RU2242133C2 - Method for manufacturing lactic acid product - Google Patents

Abstract

FIELD: food industry, dairy industry.

SUBSTANCE: The method deals with normalization of dairy raw material by fat followed by thermal treatment, homogenization,cooling up to fermentation temperature, introduction of Bifidobacterium bifidum l biomass at the quantity of 0.1-0.4%, ferment containing lactobacteria at the quantity of 1-3% and ferment Lactobacillus brevis BA-13 N 261 0.05-0.5% against milk volume. Fermentation should be continued till clot formation at 36-39 C and acidity level of 65-70 T followed by mixing, cooling and packaging. The innovation enables to improve quality and increase stability at storing lactic acid products due to decreased and stabilized acidity of the ready-to-use product at storage.

EFFECT: higher efficiency.

3 ex, 3 tbl

Description

The invention relates to the dairy industry, in particular the production of probiotic fermented milk products containing bifidobacteria.

A known method of producing kefir, which includes the process of normalization, homogenization, heat treatment, cooling to the fermentation temperature, making kefir fermentation, fermentation, cooling and bottling, and simultaneously with kefir fermentation or in the process of fermentation in heat-treated and cooled to 22-28 ° C milk make the biomass of bifidobacteria in a certain ratio with kefir yeast (RF patent №2011352, class A 23 C 9/127, 1993).

The disadvantage of this method of preparing a dairy product is a quick change in its quality during storage and sale, primarily associated with excessive increase in acidity. Under these conditions, a rapid death of bifidobacteria is observed, which, in contrast to lactobacilli, is more sensitive to adverse environmental factors, including the effects of organic acids.

A known method of protecting sour-milk products, for example sour cream, from peroxidation during storage caused by the activity of lactic acid bacteria. In production and in trading enterprises, sour cream is cooled to 2-6 ° C (TU 9222-007-16414608-01).

The disadvantage of this method is the high energy consumption for refrigeration equipment.

Also known is a method of protecting fermented milk products from peroxidation during storage by introducing into the products of the drug - nisin (AS USSR, No. 185200, class A 23 C 13/16, 1964).

However, this drug has an antibiotic nature and may have contraindications for use in some consumers.

Closest to the technical nature of the present invention is a method of preparing a fermented milk product such as fermented baked milk, which provides for the normalization of milk raw materials for fat, heat treatment, homogenization, cooling to the fermentation temperature, the introduction of biomass of bifidobacteria and fermentation, consisting of lactic acid bacteria, fermentation to form a clot, mixing , product cooling and bottling. The activation of the lyophilized biomass of bifidobacteria in this method is carried out in sterilized milk at a temperature of 37-38 ° C for 2.5-3 hours in conjunction with part of the starter culture used in the production of fermented baked milk (RF patent No. 2097974, class A 23 C 9/127, 1995).

This method of fermenting milk with activated bifidobacteria has advantages compared with fermenting simply lyophilized biomass of bifidobacteria or production ferment prepared from this biomass, from the point of view of producing fermented milk products with higher titers and with higher survival of bifidobacteria.

The disadvantage of this method is the high acidity of the product (up to 120 ° T at the end of the shelf life). At this level of titratable acidity during storage of fermented milk products, a significant death of bifidobacteria is observed, which reduces the consumer value of functional nutrition products.

The objective of the invention is to improve the quality and increase the shelf life of probiotic fermented milk products by reducing and stabilizing the acidity of the finished product in storage.

The problem is achieved in that in the known method of preparing a fermented milk product, including the normalization of milk raw materials for fat, heat treatment, homogenization, cooling to the fermentation temperature, the introduction of biomass of bifidobacteria and the fermentation, consisting of lactic acid bacteria, fermentation to form a clot, mixing, cooling the product and bottling, a yeast containing Lactobacillus brevis BA-13 strain No. 261 is additionally introduced, and a strain of Bifidobacterium bifidum 1 is used from bifidobacteria, wherein the leaven contains lactic acid bacteria, used in an amount of 1-3%, the biomass of Bifidobacterium bifidum 1 in an amount of 0.1-0.4%, and the leaven Lactobacillus brevis BA-13 No. 261 0.05-0.5% of the volume of milk, fermentation is carried out at a temperature of 36-39 ° C until reaching an acidity of 65-70 ° T.

The method is as follows.

The raw milk raw materials are cleaned on separators-purifiers, normalized by fat, subjected to heat treatment, homogenization, cooling to a temperature of 37-40 ° C, then the normalized milk mixture is fermented with industrial ferment in an amount of 1-3%, used to prepare the corresponding type of fermented milk product ( fermented baked milk, yogurt, yogurt, kefir, etc.), with sourdough, simultaneously introduce the activated biomass of bifidobacteria Bifidobacterium bifidum 1 in an amount of 0.1-0.4% and sourdough Lactobacillus brevis BA-13 No. 261, after which they are fermented at a temperature of 36-39 ° C until the acidity of 65-70 ° T. The activation of the lyophilized biomass of bifidobacteria in this method is carried out on sterilized milk as follows. The biomass of bifidobacteria is aseptically introduced into a container with sterilized milk with a temperature of 37-38 ° C, so that 1 accounting unit (10 ¹¹ CFU) is contained in 1 liter of fermented milk. A closed container with the mixture is thoroughly mixed in circular motions for 5-10 minutes, after which production ferment from lactic acid bacteria is added to it, which is necessary for preparing the appropriate type of product at the rate of 0.002 cm ³ per 1 liter of sterilized milk. The resulting suspension is placed in a thermostat and incubated for 2.5-3 hours at a temperature of 37-38 ° C. Ferment Lactobacillus brevis BA-13 No. 261 contribute in the amount of 0.05-0.5% of the volume of fermented milk. After the formation of a clot of the required acidity, the product is cooled to 6 ° C, after which it is bottled. The finished product has a pleasant soft taste of baked milk, reminiscent of the taste of fermented baked milk, a dense uniform consistency. Active product acidity (pH) is 4.6-4.8 units. The titer of bifidobacteria in the product is 10 ⁶ -10 ⁷ CFU / cm ³ , the content of Lactobacillus brevis BA-13 No. 261 (1-5) × 10 ⁸ CFU / cm ³ . By the end of storage (7 days at a temperature of 4 ± 2 ° C), the pH of the product does not change, the titer of bifidobacteria does not decrease below 10 ⁶ CFU / cm ³ , and the content of Lactobacillus brevis BA-13 No. 261 is at the level of 10 ⁸ CFU / cm ³ ( table 1).

The justification of the fermentation temperature and the used dose of Lactobacillus brevis BA-13 starter culture No. 261 in the proposed method are given in table. 2 and table 3.

Example 1

Normalized milk with a fat content of 4% is subjected to heat treatment at 100 ° C without exposure, cooled to 38 ° C, add fermented milk for fermented milk in an amount of 2%, activated biomass of bifidobacteria in milk in an amount of 0.1% and fermented Lactobacillus brevis BA-13 No. 261 in sterile milk in an amount of 0.5%. Fermentation is carried out at a temperature of 37 ° C until titratable acidity of 65 ° T is achieved. Next, the product is slowly cooled to 6 ° C, after which the bottling is carried out.

The product has a fermented milk taste like fermented baked milk and a dense uniform consistency. 1 cm ^{3 of the} finished product contains 10 ⁷ CFU of bifidobacteria and 5 × 10 ⁸ CFU / cm ^{3 of} Lactobacillus brevis BA-13 No. 261. The product has a pH of 4.8 units. By the end of the shelf life, the pH value does not change, the titer of bifidobacteria is 10 ⁷ CFU / cm ³ , the content of Lactobacillus brevis BA-13 No. 261 3 × 10 ⁸ CFU / cm ³ .

Example 2

Normalized milk with a fat content of 3.2% is subjected to heat treatment at 72 ° C for 20 min, cooled to 40 ° C, make ferment for yogurt in an amount of 2.5%, activated biomass of bifidobacteria in milk in an amount of 0.1% and leaven of Lactobacillus brevis BA-13 No. 261 in an amount of 0.1%. The fermentation of the milk mixture is carried out at a temperature of 39 ° C until a titratable acidity of 68 ° T is reached. Next, the product is slowly cooled to 6 ° C, after which the bottling is carried out. The finished product has a clean sour-milk taste with a taste of fermented baked milk and a dense texture.

1 cm ^{3 of the} finished product contains 10 ⁷ CFU of bifidobacteria and 5 × 10 ⁸ CFU of Lactobacillus brevis BA-13 No. 261. The product has a pH of 4.7 units. By the end of the shelf life, the titer of bifidobacteria is 10 ⁷ CFU / cm ³ , the content of Lactobacillus brevis BA-13 No. 261 1 × 10 ⁸ CFU / cm ³ .

Example 3

Normalized milk with a fat content of 2.5% is subjected to heat treatment at 85 ° C for 10 min, cooled to 37 ° C, make ferment for sour milk in an amount of 1.0%, activated biomass of Bifidobacterium bifidum 1 in milk in an amount of 0.2% and starter culture Lactobacillus brevis BA-13 No. 261 in an amount of 0.05%. Fermentation of the milk mixture is carried out at a temperature of 36 ° C until a titratable acidity of 70 ° T is achieved. After ripening, the product is cooled to 6 ° C, and then bottling is carried out.

1 cm ^{3 of the} finished product contains 10 ⁷ CFU of bifidobacteria and 3 × 10 ⁸ CFU of Lactobacillus brevis BA-13 No. 261. The product has a pH of 4.7 units. By the end of the shelf life, the titer of bifidobacteria is 10 ⁶ CFU / cm ³ , the content of Lactobacillus brevis BA-13 No. 261 1 × 10 ⁸ CFU / cm ³ .

Thus obtained product has a pronounced sour-milk taste, reminiscent of the taste of fermented baked milk, and a dense uniform consistency.

Depending on the type of fermented milk product, the content of bifidobacteria in it is 10 ⁶ -10 ⁷ CFU / cm ³ , and Lactobacillus brevis BA-13 No. 261 (1-5) × l0 ⁸ CFU / cm ³ . Titratable acidity of the product does not exceed 100 ° T at a pH of 4.6-4.8 units. During 7 days of storage at a temperature of (4 ± 2) ° C, the content of lactic acid bacilli Lactobacillus brevis BA-13 No. 261 remains at the same level, and the survival rate of bifidobacteria in comparison with similar fermented milk products in the declared variants is 1-2 orders of magnitude higher, which ensures the titer of bifidobacteria necessary for probiotic products, comprising at least 10 ⁶ CFU / cm ³ (Table 1).

The achieved result was obtained due to the following technological methods:

1) additional use in the composition of the starter microflora of the products of the strain of lactic acid bacilli Lactobacillus brevis BA-13 No. 261, which is also a biological component that protects sour-milk products from peroxidation during storage;

2) use for the fermentation of Lactobacillus brevis BA-13 No. 261 in an amount of 0.05-0.5%;

3) the process of fermentation of milk at a temperature of 36-39 ° C.

Thus, the proposed method allows to obtain fermented milk products containing bifidobacteria (bio-yogurt, bio-sour milk, bio-ethereal and others) with a lower degree of acidification, with a soft taste of baked milk or cream, reminiscent of the taste of fermented baked milk, and bio-fermented milk obtained without appropriate heat treatment (without using traditional for this product, the process of languishing milk for 3-4 hours), with a pronounced typical taste, which, in general, improves the organoleptic characteristics of the claimed products during storage, and also allows you to receive products at the end of the expiration date (7 days) with a titer of bifidobacteria ≥10 ⁶ CFU / cm ³ .

Claims (1)

A method of preparing a fermented milk product like fermented baked milk, including normalization of milk raw materials for fat, heat treatment, homogenization, cooling to fermentation temperature, introducing biomass of bifidobacteria and yeast consisting of lactic acid bacteria, fermentation to form a clot, mixing, cooling the product and bottling, characterized the fact that additionally enter the ferment containing strain Lactobacillus brevis BA-13 No. 261, and from bifidobacteria use the strain Bifidobacterium bifidum 1, while the ferment containing lactic acid b bacteria, used in an amount of 1-3%, biomass of Bifidobacterium bifidum 1 in an amount of 0.1-0.4%, and leaven Lactobacillus brevis BA-13 No. 261 0.05-0.5% of the volume of milk, fermentation is carried out at a temperature 36-39 ° C until the acidity reaches 65-70 ° T.