What causes the high nutritional value of dairy products. Physiological value of dairy products

Topic 5. Sanitary and hygienic assessment of milk

and dairy products

Nutritional and biological value of milk and dairy products. The nutritional and biological value of milk lies in the optimal balance of its components, easy digestibility (by 95-98%) and high use of all the plastic and energy substances necessary for the body. Milk contains all the nutritional substances necessary for the body, therefore milk and dairy products are indispensable in the nutrition of patients, children and the elderly. It contains high-grade proteins, fats, vitamins, mineral salts. In total, about 100 biologically important substances have been found in milk. The inclusion of milk and dairy products in the diet improves the balance of the amino acid composition of the proteins of the entire diet and significantly increases the supply of calcium to the body. The chemical composition of cow's milk is as follows: proteins 3.5%, fats 3.4% (not less than 3.2%), carbohydrates in the form of milk sugar (lactose) - 4.6%, mineral salts 0.75%, water 87, 8%. The chemical composition of milk varies depending on the breed of animals, the season, the nature of the feed, the age of the animals, the lactation period, and the technology of milk processing.

Squirrels milk presented casein, albumin(lactoalbumin) and globulin(lactoglobulin). They are complete and contain all the amino acids necessary for the body. Milk proteins are readily available for digestive enzymes, and casein has a regulatory effect on increasing the digestibility of other nutrients. Casein, when souring milk, splits off calcium and curdles. Albumin is the most valuable milk protein; when boiled, it coagulates, forming foam, and partially precipitates.

In human nutrition, cow, goat, sheep, mare, donkey, deer, camel, buffalo milk is used. Buffalo and sheep milk has especially high nutritional and energy properties. The most nutritious is reindeer milk, which contains up to 20% fat, protein - 10.5%, vitamins 3 times more than in cow's milk. Women's milk contains 1.25% protein, therefore, cow's and any other milk requires dilution when feeding infants. According to the nature of the proteins, the milk of various animals can be divided into casein(casein 75% or more) and albuminous(casein 50% or less). Casein milk includes the milk of most lactating farm animals, including cows and goats. Albumin milk includes mare and donkey milk. The peculiarities of albumin milk are its higher biological and nutritional value, due to the better balance of amino acids, high sugar content and the ability to form small, tender flakes when soured. Albumin milk is similar in properties to human milk and is the best substitute for it. Albumin particles are 10 times smaller than casein, the particles of which are larger and, when curdling in the stomach of an infant, cow's milk protein forms hard-to-digest large, dense, coarse flakes.

Main protein cow's milk is casein, which in milk is 81.9% of the total amount of milk proteins. Lactoalbumin found in milk in an amount of 12.1%, lactoglobulin 6%.milk fat belongs to the most valuable fats in terms of nutritional and biological properties. It is in a state of emulsion and a high degree of dispersion. This fat is highly palatable. Milk fat contains phospholipids (0.03 g per 100 g of cow's milk) and cholesterol (0.01 g). Due to the low melting point (within 28-36˚C) and high dispersion, milk fat is absorbed by 94-96%. As a rule, the fat content of milk in autumn, winter and spring is higher than in summer. With good animal care, the amount of fat in cow's milk can reach 6-7%. Carbohydrates in milk are in the form of milk sugar - lactose. It is the only milk carbohydrate found anywhere else. Lactose refers to disaccharides; upon hydrolysis, it breaks down into glucose and galactose. The intake of lactose into the intestines has a normalizing effect on the composition of the beneficial intestinal flora. Milk intolerance, noted in many people, is caused by the absence in the body of enzymes that break down galactose.

Milk sugar is of great importance in the production of lactic acid products. Under the action of lactic acid bacteria, it turns into lactic acid; while curdling the casein. This process is observed in the production of sour cream, curdled milk, cottage cheese, kefir.

Minerals. Milk contains a wide range of macro- and microelements. In the mineral composition of milk, calcium and phosphorus are of particular importance. It also contains potassium, sodium, iron, sulfur. They are found in milk in an easily digestible form. Microelements contain zinc, copper, iodine, fluorine, manganese, etc. The calcium content in milk is 1.2 g/kg.

Vitamins. Almost all known vitamins are present in milk in small quantities. The main vitamins of milk are vitamins A and D, and also contain some amounts of ascorbic acid, thiamine, riboflavin, nicotinic acid. In summer, when animals eat juicy green fodder, the content of vitamins in milk increases. The calorie content of milk is low and averages 66kcal per 100g of product. Milk contains a number of enzymes.

Milk causes a weak secretion of the gastric glands and is therefore indicated for peptic ulcer and hyperacid gastritis. Due to the presence of lactose, when drinking milk, a microflora develops in the intestines, delaying putrefactive processes. There is little salt in milk, and therefore it is recommended for people suffering from nephritis and edema. There are no nucleic compounds in milk, therefore, it is indicated for persons with impaired purine metabolism. For febrile patients, milk is both light food and drink.

The overall balance of all substances that make up milk is characterized by an anti-sclerotic orientation, which has a normalizing effect on the level of cholesterol in the blood serum.

TO fermented milk products include: sour cream, curdled milk, cottage cheese, acidophilus milk, kefir, koumiss and others. They are obtained by fermenting pre-pasteurized milk with ferments of lactic acid microbes. The medicinal properties of lactic acid products are explained by the fact that they are digested 2-3 times easier and faster than milk, which forms dense large clots in the stomach, suppression of the growth of putrefactive intestinal microflora, and the presence of antibiotics produced by the lactic fermentation bacillus that affect pathogenic microbes. I.I. Mechnikov attached great importance to fermented milk products in preventing premature aging, one of the reasons for which he saw in the “self-poisoning” of the body by products formed during the processes of putrefaction in the intestines.

Yogurt is close to milk in its nutritional properties. Fresh one-day yogurt enhances intestinal motility and has a laxative effect. Two - three-day yogurt can have a fixing effect. Under the influence of ordinary curdled milk, the intestinal microflora changes, however, lactic acid microbes contained in curdled milk do not find favorable conditions for engraftment in the intestines.

Acidophilus bacillus takes root well in the human intestine and is used to make acidophilic lactic acid products. It is more effective in the fight against putrefactive microflora. Acidophilic milk is used to prepare patients for surgery, to treat putrefactive colitis, dyspepsia in children, constipation and other diseases. If ordinary milk is digested by 32% in an hour, then lactic acid products by 91% during this time.

To make kefir, milk is fermented with kefir mushrooms. In the manufacture of koumiss, milk (mare or cow) is fermented with pure cultures of Bulgarian sticks or lactic yeast. Depending on the timing of maturation, kefir and koumiss are divided into weak (one-day), medium (two-day) and strong (three-day). The alcohol content in weak kefir is 0.2%, on average - 0.4%, in strong - 0.6%. Weak kefir has a laxative property, is used to eliminate and prevent constipation. Kumis is a well-carbonated drink due to the presence of carbon dioxide. The alcohol content in koumiss is from 1 to 2.5%. It has a strengthening effect, improves digestion, metabolism and is widely used for medicinal purposes in chronic bronchitis, pulmonary tuberculosis and anacid gastritis.

Cottage cheese is a kind of concentrate of protein and calcium, therefore it has a high biological value. It helps prevent fatty liver disease. It has anti-sclerotic properties, increases diuresis and is widely used in the nutrition of children and the elderly.

Milk is a good environment for the development of microorganisms. The main diseases transmitted to humans through milk are tuberculosis, brucellosis, foot-and-mouth disease and coccal infections. Intestinal infections (dysentery), poliomyelitis can be transmitted through milk, which can be introduced into milk at all stages of its production, transportation, processing and distribution. With milk, infectious agents can be transferred to butter, cottage cheese, curdled milk and other dairy products. In curdled milk, the causative agents of typhoid fever survive up to 5 days, in cottage cheese up to 26 days, in oil up to 21 days. The causative agent of poliomyelitis remains viable in dairy products for up to 3 months. The possibility of transmission through milk of diphtheria and scarlet fever has been proven. Milk contamination is usually associated with bacillus carriers working in dairies and other dairy facilities.

Especially dangerous infections. The milk of animals suffering from anthrax, rabies, infectious jaundice, rinderpest and other diseases is subject to destruction on the spot in the presence of representatives of the veterinary and sanitary supervision.

Tuberculosis. The greatest danger to humans is milk from animals with severe clinical manifestations of the disease, especially with udder tuberculosis. The milk of such animals is not allowed to be used for food. Animals with a positive reaction to tuberculosis are allocated to special herds, and milk on farms must be disinfected by heating to 85 ° C for 30 minutes.

Brucellosis. Brucellosis affects cows, sheep and goats. Milk from animals suffering from brucellosis is subjected to mandatory boiling at the place of receipt for 5 minutes, followed by re-pasteurization at dairies.

foot and mouth disease- the disease is caused by a filter virus that is not resistant to heat. Heating milk to 80°C for 30 minutes or boiling it for 5 minutes kills the virus. Milk is allowed to be sold on the farm only after heat treatment.

Topic 3. Sanitary and hygienic assessment of meat

and meat products

Sanitary and hygienic examination of food products carried out by a sanitary doctor in a planned manner and outside the plan in the presence of special epidemiological indications. The purpose of the sanitary examination is to establish the qualitative state of food products and to identify properties that may adversely affect the health of the population. The quality of food products produced by food enterprises is regulated by the standards and regulations established in the country.

During storage, transportation and sale, food products can change their original properties: taste, appearance, smell; products may contain harmful impurities or microorganisms that make them hazardous to health. All products, depending on their quality, are usually divided into the following categories:

Benign (standard)– products that meet all the requirements of the standard. Their use in food does not cause concern. Such products are allowed to be used for food without restrictions.

Conditionally fit- products with certain defects, which in their natural form pose a danger to human health and require mandatory (most often thermal) treatment to neutralize them. For example, fresh fish, in the muscle tissue of which larvae of a wide tapeworm were found; meat of animals suffering from brucellosis, leukemia, tuberculosis, foot and mouth disease, etc.

Products with reduced nutritional value (non-standard)- these are products that have defects that reduce their nutritional value, but do not prevent their consumption under normal conditions, that is, they do not pose a danger to human health. These products are prepared in violation of the technological processing regime, storage conditions and terms, or other reasons. For example, low-fat milk, high-moisture bread.

falsified products are products that are artificially given some properties and characteristics in order to hide flaws (or for the purpose of profit). For example, baking soda can be added to milk to hide acidity. Neutralizing lactic acid, soda does not delay the development of putrefactive microorganisms and contributes to the destruction of vitamin C. Such milk is not suitable for human consumption.

Surrogates- products similar to natural ones in terms of organoleptic characteristics (smell, taste, color, appearance), but prepared artificially with a corresponding indication on the label. These are coffee surrogates made from cereals; fruit essences instead of natural juices; soy meat, mayonnaise, black caviar.

Poor quality products- these are products that are not suitable for food in both natural and processed form, as they are dangerous to human health or unsuitable for consumption due to unsatisfactory organoleptic properties. Violation of the quality of food products may be due to the decomposition of their constituent parts, in particular protein under the influence of putrefactive microflora, fat under the influence of physical and chemical factors. Poor-quality products can become due to infection with helminth larvae, as well as contamination with pesticides and other toxic substances above the MPC. Examples of poor quality products are rancid fats, moldy bread, rotting meat, flour with a high content of ergot.

Nutritional and biological value of meat and meat products. The meat of warm-blooded animals is the most important food product, which is a source of complete protein, fat, vitamins, mineral salts, as well as extractive substances (creatine, purine bases, lactic acid, glycogen, glucose, lactic acid, etc.). According to its chemical composition, animal meat provides the body with vital proteins and contains all the essential amino acids in a favorable balance. Compared with plant products, meat has a higher digestibility, low "puffiness", high saturation.

The chemical composition, organoleptic properties and nutritional value of meat vary significantly depending on the type, age and nature of the animal's nutrition, as well as on the part of the carcass. The content of proteins in meat is 11-21%. The amount of fat varies depending on the fatness of the animal, for example, in beef from 3 to 23%, in pork up to 37%. The meat of well-fed animals not only has a high energy value, but also contains more essential amino acids and biologically valuable fats. There are few carbohydrates (glycogen) in meat, less than 1%. Of the minerals, macronutrients such as phosphorus, magnesium, potassium, and sodium are of primary importance, the content of which differs little in different types of meat. Meat is also a source of some trace elements - gland, copper, zinc, iodine, etc. Iron is 3 times better absorbed from meat than from plant products. Meat contains various vitamins: thiamine, riboflavin, pyridoxine, nicotinic and pantothenic acids, as well as choline. The entrails (offal) - liver, kidneys, etc. contain less protein, but are very rich in vitamins A, group B and others.

Water-soluble nitrogenous extractives of meat give it a peculiar aroma and taste and excite the secretion of digestive juices and the activity of the nervous system. When cooking meat, from 1/3 to 2/3 of the extractives goes into the broth, so boiled meat is preferable in chemically sparing diets. Boiled meat is widely used in dietary nutrition for gastritis, peptic ulcer, liver disease and other diseases of the digestive system.

The digestibility of meat is high: fats are digested by 94%; proteins of lean pork and veal by 90%, beef - 75%, lamb - 70%.

The main feature of meat fats is their refractoriness. Meat fats are distinguished by a significant content of solid, saturated fatty acids with a high melting point. With a decrease in fatness, significant changes occur in the composition of fat: the content of polyunsaturated fatty acids (PUFAs) decreases and the content of saturated, solid fatty acids sharply increases, and therefore the melting point of fats increases. Lean cattle meat fat has a lower biological value and is characterized by low digestibility. Saturated fatty acids predominate in beef and lamb, and the content of essential polyunsaturated fatty acids (linoleic, linolenic) is insignificant. There are a lot of PUFAs in pork. According to biological properties, pork fat is the best. Cholesterol in the muscle tissue of warm-blooded animals is 1.5 times less than in adipose tissue.

poultry meat contains more proteins: chickens - 18-20%, turkey - 24.7% and extractives; proteins and fats are better digested. There are more PUFAs in the lipids of poultry meat than in beef and lamb. White meat is rich in phosphorus, sulfur and iron. The meat of ducks and geese is not used in dietary nutrition, since the fat content is 36 - 38%.

Meat is a perishable product. When it rots, decomposition of amino acids occurs with the release of ammonia, hydrogen sulfide and other foul-smelling gases. When fats are oxidized, volatile fatty acids are released. This not only worsens the organoleptic properties of the product, but also reduces its nutritional value.

Meat can cause food poisoning, most commonly caused by salmonella. Infectious animal diseases (zoonoses) can be transmitted to humans through meat. The meat of animals suffering from anthrax and other especially dangerous infections is not allowed for food and must be destroyed. With less dangerous infections (brucellosis, tuberculosis, foot and mouth disease, leukemia, etc.), meat is used as conditionally fit. Such meat can only be sold through public catering establishments, where it is most often thoroughly boiled for 2.5 - 3 hours in pieces weighing no more than 2 kg and up to 8 cm thick. Animal meat can also be a source of human infection with certain helminths (Finnosis , trichinosis).

Health protection of consumers from these diseases is provided by veterinary supervision. Livestock is slaughtered at meat processing plants and slaughterhouses under the supervision and control of the veterinary and sanitary service.

Infection of animal meat can be intravital or post-mortem. In depleted and overworked animals, intravital bacteremia and the penetration of salmonella and other microflora from the intestine into muscle tissue and internal organs are possible. In the process of slaughtering animals and removing the viscera, direct contamination of the carcass with intestinal contents is possible. To avoid this, the intestine should be removed only after applying double ligatures to both ends. To prevent the proliferation of microbes, meat should be stored at an air temperature of 0˚ to +4˚C, and frozen meat - at a temperature below 0˚C.

BREAD

Nutritional and biological value of bread. Flour is made from cereals (wheat, rye, corn, oats, barley), from which bread, cakes are baked, and used in the preparation of various dishes. The properties of flour depend on the quality of grinding and the percentage of “yield” (the ratio of the mass of the obtained flour to the mass of the initial grain): coarse grinding flour (yield - 95-99%) contains bran, with finer grinding (yield 10-75%) wheat flour whiter and softer than less % yield. 74-85% of proteins are absorbed from wholemeal flour, up to 92% from fine flour, but the flour contains less B vitamins and minerals. When baking bread and bakery products, yeast is used, as well as milk, eggs, flavoring and aromatic substances.

Proteins in rye bread 5.0-5.2%, in rye-wheat bread - 6.3%, in wheat bread and buns - from 6.7 to 8.7%; fats in rye, rye-wheat and wheat bread 0.7-1.2%, in white buns - up to 1.9%; carbohydrates from 42.5% in rye to 52.7% in products made from premium wheat flour. Calorie black bread - 204-221 kcal, white - 229-266 kcal.

Dietary varieties of bakery products are produced: protein-wheat bread and crackers are recommended for diabetes, obesity, diathesis; protein-bran bread - for the same diseases accompanied by constipation; salt-free (achloride) bread and crackers - for diseases of the kidneys, heart, hypertension, as well as for various inflammatory processes accompanied by edema. Wheat bran (doctor's) bread is recommended for pregnant women and nursing mothers, as well as for constipation and nervous diseases; bread from crushed wheat grain - with obesity and habitual constipation. With exacerbations of hyperacid gastritis, gastric and duodenal ulcers, crackers with low acidity are used. Dairy and high-calorie buns are used for the same diseases of the stomach, as well as in the nutrition of pregnant and lactating women, in baby food, for rickets, tuberculosis, and bone fractures.

During storage, the bread becomes stale as a result of a change in the colloidal structure of starch (synersis) and the release of water. Delay the staleness of bread stabilizers or freezing. Bread should be stored in well-ventilated rooms at a temperature of 16-18ºС. Bread and bakery products are transported in trays by specialized vehicles.

Freshly baked bread does not contain microorganisms, but with high humidity, low acidity and long-term storage, bacteria (spore-forming "potato stick" - Bac.Mesentericus, conditionally pathogenic vegetative anaerobe "wonderful stick" -Bac.prodegiosus,) and mold fungi ( Aspergillus, Penicillium, Fusarium, Cephalosporium, Trichoderma, Stachibotris). The crumb of bread affected by the “potato stick” is translucent, viscous, sticky, brownish in color with an unpleasant smell of rotting potatoes or fruits (irritates the stomach, causing dyspepsia). With the defeat of the “wonderful stick”, bright red mucous spots appear in the crumb. Mold fungi can cause severe food poisoning (mycotoxicosis): ergotism, fusarium, aflatoxicosis.

food poisoning (BY) - diseases caused by the consumption of foods richly contaminated with microorganisms or containing toxic substances of a microbial or chemical nature. Food poisoning is not transmitted from a sick person to a healthy person.

Microbial food poisoning. Microorganisms (bacteria and microscopic mold fungi) and/or toxic products of their vital activity serve as the cause of microbial PD.

Food poisoning of a bacterial nature represented by toxic infections and bacterial toxicosis.

Food poisoning are a group of acute bacterial intestinal infections caused by pathogenic and opportunistic bacteria that produce endotoxins. In the gastrointestinal tract of a sick person, pathogens remain alive for 7-15 days, causing symptoms characteristic of infectious diseases with severe toxic manifestations. The main signs of food poisoning: simultaneous illness of a group of persons who consumed the same food; territorial limitation of the disease; a clear association with food intake; the suddenness of the onset (outbreak) of the disease with an incubation period of 6-24 hours, the rapid cessation of the outbreak after the withdrawal of an epidemically dangerous product. Prevention: 1. prevention of contamination of food and prepared foods; 2. ensuring storage conditions that exclude massive reproduction of microorganisms; 3. Reliable heat treatment before eating questionable (contaminated) foods.

Salmonellosis. The endogenous route of infection of meat and eggs of poultry can be associated with a lifetime disease of primary salmonellosis (infectious abortion and paratyphoid enteritis of cattle, typhoid of piglets, paratyphoid fever of calves and waterfowl) of animals intended for slaughter and secondary salmonellosis of weakened animals. The exogenous route is due to a violation of sanitary rules during carcass cutting, transportation, storage and cooking, as well as the bacteria carrier of a public catering employee. Survival of Salmonella: 1) in the refrigerator at 7-10°C 6-13 days in sausages and sausages, 45 days in pasteurized milk, 60-65 days in raw eggs, scrambled eggs and raw pork; 2) in the freezer up to 13 months. in frozen meat. Salmonella persist at high concentrations of salt and acids in foods. Salmonella die instantly when boiled, at 56 0 C - after 1-2 minutes. However, to eliminate Salmonella in large cuts of meat and dense products, a longer processing time is required. Most cases of salmonellosis are associated with meat (70-80%), milk (10%), fish (3.5%). There are frequent cases of infection through the eggs of lively infected waterfowl (ducks, geese), as well as confectionery products prepared using chicken eggs with a contaminated surface without heat treatment. If the source of salmonella is a bacteriocarrier, then any food can cause salmonellosis.

Characteristic signs of salmonellosis: incubation period 12-24 hours; sudden acute onset; bacteremia with the release of Salmonella exotoxin and the release of endotoxin into the blood after the death of Salmonella; the patient's body temperature is 38-40 0 С; repeated vomiting; stool for 1-3 days is plentiful, liquid, with green mucus and streaks of blood (especially often the appearance of blood in the stool in children, due to the involvement of the large intestine in the infectious process); dehydration of the body; signs of general toxicosis (pallor, weakness, loss of appetite, headache, muscle cramps and pain); the duration of the disease is 3-5 days, followed by a long-term isolation of bacteria with feces. There are 2 fundamentally different clinical forms of salmonellosis: typhoid-like (with all signs of gastroenteritis) and flu-like (along with dyspeptic disorders, catarrhal phenomena). Mortality is about 1%.

Prevention of salmonellosis: 1). Strict sanitary and veterinary supervision over the health of slaughtered livestock, compliance with sanitary rules for the process and conditions at slaughterhouses. 2). Ban on the free sale of raw waterfowl eggs and sale only after boiling for 15 minutes. 3). Health control of workers at food enterprises (regular preventive medical examinations with the identification of bacteria carriers, production control and health education of workers). 4). Proper heat treatment and storage of meat and dairy products, separate processing of boiled and raw meat, rejection of creams and dishes that use eggs without heat treatment.

Introduction

Relevance: An important place in the human diet is occupied by milk and dairy products. Milk contains all the nutrients needed by the human body without exception. One of the most distinctive and important properties of milk as a food product is its high biological value and digestibility due to the presence of complete proteins, milk fat, minerals, trace elements and vitamins.

The digestibility of milk and dairy products ranges from 95 to 98%. Milk also aids in the absorption of other foods. Of particular importance for the body are sour-milk products, which have a high dietary and medicinal value.

Along with cow's milk, milk of other animals is used for food: sheep, goats, deer, mares, camels, buffaloes, etc.

Sheep's milk is more than 1.5 times richer in fat and protein than cow's milk. It is used for the production of feta cheese and other types of pickled cheeses.

Goat's milk is used in a mixture with sheep's milk in the production of feta cheese and cheese. Goat milk has more vitamin C and minerals than cow milk.

Mare's milk is a white liquid with a bluish tint. It differs from cow's sweet taste due to the increased content of lactose, contains less fat, salts and proteins. It is used to make koumiss.

Purpose, objectives of the course work- studying the features of the technology for obtaining benign milk.

Nutritional value, composition and properties of cow's milk

Nutritional value of milk

Cow's milk has a high nutritional value, which is due to the optimal content of proteins, fats, carbohydrates, mineral salts and vitamins in it, and the ratio and form in which the components are present in milk contribute to their good digestibility and assimilation. Currently, over 200 different components are known in milk. The main components include water, protein, fat, lactose and minerals (see Table 2).

Milk also contains vitamins, enzymes, hormones, etc. Foreign substances may contain antibiotics, pesticides, detergents, toxic elements, radionuclides, aflatoxins, etc.

The chemical composition of milk, the degree of dispersion of its components determine the chemical and physical properties of milk. The most important properties for milk processing processes are given in Table 5.

Milk and dairy products are characterized energy value, which complements the nutritional value of the product. It can be calculated using the following formula:

E \u003d (37, 7F + 16.7B + 15.9L) * 1,

where E - energy value, kJ; W, B, L - respectively, the mass fraction of the content of fat, protein and lactose in the raw material or product,%; 37.7, 16.7 and 15.9 are coefficients.

Table 5. Chemical and physical properties of cow's milk

At a temperature of 20 °C.

- a complete food product. According to the Nobel Prize winner Academician I.P. Pavlova, "among the varieties of human food, milk is in an exceptional position as food, prepared by nature itself." Easy digestibility is one of the most important properties of milk as a food product. Moreover, milk stimulates the absorption of nutrients from other foods. More than 500 million liters of milk are drunk annually in the world, the consumption of which brings variety to the diet, improves the taste of other products. Milk has therapeutic and prophylactic properties. The main significance of milk in nature is to provide nutrition to the born young organism.

The nutritional and biological value of milk and dairy products is higher than that of other products found in nature. Milk contains more than 120 different components, including 20 amino acids, 64 fatty acids, 40 minerals, 15 vitamins, dozens of enzymes, etc.

When drinking 1 liter of milk, the daily requirement of an adult for fat, calcium, phosphorus is satisfied, 53% for protein, 35% for vitamins A, C and thiamine, 26% for energy. The energy value of 1 liter of raw milk is about 65 kcal.

The nutritional value milk is due to its chemical composition. It differs somewhat for the milk of different species and breeds of animals, may vary depending on the conditions of their feeding.

Squirrels are the most valuable component of milk. They make up about 3.3%, including casein 2.7%, albumin 0.4%, globulin 0.12%. Casein is a complex phosphoprotein and is found in the form of a calcium salt (calcium caseinate), giving the milk a white color. In fresh milk, casein forms a colloidal solution; in an acidic environment, lactic acid splits off calcium from the casein molecule, free caseic acid precipitates and a lactic acid clot is formed.

Casein coagulates under the action of rennet (produced by the glands of the gastric mucosa). After precipitation of casein from skimmed milk, whey proteins and some other components remain in the whey.

According to the content of deficient essential amino acids (lysine, tryptophan, methionine, threonine), whey proteins are the most biologically valuable part of milk proteins, important for food purposes. The main ones - lactoalbumin and lactoglobulin - have a high content of growth and protective substances. In cow's milk, these proteins make up 18% of the total amount of protein, in goat's milk they are 2 times more. When heated above 70 ° C, milk loses part of lactoalbumin and lacto globulin, they denature and precipitate. Therefore, to free milk from microbes, it is subjected to pasteurization at a temperature not exceeding 70 ° C. In addition, the composition of whey proteins includes immunoglobulins (1.9-3.3% of the total amount of proteins) - high-molecular proteins that act as antibodies and suppress foreign proteins by gluing microbes and other foreign cells.

Milk proteins contain all essential amino acids and are complete.

Fat in milk is contained in an amount of 2.8 to 5%. Milk is a natural emulsion of fat in water: the fatty phase is in the milk plasma in the form of small droplets - fat globules, covered with a protective lecithin-protein shell. When the shell is destroyed, free fat forms lumps of fat, which impairs the quality of milk. To ensure the stability of the fat emulsion, it is necessary to minimize the mechanical effects on the dispersed phase of milk during transportation, storage and processing, avoid foaming it, properly conduct heat treatment (long-term exposure at high temperatures can cause denaturation of the structural proteins of the shell of fat globules and damage to its integrity), apply additional dispersion of fat by homogenization.

Milk fat is made up of a complex mixture of acylglycerols (glycerides). Of the several thousand triglycerides of milk fat, most are heteroacid, so the fat has a relatively low melting point and a uniform consistency.

Among saturated acids, palmitic, myristic and stearic acids predominate (60-75%), among unsaturated acids - oleic (about 30%). The content of stearic and oleic acids increases in summer, and that of myristic and palmitic acids in winter. Milk fat contains low molecular weight volatile saturated fatty acids - butyric, caproic, caprylic and capric (4-10%), which determine the specific taste of milk fat. A lower content of low molecular weight acids is a sign of falsification of milk fat by other fats. In addition to oleic acid, there are also small amounts of unsaturated fatty acids - linoleic, linolenic and arachidonic (3-5%).

Unsaturated and low molecular weight fatty acids give milk fat low melting point (melting point - 27-34 ° C). These acids have more valuable biological properties than high-molecular and saturated ones. Low melting point and high dispersion ensure good digestibility of milk fat.

The disadvantages of milk fat include its low resistance to high temperatures, light rays, atmospheric oxygen, water vapor, solutions of alkalis and acids. Rancidity of fat occurs due to hydrolysis, oxidation, salting.

Associated substances in the composition of milk fat are 0.3 - 0.55%. Nasterins account for 0.2-0.4%. They are mainly represented by cholesterol in the free state or in the form of fatty acid esters, as well as ergosterol, etc. Along with simple lipids, milk fat includes a variety of phospholipids (lecithin, cephalin, etc.), which have an emulsifying ability, participate in the construction of ball shells fat. The yellow color of milk fat is due to the presence of carotenoids in it - tetraterpene hydrocarbons (carotenes) and alcohols (xanthophylls). The content of carotenes depends on the feed rations, the condition of the animals and the time of year (more in summer) and is 8-20 mg per 1 kg of milk fat.

Lactose(milk sugar) is the main carbohydrate of milk, monosaccharides (glucose, galactose, etc.) are present in it in smaller quantities, more complex oligosaccharides - in the form of traces.

The disaccharide lactose is the main source of energy for biochemical processes in the body (it accounts for about 30% of the energy value of milk), promotes the absorption of calcium, phosphorus, magnesium, and barium. In milk, lactose is in the free state in the form of a- and p-forms. A very small portion of lactose is associated with other carbohydrates and proteins. Milk sugar slowly penetrates through the intestinal wall into the blood, so it is used for nutrition by lactic acid bacteria, which heal the environment of the stomach. When milk is heated above 95 ° C, the color of milk changes from yellowish to brown due to the formation of melanoidins, which have a dark color, as a result of the reaction of milk carbohydrates with proteins and some free amino acids.

During hydrolysis, lactose is broken down into glucose and galactose, and during fermentation under the influence of enzymes, into acids (lactic, butyric, propionic, acetic), alcohols, esters, gases, etc.

minerals milk contains up to 1%, they contain more than 50 elements. The main ones are calcium, phosphorus, magnesium, potassium, sodium, chlorine and sulfur. Calcium in I liter of milk contains 1.2 g, it is necessary for the formation of bones, regulation of blood pressure. Calcium salts are of great importance not only for humans, but also for milk processing processes. For example, an insufficient amount of calcium salts causes slow rennet coagulation of milk in the manufacture of cheeses, and their excess causes coagulation of milk proteins during sterilization. About 22% of all milk calcium is associated with casein, the rest is salts - phosphates, etc. These compounds contain phosphorus, it is also part of casein, phospholipids, etc.

Magnesium performs the same role as calcium and is found in the same salts.

Sodium and potassium are found in the form of salts (ions), and some of them are associated with casein and shells of fat globules. Salts of potassium and sodium are contained in milk in the ion-molecular state in the form of well-dissociating chlorides, phosphates, citrates (salts of citric acid), etc. Sodium and potassium chlorides provide a certain osmotic blood pressure. Their phosphates and carbonates are part of systems that maintain a constant concentration of hydrogen ions.

trace elements in milk (iron, copper, silicon, selenium, tin, chromium, lead, etc.) are associated with shells of fat globules (Fe, Cu), casein and whey proteins (Fe, Cu, Zn, Mn, Al, I, Sen etc. .), are part of enzymes (Fe, Mo, Mn, Zn), vitamins (Co), hormones (I, Zn, Cu). They provide the construction and activity of vital enzymes, vitamins and hormones necessary for the body's metabolism.

Enzymes are biocatalysts for biochemical reactions. Thus, the production of fermented milk products and cheeses is based on the action of enzymes of the classes of hydrolases, oxidoreductases, granferases, and others. Many lipolytic, proteolytic and other enzymes cause profound changes in the composition of milk during the development and storage of dairy products, which can lead to a decrease in their quality. According to the activity of some enzymes, one can judge the sanitary and hygienic state of raw milk or the effectiveness of its pasteurization. So, depending on the indicator of p-oxidase activity of milk, a conclusion is made about the effectiveness of its high-temperature pasteurization. According to the catalase test, the degree of contamination of pasteurized dairy products with extraneous microflora is judged.

The high sensitivity of alkaline phosphatase to heating is the basis of the method for monitoring the efficiency of pasteurization of milk and cream (phosphorus test). The enzyme glypase catalyzes the hydrolysis of triglycerides in milk fat. In milk, as a result of cooling, redistribution of lipase from proteins to the shell of the fat ball can occur. At the same time, hydrolysis of fat occurs, low molecular weight fatty acids (butyric, caproic, caprylic, etc.) are released, and the milk becomes rancid. Spontaneous rancidity of milk due to hydrolysis of fat under the action of lipase (lipolysis) is characteristic of old and mastitis milk. Lipolysis in ordinary milk is possible after pumping milk, mixing, homogenization, etc. In cheeses such as Roquefort, Camembert lipases of microscopic fungi create a specific taste and aroma as a result of the release of volatile fatty acids during the decomposition of fat.

Hormones present in milk in small amounts; these are thyroxine, prolactin, adrenaline, oxytocin, insulin. Endogenous hormones secreted by the endocrine glands of the animal enter the milk from the blood. Exogenous hormones are residues of hormonal preparations used to stimulate productivity, feed absorption, etc.

gases, dissolved in milk, have a level of 60-80 ml / 1 l in fresh milk. In this volume of carbon dioxide 50-70%, oxygen 5-10%, and nitrogen 20-30%, there is also a certain amount of ammonia. During storage, due to the development of microorganisms, the amount of ammonia increases, and oxygen decreases. An increase in the oxygen content during pumping, transporting milk gives it an oxidized taste. During pasteurization, the content of oxygen and carbon dioxide is reduced.

Foreign chemicals can get into milk as a result of feeding, increased radiation in the area where animals are kept, etc. Substances harmful to humans include impurities of antibiotics, pesticides, heavy metals, nitrates and nitrites, residues of disinfectants, bacterial and plant poisons, and radioactive isotopes. Their content should not exceed the permissible levels established by SanPiN 2.3.2.1078.

Quality shaping factors associated with the processing of milk, which is carried out immediately after milking. It is filtered and cooled to the lowest possible positive temperatures. Timely cooling of milk helps to extend its shelf life.

The milk received at the dairy plant is checked for organoleptic characteristics, acidity and fat content. The received milk is purified from mechanical impurities, then normalized for fat, i.e. reduce or increase the fat content, using skimmed milk (skim) or cream for this.

During the separation and pumping of milk, a partial destabilization of the fat emulsion occurs - the release of free fat on the surface of fat globules, their sticking together and the formation of lumps of fat. To increase the degree of dispersion of the fatty phase, increase its stability, improve the consistency and taste of milk, it is homogenized. To do this, heated milk is sent to homogenizers, where it is passed under high pressure through a narrow slot, as a result of which the fat globules are crushed - their diameter is reduced by 10 times.

Thermal (pasteurization and sterilization) is necessary to destroy microorganisms and destroy enzymes in order to obtain products that are hygienically safe and have a longer shelf life. At the same time, the nutritional and biological value of milk should be preserved to the maximum, and there should be no undesirable changes in its physical and chemical properties.

Pasteurization it can be long-term (at a temperature of 63 ° C, milk is kept for 30 minutes), short-term (at a temperature of 72 ° C for 15-30 minutes) and instant (high-temperature at 85 ° C and above without exposure). In the process of heating, whey proteins are denatured (structural changes in molecules) and the milk acquires the taste of a boiled product or the taste of pasteurization. As a result of pasteurization and sterilization, the amount of calcium in milk decreases due to the formation of poorly soluble calcium phosphate (precipitates in the form of a milk stone or burn along with denatured proteins). This impairs the ability of milk to rennet coagulation; in the production of cottage cheese and cheese, calcium chloride is added to pasteurized milk.

Sterilization milk causes the decomposition of lactose with the formation of carbon dioxide and acids - formic, lactic, acetic, etc. Due to the denaturation of the protein shells of fat balls during sterilization of milk, rendering of fat is observed. Sterilization of milk in bottles consists in processing it in autoclaves under the following conditions: at 104 ° C for 45 minutes; at 109 °C for 30 min; at 120 °C for 20 min. Sterilization of milk in the flow is carried out at ultrasonic temperatures (UT) of 140-142 °C with exposure for 2 s and subsequent cooling and bottling under aseptic conditions. With ultrasonic sterilization, more vitamins are stored in milk than with sterilization in bottles. Most of all, vitamin C is lost (10-30%).

Insufficient heat treatment leads to incomplete inactivation of milk enzymes, which cause undesirable biochemical processes in milk and dairy products. The result can be a reduction in the quality, taste and nutritional value of products. Thus, lipases contribute to the rancidity of dairy products, and proteinases of bacterial origin cause coagulation of the U-milk.

As a result of pasteurization and sterilization, such physicochemical and technological properties of milk as viscosity, surface tension, acidity, ability to settle cream, ability of casein to rennet coagulation change. Milk acquires a specific taste, smell and color, its constituent parts change.

Everyone knows the high biological value of such a food product as milk. Especially useful milk for children.

Milk is among the food champions in terms of the content of complete proteins, fats, phosphatides, mineral salts and fat-soluble vitamins, and in total about a hundred substances were found in milk, which are very important from a biological point of view.

The chemical composition of milk

In figures, the chemical composition of milk, depending on the breed, feed, season, age of cows, lactation period and product processing technology, may look something like this:

• water 87.8%,
• fat 3.4%,
• proteins 3.5%,
• milk sugar 4.6%,
• mineral salts 0.75%.

It is important that milk proteins are an easy product for digestive enzymes, and the uniqueness casein is the ability to form a glycopolymacropeptide during digestion, which increases the digestibility of other food ingredients.

The chemical composition of milk In addition to casein, it contains complete proteins globulin and albumin containing all the amino acids that are necessary for the body. Casein in milk is associated with calcium, and when milk souring, calcium undergoes splitting and casein coagulates and precipitates.

When milk is defended, the smallest fat globules in it float up, forming a layer of delicious and healthy cream. The low (28-36 0 C) melting point of this product, as well as its high dispersity, makes almost complete digestibility of milk fat possible.

Nutritional value of milk

Milk carbohydrates, this is milk sugar - lactose, it is not as sweet as vegetable sugar, but it is not inferior to it in nutritional value. When boiled, milk sugar caramelizes, which causes the milk to acquire a brownish color and a special aroma and taste. Under the influence of lactic acid bacteria, milk sugar becomes lactic acid, and casein curdles. As a result, curdled milk, sour cream, kefir, cottage cheese are obtained - such tasty, nutritious and healthy products. Milk contains calcium, phosphorus, potassium, iron, sodium and sulfur, and in an easily digestible form, and this is very important for baby food, when milk is the main product in the children's menu. Milk also contains trace elements copper, zinc, fluorine, iodine, manganese. Because of its chemical composition, milk has important nutritional value for the human body.

The main vitamin richness and nutritional value of milk is vitamins A and D, but besides them there are ascorbic acid, riboflavin, thiamine and nicotinic acid.

Milk enzymes

In addition, milk also contains a number of enzymes, of which it should be distinguished:

• peroxidase,
• amylase,
• phosphatase
• reductase,
• catalase
• lipase.

According to GOST 13277-67, fresh high-quality milk should be a homogeneous liquid product, white in color with a slightly yellowish tinge, have a pleasant taste and smell. Apart from possible deviations in the quality of this product, caused by unacceptable changes in the composition, for example, the presence of various harmful microorganisms, its color and smell can largely depend on the feed and storage conditions.

The benefits and harms of fresh milk

A foreign smell can occur in milk when it is stored next to substances that are characterized by a pungent smell - fish, tobacco, oil products, in rotten wooden cellars.

Freshly milked milk is far from a sterile product, since there is always a certain amount of microbes in the cavity of the mammary glands of the udder. These are mainly micrococci, but there are also lactic acid bacteria.

In addition, milk is a breeding ground for microorganisms that enter it during the milking process and later. In milk, these microorganisms multiply rapidly.

Along with such microflora, pathogenic microorganisms, such as causative agents of intestinal infections, can also be found in milk.

Therefore, according to existing sanitary rules, milk is allowed for use only after neutralization.

Basically, for this, the pasteurization method is used at a temperature of 70 0 C for half an hour, or heating at least 90 0 C for a few seconds.

The nutritional value of milk and products prepared on its basis determines its importance in children's and dietary nutrition. By including such foods in your diet, you will saturate the body with calcium and other valuable substances. Milk makes a person healthier and more beautiful.

What is nutritional value?

If you are interested in certain characteristics of products, you should know for sure what they mean. Thus, nutritional value is a complete list of properties that satisfy the physiological needs of the body. Most often, this concept means the content of proteins, fats and carbohydrates in every 100 grams of products.

It is also worth noting the importance of such an indicator as biological value. It characterizes the compliance of the amino acid needs of the human body. Speaking of energy value, it is worth noting that this is the number of calories that are released during the processing of the product by the body.

Milk: chemical composition and nutritional value

Milk is the first human food, which gives the body everything it needs from birth. Due to the rich chemical composition, it is possible to maintain the active vital activity of the body. So, milk contains the following substances:

• proteins;
• fats;
• milk sugar;
• mineral salts;
• water.

It should be noted that this is a basic set of components that cannot fully characterize milk. The chemical composition and nutritional value can vary greatly, depending on the origin of the product, as well as the way it is processed.

If we consider in more detail the proteins contained in milk, they are represented by albumin, globulin and casein. The latter is involved in the formation of glycopolymacropeptide, which increases the absorption of other components. All proteins are characterized by easy absorption and contain all the amino acids necessary for the body.

Fats in milk are contained in the form of tiny particles. It is they who form everyone's favorite cream. Milk fat is 96% absorbed by the body, due to its high dispersion. Its content in the product depends on the season (in summer this figure decreases), as well as the quality of animal care.

Considering such an indicator as the nutritional, energy value of milk, one cannot fail to mention the carbohydrate component. It is represented by lactose. It is the presence of this component that determines the possibility of preparing fermented milk products.

The nutritional value of milk is determined by the high content of vitamins. The main ones are A and B. Ascorbic acid, nicotinic acid, riboflavin and thiamine are present in a small amount. The highest concentration of vitamins in milk is observed in the summer. Also, this indicator can be affected by the method of processing and storage conditions.

More about vitamins

As already mentioned, the nutritional value of milk and dairy products is largely due to the increased content of vitamins in them. So, if we take a closer look at the chemical composition, we can note the presence of the following useful components in it:

Different types of milk

The nutritional value of milk is largely determined by its origin. So, deer is considered the most nutritious. The concentration of proteins and fats reaches, respectively, 11% and 20%. As for the vitamin component, it is three times more saturated than in the case of cow's milk.

The nutritional value of milk is largely determined by the nature of the proteins that it contains. So, most farm animals (including cows and goats) give casein milk. And, for example, mare and donkey is albumin. Since it is most similar in composition to mother's milk, such milk is an ideal substitute for breastfeeding. Albumin particles are several times smaller than casein, and therefore we can talk about its good digestibility.

Whole milk

Despite the fact that milk is one of the most common products that has been known since childhood, not everyone thinks that there are several types that are characterized by certain indicators. So, for starters, you should pay attention to whole milk. The nutritional value, in this case, will be the highest, because the product has not been subjected to any processing. An exception may be the straining process, which is carried out immediately after milking.

Whole milk contains the highest amount of vitamins and minerals. There is also a high concentration of calcium, which is almost completely absorbed by the body. This product is credited with strengthening the immune system, normalizing the functioning of the nervous system, eliminating heartburn, accelerating metabolism.

However, there are a number of skeptical claims about whole milk. Given its high fat content, it is not suitable for feeding children. And in adulthood, not everyone tolerates this product well. So, according to the latest data, one sixth of the world's population suffers from lactose intolerance. Whole milk is an allergen, and can also cause dangerous infections.

Skimmed milk

The desire for harmony makes people buy products marked "0% fat". This trend has also affected milk. The amount of fat in it does not exceed 0.1%. In fact, this is the so-called reverse, which is obtained by separating cream from milk. It should be interesting to buyers that most of this milk is not sent to store shelves, but back to farms to feed animals.

Do not place high hopes on a product such as skimmed milk. Its nutritional value is negligible. Carbohydrates and proteins, respectively, 5% and 3%. Calorie content is characterized by an indicator of 35 kcal. At the same time, such milk is characterized by a rich vitamin and mineral composition. Nevertheless, doctors do not recommend using it on an ongoing basis.

It is worth paying attention to the manufacturing process. The nutritional value of powdered, skimmed milk is significantly reduced during processing. When the fat component is removed, vitamins A and D are almost completely removed from the product. Thus, the proteins and calcium that remain in the milk are not absorbed by the body. With the frequent use of skimmed and powdered milk, the body's own resources are depleted.

Powdered milk: nutritional value

In a big city, it is not always possible to find a natural product. In addition, people tend to give known substances a more convenient form, such as powder. Powdered milk is a good example. The nutritional value of this product is the same as that of the original. But for this you need to prepare the so-called reconstituted milk. To do this, the powder is diluted in water (1: 7). At the same time, it is quite possible to prepare homemade kefir, cottage cheese and other healthy products from such milk.

The nutritional and biological value of milk is preserved thanks to a special manufacturing technology. Fast drying is carried out, and the temperature does not exceed 40 degrees. Thus, all useful substances are preserved. And due to the reduced moisture content (no more than 6%), long-term storage of the product is ensured.

Nutritional value of condensed milk

It is worth admitting that few people are interested in such a question as nutritional value. For most people, this is a favorite delicacy. Nevertheless, condensed milk is not only tasty, but also a very useful product. To begin with, it is worth noting the high protein content in this product. Its concentration can reach 35%.

In fact, condensed milk is evaporated cow's milk. The nutritional value of the final product is slightly lower, but in general it is no less useful. Condensed milk is completely absorbed by the body, saturating it with calcium and phosphorus. Thus, by regularly consuming this product, you can strengthen the health of bones, eyes and enhance mental activity.

However, condensed milk should not be abused. The fact is that it contains a significant amount of sugar, which leads to a high calorie content (328 kcal) and a significant carbohydrate component (55.5 g). A large amount of the product contributes to the development of obesity, diabetes and caries.

Dairy products

The composition and nutritional value of milk make this product one of the most popular. However, in its pure form, few people love it. Most people prefer dairy products. They not only retain the benefits of milk, but also have a beneficial effect on the digestive system. So, you should especially pay attention to the following products:

• Kefir is made from pasteurized milk. A special leaven is added to it, after which the fermentation process begins. The nutritional value of this product depends entirely on the quality of the milk. If a whole product is used, then the protein component accounts for almost 3%, the fat concentration is 3%, and carbohydrates 4%.
• prepared from a pasteurized product using bacterial cultures. It will contain approximately equal amounts of fat and carbohydrates (about 3%) and 10% carbohydrates. Given the low acidity of the product, it is actively used in artificial feeding of children.
• Belakt is also a fermented milk product produced using bacteria. It has a high content of enzymes. Another feature of the product is the presence in the composition of substances that, in their properties, resemble antibiotics.
• "Narine" is a fermented milk product that came to us from Armenia. There it is actively used for breastfeeding. Due to the special bacteria contained in the sourdough, the acidity index is quite low. And, getting into the body, "Narine" activates the production of a substance that suppresses pathogenic microbes. Proteins and fats in the product account for 3% and 4%, respectively, and carbohydrates - just over 6%.
• Koumiss is traditionally made from mare's milk. Nevertheless, recipes adapted for cow's are known. In milk, starter is added, which contains bacteria and yeast. The nutritional value largely depends on the quality of the base and the degree of maturity. It can contain up to 3% protein, up to 1% fat and 6% carbohydrates. The product is useful for digestion, and also has a tonic effect.
• Yogurt is not just a popular fermented milk product, but also a delicacy loved by everyone. In ancient times, it was prepared exclusively from To get yogurt, you need to add the so-called Bulgarian stick to the base. On average, the calorie content of the finished product is characterized by an indicator of 57 kcal. Proteins, fats and carbohydrates it contains, respectively, 4%, 2% and 6%. These figures may vary, depending on the type of milk and the method of processing. It is worth noting that only pure yogurt, which does not contain dyes and flavoring additives, has exceptional benefits.

Other popular products

Since ancient times, people have been interested in such a question as the nutritional value of milk. A great variety of dairy products are prepared on its basis. Nevertheless, there are a number of popular ones that are almost always present on the table, namely:

• Cottage cheese is one of the most valuable food products, which is characterized by a high protein content (about 14%). Its preparation is based on processes. Curd is characterized by high acidity. But this indicator decreases with an increase in the level of fat content of the product.
• The process of making cheese is based on the precipitation of casein. Depending on how the milk is processed, the product can be hard, soft, brine or melted. The protein component can reach 30% (as well as fat).
• Sour cream is a product made from pasteurized cream. It is quite fatty (this figure can reach 40%).

Milk quality

The high nutritional value of milk proteins determines the popularity of this product. Nevertheless, only what is of high quality is useful for the body. The characteristics of milk largely depend on how the processing was carried out.

The milk that entered the plant is first of all checked by organoleptic index. If it turned out to be in accordance with the standards, it is carefully filtered to remove impurities. Next, the fat content is normalized by adding skim milk or cream.

The most important are the stages of pasteurization and sterilization. These processes are necessary for the destruction of pathogens, as well as a number of enzymes. Thus, it is possible to obtain a safe product, which is characterized by long-term storage.

Pasteurization is carried out by prolonged heating. As a result, milk changes its natural taste. It is also worth noting the decrease in the concentration of calcium in the product.

Is milk dangerous for humans?

The nutritional and biological value of milk makes this product one of the most useful. Nevertheless, it is worth mentioning the danger that it carries. Milk can serve as a source of dangerous infectious diseases. In this case, viruses can get into the product from the animal and during processing.

Viruses can be found not only in milk, but also in products prepared on its basis. This increases the incubation period of the bacteria. So, the most dangerous diseases transmitted through milk are the following:

• Foot and mouth disease is a viral disease that affects the mucous membranes and respiratory tract. It appears in the form of blisters and ulcers. The virus of this disease is resistant to heat. To get rid of it, you need to boil the milk for at least 5 minutes.
• Brucellosis is a disease that affects almost all body systems. Its danger lies in the fact that at the initial stage it is almost asymptomatic. Milk from animals infected with brucellosis is subjected to prolonged boiling followed by pasteurization.
• Tuberculosis - affects mainly the respiratory system. If such an infection is found in an animal, then milk is strictly forbidden to be eaten.
• Other dangerous infections are anthrax, rabies, hepatitis, plague, and others. Animals with such diseases are subject to destruction with the obligatory presence of a sanitary doctor.

Conclusion

From the very first days of a person's life, it is milk that supplies the body with all the necessary nutrients and vitamins. Thus, the benefits of this product are undeniable. To maintain bones, digestive, nervous and other body systems in optimal condition, milk simply must be present in the diet. It is important to choose a quality product, and treat it whole or fat-free with caution.

At the moment, there is a wide range of dairy products on the market, which are also characterized by high nutritional value. Among them, you can often find many copies marked "Farm" or "Rustic". Contrary to fashion trends, such products should be treated with extreme caution, because milk that has not been subjected to heat treatment and pasteurization may contain viruses that are dangerous to humans.