Taste (or, more formally, gustation) is a form of direct chemoreception and is one of the traditional five senses. A chemosensor, also known as chemoreceptor, is a Sensory receptor that transduces a chemical signal into an Action potential. Senses are the physiological methods of Perception. The senses and their operation classification and theory are overlapping topics studied by a variety of fields It refers to the ability to detect the smacks of substances such as food and poisons. Food is any substance usually composed primarily of Carbohydrates Fats water and/or Proteins that can be eaten or drunk by an In the context of Biology, poisons are substances that can cause damage, Illness, or Death to Organisms usually by 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. Olfaction (also known as olfactics or smell) refers to the Sense of smell. Flavor or flavour is the sensory impression of a Food or other substance, and is determined In the West, experts traditionally identified four taste sensations: sweet, salty, sour, and bitter. Eastern experts traditionally identified a fifth, called umami. is one of the five Basic tastes sensed by specialized receptor cells present on the human Tongue. 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. Psychophysics is a subdiscipline of Psychology dealing with the relationship between physical stimuli and their subjective correlates or Percepts Neuroscience is a field devoted to the scientific study of the nervous system is one of the five Basic tastes sensed by specialized receptor cells present on the human Tongue. In Chemistry, especially Biochemistry, a fatty acid is a Carboxylic acid often with a long unbranched Aliphatic tail ( chain) which )

Taste is a sensory function of the central nervous system. In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. 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. The tongue is the large bundle of Skeletal muscles on the floor of the Mouth that manipulates Food for chewing and swallowing (deglutition The soft palate (or velum, or muscular palate) is the soft tissue constituting the back of the roof of the Mouth. The pharynx (plural pharynges) is the part of the Neck and Throat situated immediately Posterior to (behind the Mouth and Nasal The epiglottis is a lid-like flap of Elastic cartilage tissue covered with a Mucous membrane, attached to the root of the Tongue.

Contents 1 Basic taste 1.1 History 1.2 Recent discoveries 2 Five basic tastes 2.1 Bitterness 2.2 Saltiness 2.3 Sourness 2.4 Sweetness 2.5 Yumminess (Umami) 2.6 Fattiness? 3 Further sensations 3.1 Dryness 3.2 Metallicness 3.3 Prickliness or hotness 3.4 Coolness 3.5 Numbness 3.6 Heartiness (Kokumi) 3.7 Temperature 4 Supertasters 5 Aftertaste 6 Acquired taste 7 Factors affecting taste perception 8 Disorders of taste 9 See also 10 References 11 External links

Basic taste

Psychophysicists have long suggested the existence of four taste 'primaries', referred to as the basic tastes: sweetness, bitterness, sourness, and saltiness. Sweet is one of the five Basic tastes and is almost universally regarded as a pleasurable experience Taste (or more formally gustation) is a form of direct Chemoreception and is one of the traditional five Senses Taste (or more formally gustation) is a form of direct Chemoreception and is one of the traditional five Senses 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. is one of the five Basic tastes sensed by specialized receptor cells present on the human Tongue. Monosodium glutamate, also known as sodium glutamate and MSG, is a Sodium salt of the non-essential Amino acid Glutamic acid ^[1][2][3]

Other possible categories have been suggested, such as a taste exemplified by certain fatty acids such as linoleic acid. In Chemistry, especially Biochemistry, a fatty acid is a Carboxylic acid often with a long unbranched Aliphatic tail ( chain) which ^[4][5][6] Some researchers still argue against the notion of primaries at all and instead favor a continuum of percepts ^[7][8][9], similar to color vision. Color vision is the capacity of an organism or machine to distinguish objects based on the Wavelengths (or frequencies) of the Light they reflect or emit

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. ^[10] This myth is generally attributed to the mis-translation of a German text, and perpetuated in North American schools since the early twentieth century ^[11]. 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. Senses are the physiological methods of Perception. The senses and their operation classification and theory are overlapping topics studied by a variety of fields Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus Humans receive tastes through sensory organs called taste buds or gustatory calyculi, concentrated on the upper surface of the tongue. Taste buds are small structures on the upper surface of the Tongue, Soft palate, upper Esophagus and Epiglottis that provide information about The tongue is the large bundle of Skeletal muscles on the floor of the Mouth that manipulates Food for chewing and swallowing (deglutition Scientists describe five basic tastes: bitter, salty, sour, sweet, and umami (described as savory, meaty, or brothy). is one of the five Basic tastes sensed by specialized receptor cells present on the human Tongue. 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. The olfactory epithelium is a specialized epithelial tissue inside the Nasal cavity that is involved in smell. Mouthfeel is a product’s physical and Chemical interaction in the mouth A mechanoreceptor is a Sensory receptor that responds to mechanical pressure or distortion A thermoreceptor is a Sensory receptor, or more accurately the receptive portion of a sensory neuron that codes absolute and relative changes in temperature primarily Taste and smell are subsumed under the term flavor. Flavor or flavour is the sensory impression of a Food or other substance, and is determined

History

In Western culture, the concept of basic tastes can be traced back at least to Aristotle, who cited "sweet" and "bitter", with "succulent", "salt", "pungent", "harsh", "puckery", and "sour" as elaborations of those two basics. Aristotle (Greek Aristotélēs) (384 BC – 322 BC was a Greek philosopher a student of Plato and teacher of Alexander the Great. Sweet is one of the five Basic tastes and is almost universally regarded as a pleasurable experience Pungency (also called piquancy) is a sharp and biting sensory impression An astringent (also spelled adstringent) substance is a chemical that tends to shrink or constrict Body tissues usually locally after Topical medicinal The ancient Chinese Five Elements philosophy lists slightly different five basic tastes: bitter, salty, sour, sweet, and spicy. In traditional Chinese philosophy, natural phenomena can be classified into the Wu Xing ( or the Five Phases, usually translated as five elements, Pungency (also called piquancy) is a sharp and biting sensory impression Japanese and Indian cultures each add their own sixth taste to the basic five.

For many years, books on the physiology of human taste contained diagrams of the tongue showing levels of sensitivity to different tastes in different regions. Physiology (from Greek grc φύσις physis, "nature origin" and grc -λογία -logia) is the study of the mechanical physical In fact, taste qualities are found in all areas of the tongue, in contrast with the popular view that different tastes map to different areas of the tongue. ^[12][13]

Recent discoveries

The receptors for all known basic tastes have been identified. In Biochemistry, a receptor is a Protein molecule embedded in either the Plasma membrane or Cytoplasm of a cell to which a mobile signaling The receptors for sour and salty are ion channels while the receptors for sweet, bitter, and umami belong to the class of G protein coupled receptors. Ion channels are pore-forming Proteins that help establish and control the small Voltage Gradient across the Plasma membrane of all living G protein-coupled receptors ( GPCRs) also known as seven transmembrane domain receptors, 7TM receptors, heptahelical receptors, and

In November 2005, a team of French researchers experimenting on rodents claimed to have evidence for a sixth taste, for fatty substances. ^[14] It is speculated that humans may also have the same receptors. ^[15] Fat has occasionally been raised as a possible basic taste in the past (Bravo 1592, Linnaeus 1751) but later classifications abandoned fat as a separate taste (Haller 1751 and 1763). ^[16]

Five basic tastes

For a long period, it has been commonly accepted that there are a finite number of "basic tastes" by which all foods and tastes can be grouped. Up until the 2000s, this was considered to be a group of four basic tastes. More recently, a fifth taste, Umami, was added by a wide number of authorities in this field. ^[17]

Bitterness

The bitter taste is perceived by many to be unpleasant, sharp, or disagreeable. Common bitter foods and beverages include coffee, unsweetened chocolate, bitter melon, beer, uncured olives, citrus peel, many plants in the Brassicaceae family, dandelion greens and escarole. CoFFEE is an Open source Software for computer supported collaborative learning (CSCL in a digital classroom Chocolate ( pronounced or /-ˈələt/ comprises a number of raw and processed foods that are produced from the seed of the tropical Cacao tree Momordica charantia is a tropical and subtropical Vine of the family Cucurbitaceae, widely grown for edible Fruit, which is among the most Beer is the world's oldest and most widely consumed Alcoholic beverage and the third most popular drink overall after water and tea The Olive is the Fruit of the Olive tree (Olea europaea and is a major component of the Agriculture and Gastronomy of many countries Peel, also known as rind or skin, is the outer protective layer of a Fruit or Vegetable which could be peeled off Brassicaceae or Cruciferae, also known as the crucifers, the mustard family or cabbage family is a family (the third lowest primary Endive (ˈɛndiv or /ˈɛndɪv/ Cichorium endivia is a Leaf vegetable belonging to the daisy family. Quinine is also known for its bitter taste and is found in tonic water. Quinine (ˈkwaɪnaɪn kwɪˈniːn ˈkwiːniːn is a natural white Crystalline Alkaloid having Antipyretic (fever-reducing antimalarial, Tonic water (or Indian tonic water) is a carbonated Soft drink Flavored with Quinine, which gives it a distinctively bitter taste The most bitter substance known is the synthetic chemical denatonium. Denatonium, usually available as denatonium benzoate (under Trade names such as Bitrex or Aversion) and as denatonium It is used as an aversive agent that is added to toxic substances to prevent accidental ingestion. This was discovered 1958 during research on Lignocaine, a local anesthetic, by Macfarlan Smith of Edinburgh, Scotland. Lidocaine ( INN) (ˈlaɪdoʊkeɪn or lignocaine (former BAN) (/ˈlɪgnoʊkeɪn/ is a common Local anesthetic and antiarrhythmic drug Edinburgh ( ˈɛdɪnb(ərə Dùn Èideann) is the Capital of Scotland and is its second largest city after Glasgow. Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain.

Research has shown that TAS2Rs (taste receptors, type 2) such as TAS2R38 coupled to the G protein gustducin are responsible for the human ability to taste bitter substances. TAS2R38 is a bitter Taste receptor which facilitates the tasting of Phenylthiocarbamide (PTC and Propylthiouracil (PROP, although it does GTP chemical structurepng|thumb|180px| Guanosine triphosphate]] G proteins short for guanine nucleotide-binding proteins, are a family of Proteins involved They are identified not only by their ability to taste for certain "bitter" ligands, but also by the morphology of the receptor itself (surface bound, monomeric). ^[18] Researchers use two synthetic substances, phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) to study the genetics of bitter perception. Phenylthiocarbamide, also known as PTC, or phenylthiourea, is an Organic compound that either Tastes very bitter, or is virtually Propylthiouracil ( PTU) or 6-N-Propylthiouracil (PROP is a Thioamide drug used to treat Hyperthyroidism by decreasing the amount of Genetics (from Ancient Greek grc-Latn genetikos, “genitive” and that from grc-Latn genesis, “origin” a discipline of Biology, is These two substances taste bitter to some people, but are virtually tasteless to others. Among the tasters, some are so-called "supertasters" to whom PTC and PROP are extremely bitter. A supertaster is a person who experiences Taste with far greater intensity than average This genetic variation in the ability to taste a substance has been a source of great interest to those who study genetics. In addition, it is of interest to those who study evolution since PTC-tasting is associated with the ability to taste numerous natural bitter compounds, a large number of which are known to be toxic. eVolution is the third Album by eLDee, it was due to be released in 2008

Saltiness

Saltiness is a taste produced primarily by the presence of sodium ions. Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 Other ions of the alkali metals group also taste salty. Trends The alkali metals show a number of trends when moving down the group - for instance decreasing electronegativity increasing reactivity and decreasing melting and boiling However the further from sodium the less salty is the sensation. The size of lithium and potassium ions most closely resemble those of sodium and thus the saltiness is most similar. Lithium (ˈlɪθiəm is a Chemical element with the symbol Li and Atomic number 3 Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 In contrast rubidium and cesium ions are far larger so their salty taste differs accordingly. Rubidium (ruːˈbɪdiəm /rəˈbɪdiəm/ is a Chemical element with the symbol Rb and Atomic number 37 Caesium or cesium (ˈsiːziəm is the Chemical element with the symbol Cs and Atomic number 55 Potassium, as potassium chloride - KCl, is the principle ingredient in salt substitutes. The Chemical compound potassium chloride (KCl is a Metal Halide salt composed of Potassium and Chlorine. High intake of table salt ( Sodium chloride) is associated with high blood pressure and an increased risk of cardiovascular disease

Other monovalent cations, e. An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge g. ammonium, NH₄⁺, and divalent cations of the alkali earth metal group of the periodic table, e. Ammonium is also an old name for the Siwa Oasis in western Egypt. In chemistry divalent Anions are atoms or radicals with 2 additional Electrons when compared to their elemental state (that is with 2 more electrons than Protons Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered The periodic table of the chemical elements is a tabular method of displaying the Chemical elements Although precursors to this table exist its invention is g. calcium, Ca²⁺, ions generally elicit a bitter rather than a salty taste even though they too can pass directly through ion channels in the tongue, generating an action potential. In Neurophysiology, the action potential is a self-regenerating Wave of Electrochemical activity that allows Nerve cells to carry a signal

Sourness

Sourness is the taste that detects acidity. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are The mechanism for detecting sour taste is similar to that which detects salt taste. Hydrogen ion channels detect the concentration of hydronium ions (H₃O⁺ ions) that are formed from acids and water. Ion channels are pore-forming Proteins that help establish and control the small Voltage Gradient across the Plasma membrane of all living In Chemistry, hydronium is the obsolete name for the Cation H 3 O + derived from Protonation of Water

Hydrogen ions are capable of permeating the amiloride-sensitive channels, but this is not the only mechanism involved in detecting the quality of sourness. Other channels have also been proposed in the literature. Hydrogen ions also inhibit the potassium channel, which normally functions to hyperpolarize the cell. By a combination of direct intake of hydrogen ions (which itself depolarizes the cell) and the inhibition of the hyperpolarizing channel, sourness causes the taste cell to fire in this specific manner. In addition, it has also been suggested that weak acids, such as CO₂ which is converted into the bicarbonate ion HCO₃^– by the enzyme carbonic anhydrase, to mediate weak acid transport. In Inorganic chemistry, bicarbonate ( IUPAC -recommended nomenclature hydrogencarbonate) is an intermediate form in the Deprotonation Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins The carbonic anhydrases (or carbonate dehydratases) form a family of Enzymes that catalyze the rapid conversion of Carbon dioxide to Bicarbonate

Sweetness

Main article: Sweetness

Sweetness is produced by the presence of sugars, some proteins and a few other substances. Sweet is one of the five Basic tastes and is almost universally regarded as a pleasurable experience Sugar is a class of edible Crystalline substances mainly Sucrose, Lactose, and Fructose. Sweetness is often connected to aldehydes and ketones, which contain a carbonyl group. An aldehyde is an organic compound containing a terminal Carbonyl group. A ketone (pronounced as key tone) is either the Functional group characterized by a Carbonyl group (O=C linked to two other Carbon atoms or In Organic chemistry, a carbonyl group is a Functional group composed of a Carbon Atom double-bonded to an Oxygen Sweetness is detected by a variety of G protein coupled receptors coupled to the G protein gustducin found on the taste buds. G protein-coupled receptors ( GPCRs) also known as seven transmembrane domain receptors, 7TM receptors, heptahelical receptors, and GTP chemical structurepng|thumb|180px| Guanosine triphosphate]] G proteins short for guanine nucleotide-binding proteins, are a family of Proteins involved Gustducin is a protein associated with Basic taste. Gustducin is a G protein associated with Basic taste and the Gustatory system. Taste buds are small structures on the upper surface of the Tongue, Soft palate, upper Esophagus and Epiglottis that provide information about At least two different variants of the "sweetness receptors" need to be activated for the brain to register sweetness. The compounds which the brain senses as sweet are thus compounds that can bind with varying bond strength to two different sweetness receptors. These receptors are T1R2+3 (heterodimer) and T1R3 (homodimer), which are shown to be accountable for all sweet sensing in humans and animals. ^[19] The average human detection threshold for sucrose is 10 millimoles per litre. Solubility of Pure SucroseTemperature(Cg For lactose it is 30 millimoles per litre, and 5-Nitro-2-propoxyaniline 0. Lactose (also referred to as milk sugar) is a Sugar which is found most notably in Milk. 5-Nitro-2-propoxyaniline, also known as P-4000 and Ultrasüss is one of the strongest Sweet -tasting substances known about 4000 times the intensity of Sucrose 002 millimoles per litre.

See also: Miraculin and Curculin

Yumminess (Umami)

Main article: Umami

Umami (旨味, うまみ) or yumminess is the name for the taste sensation produced by compounds such as glutamate, and are commonly found in fermented and aged foods. Miraculin is a Glycoprotein extracted from the Miracle fruit plant a shrub native to West Africa ( Synsepalum dulcificum or Curculin is a sweet Protein that was discovered and isolated in 1990 from the fruit of Curculigo latifolia ( Hypoxidaceae) a plant from is one of the five Basic tastes sensed by specialized receptor cells present on the human Tongue. Glutamic acid (abbreviated as Glu or E) is one of the 20 Alpha Amino acids It is not among the human Essential amino acids Its Fermentation in Food processing typically refers to the conversion of Sugar to Alcohol using Yeast under Anaerobic conditions In English, it is also described as "meatiness", "relish", or "savoriness". The Japanese word comes from umai (旨い) for yummy, keen, or nice. is a language spoken by over 130 million people in Japan and in Japanese emigrant communities Umami is now the commonly used term by taste scientists. The same taste is referred to as xiānwèi (鮮味 or 鲜味) in Chinese cooking. Chinese cuisine ( Traditional Chinese: 中國菜 Simplified Chinese: 中国菜 originated from the various regions of China and has become widespread in Umami is considered a fundamental taste in Chinese and Japanese cooking, but is not discussed as much in Western cuisine. European cuisine, or alternatively Western cuisine is a generalized term collectively referring to the Cuisines of Europe and other Western countries

Humans have evolved taste receptors specifically for the detection of the amino acids, e. In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this g. glutamic acid. Glutamic acid (abbreviated as Glu or E) is one of the 20 Alpha Amino acids It is not among the human Essential amino acids Its Amino acids are commonly found in meats, cheese, fish, and other protein-heavy foods. Examples of food containing glutamate (and thus strong in umami) are beef, lamb, parmesan and roquefort cheese as well as soy sauce and fish sauce. Parmigiano-Reggiano is a hard fat Granular cheese, cooked but not pressed named after the producing areas of Parma, Reggio Emilia, Modena, Roquefort ( AmE, BrE, French; from Occitan ròcafòrt) is a Sheep milk blue Cheese from the south Cheese is a Food made from Milk, usually the milk of cows, Buffalo, Goats or sheep, by coagulation. Soy sauce ( US) soya sauce ( Commonwealth) shoyu ( Japan) or sillao ( Peru) is a fermented Sauce Fish sauce is a Condiment that is derived from fish that have been allowed to ferment. The glutamate taste sensation is most intense in combination with sodium ions, as found in table salt. Sauces with umami and salty tastes are very popular for cooking, such as worcestershire sauce for Western cuisines and soy sauce and fish sauce for Asian cuisines. Worcestershire sauce (ˈwʊstəˌʃɪə wooster-sheer is a widely used fermented liquid Condiment first made at 68 Broad Street Worcester by two Soy sauce ( US) soya sauce ( Commonwealth) shoyu ( Japan) or sillao ( Peru) is a fermented Sauce

The additive monosodium glutamate (MSG), which was developed as a food additive in 1907 by Kikunae Ikeda, produces a strong umami. Monosodium glutamate, also known as sodium glutamate and MSG, is a Sodium salt of the non-essential Amino acid Glutamic acid Kikunae Ikeda (池田 菊苗 Ikeda Kikunae, October 8, 1864 &ndash May 3, 1936) was a Japanese Chemist, Tokyo Umami is also provided by the nucleotides 5’-inosine monophosphate (IMP) and 5’-guanosine monophosphate (GMP). Nucleotides are Organic compounds that consist of three joined structures a nitrogenous base a Sugar, and a Phosphate group Inosinic acid or Inosine monophosphate (IMP is a Nucleotide present in Muscle and other tissues Guanosine monophosphate, also known as 5'-guanidylic acid or guanylic acid and abbreviated GMP, is a Nucleotide that is found in RNA These are naturally present in many protein-rich foods. IMP is present in high concentrations in many foods, including dried skipjack tuna flakes used to make dashi, a Japanese broth. The skipjack tuna, Katsuwonus pelamis, is a medium-sized Perciform fish in the Tuna family Scombridae. Dashi ( 出[[wiktionary 汁|汁]] だし is a class of soup and cooking stocks considered fundamental to Japanese cooking. Japanese Cuisine has developed over the centuries as a result of many political and social changes GMP is present in high concentration in dried shiitake mushrooms, used in much of the cuisine of Asia. The shiitake ( Lentinula edodes) is an Edible mushroom native to East Asia, which is cultivated and consumed in many Asian countries as well as being dried Asian cuisine is a term used in the West as an umbrella term for the various cuisines of South Asia, East Asia and Southeast Asia and for fusion There is a synergistic effect between MSG, IMP, and GMP which together in certain ratios produce a strong umami.

Some umami taste buds respond specifically to glutamate in the same way that sweet ones respond to sugar. Glutamate binds to a variant of G protein coupled glutamate receptors. G protein-coupled receptors ( GPCRs) also known as seven transmembrane domain receptors, 7TM receptors, heptahelical receptors, and ^[20][21]

Fattiness?

Recent research has revealed a potential taste receptor called the CD36 receptor to be reacting to fat, more specifically, fatty acids. CD36 ( C luster of D ifferentiation 36 is an Integral membrane protein found on the surface of many cell types in vertebrate animals and is also known as Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water In Chemistry, especially Biochemistry, a fatty acid is a Carboxylic acid often with a long unbranched Aliphatic tail ( chain) which ^[22] This receptor was found in mice, but probably exists among other mammals as well. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands In experiments, mice with a genetic defect that blocked this receptor didn't show the same urge to consume fatty acids as normal mice, and failed to prepare gastric juices in their digestive tracts to digest fat. Gastric juice is a strong Acidic liquid PH 1 to 3 in humans which is close to being colourless This discovery may lead to a better understanding of the biochemical reasons behind this behaviour, although more research is still necessary to confirm the relationship between CD36 and the perception of fat.

Further sensations

The tongue can also feel other sensations, not generally called tastes per se or included in the five human tastes. These are largely detected by the somatosensory system.

Dryness

Some foods, such as unripe fruits, contain tannins or calcium oxalate that cause an astringent or rough sensation of the mucous membrane of the mouth or the teeth. Tannins are Astringent, bitter plant Polyphenols that either bind and Precipitate or shrink Proteins The astringency from the tannins is what Calcium oxalate is a chemical compound that forms needle-shaped crystals Examples include tea, rhubarb, grapes and unripe persimmons and bananas. Tea refers to the cured agricultural product of the leaves leaf buds and internodes of Camellia sinensis, which have been prepared and cured for the market Rheum is a genus of Perennial plants that grows from thick short Rhizomes The genus is in the family Polygonaceae, and includes the vegetable For the Tokyo University supercomputer see Gravity Pipe. GRAPE, or GRA phics P rogramming E nvironment is This article refers to the edible fruit For the British construction company see Persimmon plc; for the racehorse see Persimmon (horse. For the fruit see Banana. For other meanings see Banana (disambiguation.

Less exact terms for the astringent sensation are "dry", "rough", "harsh" (especially for wine), "tart", (normally referring to sourness) "rubbery", "hard", or "styptic",^[23]. The Chinese have a term for this: 澀 (sè), the Koreans have 떫다 (tteolda), the Japanese call it 渋い (shibui), while Thai have ฝาด (fard), the Malay use kelat, Filipinos use pakla, and in Russian there is вяжущий (vyazhuschiy) or тёрпкий (tjorpky).

In the Indian tradition, one of the 6 tastes (sweet, sour, salty, bitter, hot/pungent and dry) [1] is astringency (Kasaaya in Sanskrit). This is more or less in line with the Japanese approach to umami.

Metallicness

Most people know this taste (e. g. Cu²⁺, FeSO₄, or blood in mouth), but it is not only taste but olfactory receptors worked in this case (Guth and Grosch, 1990). Metallic taste is commonly known, however biologists are reluctant to categorize it with the other taste sensations. One of the primary reasons is that it is not one commonly associated with consumption of food. Proponents of the theory contest that the sensation is readily detectable and distinguishable to test subjects. Therefore, metallic should be added as one of the basic types of sensations in the chemical receptor senses.

Prickliness or hotness

See also: Scoville scale and Pungency

Substances such as ethanol and capsaicin cause a burning sensation by inducing a trigeminal nerve reaction together with normal taste reception. The Scoville scale is a measure of the hotness or piquancy of a Chili pepper. Pungency (also called piquancy) is a sharp and biting sensory impression Capsaicin /ˌkæpˈseˌɪsɪn/ (8- Methyl - N - Vanillyl -6-nonen Amide) is the active component of Chili peppers The sensation of heat is caused by the food activating a nerve cell called TRP-V1, which is also activated by hot temperatures. The piquant sensation, usually referred to as being "hot" or "spicy", is a notable feature of Mexican, Hungarian, Indian, Szechuan, Korean, Indonesian, central Vietnamese, and Thai cuisines. Pungency (also called piquancy) is a sharp and biting sensory impression Mexican food is a style of food that originated in Mexico. Mexican cuisine is known for its intense and varied flavors colorful decoration and variety of spices Hungarian or Magyar cuisine is the Cuisine characteristic to the nation of Hungary and its primary ethnic group the Magyars. Szechuan cuisine, Szechwan cuisine, or Sichuan cuisine ( is a style of Chinese cuisine originating in Sichuan Province of southwestern Korean cuisine as a national Cuisine known today has evolved through centuries of social and political change See also List of Indonesian cuisine Indonesian cuisine reflects the vast variety of people that live on the 6000 populated islands that make up Indonesia

The two main plants providing this sensation are chili peppers (those fruits of the Capsicum plant that contain capsaicin) and black pepper. The chili pepper, chilli pepper, or chili, is the fruit of the plants from the Genus Capsicum, which are members of the nightshade Capsicum is a Genus of Plants from the nightshade family ( Solanaceae) native to the Americas, where it was cultivated for thousands Capsaicin /ˌkæpˈseˌɪsɪn/ (8- Methyl - N - Vanillyl -6-nonen Amide) is the active component of Chili peppers Black pepper ( Piper nigrum) is a flowering Vine in the family Piperaceae, cultivated for its Fruit, which is usually dried

If tissue in the oral cavity has been damaged or sensitised, ethanol may be experienced as pain rather than simply heat. Those who have had radiotherapy for oral cancer thus find it painful to drink alcohol.

In many cases, this particular sensation is not considered a taste, so much as a painful reaction to certain marginally damaging chemicals on the taste receptors and the skin of the tongue. While the taste nerves are activated when consuming foods like chili peppers, the reaction commonly interpreted as "hot" is derived from the tongue's pain nerves firing.

Coolness

Some substances activate cold trigeminal receptors. The trigeminal nerve (the fifth Cranial nerve, also called the fifth nerve or simply V) is responsible for sensation in the face One can sense a cool sensation (also known as "fresh" or "minty") from, e. g. , spearmint, menthol, ethanol or camphor, which is caused by the food activating the TRP-M8 ion channel on nerve cells that also signal cold. Menthol is an Organic compound made synthetically or obtained from Peppermint or other mint oils } Camphor is a waxy white or transparent solid with a strong aromatic odor Transient receptor potential or TRP channels are a family of loosely related Ion channels that are non-selectively permeable to Cations including Calcium Neurons (ˈnjuːɹɒn also known as neurones and nerve cells) are responsive cells in the Nervous system that process and transmit information Unlike the actual change in temperature described for sugar substitutes, coolness is only a perceived phenomenon.

Numbness

Chinese cooking includes the idea of 麻 má, the sensation of tingling numbness caused by spices such as Sichuan pepper. Sichuan pepper (or Szechuan pepper) is the outer pod of the tiny Fruit of a number of species in the genus Zanthoxylum (most commonly The cuisine of Sichuan province often combines this with chili pepper to produce a 麻辣 málà, "numbing-and-hot", flavor. ( Postal map spelling: Szechwan and Szechuan) is a province in western China with its capital in Chengdu. The chili pepper, chilli pepper, or chili, is the fruit of the plants from the Genus Capsicum, which are members of the nightshade ^[24]

Heartiness (Kokumi)

Some Japanese researchers refer to the kokumi in foods laden with alcohol- and thiol-groups in their amino acid extracts which has been described variously as continuity, mouthfulness, mouthfeel, and thickness. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon In Organic chemistry, a thiol is a compound that contains the functional group composed of a Sulfur atom and a Hydrogen atom (-SH

Temperature

Temperature is an essential element of human taste experience. Food and drink that—within a given culture—is considered to be properly served hot is often considered distasteful if cold, and vice versa.

Some sugar substitutes have strong heats of solution, as is the case of sorbitol, erythritol, xylitol, mannitol, lactitol, and maltitol. The enthalpy of solution (or enthalpy of dissolution) is the Enthalpy change associated with the dissolution of a substance in a Solvent at constant pressure Sorbitol, also known as glucitol, is a Sugar alcohol that the body metabolises slowly Erythritol ((2 R,3 S)-butane-1234-tetraol is a natural Sugar alcohol (a type of sugar substitute which has been approved for use in the United States Xylitol (from Greek ξύλον - xyl, "wood" + suffix - itol, used to denote sugar alcohols is an Organic compound with the formula (CHOH3(CH2OH2 Mannitol or hexan-123456-hexol (C6H8(OH6 is a Polyol that is used as an osmotic Diuretic agent and a Lactitol is a Sugar alcohol used as a replacement bulk Sweetener for low Calorie Foods with approximately 40% of the sweetness of Sugar Maltitol is a Sugar alcohol (a Polyol) used as a Sugar substitute. When they are dry and are allowed to dissolve in saliva, heat effects can be recognized. The cooling effect upon eating may be desirable, as in a mint candy made with crystalline sorbitol, or undesirable if it's not typical for that product, like in a cookie. Crystalline phases tend to have a positive heat of solution and thus a cooling effect. In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating The heats of solution of the amorphous phases of the same substances are negative and cause a warm impression in the mouth. An amorphous solid is a Solid in which there is no Long-range order of the positions of the Atoms (Solids in which there is long-range atomic order are ^[25]

Supertasters

Main article: Supertaster

A supertaster is a person whose sense of taste is significantly more sharp than average. A supertaster is a person who experiences Taste with far greater intensity 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. The fungiform papillae are mushroom shaped papillae (projections on the Tongue. ^[26] 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 a 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. 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. Foods with notable aftertastes include spicy foods, such as Mexican food (e. Mexican food is a style of food that originated in Mexico. Mexican cuisine is known for its intense and varied flavors colorful decoration and variety of spices g. chili pepper), or Indian food (such as curry).

Medicines and tablets may also have a lingering aftertaste. Medicine is the art and science of healing It encompasses a range of Health care practices evolved to maintain and restore Human Health by the

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. An acquired taste often refers to an appreciation for a Food or Beverage that is unlikely to be enjoyed by a person who has not had substantial exposure to it usually 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. A connoisseur (Fr connaisseur, from connoistre, connaître meaning "to be acquainted with" or "to know sb/sth

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. Phenylthiocarbamide, also known as PTC, or phenylthiourea, is an Organic compound that either Tastes very bitter, or is virtually Temporal lobe lesions) and other neurological causes^[27]
• Plugged noses
• Zinc deficiency

It is also important to consider that flavor is the overall, total sensation induced during mastication (e. Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Flavor or flavour is the sensory impression of a Food or other substance, and is determined g. taste, touch, pain and smell). Smell (olfactory stimulation) plays a major role in flavor perception. Olfaction (also known as olfactics or smell) refers to the Sense of smell.

Disorders of taste

• ageusia (complete loss)

See also

• Optimal foraging theory
• Vomeronasal organ

References

External links

• Researchers Define Molecular Basis of Human "Sweet Tooth" and Umami Taste
• Answers to several questions of curious kids about taste

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic