The chemical composition of fresh fruits and berries depends on their type, degree of maturity, harvest time, storage methods, etc.

Fresh fruits and berries have a high water content - 72 - 96%. It determines the physiological processes in fruits and berries, and also contributes to the development of various microbiological processes that lead to their deterioration. When storing fruits, water can evaporate, which leads to a decrease in keeping quality and a decrease in their shelf life.

The main energy material of fruits and berries is carbohydrates- sugars, starch, cellulose (fiber), pectin substances, hemicellulose. The calorie content of carbohydrates is low, but the presence of sugars in fruits and berries, due to their easy digestibility, makes them especially useful for humans.

Of the sugars, fruits and berries most often and in the greatest amount contain glucose, fructose and sucrose. The total amount of sugars depends on many factors: crops, varieties, growing zones, agricultural techniques, soil and weather conditions, etc. The ratio of different sugars mainly depends on the type of fruits and berries. For example, apples and pears contain 6-12% fructose, 1-5% glucose and 0.5-5.5% sucrose; in apricots - respectively 0.1 - 3.2, 0.1 - 3.2 and 4.5 - 10%, and in cherries - 3.3 - 4.4, 3.8 - 5.3 and 0 - 0 ,eight %. The starch content in fruits and berries reaches 1%. Most of the starch is found in unripe apples. As the fruit ripens, it is hydrolyzed to form sugars and other substances.

The cell walls of fruits and berries are built mainly from cellulose (fiber), which is a polysaccharide. Its content in fruits and berries is about 1 - 2%. Fiber is almost not absorbed by the human body, but contributes to the normal functioning of the intestines.

Pectinsubstances are high molecular weight compounds of a carbohydrate nature. In fruits and berries, they are found in the form of pectin, protopectin and pectic acid. Their content in apples is 0.8 - 1.3%, in plums - 0.5 - 1.3, in raspberries - 0.1 - 0.7%. Protopectin is contained in the intercellular spaces and in the cell membranes, does not dissolve in water and determines the hardness of the fruit. As it matures, protopectin splits to form pectin and hemicellulose. This process takes place during the cooking of fruits, since at a temperature of 80 - 85 ° C protopectin is hydrolyzed. This property is used when blanching fruits to remove the skin from them.

Common organicacids, contained in fruits are apple, lemon and wine. Less often and in small quantities, fruits contain benzoic, salicylic, succinic acids, etc. The total acidity of fruits and berries ranges from 0.4 to 8%.

Certain types and varieties of fruits can simultaneously contain one, two or more acids. In stone and pome fruits, for example, malic and citric acids are found. Malic acid is especially abundant (up to 6%) in dogwood and barba rice. Citric acid is found mainly in lemons (up to 7%), cranberries and pomegranates. Tartaric acid predominates in grapes (0.3 - 1.7%). Benzoic acid is contained in a small amount (0.1%) in lingonberries and cranberries, salicylic acid - in raspberries and strawberries. Due to the fact that benzoic acid has antiseptic properties, cranberries and lingonberries are well preserved. There are few acids in cherries, pears, ab-ricos.

The taste sensation of acids in fruits is significantly influenced by Sahara, tanningsubstances. The sugar contained in the pulp of the fruit, as it were, masks the sensation of sour taste, and tannins, on the contrary, emphasize it. So, in the fruits of dogwood there are 9% sugar, but they seem very sour and tart, since they contain a relatively large amount of malic acid and tannins.

Acids play a significant role in canning or culinary processing of fruits. Thus, the amount of acids in the raw material affects the sterilization regime: the higher the acidity of the raw material, the faster the microorganisms die in it when the canned food is heated.

Carbohydrates are the most important part of fruits and vegetables. Carbohydrates account for about 90% of the total dry matter content. Fruits and vegetables contain sugars, starch, fiber (from 0.3 to 4%). When some vegetables (beans, radishes, beans, cucumbers) ripen and overripe, the amount of fiber increases, which gives them a woody taste.

Starch accumulates in fruits and vegetables during their growth (in green peas, potatoes, sweet corn). As it ripens, the mass fraction of starch in fruits decreases, and in vegetables it increases.

Vitamins. Fruits and vegetables contain almost all vitamins currently known. Vitamin C (ascorbic acid) is found in vegetable peppers, parsley; black currants, rose hips, etc. As fruits and vegetables ripen, the amount of vitamin C increases, and decreases during storage.

Carotene (provitamin A) - carotene are rich in carrots, tomatoes, leafy and green vegetables (lettuce, parsley, leeks), apricots, melons, peaches.

Vitamin B 1 (thiamine) is found in legumes and grains.

Vitamin B 2 (riboflavin) - in cereals, legumes and cabbage vegetables are relatively rich in them.

Folic acid - the richest in folic acid in strawberries. Folic acid is involved in blood formation.

Minerals. The amount of minerals in vegetables and fruits varies from 0.25 to 2%. Vegetables and fruits are a valuable source of minerals in the diet. Vegetables and fruits contain calcium, iron, magnesium, sulfur, phosphorus, potassium, zinc, as well as iodine, cobalt, arsenic, copper and other trace elements.

Cabbage, leafy vegetables, carrots are rich in calcium salts.

Iodine is found in the greatest quantities in persimmons, feijoa, oranges, bananas, green peas. Bananas, olives, blackberries, quince, cherries are rich in copper.

Dyes. The color of vegetables and fruits depends on chlorophyll, anthocyanins and carotenoids.

Chlorophyll stains vegetables and fruits green. Chlorophyll can only form in light. Spinach and nettle leaves are high in chlorophyll. Anthocyanins color vegetables and fruits from red to dark blue. They accumulate in vegetables and fruits as they ripen. Anthocyanins have antibiotic properties and protect vegetables and fruits from damage by microorganisms.

Carotenoids - pigments color vegetables and fruits in yellow and orange colors.

In the human body, carotenoids play an important role, where they are the starting substances from which vitamins of group A are formed.

Tannins have an astringent, tart and slightly bitter taste. High content of tannins in mountain ash, persimmon, dogwood, blackthorn (over 0.5%). Some tannins have antibiotic properties.

Pectin substances. In vegetables and fruits, they are found in the form of protopectin (water-insoluble substance) and pectin (water-soluble). Pectin has colloidal properties: when heated with sugar and acid, it forms a jelly (gel).

The greatest gelling ability is possessed by black currants, gooseberries, some varieties of apples, citrus fruits, plums.

The gelling properties of pectin are widely used in the confectionery industry to obtain marmalade, jelly, jam, and pastilles.

Essential oils (aromatic substances). They give fruits and vegetables their characteristic aroma. There are especially many aromatic substances in spicy vegetables (dill, parsley, tarragon), and from fruits - in lemons, oranges and other citrus fruits.

Essential oils are concentrated mainly in the skin of fruits and vegetables, there are few of them in the pulp. The maximum accumulation of essential oils takes place during the ripening of the fruit. When storing and processing fruits and vegetables, essential oils volatilize.

Phytoncides have bactericidal properties, have a detrimental effect on the microflora, releasing toxic volatile substances. The most active phytoncides of onions, garlic, horseradish. Phytoncides, protecting plants, increase their resistance against bacterial and fungal diseases.

Nitrogenous substances are found in vegetables and fruits in small quantities; most of them are in legumes (up to 6.5%), in cabbage (up to 4.8%).

In the processing of fruits and vegetables, nitrogenous substances can play a positive and negative role. In the production of wines, the presence of nitrogenous substances contributes to the development of yeast, better fermentation of juices. When cooking jam, if the foam is not removed, mold can develop in it.

Fats. Most fruits and vegetables contain very little fat (0.1-0.5%). There are a lot of them in the kernels of nuts (45-65%), in the pulp of olives (40-55%), as well as in the seeds of apricots (20-50%), in sea buckthorn berries (8%), in the seeds of fruits (23-60% ).

Fruits, berries and vegetables play an important role in human nutrition. Due to the content of carbohydrates, mainly sugars, organic acids, vitamins, tannins, etc., they are valuable food products. All fruits and vegetables, depending on their structure, are divided into several groups, which differ significantly in nutritional properties and storage stability.

Vegetables are subdivided into fruit (pome) and vegetative, fruits - into pome, stone and berries. Fruits and fruit vegetables are the succulent fruits of plants. Most of them are fruit pulp, which contains more or less cellular juice. Therefore, fruits, especially ripe ones, quickly lose their stability and are subject to spoilage under the influence of a wide variety of microorganisms.

Another group - vegetative vegetables: leafy, bulbous, cabbage - are plant shoots developed to varying degrees or its leaves (spinach, sorrel, onion, garlic, cabbage). Root crops and tubers - altered roots, overgrown and filled with reserve nutrients, and underground stems of vegetable plants (carrots, beets, potatoes).

Vegetables related to tubers and root crops are plant organs whose development cycle is not complete, since in the future they should give fruit-bearing plants (form seeds), therefore their natural resistance (natural immunity) to the action of microorganisms is much higher than that of fruits.

The chemical composition of fruits and vegetables is quite complex. So, vegetables and fruits contain a lot of water - from 65 to 95%, depending on the degree of ripeness and variety. Water makes up the bulk of the cell sap; dry substances - organic and mineral compounds - are dissolved in it.

The dry matter content in fruits and vegetables ranges from 10-20%. Exceptions are some grape varieties that can accumulate a lot of sugar and become rainy. The dry matter content in the juice of such grape varieties can reach 30% and more. Vegetables contain a relatively large amount of dry matter: carrots (on average 14%), green peas (up to 20%), corn (25% and more).

The most important component of the cell sap is sugar (mono- and disaccharides - glucose, fructose, sucrose). Fruits accumulate from 8 to 12% of sugar, only grapes, as indicated, can accumulate much more: on average 16-18%, and some varieties (for example, Muscat) up to 25-30%. Vegetables contain much less sugar - an average of 4%. Root crops (carrots, beets) have a higher sugar content.

A significant part of dry matter in fruits and vegetables is starch. By the time of full maturity, starch disappears in berries and fruits, and, on the contrary, accumulates in many vegetables. So, potatoes are rich in starch (12-15%), green peas and other legumes, as well as sweet corn. Both sugar and starch are energy materials in food that are consumed during respiration and play an extremely important role in human life. Other carbohydrates found in fruits and vegetables include cellulose, pentoses, pentosans, and pectin substances that make up the cell membranes.

Organic acids are also a very important component of fruit juice, the content of which varies greatly depending on the variety and degree of ripeness of the fruit. In wild apples, the malic acid content reaches 2%, while in some sweet (cultivated) varieties, its content does not exceed 0.05%. The most common are malic and citric acids. Tartaric acid is found in large quantities only in grapes, and in other fruits and berries it is usually absent or contained in insignificant quantities.

Many fruits and vegetables accumulate aromas (essential oils) that determine their aroma and, apparently, affect the taste. Spicy vegetables are very rich in aromatic substances - parsley, celery, dill, as well as onion vegetables - onions, garlic and, finally, citrus fruits - lemons, oranges, etc. The content of aromatic substances in vegetables ranges from 0.05 to 0.5%: So, for example, onions contain 0.05% of them, garlic - about 0.01%, in the peel of tangerines, the essential oil contains from 1.8 to 2.5%.

If we consider that fruits and vegetables contain various enzymes and vitamins that contribute to the normal course of life and digestive processes, then their nutritional value will increase even more. If animal products are suppliers of proteins, then fruits and vegetables are suppliers of vitamins - extremely important substances vital for humans. The lack of vitamins in the food of animals and humans causes metabolic disorders in the body, and their complete absence leads to various serious diseases (vitamin deficiencies). Many vitamins combine with proteins to form enzymes that aid digestion. Onions, for example, contain a proteolytic enzyme that can break down proteins into peptones. Cabbage and some root vegetables contain an enzyme similar to trypsin. Almost all vegetables contain amylase, saccharifying starch, rich in oxidase, catalase. A sufficient amount of oxidase and catalase is also found in fruits.

Dyes that give fruits and vegetables a particular color are also of great importance. There is evidence that brightly colored fruits are more resistant to the action of microorganisms.

The juices of various higher plants also contain some volatile fractions - phytoncides, which have a bactericidal effect. In some plants, the presence of phytoncides is associated with the presence of a strongly pronounced smell and taste (onion, garlic), while in other plants this is not observed (tomatoes, carrots).

In addition to organic compounds, plant tissues also contain minerals. Fruits contain mineral, or ash, elements from 0.2 to 1.8%. Mineral substances are of great physiological importance and are essential constituents of food. Thus, iron is a part of blood hemoglobin, calcium is a part of bones, phosphorus is necessary for normal functioning of nerve tissues, etc. Due to their chemical composition, fruits and vegetables are an excellent nutrient substrate for many microorganisms.

Given the wide variety of vegetables and fruits, let's get acquainted with their classification.

Vegetables are divided into:

tubers (potatoes, sweet potatoes),

root vegetables (radish, radish, rutabaga, carrots, beets, celery),

cabbage (white cabbage, red cabbage, Savoy, Brussels, cauliflower, kohlrabi),

onions (onions, leeks, wild garlic, garlic),

salad spinach (lettuce, spinach, sorrel),

pumpkin (pumpkin, zucchini, cucumber, squash, melon),

tomato (tomato, eggplant, pepper),

dessert (asparagus, rhubarb, artichoke),

spicy (basil, dill, parsley, tarragon, horseradish),

legumes (beans, peas, beans, lentils, soybeans).

Fruits are divided into stone fruits (apricots, cherries, dogwood, peaches, plums, cherries), pome fruits (quince, pears, mountain ash, apples), subtropical and tropical crops (pineapples, bananas, pomegranates, etc.), real berries (grapes, gooseberries , currants, barberries, lingonberries, blueberries, blueberries, cranberries, raspberries, blackberries, sea buckthorn) and false (strawberries).

Vegetables, fruits, berries and other edible plants have a high ability to stimulate appetite, stimulate the secretory function of the digestive glands, improve bile formation and bile division.

Plants rich in essential oils - tomatoes, cucumbers, radishes, onions, garlic, horseradish - are distinguished by their pronounced sokogonny effect. Of the pickled and pickled vegetables, cabbage has the most powerful appetite-stimulating properties, followed by cucumbers, beets, and least of all carrots.

Vegetables increase the absorption of proteins, fats, and minerals. Added to protein foods and cereals, they enhance the secretory effect of the latter, and when used together with fat, they remove its inhibitory effect on gastric secretion. It is important to note that undiluted juices of vegetables and fruits reduce the secretory function of the stomach, while diluted juices increase it.

Berries and fruits also have different effects on the secretory function of the stomach. Some (most) increase it (grapes, prunes, apples, strawberries), others (especially sweet varieties) - lower it (cherries, raspberries, apricots, etc.).

The sokogonic effect of vegetables, fruits and berries is explained by the presence of mineral salts, vitamins, organic acids, essential oils, and fiber in them. Vegetables activate the bile-forming function of the liver: some are weaker (beetroot, cabbage, swede juices), others are stronger (radish, turnip, carrot juice). When vegetables are combined with proteins or carbohydrates, less bile enters the duodenum than with purely protein or carbohydrate foods. And the combination of vegetables with oil increases the formation of bile and its entry into the duodenum, vegetables are stimulants of pancreatic secretion: undiluted vegetable juices inhibit secretion, and diluted ones stimulate it.

Water- an important factor that ensures the course of various processes in the body. It is an integral part of cells, tissues and body fluids and ensures the supply of nutrients and energy to tissues, excretion of metabolic products, heat exchange, etc. Without food, a person can live for more than a month, without water - only a few days.

Water is a part of plants in free and bound form. Organic acids, minerals, sugar are dissolved in freely circulating water (juice). Bound water entering plant tissues is released from them when their structure changes and is absorbed more slowly in the human body. Plant water is quickly excreted from the body, as plants are rich in potassium, which enhances urination. Waste products, various toxic substances are excreted in the urine.

Carbohydrates plants are divided into monosaccharides (glucose and fructose), disaccharides (sucrose and maltose) and polysaccharides (starch, cellulose, hemicellulose, pectin substances). Monosaccharides and disaccharides

dissolve in water and give the plants a sweet taste.

Glucose is part of sucrose, maltose, starch, cellulose. It is easily absorbed in the gastrointestinal tract, enters the bloodstream, and is absorbed by cells of various tissues and organs. When it is oxidized, ATP is formed - adenosine triphosphoric acid, which is used by the body for various physiological functions as a source of energy. With an excess intake of glucose into the body, it turns into fats. The richest in glucose are cherries, cherries, grapes, followed by raspberries, tangerines, plums, strawberries, carrots, pumpkin, watermelon, peaches, and apples. Fructose is also easily absorbed by the body and is converted to fats to a greater extent than glucose. In the intestine, it is absorbed more slowly than glucose, and does not need insulin for its assimilation, therefore it is better tolerated by patients with diabetes mellitus. Fructose is rich in grapes, apples, pears, cherries, cherries, then watermelon, black currants, raspberries, strawberries. The main source of sucrose is sugar. In the intestine, sucrose is broken down into glucose and fructose. Sucrose is found in beets, peaches, melons, plums, tangerines, carrots, pears, watermelons, apples, and strawberries.

Maltose is an intermediate product of the breakdown of starch; it is broken down into glucose in the intestine. Maltose is found in honey, beer, baked goods and confectionery.

Starch is the main source of carbohydrates. They are richest in flour, cereals, pasta and, to a lesser extent, potatoes.

Cellulose (fiber), hemicellulose and pectin substances are part of the cell walls.

Pectin substances are divided into pectin and protopectin. Pectin has a gelling property that is used in the manufacture of marmalade, marshmallows, pastilles, jams. Protopectin is an insoluble complexes of pectin with cellulose, hemicellulose, metal ions. The softening of fruits and vegetables during ripening and after heat treatment is due to the release of free pectin.

Pectin substances adsorb metabolic products, various microbes, salts of heavy metals that enter the intestines, and therefore foods rich in them are recommended in the diet of workers in contact with lead, mercury, arsenic and other heavy metals.

The cell membranes are not absorbed in the gastrointestinal tract and are called ballast substances. They participate in the formation of feces, improve the motor and secretory activity of the intestines, normalize the motor function of the biliary tract and stimulate the processes of bile secretion, increase the excretion of cholesterol through the intestines and reduce its content in the body. Fiber-rich foods are recommended to be included in the diet of the elderly, with constipation, atherosclerosis, but limited in case of gastric ulcer and duodenal ulcer, enterocolitis.

There are many cell membranes in rye flour, beans, green peas, millet, dried fruits, buckwheat, carrots, parsley, and beets. In apples, oatmeal, white cabbage, onions, pumpkin, lettuce, potatoes, they are somewhat less.

Dried apples, raspberries, strawberries, nuts, dried apricots, apricots, mountain ash, dates are the richest in fiber; less - figs, mushrooms, oatmeal, buckwheat, pearl barley, carrots, beets, white cabbage.

Most of the pectin substances are found in beets, black currants, plums, then in apricots, strawberries, pears, apples, cranberries, gooseberries, peaches, carrots, white cabbage, raspberries, cherries, eggplants, oranges, pumpkin.

Organic acids. Plants most often contain malic and citric acids, less often oxalic, tartaric, benzoic, etc. There is a lot of malic acid in apples, citric acid in citrus fruits, tartaric acid in grapes, oxalic acid in sorrel, rhubarb, figs , benzoic - in lingonberries, cranberries.

Organic acids enhance the secretory function of the pancreas, improve intestinal motor activity, and promote urine alkalinization.

Oxalic acid, combining with calcium in the intestine, disrupts the processes of its absorption. Therefore, foods containing large amounts of it are not recommended. Oxalic acid is removed from the body by apples, pears, quince, dogwood, decoctions of black currant leaves, grapes. Benzoic acid has bactericidal properties.

Tannins(tannin) are found in many plants. They give plants an astringent, tart taste. There are especially many of them in quince, blueberry, bird cherry, dogwood, mountain ash.

Tannins bind the proteins of tissue cells and have a local astringent effect, slow down the motor activity of the intestines, help normalize stool in case of diarrhea, and have a local anti-inflammatory effect. The astringent effect of tannins decreases sharply after eating, as tannin combines with food protein. In frozen berries, the amount of tannins is also reduced.

The richest in essential oils are citrus fruits, onions, garlic, radishes, radishes, dill, parsley, celery. They enhance the secretion of digestive juices, in small amounts they have a diuretic effect, in large amounts they irritate the urinary tract, but locally they have an irritating anti-inflammatory and disinfectant effect. Plants rich in essential oils are excluded for gastric ulcer and duodenal ulcer, enteritis, colitis, hepatitis, cholecystitis, nephritis.

Protein Soybeans, beans, peas, and lentils are the richest in protein from plant foods. The protein of these plants contains essential amino acids. Other plants cannot serve as a source of protein.

Vegetable protein is less valuable than animal protein and is less well absorbed in the gastrointestinal tract. It serves as a substitute for animal protein when the latter needs to be limited, such as in kidney disease.

Phytosterols belong to the "unsaponifiable part" of oils and are divided into sitosterol, sigmasterol, ergosterol, etc. They are involved in cholesterol metabolism. Ergosterol is a provitamin D used to treat rickets. It is found in ergot, brewer's and baker's yeast. Sitosterol and sigmasterol are found in grains, beans, soybeans, dandelion, coltsfoot.

Phytoncides are plant substances that have a bactericidal effect and promote wound healing. They are found in more than 85% of higher plants. The richest in them are oranges, tangerines, lemons, onions, garlic, radish, horseradish, red peppers, tomatoes, carrots, sugar beets, Antonov apples, dogwood, cranberries, bird cherry, lingonberry, viburnum. Some phytoncides retain their stability during long-term storage of plants, high and low temperatures, exposure to gastric juice, saliva. The consumption of vegetables, fruits and other plants rich in phytonutics helps to detoxify the oral cavity and gastrointestinal tract from microbes. The bactericidal property of plants is widely used for catarrh of the upper respiratory tract, inflammatory diseases of the oral cavity, for the prevention of influenza and the treatment of many other diseases. For example, garlic preparations are recommended for dysentery, orange and tomato juices - for infected wounds and chronic ulcers, lemon juice - for eye inflammation, etc. Phytoncides purify the air.

Vitamins- These are low molecular weight organic compounds with high biological activity, which are not synthesized in the body.

Plants are the main source of vitamin C, carotene, vitamin P. Some plants contain folic acid, inositol, vitamin K. There are few vitamins B1, B2, B6, PP and others in plants.

Vitamin C(ascorbic acid) stimulates oxidative processes in the body, activates various enzymes, participates in the normalization of carbohydrate metabolism, improves the absorption of glucose in the intestine and the deposition of carbohydrates in the liver and muscles, increases the antitoxic function of the liver, inhibits the development of atherosclerosis, increases the excretion of cholesterol through the intestines and lowers it level in the blood, normalizes the functional state of the gonads, adrenal glands, participates in hematopoiesis. The body's daily requirement for vitamin C is about 100 mg.

The main sources of vitamin C are vegetables, fruits and other plants. Most of it is in the leaves, less in fruits and stems. The peel of the fruit contains more vitamin C than the pulp. Vitamin C reserves in the body are very limited, so plant foods should be consumed throughout the year.

Vitamin C is rich in rose hips, green walnuts, black currants, red bell peppers, horseradish, parsley, dill, Brussels sprouts, cauliflower, green onions, sorrel, strawberries, spinach, gooseberries, dogwood, red tomatoes, wild garlic, oranges, lemons , raspberries, apples, cabbage, salad.

Vitamin P reduces capillary permeability, participates in the redox processes of the body, improves absorption and promotes the fixation of vitamin C in organs and tissues. Vitamin P exerts its effect only in the presence of vitamin C. The human requirement for vitamin P is 25-50 mg. It is found in the same foods as vitamin C.

Carotene in the animal body it is a source of vitamin A. Carotene is absorbed in the body in the presence of fat, bile and the enzyme lipase. In the liver, carotene, with the participation of the carotenase enzyme, is converted into vitamin A.

Carotene is found in green parts of plants, in vegetables and fruits of red, orange and yellow colors. Its main sources are red peppers, carrots, sorrel, parsley, rose hips, green onions, sea buckthorn, red tomatoes, and apricots.

With a deficiency of vitamin A, the body develops dry skin and mucous membranes, night blindness, the acuity of perception of color, especially blue and yellow, slows down the growth of bones and the development of teeth, decreases the body's resistance to infections, etc. The daily requirement of the body for vitamin A is 1.5 mg (4.5 mg carotene).

Vitamin K enters the body with animal and plant food, partially synthesized in the large intestine.

With vitamin K deficiency, symptoms of increased bleeding occur, the rate of blood coagulation slows down, and capillary permeability increases. The daily human need for vitamin K is 15 mg. Its main source is the green part of plants. Vitamin K is richest in spinach, white cabbage and cauliflower, nettle.

Folic acid synthesized in the intestine in an amount sufficient for the body. She participates in hematopoiesis, stimulates protein synthesis. The body's need for this vitamin is 0.2-0.3 mg per day. The richest in folic acid are spinach, watermelons, then melons, green peas, carrots, potatoes, cauliflower, and asparagus.

Inositol found in all plants and animal products. It is synthesized by intestinal bacteria and participates in the metabolism of proteins, carbohydrates, is part of various enzymes, and normalizes the motor activity of the stomach and intestines. The daily requirement for inositol is 1.5 g per day. Melon, oranges, raisins, peas, cabbage are the richest of plant products in inositol.

Vitamin B1(thiamine) normalizes the activity of the nervous system, participates in the metabolism of carbohydrates, proteins, fats, regulates the activity of the cardiovascular system, digestive organs. When it is insufficient, the products of incomplete metabolism of carbohydrates accumulate in the tissues, and the body's resistance to infections decreases.

Human need for vitamin B1 is 1, 5-2, 3 mg per day. Of the plant products, soybeans, peas, buckwheat, and bran are the richest in them.

Vitamin B2(riboflavin) normalizes the metabolism of proteins, fats, carbohydrates, regulates the functions of the central nervous system, liver, stimulates hematopoiesis, normalizes vision. The daily requirement for vitamin B2 is 2.0-3.0 mg per day. Its main sources are animal products. Soy, lentils, beans, green peas, spinach, asparagus, and Brussels sprouts are rich in this vitamin from plant foods.

Vitamin B6(pyridoxine) is involved in the metabolism of proteins, fats, and hematopoiesis. With its insufficiency, the activity of the central nervous system is disrupted, skin lesions, chronic diseases of the gastrointestinal tract occur. Pyridoxine is synthesized in the intestines. The body's daily need for it is 1.5-3.0 mg. Of the plant foods, the richest in vitamin B6 are beans, soybeans, buckwheat, wheat flour, wallpaper, potatoes.

Vitamin PP(nicotinic acid) normalizes the metabolism of carbohydrates, cholesterol, the state of the central nervous system, blood pressure, increases the secretory function of the glands of the stomach and pancreas. The daily requirement for vitamin PP is 15-25 mg. Legumes, barley, white cabbage, cauliflower, apricots, bananas, melons, eggplants are rich in vitamin PP from plant products.

Minerals are part of vegetables, fruits and other plants. Their composition in the same plants varies depending on the type of soil used fertilizers and the type of product. Plant foods are rich in calcium, phosphorus, magnesium, iron salts, are the main source of potassium salts, contain manganese, copper, zinc, cobalt and other trace elements, and are poor in sodium salts.

Mineral substances are part of cells, tissues, interstitial fluid, bone tissue, blood, enzymes, hormones, provide osmotic pressure, acid-base balance, solubility of protein substances and other biochemical and physiological processes of the body.

Potassium easily absorbed in the small intestine. Potassium salts increase the excretion of sodium and cause a shift in the urine reaction towards the alkaline side. Potassium ions support the tone and automatism of the heart muscle, the function of the adrenal glands. A diet rich in potassium is recommended for fluid retention in the body, hypertension, heart disease with arrhythmias, and in the treatment of prednisone and other glucocorticoid hormones.

The body's daily need for potassium is 2--3 g. Potassium salts are rich in all plant products, but especially dry fruits, berries (raisins, dried apricots, dates, prunes, apricots), then potatoes, parsley, spinach, cabbage, black currants , beans, peas, celery roots, radishes, turnips, dogwood, peaches, figs, apricots, bananas.

Calcium increases the excitability of nervous tissue, activates and normalizes the processes of excitation and inhibition in the cerebral cortex, enhances blood coagulation processes, regulates the permeability of capillary membranes, participates in the formation of teeth and bones.

Calcium enters the body with food. Calcium absorption is improved in the presence of phosphorus and magnesium ions and is impaired by fatty acids and oxalic acid. The human need for calcium is 0.8-1.5 g per day. Its main source among plant products is parsley (especially greens), apricots, dried apricots, horseradish, raisins, prunes, green onions, lettuce, cabbage, dates, dogwood, peas, parsnips.

Phosphorus is mainly found in the bone substance in the form of phosphorus-calcium compounds. Ionized phosphorus and organic phosphorus compounds are part of cells and intercellular fluids of the body. Its compounds are involved in the absorption of food in the intestines and in all types of metabolism, maintain acid-base balance. Phosphorus compounds are excreted in the urine and feces. The body's daily requirement for phosphorus is 1.5 g. The richest in them are carrots, beets, lettuce, cauliflower, apricots, and peaches.

Magnesium enhances the processes of inhibition in the cerebral cortex, has a vasodilating effect, participates in the metabolism of proteins and carbohydrates. With an excess of magnesium, the excretion of calcium from the body increases, which leads to a violation of the structure of bones. The body's daily requirement for magnesium is 0.3-0.5 g.

Magnesium is richest in bran, buckwheat and oatmeal, legumes, walnuts, almonds, as well as apricots, dried apricots, dates, parsley, sorrel, spinach, raisins, bananas.

Iron participates in many biological processes of the body, is part of hemoglobin. With its deficiency, anemia develops.

The human need for iron is 15 mg per day. The richest in them are apricots, dried apricots, apples, pears, peaches, parsley, somewhat less of it in dogwood, dates, peaches, quince, raisins, olives, prunes, horseradish, spinach. The iron of vegetables and fruits is absorbed better than the iron of inorganic drugs, due to the presence of ascorbic acid in plant products.

Manganese actively participates in the metabolism, in the redox processes of the body, enhances protein metabolism, prevents the development of fatty liver infiltration, is a part of enzymatic systems, affects the processes of hematopoiesis, increases the hypoglycemic effect of insulin. Manganese is closely related to the metabolism of vitamins C, B1, B6, E.

The body's daily requirement for manganese is 5 mg. They are the richest in legumes, leafy vegetables, especially lettuce, as well as apples and plums.

Copper participates in the processes of tissue respiration, the synthesis of hemoglobin, promotes the growth of the body, enhances the hypoglycemic effect of insulin, enhances the processes of glucose oxidation.

The body's daily requirement for copper is 2 mg. There is a lot of copper in legumes, leafy vegetables, fruits and berries, less in eggplants, zucchini, parsley, beets, apples, potatoes, pears, black currants, watermelons, horseradish, and pepper.

Zinc is part of insulin and lengthens its hypoglycemic effect, enhances the action of sex hormones, some pituitary hormones, participates in hemoglobin formation, affects the redox processes of the body. The human need for zinc is 10-15 mg per day.

Of plant foods, beans, peas, wheat, corn, oat flour are rich in zinc; in smaller quantities, it is found in white cabbage, potatoes, carrots, cucumbers, and beets.

Cobalt is a part of vitamin B. Together with iron and copper, it participates in the processes of maturation of erythrocytes. The body's daily requirement for cobalt is 0.2 mg.

Peas, lentils, beans, white cabbage, carrots, beets, tomatoes, grapes, black currants, lemons, gooseberries, cranberries, strawberries, strawberries, cherries, onions, spinach, lettuce, radishes, cucumbers are rich in cobalt.

Introduction

In this work, I examined the chemical composition and nutritional value of fresh fruits and vegetables, their classification and characteristics of individual species. The processes taking place during the storage of fresh fruits and vegetables. Factors affecting the safety of food.

I studied the composition of many fruits and vegetables, as well as the presence in them of vitamins vital for the human body such as:

· Vitamin C

· Vitamin A

Vitamin B

Vitamin B1

Vitamin B2

· Vitamin D

Vitamin E.

She spoke about the important role of organic acids, minerals, carbohydrates, proteins, fats.

Chemical composition and nutritional value of fresh fruits and vegetables

All fruits and vegetables contain a large amount of water (about 75% - 85%). The exception is walnut, which contain on average only 10% - 15% of water. The moisture in fruits and vegetables is both free and bound.

The bound moisture is removed to a lesser extent and is partially retained during the drying treatment.

Free moisture is a good breeding ground for putrefactive bacteria and microbes, so fruits and vegetables containing a lot of free moisture cannot be stored for a long time and need to be processed. Fruits and vegetables are the main suppliers of carbohydrates. These are mainly monosaccharides (glucose, sucrose), disaccharides (sucrose), polysaccharides (fiber, pectin substances).

Pectin substances and fiber are classified as ballast substances by their properties.

In addition to carbohydrates, the chemical composition of fruits and vegetables includes polyhydric alcohols (sorbitol and lures), which have a sweet taste. They are found in large quantities of rowan, plum, and to a lesser extent in apples.

Sucking fruits and vegetables also includes nitrogenous substances - proteins, amino acids, enzymes, nucleic acids, nitrogen-containing glycosides. The largest amount of proteins is found in olives (7%), legumes (5%), potatoes (2-3%), and nuts. Most fruits and vegetables contain less than 1% protein.

Fruits and vegetables are the main suppliers of enzymes.

Classification of fresh fruits and vegetables. Characteristics of individual species

When classifying fruits, two main characteristics are used - the characteristic of the structure and the characteristic of origin.

By structure, there are:

· Pome fruits (apples, mountain ash, pear, quince); they all have a skin; inside the fruit there is a five-chambered chamber containing seeds;

· Stone fruits - their structure is characterized by the presence of a skin, fruit pulp and a drupe containing a seed; stone fruits include plums, cherries, apricots, peaches, etc.;

· Berries - this group is divided into 3 groups: real berries, false and complex. For real berries, currants, grapes, gooseberries, cranberries, blackberries, lingonberries, blueberries. In real berries, the seeds are immersed directly in the pulp. Strawberries and strawberries are considered false berries. Their seeds are located on the skin. Complex berries are composed of many small berries that have grown together on one fruit. This group includes raspberries, blackberries, drupes and cloudberries;

· Walnut, which are subdivided into real nuts (hazelnuts) and drupes (walnuts, almonds). All nut-bearing fruits consist of a kernel enclosed in a woody shell. On the surface of drupe nuts there is a green flesh, which gradually darkens and dies as it ripens.

By origin, the fruits are subdivided into subtropical (among them a group of citrus fruits is distinguished) and tropical. Many subtropical and tropical fruits require high storage temperatures, and colds and freezes in cold temperatures. So, for example, bananas can be stored at temperatures not lower than +11 degrees. Pineapples - not lower than +8 degrees.

Fresh vegetables are divided into 2 groups: vegetative and generative, or fruits and vegetables. Vegetables that eat leaves, stems, roots and their modifications are vegetative. And vegetables in which fruits are used for food are called generative.

Among vegetative vegetables, depending on the part used for food, they are distinguished:

Tuberous (potatoes, bata, Jerusalem artichoke);

· Root vegetables (beets, radishes, carrots, radishes, turnips, parsley, rutabagas, celery, parsnips);

Leafy vegetables (white cabbage, kohlrabi, cauliflower, Brussels sprouts, Savoy);

Onion vegetables (onions, onions - prey, batun, garlic);

Salad spinach (spinach, lettuce, sorrel);

Spicy vegetables (tarragon, basil, cilantro, dill, celery);

· Dessert (artichoke, asparagus, rhubarb).

Generative vegetables are classified into the following subgroups:

· Tomato (tomatoes, eggplants, peppers);

Pumpkin (cucumbers, pumpkin, zucchini, melons, watermelons, squash);

Legumes (peas, beans, beans);

Cereal vegetables (sweet corn).