RU2426437C1 - Method for production of cultured milk product - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: invention is related to dairy industry. The method involves milk standardisation, homogenisation, pasteurisation, cooling, addition of lactulose at a concentration of 2 - 4% of the mixture weight, fermentation and ripening.

EFFECT: invention allows to produce a cultured product with useful prebiotic properties and long storage life with a high level of viable cells of starter population.

3 dwg, 2 ex

Description

The invention relates to the dairy industry and can be used in the production of functional dairy products.

Known methods for producing lactulose-containing dairy products in which lactulose is used as a bifidogenic factor, that is, a substance that stimulates the growth of bifidobacteria, both in the product and in the human body.

The method of production of the Primula drink (RU 2084163, 6А23С 21/02, prior. 06/05/1995, publ. 07/20/1997, bull. No. 20) provides for the introduction of pasteurized chilled milk whey of industrial starter culture and lactulose, which acts as a growth promoter of bifidobacteria in product. This stimulant is obtained by treating the sweetened whey with calcium hydroxide, followed by acidification with acid whey. Next, the mixture is subjected to electrodialysis processing. However, if lactulose is used by bifidobacteria as a growth stimulator during cultivation, then it does not remain in the finished product and will not play the role of a prebiotic in the body, that is, a substance that helps normalize the intestinal microflora.

Another way to obtain a fermented milk drink (RU 2329652, А23С 9/13, prior. 09.11.2006, publ. 07/27/2008, bull. No. 21) provides for the normalization of milk, the introduction of lactulose-containing bifidogenic concentrate in an amount of 1.5-2.5%, homogenization, heating a normalized mixture, adding an additive, mixing, cooling to a fermentation temperature, introducing a fermentation, fermentation and cooling. In this case, the bifidogenic concentrate is used to give the drink organoleptic characteristics characteristic of ryazhenka and prebiotic properties, i.e. it is understood that lactulose is not used by the microflora of the starter culture. However, this method does not address the issues of maintaining the viability of the starter microflora. Currently, this issue is acquiring special significance, since the indicator of the number of lactic acid microorganisms is normalized in all dairy products (Federal Law “Technical Regulations for Milk and Dairy Products”, dated June 12, 2008).

The closest in technical essence to the proposed method is a method for the production of a dairy product (RU 2157639, А23С 9/12, publ. 10/20/2000), which includes preparing a normalized mixture, heating, cleaning, making lacto-lactulose syrup in an amount of 0.3- 0.6%, pasteurization and cooling, the introduction of vitamin and mineral supplements and sourdough. In this method, lactulose is considered as a bifidogenic factor used by bifidobacteria and stimulates their growth, therefore, lactulose does not remain in the product and does not give it useful prebiotic properties.

The technical result of the proposed method is to increase the survival of starter microflora in fermented milk products containing lactulose and having prebiotic activity.

This technical result is achieved by introducing lactulose in a concentration of from 2 to 4% (by weight) in a normalized mixture before its fermentation and fermentation.

The results of the studies showed that some lactic acid microorganisms of starter cultures use lactulose as a nutrient in the cultivation process (up to 50% of the initial content of lactulose). It was found that the level of viability of individual cultures increases, possibly as a result of the formation of a protective polysaccharide layer. Figures 1, 2 and 3 show that under long-term storage at a temperature of 4 ± 2 ° C, lactulose added to the mixture before ripening increases the level of viable starter microflora cells by 11-20% compared with samples without lactulose. The discovered phenomenon allows to increase the shelf life of fermented milk products while maintaining a high level of live cells of starter cultures.

Figure 1 shows the effect of lactulose on the viability of the microflora of the starter culture for sour cream containing Lactococcus lactis subsp. cremoris and Lactococcus lactis subsp. lactis biovar diacetilactis. Fermentation was carried out under generally accepted technological conditions: at a temperature of 30 ± 1 ° C for 6 hours, after which the samples were stored in a refrigerator at a temperature of 4 ± 2 ° C.

Figure 2 shows the effect of lactulose on the viability of the microflora of the starter culture for yogurt containing Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, fermentation was carried out at a temperature of 40 ± 2 ° C for 5 hours, after which the samples were stored in a refrigerator at a temperature of 4 ± 2 ° C.

Figure 3 shows the effect of lactulose on the viability of the probiotic culture of Lactobacillus rhamnosus, fermentation was carried out at a temperature of 37 ° C for 5 hours, after which the samples were stored in a refrigerator at a temperature of 4 ± 2 ° C.

Given that part (50%) of lactulose is used by microorganisms, to give the product a prebiotic effect, an additional concentration of 1 to 2% is recommended, recommended for preventive nutrition. Thus, the total concentration of added lactulose should be at the level of 2-4%.

Example 1. The normalized milk mixture was homogenized and pasteurized at a temperature of 92 ° C for 5 minutes. Next, the mixture was cooled to a fermentation temperature of 42 ° C, lactulose syrup was added at the rate of 2% lactulose in the mixture and yeast for the production of yogurt (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus). Fermentation was carried out at a temperature of 40 ° C for 3 hours to an acidity of 110 ° T.

The resulting product had organoleptic characteristics characteristic of yogurt, the number of lactic acid microorganisms after a week of storage in the refrigerator was 10 ⁹ CFU / cm ³ (for comparison, in a sample without lactulose obtained under the same conditions, 10 ⁷ CFU / cm ³ ), the content of lactulose 1 % Thus, the product retains a high content of viable cells of the starter microflora, in addition, it contains lactulose and has prebiotic properties.

Example 2. The normalized milk mixture was homogenized and pasteurized at a temperature of 92 ° C for 5 minutes. Next, the mixture was cooled to a fermentation temperature of 42 ° C, lactulose syrup was added at the rate of 4% lactulose in the mixture and yeast for the production of yogurt (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus). Fermentation was carried out at a temperature of 42 ° C for 4 hours to an acidity of 115 ° T.

The resulting product had organoleptic characteristics characteristic of yogurt, the number of lactic acid microorganisms after a week of storage in the refrigerator was 10 ¹⁰ CFU / cm ³ , the content of lactulose was 2%. Thus, the product retains a high content of viable cells of the starter microflora, in addition, it contains lactulose and has prebiotic properties.

Claims (1)

A method for the production of a fermented milk product, including milk normalization, homogenization, pasteurization, cooling, lactulose incorporation, fermentation and fermentation, characterized in that lactulose is added in a concentration of from 2 to 4% by weight of the mixture.

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