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

The study of taste buds is engaged in a young and still developing science - the physiology of taste. Let us examine some of the basic postulates of the doctrine, which will help to 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 also help him in this, especially the sense of smell.

The mechanism of taste is driven by chemicals found in food and drink. Chemical particles, gathering in the mouth, turn into nerve impulses that are transmitted along the nerves to the brain, where they are decoded. The surface of the human tongue is covered with taste buds, which in an adult have 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 certain set of receptors, thanks to which we feel the whole gamut of taste diversity.

They only respond to 4 basic tastes - sweet, bitter, salty and sour. However, today the fifth one is often singled out - minds. The homeland of the newcomer is Japan, and in translation from the local language it means "appetizing taste". In fact, umami is the taste of proteins. The umami sensation is created by monosodium glutamate and other amino acids. Umami is an important component of the taste of Roquefort and Parmesan cheeses, soy sauce, as well as other non-fermented products - walnuts, tomatoes, broccoli, mushrooms, thermally processed meat.

The socio-economic conditions in which a person lives, as well as the work of his digestive system, are considered to be a completely natural explanation for the choice of food. Meanwhile, scientists are increasingly inclined to the option that taste preferences are determined by genes and heredity. This issue was first raised in 1931 during research during which the odorous molecule phenylthiocarbamide (FTC) was synthesized. 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 team, Arthur Fox, tested the FTC on his family members, who also did not feel it.

Thus, recently scientists tend to think that some people perceive the same taste differently and that some people are programmed to gain weight from french fries, while others can eat it without harm to the figure - this is a matter of heredity. In support of this statement, scientists from Duke University in the USA, together with colleagues from Norway, proved that people have a different composition of genes responsible for smells. The study focused on the relationship of the OR7D4 RT gene to a steroid called androstenone, which is found in large quantities in pork. So, people with the same copies of this gene are disgusted by the smell of this steroid, and the 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 an average of 7-10 days, then die and new ones appear. So don't be surprised if the same taste seems slightly 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, as 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 only 10 years ago.

• All pure tastes are felt by a person in exactly the same way. This means that you can not talk about several types of sweet taste. In terms of taste, there is just one sweet taste, which, however, can vary in intensity: be brighter, richer or faded. The same is true for other flavors.

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

• Good taste is formed in the womb. So, scientists have found that the taste of some products is transmitted not only through mother's milk, but also through amniotic fluid, while the child is in the mother's stomach.

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

• During air travel, due to the high noise level, a person's taste sensitivity to salty and sweet is reduced.

• The taste of biscuits is 11 times better revealed if it is 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 meals.

Sweet

The sweet taste is perhaps the most pleasant for the majority of the world's population. No wonder the expression "sweet life" appeared, and not some other. At the same time, not only flour and confectionery products are sweet, but also products of natural origin. Along with this, they are also useful. Most sugary foods are high in glucose. And as you know, glucose is the main metabolic fuel for the human body. That is why taste buds easily recognize the sweet taste, and even along the way they produce the hormones of happiness - serotonin and endorphin.It should be noted that these hormones are addictive. Here it is the explanation for the fact that depression and stress we prefer to seize with something sweet.

It is no secret that excessive consumption of sweets adversely affects the shape and condition of the skin. However, do not completely abandon desserts. Do not eat treats on an empty stomach and, if possible, try to replace them with dried fruits, honey, nuts.

Sour

Most acidic foods contain ascorbic acid. And if you suddenly crave something sour, know that this may indicate a lack of vitamin C in your body. Such taste differences can even serve as a signal of an upcoming 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. An excess of 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 many ways. For example, through the lungs through the exhalation of carbon dioxide or through the skin through the release of sweat. 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. Especially a lot of it in sour berries (gooseberries, currants, cranberries), citrus fruits and kiwi, fresh vegetables (especially bell peppers).

Taste sensations

Taste sensations, like olfactory ones, are due to the chemical properties of things, that is, taste sensations allow us to evaluate the chemical composition of products in the oral cavity. As with smells, there is no complete, objective classification for taste sensations.

This is due to the fact that in each case we have a complex of sensations. Taste buds come in just a few flavors: salty, sour, sweet, bitter, and (recently added) fatty. However, taste sensations are usually accompanied by olfactory sensations, and sometimes also sensations of pressure, heat, cold, and pain. If the taste of something is caustic, astringent, tart, such a taste is due to a whole complex of various sensations.

If a person eats with a pinched nose or with a severe runny nose, the taste of food remains, but becomes very depleted. Many dishes that used to seem so different now have the same taste. In this, by the way, closed eyes also help a lot.

The sensation of salinity, for example, can be caused not only by ordinary table salt, but also by other substances called salts in chemistry. Taste sensations arise when soluble and diffusible substances are exposed to taste areas, i.e. substances with a relatively low molecular weight.

The main taste area in humans is the mucous membrane of the tongue, especially its tip, edges and base. The middle of the tongue and its lower surface are devoid of taste sensitivity.

Different receptors are unevenly distributed on the tongue. Therefore, different taste regions have different sensitivities to the sensations of salty, sour, sweet, and bitter. The tip of the tongue is most sensitive to sweet, the edges to sour, and the base to bitter.

The same general laws apply to taste sensations as to other sense organs, in particular the law of adaptation. Some taste sensations (such as sour) can overwhelm others (salty). It is called phenomenon of compensation. Another phenomenon is contrast phenomenon- lies in the fact that the sensations reinforce each other. For example, the sensation of the sweet taste of a sugar solution is enhanced by the admixture of a small amount of table salt. Distilled water after rinsing the mouth with potassium chloride or dilute sulfuric acid seems distinctly sweet ( aftereffect phenomenon). In general, these phenomena (interactions, adaptations, temporary aftereffects) appear very clearly in the field of taste.

In the history of evolution, taste sensations are quite ancient. This explains the fact that they have a noticeable effect on the emotional state. Through the autonomic nervous system, taste, along with smell, affects the thresholds of other receptor systems, such as visual acuity and hearing, the state of skin sensitivity and proprioceptors. Taste sensations generated by chemicals coming from the external environment affect the vegetative functions, determine a pleasant or unpleasant emotional background of well-being.

The perception of food is quite different in a hungry and full person. On the one hand, food seems to be tastier to the hungry, even in food that he usually considered tasteless, he notices subtle tastes and aromas. On the other hand, a well-fed person is more picky about food, he carefully sniffs it, tastes it, analyzes taste and smells. But in both cases, the very taste of food affects the well-being, calming, relaxing, setting up for a productive rest.

There are four types of taste sensations: sweet, sour, bitter and salty. They are usually considered the main taste qualities, the combinations of which give the whole variety of human taste sensations.

In psychophysical studies of taste sensitivity, pure chemicals of a certain concentration are used, which are applied to strictly localized areas of the subject's tongue. To obtain sensations of sour, bitter, salty and sweet, solutions of hydrochloric acid, quinine, sodium chloride and sugar are used, respectively.

The question of the connection between the four qualities of taste sensations and the stimulation of certain receptors is still unresolved.

Using electrophysiological methods, the American researcher K. Pfafman (1962) showed that acid can cause discharges in single hairs, which also react to salt. However, there are fibers that react only to acid. Other researchers have found a number of single taste fibers in which action potentials are generated in response to stimuli with distilled water, without any solutes. These "water" fibers have been found in monkeys, dogs, rabbits, but have not been found in humans, calves, and rats. The cat lacks taste fibers that respond to sweets.

Differences in the feeding behavior of various animal species are undoubtedly associated with the characteristics of their taste sensitivity.

It has been repeatedly suggested that the four qualities of human taste sensations are caused by irritation of four types of receptors, presented in various combinations in each of the taste buds and distributed with different densities in separate parts of the tongue. It is well known that in humans, the tip of the tongue is more sensitive to sweet substances, while the base, on the contrary, is more sensitive to bitter ones. The sensation of salty is associated with irritation of the sides and tip of the tongue, and the sensation of sour occurs mainly with irritation of the area bounded by the sides of the tongue. One could further assume that taste information is transmitted to the central nervous system along fibers, each of which combines several types of receptors, and this explains the possibility of mixed taste sensations. However, there is currently no direct evidence for the correctness of this view.

In ascending order of taste sensitivity, the main taste sensations are as follows: salty, sour, sweet and bitter. The sensation of bitterness in the mouth occurs at a concentration of quinine equal to only 3 * 107 moles per liter of distilled water. To get the sensations of sweet, salty or sour, the concentration of the solution must be at least 1000 times greater. This circumstance has an obvious biological meaning, since bitter substances are often poisonous.

Differential taste thresholds are approximately 0.20. At the same time, only the sensation of bitter is subject to the Bouguer-Weber law.

When chemicals are applied to certain areas of the tongue, it has been found that taste sensations are subject to rapid and complete adaptation. This usually takes 30 seconds. So the sensitivity to salt falls during this time by 300 times, and to sweet by 20 times. The change in thresholds for sour and bitter is less pronounced.

Under natural conditions, adaptation does not occur, since as a result of tongue movements there is a constant change in the chemical stimulation of individual receptors. Thus, the movements of the tongue contribute to a more accurate recognition of taste substances. Olfactory, tactile, temperature and pain components also play an important role in assessing the taste of food. Taste thresholds are affected by factors that cause sensitization (see p. 83 and others). It is known that taste sensitivity is affected by temperature, and this influence has a different effect on each of the four taste qualities. With various diseases of the digestive, respiratory and other apparatuses involved in maintaining the constancy of the internal environment of the body, taste sensitivity is also affected in one way or another.

The dependence of taste sensitivity on the balance of metabolic processes in the body is evidenced by the data obtained in the study of the choice of saline solutions by rats. It turned out that usually rats prefer a 40% glucose solution mixed with a 1% sodium chloride solution to a pure 40% glucose solution. However, when 10 ml of physiological saline containing about 1% sodium chloride was injected into the abdominal cavity of rats, the animals preferred a pure glucose solution. Thus, the presence of an excess of table salt in the body immediately reduces the "salt" appetite of animals.

Human taste sensitivity also markedly decreases with saturation and increases with starvation.

Taste and smell, as protopathic types of sensitivity, have a more affective coloration than all other sensations, with the exception of pain. At the same time, an intense sensation of bitter is unpleasant, and sweet is pleasant.

Incredible Facts

Taste is not only one of the most pleasant, but also a rather complex sensation that science is only beginning to understand.

Here are some amazing facts about your ability to taste.

Taste sensations

1. Each of us has a different number of taste buds.

We have several thousand taste buds in our mouths, but this number varies from 2,000 to 10,000 in different people. Taste buds are not only on the tongue, but also on the palate and walls of the mouth, throat, and esophagus. Taste buds become less sensitive as you age, which probably explains why foods you didn't like as a child become palatable as adults.

2. You taste with your brain

When you bite into a piece of cake, it seems that your mouth is filled with taste sensations. But most of these sensations originate in your brain.

The cranial nerves and taste buds send food molecules to the olfactory nerve endings in the nose. These molecules send signals to an area of ​​the brain known as the primary taste cortex.

These messages, combined with the smell messages, give the sensation of taste.

Why do people taste the same taste differently?

Why

loss of taste

3. You can't taste good if you can't smell.

Most taste sensations are smells that are transmitted to the olfactory receptors in your brain. The inability to smell due to colds, smoking, and certain side effects of medications can affect the olfactory receptors in the brain, making it difficult for you to taste.

4. Sweet foods make food memorable.

A new study has shown that centers associated with episodic memory in the brain are activated when we eat sweets. Episodic memory is a type of memory that helps you remember what you experienced at a certain time in a certain place. Episodic memory can help control eating behavior, such as making decisions based on memories of what and when we eat.

5. Taste can be turned off

Scientists have learned to stimulate and silence the neurons in the brain responsible for the main taste sensations: sweet, sour, salty, bitter and umami. So, for example, in an experiment on mice, when they stimulated a bitter taste, the mice winced.

6. You can change your own taste sensations

Taste buds are sensitive to certain compounds in foods and medicines, which can change your ability to perceive basic taste sensations.

For example, sodium lauryl sulfate in most toothpastes, it temporarily suppresses sweetness receptors, making orange juice drunk immediately after brushing your teeth feel like unsweetened lemon juice. Also, the compound cynarine in artichokes can temporarily block sweet receptors.

Taste perception

7. The smell of ham gives food a salty taste.

There is an entire industry out there that creates the taste of the food you buy in the store. Such a phenomenon as "phantom aroma" makes us associate foods with a certain taste. So, for example, by adding the smell of ham to food, your brain will perceive it as more salty than it really is, since we associate ham with salt. And by adding vanilla to food, you will perceive the product as sweeter.

8. We prefer spicy food during the flight.

Noisy environments, such as when you're on an airplane, can change your sense of taste. The study showed that in an airplane, people have suppressed sweet receptors and enhanced receptors for the "fifth taste" - umami. For this reason, food with a strong taste is more often ordered on the plane. German airline Lufthansa has confirmed that passengers order tomato juice as often as they order beer.

9. If you are a picky eater, you may be a "super taster"

If you can't stand the taste of eggplant or are sensitive to even the slightest presence of onion in your food, you may be one of the 25 percent of people called "supertasters" who have more taste buds on their tongues, which increases taste sensitivity.

Taste sensations are exactly what cannot be clearly defined. Even scientists cannot yet explain all the complexities of this phenomenon. And marketers, in turn, successfully manipulate people with their responses based on taste. In this review, "a dozen" little-known facts about taste that will destroy a number of stereotypes.

1. Expensive wine

Certain information can distort a person's ability to taste food and drink. In 2015, in one experiment, volunteers were told they would be given 5 different brands of wine to sample, with prices ranging from £3 to £55 a bottle. In reality, they were given three brands with two different price tags.
Unaware that they were being served cheap wine, the subjects enjoyed the wine as if it were truly delicious and refined. The belief that a quality drink was poured into a glass was enough to change people's neurological chemistry. Incredibly, the brain formed a person's taste in accordance with his expectation of the cost of the product.
Price was not the only factor capable of rewiring the brain in this way. The researchers also found that consumers spend more money on heavier bottles and that alcoholic beverages are best sold in heavier glass, all because the brain associates weight with quality.

2. "Bloody Mary"

In 2013, the German airline Lufthansa noticed something strange on its aircraft that was not normally seen on the ground. During the flight, passengers very often ordered tomato juice, drinking about 1.8 million liters annually. In fact, Bloody Mary was no less popular among the Germans than beer.
This unusual phenomenon even affected those who would normally never drink tomato juice. During the experiment, Bloody Mary was served to passengers in an airplane that was on the ground. Passengers said the drink had a "stale taste". However, during simulated flight conditions, Bloody Mary's popularity rose again strongly.
Now passengers claimed that she had a "pleasant fruity aftertaste." The culprit of this is the human mind and its sense of taste. The sound of an airplane, low humidity, and cabin pressure cause the mind to “pick up” a tastier flavor for a drink.

3. Treating depression

Taste is closely intertwined with emotions. Anxiety and depression, for example, cause scents to become dull. There is evidence that the blues interfere with determining how fatty a food or even milk is. But the taste itself can help people suffering from depression and anxiety get better treatment.
When healthy volunteers were given antidepressants that contain certain neurotransmitters, they had an increased ability to detect bitterness, sweetness, and acidity. This indicates a chemical imbalance in people who have a dull taste due to bad emotions. Since their anxiety or depression is not related to the imbalance, talking therapy may be more successful than pills.
Thus, a simple taste test can result in people not being prescribed drugs they don't need. Incredibly, the researchers found that antidepressants worked with chemical transmitters in the taste buds long before they reached the brain.

4. Sixth taste

Scientists once claimed that the human palate could only detect four tastes. The appearance of umami has proved this concept wrong. Some scientists believe that there may even be a sixth taste. In fact, seven tastes claim to be recognized today. For example, mice have two receptors that sense a "chalky" taste or a "calcium taste." One of these exists in human language, but its association with the chalky taste remains unproven.
Japanese researchers believe that the calcium receptor is responsible for another yet unrecognized taste called kokumi ("hearty"). They claim that the compounds in yeast and fish milt improve food products. Western scientists have yet to test this. They also emit burning (spicy) and cooling tastes that convince the brain of false temperatures. Some believe that these are physical feelings, not tastes.
Two more conflicting theories claim that there is a taste of fat and a metallic taste. The most unusual, but perhaps the most reasonable candidate for a new taste is carbon dioxide, which gives fizz to carbonated drinks. Climbers take acetazolamide, an altitude sickness drug that inhibits enzymes. This may be why climbers report no tongue tingling when consuming carbonated drinks.

5. "Thermal tasters"

Each person has purely individual taste buds that are not repeated in other people, like fingerprints. However, most of the population belongs to the group that experiences the same basic tastes with approximately the same intensity. But for a small percentage of people, things are much stranger. There are "thermal tasters" who identify cold foods as sour and hot foods as sweet.
Some people are genetically sensitive to coriander. For them, it tastes like soap. There are also two extremes: "tasteless", who have few taste buds and most of their food is bland, and "supertasters", who have twice as many taste buds as the majority of the population.

For them, the real curse is the bitter taste, but they enjoy sweeter sugar and saltier sodium. About 25 percent of people are "supertasters," but most agree that it can be frustrating. Their pronounced ability to detect the smallest flavors makes them less prone to consuming alcohol, rich desserts, and vegetables (in particular, broccoli is unbearably bitter for supertasters).

6. Water

Almost everyone would agree that water has no taste. If so, this is usually due to chemicals in the tap water or the aftertaste of the bottle. Scientists do not agree with this statement. If water is indeed devoid of taste, then certain drinking habits in animals should not be observed.
Because water is critical to survival, living organisms must identify it by smell and taste. Indeed, water-determining cells exist in amphibians and insects. There are indications that such cells may also exist in mammals. When an animal is thirsty, this sensation is triggered by the brain's hypothalamus. The same organ also signals when to stop drinking.
But most animals stop long before the gut signals to the brain that it feels full. The only explanation is that the mouth and tongue send messages to the brain. To do this, the taste buds must somehow be able to detect the taste of water. Obviously, the human brain also reacts to water.

7. Intestine

It may seem incredible, but there are taste buds in the human gut. However, they are different from those located on the tongue. The latter tell the brain about the taste of what is in the mouth. If it tastes good, the person swallows. Food reaches the intestines, where receptors do not determine the taste of food, but hunger or satiety.
Once the brain "tastes" that something is in the gut, it triggers the release of hormones to convert the food into energy in the tract. This maintains blood sugar levels. In this sense, taste buds in the gut play an important role in health.
If they are wrong, it can cause weight gain, or worse, a disorder in glucose absorption, potentially leading to type 2 diabetes. In the future, a better understanding of gut receptors could be the starting point for blood glucose control and obesity.

8. "Sunsepalum Dulcificum"

A small red berry from West Africa makes the vinegar taste like liquid sugar. Ironically, the so-called "wonder berry" has a bland and inexpressive taste. But after eating this berry, any sour food will be perceived as very sweet. Berries contain miraculin, a protein that coats sweet taste receptors on the tongue.
When the mouth is neutral (neither alkaline nor acidic), miraculin blocks other sweeteners from attaching to the receptors. That is why the berry's own taste is so insipid. But when an acidic environment appears in the mouth, the protein "steals" a few protons, changes shape and distorts the sweet receptors. They become hypersensitive and produce insane results.
This phenomenon is not unique to miracle berries. The Malaysian lumba plant does the same trick, thanks to a protein called neoculin. Interestingly, neoculin and miraculin have nothing in common and are completely different at the molecular level. In addition, each attaches to different parts of the receptors, but do the same thing.

9. Aroma

Recently, scientists have been working with older people and patients undergoing chemotherapy or radiation therapy. Both cancer treatment and aging can cause a severe loss of the ability to recognize taste. The researchers' approach was innovative and creative. They used cutlery that practically enhances the flavor of the food.
They invented the cup, which can enhance the intensity of drinks, and the smart spoon, which can create or complement the flavors of food. On the handles of the cup and spoon there is a button that can reduce or increase the acidity, bitterness and saltiness.
Using tiny silver electrodes, flavors are produced by stimulating taste buds with electrical impulses while eating or drinking. In addition to improving a meal or restoring taste, the technology also shows promise in another area. The developers believe that people may someday experience the fullness of taste in a virtual environment.

10. Synesthetes

It may sound like fiction, but there are people who can taste the words. They even have a name - synesthetes. In people with synesthesia, senses such as sight and hearing, touch and taste are confused and mixed up. The rarest of these unusual people are speech tasters. When testing, they even tasted even the names of objects unknown to them.
Years later, subjects recalled the scent of each item. This 100 percent accuracy is what sets synesthetes apart. Many synesthetes also describe the same word in a similar way. This led researchers to speculate that certain sounds in the word, rather than the word itself, evoked the taste.