{{Short description|Basic taste}} [[File:Adriaen Brouwer - The Bitter Potion - Google Art Project.jpg|thumb|''The Bitter Draught'' by Adriaen Brouwer.|354x354px]] '''Bitterness''', also known as '''bitter''', is one of the most sensitive of tastes, and many experience it as unpleasant, sharp, or off-putting, but it is sometimes desirable and intentionally added via various bittering agents. Common bitter foods and drinks include coffee, unsweetened cocoa, South American mate, coca tea, ''Momordica charantia'', unripe olives, citrus peel, some varieties of cheese, many plants in the Brassicaceae family, ''Taraxacum'' greens, ''Marrubium vulgare'', wild chicory, and escarole. The ethanol in alcoholic beverages tastes bitter,<ref>{{cite journal |vauthors=Scinska A, Koros E, Habrat B, Kukwa A, Kostowski W, Bienkowski P |title=Bitter and sweet components of ethanol taste in humans |journal=Drug and Alcohol Dependence |volume=60 |issue=2 |pages=199–206 |date=August 2000 |pmid=10940547 |doi=10.1016/S0376-8716(99)00149-0}}</ref> as do the additional bittering ingredients found in some alcoholic beverages, including hops in beer and gentian in bitters. Quinine is also known for its bitter taste and is found in tonic water.
Bitterness is of interest to those studying evolution, as well as to various health researchers<ref name="textbookofmedicalphysiology8thed">Guyton, Arthur C. (1991) ''Textbook of Medical Physiology''. (8th ed). Philadelphia: W.B. Saunders</ref><ref name="psychologyofeating&drinking">{{cite book|last=Logue|first=Alexandra W.|year=1986|title=The Psychology of Eating and Drinking|location=New York|publisher=W.H. Freeman & Co.|isbn=978-0-415-81708-0}}{{page needed|date=August 2014}}</ref> as a large number of naturally occurring bitter compounds are known to be toxic. The ability to detect bitter-tasting, toxic compounds at low thresholds is thought to serve an important protective function.<ref name="textbookofmedicalphysiology8thed" /><ref name= psychologyofeating&drinking/><ref>{{cite journal |last=Glendinning|first=J. I. |title=Is the bitter rejection response always adaptive? |journal=Physiol Behav |volume=56 |year=1994 |pages=1217–1227|doi=10.1016/0031-9384(94)90369-7 |pmid=7878094 |issue=6 |s2cid=22945002 }}</ref> Plant leaves often contain toxic compounds, and among leaf-eating primates there is a tendency to prefer immature leaves, which tend to be higher in protein and lower in fiber and toxins than mature leaves.<ref name="encylopediahumanevolution">Jones, S., Martin, R., & Pilbeam, D. (1994) ''The Cambridge Encyclopedia of Human Evolution''. Cambridge: Cambridge University Press{{page needed|date=August 2014}}</ref> Among humans, various food processing techniques are used worldwide to detoxify otherwise inedible foods and make them palatable.<ref>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{{page needed|date=August 2014}}</ref> Furthermore, the use of fire, changes in diet, and avoidance of toxins have led to neutral evolution in human bitterness sensitivity. This has allowed for several loss-of-function mutations that have resulted in a reduced sensory capacity for bitterness in humans compared to other species.<ref>{{cite journal | last1 = Wang | first1 = X. | year = 2004 | title = Relaxation Of Selective Constraint And Loss Of Function In The Evolution Of Human Bitter Taste Receptor Genes | journal = Human Molecular Genetics | volume = 13 | issue = 21| pages = 2671–2678 | doi=10.1093/hmg/ddh289 | pmid=15367488| doi-access = free }}</ref>
==References== {{Reflist}}
{{Taste}} {{Authority control}}
Category:Gustation Category:Culinary terminology