Assessment of the quality of dairy products. Commodity assessment of the quality of dairy products. Butter and butter paste

04.10.2023 -

INSTITUTE OF BUSINESS

COURSE WORK

“Analysis of the range and assessment of the quality of drinking cow’s milk (classic) sold on the consumer market of the city of Volzhsky”

Introduction…………………………………………………………………………………3

1. Literature review.

1.1. Consumer properties of drinking cow's milk……..6

1.2. Physico-chemical properties of milk…………………………10

1.3. Organoleptic characteristics of milk……………………….12

1.4. Assortment of cow's milk……………………………..13

1.5. Factors affecting the quality and properties of milk…………15

1.6. Quality indicators of drinking milk……………………….17

1.7. Milk defects……………………………………………………………19

1.8. Labeling, packaging, storage of milk……………………...21

2.1. Overview of the consumer milk market………………………….24

2.2. Sampling for the experiment………………………...................27

2.3. Filling, packaging, labeling…………………………….31

2.4. Assessment of organoleptic indicators……………………….34

2.5. Determination of milk acidity……………………………...38

Chapter 3. Practical part. Analysis of the assortment of milk sold in the MAN store

3.1. Brief organizational and economic characteristics of the store…………………………………………………………………………………………41

3.2. Analysis of the assortment of milk in the store…………………….46

Conclusions and suggestions………………………………………………………..48

List of used literature…………………........................54

Applications………………………………………………………..56

Introduction

Since ancient times, milk has been considered a healing drink. Hippocrates attributed different healing properties to different types of milk.

Milk is the secretion (secretion) of the mammary gland of animals.

The Russian dairy industry uses mainly cow's milk. Its preparations are produced in accordance with the requirements of GOST R 52054-2003 “Natural cow's milk - raw material. Technical conditions", veterinary and sanitary rules approved by the Ministry of Health and Social Development of Russia.

Drinking milk is natural milk that has undergone heat treatment and normalized for the amount of fat. Heat treatment is the pasteurization or sterilization of milk. Pasteurization is carried out at a temperature of 74°C for 15-20 s. To completely destroy all forms of microorganisms, sterilization is used, which is carried out at a temperature of 120°C for 20 minutes or at 140°C for 4 s. After treatment by pasteurization, milk is cooled to a temperature not higher than 20°C, and after sterilization - not higher than 8°C. Based on manufacturing technology, type of additives added and purpose, milk is divided into pasteurized, pasteurized with fillers, sterilized and milk for young children.

The relevance of the research topic is due to the fact that milk is an essential food product used by humans at all periods of their lives.

A person should consume 1.43 liters of dairy products per day (in terms of milk), including: milk - 500 ml.

“Milk is an amazing food prepared by nature itself, characterized by easy digestibility and nutritional value compared to other types of food,” these are the words of the Russian physiologist I.P. Pavlov characterize the importance of milk in nutrition.

In market conditions, consumer demands and preferences are decisive in the formation of a product range. Buyers of dairy products prefer shelf-stable products that do not contain preservatives. These are ultra-high heat treated (UHT) dairy products.

The main problem solved in the process of writing a course work is the testing of theoretical knowledge in commodity science and examination of food products and the acquisition of practical skills acquired in the process of studying the range and quality of drinking cow's milk (classic).

The purpose of the course work is to analyze the assortment and assess the quality of drinking cow's milk (classic) sold on the consumer market of the city of Volzhsky.

In accordance with the goal, it is necessary to solve the following tasks:

· To study the consumer properties of drinking cow's milk;

· Show the physical and chemical properties of milk;

· Examine the organoleptic characteristics of milk;

· Consider the range of cow's milk;

· Identify factors affecting the quality and properties of milk;

· Determine the quality indicators of drinking milk;

· Identify milk defects;

· Examine the labeling, packaging, storage of milk;

· Review the consumer milk market;

· Conduct sampling for the experiment;

· Assessment of organoleptic indicators;

· Study the filling, packaging, labeling;

· Determine the acidity of milk.

The object of the study is drinking cow's milk (classic).

The subject of the study is the range and quality of milk.

The works of the authors, used in the course of writing the course work, made a certain contribution to the development of various aspects of this issue. Russian scientists paid close attention to the general problems of assessing the range and quality of milk: Eliseeva L.G., Dubtsova G.G.; Zhiryaeva E.V.; Krugliakova G.N.; Krugliakova G.V.; Matyukhina Z.P.; Kastornykh M.S.; Korolkova E.P.; Novikova A.M.; Nikolaeva M.A.; Raikova E.Yu., Dodonkin Yu.V.; Skripnikov Yu.G.; Teplov V.I.; Timofeeva V.A.; Shevchenko V.V.; Khlebnikov V.I.; Shepelev A.F.; Pechenezhskaya I.A. and many others.

The relevance, theoretical and practical significance of the problem, its insufficient development predetermined the topic of the course work, its purpose, objectives and structure.

Structure of the work: the work consists of an introduction, two chapters, a conclusion, a list of references, and an appendix.

1. Literature review

1.1. Consumer properties of drinking cow's milk

Milk is a complete food product. Academician I.P. Pavlov wrote: “Among the varieties of human food, milk is in an exceptional position... 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. Milk adds variety to the diet, improves the taste of other products, and has therapeutic and prophylactic properties.

Milk contains more than 120 different components, including 20 amino acids, 64 fatty acids, 40 minerals, 15 vitamins, dozens of enzymes, etc.

The energy value of 1 liter of raw milk is 2797 kJ. One liter of milk satisfies an adult’s daily need for fat, calcium, phosphorus, 53% for protein, 35% for vitamins A, C and thiamine, and 26% for energy.

Milk is a product of the normal secretion of the cow's mammary gland. From a physicochemical point of view, milk is a complex polydisperse system in which the dispersion medium is water, and the dispersed phase is substances in a molecular, colloidal and emulsion state. Milk sugar and mineral salts form molecular and ionic solutions. Proteins are in a dissolved and colloidal state, milk fat is in the form of an emulsion.

The composition of milk is not constant and depends on the breed and age of the cow, feeding and housing conditions, level of productivity and method of milking, lactation period and other factors. The lactation period in cows lasts 10-11 months, during which time cows produce high-quality milk.

From a technological and economic point of view, milk can be divided into water and dry matter, which includes milk fat and skimmed milk solids (SMR):

The greatest fluctuations in the chemical composition of milk occur due to changes in water and fat content. Lactose, minerals and proteins are consistent. Therefore, the content of SOMO can be used to judge the naturalness of milk.

Milk proteins are high-molecular compounds consisting of a-amino acids linked by a peptide bond characteristic of proteins. Milk proteins are divided into two main groups - caseins and whey proteins.

Casein in dry form is a white powder without taste or smell. In milk, casein is found in a colloidal solution in the form of a soluble calcium salt. Under the influence of acids, acid salts and enzymes, it coagulates (coagulates) and precipitates. These properties allow the isolation of total casein from milk. After casein is removed, whey proteins remain in the milk.

The main whey proteins are albumin and globulin. Albumin is a simple protein and is highly soluble in water. Under the influence of rennet and acids, albumin does not coagulate. When heated to 70 °C, it precipitates. Globulin is present in milk in a dissolved state. It also belongs to simple proteins; it coagulates when heated in a slightly acidic environment to a temperature of 72 ° C.

From a nutritional physiological point of view, whey proteins are more complete than casein, as they contain more essential acids and sulfur. Of the other proteins, the most important is fat globule protein, which is a complex protein. The degree of absorption of milk proteins is 96-98%.

Milk fat in its pure form is an ester of the trihydric alcohol glycerol, saturated and unsaturated fatty acids. It consists of triglycerides of saturated and unsaturated acids, free fatty acids and unsaponifiable substances (vitamins, phosphatides). Milk fat is dominated by oleic and palmitic acids, and unlike other fats, it contains an increased (about 8%) amount of low molecular weight (volatile) fatty acids (butyric, caproic, caprylic, capric).

Milk fat is found in milk in the form of fat globules ranging in size from 0.5 to 10 microns, surrounded by a lecithin-protein shell. It is poorly resistant to high temperatures, light rays, water vapor, air oxygen, alkali and acid solutions. Under the influence of these factors, it hydrolyzes, becomes salty, oxidizes and goes rancid.

In addition to neutral fats, milk contains fat-like substances: phosphatides (phospholipids) and sterols. The main phosphatides are lecithin and cephalin, and the sterols are cholesterol and ergosterol.

According to the modern nomenclature of carbohydrates, milk sugar (lactose) belongs to the class of oligosaccharides (disaccharides).

Lactose plays an important role in developmental physiology, as it is practically the only carbohydrate that a newborn mammal receives from food. This disaccharide is broken down by the enzyme lactose and is not only a source of energy, but also regulates calcium metabolism.

Lactose exists in two isomeric forms, which have different physical properties. These are a- and P-forms of lactose, each of which can be hydrated and anhydride (anhydrous).

Lactose is less sweet than sucrose and less soluble in water. The peculiarity of lactose is its slow absorption (assimilation) by the walls of the stomach and intestines. Once in the large intestine, it stimulates the activity of bacteria that produce lactic acid, which suppresses the development of putrefactive microflora.

The digestibility of milk sugar is 99%.

Minerals (milk salts) are contained in milk in an amount of 0.7-0.8%. Most of them are middle and acid salts of phosphoric acid. Of the salts of organic acids, there are mainly salts of casein and citric acids.

Depending on the concentration in milk, minerals are divided into macroelements - cations Na, K, Ca, Mg and microelements - cations Fe, Cu, Co, Zn, Pb, Mn, etc.

Vitamins. Milk contains all vital vitamins, but some are in insufficient quantities. The content of vitamins depends on the season of the year, the breed of animals, the quality of feed, the conditions of storage and processing of milk.

Fat-soluble vitamins A, D, E, K and (3-carotene) are resistant to heat and begin to break down at temperatures above 120 ° C (vitamin A), but are not resistant to air, ultraviolet rays and acids. Vitamin A gives butter its yellow color Vitamin E is a fat antioxidant and protects vitamin A from oxidative destruction.

Water-soluble vitamins, with the exception of vitamins C and B12, are resistant to heat. They withstand heating less well in an alkaline environment. Vitamin PP is almost completely preserved after heat treatment and during storage of milk. Vitamin C is destroyed to the greatest extent during pasteurization and storage.

Milk enzymes are formed in the mammary gland of the animal (native enzymes) or secreted by microorganisms. Milk enzymes such as lactase, phosphatase, reductase, peroxidase, lipase, protease, and amylase play an important role.

Milk enzymes can play both a positive and negative role; their activity depends on temperature, pH value, concentration of milk solids, the amount of the enzyme itself and other factors.

Immune bodies (antibodies) and hormones have bactericidal properties. They are formed in the animal’s body and suppress the development of microorganisms for a short time. The time during which the bactericidal properties of milk appear is called the bactericidal phase. Its duration depends on the temperature of the milk and is 3 hours at 30 °C, and more than a day at 5 °C.

Dyes (pigments) have a dual nature: animal and plant origin. Pigments of plant origin enter milk from feed (carotene, chlorophyll). The pigment riboflavin gives the yellow color to milk and the greenish-yellow color to whey.

Water is the main component of milk. Its quantity determines the physical state of the product, physicochemical and biochemical processes in it. The intensity of biochemical and microbiological processes, as well as the shelf life of dairy products, depends on the activity of water and its binding energy.

1.2. Physico-chemical properties of milk

Milk is characterized by the following basic physicochemical indicators: total (titrated) and active acidity, density, viscosity, surface tension, osmotic pressure, freezing point, electrical conductivity, dielectric constant, boiling point, light refraction. The quality of milk can be judged by changes in physicochemical properties.

Titratable acidity is the most important indicator of milk freshness. It shows the concentration of milk components that are acidic in nature. It is expressed in degrees Turner (°T) and for freshly milked milk it is 16-18 °T. The main components of milk that determine titratable acidity are acidic phosphate salts of calcium, sodium, potassium, citrate salts, carbon dioxide, and proteins. Proteins account for 3-4 °T of the total titratable acidity of milk. When milk is stored, titratable acidity increases as a result of the formation of lactic acid from lactose.

Active acidity (pH) is determined by the concentration of hydrogen ions and is one of the indicators of milk quality. For fresh milk, the pH is in the range of 6.4-6.7, i.e. milk has a slightly acidic reaction.

The density of milk is the ratio of the mass of milk at a temperature of 20 °C to the mass of the same volume of water at a temperature of 4 °C. The density of collected cow's milk is in the range of 1.027-1.032 g/cm 3 . It is affected by all the components, but primarily by proteins, salts and fat.

The osmotic pressure of milk is quite close to the osmotic pressure of human blood and is about 0.74 MPa. The main role in creating osmotic pressure is played by milk sugar and some salts. The osmotic pressure of milk is favorable for the development of microorganisms. It is closely related to the freezing point (cryoscopic temperature). The freezing point, as well as the osmotic pressure, of milk in healthy cows remains virtually unchanged. Therefore, cryoscopic temperature can be used to reliably judge whether milk has been adulterated (diluted with water). The cryoscopic temperature of milk is below zero and averages from -0.54 to -0.55 °C.

The viscosity of milk is almost 2 times greater than the viscosity of water and at 20 °C it is 1.67-2.18 cP for different types of milk. The most significant influence on the viscosity index is exerted by the amount and dispersion of milk fat and the state of proteins.

The surface tension of milk is approximately 1/3 lower than the surface tension of water. It depends primarily on the fat and protein content. Protein substances reduce surface tension and promote foam formation.

The optical properties (light refraction) of milk are expressed by the refractive index, which is 1.348. The refractive index depends on the content of dry substances, therefore it is used to control SOMO, protein content and determine the iodine number using refractometry methods.

The dielectric constant of milk and dairy products is determined by the quality and binding energy of moisture. For water, the dielectric constant is 81, for milk fat - 3.1-3.2. The dielectric constant is used to control the moisture content in butter and dry dairy products.

The boiling point of milk is 100.2 °C.

1.3. Organoleptic characteristics of milk

In terms of organoleptic indicators, cow's milk must meet the requirements given in Table 1.

Table 1. Organoleptic characteristics of milk.

Characteristic name
Appearance	Homogeneous opaque liquid. For fatty and high-fat products, a slight sediment of fat is allowed, which disappears with stirring.
Consistency	Homogeneous, not viscous, slightly viscous. Without protein flakes and fat lumps.
Taste and smell	Clean, without foreign tastes and odors, with a slight aftertaste of boiling. For baked milk and milk sterilized after packaging, there is a well-defined boiling taste. For reconstituted and recombined, a sweet aftertaste is allowed.
Color	Uniform, white with a slight yellow tint, for melted and sterilized after packaging - with a cream tint, for low-fat - with a slightly bluish tint.

1.4. Cow's milk assortment

The Russian dairy industry currently produces up to 20 types of milk, differing in processing methods, packaging, fat content, skimmed milk solids (SMR) and fillers. Depending on the degree of heat treatment, milk can be raw, pasteurized or sterilized. The main types of milk are whole (normalized or reconstituted with a fat content of 12.5 and 3.2%), high fat, low-fat, baked, protein, fortified, sterilized, milk with fillers, etc.

Natural milk is the raw material for the production of other types of milk and dairy products. This is raw or pasteurized milk, the composition of which has not been artificially changed.

Reconstituted milk is pasteurized milk with the required fat content, produced in whole or in part from dried milk products. It is prepared from whole and skim milk powder and cream powder, sometimes partially using fresh natural cream and low-fat milk. The amount of each component that needs to be added to obtain milk of the appropriate composition is first determined, and then the mixture is prepared according to the recipe. Powdered milk is dissolved in warm water with constant stirring, the remaining components are added, and the well-mixed mixture is homogenized, and then filtered, pasteurized and cooled. To improve the taste, milk is kept chilled for several hours to improve the binding and retention of water by milk proteins.

Normalized milk is pasteurized milk in which the fat content has been brought to the required standard (1; 1.5; 2.5; 3.2; 3.5; 4; 6%).

Whole milk is normalized or reconstituted milk with a specified fat content.

High fat milk - normalized milk containing 6% fat, homogenized.

Low-fat milk is pasteurized milk obtained by separating whole milk, containing no more than 0.05% fat.

Baked milk - normalized from a mixture of milk and cream to a content of 6% fat, subjected to homogenization, pasteurization at a temperature not lower than 95 ° C for 3-4 hours. Prolonged exposure to high temperatures leads to the formation of melanoidins, which causes the milk to brown, giving it a creamy appearance shade and a characteristic well-defined taste of pasteurization.

Protein milk is pasteurized milk with a high content of dry fat-free substances. It is produced in 1% and 2.5% fat content with SOMO content up to 11%. To normalize the content of dry fat-free substances, dry or condensed skim milk is added to milk. A mandatory technological operation that ensures good quality of protein milk is homogenization, followed by pasteurization and cooling of the finished product. Due to the higher protein content, the titratable acidity of this milk is higher than that of normalized milk.

Fortified milk is whole or low-fat milk fortified with vitamin C, which is added to the milk after pasteurization.

Sterilized milk is milk that has been homogenized and subjected to high-temperature heat treatment at temperatures above 100 °C.

Ionite milk is similar in composition and properties to human milk and is intended for feeding infants. It is prepared from cow's milk by ion exchange treatment. 20-25% of calcium is removed from cow's milk and replaced with equivalent amounts of potassium and sodium by passing the milk through an ion exchange resin.

After the introduction of lactose (in the form of syrup) and vitamins, thorough mixing, filling and heat treatment at 100-105 ° C is carried out, which ensures a high-quality product that does not contain pathogenic bacteria and E. coli. After aging in sterilizers, the product is cooled to 6 - 8 °C.

Ionite milk contains 3.2-3.5% fat, has an acidity of no higher than 19 °T, and contains 20% less calcium than in the original milk. This milk forms a tender, easily digestible curd. Protein and salts in it are in the same ratio as in human milk.

Milk with fillers - milk with the addition of cocoa, coffee, fruit syrups.

Cocoa milk is pasteurized milk with the addition of cocoa, sugar and stabilizer. It is produced from normalized whole or skim milk by adding pre-prepared syrup with cocoa powder and an aqueous solution of agar. Agar acts as a stabilizer that prevents sedimentation of cocoa powder. The prepared mixture undergoes pasteurization, homogenization and “ripening” - holding at a temperature of 8-10 ° C for 3-4 hours to improve the taste, then it is packaged in bags or glass bottles. The finished product must contain, at least, %: fat - 3.2, sucrose - 12 and cocoa - 2.5.

Coffee milk is pasteurized milk with added coffee and sugar. It is produced according to a scheme similar to milk production.

1.5. Factors affecting the quality and properties of milk

The chemical composition of milk and its consumer properties are influenced by various factors, such as the lactation period, breed of livestock, age, types of feed, living conditions of animals, etc. For a certain time before calving and for seven days after it, milk from cows is not used due to with the fact that its chemical composition during these periods of lactation differs sharply from usual. Old milk has a bitter-salty taste, it does not coagulate well with rennet, it contains a lot of fat, and the fat globules are very small in size. When livestock eats green feed, the composition of the milk is richer in vitamins, mineral salts and other substances. During the period of mass calving of cows (March-April), the fat content in milk is minimal, and in October-December it is maximum.

The milk of sick cows also has its own characteristics. In cows with foot-and-mouth disease, milk contains up to 10% fat; in cows with tuberculosis, the sugar content in the milk is sharply reduced.

The least quantitative changes in milk are subject to sugar content, mineral salts, proteins, which together make up the dry skimmed milk residue - SOMO (8-10%).

Milk is exposed to various influences, but, above all, mechanical and thermal.

Mechanical impact occurs both during the production and processing of milk, and during transportation. When shaking and stirring, the adsorption layer of fat globules is partially destroyed, as a result of which they can combine into grains and lumps of oil. Disaggregation of casein micelles and foaming also occur.

Heat treatment (heating and cooling) is a mandatory technological operation in the production of dairy products. To enhance bactericidal properties, and therefore preserve quality, milk must be cooled to 2-4 °C immediately after milking. When cooled, the viscosity of milk increases, partial crystallization and separation of fat globules occur, and pseudoglobulin disintegrates.

Short-term freezing of milk is a reversible process. During long-term storage of milk in a frozen state, as a result of freezing of pure water, the concentration of electrolytes in the unfrozen part increases, which leads to the discharge of colloidal particles of milk and their precipitation (coagulation of casein). After freezing-thawing, milk may become watery and sweetish as a result of the appearance of water not associated with proteins, lactose and other substances.

Warming milk produces more profound changes than cooling and stirring. When heated, gases and volatile substances are lost. At a temperature of 55 °C, enzymes begin to break down, at 70 °C, albumin coagulates, casein changes only at the border of contact with air. As a result of heating, citric acid decomposes, and acidic calcium salts turn into middle ones. Whey proteins, enzymes and some vitamins undergo significant changes; the taste of milk changes. Casein and truly soluble components of milk change slightly.

With prolonged heating and sterilization, darkening (browning) of the product occurs, which is the result of the interaction of caseinates with lactose. The resulting melanoidins are substances of a complex nature, the intensity of formation of which depends on the temperature and duration of heating, pH and concentration of dry substances.

The effect of heating on milk vitamins is determined by temperature and the presence of oxygen in the air. During pasteurization in plate heat exchangers, vitamins are practically not destroyed. Severe destruction of vitamins occurs during boiling.

1.6. Indicators of drinking milk quality

The quality of milk is assessed by an average sample selected in accordance with the requirements of regulatory documentation (ND) for this type of product.

Milk supplied to the retail chain and intended for direct consumption, according to GOST, must meet certain requirements.

According to physical and chemical indicators, the main types of milk must meet the requirements presented in table. 2.

Table 2. Physico-chemical indicators and standards of some types of milk.

Name indicator	Indicator values
Name indicator	Low-fat	Low-fat	Low fat	Classic	High fat

Density, kg/m 3, not less
Mass fraction of protein, %, not less
Acidity, about T, no more
For enriched with prebiotics
Temperature upon release from the enterprise, o C: For thermized, pasteurized and UHT-treated milk
For sterilized and UHT-treated sterilized milk
Degree of purity according to the standard, group, no less

According to organoleptic indicators, milk should be a homogeneous liquid without sediment and cream sediment, foreign tastes and odors, baked milk should have a well-defined taste of pasteurization. The color of milk is white, with a slightly yellowish tint, melted milk has a creamy tint, and low-fat milk has a slightly bluish tint.

According to microbiological indicators, pasteurized milk is divided into groups A and B.

When examining the quality of milk, microbiological indicators are established, the content of toxic elements, mycotoxins, antibiotics, pesticides and radionuclides, the amount of which should not exceed the permissible levels established by the requirements of SanPiN.

Milk containing preservative coloring substances and residues of plant protection and animal treatment chemicals used in agriculture is not allowed for sale. Milk with the following defects is also not allowed for sale: a pronounced feed taste (onion, garlic, wormwood, etc.), bitter, moldy, rancid taste and smell, viscous consistency.

1.7. Milk defects

Defects may be characteristic of freshly milked milk, and may also occur during storage as a result of the activity of microorganisms. At the same time, the composition and organoleptic properties of milk change significantly.

Defects of taste and smell.

Sour taste (high acidity). Caused by the activity of lactic acid bacteria in violation of milk storage conditions and periods.

Rancid taste occurs when fat is hydrolyzed by milk lipase or microbial lipase at low storage temperatures. The defect is often discovered when old milk containing significant amounts of lipase is ingested.

Bitter taste occurs when proteins break down to form peptones, which have a bitter taste. Protein decomposition is caused by the action of peptonizing bacteria, which enter and develop in milk due to violations of the sanitary and hygienic regime for its receipt, storage and transportation at temperatures below 10 ° C; occurs more often in reconstituted milk.

A bitter taste also occurs when there are significant amounts of bitter plants in the feed.

The oxidized taste is also called oleic, greasy, metallic or sunny. It is caused by the accumulation of fat oxidation products in milk: hydroxy acids, aldehydes, ketones. The reasons for the appearance of this defect are the action of sunlight, ultraviolet rays, air, high temperature, as well as storing milk in untinned iron and copper containers, since metals, especially copper, contribute to the oxidation of milk fat.

The salty taste appears due to changes in the salt composition of milk due to certain diseases of the animal.

Feed flavors and odors arise when characteristic flavoring substances and essential oils pass from feed into milk.

For this reason, various tastes and odors may appear in milk: wormwood, garlic-onion, radish, silage, cabbage, etc.

Foreign tastes and odors appear as a result of the adsorption of volatile compounds (hydrocarbons, ethers, ketones, etc.) by milk. Therefore, joint storage and transportation of milk with strong-smelling products is not allowed.

Milk that has the specified defects in taste and smell is not allowed to be sold as drinking milk intended for direct consumption; it is sent for processing.

Color defects. Milk may take on red, pinkish, blue, light blue or yellow hues. Changes in the natural color of milk are associated with the development of pigment-forming bacteria in it, some yeasts and the ingress of blood from a damaged udder, animals eating herbs with pigments, in some diseases (for mastitis and tuberculosis - bluish, for foot-and-mouth disease - yellow), mixing with colostrum (yellow) , storing milk in zinc containers (bluish).

Consistency defects. Sometimes milk acquires a slimy (stringy), curdled or foamy consistency. This is due to the activity of various microorganisms when milk storage conditions and periods are violated.

1.8. Packaging, labeling, transportation and storage

Milk is packaged in tanks, flasks, from which it is sold for bottling; milk is packaged in bottles with a capacity of 0.25; 0.5 and 1.0 l; in bags made of grease-proof cardboard with polymer coatings and in bags made of polyethylene film filled with titanium ("fin-pack") of similar capacity. Paper bags can be of different shapes: “tetra-pack” (triangular prism), “pure-pack” (a tall column with a square base), “tetra-brick” (brick-shaped). A lot depends on the shape of the package: convenience of purchase for the buyer, type of transport container, stability of the packaging during the production process and distribution of goods. The sharper the corners in the bags ("tetra-pack"), the faster they are damaged, leak and, accordingly, product loss. For stacking tetra-packs, special containers have been developed and used - hexagonal I-shaped boxes made of low-density polyethylene. Milk in “pure pack” and “tetra brick” packages in blocks of several pieces (10-12) is covered with shrink film and placed in container equipment.

The use of these milk packaging made it possible to completely abandon returnable glass containers. A combiblock maxi package with a capacity of 2 liters has been developed. The problem remained the issue of storing milk after opening the first combination packages. The new “combiblock standard” packaging with a “combitop” lid prevents the contamination of milk with microorganisms after opening. However, the world community is concerned about the growing use of polymer and combined materials, as they pollute the environment.

The name or number, trademark of the manufacturer is applied to the aluminum cap of a glass bottle, bag and other consumer packaging with embossing or indelible paint; name of the product, volume in liters, date or day of the deadline for sale, retail price, designation of the current standard. The fat content of milk (%) on polymer bags is conventionally indicated by the letters: H - 1.5; W - 2.5; E - 3.2; Yu - 3.5; I - 6. When bottling milk into flasks or thermal tanks, a label with the same designations is placed on the container. The packages also indicate the composition of the product and calorie content, they have pictures and instructions for opening the container. Package labeling must be clear and colorful.

Milk and cream are transported in closed, refrigerated or isothermal means of transport, and in their absence, it must be covered with tarpaulin or substitute materials.

Pasteurized cow's milk and cream should be stored at a temperature of 0 to 8°C for no more than 36 hours from the end of the technological process. Sterilized milk at temperatures from 1 to 10°C can be stored for up to 6 months; at temperatures from 0 to 20°C - no more than 4 months. Rooms and chambers for storing milk and cream should be well ventilated and darkened.

The labeling of milk for children's, dietary and therapeutic-prophylactic nutrition must indicate the date and month of the deadline for sale, the content of biologically active substances, vitamins, etc.

Sterilized baby milk in bottles at a temperature not exceeding 6°C should be stored for no more than 5 days, in bags of 200 g at a temperature not exceeding 10°C - no more than 10 days. from the end of the technological process, including at the manufacturer - no more than 3 days.

The sale of bulk milk should be carried out after it has been thoroughly mixed. It is prohibited to hold the buyer's dishes over an open flask or barrel and pour milk from it back into a common container. You cannot leave equipment (measuring cup, etc.) in a container with milk. It must be thoroughly washed daily with a hot soda solution, wiped dry with a clean towel and stored in designated places.

Packaged pasteurized milk and cream must be refrigerated before and during sale.

2. Research part. Assessment of the quality of drinking cow's milk sold on the consumer market in Volzhsky

2.1. Overview of the consumer milk market

Today, dairy products are among the most popular in Russia, regardless of the age, place of residence and financial situation of consumers. Every year, consumption volumes in the dairy market are increasing, and the demand for new products offered by the largest international companies and Russian holdings is growing quite actively. In this regard, the Institute of Economic and Social Research Foundation conducted a comprehensive marketing research that allows us to assess the degree of distribution of various brands/manufacturers in the city's retail trade network, highlight the main trends in the development of the Volgograd dairy market and determine the brand preferences of the target group of consumers for certain types of dairy products . The target group included women 25–55 years old who purchased at least two types of dairy products in the month of September 2006.

The popularity of milk is confirmed by the data obtained during the survey: during the study period, 83.5% of respondents purchased it. The majority of consumers buy milk more than once a week. At the same time, as a rule, 1 liter of product is purchased for one purchase - this answer was given by 68.3% of survey participants.

A significant portion of respondents – 40.7% of hall test participants – most often buy milk in a Pure-Pack cardboard bag. Milk in a Fin-Pack plastic bag is preferred by 22.2% of respondents. In third place in popularity is LeanPack (a polyethylene jug) - it is chosen by 12.6% of customers.

Residents of Volgograd were also asked to answer the question of which packaging they consider most convenient. From this point of view, a significant part of the respondents named the cardboard packaging Tetra Brick Aseptic and Tetra Rex - 38.9 and 24% of respondents, respectively. Fin-Pack packaging in this case is assessed negatively. This is primarily due to the fact that it is less practical to use: it breaks more often and is inconvenient to store in the refrigerator. At the same time, milk in Fin-Pack has a significant price advantage, and therefore many customers prefer it.

The majority of respondents – 77.8% – when purchasing milk, are guided by such characteristics of this product as naturalness and the absence of preservatives.

In general, the Volgograd market provides customers with a large selection of dairy products. Monitoring of retail trade enterprises was carried out in the following product groups: milk, fermented milk products, milk and milk-juice drinks, cocktails, cottage cheese products, sour cream, cottage cheese, dairy desserts and baby food products made from raw milk.

According to these groups, products from five manufacturers are most often found in city stores: OJSC Dairy Plant No. 3 Volgogradsky (Volgograd), OJSC Wimm-Bill-Dann Food Products (Moscow), LLC Danone-Industry (Moscow region) , OJSC "Dairy plant "Voronezh" (Voronezh) and OJSC "Volgomyasomoltorg" (Volgograd).

The first six positions in the ranking of milk representation in retail outlets belong to the brands “Volzhskaya Burenka” and “Belyanochka” (dairy plant No. 3 “Volgogradsky”). These brands are most often found on the shelves of Volgograd stores - in 64.0 and 53.3% of retail outlets, respectively.

The widest range of products - 141 types of dairy products - is offered by Wimm-Bill-Dann Food Products. There are several brands on the Volgograd market that belong to this manufacturer: “House in the Village”, “Kubanskaya Burenka”, “Vesely Milkman”, BioMax, Neo, “Miracle”, “Our Doctor”, “Ryzhy Up”. The release of a large number of brands allows us to reach consumers of dairy products in all price segments of the market.

Wimm-Bill-Dann is a leader in the segment of milk and milk-juice drinks and cocktails, with milkshakes from the Mazhitel Neo series being the most popular.

Leadership in the group of dairy desserts belongs to two companies – Danone and Campina. Baby food products made from raw milk are represented by the products of Azov Baby Food Plant OJSC (Rostov Region), Baby Food Istra-Nutritsia OJSC (Moscow Region) and EKZ Lebedyansky OJSC (Lebedyan, Lipetsk Region)

As for preferences for milk brands, a significant proportion of respondents choose the brand "Belyanochka" (JSC "Dairy Plant No. 3 "Volgogradsky"). The second and third positions are occupied by milk "Vkusnoteevo" (JSC "Dairy Plant "Voronezhsky") and "Rossiyskoe" (JSC "Volgomyasomoltorg").

The Belyanochka brand is also the most famous regional brand of dairy products - it was noted by 87.5% of respondents.

It is worth noting that mainly representatives of the target audience recalled those brands of dairy products that are either actively advertised through federal channels or have a good level of distribution in city stores. For 73% of respondents, television advertising is the main source of information about new dairy products appearing on the market.

The Volgograd dairy market, like many other regional markets, is characterized by seasonality, which manifests itself in changes in consumer preferences. If milk is in great demand in the winter season, then in the summer, Volgograd residents more often purchase fermented milk products. For other types of dairy products - desserts, cocktails, yoghurts - seasonal fluctuations in demand are not so noticeable.

According to the experts who took part in the study, Volgograd buyers, when purchasing dairy products, mainly pay attention to cost and quality, and only then to the attractiveness of the packaging. In turn, the price factor is important, but does not determine the consumer behavior of Volgograd residents. In conditions when supply exceeds demand on the dairy market, the Volgograd consumer gives preference to a quality product. A product of poor quality, even at the lowest price, will not be in mass demand.

2.2. Sampling procedure

An examination of milk from various producers was carried out in the MAN store.

Store opening hours are from 8-00 to 21-00. Works without breaks for lunch and weekends.

An examination of the consumer properties of dairy products determines the compliance of commercial qualities with current state standards and technical specifications for certain types of products. Examination methods make it possible to assess quality changes associated with production technology, use of raw materials, packaging, storage, transportation, and sales conditions.

To control the quality of milk and dairy products in transport and consumer packaging based on organoleptic and physico-chemical indicators, a sample is taken from each batch of products.

A batch is considered to be a set of units of products of the same name in a homogeneous container with the same physical and chemical characteristics (of the same grade), intended for control, produced at the same manufacturing plant, on the same technological equipment, during the same technological cycle, according to a single production regime, on the same production date. and executed in one accompanying document.

When taking a sample from each unit of transport container, take: one unit of consumer container with milk products (or 5% of the volume of transport container).

To control the quality of milk according to microbiological indicators, one unit of transport or consumer packaging with products is separated from the batch.

If foreign substances or mold are detected in milk in transport containers included in the sample, each unit of transport container with products in the batch is subject to control. Based on the results of the control, only products that meet the requirements of regulatory and technical documentation are subject to acceptance. If foreign substances or mold are detected in milk and dairy products in consumer packaging, the batch is not subject to acceptance.

First of all, samples are taken for microbiological analyzes in sterile containers using devices that must be sterilized each time before use.

An average, or combined, sample is a part of a product taken from controlled packaging units from one batch in one container. The pooled sample is composed of point samples. Selection of spot samples of liquid, viscous and condensed products is carried out with a mug or scoop with a capacity of 0.10; 0.25; 0.50 l with a rigid handle 0.5 to 1 m long, a metal or plastic tube with an internal diameter (9+ 1.0 mm) along its entire length and with holes at the ends.

For microbiological analysis, a combined milk sample of 500 cm 3 is composed of spot samples taken from each flask; A sample with a volume of 50-60 cm 3 is isolated from the combined sample. The sample is placed in a sterile container and closed with a sterile stopper. Microbiological analysis is carried out no more than 4 hours from the moment of sampling. Samples must be stored and transported under conditions that ensure the temperature of the products does not exceed 6°C, preventing freezing.

Also, after mixing, a sample is isolated from the combined sample for physical and chemical analysis (average or laboratory sample).

Samples are placed in glass, metal, porcelain or polymer containers. The containers must be dry, clean, odorless, have appropriate capacity and shape, convenient for analysis. Cover containers with cork, plastic, or foil-wrapped rubber stoppers or lids.

Samples are sealed or sealed. Bottles and jars are tied around the neck with strong thread or twine, the ends of which are thrown onto the top of the cork or lid and sealed there. The parchment is tied or stitched with strong thread or twine and sealed.

Samples are provided with a label indicating the name of the product, manufacturer, batch number and production date. The sampling report shall indicate:

Sampling location;

Name of the manufacturer;

Name, grade and date of production of the product;

Number, batch volume;

Temperature of the product at the time of sampling;

Date and hour of sampling;

Positions and signatures of the persons who took the sample;

Indicators that must be defined in the product;

Name of the deliverer, receiver, number and date of the transport document;

Designations of a standard or technical specification for a product.
Milk samples must be delivered to the laboratory immediately after collection. Before analysis, milk samples should be stored at a temperature of 2 to 8°C.

Physico-chemical analysis of product samples is carried out immediately after delivery to the laboratory, but no later than 4 hours after their collection. When preparing samples for analysis of physicochemical parameters, they are mixed by pouring them into another container (at least two times) or turning the container over (at least three times).

Milk samples are brought to a temperature of 20+2°C.

For microbiological analysis, samples are neutralized by adding a sterile solution of sodium bicarbonate with a mass concentration of 100 g/dm 3. Before sowing, tenfold dilutions of the product are prepared in sterile solutions of sodium chloride, sodium citrate (for cheeses) or phosphate buffer.

During the course work, an examination of drinking cow's milk (classic) from 3 different manufacturers was carried out. The results are shown below. In accordance with the above requirements, milk samples from various manufacturers were taken at the MAN store on August 20, 2007.

The following samples were used to evaluate organoleptic and physicochemical parameters.

Sample No. 1.

Drinking milk pasteurized “Special” classic (3.2%). Product of the Molvest company. Manufacturer JSC Voronezh Dairy Plant, Voronezh, st. 45 Infantry Division, 259.

Sample No. 2.

Mass fraction of fat 3.2%. Product of the UNIMILK company. Manufacturer: branch of the Volgograd Dairy Plant, OJSC UniMilk Company, Volgograd, st. Przhevalsky, 20.

Sample No. 3.

With a fat mass fraction of 3.5%. Manufacturer OJSC Dairy Plant No. 3 Volgogradsky, Volgograd, st. Przhevalsky, 20.

2.3. Filling, packaging, labeling

To package the product, containers are used that are manufactured in accordance with regulatory or technical documents approved in the prescribed manner, from materials that meet the requirements.

The following are used as consumer packaging: glass bottles; bottles made of polyolefins (polyethylene, polypropylene and their mixtures); bags made of combined materials based on paper and polymers, waxed paper and polyethylene; bags made of combined materials based on paper, aluminum foil and polymers; packages made from blanks based on cardboard and polyethylene; packages made from blanks based on cardboard, polyethylene and aluminum foil; bags made of polyethylene films filled.

To seal glass bottles, varnished aluminum foil and crown cap are used, and for polyolefin bottles, foil with thermal adhesive coatings and/or screw caps approved by the State Sanitary and Epidemiological Service of the Russian Federation for contact with food products are used.

The product can be packaged in other types of consumer containers of various capacities from packaging materials approved by the State Sanitary and Epidemiological Service of the Russian Federation for contact with dairy products and ensuring the preservation of the quality of the product during its transportation, storage and sale. Polymer reusable boxes, trays and boxes made of corrugated cardboard, heat-shrinkable and stretchable polymer films manufactured in accordance with regulatory or technical documents approved in the prescribed manner are used as group packaging.

It is allowed to use other types of group packaging that ensure the safety of the product, made from materials approved by the State Sanitary and Epidemiological Service of the Russian Federation for use in dairy industry enterprises. Flat or universal pallets, manufactured in accordance with regulatory or technical documents approved in the prescribed manner, are used as transport packaging.

The group packaging is placed on pallets in such a way that the markings of at least one group packaging unit are visible on each side of the transport container. It is allowed to use other types of transport containers that ensure the safety of the product, made from materials approved by the State Sanitary and Epidemiological Service of the Russian Federation for use in dairy industry enterprises.

Methods for laying transport containers are carried out in quantities that do not cause deformation of the lower rows and ensure the safety and quality of the product.

Shrinkable and stretchable polymer films are used for wrapping transport containers. It is allowed to use other types of banding materials that ensure the safety of the product, made from materials approved by the institutions of the State Sanitary and Epidemiological Service of the Russian Federation for banding food products.

Products sent to the Far North and hard-to-reach areas are packaged in accordance with GOST 15846.

Limits of permissible negative deviations of the net contents from the nominal quantity (no more than 10 kg or 10 l) in accordance with GOST R 8.579.

During the experiment, measurements of the net mass of milk of samples No. 1, 2, 3 were carried out, it was found that samples No. 1, 3 have no deviation in net weight, and sample No. 2 has a deviation of 3 ml.

In table 3. An assessment of milk labeling from various manufacturers is presented.

Table 3. Labeling.

The name of indicators	Sample No. 1	Sample No. 2	Sample No. 3
Product name	Drinking milk pasteurized “Special” classic	Classic pasteurized drinking milk “Summer Day”	Selected drinking milk, pasteurized
Norm of mass fraction of fat
Manufacturer's name and location	JSC Voronezh Dairy Plant. Russia, Voronezh, st. 45 Infantry Division, 259.	Branch of the Volgogradsky Dairy Plant of OJSC UniMilk Company.	OJSC Dairy Plant No. 3 Volgogradsky. Russia, Volgograd, st. Przhevalsky, 20.
Trademark	There is “Vkusnoteevo” (See in the appendix)	There is a “Summer Day” (See Appendix)	There is “Prostokvashino” (See Appendix)
Product net weight, volume
Product Composition Information	Made from fat and protein standardized cow's milk	Made from a mixture of normalized and reconstituted cow's milk	Made from natural cow's milk
Continuation of Table 3.

Nutritional value (content per 100 g of product)	Fat – 3.2 g; Protein – 2.6 g; Carbohydrates – 4.7 g; Calorie content – 58 kcal.	Fat – 3.2 g; Protein – 2.6 g; Carbohydrates – 4.7 g; Calorie content – 58 kcal.	Fat – 3.5 g; Protein – 2.8 g; Carbohydrates – 4.7 g; Calorie content – 61 kcal.
Storage conditions	Store at temperatures from +2 to +6 degrees C	Store at a temperature of (4+-2) degrees C.	Store at a temperature of 4 to 4 degrees C
Date of manufacture
Best before date
Standard designation	9222-003-00426012-04	GOST R 52090-2003	9222-242-00419785-04
Certification Information	There is a certificate of conformity AYA 60	Certificate designation missing	There is an AYA 28 certificate

2.4. Assessment of organoleptic indicators

Organoleptic indicators - appearance, color, smell, consistency, taste - are determined by the senses (vision, smell, touch). Smell and taste assessments are carried out by specially trained and certified experts.

The smell and taste of milk is determined both immediately after sampling and after storage and transportation for no more than 4 hours at a temperature of 4+2°C.

The analyzed milk samples are compared with a milk sample without odor and taste defects. Smell and taste are assessed on a five-point scale (Table 4).

Table 4. Organoleptic assessment of milk quality.


High level
Average level
Below the average
Non-standard

Milk with a score of 20-18 points is classified as highest, 17-15 as first or second grade, depending on other indicators.

Milk with a score of 15-10 points is classified as second grade in the winter-spring period of the year, and non-grade milk in other periods of the year.

Table 5. Comparative characteristics of samples of drinking cow's milk (classic) from various manufacturers.

Manufacturer's name	Name of product	Characteristics of products in accordance with the requirements of regulatory documents (GOST, TU, Industry Standards, etc.)	Organoleptic characteristics, in accordance with the requirements of regulatory documents	Actual assessment results
Manufacturer OJSC Voronezh Dairy Plant. Voronezh, st. 45 Infantry Division, 259.	Classic pasteurized drinking milk	Manufactured in accordance with TU 9222-003-00426012-04 from cow's milk normalized by mass fraction of fat and protein		Appearance: homogeneous opaque liquid. Total 5 points Consistency – liquid. Slightly viscous. Total 5 points. The taste and smell are clean, without any foreign tastes or odors, a total of 5 points. Color – white, uniform throughout the mass. Total 5 points. Total: 20 points
Continuation of table 5.

Manufacturer: branch of Volgograd Dairy Plant OJSC UniMilk Company. Volgograd, st. Przhevalsky, 20.	Classic pasteurized drinking milk	Manufactured in accordance with GOST 52090-2003 from a mixture of normalized and reconstituted cow's milk	Appearance: homogeneous opaque liquid. For fatty and high-fat products, a slight sediment of fat is allowed, which disappears with stirring. Consistency - homogeneous, not viscous, slightly viscous. Without protein flakes and fat lumps. The taste and smell are clean, without foreign tastes and odors, with a slight aftertaste of boiling. For baked milk and milk sterilized after packaging, there is a well-defined boiling taste. For reconstituted and recombined, a sweet aftertaste is allowed. Color - uniform, white with a slight yellow tint, for melted and sterilized after packaging - with a cream tint, for low-fat - with a slightly bluish tint.	Appearance: opaque liquid with particles of undissolved milk powder. Total 4 points. Consistency – liquid, homogeneous, not viscous. Total 4 points. The taste and smell are clean, with a sweetish aftertaste. Total 3 points. Color – uniformly white with a faint yellow tint. Total 4 points. Total: 15 points
Continuation of table 5.

Manufacturer OJSC Dairy Plant No. 3 Volgogradsky. Volgograd, st. Przhevalsky, 20.	Selected drinking milk, pasteurized	Manufactured in accordance with TU 9222-242-00419785-04 from natural cow's milk	Appearance: homogeneous opaque liquid. For fatty and high-fat products, a slight sediment of fat is allowed, which disappears with stirring. Consistency - homogeneous, not viscous, slightly viscous. Without protein flakes and fat lumps. The taste and smell are clean, without foreign tastes and odors, with a slight aftertaste of boiling. For baked milk and milk sterilized after packaging, there is a well-defined boiling taste. For reconstituted and recombined, a sweet aftertaste is allowed. Color - uniform, white with a slight yellow tint, for melted and sterilized after packaging - with a cream tint, for low-fat - with a slightly bluish tint.	Appearance: homogeneous opaque liquid. Total 5 points. The consistency is homogeneous, not viscous. Total 4 points. The taste and smell are pure, without foreign tastes or odors. Total 5 points. The color is uniformly white throughout the mass. total 5 points. Total: 19 points.

Conclusion: Sample No. 1, pasteurized drinking milk “Osoboe” classic (3.2%). Product of the Molvest company. Manufacturer JSC Voronezh Dairy Plant, Voronezh, st. 45 Rifle Division, no. 259 after an organoleptic assessment is assessed as excellent.

Sample No. 2, pasteurized classic drinking milk, fat mass fraction 3.2%. Product of the UNIMILK company. Manufacturer: branch of the Volgograd Dairy Plant, OJSC UniMilk Company, Volgograd, st. Przhevalskogo, 20, after an organoleptic assessment is assessed as good.

Sample No. 3, selected pasteurized drinking milk with a fat mass fraction of 3.5%. Manufacturer OJSC Dairy Plant No. 3 Volgogradsky, Volgograd, st. Przhevalskogo, 20, after an organoleptic assessment is assessed as excellent.

2.5. Determination of milk acidity

State standards establish requirements and norms for the physical and chemical indicators of milk and dairy products, as well as methods for determining these indicators.

Total (titratable) acidity is expressed in degrees Turner (°T). Turner degrees refers to the number of milliliters of 0.1 N. alkali solution (NaOH or KOH) required to neutralize 100 ml of milk or product. Titration is carried out in the presence of the indicator phenolphthalein.

The acidity of freshly milked milk is 16-18°T. It is created by acidic salts, proteins, carbon dioxide, acids and other components of milk. When storing raw milk, the titratable acidity increases (lactic acid is formed during the fermentation of milk sugar), and the resistance of proteins to heat decreases. Therefore, milk with an acidity of more than 22°T cannot be delivered to a dairy plant (except for protein milk with an acidity of up to 25°T).

The active acidity of milk is determined by the pH value at 20°C and is 6.55-6.75 for fresh milk. The pH of the environment is important for the life of lactic acid bacteria and the formation of fermentation products.

Acidity is determined based on the requirements of GOST 3624-92 “Milk and dairy products. Tetrimetric methods for determining acidity".

The acidity of milk is the main indicator by which its freshness is determined. It is expressed in Turner degrees (T).

The Turner degree refers to the number of milliliters of decinormal alkali (0.1 N) required to neutralize the acids contained in 100 ml of milk. Acidity is caused by the presence of lactic acid, acid salts and other substances.

Equipment, glassware, reagents:

· Stand with burette for titration;

· Mora pipettes 10 ml;

· Conical flasks 150-200 ml;

· Measuring cylinder 100 ml;

· Chemical glasses for 100-150 ml;

· Technochemical scales with weight;

· Glass rod (thick);

· Porcelain mortar and pestle;

· 1% phenolphthalein solution;

· 0.1N solution of sodium hydroxide or potassium hydroxide;

· 2.5% cobalt sulfate solution.

Progress of determination.

1. We strengthen the burette in a tripod in a strictly vertical position and fill it with 0.1 N alkali solution above the upper divisions. By pouring the alkali solution from the burette into the glass, we bring it exactly to the zero mark and observe whether the tap is leaking.

2. Mix the milk well, pipette 10 ml of milk into a glass, add 20 ml of distilled water and three drops of a 1% alcohol solution of phenolphthalein. Shake the liquid, place a sheet of white paper on a tripod and place a flask or glass on it.

3. Pour alkali into the resulting mixture in small portions from a burette, shaking the flask each time until a permanent pink color appears. After this coloration appears, the alkali must be added drop by drop, otherwise the solution can be overtitrated. The end of the titration is determined by the pink color of the liquid that does not disappear within a minute.

4. Calculate the acidity (b) of milk using the formula:

where a is the amount of alkali used for titration, ml;

k - correction factor for alkali.

Physico-chemical (acidity) parameters of milk are presented in Table 6.

Table 6. Acidity of milk of samples No. 1, 2, 3.

Conclusion: The acidity of milk in samples No. 1, 2, 3 is within normal limits.

Chapter 3. Practical part. Analysis of the range of classic milk sold in the MAN store

3.1. Brief organizational and economic characteristics of the store

MAN store, located at: Volgograd region, Volzhsky, st. Druzhby, 75 "a", is a structural subdivision of LLC "Gurman", LLC "April-06", IP Karev N.A.

The store has a complex of premises necessary for the rational functioning of the trade and technological process. According to their functional purpose, the premises are divided into the following groups: retail (sales area with an area of 376 sq. m); for receiving, storing and preparing goods for sale; auxiliary; administrative and household; technical.

Store opening hours are from 8-00 to 21-00. Works without breaks for lunch and weekends.

In the MAN store, the organizational management structure is represented by a director, who has a deputy. The management functions of the director and deputy director were differentiated according to specific types of activity of the enterprise, which adopted a functional management structure.

Director of retail chain

Deputy Director

Departments

Performers

Rice. 3.1. Functional management structure

The functional structure of management is that the head of the enterprise transfers (delegates) part of his powers to his deputies or heads of functional departments. The functional form of management allows you to disperse administrative and managerial work and entrust it to the most qualified personnel. At the same time, the use of such a structure leads to the need for complex coordination between management bodies in the preparation of almost every document that is considered important. This reduces the efficiency of work, lengthens the time it takes to complete documentation and the time it takes to make decisions. In addition, there are often contradictions in wording and ambiguity in the approach to performing individual tasks, and inconsistency of the content of some orders with others. The management apparatus, eliminating these shortcomings, loses time and additional resources.

In table 7 shows the staffing schedule of the MAN store.

Table 7. Staffing list of the MAN store

Job title	Subdivision	Quantity
Director
Deputy directors
Secretary
Accountant	Store accounting
Economist	Planning and economic
Head sections
Commodity experts	Sales Department
Sellers (consultants, cashiers)
Engineers	Maintenance department
Marketers	Marketing department
Businessmen	Sales department
Loaders	Maintenance department
Warehouse workers

To carry out and implement the main activities of the store, the following functions are assigned to the various structural divisions of the store:

· the marketing department conducts targeted marketing research, planning and strategic forecasting, maintains relations with advertising media and public relations, and also resolves issues of logistics support for clients and the implementation of services provided to customers;

· the economic planning department carries out work on economic analysis and long-term forecasting of the development of trade and commercial activities, a group for monitoring and evaluating the implementation of commercial activities;

· the commercial department carries out the main work in the store on the purchase and sale of goods in the store, the acceptance of goods in terms of quality and quantity, the search for new types of products, etc.;

· the engineering and economic department (warehousing departments) carries out complex activities, including the entire set of operations associated with warehousing, loading and unloading, as well as the physical movement of goods to end consumers.

To improve the organization of workers' work and reduce the loss of working time due to uneven customer flows in the store, a rational operating mode for the store and its employees has been established.

In order to use time more efficiently for preparatory and final operations, 30% of shift workers come to work 30 minutes before the store opens and stay the same amount after the store closes. At the same time, the schedules provide for a strict priority order for all sellers.

The store strictly adheres to internal rules: employees come to work on time, leave work, and take a lunch break according to their work schedule. Much work is being done to monitor labor safety. Compliance with labor protection rules and safety requirements is important when operating all types of equipment. Workers servicing the equipment are provided with operating instructions that contain safety requirements, indications of maximum loads, etc.

Store managers pay great attention to fire safety measures. The causes of fires can be different, so fire safety requirements are observed in all premises.

For a comprehensive assessment of the effectiveness of the trading and purchasing activities of the MAN store, an analysis of the system of indicators is necessary. The main indicators of the economic activity of the enterprise are:

Trade turnover;

Distribution costs;

Profit;

Profitability.

In our opinion, it is the internal analysis of these indicators that will reflect the mechanism for achieving maximum results by the enterprise. Based on this approach, we assessed the results of the economic and financial activities of the MAN store for the period (2004-2006). (See Table 8.)

Table 8. Indicators of the efficiency of economic activities of the MAN store

Based on the data in table. 3.2., we can draw the following conclusions: in 2006, the MAN store achieved a turnover of 1,459,170 thousand rubles, which is 59,170 thousand rubles. more than in 2005. The amount of trade turnover for an enterprise is the totality of the amounts of trade revenue deposited at the cash desk or bank, the volume of small wholesale sales (by bank transfer), the provision of additional services to customers, etc. Trade turnover in 2006 increased both due to an increase in retail prices and due to the expansion of the Meat and Poultry department.

Let's consider the structure of trade turnover, i.e. sales volume of individual product groups in the MAN store (See Table 9.).

Table 9. Analysis of the turnover structure of the MAN store for 2004-2006

Product groups
Product groups	Sales volume, thousand rubles.	Sales volume, thousand rubles.	Sales volume, thousand rubles.
1. Grocery
2. Bread and confectionery
3. Dairy products
4. Gastronomic products
5. Liquor products
6. Fish products
7. Semi-finished meat and poultry products

From the data in table. 9. It can be seen that in the structure of trade turnover in 2004, the largest share was the sale of alcoholic beverages (24.6%), followed by the sale of semi-finished products from meat and poultry. The smallest share in trade turnover was the sale of gastronomic products, only 10%.

In 2005, there was an increase in sales of alcoholic beverages, which was reflected in the structure of trade turnover, since their share was 26.6%, the sales structure of semi-finished products from meat and poultry decreased slightly to 15% (15.4 in 2004), the smallest share Gastronomic goods also accounted for a significant share (9.4%).

In 2006 the situation did not change. Also in first place in the structure are alcoholic beverages (24%), in second place are meat and poultry products (19.9%), and in third are bakery products and confectionery products (13.4%).

3.2. Analysis of the milk assortment in the MAN store

When forming an assortment in a MAN store, a set of properties and indicators of the assortment is regulated, which requires an understanding of their essence and knowledge of the nomenclature of properties and indicators of the assortment. The most important principle of forming a product range is to ensure its compliance with the nature of the population’s demand. In this regard, the range of goods offered to the buyer must have sufficient breadth and depth. The MAN store operates on the basis of an assortment list.

Forming a product range is a big and responsible job. Modern assortment policy involves solving such most important problems as: meeting the demand of specific consumer groups, flexible response to market demands, ensuring the financial stability of a trading enterprise.

Let us determine the indicators of the milk assortment in the MAN store.

Let's consider the breadth of the range of milk sold by the MAN store. As noted above, the range of classic milk contains the following groups:

Classic milk 3% fat;

Classic milk 3.2% fat;

Classic milk 3.5% fat;

Classic milk 4% fat;

Classic milk 4.5% fat.

In 2004, the store had 3 milk assortments; 3.2; 3.5% fat. There was no 4 and 4.5% fat content. Consequently, the breadth of the range:

In 2004, W = 3/5 = 0.6 or 60%.

In 2005, the assortment included milk 3; 3.2; 3.5; 4% fat. There was 4.5% fat missing. Consequently, the breadth of the range:

In 2005: W = 4/5 = 0.8 or 80%.

In 2006, the breadth of the classic milk range changed; all groups were present.

In 2006: W = 5/5 =1 or 100%.

The completeness of the assortment of goods in stores is influenced by factors, often random ones (for example, delivery delays, violation of the delivery schedule, etc.).

Increased completeness of the assortment can serve as one of the means of stimulating sales and satisfying various needs caused by different tastes, habits and other factors.

If we consider the completeness of the assortment for the period under study, then it is advisable to enter the obtained data in the table. 10.

Table 10. Indicators of assortment completeness for 2005 – 2006.

* the assortment of the Magnit store, located in a neighboring microdistrict, was taken as the base indicator.

As can be seen from the data in table. 10, the total number of classic milk items in 2005 was 11 versus 14 basic ones. Classic milk with 3% fat content was most fully represented (about 66) and milk with 4% fat content was completely absent. The overall assortment completeness indicator is 103%. In 2006, there was an increase in the completeness of the range due to milk with 4.5% fat content.

Conclusions and offers

In general, the main results of the course research can be summarized in the following conclusions:

1. The Russian dairy industry uses mainly cow's milk. Its preparation is carried out in accordance with the requirements of GOST R 52054-2003 “Natural cow's milk - raw material. Technical conditions", veterinary and sanitary rules approved by the Ministry of Health and Social Development of Russia.

2. Milk must be natural, whole, fresh, without defects in taste, smell, consistency and color, not frozen, with a density of at least 1027 kg/m3, and an acidity of no more than 20 °T.

3. Depending on the organoleptic and physico-chemical indicators, the prepared milk is divided into grades: highest, 1st, 2nd and non-grade.

4. According to the new regulatory documentation, milk is allowed to be produced from natural milk, normalized, reconstituted, recombined milk and mixtures thereof.

Natural milk is raw milk without extractions or additions of dairy and non-dairy components. It is allowed to clean milk from mechanical impurities and cool it to a temperature of 4 ± 2 °C.

Normalized milk is milk in which the values of the mass fraction of fat, protein (and sometimes dry skimmed milk residue) are given in accordance with the standards established in regulatory or technical documents.

Reconstituted milk is milk made from concentrated, condensed or powdered milk and water.

Recombined milk is made from separate parts of milk and water.

5. The technological scheme for the production of drinking milk includes: milk purification using centrifugal milk purifiers; normalization for fat content with skim milk or cream, for protein content with skim milk powder; homogenization; heat treatment; cooling and bottling.

6. Depending on the heat treatment mode, drinking milk is divided into:

For pasteurized - heat treatment before packaging at a temperature above 67 ° C with exposure from 2 to 30 minutes;

Melted - heat treatment before packaging at a temperature from 85 to 99 ° C with exposure for at least 3 hours or at a temperature above 105 ° C - for at least 15 minutes;

Sterilized - heat treatment at temperatures above 100 °C and exposure times that ensure the production of a product that meets the requirements of industrial sterility;

Ultra-high temperature-treated (UHT-treated) - heat treatment before packaging at temperatures above 135 ° C with a holding time of up to 10 s;

UHT-treated sterilized - with UHT treatment before packaging and sterilization after packaging.

7. Depending on the mass fraction of fat, milk of any heat treatment is divided into skim milk - no more than 0.1% fat; low-fat - from 0.3 to 1.0%; low fat - from 1.2 to 2.5%; classical - from 2.7 to 4.5%; fatty - from 4.7 to 7.0%; high fat - from 7.2 to 9.5%.

In addition, the industry produces fortified (with the addition of vitamin C of at least 100 mg/l) and protein-free or low-fat milk with a high content of milk protein (SOMO content - up to 11%).

8. Quality examination. Sampling is carried out after establishing the homogeneity of the batch and checking the condition of the container (malfunction, contamination, leaks, lack of seals, etc.). Before sampling, the temperature of the milk and the mass of the product in small packaging are also measured. Sampling is carried out in accordance with regulatory documentation.

9. The quality of milk, like all dairy products, is determined by organoleptic, physicochemical indicators and SanPiN requirements.

10. Organoleptic indicators. Appearance and consistency - opaque, homogeneous, non-viscous, slightly viscous liquid. For full-fat and high-fat milk, slight fat sedimentation is allowed.

The taste and smell are characteristic of milk, without any foreign tastes or odors, with a slight aftertaste of boiling. For baked and sterilized milk there is a pronounced boiling taste, for reconstituted and recombined milk there is a sweetish taste.

The color is white, uniform throughout the mass, for melted and sterilized - with a creamy tint, for skimmed - with a slightly bluish tint.

11. Milk defects. If production technology, storage conditions and periods are violated, defects in taste, smell and consistency may appear in milk.

The sour taste occurs due to the accumulation of lactic acid, which accumulates during lactic acid fermentation (increased storage temperature).

The bitter taste appears as a result of the development of putrefactive bacteria during long-term storage of milk at low temperatures.

Grey taste - occurs when milk is stored in the light as a result of oxidation of milk fat.

Foreign tastes and odors may appear if the product is placed in the wrong location as a result of the adsorption of volatile substances by milk.

Sometimes milk acquires a mucous, viscous, viscous, curdled, foamy consistency. The reason is the development of foreign microorganisms due to poor sanitary conditions of production.

12. Physico-chemical indicators: mass fraction of fat, protein from 2.6 to 2.8%, density, acidity 20-21 °T, temperature at release from the enterprise, absence of phosphatase, purity group not lower than 1st class.

14. Shelf life according to SanPiN 2.3.2.1324-03 “Hygienic requirements for shelf life and storage conditions of food products” for milk in consumer and transport containers is 36 hours at a temperature of 4 ± 2 °C.

Sterilized and UHT-treated sterilized milk should be stored at a temperature of 2 to 25 °C.

Storage conditions and expiration dates for milk are established by the manufacturer.

15. During the course work, the quality of milk was assessed by organoleptic and physico-chemical indicators (determination of acidity) in milk from different manufacturers, sold in the MAN store in Volzhsky. It has been established that batches of milk that were sold on August 20, 2007 are subject to sale. No deviations from the requirements of regulatory documents have been identified.

1. Modern quality management is based on the premise that quality management activities cannot be effective after the product has been manufactured. This activity must be carried out during production. If all farms understand the need for such work on the quality of milk produced and join this process, Russian agriculture will be able to move to a new level of food production.

2. Experts note that the period of revolutionary changes in the Volgograd market: for example, the emergence of a new assortment, is behind us. Expanding the product range and stimulating sales of a particular product occurs mainly through the introduction of a new brand to the market, changes in the design and volume of packaging. At the same time, representatives of trade enterprises believe that regional manufacturers, when making changes to their products, pay insufficient attention to promoting their own products, shifting this burden to the distribution network.

3. By examining milk produced by 3 different manufacturers, evaluating the packaging and information on it, we can recommend that the Volgogradsky Dairy Plant Branch of OJSC UniMilk Company mark it with the certificate number and indicate the composition of normalized and reconstituted milk in %.

4. Expand the range of classic milk in the MAN store, since it is presented only with 3.2 and 3.5% fat content from 4 manufacturers. 3 milk was not available for sale; 4; 4.5% fat.

5. An equally important way to improve trade would be to require suppliers to package incoming milk properly, which would reduce leakage and related costs. Require suppliers to comply with regulatory requirements for the packaging of their products in order to reduce costs associated with these costs.

The practical implementation of our proposals will increase turnover and profits, and additionally attract regular customers to the MAN store.

Bibliography

1. Goncharova V.N., Goloshchapova E.Ya. 2002. Commodity science of food products. M.: Economics, 270 p.

2. Dubtsov G.G. Food merchandising. 2001. – M.: Higher School. – 264 p.

3. Kruglyakov G.N., Kruglyakova G.V. Commodity research of meat and egg products. Merchandising of dairy products and food concentrates: Textbook. 2001. – M.: “Marketing”, – 488 p.

4. Kruglyakov G.N., Kruglyakova G.V. Merchandising of food products: Textbook. 1999 – Rostov n/d: “March”. – 448 p.

5. Matyukhina Z.P., Korolkova E.P. Food merchandising: Textbook. 2000. – M.: IRPO; Ed. Center "Academy", - 272 p.

6. Nikolaeva M.A. Merchandising of consumer goods. Theoretical basis. 2000. – M.: Publishing house NORMA, – 283 p.

7. Raikova E.Yu., Dodonkin Yu.V. Commodity theory. 2002. – M.: “Academy”, Craftsmanship, – 240 p.

8. Commodity research and organization of trade in food products/A.M. Novikova et al. 2002– M.: ProfObrIzdat. – 480 s.

9. Commodity research and examination of food products: Textbook/Ed. L.G. Eliseeva. 2006. – M.: MTsFER – 800 p.

10. Commodity research and examination of edible fats, milk and dairy products / Ed. Kastornykh M.S. and others. 2003. – M.: “Academy” – 288 p.

11. Timofeeva V. A. Commodity research of food products. 2001. – Rostov n/a: “Phoenix”. – 448 p.

12. Chemical composition of food products. Ed. Nesterina M.F., Skurikhina I.M. 1979. - M.: Food industry, 234 p.

13. Chechetkina N.M., Putilina T.I., Gorbuneva V.V. Commodity expertise. 2000.- Rostov n/a: “Phoenix” – 512 p.

14. Shepelev A.F. et al. Commodity research and examination of food products. 2001. – Rostov – on – Don: March. – 680 s.

15. GOST R 51917 2002 "Dairy and milk-containing products. Terms and definitions."

16. GOST R 52054-2003 "Natural cow's milk - raw materials. Technical conditions."

17. GOST R 52090-2003 "Drinking milk. Technical conditions".

18. Sanitary rules and regulations. SanPiN 2.3.2.560-96. – M.: 1997.

Applications.

Annex 1.

Trademark "Belyanochka".

Appendix 2.

Trademark "Prostokvashino"

Products produced under the Prostokvashino brand help create a relaxed atmosphere of fun in the family, where both children and adults feel equal, and caring for others does not become a burden for anyone. "Prostokvashino" is a brand of traditional natural dairy products for the whole family.

The best specialists of the UNIMILK company used their experience and the latest technological advances to create high-quality and very special dairy products under the Prostokvashino brand.

Today, perhaps the entire range of dairy products is produced under the Prostokvashino brand. The main difference between Prostokvashino products is their increased (traditional) fat content, the absence of “artificial” components and the highest quality.

Our brand is liked by both children and adults. Favorite cartoon characters from childhood - the cat Matroskin, Uncle Fyodor, Sharik and the postman Pechkin on the packaging design turn the consumption of dairy products of this brand into a real family holiday.

Appendix 3.

Trademark "Summer Day".

Everyone knows that milk in summer is the most delicious and contains many vitamins and nutrients. From such milk, according to internal quality standards (more stringent than the requirements of generally accepted standards), excellent dairy products can be prepared. But this will already be a “special” product, and buyers will know about it with the help of a special symbol - the “Summer Day” logo.

Appendix 4.

Determination of acidity in classic milk samples

1. Sample 1. Drinking milk pasteurized “Special” classic (3.2%)

2.1 x 0.9801 x 10 = 20 degrees T.

There are no discrepancies in acidity in sample 1.

2. Sample 2. Pasteurized drinking milk classic “Summer Day” (3.2.%)

Experiment 1. 2 ml of alkali was used for titration, correction for alkali 0.98. Therefore, the acidity of milk is

Experiment 2. 2 ml of alkali was used for titration, correction for alkali 0.98. Therefore, the acidity of milk is

2.2 x 0.9801 x 10 = 21 degrees T.

Average value: (21 + 21) / 2 = 21 degrees T.

There are no discrepancies in acidity in sample 2.

3. Sample 3. Selected pasteurized drinking milk (3.5%)

Experiment 1. 2 ml of alkali was used for titration, correction for alkali 0.98. Therefore, the acidity of milk is

2.1 x 0.9801 x 10 = 20 degrees T.

Experiment 2. 2 ml of alkali was used for titration, correction for alkali 0.98. Therefore, the acidity of milk is

2.1 x 0.9801 x 10 = 20 degrees T.

Average value: (20 + 20) / 2 = 20 degrees T.

There are no discrepancies in acidity in sample 3.

Appendix 5.

Tasting sheet

Sample 1. Pasteurized drinking milk “Special” classic (3.2%)

Name indicator	Point rating		Total points
Name indicator		Average value	Total points
Appearance
Consistency
Taste and smell

Appendix 6.

Tasting sheet

Sample 2. Classic pasteurized drinking milk “Summer Day” (3.2.%)

Name indicator	Point rating		Total points
Name indicator		Average value	Total points
Appearance
Consistency
Taste and smell

Student………………………………………………………………………….

Appendix 7.

Tasting sheet

Sample 3. Selected pasteurized drinking milk (3.5%)

Name indicator	Point rating		Total points
Name indicator		Average value	Total points
Appearance
Consistency
Taste and smell

Student………………………………………………………………………….

Municipal budgetary educational institution

Secondary school No. 14

Kirovsky district of the urban district of the city of Ufa

Republic of Bashkortostan

Determination of the quality of milk and dairy products

Scientific supervisor: Nuryeva G.I.

Chemistry teacher MBOU Secondary School No. 14

Ufa-2015

Table of contents

Introduction

1.Literature review. Chemical properties of milk.

2. Main part. Research into milk and dairy products.

2.1. Determination of the degree of purity of milk and dairy products.

Conclusion

Application

Introduction.

Milk - a complete and healthy food product. It contains all the nutrients necessary for life that are needed to build the body. The natural purpose of milk in nature is to provide nutrition to the young body after birth.

The protein content in human milk, compared to the milk of various animals, is the lowest - 1.6%, in cow's milk - 3.4%, and in dog's milk - 7.3% protein. Milk fat serves primarily to satisfy the body's energy needs. In areas with a cold climate, the body's energy requirement is higher than in areas with a temperate climate. This is why the milk of a female reindeer has a higher fat content - 19.7%. Milk survived many civilizations before it became a food product and has its own purpose:

As a food product for the population,

Means for feeding young animals and feed in livestock farming,

Raw materials for food production,

A source of individual milk components, which, in turn, serve as raw materials for pharmacology and other industries.

The increasing importance of milk as a complete food product and as a raw material has led to an increase in demand for it. As a result, milk production has become one of the most important sectors of agricultural production. Currently, milk makes up a significant share of our country's gross agricultural product. The nutritional value of 1 liter of milk is 685 kcal. Calorie content depends mainly on the fat and protein content. Due to the content of essential nutrients in milk, mainly protein, carbohydrates, vitamins, and minerals, it is also a protective factor.

Fresh natural milk obtained from healthy animals is characterized by certain physicochemical and organoleptic properties, which can vary sharply at the beginning and end of the lactation period, under the influence of animal diseases, certain types of feed, when milk is stored unrefrigerated and when it is adulterated. Therefore, based on the physicochemical and organoleptic properties of milk, one can evaluate the naturalness and quality of the prepared raw materials, i.e., its suitability for industrial processing. But determining the quality of milk is necessary not only for the industry, but also for the consumer, who has the right to know what is being offered to him and whether it is harmful to his health.

We set ourselves the goal of learning to determine the quality of milk and dairy products, with further application of our knowledge in everyday life. The object of our research is milk and kefir. Quantitative studies were carried out using the method of weight and volumetric analysis. All the methods we use can determine the quality of the milk and dairy products we eat. The results obtained after conducting experiments help us solve real problems in everyday life and consume dairy products wisely.

Main part.

1. Chemical properties of milk.

Components

True Not true

Main

Minor

Outsiders

water

salt

antibiotics

protein

lemon acid

herbicides

lactose

phosphatides

insecticides

sterols

radionuclides

enzymes

vitamins

gases

Milk fat, lactose, caseins, lactoglobulin and lactoalbumin are specific components of milk. They are synthesized in the mammary gland and are found only in milk. The remaining components can be found in other biological compounds.WITHFrom a technical and economic point of view, milk can be divided into water, solids and skimmed solids. The largest specific gravity in milk is water (more than 85%; the remaining components included in the composition of dry substances or dry residues account for 11-14%). The content of the so-called skimmed milk solids (SMR) is 8-9%. It is determined according to GOST 3626-73 by drying a sample of milk at 102+ 2°to constant mass. It can be found by calculation - adding the SOMO content and the amount of fat in milk. To do this, the content of SOMO is determined by a formula using the fat content and density of milk. Dry residueincludes all the nutrients of milk. It determines the yield of finished products in the production of dairy products. The content of dry matter and its individual components is not constant during the lactation period. The amount of fat varies the most, followed by protein. The content of lactose and salts, on the contrary, remains almost unchanged throughout the entire lactation period. The amount of fat varies the most, followed by protein. The content of lactose and salts, on the contrary, remains almost unchanged throughout the entire lactation period.The range of vibrations is closely related to the particle size of the individual components. This relationship was formulated by Wigner in the law named after him: “The content of the various components of the dry matter of milk fluctuates the less, the more finely distributed they are present in the milk.”

Natural changes in the content of the main components - fat and protein - are of economic and technological interest. Payment for milk depending on fat content, due to fluctuations in this indicator, requires constant monitoring of fat content. Fluctuations make it difficult to maintain a constant ratio between certain components in the finished product: for example, in condensed milk between fat and skim solids. Adulteration of milk with water can be accurately determined only by the content of lactose and ions by determining its freezing point.

Fat occupies a special economic position and serves as the basis for payment for milk, since it is subject to sharp fluctuations (up to 4% range), followed by proteins, lactose changes slightly. These fluctuations depend on the breed of livestock, stage of lactation, age, health of the animal, feeding ration, milking and housing conditions, and muscle load of the animals.

Changes in the composition of milk after milking can be explained by microbiological and technological influences. However, different indicators can be obtained using different methods of analysis. For example, when determining fat content using the butyrometric method, fat content is 0.05% higher than when using the gravimetric method. From the indicator characterizing the lactose content, it is often not clear which form of lactose is taken into account - monohydrate or anhydrous, which leads to differences between the indicators of its content, reaching 0.24% for every 100 g of milk. Therefore, quantitative data on the content of dry matter and components of milk require more precise determination when used for comparison purposes.

All components of milk have different effects on its physical and chemical properties. For example, the viscosity and surface tension of milk largely depend on the mass fraction of protein, the dispersity and hydration properties of proteins, but the values of electrical conductivity and osmotic pressure have almost no effect. Almost all components of milk affect its density and acidity, the minerals of milk significantly affect its acidity, electrical conductivity, osmotic pressure and freezing point, but do not affect viscosity, etc.Fresh raw milk is characterized by certain organoleptic properties (indicators): appearance, consistency, color, taste and smell. “Cow's milk, purchasing requirements” milk must be a homogeneous liquid without sediment or flakes, from white to faint yellow in color, without foreign tastes and odors.The white color and opacity (turbidity) of milk is caused by light-scattering colloidal particles of proteins and fat globules, the yellowish tint is due to fat-soluble carotene, a mild (sweetish) taste unique to milk - lactose, chlorides, fatty acids, as well as fat and proteins. The pleasant, subtle smell of raw milk depends on the presence in it of a small amount of dimethyl sulfate, acetone, volatile fats, acids, acetaldehyde and other carbonyl compounds.

The amount of chlorides in milk depends on the health of the animals and the st. lactation, the content of dimethyl sulfide depends on the type of feed being fed, acetone depends on feeding regimes and the health status of the animals, fatty acids on the degree of fat hydrolysis. A pronounced taste and smell in milk is considered abnormal. Aromatic and flavoring substances are adsorbed primarily on proteins, with which they end up in dairy products. Therefore, a dairy product with normal taste can only be obtained from raw milk, which is impeccable in terms of smell and taste. During the processing and processing of milk, physical and chemical processes occur that contribute to the formation of new flavoring and aromatic substances from its components.

The causes and timing of the occurrence of defects in the organoleptic parameters of milk are varied and depend on a number of factors: before milking - these are defects caused by changes in the chemical composition of milk due to disruption of physiological processes in the animal’s body; entry into the mammary gland with the blood of feed substances that have a specific taste (mastitic, old-growth) and smell (cow, silage, cabbage, garlic). After milking - if the rules of storage, transportation and primary processing of milk are violated: rancid, oxidized, soapy and other tastes and odors of milk are caused by lipolysis and fat oxidation.

Various defects are caused by the adsorption of odors from poorly washed containers, unventilated rooms, lubricating oils, gasoline, etc., as well as contamination of milk by detergents and disinfectants, medications, pesticides and other chemicals.

Knowledge of the causes of defects in the taste and smell of milk is very important for dairy plant workers, as it allows the development of measures to prevent or mitigate them.

Perceivedauthoritiesfeelingssuchpropertiesmilk, how taste, smell and appearance play a decisive role in shaping consumer demand. These are assessedpropertiesorganoleptically. At different times, the concepts of “organoleptics” and “sensory” were developed. Both of them include the assessment of properties perceived directly by the senses. However, the results of the organoleptic analysis are of a pronounced subjective nature, since the performance of the sensory organs of the experts conducting the assessment-test for taste, smell and appearance is not controlled.

highly qualified experts using special methods andunder conditions of reproducibility of resultsassessments. The results of an organoleptic assessment cannot be processed statistically, but the results of a sensory assessment can be processed statistically.

SensorygradeincludesfollowingFeel: gustatory - taste;olfactory - sense of smell; haptic - touch; optical - vision. Sensory perception is a 6-stage process:perception, awareness, recording, remembering, reproduction, evaluation.Perceptioncarried outWithwith helporgansfeelings- mouth, noseAndeye. Only well-trained and constantly practicing experts canprovide reproducible assessment results with an accurate description of sensations.

But since we are not highly qualified experts, we will not study the organoleptic properties of milk, but will consider only the physicochemical properties of the product. We carried out quantitative studies using the methods of weight and volumetric analysis. Due to the lack of special equipment, only part of the milk characteristics were considered.

2.1. Determination of the degree of purity of milk.

Currently, over 100 enzymes are known. Most of them are of natural origin and pass into milk from mammary gland cells during secretion. Some enzymes are formed by microorganisms that enter during milking. Their effect on the quality of the product is always negative. Also, during milking and transportation and storage, animal hair, food particles, and dust can get into the milk. Contaminated milk quickly loses its quality and spoils.

To determine the presence of mechanical impurities in milk, a cone-shaped vessel is used, in the narrowed part of which there is a mesh. Place a filter of 250 ml of milk on the mesh and transfer the filter to a sheet of clean and dry paper to dry and determine its contamination by eye.

In our experiment to determine the degree of purity of milk, we used a regular funnel for filtering, and a four-layer gauze napkin served as a filter.

According to the degree of purity, milk is divided into three groups: 1st - there are no traces of impurities on the filter - mechanical impurities in milk are less than 3 mg per 1 liter; 2nd - a slightly grayish sediment is visible on the filter - mechanical impurities in milk 4-6 mg per 1 l; 3rd - a dirty gray sediment is clearly visible on the filter = mechanical impurities 7 mg or more per 1 liter.

We conducted this experiment and noticed that the milk we examined belonged to the 1st group in terms of purity, since we did not see any traces of dirt on the filter.

2.2. Determination of milk density.

Density depends on temperature (decreases as it increases), chemical composition (decreases with increasing fat content and increases with increasing amounts of protein, lactose and salts), and also on the pressure acting on it. When milk is diluted with water, its density sharply decreases, therefore, the density value indirectly judges the naturalness of the milk if falsification is suspected. However, milk that does not meet the requirements of GOST 13264-88 in terms of density, that is, it is below 1.027 per 1 cm cube, but whose integrity is confirmed by a table sample, is accepted as varietal. Almost all components of milk affect its density, which ranges from 1.027-1.032 g per 1 cm3. Milk, in which the lighter component fat has been removed, has a density of 1.03601.038 g per 1 cm3.

The density of milk is determined using a special hydrometer-lactodensimeter with a scale from 1.015 to 1.040 per 1 cm cubed and a pressure value of 0.001. The device also has a thermometer. But if you don’t have a lactodensimeter, you can use a regular hydrometer and thermometer.

A dry and clean hydrometer is lowered into a flask with milk to division 1.030 and released. After a couple of minutes, take readings from the device along the upper edge of the meniscus and measure the temperature using a thermometer. If the temperature of the milk differs from 20 degrees, then the density is converted to this temperature using a conversion table (see Table 4).

After we carried out the experiment and took readings from the instruments, the hydrometer showed 1.029, the thermometer - 20 degrees. According to the table, the density of the milk we are studying is 1.029 g per 1 cm cubed. That is, we can conclude that the milk we took is natural.

2.3. Determination of acidity of milk and dairy products.

The acidity of freshly milked milk is 16-18ºT. It is caused by acidic salts - dehydrophosphates and dehydrocitrates (about 9-13ºT), proteins - casein and whey proteins (4-6ºT), carbon dioxide, acids (lactic, citric, ascorbic, free fatty and other components of milk (1-3ºT).

When storing raw milk, titratable acidity increases as microorganisms develop in it, which ferment milk sugar to form lactic acid. An increase in acidity causes undesirable changes in the properties of milk, for example, a decrease in the resistance of proteins to heat. Therefore, milk with an acidity of 21ºT is accepted as ungraded, and milk with an acidity above 22ºT cannot be delivered to dairies.

The acidity of milk depends on the breed of animals, on feed rations, age, physiological state, etc. Acidity changes especially strongly during the lactation period and during animal diseases. Deviation of the natural acidity of milk from the physiological norm affects the technological properties of milk.

The acidity of milk and dairy products is expressed in degrees Turner. This value shows how many milliliters of alkali solution with a concentration of 0.1 mol/l are consumed to neutralize 100 ml or 100 g of product.

To determine the acidity of milk, measure 10 ml of the product using a pipette, pour it into a 100 ml conical flask, add 20 ml of distilled water, 3 drops of an alcohol solution of phenolphthalein, mix everything and titrate one drop with an alkali solution until a pale pink color appears. , not disappearing within 1 minute.

To determine the acidity of kefir using a pipette, 10 ml of the product is then placed in a conical titration flask and, without removing the pipette from the flask, washed with 20 ml of distilled water. Then everything is titrated with an alkali solution.

In order to express the acidity of milk and kefir in Turner degrees, it is necessary to multiply the volume of alkali that was used to titrate the milk by 10.

The results we obtained during the experiment to determine the acidity of milk and dairy products are shown in Table No. 5. As can be seen from these data, both milk and kefir are classified as low-grade products in terms of acidity values. Fermented milk products are characterized by significantly higher acidity, but according to this indicator, these products meet the requirements of GOST. Determination of the pH of milk and kefir showed that the higher the acidity of the product (T), the lower the pH value.

2.4. Determination of protein content.

AtaddingTomilkformaldehydeis happeningdestructiontertiaryprotein structure, and the environment becomes acidic.

Using the titration method, the amount of sodium hydroxide solution required to neutralize the hydrogen ions is determined, and then the protein content of the milk is calculated using an empirical factor of 1.92 (1.3). On average, the protein content in cow's milk is in the range of 2.9-4%.

There is a special method for determining the protein content in milk: you need to measure 10 ml of fresh milk, heated to 30 degrees, using a pipette, place it in a 100 ml conical flask, add 3-4 drops of phenolphthalein to it. Then everything is titrated with sodium hydroxide solution until a pale pink color appears. After titration, add 2 ml of neutral formalin solution to the flask with the solution, mix everything with a stick, and the pale pink color will disappear. Next, the solution with formaldehyde added to it is again titrated with sodium hydroxide solution until the same pale pink color appears.

To calculate the protein content in milk, it is necessary to multiply the volume of sodium hydroxide solution used for titration after adding formalin by an empirical coefficient of 1.92.

The results that we obtained after conducting the experiment described above showed that the protein content in the milk we took was normal and equal to 3.59%

Conclusion.

Determining the quality of milk is an integral part of the process of its production and processing in the dairy industry. The manufacturer, before accepting cow's milk, checks whether it meets the requirements of GOST 13264-70 and what grade it belongs to. This is necessary to know, since any deviation from the natural composition and quality of milk from the physical norm affects its technological properties, which will subsequently complicate the processing of milk and the production of dairy products from it.

To determine the quality of milk, it is necessary to carry out a number of experiments: determining the degree of purity of milk by the sediment on the filter, a reductase test by the duration of discoloration of methylene blue, determining the density of milk using a hydrometer and thermometer, determining the acidity of milk and dairy products by the amount of sodium, determining the protein content in milk using the titration method. Table No. 6 of the appendix presents the results of determining the physical and chemical parameters of milk. From the data in the table it follows that according to the reductase test, milk is classified as first grade, and according to acidity it is classified as an ungraded product. Based on the density, we can conclude that the milk is not diluted with water. The protein content is normal. The results obtained after conducting the experiments described above showed us how high-quality products producers of milk and dairy products offer consumers. This is very important to know, since consumption of low-quality goods is harmful to health and sometimes leads to death. That is why the packaging of milk and dairy products must indicate the type of product, components present in the product, storage temperature, production date and shelf life.

However, the experiments we conducted to determine the quality of milk and dairy products proved to us that product packaging does not always correspond to its contents. But this can be explained by the fact that milk is subjected to various technological influences, during which it changes its properties.

Table 1 (milk purity level)

Trademark

Product

Experimental results

"White cloud"

Milk

Kefir

No mechanical impurities detected

"Eater"

Milk

No mechanical impurities detected

Kefir

No mechanical impurities detected

Table 2 (Determination of milk density)

Brand

Product

Density

"White cloud"

Milk

1,0362

"Eater"

Milk

1,0357

MEETS THE STANDARD

Table 3 (Determination of acidity)

Brand

Product

Acidity

In experience

Norm

"White cloud"

Milk

16-20

Kefir

136

Up to 120

"Eater"

Milk

16-20

Kefir

128

Up to 120

Table 4(Determination of protein content)

Brand

Product

Experience result

"White cloud"

Milk

Fine

Kefir

Fine

"Eater"

Milk

Fine

Kefir

Fine

List of used literature

1. Workshop on the basics of agriculture. - M.: “Education”, 1991.

2. Zhvanko Yu.N., Pankratova G.V., Mamedova Z.I. Analytical chemistry and technological control in public catering. – M.: “Higher School”, 1989.

3. Zlotnikov E.G., Estrin E.R. Features of the organization of experimental work // Chemistry at school. - 1997, No. 4, pp. 66-68.

4Volkov V.N., Solodova R.I., Volkova L.A. Determination of the quality of milk and dairy products // Chemistry at school, 2002, No. 1, pp. 57-62.

5. Encyclopedia for children on chemistry. Moscow 2000.

Physical (density), chemical (fat content, fat content, etc.) and biochemical (acidity, reductase test) parameters of milk are determined in laboratory conditions. At home, such milk analysis is not performed, since this requires appropriate instruments, reagents, and special (laboratory) training. However, you should know what the most important indicators are by which milk is characterized when selling it to the state.

One of the main techniques in analysis is the correct selection of average milk samples that are sent to laboratories for analysis.

Determination of milk purity. The purity of milk and the presence of mechanical impurities in it are determined by filtration. At the end of filtering, the filter, placed on a sheet of paper, is compared with the standard (Fig. 15) to establish the purity group. According to GOST 13264-70, milk delivered by the supplier is classified into group 1 if the sediment on the filter is invisible, group II if the sediment is slightly noticeable, and group III if the sediment is clearly visible.

Acidity of milk. The acidity of milk when received at the factory is determined from each vessel, flask, bucket, etc. The acidity is used to judge whether milk is fresh or with high acidity.

Acidity refers to the number of milliliters 0.1 N. alkali solution, which must be added to 10 ml of milk to obtain a neutral reaction with the indicator phenolphthalein. The amount of alkali must be multiplied by 10 to express the titratable acidity in conventional degrees (°T). The usual average acidity of fresh milk is 16-17 °T. The acidity of milk from individual cows varies, depending on the individual characteristics of the animals: their lactation period, etc.

In collected milk produced from a large number of cows, the acidity changes slightly, provided sanitary and hygienic rules are observed.

Under conditions favorable for the development of microorganisms, due to the fermentation of milk sugar and the formation of lactic acid, the acidity of milk quickly increases. The technological properties of such milk are reduced. Highly acidic milk curdles when heated.

Bacterial contamination of milk is determined using a reductase test. Reductase is an enzyme, a waste product of bacteria contained in milk or caught in

it during receipt or processing. This enzyme is capable of decolorizing methylene blue. The faster the blue discolors, the more reductase there is in the milk, and therefore bacteria. This property is widely used in factories when determining the degree of bacterial contamination of milk (Table 5).

The density of milk is determined no earlier than 2 hours after milking. During this time, gases from fresh milk evaporate. Its temperature should be within 15-25 °.

Determination of milk fat content. To determine the fat content in milk, the World balls are freed from the protein shells. Concentrated sulfuric acid is used as a solvent. For a more complete release of the fat released from the membranes, isoamyl alcohol is used. During subsequent centrifugation of the mixture, fat, as the lightest component, is concentrated in the graduated scale of a glass instrument - a butyrometer.

If milk is examined soon after collection, then it is mixed well, turning closed sample bottles up to 6 times. This prevents the formation of foam, which leads to incorrect measurements. Samples of long-standing milk are especially carefully prepared. Sometimes they are heated in water to wash away the fatty layer adhering to the walls of the bottle, and then mixed.

The required number of numbered butyrometers is installed in the tripod. Butyrometers are numbered by bending tin plates with carved numbers around the scale.

10 ml of sulfuric acid is measured into each butyrometer using a dispenser. Then 10.78 ml (II g) of well-mixed milk is pipetted. Carefully pour milk along the wall into the butyrometer. To avoid premature heating, the milk layer should be located above the acid layer. In this case, the end of the pipette should not touch the sulfuric acid.

Measure out 1 ml of isoamyl alcohol with a dispenser, being careful not to wet the neck of the butyrometer, which may subsequently lead to the plug popping out.

The filled butyrometers are closed with rubber stoppers and inserted into the centrifuge, the centrifuge lid is screwed on and centrifuged for 5 minutes at a speed of about 1000 rpm. At the end of centrifugation, the butyrometers are placed with their plugs down in a water bath at 65 °C for 5 minutes.

After removing the butyrometer from the bath and drying it with a napkin, count the amount of fat on the scale.

Important indicators of milk quality are the dry matter content, which is determined using a drying cabinet, and the amount of dry non-fat residue (DSFR). These values, in addition to laboratory tests, can be determined by calculation. By the amount of fat in the dry matter of milk one can judge the naturalness of the latter. If the fat in the dry matter of milk is less than 25%, such milk is suspected of being unnatural.

25.04.2019

Milk

Milk - a product of normal physiological secretion of the mammary glands of farm animals, obtained from one or more animals during lactation during one or more milkings, without any additions to this product or extraction of any substances from it.

Whole milk – raw materials for the production of milk processing products, in which the constituent parts have not been affected by their regulation.

Reconstituted milk– a dairy product packaged in consumer containers, or raw materials for the production of milk processing products, except for drinking milk, made from concentrated, or condensed, or dry dairy products and water.

Normalized milk– raw materials for the production of milk processing products, in which the mass fractions of milk fat and milk protein and (or) skimmed milk solids or their ratios are brought into accordance with the indicators of the standard or technical document of the manufacturer, in accordance with which the milk processing product is produced.

Skimmed milk– raw materials for the production of milk processing products with a mass fraction of milk fat less than 0.5%, obtained by separating milk fat from milk.

Pasteurized, sterilized, UHT, UHT milk– milk subjected to heat treatment in order to comply with the established requirements of the technical regulations TR CU/033/2013 for microbiological safety indicators.

Drinking milk – whole milk, skimmed, normalized, fortified.

Milk products

Milk products – milk processing products, including a milk product, a milk composite product, a milk-containing product, a by-product of milk processing, milk-based baby food products, adapted or partially adapted initial or subsequent milk formulas (including dry), dry fermented milk mixtures, milk drinks (including dry ones) for feeding young children, ready-to-eat milk porridges, and dry milk porridges (reconstituted until ready at home with drinking water) for feeding young children.

Milk product– a food product that is produced from milk and (or) its components, and (or) dairy products, with or without the addition of milk processing by-products (except for milk processing by-products obtained during the production of milk-containing products) without the use of non-dairy fat and non-dairy protein and which may contain components functionally necessary for milk processing.

Dairy compound product– a food product made from milk and (or) its components, and (or) dairy products with or without the addition of by-products of milk processing(except for by-products of milk processing obtained during the production of milk-containing products) and non-dairy components (except for fats of non-dairy origin introduced into the composition as an independent ingredient (does not apply to dairy products for feeding young children, in the production of which fats of non-dairy origin are used) ), which are added not for the purpose of replacing milk components. At the same time, the finished product must contain more than 50% of milk components, and more than 40% in ice cream and sweet milk processing products.

Milk product– a food product made from milk and (or) its components, and (or) dairy products, and (or) by-products of milk processing and non-dairy components, using technology that provides for the possibility of replacing milk fat in an amount of no more than 50% of fat phase exclusively as a substitute for milk fat and allowing the use of protein of non-dairy origin not for the purpose of replacing milk protein, with a mass fraction of milk solids in the dry substances of the finished product of at least 20%.

In milk, the main (dispersion) medium is water, and the dispersed phase is substances that are in a molecular, colloidal and emulsion state. Milk sugar and mineral salts form
molecular and ionic solutions. Proteins are in a dissolved and colloidal state, milk fat is in the form of an emulsion.

Average chemical composition of cow's milk: water 87.5%; milk fat 3.8%; dry skimmed milk residue (SMR) – 8.7%, including casein – 2.7%; whey proteins – 0.6%; minerals – 0.7%, milk sugar (lactose) – 4.7%.

The greatest fluctuations in the chemical composition of milk occur due to changes in water and fat content. Lactose, minerals and proteins are consistent. Therefore, by the amount of dry skim milk residue, one can judge the naturalness of the milk.

Milk can be adulterated by adding water, skim milk, neutralizing substances, or skimming the cream.

When milk is adulterated with water, the density decreases (less than 1.027 g/cm 3 ), fat content, dry residue (less than 11.2%), SOMO (less than 8.0%), as well as acidity.

When milk (cream) is adulterated with water, its natural color changes. The milk becomes a little clearer, with a less pronounced yellow tint and taste, and the consistency is watery.

When milk is adulterated by adding skim milk or skimming off the fat, the density increases to 1.034 g/cm 3 , dry residue and fat content decrease, SOMO does not change. Dilution of milk with water is determined by density, which should be in the range of 1.027–1.032 g/cm 3 . The density of milk is determined at 20 °C using a lactodensitometer. If the milk density becomes less than 1.027 g/cm 3 by 0.003, this indicates that approximately 10% of the total volume of water was added to the milk.

The dilution of milk with water can be determined by the cryoscopic temperature (the initial freezing temperature at which ice and water are in equilibrium).

The cryoscopic temperature of milk is constant and ranges from -0.55–0.56 °C. The dependence of cryoscopic temperature on the amount of added water is shown in Table 1.

Table 1 - Determination of the amount of water added to milk by cryoscopic temperature

The cryoscopy method is used abroad as an arbitration method to resolve controversial issues.

The fact that water has been added to milk can be determined by a neutral test. The fact is that well, river, lake water always contains salts of nitric acid (nitrates), there are practically none in natural milk: to determine the presence of added water, pour 1.5–2 cm into a test tube 3 concentrated chemically pure sulfuric acid. One drop of formalin is added to the same amount of controlled milk and mixed. Milk is carefully poured along the wall into a test tube with sulfuric acid. If there is water in milk at the border withWhen acid touches milk, a blue-violet ring is formed. There will be no such ring in natural milk.

The most important chemical indicator by which the freshness of milk is determined is titratable acidity, which is expressed in degrees Turner (°T). The acidity of fresh milk depends on the presence of proteins, lactic acid, mineral acids, and salts.

The acidity of fresh milk should be in the range of 16–18 °T, and for most types of milk sold it should not exceed 21 °T.

When storing milk, acidity increases due to the fermentation of milk sugar (lactose) under the action of enzymes of lactic acid microorganisms (Table 2).

Table 2 - Relationship between acidity and milk quality

Sometimes individual distributors add soda to milk in order to reduce acidity, since factories do not accept milk with an acidity of more than 21 °T.

The fact of falsification with soda is established as follows.

About 2 cm is poured into the test tube 3 milk and add 3-4 drops of rosolic acid along the wall (without stirring). The formation of a bright crimson ring on the surface of the milk indicates the presence of soda. In the absence of soda, the ring has an orange color.

Organoleptic assessment of milk quality is carried out for compliance with the requirements specified in the regulatory and technical documentation for the following indicators: appearance and consistency, taste and smell, color.

When assessing the appearance, pay attention to the homogeneity of the milk, the absence of sediment, and the fullness of the container. A dense fat plug is not allowed on the surface of pasteurized milk.High-fat milk, baked and sterilized milk should not contain cream sediment.

If the technology and storage conditions are violated, the consistency of the milk may become flaky with the formation of a loose protein sediment.

The color of milk is white, in the summer - with a yellowish tint, in low-fat milk - with a bluish tint, in baked and sterilized milk - creamy due to the formation of melanoidin and other compounds.

Taste and smell are determined at room temperature. It must be clean, free of foreign tastes and odors.

Using organoleptic indicators, you can detect signs of milk falsification.

The most common and “innocent” counterfeit is selling skim milk as whole milk. Skim milk has a bluish tint and is watery; a drop of it leaves an almost imperceptible watery mark on the nail. This milk has an impersonal taste.

Milk diluted with water also has a bluish tint and a watery taste. When shaken, it produces little foam, and a drop leaves almost no mark on the nail.

Lime (limewater), potash and soda are added to milk in the summer to prevent it from souring. To detect the presence of these impurities in milk, you need to strain part of the milk through paper and add a few drops of some acid, for example, acetic or citric. Fake milk, unlike unadulterated milk, will begin to bubble from the release of carbon dioxide.

You can find out about the presence of these alkalis using litmus paper: in adulterated milk it changes its color, but in unadulterated milk it does not.

Milk with an admixture of water gives a wide blue ring at the walls of the dish, does not form a convex drop on the nail, spreads out, and if it also contains solid impurities (flour, chalk, potash, etc.), then a sediment remains on the nail.

Normalized pasteurized whole milk, produced from spray-dried reconstituted milk, has a slightly watery taste with a high-temperature processing (“nutty” taste)
taste), contains a reduced amount of SNF - less than 8%, after centrifugation in a conical tube, an insoluble, crude protein precipitate appears.

Dairy products

Fermented milk product is a dairy product or a dairy composite product that is produced by a method leading to a decrease in the active acidity (pH), an increase in the acidity and coagulation of milk protein, fermentation of milk and (or) dairy products, and (or) their mixtures with non-dairy products components that are not introduced to replace milk components (before or after ripening), or without adding these components using starter microorganisms and contain live starter microorganisms in the amount established in Appendix No. 1 to the technical regulations TR CU 033/2013.

Fermented milk products are divided into three main groups: fermented milk drinks; sour cream; cottage cheese and curd products. These products play a special role in human nutrition, since, in addition to their high nutritional value and digestibility, they have therapeutic and prophylactic properties.

Fermented milk drinks and sour cream are produced in two ways: thermostatic and tank.

With the thermostatic method, the clot of fermented milk products is undisturbed; with a tank, it has a creamy consistency.

Most fermented milk drinks and sour cream are prepared using the tank method.

In commodity science, fermented milk drinks are classified into groups according to the nature of the curd and general organoleptic characteristics:

mixed fermentation products (kefir, kumiss, etc.);
curdled milk (common curdled milk, acidophilic milk, Southern milk, yoghurt, Varenets, fermented baked milk, etc.);
acidophilus products (acidophilus milk, acidophilus, etc.).

Each of these groups is divided into subgroups: without food fillers and flavoring additives; fermented milk drinks with food fillers and flavoring additives; fermented milk drinks for children and special foods.

Kefir – a fermented milk product produced by mixed (lactic and alcoholic) fermentation using a starter prepared with kefir grains, without the addition of pure cultures
lactic acid microorganisms and yeast.

Kumis – a fermented milk product produced by mixed (lactic and alcoholic) fermentation of mare’s milk using starter microorganisms (Bulgarian and acidophilus lactic acid rods) and yeast.

Kumys product– a fermented milk product made from cow’s milk in accordance with kumys production technology.

Ayran – a fermented milk product produced by mixed (lactic and alcoholic) fermentation using starter microorganisms (thermophilic lactic acid streptococci, Bulgarian lactic acid coli) and yeast with or without the addition of water, table salt.

Acidophilus – a fermented milk product produced using equal proportions of starter microorganisms (lactic acidophilus, lactococci and starter prepared with kefir grains).

Varenets – a fermented milk product produced by fermenting milk and (or) dairy products, previously sterilized or subjected to other heat treatment at a temperature
97 °C using starter microorganisms (thermophilic lactic acid streptococci) until characteristic organoleptic properties are achieved.

Mechnikovskaya sour milk– a fermented milk product produced using starter microorganisms (thermophilic lactic acid streptococci and Bulgarian lactic acid bacillus).

Curdled milk – a fermented milk product produced using starter microorganisms (lactococci and (or) thermophilic lactic acid streptococci).

Ryazhenka – a fermented milk product produced by fermenting baked milk with or without the addition of dairy products using starter microorganisms (thermophilic lactic acid streptococci) with or without the addition of Bulgarian lactic acid bacillus.

The quality of fermented milk drinks is determined by organoleptic indicators: taste and smell, appearance and consistency, color, as well as acidity and alcohol content (for koumiss).

The consistency and character of the curd of fermented milk drinks depend on the raw materials and technology, as well as on the production method.

In mixed fermentation products (lactic acid and alcoholic), individual gas bubbles are allowed, which arise as a result of alcoholic fermentation. Excessive gas formation, rupture is not allowed
curd and separation of whey from the curd more than 2% for kefir or more
3% for curdled milk.
The organoleptic properties of yoghurts produced using food fillers, stabilizers, flavors and coloring agents should be as follows: uniform color throughout the mass; consistency – moderately viscous; taste, smell and aroma – sufficiently pronounced in accordance with the type of fruit aroma used; uniform distribution of particles of fruits or berries used (in “Miracle Yogurt”).

The most common technological falsification of fermented milk drinks occurs. It consists of a violation of the qualitative and quantitative composition of the microflora (for example, the absence of bifid flora in bifido products), as well as a discrepancy between the mass fraction of milk fat and SOMO with the normative and technical documentation (NTD).

It should be borne in mind that long-term storage of fermented milk drinks (more than 14 days), during the production of which, due to heat treatment of the finished product or the introduction of preservatives,inactivation of enzymes and destruction of beneficial microflora have reduced therapeutic and prophylactic properties. The microflora of the human stomach and intestines is enriched by fermented milk drinks containing live lactic acid bacteria (Metchnikoff and acidophilus bacilli, bifidobacteria).

The guaranteed shelf life of fermented milk drinks without aseptic filling and heat treatment is on average 36 hours at a temperature of 6–8 °C. With aseptic filling and heat treatment, the storage duration increases to 90 days at temperatures up to 6 °C.

Sour cream

Sour cream is a fermented milk product produced by fermenting cream with or without the addition of dairy products using starter microorganisms - lactococci or a mixture of lactococci and thermophilic lactic acid streptococci. The mass fraction of fat must be at least 10%.

Sour cream has great nutritional value due to the content of a significant amount of milk fat (from 10 to 42%), the presence of protein (2–3%), lactose (3%), organic acids (0.7–0.8%) and other components .

The consistency, taste and smell of low-fat sour cream differs from high-fat sour cream. When producing sour cream, the use of thickeners and stabilizers is not allowed.

The quality of sour cream is controlled by organoleptic indicators (appearance and consistency, taste and smell, color), as well as by acidity and mass fraction of protein. Depending on the mass fraction of milk fat, the acidity of sour cream ranges from 55 to 100 °T.

In appearance and consistency, sour cream is a homogeneous thick mass with a glossy surface. For a product with a mass fraction of fat from 10 to 20%, an insufficiently thick, slightly viscous consistency with
slight graininess. The fat phase should contain only milk fat.

Sour cream is stored at a temperature of 2 to 6 °C. The expiration date is set by the manufacturer, taking into account the requirements of regulatory legal acts in the field of food safety.

Adulteration of sour cream can be technological (reduced fat content and dry matter content, increased acidity).

When adulterating sour cream by weight in retail trade and public catering, adulteration with water or milk is used. Due to this, the mass fraction of fat and SOMO is reduced, and the whey is separated from the clot. When sour cream is adulterated by adding fermented milk drinks (for example, kefir), the mass fraction of fat decreases, titratable acidity increases, the taste and smell characteristic of kefir appear, and the composition of the microflora is disrupted. When staining a smear of adulterated sour cream on a glass slide under a microscope,foreign rod-shaped bacteria and milk yeast, which are part of the kefir microflora, are detected. When microscopying unadulterated sour cream, only lactococci and lactic acid streptococci are visible (spot microorganisms are visible under a microscope).

Cottage cheese and curd products

Cottage cheese is a fermented milk product produced using starter microorganisms (lactococci or a mixture of lactococci and thermophilic lactic acid streptococci) and methods of acid or acid-rennet coagulation of milk protein with subsequent removal of whey by self-pressing, and (or) pressing, and (or) separation (centrifugation ), and (or) ultrafiltration with or without the addition of milk components (before or after ripening) in order to normalize dairy products.

Curd product - a dairy product, or a dairy composite product, or a milk-containing product made from cottage cheese and (or) milk processing products in accordance with the technology for the production of cottage cheese with or without the addition of dairy products, with or without the addition of non-dairy components, including non-dairy fats and (or) non-dairy proteins (for milk-containing products), with or without subsequent heat treatment.

Cottage cheese has high nutritional and dietary value. Due to its significant content of amino acids and phospholipids, cottage cheese is used to prevent liver diseases.

Cottage cheese of different types contains from 14 to 18% protein, up to 23% milk fat, many minerals and vitamins. In low-fat cottage cheese, the mass fraction of fat should be less than 1.8%. Current interstate GOST 31453-2013 “Cottage cheese. Technical Specifications" provides for the production of cottage cheese, in addition to low-fat, with a fat content of 2.0; 3.0; 3.8; 4.0; 5.0; 7.0; 9.0; 12.0; 15.0; 18.0; 19.0; 20.0 and 23.0%.

The examination of the quality of cottage cheese is carried out according to organoleptic indicators (taste and smell, consistency, color), as well as acidity, mass fraction of protein and moisture.

Cottage cheese is not divided into commercial grades. The taste and smell are pure, fermented milk, without foreign tastes or odors. Curds made from reconstituted milk may taste like reconstituted milk. The color is white or with a creamy tint, uniform throughout the mass. Consistency and appearance: soft, spreadable or crumbly with or without noticeable particles of milk protein. For low-fat cottage cheese, a slight release of whey is allowed.

The Technical Regulations of the Customs Union TR/TS 033/2013 “On the safety of milk and dairy products” introduced the term “curd product”. It is produced using cottage cheese technology with the addition of vegetable proteins and fats.

Curd products are produced in the form of sweet and salty curds, curd mass, glazed curds, curd cakes, pastes, and creams.

In addition to organoleptic indicators, when examining curd products, compliance with the standard of mass fraction of moisture, fat, sucrose, glaze and acidity of the product is taken into account.

Store cottage cheese at temperatures of 2–6 °C. The expiration date is set by the manufacturer. For cottage cheese products, the shelf life is 36 hours at a temperature of 0–2 °C. Semi-finished cottage cheese products can be stored at a temperature of -18 ° C for no more than 3 months, cottage cheese at the same temperature - up to 6 months.

Counterfeiting of cottage cheese and cottage cheese products can be technological and assortment-based. When receiving cottage cheese in wide-necked flasks, a sample should be taken along the entire height of the flask, since layer-by-layer adulteration with low-fat cottage cheese is possible.

Ice cream

Ice cream represents whipped (air-saturated) frozen and consumed frozen sweet dairy products, dairy composite products, milk-containing products.

Ice cream can be hardened or soft. Hardened ice cream is ice cream that has been frozen to a temperature not higher than -18 ° C after processing in a freezer and has maintained the specified temperature during storage, transportation and sale.

Soft ice cream is ice cream that has a temperature from -5 to -7 °C and is sold to consumers directly after processing in a freezer.

Ice cream with milk fat substitute is ice cream with a fat mass fraction of no more than 12%.

All three types of ice cream, according to GOST 31457-2012 “Milk, cream and ice cream ice cream. Technical specifications”, depending on the use of food flavoring products and/or flavorings, are divided into the following subtypes:

without food flavorings and flavorings;
with food products (coffee, raisins, chocolate, tea, jam, etc.);
with aroma;
with food flavoring and aroma products.

In accordance with the same standard, ice cream, depending on the surface design, is divided into:

decorated;
glazed;
glazed decorated;
in wafer products;
in cookies.

In addition to milk, cream and ice cream ice cream, sherbet ice cream and frozen desserts with the addition of milk and dairy products are also produced.

Sherbet ice cream is a whipped, frozen and consumed frozen sweet and sour food product made from sugars, fruits and/or their products, a mixture of milk ice cream and milk and/or dairy products and/or by-products of milk processing, without the use of fats of non-dairy origin (GOST 32256-2013 “Ice cream sherbet and frozen desserts with the addition of milk and dairy products. General technical conditions”).

Ice cream has high nutritional and biological value, pleasant taste, delicate texture (“melts in your mouth”). It has a beneficial effect on the secretory and motor functions of the digestive organs and is often used for gastric bleeding and after operations of the gastrointestinal tract.

In pre-revolutionary Russia, a small amount of ice cream was produced by small entrepreneurs, as well as individual restaurants and cafes. The first large-scale industrial production of ice cream was organized in Moscow in 1932.

The quality of ice cream is examined in accordance with GOST or TU according to the following organoleptic indicators: taste and smell, consistency, color.

The taste and smell of ice cream must be pure, characteristic of this type of ice cream and the raw materials used for its production, without foreign tastes and odors.

The consistency should be uniform throughout the ice cream, fairly dense (without noticeable ice crystals and lumps of fat).

A slightly snowy consistency is allowed in milk, fruit and berry ice cream, as well as in amateur types of ice cream with reduced fat content.

The color of the ice cream is uniform, characteristic of this type of ice cream. Uneven coloring is allowed if fruit and berry fillers are used.

Ice cream is not allowed for sale: it has a taste that is not typical for this type; with the presence of foreign tastes and odors; with a heterogeneous or sandy consistency; with large ice crystals, lumps of milk fat and stabilizer; as well as ice cream in rusty, crumpled, unsealed sleeves, in deformed, dirtyworn and torn packaging, with unclear markings and paint bleeding into the product.

The permissible deviation of the net mass of ice cream in metal sleeves and cardboard boxes with polyethylene liners is ± 0.5%.

The deviation of the average mass value when simultaneously weighing 10 servings of small-packed ice cream, taken randomly from a batch, should not exceed ± 1.5% for manual weight packaging, and ± 3.0% for volumetric mechanized and manual packaging. The deviation of the mass of one portion during piece-by-piece weighing should not exceed ± 3% for manual weighing packaging, and ± 6% of the established nominal weight value for volumetric mechanized or manual packaging.

The deviation in the weight of an individual portion of up to 1 kg of large-packaged ice cream when weighed individually should not exceed ± 2% and ± 1% for a weight over 1 kg.

To create a reserve for the period of current repairs of enterprises and for the period of mass demand for the product in the summer, there is a need for long-term storage of ice cream.

As ice cream is stored, the ability of stabilizers and other components (for example, proteins) to bind water gradually deteriorates. Previously bound water is released and freezes, promoting the enlargement of crystals.

During storage, ice cream easily picks up odors from the chamber air, as well as odors inherent in packaging materials. Sometimes the color changes, especially in fruit ice cream.

The temperature of ice cream stored for long-term storage should be as low as possible, which is more conducive to preserving the original structure (Table 3).

Table 3 - Acceptable shelf life of ice cream, months

In accordance with the technical documentation for hardened ice cream, the air temperature in storage chambers should not be higher than - 20 ° C (Table 4).

Table 4 - Permissible shelf life of ice cream at low temperatures, months. (below -20 o C)

Butter and butter paste

Butter

Butter -butter from cow's milk, in which the mass fraction of fat is at least 50% (TR CU 033/2013).

Cow's milk butter is a dairy product or dairy composite product on an emulsion fat base, the predominant component of which is milk fat, which is produced from cow's milk, dairy products and (or) milk processing by-products by separating the fat phase from them and uniformly distributing them into her milk plasma.

Butter paste is a dairy product or dairy composite product on an emulsified fat basis, in which the mass fraction of fat is from 39 to 49% inclusive and which is produced from cow's milk, dairy products and (or) by-products of milk processing through the use of stabilizers with or without the addition of addition of non-dairy components is not intended to replace milk components.

The consumer properties of butter and butter paste are determined by the quality of the milk and cream used and production technology.

When sold by dairies, it is not indicated by what method the butter was produced. Knowledge of the production method is very important, since the consumer properties of cow butter differ significantly, although they comply with the requirements of technical regulationsTR CU 033/2013 “On the safety of milk and dairy products”, GOST 32261-2013, GOST 52253-2004.

There are two methods for producing butter:

churning pre-prepared cream with a fat content of 30–40%;
transformation of high-fat cream in special devices - butter makers.

The essence of oil productionchurning methodconsists of concentrating milk fat by separating milk, churning chilled cream and mechanically processing butter grains.

When producing butter by converting high-fat cream, hot cream is separated a second time, high-fat cream is obtained, which is normalized for moisture and other components, cooled and packaged.

Oil obtained by churning contains significantly less phospholipids, including lecithin, which negatively affects the taste and smell. This oil has good heat resistance and spreadability, and melts well. The disadvantages of oil produced by churning include: increased bacterial contamination; high air content; insufficient moisture dispersion; uneven composition of components; duration of the technological process (about a day).

The butter produced by converting high-fat cream is characterized by good moisture dispersion, low bacterial contamination and reduced air content, high stability, more pronounced taste and smell, and dense plastic consistency.

Disadvantages: low thermal stability, increased fat content in plasma and leakage of liquid fat, poor separation of plasma (protein) when overheated, low structure recoverability.

Depending on the specific production technology, butter is divided into sweet cream and sour cream. Sweet cream and cultured butter are divided into salted and unsalted.

The range of butter includes:

sweet cream and sour cream salted and unsalted – Traditional;
sweet cream and sour cream, salted and unsalted – Amateur;
sweet cream and sour cream, salted and unsalted - Peasant.

In accordance with GOST 32261-2013 “Butter. Technical conditions", butter is divided into grades: highest and first. The quality of the oil is organoleptically assessed on a 20-point scale. High-grade butter should receive 17–20 points, first-grade butter – 11–16. Oil that received less than 11 points, including less than 5 points for taste and smell, less than 3 points for consistency, less than 1 point for color, less than 2 points for packaging and labeling, is not allowed for sale.

Sweet cream butter is produced from fresh (sweet) pasteurized cream.

Cultured butter is made from fermented cream.

In recent years, production volume has increased and the range of butter has expanded, with milk fat partially replaced by vegetable fat.

These types of oil have increased biological value due to the addition of refined deodorized vegetable fats and in them milk fat is replaced with vegetable fat (from 10 to 30%). These oils have a soft, elastic consistency, low heat resistance, and free fat leaks out on the surface. Oils with partial replacement of milk fat with vegetable fat are not suitable for producing creams in the production of cakes.

Expert assessment of oil quality, in addition to organoleptic indicators, involves monitoring the mass fraction of fat, moisture, SOMO, table salt, titratable acidity, heat stability, acidic and
peroxide numbers of milk fat.

Butter paste made from cow's milk, in accordance with GOST 52253-2004, is divided into sweet cream and sour cream, which, in turn, are divided into salted and unsalted. According to GOST 52253, the quality of butter and butter paste made from cow's milk is assessed according to the same indicators.

Canned milk

Canned milk is a product the raw material for the production of which (mainly) is natural milk or milk with food fillers, the properties of which, as a result of technological processing, are preserved for a long time without significant changes.

According to commodity classification, canned milk is divided into two classes: liquid and dry. Each of these classes is divided into groups: canned milk without food fillers (prepared from natural raw materials), with food fillers, and canned milk for baby and diet food.

In our country, the most common assortment of canned liquid milk is: sterilized condensed milk, canned condensed milk with sugar and food fillers, condensed cream, etc.

Examination of the quality of canned condensed milk is carried out in accordance with the normative and technical documentation according to their organoleptic indicators (appearance,color, structure and consistency, smell, taste and aroma). Physicochemical indicators include monitoring the mass fraction of sucrose, dry substances, titratable acidity, viscosity, purity, and lactose crystal sizes.

With increasing temperature and increasing storage duration, as a result of the influence of enzymes, physical and physicochemical transformations, the organoleptic properties of condensed canned food may deteriorate. In particular, the color changes, the process of thickening occurs, lactose crystals settle, and sediment appears at the bottom of the jar. The reason for the appearance of lumps (“buttons”) in sweetened condensed milk may be the development of mold fungi.

Currently, condensed milk with sugar, which has the additional name “Verkhovskoye”, “Onezhskoye”, “Vologodskoye”, etc., is supplied to the retail chain in increasing volumes. Similar types of canned food are produced according to specifications based on spray-dried milk powder, and milk fat is partially replaced with vegetable oils. In such canned condensed milk, the likelihood of separation (fat moving to the top layer) and lactose sedimentation is higher than in sweetened condensed milk produced in accordance with GOST.

The guaranteed shelf life of condensed milk and cream with sugar in metal cans No. 7 at temperatures from 0 to 10 °C is 12 months. (condensed milk with sugar “Verkhovskoe”, made from reconstituted milk – 6 months); sterilized condensed milk – 12 months; condensed milk with sugar and cocoa at a temperature of 11 to 20 ° C - no more than 3 months; condensed cream – 3 months.at temperatures from 0 to 10 °C. Relative air humidity should be no more than 75%.

Dry dairy productsby structure they are classified as free-flowing powders. They are produced from normalized pasteurized condensed whole or skim milk, cream, buttermilk and dried on spray and roller dryers. The mass fraction of moisture in dry products ranges from 2 to 7%; the structure, size and solubility of particles of dry dairy products depend on the drying method. Spray dried milk powder consists of agglomerated particles.

Film milk dried on roller dryers is characterized by a structure in the form of crushed films (scales).

Film-dried milk powder is inferior in quality to spray-dried milk powder. With this method, under the influence of high temperature, irreversible denaturation of proteins occurs, milk fat is released in a free state, sulfhydryl groups are formed, the solubility of milk decreases, and drying or burning of milk powder is possible.

Spray-dried milk powder has higher quality and solubility, since almost instantaneous drying eliminates local overheating of the product and protein denaturation.

The main range of dry dairy products: whole cow's milk powder 20 and 25% fat, Domestic milk powder, skimmed cow's milk powder, powdered cream, high-fat cream powder, fermented milk powder, baby food powder.

The quality and safety of dry dairy products must meet the requirements of technical regulations, GOST or TU. Quality examination is carried out, first of all, according to organoleptic indicators: appearance, consistency, taste and smell, color. Titratable acidity, solubility, content of heavy metals and the total number of microorganisms, mass fraction of moisture, protein, degree of purity, etc. are standardized.

As with the storage of canned condensed milk, as a result of enzyme activity, physical and physicochemical changes in the components in dry milk products, their organoleptic characteristics may deteriorate.

The quality of dry dairy products during storage decreases due to the melanoidin reaction, especially at elevated temperatures (20–25 ° C) and a moisture mass fraction of more than 4%. During storage, dry dairy products can cake and self-compact, and gradual oxidation of lipids with atmospheric oxygen occurs.

To increase the stability of dry dairy products during storage, various antioxidants are used (gallic acid, butyloxyanisole, flavones, tocopherol, ascorbic and sorbic acids, etc.).

Guaranteed shelf life of whole and skim milk powder, Smolensky whole milk powder, dry cream and dry fermented milk products in metal or combined cans at temperatures from 0 to 10 °C - 8 months, at temperatures from 0 to 20 °C - 3 months The shelf life of baby food products, depending on the type, at temperatures from 1 to 10 °C is from 6 to 12 months.

Cheeses and cheese products

Cheese is a dairy product or a dairy composite product made from milk, dairy products and (or) by-products of milk processing with or without the use of special starters, technologies that ensure coagulation of milk protein using milk-clotting enzymes, or an acid or thermal acid method, followed by separation of the cheese mass from the whey, its molding, pressing, with or without salting, ripeningwith or without ripening with or without the addition of non-dairy components introduced not for the purpose of replacing the constituents of milk.

Cheese product is a milk-containing product produced in accordance with cheese production technology.

Cheese, cheese product soft, semi-hard, hard, super-hard - cheese, cheese product that have the appropriate specific organoleptic and physico-chemical properties regulated by the appendices to the technical regulations TR CU 033/2013.

Cheese, cheese product, brine - cheese, cheese product, ripened and (or) stored in a salt solution.

Cheese, processed cheese, cheese product, processed cheese product, smoked – cheese, processed cheese, cheese product, processed cheese product, smoked and having specific organoleptic properties characteristic of smoked food products. The use of smoke flavors is not permitted.

Also, this Technical Regulation identifies cheeses and cheese products with mold and slugs.

Cheese, cheese product with mold - cheese, cheese product produced using mold fungi located inside and (or) on the surface of the finished cheese, cheese product.

Cheese, slime cheese product – cheese, cheese product produced using slime microorganisms developing on the surface of the finished cheese, cheese product.

For example, the mass fraction of moisture in dry cheeses is 2–10%, super-hard cheeses – 30–35%, soft – 55–80%; the mass fraction of fat is 1–40%, 1–60%, 1–60%, respectively. Based on size and weight, hard cheeses are divided into large and small. According to technology and organoleptic indicators - for cheeses of the Swiss group, Dutch group, Cheddar group and grated cheeses.

The examination of rennet cheeses is carried out according to organoleptic indicators using a 100-point system. Depending on the amount of points scored, the type of cheese is determined.

The 100-point score includes the following indicators:

taste and smell – 45 points;
consistency – 25;
dough color – 5;
appearance – 10;
packaging and labeling – 5 points.
drawing – 10 points.

The overall score for premium cheeses is 87–100 points, including for taste and smell - at least 37 points; first grade – 75–86 points, including taste and smell – at least 34 points.

Cheeses that have a total score of less than 75 points, including those for taste and smell - less than 34 points, with pronounced fodder, sour, musty, bitter, rancid, putrefactive, foreign tastes and the smell of petroleum products are not allowed for sale.

In addition to the organoleptic assessment, in accordance with the technical documentation, the main physical and chemical indicators are determined: mass fraction of fat, salt, moisture, titratable and active acidity, sodium nitrate content.

The shelf life of rennet, brine and processed cheeses depends on the quality, type, packaging and storage conditions of the cheese. Long-term storage of hard and brine cheeses is carried out in commercial refrigerators at temperatures from 0 to -4 ° C and relative air humidity of 75–80%. Under these conditions, hard cheeses are stored for 6–8 months.

Soft cheeses are stored at a temperature of 0 to 4 °C at a relative humidity of 80–85% for 1 to 1.5 months.

Hard rennet cheeses packaged in polymer films are stored on average for a month less than paraffin cheeses. This is explained by the development of mold on the surface of the cheese due to poor vacuumization of the packaging, damage to the films and loose fit of the shrink films to the surface of the cheese.

Cheeses from the Dutch group are stored in commercial refrigerators for 3 to 4 months. depending on the chamber cooling system. With air cooling, cheeses are stored for a month longer than with radiator cooling. The timing of sales of cheeses in trade depends on the storage temperature. Table 5 shows the timing of sales of various types of cheeses in retail trade.

Table 5 — Terms of sales of cheeses in retail trade

Cheeses of the Swiss group are easily distinguished from cheeses of the Dutch group. Swiss and other cheeses with a high second heating temperature (Swiss, Sovetsky, Altai, etc.) have a large mass of up to 50–100 kg. Due to the long ripening period (up to 5–6 months), these cheeses have a compacted rind up to 3–5 mm, the pattern consists of round eyes with a diameter of 6–20 mm, the dough is dense and at the same time elastic, cheeses of this group are easy to distinguish by taste and smell. They have a sweetish, slightly spicy taste and smell resulting from propionic acid fermentation.

Russian cheese is a semi-hard rennet cheese with enhanced lactic acid fermentation. This type of cheese is most easily distinguished from other hard cheeses by its pattern. Russian cheese is practically the only cheese where the formation of the pattern does not occur during ripening, but is explained by the molding conditions. The cheese mass is poured into molds and lightly pressed. As a result, the pattern consists of ragged eyes 3–4 mm in size, evenly distributed throughout the mass. Russian cheese has a slightly sharp, pronounced sour-milk taste and smell.

The quality of the cheese can be determined by its appearance, and the correspondence of the fat content and production date indicated in the accompanying documents can be determined by labeling (production marking and production date).

The production date of hard rennet cheeses (day, month, and sometimes brewing number) is indicated by pressing casein or plastic numbers into the cheese dough or by imprinting metal numbers. Using these numbers, you can determine the age of the cheese and shelf life. On each head, the date (top row) and month (bottom row) are indicated on the surface.

Production marking is applied with indelible paint using a stamp, which indicates the mass fraction of fat, the number of the enterprise and the abbreviated name of the region where the enterprise is located. When packaging cheese in polymer films, markings can also be applied to the film.

The production labeling for low-fat cheeses does not indicate the mass fraction of fat in the cheese. Semi-hard cheeses of 50% fat content from the Swiss, Dutch, Cheddar and Russian groups are marked on one of the surfaces, closer to the side, in the shape of a square; cheeses 55% fat - in the shape of a circle; cheeses 45% fat - in the shape of a regular octagon; cheeses 40% fat (for melting) - in the shape of an equilateral triangle; cheeses with 30% fat content have a production mark in the shape of a regular hexagon; cheeses 20% fat – in the shape of an isosceles trapezoid.

Cheeses with 55% and 50% fat content have an elastic, slightly oily consistency and a more intense yellow color. Cheeses bylow fat content have a slightly yellowish tint and a firmer, crumbly consistency.

When assessing the appearance of cheese, attention is paid to the shape of the cheese, the condition of its surface, coating, and rind. As mentioned, by the shape of the cheese you can determine what type of cheese it is and indirectly determine its quality. If the surface of block or cylindrical cheeses has a slightly convex shape, this indicates a poor-quality product in which the cheese dough is torn as a result of the development of foreign gas-forming bacteria.

Deformed cheeses with incorrect sediment at the base are not allowed for sale.

When assessing the appearance of cheese, they take into account the condition of the surface, the quality and strength of the coatings.

Cheeses coated with paraffin-based materials should not have paraffin sagging, cracks, or crumbling paraffin. If you run your fingers over the surface of the cheese with a force of 2-3 kg, the paraffin should not crack or crumble. When packing cheeses in films, pay attention to the integrity and tightness of the packaging and the tightness of its adherence to the surface of the cheese. When coatings under paraffin or film are damaged, mold, yeast and other bacteria intensively develop. Such cheeses cannot be stored.

Assessment of the quality of dairy products. Commodity assessment of the quality of dairy products. Butter and butter paste

Characteristic name

Appearance

Consistency

Taste and smell

Color

Name

Product name

Departments

Performers

Milk

Milk products

Dairy products

Sour cream

Cottage cheese and curd products

Ice cream

Butter and butter paste

Butter

Canned milk

Cheeses and cheese products

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