MINISTRY OF EDUCATION OF YOUTH AND SPORTS

TECHNICAL UNIVERSITY OF MOLDOVA

Department of Technology and Catering

Course work

On milk processing technology on the topic:

“Technology of liquid fermented milk products and drinks”

Performed:

Student gr. TL - 052

Checked:

Senior Lecturer Popescu L.

Chisinau 2009

Introduction

1. An assortment of liquid dairy products.

Terms and definitions ………………………………… ..3

2. Quality indicators of the finished product ………… .5

3. General technology …………………………………………… .8

4. The theoretical basis of production ……………… 10

5. The influence of various factors on the production process. 14

6. Vices …………………………………………………………… 17

List of references.

Introduction

The national fermented milk product is a fermented milk product that has a historically established name in the country, depending on the type of yeast and specific technology.

Sour-milk products include liquid sour-milk products and drinks, as well as cottage cheese and curd products and sour cream. Liquid fermented milk products and drinks include the following products.

1. Assortment of liquid fermented milk products .

Yogurt   - a national dairy product made by fermenting milk with pure cultures of lactococci and / or thermophilic lactic streptococci, the total content of which in the finished product at the end of the shelf life is at least 107 CFU per 1 g of product, without the addition of non-dairy components.

Mechnikovskaya yogurt   - a national fermented milk product made by fermenting milk with pure cultures of thermophilic lactic streptococci and Bulgarian lactic acidum, the total content of which in the finished product at the end of the shelf life is at least 107 CFU per 1 g of product, without the addition of non-dairy components.

Ryazhenka   - a national dairy product made by fermenting baked milk with pure cultures of thermophilic lactic streptococci, the total content of which in the finished product at the end of the shelf life is at least 107 CFU per 1 g of product, without the addition of non-dairy components.

Varenets - a national fermented milk product made by fermenting sterilized or heat-treated at a temperature of (97 ± 2) ° C for 40 to 80 minutes with pure cultures of thermophilic lactic streptococci, the total content of which in the finished product at the end of the shelf life is at least 107 CFU in 1 g of the product, without the addition of non-dairy components.

Kefir    - national fermented milk product of mixed lactic acid and alcoholic fermentation, made by fermenting milk with starter culture prepared on kefir fungi without adding pure cultures of lactic acid bacteria and yeast, the content of lactic microorganisms in the finished product at the end of shelf life is at least 107 CFU per 1 g of product, and yeast not less than 104 CFU in I g of the product, without the addition of non-dairy components.

Acidophilus   - a national fermented milk product made by fermenting milk with pure cultures of lactic acidophilus bacillus, lactococcus and yeast prepared on kefir fungi in equal proportions, the total content of lactic acid microorganisms in the finished product at the end of the shelf life is at least 107 CFU per 1 g of product, without the addition of non-dairy components.

Ayran    - national fermented milk product of mixed lactic acid and alcoholic fermentation, made by fermenting milk with pure cultures of thermophilic lactic streptococci, Bulgarian lactic acid bacillus and yeast, the content of lactic microorganisms in the finished product at the end of shelf life is at least 107 CFU per 1 g of product, and yeast CFU in 1 g of the product, without the addition of non-dairy components.

Koumiss   - national fermented milk product of mixed lactic acid and alcoholic fermentation, made by fermenting mare's milk with pure cultures of Bulgarian and acidophilic lactic acid bacilli and yeast, the content of lactic microorganisms in the finished product at the end of the shelf life is at least 107 CFU per 1 g of product, and yeast at least 105 CFU in 1 g of the product, without the addition of non-dairy components.

Yogurt - a fermented milk product with a high content of dry skimmed milk substances, produced by fermenting with a protosymbiotic mixture of pure cultures of thermophilic lactic streptococci and Bulgarian lactic acid bacillus, the content of which in the finished product at the end of the shelf life is at least 10 7 CFU per 1 g of product (food additives can be added , fruits, vegetables and products of their processing).

1.1. Classification of liquid dairy products and drinks

Sour-milk drinks, depending on the dairy raw materials from which they are produced, are divided into products :

From natural milk;

From normalized milk;

From reconstituted milk;

From recombined milk;

From their mixtures.

Sour-milk drinks, depending on the mass fraction of fat, are divided into products :

Fat-free (ppm,%, 0.1);

Low-fat (ppm,%, 0.3; 0.5; 1.0);

Low-fat (ppm,%, 1.2; 1.5; 2.0; 2.5);

Classic (m,%, 2.7; 3.0; 3.2; 3.5; 4.0; 4.5);

Fatty (ppm,%, 4.7; 5.0; 5.5; 6.0; 6.5; 7.0);

High-fat (ppm,%, 7.2; 7.5; 8.0; 8.5; 9.0; 9.5).

2. Indicators of the quality of the finished product .

According to organoleptic indicators, sour-milk drinks must meet the requirements,    specified in table 1

Table 1

Organoleptic indicators of fermented milk drinks

According to physico-chemical indicators, sour-milk drinks must comply with the requirements specified in table. 2

table 2

Physico-chemical characteristics of dairy products

Phosphatase in the product is not allowed.

Table 3

Microbiological indicators of fermented milk drinks are shown in table. 4

Table 4.

Microbiological indicators of fermented milk drinks

The following raw materials are used for the production of fermented milk drinks :

raw cow's milk not lower than the second grade according to GOST E52054; whole milk powder of the highest grade according to GOST 4495; Skimmed milk powder according to GOST 10970; dry cream in accordance with GOST 1349; unsalted butter in accordance with GOST 37; starter cultures on pure cultures of lactic acid microorganisms produced in accordance with TU 9229-369-0019785-04 “Starter cultures, bacterial concentrates, yeast and test cultures”; drinking water according to SanPiN 2.1.4.1074 (for recombined or reconstituted milk).

3. General technology of fermented milk products .

Milk and other raw materials are accepted in terms of weight and quality established by the quality control department (laboratory) of the enterprise, as well as on the basis of certification documents of suppliers.

Immediately after taking milk

1. heat up    to a temperature of 35 ... 40 ° C and cleaned on centrifugal milk cleaners or other equipment without heating. To clean raw milk, it is also recommended to use a bacteriofuge with a specially integrated airtight separator to remove bacteria from the milk.

2.   After this milk is sent for processing or cooled    to a temperature of (4 ± 2) ° С and stored in intermediate storage tanks. Storage of milk cooled to a temperature of 4 ° C before processing should not exceed 12 hours, cooled to a temperature of 6 ° C-6h.

3.   Milk selected by quality normalize   by mass fractions of fat and protein in such a way that they are in the finished product were not less than provided by the standard.

Normalization, as well as the preparation of butter, the restoration of dry milk products is carried out in such a way as was shown in the technology of drinking milk.

4.    Normalized mixture heat up    to a temperature of (43 ± 2) ° С and cleaned by centrifugal milk cleaners or filters.

5.    Peeled milk homogenize   at a pressure of (15.0 ± 2.5) MPa at a temperature of 45 to 85 ° C. If necessary, it is allowed to homogenize milk at pasteurization temperature.

Instead of complete homogenization, it is allowed to use separate homogenization of milk. When using separate homogenization, milk normalized by fat and heated in the second section of plate pasteurizer regeneration to a temperature of 55 ... 65 ° C is separated. In this case, the mass fraction of fat in the resulting cream is from 16 to 20%. The resulting cream is homogenized on a two-stage homogenizer at a pressure of 8 to 10 MPa in the first stage and 2 to 2.5 MPa in the second. The homogenized cream in the stream is mixed with skim milk leaving the cream separator and sent to the pasteurization section.

In order to improve the taste of fermented milk drinks, it is also recommended to homogenize milk intended for their production with a fat mass fraction of less than 2.5%.

6.    Purified and homogenized mixture pasteurize    at a temperature of (92 ± 2) ° С with an exposure of 2 to 8 minutes or (87 ± 2) ° С with an exposure of 10 to 15 minutes. It is allowed to hold milk at these temperatures from 30 to 40 minutes. In the production of ryazhenka, milk is pasteurized at temperatures from 95 to 99 ° C with an exposure of 3 to 4 hours to a pronounced light cream color, and Varenets - at the same temperatures with an exposure of 60 to 80 minutes.

In the production of fermented baked milk, it is necessary to take into account the degree of bacterial contamination, the composition, thermal stability of the raw materials, etc. Pre-pasteurization of the normalized mixture at a temperature of (76 ± 2) ° С is allowed followed by heating to a temperature of 95 ... 99 ° С with an exposure from 3 to 4 hours to a pronounced light cream color. Moreover, during heating, the mixture is stirred 1-2 times per hour to prevent the formation of foam.

7.   After pasteurization and aging, milk cooled to the fermentation temperature   : (40 ± 2) ° С or (30 ± 2) ° С in the production of yogurt; (42 ± 2) ° С in the production of Mechnikovsky yogurt, yogurt, fermented baked milk, Varents, etc .; (37 ± 2) ° С in the production of acidophilic fermented milk drinks; from 18 to 25 ° C in the production of kefir, etc., that is, to a temperature optimal for the development of microflora, used in the production of one or another sour-milk drink. Storage of unfermented mixture at the fermentation temperature is not allowed.

In the tank production method, milk is fermented and fermented in fermented milk beverage tanks with a cooling jacket, equipped with special mixers that ensure uniform and thorough mixing of milk with fermentation and fermented milk clot. In order to avoid foaming, which affects the separation of whey during storage of fermented milk drinks, milk is fed into the tank through the lower nozzle.

Ferment is prepared in accordance with the current technological instructions for the preparation and use of starter cultures and bacterial concentrates for fermented milk products at dairy enterprises, approved in the established manner.

Ferment is introduced into milk in a stream using a metering pump simultaneously with milk, or after some time from the start of filling the tank, or after filling the tank. The volume fraction of the starter culture in relation to the volume of the fermented mixture prepared in sterilized or pasteurized milk is 3 ... 5%. During the introduction of the starter culture, milk must be mixed to evenly distribute the starter culture in the product volume and to prevent the formation of protein flakes. Fermented milk is mixed for 10 ... 15 minutes.

In the tank production method, after stirring, the fermented milk is left alone for fermentation. It is allowed to re-mix after 1 ... 1.5 hours after fermentation.

With the thermostatic production method, milk is fermented in fermented milk tanks with a cooling jacket, equipped with special mixers, which ensure uniform and thorough mixing of milk with sourdough. Fermented milk is immediately poured into consumer containers with continuous stirring. Bottling from each tank should be completed within 45 ... 60 minutes in order to avoid the formation of flakes of coagulated protein. The mixture is ripened in a thermostatic chamber at the temperature indicated below.

The temperature and duration of fermentation in the production of fermented milk drinks varies depending on the microflora of the ferment used. The modes are the same when producing the same type of fermented milk drink by tank or thermostatic production methods. The end of the ripening is determined by the nature of the clot and its acidity. The clot should be even, dense enough and not secrete serum. Fermentation temperature and duration:

In the production of yogurt - for 5 to 7 hours at a temperature of (30 ± 2) ° C and from 3 to 4 hours at a temperature of (40 ± 2) ° C

when using dry lactococcal bacterial concentrate, milk is fermented at a temperature of (30 ± 2) ° C from 8 to 10 hours, when using dry thermophilic lactococcal bacterial concentrate is used at a temperature of (40 ± 2) ° C from 6 to 8 hours; I in the production of fermented baked milk, yogurt, Mechnikovsky curdled milk, Varents, etc. - for 4 to 6 hours at a temperature of (40 ± 2) ° C or when using dry tank concentrate - for 8 ... 10 hours at a temperature ( 40 ± 2) ° С;

in the production of acidophilic fermented milk drinks - for 7 ... 9 hours at a temperature of (37 ± 2) ° С;

in the production of kefir - for 8 to 12 hours at a temperature of 18 to 25 ° C. In addition, in the production of kefir produce ripening of the fermented mixture for 9 to 13 hours at a temperature of (14 ± 2) ° C.

Fermented mixes are fermented until the formation of a milk-protein clot and acidity: from 75 to 80 ° T in the production of yogurt; from 65 to 70 ° T - in the production of ryazhenka; from 85 to 100 T - in the production of kefir, etc.

8.    At the end of fermentation in the tank production method, ice water is supplied with a temperature of (2 ± 2) ° С to the inter-wall space of the tank for partial cooling of the clot to a temperature: in the production of yogurt - 25 ... 35 ° С, in the production of fermented baked milk - (22 ± 5 ) ° C; in the production of kefir - (14 ± 2) ° С

In the reservoir production method, after 60 to 90 minutes after the water supply, the stirrer is turned on and the clot is mixed for 10 to 30 minutes depending on the design of the stirrer and the viscosity of the clot to obtain a uniform consistency of the clot. When storing fermented milk drinks with a heterogeneous, lumpy consistency, serum may be released. Further mixing, if necessary, is carried out periodically, including the mixer for 5 ... 15 minutes.

In the production of kefir, a milk clot that is mixed and cooled to a temperature of (14 ± 2) ° C is left alone to ripen for a period of 9 to 13 hours. It is allowed to send mixed and partially cooled clot to the bottling with subsequent maturation and cooling of the packaged kefir in the refrigerator. From the moment of fermentation to the end of ripening, no less than 24 hours should pass.

2 to 5 minutes - in the production of kefir or for 5 to 15 minutes - in the production of fermented baked milk and yogurt.

When stirring, pumping and pouring a sour milk clot, it is recommended to avoid intense mechanical stress (long narrow pipelines, pumps, leading to significant damage to the clot, etc.), air leaks that negatively affect the quality of the finished product. It is advisable to pour the fermented clot by gravity with a minimum level difference in height.

A mixed clot using a pump designed for viscous liquids, served on the bottling in consumer containers. In the presence of plate coolers, the clot before bottling can be cooled to a temperature of (4 ± 2) ° С.

9.   The packaging and labeling of fermented milk drinks is carried out in accordance with the requirements of the current standard for this product. The duration of pouring of fermented product from one container should not exceed 2 hours.

If necessary, the packaged fermented milk drink is cooled in the refrigerator to a temperature of (4 ± 2) ° С, after which the technological process is considered complete and the product is ready for sale.

In a thermostatic production method, upon termination of ripening, the packaged product is placed in a refrigerator and cooled to a temperature of (4 ± 2) ° С. In the case of the production of kefir in the refrigerator for 8 ... 13 hours, the maturation of the milk-protein clot occurs. After this, the technological process is considered complete and the product is ready for sale.

4. The theoretical basis of production

The production of fermented milk products is a complex biochemical process, as a result of which the taste and smell characteristic of only this fermented milk product, consistency and appearance are formed. Sour-milk products are obtained by fermentation of heat-treated milk, cream, buttermilk, whey or mixtures thereof.

According to GOST 51917, a dairy product is a dairy product made by fermenting milk or cream with kefir fungi and / or pure cultures of lactic acid, propionic acid, acetic acid microorganisms and / or yeast and / or their mixtures. The total content of lactic acid microorganisms in the finished product at the end of the shelf life is at least 107 CFU per 1 g of product. After ripening, the use of food additives, fruits, vegetables and their processed products is allowed. Bifidoproduct is a product containing bifidobacteria, the amount of which at the end of the shelf life is not less than 106 CFU per 1 g of product.

The technological process for producing fermented milk products includes the following general operations:

• normalization of milk raw materials for fat, in the production of kefir - additionally for protein, yogurt - for the mass fraction of milk solids;
• heat treatment
• homogenization
• fermentation and fermentation,
• cooling
• packaging.

In the production of fermented milk products, both biochemical and physicochemical processes are carried out.

• milk sugar fermentation
• casein coagulation
• gelation.

BIOCHEMICAL AND PHYSICAL AND CHEMICAL PROCESSES IN THE PRODUCTION OF Dairy Products

Dairy products play an important role in the nutrition of people, especially children, the elderly and the sick. The dietary properties of dairy products consist primarily in the fact that they improve metabolism, stimulate the secretion of gastric juice and stimulate appetite. The presence in their composition of microorganisms that can take root in the intestine and suppress putrefactive microflora leads to inhibition of putrefactive processes and the cessation of the formation of toxic protein breakdown products entering the human blood

MILK SUGAR fermentation

The most important biochemical process that occurs during the production of fermented milk products is the fermentation of milk sugar caused by microorganisms of bacterial starter cultures. Its speed and direction determine the consistency, taste and smell of the finished products according to the nature of the fermentation of milk sugar, dairy products can be divided into two groups. The first group includes products whose preparation is mainly based on lactic acid fermentation (yogurt, yogurt, acidophilus, cottage cheese, sour cream), the second group includes products with mixed fermentation, the production of which involves lactic acid and alcoholic fermentation (kefir, koumiss, acidophilus yeast milk).

With lactic acid fermentation, each pyruvic acid molecule formed from a glucose molecule is reduced with the participation of the redox enzyme lactate dehydrogen-1 to lactic acid:

By increasing the acidity of milk during lactic acid fermentation, it is possible to calculate how much milk sugar has been fermented. For example, the acidity of milk increased by 60T (the acidity of fresh milk was 17 ° T, after fermentation of milk sugar - 77T). 1˚T corresponds to I cm3 0.1 n. alkali solution or 1 cm 30.1 N. lactic acid solution, which is 90 / (10 1000) \u003d 0.009 g of lactic acid. Therefore, 60T will correspond to 600.009 - 0.54 g of lactic acid.

From the total reaction of lactic acid fermentation, it follows that 4 moles of lactic acid are formed from 1 mole of milk sugar, i.e. 4-90 \u003d 360 g of lactic acid are formed from 342 g of milk sugar. Therefore, to obtain 0.54 g of lactic acid, it took milk sugar

Many lactic acid bacteria, when fermenting sugar, in addition to lactic acid, form a number of other chemicals that give dairy products a specific taste and aroma. These include volatile acids (acetic, propionic, etc.), carbonyl compounds (diacetyl, acetoin, acetaldehyde), alcohol, and carbon dioxide.

Depending on the products accumulated during fermentation, all lactic acid bacteria are divided into homoenzymatic and heteroenzymatic. Lactic acid bacteria (lac. Lactis, Lac. Cremoris, Lac. Diacetilactis, Str. Thermophilus, L. bulgaricus, L. acidophilus), which form lactic acid as the main fermentation product, are classified as homo-enzymatic; bacteria (Leuc. cremoris, Leuc. dextranicum, etc.), which in addition to lactic acid in significant quantities form other fermentation products, are heterozymatic.

By a certain combination of various types of lactic acid bacteria and regulation of the fermentation temperature, you can get a product with the desired taste, aroma, consistency and dietary properties.

In fermented milk products with mixed fermentation (kefir, koumiss, etc.), a large amount of ethyl alcohol and carbon dioxide is formed along with lactic acid. The causative agent of alcoholic fermentation in these products is yeast. During alcoholic fermentation, pyruvic acid under the action of the pyruvate decarboxylase enzyme, which catalyzes the removal of carbon dioxide, is split into acetic aldehyde and carbon dioxide:

Acetic aldehyde with the participation of the redox enzyme alcohol dehydrogenase is reduced to ethyl alcohol:

The ability of yeast to produce alcohol and carbon dioxide depends on many factors: the type of yeast used, the amount of milk sugar in the feed, temperature, pH of the medium, etc.

CASEIN COAGULATION AND GEL

The accumulation of lactic acid during lactic acid fermentation of lactose is essential for the formation of a protein clot, which determines the consistency of fermented milk products. The essence of acid coagulation is as follows. The resulting (or introduced) lactic acid reduces the negative charge of casein micelles, since H-ions inhibit the dissociation of carboxyl groups of casein, as well as hydroxyl groups of phosphoric acid. As a result, the equality of positive and negative charges and the isoelectric point of casein is achieved (pH 4.6-4.7).

With acid coagulation, in addition to reducing the negative charges of casein, the structure of the casein-calcium phosphate complex is disturbed (calcium phosphate and structure-forming and calcium are cleaved). Since calcium and calcium phosphate are important structural elements of the complex, their transition into solution further destabilizes casein micelles

In the production of cottage cheese by the acid-rennet method, casein is combined with lactic acid and rennet.

Under the action of rennet, casein is converted to paracasein, which has an isoelectric point in a less acidic environment (pH 5–5.2).

At an isoelectric point, casein or a pair of casein particles in a collision aggregate, forming chains or filaments, and then a spatial grid, into the cells or loops of which a dispersion medium with fat globules and other components of milk is captured. Gelation occurs. In the production of fermented milk products and cheese, the gelation process can be conditionally divided into four stages: the stage of latent coagulation (induction period), the stage of mass coagulation, the stage of structure formation (clot densification) and the syneresis stage.

In colloidal systems, gel formation is affected by the concentration of the dispersed phase, size, particle shape, temperature, etc. The resulting clot (gel) has certain mechanical properties: viscosity, ductility, elasticity, and strength. These properties are associated with the structure of the system; therefore, they are called structural-mechanical or rheological.

Structural and mechanical properties of clots are determined by the nature of the bonds that arise between protein particles during the formation of the structure. Links can be reversible and irreversible. Reversible (thixotropically reversible) bonds are restored after violation of the structure of the clot. They cause the phenomenon of thixotropy (Fig. 1a) ((Greek. Thixis - touch + trope - change) - the ability of structures after their destruction as a result of some mechanical action to spontaneously recover in time.

Irreversible (irreversibly collapsing) bonds do not have the property to recover after mechanical action on a clot. The phenomenon of syneresis is associated with them. Syneresis (Fig. 1b) - compaction, contraction of a clot with shortening of casein filaments and displacement of the fluid enclosed between them. Figure 2. The rate of syneresis is determined by the water-holding capacity of casein and depends on the concentration of dry substances in the raw materials, the composition of bacterial starter cultures, the modes of heat treatment of homogenization, the method of milk clotting and other factors.

For fermented milk drinks and sour cream, syneresis is an undesirable phenomenon. Therefore, when developing them, bacterial starter cultures of the desired composition are used and the technological process is conducted under conditions that prevent the occurrence of syneresis. In the production of cottage cheese, on the contrary, it is required to remove excess serum from the clot. Therefore, such treatment regimes of milk are selected that would contribute to the production of a dense, but easily giving off whey clot. To enhance syneresis, crushing, heating of a clot, etc. are also used.

The nature of the bonds in the structure of the bunch (product) can be determined by measuring the so-called effective viscosity - the viscosity due to the formation of internal structures in the product. In this case, the effective viscosity of undamaged η n, destroyed ηp and reduced ηp structures is determined and compared with each other (Table 5)

As can be seen from Table 5, during the formation of clots of yogurt and fermented milk drinks, irreversibly destroyed (non-thixotropic bonds) are mainly formed. Thixotropic bonds, characterized by spontaneous recovery after mechanical stress, are few in them. Sour cream is characterized by a lower loss of viscosity during the destruction of the structure and a large number of thixotropic bonds in comparison with sour-milk drinks.

Table 5

BIOCHEMICAL BASES OF PRODUCTION SEPARATE TYPES OF DAIRY PRODUCTS

The quality of the produced fermented milk products depends on the nature of the formed clots, as well as the degree of accumulation of flavoring and aromatic substances. The nature of the clots is determined by the level of accumulation of lactic acid, the ability of proteins to form spatial structures, retain moisture, etc. The formation of flavoring and aromatic substances depends on the composition of the bacterial starter cultures, the conditions of fermentation, ripening and cooling of products.

Dairy drinks

The main process that determines the consistency of all fermented milk drinks is gelation. The clots of these products are different: in some cases the clot is dense (prickly), in others it is even and tender (creamy) or flocculent, etc.

During the formation of the structure of product clots, irreversibly collapsing bonds are mainly formed; there are few thixotropically reversible bonds in them; therefore, it is so important to carry out the process under such conditions that would ensure minimal separation from the serum clot. This primarily relates to the pasteurization, homogenization and fermentation of milk.

It is known that the synergistic properties of clots depend on the pasteurization temperature of milk. To increase the strength of the clots and prevent whey secretion during storage of yogurt and other fermented milk drinks, it is recommended to use high pasteurization temperatures of milk (85-87 ° C with holding for 5-10 minutes or 90-94 ° C with holding for 2-8 minutes).

The duration of fermentation of milk during the development of products is determined by the type of bacterial yeast and the temperature of fermentation. The end of the ripening is usually set to obtain a sufficiently strong clot and titratable acidity of 75-85 ° T. In the production of fermented milk drinks by the reservoir method, it is necessary to obtain a clot with the maximum number of thixotropically reversible bonds, therefore, before stirring and cooling the clot, the pH value should be controlled (pH): it should be 4.5-4.4 for kefir, 4.7- for acidophilus 4.55, fermented baked milk - 4.45-4.35. Additionally check the viscosity of the clot by the duration of the outflow from a pipette with a capacity of 100 cm 3 at 20 ° C or using a capillary viscometer.

The specific fermented milk taste and smell of products are formed mainly during their ripening and ripening. The taste and smell of the products of the compound, which are formed during the heat treatment of milk, supplement (they play the main role in the production of jam and fermented baked milk).

The main flavoring and aromatic substances of fermented milk products are lactic and acetic acids, diacetyl, acetaldehyde (its high concentration is typical for yogurt), etc. Ethyl alcohol and carbon dioxide give a refreshing, slightly spicy taste to koumiss and kefir. The retention of alcohol in drinks is determined by the type of yeast, the temperature and the duration of maturation. In koumiss, it is 1 - Н "6, in kefir - 0.01-0.03%. Protein decomposition (proteolysis) is also characteristic of them, therefore, released amino acids and peptides can take part in shaping the taste of these products.

5 . INFLUENCE OF MILK COMPOSITION, BACTERIAL FERTILIZERS AND OTHER FACTORS ON FERMENTATION LACTOSES AND CAZEIN COAGULATION

The quality of fermented milk products, mainly their consistency, depends on the composition and properties of milk, the type and activity of bacterial starter cultures, pasteurization, homogenization, fermentation, ripening and other factors.

The composition and properties of the feedstock    determine the coagulation rate of milk proteins and the strength of the resulting clots. The development of microorganisms of bacterial starter cultures fermenting milk sugar also depends on them.

The composition and properties of milk change during the year, the stage of lactation, with diseases of animals, etc. From the practice of dairy plants, it is known that in the fall and especially in the spring there is a slow fermentation of milk. This may be due to a decrease in its biological value. For example, in spring, the content of vitamins (biotin, niacin, B 6, etc.), free amino acids (valine, leucine, phenylalanine, etc.) and trace elements (Mn, Co, Fe, etc.), which are necessary for the multiplication of lactic acid, decrease in milk. bacteria. In addition, the cause of non-fermentation of milk at this time of the year may be the presence of antibiotics and other substances that inhibit the development of lactic acid bacteria. Lactic acid bacteria develop poorly in old-milk milk and in milk obtained from cows with mastitis.

In the spring, the technological properties of milk also deteriorate - the rate of formation and density of the acid clot decrease. This is due to a decrease in the content of dry substances, casein, the size of casein micelles in milk, and an increase in the acidity of milk.

· Individual characteristics and breeds of animals

The ability of milk to rennet coagulation is determined by the concentration of proteins, calcium salts and depends on the individual characteristics and breed of animals, feed, stage of lactation and other factors. Milk coagulates poorly at the beginning and end of lactation, as well as in case of animal disease.

· Storage time

The properties of milk (and the properties of the clot obtained from it) change during storage. So, after prolonged storage of milk (raw and pasteurized) at low temperatures, the viscosity and strength of the acid clot increase, the syneresis slows down. Therefore, milk stored at low temperatures, it is advisable to send to the production of sour-milk drinks and should not be used. for curd production

· The composition of the starter cultures.

Not only the taste of fermented milk products, but also their consistency depends on the composition of the starter cultures. The main component of the microflora of the starter cultures of all fermented milk products, providing the formation of a clot, is milk lactococcus (Lac. Lactis). The inclusion of energetic acid-forming agents in the starter culture results in a dense prickly clot with intensive separation of serum, and low-energy acid-forming agents - a more tender clot. Introduction of Str. thermophilus, lac. cremoris and thermophilic sticks helps to increase the viscosity of the product, gives the clot elastic - properties, prevents the secretion of serum.

Therefore, by selecting the composition of the starter cultures, you can adjust the properties of the clot and provide the optimal consistency and taste of fermented milk products.

· Heat treatment

Heat treatment of milk affects the rate of clot formation, structural and mechanical properties, and syneresis.

According to VNIMI and VNIIMS, with increasing pasteurization temperature, the strength of acid and acid rennet clots increases (Table 6).

Table 6.

With an increase in the temperature of pasteurization of milk (from 63 to 90" C )   the intensity of separation of serum from the clot decreases The increase in the strength of clots and the deterioration of serum excretion from them after high heat treatment temperatures can be explained by an increase in the content of denatured whey proteins in the clot, which increase the rigidity of the spatial structure and the water-holding capacity of casein.

Thus, by regulating the heat treatment of milk, it is possible to obtain a clot with the desired rheological properties, i.e., to improve the consistency of the fermented milk product

· Milk homogenization

When producing fermented milk drinks, it is recommended to homogenize milk before fermentation (for kefir and yogurt obtained by the reservoir method, it is mandatory). As a result of homogenization, the dispersion of fat increases, the crushed fat in the clots is distributed more evenly, the strength of the clot increases, while the viscosity of the products increases slightly and the excretion of serum decreases.

At the same time, the homogenization of milk with increased (above 10%) fat and cream contributes to a significant increase in the viscosity of clots and a decrease in their ability to separate serum. Moreover, the increase in viscosity of the resulting clots depends on the pressure and the method of homogenization of the raw material.

Structural, mechanical and synergistic properties of clots significantly depend on the method of coagulation of proteins

· Type of coagulation

Clots formed during acidic coagulation of proteins are less strong than acid rennet (the spatial structure of acid clots is supported by weak bonds, the structure of acid rennet is additionally stabilized and strengthened by calcium bridges formed between parts of paracasein); they are made up of smaller protein particles and produce less serum. However, along with an increase in the strength of acid rennet clots, their fragility, degree of dispersion, and ability to separate serum during processing also increase.

· Duration and clotting temperature

The duration and temperature of coagulation (fermentation) of milk are important factors affecting the consistency of fermented milk products. The duration of fermentation of milk is usually set by increasing acidity, viscosity or strength of the resulting clot. It is especially important to determine the moment of clot readiness in the production of beverages by the reservoir method. Sometimes there is a liquid consistency of products and sediment of whey. This is caused by the wrong choice of the moment of mixing of the clot. Serum is released when the clot is mixed when it has a minimum viscosity and exhibits insignificant thixotropic properties.

In addition, the accumulation of products that give them a certain taste and aroma (volatile acids, diacetyl, acetaldehyde, etc.) depends on the temperature and duration of milk fermentation.

To stop lactic acid fermentation and harden the structure of the formed clot, sour-milk products are cooled to 8 ° C and stored at this temperature. Mixed fermentation products are subjected to maturation before cooling, for the development of yeast and aromatizing bacteria. In the process of maturation and aging in the refrigerator, aromatic substances, alcohol and carbon dioxide are accumulated in the products, and the partial decomposition of proteins occurs under the influence of proteolytic enzymes of lactic acid bacteria and yeast. In this case, various soluble polypeptides and free amino acids are formed, affecting the texture, taste and smell of the products.

In the production of sour cream, an additional goal of cooling and ripening is the solidification of fat, which helps to improve the structure and consistency of the product.

5. FAULTS OF Dairy Products .

Bibliography

1 TO. K. Gorbatova “BIOCHEMISTRY OF MILK AND DAIRY PRODUCTS” St. Petersburg GIORD 2004

2.N. A. Tikhomirova “Technology and Organization for the Production of Milk and Dairy Products” 2007 Moscow DeLi Print

Sour-milk products are produced in two ways: thermostatic and reservoir.

Scheme: milk acceptance - normalization - pasteurization - cooling - 1 (tank) fermentation in the tank - fermentation - cooling - ripening - packaging - storage - sale. 2 (thermostatic) fermentation in a thermostat and bottling in consumer containers - fermentation in a thermostat chamber - cooling in a refrigerating chamber - ripening - storage - sale.

Acceptance and evaluation of milk: the mass fraction of fat, density, acidity, temperature, organoleptic indicators are determined. Use raw materials: not less than 2 grades with acidity less than 20 degT, reductase test not less than 1 class, fur. contamination no more than 1 group, density no lower than 1,027g / cm3. Skim milk: acidity less than 20 degT, density not lower than 1,030g / cm3

Milk purification: carried out at 43 ° C. Homogenization: at R-15MPa, 45-48 deg. Pasteurization: 85-87 degrees C - 10-15 min, 92 degrees C - 2-8 min. Cooling? to the fermentation temperature. Fermentation: fermentation 3-5% of the total volume, stirring 15min. Fermentation: 10-12 hours, the end of fermentation is determined by acidity (65-90 degT) and clot density. Cooling: ice water with stirring (30-60min), until a homogeneous mass. The introduction of fillers: in a partially cooled clot, we add fillers, mix, serve for bottling. Storage: no more than 36 hours at 6 degrees from the moment of completion of those. percent

Technology for the preparation of liquid fermented milk products.

Sour milk drinks TU 46.073-2003

Developed by the National Association of Dairymen of Ukraine. It applies to sour-milk drinks, which are fermented with a special yeast with or without sugar, stabilizers, milk powder, natural fruit fillers, with further heat treatment.

Assortment: drink "Jubilee" (1, 2.5%); Yubileiny drink with fruit filling (1, 2.5%); Drink “Snowball” (1.0, 2.5, 3.2, 3.5%); drink “Snowball fruit and berry” (1%); non-fat yogurt (1.5, 2.5, 3.2, 3.5%); fruit and berry yogurt (1, 3.5%).

Organoleptic indicators. Appearance and consistency: homogeneous, moderately viscous. With the reservoir method, with a disturbed clot; with thermostatic - with undisturbed. With the presence of soft particles of fruits and berries, separation of serum is allowed no more than 2-3%. The “Snowball” drink has a slight powderiness.

Taste and smell. Pure sour-milk, moderately sweet, with a taste and smell of the introduced filler.

Colour. Depends on the filler or milky white.

Acidity. Anniversary - 80-110 degT (pH - 4.6-4.0); "Snowball" - 80-120 degradT (pH - 4.6-3.9); yogurt - 80-140 degT (pH - 4.4-3.8)

Sucrose added more than 7%, jam - more than 4%.

Microbiological indicators. Bacteria of the Escherichia coli group are not allowed in 0.1 g of the product. Salmonella is not allowed in 25 g of product. Staphylococcus aureus is not allowed in 0.1 g of product. The number of lactic acid microorganisms is not less than 1 million in cm3.

Storage. At a temperature of 4 + -2gardS. If the product is without stabilizers and leaks - no more than 36 hours. Demon stabilizers, but in sealed packaging - no more than 3 days. With stabilizer and in sealed packaging up to 14 days.

This is a fermented milk drink obtained by fermenting milk with yeast on kefir fungi.

Assortment: non-greasy, 1%, 2.5%, 3.2%.

Acidity 850120 deg.

Appearance and consistency. Homogeneous, with a disturbed clot in the reservoir method of production and with undisturbed in the thermostatic method. Gas formation is allowed in the form of separate bubbles.

Taste and smell. Pure sour-milk, refreshing, slightly spicy.

A slight separation of serum is allowed - no more than 2%. Microbiological indicators. Bacteria of the Escherichia coli group - not allowed in 0.01 g prod. Pathogens - not allowed in 1 g of product.

Shelf life, as with dairy products.

Diagram of directions of milk processing for kefir.

Milk 3.4% - normalized mixture - (fermentation 5%): 1 - kefir 1%; 2 - kefir 2.5%; 3 - kefir 3.2%.

Sour-milk drink made from baked milk, fermented with pure cultures of thermophilic lactic streptococci, with or without added Bulgarian sticks.

Assortment: 1%, 2.5%, 4%.

Acidity 70-110 deg.

Appearance and consistency. Homogeneous, foam is allowed.

Taste and smell. Pure, sour-milk, with a pronounced taste of pasteurization.

Colour. Light cream due to the presence of melonoidins due to milk languishing.

Technological features. The pasteurization temperature is 95-98 degrees C with an exposure of 3-5 hours, in order to obtain a light cream color and a specific taste.

Storage. In the presence of stabilizers no more than 14 days.

The requirement for raw materials is the heat resistance of milk.

Yogurt.

A fermented milk product produced from milk by fermenting it with pure cultures of lactic acid bacteria.

Common yogurt.

Prepared only thermostatically. Sourdough contains thermophilic lactic streptococcus and Bulgarian stick. The temperature of the starter culture is 40 degrees C. Duration of ripening 3-4 hours. A dense clot forms without gas formation. Taste and smell - pure sour milk. Color - milky white. Acidity 80-130 deg. Storage: at a temperature not exceeding 8 degrees C - 36 hours.

Southern curdled milk.

Thermostatic method. Sourdough is the same and + milk yeast. Fermentation for 6-8 hours. Color - milky white. Taste - pure sour-milk, alcoholic taste. The clot is dense. In the presence of mucous strains, there may be a viscous consistency. Acidity - 90-140 deg.

Acidophilic curdled milk.

Sourdough - acidophilus bacillus, lactic streptococcus. Sour milk taste. The consistency is tender, in the presence of mucous strains - viscous. Acidity - up to 140 deg

Taste and smell: pure sour-milk, with a pronounced aftertaste and aroma of pasteurized cream (during pasteurization of cream, diacetyl and acetoin are formed). All kinds of sour cream have a slightly fodder flavor (especially in the winter-spring period), and a slight bitterness.

Color: white with a cream shade.

Physical and chemical indicators.

Acidity: 10.15.30% - 60-90 deg; 20.25% - 60-100 deg. Phosphatase is absent. The temperature of the outlet from the factory is less than 6 ° C. For sour cream produced using dry dairy products, an increase in the upper acid limit by 10 degT is allowed.

Microbiological indicators.

E. coli bacteria are not allowed in 0.001 g of product. Pathogens are not allowed in 25 g of the product. Staphylococcus aureus is not allowed in 1 g of product.

Diagram of directions of milk processing for sour cream.

Milk 3.4% (for separation) -: 1 - skim milk residue; 2 - cream (for normalization) -: 1 - sour cream 10%; 2 \u003d (adding fillers) dessert sour cream.

In crust, time produce more than 300 species. All of them are produced by fermenting raw materials with pure bacterial starter cultures. Under certain conditions, microflora turns t. And. secondary microflora. It gives products a specific taste and smell. Use: Mesophilic streptococci, thermophilic streptococci and sticks, yeast. Their use in various combinations allows you to get a large number of acids. products.

In the production of fermented milk products, milk is used, in which the protein content is not less than 3%, lactose is not less than 4.5%. In addition, in the production of cottage cheese, the rennet coagulability of milk is determined by the rennet method, it should be 1 or 2 classes. Sour milk production. Products are carried out in 2 ways. 1) reservoir 2) thermostatic. When the reservoir uses large production areas, but this is a relatively cheap method. The thermostatic method requires additional, equipment costs, but requires less production. areas. Diagram of the production of fermented milk products in a thermostatic way.

Acceptance and quality assessment of raw materials, reservation, heating and cleaning, fat normalization, pasteurization, cooling to 1 fermentation (for mesoph. 30-32 ° C, for thermophile. 40-42 ° C, for kefir fungus 20 ° C), packaging fermentation (in each container), hermetic capping, ripening and ripening in a thermostatic chamber, cooling (up to t 6-8), storage and sale. (72 hours) Shelf life of sour cream 5 days. Cottage cheese is produced in 2 ways: Traditional and separate. In addition, depending on the method of fermentation of milk, cottage cheese is produced: Acidic method (add only starter) Rennet method (in addition to fermentation, rennet and calcium chloride are added). Defects of fermented milk products: Defects of taste and smell. Overly sour taste and smell. Fermentation and fermentation modes, as well as transportation and storage, are violated. Feed taste and smell. Mild taste and smell. Due to the violation of technological regimes of ripening. Rancid taste and smell. High fat foods. Color defects: uneven. Defects of consistency: heterogeneous with separation of serum - violation of the modes of transportation and storage.

55. The technology of production of butter.

For the production of butter, milk of at least 2 grades, cream of 1 or 2 grades is used. In cream of the 1st grade, mechanical impurities, protein flakes, traces of freezing are not allowed. For cream of the 2nd grade, a slightly pronounced fodder taste and smell, individual protein flakes are allowed. The temperature of incoming cream of the 1st grade should not be higher than 10 ° С, 2 grades should not be higher than 15 ° С. It is most preferable to use high fat raw materials.

Butter production is carried out in 2 ways: 1) Churning; 2) Convert High Fat Cream

Technological scheme for the production of butter by the method of churning. Acceptance and evaluation of the quality of raw materials, cooling (up to 14-6 ° С), reservation, heating (30-35 ° С), cleaning, separation (receiving cream (32-35% fat), heat treatment of cream (pasteurization), physical maturation cream (low-temperature processing), cream churning, oil grain processing, buttermilk separation, oil washing, mechanical oil processing, packaging, storage and sale.

Cleaning, separation is carried out: in separators of open or closed type. The fat content of the cream obtained depends on the type of oil produced.

Heat treatment is carried out in order to destroy all harmful microflora, as well as inactivation of enzymes that accelerate oil spoilage. Pasteurization is lower than at 85 ° C. For cream I grade I pasteurized summer 85-90, in the winter 92-95. For oil produced from cream of grade 2 t, regardless of the time of the year 95, s is preceded. Cream deodorization. Cream must go through the stage of physical maturation. When whipping cream that did not pass this stage, the product is soft with a spreading texture with a large waste of fat in buttermilk.

Churning cream is carried out in the oil makers of continuous or periodic action. The cream whipping temperature depends on the season, the fat content in the cream and the degree of solidification of the fat in the cream. For summer, it is equal to 7-12 ° С, winters 8-14. The churning process can be divided into 3 stages: I) Beginning of churning (the inspection window of the churn is covered with a film of cream). 2) The formation of individual oil grains (the window brightens 3) Finish, the formation of oil grains (the window is transparent and oil grains are visible). Duration of churning of a periodic churn 20-30 min. Separated from buttermilk oil grains are washed 2 times with drinking water t which is 2 ° C lower than churning, to remove lactose residues, protein, min from oil grains. substances. The volume of wash water is 50% of the initial volume of cream. The washed grain is pressed, molded. For this, the churn is transferred to the deboning mode, lasting 5 minutes.

Packing is carried out at the outlet of the churn, both in cardboard boxes and in small containers of 180-200 g. Be sure to indicate on the packaging: product labeling, name, GOST, manufacturer, storage conditions and shelf life, composition and value.

Store at 14-6 ° C for no more than 20 days. In frozen form, at t -20, -25 ° C, you can store up to 3 months.

Defects of butter: defects of taste and smell, consistency, color. Taste and smell: bitter, rancid, empty, fodder smell. Consistency; crumbly, too soft, too wet. Color: uneven, the top layer is yellow and individual pieces of fat are visible).

Sour-milk products are products produced by fermenting milk or cream with pure cultures of lactic acid bacteria with or without the addition of yeast or acetic acid bacteria. Some dairy products are obtained as a result of lactic acid fermentation only; this forms a fairly dense, uniform clot with a pronounced sour-milk taste. Other products are obtained as a result of mixed fermentation - lactic acid and alcohol.

Sour-milk products are of great importance in human nutrition due to medicinal and dietary properties, pleasant taste, easy digestibility.

In the production of some dairy products, food, flavor and aromatic substances are used, which also increases their nutritional and dietary value.

Yogurt, yogurt, acidophilic products, kefir, koumiss are produced in a thermostatic or reservoir way. Pre-milk pasteurized, homogenized and fermented.

With the thermostatic method, the fermentation of milk and the ripening of the product is carried out in bottles in thermostatic and cold storage chambers. The milk is fermented, mixed, poured into bottles, corked and immediately sent to a thermostat until a sufficiently strong clot forms in the bottles. After the ripening, the product is sent to the refrigerator for cooling and ripening. In the tank method, the fermentation of milk and the ripening of the product are carried out in one tank. During the ripening process, the milk is continuously stirred to break the clot. The product is then cooled and left to ripen, after which it is again mixed and poured into glass bottles or paper bags.

Yogurt is a fermented milk product with an undisturbed clot. It is produced from milk with or without flavoring and aromatic substances. Sugar, honey, vanillin, cinnamon, fruit and berry creams or preserves are used as flavoring substances.

Ordinary yogurt - produced by fermenting pasteurized milk with or without the addition of Bulgarian sticks.

Acidophilic yogurt - obtained by fermentation of milk and acidophilus bacillus.

Fermented baked milk - produced by ripening a melted mixture of milk and cream with or without the addition of a Bulgarian stick.

Varenets - made by fermenting sterilized or baked milk with or without the addition of a Bulgarian stick.

Southern yogurt - obtained by fermenting milk and Bulgarian sticks with the addition of yeast, fermenting lactose.

Salty yogurt (with jam or jam) - is produced by fermenting whole milk and Bulgarian sticks with the addition of jam or jam.

Yogurt - it differs from other sour-milk products with a high content of dry skim milk substances. It is prepared from milk or milk mixture with the addition of milk powder, sugar, fruit and berry syrups.

Yogurt is produced at 1.5%, 3.2% and 6% fat. Unsweetened, sweet, with vanilla and fruit and berry yogurt are produced depending on the tastes and aromatic substances used, the color of which depends on the color of the syrup introduced. Acidophilic dairy products - they are obtained by fermenting milk with pure cultures of acidophilus bacillus. These products include the following:

Acidophilus milk is produced from whole or skim milk with or without sugar, which is fermented with pure acidophilus bacillus cultures. Acidophilus milk is released in fatty, non-fat, and also with the addition of vitamin or cinnamon. Acidophilus is prepared from whole or skim milk with or without added sugar, fermented with pure cultures of acidophilus bacillus and kefir yeast. Acidophilus may be fatty or non-greasy.

Acidophilus-yeast milk is prepared from whole or skim milk with or without added sugar, fermented with pure cultures of acidophilus bacillus and yeast.

Kefir is a fermented milk drink of mixed fermentation (lactic acid and alcohol) produced by fermenting milk with kefir fungi. Kefir is in the greatest demand of the population, as it has not only dietary, but also medicinal properties. It also quenches thirst, and thanks to the taste, the presence of carbon dioxide and a small amount of alcohol, it stimulates appetite. Koumiss is obtained from mare and cow's milk. Koumiss from mare's milk. Compared to cow's milk, mare’s milk has more sugar and less fat, so when it is ripened, the proteins do not fall out in the form of a dense clot, but form flakes, which are easily destroyed by shaking. Mare's milk koumiss has a specific taste. Koumiss from cow's milk is a mixed fermentation product. It is made from skim milk with added sugar. When milk is fermented, tiny flakes of protein are formed that are easily absorbed by the body. Koumiss increases appetite, improves digestion and metabolism. Depending on the degree of maturation, koumiss is distinguished: weak with an alcohol content of 0.1-0.3%, medium containing 0.2-0.4% alcohol, in which alcohol is strong up to 1%.

Sour cream is made by ripening normalized cream. Sour cream has a high fat content from other dairy products.

Normalized, pasteurized and homogenized cream is cooled to the fermentation temperature. Then the cream and sourdough are mixed and left to ripen. The end of the ripening is determined by the moment when the clot has optimal acidity and strength. Duration of ripening 13-16 hours.

At the end of the ripening cream is thoroughly mixed and sent for packaging, cooling and ripening. Maturation occurs at a temperature of 5-8 degrees for 6-48 hours, depending on the container volume and temperature. Sour cream of 30% fat is the main type of sour cream, which is made by fermenting normalized cream. The development of this type of sour cream from canned raw materials is allowed. Produce the highest and 1st grades.

Sour cream 36% fat - prepared only from fresh, normalized pasteurized cream. It is not divided into varieties.

Amateur sour cream of 40% fat is produced only from cream and is packaged in the form of briquettes. It has a dense, non-blurry consistency. It is not subdivided into varieties.

Sour cream diet 10% fat is obtained from pasteurized cream enriched with vitamins C and B. It is not divided into varieties.

They also produce sour cream of 20% and 25% fat content.

Cottage cheese - a fermented milk protein product produced by staining milk with the use of rennet or with the removal of part of the serum.

The cottage cheese contains 14-17% of proteins, up to 18% of fat, 2.4-2.8% of milk sugar. It is rich in calcium, phosphorus, iron, magnesium - the substances necessary for the growth and proper development of a young organism.

Cottage cheese is produced from raw and pasteurized milk. For direct consumption, cottage cheese is prepared from whole normalized or skim pasteurized milk. Get the cottage cheese acid-rennet and acidic method. A variety of acid rennet is a separate method. In the acid-rennet method for the production of cottage cheese, milk is curdled with acid and rennet. At the same time, you can cook cottage cheese of any fat content. Normalized, pasteurized and chilled milk is fermented with leaven. The fermentation of milk is completed after 6-7 hours from the moment of making the fermentation, and with the accelerated method after 4-4.5 hours. The finished clot is cut, i.e. crushed into cubes, for better separation of serum. The released serum is released from the bath, and the clot is placed in bags, which are laid for self - pressing for an hour. During self - pressing, the serum spontaneously separates from the clot. Cottage cheese is pressed to a standard moisture content depending on its type.

With the acidic method of producing cottage cheese, milk coagulates under the influence of lactic acid. In this way, low-fat cottage cheese is prepared from skimmed pasteurized milk.

With a separate method of production, fat-free cottage cheese is obtained, followed by mixing it with cream with 50-55% fat content.

Fat-free cottage cheese is subjected to grinding to obtain a uniform consistency. In this way, you can get cottage cheese of any fat content.

Depending on the raw materials used, cottage cheese is produced fat, bold and not fat. The quality of cottage cheese can be of the highest and first grades.

Cottage cheese is a very unstable product in storage, even at low temperatures. At 0 0 - it can be stored up to 7 days. For longer storage, the cottage cheese is frozen. Bold usually at 12 0, not bold at 18 0; at these temperatures, frozen cottage cheese is stored for 4-6 months.

Curd Products

Cottage cheese products are produced from cottage cheese subjected to grinding, grinding with the addition of flavoring and aromatic substances.

Curd products include curds, cheeses, creams, cakes and pastes.

Curd masses. They can be not packaged and packaged in 250 and 500 grams, depending on the fillers they are divided into sweet and salty, without additives and with additives. Sweet curd masses by fat content can be with a high fat content - from 20 to 40%, fat - from 13 to 17%, bold from 6 to 8% and not fat. Salty curd masses are produced in bold, bold and not fatty.

Curd cheese. I pack them from 50 to 125 grams. They are divided into sweet and salty, with and without additives, with a high content of fat - fatty, bold and not fatty.

Slavic cheese. It is produced from fat cottage cheese with the addition of butter, flavoring and aromatic substances.

Glazed curds. Prepared from the same raw materials as the Slavic ones, but coated with chocolate icing.

Diabetic cheeses. Prepared using food xylitol.

Curd creams. They are made from cottage cheese with the addition of cream or butter, as well as flavoring and aromatic substances. Curd creams are produced in 18%, 12% and 5% fat content. Creams have a gentle oily consistency.

Curd cakes. This is a product of fat cottage cheese with the addition of butter, flavors and aromatic substances, decorated with drawings of cream, made of jelly or coated with chocolate glaze.

Depending on the fillers added, the cakes are called "Coffee", "Chocolate", etc. The fat content in the cakes is from 22 to 26%.

Curd pasta. They are produced from fatty cottage cheese, with the addition of cream, flavoring and aromatic substances, as well as from a mixture of gelatin with cream. They release sweet and salty curd paste.

Protein-based pastes also belong to this group. They do not contain a large amount of fat, but are rich in valuable milk protein. These types of pastes include the following:

• - Milk protein paste "Health" is prepared by adding cream, sugar, fruit and berry syrups, table salt to the protein base from skim milk. I produce pasta of 5% fat and not greasy, without and with the addition of flavoring substances;
• -acidophilic paste is produced on a protein basis from normalized or skim milk. Depending on the added syrups, sweet, fruit and berry paste, fat-free, special paste is produced;

Yubileinaya pasta is prepared on a protein basis with the addition of lemon syrup. The paste contains 4% fat and 15% sugar.

In the preparation of fermented milk products, the ability to ferment milk is used. Common in the production of all fermented milk drinks is the fermentation of prepared milk with starter cultures and, if necessary, maturing. The specifics of the production of individual products differ only in the temperature conditions of certain operations, the use of starter cultures of different compositions and the introduction of fillers.

There are two groups of fermented milk products. The first consists of products obtained as a result of lactic acid fermentation (yogurt, acidophilus milk, etc.), the second is products obtained as a result of mixed (lactic acid and alcohol) fermentation (kefir, koumiss, etc.). The taste and consistency of these products depend on many factors: the properties of milk, types of starter cultures, fermentation methods, etc. Pure cultures of lactic acid bacteria with or without the addition of cultures of milk yeast are used as starter cultures: lactic acid streptococci, Bulgarian bacillus, acidophilus bacillus, aroma-forming bacteria and others

Yogurt (ordinary, Mechnikovskaya, Ukrainian (fermented baked milk), Varenets, acidophilic, southern (matsun), yogurt, etc.) differ depending on the milk used (pasteurized and sterilized), the type of lactic yeast.

Yogurt Production Technology  reservoir method: acceptance and assessment of milk quality; cleaning; normalization (to fat content of 2.5-3.0%); pasteurization (80 ° C without air); homogenization (at 60 ° C); cooling to 30-45 ° C; fermentation (5% fermentation); fermentation in tanks (from 1.5 to 12 hours); cooling and ripening; definition of quality.

Fermented baked milk is prepared from a mixture of milk with cream of 6% fat content. The mixture is subjected to languishing, i.e. pasteurization at a temperature of 95 ° C for 3-5 hours. Then the milk is fermented with pure cultures of thermophilic streptococcus.

Varenets is made from baked milk, which is fermented with pure cultures of thermophilic streptococcus. Pieces of milk foam located on its surface give a pleasant taste to Varents.

Yogurt is prepared from milk or a mixture of milk with cream, which is pasteurized at 60-70 ° C for 30 minutes, then cooled to 45 ° C and add 2-3% leaven. Sourdough consists of pure cultures of thermophilic streptococcus and Bulgarian sticks (50:50). Fermented milk is poured into a fermentation tank. To prevent yogurt from becoming too acidic, it is quickly cooled after active fermentation.

Acidophilic fermented milk products (acidophilus, acidophilus milk, acidophilus-yeast milk, acidophilus yogurt and acidophilus paste). An obligatory component of all these products is acidophilus bacillus, resistant to the action of many antibiotics used for treatment. Acidophilus milk is also used to feed young farm animals for the prevention and treatment of diseases of the digestive system.

Kefir  prepared from pasteurized milk at a temperature of 80 ° C and cooled to 22-26 ° C milk. 5% yeast is added to milk, fermented for 12 hours with kefir fungus, which causes various changes in milk: lactic acid bacilli and lactic acid streptococci cause lactic acid fermentation, and yeast - alcohol. Then it is poured and sold into a distribution network. It is undesirable to store kefir for more than three days, since with an extension of the shelf life it acquires a strongly acidic taste.

Sour cream is produced with different fat content - from 10% (dietary) to 40% (amateur). In the preparation of sour cream, the cream is pasteurized at 80 ° C, cooled to 18-22 ° C, 5% starter is added (fermentation mode for 5-8 hours at a temperature of 18-22 ° C), cooled to 8-10 ° C (maturing occurs during days). The consistency of ripened sour cream becomes thick due to hardening and crystallization of fat and swelling of proteins.