translation of a German text, and perpetuated in North American schools since the early twentieth century ^[3]. 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 four basic tastes.

Supertasters

Main article: Supertaster

A supertaster is a person whose sense of taste is significantly more acute than average. Women are more likely to be supertasters, as are Asians, Africans and South Americans. Among individuals of European descent, it is estimated that about 25% of the population are supertasters. The cause of this heightened response is currently unknown, although it is thought to be, at least in part, due to an increased number of fungiform papillae.^[4] The evolutionary advantage to supertasting is unclear. In some environments, heightened taste response, particularly to bitterness, would represent an important advantage in avoiding potentially toxic plant alkaloids. However, in other environments, increased response to bitter may have limited the range of palatable foods. In our modern, energy-rich environment, supertasting may be cardioprotective, due to decreased liking and intake of fat, but may increase cancer risk via decreased vegetable intake. It may be a cause of picky eating, but picky eaters are not necessarily supertasters, and vice versa.

Aftertaste

Main article: Aftertaste

Aftertaste is the persistence of a sensation of flavor after the stimulating substance has passed out of contact with the sensory end organs for taste. Some aftertastes may be pleasant, others unpleasant.

Alcoholic beverages such as wine, beer and whiskey are noted for having particularly strong aftertastes. Foodstuffs with notable aftertastes include spicy food, such as Mexican food (e.g. chili pepper), or Indian food (such as curry).

Medicines and tablets may also have a lingering aftertaste.

Acquired taste

An acquired taste is an appreciation for a food or beverage that is unlikely to be enjoyed, in part or in full, by a person who has not had substantial exposure to it, usually because of some unfamiliar aspect of the food or beverage, including a strong or strange odor, taste, or appearance. The process of “acquiring” a taste involves consuming a food or beverage in the hope of learning to enjoy it. In most cases, this introductory period is considered worthwhile, as many of the world's delicacies are considered to be acquired tastes. A connoisseur is one who is held to have an expert judgment of taste.

Factors affecting taste perception

Many factors affect taste perception, including:

• Aging
• Color/vision impairments
• Hormonal influences
• Genetic variations - See Phenylthiocarbamide
• Oral temperature
• Drugs and chemicals
• CNS Tumors (esp. Temporal lobe lesions)
• Plugged noses

It is also important to consider that flavor is the overall, total sensation induced during mastication (e.g. taste, touch, pain and smell). Smell (olfactory stimulation) plays a major role in flavor perception.

Disorders of taste

• ageusia (complete loss)
• hypogeusia (partial loss)
• parageusia (unpleasant taste)
• dysgeusia (inaccurate taste)

See also

• Optimal foraging theory
• Vomeronasal organ

References