Carbohydrates are an integral component of the cells and tissues of any living organism, be it a plant, animal, or human being. They make up the bulk of the organic matter of the planet Earth. Carbohydrates are a fairly broad class of compounds. Among them, you can find substances with different properties. Due to this feature, the functions of carbohydrates are very wide. Today we will analyze the main properties, physiological role and use of carbohydrates in different areas of the food (and not only) industry.
Carbohydrate sources
The main sources of carbohydrates are plant products. Namely: bread, cereals, vegetables, fruits, berries. As for animal products, some of them are also rich in carbohydrates. This is, first of all, milk, which contains the so-called milk sugar.
Food products may contain different carbohydrates. Therefore, the meaning, application of carbohydrates and their functions are very extensive. Cereals and potatoes contain starch - a complex carbohydrate insoluble in water, which is broken down into simple sugars by the action of digestive juices. In fruits, vegetables and berries these substancespresented in the form of simple sugars: fruit, beetroot, cane, grape, and so on. They dissolve in water and are perfectly absorbed by the body. Water-soluble sugars are rapidly absorbed into the bloodstream.
Consumption of carbohydrates
It is believed that the bulk of carbohydrates should be consumed in a complex form, and only 20-25% in a simple one. This contributes to the gradual entry of sugars into the tissues. If a person receives enough carbohydrates from food, they are deposited in the liver and muscles in the form of "animal starch" glycogen. With a lack of carbohydrates, the glycogen store is broken down into glucose and used for the needs of the body (nutrition of cells and tissues). If the body receives an excess of them, they turn into body fat. By the way, carbohydrates also include fiber, which is necessary for proper digestion.
Carbohydrates are essential components of the diet, so they not only determine the body's energy homeostat, but also participate in the biosynthesis of a number of carbon-containing polymers. Over a lifetime, an average person consumes about 14 tons of these compounds. Of these, approximately 2.5 tons - in a simple form. The use of proteins, fats, carbohydrates and their derivatives in food is not uniform. Carbohydrates are the main part of our diet. They consume 4 times more than proteins or fats. With a simple, mixed diet, about 60% of a person's energy comes from carbohydrates. Their main task in the body is to provide energy. The more physical activity in a person's life, the morehe needs carbohydrates. With a sedentary lifestyle, the need for these substances decreases. For those who do not engage in physical labor, the daily requirement for carbohydrates is approximately 400 grams.
About 50-65% of carbohydrates enter our body with grain products. 15-25% - with sugar and sugar-containing products. About 10% - with root and tuber crops. And about 5-7% - with fruits and vegetables.
Carbohydrates are a very strong irritant of the external secretion of the pancreas and the most active stimulator of insulin synthesis, which plays an important role in the regulation of carbohydrate metabolism and maintaining optimal glucose homeostasis. Over the years, simple carbohydrate overload leads to hyperplasia of β-cells, then to the weakening of the insular apparatus and the creation of prerequisites for the development of diabetes.
Classification of carbohydrates
Depending on the structure, the ability to dissolve and the rate of assimilation, carbohydrates that are part of food are divided into simple and complex. Simple include monosaccharides (fructose, glucose, galactose) and disaccharides (sucrose, lactose). To complex - polysaccharides (fiber, starch, glycogen). In addition to the carbohydrates given as an example, there are other, lesser-known substances in each of the classes.
Simple carbohydrates
Mono- and disaccharides dissolve well in water and are quickly absorbed by the body. They have a pronounced sweet taste, which is why they are often called simply sugars. The most abundant monosaccharide isglucose contained in various fruits and berries, as well as synthesized during the breakdown of di- and polysaccharides. Glucose, once in the body, quickly finds a use for itself. It forms glycogen, nourishes brain tissue and muscles (including the heart), and regulates blood sugar levels. During exercise, glucose can be used directly as an energy source.
Fructose has similar properties. It can be considered as a very valuable, easily digestible carbohydrate. But, compared with glucose, fructose is still more slowly absorbed by the intestines, and once in the blood, it leaves the bloodstream faster. Up to 80% of fructose is retained in the liver, preventing blood sugar saturation. However, in the liver, fructose synthesizes glycogen more easily than glucose. Compared to sucrose, fructose is more digestible and has more sweetness. Due to the latter property, less fructose can be used for the desired level of sweetness of the product, thereby reducing the overall consumption of sugars. This takes place in the construction of a calorie-restricted diet. Considering the use of carbohydrates in life, special attention should be paid to dietary nutrition. Fructose is often used as a sweetener in foods for people with diabetes.
With an excess of sucrose, fat metabolism is disturbed and fat formation increases. In addition, it has long been proven that with an increase in the amount of sugar entering the body, the synthesis of fats from complex carbohydrates, directly from fat and even protein, increases. Hence,The amount of sugar a person consumes can greatly regulate fat metabolism.
With the abundant use of sugar, cholesterol metabolism disorders and an increase in its content in the blood begin. In addition, excess sugar has a bad effect on the work of the intestinal microflora - the mass of putrefactive microorganisms increases, putrefactive processes accelerate, and flatulence develops. Least of all, these side effects are observed with the use of fructose. Fruits and berries are the main source of this carbohydrate. A lot of fructose and glucose is found in honey: 37.1 and 36.2%, respectively. All the sugar that is in watermelon is fructose, it is about 8% here.
The next monosaccharide is galactose. It is not found in foods in its free form. Galactose is a breakdown product of lactose, the main carbohydrate in milk.
As for disaccharides, the main one in our diet is sucrose. Upon hydrolysis, it breaks down into fructose and glucose. The main sources of sucrose are beet and cane sugar. In granulated sugar, the content of this carbohydrate reaches 99.75%. In addition, sucrose is found in fruits, vegetables and gourds.
Complex carbohydrates
Polysaccharides are characterized by a more complex molecular structure and extremely low solubility in water. This class includes: starch, fiber, glycogen and pectin. The use of carbohydrates of this class is widespread to varying degrees. Starch is of primary nutritional value. Its high content in grain crops is the main factor that determines theirnutritional value. In the average person's diet, starch accounts for up to 80% of the total amount of carbohydrates consumed. Once in the body, it turns into simple carbohydrates and performs their functions.
As for glycogen, in our body it plays the role of an energy material that feeds working muscles and internal organs. Glycogen is restored through reosynthesis at the expense of glucose.
Pectin is a soluble substance that is well absorbed in the body. As modern studies in the field of he althy nutrition show, pectin can be used for preventive and therapeutic purposes in diseases of the gastrointestinal tract.
Fiber is very similar in structure to polysaccharides. Grain products are famous for its high content. In addition to the amount of fiber in the product, its quality is of great importance. The more tender this carbohydrate, the better it breaks down in the intestines, and the more benefits it brings to a person. The fiber of vegetables and potatoes has these properties. An important feature of this polysaccharide is the ability to remove cholesterol from the human body. Now let's take a closer look at the use of carbohydrates.
Parenteral nutrition
The use of carbohydrates in medicine today is rapidly developing. Parenteral nutrition is the intravenous administration of nutrients into the body. It is used in cases where the patient is unable to feed himself. The use of carbohydrates in parenteral nutrition is very common. They are used according tothe simple reason is that they are the most affordable source of energy for the human body. The energy value of carbohydrates is 4 kcal/g. The daily human need for energy ranges from 1.5 to 2 thousand kilocalories. Hence the problem of the isolated use of carbohydrates to cover this need. In terms of an isotonic glucose solution, to fully cover a person's need for calories, it is necessary to pour from 7 to 10 liters of the solution. This can lead to the development of overhydration, pulmonary edema and cardiovascular disorders.
The use of more concentrated glucose solutions is fraught with other unpleasant consequences - the occurrence of plasma hyperosmolarity and irritation of the intima of the veins (development of phlebitis and thrombophlebitis). And in order to eliminate the risk of osmotic diuresis, it is necessary to maintain the rate of glucose infusion in the range from 0.4 to 0.5 g / kg / h. If you translate this figure into an isotonic glucose solution, you get a little more than 500 mm per hour for a patient weighing 70 kg. Insulin is added to the glucose solution to prevent impaired carbohydrate tolerance and the resulting complications. The calculation is carried out according to the formula: 1 unit per 3-4 grams of dry glucose. Insulin not only has a positive effect on glucose utilization, but also contributes to the normal absorption of amino acids.
The use of carbohydrates in medicine depends on their type. In parenteral nutrition are widely used: fructose, glucose, sorbitol, dextran, glycerol and ethylalcohol.
Diet food
There are many diets that are based on the complete or partial exclusion of carbohydrates from the diet, as well as an increase in the intake of proteins and fats. The US Department of Agriculture conducted a survey, according to which it was revealed that people who eat carbohydrate-rich foods are predominantly of normal weight. Foods high in carbohydrates are more nutritious but lower in calories.
As you know, in America, more than half of the population is overweight. And the number of such people is steadily growing. A long-term survey of the population on the subject of food consumed showed that people whose diet is dominated by carbohydrates receive fewer calories than lovers of proteins and fats, with the same amount of food eaten. This group of people of all those surveyed, and there were more than 10,000 people, had the lowest body weight. The reason is that for every 1,000 calories of carbohydrate-containing foods, there is a lot of fiber and water. This group of people received more nutrients with food, namely: vitamins A and C, carotene, calcium, iron and magnesium. Fats, cholesterol, zinc, sodium and vitamin B12 were found in their diets to a small extent.
The use of carbohydrates and fats in foods is closely related. However, as well as the use of carbohydrates with proteins. The high efficiency of carbohydrates as energy sources lies in their ability to conserve protein. When a large amount of carbohydrates is ingested, the body uses as energymaterial is less than amino acids. In general, these substances are not indispensable components of nutrition, since they can be synthesized from amino acids and glycerol, however, their role should not be underestimated. The use of carbohydrates in food should be at least 50 grams per day. Otherwise, metabolic disturbances may occur.
However, excessive consumption of carbohydrates leads to the formation of subcutaneous fat. When building a diet, it is important not only to satisfy a person's need for these substances, but also to balance the consumption of their different types. It is important to monitor the ratio of simple and complex carbohydrates. When a lot of sugars enter the body, they cannot be fully synthesized into glycogen and turn into triglycerides, which contribute to the formation of fatty tissues. When insulin is elevated in the blood, this process speeds up.
Complex carbohydrates, unlike simple ones, break down slowly, so their content in the blood increases gradually. In this regard, it is advisable that the main carbohydrate part in foodstuffs is made up of precisely digestible substances. Their share should be from 80 to 90 percent. The lack of complex carbohydrates is especially noticeable for those who suffer from diabetes, obesity, atherosclerosis and diseases of the cardiovascular system.
As you already understood, most carbohydrates are used in nutrition and medicine. But the scope of carbohydrates does not end there. Where else are they used?
Glucose
This carbohydrate is well absorbed by the body and can be used as part of some medications. In addition, glucose is widely used in the confectionery industry. With its help, marmalade, caramel, gingerbread and other products are made. In the textile industry, it plays the role of a reducing agent. And in the production of glyconic and ascorbic acids, glucose is the starting product. With its help, they also carry out the synthesis of some industrial sugars.
Glucose fermentation is of great importance. It occurs when pickling cabbage, cucumbers, milk and other products, as well as when ensiling fodder. Alcoholic fermentation of glucose is used in beer production.
Starch
Starch is a valuable nutrient. To make it easier for the body to digest, the products are subjected to heat treatment. Under high temperature conditions, partial hydrolysis of starch occurs, as well as the formation of water-soluble dextrins. Dextrins, once in the digestive tract, are hydrolyzed to glucose, which is well absorbed by the body. If we talk about the use of carbohydrates in industry, starch cannot be ignored. The main products that are obtained from it are glucose and molasses. This further expands the area in which the use of carbohydrates takes place. Briefly describe the process of obtaining glucose and molasses from starch as follows.
Starch is heated in a mixture with dilute sulfuric acid. Excess acid is neutralized with chalk. The precipitate of calcium sulfate, which is formed duringneutralization, filtered. Then the solution is evaporated and glucose is isolated from it. If you do not bring the hydrolysis process to the end, you get a mixture of glucose with dextrins, which is called molasses. It is used in the confectionery industry. In addition, starch-derived dextrins have found widespread use as adhesives and paint thickeners. Starch proves how varied the use of carbohydrates can be. The chemistry of the processes, however, is not at all complicated.
Previously, starching was used, which allows you to breathe a second life into the fabric and extend its service life. Starch and products derived from it are also used in the textile, pharmaceutical and foundry industries.
Pulp
The practical benefits of carbohydrates have always been no less important than their biological role. The use of carbohydrates can be found in completely different areas of human activity. Cellulose (fiber) has been used by man since ancient times. At first, people began to use wood as a fuel and building material. Then they learned to make thread from cotton, flax and other fibrous plants. Later, technologies appeared that made it possible to obtain paper from wood. Paper, at its core, is a thin layer of cellulose fibers that are pressed and glued. The result is a durable, smooth surface that won't bleed.
Initially, only vegetable raw materials (cotton and rice stalks) were used to make paper. Fibers were extracted from it purely mechanically. But asdevelopment of society, the listed sources were not enough to cover the need for paper. Most of it goes to newspapers. Given that the quality of the paper does not play a special role here, they began to add up to 50 percent of ground wood to it. Later, technologies appeared that made it possible to get rid of such accompanying wood substances as resins, lignin, and so on. This is how varied the practical use of carbohydrates can be.
To date, the most common method for isolating cellulose is sulfite. It is used in various areas where carbohydrates are used. The chemistry of the process is quite simple. According to this method, the wood is crushed and boiled in a mixture with calcium hydrosulfate. Then, the cellulose freed from all kinds of impurities is separated on filters. The resulting lye contains monosaccharides, so it is used as a raw material for the production of alcohol. And cellulose is also used in the manufacture of viscose, acetate and copper-ammonia fibers.
Sometimes carbohydrates are confused with carbohydrates. Despite the fact that these two classes of substances are consonantly named, they have nothing to do with each other. The use of saturated hydrocarbons in everyday life and at work is a completely different story.
Conclusion
Today you have deepened your knowledge of substances such as carbohydrates. The properties, use of carbohydrates and their benefits for humans confirm that these substances are the most important biological components on our planet. They areliterally everywhere and in everything. But this is not the main thing, but the fact that without carbohydrates our life would be impossible. The use of carbohydrates in life is too extensive.
