Taste method. physiological basis of the taste method. flavor substances. Big encyclopedia of oil and gas

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TASTING MECHANISM

When tasting, a number of physiological stimulants of the sense organs are used, which are the components of wine that cause taste and olfactory sensations. The terminology of this process needs some clarification.
A stimulus, or exciter, is a physical or chemical agent that causes stimulation, excitation, or response of specific sensory receptors.
Sensation is a subjective phenomenon, a reflex, which is the result of stimulation of the organoleptic apparatus.
Perception is sensory awareness, interpretation of sensation, it is the experience acquired by the taster that allows him to interpret sensations. Hence the need for special training of the taster, so that he always keeps in mind a large number of memories of various sensory sensations. This is the reason why the sharpness of the sense of taste by experienced tasters seems to be indispensable in winemaking at the present time. More detailed coverage of the issue of sensations is given in the works (Manan, 1965; Wedel and co-workers, 1972).
Other definitions of interest to the taster are sensation and identification thresholds. The threshold of sensation, or detection, is the smallest value of the stimulus that excites the sensation. It corresponds to the minimum amount of the product that causes sensation, although it may not be identified. For example, 18% of people perceive 0.5 g of sucrose per 1 liter of water, but can only accurately identify it at a concentration of 1 to 2 g per 1 liter of water.
The threshold of identification, or recognition, exactly corresponds to the minimum amount of recognized and identified product.
These thresholds depend on the sharpness of the taste sensations of people, and this is one of the important qualities in the selection of tasters.
Wine tasting is an expression of the sum of sensations perceived simultaneously or sequentially. When drinking wine without sufficient attention, these sensations merge into one. Analytical tasting aims at separating, arranging and finally identifying different sensations.

Many of our sense organs are involved in tasting, the perceived sensations come from various types of stimulation of our sense perceptions: visual, olfactory, gustatory, to which we must also add tactile (tactile) and thermal receptors of the oral cavity, as well as a general chemical susceptibility that causes sensations of irritating character or, as an extreme case, pain.
When tasting wine, taking it into the mouth, one must take into account that the perceived sensations come not only from the organ of taste, but also from the organ of smell. The nose participates in the creation of these sensations even more than the tongue, and therefore the word "taste" of a substance is usually understood as the sensation that is actually perceived, first of all, by smell. When tasting, the warmth of the mouth, the movement of the cheeks, the tongue, the slight inhalation of air that some tasters produce, even their normal breathing sends volatile substances into the nose that make up the aroma and bouquet of the wine. A swallowing movement that is hard not to do when tasting, defiant
slight compression of the oral cavity, in the same way sends vapors of the substance into the nasopharynx and promotes the perception of smell. Part of the nasal cavity still perceives the sensation of wine when, after tasting, liquid is released from the mouth or swallowed, and exhaled through the nose. At this moment and for many subsequent exhalations, they perceive the smell that has impregnated the mucous membranes of the mouth.
During tasting, it is not difficult to get rid of olfactory sensations, so that only taste sensations remain in the full sense of the word; if you pinch your nostrils while tasting, you have to wonder how poorly the taste is perceived; under these conditions, one cannot even say that you feel the taste of wine. Similar occurs with a cold.
Thus, in the complete absence of smell, perception disappears. Usually in such cases they say that "taste is lost", when in reality it is a question of smell.
As has already been said, taste in the conventional sense of the word also includes the olfactory sensations perceived by the internal pathways, while taste as such is only that part of the taste sensation which is perceived by the tongue. The term "bouquet" means the totality of sensations perceived by the nose or mouth during tasting.
In table. 2.1 is a list of sense organs and sensations associated with tasting, which are grouped in accordance with rational terminology.

visual sensations

Sight is the first of the senses through which tasting is performed. Visual sensations give an idea of ​​the color (intensity, hue) and transparency (haze, shine) of the wine. But the appearance of the wine also speaks of other qualities: its fluidity, the release of carbon dioxide, the effect of capillary phenomena on the walls of the glass, depending on the percentage of alcohol. These are elementary data that prepare and greatly facilitate the judgment of wine with the help of other senses. Cloudy wine often gets a poor taste rating. The color speaks of the age and condition of the wine. Tasting wine without seeing it is very difficult and therefore it is possible to confuse, when blind tasting, dry white wine with low acidity with rose or red wine containing little tannin. Illumination can have an indirect effect even on the sharpness of smell: with sufficient lighting, odors are perceived better.

Table 2.1
Sense organs associated with tasting

Olfactory sensations

These sensations are of the greatest importance for tasting. The olfactory organ is located in the upper part of the nose (Fig. 2.1). The nose itself is not
organ of smell in the exact sense of the word, it is just a channel for the access of inhaled air to the mucous olfactory membrane. In the nasal cavity there are three shells located one above the other. The mucous olfactory membrane is located at the level of the middle shell on the other side of a narrow gap with a hole of 1-2 mm, called the olfactory gap.

Sensitive mucous membrane, thin and smooth, pigmented yellow. This yellow spot is very small in size (approximately 2.5 cm 2). On its surface are thin extensions of neurons, or olfactory cilia, which are bathed in a mucous fluid.

Rice. 2.1.
1 - lower sink; 2 - medium sink; 5-top sink; 4 - olfactory mucosa.

The shape of the olfactory organ makes it possible to understand that the mucous membrane is somewhat away from the path of inhaled air, and, since access to it is possible only through a narrow gap, during normal breathing, only a small part of the gases that have a smell can enter it. The amount of odors entering this shell increases and thereby enhances the sensation by making successive breaths through the nose, “sniffing” the tasting drink and drawing in its smell with the nose.
The loss of smell caused by a runny nose is a consequence of the closure of the olfactory fissure during inflammation of the tissues and the occurrence of swelling of the tissues.
The sensation of taste is inevitably accompanied, although at first it is difficult to distinguish, by an olfactory sensation. Most of our foods give off odor-laden vapors that enter the nasal cavity with inhaled air and play a crucial role in creating the sensation of taste. Smell is caused by the contact of the sensory field with material particles in negligible amounts. This phenomenon is periodic, like breathing. It is felt during chewing movements of the mouth and manifests itself in full by the end of swallowing, since the walls of the pharynx at this time represent a vast area for the evaporation of wine.
The human sense of smell is exceptionally subtle. In its sensitivity, it is far superior to chemical reagents. The sense of smell is much more multifaceted and sensitive than taste, and the smell is much more complex than the sense of taste in the full sense of the word. If they can be reduced to just four elementary sensations of taste, then smells are the result of a significant number of elementary sensations. Of the many classification systems, odors can be classified into nine major groups: animal, balsamic, woody, chemical, spicy, empyreomatic, floral, fruity, vegetal. All of them are present in the smells of wines, but the wines of the best brands have a complex aroma or bouquet that is difficult to analyze. An experienced taster, upon careful examination, recognizes in them a mixture and sequence of pleasant smells, reminiscent of the smell of some flower, this or that fruit, distinguishes oily, sour, aromatic and other tones in them. Most often, one or another aroma prevails in the bouquet of wine. But a mixture of many mutually complementary smells forms a single whole, a new fragrance, in which it is difficult to single out its constituent elements.
When mixed, various odors are masked, mutually destroyed. For example, experiments show that the threshold for identifying an odorant by smell is greatly shifted when it is mixed with other odor-producing products.
The following observations regarding ethyl acetate, the substance that gives wines affected by acetic souring their specific character, are an example of olfactory interference. In an aqueous solution of ethyl acetate, its smell is easily captured even at concentrations of 25 to 30 mg/l. In a 10% alcohol solution, the threshold of sensation shifts, the smell is detected only at a concentration of 40 mg / l, therefore, the own smell of ethyl alcohol masks other smells. This example shows why too high alcohol content can reduce the bouquet of wine. If an ester of some other fatty acid (for example, ethyl enanthate, which also does not exist in wines) is added to an ethyl acetate solution, then only the content of 150 mg of ethyl acetate in 1 liter makes it possible to identify it. Finally, in wines, the smell of ethyl acetate appears only when its content reaches 180-200 mg per 1 liter. The more complex the mixture of odors and the more intense they are, the more the specific aroma of ethyl acetate is drowned out.
The harmonic fusion of normal aromas of wine explains the impossibility of enhancing the bouquet with artificial smells. Such an attempt is illegal and deserving of condemnation. In addition, it does not end with success, since when artificial substances are added in small quantities, their smell drowns in the totality of wine smells without any result; if a certain threshold is exceeded, this smell becomes predominant and gives an artificial tone, which is immediately determined by a trained taster.
It was shown above that in tasting, the sense of smell is involved in creating the impression of taste. Such sensations are called taste-olfactory. Of course, odorants are also involved in the formation of taste sensations, body sensations, oiliness. If the wine is deprived of all aromatic substances, by treating it, for example, with coal powder, it will immediately lose its body, although the fundamental balance of the wine will not change much.

Taste sensations

The taste receptors are located in the papillae of the tongue. Cells susceptible to taste and grouped into taste buds are very unevenly distributed on its surface. However, of the four types of papillae, only the trough-shaped, located on the back of the tongue, and the mushroom-shaped, located mainly at the tip and having papillae that are sensitive to a specific taste (Fig. 2.2), participate in perception. Nerve fibers that provide signal transmission to the brain of excited taste cells form three cranial nerves (glossopharyngeal, lingual, trigeminal). The taste-perception center in the brain is located near the motor centers of chewing and swallowing. The perception of taste is closely related to these: functions.
It is assumed that there are only four elementary tastes felt by the tongue: sweet, sour, salty and bitter. All the tastes felt by man necessarily belong to these four categories. One and the same substance can have only one taste, or it can present simultaneously, and sometimes successively, several elementary tastes.

Rice. 2.2. Distribution on the surface of the tongue of mushroom-shaped, filiform, stratified and trough-shaped papillae and papillae of perception of four elementary tastes:
1 - sweet, 2 - salty; 3 - sour; 4 - bitter; 5 - trough-shaped papillae; 6 - foliate papillae; 7- filiform; 8 - mushroom.

When a complex mixture is tasted, consisting of substances that have four elemental tastes, it is perceived as one whole. Depending on the taste, the duration of arousal from wine may be different. The taste of sweet is felt immediately, bitter - develops gradually: it grows and is perceived slowly, after the liquid is removed from the mouth. These facts are important to know because they explain the aftertaste that is perceived during tasting. The first taste impressions received are very different from the last, and this difference must be carefully noted over time. The first taste impressions can give a feeling of sweetness, be pleasant, but then gradually give way to excessive bitterness, an unpleasant aftertaste.
Differences in perceptual speed are due, at least in part, to the fact that different tastes are perceived by different parts of the tongue. The taste of sweet is felt only by the tip of the tongue, sour - by the lateral and part of the lower surfaces of the tongue, salty - by the edges, but by no means by the middle of the tongue, bitter - only by the back of the tongue and only during swallowing. Most of the surface of the tongue is insensitive. On the other hand, it should be noted that in the mouth, taste in the proper sense of the word is perceived only through the tongue. Lips, cheeks, palate, which do not have taste buds, give only tactile or thermal sensations.
Four elemental tastes are concentrated in wine, of which the main ones are sour and sweet. In addition, one cannot ignore the concentration of mineral salts in wine: the salty taste that they impart is clearly felt, although in wine it is masked by other flavors. However, there is no doubt that the mineral salts contained in the wine give it a fresh taste. On the other hand, a slight bitterness accompanied by moderate astringency is a necessary quality in good red wines. These flavors owe their origin to certain polyphenols. Other normal constituents of wine may be slightly bitter (eg butanediol-2,3). In addition, there may be wines in which the bitter taste is predominant as a result of faults or microbial diseases in the wine.

Fortitude

Aftertaste is the final taste that persists for some time after the liquid has been swallowed or removed from the mouth. Feelings of this kind, lasting for a more or less long time, are usually called persistence or aftereffect. They may be of a gustatory, olfactory, or general chemical order and are of great interest in terms of determining the class and quality of a wine. Aftertaste is also called the final sensation, different from the previous ones. It is usually bad.
Wedel et al. (1972) give the following definition of intense lingering: "In the totality that makes up the sensation of lingering, careful observation of olfactory sensations shows that after a period of some uniform intensity, it decreases sharply." Therefore, it was agreed to designate this first period by the term "intense fragrance stability". The taster can measure its duration in seconds. The unit of measurement is taken as a kodalia (from the French caudal - tail); it corresponds to 1 s of durability. The authors propose to use this unit of measure when classifying very distinct wines. They provide for five classes corresponding to the following number of kodalia: up to 3, from 4 to 6, from 7 to 9, from 10 to 12, more than 12. The method is tested and requires confirmation.

Other sensations

These sensations include chemical, tactile, thermal and, less often, painful sensations. These sensations are perceived by a large number of corresponding receptors scattered throughout the oral cavity. The taste of rather concentrated alcohol, acrid and burning, is more related to the reaction of the mucous membranes than to the taste in the proper sense of the word. The same can be said for the astringent or astringent taste of some polyphenols, which causes an unpleasant metallic taste. In fact, these impressions are not transmitted to the brain by the nerves that transmit sensations of taste in the proper sense, moreover, the tongue and cheeks are extremely sensitive organs of touch. They create impressions of temperature, consistency, volume, viscosity, oiliness.

The taste system evaluates food taste- a complex of sensations perceived during their testing, – tasting (evaluation of a food product in the oral cavity).

Taste – a feeling that occurs when the taste buds are excited and is determined both qualitatively and quantitatively.

Taste assessment is reduced to determining the type of taste and its intensity. The standards of primary flavoring substances in merchandising are considered to be, respectively: sweet – sucrose; sour – hydrochloric acid; salty – salt; bitter – quinine (caffeine). All other types and shades of taste can be obtained by mixing three of the four possible primary tastes in the required proportions.

The qualitative definition of taste is caused by the action of substances on the taste buds, which are located mainly on the tongue. In addition, they are found on the mucous surface of the oral cavity, pharyngeal walls, tonsils, and larynx. The total number of taste buds in the human oral cavity reaches 9 thousand. In addition, the definition of taste is associated with the touch of food in the oral cavity.

The taste apparatus of the human mouth is a chemical analyzer, more sensitive than modern instruments. All the richness of various shades, combinations of taste sensations arises as a result of irritation of special sense organs. – taste buds (buds), each of which consists of several sensitive chemoreceptor cells connected to sensory neurons. Chemoreceptor cells respond to certain chemicals.

Taste buds are differentiated to perceive the main types of taste: sweet, salty, sour and bitter. The bulbs located at the tip of the tongue are most sensitive to sweet taste, at the edges of the front of the tongue - to salty, at the edges of the back of the tongue – to sour, at the base – to bitter.

All substances that cause the taste of food are soluble in water. Only in dissolved form can they affect the chemical analyzers of the taste apparatus.

The sensation threshold also depends on the temperature of the solution, which is probably due to a change in the state of the taste bud protein molecule. The best perception of flavoring substances occurs at a temperature of solutions close to the temperature of the human body (36.5 ° C). Hot solutions of the same substances in the indicated concentrations seem tasteless, that is, they do not cause any sensations. When cooled to a temperature of 30 ° C, the sweet taste is more pronounced than salty or bitter.

When evaluating taste, the speed of taste sensation is also important: salty taste is perceived the fastest, sweet and sour are slower. Bitter taste is perceived most slowly.

Allocate the following characteristics of taste.

Sour taste-- characterizes the basic taste characteristic of aqueous solutions of most acids (for example, citric and tartaric acids); complex olfactory-tasting sensation, caused mainly by the presence of organic acids.

acidity – organoleptic property of individual substances or mixtures that causes a sour taste.

Sour taste-- characterizes a lower degree of intensity of the taste of the sour product.

Bitter taste -- characterizes the basic taste caused by aqueous solutions of chemicals such as quinine and caffeine, as well as some alkaloids.

Bitterness – organoleptic property of individual substances or mixtures that cause a bitter taste.

Salty taste -- characterizes the basic taste caused by aqueous solutions of chemicals such as sodium chloride.

Salinity – organoleptic property of individual substances or mixtures that cause a salty taste.

Sweet taste -- characterizes the basic taste caused by aqueous solutions of chemicals such as sucrose.

Sweetness – organoleptic property of individual substances or mixtures that cause sweet taste.

Alkaline taste- characterizes the main taste caused by aqueous solutions of chemicals such as sodium bicarbonate.

Alkalinity – organoleptic property of individual substances or mixtures that cause an alkaline taste.

Astringent, tart taste - characterizes the complex sensation caused by the contraction of the mucous surfaces of the oral cavity and arising from the action of substances such as tannins. Astringency – organoleptic property of individual substances or mixtures that cause astringent taste.

Metallic taste -- characterizes the basic taste caused by aqueous solutions of chemicals such as ferrous sulfate.

Tasteless, fresh taste – a product that does not have a characteristic taste.

aftertaste – a taste sensation after ingestion or removal of the product from the oral cavity, which is different from those perceived during its stay in the oral cavity.

Food products have either one taste (sugar – sweet, salt – salty, acids – sour), or differ in a combination of the main types of taste. In this case, we can talk about a harmonious and inharmonious combination of taste. . Yes, g harmoniously, as a whole, sweet or salty tastes are combined with sour or bitter. An example is the sweet-sour taste of fruits, confectionery, the sweet-bitter taste of chocolate, sour-salty pickled vegetables, salty-bitter olives. inharmonious combinations such as salty-sweet, bitter-sour are considered. These combinations are perceived as two different tastes, they are not characteristic of food products, they are rare and usually occur due to spoilage (for example, the bitter-sour taste of pickled vegetables).

Taste perception depends on the chemical composition, viscosity and amount of food; the nature of odorous and gustatory substances and the intensity of release, the rate of removal, the nature of their effect on the organ of taste; availability of these substances in a certain period; food intake conditions (in particular, breathing, quantity and speed of saliva flow, duration, temperature) and quality of chewing of the product.

It has been established that the evaluation of the intensity of the main tastes can be influenced by the color of the product. Thus, yellow and light green colors increase the assessment of the intensity of the acidity of the product, and the red color enhances the assessment of the intensity of sweetness compared to colorless. It should also take into account the moments of suppression of one taste by another. For example, sour taste is suppressed by sweet, and to a lesser extent – salty and bitter. Salty and bitter tastes are suppressed by certain concentrations of sucrose and citric acid; the sweet taste is weakly suppressed by small concentrations of citric acid.

A taste that persists despite the cessation of the impulse that caused it is called secondary taste . It can be the same and contrast. the same it is because after the cessation of the taste impulse, a taste sensation remains, identical in quality to that which was during the exposure to the taste impulse. Contrasting called secondary taste, which occurs after the removal of the current taste impulse.

All food products evoke a certain secondary taste sensation, either the same or contrasting. If the secondary taste is the same and matches the main taste profile of the product and quickly disappears when a piece of this product is swallowed, this proves that the quality of the product is high. But if after swallowing the secondary taste remains in the mouth, then the product is inferior to the first one in terms of consumer value. In the practice of organoleptic analysis, a secondary contrasting taste is very often encountered, for example, distilled water after rinsing the mouth with a salt solution seems sweetish. After experiencing a sweet taste for a short time, the sour taste is perceived more acutely, and the unpleasant sensation is intensified. Therefore, aged wines are not evaluated after sweet wines; lightly salted products are not evaluated after evaluation of dry-salted products.

Deliciousness (flavor– flavor) – a complex sensation in the oral cavity caused by the taste, smell and texture of a food product, determined (evaluated) both qualitatively and quantitatively.

Taste can be affected by tactile, thermal, pain and/or kinesthetic sensations.

The assessment of the quality of a food product based on the complex perception and analysis of optical, olfactory, tactile, gustatory, acoustic and other impulses (stimuli) is called the assessment of goodness or flavor, in contrast to its taste.

Quantitative changes in the individual components of goodness at a certain moment lead to a qualitative leap and as a result a high quality product is formed, which has a harmonious or full taste value. Over time, the balance between the individual components of goodness is disturbed and this leads to a deterioration in the quality of the product. An example is the process of maturation, aging and death of wine.

When evaluating taste, it is necessary to take into account such phenomena due to the physiological characteristics of the sense organs as adaptation and fatigue.

Adaptation – this is a decrease in the sensitivity of the organ of taste, caused by prolonged exposure to a taste impulse of the same quality and constant intensity. When testing a large number of samples with the same taste, the same intensity, adaptation is the cause of distorted results. The organs of taste, in contrast to vision and similarly to smell, are characterized by rapid adaptation.

Fatigue- reduces the perception of taste due to the fatigue of taste buds under the influence of a repetitive impulse. It occurs after a different time depending on the properties of the product, the physiological and psychological state of the testers, training, working conditions.

Olfactory and gustatory sensations

Perception of smells. The sense of smell is an extremely subtle sense. A person easily distinguishes and remembers up to 1000 smells, and an experienced specialist is able to distinguish between 10,000 - 17,000 smells. Along with the concept of smell, the terms ʼʼaromaʼʼ are used to denote a pleasant smell and ʼʼbouquetʼʼ to characterize a complex aroma͵ developing as a result of enzymatic and chemical processes, for example, during aging of wines and cognacs, during the maturation of rennet cheeses, canned fish such as ʼʼSpratsʼʼ and ʼʼSardinesʼʼ, during the fermentation of tea, roasting coffee beans, etc.

The olfactory organ is located in the nasal cavity. The olfactory epithelium is located on an area of ​​​​3 - 5 cm 2, has a yellow color due to the presence of grains of the coloring matter in special sensitive cells located in the mucous membrane of the upper part of the septum, nasal arch and other parts of it. The olfactory epithelium, located in the upper part of the nasal cavity, is in direct connection with the oral cavity. Molecules of volatile aroma-forming substances in the oral cavity easily enter the nasal cavity through the nasopharynx.

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

The stimulating effect of certain odors on the ability for intensive physical or mental work, as well as the calming effect of certain odors on the nervous and other systems of a person, have been found.

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 origin of odor by the permeability of the cell membrane by molecules of a volatile substance, but does not substantiate a wide range of perceived olfactory sensations. According to the stereochemical hypothesis, odor recognition depends on the conformity 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 the hypothesis about the mechanism of the sense of smell. It is based on the interaction of enzymes activated by odorous molecules with the corresponding coenzymes.

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

fragrant-floral (some ketones that smell of violets, as well as the smell of musk);

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

The smell of burning (roasted coffee and furfural);

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

The most widespread developed by Amur in 1962 ᴦ. classification that distinguishes seven basic, or primary, odors:

camphor (hexachloroethane);

musky (musk, xylene);

floral (a-amylpyridine);

mint (menthol);

ethereal (ethyl ether);

acute (formic acid);

putrefactive (hydrogen sulfide).

Ways to restore olfactory sensitivity

A glass of water is poured into an enameled pan, 2 drops of mint essential oil and a teaspoon of cologne are added to it, and then heated to a boil and breathe over the steam for 3-5 minutes, making forced long breaths during the entire procedure. The course of treatment - 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 mint essential oil. Breathe over the steam for 3-5 minutes each nostril, making forced breaths. The course of treatment is 10 procedures daily or every other day.

A coin with a denomination of 1 or 2 rubles. smeared with honey, applied to the very middle of the back of the nose and fixed with a plaster. Better yet, use an old copper coin. You need to keep the coin for at least 30 minutes daily. Often after 15 - 20 procedures, the sense of smell is completely restored.

10 drops of lemon juice and cologne are added to a glass of water heated to 50 ° C. Gauze or cotton fabric is soaked with 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 into the middle of the forehead. The course of treatment - 7 - 10 procedures daily.

It is useful to learn to strain and relax the muscles of the nose. This exercise restores the sense of smell well. Keep the muscles in a tense or relaxed state for at least a minute. Doing the exercise is extremely important daily for 10 minutes.

Warming up with a blue lamp has a positive effect on hyposmia. You can also use a regular 40W light bulb. Put on sun glasses, 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. Perform the procedure for 10-15 minutes daily or every other day for a week.

It helps to improve the sense of smell and the well-known procedure according to the yogi system - drawing warm salted water into the nose. Salt on the tip of a knife is added to a glass of warm boiled water. Closing one nostril with your finger, slowly draw in the water of the open nostril until it is in the throat. Next, the water is spit out. Do the same with the other nostril. You can release water not through the mouth, but through the 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 sense of smell is inextricably linked to the sense of taste. In analytical terminology, four basic types of taste are distinguished:

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

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

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

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

Other types and shades of tastes are complex sensations of these tastes. The term ʼʼstimulusʼʼ is recommended to denote a substance or electrophysical effect that causes a taste sensation when interacting with chemoreceptors.

Recently, alkaline and astringent have been added to the four types of flavors. Alkaline arises from chemical irritation of the mucous membrane in the oral cavity and is not caused by specific taste buds. A typical stimulus for an alkaline taste sensation 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 occurs most quickly, then sweet, sour, much more slowly - bitter. This is due to the uneven arrangement of taste buds.

The external perceiving part of the human taste organ is represented by taste buds, which are located in the so-called papillae (kidneys) of the tongue. Separate bulbs are also scattered in the mucous membrane of the soft palate, the back wall of the epiglottis and even on the side walls of the larynx. The total number of taste buds can reach several thousand.

Taste buds are subject to rapid death and neoplasm. 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 pronounced specificity. At the very tip of the tongue and along the edges are large mushroom-shaped papillae, each of which has 8-10 bulbs. Sweet tastes are most felt at the end of the tongue, salty at the edges of the front of the tongue, and sour at the edges of the back of the tongue. At the base of the tongue are grooved papillae, each of which contains 100-150 taste buds that perceive a bitter taste.

The taste organ (tongue) of a person 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 that are transmitted along the 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 residence of the tongue against the palate facilitates the penetration of the tested 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 organ of taste is not well understood. Existing hypotheses are based on physicochemical, chemical and enzymatic prerequisites. A certain relationship has been established between the chemical nature of the gustatory substance and the sensation of taste caused by it. But substances of different structure can have the same taste and, on the contrary, substances of the same chemical. Nature has different flavors. Not only sugars are felt sweet, but also many amino acids, saccharin. The protein tuamatin has been isolated from vegetable raw materials, which has a molecular weight of 22,000, consists of 207 amino acid residues and is 8,000 times sweeter than sucrose.

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

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

Sour taste is caused by inorganic acids, as well as organic acids and their salts. The taste quality of sour depends mainly on the concentration of hydrogen ions. For organic acids, the intensity of sour taste sensation exceeds that expected at the corresponding concentration of hydrogen ions.

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

The 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 basic tastes, as well as changing their intensity, can cause such complex complex phenomena as taste rivalry, taste compensation, disappearance of repeated taste, contrasting taste, and other sensory sensations.

Influence of factors on gustatory and olfactory sensations.Adaptation is the adaptability of the organs of taste and smell, which consists in a decrease in their sensitivity caused by prolonged exposure to a stimulus (continuous or repeated) of the same quality and unchanged intensity. When the stimulus stops exposure, the restoration of gustatory and olfactory sensitivity occurs. 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, his own body.

G.A. Vuks gives information about the development of adaptation of the olfactory organ to smells. So, the time that 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 that arrive sequentially one after another in significant periods of time, the susceptibility of the organ of taste or smell can increase and persist for a long time. Such a phenomenon is called sensitization.

An increase in sensitivity is achieved with the help of stimuli, the intensity of which 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 the persistence of maintaining this property.

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

sensitization to the code smell entails a slight increase in sensitivity to other smells.

Sensitization to red tends to reduce sensitivity to green, and in some cases to yellow. Sensitization to green leads to worse sensitivity to red, ᴛ.ᴇ. along with selectivity, a parallel change in the thresholds of other colors is observed. Such a phenomenon is typical of taste: sensitization to one of the basic tastes affects other basic tastes. However, these patterns have not been fully explored. 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 can reduce sweet sensitivity in some tasters and increase it in others.

According to the taster profile, hypersensitivity to certain chemicals can be observed. There are cases when a laboratory assistant performing a chemical analysis of the mass fraction of sodium chloride in a food product, over time, could accurately determine the salinity of the product with a sensor. Similar cases are known in the distillery industry, when the 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 susceptibility to smells and tastes. Some people have a lack of smell in relation to either all odorous substances, or to one substance, or to a group of substances. This phenomenon is called anosmia and found with respect to butyric acid, trimethylamine, hydrocyanic acid, skatole alcohol, and a number of other substances.

Anosmia is more common in men (about 20%), less often in women (about 5%). It is believed that it is inherited by descendants of the same sex. Anosmia retains a normal sense of smell in relation to many common odors. In most cases, a person does not realize that he has a partial lack of smell. This phenomenon is extremely important when choosing specialists in sensory analysis.

Loss of smell must be due to injury after illness, traffic accidents or medication. Diseases of the nasopharynx often lead to a decrease in the function of smell: chronic rhinitis and chronic inflammatory diseases of the paranasal sinuses - sinusitis, frontal sinusitis, sphenoiditis, rhinovirus infections. The sense of smell can be reduced due to adenoids, polyps in the nose, curvature of the nasal septum.

Cases of reduced olfactory sensitivity to all or individual odorous substances are not uncommon. This phenomenon is called hyposmia. Much less often, an unusually high olfactory sensitivity of a person either to all odorous substances, or to one substance, or to group of substances. Such a phenomenon is called hyperosmia.

Smell hallucinations are also possible, manifested in the fact that a person feels a smell that is not really there. This type of olfactory lesion is commonly called spontaneous olfaction or parosmia.

Lack of taste sensitivity to either all flavors, or to to one substance, or to a group of substances, it is customary to call ageusia. Reduced taste sensitivity to all or certain substances is commonly called hypogeusia, and unusually high sensitivity - hypergeusia. The perverted ability to taste a taste that is not characteristic of a given substance or group of substances is denoted by the term parageusia.

Scientists believe that the taster's behavior can be predicted based on body type. It has been noted that tasters with a thin and fragile body structure (leptosomes) have twice as many taste dislikes as full and squat ones (picnics).

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

Some studies have compared levels of taste sensitivity with the social status and cultural level of the test tasters. Thus, in groups with low characteristics of status and culture, high thresholds for recognizing basic tastes were observed. The Japanese are considered the most subtle in terms of taste perception. 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 in people are significant: for smell 1000: 1, for the organ of taste 64: 1. A small (not precisely taken into account) part of the population is completely devoid of sensitivity to taste or smell.

The influence of age. FROM Sensitivity to odors decreases in a logarithmic sequence with age. This applies not only to the sense of smell, but also to sight, hearing, taste and touch. It is believed that a person loses up to 50% of visual acuity and hearing by the age of 13-15, the ability to perceive smell and taste - by 22-29, tactile sensitivity - by 60 years. The age factor is not decisive. Given the dependence on natural data, lifestyle, nutrition, habits, the nature of work, the fitness of sensory organs, with age, a person can increase the sensitivity of smell, taste, touch, and much less often - hearing and vision.

Memory and smell representation - this is the ability of a person to recognize those smells that he had previously encountered, ᴛ.ᴇ. memorize and recognize a known smell. Usually a person is able to distinguish from several hundred to several thousand different odors. Qualified tasters must be able to recognize at least 10,000 odors. Specialists develop their abilities by exercises and can distinguish up to 17 thousand varieties of smell. The ability to remember smells in people is very different. masking odors are called cases of suppression of one odor by another. If two or three odors act simultaneously on the olfactory organ, it may happen that none of them will show their true properties, and the perceived sensation of smell will be indefinite or not perceived at all.

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

For example, fructose is sweeter in an acidic environment, and glucose with increasing acidity feels less sweet. The taste perception of sugar mixtures is not a simple summation of the sweet taste intensities of the components. Usually a mixture of sugars is less sweet compared to the calculated data on the sum of the components.

With the simultaneous exposure to two different taste impulses, the feeling of a weaker one may disappear. Salty, sweet, sour tastes easily disappear.

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

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

Taste modifications. A tropical plant known as a sweet taste inhibitor Gymnema sylvestre, ĸᴏᴛᴏᴩᴏᴇ grows in South India, Ceylon and the tropics of West Africa. The fruit of another tropical plant Miracle fruit modify the sour taste. For example, lemons take on the taste of sweet and sour oranges. The effect of taste modification lasts for 30-60 minutes. fruit properties 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 the product has been tasted, it persists 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 characteristic of rancidity of fats.

Taste contrast can be a source of error in sensory tests. 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 foods should not be judged after hard or medium salted foods. Taste contrast is extremely important to consider when determining the order in which samples are submitted for tasting.

Taste illusions. L. Bartoshchuk discovered that after tasting 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 get the harmony of bitter and sweet, it is almost impossible to combine bitter and salty, as well as bitter and sour tastes. Taste harmony develops during the maturation of wines, canned food. Knowledge of technology, organoleptic laws and experience with food products contribute to the creation of taste harmony.

Effect of color on taste. It is noted that red solutions are perceived as sweeter than a colorless sweet solution of the same concentration. Yellow and light green colors increase the subjective assessment of the acid. Experiments carried out at the University of Tartu have shown that thirst quenching is best achieved with soft drinks when they are light green in color. Often there are complex associations between color, taste and smell.

For example, dark green increases the intensity of taste and smell, yellow gives a more intense sense of smell, and red and light green make smells easier to perceive. Blue colors of different shades cause sensations of bitter taste and unpleasant technical shades in the smell. G. A. Vuks compiled a semantic map that can be used to describe the smell and taste of different food products. In particular, the taste of raspberry jam is described in terms of: warm, heavy, soft, etc.

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

Tasting and olfactory sensations of tasters are also influenced by other factors: for example, the shape of the food, 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 gustatory method is a method based on the perception of taste with the help of taste buds.

Taste - a feeling that occurs when the taste buds are excited and is determined both qualitatively and quantitatively. The qualitative definition of taste is caused by the influence of substances on the taste buds, which are located in the papillae on the tongue, on the mucous surface of the oral cavity, the walls of the pharynx, tonsils, and larynx. The taste bud (kidney) consists of several sensory chemoreceptor cells connected to sensory neurons and surrounded by supporting cells. The total number of taste cells in the human oral cavity reaches 9,000.

Usually, taste is understood not only as sensations that occur when chemoreceptor cells are stimulated, but also as tactile sensations (consistency and astringency; a sharp, burning taste is felt as a result of a burn of the mucous membrane with pepper, mustard) and olfactory (when chewing food, volatile substances pass into the nasal cavity and irritate the olfactory organs).

Chemoreceptor cells respond to certain chemicals. All substances that cause the taste of food products are soluble in water; only in dissolved form can they affect the chemical analyzers of the taste apparatus.

Recognition of a signal by a receptor is a basic property of the brain. It performs the classification of objects, information about which is transmitted by the receptor. Recognition is determined by the weak interaction realized with structural correspondence. However, in order to influence the nerve endings that cause taste sensations, a certain minimum concentration of a substance, called the "sensation threshold", is necessary. For example, the threshold for sensing sucrose is 0.4 g per 100 ml of water; table salt - 0.05; hydrochloric acid - 0.003; quinine hydrochloride - 0.000008 g. The threshold of sensation also depends on the temperature of the solution. The best perception of flavoring substances occurs at a temperature of solutions close to the temperature of the human body (35 ° C). When evaluating taste, the speed of taste sensation is also important: salty taste is perceived the fastest, then sweet and sour. Bitter taste is perceived most slowly.

Flavoring substances of food products can be divided into the following groups:

1. Glucophoric (sweet) substances - mono- and disaccharides, saccharin, glycerin, glycine. Carriers of sweetness are glucophoric groups - CH(OH). Different substances are characterized by varying degrees of sweetness:

Lactose - 0.16% to the sweetness of sucrose;

Glucose - 74.3% of the sweetness of sucrose

Sucrose - 100.0% to the sweetness of sucrose;

Fructose - 173.3% of the sweetness of sucrose;

Saccharin - 5500.0% of the sweetness of sucrose, and hence the threshold of sensation.

2. Acidic substances - mineral and organic acids, acidic salts cause a sour taste due to the presence of free hydrogen ions.

3. Salty substances - chlorine salts with low molecular weight. The salty taste is determined by the presence of free chloride ions.

4. Bitter taste - salts KC1, CaCl, MgCl and other glucosides, essential oils, such as onion vegetables, citrus fruits (naringin, hespiridin), alkaloids (theobromine, caffeine).

Food products have either one taste, or differ in a combination of the main types of taste. In this case, we can talk about a harmonious or inharmonious combination of taste.

Harmoniously, as a whole, sweet or salty tastes are combined with sour or bitter (sweet-sour taste of fruits, sweet-bitter taste of chocolate, sour-salty taste of pickled vegetables, salty-bitter - olives). Combinations of salty-sweet, bitter-sour are considered inharmonious, since these combinations are perceived as 2

different tastes, they are not characteristic of food products, are rare and occur, as a rule, as a result of spoilage.

When evaluating taste, it is necessary to take into account such phenomena due to the physiological characteristics of the sense organs as adaptation and fatigue.

Adaptation is a decrease in the susceptibility of the organ of taste, caused by prolonged exposure to a taste impulse of the same quality and constant intensity.

Fatigue reduces the perception of taste due to fatigue of the taste buds under the influence of a repeated impulse.

Pathways and centers of taste. Conductors for all types of taste sensitivity are the so-called "drum string" and the glossopharyngeal nerve, the nuclei of which are located in the medulla oblongata. Many of the fibers are specific, responding only to salt, acid, quinine, or sugar. The most convincing hypothesis is that the four main taste sensations - bitter, sweet, sour and salty - are encoded not by impulses in single fibers, but by the distribution of the frequency of discharges in a large group of fibers differently excited by the taste substance.

Afferent signals caused by gustatory stimulation enter the nucleus of the solitary bundle of the brainstem. From this nucleus, the axons of the second neurons ascend as part of the medial loop to the thalamus, where the third neurons are located, the axons of which are directed to the cortical center of taste.

7.2. Taste sensations and perception

In different people, the absolute thresholds of taste sensitivity differ significantly up to "taste blindness" to individual agents. The absolute thresholds of taste sensitivity strongly depend on the state of the body, changing, for example, during starvation and pregnancy. The absolute threshold of taste sensitivity is estimated by the appearance of an indefinite taste sensation that differs from the taste of distilled water. Differential thresholds of taste discrimination are minimal at medium concentrations of substances, but increase sharply when moving to high concentrations. Thus, a 20% sugar solution is perceived as the most sweet, a 10% sodium chloride solution as the most salty, a 0.2% hydrochloric acid solution as the most acidic, and a 0.1% solution of quinine sulfate as most bitter. Threshold Contrast (dI/I) varies considerably for different substances.

Taste adaptation. With prolonged action of the gustatory substance, adaptation to it develops, which is proportional to the concentration of the solution. Adaptation to sweet and salty develops faster than to bitter and sour. Cross-adaptation was also found, i.e. change in sensitivity to one substance under the action of another. Sequential application of several taste stimuli gives the effects of taste contrast. For example, adaptation to bitter increases the sensitivity to sour and salty, and adaptation to sweet sharpens the perception of all other taste sensations. When mixing several flavoring substances, a new taste sensation arises, which differs from the taste of the components that make up the mixture.