JP3061331B2 - Fermented milk with low water separation and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a Bifidobacterium longum having a high viscosity-producing ability (Bifidobac
terium longum ) as a starter and a fermented milk with low water separation and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, fermented milk has been produced by inoculating a raw material mix mainly composed of milk with a conventional lactic acid bacterium such as Lactobacillus bulgaricus or Streptococcus thermophilus. Lactobacillus acidophilus or Bifidobacterium, etc., which are established within, are inoculated and used in combination. Intestinal bacteria such as Lactobacillus acidophilus and Bifidobacterium are known to improve the intestinal flora and have an effect on human health and prevention of aging. The fermented milk produced using lactic acid bacteria in this way has an appropriate sourness and good flavor, and also has a good texture because it is curdled by a decrease in pH. However, when this fermented milk is stored for a long time, or when the fermented milk left uneaten is temporarily stored, considerable water separation occurs during storage, not only the appearance becomes unfavorable, but also the original flavor, tissue, Texture cannot be obtained. In order to solve such a problem, a method has been proposed in which a stabilizer such as agar, gelatin, or pectin is added to fermented milk to prevent water separation from the fermented milk. However, the addition of a stabilizer naturally raises a new problem that not only increases the cost but also gives a texture such as a sticky feeling and a stickiness peculiar to the stabilizer.

[0003]

SUMMARY OF THE INVENTION In view of the above problems, the inventors of the present invention have low water separation without adding a stabilizer.
We studied to produce fermented milk with a fine-grained tissue and texture, and found that the above problems could be solved by using Bifidobacterium longum, which has a high viscosity producing ability. Thus, the present invention has been completed. Therefore, an object of the present invention is to provide fermented milk with low water separation using Bifidobacterium longum having a high viscosity-producing ability and a method for producing the same.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a low-separation fermentation obtained by producing a high viscosity in a fermented milk raw material medium using Bifidobacterium longum having a high viscosity-producing ability as a starter. About milk. Further, the present invention provides a medium used as a raw material for fermented milk, inoculated as a starter with Bifidobacterium longum having a high viscosity producing ability, cultivated under conditions where high viscosity occurs, and caused the medium to become viscous and water-separated. The present invention relates to a method for producing fermented milk having a low content.

[0005] The term "Bifidobacterium longum having a high viscosity-producing ability" as used in the present invention refers to a medium containing skim milk (11.53% skim milk, 0.5% yeast extract, 0.03% ascorbic acid). ), When the culture is cultured at 38 ° C. for 16 hours, the spinnability of the culture becomes 8 cm or more. In addition, this spinnability, after sufficiently stirring the culture,
The culture was collected with a 2 ml volume pipette, and the stringing length of the culture dropped from the pipette was measured.

In the present invention, various samples were searched in order to obtain a strain having a high viscosity-producing ability. As a result, a strain having a high viscosity-producing ability was found among strains isolated from adult feces, and Bifidobacterium was found. -Longam SBT2927 strain and Bifidobacterium longum SBT2937 strain were obtained. These strains exhibit the mycological properties of Bifidobacterium longum and have been deposited with the Japan Institute of Micro-Technology as Micro-Technology Bacteria No. 13100 and Micro-Technology Bacteria No. 13101. These strains are specific strains in that acetic acid production is low at a low temperature such as 32 ° C and high viscosity is produced at a high temperature such as 38 ° C. This is based on the new finding that the cells show high viscosity when cultured in. Therefore, the condition under which high viscosity occurs in the present invention means that the culture is performed at such a temperature of about 38 ° C.

Next, the method for separating Bifidobacterium longum having a high viscosity-producing ability of the present invention will be described. Adult feces were homogenized in 9-fold dilution water, serially diluted 10-fold, and the appropriate dilutions were spread on a BL plate medium. After anaerobically culturing the plate at 37 ° C. for 3 days, circular yellow-brown colonies were selected from the resulting colonies. The colonies thus selected were inoculated and cultured in a reduced skim milk medium, and strains having high viscous productivity were selected.

The mycological properties of the highly viscous strain of the present invention are as follows. 1. Taxonomic properties (1) Bacterial form (observation with an optical microscope) When anaerobic culture was carried out using a BL agar plate medium at 37 ° C for 48 to 72 hours by a steel wool method, size: 0.3 to 0.8 x 4 Shape: bacillus polymorphism (club-shaped, Y-shaped, etc.) (2) Gram-stainability Positive when cultured under the same conditions as in (1) above. (3) Morphology of colonies The morphology of colonies when cultured under the same conditions as in (1) above is as follows. Shape: Circular Uplift: Hemispherical uplift Peripheral: Smooth Size: 0.7 to 4 mm in diameter Color: Yellowish brown Surface: Smooth (4) Spore formation: Negative (5) Gas production: None (6) Motility: None (7) Catalase activity: Negative (8) Milk coagulation: Coagulation (9) Gelatin liquefaction: None (10) Nitrate reduction: None (11) Indole production: None (12) Hydrogen sulfide production: None (13) Molar ratio of acetic acid / L (+) lactic acid: 1.5 or more (14) Acetic acid-producing ability: Available (15) Fermentability of sugar Mitsuoka's method [Mitsuoka Tomohashi: Clinical Laboratory, 18 , 1163-1
172 (1974)]. Table 1 shows the results.
Shown in

[0009]

[Table 1]

[0010] From the above properties, SBT2927 of the present invention
Strain and SBT2937 strain were from Bergey's Man
ual of Systematic Bacteri
logic Vol. 2 (1986), according to the Bifidobacterium longum.
acterium longum ).

2. Furthermore, SBT2927 strain and SBT
2937 strain and the conventional Bifidobacterium longum as SBT2928 strain
No.), ATCC 15707 strain and a strain isolated from commercially available fermented milk, the following comparative test was conducted for differences in mycological properties. 11.53% skim milk powder for each strain,
A reduced skim milk medium containing 0.5% yeast extract and 0.03% ascorbic acid was inoculated, and the spinnability of each culture when cultured at 38 ° C. for 16 hours was measured. Table 2 shows the results.

[0012]

[Table 2]

The SBT2927 strain and the SBT2937 strain exhibited spinnability of 9 to 10 cm, whereas SBT2
The 928 strain, the ATCC 15707 strain and the strain isolated from commercial fermented milk did not show any spinnability. in this way,
Since the SBT2927 strain and the SBT2937 strain have higher viscous productivity than other strains, by using them as starters for fermented milk, it is possible to produce fermented milk with improved tissue and low water separation.

Here, a method for producing fermented milk with low water separation using the Bifidobacterium longum having a high viscosity-producing ability of the present invention as a starter will be described. In the present invention, for example, 11.53% of skim milk powder, 0.5 of yeast extract
% And ascorbic acid 0.03% are inoculated with Bifidobacterium longum having a high viscosity-producing ability in a reduced skim milk medium, and cultured at 38 ° C. for about 16 hours to prepare a starter for fermented milk. Then, a starter prepared by inoculating this starter and a lactic acid bacterium conventionally used as a starter, for example, Streptococcus thermophilus, Lactobacillus acidophilus, etc., is appropriately inoculated into a raw material mix, and fermented by a conventional method. Low fermented milk can be produced. Examples of the fermented milk of the present invention include hard yogurt and soft yogurt. According to the present invention, fine and stable yogurt can be obtained without reducing or using the amount of agar, gelatin, pectin, etc. conventionally used as a stabilizer for fermented milk.
Further, in the present invention, sucrose, flavors, pigments and other additives used in the production of fermented milk may be added.

Next, the present invention will be described specifically with reference to examples.

Example 1 Bifidobacterium longum SBT2
927 strains (Microtechnical Laboratories No. 13100) or SBT
2937 strain (Microtechnical Laboratories No. 13101) to skim milk powder 1
A reduced skim milk medium containing 1.53%, yeast extract 0.5% and ascorbic acid 0.03% was inoculated at 38 ° C.
For 16 hours to obtain a bulk starter. As controls, the Bifidobacterium longum SBT2928 strain, ATCC15707 strain, and strains isolated from commercially available fermented milk used in the spinnability test were similarly cultured to prepare bulk starters. On the other hand, Streptococcus thermophilus SBT1021A strain (No. 10658) and Lactobacillus acidophilus SBT2062 strain (No. 10730) were combined with 11.53% of skim milk powder and 0.5% of yeast extract. The resulting reduced skim milk medium was inoculated and cultured at 32 ° C. for 16 hours to obtain a bulk starter. In addition, the lactic acidity at this time was 1.20 to 1.40%.

[0016]

Test Example 1 A water separation test was performed on each of the bulk starters of Bifidobacterium longum prepared in Example 1. The bulk starter was scooped with a spoon into a mass of 4 to 5 g, and about 200 g was collected and weighed in a large petri dish having a diameter of 20 cm. Then, the petri dish was wrapped and left at 5 ° C. for 2 hours.
o. The syneresis obtained by filtration with filter paper No. 2 was weighed. The water separation rate was calculated by Equation 1. Table 3 shows the results. Water separation rate (%) = [water separation (g) / bulk starter sampling (g)] x 100 [Equation 1]

[0017]

[Table 3]

The syneresis rate of the SBT2927 strain and the SBT2937 strain is about 3 to 4%.
It was 1/8 to 1/9 of the water separation rate of the CC15707 strain and the strain isolated from commercially available fermented milk.

[0019]

Example 2 A bulk starter of Bifidobacterium longum of the present invention prepared in Example 1 and a Streptococcus prepared in Example 1 were mixed with a raw material mixture containing 50% by weight of raw milk, 6% by weight of skim milk powder and 1.45% by weight of unsalted butter. 5% each of a bulk starter of Thermophilus and Lactobacillus acidophilus was inoculated, and the lactic acid acidity was 0.80 at 38 ° C.
% To obtain fermented milk with low water separation. As a control, a bulk starter of Bifidobacterium longum and a bulk starter of Streptococcus thermophilus and Lactobacillus acidophilus prepared by culturing the strain used for the spinnability test in Example 1 were inoculated at 5% each. And fermented milk at 38 ° C. until the lactic acidity reached 0.80%.

[0020]

Test Example 2 Each fermented milk prepared in Example 2 was subjected to a water separation test. Scoop the fermented milk with a spoon to a mass of 4-5 g
Approximately 00 g was collected and weighed. Then, the petri dish was wrapped and left at 5 ° C. for 2 hours.
o. The syneresis obtained by filtration with filter paper No. 2 was weighed. The water separation rate was calculated by Equation 2. Table 4 shows the results. Water separation rate (%) = [water separation (g) / fermented milk collection (g)] x 100 [Equation 2]

[0021]

[Table 4]

The water separation rate of the SBT2927 strain and the SBT2937 strain is about 3 to 4%, and the SBT2928 strain, AT
The water separation rate was about 1/4 of the CC15707 strain and the strain isolated from the commercially available fermented milk. Further, the obtained fermented milk with low water separation exhibited excellent texture and texture with fine texture.

[0023]

According to the present invention, by using Bifidobacterium longum having a high viscosity-producing ability as a starter, fermented milk with low water separation can be produced, and a fine-grained and excellent tissue can be obtained. The fermented milk having a texture can be provided, and the flavor deterioration of the fermented milk can be prevented.

────────────────────────────────────────────────── (5) References JP-A-58-76045 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A23C 9/12-9/148 BIOSIS (DIALOG) )

Claims (4)

(57) [Claims] 1. A a high viscosity production ability Bifidobacterium longum (Bifidobacterium lo
fermented milk having low syneresis, which is composed of fermented milk having high viscosity by using Ngum ) as a starter. 2. A medium serving as a raw material for fermented milk, which has a high viscous producing ability, Bifidobacterium longum ( Bifido).
(Bacterium longum ) as a starter, culturing under conditions that produce high viscosity, and causing the medium to have high viscosity. Wherein a high viscosity production ability Bifidobacterium longum (Bifidobacterium lo
ngum ) is Bifidobacterium longum ( Bif)
idobacterium longum ) SBT29
3. The method for producing fermented milk according to claim 2, wherein the fermented milk is No. 27 (No. 13100). Wherein a high viscosity production ability Bifidobacterium longum (Bifidobacterium lo
ngum ) is Bifidobacterium longum ( Bif)
idobacterium longum ) SBT29
37. The method for producing fermented milk according to claim 2, wherein the fermented milk is 37 (Microtechnological Laboratory No. 13101).