RU2544052C2 - Method for production of bacterial concentrate of probiotic microorganisms consortium - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: invention relates to biotechnology and may be used as a direct addition starter for probiotic sour cream preparation. The method involves preparation of a nutritional medium where one additionally introduces sodium selenite in an amount of 30-50 mcg/ml, sterilisation and cooling to 35°C, inoculum introduction into the nutritional medium; the inoculum is represented by combined starter based on Bifidobacterium bifidum 8₃, Lactococcus lactis subspecies cremoris 24₄, Propionibacterium freudenreichii subspecies shermanii AC-2503 taken at a ratio of 40:30:30, biomass propagation and separation from culture liquid. One performs mixing with a protective medium, dispensing, closuring and freezing.

EFFECT: invention allows to enhance organoleptic properties of exo-polysaccharide potential and increase storage life of the bacterial concentrate.

2 cl, 5 tbl, 8 dwg, 3 ex

Description

The invention relates to biotechnology and can be used as a direct starter culture for the preparation of probiotic sour cream.

A known method for the production of bacterial concentrate, including the preparation of a nutrient medium, sterilization, cooling, inoculum, biomass, separation of biomass from the culture fluid, mixing with a protective medium, bottling, capping, freezing, drying and storage (see TU 9229-001-48774768 -02).

The disadvantage of this method is the low biochemical activity of the concentrate and the complexity of its preparation in a production environment.

The closest way to the claimed invention in terms of features is a method for the production of a bacterial concentrate, including preparation of a nutrient medium, sterilization, cooling, inoculum application, biomass growth, separation of biomass from the culture fluid, mixing with a protective medium, filling, capping, freezing, storage (see . RU No. 2372782, A23C 9/12, November 20, 2009).

However, the disadvantage of this method is that when using this concentrate, the organoleptic and structural-mechanical properties characteristic of sour cream are not formed and it has a short shelf life.

The objective of the invention is to increase consumer, rheological properties and storage capacity of the finished product.

In addition, the creation of a consortium of probiotic microorganisms from specially selected cultures of probiotic microorganisms will increase the biochemical and functional properties of concentrates.

The technical result provided by the implementation of the present invention is to increase the organoleptic properties, exo-polysaccharide potential and reduce hydrolytic and oxidative processes during storage of the product.

The specified technical result in the implementation of the invention is achieved by the fact that in the method for preparing a bacterial concentrate of a consortium of probiotic microorganisms, including the preparation of a nutrient medium, sterilization, cooling, inoculum, biomass, separation of biomass from the culture fluid, mixing with a protective medium, bottling, capping, freezing , storage, according to the invention, sodium selenite in an amount of 30-50 μg / ml is additionally introduced into the nutrient medium, and as an inoculum The user on the basis of a combined starter Bifidobacterium bifidum August _3, Lactococcus lactis subspecies cremoris April ₂₄ Propionibacterium freudenreichii subspecies shermanii AC-2503 in the ratio 40:30:30.

Distinctive features of the proposed method is the optimization of the nutrient medium by introducing sodium selenite, as well as the use of specially selected strains of probiotic microorganisms, the choice of their optimal ratio and cultivation conditions of probiotic microorganisms, in which high organoleptic, rheological properties, a decrease in oxidative processes and product stability in the process are noted storage.

To implement the proposed method, experimental studies were conducted, during which the dose of sodium selenite, starter cultures of probiotic microorganisms and their optimal ratio were selected.

The selection of strains for production-valuable properties is an important aspect of the development of a probiotic product. The basis of the starter cultures for classic sour cream is the lactic acid bacteria Lactococcus lactis subspecies lactis and Lactococcus lactis subspecies Cremoris. Years of experience in the selection of microflora of starter cultures show that the strains that have similar activity of acid formation are best combined. Therefore, along with bifidobacteria, lactic acid bacteria of the species Lactococcus lactis subspecies Cremoris were chosen as the basis of the starter culture for the probiotic product, since this type of microorganism, actively developing in milk, forms a dense sour cream-like clot and, being a less active acid-forming agent, is characterized by a low post-oxidative potential.

Co-cultivation of bifidobacteria with lactic acid bacteria has several advantages. Lactic acid bacteria bind oxygen dissolved in milk and thereby create conditions favorable for the growth of bifidobacteria. Proteolytically active strains of lactobacilli break down casein with the formation of bifidogenic factors: peptides and amino acids.

In order to increase the functional properties and improve the consistency of the developed product, it is advisable to introduce propionic acid bacteria into the composition of the combined starter culture.

Consistency is one of the determining indicators of the quality of sour cream. The structural and mechanical properties of sour milk clots are due to the colloidal state of casein-calcium phosphate complex micelles, the denaturation of whey proteins, the dispersion and physical state of the fat emulsion, and the synthesis of natural stabilizers by starter microorganisms.

The polysaccharides accumulated during fermentation combine with milk proteins, forming carbohydrate-protein complexes, increasing the hydrophilicity of the clot, and have a positive effect on the consistency of sour cream. Therefore, when selecting cultures for combined starter culture, it is necessary to study the degree of polysaccharide production by the studied strains. The results are presented in table 1.

Table 1 The polysaccharide potential of microorganisms Object of study The relative viscosity of the culture fluid, cSt The concentration of polysaccharides, μg / cm ³ R. Freudenreichii subsp. Freudenreichii AC-2500 1.88 19.70 ± 0.61 P. cyclohexanicum Kusano AC-2560 3.86 29.60 ± 0.43 Propionibacterium Freudenreichii subsp. Schermanii AC-2503 4.45 30.2 ± 0.26 Bifidobacterium longum DK-100 1.92 5.9 ± 0.04 Bifidobacterium bifidum 8 ₃ 2.41 7.8 ± 0.021 Bifidobacterium longum B379M 2,4 7.5 ± 0.03 Lactococcus lactis subsp. cremoris 24 ₄ 4.62 23.8 ± 0.21 Lactococcus lactis subsp. cremoris 18P 4.45 18.3 ± 0.17 Lactococcus lactis subsp. cremoris T-18-20 4,57 19.6 ± 0.31

As can be seen from the data presented, the strains of Propionibacterium freudenreichii subsp found the greatest ability to produce exopolysaccharides. shermanii AC-2503, Bifidobacterium bifidum 8 ₃ and Lactococcus lactis subspecies cremoris 24 ₄ .

According to modern concepts, the role of natural stabilizers is played by exopolysaccharides, density and water-holding ability of clots, which means the consistency of the product is to a certain extent determined by the ability of the starter bacteria to produce exopolysaccharides. Microbial polysaccharides are represented by a wide range of polymers, the most diverse in composition, structure, type of bonds.

To obtain finished products with specified quality indicators, it is necessary to use starter cultures with a stable set of characteristics.

At the initial stage of research, the biotechnological potential of various strains of Lactococcus lactis subspecies Cremoris was studied. The results are presented in table 2.

table 2 Biotechnological potential of various strains of Lactococcus lactis subsp cremoris Indicators Strain characteristics L. cremoris 18P L. cremoris T-18-20 L. cremoris 24 ₄ Appearance and Consistency Homogeneous, tender, moderately viscous, glossy clot surface Homogeneous, moderately viscous, glossy clot surface Homogeneous dense, viscous, glossy clot surface Taste and Aroma Pure tender sour milk Pure fermented milk Pure sour-milk, delicate creamy aftertaste Fermentation activity, h 12-14 10-12 10-12 Acidity Titratable, ° T 68-70 72-74 70-72 Active pH 4.99 ± 0.05 4.96 ± 0.01 4.98 ± 0.03 Cell growth when 20% bile + + + 40% bile ± ± ± 2% aCl + + + pH = 4.5 + + + Phenol resistance + + + Adhesive activity: SPA * 3.48 3.36 3.68 KUE,% ** 85 84 86 I AM*** 4.14 ± 1.1 4.08 ± 0.06 4.28 ± 1.12 Notes: SPA * - average rate of adhesion; KUE ** - the participation coefficient of red blood cells; IAM *** - microorganism adhesion index; “-” - lack of growth; "±" - small growth (10 ⁵ -10 ⁶ cfu / cm ³ ); "+" - active growth (10 ⁸ -10 ⁹ cfu / cm ³ )

From the data of table 2 shows that the strains of L. Cremoris have a pronounced biochemical activity. Ferments are characterized by good organoleptic characteristics. The resistance of the studied cultures to various concentrations of bile, sodium chloride and phenol was revealed. The studied strains are highly adhesive; the strain L. cremoris 24 ₄ , which also has the highest exopolysaccharide potential, showed the maximum ability for the adhesive process.

In the next series of experiments, the biotechnological potential of bifidobacteria and propionic acid bacteria was studied. The results are presented in tables 3 and 4.

Table 3 Biotechnological potential of propionic acid bacteria Indicators Strain characteristics R. Freudenreichii AC-2500 R. cyclohexanicum Kusano AC-2560 R. shermanii AC-2503 Appearance and Consistency Homogeneous liquid Homogeneous thick Homogeneous thick, moderately viscous Taste and Aroma Pure fermented milk Pure fermented milk Pure fermented milk slightly spicy Acidity: Titratable, ° T 76 ± 2 70 ± 2 72 ± 2 Active pH 4.64 ± 0.03 4.98 ± 0.01 4.92 ± 0.01 The number of viable cells, CFU / cm ³ 3 · 10 ⁹ 1 · 10 ⁹ 5 · 10 ⁹ Cell growth when 20% bile + + + 40% bile ± ± ± 2% NaCl ± + + 4% NaCl ± ± + pH = 4,5 ± ± + Phenol resistance ± ± + Adhesive activity: SPA 3.2 3.9 4.6 KUE,% 79 82 85 I AM 4 ± 1,5 3.7 ± 1.8 5.4 ± 1.1

From the data of table 3 it follows that all strains of propionic acid bacteria have high biochemical activity, as evidenced by the rapid fermentation of milk and the maximum number of viable cells 10 ^9-10 cfu / cm ³ . The studied cultures showed resistance to a high concentration of bile, sodium chloride and developed in a medium with a low pH value, which indicates a high survival rate of these cultures in the human gastrointestinal tract. It should be noted that P. shermanii AC-2503 has the highest biotechnological potential.

The biotechnological potential of bifidobacteria is presented in table 4.

Table 4 Biotechnological potential of bifidobacteria Indicators Strain characteristics B. longum DK-100 B. bifidum 8 ₃ Bifidobacterium longum B 379M Appearance and Consistency Homogeneous liquid Homogeneous, moderately liquid Homogeneous, moderately liquid Taste and Aroma Pure, delicate sour milk Pure tender, sour milk Pure tender, sour milk Acidity Titratable, ° T 63 ± 2 67 ± 2 65 ± 2 Active pH 4.99 ± 0.03 4.98 ± 0.02 4.98 ± 0.01 The number of viable cells, CFU / cm ³ 2 * 10 ⁹ 4 * 10 ⁹ 3 * 10 ⁹ Cell growth when 20% bile + + + 40% bile + + + 2% NaCl + + + 4% NaCl + + + pH = 4.5 Phenol resistance + + + Adhesive activity: SPA 4.3 3.3 3.8 KUE,% 84 82 90 I AM 4.1 4.22 3.42

An analysis of the results showed that the studied strains of bifidobacteria have a fairly high biochemical activity, as evidenced by the rapid fermentation of milk and a significant number of viable cells in the starter cultures - 10 ⁹ cfu / cm ³ . Ferments based on activated cultures of bifidobacteria are characterized by good organoleptic characteristics. It was noted that strain B. bifidum 8 ₃ when ripening forms a denser clot in comparison with B. longum DK-100.

Based on the studies, strains of Bifidobacterium bifidum 8 ₃ , Lactococcus lactis subspecies cremoris 24 ₄ and Propionibacterium freudenreichii subsp were selected to create a consortium of probiotic microorganisms. shermanii AC-2503 with high exopolysaccharide and biotechnological potential.

When creating a consortium of bifidobacteria, lacto- and propionic acid bacteria, it is necessary to select the optimal cultivation parameters at which mutual stimulation, balanced growth and stable equilibrium of the selected cultures, as well as preservation of the production-valuable properties of each representative of the microbial association, are observed.

The difficulty in compiling a consortium of starter cultures in this case lies in the fact that the cultures that make up the starter culture need different temperature optima and have an uneven reproduction rate. Considering the various optimal development temperatures of L. cremoris 24 ₄ - 25-27 ° С, propionic acid bacteria - 30 ° С, bifidobacteria - 36-38 ° С, it was necessary to select the conditions for the joint cultivation of these microorganisms in a symbiotic sourdough.

When choosing strains, the stability of technological and functional properties, such as organoleptic properties, the ability to accumulate biomass, the ability to form viscous clots through the synthesis of exopolysaccharides, and also the compliance with the criteria for probiotic microorganisms, were taken into account.

Cultures of L. cremoris, bifidobacteria and propionic acid bacteria were cultured at 30 ° C, 35 ° C, 37 ° C (see figure 1).

As can be seen from figure 1 at an intermediate temperature of 35 ° C, the values of the specific growth rates of the studied microorganisms approach, therefore, at this temperature there will be a uniform development of the selected strains in the association.

The optimal ratio of microorganisms in the consortium was chosen taking into account the balanced growth of cultures and organoleptic indicators of clots. The results are shown in table 5.

Table 5 The choice of crop ratios in the combined sourdough Indicators Ratio B. Bifidum 8 ₃ : L. Cremoris 24 ₄ : P. Shermanii AC-2503 20:30:50 20:40:40 40:30:30 Consistency and appearance Uniform, viscous Uniform, viscous Homogeneous, moderately viscous, dense Taste and Aroma Pure, sour-milk, spicy Pure, sour milk Delicate, clean, sour milk Fermentation activity, h 10-12 10-12 10-12 Acidity, ° T 74-76 74-76 70-72 The titer of viable cells, CFU / cm ³ B. bifidum 83 3 * 10 ⁸ 8 * 10 ⁸ 5 * 10 ⁹ L. cremoris 244 3 * 10 ⁹ 6 * 10 ⁹ 3 * 10 ⁹ P. shermanii 6 * 10 ⁹ 5 * 10 ⁹ 4 * 10 ⁹ The content of VFA, mg / 100 g 3.2 3.6 3.8

The data in table 5 indicate that a balanced growth of all microorganisms is observed with a ratio of B. Bifidum 8 ₃ : L. Cremoris 244: P. Shermanii AC-2503, equal to 40:30:30. In this case, the clot is characterized by a moderately viscous consistency and high organoleptic characteristics. Good compatibility and strong symbiotic relationships are evidenced by the high density of crop populations, which guarantees the stability of the microbial consortium.

The selected cultivation conditions for a consortium of probiotic microorganisms provide high biochemical activity and good organoleptic characteristics of the combined starter culture.

Sourdough is a fundamental quality factor in the production of sour cream. It is the starter cultures that give the product the most characteristic features - viscosity, clot structure, texture, flavor, and also determine the stability of quality indicators during storage.

The structure and consistency of fermented milk products largely depend on the ability of starter cultures to produce extracellular polysaccharides.

According to published data, the synthesis and qualitative composition of bacterial exometabolites depend on cultivation conditions. It is known that during the cultivation of Bifidobacterium longum B379M and Propionibacterium freudenreichii subsp. shermanii strain KM 186 on a nutrient medium with the addition of sodium selenite increases the viscosity of the culture fluid and increases the concentration of exopolysaccharides (RU No. 23333655, A23C 9/12, A23L 1/304, C12N 1/18, September 20, 2008). As for lactococci, such information is not available in the literature. In addition, it was found that the synthesis of biologically active substances depends on the species and strain affiliation.

Therefore, at the next stage, the effect of various doses of sodium selenite on the biosynthesis of exopolysaccharides (EPS) by probiotic microorganisms was studied. The research results are presented in figure 2.

As can be seen from the data presented in figure 2, the addition of sodium selenite to the nutrient medium stimulates the synthesis of exopolysaccharides. The greatest increase in exopolysaccharides is observed in the range of sodium selenite concentrations from 30 to 50 μg / ml. A further increase in selenite concentration of more than 50 μg / ml does not lead to a significant increase in exopolysaccharides. An interesting fact is that an increase in the concentration of sodium selenite in the nutrient medium does not inhibit the growth of microorganisms, and the number of viable cells at the end of cultivation is (10 ¹⁰ -10 ¹¹ ) cfu / cm ³ . This indicates a high resistance of microorganisms to sodium selenite. Resistance to bacteria selenium may be due to the presence of polysaccharides associated with cells that prevent the entry of selenium into cells, which are then released into the medium. From the literature it is known about the protective biological functions of the EPS of microorganisms, which play a major protective role, since they act much faster compared to inducible defense systems.

As a result of the studies, the optimal dose of sodium selenite of 30-50 μg / ml was selected, which ensures a high amount of exopolysaccharides and active growth of microorganisms.

Further studies examined the growth of biomass and the synthesis of EPS during co-cultivation of B. Bifidum 8 ₃ , L. Cremoris 24 ₄ , and P. Shermanii AC-2503, taken in a ratio of 40:30:30 on nutrient medium with the addition of sodium selenite in an amount of 30 mcg / ml. The research results are presented in figure 3 and 4.

As can be seen from the data presented in figure 3, the synthesis of exopolysaccharides by cultures of combined starter culture begins in the early stages of growth and continues throughout the cultivation period. The maximum amount of exopolysaccharides was observed in the stationary phase of growth and amounts to 39.6 μg / ml.

When co-culturing cultures of B. Bifidum 8 ₃ , L. Cremoris 24 ₄ and P. Shermanii AC-2503 on a nutrient medium with sodium selenite, balanced growth of microorganisms was noted and the number of viable cells after 20 hours of cultivation was (10 ¹⁰ -10 ¹¹ ) cu / cm ³ (figure 4).

It should be noted that exopolysaccharides play an important role in the formation of symbiotic systems. Thus, the data available in the literature indicate that the recognition and primary contacts of symbionts occur due to the interaction of polysaccharides of the bacterial cell surface, which provide high adaptive, physiological resistance of microorganism cells.

When studying the morphology of microorganisms at various concentrations of sodium selenite, it was noted that with an increase in sodium selenite, an accumulation of cells (cohesion) is observed. The same dynamics is characteristic during cultivation of a consortium of microorganisms (figure 5).

The data presented in Fig. 5 indicate that, when microorganisms are co-cultured in an environment with sodium selenite, microcolonies are formed, which ensures high survival when exposed to adverse environmental factors. Probably, in the conditions of intercellular contacts, by means of aggregation, the cells maintain their vital activity.

Thus, as a result of the studies, it was found that the introduction of sodium selenite into the nutrient medium allows one to increase the synthesis of exopolysaccharides and strengthen the symbiotic relationships between probiotic bacteria, which increases the production-valuable properties of the consortium.

To determine the dose of frozen bacterial concentrate during the production of sour cream, a series of experiments was conducted to study the biochemical activity of the concentrate. As a result, it was found that one bottle containing 5 ml (5 activity units) of direct starter culture is capable of fermenting 200 kg of cream in (12-14) hours at a temperature of 35 ° C. Frozen bacterial concentrate was used to ferment cream.

Sour cream is characterized by good organoleptic characteristics and contains a high number of viable cells of probiotic bacteria. Sour cream refers to structured dispersed systems. A characteristic feature of sour cream is that its viscous properties undergo significant changes not only with a change in the temperature of the product, but also with a change in the shear rate gradient that occurs with various types of mechanical impact on the product.

Studies of the effective viscosity of the destroyed structure of the experimental sample of sour cream were carried out on a rotational viscometer at a temperature of 20 ° C. Sour cream fermented with a bacterial concentrate without the addition of sodium selenite was used as a control sample. The results are presented in Fig.6.

As can be seen from the data of Fig.6, the viscosity of the experimental sample of sour cream is 15% higher than in the control sample. With increasing spindle speed and mechanical stress, a decrease in effective viscosity is observed. In the experimental sample of sour cream, the viscosity loss is 60.27, in the control - 73.87%.

Thus, the structure of the prototype of sour cream is more resistant to mechanical stress, so the consistency of the product will be less affected by technological factors.

The shelf life of a food product is an indicator of high quality. Preservation of organoleptic characteristics, biological and nutritional value over a certain period of time ensures the functional effectiveness of the probiotic product and its competitiveness. When storing foods containing a significant amount of fat, lipids change with the formation of substances that reduce nutritional value and dietary quality. This must be taken into account when determining the expiration dates of sour cream.

Therefore, in the next series of experiments, changes in the quality characteristics of sour cream during storage were investigated. Samples of sour cream of 15% fat were stored at a temperature of (4 ± 2) ° С. As you know, the conversion of milk fat mainly occurs as a result of enzymatic hydrolysis and oxidation under the influence of atmospheric oxygen. To determine the intensity of these processes in the studied samples, the values of acid and peroxide numbers were determined. The results are presented in Fig.7 and 8.

As can be seen from the data of Fig.7, in the control sample noted a higher rate of formation of free fatty acids and peroxides. The values of the acid number at the initial stage in the samples differ slightly, since at first there is an accumulation of free fatty acids that form the taste and aroma of sour cream. Increased hydrolysis with a further increase in the concentration of free fatty acids leads to the oxidation of the liberated unsaturated fatty acids with atmospheric oxygen with the formation of ketones and aldehydes, which worsen the organoleptic characteristics of the product.

The peroxide value in the prototype is lower than in the control (see Fig. 8). This can be explained by the fact that in the experimental sample of sour cream, a high number of viable cells of starter microorganisms is preserved, which have their own antioxidant defense mechanism through the synthesis of enzymes and antioxidant properties of the residual amount of selenium. The combined effect of these factors leads to a decrease in the rate of oxidative processes in the experimental sample of sour cream.

The totality of the data obtained indicates that sour cream produced using a bacterial concentrate has good organoleptic, rheological characteristics, high exopolysaccharide potential and is characterized by increased storage stability.

The inventive method is as follows.

To prepare a nutrient medium, whey is clarified, growth components are added and 30-50 μg / ml sodium selenite is added, sterilized, cooled, 5% of the inoculum of a microorganism consortium consisting of Bifidobacterium bifidum 8 ₃ , Lactococcus lactis subspecies cremoris 24 ₄ , Propionibacteriumpuden, are added. shermanii AC-2503, taken in the ratio of 40:30:30, increase the biomass for 20-22 hours under conditions of periodic cultivation with a single neutralization of the medium after 10 hours to maintain the pH at an optimal level with a solution of sodium carbonate. Then the bacterial mass is separated from the culture fluid by centrifugation. The resulting cell suspension is mixed with a protective medium in a 1: 1 ratio, poured into 5 ml vials, frozen at a temperature of minus 25 ° C, then the vials are sealed with sterile plugs and rolled up with metal caps. Frozen concentrate is stored for up to 8 months at a temperature of minus 18 ° C.

Examples confirming the possibility of carrying out the invention.

Example 1. To prepare a nutrient medium, whey is clarified, growth components are added and 30 μg / ml sodium selenite is sterilized, cooled to 35 ° C, 3% of the inoculum of a consortium of microorganisms consisting of B. bifidum 8 ₃ , L. cremoris 24 _{4 is} added , P. shermanii AC-2503, taken in a ratio of 40:30:30, increase the biomass for 20 hours under conditions of periodic cultivation with a single neutralization of the medium after 10 hours to maintain the pH at an optimal level with a solution of sodium carbonate. Then the bacterial mass is separated from the culture fluid by centrifugation. The resulting cell suspension is mixed with a protective medium in a 1: 1 ratio, poured into 5 ml vials, frozen at a temperature of minus 25 ° C, then the vials are sealed with sterile plugs and rolled up with metal caps. Frozen concentrate is stored for up to 8 months at a temperature of minus 18 ° C.

Example 2. To prepare a nutrient medium, whey is clarified, growth components are added and 50 μg / ml sodium selenite is sterilized, cooled to 35 ° C, 5% of the inoculum of a consortium of microorganisms consisting of B. bifidum 8 ₃ , L. cremoris 24 _{4 are} added , P. shermanii AC-2503, taken in the ratio of 40:30:30, increase the biomass for 22 hours under conditions of periodic cultivation with a single neutralization of the medium after 10 hours to maintain the pH at an optimal level with a solution of sodium carbonate. Then the bacterial mass is separated from the culture fluid by centrifugation. The resulting cell suspension is mixed with a protective medium in a 1: 1 ratio, poured into 5 ml vials, frozen at a temperature of minus 25 ° C, then the vials are sealed with sterile plugs and rolled up with metal caps. Frozen concentrate is stored for up to 8 months at a temperature of minus 18 ° C.

Example 3. For the preparation of sour cream, the cream is normalized to a mass fraction of fat of 15%, then pasteurized at a temperature of 95 ° C for 5-10 minutes, homogenized at a pressure of 8-12 MPa, cooled to a temperature of 35 ° C, fermented with a frozen bacterial concentrate based 5 units activity (5 cm ³ ) per 200 l of cream, stirred for 10-15 minutes and left to ripen to form a clot with an acidity of 55-60 ° T. Duration of ripening is 10-12 hours. After ripening, the product is cooled to 15-20 ° C, stirred, packaged, sent for cooling and ripening, storage at t = (4 ± 2) ° C for no more than 10 days.

Claims (2)

1. A method of obtaining a bacterial concentrate of a consortium of probiotic microorganisms, including the preparation of a nutrient medium, sterilization, cooling, inoculum, biomass, separation of biomass from the culture fluid, mixing with a protective medium in a ratio of 1: 1, filling, capping, freezing, characterized in that sodium selenite is additionally added to the nutrient medium in an amount of 30-50 μg / ml, and a combination starter based on Bifidobacterium bifidum 8 ₃ , Lactococcus lactis subspecies cremoris 24 is used as an inoculum ₄ , Propionibacterium freudenreichii subspecies shermanii AC-2503, taken in the ratio 40:30:30. 2. The method according to claim 1, characterized in that the inoculum is cultured at 35 ° C.

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