Taste is one of the five senses of man. And as scientists believe, one of the most ancient. With the ability to distinguish tastes, a person can enjoy their favorite food and identify potentially dangerous products. How do taste buds work and why do we need to distinguish between different types of tastes?
Role of receptors
The ability to distinguish the taste of food helped the ancient man to survive. Thanks to this skill, our ancestors could determine wholesome food and reject dangerous food. Thanks to the taste buds, each of us has our favorite dishes and those that you don’t even want to approach. That is, since ancient times, receptors help a person identify tasty and safe food.
In the language of an adult can be located up to 10 thousand taste buds, papillae, which are regularly updated (approximately every 2-3 weeks). They perceive the taste of food consumed and transmit signals to the brain. And he already decides what "installation" to give: you can eat or refuse.
As a person ages, some of the receptors also die and do not renew. In the language of an older person there can be only 5 thousand taste buds. By the way, heavy smokers also poorly distinguish tastes, since nicotine paralyzes this ability of the body. But in pregnant women, receptor sensitivity, on the contrary, is exacerbated.
The ability to distinguish tastes depends not only on the papillae on the tongue, but also on the efficiency of the sense of smell. In the upper part of our nose there are specific cells that perceive the smell of food. And if it is suspicious, the brain pushes us not to taste the product. In addition, it is the nose that is responsible for recognizing certain tastes. Probably everyone knows that food can be astringent, spicy, tart. And these flavors do not recognize the receptors on the surface of the tongue, but the nose.
How many tastes we recognize
Until the end of the twentieth century, experts identified four basic tastes: sweet, salty, sour and bitter. But a few years ago, this classification was revised. To the traditional tastes they added one more - the taste of the minds. This term came to us from Japanese and denotes a specific flavor characteristic of high-protein food.
They say, for the first time, the existence of taste by the minds (though it was then called differently) was spoken by the French court physician and astronomer Jean-François Fernel in the 16th century. But his theory in those days was not perceived adequately. The second time they talked about the existence of protein taste at the beginning of the twentieth century. It was the Japanese chemist Kikun Ikeda. He managed to extract the substance “umami” (glutamate amino acid) from seaweed. But the beginning of the war suspended the study in this area. And only 100 years later, in 2000, the researchers accepted the theory of the existence of the fifth taste - umami ("appetizing"). It can be tasted in soy sauce, parmesan and roquefort. Some argue that Umami is a combination of all tastes at once. In addition, in recent years, scientists have started talking about another specific taste - fat. True, it is not yet included in the classifier.
Another discovery at the end of the twentieth century concerned the so-called taste map. Until the 1980s, it was widely believed that the receptors responsible for the perception of different tastes were distributed in language in groups. But it turned out that this delusion and receptors are distributed over the entire surface of the tongue.
In addition, researchers are increasingly saying that a person perceives a lot more tastes than is commonly believed, since pure in nature almost does not exist. And even those that are called clean can vary significantly in intensity. Take at least bitter substances. All of them can be perceived by our receptors in different ways. For example, solutions of morphine, opium and quinine are bitter, but each of them has different bitterness. By the way, quinine, a natural substance added to gin and some non-alcoholic beverages, is considered to be a “reference” bitterness.
Sour taste is also different. Oxalic, tartaric, citric, malic, sulfuric, hydrochloric or nitric acids - they are all different, but if you prepare solutions of different concentrations from them, the taste of all substances can be balanced.
But as for sweet, in its pure form, it is always the same to the taste. That is, even the most experienced taster will not be able to find the taste difference between glucose, fructose, sucrose and lactose, since their taste is sweet in its pure form. If we talk about salt. Only one product has that pure salty taste - table salt. The rest is brackish with a sour or bitter aftertaste.
Our receptors perceive complex (mixed) tastes differently, highlighting for themselves only the most pronounced "notes." For example, the taste of apples is always a mixture of sour and sweet, the only difference is in what flavor predominates. Cucumber pickle is not purely salty, but salty-sour. More rarely, but there is a mixture of sweet and bitter in nature. The best example is chocolate, which combines the bitterness of cocoa and the sweetness of sugar. But a mixture of purely bitter and purely sour or salty causes aversion in the majority. In nature, this taste has potentially dangerous plants for humans.
When taste buds cheat
Interestingly, in some conditions, receptors may incorrectly perceive the real taste of food. For example, after tasting cheese, the wine will seem more delicious, and if the products are consumed in the reverse order, the perception of the sweet will be broken. Quite ordinary coffee and milk can get a pronounced sour taste if you chew iris root before drinking a drink.
Sometimes the mechanism of taste perception is broken not partially or temporarily, but completely. In such cases, they say about agevzii - a state of total inability to taste.
If the taste perception is severely blunted, they are talking about hypogewsia, and constantly incorrect recognition of the taste of food is paragevsia. Any of these disorders may occur after damage to the mucous membrane of the tongue (for example, after a burn or inflammation). Receptors can break down due to disorders in the brain, against the background of diseases of internal organs or improper metabolism. For example, in gallbladder diseases, bitterness can always be felt on the tongue. If the stomach is sick, a sour taste remains in the mouth, and in some forms of diabetes mellitus - sweet.
Why should a person recognize tastes?
Among human feelings, the ability to distinguish tastes is considered the oldest. Over the course of millions of years, this skill has evolved with a person, because the choice of the wrong food can lead to loss of energy, health problems and even death.
In the course of his development, a person at the subconscious level has determined: if he needs energy, he must look for sweet food. If the body feels a lack of minerals and salts, it requires salty. If there is a need to replenish reserves of proteins and amino acids, the body asks for food to taste with minds. But why did the ancient man have to recognize the bitter and sour? Receptors that react to the sour, like the rest, we got from our ancestors. The sour taste indicated to the ancient man that before him was either an unripe fruit, or spoiled (fermentation processes began in it). Bitter taste since ancient times was perceived as a warning about poisons. Simply put, the ability to recognize sour and bitter protected the primitive man from poisoning.
From the point of view of physiology, in many ways we still resemble our ancestors. But also in the course of evolution there have been changes. Including in the perception of different tastes. For a modern person, sour is no longer only unripe or sour, but also a source of vitamin C. Our bodies do not produce ascorbic acid, but nevertheless it is extremely important for survival, therefore the body is looking for it in food.
The ability to distinguish different tastes depends on the influence of chemicals on the receptors that are available in the language.
Thus, a sweet taste in the mouth appears when the tongue comes in contact with carbohydrates and alcohols. Salty cause potassium and sodium salts. Bitter is usually manifested under the influence of alkaloids, which are often poisonous. And the taste of sour is the result of the contact of taste receptors and hydrogen ions.
But the ability of the body to recognize tastes and respond to receptor signals depends not only on the ability to avoid dangerous products, but also on two other important functions. First, the signals sent by the receptors activate the production of gastric juice. This means that the speed of food digestion depends on the ability to distinguish tastes. Secondly, it depends on the receptors on the tongue whether the meal will bring pleasure. If a person eats food that he likes, the secretion of hormones of happiness and good mood increases in the body.
What does it mean if you want to eat a certain taste
It happens that sometimes the body requires something sour, salty or sweet. Why it happens? It turns out that ignoring such signals is not worth it. For example, if the body requires a sweet, then perhaps it is experiencing a lack of energy. Sweet in the understanding of the body is glucose, that is, "fuel" for it. In addition, the body may require sugar when the levels of serotonin and endorphin, hormones responsible for well-being, decrease sharply. That is why many unknowingly seize the stresses of chocolate. Taste receptors transmit a signal to the brain, and he begins to produce the substances necessary to improve mood. But you should not always go on about your body. Frequent seizure of stress and bad mood may lead to obesity.
If the body requires sour, then it is quite possible, it lacks vitamin C (ascorbic acid). This substance perfectly strengthens the immune system and helps to fight colds, but you should not overdo it as well. Excessive passion for sour food can badly affect the enamel of the teeth. By the way, if the body requires a sour, sometimes it can be outwitted. It is not necessary to always “feed” your receptors with citrus or kiwi, sometimes sweet pepper helps to pacify cravings. Although not sour, it is rich in vitamin C.
According to the observations of American researchers, if the body requires salt, it is not necessary to immediately eat salt. In this way, the body sends signals about the lack of minerals, and it is not always sodium or chlorine. To restore the reserves of nutrients, you can use more useful fruit and vegetable salads, cereals and nuts. But the abuse of salt can lead to various diseases. It is hardly the only case when salt should be given to the organism’s requirements, in hot weather. In the summer, such a signal can indicate dehydration, and salt helps retain moisture in the tissues, preventing dehydration and thermal shock.
The body usually does not ask for bitter food, since nature has laid down that it is a taste of poison. But if the body suddenly demands "something like this" - neither sweet, nor sour, nor salty, perhaps he wants bitter chocolate. This can happen when the body feels fatigued and decreases in mental performance. Chocolate helps to improve brain function.
The theme of the evolution of taste interests many scientists around the world. In recent years, many interesting discoveries have been made and we have learned a lot about why a person recognizes different types of tastes. Nevertheless, studies in this area continue, and Homo Sapiens continues to evolve, adapting to the realities of the modern world. It is possible that over time, a person's taste preferences will also change. In the meantime, we, like thousands of years ago, our ancestors, are carefully trying new products, trying to guess what the food is: good or danger.