Chemical composition of fruits and vegetables. Chemical composition and nutritional value of fresh fruits and vegetables

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Federal Agency for Education

SEI HPE "Samara State Economic University"

Department of Service

Course work

by discipline

commodity scienceand examination of food products

on the topic

2nd year students

Daytime education

Specialty "Service"

Yakovishenoy Evgenia Valerievna

Samara 2008

Introduction

I.I Chemical composition of vegetables and fruits

I.II Group characteristics of vegetables and fruits

II.I Benefits of vegetables and fruits

II.II Damage to vegetables and fruits

III.I Harm and benefits of watermelons

Conclusion

Applications

Used sources

Introduction

Relevance of the chosen topic

In the 20th century, significant changes took place in human nutrition. The diet has become dominated by refined foods, the consumption of animal products has risen sharply, and the share of vegetables and fruits has declined. The accompanying hypodynamia completed the picture: from overeating and inactivity, a person began to get sick heavily and often.

Vegetables are the most important suppliers of vitamins C, P, some B vitamins, provitamin A - carotene, mineral salts (especially potassium salts), a number of trace elements, carbohydrates - sugars, phytoncides that help destroy pathogenic microbes, and, finally, ballast substances, necessary for normal bowel function.

A remarkable property of vegetables is their ability to significantly increase the secretion of digestive juices and enhance their enzymatic activity.

Meat and fish meals are better absorbed by the body if they are consumed with vegetables. Vegetable dishes enhance the secretion of the digestive glands and thereby prepare the digestive tract for the digestion of protein and fatty foods. Therefore, it is useful to start lunch with vegetable snacks: vinaigrettes and salads, and then move on to soups, borscht, etc.

Vegetables are not only suppliers of important nutrients and vitamins, they are also dynamic regulators of digestion, increase the ability to assimilate nutrients, and therefore the nutritional value of most products. Vegetables are very valuable and necessary for the body every day at all times of the year.

In most regions of the Russian Federation, the consumption of vegetables and fruits fluctuates sharply and depends on the time of year. As a rule, they are sufficient in the second half of summer and autumn, and somewhat lacking in late winter and early spring. In addition, the nutritional value of vegetables and fruits from the previous year's harvest in the spring months is significantly reduced. The lack of nutrition of vegetables in winter and early spring is one of the reasons for the decrease in the overall resistance of the body to colds and infectious diseases. daily rate consumption of vegetables, except for potatoes, should be for an adult in all seasons from 300 to 400 grams. In no case should this amount be reduced during the winter and spring months.

The cultivation of early vegetables, the development of suburban greenhouse farming, and the improvement of storage and canning methods ensure their consumption all year round. The best way to preserve vegetables and fruits, the most perfect for preserving their nutritional value and taste properties, is freezing. Quick-frozen fruits and tomatoes are very useful. It is gratifying that recently more and more of them appear on the shelves of our stores. Unfortunately, we still do not make enough use of the huge variety of vegetables and fruits that nature gives us. Suffice it to say that of the many varieties of cabbage, white cabbage is the most common in our country. But it is not at all the most useful: cauliflower, Brussels sprouts, kohlrabi and other types of cabbage are much richer in vitamin C. In the spring, a variety of vegetables are undeservedly little used in our diet: green onions, lettuce, spinach, rhubarb, etc. Green onions are especially useful at this time of the year, 100 grams of which contain about 30 milligrams of vitamin C and 2 milligrams of carotene - provitamin A , which greatly helps to meet the daily requirement of an adult for vitamin C.

ChapterI

I. IThe chemical composition of vegetables and fruits

Vegetables are divided into:

tubers (potato, sweet potato),

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

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

onion (onion, leek, wild garlic, garlic),

lettuce-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, dogwoods, peaches, plums, sweet 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 excite appetite, stimulate the secretory function of the digestive glands, improve bile formation and bile division.

Plants rich in essential oils, such as tomatoes, cucumbers, radishes, onions, garlic, and horseradish, are distinguished by a pronounced juice effect. Of pickled and pickled vegetables, cabbage has the strongest appetite-stimulating property, followed by cucumbers, beets, and, least of all, carrots.

Berries and fruits also have a different effect 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 juice action 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, rutabaga juices), others are stronger (radish, turnip, carrot juice). When vegetables are combined with proteins or carbohydrates, less bile enters the duodenum than with pure 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 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, the removal of metabolic products, heat exchange, etc. A person can live without food for more than a month, without water - only a few days.

Plants contain water in both free and bound form. Organic acids, minerals, sugar are dissolved in freely circulating water (juice). Bound water, which enters the tissues of plants, 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 increases urination. Metabolic products, various toxic substances are excreted with urine.l

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 cause the sweet taste of plants.

Glucose is part of sucrose, maltose, starch, cellulose. It is easily absorbed in the gastrointestinal tract, enters the bloodstream, and is absorbed by the cells of various tissues and organs. When it is oxidized, ATP is formed - adenosine triphosphoric acid, which is used by the body to carry out various physiological functions as an energy source. When excess glucose enters the body, it turns into fat. The richest in glucose are cherries, cherries, grapes, then raspberries, tangerines, plums, strawberries, carrots, pumpkins, watermelons, peaches, apples. Fructose is also easily absorbed by the body and, to a greater extent than glucose, passes into fats. In the intestines, it is absorbed more slowly than glucose, and does not need insulin for its absorption, therefore it is better tolerated by patients with diabetes mellitus. Fructose is rich in grapes, apples, pears, cherries, sweet 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, strawberries.

Maltose is an intermediate product of the breakdown of starch and is broken down into glucose in the intestines. 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 membranes.

Pectin substances are divided into pectin and protopectin. Pectin has a gelling property, which is used in the manufacture of marmalade, marshmallows, marshmallows, 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.

Pectins 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.

Cell membranes are not absorbed in the gastrointestinal tract and are called ballast substances. They are involved in the formation of feces, improve the motor and secretory activity of the intestine, 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. Foods rich in fiber are recommended to be included in the diet of the elderly, with constipation, atherosclerosis, but limited with peptic ulcer of the stomach and duodenum, enterocolitis.

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

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

Pectin substances are most found in table beets, black currants, plums, then in apricots, strawberries, pears, apples, cranberries, gooseberries, peaches, carrots, white cabbage, raspberries, cherries, eggplants, oranges, pumpkins.

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 motility, and promote alkalinization of urine.

Oxalic acid, combining in the intestines with calcium, disrupts the processes of its absorption. Therefore, products containing it in large quantities 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) found in many plants. They give plants an astringent, tart taste. Especially a lot of them in quince, blueberries, bird cherry, dogwood, mountain ash.

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

Essential oils are richest in citrus fruits, onions, garlic, radishes, radishes, dill, parsley, celery. They increase the secretion of digestive juices, in small quantities they have a diuretic effect, in large quantities they irritate the urinary tract, locally they have an irritating anti-inflammatory and disinfectant effect. Plants rich in essential oils are excluded from peptic ulcer of the stomach and duodenum, enteritis, colitis, hepatitis, cholecystitis, nephritis.

Squirrels From herbal products soybeans, beans, peas, lentils are the richest in protein. 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 digestible 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 and is used to treat rickets. It is found in ergot, brewer's and baker's yeast. Sitosterol and sigmasterol are found in grains of cereals, beans, soybeans, dandelion, coltsfoot.

Phytoncides are substances of plant origin 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, radishes, horseradish, red peppers, tomatoes, carrots, sugar beets, Antonov apples, dogwood, cranberries, bird cherry, lingonberries, viburnum. Some phytoncides retain their stability when long-term storage plants, high and low temperatures, exposure to gastric juice, saliva. The use of vegetables, fruits and other plants rich in phytochemicals helps to neutralize the oral cavity and gastrointestinal tract from microbes. The bactericidal property of plants is widely used in catarrhs of the upper respiratory tract, inflammatory diseases oral cavity, for the prevention of influenza and the treatment of many other diseases. So, for example, garlic preparations are recommended for dysentery, orange and tomato juice- for infected wounds and chronic ulcers, lemon juice- with inflammation of the eyes, etc. Phytoncides purify the air.

vitamins- These are low molecular weight organic compounds with high biological activity, 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 intestines 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 sex glands, adrenal glands, participates in hematopoiesis. The daily requirement of the body for vitamin C is about 100 mg.

The main source of vitamin C are vegetables, fruits and other plants. Most of it is in the leaves, less in the fruits and stems. There is more vitamin C in the peel of the fruit than in 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 walnut, black currant, red Bell pepper, horseradish, parsley, dill, Brussels sprouts, cauliflower, green onions, sorrel, strawberries, spinach, gooseberries, dogwood, red tomatoes, wild garlic, oranges, lemons, raspberries, apples, white cabbage, lettuce.

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 shows its effect only in the presence of vitamin C. A person's need for vitamin P is 25-50 mg. It is found in the same foods as vitamin C.

Carotene in the animal body is a source of vitamin A. Carotene is absorbed in the body in the presence of fat, bile and lipase enzyme. In the liver, carotene is converted to vitamin A by the enzyme carotenease.

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

With vitamin A deficiency, dry skin and mucous membranes, night blindness develop in the body, the sharpness of color perception decreases, especially blue and yellow, bone growth and tooth development slow down, the body's resistance to infections decreases, etc. The body's daily need for vitamin A is 1.5 mg (4.5 mg carotene).

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

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

Folic acid synthesized in the intestine in sufficient quantities for the body. It is involved in hematopoiesis, stimulates protein synthesis. The body's need for this vitamin is 0.2 - 0.3 mg per day. Spinach, watermelons, then melons are the richest in folic acid, green pea, carrots, potatoes, cauliflower, asparagus.

Inositol found in all plants and animal products. It is synthesized by intestinal bacteria and is involved 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. From plant products, melon, oranges, raisins, peas, and cabbage are the richest in inositol.

Vitamin B1(thiamine) normalizes activity nervous system, participates in the metabolism of carbohydrates, proteins, fats, regulates the activity of cardio-vascular system, digestive organs. With its insufficiency, 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 plant foods, they are the richest in soy, peas, buckwheat grain, bran.

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

Vitamin B6(pyridoxine) is involved in the metabolism of proteins, fats, 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 intestine. The daily requirement of the body in it is 1.5-3.0 mg. Of the plant products with vitamin B6, beans, soybeans, buckwheat, wheat flour, wallpaper, and potatoes are the richest.

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. From vegetable products vitamin PP is rich in legumes, barley, white cabbage, cauliflower, apricots, bananas, melons, eggplants.

Minerals found in vegetables, fruits and other plants. Their composition in the same plants varies depending on the type of soil, the fertilizers used and the variety of the product. Vegetable products are rich in salts of calcium, phosphorus, magnesium, iron, are the main source of potassium salts, contain manganese, copper, zinc, cobalt and other trace elements, 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 to 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 arrhythmia and in the treatment of prednisolone and other glucocorticoid hormones.

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

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

Calcium enters the body with food. Calcium absorption improves in the presence of phosphorus and magnesium ions and worsens under the influence of fatty acids and oxalic acid. A person's need for calcium is 0.8-1.5 g per day. Its main source among plant products are parsley (especially greens), apricots, dried apricots, horseradish, raisins, prunes, green onions, lettuce, cabbage, dates, dogwood, peas, parsnips.

Phosphorus mainly found in the bone substance in the form of phosphorus-calcium compounds. Ionized phosphorus and organic phosphorus compounds are part of the 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 from the body with urine and feces. The body's daily need for phosphorus is 1.5 g. Carrots, beets, lettuce, cauliflower, apricots, and peaches are the richest in them.

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

Magnesium is the 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 requirement for iron is 15 mg per day. They are richest in apricots, dried apricots, apples, pears, peaches, parsley, slightly less in dogwood, dates, peaches, quince, raisins, olives, prunes, horseradish, spinach. Iron from vegetables and fruits is absorbed better than iron from inorganic drugs due to the presence of ascorbic acid in plant products.

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

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

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

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

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.

From vegetable products zinc is rich in beans, peas, wheat, corn, oat flour, in a smaller amount it is found in white cabbage, potatoes, carrots, cucumbers, beets.

Cobalt is part of vitamin B. Together with iron and copper, it is involved in the maturation of red blood cells. The daily requirement of the body 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.

I. IIGroup characteristics of vegetables and fruits

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

Vegetables are divided into:

tubers (potatoes, sweet potatoes),

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

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

onions (onion, leek, wild garlic, garlic),

lettuce-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).

The fruits are divided into:

stone fruits (apricots, cherries, dogwoods, 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)

false (strawberries).

ChapterII

II. IThe benefits of vegetables and fruits

Vegetables are of great importance in human nutrition. To eat right means to correctly combine plant and animal food in accordance with age, the nature of work, and the state of health. When we eat meat, fats, eggs, bread, cheese, acidic inorganic compounds are formed in the body. To neutralize them, you need basic, or alkaline, salts, which vegetables and potatoes are rich in. Green vegetables contain the highest amount of acid-neutralizing compounds.

Consumption of vegetables helps to prevent many serious diseases, increases the tone and performance of a person. In many countries of the world in the treatment of various diseases diet food fresh vegetables take the lead. They are rich in ascorbic acid (vitamin C), which ensures normal carbohydrate metabolism and helps to eliminate toxic substances from the body, resistance to many diseases, and reduces fatigue. Many vegetables contain B vitamins that affect human performance. Vitamins A, E, K, PP (nicotinic acid) are present in green peas, cauliflower and green vegetables. In cabbage there is a vitamin and that prevents the development of duodenal ulcer.

Organic acids, essential oils and vegetable enzymes improve the absorption of proteins and fats, enhance the secretion of juices, and promote digestion. The composition of onions, garlic, horseradish, radish includes phytoncides with bactericidal properties (destroy pathogens). Tomatoes, peppers, leaf parsley are rich in phytoncides. Almost all vegetables are suppliers of ballast substances - fiber and pectin, which improve bowel function, help to remove excess cholesterol from the body and harmful products digestion. Some vegetables, such as cucumber, have a low nutritional value, but due to their content of proteolytic enzymes, when consumed, they have a positive effect on metabolism. Green vegetables are of particular value. When fresh, they are not only better and more fully absorbed by humans, but also help (with enzymes) digestion of meat and fish in the body. At the same time, when cooked, greens lose a significant part of their useful properties.

To meet the need for vitamins, carbohydrates, proteins, acids, salts, an adult needs to consume daily more than 700 g (37%) of food of animal origin and more than 1200 g (63%) of vegetable, including 400 g of vegetables. The annual need for vegetables per person varies depending on the region of the country and is 126--146 kg, including cabbage various kinds 35--55 kg, tomatoes 25--32, cucumbers 10--13, carrots 6--10, beets 5--10, onions 6--10, eggplants 2--5, sweet peppers 1--3, green peas 5-8, melons 20-30, other vegetables 3-7.

Vegetables increase the digestibility of proteins, fats, 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 vegetable and fruit juices reduce the secretory function of the stomach, while diluted ones increase it.

II. IIHarm to vegetables and fruits

It is clear to many that the attractive appearance of any fruit and the absence of obvious signs of rot or immaturity does not yet indicate its suitability for food. Too many factors influence it on the long journey of turning a seed into a dish on our table. What is at least the unfavorable ecological situation in which nine-tenths of domestic greenery is grown. Soil soaked through with harmful mixtures; air saturated with toxic exhaust from automobiles and industrial pipes; water polluted by industrial emissions - all this, of course, does not add useful properties to vegetables and fruits.

In the process of cultivation, harvesting, pre-sale preparation and the actual sale, each fruit passes through dozens of hands, which are far from always clean and healthy. But some infections may well "settle in the womb" of some tomato or apple, in order to subsequently move into your body. But that's not all. A huge problem is represented by all kinds of additives and preservatives, which are stuffed with fruits and vegetables. Abundant treatment of gardens and agricultural fields with various pesticides in an attempt to preserve and increase the harvest cannot but affect the content of harmful substances in products. It makes no sense at all to talk about imported products, since the fruit cannot naturally preserve freshness and beauty, despite long-term storage and long-term transportation. But domestic entrepreneurs do not disdain "chemistry" to give an attractive appearance to their agricultural products. And all would be fine, exercise proper control over the quality and compliance of such additives. But many not very clean businessmen do not fill their heads with such “trifles”. And the layman cannot carry out an independent check.

Russia ranks second in the use of chemicals in agriculture. And the last - by their detection in foodstuffs grown on fertilized fields. The word "pesticides" from the Latin language literally translates as "I kill the infection." At one time, this drug became a salvation for agriculture. Later - misfortune. Mankind has faced the question: in connection with the progress, fresh fruits and vegetables - good or bad for the body? Today, many US universities have decided to teach only traditional farming. And yet, in America, agricultural products are tested for 100 pesticides, in Europe - for 57. For comparison, in our markets, tests for pesticides are not carried out at all. For 4 pesticides, fruits and vegetables are examined only in one central laboratory in Moscow. And then, if there are suspicions. But, according to experts, such inattention to the problem is explained not by lack of money, but by the lack of it. Pesticides are not actively used in our country just because they are expensive in our country. In any case, they are washed off with water, just wash the fruit well. More difficult - with nitrates, which are introduced into the soil. The permissible level of nitrates per 1 kilogram of greenhouse cucumbers is 400 milligrams, and the permissible dose of an adult is 300 milligrams, and even less for a child and an elderly person. Therefore, it is better not to rush to fortify your body with early fruits, the most dangerous of which is watermelon. To ensure redness, sellers inject a syringe of vodka into the stem. Only the inventors themselves never eat their "drunk" know-how. In addition, the largest berry in the world works like a huge sponge and absorbs harmful substances from water and soil, including nitrates. But regardless of the ecological situation, or the presence of nitrates in fruits, vegetables and fruits in excessive amounts do harm on their own. For example, apricots, especially fresh ones, should not be consumed on an empty stomach, as well as after taking indigestible food (mushrooms, beans, peas). Drinking cold water after taking apricots causes diarrhea. Fresh apricots are harmful for patients with peptic ulcer and acute gastritis. Due to the high sugar content, apricots, especially in dried form (dried apricots, apricots), are prohibited for patients with diabetes. Side effects of apricots on the digestive tract can be prevented or removed with dill water, fresh dill or anise. Many people like to eat apricot kernels. It is important to remember that they can cause severe poisoning. After 0.5-5 hours, you may feel general weakness, sore throat, headache, nausea, vomiting, a feeling of fear. In severe cases, convulsions and loss of consciousness are noted. One of the symptoms of poisoning is the reddening of the mucous membranes of the mouth. When breathing, the smell of bitter almonds is sometimes felt. home treatment may consist in gastric lavage, cleansing enemas. When using apricot seeds in small doses, poisoning does not occur.

Orange juice is contraindicated during an exacerbation of gastric ulcer and duodenal ulcer, with diseases of the pancreas and small intestine.

Watermelon has the property of accumulating chemicals (saltpeter, etc.) used as fertilizer in fruits and root crops. After cutting such a watermelon, yellow, somewhat compacted areas ranging in size from 0.3-0.5 to 2x2 cm or more are visible in the pulp. Even healthy people such watermelon causes nausea, vomiting, stomach pain and diarrhea. It is even more dangerous for young children and renal patients. Children may have diarrhea, in some cases - convulsions and dehydration. In renal patients, renal colic and a sharp deterioration in health very quickly occur.

Eggplant. When eggplants are fully ripe, the amount of alkaloid solanine M sharply increases in them, so young and small-sized fruits should be eaten. In case of poisoning with mature fruits, nausea, vomiting, diarrhea, intestinal colic, eclipse of consciousness, convulsions, shortness of breath occur. Help in case of poisoning: before the doctor arrives: the patient is given milk, mucous soups, egg white.

Hawthorn. Prolonged and uncontrolled use of hawthorn or medicines, developed on its basis, can cause depression of the heart rhythm, so treatment with hawthorn must be carried out under the supervision of a physician. Taking hawthorn fruit on an empty stomach often causes intestinal spasm. After taking it, you can not drink cold water, so as not to provoke the occurrence of intestinal colic.

Grape. It is better to eat grapes not earlier than 2 days after cutting from the bushes, since fresh, freshly picked grapes cause the formation of a large amount of gases (this is especially important to remember for people suffering from diseases of the stomach, intestines, kidneys and urinary tract). Such patients should only drink grape juice and discard the skin. Grape treatment is contraindicated in a number of chronic diseases, such as diabetes, diseases of the gastrointestinal tract, etc. Therefore, self-treatment with grapes is best avoided. AT this case it is advisable to get medical advice. In addition, grapes cause tooth decay, so after eating it, you should rinse your mouth with water and a small amount of soda.

Pear. Like any fruit, pear should not be abused. It should be eaten in moderation, not on an empty stomach, and not immediately after a meal, but 0.5-1 hour after a meal. After you have eaten a pear, you should not drink raw water, and also eat dense and heavy food.

Wild strawberry. Some people have an increased sensitivity to strawberries, which causes an allergic reaction, accompanied by persistent hives (pruritus). In this case, you can not use strawberries.

Melon. Overeating melon can lead to disruption of the intestines. Melon is contraindicated in diabetes mellitus, gastric ulcer and duodenal ulcer, dysentery and other intestinal disorders. Do not use melon with alcohol, honey or drink cold water. This can cause bloating, intestinal colic, and severe diarrhea. Melon is also contraindicated in nursing mothers, as diarrhea may occur in a child.

Figs. Due to the high sugar content, figs are contraindicated in patients with diabetes mellitus, with acute inflammatory diseases of the gastrointestinal tract. Figs are also contraindicated for gout, as they contain a lot of oxalic acid.

White cabbage. Cabbage should not be eaten by people with hyperacidity gastric juice and diseases of the pancreas.

Potato. It should be warned about one feature of potato tubers - they must be stored in a dark place. Otherwise (if the tubers lie in the light, especially in the sun), they become poisonous, unsuitable for food use. Tubers visually declare their changes themselves - they turn green in the light. Poisonous substances are formed only in this greenish surface part of the potato, without penetrating into the depths. Another inconvenience that we encounter when storing potatoes is the appearance of white "sprouts" of stolons. At the same time, the nutritional quality of tubers does not significantly deteriorate, so you should not be afraid of sprouts (when peeling potatoes, they will still go to waste). But when cooking potatoes "in uniform", the sprouts must be broken off, as they contain the same toxic substances as in the green tubers.

cilantro. As a green seasoning, cilantro should not be used for stomach ulcers, coronary heart disease, thrombophlebitis, diabetes, hypertension. In addition, with excessive introduction of nitrogen fertilizer into the soil, plants accumulate nitrates, sometimes causing food poisoning.

Hazelnut (hazelnut) Hazelnut is good only in small quantities. It is enough to eat a little more than usual and the person soon begins to have headaches in the middle part of the head. This is due to the fact that the intake of nut kernels causes a spasm of cerebral vessels.

Lemon. Lemon and products based on it are non-toxic. However, they can harm patients with gastritis, gastric ulcer and duodenal ulcer. In them, lemon causes heartburn, severe spastic pain and even vomiting. So such patients should use lemons only in a small amount(1-2 slices) with tea and only after meals.

Onion. Excessive consumption of fresh onions can provoke an exacerbation of diseases of the stomach, kidneys and liver.

Raspberry. Raspberries should not be eaten with gout and nephritis.

Carrot. You can not eat root crops and the upper parts of root crops that are on the surface of the earth and have green color. They negatively affect the activity of the heart.

Sea buckthorn. Sea buckthorn oil is contraindicated in diseases of the gallbladder, gastrointestinal tract and pancreas. Fresh fruits and sea buckthorn juice contain a lot of acids, so they should not be used for gastric ulcer and duodenal ulcer.

Cucumber. Pickled and pickled cucumbers should not be eaten by patients suffering from gastrointestinal ailments with high acidity of gastric juice, hypertension, as well as atherosclerosis, hypertension, heart defects. Salted and pickled cucumbers excite the appetite, so they are contraindicated in obesity.

Walnut. Walnut fruits can cause allergic reactions (urticaria, allergic stomatitis, diathesis, etc.). Walnut fruits are harmful to patients who have skin diseases such as eczema, psoriasis and neurodermatitis. Taking even a small amount of nuts contributes to the exacerbation of these diseases.

Capsicum. Hot pepper should not be used for hemorrhoids, diseases of the stomach, intestines, especially for stomach ulcers, liver diseases (cirrhosis, acute and chronic hepatitis) and kidneys (acute and chronic nephritis and nephrosis).

Sweet pepper (Bulgarian). Contraindicated in patients with severe ischemic disease (angina pectoris), cardiac arrhythmia, hypertension, peptic ulcer of the stomach and intestines, suffering from gastritis with high acidity of gastric juice, colitis, with exacerbation of chronic diseases of the liver and kidneys, hemorrhoids, with increased excitability of the nervous system; with epilepsy and insomnia.

Peach. Due to the high sugar content, peach should not be eaten by diabetics.

Parsley. During pregnancy, parsley should not be consumed, there is a risk of miscarriage.

Rhubarb. Rhubarb should not be given on an empty stomach to patients with hyperacid gastritis or peptic ulcer of the stomach and duodenum. These patients usually experience severe stomach pain within 10-15 minutes after taking rhubarb. Rhubarb should not be used by patients with kidney stone disease. It is dangerous to use rhubarb for children and pregnant women.

Black radish. The internal use of radish is contraindicated for "cardiac" and "liver" patients, with gastric ulcer and 12 duodenal ulcer, inflammation of the gastrointestinal tract.

Beet. When you receive fresh juice beets there is a strong spasm of blood vessels. Therefore, freshly squeezed juice should be allowed to stand for 2-3 hours, so that harmful volatile fractions “gone away”. After that, you can drink it. Beetroot juice should not be consumed with yeast bread or washed down with any acidic juice. It is best to take it on an empty stomach, 10-15 minutes before meals, slightly warmed. Beetroot juice should be drunk in small sips, holding it longer in the mouth. Patients with a sensitive stomach, raw beetroot juice should be mixed with oatmeal.

Tomato (tomato). Eating tomatoes in large quantities leads to the formation of kidney stones.

Black chokeberry. Overuse chokeberry unsafe with increased blood clotting - it can lead to the formation of blood clots in the blood vessels. In addition, treatment with juice and fruits is not recommended for increased blood clotting, peptic ulcer of the stomach and duodenum 12, as well as gastritis.

Garlic. Garlic should not be used by patients with epilepsy, hypertension, inflammation of the kidneys, as well as pregnant women.

Sorrel. Sorrel is not recommended for use in violation of salt metabolism (rheumatism, gout) and related diseases, inflammation of the intestine and tuberculosis. Never eat sorrel boiled as it promotes arthritis.

ChapterIII

III. IHarm and benefitwatermelons

We will analyze the benefits and harms of fruits using a specific example of watermelons.

Watermelon leads its pedigree from wild plants of tropical Africa. Botanists consider the Namib Desert and the Kalahari semi-desert to be the center of origin of botany, where wild watermelon thickets can still be found in the valleys. Modern watermelon is a descendant of huge perennial woody vines that live in the humid tropics. In ancient Egypt, watermelon as a cultivated plant was known 4000 years ago. However, then it was grown not at all because of the juicy and sweet pulp, but to obtain very valuable oil from its seeds. In Europe, watermelon appeared after the Crusades. In Russia, it was brought in Vstrongstrong-X centuries from India during the busy trade with Kievan Rus. Initially, it took root in the Volga region, and by the XVstrongstrong century it had spread widely and was grown even in the central regions, as a greenhouse crop.

The most popular watermelons in Russia are, of course, Astrakhan. This is a kind of brand, a guarantee of taste and quality. Merchants know this very well and often shamelessly take advantage of the gullibility of inexperienced buyers. However, nature is used to doing everything on time, and if watermelons are supposed to ripen by mid-late August, then it will be so. A reasonable question may arise: where do these delicious berries come from in our cities at the end of July?

Indeed, in Astrakhan, a trial harvest of watermelons takes place in early August, a selective one - in the middle of the month, but a massive one begins on the 25th, so the indigenous striped "Astrakhan" should appear in Moscow only by September.

Option one: early ripening varieties from other watermelon-bearing regions of Russia and neighboring countries, but this option is unlikely, because they have not yet become widespread, moreover, even for them, according to the All-Russian Research Institute of Irrigated Vegetable and Melon Growing (VNIIOB), located in Astrakhan region, 53-55 days are needed with a temperature of 25-30.C. It does not pose any threat to health, only benefits, but more on that below.

Option two: mid-ripening varieties (traditional Astrakhan watermelon), spurred on by nitrogen fertilizers and, above all, ammonium nitrate. This option is more common and completely indifferent to health. We will consider it in more detail.

Watermelon is a dietary product. In the sense that there are practically no contraindications for the use of watermelon. Watermelon consists of water (up to 80 percent of the fruit weight), fructose, a small amount of glucose, sucrose, trace elements and vegetable fiber. Fructose is unique in that it is absorbed by the body without the need for insulin at all. It means that sweet watermelon can eat even patients with insulin-dependent diabetes.

The striped delicacy also has a pronounced diuretic effect, literally washing the body from the inside, which makes it possible to recommend the fragrant pulp to those suffering from diseases of the heart, blood vessels and joints. Watermelon is also useful for hearts for a reason, which we will discuss in the next section.

Watermelon is a real treasury of magnesium, without which a person simply cannot do without. A chronic lack of magnesium in food leads to an increase in blood pressure. Magnesium and its "partner" - calcium - provide constriction and expansion of blood vessels, a mechanism that maintains stability blood pressure in the body.

Magnesium is important for bile secretion and deactivation of cholesterol, for binding salts of oxalic acid (oxalates) and preventing the formation of kidney stones, to reduce nervous excitability, relieve muscle spasms, and normalize intestinal motility.

And this wonderful trace element in 100 grams watermelon pulp contains as much as 224 milligrams - more only in almonds. Thus, to pay off the daily human need for magnesium, it is enough to eat 150 grams of watermelon.

Watermelon and potassium are rich, although it is less than in dried apricots, bananas and persimmons, but if we compare the caloric content of the same bananas and watermelon, then the “Russian” who grew up on melon is clearly in a more advantageous position - there are three times more calories in a banana.

But despite all this many advantages, watermelons also have a number of negative qualities. For example, nitrates. They act on watermelons like steroid anabolics on bodybuilders: growth is at an accelerated pace and an impressive weight and volume of the fetus is gained very quickly. Everything would be fine, but nitrates categorically refuse to leave the watermelon. And acute nitrate poisoning at this time of the year is by no means uncommon. It is especially difficult in children, because nitrates compete with oxygen for our hemoglobin. And instead of an oxygen carrier, hemoglobin (in the form of methemoglobin) causes serious problems with cellular respiration.

Nitrates have another bad feature- accumulate in the body, causing chronic intoxication. Doctors call this the "cumulative effect." Children overloaded with nitrates grow worse, get sick more often, adults become irritable, sleep worse.

The most interesting thing is that it is almost impossible to distinguish a “pumped up” watermelon from a normal one by eye. Special measuring instruments that determine the content of nitrates in vegetables and fruits can help, similar to the portable Marion.

1.2. Chemical composition of fresh fruits and vegetables, their nutritional value.

The chemical composition and physical properties of fresh fruits and vegetables are determined by the structure and composition of the tissues that form them.

In fruits and vegetables, as well as in their processed products, there are various substances: easily digestible sugars (glucose, fructose, sucrose), polysaccharides (starch, fiber, inulin), organic acids (malic, citric, tartaric, etc.), polyphenols , mineral salts, vitamins, nitrogenous, aromatic, coloring and pectin substances. Some substances are not essential for human nutrition, but play an important role in such life processes of fruits and vegetables as aging, germination, disease resistance, etc. These include, for example, nucleic acids.

Some fruits and vegetables have medicinal value and are used in medicine. For example, raspberries containing salicylic acid have good diaphoretic and diuretic properties; blueberries and pears - fixing, and plums - laxative. The medicinal properties of cabbage juice have been established for peptic ulcer, diabetes mellitus, hypertension, and pectin substances for intestinal diseases. The healing properties of grapes, lemons, oranges, strawberries, currants, garlic, onions, etc. are also well known.

The chemical composition of fruits and vegetables is not constant, but can change during their growth, ripening and depends on a number of factors: species, variety, degree of maturity, harvesting time, commodity processing, storage time, etc.

Water

Included in all fruits and vegetables. while its content in some of them, such as cucumbers, reaches 98%. The role of water for the quality and preservation of fruits and vegetables is exceptionally great.

Minerals .

Inorganic (mineral) substances are an integral part of mineral salts and organic compounds. They are present in all fruits and vegetables, playing an important role in metabolic processes and building tissues of the human body.

To macronutrients include calcium, phosphorus, magnesium, potassium, sodium and sulfur.

Calcium (Ca) is necessary for the formation of bone tissue, maintaining the normal functioning of the nervous system and the heart.

Phosphorus (F) takes part in the metabolism of proteins and fats. affects the functions of the central nervous system, is part of the bones.

Magnesium (Mg) has a vasodilating property, affects the nervous system, normalizes the activity of the heart muscles, improves its blood supply.

Sulfur (S) is part of some amino acids, vitamin B1, the hormone insulin, which regulates the absorption of glucose in the human body.

trace elements - these are iodine, fluorine, manganese, copper, zinc, bromine, aluminum, chromium, nickel. Most micronutrients are as important to human nutrition as macronutrients.

Iodine (I) necessary for the normal functioning of the thyroid gland.

Fluorine (F) plays an important role in the formation of bones, teeth.

Manganese (Mn) takes an active part in hematopoiesis, bone formation, affects the immune system and metabolism.

Copper (Cu) takes part in hematopoiesis.

Zinc (Zn) is part of all tissues, affects the function of the pancreas and fat metabolism, promotes the growth of a young organism, hair, nails.

Carbohydrates - is a group of natural organic compounds, which include carbon, hydrogen and oxygen. Carbohydrates are the primary products of photosynthesis and the main original products biosynthesis of other substances in plants. Therefore, they are mainly found in plant products. Carbohydrates make up an essential part of the human diet. In fruits and vegetables, they are present in the following forms:

monosaccharides: glucose (grape sugar), fructose (fruit sugar), mannose (found in fruits);

disaccharides : sucrose (beet sugar), maltose (malt sugar);

Polysaccharides : starch, fiber (cellulose), inulin;

pectin substances : protopectin (an insoluble high-molecular compound that determines the hardness of unripe fruits and vegetables), pectin (a high-molecular substance soluble in the cell juice of fruits that helps soften their tissues when ripe), pectin and pectic acid.

Squirrels - natural high-molecular organic compounds built from amino acid residues. The composition of complex proteins, in addition to amino acids, includes carbohydrates, amino acids, etc.

Fats - organic compounds, mainly esters of glycerol and monobasic fatty acids. It is one of the main components of cells and tissues of living organisms. Fats are the source of energy in the body.

Enzymes - These are special proteins that increase the speed of all chemical reactions in the cells of all living organisms. Enzymes are involved in the implementation of all metabolic processes, in the implementation of genetic information. Without the participation of enzymes, the digestion and assimilation of nutrients, the synthesis and breakdown of proteins, fats, carbohydrates and other compounds in the cells and tissues of all organisms is impossible.

organic acids - give food products a taste, can improve their shelf life, promote digestion.

vitamins - are low molecular weight organic compounds of various chemical nature. In small quantities, they are necessary for the normal metabolism and vital activity of living organisms. All vitamins are divided into all groups:

water soluble - B1 (thiamine), B2 (riboflavin), B3 (pantothenic acid), B6 (pyridoxine), B12 (cyanocobalamin), Sun (folic acid), C (ascorbic acid), PP (nicotinic acid);

fat soluble - A (retinol), D (calciferols), E (tocopherols), H (biotin), K (phylloquinone).

Coloring substances (pigments) determine the color of fruits and vegetables.

Chlorophyll causes the green color of fresh fruits and vegetables.

aromatic substances . Fruits and vegetables contain various essential oils that give them their characteristic odor.

Phytoncides . Phytoncides are biologically active substances formed by plants that kill or suppress the growth and development of microorganisms, in other words, strengthen the immunity of both plants and humans and animals.

The chemical composition of vegetables and fruits depends on their variety, type, degree of maturity, harvesting time and other factors.

The composition of vegetables includes organic and mineral substances, both soluble and insoluble in water.

Water-soluble substances include sugars, organic acids, pectin, most vitamins, some nitrogenous substances, glycosides, some minerals and others, which are mainly found in the cell juice of fruits and vegetables.

Substances insoluble in water include cellulose, protopectin, hemicelluloses, starch, some nitrogenous and mineral substances.

Water.

A significant amount of water in fruits and vegetables contributes to their better absorption. However, due to the high moisture content in fruits and vegetables, harmful microorganisms easily develop, causing rapid spoilage. Increased evaporation of moisture leads to wilting, so fruits and vegetables are classified as perishable products.

Carbohydrates.

Carbohydrates account for about 90% of the total dry matter content of fruits and vegetables.

From the carbohydrates of fruits and vegetables, sugars, starch, inulin, fiber and pectin substances have special attention.

Sahara are represented mainly by glucose, fructose and sucrose and determine mainly the nutritional value of fruits and vegetables. Of the vegetables, melons, watermelons, and svela are the most sugar-rich.

Starch found in significant quantities in potatoes, nut kernels, in immature grains of legumes. A lot of it in bananas and dates.

Inulin, similar in composition to starch, found in earthen pear and in chicory.

Starch and inulin are reserve substances that are insoluble in water, therefore, fruits and vegetables containing them have a better storability. However, it should be noted that starch and inulin have increased hygroscopicity. This circumstance should be taken into account when storing dried potatoes and other starchy fruits and vegetables.

Cellulose makes up the bulk of the cell walls of fruits and vegetables. It is almost not absorbed by the human body, but loosens food and causes increased intestinal motility, contributing to better digestion.

pectin substances. Pectin has the ability to form jelly in the presence of acid and sugar in an aqueous solution. This property of pectin is used in the manufacture of jelly, marmalade, marshmallows, marshmallows. Pectin of some varieties of apples, quince, blackcurrant, apricots is distinguished by a high jelly-like ability.

organic acids.

Fruits and vegetables contain various organic acids, which are in a free state or in the form of salts.

The most common in fruits and vegetables are malic, tartaric, citric and oxalic acids. Less common are benzoic, salicylic, formic, etc. There are much more organic acids in fruits than in vegetables.

Tannins.

In fruits and vegetables, they are not only reserve, but also protective substances against various microorganisms. They participate in the formation of the taste of fruits, but their significant content gives the fruits an astringent taste.

Especially a lot of tannins in unripe fruits, such as persimmons. As fruits and vegetables ripen, the amount of tannins in them decreases sharply.

Coloring substances.

Coloring fruits and vegetables contain mainly chlorophyll, carotene, xanthophyll and various types of anthocyanins.

Chlorophyll gives plants a green color. At the beginning of their ripening, almost all fruits are green in color, but as they ripen, chlorophyll disappears. These properties of the breakdown of chlorophyll and the formation of a different color are used to determine the time for harvesting fruits and vegetables.

Anthocyanins color fruits and vegetables in various colors - from red to dark blue. They are found in the pulp cell sap solution or in the skin.

Carotene(provitamin A) gives fruits and vegetables an orange-yellow color. This pigment is found in significant quantities in carrots, pumpkins, and apricots. Its isomer close to carotene lycopene, which has a red color, together with carotene gives the tomatoes an orange-red color.

Xanthophyll contributes to the formation of yellow color of apples, pears, apricots, peaches, etc.

Glucosides.

According to the chemical composition, they are a combination of sugar with alcohol, aldehydes, phenols or acids.

All glucosides found in fruits and vegetables have a bitter taste.

nitrogenous substances.

Nitrogenous substances are included in the composition of fruits and vegetables in the form of proteins and non-protein nitrogen compounds (amino acids, ammonia compounds, etc.). Nut and immature legumes are richest in them.

Fats.

Essential oils.

The smell of vegetables and fruits depends on the presence of essential oils in them, which are a mixture of chemicals. The maximum accumulation of essential oils occurs when the fruits ripen. During storage and processing of fruits and vegetables, essential oils evaporate.

Minerals.

Basically, these are salts of organic acids, which are well absorbed by the human body and contribute to its growth, development, increase resistance against various diseases.

Vitamins.

Vitamin C is most common in fruits and vegetables. In addition to vitamin C, vitamin A (in carrots, apricots, pumpkin, etc.), vitamins of group B (especially in greens, tomatoes) and vitamin K (in vegetable greens and cabbage). All these vitamins are more digestible than vitamin C during the storage of fruits and vegetables, but are largely destroyed by thermal exposure.

Fresh vegetables.

Depending on what part of the plant is eaten, fresh vegetables are divided into vegetative and fruit. Vegetables that eat growth products - leaves, stems, roots and their modifications - are vegetative. Vegetables in which the products of fertilization - fruits are used as food, are called fruit.

Vegetative vegetables. According to the part of the plant used, this group of vegetables is divided into the following subgroups:

tubers (potato, sweet potato, Jerusalem artichoke);

root crops (carrots, beets, radishes, radishes, turnips, rutabaga, parsley, parsnips, celery);

onion (bulb onion, leek, batun, garlic, etc.);

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

lettuce-spinach (lettuce, spinach, horseradish, etc.);

dessert (asparagus, artichoke, rhubarb);

spicy (dill, savory, tarragon, horseradish, etc.)

Fruit vegetables. This group of vegetables consists of the following subgroups

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

tomato (tomatoes, eggplants, peppers);

legumes (peas, beans, beans);

cereals (sweet corn).

Fresh fruits.

Depending on which parts of the flower are involved in their formation (ovary or fruiting), the fruits are divided into groups that differ in commercial properties.

There are pome fruits, stone fruits, berries, nut fruits, subtropical and tropical fruits.

pome fruits differ in that inside the fleshy fruit there is a five-celled chamber that contains seeds. These include apples, pears, quince, mountain ash, medlar.

stone fruits consist of skin, fruit pulp and a stone with a kernel enclosed in it. This group includes apricots, peaches, plums, cherries, sweet cherries, dogwoods.

Berries divided into real, false and complex. These include grapes, currants, gooseberries, cranberries, blueberries, blueberries, lingonberries. in the berries of this subgroup, the seeds are immersed directly in the pulp. False berries include strawberries and strawberries. They have a fleshy juicy fruit, formed from an overgrown fruit. Complex berries include raspberries, blackberries, stone fruits, cloudberries. They consist of fused small fruitlets on one fruit bed.

To subtropical and tropical fruits include lemons, tangerines, oranges, pomegranates, persimmons, figs, bananas, pineapples, etc. The fruits listed belong to various botanical families, but in trade practice they are usually distinguished into a separate group - according to the growing area.

Nut fruits consist of a core enclosed in a dry woody shell. These include hazelnuts, hazelnuts, walnuts, almonds, pistachios, peanuts.

Natural loss of fruits and vegetables during storage.

During storage and transportation, fruits and vegetables evaporate moisture and consume organic matter respiration, resulting in a loss of their mass. Such losses are classified as natural, and a significant part of them falls on the evaporation of moisture (65-90%) and the consumption of organic substances for respiration (10-35%). These losses are inevitable under any conditions of storage and transportation of fruits and vegetables.

The norms of natural loss do not include losses resulting from damage to containers, as well as rejects and waste received in the process of preparation, processing and storage of fruits and vegetables.

The size of the natural loss is normalized, they are different for certain types of fruits and vegetables, methods and periods of storage, time of year, distance of transportation.

The natural loss of fruits and vegetables is written off from financially responsible persons according to the actual size, but above the established norms, which are limiting and apply only if, when checking the actual availability of goods, there is a shortage against the accounting data, confirmed by a collation sheet.

FRUIT AND VEGETABLE PRODUCTS.

Along with the use of fresh vegetables and fruits, a significant part of these products is preserved, which makes it possible not only to protect them from spoilage, but also to obtain products with new nutritional and taste properties.

The most widespread are the following methods of preservation: pickling, salting, urinating, pickling, drying, freezing, canning at high temperatures in airtight containers.

Fermentation, salting and urinating are different names for the same method of processing fruits and vegetables. This method is based on lactic acid fermentation of sugars, as a result of which lactic acid is formed. It prevents the vital activity of harmful microorganisms that can cause spoilage of the product. The difference in names is explained by the fact that in the past cabbage and beets were fermented without salt (due to its lack) and such processing was called fermentation, and all other vegetables were fermented with the addition of salt. The processing of berries and fruits, sufficiently acidic and fresh, is called urination.

Dried vegetables and fruits.

Drying- This is the removal of moisture from fresh fruits and vegetables under the influence of high temperatures. Vegetables are considered canned if the moisture content in them is brought to 12-14%, in fruits - up to 15-20%. One of the important advantages of dried fruits and vegetables compared to fresh ones is the high efficiency of transportation. However, it should be borne in mind that during drying, significant changes in the composition of fruits and vegetables, loss of vitamins, and deterioration in organoleptic parameters can occur.

All kinds of fruits and vegetables can be used for drying, but dried apples, pears, apricots, plums, grapes, potatoes, carrots, onions, cabbage, etc. are mainly produced.

Dried apricots go on sale under the following names: apricots, kaisa, dried apricots

Apricots are whole apricots, dried with a stone.

Kaisa are apricots, in which the stone is squeezed out through an incision at the stalk before drying.

Dried apricots are apricots cut or torn in half along the fruit and dried without a stone.

Dried grapes with seeds are called raisins, without seeds - sultanas.

Storage of dried fruits and vegetables.

Dried fruits and vegetables are hygroscopic and when stored in a damp room, they become moist, moldy and spoil. Therefore, they must be stored in a dry room at a temperature not exceeding 20 ° C and a relative humidity of not more than 70%.

Besides, dried fruit and vegetables must be protected from damage by various pests (moths, beetles, mites), which multiply rapidly at high humidity of the product. If pest damage is found on individual specimens, the product must be dried for 12-20 minutes at a temperature of 95 ° C.

Vegetable and fruit preserves in hermetic containers.

Preservation in a hermetic container means that the raw materials processed and isolated from the surrounding air are subjected to heat treatment 9 at a temperature of 85-120 ° C), as a result of which microorganisms are destroyed and enzymes are destroyed. Such products can be stored without changing the quality for a long time.

All canned fruits and vegetables are divided into vegetable, fruit and mixed. Separately, a group of canned food for children and diet food is distinguished.

Canned vegetables. Depending on the method of production, they are divided into natural, snack, lunch, concentrated tomato products, vegetable juices, drinks, and marinades.

natural canned food- these are vegetables blanched and packed in jars, filled with a solution of salt or tomato juice, corked and sterilized. Vegetables should be at least 55-65%. Natural canned food includes green beans, green peas, cauliflower, carrots, and beets. By quality, natural canned food is divided into the highest and 1st grade.

snack food- these are ready-to-eat snack dishes containing from 6-15% vegetable oil, various amounts of spicy greens, carrots, onions and spices, filled with tomato sauce. They are made from peppers, tomatoes, zucchini, eggplant: vegetable caviar from pureed fried eggplant, zucchini and squash; vegetables, cut into circles, fried and filled with tomato sauce (eggplant, zucchini, peppers); stuffed vegetables; vegetable salads and vinaigrettes - mixtures of chopped vegetables (cabbage, tomatoes, peppers, etc.).

Canned stuffed and sliced produce the highest and 1st grades. Vegetable caviar and salads are not divided into commercial varieties.

canned lunch are canned ready-made dishes from fresh, pickled or salted vegetables with or without meat, with the addition of fat, tomato paste, salt, sugar, spices. Lunch canned food is divided into first and second courses. The first dishes include borscht, cabbage soup, pickle, soups, the second - vegetable or vegetable-mushroom pickles, meat with vegetables, cabbage rolls, etc.

To concentrated tomato products include tomato puree, tomato paste, tomato sauces, dry tomato powder.

Tomato puree and tomato paste are prepared from the pureed mass of tomatoes, which is boiled down to a certain concentration. Tomato paste is produced with and without salt. By quality, tomato puree and tomato paste are divided into the highest and first grades.

Tomato sauces are made from tomatoes or concentrated tomato products. Sugar, spices, vinegar are added to sauces, used in cooking as a seasoning.

vegetable juices make natural and with sugar; from tomatoes, carrots and beets, as well as blended.

Fruit preserves. These include compotes, fruit and berry puree, pastes, sauces, juices, fruit and berry marinades.

compotes are canned food from one or more types of fruits and berries in sugar syrup and subjected to heat sterilization. Their names correspond to the names of the main type of raw material from which they are made (cherry, peach, apricot). In addition, Assorted compote is produced - from a mixture of several fruits and berries, as well as dietary compotes (instead of sugar, syrup on sorbitol and xylitol is introduced).

By quality, compotes are divided into the highest, 1st and table grades. They differ in organoleptic characteristics - appearance, texture of fruits, quality of syrup.

Puree from fruits and berries is a pureed mass with a dry matter content. Puree is also used as a semi-finished product for making jam, sauce, confectionery.

Pastes fruity obtained by boiling mashed potatoes without sugar.

Canned food for baby food are made in the following assortment: vegetable, fruit, fruit and vegetable, meat and vegetable. They must have excellent taste, the necessary calorie content. contain vitamins and minerals.

Diet canned food intended for therapeutic nutrition of patients. They develop the composition of dietary canned food, taking into account which chemicals are desirable and which are contraindicated for this category of consumers.

Storage of vegetable and fruit preserves. Canned fruits and vegetables are packed in glass jars or aluminum tubes. After sterilization, canned food is cooled with water, dried, labeled and placed in boxes.

Marking. Three to six characters are stamped sequentially in one row on the lid of the can. At the beginning, an index is placed indicating who owns the plant (K is the index of the Ministry of the Fishing Industry); then the manufacturer's number; year of manufacture, indicated by the last digit of the current year. For example, TsS546 - means that the cannery No. 54 belongs to Tsentrosoyuz, canned food was produced in 1986.

Five to seven characters are stamped on the bottom of the cans: the first is the shift number, the second two are the date of manufacture (before the 9th day they put 0 in front), the fourth (letter) is the month of manufacture (A - January, B - February, etc. excluding the letter H), the next three digits of the sign are the assortment number of canned food. For example, canned food "Corn", produced on the second shift on July 25, will have the mark 225Ж007.

store canned fruits and vegetables at a temperature of 0-20 o C. At a temperature below 0 o C, canned food freezes, which leads to a loss of organoleptic properties of products. During the storage of canned fruits and vegetables, for various reasons, the following types of defects often occur: bombing, souring, darkening of the contents, softening of fruits and vegetables, smudges, rusting of metal cans and lids.

Quick frozen fruits and vegetables.

In recent years, the production of fresh, quick-harvested fruits and vegetables has sharply increased. Fruits and vegetables are frozen in quick freezers at a temperature of -25 to 50 ° C.

With rapid freezing to a low negative temperature, biochemical processes in the product and the development of microorganisms almost completely stop. The quality of the product depends on the speed of freezing. During rapid freezing, small ice crystals are formed in the intercellular spaces and cells, which do not cause significant deformation of the tissue structure. When frozen, almost all the aromatic qualities and vitamins of fruits and vegetables are preserved unchanged.

Not all types and varieties of fruits and vegetables are suitable for freezing. High quality products are obtained by freezing green peas, vegetable peppers, carrots, beets, tomatoes, spinach, young mushrooms, strawberries, raspberries, cherries, plums, apricots, apples and pears.

Vegetables before freezing are peeled, washed, cut, blanched. In addition to certain types of vegetables, vegetable mixtures are frozen for the preparation of first and second courses.

Fruits are frozen whole or cut into pieces, with or without sugar.

Quick-frozen fruits and vegetables are packed in cardboard boxes, polyethylene bags. Store frozen products at a temperature of -18 o C and a relative humidity of 90-95%.

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