WO2013073424A1

WO2013073424A1 - Liquid fermented milk and method for producing same

Info

Publication number: WO2013073424A1
Application number: PCT/JP2012/078793
Authority: WO
Inventors: 祐子後藤; 伊代田中; 滋山田; 雅弘北島
Original assignee: 株式会社明治; オリエンタル酵母工業株式会社
Priority date: 2011-11-14
Filing date: 2012-11-07
Publication date: 2013-05-23
Also published as: JP6181557B2; JPWO2013073424A1; SG11201402248QA; CN103813715A

Abstract

Provided is a method for producing a liquid fermented milk having favorable flavor and appearance, having no occurrence of solid content floating up, having no contained large particles observed with the naked eye after completion of stirring fermentation, and having a rich aroma and the like deriving from fermentation by yeast. The method for producing a liquid fermented milk contains: (A) a static fermentation step that, after adding a lactobacillus to the starting material for fermented milk, causes static fermentation to obtain a lactic acid fermentation product; (B) a stirring fermentation step that, after adding yeast to the lactic acid fermentation product obtained in step (A), causes stirring fermentation to obtain a liquid fermented milk; and (C) a homogenization step for subjecting the liquid fermented milk obtained in step (B) to homogenization processing.

Description

Liquid fermented milk and method for producing the same

The present invention relates to liquid fermented milk and a method for producing the same.

In the production of fermented milk, a technique is known in which lactic acid bacteria and yeast are used in combination for the purpose of imparting a unique flavor by yeast.
For example, Patent Document 1 discloses a step of partially degrading lactose contained in animal milk by lactose-degrading enzyme, a step of performing lactic acid fermentation with lactic acid bacteria that do not accumulate galactose in the medium, and fermented milk obtained by the lactic acid fermentation. A method for producing a kefir-like dairy product is described, which comprises a step of subjecting to a lactose-fermenting yeast and subjecting the alcohol fermentation to substantially the disappearance of lactose in the medium.
Patent Document 2 describes Examples 5-1 to 5-3, where skim milk powder is added to deionized water, sterilized, inoculated with a lactic acid strain, fermented at 37 ° C. for 24 hours, and fermented milk is obtained. It is described that, after adding HF liquid sugar and fructose to this fermented milk, a yeast starter was inoculated, and fermentation was performed at various fermentation temperatures and fermentation times to obtain a fermented product. In addition, in Patent Document 2, when the sensory evaluation was performed on the fermented product obtained in the above-mentioned Examples, there was a milk-like flavor with reduced sweetness, and a unique aroma that matched yogurt odor and fruit odor. It is described that it was obtained.

On the other hand, as a fermentation method, a method combining stationary fermentation and stirring fermentation is known.
For example, in Example 1 of Patent Document 3, after adding a non-fat dry milk culture solution of lactic acid bacteria starter to a whey powder solution and standing fermentation, a glucose solution and a yeast extract solution are added to the obtained lactic acid bacteria fermentation solution. Then, it is described that a culture solution of yeast starter was added thereto, and aerated and stirred culture was performed at 200 rpm, 30 ° C. for 20 hours while blowing sterile air to obtain lactic acid bacteria / yeast fermented whey.

Japanese Patent Laid-Open No. 10-56961 Japanese Patent No. 3929630 JP-A-7-75521

In the production of liquid fermented milk, generally, after adding lactic acid bacteria to the raw material of fermented milk (for example, skim milk powder, raw milk, etc.), it is allowed to stand and form a card that is a lactic acid fermentation product, The card is finely crushed to obtain liquid fermented milk.
The present inventor examined the combined use of lactic acid bacteria and yeast in order to give a rich fragrance and the like when developing liquid fermented milk.
However, if lactic acid bacteria and yeast are added to the raw material of fermented milk at the same time, followed by stationary fermentation, solids will float due to the carbon dioxide produced by the yeast, and subsequent processing such as homogenization and sterilization Turned out to be impossible.
Moreover, after adding lactic acid bacteria to the raw material of fermented milk and making it leave and ferment and forming a card | curd, the liquid obtained by crushing this card | curd finely and yeast were mixed, and it was made to leave still fermentation after that. In some cases, it was found that the solid matter floated by the carbon dioxide produced by the yeast, making it impossible to perform subsequent homogenization and sterilization treatments.
Therefore, an object of the present invention is to provide a liquid fermented milk having a rich fragrance and the like derived from fermentation by yeast using lactic acid bacteria and yeast, and having a good appearance and drinking mouth, and a method for producing the same.

As a result of intensive studies to solve the above-mentioned problems, the present inventor added lactic acid bacteria to the raw material of fermented milk, allowed to stand and ferment, then added yeast and stirred and fermented. It is found that liquid fermented milk having a good appearance and drinking mouth can be obtained without having coarse particles observed with the naked eye after completion of stirring and fermentation, without causing solid content to float, The present invention has been completed.

That is, the present invention provides the following [1] to [9].
[1] (A) After adding lactic acid bacteria to the raw material of fermented milk, static fermentation is performed to obtain a lactic acid fermentation product by static fermentation; and (B) after adding yeast to the lactic acid fermentation product, A method for producing liquid fermented milk, comprising a step of stirring and fermenting to obtain liquid fermented milk.
[2] Production of liquid fermented milk according to the above [1], wherein the stationary fermentation in the step (A) is performed in 3 to 45 hours, and the stirring fermentation in the step (B) is performed in 20 to 65 hours. Method.
[3] The stationary fermentation in the step (A) is performed at a temperature of 20 to 44 ° C., and the stirring fermentation in the step (B) is performed at a temperature of 20 to 44 ° C. 2] The manufacturing method of liquid fermented milk of description.
[4] From the start of the stationary fermentation in the step (A) to the end of the stirred fermentation in the step (B), no other than the yeast starter is added. The manufacturing method of the liquid fermented milk in any one.
[5] The liquid fermentation according to any one of [1] to [4] above, wherein the raw material of the fermented milk contains one or more selected from the group consisting of skim milk powder, skim milk, raw milk, and milk protein concentrate. Milk production method.
[6] Production of liquid fermented milk according to any one of [1] to [5], further comprising (C) a homogenization step of performing homogenization treatment on the fermented milk after step (B) Method.
[7] Liquid fermented milk obtained by the method for producing liquid fermented milk according to [6] above.
[8] The liquid fermented milk according to the above [7], wherein the median diameter of the particles constituting the solid content of the liquid fermented milk is 30 μm or less.
[9] A beverage comprising the liquid fermented milk according to [7] or [8] above, wherein the median diameter of particles constituting the solid content of the beverage is 2.5 μm or less.

According to the method for producing liquid fermented milk of the present invention, stationary fermentation is carried out after the addition of lactic acid bacteria, and then stirring fermentation is carried out after the addition of yeast, so that the solid content found when only stationary fermentation is carried out. As a result, the solid particles, which are not floated or agitation culture, are not coarsened, and a liquid fermented milk having a uniform liquid appearance and a good drinking mouth can be obtained.
In addition, according to the method for producing liquid fermented milk of the present invention, since yeast is used in addition to lactic acid bacteria, the sourness derived from lactic acid, which is a fermentation product of lactic acid bacteria, and the richness derived from the fermentation product of yeast. A liquid fermented milk having a fragrance, a savory flavor, and a slight alcohol flavor can be obtained. In addition, since the liquid fermented milk of this invention has an alcohol content less than 0.5 weight%, it can use for drinking as a non-alcoholic drink.
The liquid fermented milk of the present invention can be used for drinking alone or after being mixed with other materials such as sugar and water.
For example, after homogenizing the liquid fermented milk obtained in the present invention, the processed liquid fermented milk and other materials (for example, water, sugar, etc.) are mixed, and the resulting mixture is mixed. By further performing the homogenization treatment, it is possible to obtain a beverage having an appearance as a homogeneous liquid material, a good drinking mouth, and palatability. This beverage has a high commercial value without causing a precipitate (solid content) at the bottom or the like of a container for containing the beverage.

The method for producing liquid fermented milk of the present invention includes (A) a stationary fermentation step in which a lactic acid bacterium is added to the raw material of fermented milk, followed by stationary fermentation to obtain a lactic acid fermentation product, and (B) step (A). After adding yeast to the lactic acid fermentation product obtained in step 1, the mixture is stirred and fermented to obtain a liquid fermented milk.
Moreover, the manufacturing method of the liquid fermented milk of this invention performs the homogenization process with respect to the liquid fermented milk obtained by (C) process (B), and the homogenization process of obtaining the liquid fermented milk after the homogenization process, Can be included.
Hereinafter, each step will be described in detail.

[Step (A); stationary fermentation step]
Step (A) is a step of obtaining a lactic acid fermentation product by adding lactic acid bacteria to the raw material of fermented milk and then allowing it to stand and ferment.
The raw material of the fermented milk may be any material that can obtain a liquid product having a nonfat milk solid content of 5% by weight or more, preferably 8% by weight or more at the end of the stirring fermentation in the step (B). .
As the main raw material of fermented milk, any milk can be used without particular limitation as long as it is milk such as animal milk (milk, sheep milk, goat milk, buffalo milk, etc.) and soy milk and processed products thereof, For example, whey powder produced using whey as a raw material, whey protein concentrate, and the like can be used in addition to skim milk powder, skim milk, raw milk, milk protein concentrate, and the like. The main raw material of fermented milk can use said 1 type individually or in combination of 2 or more types.
As a secondary ingredient of fermented milk, any known foods and food additives that do not significantly delay the fermentation time can be used without particular limitation. Examples include glucose and yeast extract used in the examples.
In addition, in this specification, the main raw material of fermented milk means the raw material derived from milk. The auxiliary raw material of fermented milk means raw materials other than milk-derived raw materials (however, excluding lactic acid bacteria and yeast).
The ratio of the main raw material in the whole quantity of the raw material of fermented milk is not specifically limited.
Water can be added to the raw material of fermented milk as needed. For example, when only skim milk powder is used as the main raw material of fermented milk, it is preferable to add 50 to 150 parts by weight of water to 10 parts by weight of skim milk powder.
When adding water, lactic acid bacteria may be added to the mixture of fermented milk raw material and water, or water may be added to the mixture of fermented milk raw material and lactic acid bacteria, and fermented milk. The raw material, water and lactic acid bacteria may be mixed at the same time.

The lactic acid bacterium is not particularly limited as long as it contains a lactic acid bacterium that is a living bacterium, but usually a liquid product obtained by culturing lactic acid bacterium in the presence of a nutrient source is used.
Such a liquid material is, for example, a mixture containing a nutrient source such as skim milk powder, water, and lactic acid bacteria at a predetermined temperature (for example, 35 to 40 ° C.) for a predetermined time (for example, 10 to 20 hours). ) After culturing to obtain a mother starter, this mother starter, water, and a nutrient source such as skim milk powder are mixed, and the resulting mixed solution is subjected to a predetermined temperature (for example, 35 to 40 ° C.). Then, it can be obtained by further culturing for a predetermined time (for example, 10 to 20 hours).
The number of lactic acid bacteria in the lactic acid bacteria is not particularly limited, but is, for example, 1 × 10 ⁷ to 1 × 10 ⁹ cfu / ml.
As the lactic acid bacteria, one or two or more kinds of lactic acid bacteria selected from general lactic acid bacteria used for producing fermented milk can be used. Examples of lactic acid bacteria include lactic acid bacteria belonging to the genus Lactobacillus and lactic acid bacteria belonging to the genus Streptococcus.
Examples of lactic acid bacteria belonging to the genus Lactobacillus include Lactobacillus helveticus, Lactobacillus delbruekii subsp. Bulgaricus, Lactobacillus acidophilus (Lactobacillus acidophilus), and the like. Can be mentioned.
In the present invention, Lactobacillus helveticus is preferable from the viewpoint of preventing the growth of contaminating microorganisms even in fermented milk that requires fermentation for a long time because the acidity increases more than other lactic acid bacteria. In addition, Lactobacillus helveticus can obtain a commercial item easily.
Examples of Streptococcus lactic acid bacteria include Streptococcus thermophilus.

In this specification, stationary fermentation means fermenting in the state which left still, without stirring.
The time for stationary fermentation is preferably 3 to 45 hours, more preferably 5 to 45 hours, still more preferably 8 to 45 hours, still more preferably 10 to 40 hours, still more preferably 15 to 35 hours, and particularly preferably 20 hours. ~ 30 hours.
The temperature of the stationary fermentation is preferably 25 to 50 ° C, more preferably 30 to 45 ° C, still more preferably 32 to 43 ° C, and particularly preferably 35 to 40 ° C.
The card | curd which is a fermentation product is obtained by stationary fermentation. This card is finely crushed in the step (B) to become a liquid material.

[Step (B): Stirring fermentation step]
Step (B) is a step of adding liquid yeast to the lactic acid fermentation product obtained in step (A), followed by stirring and fermentation to obtain liquid fermented milk.
The yeast is not particularly limited as long as it contains yeast that is a living bacterium, and examples thereof include dry yeast (dry yeast).
Dry yeast is yeast that is dormant due to drying. Dry yeast can be used in the state of the liquid substance formed, for example by mixing with water.
Examples of the yeast include Saccharomyces cerevisiae, Saccharomyces pastrianus, Saccharomyces paradoxus, and Saccharomyces bayanus.
In the present invention, Saccharomyces cerevisiae is preferred from the viewpoint of versatility because it is a commercially available product and can be easily obtained. Examples of commercially available products of Saccharomyces cerevisiae include Saff Instant Dry Yeast Red (manufactured by Lesaffre), Oriental Dry Yeast (manufactured by Oriental Yeast Co., Ltd.), and the like.
Yeast can be used individually by 1 type or in combination of 2 or more types.
Since the lactic acid fermentation product obtained in the step (A) is obtained by stationary fermentation, it is not liquid but has a solid card form. In the step (B), the curd may be finely crushed and then yeast may be added. Alternatively, after adding yeast to the curd, the curd may be finely broken by stirring.

The speed of stirring is not particularly limited, but is preferably 10 to 150 rpm, more preferably from the viewpoint of crushing the curd formed by the action of lactic acid bacteria by shearing, removing carbon dioxide produced by yeast, and suppressing the floating of the solid matter. Is 30 to 100 rpm.
The stirring may be either continuous stirring or intermittent stirring, but continuous stirring is preferable from the viewpoint of removal of carbon dioxide gas produced by yeast and suppression of solid floating.
The stirring fermentation time is preferably 20 to 50 hours, more preferably 25 to 45 hours, still more preferably 30 to 40 hours, and particularly preferably 35 to 40 hours.
The temperature of the stirring fermentation is preferably 20 to 44 ° C, more preferably 25 to 42 ° C, still more preferably 30 to 40 ° C, and particularly preferably 35 to 38 ° C.
The total of the stationary fermentation time in the step (A) and the stirring fermentation time in the step (B) is preferably 40 to 85 hours, more preferably 45 to 45 hours from the viewpoint of the flavor and practicality of the liquid fermented milk. 80 hours, more preferably 50 to 75 hours, further preferably 55 to 70 hours, particularly preferably 60 to 70 hours.
In addition, after completion | finish of stirring fermentation, lactic acid etc. can be added and the lactic acid acidity of liquid fermented milk can be adjusted. The lactic acid acidity of the liquid fermented milk is preferably 2.1 to 2.7% from the viewpoint of giving an appropriate acidity.

[Step (C): Homogenization step]
Step (C) is a step of homogenizing the liquid fermented milk obtained in step (B). Here, the homogenization is not limited to the homogenization process using a homogenizer (homogenizer), but also includes known shearing processes such as stirring, a homomixer, and an extruder.
For example, when using a homogenizer (homogenizer), the homogenization treatment is performed at a pressure of 7 to 13 MPa as the first-stage homogenization treatment, and then at a pressure of 4 to 6 MPa as the second-stage homogenization treatment. This is done by applying pressure.
As the step (C), the homogenization process combining the first stage and the second stage may be performed only once, or the homogenization process combining the first stage and the second stage may be performed twice or more. Good. For example, after performing the homogenization process combining the first stage and the second stage, heat sterilization and cooling may be performed, and then the homogenization process combining the first stage and the second stage may be further performed.
The median diameter of the particles constituting the solid content contained in the treated liquid fermented milk obtained in the step (C) is preferably 30 μm or less, more preferably 25 μm or less, further preferably 20 μm or less, particularly preferably 15 μm. It is as follows.

The liquid fermented milk obtained in the step (C) may be used alone for drinking, or may be mixed with other components for drinking. Examples of other components mixed with the liquid fermented milk include sweeteners such as sugar for imparting sweetness, acidity adjusting agents such as lactic acid, salt, fragrance, and fruit juice.
A homogenization process can also be performed with respect to the mixture of liquid fermented milk and another component. The homogenization process in this case may be only one stage or a plurality of stages (for example, combined use of the first and second stages). The total pressure of the homogenization treatment is preferably 10 to 20 MPa. In this case, the median diameter of the particles constituting the solid content contained in the homogenized beverage (mixture of liquid fermented milk and other components) is preferably 2.5 μm or less, more preferably 2. It is 0 μm or less, more preferably 1.5 μm or less, and particularly preferably 1.0 μm or less.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
[Example 1]
(1) Preparation of lactic acid bacteria starter Nonfat dry milk (manufactured by Meiji Co., Ltd.), powdered yeast extract (trade name: yeast extract T-154, manufactured by Oriental Yeast Co., Ltd.), lactic acid bacteria (Lactobacillus helveticus, “FLAV 54 LYO 5D” manufactured by Danisco Co., Ltd.) ) And water were used to prepare lactic acid bacteria starters. This lactic acid bacteria starter contained skim milk powder 10% by weight, water 90% by weight, yeast extract 0.002% by weight, and lactic acid bacteria 3 × 10 ⁸ cfu / ml. The lactic acid acidity of this lactic acid bacteria starter was 1.6%.
(2) Preparation of yeast starter Dry yeast (trade name: Saff Instant Dry Yeast Red, manufactured by Lesaffre) was added to 40 ° C sterilized water, and the mixture was allowed to stand for 20 minutes. Used in the preparation of fermented milk.

(3) Preparation of liquid fermented milk 86.69 parts by weight of water heated to about 40 ° C., 10.76 parts by weight of nonfat dry milk (manufactured by Meiji Co., Ltd.), and glucose (trade name: Glufinal, manufactured by Sanei Saku Kasei Co., Ltd.) After mixing 0.5 part by weight and 0.04 part by weight of powdered yeast extract (trade name: yeast extract T-154, manufactured by Oriental Yeast Co., Ltd.), the resulting mixture was sterilized at 75 ° C. for 30 minutes. And then cooled to 37 ° C. To the mixed solution after cooling, 2 parts by weight of the lactic acid bacteria starter was added and subjected to static fermentation at 37 ° C. for 16 hours to form a curd.
After the stationary fermentation, the stirrer is started and the curd is crushed. At the same time, the yeast starter is converted to the weight of the dry yeast to be 0.01 parts by weight (total 100 parts by weight above). And stirred and fermented at 37 ° C. for 42 hours. Stirring was continuously performed at 60 rpm.
After the stirring fermentation was completed, the lactic acid acidity of the obtained liquid fermented milk was confirmed to be 2.4%. Therefore, lactic acid was added to adjust the acidity to 2.5%.
Next, the liquid fermented milk was subjected to a homogenization treatment of 10 MPa as the first stage and 5 MPa as the second stage. The liquid fermented milk after the treatment was sterilized at 75 ° C. for 30 minutes and then cooled to 10 ° C. or lower.
In the obtained liquid fermented milk, the total solid content is 11.6% by weight, the non-fat milk solid content is 10.4% by weight, the lactic acid acidity is 2.5%, and the pH is 3. 3. In addition, liquid fermented milk is a homogeneous, milky white liquid that does not contain floating solids and coarse particles, and has a sourness derived from lactic acid fermentation and a flavor derived from yeast fermentation (such as mellowness and fruit). Fragrance) and a slight alcohol fragrance. In the liquid fermented milk, no off-flavor, off-flavor, or foreign matter was observed.

(4) Preparation of beverage The liquid fermented milk obtained in (3) above was homogenized at a total pressure of 15 MPa with a homogenizer (homomixer), and then heated at 85 ° C for 2 minutes, Subsequently, it cooled to 10 degrees C or less. The median diameter of the particles constituting the solid content of the liquid fermented milk after the homogenization treatment was 14.05 μm.
On the other hand, after adding 0.2 parts by weight of soybean polysaccharide (trade name: SM900, manufactured by San-Ei Gen FFI Co., Ltd.) to 82.02 parts by weight of water heated to 40 ° C., an aqueous solution was obtained. The aqueous solution was cooled to 10 ° C. or lower. In this aqueous solution, 10.112 parts by weight of sugar, 0.063 parts by weight of lactic acid (trade name: 50% lactic acid, manufactured by Daiichi Fine Chemical Co., Ltd.), 0.004 parts by weight of sodium chloride, and a liquid that has been treated with the above homomixer 7.6 parts by weight of fermented milk (a total of 100 parts by weight above) was added to obtain a mixed solution. After heating this mixed liquid to 60 degreeC, it homogenized by the pressure of a total of 15 MPa with a homogenizer, and then cooled to 10 degrees C or less. The mixed liquid after cooling was heated at 110 ° C. for 1 minute using an autoclave to obtain a beverage.
With respect to this beverage, the median diameter of the particles constituting the solid content was measured and found to be 1.0 μm. In addition, the simulated beverage was milky white and homogeneous liquid without any solid surface floating or abnormal appearance due to coarse particles.

[Example 2]
The experiment was conducted in the same manner as in Example 1 except that the time for stationary fermentation was set at 24 hours and the time for stirring fermentation was set at 40 hours.
As a result, the liquid fermented milk before the homogenization treatment, like Example 1, is a homogeneous, milky white liquid that does not contain floating solids and coarse particles, and has a sourness derived from lactic acid fermentation. I had it. In the liquid fermented milk, no off-flavor, off-flavor, or foreign matter was observed.
The median diameter of the particles constituting the solid content of the liquid fermented milk after the homogenization treatment was 10 μm.
Moreover, the median diameter of the particle | grains of the obtained drink was 0.8 micrometer. Further, this beverage was milky white and homogeneous liquid with no precipitation at the bottom of the container containing the simulated beverage.
[Example 3]
The experiment was conducted in the same manner as in Example 1 except that the time for stationary fermentation was set to 5 hours and the time for stirring fermentation was set to 59 hours.
As a result, in the liquid fermented milk before homogenization treatment, the particle size of the particles is slightly large, and although sedimentation of coarse particles was seen when left for a long time, it did not contain any floating solids, and was a milky white liquid, It had a sour taste derived from lactic acid fermentation. In the liquid fermented milk, no off-flavor, off-flavor, or foreign matter was observed.
Moreover, the median diameter of the particle | grains of the obtained simulation drink was 2.1 micrometers. A slight amount of precipitate was observed at the bottom of the container containing the beverage.

[Comparative Example 1]
Experiments were carried out in the same manner as in Example 1 except that a lactic acid bacteria starter and a yeast starter were added simultaneously, the time of stationary fermentation was set to 64 hours, and stirring fermentation was not performed.
As a result, in liquid fermented milk, the solid content floated on the liquid surface at the end of fermentation, dried and hardened, and the appearance was poor. For this reason, the solid content was pulverized manually and then homogenized.
Moreover, the median diameter of the particle | grains of the obtained drink was 3.1 micrometers. A larger amount of precipitate than in Example 3 was observed at the bottom of the container containing the beverage.
[Comparative Example 2]
Experiments were conducted in the same manner as in Example 1 except that a lactic acid bacteria starter and a yeast starter were added simultaneously, the time for stirring fermentation was set to 64 hours, and stationary fermentation was not performed.
As a result, at the end of the fermentation of the liquid fermented milk, although the solid content did not rise to the liquid surface, an abnormality in the appearance due to the sedimentation of the coarse particles was observed. The subsequent treatment of the liquid fermented milk was carried out including the coarse particles that settled.
Moreover, the median diameter of the particle | grains of the obtained drink was 4.6 micrometers. A larger amount of precipitate than in Comparative Example 1 was observed at the bottom of the container containing the beverage.
[Comparative Example 3]
Experiments were carried out in the same manner as in Example 1 except that the lactic acid bacteria starter and the yeast starter were added simultaneously, the time for stationary fermentation was set at 24 hours, and the time for stirring fermentation was set at 40 hours.
As a result, the liquid fermented milk had a solid content that floated on the liquid surface, dried and hardened at the end of fermentation, and had a poor appearance. For this reason, the solid content was pulverized manually and then homogenized.
Moreover, the median diameter of the particle | grains of the obtained simulation drink was 2.0 micrometers. Some precipitates were observed at the bottom of the container for containing the beverage.
The results are shown in Table 1. In Table 1, regarding the comprehensive evaluation, “◎” represents “very good”, “◯” represents “good”, and “x” represents “bad”.

From Table 1, when the lactic acid bacteria starter was added and then static fermentation was performed, and then the yeast starter was added and then stirred and fermented (Examples 1 to 3), coarse particles were not generated, and solid content It can be seen that no levitation occurs.
On the other hand, when only stationary fermentation was performed (comparative example 1), there existed problems, such as solid content rising. When only the stirring fermentation was performed (Comparative Example 2), the appearance of abnormalities due to sedimentation of coarse particles was observed, although no solid content was observed. Although stationary fermentation and stirring fermentation were combined, when the lactic acid bacterium starter and the yeast starter were added simultaneously (Comparative Example 3), there was a problem such as solid content rising.

Claims

(A) After adding lactic acid bacteria to the raw material of fermented milk, it is subjected to stationary fermentation to obtain a lactic acid fermentation product,
(B) After adding yeast to the lactic acid fermentation product, stirring fermentation to obtain liquid fermented milk by stirring and fermentation;
A method for producing liquid fermented milk comprising
The method for producing liquid fermented milk according to claim 1, wherein the stationary fermentation in the step (A) is performed in 3 to 45 hours, and the stirring fermentation in the step (B) is performed in 20 to 65 hours.
The liquid fermentation according to claim 1 or 2, wherein the stationary fermentation in the step (A) is performed at a temperature of 20 to 44 ° C, and the stirring fermentation in the step (B) is performed at a temperature of 20 to 44 ° C. Milk production method.
The liquid according to any one of claims 1 to 3, wherein nothing other than yeast is added from the start of the stationary fermentation in the step (A) to the end of the stirred fermentation in the step (B). A method for producing fermented milk.
The method for producing liquid fermented milk according to any one of claims 1 to 4, wherein the raw material of the fermented milk contains one or more selected from the group consisting of skim milk powder, skim milk, raw milk, and milk protein concentrate.
The method for producing liquid fermented milk according to any one of claims 1 to 5, further comprising (C) a homogenization step of performing homogenization treatment on the fermented milk after step (B).
Liquid fermented milk obtained by the method for producing liquid fermented milk according to claim 6.
The liquid fermented milk according to claim 7, wherein the median diameter of the particles constituting the solid content of the liquid fermented milk is 30 µm or less.
A beverage containing the liquid fermented milk according to claim 7 or 8, wherein the median diameter of particles constituting the solid content of the beverage is 2.5 µm or less.