The sense of taste is associated with irritation of not only chemical, but also mechanical, temperature and even pain receptors of the oral mucosa, as well as olfactory receptors. The taste analyzer determines the formation of taste sensations and is a reflexogenic zone. Using a taste analyzer, they evaluate different qualities taste sensations, the strength of sensations, which depends not only on the strength of irritation, but also on the functional state of the body.

Structural and functional characteristics of the taste analyzer.

Peripheral department. Taste receptors (taste cells with microvilli) are secondary receptors; they are an element of taste buds, which also include supporting and basal cells. Taste buds contain cells containing serotonin and cells that produce histamine. These and other substances play a certain role in the formation of the sense of taste. Individual taste buds are multimodal structures, as they can perceive different types of taste stimuli. Taste buds in the form of separate inclusions are located on the back wall of the pharynx, soft palate, tonsils, larynx, epiglottis and are also part of the taste buds of the tongue as an organ of taste.

The peripheral section of the taste analyzer is represented by taste buds, which are located mainly in the papillae of the tongue. Taste cells are dotted at their ends with microvilli, which are also called taste hairs. They come to the surface of the tongue through the taste pores.

The taste cell has a large number of synapses that form fibers of the chorda tympani and glossopharyngeal nerve. The fibers of the chorda tympani (a branch of the lingual nerve) approach all fungiform papillae, and the fibers of the glossopharyngeal nerve approach the grooved and foliate papillae. The cortical end of the taste analyzer is located in the hippocampus, parahippocampal gyrus and in the lower part of the posterocentral gyrus.

Taste cells continually divide and continually die. The replacement of cells located in the front part of the tongue, where they lie more superficially, occurs especially quickly. Replacement of taste bud cells is accompanied by the formation of new synaptic structures

Wiring department. The taste bud contains nerve fibers that form receptor-afferent synapses. The taste buds of different areas of the oral cavity receive nerve fibers from different nerves: the taste buds of the anterior two-thirds of the tongue - from the chorda tympani, which is part of the facial nerve; the kidneys of the posterior third of the tongue, as well as the soft and hard palate, tonsils - from the glossopharyngeal nerve; taste buds, located in the pharynx, epiglottis and larynx, come from the superior peglottic nerve, which is part of the vagus nerve.

These nerve fibers are peripheral processes of bipolar neurons located in the corresponding sensory ganglia, which represent the first neuron of the conduction section of the taste analyzer. The central processes of these cells are part of a single bundle of the medulla oblongata, the nuclei of which represent the second neuron. From here, the nerve fibers in the medial lemniscus approach the visual thalamus (third neuron).

Central department. The processes of thalamic neurons go to the cerebral cortex (fourth neuron). The central, or cortical, section of the taste analyzer is localized in the lower part of the somatosensory zone of the cortex in the area of ​​​​the tongue. Most of the neurons in this area are multimodal, i.e., they respond not only to taste, but also to temperature, mechanical and nociceptive stimuli. The gustatory sensory system is characterized by the fact that each taste bud has not only afferent, but also efferent nerve fibers that approach the taste cells from the central nervous system, which ensures the inclusion of the taste analyzer in the integral activity of the body.

The mechanism of taste perception. For a taste sensation to occur, the irritating substance must be in a dissolved state. A sweet or bitter taste substance, dissolving into molecules in saliva, penetrates the pores of the taste buds, interacts with the glycocalyx and is adsorbed on the cell membrane of the microvilli, into which “sweet-sensing” or “bitter-sensing” receptor proteins are built. When exposed to salty or sour taste substances, the concentration of electrolytes near the taste cell changes. In all cases, permeability increases cell membrane microvilli, the movement of sodium ions into the cell occurs, depolarization of the membrane occurs and the formation of a receptor potential, which spreads both along the membrane and through the microtubular system of the taste cell to its base. At this time, a mediator (acetylcholine, serotonin, and possibly hormone-like substances of a protein nature) is formed in the taste cell, which in the receptor-afferent synapse leads to the emergence of a generator potential, and then an action potential in the extrasynaptic sections of the afferent nerve fiber.

Perception of taste stimuli. Microvilli of taste cells are formations that directly perceive a taste stimulus. The membrane potential of taste cells ranges from -30 to -50 mV. When exposed to taste stimuli, a receptor potential of 15 to 40 mV arises. It represents a depolarization of the surface of the taste cell, which causes the emergence of a generator potential in the fibers of the chorda tympani and glossopharyngeal nerve, which turns into propagating impulses upon reaching a critical level. From the receptor cell, excitation is transmitted through the synapse to the nerve fiber using acetylcholine. Some substances, such as CaCl2, quinine, and heavy metal salts, do not cause primary depolarization, but primary hyperpolarization. Its occurrence is associated with the implementation of negative rejected reactions. In this case, no propagating impulses arise.

Unlike olfactory sensations, taste sensations can easily be combined into groups based on similar characteristics. There are four main taste sensations - sweet, bitter, sour and salty, which in their combinations can give diverse shades of taste.

The sensation of sweetness is caused by carbohydrates contained in food substances (dihydric and polyhydric alcohols, monosaccharides, etc.); the sensation of bitterness is due to the effect of various alkaloids on the taste buds; the feeling of sourness arises from the action of various acids dissolved in water; The feeling of saltiness is caused by table salt (sodium chloride) and other chlorine compounds.

Olfactory and gustatory sensations

Perception of smells. The sense of smell is an extremely subtle sense. A person can easily distinguish and remember up to 1000 odors, and an experienced specialist is able to distinguish between 10,000 and 17,000 odors. Along with the concept of smell, the terms “aroma” are used to denote a pleasant smell and “bouquet” to characterize the complex aroma that develops as a result of enzymatic and chemical processes, for example, during the aging of wines and cognacs, during the ripening of rennet cheeses, canned fish types “Sprats” and “Sardines”, for fermenting tea, roasting coffee beans, etc.

The organ of smell is located in the nasal cavity. The olfactory epithelium is located on an area of ​​3 - 5 cm2, has yellow due to the presence of grains of the dye in special sensitive cells located in the mucous membrane of the upper part of the septum, the arch of the nose and its other parts. The olfactory epithelium, located in the upper part of the nasal cavity, is in direct communication with the oral cavity. Molecules of volatile aroma-forming substances located in the oral cavity easily enter the nasal cavity through the nasopharynx.

A type of smell occurs when the trigeminal nerve, which has many endings in the nasal cavity, is stimulated. The nerves of the pharynx and tongue, the vagus nerve of the larynx and other nerves are poorly excited when exposed to aroma-forming substances.

The stimulating influence of certain odors on the ability to perform intense physical or mental work, as well as the calming effect of certain odors on the nervous and other human systems, have been discovered.

Over the past 100 years, about 30 different odor hypotheses have been identified, but there is still no scientifically proven theory. The stereochemical and membrane hypotheses are more widely known. The latter explains the occurrence of odor by the permeability of the cell membrane by volatile molecules, but does not justify the wide range of perceived olfactory sensations. According to the stereochemical hypothesis, odor recognition depends on the correspondence of the size and shape of the molecules of the aroma-forming substance (the so-called particle geometry) to certain openings (pores) in the olfactory region of the nose. P. Martin (England) received the Nobel Prize for his hypothesis about the mechanism of the sense of smell. It is based on the interaction of enzymes activated by odorant molecules with the corresponding coenzymes.

Along with unresolved difficulties in the theoretical interpretation of the mechanism of perception of odors by the olfactory organ, the problem of classification of odors remains unresolved. Several classification systems have been proposed, dividing odors into 7, 9, 10, 11 groups, which in combination create the existing shades. For example, the classification created by Crocker and Tsunderson (1927 ᴦ.) divides all known odors into four groups:

· aromatic-floral (some ketones have a violet scent, as well as a musky scent);

· acidic (elements of this smell are contained in formic and acetic acids);

· burning smell (roasted coffee and furfural);

· caprylic (goat, found in fusel oils, rancid fats, kerosene, gasoline, in the smell of decomposing corpses and animal excretions).

The one developed by Amur in 1962 became the most widespread. a classification that identifies seven basic, or primary, odors:

camphor (hexachloroethane);

· musky (musk, xylene);

· floral (a-amylpyridine);

mint (menthol);

· ethereal (ethyl ether);

· spicy ( formic acid);

putrefactive (hydrogen sulfide).

Methods for restoring olfactory sensitivity

Pour a glass of water into an enamel pan, add 2 drops of mint essential oil and a teaspoon of cologne, and then heat it to a boil and breathe over the steam for 3 - 5 minutes, taking forced long breaths throughout the entire procedure. The course of treatment is 6 - 8 procedures daily or every other day.

Pour a glass of water into an enamel pan, bring it to a boil and add 10 - 12 drops of lemon juice and 1 drop of lavender or peppermint essential oil. Breathe over the steam for 3 - 5 minutes with each nostril, taking forced breaths. The course of treatment is 10 procedures daily or every other day.

A coin of 1 or 2 rubles. Lubricate with honey, apply to the very middle of the bridge of the nose and secure with a plaster. Even better is to use an old copper coin. You need to hold the coin for at least 30 minutes every day. Often after 15 - 20 procedures, the sense of smell is completely restored.

Add 10 drops of lemon juice and cologne to a glass of water heated to 50°C. Gauze or cotton cloth is soaked in this water and applied to the entire surface of the nose for 5 - 7 minutes. The course of treatment is 10 procedures daily.

Vietnamese balm “Golden Star” is left in the sun for several hours in a closed jar, then rubbed into the bridge of the nose and the middle of the forehead. The course of treatment is 7 - 10 procedures daily.

It is useful to learn how to tense and relax the muscles of the nose. This exercise restores your sense of smell well. You need to keep your muscles tense or relaxed for at least a minute. It is extremely important to do the exercise every day for 10 minutes.

Warming with a blue lamp has a positive effect on hyposmia. You can also use a regular 40 W light bulb. Put on sunglasses, remove the lampshade from the table lamp, tilt your head back so that the light falls inside the nasal cavity. The distance from the lamp to the nasal cavity should be no more than 25 cm. Carry out the procedure for 10 - 15 minutes daily or every other day for a week.

A well-known procedure according to the yogic system - drawing in warm salted water through the nose - also helps improve the sense of smell. Add salt to a glass of warm boiled water at the tip of a knife. Having closed one nostril with your finger, slowly draw in water through the open nostrils until it ends up in the throat. Next, the water is spat out. Do the same with the other nostril. You can release water not through your mouth, but through your nose. It is advisable to use all the poured water. The course of treatment is at least 10 procedures.

The described procedures can be varied as desired. Despite their simplicity, they are great for improving your sense of smell.

Taste sensations. The perception of smell is inextricably linked with the sensation of taste. In analytical terminology, there are four basic types of taste:

salty- a sensation for which the typical taste stimulus is a solution of sodium chloride;

sweet- a sensation for which the typical taste stimulus is an aqueous solution of sucrose;

bitter- a sensation for which typical taste stimuli are aqueous solutions of caffeine, quinine and some other alkaloids;

sour- a sensation for which typical taste stimuli are aqueous solutions of tartaric, citric and a number of other acids.

The remaining types and shades of tastes represent complex sensations of these tastes. The term “stimulus” is recommended to denote a substance or electrophysical effect that causes a taste sensation when interacting with chemoreceptors.

IN Lately Alkaline and astringent are added to the four types of flavors. Alkaline occurs from chemical irritation of the mucous membrane in the oral cavity and is not caused by specific taste buds. The typical stimulus for an alkaline taste is an aqueous solution of sodium bicarbonate, and for an astringent taste an aqueous solution of tannins.

Taste sensations are perceived at different speeds. The sensation of salty taste arises most quickly, then sweet, sour, and much more slowly - bitter. This is due to the uneven distribution of taste buds.

The external receptive part of the human taste organ is represented by taste buds, which are located in the so-called papillae (buds) of the tongue. Individual bulbs are also scattered in the mucous membrane of the soft palate, the posterior wall of the epiglottis, and even on the lateral walls of the larynx. Total taste buds can reach several thousand.

Taste buds are subject to rapid death and new formation. With age, the number of taste buds can decrease by two to three times, which leads to a severe decrease in taste sensations.

Taste receptors on the tongue have a distinct specificity. At the very tip of the tongue and along the edges there are large mushroom-shaped papillae, each of which has 8 - 10 bulbs. Sweet taste is most felt by the end of the tongue, salty - by the edges of the front part of the tongue, sour - by the edges of the back part of the tongue. At the base of the tongue there are grooved papillae, each of which has 100 - 150 taste buds that perceive bitter taste.

The human taste organ (tongue) is a chemical analyzer. The mechanism of its functioning is that a substance dissolved in water or saliva penetrates through the taste pores to the bulbs, in which chemical irritations are converted into nerve impulses transmitted along nerve fibers to the central nervous system.

The chemical receptor on the tongue is a protein. Immersing the tongue in the solution is usually not enough to produce a sensation of taste. In this case, there is a sensation of touch, sometimes cold. The perception of taste occurs better when the tongue comes into contact with the walls of the vessel, and the placement of the tongue towards the palate facilitates the penetration of the sample solution into the pores of the taste buds of the bulbs

There is no generally accepted theory of taste, since the mechanism of functioning of the cells of the taste organ has not been sufficiently studied. Existing hypotheses are based on physicochemical, chemical and enzymatic premises. Some relationship has been established between the chemical nature of the flavoring substance and the sensation of taste it evokes. But substances with different structures can have the same taste and, on the contrary, substances with the same chemical properties. nature have different tastes. Not only sugars are perceived as sweet, but also many amino acids and saccharin. The protein tuamatin was isolated from plant raw materials, which has a molecular weight of 22 thousand, consists of 207 amino acid residues and is 8 thousand times sweeter than sucrose.

With the exception of sodium chloride, which has a purely salty taste, all other salts produce more or less mixed taste sensations. The quality of the salty taste is mainly determined by the anion, and the intensity of the taste by the cation. At a sodium chloride concentration (mol/l) of 0.009, the solution has no taste; in the range of 0.01 - 0.03, solutions have sweet taste of varying intensity, 0.04 and above - salty. At a potassium chloride concentration (mol/l) of 0.009 - 0.02, solutions have a sweet taste, 0.03 - 0.04 - bitter, 0.05 - 0.1 - bitter and salty, and starting from 0.2 and above - salty, bitter and sour. Potassium iodide has a bitter taste, potassium bromide has a salty-bitter taste, and calcium chloride has a bitter taste.

The intensity of the organoleptic sensation of table salt in fish is 0.4 - 1% lower than in a solution of the corresponding concentration.

Causes sour taste inorganic acids, as well as organic acids and their salts. Taste quality acidity depends mainly on the concentration of hydrogen ions. For organic acids, the intensity of the sour taste sensation exceeds that expected at the appropriate concentration of hydrogen ions.

Typical bitter substances are the alkaloids quinine and caffeine. Many mineral salts, most nitro compounds, some amino acids, peptides, and phenolic components of smoke and smoked products have a bitter taste.

Threshold concentrations of compounds in aqueous solutions and products do not coincide, and this must be taken into account in technological developments. Some substances can mask or, on the contrary, enhance the taste sensations of other food components. Mixing of basic tastes, as well as changes in their intensity, can cause such complex complex phenomena as competition of tastes, compensation of tastes, disappearance of a repeated taste, contrasting taste, and other sensory sensations.

Influence of factors on taste and olfactory sensations.Adaptation is an adaptation of the organs of taste and smell, consisting in a decrease in their sensitivity caused by prolonged exposure to a stimulus (continuous or repeated) of the same quality and constant intensity. When the stimulus stops influencing, taste and olfactory sensitivity is restored. In contrast to vision, the organs of smell and taste are subject to rapid adaptation. Adaptation to odors in humans is more pronounced than To tastes. In particular, a person usually does not smell his clothes, his home, or his own body.

G.A. Wookes provides information about the development of adaptation of the olfactory organ to odors. Thus, the time, which is extremely important for adaptation to the smell of certain substances, will be as follows (min): iodine solution - 4, garlic - 45 or more, camphor - 2 or more, phenol - 9 or more, coumarin - 1 - 2, essential oils- 2 - 9.2, cologne - 7 - 12.

In some cases, with repeated exposure to very weak stimuli arriving sequentially one after another V over significant periods of time, the sensitivity of the organ of taste or smell may increase and persist for a long time. This phenomenon is usually called sensitization.

Increased sensitivity is achieved with the help of stimuli whose intensity is equal to the threshold, as well as due to the activity of the taster himself. The interval between repeated exposure to a stimulus depends on the type of stimulus and the sensory abilities of the tasters. For example, for hearing and vision, this interval should be 3 minutes for one taster and 1.5 minutes for another. Sensitization is characterized by resistance to maintaining this property.

G.A.Vuks notes that experimentally induced olfactory sensitization can be maintained for 7 - 22 days and then recover after several workouts. To increase sensitivity to a certain stimulus by an average of 60 - 70%, you need to feel its effect on the corresponding sensory analyzer for 30 - 35 minutes with an interval of 1 - 2 minutes.

sensitization to a code odor entails a slight increase in sensitivity to other odors.

Sensitization to red tends to reduce sensitivity to green and, in some cases, to yellow. Sensitization to green leads to deterioration of sensitivity to red, ᴛ.ᴇ. Along with the selectivity of observations, a parallel change in the thresholds of other colors is possible. This phenomenon is typical for taste: sensitization to one of the basic tastes affects other basic tastes. However, these patterns have not been fully studied. For example, it has been found that sensitization to bitter simultaneously increases sensitivity to sweet taste, and sensitization to sweet improves sensitivity to bitter taste. Salt sensitization may reduce sweet sensitivity in some tasters and increase it in others.

According to the taster profile, increased sensitivity to certain chemicals. There are known cases when a laboratory assistant performing a chemical analysis of the mass fraction of table salt in a food product was able, over time, to accurately sense the salinity of the product. Similar cases are known in the distillery industry, when a taster, thanks to the sensitization of taste and smell analyzers, determines the alcohol content in drinks with high accuracy. In the perfume industry, tasters are selectively sensitive To certain smells.

Individual sensitivity to smells and tastes. Some people have a lack of sense of smell in relation to either all odorous substances, or to one substance, or to a group of substances. This phenomenon is usually called anosmia and was found in relation to butyric acid, trimethylamine, hydrocyanic acid, alcohol, skatole and a number of other substances.

Anosmia is more common in men (about 20%), less common in women (about 5%). It is believed that it is inherited by descendants of the same sex. With anosmia, a normal sense of smell remains for many common odors. In most cases, a person does not realize that he has a partial lack of smell. Extremely great importance This phenomenon has a bearing on the selection of sensory analysts.

Loss of smell must be due to injury following illness, traffic accidents, or the effects of medications. Diseases of the nasopharynx often lead to a decrease in the function of smell: chronic runny nose and chronic inflammatory diseases of the paranasal sinuses - sinusitis, sinusitis, sphenoiditis, rhinovirus infections. The sense of smell may be reduced due to adenoids, nasal polyps, or a deviated nasal septum.

There are frequent cases of reduced olfactory sensitivity to all or individual odorous substances. This phenomenon is usually called hyposmia. Much less common is unusually high olfactory sensitivity of a person either to all odorous substances, or to one substance, or To group of substances. This phenomenon is usually called hyperosmia.

Olfactory hallucinations are also possible, manifested in the fact that a person perceives an odor that is not really there. This type of damage to the sense of smell is usually called spontaneous smell or parosmia.

Lack of taste sensitivity to all flavoring substances, or To one substance, or a group of substances is usually called ageusia. Reduced taste sensitivity to all or individual substances is usually called hypogeusia, and unusually high sensitivity - hypergeusia. The perverted ability to perceive a taste that is not characteristic of a given substance or group of substances is designated by the term parageusia.

Scientists believe that taster behavior can be predicted based on body type. It has been noted that tasters with a thin and fragile body structure (leptosomics) have twice as many taste aversions as plump and squat ones (picnics).

The results of studies on the influence of gender, age, salivary pH on the levels of taste sensitivity of the taster are ambiguous. It has been established that the pH values ​​of saliva correlate with the taster’s sensitivity to bitter solutions and bitterness of food products. After tasting, the acidic reaction of saliva, as a rule, decreases, and its alkalinity increases.

Some studies have compared levels of taste sensitivity with social status and the cultural level of the tested tasters. Thus, in groups with low characteristics of status and culture, high thresholds for recognizing basic tastes were observed. The Japanese are considered to be the most subtle in their perception of taste. It was found that genetic disorders of the taste analyzer are more common among Europeans, and only 6 - 10% of such disorders are observed in African blacks.

Individual differences in sensitivity thresholds among people are significant: for the sense of smell 1000: 1, for the organ of taste 64: 1. A small (not exactly taken into account) part of the population is completely devoid of sensitivity to taste or smell.

The influence of age. WITH With age, sensitivity to odors decreases in a logarithmic sequence. This extends not only to the sense of smell, but also to vision, hearing, taste and touch. It is believed that a person loses up to 50% of visual acuity and hearing by the ages of 13–15, the ability to perceive smell and taste by 22–29, and tactile sensitivity by 60 years. The age factor is not determining. Taking into account the dependence on natural data, lifestyle, nutrition, habits, nature of work, training of sensory organs, with age a person may increase the sensitivity of smell, taste, touch, and much less often - hearing and vision.

Memory and representation of smell - this is a person’s ability to recognize those odors that he had previously encountered, ᴛ.ᴇ. remember and recognize a known smell. Typically, a person is able to distinguish between several hundred and several thousand different odors. Qualified tasters must have the ability to recognize at least 10 thousand odors. Specialists develop their abilities through exercises and can distinguish up to 17 thousand varieties of smell. People's ability to remember smells varies greatly. Masking Odors are cases where one odor is suppressed by another. If two or three odors act on the olfactory organ at the same time, it may happen that none of them will show their true properties, and the perceived sensation of smell will be vague or not perceived at all.

Compensation for odors and tastes. Compensation is characterized by an increase, decrease, or disappearance of the sensation caused by a primary taste or smell, and is associated with the presence of small quantities of a substance of another taste or smell. There are positive and negative compensation. In the first case, the main taste or smell is enhanced by the influence of another taste or smell, in the second the main sensation is weakened.

For example, fructose turns out to be sweeter in an acidic environment, and glucose tastes less sweet as the acidity increases. The taste perception of sugar mixtures is not a simple summation of the sweet taste intensities of the components. Typically, a mixture of sugars is less sweet compared to the calculated data for the sum of the components.

When exposed to two different taste impulses simultaneously, the sensation of the weaker one may disappear. Salty, sweet and sour tastes disappear easily.

When mixing the odors of two substances that do not chemically react with each other, a mutual weakening of these odors may occur, ᴛ.ᴇ. their mutual compensation. Discovered a large number of odorous substances, the odors of which are mutually compensated.

It is not allowed to suppress objectionable odors and tastes in food products that characterize negative quality attributes (for example, when using stale raw materials, fats with signs of oxidation, components with objectionable odors, etc.).

Flavor modifications. A tropical plant is known as a sweet taste inhibitor Gymnema sylvestre, ĸᴏᴛᴏᴩᴏᴇ grows in South India, Ceylon and the tropics of West Africa. Fruits of another tropical plant Miracle fruit modify sour taste. For example, lemons take on the taste of sweet and sour oranges. The effect of taste modification lasts for 30 - 60 minutes. Properties of fruits Miracle fruit used in winemaking to soften the sour taste of wines, as well as in the baking and confectionery industry.

Secondary, or residual, the taste appears after tasting the product, it lasts for some time and differs from the characteristic taste. Residual taste usually reduces the consumer value of the product. The appearance of a long-lasting bitter secondary taste is typical when fats go rancid.

Flavor contrast may be a source of error in sensory testing. For example, ordinary water, especially distilled water, seems sweetish if a salty taste is felt before tasting it. A sour taste seems more sour and even unpleasant if it was preceded by a sensation of sweetness. The phenomenon of taste contrast can distort the results of evaluations of aged wines if sweeter ones were tasted before them. For the same reason, lightly salted products should not be rated after heavily or medium salted ones. Flavor contrast is extremely important to consider when determining the order in which samples are presented for tasting.

Taste illusions. L. Bartoshchuk discovered that after testing the artichoke pure water feels sweet.

Concept taste harmony characterizes the desirability of sensations and is associated with the compatibility of different tastes. Sweet and sour, salty and sweet harmonize well, it is more difficult to achieve harmony between bitter and sweet, it is almost impossible to combine bitter and salty, as well as bitter and sour tastes. Taste harmony develops during the ripening of wines and canned food. Knowledge of technology, laws of organoleptics and experience in working with food products contribute to the creation of taste harmony.

The influence of color on taste. It was noted that red solutions are perceived as sweeter compared to a colorless sweet solution of the same concentration. Yellow and light green colors increase the subjective assessment of acid. Experiments conducted at the University of Tartu showed that thirst quenching is best achieved by soft drinks if they are colored light green. Complex associations between color, taste and smell often arise.

For example, dark green color increases the intensity of taste and smell, yellow color gives a denser sensation of smell, and red and light green contribute to easier perception of odors. Blue colors different shades cause a sensation of bitter taste and unpleasant technical shades in the smell. G.A.Vuks compiled a semantic map with which you can describe the smell and taste of different food products. In particular, the taste of raspberry jam is described by the following terms: warm, heavy, soft, etc.

Influence of external factors. The sensitivity of smell and other sensory perceptions changes under the influence of external conditions. Particularly important are the degree of air purification, temperature, relative humidity air, room illumination; for example, in an odorless (deodorized) room, the impressionability of the sense of smell increases by 25%. Thus, as the temperature rises, the intensity of the odor increases. The optimal temperature is considered to be 37 - 38 "C. A further increase in temperature does not increase the intensity of the odor, but, on the contrary, reduces it. Temperature fluctuations in the odorimetric laboratory cause significant errors in the results. High relative air humidity favors better perception of odors. Indoor lighting mainly affects on the general condition of the central nervous system and indirectly on the human sense of smell.

Other factors also influence the taste and olfactory sensations of tasters: for example, the form of the food product, the state of hunger and satiety, associations, personal motives and authorities.

Olfactory and gustatory sensations - concept and types. Classification and features of the category "Olfactory and gustatory sensations" 2017, 2018.

The simplest joy in a person’s life is delicious food. It would seem that you go to the kitchen, open the refrigerator, spend a certain amount of time at the stove - and voila! – a fragrant dish is already on the table, and endorphins are in your head. However, from the point of view of science, the entire meal from start to finish is a complex multifaceted process. And how difficult it sometimes is for us to explain our eating habits!

The study of taste buds is carried out by a young and still developing science - the physiology of taste. Let's look at some basic tenets of the teaching that will help us better understand our taste preferences and momentary weaknesses.

Human taste buds

Taste is one of the five senses of perception, which are very important for human life. The main role of taste is to select and evaluate food and drink. Other senses, especially smell, help him a lot in this.

The taste mechanism is driven by chemicals found in food and drink. Chemical particles, collecting in the mouth, turn into nerve impulses that are transmitted along the nerves to the brain, where they are deciphered. The surface of the human tongue is covered with taste buds, of which an adult has from 5 to 10 thousand. With age, their number decreases, which can cause certain problems with distinguishing tastes. The papillae, in turn, contain taste buds, which have a specific set of receptors, thanks to which we experience the whole gamut of taste diversity.

They respond to only 4 basic tastes - sweet, bitter, salty and sour. However, today a fifth element is often identified – umami. The newcomer’s homeland is Japan, and translated from the local language it means “appetizing taste.” In fact, umami is the taste of protein substances. Monosodium glutamate and other amino acids create the umami sensation. Umami is an important component of the flavor of Roquefort and Parmesan cheeses. soy sauce, as well as other non-fermented foods - walnuts, tomatoes, broccoli, mushrooms, thermally processed meat.

The socio-economic conditions in which a person lives, as well as his work, are considered a completely natural explanation for the choice of food. digestive system. Meanwhile, scientists are increasingly inclined to believe that taste preferences are determined by genes and heredity. This question was first raised in 1931 during research involving the synthesis of the odoriferous molecule phenylthiocarbamide (PTC). Two scientists perceived the substance differently: for one it was bitter and very odorous, while the other found it completely neutral and tasteless. Later, the head of the research group, Arthur Fox, tested the FTC on members of his family, who also did not feel it.

Thus, recently scientists have tended to think that some people perceive the same taste differently and that some are programmed to gain weight from French fries, while others can eat them without harm to their figure - this is a matter of heredity. In confirmation this statement Scientists from Duke University in the USA, together with colleagues from Norway, have proven that people have a different composition of genes responsible for odors. The study focused on the relationship of the OR7D4 RT gene to a steroid called androstenone, which is found in high quantities in pork. Thus, people with identical copies of this gene are disgusted by the smell of this steroid, and owners of two different copies of the genes (OR7D4 RT and OR7D4 WM), on the contrary, do not feel any hostility.

Interesting facts about tastes

• Taste buds on the human tongue live on average 7-10 days, then they die and new ones appear. So don't be surprised if the same taste tastes a little different from time to time.

• About 15-25% of people in the world can safely be called “supertasters,” that is, they have an extremely sensitive taste, since there are more papillae on the tongue, and therefore more taste buds.

• The taste buds on the human tongue for sweet and bitter tastes were discovered just 10 years ago.

• All pure tastes are felt absolutely equally by a person. This means that we cannot talk about several types of sweet taste. To taste, there is just one sweet taste, which, however, can vary in intensity: be brighter, richer or faded. The situation is similar with other tastes.

• Taste buds are most sensitive between 20-38 degrees. If you cool your tongue, for example, with ice, then you may no longer feel the taste of sweet food or it may change significantly.

• Good taste is formed in the womb. Thus, scientists have found that the taste of some foods is transmitted not only through mother’s milk, but also through the amniotic fluid while the baby is in the mother’s belly.

• American scientists conducted a study that established the dependence of taste preferences on a person’s age and gender. So, girls mostly prefer sweets, fruits, and vegetables. Boys, on the contrary, love fish, meat, poultry and, for the most part, are indifferent to chocolate.

• During air travel due to high level noise, a person’s taste sensitivity to salty and sweet things decreases.

• The taste of the cookies is 11 times better when washed down with milk drinks. But coffee, on the contrary, “kills” all other sensations. Therefore, if you want to fully enjoy your dessert, it is better to choose the right drinks and drink coffee separately from other food.

Sweet

Sweet taste is perhaps the most pleasant for the majority of the world's population. It is not for nothing that the expression “sweet life” appeared, and not any other. At the same time, not only flour and confectionery products are sweet, but also foods natural origin. Along with this, they are also useful. Most sweet foods contain large amounts of glucose. And as you know, glucose is the main metabolic fuel for the human body. That is why taste buds easily recognize sweet tastes, and at the same time produce happiness hormones - serotonin and endorphin.Please note that these hormones are addictive. This is the explanation for the fact that we prefer to eat depression and stress with something sweet.

It's no secret that excessive consumption of sweets has an adverse effect on your figure and skin condition. However, you shouldn’t give up desserts completely. Do not eat treats on an empty stomach and, whenever possible, try to replace them with dried fruits, honey, and nuts.

Sour

Most acidic foods contain ascorbic acid. And if you suddenly have a craving for something sour, know that this may indicate a lack of vitamin C in your body. Such taste changes can even serve as a signal of an oncoming cold. The main thing is not to overdo it: you should not actively supply your body with this useful substance, everything is good in moderation. Excess acid negatively affects the functioning of the digestive system and the condition of tooth enamel.

If a lot of acid is involved in the metabolism, the body will try to get rid of its excess. This happens in different ways. For example, through the lungs by exhaling carbon dioxide or through the skin by sweating. But when all possibilities are exhausted, acids accumulate in the connective tissue, which impairs the functioning of the digestive system and provokes the accumulation of toxins in the body.

The daily requirement of vitamin C for adult men and women is 70-100 milligrams. It is especially abundant in sour berries (gooseberries, currants, cranberries), citrus fruits and kiwis, and fresh vegetables (especially bell peppers).

Who doesn't know the desire to eat something tasty? Some people like sweets, some prefer sour, and for some people, serve something salty or spicy.

Researchers claim that not only the food itself, but also its taste brings great benefits to the body and has a healing effect.

Taste buds, what are they?

What these eating habits depend on is sometimes very difficult to explain. Science deals with this, and even a new direction has emerged that studies the physiology of taste and taste buds - taste therapy.

Tongue receptors, which are located on the human tongue, on the walls of the pharynx, palate, and tonsils, help us distinguish taste. Information from the receptors is transmitted along the fibers of the glossopharyngeal, facial and other nerves to the cerebral cortex, and there a sensation of one or another taste is formed.

Taste buds are special cells that are located in the bulbs, and the bulbs are on the taste buds. Taste buds line the surface of the tongue.

But taste cells are also located on the walls of the pharynx, tonsils and help us feel all the delights of the food we eat.

Information that the brain receives not only from taste buds, but also from olfactory, thermal, tactile, and nervous ones helps to get a complete picture of taste.

You have probably noticed more than once that during illness, with nasal congestion and congestion, the taste of food is distorted, it seems completely tasteless to us.

The perception of taste is not complete without teeth; nerve endings on the roots of teeth, like pressure sensors, transmit information to the brain about the hardness and structure of food.

Dentists say that if the nerve endings are removed along with the teeth, then the sensation of the taste of food changes.

Taste buds do not perceive well or distort the taste of food if the body temperature is above 38 degrees or, on the contrary, very low. Different combinations of foods often change the perception of taste.

Let's say the taste of wine is enhanced by the influence of cheese. If you eat something sweet before taking a sip of wine, you may experience completely unexpected taste sensations.

The perception of taste is also impaired from frequent burns of the mucous membranes of the mouth and tongue, when a person takes too hot food, and from chemical burns, when alcohol or the like of alcohol is taken in excessive doses.

In order to keep taste buds healthy longer, doctors do not recommend giving children too hot, spicy food, especially stuffed with food additives, under the influence of which a violation of the sense of taste may occur.

Taste receptors work only in the presence of saliva, which dissolves dry substances and activates taste buds; in addition, saliva washes away food debris, preparing the tongue for new taste sensations.

But the most important function of saliva is that it binds acids and protects the taste buds from harmful effects on them.

Main types of taste

Traditionally, there were four main tastes: bitter, sweet, sour and salty, as you can see in the picture.

It was believed that receptors that recognize individual tastes are located in groups, so sweet is on the tip of the tongue, sour on the sides...

Modern functional and molecular data show that the receptors are distributed over the entire surface of the tongue, but differ in density.

Based on these data, we can say with confidence that the “language map” presented above is an erroneous, outdated idea.

What is umami? In the 20th century in countries South-East Asia, in America and Europe, in connection with the production of a food additive called , which changes the taste of food, they began to highlight new taste– umami.

Umami is the taste of monosodium glutamate and is considered the fifth taste. Experts explain it differently, some say that it resembles meat broth, others that it has an astringent-piquant taste.

Sweet taste felt under the influence of sugar, it is associated with tenderness and respect, and its lack in the body creates the presence of anxiety.

Sour taste depends on the content of inorganic and organic acids in food, it creates the impression of confidence and satisfaction. The lack of this taste gives rise to anger and anger.

Salty taste caused by the presence of inorganic ions, it evokes associations of fullness and calmness, and its absence gives rise to internal fear.

Bitter taste due to the presence of alkaloids, it is associated with love and joy, and its absence leads to devastation.

Spicy taste causes determination, while its lack in the body develops sadness.

The following facts are also interesting: our tongue senses sweet taste the least of the listed tastes. To determine it, the concentration of sugar must exceed 1:200, for salt 1:400, for acid 1:130,000, for bitterness 1:2,000,000. But to determine the taste of a substance, it must be dissolved; this function in the body is performed by saliva.

But in the East, six receptor sensations have long been accepted. Their bitter taste is further divided into two. There are purely bitter ones, like hina (we often say that cucumber is bitter) and hot ones, which include mustard, pepper, and radish.

Modern experts offer a more extensive classification. In addition to the above, there are mint, tart, metallic, alkaline, and even the taste of fat and water, but this is not official yet.

The taste of fat was discovered quite recently by the Japanese; they discovered that rats perfectly recognize lipids with their taste buds.

An interesting fact is that in the human tongue there are more than 30 receptors that determine bitter taste, but there is only one for sweet, and only one for umami. In total, our tongue has about 10 thousand taste receptors!

Mixing tastes

Taste sensations can be pure or mixed. The receptors of the tongue feel the bitter taste in the same way, regardless of the history of its origin, only its effect is emphasized - weak or strong. That's why we never talk about several types of sweet, or bitter, or salty. We feel well either the brightness of the taste or its dullness. And here it is important to emphasize that only table salt has a purely salty taste, while other salty tastes differ in intensity.

If several pure tastes are mixed, the result is mixed tastes. And then our receptors capture a variety of sensations that either like or cause rejection. The perception of taste improves the quality of human life, enriching it with new flavor colors.

Taste therapy is a very pleasant type of treatment, where you can prescribe the treatment yourself, because it is just eating, albeit with a specific purpose.

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Health to you, dear readers!

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If a person accidentally bites into an unripe banana or persimmon, he will feel a tart taste - a drying and astringent sensation on the tongue and in the mouth. These taste sensations do not go away for a long time and not everyone likes them.

Astringency is a familiar sensation that is present in many types of food and drink, including unripe fruit, nut skins, tea and red wine. The source of astringency is tannins found in plant polyphenols, which are found in leaves, seeds, and peels of plants. In addition to polyphenols, astringency can be caused by metal salts, acids and dehydrating substances. Although astringency produces an unpleasant sensation when overextended, it can sometimes add a refined flavor to the palate (eg tea or wine).

Inexperienced people usually attribute astringency to taste, and therefore say “tart taste” when describing the sensation in the mouth after a particular product. This is what they thought in ancient india Therefore, tart taste is one of the main ones in Ayurveda.

However, at present, scientists have excluded astringency from the human taste system, which has five varieties:

• salty;
• sour taste;
• umami;
• sweet taste;
• bitter taste.

These sensations are caused by taste buds on the tongue, which, after contact with food, transmit this information to the brain through the taste nerves. Although there is still scientific debate about the nature of astringency, many are inclined to believe that astringency is caused by signals in the trigeminal nerve, like the sensation of a spicy food (for example, red pepper).

To put it simply, why astringency is not related to taste, the difference is that the five main types of taste sensations transmit information to the taste nerve, while hot and astringent transmit information to the trigeminal nerve. On the one hand, these nerves are connected to each other, on the other hand, the trigeminal nerve, in addition to information about taste sensations, also collects other data about stimuli during external environment and pathologies within the body. It transmits sensations of touch, texture, pain and temperature to the brain.

Briefly about taste sensations

Taste or taste perception is one of the five traditional perceptive senses of humans. These include sight, smell, hearing, taste and touch.

Taste occurs when a certain substance in the mouth reacts chemically with taste buds called taste buds. This allows, together with the sense of smell and stimulation of the trigeminal nerve, to determine the shades of taste sensations: the type of food, its smell, and other properties.

The greatest concentration of taste buds is located at the end of the tongue. It itself is covered with thousands of small projections called papillae, which can be seen on the tongue with the naked eye. Each papilla contains hundreds of taste buds through which food is perceived.

It is believed that the human tongue contains from 2 to 5 thousand taste buds located in the back and front of the tongue. Other places of their location are middle, lateral and downside tongue as well as throat. Each kidney contains from 50 to 100 cells. With age, the sense of taste decreases as the number of taste cells begins to decrease after the age of twenty.

It has long been believed that there is a constant number of “primary tastes” from which more complex sensations arise through combination (such views were consolidated by early views in psychology that also existed on primary colors). At the beginning 20 tbsp. Scientists in both psychology and physiology believed that there were only four main types of taste sensations: sweet, sour, salty and bitter. Umami as a taste has only recently been recognized, and in China and India, pungent or savory flavors are still considered the sixth taste.

Currently, new research has emerged that refutes the idea that the tongue is divided into zones, each of which is responsible for a specific taste sensation. Scientists now claim that each taste bud is capable of perceiving all types of tastes. Therefore, questions like: “Which part of the tongue perceives bitter taste?” can be considered meaningless. It can be perceived by any part of the tongue, as well as the throat and other places in the oral cavity where there are taste buds.

Feeling sweet

Sweet taste is generally considered a pleasant sensation. It is caused by the presence of sugars and some other substances. Sweet taste comes from aldehydes and ketones. It is determined by a type of taste bud connected by G-protein and gastducin.

Thus, each part of the brain that determines sweet taste consists of two sections that respond to two various types receptors that can act with different strengths. These two receptors are called T1R2+3 (heterodimer) and T1R3 (homodimer) in biochemical terminology.

These receptors determine all sensations of sweetness in humans and animals. The standard threshold for the sensation of sweet taste is considered to be the ratio of sweet substances to sucrose, which has an index of 1. The average threshold at which a person begins to perceive a sweet taste is a sucrose content of 10 mmol/l. For lactose this figure is 30 mmol/l. Therefore, the lactose index is 0.3. There is a very sweet substance, 5-nitro-2-propoxyaniline, with an index of 0.002 mmol/l. It is 4 thousand times sweeter than sugar and is prohibited for consumption.

Where does the acid come from?

Sour taste is the sensation of acidity. The sour taste of various substances is assessed in relation to the standard - diluted hydrochloric acid, which has an index of 1. For comparison, tartaric acid has an index of 0.7, citric acid - 0.46, carbonic acid - 0.06.

Sour taste is determined by a small set of cells distributed in the taste buds of the tongue. Cells sensitive to it are determined by the content of a protein controlled by the PKD2L1 gene. There is a hypothesis that weak acids (such as acetic acid, which is completely insoluble at physiological pH values) can penetrate taste cells and cause a bioelectrical response.

According to this mechanism, intercellular ions suppress potassium conduction channels, which normally function to polarize the electrical charge of cells. The combination of direct ion penetration, which depolarizes the cells, returning them to a neutral charge, and inhibition of hyperpolarized potassium channels causes taste cells to produce an electrical charge and release neurotransmitters. This is the name given to biologically active substances that transmit electrical impulses from one nerve cell to another. As a result, a person feels acid. Despite this knowledge, the mechanism by which sour taste is determined is still not well understood.

Salty, bitter and umami

Salinity is caused by sodium ions and some other alkali metal ions. But the further an alkali metal is from sodium in the periodic table, the less salinity it has. For example, lithium and potassium ions are very similar in size to sodium ions, and therefore have a very similar salty taste. But ions of metals such as rubidium and cesium, which are significantly larger in size than sodium ions, also differ greatly in taste.

The standard of salinity is sodium chlorine. That is, ordinary table salt, which has an index of 1. The taste of potassium in potassium chloride is the main ingredient in salt substitutes, and its salinity index is 0.6.

Bitter taste is the sensation to which humans are most sensitive. Many people describe bitter taste as unpleasant, pungent, and disgusting. But this is not at all necessary and depends more on the extent to which the bitter taste is present in the food. Sometimes the bitter taste can be a desirable ingredient because it adds a pleasant flavor with other seasonings.

The fifth taste that scientists have decided to consider as such is umami. It stimulates appetite. Umami is described as a savory, meaty taste sensation.

The chemical that causes umami is monosodium glutamate. This is a flavoring additive invented by the Japanese Kikunae Ikeda in 1908. Monosodium glutamate produces a strong umami flavor and is an integral part of Western cuisine. The nomenclature of taste buds responsible for the perception of umami is TAS1R1 and TAS1R3. Umami can be experienced when eating cheese or soy sauce. It is found in fermented and aged foods, as well as in tomatoes, grains, and legumes.