Method for producing fermented milk and fermented milk-like acidic gel
By adjusting pH and solid content in milk to its isoelectric point and adding lactic acid, the method produces fermented milk and acidic gels with controlled hardness and flavor, addressing flavor alteration and storage needs in existing methods.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MEGMILK SNOW BRAND CO LTD
- Filing Date
- 2022-03-29
- Publication Date
- 2026-05-12
AI Technical Summary
Existing methods for producing fermented milk and fermented milk-like acidic gels are limited by the use of specific acidification agents, which can alter flavor and require fermentation processes, and often necessitate dedicated storage for temperature control.
A method involving adjusting the pH of milk to near its isoelectric point and controlling the solid content concentration to produce gels without fermentation, using lactic acid to maintain flavor and hardness, and optionally adding lactic acid bacteria or yeast.
Enables the production of versatile, flavor-preserving fermented milk and acidic gels with controlled hardness, eliminating the need for fermentation and dedicated storage.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a method for producing fermented milk and fermented milk-like acidic gels.
Background Art
[0002] Fermented milk is a food in which milk protein is coagulated by acid. Therefore, when producing fermented milk, lactic acid bacteria must be inoculated into raw milk and a fermentation process of acid-coagulating the raw milk must be passed through. In particular, in the case of set-type fermented milk, there are problems such as the need for a dedicated fermentation storage and a cooling storage, and the need to secure a large space for temperature control. As a method for producing fermented milk-like acidic gels without using lactic acid bacteria or a fermentation storage, there is the following prior art.
[0003] Patent Documents 1 and 2 disclose a method for producing an acid-coagulable milk food excellent in thermal stability and physical properties by adjusting the pH of raw milk to 5.5 to 6.2 with citric acid or phosphoric acid and performing ultrafiltration treatment. Patent Document 3 discloses a method for acidifying and gelling milk by adding 0.3 to 0.6% of glucono-delta-lactone to milk or soy milk and reacting it in the temperature range of 10 to 40°C. Patent Document 4 discloses a step of blending a citrate and a thickener in a raw material liquid containing milk components and adjusting the pH of the raw material liquid to weakly acidic of 5.1 to 6.5, and suppressing the aggregation of protein in a weakly acidic gel-like milk processed product by setting the weight ratio of fat / protein in raw milk to 1.8 or less. However, in Patent Documents 1, 2, and 3, the means of acidification are limited methods such as phosphoric acid, citric acid, and glucono-lactone, respectively. In addition, Patent Document 4 is also a limited method because, in addition to the means of acidification being citric acid, it gels milk by the raw material composition and the blending of a thickener. Furthermore, since these methods add specific components for acidification, there is a possibility that the composition and flavor may be different from those of fermented milk obtained by fermenting lactic acid bacteria.
Prior Art Documents
Patent Documents
[0004] [Patent Document 1] Japanese Patent Publication No. 2018-64482 [Patent Document 2] Japanese Patent Publication No. 2018-64481 [Patent Document 3] Patent No. 4827100 [Patent Document 4] Japanese Patent Publication No. 2017-55751 [Overview of the project] [Problems that the invention aims to solve]
[0005] The present invention aims to provide a novel method for producing a milk acidic gel that is highly versatile and has minimal impact on flavor. Specifically, it aims to provide a novel method for producing fermented milk and a fermented milk-like acidic gel without going through a fermentation process. [Means for solving the problem]
[0006] The inventors of this invention diligently studied to solve the above problems and discovered that the hardness of gel-like foods can be controlled by adjusting the milk protein in the raw milk to near its isoelectric point and by controlling the solid content concentration in the raw milk, thus completing the present invention. In other words, the present invention includes the following steps. <1> A method for producing fermented milk and a fermented milk-like acidic gel, comprising the following steps: (1) A process of providing a prepared milk containing 10-20% by weight of solids. (2) A process to control the temperature of the above-mentioned prepared milk to 0-10°C. (3) The process of adjusting the pH of the above-mentioned formula milk to 4.0-5.2 The manufacturing method comprising the above. <2> The step of providing a blended milk containing 10-20% by weight of the solids in step (1) above is a step of providing raw milk, skim milk, reconstituted milk, reconstituted skim milk, or milks to which auxiliary ingredients have been added. <1> The manufacturing method described above. <3> The process includes step (3) followed by step (4), in which the pH-adjusted formula milk is left to stand at a temperature between 10 and 35°C. <1> or <2> The manufacturing method described above. <4> Furthermore, the following steps (5) are included. <1> ~ <3> A manufacturing method described in any of the following. (5) A step in which, in any one or more of steps (1) to (4) above, one or a combination thereof is added to the prepared milk: lactic acid bacteria, bifidobacteria, and yeast. <5> The step of adjusting the pH of the prepared milk in step (3) above to 4.0 to 5.2 is, This is a process that involves adjusting the solution using organic acids. <1> ~ <4> A manufacturing method described in any of the following. <6> It does not include the fermentation process. <1> ~ <5> A manufacturing method described in any of the following. <7> <1> ~ <6> Fermented milk and fermented milk-like acidic gel produced by the manufacturing method described in any of the above. <8> A method for gelling milk, comprising the step of adjusting the pH of a prepared milk containing 10-20% by weight of solids at 0-10°C to 4.0-5.2. <9> Furthermore, the process includes a step of letting it stand in the range of 10 to 35°C. <8> The method for gelling milk as described above. [Effects of the Invention]
[0007] This method allows for the production of fermented milk and a fermented milk-like acidic gel by adjusting the raw milk to near its isoelectric point and controlling its solid content within a predetermined range. Furthermore, using lactic acid to adjust the isoelectric point has the advantage of preserving the original flavor of the fermented milk. [Modes for carrying out the invention]
[0008] The manufacturing method of the present invention includes the following steps (1) to (3), and may also include steps (4) and (5) as needed. Each step will be described below. Process (1): Process to provide a prepared milk containing 10-20% by weight of solids. In the present invention, step (1) is the step of providing a formula milk containing 10 to 20% by weight of solids. This is because if the solids concentration in the formula milk is less than 10% by weight, it does not gel easily even after a long time, and if it exceeds 20% by weight, it lacks smoothness. The gel tends to become harder when the solids concentration in the formula milk is high, and softer when it is low, so it is desirable to adjust the solids concentration by adjusting the amount of skim milk added. The compounded milk used in this invention can be any milk containing a protein that gels at its isoelectric point, such as raw milk, skim milk, reconstituted milk obtained by dissolving whole milk powder, reconstituted skim milk obtained by dissolving skim milk powder, or soy milk. Furthermore, any auxiliary ingredients may be added to these compounded milks. The auxiliary ingredients are not limited and can be selected as appropriate. Auxiliary ingredients can be added within the range that allows the compounded milk, which is the main ingredient, to gel. Examples of auxiliary ingredients include flavorings, fruits and vegetables, fruit and vegetable juices, fruit and vegetable extracts, ingredients containing nutrients, milk ingredients, functional ingredients, thickeners, emulsifiers, colorings, preservatives, and other food additives. Furthermore, raw milk and skim milk may be concentrated using a membrane or evaporator. It is also desirable to sterilize the compounded milk using a known sterilization method. Among these, it is preferable to heat sterilize by holding at 63°C for 30 minutes, or by a method having an equivalent or greater sterilization effect. In addition to the above, dairy ingredients include whole fat condensed milk, skimmed condensed milk, sweetened condensed milk, sweetened skimmed condensed milk, unsweetened condensed milk, unsweetened skimmed condensed milk, whey, whey powder, defatted whey, defatted whey powder, whey protein concentrate (WPC), whey protein isolate (WPI), α-lactalbumin, β-lactoglobulin, milk protein concentrate (MPC), casein, sodium caseinate, calcium caseinate, cream, fermented cream, compound cream, cream powder, butter, fermented butter, buttermilk, buttermilk powder, and butter oil. The protein content in the fermented milk and fermented milk-like acidic gel of the present invention is not particularly limited as long as it can gel near the isoelectric point, but is preferably 1 to 20% by weight. More preferably, it is 1 to 15% by weight, and most preferably 3 to 10% by weight.
[0009] Step (2): A step of controlling the temperature of the above-prepared milk to 0 to 10°C In the present invention, step (2) is a step of adjusting the temperature of the prepared milk in step (1) to 0 to 10°C. Among these, it is preferable to adjust the temperature of the prepared milk to 0 to 5°C, and more preferably to 0 to 3°C. In the present invention, a step of preparing the prepared milk adjusted to 0 to 10°C in advance is also regarded as a step including steps (1) and (2) of the present invention.
[0010] Step (3): A step of adjusting the pH of the above-prepared milk to 4.0 to 5.2 In the present invention, step (3) is a step of adjusting the pH of the prepared milk to 4.0 to 5.2. This is because hydrophobic interaction becomes stronger when the pH is near the isoelectric point, causing the protein to gel. The isoelectric point varies depending on the type of protein, but in the present invention, it is 4.0 to 5.2, preferably 4.2 to 5.0, and more preferably 4.4 to 4.8. By adjusting the temperature of the prepared milk to 0 to 10°C in step (2), the aggregation rate of milk protein is reduced, and it does not coagulate immediately even at the pH near the isoelectric point in step (3), maintaining a liquid state, enabling the transportation and filling of the prepared milk with adjusted pH. The pH adjustment can be to 4.0 to 5.2, and any acidic material that does not affect the desired flavor of the final product may be used. It is preferably adjusted with an organic acid. Examples of organic acids include lactic acid, acetic acid, tartaric acid, etc. Among these, lactic acid is preferable because it does not affect the flavor of fermented milk or fermented milk-like acidic gel. The concentration, addition amount, and type of the acidic material are not limited and are appropriately determined so that the pH of the prepared milk can be adjusted to 4.0 to 5.2. As the acidic material, in addition to the above organic acids, flavor components, fruit juices, vegetable juices, flavors, etc. may also be used.
[0011] Step (4): Step of allowing the pH-adjusted formulated milk to stand In the present invention, step (4) is a step of allowing the pH-adjusted formulated milk in step (3) to stand as necessary. The standing temperature is preferably 5 to 40°C, more preferably 10 to 35°C. Since the gel obtained becomes harder as the temperature is increased and tends to be a softer gel as the temperature is decreased, the gel of a desired hardness can also be adjusted by changing the temperature to be controlled. By combining the preparation of the solid content concentration and the temperature at the time of allowing the formulated milk to stand, the aggregation rate of milk proteins can be controlled, and the physical properties of the acidic gel can be adjusted. In addition, by adjusting the temperature at the time of allowing the formulated milk to stand to a low temperature, storage after producing the product can be carried out simultaneously, and a large space that enables temperature control such as in a fermentation storage can be reduced. Here, when commercializing fermented milk and fermented milk-like acidic gels in a state of being filled in a container, it is desirable to perform the filling into the container before allowing it to stand. As an example of before the standing step, the following three patterns of order can be mentioned. Pattern 1. Step of providing formulated milk (the above step (1)) → Filling step → Temperature control step (the above step (2)) → pH adjustment step (the above step (3)) → Standing (the above step (4)) Pattern 2. Step of providing formulated milk (the above step (1)) → Temperature control step (the above step (2)) → Filling step → pH adjustment step (the above step (3)) → Standing (the above step (4)) Pattern 3. Step of providing formulated milk (the above step (1)) → Temperature control step (the above step ()) → pH adjustment step (the above step (3)) → Filling step → Standing (the above step (4))
[0012] Step (5): Step of adding any one or a combination of lactic acid bacteria, bifidobacteria, and yeast to the formulated milk in (1) to (4) above In the present invention, step (5) is a step of adding one or a combination of lactic acid bacteria, bifidobacteria, and yeast to the prepared milk in any of steps (1) to (4), as needed. The types of lactic acid bacteria, bifidobacteria, and yeast are not limited and can be selected as appropriate. Furthermore, the concentration and amount of lactic acid bacteria, bifidobacteria, and yeast added are not limited and can be determined as appropriate to produce the desired fermented milk or fermented milk-like acidic gel. In this invention, fermented milk refers to a product containing a certain number of viable bacteria and non-fat milk solids. In addition to the definition set forth in the Ministerial Ordinance on Standards for Ingredients of Milk and Dairy Products (Milk and Dairy Products Ordinance), any product containing 8.0% or more non-fat milk solids and 10 million or more lactic acid bacteria (or yeast) per milliliter is included in the fermented milk of this invention. If the product is not manufactured as fermented milk, it is not necessary to add lactic acid bacteria, bifidobacteria, or yeast. In this invention, fermented milk-like acidic gel refers to a product that does not contain the specified number of viable lactic acid bacteria (or yeast) as defined above, or does not contain any at all. Thus, the manufacturing method of the present invention makes it possible to produce fermented milk or a fermented milk-like acidic gel without going through a fermentation process, in the same way as when it has gone through a fermentation process using lactic acid bacteria (or yeast).
[0013] The manufacturing method of the present invention is based on having the above steps, but it goes without saying that, as long as the effects of the present invention are not impaired, other steps used in food manufacturing can be interposed between the above steps or added before or after the above steps. Such processes include sterilization, filling into containers, and homogenization, and can be carried out either at the raw material stage or at the stage of the manufactured acidic gel.
[0014] The fermented milk and fermented milk-like acidic gel obtained by the manufacturing method of the present invention can be used as food as is. In particular, since the hardness of the gel can be controlled by adjusting the pH and the solid content in the prepared milk, gel-like foods of desired hardness can be freely produced. Furthermore, as with known fermented milk, it can be further processed to become other food products. Examples of such food products include desserts and milk beverages.
[0015] The following describes some embodiments of the present invention in detail, but the present invention is not limited to these embodiments. [Examples]
[0016] [Evaluation Method for Acidic Gels] The evaluation method for the acidic gels produced in the following examples and comparative examples will be described below. (Method for measuring hardness) A texture analyzer (Stable Micro Systems, TA-XT plus) was used to measure the hardness of the acidic gel. A 16mm diameter cylinder was used as a jig, and the jig was inserted 10mm into the acidic gel at a speed of 1mm / sec. The load on the acidic gel was measured using a load cell.
[0017] (Sensory evaluation) The sensory evaluation of the acidic gel was conducted by a panel of sensory evaluation specialists. The panel consisted of four specialists who evaluated the smoothness of the acidic gel at a temperature of 10°C when eaten, using a two-point scale: "○: Smooth" and "×: Not smooth." The results are shown in Table 1 below, with "○" indicating that three or more people gave "○" and "×" indicating that two or fewer people gave "○."
[0018] [Example 1] Acidic gels were prepared under each condition, and their hardness was measured and sensory evaluation was performed. 1. Method for producing acidic gel The acidic gel was prepared using the following procedure. (i) Skim milk powder was dissolved in water to a concentration of 10 wt% to prepare reconstituted milk (10 wt%), which was then immersed in hot water and pasteurized at 90°C for 10 minutes to prepare the prepared milk. Next, the pasteurized prepared milk was immersed in ice water and cooled to 10°C to adjust the consistency. The solids content and casein:whey ratio of the prepared milk are shown in Table 1. (ii) 50g of the prepared milk was measured into a 100g capacity cup-type container and cooled to 3°C. (iii) The pH was adjusted to 4.6 using lactic acid (20 wt%). (iv) The pH-adjusted formula milk was then left to stand at 10°C for 20 hours. 2. Evaluation Results The hardness of the obtained acidic gel after 10 mm penetration was 8.7 gf. The sensory evaluation of the smoothness of the obtained acidic gel was "〇".
[0019] [Example 2] 1. Method for producing acidic gel An acidic gel was prepared in the same manner as in Example 1(i), except that skim milk powder was dissolved in water at a concentration of 20 wt%. 2. Evaluation Results The hardness of the obtained acidic gel at a penetration depth of 10 mm was 22.6 gf, which was harder than the acidic gel obtained in Example 1. Furthermore, the sensory evaluation of the smoothness of the obtained acidic gel was "○".
[0020] [Table 1]
[0021] [Consideration] Table 1 summarizes the manufacturing conditions and evaluation results for each of the above acidic gels. Examples 1 and 2 show that the hardness of the compounded milk can be controlled by adjusting the solid content concentration, and that a higher solid content concentration tends to result in a harder acidic gel. [Industrial applicability]
[0022] According to the manufacturing method of the present invention, by adjusting the milk to near its isoelectric point and adjusting the solid content concentration of the raw milk, it is possible to provide fermented milk and a fermented milk-like acidic gel with a desired hardness. Furthermore, by using lactic acid to adjust the isoelectric point, it is possible to provide fermented milk and a fermented milk-like acidic gel without impairing the original flavor of the fermented milk.
Claims
1. A method for producing fermented milk and a fermented milk-like acidic gel, comprising the following steps: (1) A process of providing a compounded milk containing 10 to 20% by weight of solids. (2) A process to control the temperature of the above-mentioned prepared milk to 0-10°C. (3) A step to adjust the pH of the above-mentioned formula milk to 4.0 to 5.
2. (4) The process of letting the pH-adjusted formula milk stand at a temperature of 10 to 35°C. The manufacturing method comprising the above.
2. The manufacturing method according to claim 1, wherein the step of providing a blended milk containing 10 to 20% by weight of the solids in step (1) is the step of providing raw milk, skim milk, reconstituted milk, reconstituted skim milk, or milks to which auxiliary ingredients have been added.
3. The manufacturing method according to claim 1 or 2, further comprising the following step (5). (5) A step in which, in any one or more of steps (1) to (4) above, one of lactic acid bacteria, bifidobacteria, and yeast, or a combination thereof, is added to the prepared milk.
4. The step of adjusting the pH of the prepared milk in step (3) above to 4.0 to 5.2 is, The manufacturing method according to any one of claims 1 to 3, wherein the step is to adjust using an organic acid.
5. A manufacturing method according to any one of claims 1 to 4, which does not include a fermentation step.
6. Fermented milk and a fermented milk-like acidic gel produced by the manufacturing method described in any one of claims 1 to 5.
7. A method for gelling milk, comprising the steps of adjusting the pH of a prepared milk containing 10 to 20% by weight of solids at 0 to 10°C to 4.0 to 5.2, and further, the step of letting it stand in the range of 10 to 35°C.