JP6650716B2 - Manufacturing method of soft yogurt - Google Patents

Description

The present invention relates to a method for producing a stirred fermented milk, which comprises a step of mixing an auxiliary raw material solution with the fermented milk.
In the present invention, the term "stirred fermented milk" means soft yogurt and does not include drink yogurt or frozen yogurt.

  Stirred fermented milk is fermented milk produced by a method in which a curd in a fermented product obtained by fermenting a raw material of fermented milk is crushed and then filled into a container, and is also referred to as a pre-fermented fermented milk.

2. Description of the Related Art In recent years, stirred fermented milk having improved functionality and taste by adding a raw material other than a milk raw material (hereinafter, referred to as “auxiliary raw material”) as a main raw material of fermented milk has been provided. Some of the auxiliary ingredients used in the production of stirred fermented milk are those that are not suitable for fermentation by mixing with milk ingredients in advance, such as those that are sensitive to heating, those that inhibit fermentation of lactic acid bacteria, and those that easily precipitate. There is.
Therefore, in the production of stirred fermented milk containing such auxiliary ingredients, after crushing the curd in the fermented milk base obtained by fermenting the milk ingredients, adding the auxiliary ingredients to the crushed fermented milk base, mixing Is done. In the addition and mixing of the auxiliary material, generally, from the viewpoint of the efficiency, a material obtained by dissolving or dispersing the auxiliary material in water or a liquid auxiliary material (hereinafter collectively referred to as “auxiliary material solution”) is preferably used. .

However, when the auxiliary raw material solution is mixed with the fermented milk base, there is a problem that the milk component concentration of the fermented milk produced by mixing the auxiliary raw material solution is reduced, and a sufficiently desirable viscosity as a product cannot be obtained.
For this reason, it has been practiced to increase the concentration of fermented milk-based milk components (particularly, protein) in consideration of the amount of the added auxiliary raw material solution (for example, see Patent Document 1).

In addition, the following is reported as a technique for increasing the viscosity of stirred fermented milk.
Patent Document 1 describes that fermentation is performed by adding a lactic acid bacterium starter belonging to Lactobacillus bulgaricus and Streptococcus thermophilus having high viscous production performance to a mix as a raw material liquid.
Patent Document 2 discloses that a whey powder and / or whey protein concentrate is added to a raw material of fermented milk, and selected from microorganisms having a high viscous production ability belonging to Lactobacillus bulgaricus and Streptococcus thermophilus. It describes that a lactic acid bacterium starter is added for fermentation.

JP-A-1-235543 JP-A-6-14708

  The method of increasing the protein concentration of the fermented milk base described above has a certain effect on suppressing the viscosity decrease of the stirred fermented milk, but it is easy to feel the roughness derived from the protein, the texture becomes powdery, and the flavor is increased. There was a tendency for it to be undesirable.

  Further, the methods using specific lactic acid bacteria as described in Patent Documents 1 and 2 have problems in obtaining and managing them.

Therefore, an object of the present invention is to provide a novel technique for suppressing a decrease in viscosity of a stirred fermented milk containing an auxiliary raw material solution.
In particular, an object of the present invention is to provide a novel technique for suppressing a decrease in the viscosity of the stirred fermented milk without deteriorating the texture and flavor.
In the present specification, “suppressing a decrease in viscosity” means suppressing a decrease in the viscosity of a product caused by mixing an auxiliary raw material solution with a fermented milk base.

  The present invention to solve the above-mentioned problems, the starter is added to the fermented milk raw material, a step of preparing a fermented milk base by fermentation, a step of crushing the prepared fermented milk base, the crushed fermented milk base, the crushed fermented milk base, This is a method for producing stirred fermented milk, which comprises the step of mixing an auxiliary raw material solution to prepare stirred fermented milk within 10 minutes after crushing.

  By using this production method, it is possible to suppress a decrease in viscosity in producing a stirred fermented milk containing an auxiliary raw material solution. That is, by using the present production method, it is possible to obtain a sufficient viscosity required for a stirred fermented milk without increasing the protein concentration of the fermented milk base, thereby providing a stirred fermented milk having a smooth texture. can do.

In a preferred embodiment of the present invention, the mixing amount of the auxiliary material solution is 3% by mass or less based on the fermented milk base mixed with the auxiliary material solution.
By setting the content of the auxiliary raw material solution in the above range, the viscosity of the stirred fermented milk can be set in a particularly favorable range.

In a preferred embodiment of the present invention, the auxiliary raw material solution contains, for example, any one selected from the group consisting of proteins, carbohydrates, inorganic salts, vitamins, flavors, sweeteners, and food additives.
Many of these components are denatured by heating, or affect fermentation, or react with milk components to form a precipitate. is there.

According to the method for producing a stirred fermented milk of the present invention, it is possible to provide a stirred fermented milk containing an auxiliary material excellent in palatability and functionality and having a good viscosity.
The method for producing stirred fermented milk of the present invention does not require special raw materials or equipment, and can be carried out using conventional production equipment, and thus has high utility in industrial production.

It is a schematic process drawing showing an embodiment of a manufacturing method of the present invention. It is a graph which shows the viscosity change of each stirring type fermented milk which mixed room temperature water with the fermented milk base (low-fat type) immediately after crushing, and every 10 minutes-60 minutes after crushing. It is a graph which shows the viscosity change of each stirring-type fermented milk which mixed room temperature water with the fermented milk base (fat containing type) immediately after crushing, and every 10 minutes-60 minutes after crushing. Stirred fermented milk in which room temperature water was mixed 10 minutes after crushing with the fermented milk base, and the protein concentration of the fermented milk base was increased in advance, and the fermented milk base was mixed with room temperature water 16 hours after crushing. It is a graph which shows the viscosity change of fermented milk. Stirred fermented milk in which room temperature water was mixed 10 minutes after crushing with the fermented milk base, and the protein concentration of the fermented milk base was increased in advance, and the fermented milk base was mixed with room temperature water 16 hours after crushing. It is a graph which shows the particle size distribution of each sample 40 hours after crushing of fermented milk.

Hereinafter, embodiments for carrying out the present invention will be described.
In the present specification, the classification of milk and dairy products is based on “Ministerial ordinance on milk and dairy product ingredient specifications” (hereinafter referred to as “dairy ordinance”) unless otherwise specified.
In the present specification, “%” percentage is expressed by mass unless otherwise specified.

  FIG. 1 schematically shows the steps of the embodiment of the method for producing a stirred fermented milk of the present invention. Hereinafter, each step will be described.

<1> Preparation of fermented milk base In the production method of the present invention, a fermented milk base is prepared by adding a starter to the fermented milk raw material and fermenting.
In the present invention, the “fermented milk raw material” is a raw material obtained by preparing various raw materials including fermented milk raw materials such as milk and dairy products used in the production of fermented milk. Cream, skim-concentrated milk, skim milk powder and the like are preferably used as milk products in the raw material of fermented milk. Further, as the fermented milk raw material, any raw material that can be used in the production of fermented milk can be used as long as fermentation milk is not hindered.

  As the starter, those usually used in the production of fermented milk can be used. As the lactic acid bacteria used in the present invention, those usually used for the production of fermented milk can be used without any particular limitation. For example, as Lactococcus genus bacteria, Lactococcus lactis (L. lactis), Lactococcus lactis subsp. Lactis, Lactococcus lactis subsp. Lactis bio Strains such as L. lactis subsp. Lactis biovar. Diacetylactis and L. lactis subsp. Cremoris have been identified as genus Lactobacillus as Lactobacillus strains.・ L. delbrueckii subsp. Bulgaricus (L. delbrueckii subsp. Bulgaricus), Lactobacillus reuteri (L. delbrueckii subsp. Bulgaricus) . reuteri), easy Strains, such as Bacillus helveticus (L. helveticus) are as Streptococcus (Streptococcus) genus, Streptococcus salivarius subsp thermophilus (S. salivarius subsp. Thermophilus) (Streptococcus thermophilus) strains, such as are used.

The amount of the lactic acid bacterium can be appropriately adjusted within a usual range. For example, it is preferable to add an amount such that the bacterial concentration in the raw material of fermented milk is at least 1 × 10 ⁵ CFU / g, and preferably at least 1 × 10 ⁷ CFU / g.

  In addition to the lactic acid bacteria, bacteria belonging to the genus Bifidobacterium can also be used. For example, B. longum, B. breve, B. bifidum, B. infantis (B. infantis) ) Can be used.

  The method of adding the starter is not particularly limited, and it can be added in the form of bacterial powder or in the state of culture (culture).

  The fermentation temperature may be within a range in which bacteria such as lactic acid bacteria can grow efficiently, and is usually 30 to 50 ° C, preferably 35 to 43 ° C. The fermentation may be carried out until the lactic acid bacteria have sufficiently grown. Usually, the fermented milk raw material has a pH of 5.0 or less, preferably has a pH of 4.8 or less, more preferably has a pH of 4 or less. It may be carried out until it becomes approximately .2 to 4.8. The fermentation time is about 3 to 10 hours, preferably about 3 to 6 hours when the culture temperature is about 35 to 43 ° C.

<2> Crushing of curd Subsequently, the curd in the fermented milk base obtained by the method described above is crushed. Any of a filter method, a pressure valve method, a mixer method, and the like may be used for crushing the curd.
Crushing of the card can be performed using a commonly used crushing device. For example, crushing by a filter method can be performed by, for example, installing a filter in a conduit for supplying a fermented milk base and continuously feeding the fermented milk base toward a filter installation portion in the conduit. The shape of the filter can be used without any particular limitation, such as a flat shape or a cylindrical shape. Examples of such a filter include a cross filter (manufactured by rubberfub) and a notch wire (manufactured by Fujitok).

  Crushing by the pressure valve method can be performed by a device called a diaphragm valve or a back pressure valve. Examples of the diaphragm valve include a valve manufactured by GEMU, and examples of the back pressure valve include a valve manufactured by Kofloc Corporation.

The thus obtained crushed fermented milk-based non-fat milk solid content is preferably larger than 8% by mass from the viewpoint of satisfying the specification of fermented milk (the non-fat milk solid content is 8.0% by mass or more). is necessary. The solid content of non-fat milk based on fermented milk can be determined in consideration of the amount of an auxiliary material solution described below as long as the above conditions are satisfied. The upper limit of the solid content of non-fat milk based on fermented milk is preferably 13% by mass, more preferably 12% by mass, and particularly preferably 11% by mass.
In addition, the protein content of the fermented milk base is preferably 3.8 to 5% by mass, more preferably 4 to 4.8% by mass, and particularly preferably 4.2 to 4.6% by mass.

The fat content of the fermented milk base is preferably 4% by mass or less, more preferably 3.5% by mass or less, and particularly preferably 0.5% by mass or less.
This is because when the fat content of the fermented milk base is low, the viscosity tends to be reduced particularly by mixing the auxiliary raw material solution. In addition, when the fermented milk-based fat content is low, the conventional method of increasing the fermented milk-based protein content is difficult to use because the protein-derived graininess (flouriness) is easily felt. The method of the invention is very useful. In particular, when a fermented milk base having a fat content of 0.5% by mass or less is used, the viscosity tends to decrease due to the mixing of the auxiliary raw material solution, and the protein-based roughness (powder) has a low fat content. ), The effect of the production method of the present invention becomes remarkable.

<3> Mixing of auxiliary raw material solution Subsequently, the auxiliary raw material solution is mixed with the crushed fermented milk base. Here, the mixing of the auxiliary raw material solution is performed immediately after crushing the curd in the fermented milk base and within 10 minutes after crushing. In the industrial production line, the point at which the crushed material (fermented milk base) is discharged from the crusher can be regarded as immediately after crushing.

  The auxiliary material contained in the auxiliary material solution is not particularly limited as long as it can be dissolved or dispersed in water. For example, proteins, carbohydrates, inorganic salts, vitamins, flavors, sweeteners, and food additives. The auxiliary raw material solution may contain these components alone or in combination of two or more. Examples of the auxiliary raw material solution include a lactoferrin solution and a calcium solution. Further, a liquid composition containing plural kinds of the above components such as fruit juice may be used.

  The auxiliary material solution is appropriately sterilized and then added to and mixed with the fermented milk base. The mixing amount of the auxiliary raw material solution is not particularly limited as long as it is within a range conforming to the specification of fermented milk, but is usually 10% by mass or less, preferably 5% by mass or less, based on the total amount of the auxiliary raw material solution and the fermented milk base. It is preferably at most 3% by mass. In the production of stirred fermented milk, a decrease in viscosity due to the mixing of the auxiliary raw material solution is likely to occur when water is mixed in a certain amount or more. Therefore, when the mixing amount of the auxiliary material solution is 1% by mass or more, particularly 2% by mass or more based on the mixing amount of water, based on the total amount of the auxiliary material solution and the fermented milk base, the production method of the present invention is particularly effective. Useful.

  In addition, the temperature at the time of adding the auxiliary material solution can be set in a range of 5 to 40 ° C.

  The viscosity of the fermented milk base at the time of mixing the auxiliary raw material solution is preferably 500 to 2000 mPa · s. By mixing an auxiliary raw material solution with a fermented milk base having such a viscosity, a stirred fermented milk having a preferable viscosity can be produced.

  The temperature of the fermented milk base at the time of mixing the auxiliary material solution is preferably 5 to 43 ° C.

As described above, by mixing the auxiliary raw material solution with the fermented milk base, a stirred fermented milk is produced.
The manufactured stirred fermented milk shows an increase in viscosity over time. The viscosity of the stirred fermented milk produced by the production method of the present invention when provided to consumers is preferably in the range of 2700 to 5500 mPa · s.
It is to be noted that the stirred fermented milk is generally provided to the consumer in about 40 hours to 10 days from the end of crushing the curd in the fermented milk base during the production process.
Therefore, the stirred fermented milk produced by the production method of the present invention, the curd crushing in the fermented milk base is completed, and at 10 ° C. within a period of 40 hours to 10 days after the addition of the auxiliary raw material solution. The viscosity is preferably in the range of 2700 to 5500 mPa · s, and more preferably in the range of 3800 to 5500 mPa · s.

The stirred fermented milk is filled into a container having a volume of about 80 to 500 ml, preferably about 80 to 250 ml, and sealed. The product in the container is usually stored at 10 ° C. or lower, preferably 5 ° C. or lower.
The container is preferably made of paper, glass, or plastic (for example, polypropylene, polyethylene terephthalate (PET), polystyrene, or polyethylene).

<4> Other Steps In the present invention, in addition to the steps described above, steps such as sterilization and cooling of raw materials usually performed in the production of fermented milk can be appropriately performed.

Fermented milk bases A to C were produced using the following raw materials and methods.
Non-fat concentrated milk: non-fat milk solids 34.6% by mass, fat 0.36% by mass, Morinaga Milk Products WPI (whey protein isolate): 94.6% by mass non-fat milk solids, fat 0 5% by mass, Fonterra Cream: 45% by weight of fat, Morinaga Dairy Co. Starter: Lactic acid bacteria starter (Premium 1.0), Christian Hansen

  According to the composition shown in Table 1, fermented milk raw materials were prepared. The prepared fermented milk material was inoculated with a starter at 0.02% by mass and fermented at 40 ° C. When the pH reached 4.5, the curd was crushed by a filter-type crusher, and the fermentation was terminated by cooling to 10 ° C. to prepare a fermented milk base.

Table 2 shows the composition of the manufactured fermented milk base.
Fermented milk base A is a so-called normal non-fat type fermented milk base, and fermented milk base B is a fermented milk base in which protein-based non-fat milk solid content is increased relative to fermented milk base A. is there.
Fermented milk base C is a conventional fat-containing type fermented milk base.

<Test 1> Examination of mixing timing of fermented milk base and auxiliary raw material solution In this test, the effect of mixing timing of auxiliary raw material solution to fermented milk base on viscosity change of stirred fermented milk was examined. did. In this test, room temperature water was used as a substitute for the auxiliary raw material solution.

(1) Non-fat type stirred fermented milk Fermented milk base A produced by the method described above was mixed with room-temperature water at the timing shown in Table 3 (Test Examples 1 to 7). The mixing amount of the room temperature water was 3% by mass based on the total amount of the fermented milk base and the room temperature water. In addition, as Reference Example 1, a test was similarly performed in the case where the same amount of room temperature water was added to the raw material of fermented milk before fermentation. The temperature of the fermented milk base at the time of adding the normal temperature water is as described in Table 3.

  Immediately after the end of crushing, 16 hours, 40 hours, and 7 days after the end of crushing, the viscosity at 10 ° C. of each manufactured stirred fermented milk was measured. The viscosity was measured using a B-type viscometer. The value (unit: mPa · s) after 10 seconds from the start of the measurement when the rotation was measured at 60 rpm using a 4-rotor was defined as the measured value of the viscosity.

The results are shown in Table 4 and FIG.
As can be seen from FIG. 2, all of the stirred fermented milks of Test Examples 1 to 7 showed an increase in viscosity over time immediately after crushing. Regarding the stirred fermented milk of Test Example 1 in which room temperature water was mixed immediately after crushing and the stirred fermented milk of Test Example 2 in which room temperature water was mixed 10 minutes after crushing, 16 hours, 40 hours, and 7 hours after the end of crushing The viscosity increased remarkably with the passage of days and time, and the viscosity after 40 hours to 7 days showed a significantly higher value than the viscosity of the stirred fermented milk of Test Examples 3 to 7.

  Looking at specific numerical values, the stirred fermented milks of Test Example 1 and Test Example 2 each exhibit a viscosity of 3500 mPa · s or more after crushing 16 hours, and a viscosity of 3800 mPa · s or more after crushing 40 hours. Indicated. Further, these stirred fermented milks showed an increase in viscosity even after 40 hours, and showed a viscosity of 4400 mPa · s or more after 7 days. Here, after 40 hours of crushing, it is generally a measure of the time to ship the product. That is, by adding and mixing the auxiliary raw material solution within 10 minutes immediately after crushing the fermented milk base, a decrease in the viscosity of the stirred fermented milk is suppressed, and it is possible to provide a stirred fermented milk having a favorable texture. I understand.

(2) Stirred Fermented Milk of Fat-Containing Type Room-temperature water was mixed with the fermented milk base C produced by the method described above at the timing shown in Table 5 (Test Examples 8 to 14). The mixing amount of the room temperature water was 3% by mass based on the total amount of the fermented milk base and the room temperature water. In addition, as Reference Example 2, the same test was conducted for the case where the same amount of room temperature water was added to the raw material of fermented milk before fermentation. The temperature of the fermented milk base at the time of adding the normal temperature water is as described in Table 5.

  The viscosity at 10 ° C. of each manufactured stirred fermented milk immediately after crushing, 16 hours after crushing, 40 hours after crushing, and 7 days after crushing was measured by the above-described method.

The results are shown in Table 6 and FIG.
As can be seen from FIG. 3, all of the stirred fermented milks of Test Examples 8 to 14 showed an increase in viscosity over time immediately after crushing. For Test Example 8 in which room-temperature water was mixed immediately after crushing and in Test Example 9 in which room-temperature water was mixed 10 minutes after crushing, the viscosity was remarkable as time elapses, 16 hours, 40 hours, and 7 days after crushing. The viscosity after 40 hours to 7 days showed a remarkably high value as compared with the viscosities of Test Examples 10 to 14.

Looking at specific numerical values, the stirred fermented milks of Test Examples 8 and 9 all show a viscosity of 3800 mPa · s or more after 16 hours of crushing and a viscosity of 4300 mPa · s or more after 40 hours of crushing. Indicated. In addition, these stirred fermented milks showed an increase in viscosity even after 40 hours of crushing, and had a viscosity of 5000 mPa · s or more after 7 days of crushing.
In addition, in the production of the stirred fermented milk in which the auxiliary raw material solution is added using the normal fat-containing fermented milk base C, even if the auxiliary raw material solution (normal temperature water) is mixed after 20 minutes of crushing, The viscosity increased after 40 hours, and the viscosity was 5000 mPa · s or more after 7 days of crushing (Test Example 10).

<Test 2> Comparison with a method of increasing the protein concentration of fermented milk base In this test, the method of the present invention in which the auxiliary raw material solution was mixed with the fermented milk base immediately after crushing and within 10 minutes after crushing, What is the difference in viscosity change and palatability of stirred fermented milk between the conventional method of increasing the protein concentration of the base and mixing the auxiliary material solution before filling the container (for example, 16 hours after crushing)? A comparison was made to see if there was any. In this test, room temperature water was used as a substitute for the auxiliary raw material solution.

  Room temperature water was mixed with the fermented milk base A produced by the method described above 10 minutes after crushing (Test Example 15). Further, room temperature water was mixed with fermented milk base B (having a higher protein content than fermented milk base A) 16 hours after crushing (Test Example 16). The mixing amount of the room temperature water was 3% by mass based on the total amount of the fermented milk base and the room temperature water. The temperature of the fermented milk base at the time of adding the normal temperature water was 10 ° C. in all cases.

(1) Evaluation of viscosity The viscosity of each stirred fermented milk was measured in the same manner as in Test 1.
The results are shown in Table 7 and FIG.
As can be seen from FIG. 4, both the stirred fermented milks of Test Examples 15 and 16 showed an increase in viscosity over time immediately after crushing. In Test Example 16 in which the protein concentration of the fermented milk base was increased in advance, the viscosity increase was gradual at 16 hours, but the viscosity increased remarkably as time passed after 40 hours and 7 days. . On the other hand, for Test Example 15 in which room temperature water was mixed 10 minutes after the crushing, 16 hours after the end of the crushing, 40 hours after, and 7 days after, the viscosity increased remarkably as time passed, and 40 hours after the end of the crushing, After 7 days, the viscosity was the same as that of Test Example 16.

  From this, according to the method of the present invention in which the auxiliary raw material solution is added to the fermented milk base immediately after crushing and within 10 minutes after crushing and mixed, the protein concentration of the fermented milk base can be increased without increasing the protein concentration in advance. It has been found that the decrease in viscosity can be suppressed as in the conventional method in which the viscosity is increased.

(2) Sensory Evaluation Four specialized panelists ate the stirred fermented milk 40 hours after crushing, and evaluated which of the stirred fermented milks in Test Examples 15 and 16 felt powdery.
As a result, all the panelists evaluated that the stirred fermented milk of Test Example 16 was powdery.

(3) Particle Size Measurement For the stirred fermented milks of Test Examples 15 and 16, the particle size distribution of the sample 40 hours after crushing was measured. The particle size distribution was measured using a laser diffraction / scattering particle size distribution analyzer LA-950 (manufactured by HORIBA).

FIG. 5 shows the results. In FIG. 5, almost all the measured particles are covered, and the horizontal axis of the graph represents the actual particle diameter (unit: μm), and the vertical axis represents the ratio of the particle having the particle diameter to all the particles. Represents.
Although any stirred fermented milk had a particle size peak around 20 μm, the stirred fermented milk of Test Example 15 had a particle diameter of 40 μm or more compared to the stirred fermented milk of Test Example 16. Was reduced by about 10%. Here, the particles having a particle size of 40 μm or more cause “graininess” and “powderness” with respect to the texture of the fermented milk.
According to the method of the present invention in which the auxiliary raw material solution is added and mixed within 10 minutes from immediately after crushing with respect to the fermented milk base, the content of particles causing roughness can be reduced, and the stirring type having a smooth texture can be obtained. It was found that fermented milk could be obtained.

The reason why the above-described effects can be obtained by the method of the present invention can be considered as follows.
After the card is crushed, the viscosity increases with time because a network structure centered on the protein destroyed by the crushing is reconstructed. Here, it is considered that the auxiliary material solution is mixed at a relatively early stage in the reconstruction of the network structure, whereby the network structure is constructed while uniformly taking in the auxiliary material solution. As a result, it is possible to suppress the generation of agglomerates that cause roughness, and a smooth structure having a certain or more viscosity is constructed.
In particular, when a fermented milk base having a fat content of 0.5% by mass or less is used, aggregation of proteins is likely to occur, and the speed of reconstruction of the network structure after crushing is increased. It is considered that if the delay is too long, the viscosity tends to decrease. Therefore, the method of the present invention is particularly useful when a fermented milk base having a fat content of 0.5% by mass or less is used.

  From the above test results, according to the method of the present invention in which an auxiliary material solution is added to the fermented milk base immediately after crushing and within 10 minutes after crushing and mixed, a conventional method of increasing the protein concentration of the fermented milk base and It was found that it was possible to produce a stirred fermented milk having a smooth texture and fine particles, while achieving the same viscosity.

<Example 1> Production of yogurt containing lactoferrin (1) Preparation of fermented milk base 30% by mass of defatted concentrated milk (manufactured by Morinaga Dairy) and 5.5% by mass of 45% by mass cream (manufactured by Morinaga Milk). , 0.5 mass% of WPI (manufactured by Fonterra) and 6 mass% of sugar are mixed and dissolved to prepare a fermented milk raw material, and the fermented milk raw material is heated to 70 ° C. in a hot water bath and homogenized. did. Next, the mixture was heated to 90 ° C., kept for 5 minutes, and sterilized. The fermented milk raw material after sterilization is once cooled to 40 ° C. in a cooling tank, and thereafter, a mixed starter (manufactured by Christian Hansen Co.) of Bulgaricus bacterium and Thermofils bacterium is added to the fermented milk raw material at 0.02% by mass. Then, the fermentation was carried out at 40 ° C., and when the lactic acid acidity reached 0.80%, the fermentation was terminated to prepare a fermented milk base. The value of lactic acidity is determined by the “Method for measuring acidity of milk and dairy products” in “Ministry Ordinance on Milk and Dairy Product Component Standards” (0.1 mol / l sodium hydroxide solution using phenolphthalein as an indicator). (Measurement by titration according to Example 1).
(2) Preparation of lactoferrin solution 3.5% by mass of lactoferrin (manufactured by Morinaga Milk Industry Co., Ltd.) was dissolved in water, heated to 80 ° C. in a water bath, and sterilized by holding for 5 minutes. Then, it cooled to 10 degreeC in the cooling layer, and prepared the lactoferrin solution.
(3) Mixing of fermented milk base and lactoferrin solution The fermented milk base prepared in the above (1) is crushed by a crusher using a crusher, and immediately after crushing (within 1 minute), the lactoferrin solution prepared in the above (2) is mixed with The fermented milk base mixed with the base and the lactoferrin solution was adjusted to 3% by mass based on the total amount of the lactoferrin solution, and the fermented milk base mixed with the lactoferrin solution was cooled to 10 ° C. to produce a fermented milk containing lactoferrin (stirred type).
(4) Measurement of Viscosity The viscosity of the manufactured stirred fermented milk is 1850 mPa · s immediately after crushing, 3650 mPa · s after 16 hours of crushing, 4240 mPa · s after 40 hours of crushing, and 4860 mPa · s after 7 days of crushing. s, and it was confirmed that the milk had a viscosity suitable for stirring fermented milk.

  INDUSTRIAL APPLICABILITY The present invention is suitable for producing a stirred fermented milk containing auxiliary ingredients.

Claims (3)

Add the starter to the fermented milk raw material, the step of preparing the fermented milk base by fermenting, the step of crushing the prepared fermented milk base, the crushed fermented milk base, immediately after the crushing within 10 minutes after crushing, method for producing a soft yoghurt comprising the step, for preparing a soft yogurt by mixing auxiliary raw material solution. The method for producing soft yogurt according to claim 1, wherein the mixing amount of the auxiliary material solution is 3% by mass or less based on the fermented milk base mixed with the auxiliary material solution. The method for producing a soft yogurt according to claim 1, wherein the auxiliary raw material solution contains any one selected from the group consisting of proteins, carbohydrates, inorganic salts, vitamins, flavors, sweeteners, and food additives. .