Modern nutritional science considers vegetables and fruits to be vital foods, as they are the main source of many vitamins, minerals, organic acids, aromatic substances and easily digestible carbohydrates. The chemical composition of fruits and vegetables depends on many factors: growing conditions, agricultural technology, climatic conditions, growing area, etc. The substances that make up fruits and vegetables are subdivided into inorganic - water, minerals and organic - proteins, fats, carbohydrates, vitamins, enzymes, aromatic substances.

Water

In terms of water content, various types of fruits and vegetables differ markedly: from 75% in potatoes, to 97% in cucumbers, especially nut-bearing ones - up to 7-8%.
The ability to maintain a certain shape at a high water content is due to the presence of proteins and pectin substances that can retain a large amount of water. The water contained in fruits and vegetables is unevenly distributed over the tissues: there is less water in the integumentary tissues than in the pulp. Most of the water in fruits and vegetables is free, and only a small part is bound. For this reason, it is easy to dry fruits and vegetables to 10-12% moisture. Further removal of each percentage is associated with certain difficulties and can be achieved using special drying methods. Fruits and vegetables evaporate water both on the mother plant and after harvest. However, on the mother plant, the loss of moisture is compensated by the root system, and after harvesting, it is not compensated. Therefore, moisture evaporation during storage can have the most adverse effect on the normal course of metabolic processes. Evaporation of moisture causes a weakening of cell turgor, tissue wilting, increased consumption of nutrients, is the main reason for a decrease in their mass during storage. For successful storage, effective protection of fruits and vegetables from wilting is needed, therefore, a high relative humidity of -85-95% must be maintained in storage facilities.

Many chemicals are dissolved in water: carbohydrates, some minerals, vitamins, acids, tannins. They constitute soluble solids and are determined by a refractometer. With an average moisture content in various fruits and vegetables from 75 to 95% of water, the share of dry matter is from 5 to 25%, most of them are carbohydrates. The dry matter content depends on the variety, climatic conditions (in hot summers there are more of them than in rainy ones), degree of maturity (less in immature than in mature ones).

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.

Proteins are organic high molecular weight compounds made up of amino acids. In a protein molecule, amino acids are interconnected by peptide bonds. The variety of proteins is determined by the sequence of placement of amino acid residues in the polypeptide chain (primary protein structure). In addition, there is a secondary structure of a protein that characterizes the type of folding of polypeptide chains (right α-helix, α-structure, and β-bend), a tertiary structure of a protein, which characterizes the location of its polypeptide chain in space, and a quaternary structure that characterizes proteins containing includes several polypeptide chains linked by non-covalent bonds. Legumes contain significantly more proteins in grains than grains, but they are inferior to them in terms of the amount of starch.

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. The process of splitting starch is called saccharification and is used in the food industry for the production of beer and alcohol.

Glycogen (animal starch) is similar in structure to amylopectin, it is found in various tissues of fungi, corn grain. Glycogen dissolves in warm water to form a colloidal opalescent solution. During hydrolysis, it turns first into dextrins, then into maltose and glucose.

Sahara

From monosaccharides found in fruits and vegetables pectose (arabinose and xylose), hexose - (glucose, fructose). Glucose (grape sugar) is found in grapes, cherries, cherries, raspberries, currants (in combination with fructose), fructose predominates in pome fruits. Of the disaccharides, fruits and vegetables contain sucrose; it predominates in apricots, peaches, and plums. Fruits and berries have a rather high sugar content - from 19 to 30% in grapes, from 3.2 to 12.8% - in fruits. In vegetables, the sugar content is lower, but many of them are rich in sugars: melons - 7-17%, watermelons - 6-10%, beets - 6-8%. The mushrooms contain trehalose. All sugars are water-soluble, sweet in taste, fermented by yeast and lactic acid bacteria, with strong and prolonged heating they caramelize, form melanoidins with amino acids and proteins, which causes browning of fruits and vegetables during storage. Sugars are of great importance in the metabolism of fruits and vegetables. They are spent on respiration, provide energy and a large amount of intermediate products that are used in the post-harvest ripening of fruits, and determine the resistance to microorganisms.
Close to sugars and sugar alcohols: sorbitol - in mountain ash, apricots, plums, apples; mannitol - in pineapples, carrots, pears, mushrooms. When oxidized, sugars are formed.

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 B1 (thiamine) is found in legumes and grains. Vitamin B2 (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.
The total content and qualitative composition of minerals in vegetables and fruits are not the same. For example, apples contain about 0.3%, apricots - 0.7, potatoes - 1.0% of minerals. 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 produce marmalade, jelly, jam, and pastilles. The pectin content in vegetables and fruits ranges from 0.5 to 2.5%.

Pectin substances (pectin, protopectin, pectic acid) are found in fruits and berries and are similar in composition to carbohydrates. By its chemical nature, it is polygalacturonic acid methyl ester. Pectin is found in the cell juice of fruits and berries in the form of a colloidal solution. In the presence of sugar and acid, pectin can form jelly. This property is used in the production of confectionery: jelly, marmalade, etc. Different products contain different amounts of pectin, and therefore have different gelling properties (the highest, g / 100g - apples - 1.0, gooseberries - 0.7, black currants - 1.1, less - cherries - 0.4, pear - 0 , 6).
Pectin substances of juices interact with polyphenolic and other substances of the cell, forming sediments.

The addition of enzymes that cause the breakdown of pectin substances to galacturonic acid prevents clouding of juices and wines. Pectin is not absorbed by the human body, however, there is evidence of its beneficial role in human poisoning with toxic substances, radiation exposure (while it acts as an antidote, from the Latin "anthidotum metalborum" - an antidote for metal poisoning), in suppressing the development of putrefactive bacteria. Unripe fruits contain protopectin, which is a combination of pectin and cellulose, so unripe fruits have a tough consistency. As the fruits ripen, protopectin turns into pectin, and accordingly the fruits become softer. Protopectin does not dissolve in water. Pectic acid is formed in overripe fruits. Does not form jelly with sugar and acids.

Fiber (cellulose) and semi-cellulose (hemicellulose) - is found mainly in the walls of plant cells. Their content varies significantly in horseradish, dill, rose hips, nuts, raspberries, currants, sea buckthorn (2.5-55%), less in cucumbers, zucchini, squash, lettuce, green onions, cherries, apples, plums (0.5-0.8%) ... It does not dissolve in water, is not assimilated by the body, therefore it has no nutritional value (and, therefore, reduces the nutritional value of the product), but promotes intestinal function. The less it is in the product, the more delicate its consistency. Hydrolysis produces simple sugars. Inulin is found in the tubers and roots of some plants: garlic (15-20%), Jerusalem artichoke (13-20%) and artichokes (1.9%), replacing starch in them. Inulin easily dissolves in warm water, forming colloidal solutions. When inulin is hydrolyzed, fructose is formed.

Chemical composition of fresh fruits and vegetables. The nutritional value of fresh fruits and vegetables is due to the presence of carbohydrates, organic acids, tannins, nitrogenous and mineral substances, and vitamins in them. Fruits and vegetables improve appetite, increase the digestibility of other foods. Some fruits and vegetables have medicinal value (raspberries, black currants, grapes, blueberries, strawberries, pomegranate, carrots, etc.), as they contain tanning, coloring and pectin substances, vitamins, phytoncides and other compounds that perform a certain physiological role in the body person. Many fruits contain antibiotics and radiation-protective substances (antiradiants), which are able to bind and remove radioactive elements from the body. The content of individual substances in fruits and vegetables depends on their variety, degree of maturity, growing conditions and other factors.

Water. Fresh fruits contain 72-90% of water, nut-bearing fruits - 6-15, fresh vegetables - 65-95%. Due to the high water content, fresh fruits and vegetables are unstable in storage, and the loss of water leads to a decrease in quality, loss of their presentation (wilting). A lot of water is contained in cucumbers, tomatoes, lettuce, cabbage, etc., therefore, many vegetables and fruits are perishable.

Minerals. The content of minerals in fruits and vegetables ranges from 0.2 to 2%. Macronutrients in fruits and vegetables contain: sodium, potassium, calcium, magnesium, phosphorus, silicon, iron; from micro- and ultramicroelements contain: lead, strontium, barium, gallium, molybdenum, titanium, nickel, copper, zinc, chromium, cobalt, iodine, silver, arsenic.

Carbohydrates. Fruits and vegetables contain sugars (glucose, fructose, sucrose), starch, fiber, etc. The percentage of sugars in fruits is from 2 to 23%, in vegetables - from 0.1 to 16.0%. Starch accumulates in fruits and vegetables during their growth (in potatoes, green peas, sweet corn). As vegetables (potatoes, peas, beans) ripen, the mass fraction of starch in them increases, and in fruits (apples, pears, plums), it decreases.

Fiber in fruits and vegetables - 0.3-4%. It makes up the bulk of their cell walls. When some vegetables (cucumbers, radishes, peas) become overripe, the amount of fiber increases and their nutritional value and digestibility decrease.

Organic acids. Fruits contain from 0.2 to 7.0% acids, vegetables - from 0.1 to 1.5%. The most common fruit acids are malic, citric, and tartaric. Oxalic, benzoic, salicylic and formic acids are found in smaller quantities.

Tannins give the fruit an astringent taste. There are especially many of them in quince, persimmon, mountain ash, pears, apples. Oxidized by the action of enzymes, these substances cause darkening of the fruit when cutting and pressing, and a decrease in their quality.

Dyes (pigments) give fruits and vegetables a certain color. Anthocyanins color fruits and vegetables in various colors from red to dark blue. They accumulate in fruits during their full ripeness, so the color of the fruits is one of the indicators of its degree. Carotenoids color fruits and vegetables orange-red or yellow. Carotenoids include carotene, lycopene, xanthophyll. Chlorophyll gives fruits and leaves a green color. When fruits ripen (lemons, tangerines, bananas, peppers, tomatoes, etc.), chlorophyll is destroyed and, due to the formation of other dyes, the color characteristic of mature fruits appears.

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 citrus fruits (lemons, oranges).

Glycosides (glucosides) give vegetables and fruits a sharp, bitter taste and specific aroma, some of them are poisonous. Glycosides include solanine (in potatoes, eggplants, unripe tomatoes), amygdalin (in seeds of bitter almonds, stone fruits, apples), capsaicin (in pepper), sinegrin (in horseradish), etc.

Vitamins. Fruits and vegetables are the main sources of vitamin C (ascorbic acid) for the human body. In addition, they contain carotene (provitamin A), vitamins of group B, PP (nicotinic acid), vitamin P, etc.

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

Fats. Most fruits and vegetables contain very little fat (0.1-0.5%). There are many of them in the kernels of nuts (45-65%), in the pulp of olives (40-55%), as well as in the pits of apricots (20-50%).

Phytoncides have bactericidal properties, have a detrimental effect on the microflora, releasing toxic volatile substances. The most active phytoncides of onions, garlic, horseradish.

Ticket (37)

Tubers

The potato is of great importance in human nutrition and is rightfully considered the second bread, and in Siberia it is jokingly called "Siberian fruit". It is widely used in food in a variety of forms - over 100 different dishes can be prepared from it. It serves as a raw material for various products - chips, potato crumbs, flakes, mashed potatoes, quick-frozen semi-finished products, as well as for the production of starch and alcohol. Potatoes are also important as a fodder crop.

Tuber structure. In a potato tuber, a top and a base are distinguished, i.e. the place of attachment to the underground stem. Young tubers are covered with a thin layer of epidermis. In the process of maturation, cells are formed in the epidermis, in which a cork substance accumulates, they coarse and turn into a dense skin - periderm. The thickness and density of the skin, its integrity, and the condition of the cork layer affect the quality and suitability of potatoes for storage.

Eyes and lentils are located on the surface of the skin. The eyes consist of a group of kidneys and are located at different depths in the thickness of the skin. Lentils are numerous small holes and serve as an apparatus for air exchange.

The core (pulp) of the tuber is divided into the outer, rich in starch, and the inner, more watery, which contains less starch.

Chemical compositionaw potato tubers depends on the variety, growing conditions, maturity of tubers, terms and conditions of storage, etc.

On average, potatoes contain (in%): water - 75.0; starch 18.2; proteins - 2.0; sugars - 1.5; fiber - 1.0; fat - 0.1; mineral substances - 1.1; pectin substances - 0.6.

A significant proportion of potato dry matter is carbohydrates, where starch accounts for a large proportion (in most table varieties, its amount is 15 - 18%).

Starch is unevenly distributed in the tuber: more in the outer layers and less in the center. Potatoes with different starch content have different technological properties, which determines their culinary use. Tubers with friable white or cream-colored flesh (i.e., containing a large amount of starch) are advisable to use for the preparation of mashed potatoes, potato products, soups - mashed potatoes. Tubers with firm or watery flesh - for soups, boiled and fried potatoes.

Most of the nitrogenous substances of potatoes are protein - tuberin, which is complete.

The amount of vitamin C in potatoes is on average 10 - 18 mg%, after 4 - 5 months of storage - 15 mg%, and there is more of it in the bark than in the core. As we can see, there is a relatively small amount of vitamin C in potatoes, however, given the place of potatoes in our diet, we can say that for most of the year we satisfy the body's need for ascorbic acid precisely due to this vegetable. Other vitamins in potatoes contain: B 1, B 2, B 6, B 3, PP.

There are very few organic acids in potatoes. Of these acids, there are malic, citric, oxalic, as well as chlorogenic, coffee, and cinchona. The latter predominate in tubers when they are damaged or diseased.

Economic and botanical varieties of potatoes... According to the ripening period, potato varieties are distinguished: early (their ripening period is up to 80 days), mid-early (80 - 90 days), mid-ripening (from 90 to 100 days), medium-late (up to 120 days), and late-ripening (from 120 to 140 days or more). ).

According to their purpose, potato varieties are subdivided into canteens, technical, fodder and universal.

For table varieties characterized by fast digestibility, good taste, shallow eyes, preservation of the natural color of the pulp during cutting and after cooking. To facilitate the process of cleaning tubers on potato-cleaning machines and to reduce waste, the best varieties are potatoes with a round or round-flat shape, of medium size.

Various factors influence the taste of potatoes and their culinary advantages: chemical composition (as we have already said, the amount of starch), size of starch grains, structure of skin and pulp, etc.

Technical grades used to produce starch and alcohol. They are characterized by high starchiness, and for starch production, varieties with larger starch grains are preferable.

Fodder varietiesmust have a high dry matter content.

Universal varieties have features that allow them to be used as canteens and for technical processing.

Depending on the starch content, potato varieties are distinguished with a low starch content (12 - 15%), medium (16 - 20%) and high (more than 20%), according to the size of starch grains - coarse-grained and fine-grained.

The most important zoned economic and botanical potato varieties suitable for long-term storage are: Agronomical, Berlichingen, Veselovsky, Lorkh, Lyubimets, etc.

The size of the tubers is determined by their largest diameter, and the shape - by the ratio of the width (largest transverse diameter) to length (largest diameter) - the shape index. For elongated tubers, this ratio is 1: 1.5 or more. Tubers with a smaller width-to-length ratio are considered round-oval. On this basis, the following forms of tubers are also distinguished: onion, round, oval, elongated-oval, long, etc.

The main types of color of tubers: white - with various manifestations of yellowness (Lorkh, Ogonyok); red - with shades from light pink to intense red (Woltmann, Berlichingen); violet-blue - from bright blue to light blue (Phytophtoric, Chugunka).

Tubers also differ in the external characteristics of the skin (smooth, flaky, reticulate), in the number of eyes and their depth (few, many, deep, superficial).

Tubers differ in the color of the pulp (white, white with pink spots, white-yellow, yellow, pink, blue-violet).

Quality requirements.Fresh food potatoes.

The quality of potatoes is determined by their appearance, size, and the presence of tubers with permissible deviations. The presence of soil adhering to the tubers should be no more than 1%.

Tubers should be whole, dry, not germinated, uncontaminated, free from diseases.

In a batch of potatoes, the content of tubers with greening of more than, of the surface, wilted, with slight wrinkling in a batch of potatoes of the current year, crushed, damaged by rodents, wet, dry, ring and button rot, late blight is not allowed (up to 2% is allowed in areas where this disease is spread) , slightly frozen, steamed and with signs of "suffocation", as well as tubers with foreign odors caused by the use of waste water for irrigation, pesticides. Such potatoes are used for feeding purposes and as a waste.

Potatoes that do not meet the requirements of the standard, but are suitable for sale and processing in excess of the allowed quantities, are considered non-standard.

Potatoes unsuitable for sale and processing are classified as waste (crushed tubers, less than 20 mm in size, frozen, damaged by rodents, affected by diseases).

In a number of foreign countries, according to the standards, potatoes are divided by quality into several commercial varieties: in the USA - into four varieties (selected, No. 1, commercial, No. 2), in Poland - into two varieties. The standards take into account the peculiarities of botanical varieties, more clearly define the nature of mechanical damage, more rigidly - the tolerance of damage, etc.

Jerusalem artichoke (earthen pear) - these are small tubers of a perennial plant, very undemanding to external conditions and growing in all regions of Russia, except for the northern ones. It is eaten fried, baked and boiled, and also used to obtain fructose and alcohol, is also important as a fodder crop.

Sweet potato - sweet potatoes (common in South America, Japan, China, India). In appearance, composition and storage conditions it is close to potatoes. Contains up to 20% starch and 3-4% sugar.

Ticket (38)

Roots

Types of root crops

Throughout the history of human civilization, people actively eat many types of root crops. In addition, the beneficial properties of root crops are used in folk medicine. as well as in the pharmaceutical and cosmetic industry. As a rule, root vegetables are famous for their vitamin and mineral composition, as well as nutritional value.

The distinctive properties of root crops are due to the chemical composition of this part of the plant, in which the reserve of elements necessary for growth, as well as vitamins and other compounds, is concentrated. Experts in the modern food industry operate with such a concept as table roots. In turn, table roots are understood as juicy underground components of crops that are grown for culinary purposes.

In addition to cooking, root vegetables are used as a highly nutritious and vitamin-rich pet food. All types of root crops belong to such plant families as Umbrella, for example, carrots, parsnips or parsley, as well as Astro, for example, Scorzonera and Cabbage, i.e. turnips, rutabaga or radish.

Root composition

The chemical composition of root crops, however, as well as other basic biological and consumer characteristics of products, depend primarily on the species of the plant. However, it should be especially emphasized that all types of root crops can boast of a unique and naturally balanced vitamin and mineral composition, which is enriched with a significant amount of compounds that are really vital for both the plant and the human body.

The composition of root vegetables contains nutrients, as well as vitamins of groups C, A, E, PP. In addition, the composition of root crops includes essential amino acids, minerals, natural sugar-containing and pectin compounds. Eating root vegetables regularly can significantly improve a person's health.

Roots

Root vegetables include vegetables, the edible part of which is an overgrown fleshy root. In some species, greens are also used for food. Depending on the structure of the root, three types of root crops are distinguished: carrot, beetroot and rare.

Carrot-type root vegetables are vegetables with an elongated root shape, which can be cylindrical, conical, elongated - conical, spindle-shaped and blunt or sharp. In root crops of this type, the bark (phloem) and the core (xylem) are clearly distinguished. There is a cork cambium between them. From above, the root crop is covered with natural periderm. In terms of composition and quantity of nutrients, the bark is more valuable than the core. Root crops of this type include carrots, parsley, celery, parsnips.

Beet-type root vegetables - vegetables with rounded, round-flat, oval or elongated roots. Presented by table and sugar beets. Only table beet is used as a vegetable crop. The root vegetable has dark red flesh with rings of a lighter toga, which is due to the alternation of xylem (light rings) and phloem (dark rings) tissues. The less specific gravity is occupied by xylem, the higher the nutritional value of beets.

Root crops of the rare type - vegetables with rounded, repetitive, elongated-conical roots. A feature of their internal structure is the radial arrangement of the secondary xylem, phloem, and parenchymal tissue. The cambial layer is located directly under the periderm. Root crops of this type include radish, radish, rutabaga and turnip.

For root crops of all types, common morphological features are characteristic: the head in the upper part with leaf petioles and buds at the base, the root body (the main edible part) and the root tip (main), and the beet-type root crops have lateral roots. The rest of the root crops have thin lateral roots during harvesting that are easily torn off and, as a rule, are absent. The tips of the root are the most vulnerable part of the root crop, therefore, during storage, it easily bogs down and is affected by microorganisms (white or root rot). Trimming the tip after harvesting improves the preservation of the root crop. From above, the root vegetables are covered with natural periderm (peel), adherent to the pulp and protecting it from adverse external influences.

The peculiarity of all root crops is their ability to heal mechanical damage by suberinizing cells, as well as their easy digestibility. The most easily withering are carrot-type root crops, radishes, the least - beets, radishes, turnips and rutabagas.

Ticket (39)

Tomato vegetables

Tomato vegetables include tomatoes, sweet and hot peppers, eggplants. They take about 20 % cultivated areas of vegetables, are widely used in the canning industry, home cooking, as well as fresh. Tomato processing products - tomato paste, sauce, mashed potatoes - are an integral part of many types of canned vegetables and fish. Tomato juice is one of the most popular drinks. Sweet pepper is a valuable raw material that is part of many canned vegetables. Hot peppers are used for pickling and pickling vegetables.

Tomato vegetables are heat-loving crops. They grow in the southern regions of Ukraine, in Moldova, the Lower Volga region, in the North Caucasus, in the Rostov region. The bulk of vegetables is produced by collective and state farms.

Tomatoes are grown mainly in seedlings. According to the ripening time, the varieties are divided into early (growing season 110-115 days), mid-ripening (120-130 days) and late-ripening (135-150 days). The fruit of the tomatoes is a juicy, multi-seeded berry. Consists of skin, pulp and seed chambers (from 2 to 6-8) The color of the skin and pulp is caused by dyes. Lycopene predominates in fruits with a red colored pulp, carotene and xanthophyll in yellow-colored fruits. The shape of the fruit is a varietal characteristic. There are fruits that are flat-round, round, plum-shaped, and conical. Fruit weight varies from 20-60 g in small-fruited varieties to 100-300 g and more in large-fruited.

In fruits, the following phases of maturity are distinguished: green (not finished growth), milky white, brown, pink and red (mature). Fruits of an intermediate degree of maturity - milky white, brown, pink - are capable of post-harvest ripening.

The chemical composition of tomatoes (in%): water - 93-94; dry matter - 6-7 (including sugars - 3-4); nitrogenous substances - about 1; fiber 0.6-0.7; organic acids - 0.5. The content of vitamin C is 20-40 mg%. Dry hot weather contributes to the accumulation of sugars in fruits. In a rainy, cool summer, fruits contain less dry matter and sugars, but more organic acids.

In the zones of commercial production of tomatoes, the following varieties are zoned: early- White filling. Kievskiy 139, Canning Kievskiy, Moldavskiy early, Talalikhin, Morning, Svitanok; mid-season- Volgograd, Donetsk, Custom 280, New Transnistria, Torch. The varieties suitable for machine harvesting include: Torch, Novinka Pridnestrovie, Kubansky Shtambovy, Nistru, Novinka Kuban.

Federal Agency for Education

GOU VPO "Samara State Economic University"

Department of Service

Course work

by discipline

Merchandising and examination of food products

on the topic

2nd year students

Full-time education

Specialty "Service"

Yakovishenoy Evgeniya Valerievna

Samara 2008

Introduction

I.I.The chemical composition of vegetables and fruits

I.II Group characteristics of vegetables and fruits

II.I The benefits of vegetables and fruits

II.II Harm 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 have taken place in human nutrition. Refined foods began to dominate in the diet, the consumption of animal products increased sharply, and the share of vegetables and fruits decreased. The added physical inactivity 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 microelements, 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 dishes are better absorbed by the body if they are consumed with vegetables. Vegetable dishes increase the secretion of the digestive glands and thus prepare the digestive tract for the digestion of protein and fatty foods. Therefore, it is useful to start lunch with vegetable snacks: vinaigrette 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 foods. Vegetables are very valuable and necessary for the body every day in all seasons.

In most regions of the Russian Federation, the consumption of vegetables and fruits fluctuates sharply and depends on the season. As a rule, there are enough of them 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 of the previous year's harvest is significantly reduced in the spring months. The lack 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. The daily intake of vegetables, except for potatoes, should be for an adult at all seasons of the year from 300 to 400 grams. This amount should never be reduced during the winter and spring months.

The cultivation of early vegetables, the development of the suburban greenhouse economy, and the improvement of storage and canning methods ensure their consumption all year round. Freezing is the best way to preserve vegetables and fruits, the most perfect for preserving their nutritional value and taste. Quick-frozen fruits and tomatoes are very healthy. It is gratifying that recently more and more of them appear on the shelves of our stores. Unfortunately, we still do not sufficiently use 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 period, 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 contains 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.

Chapter I

I . I The chemical composition of vegetables and fruits

Vegetables are divided into:

tubers (potatoes, sweet potatoes),

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

cabbage (white cabbage, red cabbage, savoy, Brussels sprouts, 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 biliary division.

Plants rich in essential oils - tomatoes, cucumbers, radishes, onions, garlic, horseradish - are distinguished by a 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.

Berries and fruits also have different effects on gastric secretory function. 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 juices 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 part of plants in free and bound form. Organic acids, minerals and 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 increases 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, then raspberries, tangerines, plums, strawberries, carrots, pumpkin, watermelon, peaches, and apples. Fructose is also easily absorbed by the body and, to a greater extent than glucose, is converted into fats. In the intestine, 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, 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 starch breakdown; in the intestine it is broken down into glucose. 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, which is used in the manufacture of marmalade, marshmallows, pastilles, jams. Protopectin is an insoluble complex 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 are involved 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 acid 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 flavor. 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, 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. 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 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, radish, horseradish, red pepper, 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. So, 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 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 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 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 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, white cabbage, salad.

Vitamin P reduces capillary permeability, participates in the redox processes of the body, improves absorption and promotes fixation of vitamin C in organs and tissues. Vitamin P shows 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 lipase enzyme. In the liver, carotene, with the participation of the enzyme carotenase, is converted into vitamin A.

Carotene is found in the 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, dry skin and mucous membranes develop in the body, 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. It participates in blood formation, 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.

The 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. When it is insufficient, the activity of the central nervous system is disrupted, skin lesions occur, and chronic diseases of the gastrointestinal tract. 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. From plant foods rich in vitamin PP are legumes, barley, white cabbage, cauliflower, apricots, bananas, melons, eggplants.

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, and 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 requirement 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 the 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 contained 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 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 oat groats, 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 most rich 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, oatmeal 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.

I . II Group 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 vegetables (radish, radish, rutabaga, carrots, beets, celery),

Cabbage (white cabbage, red cabbage, savoy, Brussels sprouts, 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).

The 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)

• false (strawberries).

Chapter II

II . I The 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, nature of work, and 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 are rich in vegetables and potatoes. Green vegetables contain the largest amount of acid-neutralizing compounds.

The 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 with dietary nutrition, fresh vegetables occupy a leading place. They are rich in ascorbic acid (vitamin C), which ensures the normal metabolism of carbohydrates and promotes the elimination of toxic substances from the body, resistance to many diseases, and reduction of 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. Cabbage contains vitamin and, which prevents the development of duodenal ulcer.

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

To meet the need for vitamins, carbohydrates, proteins, acids, salts, an adult needs to consume more than 700 g (37%) of animal food and more than 1200 g (63%) of vegetable food, including 400 g of vegetables daily. The annual demand for vegetables per person varies depending on the region of the country and is 126-146 kg, including cabbage of various types 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 absorption of proteins, fats, and minerals. When 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, and diluted ones increase it.

II . II Harm to vegetables and fruits

Many people understand that the attractive appearance of any fruit and the absence of obvious signs of rot or immaturity does not mean its suitability for food. Too many factors influence it on the long journey of turning the seed into a dish on our table. What is at least an unfavorable ecological situation in which nine-tenths of domestic greens are grown. Soil soaked through with harmful mixtures; air saturated with toxic exhaust from cars 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, collection, pre-sale preparation and 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 a tomato or apple, in order to subsequently move into your body. But that's not all. All kinds of additives and preservatives with which fruits and vegetables are stuffed are a huge problem. 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 the products. It makes no sense at all to talk about imported products, since the fruit cannot naturally preserve freshness and beauty, despite prolonged storage and long transportation. But domestic entrepreneurs do not hesitate to use "chemistry" to give an attractive appearance to their agricultural products. And everything would be fine if proper control over the quality and conformity of such additives was carried out. But many not very clean businessmen do not bother themselves 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 - according to their detection in food products grown in fertilized fields. The word "pesticides" literally translates from Latin as "I kill the infection." At one time, this drug became a salvation for agriculture. Later - a misfortune. Humanity faced the question: in connection with the progress of fresh fruits and vegetables - benefit or harm to the body? Today, many US universities have decided to teach only traditional farming. And, nevertheless, 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. Fruits and vegetables are tested for 4 pesticides only in one central laboratory in Moscow. And then, if suspicions arise. But, according to experts, this lack of attention to the problem is explained not by lack of money, but by the lack of it. We do not actively use pesticides just because they are expensive in our country. In any case, they can be washed off with water; you just need to wash the fruit well. It is 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 for an adult is 300 milligrams, for a child and an elderly person it is even less. Therefore, it is better not to rush to vitaminize your body with early fruits, the most dangerous of which is watermelon. To ensure redness, sellers inject a syringe of vodka into the stalk. Only the inventors themselves never eat their "drunken" 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 environmental situation or the presence of nitrates in fruits, vegetables and fruits in excessive quantities are harmful in themselves. For example, apricots, especially fresh ones, should not be eaten on an empty stomach, as well as after ingestion of indigestible food (mushrooms, beans, peas). Drinking cold water after taking apricots causes diarrhea. Fresh apricots are harmful to 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 mellitus. The side effects of apricots on the digestive tract can be prevented or eliminated 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, and a feeling of fear. In severe cases, convulsions and loss of consciousness are noted. One of the symptoms of poisoning is the staining of the mucous membranes of the mouth in a scarlet color. When breathing, the smell of bitter almonds is sometimes felt. Home treatment may include gastric lavage, cleansing enemas. When using apricot seeds in small doses, poisoning does not occur.

Orange juice is contraindicated in the period of exacerbation of gastric ulcer and duodenal ulcer, in diseases of the pancreas and small intestine.

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

Eggplant. When the eggplants are fully ripe, the amount of the alkaloid solanine M increases sharply in them, so young and small 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 arrival of the doctor: the patient is given milk, mucous soups, egg white.

Hawthorn. Long-term and uncontrolled intake of hawthorn or medicines developed on its basis can cause depression of the heart rhythm, therefore, treatment with hawthorn must be carried out under the supervision of a doctor. 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 onset of intestinal colic.

Grapes. It is better to eat grapes not earlier than 2 days after cutting from the bushes, since fresh, just picked grapes cause the formation of a large amount of gas (this is especially important to remember for people suffering from diseases of the stomach, intestines, kidneys and urinary tract). Such patients should drink only grape juice, and throw away the peel. Treatment with grapes is contraindicated in a number of chronic diseases such as diabetes mellitus, diseases of the gastrointestinal tract, etc. Therefore, self-medication with grapes is best avoided. In this case, it is advisable to seek medical advice. In addition, grapes cause tooth decay, so after consuming it, you should rinse your mouth with water and a little soda.

Pear. As with any fruit, pear should not be overused. 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, do not drink raw water or eat dense and heavy foods.

Wild strawberries. Some people have hypersensitivity to strawberries, which causes an allergic reaction with persistent hives (pruritus). In this case, you cannot use strawberries.

Melon. Overeating melon can lead to intestinal dysfunction. Melon is contraindicated in diabetes mellitus, gastric ulcer and duodenal ulcer, dysentery and other intestinal disorders. Do not consume melon with alcoholic drinks, honey, or wash it down with cold water. This can cause bloating, intestinal colic, and severe diarrhea. Melon is also contraindicated in nursing mothers, as diarrhea can occur in the baby.

Fig. Due to the high sugar content, figs are contraindicated in patients with diabetes mellitus, in 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 high acidity of gastric juice and diseases of the pancreas.

Potatoes. One feature of potato tubers should be warned - 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 clearly declare their changes themselves - they turn green in the light. Poisonous substances are formed only in this green surface of the potato, without penetrating into the depths. Another inconvenience that we face when storing potatoes is the appearance of white stolons - "sprouts". At the same time, the nutritional quality of the 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 their uniforms," \u200b\u200bthe sprouts must be broken off, since they contain the same toxic substances as in the green tubers.

Kinza. As a green seasoning, cilantro should not be used for stomach ulcers, coronary heart disease, thrombophlebitis, diabetes mellitus, hypertension. In addition, when nitrogen fertilization is excessively introduced into the soil, plants accumulate nitrates, sometimes causing food poisoning.

Hazelnuts (hazelnuts) Hazelnuts are good only in small quantities. It is enough to eat a little more than usual and the person will soon have headaches in the middle of the head. This is due to the fact that taking nut kernels causes spasm of the cerebral vessels.

Lemon. Lemon and products based on it are non-toxic. However, they can harm patients with gastritis, gastric ulcer and 12 duodenal ulcer. Their lemon causes heartburn, severe spastic pains and even vomiting. So such patients should eat lemons only in small quantities (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.

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

Carrot. Do not eat root vegetables and the tops of root crops that are on the surface of the earth and have a 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. Salted and pickled cucumbers should not be eaten by patients suffering from gastrointestinal ailments with increased acidity of gastric juice, hypertension, as well as atherosclerosis, hypertension, heart defects. Pickled and pickled cucumbers stimulate the appetite, so they are contraindicated in obesity.

Walnut. Nut 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. Bitter pepper should not be used for hemorrhoids, for 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), heart rhythm disturbances, hypertension, gastric ulcer and intestinal ulcers, suffering from gastritis with increased acidity of gastric juice, colitis, with exacerbation of chronic liver and kidney diseases, hemorrhoids, with increased excitability of the nervous system; with epilepsy and insomnia.

Peach. Peach, due to its high sugar content, cannot 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 gastric ulcer and 12 duodenal ulcer. These patients usually experience severe stomach pains 10-15 minutes after taking rhubarb. Rhubarb should not be used by patients with nephrolithiasis. It is dangerous to use rhubarb for children and pregnant women.

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

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

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

Chokeberry. Excessive consumption of chokeberry is 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, gastric ulcer and 12 duodenal ulcer, as well as gastritis.

Garlic. Garlic should not be consumed by patients with epilepsy, hypertension, kidney inflammation, as well as pregnant women.

Sorrel. Sorrel is not recommended for use in case of salt metabolism disorders (rheumatism, gout) and related diseases, with intestinal inflammation and tuberculosis. Never eat boiled sorrel as it contributes to the development of arthritis.

Chapter III

III . I The harm and benefits of watermelons

Let's analyze the benefits and harms of fruits using a specific example of watermelons.

The watermelon originates from the wild plants of tropical Africa. The center of origin of botanists is considered the Namib Desert and the Kalahari semi-desert, where you can still find thickets of wild watermelon in the valleys. The 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 a very valuable oil from its seeds. In Europe, the watermelon ended up after the Crusades. It was brought to Russia in Vstrongstrongstrong-X centuries from India during the time of lively trade with Kievan Rus. Initially, it took root in the Volga region, and by the XVstrongstrong century it was widely distributed and grown even in the central regions as a greenhouse culture.

The most popular watermelons in Russia are definitely Astrakhan. This is a kind of brand, a guarantee of taste and quality. Traders know this very well and often shamelessly take advantage of the gullibility of unsophisticated 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, the trial harvesting of watermelons takes place in early August, selective - in the middle of the month, but the mass one starts on the 25th, so the native striped "Astrakhanians" 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 entered wide practice, in addition, 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-season varieties (traditional Astrakhan watermelon), spurred on by nitrogen fertilizers and, above all, ammonium nitrate. This option is more common and completely indifferent to health. Let us 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. This means that even patients with insulin-dependent diabetes can eat sweet watermelon.

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 cores are also useful for a reason, which we will discuss in the next section.

Watermelon is a real treasure of magnesium, without which a person simply cannot do. Chronic lack of magnesium in food leads to high blood pressure. Magnesium and its companion, calcium, provide for the narrowing and dilation of blood vessels, a mechanism that maintains the stability of blood pressure in the body.

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

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

Watermelon is rich in potassium, although it is less than in dried apricots, bananas and persimmons, but if we compare the calorie content of the same bananas and watermelon, then the “Russian” grown on melons 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 as steroid anabolic steroids for bodybuilders: growth is accelerated and an impressive weight and volume of the fetus is gaining very quickly. Everything would be fine, but nitrates categorically refuse to leave the watermelon. And acute poisoning with nitrates at this time of year is by no means uncommon. It is especially difficult in children, since nitrates compete with oxygen for our hemoglobin. And instead of carrying oxygen, hemoglobin (in the form of methemoglobin) causes serious problems with cellular respiration.

Nitrates have another bad feature - they 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 devices that determine the content of nitrates in fruits and vegetables, like the portable "Marion", can help.

The next danger that can lurk in the watermelon, as well as on its surface, is microbes. The fruit ripens on the ground, then transported, stored - and all this is far from sterile. If the watermelon cracks during loading and unloading, then the flowing juice not only attracts well-known carriers - flies - but also becomes an excellent breeding ground for a wide range of microorganisms that love the human body, causing acute intestinal infections.

A common technique of sellers - to prove the ripeness of a watermelon, to cut a small pyramid out of it, show it to the buyer and insert it back into the watermelon (sale "on the cut") does not bode well either.

Conclusion

Vegetables are of great importance in human nutrition. The 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 with dietary nutrition, fresh vegetables occupy a leading place. They are rich in ascorbic acid (vitamin C), which ensures the normal metabolism of carbohydrates and contributes to the elimination of toxic substances from the body, resistance to many diseases, reduction of 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. Cabbage contains vitamin and, which prevents the development of duodenal ulcer.

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

Attachment 1

Nutritional value of vegetables

This table provides the following information: the amount of proteins, fats, carbohydrates and fiber in some vegetables, as well as the calorie content per 100 g of product.

Appendix 2

Nutritional value of fruits

This table provides the following information about some fruits: the amount of proteins, fats, carbohydrates and fiber, as well as the calorie content per 100 g of product.

Used sources

vegetable fruit chemical composition

1.A.A. Pokrovsky "Conversations on Nutrition" M. Economics 1994

2.D.I. Grave. V.S. Mikhailov "Reserves of plant food" K. Shtiintsa 1996

3.V.G. Liflyandsky. M.N. Andronova "Healing properties of food" SP. ABC 1997

4. Commodity science and organization of trade in foodstuffs. Moscow. 2000 year

5. Korobkina Z. V. Commodity research. - M .: Economics, 2002.

6. Brozovsky D.I., Borisenko N.M. Fundamentals of commodity science. - M .: Economics, 2004.

7. Drobysheva S.T. and others. Theoretical foundations of commodity science of food products. - M .: Economics, 2005.

8. Bazarova V.I., Borovikova L.A. and other Research of food products. - M .: Economics, 2006.

9.http: //www.tharnika.ru/

Introduction

2. Classification of fresh fruits and vegetables. Characteristics of individual species

3. Transportation and acceptance of fresh fruits and vegetables

4. Processes during the storage of fresh fruits and vegetables

5. Factors affecting the safety of food

Conclusion

List of references

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 such vitamins vital for the human body 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.

1. 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 nut-bearing, 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 mountain ash, plums, 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.

1. 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 consist of many small berries that have grown together on one fruit. This group includes raspberries, blackberries, stoneberries and cloudberries;
• Walnuts, which are subdivided into real nuts (hazelnuts) and drupes (walnuts, almonds). All nuts are composed 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 colder 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 for which leaves, stems, roots and their modifications are used are vegetative. And vegetables in which fruits are used for food are called generative.

Among vegetative vegetables, depending on the parts 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, eggplant, pepper);
• pumpkin (cucumbers, pumpkin, zucchini, melons, watermelons, squash);
• legumes (peas, beans, beans);
• cereal vegetables (sweet corn).

1. Transportation and acceptance of fresh fruits and vegetables

When transporting fresh fruits and vegetables, it is necessary to comply with specific requirements due to their properties. In particular, the transport of fresh fruits and vegetables without packaging is not allowed. Some fruits and vegetables (potatoes, cabbage, beets) are transported in bulk during the period of mass harvesting. When transporting watermelons without packaging, they must be thrown with straw.

During the acceptance of fresh fruits and vegetables, their quality is assessed by general and specific indicators in accordance with the current instructions. General indicators include appearance and size. Deviations in size are allowed only within the normal range.

Specific indicators include:

• The degree of maturity, which is subdivided into consumer, volumetric and physiological. Cucumbers are sold only to the consumer degree of maturity, physiological degree of maturity is not allowed. For some fruits (apples of late varieties), the volumetric physiological degree of maturity is the same;
• Taste and smell;
• The density of the bunch, the presence of incomplete brushes, the number of grapes that fell off;
• Moisture (determined only for nuts);
• Consistency (for bananas and oranges).

During the acceptance of the fruits of vegetables, sorting is carried out, while the following quality categories are distinguished:

• Standard fruits and vegetables - meet the requirements of current standards; also includes defective fruits and vegetables within the tolerance limits;
• Non-standard fruits and vegetables with defects, limited to acceptable standards, but in excess of the established standards;
• Waste with defects, not allowed by the standards.

1. Suitable Processes for Storing Fresh Fruit and Vegetables

During storage, various physical and biological processes occur in fruits and vegetables, such as evaporation of moisture, respiration, ripening, healing and thickening of the skin, hydrolytic decomposition of complex organic substances.

Breathing is the most important biochemical process and serves as a source of energy for metabolic processes. Breathing is accompanied by loss of mass of fruits and vegetables, release of energy, heat and moisture. In the process of breathing, there is a change in the gas composition of the environment surrounding the product, significant losses in both the quantity and quality of fresh fruits and vegetables.

The intensity of the respiration process depends on the type of fruits and vegetables, their physiological state (degree of maturity, freshness, damage, moisture content) and storage conditions (temperature, illumination and gas composition of the environment).

Breathing is oxygen-free (aerobic) and oxygen-free (anaerobic).

Hydrolytic processes: under the influence of enzymes, hydrolysis occurs, and always in the presence of water.

1. Factors affecting the safety of food

fruit vegetable nutritional value

Temperature is one of the most important conditions for storing food. Temperature affects the intensity of all processes. As the temperature rises, the evaporation of water increases, the activity of enzymes increases, chemical reactions are accelerated, and conditions are created for the development of pests.

The optimal temperature indicators for different products are different. Their range ranges from -18 to +25 degrees. For most products, freezing almost completely excludes the occurrence of harmful chemical processes, although there are those for which the optimal temperature is from 0 to +4 degrees and its fluctuations are highly undesirable.

Air humidity. This factor is closely related to temperature. The choice of relative humidity depends on the product. Dry food requires low moisture content (65-70%); food with high moisture content requires 85 to 90% moisture.

Gas environment. The increased oxygen content in the atmosphere and its contact with the product lead to the oxidation of fats (staff), to a change in the color of wines. The gas composition of the medium can be changed. Oxygen must be excluded from the gas environment. The inclusion of inert gases in the gas composition of the medium, on the contrary, has a positive effect on the storage of many products.

Most often, a controlled atmosphere is used when storing fresh fruits and vegetables. In it, the proportion of oxygen decreases, and the proportion of carbon dioxide increases. This leads to a delay in the processes of ripening and overripening, a decrease in the activity of microbiological diseases, the consistency of the products is better preserved.

In addition to the controlled gas environment, a modified gas environment is used. It involves the use of polymeric films with a selective medium.

Shine. Almost all foods require no light. For example, when storing potatoes in the light, a green poisonous substance is formed on the surface of the tubers - corned beef. Light destroys vitamins, negatively affects the properties of colored products, especially when using natural dyes.

Ventilation is most important when storing plant products. Distinguish between natural, artificial and forced ventilation. The latter is used in modern vegetable stores and provides better preservation of products.

Sanitary regime. It includes disinfection and pest and rodent control measures.

The quality of packaging materials.

6. Nutritional value of fruits and vegetables

The nutritional value and organoleptic (taste and aroma) properties of vegetable fruits are determined by the chemical substances of which they are composed.

The composition of herbal products includes proteins, fats, carbohydrates, vitamins, organic acids, minerals and trace elements.

The predominant component of all raw materials is water. Its fruits contain 75-90%, and vegetables - 65-96%.

Proteins. Protein substances play an important role in human nutrition. The main sources of protein are meat and fish. In vegetables and fruits, the protein content is relatively low. However, due to the special importance of protein nutrition, plant products should be used as an important additional source of protein.

Fats are essential in nutrition. The fat content in the tissues of fruits and vegetables is very low; they are found in significant quantities in seeds. Vegetable oils contain essential linoleic and linolenic acids, which have a higher biological value and are better absorbed by the body than animal fats.

Carbohydrates are an energy material and serve as a reserve nutrient for the human body. Fruits are especially rich in carbohydrates from plant materials. They contain carbohydrates mainly in the form of various sugars (sucrose, glucose, fructose) and starch. The main part of carbohydrates in a normal diet enters the body in the form of starch, and only a small part in the form of sugar. The starch in the body is converted into glucose, which is absorbed into the blood and nourishes the tissues of the body.

Vitamins are substances necessary for the normal functioning of the human body. They increase the efficiency and resistance of the body to infectious diseases, have a positive effect on its growth and development.

Vitamin C is an antiscorbutic agent and is essential for proper growth and development of the body.

The main source of vitamin C is vegetables, fruits, berries, rose hips, black currants, lemon, orange, etc.

Vitamin A is one of the most important and abundant vitamins for the normal growth of the body. The lack of this vitamin in the human body lowers its immunity to various infections.

Free vitamin A is found only in the liver oil of marine fish and whales. Vegetable raw materials do not contain vitamin A, but they contain provitamin A - carotene, from which vitamin A is formed in the human body. Carotene is rich in apricots, black currants, sweet red peppers, plums, carrots, spinach, red tomatoes and green peas.

Vitamin B1 is found in almost all fresh fruits and vegetables, baker's and brewer's yeast. The absence or lack of this vitamin in the body causes disorders of the nervous system.

Vitamin B2 is found in carrots - 0.005 - 0.01 mg per 100 g, in cabbage, onions, spinach, tomatoes up to 0.05 mg per 100 g.

Vitamin D is extremely important for children, since its insufficient content in food leads to rickets. This vitamin is found only in animal products.

The richest source of vitamin D is fish oil, liver of animals and birds. Vitamin D is found in milk, butter, and egg yolks.

Vitamin E is widespread in nature; it is found not only in animal products, but also in many plant foods. The most rich in vitamin E are the germ of cereals and green leaves of plants.

Organic acids. All fruits and vegetables contain certain organic acids.

Organic acids play an important role in metabolism. In the human body, they dissolve some unwanted deposits.

Meat and fish contain lactic acid. In fruits and vegetables, malic, citric, tartaric and other acids are most common.

Malic acid predominates in pome fruits, as well as cornel, apricots, peaches, tomatoes and berries. Citrus fruits and cranberries contain a lot of citric acid. Tartaric acid is found in grapes. Sorrel and rhubarb are rich in oxalic acid.

Minerals. The main minerals are calcium, sodium, potassium, iron salts, as well as sulfur, phosphorus and chlorine. Mineral salts are found in every cell of a living organism. Without them, as well as without water, life is impossible.

Iron salts are rich mainly in lettuce, cabbage, strawberries, apples, potatoes, peas, fish, meat, eggs; potassium salts - radishes, spinach, carrots, cabbage, oranges, lemons, tangerines. Correct and rational use of products, as well as the implementation of the recommended processing regimes for canning, allow you to almost completely preserve the nutrients and vitamins contained in them.

Conclusion

Having carefully studied the above material, I can draw the following conclusions.

Some fruits and vegetables have a lot of moisture, therefore, they cannot be stored for a long time, because moisture is a good breeding ground for putrefactive bacteria and microbes.

There are two main features of the classification of fruits:

• By structure
• By origin.

During storage, various physiological and biological processes take place in fruits and vegetables, such as moisture evaporation, respiration, ripening, healing and skin tightening.

The safety of fruits and vegetables is influenced by such factors as: temperature, air humidity, gas environment, light, ventilation, sanitary regime, quality of packaging materials.

List of references

1. Merchandising of food products Burova Marina - M .: "PRIOR Publishing House", 2000. - 144p.
2. Home canning G.G. Tokarev. - D66 SPb .: LLC Publishing House "Polygon", 2004. - 220c .: ill.

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 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 areas, 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 ,8 %. The starch content in fruits and berries reaches 1%. Most 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 it contributes to the normal functioning of the intestines.

Pectinsubstances- These are high-molecular 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 intercellular spaces and in 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 when cooking 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 preserving or cooking fruits. So, 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.