The chemical composition of food goods

For maintaining the normal vital activity of the organism of human, compensation of his power expenditures and the restoration of cloths are necessary the nutrients. They enter the human organism together with the food, which is for it the energy source, by construction (plastic) material they participate in the regulation of the processes of exchange of substances. The chemical composition of products is diverse and depends on the chemical composition of source material, technological regime and method of production, conditions of storage and transportation and other factors.

Inorganic and organic matters enter into the composition of food goods. To the inorganic substances include the water and mineral (ash) connections; to the organic - carbohydrates, fats, ferments, vitamins, organic acids, which color, aromatic and other.

1. Inorganic substances

Water has important significance for the human organism, since it is the component part of its cells and cloths and it is necessary for the realization of biochemical processes. It plays important role in the maintenance of a constant temperature of body. To adult person it is necessary in average 1750-2200 g of water in a 24 hour period. This need is covered, first of all, due to the drinking water and the food. Living organism is very sensitive to a deficiency in the water: severe indisposition is experienced with loss by 10% of moisture of men, while death begins with loss by 20%.

Water is located in all products, but in different quantities: in the sugar - 0,14%; in the flour - 12-14; in the bread - 40-50; in the meat, the fish - 65-80; in the vegetables, fruits -65-95%, and etc.

They conditionally divide into the free and connected the water, which is contained in the foodstuffs. It significantly influences the nourishing value, the fitness for the storage, the taste, the consistency of products. The products, which contain a large quantity of free water, relate to those being perishable, since it is favorable medium for the microorganisms and products rapidly undergo damage (putrefaction, molding, fermentation). On the contrary, the products, in which it is small water, are more posting in the storage. At the same time the products, rich in moisture, have the low energy value (although their biological value can be high). Each product must contain water in the specific quantities, what provided in many standards is one of the basic qualitative exponents. Depending on the special features of products themselves, and also conditions of environment they can lose moisture or, on the contrary, be moistened. The high hygroscopic (ability to absorb moisture) possesses sugar, salt, flour, dry fruits and vegetables, caramel and other products. The decrease of moisture in the fresh fruits, the vegetables, the boiled wurst, the meat, the fish and others during the storage leads to lowering in the quality and commodity losses.

The definite requirements are presented to the drinking water. It must be clean, transparent, colorless, without the smell, outside aftertastes and harmful microorganisms, the moderate hardness or soft.

Mineral substances are otherwise called ash elements, since after the combustion of product they remain in the form ashes. Ash elements have great significance for the vital activity of the human organism: they enter into the composition of cloths, they participate in the exchange of substances, in the formation of ferments, hormones, digestive juices. Deficiency or absence of separate elements in the organism leads to the severe illnesses. To the human organism be required in a 24 hour period 20-30 g of ash elements.

Depending on the content in the products ash elements divide into macro cells (calcium, phosphorus, sulfur, potassium, sodium, iron, magnesium, chlorine and others) and the micro cells (iodine, copper, aluminum, zinc, cobalt, manganese, fluorine and other). Are separated also ultra-micro cells (radium, thorium, mercury and others). Each of the mineral substances plays the leading role in the vital activity of organism. For example, phosphorus participates in the respiration, it is necessary for the normal activity of nervous system and work of muscles; potassium contributes to isolation from the organism of water and salts of sodium; iron participates in the formation of hemoglobin of the blood; iodine ensures the normal activity of the thyroid gland; manganese and fluorine contribute to the formation of the bones and etc.

Some elements are necessary for the organism in very small quantities (copper, lead, zinc, tin and others) and with their content in significant quantities become poisonous and dangerous for the life. The especially large danger in this respect presents the conserve foodstuffs, processed in the copper equipment and which were being stored in the hermetically sealed metallic banks for a long time. Therefore the content of copper, zinc, tin strictly is limited in food products, but the presence of salts of mercury, lead, and arsenic is not allowed.

The sources of mineral elements are products of plant and animal origin, and also drinking water. Are especially rich in mineral salts the vegetables, the fruits, grain flour, the products of sea and others.

Ash content is the qualitative index with the determination of the type of flour, starch, and also is characterized the value of the surface finish of product (sugar, cocoa- powder).

1. Organic substances

Carbohydrates are contained in essence in the products of plant origin. They play the leading role in the plastic processes and the functional activity of individual organs, the exchange of substances and the safety reactions of organism. On the average to adult person be required in a 24 hour period 400-500 g of carbohydrates. With the deficiency in the food ration of carbohydrates to the production of energy in the organism is expended more than protein, and the superfluity of carbohydrates leads to formation and deposit into the bones person of fat. With the oxidation of 1g of the available carbohydrates in the organism it is allocate by 3, 75 kcal (15, 7 kJ) of energy.

Carbohydrates divide into the monosaccharide (simple of sugar), oligosaccharides (complex of sugar) and polysaccharides (not sugar alike).

Monosaccharide (glucose - grape sugar; fructose - fruit sugar). They sweet, are dissolved well in the water, are easily mastered by the human organism, easily they ferment by yeast(s), by the lactic acid bacteria (these properties they are used with the production of alcohol, faults, grain crops, sour fruits and vegetables, sour-milk products).

Oligosaccharides (saccharine - beet bin or reed sugar; maltose – malt sugar; lactose - milk sugar). They all in the process of exchange of substances are converted into the monosaccharide. They, as the monosaccharide, sweet, are dissolved well in the water, they are easily mastered by the human organism; under the action of the ferments of the digestive tract easily they will be hydrolyzed, and in the industry this property is used with obtaining of artificial honey; with the heating they are caramelized (they are formed the dark-colored substances); are crystallized, i. e. they are sugared (during the storage of jam, candies, caramel, honey).

Polysaccharides (starch, glycogen, inulin, cellulose tissue and other) do not possess sweet taste; therefore they are called not sugar alike carbohydrates.

Starch is accumulated in the form grains of the characteristic of form and size in the bulbs, the roots, the stems, the seeds of plants. Is most rich in starch of grain of herbs, potatoes, flour, and bread. In the water the starch is not dissolved, while in the hot - it will swell and paste is formed. Under the action of ferments, acids the starch is splinter to the glucose and is mastered well by the human organism.

Glycogen (animal starch) performs the role of reserve nutrient in the organism; it is formed from the glucose. It is contained in the liver, the meat, and the fish. Glycogen participates in the fermentative processes during ageing of meat after the slaughter of animal.

Inulin is encountered in the plants more thinly frequently than starch. It is located in the roots of chicory, the tubers of girasol and others.

Cellular tissue (cellulose) enters into the composition of the integument cloths of plants, composing the basis of cellular walls. It is barely mastered by the human organism because of the absence of ferments for its splitting to the glucose; however, it strengthens the peristalsis of bowels, the secretion of gastric juice and contributes to the movement of food. The high content of cellulose tissue in the product reduces its nourishing value and comprehensibility.

Fats - these are the esters of triatomic alcohol of glycerin and different fatty acids. In the organism the fats participate in the exchange of substances, the synthesis of proteins, the formation of cloths, serve as the source of the fat-soluble vitamins (A, D, E, K), are the source of energy (with the oxidation 1 g of fat it is allotted by 9,3 kcal. The daily need for the fats on the average is 80-100 g.

By the origin distinguish fats plant, animals, combined; depending on consistency and those and, etc are liquid and solid.

Fats have a number of general properties. They more easily water; they are dissolved in the organic solvents (gasoline, acetone, ether); with the water the fats in the presence of weak alkalis, proteins or other colloids can form emulsions, i. e. to be distributed in the water in the form of the smallest balls (in the milk), or vice versa, the smallest droplets of water. They distribute in the fat (in the margarine, the mayonnaise); fats are non-volatile, but with the strong heating (240-250°С) they are decomposed with the formation of the substances, which have unpleasant smell and which irritate the mucous membrane of eyes. During the storage in air (long before of light, oxygen, heat) the fats are oxidized, which leads to rancidification and salting, reduction in the quality of products and formation of aldehydes, ketones and other harmful for the organism substances.

Fats are contained in many foodstuffs, but in different quantities. There are many fats in oil, fat, margarine, pork, nuts and others. It is very small fat in the majority of fruits, vegetables, in some forms of fishes (pike, pike-perch, codfish) and others.

Oily substances enter besides fats into the composition of foodstuffs. The greatest value has a lecithin (in the sour cream, the cream, butter, eggs, liver, roe and others). It contributes to the correct exchange of fats in the organism, detains the development of atherosclerosis, and prevents the deposit of fat in the liver.

Proteins - chief constituent of the food. Without them cannot exist not one living cell. They are necessary for constructing the cloths of body and restoration of the dying off cells, formation of ferments, vitamins, hormones and immune bodies; as the construction, plastic and energy material (1g of protein gives 4,1 kcal (16,7 kJ). Not prosperity of protein in the nourishment leads to the delay of the growth of children and to a whole series of heavy disorders in the organism of adult. The daily need of adult person for the proteins is 80-100 g, including half they must compose animal proteins.

Proteins consist of amino acids. Some amino acids are synthesized in the organism, but there are nine amino acids, which in the organism cannot be synthesized, they are irreplaceable. The proteins, into which enter all irreplaceable amino acids, are called full (proteins of meat, fish, eggs, milk). The proteins, which do not contain of at least one irreplaceable amino acid, carry to the inferior (proteins of millet, corn and others). Therefore for the satisfaction of the needs of organism for the amino acids it is necessary to use different combinations of products. Thus, the proteins of grain flour goods it is expedient to combine with the proteins of milk, meat, and fish.

In composition proteins divide into the simple (proteins) and the complex (proteids). The simple proteins include: albumen, globulins, glutelin, prolamine; to the complex - phosphoproteins, chromium proteins, the glucoproteids.

In the organism of animals, plants and food products the proteins are located in the liquid state (milk, the blood), semi-fluid (egg) and solid (sinew, hair, nails).

Proteins have a number of the general properties: with heating higher than 50-60°C they are denatured (with the melting of eggs, obtaining of cheese and sour-milk products it is formed cluster); almost all proteins will swell in the water and increase in the volume (with the production of bread, the melting of macaroni articles, croup); under the action of ferments, acids, alkalis - they will be hydrolyzed (during ripening of cheeses; to the damage of meat, fish).

Ferments - this of the substance of protein nature, the accelerating chemical reactions, which flow in the living organism. Otherwise they call them biocatalysts. There is not one process of vital activity, which would manage without the participation of various ferments. Ferments are manufactured only by living cells of plants, animals, microorganisms, but they manifest their action both in the cell and outside it.

Ferments have exceptionally important significance in the nourishment of man. Over-boiling and mastering proteins, fats, carbohydrates flow with the participation of the ferments, isolated by the cells of organism. Ferments play large role in the production of many food goods (grain crops, beer, tea, sour fruits and of vegetables, sour-milk products, cheese and other). In the industry different fermentation preparations widely are used. For shortening of the duration of the processes of production and improvement in the quality of products. In the process of storage the ferments can have both a positive and negative effect on quality. The positive action of ferments is manifested, for example, during the ripening of fruits and vegetables, ripening of meat and fish, storing of flour, cheese and other goods. In certain cases ferments can cause worsening in the quality or spoiling of foodstuffs (acescence milk, the rancidification of fats, the germination of grain, the appearance of sweet taste in the potatoes, damage of meat, fish and i.e.).

Ferments possess the properties of protein substances; they undergo, intumescense denaturing and other changes under the effect of the chemical and physical actions. The characteristic properties of ferments are: specificity (each ferment acts only on the specific substance, for example, ferment saccharine it splits only saccharine; lactase - lactose); sensitivity to a change in the temperature - most favorable 30-50°[S] (with the heating to 70-80°[S] and above ferments they are destroyed, and at a minus temperature they remain, but activity sharply it is lowered). An increase in the humidity of product strengthens the action of ferments, their activity slows down during the desiccation; some ferments act only in the acid medium, others - in the neutral, some manifest activity in the alkaline medium.

Vitamins. They are irreplaceable in the nourishment of man, they contribute to normal exchange of substances, to increase in the organism, and they increase its resistibility to the diseases. With the long absence of vitamins in the food appear severe illnesses - avitaminoses, with their deficiency - hypovitaminoses, their excess entering into the organism it leads to hypervitaminosis. The majorities of vitamins designate by the letters of Latin alphabet, but are established also the designations of vitamins by their chemical composition; All vitamins conditionally divide into the fat-soluble (A, D, E, [k]), water-soluble ([s], R, [RR], group in others) and vitamin alike substances.

A deficiency in the vitamin A (retinol) in the organism leads to the delay of increase, the diseases of eyes, reduction in the resistibility of organism to infections. Vitamin A is encountered in the products of animal origin (liver cracks, butter, egg yolk and other). In the plant food it is found in the form carotene, which under the action of ferments is converted in the organism into the vitamin a. There is much carotene in the carrot, the apricots, the pumpkin and others; it is better mastered by organism together with the fats.

Vitamin D (calcipherol) regulates mastering calcium and phosphorus by organism. It is contained in the products of animal origin (fish oil, butter, the liver of animals, the yolk of chicken eggs). It has provitamins, which under the action of solar rays can be converted in the human organism into the vitamins D2, D3.

Vitamin E (tocopherol) is called the factor of multiplication. Are rich in it sea-buckthorn, maize, soybean oil, embryos of wheat, barley, rye and others

Vitamin K (phylloquinone) plays important role in the processes of coagulation of the blood. Much it in the cabbage, the pumpkin, nettle and others

Vitamin C (ascorbic acid) increases the resistibility of organism to infectious diseases, actively it participates in the synthesis of many substances, which are expended on the construction of bone and connective tissue, it protects from the disease by scurvy. The basic source of vitamin C is fruits, vegetables (black currant, cabbage, citrus fruits and other). Vitamin C is unstable; easily it is destroyed with the access of oxygen, the heating. During the fermentation, the freezing it remains comparatively well.

The vitamin B1 (thiamine) actively participates in the fermentative processes, the exchange of substances. Its absence in the food leads to the disease of nervous system, are rich in the vitamin B1 dry brewing yeasts, pea, pork, bread from the wallpaper flour.

The vitamin B1 (riboflavin) contributes to an increase in the organism; it participates in the carbohydrate exchange of substances, the oxidation-reduction processes, is contained in the same products as the vitamin B1.

1. Other substances of the foodstuffs.

Besides the base materials examined the foodstuffs contain organic acids, essential oils, glycosides, alkaloids, tanning, coloring substances, bactericides, extractive, pectin substances.

Organic acids are contained in the fruits and the vegetables in the Free State, and also they are formed in the process of their processing (with the fermentation). K. by them carries acetous, milk, lemon, apple, benzoic and other acids. A small quantity of acids, which are contained in the food, renders the exciting action on the digestive glands and it contributes to the best mastering of substances. Besides the gustatory organic acids have the canning value. Therefore the sour and rickle products, cranberry and mountain cranberry, that contain the increased quantity of acids, remain well. Acidity is the important index of quality of many food products. The day need of adult person for the acids is 2 g.

Essential oils cause the aroma of foodstuffs. Their total quantity for the majority of products is determined by the portions of percentage. The aroma of foodstuffs is the important qualitative index. The pleasant aroma of food tempts appetite and improves its mastering. The property of aromatic substances is easy to evaporate necessary to consider during the culinary working and storing some foodstuffs (spices, tea, and coffee). With the spoiling of products appear the unpleasant smells, caused by the formation of such substances as hydrogen sulfide ammonia, indole, skatole and other

Glycosides - derivatives of carbohydrates, which are contained in the fruits and the vegetables (solanin, sinigrin, amygdalin and other). They possess sharp smell and bitter taste, at the small doses they excite appetite, in the large - they are poisons for the organism.

Alkaloids - substance, stir upping acting on the nervous system, at the large doses are poisons. They are contained in the tea, the coffee (caffeine), the chocolate (theobromine), are the nitrogenous organic bodies.

Tanning substances give the specific binding taste to the foodstuffs (tea, coffee, some fruits). Under the action of atmospheric oxygen they are oxidized and acquire dark painting. By this are explained the dark color of tea, the darkening of in air cut apples and T. d.

The coloring substances cause the color of foodstuffs. To them carry the chlorophyll, the carotenoids, [flavonovye] pigments, anthocyan, chromoproteins and others

Chlorophyll - green pigment, which is found in the fruits and the vegetables. It is dissolved well in the fats, with the heating in the acid medium it is converted into the pheophytin - the substance of brown painting (with the melting of fruits and vegetables).

Carotenoids - pigments, which impart to products yellow, orange and red painting. To them carry the carotene, the lycopene, xanthophyll and others Carotene is found in the carrot, the apricots, the citrus fruits, the lettuce, the spinach and others; lycopene gives red color to tomatoes; xanthophyll tinctures products into the yellow colored.

Anthocyan - pigments of different painting. Painting is given to the skin of grapes, cherries, mountain cranberry; they are contained in beet and others

Chromoproteins - pigments, which cause the red painting of the blood, meat.

Bactericides possess bactericidal properties, are contained in an onion, the garlic, the horseradish.

Extractive substances are contained in the meat, to fish are given smell and aroma to bouillon.

Pectin substances are contained in the fruits, the berries, the vegetables and possess the ability to form jellies in the presence of sugar and acid. This property widely is used in the confectionery industry with the production of jelly-candy, pastille, jam, jelly and others.