Taste
Taste is one of the senses experienced by humans and other animals. It is felt by the tongue while eating, and is used to sense the flavor of food that is in the mouth. Humans can sense five tastes: sweet, sour, bitter, salty, and umami.
Humans have taste receptors on taste buds and other areas including the upper surface of the tongue and the epiglottis.[1][2] The perception of taste is organised by a special part of the cerebral cortex. The gustatory cortex is responsible for the perception of taste.
Basic tastes
Bitterness
Many common foods are bitter, like coffee, bitter melon, olives and citrus peel.
Bitterness is of interest to those who study evolution, as well as various health researchers.[3][4] Many naturally bitter compounds are toxic. The ability to detect bitter-tasting, toxic compounds at low thresholds may have a protective function, but some test have not confirmed this.[5] Plant leaves often contain toxic compounds, and among leaf-eating primates there is a tendency to prefer immature leaves. Young leaves tend to be higher in protein and lower in fiber and poisons than mature leaves.[6] Amongst humans, various food processing techniques are used worldwide to detoxify otherwise inedible foods and make them palatable.[7]
Animals which eat a lot of bitter plant material, such as browsers do have ways of dealing with it. They produce tannin-binding proteins, which other animals do not. Tannins are bitter compounds common in material from trees and bushes, though not grass.
Saltiness
Saltiness is felt when there is sodium in the food. A common spice that is salty is common salt, sodium chloride.
Savouriness
Savouriness (or savoriness) is the taste of savoury foods. It is also known by the Japanese word Lua error in Module:Unicode_data at line 293: attempt to index local 'data_module' (a boolean value)., and comes from umai, which means 'yummy'. This taste was known for a long time, but only became an official scientific term in 1985.[8]
To taste savoriness, your tongue has special parts that detect amino acids that are in foods like meats and cheeses.[9]
Sourness
Sourness is tasted when acids are on your tongue. Many foods have acid in them and are sour, like lemons and vinegar.
Sweetness
Sweetness is a taste felt when sugars are in the food. Most people consider sweetness to be a pleasant taste.
Spicy/hot
This sensation is not a special sense of taste because it does not have specific taste buds. It is a complex sensation.
Substances such as ethanol and capsaicin cause a burning sensation called chemesthesis, piquance, spiciness, hotness, or prickliness. Two main sources of this sensation are capsaicin from chili peppers and piperine from black pepper.
Foods like chili peppers activate nerve fibers directly giving the sensation of "hot". Many parts of the body with exposed membranes but no taste sensors (such as the nasal cavity, under the fingernails, surface of the eye (cornea) or a wound) produce a similar sensation of heat or sometimes pain, when exposed to such chemicals.
Other sensations
The tongue can also feel other sensations not generally included in the basic tastes. These are largely detected by the somatosensory system.
Also, it is known that smell and sight contribute to the overall sensation of eating and drinking. The temperature of food makes a difference to its appreciation.
The strange coolness of spearmint, menthol and camphor is caused by their molecules triggering a sensory system which normally works to sense low temperatures.
There is still much to learn about the taste system. Consider, for example, the tastes of ginger and horseradish.
TasteSweetness Media
Taste buds and papillae of the human tongue
Taste receptors of the human tongue
Signal transduction of taste receptors
Active brain areas in taste perception
This diagram linearly (unless otherwise mentioned) tracks the projections of all known structures that allow for taste to their relevant endpoints in the human brain.
References
- ↑ Witt, Martin (2019). "Anatomy and development of the human taste system". Smell and taste. Handbook of Clinical Neurology. Vol. 164. pp. 147–171. doi:10.1016/b978-0-444-63855-7.00010-1. ISBN 978-0-444-63855-7. ISSN 0072-9752. PMID 31604544. S2CID 204332286.
- ↑ Human biology (page 201/464) Daniel D. Chiras. Jones & Bartlett Learning, 2005.
- ↑ Guyton, Arthur C. 1991. Textbook of medical physiology. 8th ed, Philadelphia: W.B. Saunders.
- ↑ Logue A.W. 1986. The psychology of eating and drinking. New York: Freeman.
- ↑ Glendinning J.I. (1994). "Is the bitter rejection response always adaptive?". Physiol Behav. 56 (6): 1217–1227. doi:10.1016/0031-9384(94)90369-7. PMID 7878094. S2CID 22945002.
- ↑ Jones S; Martin R. & Pilbeam D. 1994. The Cambridge Encyclopedia of Human Evolution. Cambridge University Press
- ↑ Johns T. 1990. With bitter herbs they shall eat it: chemical ecology and the origins of human diet and medicine. Tucson: University of Arizona Press.
- ↑ Kawamura Y. and M.R. Kare (eds) 1987. Umami: a basic taste. Marcel Dekker.
- ↑ Ikeda, Kikunae (1909). "New Seasonings". Journal of the Chemical Society of Tokyo. 30: 820–836. [in japanese]