JP2018023333A - Manufacturing method of concentrated fermented milk containing water absorptive raw material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of manufacturing concentrated fermented milk containing a food raw material (for example, dry mango which absorbs water and swells) with a simple method and at low cost without using specific facility.SOLUTION: There is provided a manufacturing method of concentrated fermented milk containing a water absorptive raw material including (A) a high Brix liquid impregnation process for impregnating edible solid water absorptive raw material into a high Brix liquid having large Brix value at a level with which the water absorptive raw material does not absorb water or keeps water absorptive performance thereof to obtain high Brix liquid containing the water absorptive raw material, and (B) a water penetration process for mixing the high Brix liquid containing the water absorptive raw material obtained in the process (A), and a fermented milk mix before fermentation or fermented milk after fermentation, then leaving the resulting fermented milk mix or fermented milk containing the water absorptive raw material, and making moisture contained in the fermented milk mix or the fermented milk penetrate into the water absorptive raw material to obtain the concentrated fermented milk mix or the concentrated fermented milk containing water absorbed water absorptive raw material.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing concentrated fermented milk containing a water-absorbing material.

Conventionally, yogurt containing food materials such as fruits is known.
For example, Patent Document 1 discloses a process of fermenting raw milk with animal lactic acid bacteria to obtain fermented milk, and fermented fruit and / or fermented fruit and / or vegetable processed products with vegetable lactic acid bacteria. A step of obtaining a processed product of fermented vegetables, and a step of mixing the obtained fermented milk and the processed product of fermented fruits and / or fermented vegetables such that the fermented milk is 65 wt% or more and 95 wt% or less. The manufacturing method of the yogurt with fruits and vegetables provided with is described.
Patent Document 2 describes a method for producing a soft yogurt containing heat-resistant fruit juice jelly comprising the following steps.
(A) After 1 to 3% glucomannan is used and swelled with warm water, an alkaline solution is mixed, and this is immersed in hot water directly or filled in a container and kept warm, and the obtained heat resistance Step of immersing jelly in concentrated fruit juice and infiltrating fruit juice into heat-resistant jelly (b) Using heat-resistant jelly that has been permeated with fruit juice obtained in the previous step as raw materials, and supplementing sugars, stabilizers, acidulants, etc. Step of adding, sterilizing and cooling to prepare a preparation (c) Mixing the preparation with heat-resistant fruit juice jelly obtained in the previous step, and fermented and cooled stirred yogurt, soft yogurt with heat-resistant fruit juice jelly Manufacturing process

On the other hand, thick yogurt is conventionally known.
For example, in Patent Document 3, whole fat milk is concentrated by a reverse osmosis membrane (milk reverse osmosis membrane concentration equipment), heat-sterilized in a non-homogeneous state, inoculated with lactic acid bacteria, filled into a container, and allowed to stand and ferment. The milk fat content and non-fat milk solid content are 2.0 to 7.0 wt% and 8.0 to 14.0 wt%, respectively, characterized in that a high fat cream layer is formed on the upper surface layer A method for producing a stationary fermentation type concentrated yogurt is described.

JP 2007-282523 A JP 9-37712 A JP-A-6-14707

As in the technique described in Patent Document 3 described above, conventionally, special equipment such as a milk reverse osmosis membrane concentration equipment has been required to produce a thick yogurt.
An object of the present invention is to provide a method capable of producing concentrated fermented milk containing a food material (for example, fruit) by a simple method and at low cost without using special equipment.

  As a result of intensive studies to solve the above problems, the present inventor has found that an edible solid water-absorbing material (for example, dried fruit) is so large that the water-absorbing material does not absorb water or can maintain its water-absorbing ability. After immersing in a high Brix liquid (for example, sucrose aqueous solution) having a Brix value (for example, an aqueous sucrose solution) to obtain a high Brix liquid containing a water absorbing material, the high Brix liquid containing the water absorbing material and before fermentation If the fermented milk mix or the fermented milk after fermentation is mixed, the water contained in the fermented milk mix or fermented milk penetrates into the water-absorbing material and absorbs the water-absorbing material (for example, absorbs and swells) And having a texture similar to that of fresh fruits) and a product containing a concentrated fermented milk mix or concentrated fermented milk, and the present invention has been completed.

The present invention provides the following [1] to [8].
[1] An edible solid water-absorbing material is immersed in a high Brix solution that has a large Brix value so that the water-absorbing material does not absorb water or can maintain its water-absorbing capacity. After mixing the high Brix liquid soaking process with the above water-absorbing material and the fermented milk mix before fermentation or the fermented milk after fermentation, the obtained fermented milk mix or fermented milk containing the water-absorbing material is obtained. Including a moisture permeation step of allowing the moisture contained in the fermented milk mix or fermented milk to penetrate into the water-absorbing material and obtaining a concentrated fermented milk mix or concentrated fermented milk containing the absorbed water-absorbing material. A method for producing concentrated fermented milk containing a water-absorbing material.
[2] The concentrated fermented milk containing the water-absorbing material according to the above [1], wherein the water content of the water-absorbing material before dipping in the high-Brix solution is 50% by weight or less in the high Brix solution dipping step. Manufacturing method.
[3] In the high Brix liquid immersion step, the edible solid water-absorbing material comprises at least one selected from dried fruits, dried vegetables, jelly, gummy, marshmallow, candy, gum, agar, and konjac. The manufacturing method of the thick fermented milk containing the water absorption raw material as described in [1] or [2].
[4] The method for producing concentrated fermented milk containing a water-absorbing material according to any one of [1] to [3], wherein the high Brix liquid used in the high Brix liquid immersion step has a Brix value of 50 or more. .
[5] The above [1] to [1], wherein the high Brix solution used in the high Brix solution dipping step comprises at least one selected from sugar solution, sugar alcohol solution, dietary fiber solution, concentrated fruit juice, honey, and maple syrup. [4] A method for producing concentrated fermented milk containing the water-absorbing material according to any one of [4].
[6] In any one of the above [1] to [5], including a heat sterilization step of heating and sterilizing the high Brix solution containing the water-absorbing material between the high Brix solution immersion step and the water permeation step. The manufacturing method of the thick fermented milk containing the water absorption material of description.
[7] In the water penetration step, the water-absorbing material is used so that the viscosity of the concentrated fermented milk mix or the concentrated fermented milk increases in a range of 1,000 mPa · s or more as compared to the time before the moisture penetration step. The method for producing concentrated fermented milk containing a water-absorbing material according to any one of the above [1] to [6], wherein a blending ratio of the high Brix liquid containing and the fermented milk mix before fermentation or the fermented milk after fermentation is defined .
[8] The water absorption according to any one of [1] to [7], wherein in the water penetration step, the weight of the water-absorbing material that has absorbed water is 120% or more with reference to (100%) before water absorption. A method for producing concentrated fermented milk containing ingredients.

According to the present invention, a water-absorbing material can be obtained by a simple method and at a low cost without using special equipment (for example, a water removing device for removing whey and enriching fermented milk). It is possible to produce concentrated fermented milk (hereinafter also referred to as concentrated fermented milk of the present invention) containing (for example, food materials such as fruits).
Further, according to the present invention, when obtaining concentrated fermented milk, since whey is not removed, nutritional components contained in whey can be included in the concentrated fermented milk as it is, and nutritionally. Is more advantageous. Moreover, the problem of how to dispose of the removed whey does not arise.
Moreover, conventionally, when obtaining concentrated fermented milk without removing whey, in order to give a natural flavor as concentrated fermented milk, a material having no specific flavor is selected as a raw material for concentrated fermented milk There was a need. Moreover, such selection of raw materials involved complicated operations. In this regard, according to the present invention, a special raw material known as a raw material for fermented milk can be used without requiring a special raw material for imparting the flavor of the concentrated fermented milk. It is possible to easily design a raw material for producing milk. Moreover, since a special raw material is not required, the concentrated fermented milk of this invention can be prepared as what has a natural flavor which is not artificial. However, the concentrated fermented milk of the present invention can also contain natural foods such as honey and additives such as artificial sweeteners.

In addition, according to the present invention, a heat sterilization step can be provided after the high Brix liquid immersion step, so that even if an unsterilized water-absorbing material (for example, dried fruit) is used, the contaminating microorganisms can be removed. A product that can be stored for a long period of time (the concentrated fermented milk of the present invention) can be produced.
Furthermore, according to the present invention, since a high Brix solution immersion step is provided, the water-absorbing material (for example, dried fruit) has absorbed water and swelled as compared with the case where it is simply immersed in the fermented milk mix or fermented milk. A water-absorbing material (for example, dried fruit) can have a texture (fruitiness) more similar to a raw water-absorbing material (for example, fruit).

The method for producing concentrated fermented milk containing a water-absorbing material of the present invention (hereinafter also referred to as the production method of the present invention) is that the edible solid water-absorbing material does not absorb water or maintains its water-absorbing capacity. A high Brix liquid immersion process for obtaining a high Brix liquid containing a water-absorbing material by immersing it in a high Brix liquid having a large Brix value, and a high Brix liquid containing a water-absorbing material obtained in the high Brix liquid immersion process And after mixing the fermented milk mix before fermentation or fermented milk after fermentation, leave the obtained fermented milk mix or fermented milk containing the water-absorbing material and leave the moisture contained in the fermented milk mix or fermented milk. A moisture permeation step for obtaining a concentrated fermented milk mix or concentrated fermented milk containing the water-absorbing material that has been permeated into the water-absorbing material.
Moreover, the manufacturing method of this invention can include the heat sterilization process of heating and sterilizing the high Brix liquid containing a water absorption raw material between a high Brix liquid immersion process and a water penetration process.
Hereinafter, each process will be described in detail.

[High Brix liquid immersion process]
The high Brix liquid immersion process involves immersing the edible solid water-absorbing material in a high Brix liquid that has a large Brix value so that the water-absorbing material does not absorb water or can maintain its water-absorbing capacity. This is a process for obtaining a high Brix solution.
Examples of edible solid water-absorbing materials include dried fruits, dried vegetables, jelly, gummy, marshmallow, candy, gum, agar, konjac and the like.
Here, the dried fruits include dried mango, dried apple (dried apple), dried berry, raisin (dried grape), dried papaya, dried banana, dried strawberry, dried kiwi, dried melon, dried fig, dried pineapple, dried orange , Dried prunes, dry peaches, dry malon, and the like, which are dried fruits.

As dried vegetables, dried aloe, dried tapioca (starch derived from cassava rhizome), dried nata de coco (fermented product of coconut juice), dried winter rice cake, dried tomato, dried carrot, dried cucumber, dried cucumber, dried burdock root, dried lotus root , Dried vegetables such as dried radish, dried onion, dried green onion, dried green curd, dried spinach, dried spinach, dried Chinese cabbage, dried cabbage, and dry lettuce.
Examples of the jelly include mango jelly, apple jelly, grape jelly, papaya jelly, strawberry jelly, kiwi jelly, melon jelly, pineapple jelly, and orange jelly, which are fruit juice and / or vegetable juice solidified with a gelling agent. .
Gummies include mango-flavored gummy, apple-flavored gummy, grape-flavored gummy, papaya-flavored gummy, strawberry-flavored gummy, kiwi-flavored gummy, melon-flavored gummy, pineapple-flavored gummy, orange-flavored gummy, etc. , Fruit juice and / or vegetable juice processed into gummi.

The water content of the water-absorbing material before dipping in the high Brix solution is to increase the texture similar to that of the raw water-absorbing material by absorbing a large amount of water in the water-absorbing material in the water infiltration process, which is a subsequent process. Preferably it is 50 weight% or less, More preferably, it is 40 weight% or less, More preferably, it is 30 weight% or less, Most preferably, it is 25 weight% or less.
The lower limit of the water content is not particularly limited, but is usually 5% by weight from the viewpoint of the performance of the apparatus for reducing the water content.
Examples of high Brix solutions include sugar solutions (eg, sucrose aqueous solution, starch syrup aqueous solution, reduced starch syrup aqueous solution, isomerized sugar aqueous solution, glucose fructose liquid sugar aqueous solution, fructose aqueous solution, glucose aqueous solution, etc.), sugar alcohol liquid (eg trehalose). Aqueous solution, etc.), dietary fiber solution (for example, indigestible dextrin solution, polydextrose solution, etc.), concentrated fruit juice, honey, maple syrup and the like.
In the present invention, “a high Brix liquid having a Brix value that does not absorb water or can maintain its water absorption capacity” means that the water absorbent material does not absorb water at all after it is immersed in the high Brix liquid. In addition, the water content of the water-absorbing material is maintained at 50% by weight or less (preferably 40% by weight or less, more preferably 30% by weight or less, particularly preferably 25% by weight or less).
In the present invention, the range of increase in the moisture content of the water-absorbing material by immersion in the high Brix solution (in other words, the value obtained by subtracting the moisture content before immersion (%) from the moisture content after immersion (%)) is preferably Is 25% by weight or less, more preferably 20% by weight or less, and particularly preferably 15% by weight or less.

The Brix value of the high Brix liquid is preferably 50 or more, more preferably 55 or more, still more preferably 60 or more, particularly preferably from the viewpoint of preventing moisture from moving to the water-absorbing material and improving the storage stability of the water-absorbing material. Is 65 or more.
The upper limit of the Brix value is not particularly limited. However, if the Brix value is excessive, it may be difficult to keep the high Brix liquid in a liquid state, and it may be difficult to immerse the water-absorbing material in the high Brix liquid. Therefore, it is usually 90, preferably 85, more preferably 80, and further preferably 75.
Here, the Brix value is expressed as “1” (“1 degree” or “1 ° Bx”) when 1 g of sucrose is dissolved in 100 g of an aqueous solution at 20 ° C. In other words, the Brix value of an aqueous solution exhibiting the same sugar refractive index value as this sucrose aqueous solution is defined as “1”. The Brix value can be measured with a commercially available Brix meter.
The amount of the water-absorbing material in the total amount of 100 parts by weight of the water-absorbing material and the high Brix liquid is not particularly limited, but is, for example, 10 to 70 parts by weight (preferably 20 to 60 parts by weight, more preferably 30 to 55 parts by weight). It is.

[Heat sterilization process]
The heat sterilization process is a process of heating and sterilizing the high Brix liquid containing the water-absorbing material obtained in the high Brix liquid immersion process.
The heating temperature is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, further preferably 80 ° C. or higher, and particularly preferably 90 ° C. or higher, from the viewpoint of sufficient sterilization. Although the upper limit of heating temperature is not specifically limited, Usually, it is 140 degreeC.
Although the heating time varies depending on the heating temperature, it is preferably 1 minute or more, more preferably 2 minutes or more, and particularly preferably 3 minutes or more from the viewpoint of sufficient sterilization. The upper limit of the heating time is not particularly limited, but is usually 30 minutes.
The heating is performed, for example, after filling a high Brix liquid containing a water-absorbing material into a sealed container (for example, a pouch container). Heating may be performed using a continuous or holding indirect heat exchanger.
The heat sterilization process can be omitted when the water-absorbing material used in the high-brix liquid immersion process, which is the previous process, is sterilized or has no bacteria as a property of the water-absorbing material.

[Moisture penetration process]
The moisture permeation process was obtained after mixing the high Brix liquid containing the water-absorbing material obtained in the previous process (high Brix liquid immersion process or heating process) with the fermented milk mix before fermentation or the fermented milk after fermentation. Leave the fermented milk mix or fermented milk containing the water-absorbing material, let the moisture contained in the fermented milk mix or fermented milk penetrate into the water-absorbing material, and then absorb the water-absorbed thick fermented milk mix or concentrated fermented milk It is a process to obtain.
In the present specification, the “fermented milk mix before fermentation” refers to a raw material of fermented milk (for example, raw milk, which can obtain fermented milk by adding a starter microorganism (for example, lactic acid bacteria) and fermenting it. A product obtained by adding a sweetener, a stabilizer or the like as necessary.
When using a fermented milk mix before fermentation in the moisture permeation process, the concentrated fermented milk mix containing the water-absorbing material absorbed in the water-penetration process is further fermented in the fermentation process to contain the water-absorbing material that has absorbed water. Becomes thick fermented milk. In this case, a conventional fermentation method known as a method for producing fermented milk can be employed as the fermentation step.
In the present invention, the form of fermentation may be either a pre-fermentation type or a post-fermentation type.
In the present invention, “fermented milk after fermentation” refers to a product obtained by adding a starter microorganism (for example, lactic acid bacteria) to a fermented milk mix and fermenting it.

When the target of mixing with the high Brix liquid containing the water-absorbing material is fermented milk after fermentation, the blending ratio of the high Brix liquid containing the water-absorbing material and fermented milk after fermentation is the viscosity of the concentrated fermented milk (measurement It is preferable that the temperature is set to increase in a range of 1,000 mPa · s or more as compared with the viscosity of the fermented milk (measurement temperature: 10 ° C.) before the moisture permeation step. The width is more preferably 1,500 mPa · s or more, and particularly preferably 2,000 mPa · s or more. When the width is 1,000 mPa · s or more, the rich feeling of fermented milk can be further enhanced.
Considering the preferable numerical range of the above viscosity range and the provision of moderate sweetness, the high Brix liquid containing water-absorbing material and the ratio of fermented milk after fermentation (high Brix liquid containing water-absorbing material: fermented milk) are For example, 1: 2 to 1:15 (preferably 1: 3 to 1:12, more preferably 1: 4 to 1:10).

When the object to be mixed with the high Brix liquid containing the water-absorbing material is a fermented milk mix before fermentation, the blending ratio of the high Brix liquid containing the water-absorbing material and the fermented milk mix before fermentation is that of the concentrated fermented milk mix. The viscosity (measurement temperature: 10 ° C.) may be determined to increase in a range of 1,000 mPa · s or more compared to the viscosity (measurement temperature: 10 ° C.) of the fermented milk mix before the moisture penetration step. preferable. The width is more preferably 1,500 mPa · s or more, and particularly preferably 2,000 mPa · s or more. When the width is 1,000 mPa · s or more, the rich feeling of the fermented milk mix (and fermented milk after the fermentation process) before fermentation can be further increased.
Considering the preferable numerical range of the above-mentioned viscosity range and imparting an appropriate sweetness, the mixing ratio of the high Brix liquid containing the water-absorbing material and the fermented milk mix before fermentation (high Brix liquid containing the water-absorbing material: fermented milk mix ) Is, for example, 1: 2 to 1:15 (preferably 1: 3 to 1:12, more preferably 1: 4 to 1:10).

The weight of the water-absorbing material (for example, dried fruit) that has absorbed water is preferably 120% or more, more preferably 150% or more, and still more preferably, based on (100%) before water absorption (before the high Brix liquid dipping step). It is 170% or more, more preferably 180% or more, and particularly preferably 190% or more. The larger the weight, the stronger the flesh feel similar to a raw water-absorbing material (for example, fruit), which is preferable.
The concentration (protein content) of the concentrated fermented milk mix or concentrated fermented milk is preferably at least 102% based on the concentration (protein content) of the fermented milk mix or fermented milk at the time prior to the moisture infiltration step (protein content). More preferably, it is 103% or more, further preferably 104% or more, and particularly preferably 105% or more. The higher the concentration, the stronger the rich feeling of the concentrated fermented milk mix or concentrated fermented milk, which is preferable.
Although the upper limit of this density | concentration is not specifically limited, For example, in the case of dried fruit, it is 300% normally.

Hereinafter, the present invention will be described by way of examples. The following examples do not limit the present invention, and the present invention can take various embodiments as long as they do not depart from the scope of the claims.
[Example 1]
45 parts by weight of dry mango (water content: 13.7% by weight) and high Brix solution (30% by weight of reduced starch syrup, 14% by weight sucrose sugar, 2.5% by weight concentrated apple juice; Brix value: 73 ) After 55 parts by weight were mixed to obtain a mixture, this mixture was hermetically filled in a pouch container to obtain a pouch container containing the mixture. Next, the pouch container containing this mixture was sterilized by heating at 95 ° C. for 4 minutes.
After sterilization, the mixture was taken out from the pouch container, and the moisture content of the dry mango contained in the mixture was measured. As a result, the moisture content was 24.7% by weight and not more than 50% by weight (to satisfy the above-described present invention). The range of water content).
On the other hand, the mixture taken out from the sterilized pouch container and soft yoghurt (viscosity: 2,880 mPa · s at 10 ° C .; protein content: 5.0% by weight) are mixed at a weight ratio of 1: 4 and mixed. These mixtures (concentrated fermented milk containing the water-absorbing material of the present invention) were stored at a refrigeration temperature (10 ° C.) for 16 days from that time.

After storage, the viscosity (measurement temperature: 10 ° C.) of yogurt (the part other than dry mango in the mixture) was measured, and the viscosity on the 8th day was 5,900 mPa · s, and the viscosity on the 16th day was 6,220 mPa · s. The yogurt concentration (protein content: 5.6% by weight) was 112% based on the standard (100%) of the soft yogurt concentration (protein content: 5.0% by weight) before mixing with the mixture. It was.
On the other hand, the weight of the dry mango after storage (water swelled and swollen) was 191% based on the reference (100%) before mixing with the high Brix solution.
When the dry mango after storage (water-swelled and swollen) was visually observed, it had an appearance similar to that of a raw mango.
Furthermore, when the mixture after storage (containing yogurt and dry mango swollen after absorbing water) was eaten, yogurt had a rich flavor compared to normal yogurt while having a natural flavor. Was. The dry mango which swelled by absorbing water had a texture (fruit feeling) close to that of raw mango. When the mixture after storage was kept at 10 ° C. for 18 days, no microbial contamination was observed.

[Comparative Example 1]
Dry mango (water content: 13.7% by weight) and soft yoghurt (viscosity: 2,000 mPa · s at 10 ° C .; protein content: 5.2% by weight) are mixed at a weight ratio of 9:91 and mixed. The mixture was stored at refrigeration temperature (10 ° C.) for 16 days from the time when it was taken.
After storage, the viscosity of yogurt (measurement temperature: 10 ° C.) was measured and found to be 6,625 mPa · s. The yogurt concentration (protein content: 5.7% by weight) was 110% based on the standard (100%) of the yogurt concentration (protein content: 5.2% by weight) before mixing with dry mango. It was.
On the other hand, the weight of the dried and dried mango after storage was 164% based on the reference (100%) before mixing with soft yogurt.
When the dried mango that was swollen after storage after water absorption was visually observed, it had an appearance similar to that of a raw mango.
Furthermore, when the mixture after storage was eaten, the yogurt had a rich taste as compared with normal yogurt while having a natural flavor. The dry mango which swelled by absorbing water has a raw texture close to that of dry (dry), but the texture of raw mango (feel of flesh) was insufficient as compared with Example 1.
On the other hand, when the mixture after storage was kept at 10 ° C. for 2 weeks, mold was detected and microbial contamination occurred.

Claims (8)

An edible solid water-absorbing material is soaked in a high Brix solution that has a large Brix value so that the water-absorbing material does not absorb water or can maintain its water-absorbing capacity. Brix liquid immersion process,
After mixing the high Brix liquid containing the water-absorbing material and the fermented milk mix before fermentation or the fermented milk after fermentation, the fermented milk mix or fermented milk containing the obtained water-absorbing material is left to stand, and the fermented milk mix or Moisture permeation step for allowing moisture contained in fermented milk to penetrate into the above water-absorbing material and obtaining a concentrated fermented milk mix or concentrated fermented milk containing the absorbed water-absorbing material,
A method for producing concentrated fermented milk containing a water-absorbing material.   2. The method for producing concentrated fermented milk containing a water-absorbing material according to claim 1, wherein the water content of the water-absorbing material before dipping in the high-Brix solution is 50% by weight or less.   3. The edible solid water-absorbing material in the high Brix liquid dipping step comprises at least one selected from dried fruits, dried vegetables, jelly, gummy, marshmallow, candy, gum, agar, and konjac. A method for producing a concentrated fermented milk containing the water-absorbing material as described in 1.   The method for producing concentrated fermented milk containing a water-absorbing material according to any one of claims 1 to 3, wherein the high Brix liquid used in the high Brix liquid immersion step has a Brix value of 50 or more.   5. The high Brix solution used in the high Brix solution immersion step comprises one or more selected from sugar solution, sugar alcohol solution, dietary fiber solution, concentrated fruit juice, honey, and maple syrup. A method for producing a concentrated fermented milk containing the water-absorbing material according to Item.   The water-absorbing material is contained in any one of claims 1 to 5 including a heat sterilization step of heating and sterilizing the high-Brix solution containing the water-absorbing material between the high-Brix liquid immersion step and the water permeation step. Of producing concentrated fermented milk.   In the water permeation step, the viscosity of the concentrated fermented milk mix or the concentrated fermented milk is increased to a value of 1,000 mPa · s or more compared to the time before the water permeation step. The method for producing concentrated fermented milk containing a water-absorbing material according to any one of claims 1 to 6, wherein a blending ratio of the high Brix liquid and the fermented milk mix before fermentation or the fermented milk after fermentation is determined.   The concentrated fermentation containing a water-absorbing material according to any one of claims 1 to 7, wherein in the water permeation step, the weight of the water-absorbing material that has absorbed water is 120% or more with reference to (100%) before water absorption. Milk production method.