JP6978958B2 - Method for producing fermented milk containing bifidobacteria and lactic acid bacteria - Google Patents

Description

The present invention relates to a method for producing fermented milk capable of improving the survivability of bifidobacteria during storage of fermented milk containing bifidobacteria and lactic acid bacteria.

Bifidobacterium spp., Like lactic acid bacteria represented by Lactobacillus spp., Have various effects such as improvement of intestinal flora, improvement of feces, improvement of intestinal function, infection protection, immunostimulation, and cancer prevention. It has been clarified that it has. These bacteria are thought to contribute to human health through the improvement of the intestinal environment.

In order for Bifidobacterium spp. To exert such an effect, it is required to maintain a high viable cell count in products such as fermented milk. However, since bifidobacteria are generally anaerobic bacteria, they have poor survival and die rapidly, especially in the presence of oxygen.

So far, the applicant has used sweet tea essence and the like for products such as fermented milk for the purpose of enhancing the survival of bifidobacteria in products such as fermented milk using the above-mentioned bifidobacteria. It has been reported that it is added to (Patent Document 1).

However, in the fermented milk produced by this method, the bifidobacteria contained therein have a survival rate of about 40% when stored at 10 ° C. for 21 days. In general, it is preferable that the viable cell count of Bifidobacterium spp. Is high at the time of ingestion, and therefore it is desired that the viable cell count is maintained even at the time of storage.

Patent No. 5654824

Therefore, an object of the present invention is to provide a technique for improving the survivability of bifidobacteria during storage of fermented milk containing bifidobacteria.

As a result of diligent research to solve the above problems, the present inventors separately set a predetermined pH for bifidobacteria and lactic acid bacteria when producing fermented milk containing bifidobacteria. We have found that the survival of bifidobacteria during storage of fermented milk can be improved by fermenting them to fermented milk and mixing them to make fermented milk, and completed the present invention.

That is, in the present invention, a culture medium (A) having a pH of 4.3 to 4.7 obtained by inoculating a Bifidobacterium genus bacterium into a medium A containing milk as a main component and culturing it is used.
A culture medium (B) having a pH of 4.8 to 5.4 obtained by inoculating a medium B containing milk as a main component with lactic acid bacteria and culturing the medium B is used.
It is a method for producing fermented milk, which is characterized by mixing.

Further, the present invention is a fermented milk produced by the above-mentioned method for producing fermented milk.
The fermented milk is characterized in that the viable number of Bifidobacterium spp. When stored at 10 ° C. for 21 days is 1 × 10 ^{9 cells / ml or more.}

In the method for producing fermented milk of the present invention, bifidobacteria and lactic acid bacteria are separately fermented to a predetermined pH and mixed to obtain fermented milk, whereby bifidobacteria at the time of storage of fermented milk are obtained. It can improve the survival of Bifidobacterium.

Therefore, the fermented milk produced by the method for producing fermented milk of the present invention can maintain a high viable count of bifidobacteria, which is useful for promoting health, until the product is consumed.

The method for producing fermented milk of the present invention (hereinafter referred to as "the production method of the present invention") is
Bifidobacterium genus bacteria are inoculated into medium A containing milk as a main component and cultured to obtain a culture medium (A) having a pH of 4.3 to 4.7.
A culture medium (B) having a pH of 4.8 to 5.4 obtained by inoculating a medium B containing milk as a main component with lactic acid bacteria and culturing the medium B is used.
It is a method characterized by mixing.

The medium A used in the production method of the present invention is a medium containing milk as a main component, and the medium is not particularly limited as long as it can cultivate Bifidobacterium spp., For example, milk or skim milk powder solution. , A medium using one or more selected from a whole milk powder solution and a whey powder solution. In addition, these media include milk-derived peptides such as milk peptides and whey peptides, plant-derived extracts such as sweet tea extract, culture aids such as yeast extract, and / or glucose, fructose, oligosaccharides and the like (Bifizus). Sugars (which can be assimilated into fungi or lactic acid bacteria) may be appropriately contained.

The bacterium belonging to the genus Bifidobacterium used in the production method of the present invention is not particularly limited, and for example, Bifidobacterium longum, Bifidobacterium mongolianse, Bifidobacterium breve, Bifidobacterium bifidam, and bi. Examples thereof include Fidobacterium pseudocatenuratam, Bifidobacterium animalis, and Bifidobacterium lactis. Among these Bifidobacterium spp., Bifidobacterium breve, Bifidobacterium bifidam, Bifidobacterium pseudocatenuratam, Bifidobacterium animalis, and Bifidobacterium lactis are preferable. In addition, one or more of these bifidobacteria can be used.

Particularly preferred as the Bifidobacterium genus bacterium used in the production method of the present invention are Bifidobacterium Breve YIT12272 (FERM BP-11320, Contract date: February 16, 2010), Bifidobacterium Bifidum YIT10347. (FERM BP-10613, Contract date: June 23, 2005). All of these bifidobacteria and lactic acid bacteria described below have a deposit number listed at the National Institute of Technology and Evaluation Patent Organism Deposit Center (Kazusakamatari, Kisarazu City, Chiba Prefecture, Japan 292-0818). It has been deposited at 2-5-8, Room 120).

In the production method of the present invention, the above-mentioned medium A is inoculated with Bifidobacterium spp. And cultured to pH 4.3 to 4.7, preferably 4.3 to 4.5 to obtain a culture solution (A). Just do it. Therefore, the conditions for culturing the bifidobacteria are not particularly limited, but for example, the amount of the bifidobacteria is 0.1 to 4% by mass (hereinafter referred to as "%") with respect to the medium A. Examples thereof include conditions for inoculating and stirring and culturing the medium in an atmosphere of 32 to 40 ° C. or a nitrogen atmosphere.

When inoculating the above-mentioned medium A with a bacterium belonging to the genus Bifidobacterium, it is preferable to inoculate the lactic acid bacterium together with the bacterium belonging to the genus Bifidobacterium. The lactic acid bacterium inoculated into the medium A is not particularly limited, and examples thereof include Streptococcus thermophilus, Lactobacillus delbrucky subspecies bulgaricus, Lactococcus lactis, and Lactococcus cremoris. Among these lactic acid bacteria, Lactococcus lactis is preferable. Lactococcus lactis YIT2027 (FERM BP-6224, contract date: February 10, 1997) is particularly preferable as the lactic acid bacterium used in the production method of the present invention. In addition, one or more of these lactic acid bacteria can be used. When the lactic acid bacterium is inoculated into the medium A, it may be inoculated in an amount of 0.001 to 0.5%.

The medium B used in the production method of the present invention is a medium containing milk as a main component, and the medium is not particularly limited as long as it can cultivate lactic acid bacteria, but for example, milk, skim milk powder solution, whole milk powder solution, etc. Examples thereof include a medium using one or more selected from whey powder solutions. In addition, these media include milk-derived peptides such as milk peptides and whey peptides, plant-derived extracts such as sweet tea extract, culture aids such as yeast extract, and / or glucose, fructose, oligosaccharides and the like (lactic acid bacteria). Sugars (which can be assimilated into) may be appropriately contained.

The lactic acid bacterium to be inoculated into the medium B used in the production method of the present invention is not particularly limited, and is, for example, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus plantarum, Streptococcus thermophilus, Lactobacillus delbrucky. Examples include Subspecies Bulgalix, Lactococcus lactis, Lactococcus cremoris and the like. Among these lactic acid bacteria, Streptococcus thermophilus, Lactobacillus delbrucky subspecies bulgarix, Lactococcus lactis, and Lactococcus cremoris are preferable. In addition, one or more of these lactic acid bacteria can be used.

Particularly preferable as the lactic acid bacterium to be inoculated into the medium B used in the production method of the present invention is Streptococcus thermophilus YIT2021 (FERM BP-7537, contract date: November 1, 1996).

In the production method of the present invention, the above-mentioned medium B may be inoculated with lactic acid bacteria and cultured to a pH of 4.8 to 5.4, preferably 4.9 to 5.3 to obtain a culture solution (B). Therefore, the conditions for culturing lactic acid bacteria are not particularly limited, but for example, lactic acid bacteria are inoculated into medium B in an amount of 0.0001 to 0.01%, and this is statically cultured at 28 to 35 ° C. in an air atmosphere. Conditions to be used are mentioned.

In the production method of the present invention, in preparing and culturing the above-mentioned medium, operations such as homogenization of the medium and the culture medium and sterilization may be appropriately performed in the production of normal fermented milk.

Fermented milk is obtained by mixing the culture solution (A) and the culture solution (B) obtained as described above. The pH of the fermented milk after mixing is not particularly limited, but is 4.5 to 5.2, preferably 4.6 to 5.1. In order to adjust the pH of the fermented milk after mixing within the above range, the mixing ratio of the culture solution (A) and the culture solution (B) may be appropriately adjusted, and if necessary, citric acid, malic acid, acetic acid, etc. An acid such as lactic acid or an alkali such as baking soda or potassium carbonate may be used. The mixing ratio of the culture solution (A) and the culture solution (B) is not particularly limited, but may be, for example, 1: 9 to 8: 2, preferably 2: 8 to 7: 3, and more preferably 3. : 7 to 6: 4 may be used.

This fermented milk contains, if necessary, sugars (sucrose), trehalose, glucose, fructose, galactose, psicose and other sugars, polysaccharide alcohols such as maltitol, lactitol, palatinit, xylitol, yogurt, citrus, vanilla, milk and the like. Perfume, pectin, sodium carboxycellulose, soybean polysaccharide, sodium alginate, welan gum, succinoglycan, stabilizers such as gelatin, thickening polysaccharides such as gellan gum, guagam, xanthan gum, ascorbic acid, vitamin B group, tocopherol, etc. It may contain arbitrary components added to ordinary fermented milk, such as vitamins, sucralose, stevia, acesulfam potassium, high-sweetness sweeteners such as aspartame, and the like. Further, the form of the fermented milk is not particularly limited, and may be a beverage such as a fermented milk, a dairy product lactic acid bacteria beverage, or a food containing milk as a main raw material, which is specified by an ordinance of the Ministry of Milk, etc.

The fermented milk of the present invention thus obtained may be anaerobically filled in a container to obtain a product. The viable cell count of Bifidobacterium spp. When stored at 10 ° C. for 21 days is 1 × 10 ⁹ cells / ml or more, preferably 1.2 × 10 ⁹ cells / ml or more. In addition, the initial viable cell count of Bifidobacterium spp. Before storage is 1.2 × 10 ^{9 to} 2.3 × 10 ⁹ cells / ml, preferably 1.6 × 10 ⁹ to 2. .3 × 10 ⁹ pieces / ml. In addition, the survival rate of Bifidobacterium spp. When stored at 10 ° C. for 21 days is 50% or more, preferably 60% or more, more preferably 70% or more, still more preferably 80. % Or more. The viable cell count is measured in the TOS medium, and the survival rate is determined by the formula described in the examples.

Since the fermented milk of the present invention contains a large amount of Bifidobacterium spp. Even during storage, ingestion of this is useful for improving health.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Example 1
Preparation of fermented milk:
Milk peptide (CE90GMM, manufactured by Nippon Shinyaku Co., Ltd.) and sweet tea extract (YTX-13, manufactured by Yakult Materials Co., Ltd.) were added to a 22% skim milk powder aqueous solution at 0.1% and 0.2%, respectively, and dissolved. , The culture medium a was prepared by heat sterilizing at 120 ° C. for 3.5 seconds. 2% of Bifidobacterium Breve YIT12272 starter (live starter count: 1.2 × 10 ⁹ cfu / ml) and Lactococcus lactis YIT2027 starter (live starter count: 1.5) in this medium. × 10 ⁹ cfu / ml) was inoculated at 0.01%, and the mixture was stirred and cultured in an air atmosphere at 37 ° C. until the pH became 4.4 (acidity was 23) to obtain 160 g of the culture solution (a).

On the other hand, an aqueous solution of 7% whole milk powder and 13% skim milk powder was sterilized by heating at 120 ° C. for 3.5 seconds to prepare a culture medium b. Starter of Streptococcus thermophilus YIT2021 to the medium (viable count of ^{starter: 1.3 × 10 9 cfu / ml} ) pH at 0.0001% inoculum to 32 ° C. 5.1 (acidity 6.3) The static culture was carried out until 436 g of the culture solution (b) was obtained.

The total amounts of the culture solution (a) and the culture solution (b) were homogenized at 15 MPa and mixed to obtain a mixed solution (pH 4.8). This mixed solution was mixed with 402 g of a syrup aqueous solution containing 10% sugar, 0.003% sucralose, 1% sodium carboxymethyl cellulose and 0.06% gellan gum and 2 g of yogurt flavor to obtain 1000 g of fermented milk. This was sealed in a glass test tube with a butyl rubber stopper and anaerobically filled to obtain the product of the present invention.

Comparison example 1
Preparation of fermented milk:
The same culture medium a as in Example 1 was inoculated with 2% of the starter of Bifidobacterium Breve YIT12272 and 0.01% of the starter of Lactococcus lactis YIT2027, and the pH was 4.8 at 37 ° C. (acidity was 14). ) Was carried out by stirring to obtain 160 g of the culture solution (a'). Moreover, 436 g of the culture solution (b) was obtained in the same manner as in Example 1.

The total amounts of the culture solution (a') and the culture solution (b) were homogenized at 15 MPa and mixed to obtain a mixed solution (pH 5.0). This mixed solution was mixed with 402 g of the same syrup aqueous solution and 2 g of yogurt flavor as in Example 1 to obtain 1000 g of fermented milk. This was sealed in a glass test tube with a butyl rubber stopper and anaerobically filled to obtain a comparative product.

Comparison example 2
Preparation of fermented milk:
160 g of the culture solution (a') was obtained in the same manner as in Comparative Example 1. Further, 436 g of the culture solution (b) was obtained in the same manner as in Example 1.

The total amounts of the culture solution (a') and the culture solution (b) were homogenized at 15 MPa and mixed (pH 5.0), and the pH was further adjusted to 4.8 with lactic acid to obtain a mixed solution. This mixed solution was mixed with 402 g of the same syrup aqueous solution and 2 g of yogurt flavor as in Example 1 to obtain 1000 g of fermented milk. This was sealed in a glass test tube with a butyl rubber stopper and anaerobically filled to make a comparative product.

Trial example 1
Preservation test:
Measure or calculate the pH, acidity, viable cell count, and survival rate of the product of the present invention of Example 1 and the comparative products of Comparative Example 1 and Comparative Example 2 at the time of manufacture (storage days 0 days) and at 10 ° C. And it is shown in Table 1. The pH and acidity were measured according to a conventional method. The viable cell count was measured using a TOS medium (manufactured by Yakult Pharmaceutical Co., Ltd.), and the survival rate of Bifidobacterium spp. After storage was calculated by the following formula.

[Number 1]
Survival rate (%) = number of viable bacteria after storage ÷ number of viable bacteria at the time of manufacture x 100

In addition, the flavors of the product of the present invention of Example 1 and the comparative products of Comparative Example 1 and Comparative Example 2 were evaluated by the following evaluation criteria by a panel of three skilled persons, and graded, and the total of the scores of all the panels was used. The average value was calculated. The results are shown in Table 1.

<Flavor evaluation criteria>
Score: Content 0: No difference in acidity from 0th day of storage 1: Slight difference in acidity from 0th day of storage 2: Difference in acidity from 0th day of storage 3: With 0th day of storage There is a considerable difference in the acidity of

The product of the present invention of Example 1 is a product of Comparative Example 1 and Comparative Example 2 by mixing a culture solution in which a bacterium belonging to the genus Bifidobacterium is cultured to a pH of 4.4 and a culture solution in which a lactic acid bacterium is cultured to a pH of 5.1. It was found that the viable count and survival rate of Bifidobacterium spp. During storage of fermented milk were higher than those of the comparative product, and that the acidity and pH were also less changed.

Example 2
Preparation of fermented milk:
Whey peptide (LE80GF-US, manufactured by Nippon Shinyaku Co., Ltd.) and sweet tea extract (YTX-13, manufactured by Yakult Materials Co., Ltd.) were added to a 14% skim milk powder medium at 0.06% and 0.2%, respectively. The culture medium c was prepared by dissolving and sterilizing by heating at 120 ° C. for 3.5 seconds. This medium is inoculated with 4% of a starter of Bifidobacterium Bifidum YIT10347 (live cell count of starter: 5.3 × 10 ⁸ cfu / ml), and the pH becomes 4.6 (acidity 13) at 37 ° C. The cells were statically cultured in an air atmosphere until 300 g of the culture solution (c) was obtained.

230 g of the culture solution (b) was obtained in the same manner as in Example 1.

300 g of the culture solution (c) and 230 g of the culture solution (b) were homogenized at 15 MPa and mixed to obtain a mixed solution (pH 4.8). This mixed solution was mixed with 468 g of an aqueous syrup solution containing 8% sugar, 0.003% sucralose, 0.9% sodium carboxymethyl cellulose and 0.05% gellan gum and 2 g of yogurt fragrance to obtain 1000 g of fermented milk. This was sealed in a glass test tube with a butyl rubber stopper and anaerobically filled to obtain the product of the present invention.

Example 3
Preparation of fermented milk:
In Example 2, a culture solution (c) was obtained in the same manner except that the amount of whey peptide added to the culture medium c was 0.12%. The pH of this culture was 4.6 and the acidity was 13.

The product of the present invention was obtained in the same manner as in Example 2.

Example 4
Preparation of fermented milk:
In Example 2, a culture solution (c) was obtained in the same manner except that the amount of whey peptide added to the culture medium c was 0.18%. The pH of this culture was 4.6 and the acidity was 13.

The product of the present invention was obtained in the same manner as in Example 2.

Comparison example 3
Preparation of fermented milk:
In Example 2, the culture medium was prepared in the same manner except that the amount of whey peptide added to the culture medium c was 0.12%. This medium is inoculated with 4% of a starter of Bifidobacterium Bifidum YIT10347 (live cell count of starter: 5.3 × 10 ⁸ cfu / ml), and the pH becomes 4.8 (acidity 11) at 37 ° C. The cells were statically cultured in an air atmosphere until 300 g of a culture solution (c') was obtained.

The total amount of the culture solution (c') and the culture solution (b) was homogenized at 15 MPa and mixed (pH 5.0), and the pH was further adjusted to 4.8 with lactic acid to obtain a mixed solution. This mixed solution was mixed with 468 g of the same syrup aqueous solution and 2 g of yogurt flavor as in Example 2 to obtain 1000 g of fermented milk. This was sealed in a glass test tube with a butyl rubber stopper and anaerobically filled to make a comparative product.

Trial example 2
Preservation test:
In the same manner as in Test Example 1, for the products of the present invention of Examples 2 to 4 and the comparative products of Comparative Example 3, the viable cell count and survival rate of the products at the time of manufacture and storage at 10 ° C. were measured or calculated, and the table was obtained. Shown in 2.

It can be seen that the products of the present invention of Examples 2 to 4 have a higher viable count and survival rate of Bifidobacterium spp. During storage of fermented milk than the comparative products of Comparative Example 3.

The method for producing fermented milk of the present invention can be used for producing fermented milk containing Bifidobacterium spp., Which is useful for promoting health.

that's all

Claims (12)

Bifidobacterium genus bacteria are inoculated into medium A containing milk as a main component and cultured to obtain a culture medium (A) having a pH of 4.3 to 4.7.
A culture medium (B) having a pH of 4.8 to 5.4 obtained by inoculating a medium B containing milk as a main component with lactic acid bacteria and culturing the medium B is used.
A method for producing fermented milk, which comprises mixing. Bifidobacterium spp. Are selected from the group consisting of Bifidobacterium breve, Bifidobacterium bifidam, Bifidobacterium pseudocatenulatum, Bifidobacterium animalis and Bifidobacterium lactis. The method for producing fermented milk according to claim 1, wherein the fermented milk is one or more. 2. The method for producing fermented milk according to the description. The method for producing fermented milk according to any one of claims 1 to 3, wherein the culture solution (A) is obtained by inoculating medium A with lactic acid bacteria together with bifidobacteria and culturing the medium A. The method for producing fermented milk according to claim 4, wherein the lactic acid bacterium inoculated into the medium A is Lactococcus lactis. The method for producing fermented milk according to any one of claims 1 to 5, wherein the pH of the fermented milk after mixing the culture solution (A) and the culture solution (B) is 4.5 to 5.2. The method for producing fermented milk according to any one of claims 1 to 6, wherein the viable number of Bifidobacterium spp. When stored at 10 ° C. for 21 days is 1 × 10 ^{9 cells / ml or more.} The method for producing fermented milk according to any one of claims 1 to 7, wherein the initial viable number of Bifidobacterium spp. Is 1.2 × 10 ^{9 to} 2.3 × 10 ^{9 cells / ml.} The method for producing fermented milk according to any one of claims 1 to 8, wherein the survival rate of Bifidobacterium spp. When stored at 10 ° C. for 21 days is 50% or more. A fermented milk produced by the method for producing a fermented milk according to any one of claims 1 to 9.
Fermented milk characterized in that the viable number of Bifidobacterium spp. When stored at 10 ° C. for 21 days is 1 × 10 ⁹ cells / ml or more. The fermented milk according to claim 10, wherein the initial viable number of Bifidobacterium spp. Is 1.2 × 10 ^{9 to} 2.3 × 10 ^{9 cells / ml.} The fermented milk according to claim 10 or 11, wherein the survival rate of Bifidobacterium spp. When stored at 10 ° C. for 21 days is 50% or more.