RU2555535C1 - Method of protection of fermented milk products against spoilage with fungi - Google Patents

Abstract

FIELD: biotechnology.

SUBSTANCE: method comprises applying to fermented milk products by mixing of liquid culture of strain of propionic acid bacteria Propionibacterium freudenreichii R13-slg RNCIM B-11325 in the amount of 0.5-2.5 vol. % or freeze-dehydrated powder of this culture in an amount of 0.04-0.10 wt %, after which the product storage at 0-4°C for up to 2-3 months, at 20-22°C for up to 30-35 days and at 30-35°C for up to 2-8 days.

EFFECT: enrichment of fermented milk products with viable probiotic cells and vitamin B₁₂ and safety of fermented milk products, which is recorded by the absence of fungal growth, the absence of change of taste, smell, formation of bubbles.

2 dwg, 1 tbl, 23 ex

Description

The invention relates to the field of food biotechnology, and in particular to methods of protecting food products from spoilage by microorganisms using classic (“milk”) propionic acid bacteria.

To protect food from bacterial and fungal spoilage, physical (sterilization and pasteurization), chemical (addition of weak organic acids or antimicrobial compounds of animal, plant and microbial origin) or biological methods (using live bioprotective bacterial cultures) are used [Dalié DKD, Deschamps AM, Richard-Forget F. "Lactic acid bacteria - potential for control of mold growth and mycotoxins: a review." Food control. 2010. V.21. 370-380.]. One of the main advantages of biological methods of product protection over chemical preservatives is their compliance with environmental safety criteria. To prevent product spoilage, the use of lactic acid and classical propionic acid bacteria, in particular strains of Propionibacterium freudenreichii, which are probiotics, is promising. The safety of human Propionibacterium freudenreichii strains is recognized by the European Food Safety Authority (EFSA, http://www.efsa.europa.eu/EFSA/en.html) and the American Food and Drug Administration , USA), and it is listed on the GRAS (Generally Recognized As Safe) list under number: 21 CFR133.195.

A known method for the protection of dairy products using a strain of Lactobacillus delbrueckii ANTI MUFFA (FERM B-19705) [Miyamoto T., Naito Y. "Lactic Acid Bacteria" // United States Patent Application Publication, Pub. No: US 2008/0286406 A1. Pub. Date: Nov. 20, 2008]. However, this method of product protection is effective only against fungi of the genus Penicillum.

A known method of preventing spoilage of dairy products based on a joint culture of Propionibacterium jenseii SM11 and Lactobacillus paracasei subsp. paracasei (strains SM20, SM29 or SM63) free of extracellular metabolites. When introduced in an amount of 10 ¹ -10 ⁷ KOE / ml into the products and stored at 6 ° C, the products may not grow yeast (Candida pulcherrima, Candida parapsilosis and Zygosaccharomyces bailii) and mycelial fungi (Penicillum spp.) For 21 days [ Schweninger MS, Meile, L. "Mixture of Propionibacterium jensenii and Lactobacillus sp. With antimicrobial activities for the use as natural preservation system" // United States Patent 7927639 B2, Date of Patent Apr. 19, 2011]. The disadvantages of this method are the need to store fermented milk products only at low temperatures (in the refrigerator at 6 ° C) and a narrow range of suppressed mushroom species.

Closest to the proposed method, which should be taken as the closest analogue, is a method of protecting dairy products from bacterial and fungal spoilage using the propionic acid bacteria preparation Propionibactrium shermanii strain ATCC 9617 (added in an amount of 0.5-2.5%), which contains live cells of these bacteria [Ayres JW, Sandine WE, Weber GH "Preserving Food Using metabolites of Propionibacteria other than propionic acid" // United States Patent 5096718, Date of Patent Mar. 17, 1992]. The method ensures the absence of mold on the surface of fermented milk products (yogurt) during storage from 7 to 13-20 days at 20-22 ° C, depending on the dose of Propionibactrium shermanii strain ATCC 9617 and from 14 to 30 days at 0-4 ° C. Increasing the dose of the drug leads to a later appearance of fungal colonies on the surface of the yogurt, but accelerates its expansion, the active release of carbon dioxide begins on days 4-13 at storage temperatures of 20-22 ° C and even 0-4 ° C. The disadvantages of the closest analogue are its low efficiency, short shelf life of yogurt, a narrow range of fermented milk products protected from spoilage by mushrooms and the low level or lack of enrichment of fermented milk products with probiotic living cells and vitamin B ₁₂ .

The aim of the present invention is a method of protecting fermented milk products from spoilage by mushrooms, which allows to increase the shelf life of fermented milk products and enrich them with living cells of probiotic bacteria and vitamin B ₁₂ .

The essence of the invention lies in the fact that the new strain of the probiotic Propionibacterium freudenreichii R13-slg (registration number VKPM: B- 11325 ) in an amount of 0.5-2.5 vol. % of a liquid culture or freeze-dried powder of this culture in an amount of 0.04-0.1 (wt.%) is added by stirring into sour-milk products (yogurt, grain curd, cottage cheese, sweet curd mass, “Agusha” type drink) containing spores of various types of fungi and susceptible to mushroom damage, while registering the absence of mushroom spoilage when storing these products at a temperature of 30-35 ° C for at least 2-4 days, at a temperature of 20-22 ° C up to 30-35 days and at 0-4 ° C up to 2-3 months. The protection of fermented milk products is judged by the absence of mushroom growth in products and changes in taste, smell, and the appearance of bubbles in the product. These dairy products contain during the shelf life of living cells of the probiotic (2-9) × 10 ⁷ KOE per 1 g of product and vitamin B ₁₂ - 2.0-4.0 μg per 100 grams of product.

The following materials show the achievement of the goal.

From table 1 it follows that the proposed method achieve a significant increase in the shelf life of fermented milk products (in the absence of the development of damage by fungi and changes in their organoleptic properties), as well as the enrichment of products with live probiotic cells of propionic acid bacteria and vitamin B ₁₂ . Sour-milk products with the introduced strain P. freudenreichii in the proposed method have a titer of living probiotic cells (2-9) × 10 ⁷ KOE per 1 gram of product and also contain vitamin B ₁₂ 2.0-4.0 μg per 100 grams of product.

Table 1 Way Duration of storage of fermented milk products 0-4 ° C 20-22 ° C 30-35 ° C The proposed method 2-3 months 30-35 days 2-4 days The closest analogue 1 month 7-20 days There is no data

The experiments are carried out in 3-fold repetition. The error of the average values is 5-10%.

The figure 1 shows that the introduction of Propionibacterium freudenreichii R13-slg (VKPM B-11325) in the Agusha curd prevents the development of spoilage from various types of fungi when stored at 30 ° C for 96-192 hours, compared with the control curd, to which this probiotic strain is not added.

The strain Propionibacterium freudenreichii R13-slg isolated E.P. Ryzhkovoy from hard natural cheese.

The strain Propionibacterium freudenreichii R13-slg was deposited in the All-Russian Collection of Industrial Microorganisms (VKPM) under the number B-11325.

The strain is identified phenotypically and phylogenetically (by sequence of the 16S rRNA gene) as belonging to the species P. freudenreichii. The level of similarity of the nucleotide sequences of the 16S rRNA gene of P. freudenreichii R13-slg with the typical representatives of the species is at least 99.3%. The 16S rRNA gene sequence (Figure 2) is used to characterize (identify) the strain.

Cultural and morphological characteristics of the strain. A typical cell size is 0.5 × 1-2 μm (longer arcuate rods are found, up to 3-5 μm). Colonies are smooth, convex, shiny, with even edges of a light brown shade with a diameter of 0.8-1.5 mm.

Physiological and biochemical properties of the strain.

The strain grows microaerophilically on liquid media containing one of the sugars: glucose, fructose, lactose. Maltose, sucrose and starch do not ferment. Carries out propionic acid fermentation: the ratio of propionic acid: acetic acid = 2: 1. Active acid formation. The maximum formation of propionates in liquid media is up to 0.92-0.96%. The optimum temperature for growth is 28-30 ° C. Dies at 90 ° C (10 min). Catalopositive. Heat resistant. Forms corrinoids ~ 500-600 mcg / g ASB. Does not restore nitrates. The strain exhibits probiotic significant properties, produces propionicins and exhibits a probiotic effect against the animal organism, i.e. is a probiotic.

The strain is grown on a standard semi-synthetic liquid medium with glucose, peptone (or tryptone - 1.0 g / l) and yeast extract for 72-96 hours. To accumulate the culture, use whey containing lactic acid / lactate (after preparation of the cottage cheese) and corn or yeast extract (0.1%), salts and trace elements. The optimum temperature for growth is 28-30 ° C.

The strain contains liquid glucose-corn medium (GCS) for 3-5 months at 6-10 ° C. The strain is stored in a freeze-dried state for up to 5 years or more or on solid GCS (grown by injection in a “column”, ie anaerobically) for up to 3 years.

The strain is not zoopathogenic and phytopathogenic.

The culture of the strain in a liquid or lyophilized state is introduced into the finished fermented milk product.

Example 1

In a standard package with Agusha curd (Wimm-Bill-Dann, WBD-PEPSI), a liquid culture of P. freudenreichii VKPM B-11325 strain in an amount of 0.5 is added by mixing. vol% and an aqueous suspension of spores of the fungi Aspergillus niger, Penicillium chrysogenum, Saccharomyces cerevisiae, Geotrichum candidum at the rate of 100 spores per 1 gram of product. Only spores of fungi are introduced into the control curd, i.e. do not introduce a strain of the probiotic P. freudenreichii. The products are stored in the refrigerator at a temperature of 0-4 ° C for 3 months and after 14 days, 30 days, 2 months and 3 months, the safety of the Agusha curd is assessed by the absence of mold, bubble formation (foaming), and changes in organoleptic properties. The development of mushrooms in the curd is visually controlled (Figure 1a, b, c - see examples 17 and 18), note the absence or growth of mushroom colonies, foaming, test changes in organoleptic properties - taste and smell.

It is established that the introduction of the strain P. freudenreichii VKPM B-11325 in an amount of 0.5 vol. % prevents mushroom spoilage of the curd for 2 months, does not note the growth of mushrooms, foaming from the formation of bubbles of carbon dioxide, changes in the taste and smell of the product, which significantly exceeds the storage time of dairy products according to the closest analogue (prototype).

The product during this period is a source of probiotic cells in the amount of 2.75 × 10 ⁷ KOE per gram of product, and also contains vitamin B ₁₂ , namely 3.0 μg per 100 g of product, which is significantly higher compared to the control (without making liquid culture of P. freudenreichii).

Example 2

The experiment is carried out according to example 1, but in the curd "Agusha" (enterprise Wimm-Bill-Dann, WBD-PEPSI) contribute by stirring a liquid culture of the strain P. freudenreichii VKPM B-11325 in an amount of 2.5 vol. %

It is established that the introduction of the strain P. freudenreichii VKPM B-11325 in an amount of 2.5 vol. % prevents mushroom spoilage of the curd for 3 months (on days 14, 30 days, 2 and 3 months - they do not note mushroom growth, foaming from the formation of carbon dioxide bubbles, changes in the taste and smell of the product), which significantly exceeds the storage time of fermented milk products in the nearest analogue (table 1).

The product during this period is a source of probiotic cells in the amount of 9.0 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ : 4.0 μg per 100 g of product.

Example 3

The experiment is carried out according to example 1, but the cottage cheese "Agusha" (Wimm-Bill-Dann, WBD-PEPSI) is incubated at room temperature - 20-22 ° C for 1.5 months with an assessment of the safety of the product at 14, 30, 35 and 45 days

It is established that the introduction of a liquid culture of the strain P. freudenreichii VKPM B-11325 in an amount of 0.5 vol. % prevents mushroom spoilage of the curd for 30 days when incubated at 20-22 ° C, don’t notice mushroom growth, foaming from the formation of carbon dioxide bubbles, changes in the taste and smell of the product, which significantly exceeds the storage time of fermented milk products according to the closest analogue (Table 1 )

The product during this period is a source of probiotic cells in the amount of 4.75 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ : 3.0 μg per 100 g of product.

Example 4

The experiment is carried out analogously to example 3, but in the curd "Agusha" (enterprise Wimm-Bill-Dann, WBD-PEPSI) contribute liquid culture P. freudenreichii VKPM B-11325 in an amount of 2.5 vol. %

It is established that the addition of liquid culture P. freudenreichii VKPM B-11325 in an amount of 2.5 vol. % prevents mushroom spoilage of the curd for 35 days when stored at 20-22 ° C (on the 14th, 30th and 35th days they do not show mushroom growth, foaming of the product from the formation of carbon dioxide bubbles, changes in its taste and smell of the product), which significantly exceeds the time preservation of fermented milk products by the closest analogue.

The product during this period is a source of probiotic cells in the amount of 7.75 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ : 3.5 μg per 100 g of product.

Example 5

The experiment is carried out analogously to example 1, but the cottage cheese "Agusha" (enterprise Wimm-Bill-Dann, WBD-PEPSI) is incubated at 30 ° C for 6 days with an assessment of the safety of the product on 1, 2, 3, 4, 5 and 6 days.

It is established that the introduction of a liquid culture of P. freudenreichii VKPM B-11325 in an amount of 0.5 vol.% Prevents mushroom spoilage of the curd for 3 days (on the 1st, 2nd and 3rd day no mushroom growth, foaming from the formation of carbon dioxide bubbles, changes are noted taste and smell of the product) at a storage temperature of 30 ° C.

Example 6

The experiment is carried out analogously to example 2, but the cottage cheese "Agusha" (enterprise Wimm-Bill-Dann, WBD-PEPSI) is incubated at 30 ° C for 6 days with an assessment of the safety of the product on 1, 2, 3, 4, 5 and 6 days.

It is established that the introduction of a liquid culture of P. freudenreichii VKPM B-11325 in an amount of 2.5 vol.% Prevents mushroom spoilage of the curd for 4 days (on the 1st, 2nd, 3rd and 4th day, mushroom growth is not observed, foaming from the formation of carbon dioxide bubbles , changes in the taste and smell of the product) at a storage temperature of 30 ° C.

Example 7

The experiment is carried out analogously to example 5, but the cottage cheese "Agusha" (enterprise Wimm-Bill-Dann, WBD-PEPSI) is incubated at 35 ° C for 6 days with an assessment of the safety of the product on 1, 2, 3, 4, 5 and 6 days.

It is established that the introduction of a strain of P. freudenreichii VKPM B-11325 in an amount of 0.5 vol.% Prevents mushroom spoilage of the curd for 3 days (on the 1st, 2nd and 3rd day no mushroom growth, foaming from the formation of carbon dioxide bubbles, taste changes and product odor) at a storage temperature of 35 ° C.

The product during this period is a source of probiotic cells in the amount of 1.75 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ : 3.5 μg per 100 g of product.

Example 8

The experiment is carried out analogously to example 6, but the cottage cheese "Agusha" (enterprise Wimm-Bill-Dann, WBD-PEPSI) is incubated at 35 ° C for 6 days with an assessment of the safety of the product on 1, 2, 3, 4, 5 and 6 days.

It is established that the introduction of a strain of P. freudenreichii VKPM B-11325 in an amount of 2.5 vol.% Prevents mushroom spoilage of the curd for 4 days (on the 1st, 2nd, 3rd and 4th day no mushroom growth is noted, foaming from the formation of carbon dioxide bubbles, changes in the taste and smell of the product) at a storage temperature of 35 ° C.

Example 9

The experiment is carried out analogously to example 1, but instead of the liquid culture, the powder of the lyophilized dried culture P. freudenreichii VKPM B-11325 in the amount of 0.04% is introduced into the agarusha curd (Wimm-Bill-Dann, WBD-PEPSI) instead of a liquid culture.

It is established that the powder of the lyophilized dried culture P. freudenreichii VKPM B-11325 in an amount of 0.04% prevents mushroom spoilage of the curd for 2 months (no mushroom growth, foaming from the formation of carbon dioxide bubbles, changes in the taste and smell of the product), which is significant exceeds the storage time of fermented milk products by the closest analogue.

The product during this period is a source of probiotic cells in the amount of 3.75 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ : 3.0 μg per 100 g of product.

Example 10

The experiment is carried out analogously to example 9, but curd "Agusha" (enterprise Wimm-Bill-Dann, WBD-PEPSI) contribute powder freeze-dried culture P. freudenreichii VKPM B-11325 in an amount of 0.1%.

It is established that the powder of the lyophilized dried culture P. freudenreichii VKPM B-11325 in the amount of 0.04% prevents fungal spoilage of the curd for 3 months (on day 14, 30 days, 2 and 3 months do not mark the growth of fungi, foaming from the formation of dioxide bubbles carbon, changes in the taste and smell of the product), which significantly exceeds the storage time of fermented milk products by the closest analogue.

The product during this period is a source of probiotic cells in the amount of 5.75 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ : 3.5 μg per 100 g of product.

Example 11

The experiment is carried out analogously to example 9, but in the curd “Agusha” (enterprise Wimm-Bill-Dann, WBD-PEPSI) incubated at room temperature 20-22 ° C for 1.5 months with an assessment of the safety of the product at 14, 30, 35 and 45 days

It is established that the introduction of a dry powder of P. freudenreichii VKPM B-11325 in an amount of 0.04% prevents mushroom spoilage of the curd when stored for 30 days at 20-22 ° C (no mushroom growth, foaming from the formation of carbon dioxide bubbles, taste changes and product odor), which significantly exceeds the storage time of fermented milk products by the closest analogue.

The product during this period is a source of probiotic cells in an amount of 2.0 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ : 2.0 μg per 100 g of product.

Example 12

The experiment was carried out analogously to example 11, but dry powder P. freudenreichii VKPM B-11325 in the amount of 0.1% was added to the Agusha curd (Wimm-Bill-Dann, WBD-PEPSI).

It is established that the introduction of a dry powder of P. freudenreichii VKPM B-11325 in an amount of 0.1% prevents the fungus spoilage of the curd for 35 days when stored at 20-22 ° C (on the 14th, 30th and 35th days no mushroom growth is noted, foaming from the formation of bubbles of carbon dioxide, changes in the taste and smell of the product), which significantly exceeds the storage time of dairy products by the closest analogue.

The product during this period is a source of probiotic cells in the amount of 5.75 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ : 3.5 μg per 100 g of product.

Example 13

The experiment is carried out analogously to example 9, but the cottage cheese "Agusha" is stored at 30 ° C for 6 days with an assessment of the safety of the product on 1, 2, 3, 4, 5 and 6 days.

It is established that the introduction of a dry powder of P. freudenreichii VKPM B-11325 in an amount of 0.04% prevents fungal spoilage of the curd for 2 days (on the 1st, 2nd and 3rd day, mushroom growth, foaming from the formation of carbon dioxide bubbles, taste changes and product odor) at a storage temperature of 30 ° C.

Example 14

The experiment is carried out analogously to example 13, but dry powder P. freudenreichii VKPM B-11325 in an amount of 0.1% is added to the curd "Agusha".

It is established that the introduction of a dry powder of P. freudenreichii VKPM B-11325 in an amount of 0.1% prevents the fungal spoilage of the curd for 3 days (on the 1st, 2nd and 3rd day no mushroom growth, foaming from the formation of carbon dioxide bubbles, taste changes and product odor) at a storage temperature of 30 ° C.

The product during this period is a source of probiotic cells in an amount of 5.75 × 10 ⁷ CFU per gram of product, and also contains more vitamin B ₁₂ : 3.5 μg per 100 g of product.

Example 15

The experiment is carried out analogously to example 13, but the cottage cheese "Agusha" is stored at 35 ° C. It is established that the introduction of a dry powder of P. freudenreichii VKPM B-11325 in an amount of 0.04% prevents mushroom spoilage of the curd for 2 days (no mushroom growth, foaming from the formation of carbon dioxide bubbles, changes in the taste and smell of the product) at a storage temperature of 35 ° C.

Example 16

The experiment is carried out analogously to example 13, but dry powder P. freudenreichii VKPM B-11325 in an amount of 0.1% is added to the curd "Agusha".

It is established that the introduction of a dry powder of P. freudenreichii VKPM B-11325 in an amount of 0.1% prevents mushroom spoilage of the curd for 2 days (on the 1st, 2nd day, mushroom growth, foaming from the formation of carbon dioxide bubbles, changes in the taste and smell of the product are not observed ) at a storage temperature of 35 ° C.

Example 17

The experiment is carried out analogously to example 13, but spores of Aspergillus ochraceus and Penicillum chrysogenum in the amount of 100 spores in 1 ml are added to the Agusha curd (Wimm-Bill-Dann, WBD-PEPSI).

It is established that the dry powder of P. freudenreichii VKPM B-11325 in an amount of 0.04% prevents fungal spoilage of the curd for 4 days (on the 1st, 2nd, 3rd and 4th day no mushroom growth is noted, foaming from the formation of carbon dioxide bubbles (figure 1 ), changes in the taste and smell of the product) at a storage temperature of 30 ° C.

Example 18

The experiment is carried out analogously to example 13, but spores of Penicillium fungi in the amount of 100 spores in 1 ml are added to the Agush curd, and stored at 30 ° C for 10 days.

It is established that the dry powder of P. freudenreichii VKPM B-11325 in an amount of 0.04% prevents fungal spoilage of the curd for 8 days (i.e., during this period no mushroom growth, foaming from the formation of carbon dioxide bubbles are noted (figure 1) , changes in the taste and smell of the product) at a storage temperature of 30 ° C.

That is, with a lower variety of contaminant fungi in fermented milk products, the method allows you to save fermented milk products even longer.

Example 19

The experiment is carried out analogously to example 1, but the liquid culture of P. freudenreichii VKPM B-11325 in an amount of 0.5 vol.% And an aqueous suspension of spores of fungi Aspergillus niger, Penicillium chrysogenum, Saccharomyces cerevisiae at the rate of 10 spores per 1 ml of product are added to the Agusha drink "(Wimm-Bill-Dann, WBD-PEPSI). Only mushroom spores are added to the control curd. Drink with P. freudenreichii VKPM B-11325 and a control drink stored at 30 ° C for 6 days with an assessment of the safety of the product at 1, 2, 3, 4, 5 and 6 days.

It is established that the introduction of P. freudenreichii VKPM B-11325 in an amount of 0.5 vol% prevents mushroom spoilage of the curd for 2 days (no mushroom growth, foaming from the formation of carbon dioxide bubbles, changes in taste, smell of the product of its consistency) are noted at a temperature storage 30 ° C.

Example 20

The experiment is carried out according to example 1, but the liquid culture of P. freudenreichii VKPM B-11325 in an amount of 2.5 vol.% And an aqueous suspension of spores of the fungi Aspergillus niger, Penicillium chrysogenum, Saccharomyces cerevisiae at the rate of 100 spores per 1 ml of product are added to the sweet curd mass (Wimm-Bill-Dann, WBD-PEPSI). Only mushroom spores are added to the control sample of sweet curd mass. The experimental and control samples of the curd mass are stored at 30 ° C for 6 days with an assessment of the safety of the product at 1, 2, 3, 4, 5, and 6 days.

It is established that the introduction of P. freudenreichii VKPM B-11325 in an amount of 2.5 vol.% Prevents fungal spoilage of sweet curd mass for 3 days (on the 1st, 2nd and 3rd day no growth of mushrooms, changes in the taste and smell of the product, its consistency ) at a storage temperature of 30 ° C.

Example 21

The experiment is carried out according to example 20, but the liquid culture of P. freudenreichii VKPM B-11325 in an amount of 2.5 vol.% And an aqueous suspension of spores of the fungi Penicillium sp. at the rate of 2 spores per 1 ml of product, they are added to the grain curd (Wimm-Bill-Dann, WBD-PEPSI).

It is established that the application of P. freudenreichii VKPM B-11325 in an amount of 2.5 vol.% Prevents fungal spoilage of grain curd for 2 days (on the 1st, 2nd and 3rd day no growth of mushrooms, changes in taste and smell of the product are noted) at a storage temperature 30 ° C.

Example 22

The experiment is carried out analogously to example 1, but yogurt (Wimm-Bill-Dann, WBD-PEPSI) is taken and the liquid culture of the strain P. freudenreichii VKPM B-11325 is added in the amount of 0.5% by volume.

It is established that the introduction of the strain P. freudenreichii VKPM B-11325 in an amount of 0.5 vol.% Prevents fungal spoilage of yogurt for 2 months (on day 14, 30 days and 2 months there is no growth of fungi, foaming from the formation of carbon dioxide bubbles, changes in the taste and smell of the product), which significantly exceeds the storage time of fermented milk products according to the closest analogue.

The product during this period is a source of probiotic cells in the amount of 4.75 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ , 3.05 μg per 100 g of product, which is significantly higher compared to the control (without liquid cultures of P. freudenreichii VKPM B-11325).

Example 23

The experiment is carried out analogously to example 22, but no spores of fungi are introduced into the yogurt (Wimm-Bill-Dann, WBD-PEPSI), but the incubation is carried out at 30 ° C for 10 days with a product safety rating of 2, 4, 5, 6, 7, 8, 9, 10 days.

It is established that the introduction of a strain of P. freudenreichii VKPM B-11325 in an amount of 0.5 vol% prevents mushroom spoilage of the curd for 8 days (no mushroom growth, foaming from the formation of carbon dioxide bubbles, changes in the taste and smell of the product), which significantly exceeds the storage time of fermented milk products by the closest analogue.

The product during this period is a source of probiotic cells in the amount of 3.75 × 10 ⁷ KOE per gram of product, and also contains more vitamin B ₁₂ , 2.75 μg per 100 g of product, which is significantly higher compared to the control (without liquid cultures of P. freudenreichii VKPM B-11325).

For all of the above examples, it can be seen that all of the listed fermented milk products are stored longer when using the proposed method in comparison with the closest analogue.

Claims (1)

A method of protecting fermented milk products from spoilage by fungi by introducing propionic acid bacteria into them, characterized in that a liquid culture of the Propionibacterium freudenreichii R13-slg VKPM B-11325 strain in an amount of 0.5-2.5 vol.% Or freeze-dried is added to the fermented milk products the dried powder of this culture in an amount of 0.04-0.10 wt.%, after which, when stored at 0-4 ° C for up to 2-3 months, at 20-22 ° C for 30-35 days and at 30-35 ° C up to 2-8 days, their preservation is recorded by the absence of mushroom growth, the absence of changes in taste, smell, bubble formation and o ogaschenie them viable probiotic cells, and vitamin B _12.

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