There are about ten thousand taste receptors in the human language, two thousand are located under the tongue, on the lips, nose, larynx, the inner surface of the pussy. Each separately taken receptor lives long - from ten to fourteen days, after which he dies, and a new one comes to change. This is one of the reasons that, throughout his life, a person has the taste of the same product in different ways, and with age notes the change in its preferences.
Taste receptors are called the sensitive cells located in the oral cavity (mainly on the mucous membrane of the language and nose), which, after exposure to various chemicals, give a feeling called "Taste".
Each single cell reacts only one definite taste and the other remains indifferent. Therefore, flavor receptors are located uneven layers, and groups whose cells react only to the same taste. These groups are collected in bundles and are attached to papillas of flavoring bulbs, which completely cover the surface of the tongue and are hidden under small tubercles.
Taste receptors
In large papillas, it contains about five hundred bulbs, on small - only a few. They are attached to the finest hairs (microvins), which through microscopic openings go to the surface of the tubercles and are responsible for the definition of taste. From the opposite side of the receptor, there is a complex network of nerve fibers, which comes the brain obtained from receptors information.
Like most cells, taste receptors live for long, no more than two weeks, after which they die and replace them new. How quickly will the replacement, largely depends on the nerve endings associated with it: if it happens that the receptor will distort, and the connection between it and the nerve for some reason will be interrupted, the cell will not regenerate, until the nerve does not give the signal.
With age, the number of taste receptors is reduced, as a result of which a person decreases the ability to feel the taste.
Basic tastes
Most scientists believe that taste cells are capable of identifying only four tastes: bitter, sweet, salty and sour. If they are arranged tightly to each other, a person prefers soft products to taste if their density is low - more acute food.
To date, it is not known exactly where the receptors respond to one taste are located. Some researchers argue that sensitive to sweet and salty cells are located on the tip of the language that are responsible for bitterness - under its basis, for sour - side. Other this theory refute, arguing that taste nipples with cells responsible for a certain taste are located all over the surface of the language, more in some places, in others - less.
Receptors that are responsible for the sweet, sour and salty taste in the oral cavity are significantly less than flavor cells responsible for the bitterness. This is caused by the need to protect itself from poisons, the toxic compounds of which are contained in plants.
On flavoring cells, the products carrying with them are one or another affect differently. While sweet and bitter substances simply transmit the feeling of taste in the bark of the brain, acidic and salty components, especially in a strong concentration, are able to damage the taste cells, the mucous membrane of the oral cavity, cause pain (burning, scratch, etc.).
This is due to the fact that the basic sensations are joined by tactile, causing a painful reaction at the nerve endings, and they transmit the corresponding reaction to the brain.
How the taste is defined
The taste sensations in the brain transmit facial, languagehilia and wandering cranial nerves. At first, the impulses fall into the brain barrel, where the data is processed and the nerve fibers go to the thalamus (to the intermediate brain, which is the subcortex center of all types of sensitivity).
In Talamus, there is an additional processing of flavoring pulses, after which information about them go further and turn out to be the part of the cerebral cortex, which, after processing the signal, gives information in the form of awareness of the basic taste (salty, sweet, bitter, sour).
At the same time, in the Talamus there is a mixing of information on the main taste with other sensations received from the oral cavity (first of all about the composition of food, its temperature), and also mixed with the feelings obtained during irritation of the pain sensitive to the nervous fibers (pended products) and from the organ smell.
These sensations are mixed with the obtained perception of the main taste, as a result of which its shades appear, which are recognized by a person during eating. 
In some cases, with a combination of several different flavors, the sensation of the substance that has been received for taste receptors is changed to the opposite (after the cheese the taste of wine is enhanced, after the sweet may seem nasty). This is happening at different temperatures: taste cells are most sensitive from 20 to 38 ° C, if the language is cooling, the taste of sweet dishes will not be felt.
The ability to affect the taste has an African plant known as a magic fruit (synsepalum dulcificum). Its small red-colored fruit with a large white grain affects taste receptors in such a way that the cells responsible for the recognition of sour, are disconnected for several hours (this is due to Miraculine protein).
Other tastes
Although most scientists agree that taste cells are capable of identifying only four basic tastes, there are cells that are responsible for other tasteings and how many of them are not yet determined, therefore the likelihood is that soon the list will expand. First of all, it concerns alkaline, tart, mint, burning, metal flavors. There are also assumptions that there are receptors that determine fatty acids.
The Chinese and other peoples of Southeast Asia to the basic sensations also include the taste of minds (Japanese scientists argue that the taste cells that fix the minds are not only in the language, but also throughout the digestive tract).
The glutamate sodium and some amino acids (sensation obtained from soy sauce, parmesan, broccoli, mushrooms, tomatoes) affect the minds of the minds. The taste does not have any minds, but makes food tastier, reinforcing fragrance, and also causes an increased salivation and a soft feeling in the language.
in the language there are taste receptors, for what taste corresponds to the tip of the language?
- Sweet - it's for sure
- It is not true, the language reacts the same in all parts of the tastes not to be fooled on this nonsense! The only thing that can occur is different their quantitative concentration in different places
- If I'm not mistaken, for sour
- The taste arises when exposed to various soluble substances on taste receptors. If the atoms of the substance cannot move freely enough, we do not feel the taste of this substance. That is why we can experience the taste of only soluble substances. In animals living in water, taste receptors are located on the body surface. For example, the fish can feel the taste with its tail fins! In animals living on the earth's surface, taste receptors are concentrated mainly in the mouth, and people are only in the language.
If you consider your tongue in the mirror (I, unfortunately, there is no picture), you will see that it is covered with small tubercles with papillars.
Taste receptors are located on the walls of these puffs. The number of taste receptors in animals depends on individual characteristics. For example, whales swallow, not chewing, whole shoals of fish, because they have very little taste receptors or do not have them at all. Pigs have 5500, the cow is 35,000, and the antelope has 50,000 taste receptors. A person is not so much of 3000. In a human language, taste receptors are distributed in different zones. Each zone perceives a certain taste. The back of the tongue is more susceptible to bitter. The sides are sensitive to sour and salty, and the tip of the tongue to the sweet taste. In the center of the language, flavoring receptors are absent. In this place, the taste is not felt at all. There is also interesting that the smell is played in the taste process. Tasty or tastelessly mostly defines our sense of smell. It is not surprising that we seem delicious products such as tea, apples, oranges and. For example, when we drink, we first feel warm, then bitterness and in the end sweetness (if sugar was added). We can say that coffee is really tasty only when his smell, passing through the larynx and the nose, will give a signal to our brain. And if you hold the nose, then you will not only be able to determine the taste of coffee, but you will not even be able to determine the difference between two completely different products that you eat or drink! Like this! :)))
- Sweet)
- Sweet - we lick ice cream and lollipops (chup-chups) just the tongue of the tongue!
- sweetness 😉
- And it seems to me that for the sweet, the sides for the salty, and everything else is for sour and bitter ....
- Taste's receptors are located in the language uneven: the tip of the language is responsible for the sweet taste, the side edges of the front of the tongue for the salty taste, the side edges of the back of the tongue for sour taste, the root of the tongue for the bitter taste.
Human language is its taste of taste, the mechanism of its functioning is that the substance dissolved in water or saliva, in the pores falls on flavoring bulbs in which chemical irritations turn into nerve impulses transmitted to the central nervous system.
The feeling of taste can vary depending on the mass fraction of the substance, so the solution of the cooking salt below the threshold concentration is perceived sweet.
- sweet and sour it is on tongue crows !!!
The whole language is entirely.
Language map - once hanging in almost any school, a visual manual - was aimed at showing how each of the areas of the tongue is alone responsible for one of the "four base tastes": sweet, sour, bitter or salty. In fact recognize all tastes - moreover, more or less equally - you can anywhere in the nose and languageIf only there were flavoring bulbs. In addition, the basic tastes are more than four.
According to the map sweet always feel the tip of the language, and gorky - his back. Rear side edges of the language recognize sour, and front side - salty. The map was based on the results of research by German scientists, published in 1901, but in the translation of the article into English inaccuracy was briefedAnd it made it a very influential psychologist from Harvard with an unsuitable name to Edwin Boring (1886-1968). The German examination demonstrated that the human language has a relative sensitivity zone to different tastes; Translated it turned out that every taste could be felt only one zone.
But what is really incomprehensible in all this story with the card, so this is the vitality of her incorrect interpretation - despite the fact that it is not difficult to refute it. (Just put a pinch of sugar to the site of the language, which, judging by the map, feels only salty.) Only in 1974 the theory was reassessing. Dr. Virginia Collingz (also from the USA) proved that, although four basic tastes really vary on the surface of the tongue, the degree of such variations is very insignificant.. She also demonstrated that all taste bulbs feel absolutelyall tastes.
Another confusion generated by the notorious language map was that basic tastes of only four. Their at least five. The fifth is calledummy And is the taste of protein in spicy products, for example in bacon, cheese, seaweed or "Marmite". He first allocated him in 1908, Professor-Chemist Kikunae Ikyda from Tokyo University, but as the official "fifth" basic tasteummy It was recognized only in 2000, when researchers from the University of Miami discovered in the human language of protein.
The term minds comes from the Japanese Itath, which means "tasty". Professor Icy also found out that the key ingredient of the minds is glutamate sodium. ICED was the guy not mistakes: he sold his recipe "Ahinoto" - companies to this day owning the third world market of synthetic glutamate, the annual production of which is one and a half million tons.
Given the significance of the protein to feed a person, it is quite logical that the minds stimulate the center of pleasure in the brain. Strong, weathered red wine, for example, has the taste of minds. Bitter taste, on the contrary, warns us of possible danger.
"Taste", by the way, should not be confused with the taste - experience is much more dissolved and not only taste, but also smell, vision, touch, and even rumor. (It is considered, for example, that the sound of crisp food enriches the total taste experience.)
Lexico-taste synesthesia is a rather rare state in which the brain confuses the taste and speech, so that every word begins to have his own special taste. So, in one of the experiments, the participant had a feeling of taste of Tuna whenever she thought about the word "kastanets."
Taste. The smell perception is inextricably linked with the feeling of taste. In analytical terminology, four main types of taste are distinguished:
1. Salted - sensation for which a typical flavoring stimulus is a sodium chloride solution;
2. Sweet - sensation for which a typical taste stimulus is an aqueous solution of sucrose;
3. Gorky - the feeling for which the tipic flavors are aqueous solutions of caffeine, quinine, and some other alkaloids;
4. Sour - sensation for which typical flavoring stimuli is aqueous solutions of wine, lemon, and a number of other acids.
The remaining species and shades of tastes are complex matter of these flavors. The term "stimulus" is recommended to denote a substance or electrophysical effect that causes the feeling when interacting with chemoreceptors.
Recently, alkaline and binders are added to the four types of tastes. Alkaline arises from chemical irritation of the mucous membrane in the oral cavity and is not due to specific taste receptors. A typical incentive for the sensation of alkaline taste is an aqueous solution of sodium bicarbonate, and aqueous solution of tannins is aqueous solution.
In foreign literature, the term "umami" is often used in the description of the taste of food products, which designate a pleasant sensation caused by glutamic sodium and nucleotides. The substances giving the feeling of "umami" intensify the taste of the food product, increases some of its characteristics, such as pleasant, feeling of fullness, the perfection of taste.
Taste sensations are perceived at different speeds. The most quickly there is a feeling of saline taste, then sweet, sour, much slower - bitter. This is explained by the uneven arrangement of taste receptors (Fig. 1).
Fig. 1. Differentiation of taste sensations perceived by the human language
The outer perceived part of the human taste body is represented by flavoring bulbs, which are in the so-called papillas (kidneys) of the language. Separate bulbs are also scattered in the mucous membrane of a soft palate, the rear wall of the native and even on the side walls of the larynx. The total number of flavoring bulbs can reach several thousand.
Taste receptors are subject to rapid dying and neoplasm. With age, the amount of flavoring bulbs can decrease in two or three times, and this leads to a strong decrease in taste sensations.
Taste's taste receptors have explicit specificity. At the tip itself, large mushroom-like nipples are located on the edges, in each of which 8-10 bulbs. The sweet taste is most felt by the end of the tongue, salty - edges of the front of the tongue, sour - edges of the back of the tongue. At the base of the language there are grooved papillas in each of which 100-150 flavoring bulbs, which perceive bitter taste.
The body of the taste (language) of a person is a chemical analyzer. The mechanism of its functioning is that the substance dissolved in water or in saliva penetrates through the flavoring pores to the bulbs in which chemical irritations are converted into nerve impulses transmitted by nerve fibers into the central nervous system. The chemical receptor in the language serves the protein, the composition and properties of which are studied.
Immersion language into solution is usually not enough to cause a feeling of taste. At the same time there is a feeling of tanging, sometimes cold. The perception of taste is better when contacting the tongue with the walls of the vessel, and the pressing of the tongue towards the neba facilitates the penetration of the dried solution in the pores of the flavoring pores of the bulbs (Fig. 2).
Fig. 2. Sketchy image of flavoring bulbs. 1 Delicious time, 2 - cell of the sense organ, 3 - nerve fibers, 4 - connecting fabric, 5 - main cells, 6 - flavor cells, 7 - multilayer epithelium
There is no generally accepted theory of taste, since the mechanism of functioning of the cells of the taste body is not sufficiently studied. Existing hypotheses are based on physico-chemical; Chemical and enzymatic prerequisites. There is some dependence between the chemical nature of the flavoring agent and the sensation of taste caused by it. But the substances of different buildings may have the same taste and vice versa, the substances of the same chemical nature have a different taste. Sweets are felt not only sugar, but many amino acids, Sakharin. From vegetable raw materials, a protein Tuamatin was isolated, which has a molecular weight of 22 thousand, consists of 207 residues of amino acids and 8 thousand times the sweeter of sucrose.
The feeling of taste may vary depending on the mass fraction of the substance. The solution of the cooking salt below the threshold concentration is perceived sweet. Solutions of potassium chloride as the concentration increases the taste from the sweet, then bitter, bitterly salty to the sensation of a complex taste, which combines salty, bitter and sour. Substances with intense sweet taste (Sakharin, aspartames, cyclamatics) used as substitutes of sugars, have a bitter taste with an increased mass fraction.
Crystalline salts soluble in water, which dissociate with the formation of positive and negative ions, have salted taste. With the exception of sodium chloride, which has a purely salty taste, all other salts cause more or less mixed taste. The quality of salt taste is mainly determined by anion, and the intensity of taste with a cation. At the concentration of sodium chloride (mol / l) 0.009, the taste solution does not have, in the range of 0.01-0.03 solutions have a sweet taste of different intensity, and within the concentration of 0.04 and above - salty. Solutions of potassium chloride in the range of 0.009-0.02 have a sweet taste, and 0.03-0.04 - bitter, from 0.05 to 0.1 - bitter and salty, and starting from 0.2 and higher - salty, bitter and sour. Yodid Potassium has a bitter taste, Potassium bromide - salty-bitter. Calcium chloride is bitter.
The intensity of the organoleptic sensation of the cook salt in the fish in the range of 0.4-1% is less compared to the sensation of it in the solution of the corresponding concentration.
A sour taste causes inorganic acids, as well as organic acids and their salts. The flavor quality of the acid corresponds mainly with the concentration of hydrogen ions. For inorganic acids, the assertion is fair, for organic acids the intensity of the feeling of acid taste is superior to expected at the corresponding concentration of hydrogen ions.
Compounds having a bitter taste belong to different classes. Typical bitter substances are alkaloids of quinine and caffeine. Many mineral salts, most of the nitro compounds, some amino acids, peptides, phenolic components of smoke and smoked phenolic components have a bitter taste.
The flavoring threshold concentrations of compounds in aqueous solutions and products do not coincide, and this should be taken into account in technological developments. Some substances can mask or, on the contrary, strengthen the taste sensations of other components of food. Mixing the main tastes, as well as the change in their intensity, can cause such complex complex phenomena as rivalry of tastes, compensation of flavors, the disappearance of the re-taste, contrast taste and other sensory sensations.
The invention of the new dish is more important for happiness
mankind than the opening of the new planet.
Jean-Antelm Bryia-Savaren
The easiest joy in our life is to eat delicious. But how difficult it is to explain from the point of view of science that happens! However, the physiology of taste is still at the very beginning of its path. So, for example, Sweet and Gorky receptors were open only ten years ago. But they are not sufficient enough to explain all the joy of gourmet.
From language to the brain
How many flavors feel our tongue? Everyone knows sweet taste, sour, salty, bitter. Now, the German physiologist Adolf Fick is now to this four-century, the German physiologist has officially added the fifth - the taste of the minds (from the Japanese word "Umai" - delicious, pleasant). This taste is characteristic of protein products: meat, fish and broths based on them. In an attempt to find out the chemical basis of this taste, a Japanese chemist, Professor of the Tokyo Imperial University Kikunae Ikyda analyzed the chemical composition of the sea algae Laminariajaponica., the main ingredient of Japanese soups with a pronounced taste of minds. In 1908, he published a work on glutamic acid, as a carrier of taste of minds. Later, Icyd patented the technology of obtaining glutamate sodium, and the company "ADZINOTO" began its production. Nevertheless, the minds were recognized as the fifth fundamental taste only in the 1980s. Today, new tastes are discussed, until not included in the classification: for example, a metal taste (zinc, iron), the taste of calcium, licorch, the taste of fat, the taste of clean water. It was previously believed that "fatty taste" is just a specific texture and smell, but research on rodents conducted by Japanese scientists in 1997 showed that their taste system recognizes lipids. (We will tell you more about this further.)
The human language is covered with more than 5,000 papillas of different shapes (Fig. 1). Mushrooms occupy mainly two front-thirds of the language and scattered over the entire surface, the groove (cupid) are located behind, the root of the language, they are big, they are easy to see, sheets are closely located in the lateral part of the tongue. Each of the papillates contains taste buds. A little taste kidneys is also in the epiglotan, the back wall of the throat and on a soft nurse, but mostly they are, of course, focused on the papillas of the tongue. The kidneys have their own specific set of taste receptors. So, at the tip of the language more receptors to sweet - it feels it much better, the edges of the tongue are better feeling sour and salty, and its base is bitter. In total, we have about 10,000 taste kidneys in your mouth, and thanks to them we feel taste.
Each flavor kidney (Fig. 2) contains several dozen flavor cells. There are cilia on their surfaces, on which the molecular machine is localized, providing recognition, amplification and conversion of flavor signals. Actually, the flavoring kidney itself does not reach the surface of the mucous membrane - only taste time in the oral cavity. The substances dissolved in the saliva diffuse through the time in the liquid-filled space over the flavor kidney, and there they come into contact with the cilia - the outer parts of the taste cells. On the surface of the ciliation there are specific receptors, which selectively associate molecules dissolved in saliva, are activated to the active state and the cascade of biochemical reactions in the flavor cell is launched. As a result, the latter releases the neurotransmitter, it stimulates the flavoring nerve, and the electrical impulses carrying information about the intensity of the taste signal are leaving the nervous fibers in the brain. Receptor cells are updated approximately every ten days, so if you burn the tongue, then the taste is lost only for a while.
The molecule of the substance causing a certain taste can only be contacted with its receptor. If there is no such receptor or it or the biochemical reaction cascades associated with it do not work, then the substance will not cause the taste. Significant progress in understanding the molecular mechanisms of taste was reached relatively recently. So, the bitter, sweet and minds we recognize thanks to the receptors open in 1999-2001. All of them belong to the extensive GPCR family ( G Protein-Coupled Receptors) conjugate with G-proteins. These G-proteins are inside the cell, are excited when interacting with active receptors and launch all subsequent reactions. By the way, in addition to flavoring substances, GPCR receptors can recognize hormones, neurotransmitters, odorous substances, pheromones - in a word, they are similar to antennas that take a wide variety of signals.
Today, the receptor of sweet substances is a dimer of two receptor proteins T1R2 and T1R3, the T1R1-T1R3 dimer is answered for the taste of minds (glutamate has other receptors, and some of them are located in the stomach, innervated by a wandering nerve and are responsible for feeling pleasure From food), but the feeling of bitterness We are obliged to existence of about thirty T2R group receptors. A bitter taste is a danger signal, since such a taste have most of the poisonous substances.
Apparently, for this reason, "bitter" receptors are more: the ability to distinguish danger in time maybe a matter of life and death. Some molecules, such as saccharine, can activate both a pair of sweet T1R2-T1R3 receptors and bitter T2R (in particular, HTAS2R43 in humans), so Sakharin in the language seems both sweet and bitter. This allows us to distinguish it from sucrose, which activates only T1R2-T1R3.
Fundamentally different mechanisms underlie the formation of sensations of sour and salty. The chemical and physiological determination of the "sour", in fact, coincide: the increased concentration of H + ions in the analyzed solution is responsible for it. Food salt is, as you know, sodium chloride. When a change in the concentration of these ions - carriers of sour and salty flavors occurs, the corresponding ion channels react immediately, that is, transmembrane proteins, selectively transmitting ions into the cell. The acid receptors are actually ionic channels permeable for cations that are activated by extracellular protons. Salted receptors are sodium channels, the flow of ions through which increases with increasing the concentration of sodium salts in the flavor. However, potassium and lithium ions are also felt as "salty", but the corresponding receptors are definitely not yet found.
Why is the taste of a taste? Air with difficulty passes into the upper part of the nasal moves, where olfactory cells are located. Temporarily disappears the smell, so we feel bad and taste too, since these two sensations are closely connected (and the sense of smell is more important than richer than food flavors). The odorless molecules are released in the mouth, when we fierce food, climb up the nasal strokes and are recognized by olfactory cells there. How important is the smell in the perception of taste, you can understand by closing your nose. Coffee, for example, will be just bitter. By the way, people who complain about the loss of taste in fact basically have problems with the smell. It has about 350 types of olfactory receptors, and this is enough to recognize a huge set of smells. After all, each fragrance consists of a large number of components, so many receptors are used immediately. As soon as the odorless molecules are associated with olfactory receptors, it starts the chain of reactions in the nerve endings, and a signal is formed, which is also sent to the brain.
Now about temperature receptors, which are also very important. Why does the mint give a feeling of freshness, and the pepper burns the tongue? Mentol entersing mint activates TRPM8 receptor. This cationic canal opened in 2002, begins to work when the temperature drops below 37 o C - that is, it is responsible for the formation of the feeling of the cold. Menthol reduces the TRPM8 activation threshold, so when it falls into the mouth, the feeling of the cold occurs at a constant ambient temperature. Capsaicin, one of the components of burning pepper, on the contrary activates heat receptors TRPV1 - ion channels close to the TRPM8 structure. But unlike cold, TRPv1 is activated by increasing the temperature above 37 ° C. That is why the capsaicin causes a feeling of burning. The spicy tastes of other spices are cinnamon, mustard, cumin - also recognized by temperature receptors. By the way, the meal temperature is of great importance - the taste is expressed as much as possible when it is equal to or slightly above the temperature of the oral cavity.
Oddly enough, the teeth also participate in the perception of taste. About food texture We are reported to pressure sensors located around the roots of the teeth. Chewing muscles, which "evaluate" the hardness of food take part in this. It has been proven that when there are many teeth with remote nerves in the mouth, the feeling of taste is changing.
In general, the taste is, as doctors say, a multimodal feeling. The following information should be held together: from chemical electoral taste receptors, thermal receptors, data from mechanical sensors of teeth and chewing muscles, as well as olfactory receptors that are volatile components of food.
Approximately 150 milliseconds, the first information about the taste stimulation comes to the central cortex of the brain. Delivery is carried out four nerves. The facial nerve transmits signals coming from flavor kidneys, which are located on the front of the tongue and on the nose, the triple nerve transmits information about the texture and temperature in the same zone, the languagehlock nerve forwards the taste information from the rear third of the language. Information from the throat and the palmist transfers the wandering nerve. Then the signals pass through the oblongable brain and turn out to be in Talamus. It is there that flavoring signals are connected with olfactory and together go into the taste zone of the cerebral cortex (Fig. 3).
All product information is processed by the brain at the same time. For example, when in the mouth of a strawberry, it will be a sweet taste, strawberry smell, juicy with bones consistency. Signals from the senses treated in many parts of the cerebral cortex are mixed and give a comprehensive picture. A second, we already understand what we eat. Moreover, the overall picture is created by nonlinear addition of components. For example, the acidity of lemon juice can be masked with sugar, and it will seem not so sour, although the proton content in it does not decrease.
Small and big
Little children have more taste buds, so they are so exacerbily perceived and so legible in food. The fact that in childhood seemed bitter and nasty, easily swallowed with age. In the elderly, many taste kidneys die off, so food them often seems fresh. There is an effect of addiction to taste - with the time of the severity of the sensation decreases. Moreover, addictive to the sweet and salty is developing faster than to the bitter and sour. That is, people who are accustomed to saline or sweeten food, do not feel salt and sugar. There are other interesting effects. For example, getting used to the bitter increases the sensitivity to the acidic and salty, and the adaptation to sweetly aggravates the perception of all other flavors.
The child learns to distinguish the smells and taste is already in the womb. Inhaling the amniotic fluid, the embryo masters the entire palette of odors and tastes that perceives the mother. And then then forms the addiction with which it will come to this world. For example, pregnant women ten days before birth offered candy with Anis, and then watched the newborns in the first four days of life behaved. Those whose moms ate anise candy clearly distinguished this smell and turned their heads in his side. According to other studies, the same effect is observed with garlic, carrots or alcohol.
Of course, taste addictions are greatly dependent on family traditions, from the country's customs in which a person grew up. In Africa and Asia, grasshoppers, ants and other insects are delicious and nutritious food, and Europeans have a vomit reflex. Anyway, nature left a little space for choice: how exactly you will feel this or that taste is largely predetermined genetically.
The genes dictate the menu
It sometimes seems to us as if we ourselves choose what food to love, as a last resort, what we eat what our parents were taught. But scientists are increasingly inclined to make genes for us. After all, people feel the taste of the same substance in different ways, and the thresholds of taste sensitivity also differ very much - up to the "taste blindness" to individual substances. Today, the researchers were seriously wondering if some people are really programmed to eat french fries and gain weight, while others are happy to eat boiled potatoes? This is especially worried about the United States, which faced the real obesity epidemic.
For the first time, the question of the genetic predestination of smell and taste was raised in 1931, when the chemist of the company "DUPON" Arthur Fox synthesized the sputum molecule of Phenylthiocarbeamide (FTK). His colleague noticed a sharp smell, which proceeded from this substance, to the great surprise of Fox, who did not feel anything. He also decided that the substance was tasteless, and the same colleague found him very bitter. Fox checked FTK on all members of his family - no one felt smell ...
This publication of 1931 gave rise to a number of sensitivity studies - not only to FTK, but in general to the bitter substances. Approximately 50% of Europeans turned out to be insensitive to the bitterness of phenyltocarbamide, but only 30% of Asians and 1.4% of Amazonian Indians. The gene responsible for this was discovered only in 2003. It turned out that it encodes the receptor protein of flavor cells. At different individuals, this gene exists in different versions, and each of them encodes a slightly different receptor protein - respectively, phenyltocarbamide can interact well with it, poorly or at all. Therefore, different people distinguish bitterness to varying degrees. Since then, about 30 genes encoding the recognition of bitter taste have been found.
How does this affect our taste addiction? Many are trying to answer this question. It seems that those who distinguish the bitter taste of FTK are disgusted with broccoli and Brussels cabbage. These vegetables contain molecules whose structure is similar to FTK. Professor Adam Ancient from Michigan University in 1995 formed three groups of people by their ability to recognize in solution close to FTK, but less toxic connection. The same groups checked on taste addiction. Those who felt the very small concentrations of the test substance found coffee and saccharin too bitter. Ordinary sucrose (sugar that gets from cane and beets) seemed to them more sweet than others. And burning pepper ZHAG is much stronger.
There is still a controversial question about the taste of fat. For a long time, it was believed that fat we recognize with the help of smell, since lipids allocate fragile molecules, as well as due to a specific texture. Special flavor receptors for fat no one even searched. These ideas in the 1997 study group of Toru Fusiki from the University of Kyoto. From the experiment it was known that the rat was preferred a bottle of food containing fats. To check whether it is connected with a consistency, Japanese biologists offered to rodents without smelling two solutions - one with lipids, and the other with a similar consistency, symotic thanks to the thickener. Rousing unmistakably chose a solution with lipids - apparently, guided by the taste.
In fact, it turned out that rodent language can recognize the taste of fat using a special receptor - glycoprotein CD36 (fatty acid conveyor). French researchers under the guidance of Phillip Benar proved that when the gene encoding CD36 is blocked, the animal ceases to give preference to fatty food, and in the gastrointestinal tract, the secretion does not change in the grease. At the same time, the animals were still preferred sweet and avoided bitter. So, a specific receptor was found for fat.
But man is not rodent. The presence in our body of the CD36 transport protein is proved. It transfers fatty acids into the brain, the heart is produced in the gastrointestinal tract. But is it in language? Two laboratories, American and German, tried to clarify this issue, but there are no publications yet. Research on African Americans, in which a wide variety of gene encoding CD36 protein has been found, as if showing that the ability to recognize fat in food is indeed associated with some modifications of a particular gene. There is hope that when the answer will be found to the question "Can our language feel the taste of fat," doctors will appear new opportunities for the treatment of obesity.
Gourmet animals?
In the XIX century, the famous French grocery and the author of the widely quoted book "Physiology of Taste" Jean-Antelm Bryia-Savaren insisted that only a sensible man is enjoying a meal that is generally needed just to maintain life. Indeed, modern studies have shown that animals perceive the taste otherwise than we. But is it so much different than the taste sensations in people and other representatives of the detachment of primates?
The experiments were performed on 30 types of monkeys, which were given to try clean water and solutions with different tastes and different concentrations: sweet, salty, acidic, bitter. It turned out that their taste sensitivity strongly depends on who and what tries. Primates feel like we, sweet, salted, sour and bitter. The monkey distinguishes the fructose fruit from the sucrose beets, as well as the tannins of the tree bark. But, for example, Wattiuti is a breed of monkeys, which is powered by leaves and greens, is more sensitive to alkaloids and quinine in the crust of trees than fruita primates of South America.
Together with American colleagues from the University of Wisconsin, French researchers confirmed this by the electrophysiological experiments and brought together a picture obtained on different types of monkeys. In electrophysiological experiments, the electrical activity of the fibers of one of the taste nerves was recorded - depending on which product eats an animal. When electrical activity was observed, it meant that the animal feels the taste of this food.
And what about a person? To determine the thresholds of sensitivity, the volunteers blindly gave to try first very diluted, and then increasingly concentrated solutions, until they formulated clearly, what is the taste of the solution. The human "taste tree" is generally similar to those that they got for monkeys. The person is also far away in the opposite sides of the taste sensations from what brings energy to the body (sugar), and what can harm (alkaloids, tannin). There is a correlation between the substances of the same type. One who is very sensitive to sucrose, has chances of being also sensitive to fructose. But but there is no correlation between the sensitivity to quinine and the tannin, but someone, sensitive to fructose, is not necessarily sensitive to the Tanin.
Since we and the monkeys are so similar to the taste of taste, does that mean that we are very close to the evolutionary tree? According to the most believable version, by the end of the Paleozoic and the emergence of the first terrestrial creatures, the evolution of plants and animals was parallel. Plants were to somehow resist the active ultraviolet radiation of the young sun, so only those specimens that had enough polyphenols for protection were able to survive on land. The same compounds protected plants from herbivores, as they are toxic and difficult to digest.
The vertebrates during the evolution developed the ability to distinguish a bitter or astringent taste. It is these tastes that surrounded primates when they appeared in the Cenozoic Era (Eocene), and then the first people. The appearance of plants with flowers, which turned into fruit with a sweet pulp, played a big role in the evolution of taste. Primates and fruit plants evolved together: Primates eaten sweet fruits and scattered their seeds, contributing to the growth of trees and Lian in the tropical forests. But the ability to recognize the taste of salt (especially cooking) could hardly arise during the coevolution with plants. Perhaps she came from water vertebrates, and primates simply inherited her.
Interestingly, primates when choosing a meal are guided only by nutritional value and taste? No, it turns out, they can eat plants and with therapeutic goal. Michael Huffman from the Kyoto University in 1987 in the west of Tanzania watched the chimpanzee, who had problems with the stomach. Monkey eaten the stems of a bitter plant Vernonia amygdalina. (Vernonia), which chimpanzees are usually not eaten. It turned out that the shoots of the tree contain substances that help against malaria, dysentery and schistosomiasis, as well as possessing antibacterial properties. Observation of the behavior of wild chimpanzees gave scientists to food for reflection: new vegetable drugs were created.
In general, the taste has not changed much in the process of evolution. And primates and people taste sweet pleasant - in their organisms there is an endorphin. Therefore, perhaps the Great French Culinary was not entirely right - Primates can also be gourmet.
According to the magazine
"LA RECHERCHE", №7-8, 2010