JP2023146239A - Fermented milk and method for producing fermented milk-like acidic gel - Google Patents

Abstract

To provide a novel method for producing acidic gel of milk that is highly versatile and has little effect on flavor, that is, to provide a fermented milk and a novel method for producing fermented milk-like acidic gel without going through a fermentation step.SOLUTION: Provided are a fermented milk and a method for producing a fermented milk-like acidic gel, and the method includes the following steps (1) to (4): (1) a step of providing a formulation milk; (2) a step of controlling the temperature of the formulation milk at 0 to 10°C; (3) a step of adjusting the pH of the formulation milk to 4.0 to 5.2; (4) a step of leaving pH-adjusted formulation milk at a temperature of 10 to 35°C.SELECTED DRAWING: None

Description

The present invention relates to a method for producing fermented milk and fermented milk-like acidic gel.

Fermented milk is a food product made by coagulating milk proteins with acid. Therefore, when producing fermented milk, it is necessary to go through a fermentation process in which lactic acid bacteria are inoculated into raw milk and the raw milk is coagulated with acid. In particular, set-type fermented milk requires dedicated fermentation warehouses and cooling chambers, and there are issues such as the need to secure a large space for temperature control.
The following prior art is a method for producing fermented milk-like acidic gel without using lactic acid bacteria or a fermenter.

Patent Documents 1 and 2 disclose that the pH of raw milk is adjusted to 5.5 to 6.2 with citric acid or phosphoric acid, and then subjected to ultrafiltration treatment to produce an acid coagulant with excellent thermal stability and physical properties. A method of manufacturing a dairy food product is disclosed.
Patent Document 3 discloses that 0.3 to 0.6% glucono delta lactone is added to milk or soy milk and reacted in a temperature range of 10 to 40°C to acidify the milk and gel it. A method is disclosed.
Patent Document 4 describes a process in which a citrate and a thickener are blended into a raw material liquid containing milk components to adjust the pH of the raw material liquid to a weak acidity of 5.1 to 6.5. A method for suppressing protein aggregation in a weakly acidic gel-like milk product by controlling the fat/protein weight ratio to 1.8 or less is disclosed.
However, in Patent Documents 1, 2, and 3, the means for acidification is limited to phosphoric acid, citric acid, gluconolactone, etc., respectively. Further, Patent Document 4 is also a limited method because, in addition to using citric acid as a means of acidification, the milk is gelatinized by the raw material composition and the addition of a thickener. Furthermore, since these methods add specific ingredients for acidification, the composition and flavor may be different from that of fermented milk obtained by fermenting lactic acid bacteria.

Japanese Patent Application Publication No. 2018-64482 Japanese Patent Application Publication No. 2018-64481 Patent No. 4827100 Japanese Patent Application Publication No. 2017-55751

An object of the present invention is to provide a novel method for producing acidic milk gel that has high versatility and has little effect on flavor. That is, the object of the present invention is to provide a novel method for producing fermented milk and fermented milk-like acid gel without going through a fermentation process.

In order to solve the above problems, the present inventors have made extensive studies and found that the hardness of gel-like foods can be controlled by adjusting the milk protein to near its isoelectric point and by controlling the temperature within a predetermined range after the adjustment. This discovery led to the completion of the present invention. That is, the present invention includes the following steps.
<1>
A method for producing fermented milk and fermented milk-like acidic gel, comprising the following steps:
(1) Step of providing the formula milk (2) Step of controlling the temperature of the above formula milk at 0 to 10°C (3) Step of adjusting the pH of the above formula milk to 4.0 to 5.2 (4) ) The production method includes the step of leaving the pH-adjusted formula at a temperature of 10 to 35°C.
<2>
The production according to <1>, wherein the step of providing the formula milk in step (1) is a step of providing raw milk, skim milk, reduced milk, reduced skim milk, or a product obtained by adding an auxiliary material to these milks. Method.
<3>
The manufacturing method according to <1> or <2>, further including the following step (5).
(5) In (1) to (4) above, the step of adding any one or a combination of lactic acid bacteria, bifidobacteria, and yeast to the formula <4>
The step of adjusting the pH of the formula milk in the step (3) to 4.0 to 5.2,
The manufacturing method according to any one of <1> to <3>, which is a step of adjusting using an organic acid.
<5>
The manufacturing method according to any one of <1> to <4>, which does not include a fermentation step.
<6>
Fermented milk and fermented milk-like acidic gel produced by the production method according to any one of <1> to <5>.
<7>
A method for gelling milk, the method comprising the step of adjusting the pH of formula milk at 0 to 10°C to 4.0 to 5.2, and then controlling the temperature of the formula milk.
<8>
The milk gelling method according to <7>, wherein the step of controlling the temperature is a step of controlling the temperature within a range of 10 to 35°C.

According to this method, fermented milk with a desired hardness and fermented milk-like acidic gel can be provided by adjusting the milk to near its isoelectric point and controlling the temperature within a predetermined range after the adjustment. Furthermore, if lactic acid is used to adjust the isoelectric point, there is an advantage that the original flavor of fermented milk will not be impaired.

The manufacturing method of the present invention includes the following steps (1) to (4), and may include step (5) as necessary. Each step will be explained below.
Step (1): Step of providing formula milk
In the present invention, step (1) is a step of providing formula milk.
The formula milk in the present invention may be any milk as long as it contains a protein that gels at the isoelectric point, such as raw milk, skim milk, reduced milk obtained by dissolving whole milk powder, reduced skim milk obtained by dissolving skim milk powder, soy milk, etc. can be mentioned. Further, arbitrary auxiliary raw materials may be added to these formula milks. The auxiliary raw materials are not limited and can be selected as appropriate. The auxiliary raw materials can be added to the extent that the formula milk, which is the main raw material, can be gelled. Examples of auxiliary raw materials include fragrances, fruit and vegetable fruits, fruit and vegetable juices, fruit and vegetable extracts, materials containing nutritional components, dairy materials, functional materials, thickeners, emulsifiers, colorants, and preservatives. Food additives such as Furthermore, raw milk and skim milk may be concentrated using a membrane, an evaporator, or the like. Further, it is desirable to use the formula after sterilizing it using a known sterilization method. Among these, it is preferable to sterilize by heating at 63° C. for 30 minutes using a holding method, or by a method having a sterilizing effect equal to or higher than this.
In addition to the above, milk ingredients include whole fat concentrated milk, skim concentrated milk, sweetened condensed milk, sweetened skimmed condensed milk, unsweetened condensed milk, unsweetened skimmed condensed milk, whey (whey), whey powder, desalted whey, desalted whey powder , whey protein concentrate (WPC), whey protein isolate (WPI), alpha-lactalbumin, beta-lactoglobulin, milk protein concentrate (MPC), casein, sodium caseinate, calcium caseinate, cream, fermented cream, Examples include compound cream, cream powder, butter, fermented butter, buttermilk, buttermilk powder, and butter oil.
The protein content in the fermented milk and fermented milk-like acid gel of the present invention is not particularly limited as long as it can be gelled near the isoelectric point, but is preferably 1 to 20% by weight. More preferably 1 to 15% by weight, most preferably 3 to 10% by weight.

Step (2): A step of controlling the temperature of the above formula milk at 0 to 10°C In the present invention, step (2) is a step of adjusting the temperature of the formula milk of the above step (1) to 0 to 10 °C. be. Among these, it is preferable to adjust the temperature of the formula milk to 0 to 5°C, and more preferably to 0 to 3°C. In the present invention, the step of preparing formula milk that has been adjusted to a temperature of 0 to 10° C. is also considered to be a step including step (1) and step (2) of the present invention.

Step (3): A step of adjusting the pH of the above formula milk to 4.0 to 5.2 In the present invention, step (3) is a step of adjusting the pH of the formula milk to 4.0 to 5.2. be. This is because by setting the pH near the isoelectric point, hydrophobic interactions become stronger and the protein gels. 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 formula to 0 to 10°C in step (2), the rate of aggregation of milk proteins is reduced, and even at a pH near the isoelectric point in step (3), it does not coagulate immediately and remains liquid. , transportation and filling of pH-adjusted formula becomes possible. The pH can be adjusted to 4.0 to 5.2, and any acidic material may be used as long as it does not affect the desired flavor of the final product, and it is preferably adjusted with an organic acid. Examples of organic acids include lactic acid, acetic acid, tartaric acid, and the like, and among these, lactic acid is preferred because it does not affect the flavor of fermented milk or fermented milk-like acid gel. The concentration, amount, and type of the acidic material are not limited, and are appropriately determined so that the pH of the formula can be adjusted to 4.0 to 5.2. In addition to the above-mentioned organic acids, the acidic materials may include flavor components, fruit juices, vegetable juices, flavors, and the like.

Step (4): A step of controlling the temperature of the pH-adjusted formula milk at 10 to 35°C and letting it stand In the present invention, step (4) is a step of controlling the temperature of the pH-adjusted formula milk at 10 to 35°C. This is the process of adjusting the temperature to ~35°C. This is because if the temperature is lower than 10°C, it will be difficult to gel even if left standing for a long time, and if the temperature is higher than 35°C, although it will gel, it will lack smoothness. If the temperature is raised, the resulting gel will become harder, and if the temperature is lowered, a softer gel will be obtained. Therefore, by changing the temperature to be controlled, the desired hardness of the gel can be adjusted. By adjusting the temperature of the formula and letting it stand, an acidic gel similar to fermented milk can be produced. The aggregation rate of milk proteins is controlled by the temperature at which the formula is left to stand, and the physical properties of the acidic gel are adjusted. Furthermore, by adjusting the temperature at which the formula milk is left at rest as low as possible, it is possible to store the product at the same time after it is manufactured, and it is possible to reduce the need for a large space such as a fermentation warehouse where the temperature can be controlled.
Here, when producing a product with fermented milk or fermented milk-like acid gel filled in a container, it is desirable to fill the container before allowing it to stand still. Before the standing step, for example, the following three patterns can be used.
Pattern 1.
Providing process of formula milk (step (1) above) → Filling process → Temperature control process (step (2) above) → pH adjustment process (step (3) above) → Standing (step (4) above)
Pattern 2.
Providing process of formula milk (step (1) above) → Temperature control process (step (2) above) → Filling process → pH adjustment process (step (3) above) → Standing (step (4) above)
Pattern 3.
Providing process of formula milk (step (1) above) → Temperature control process (step (2) above) → pH adjustment process (step (3) above) → Filling process → Standing (step (4) above)

Step (5): In the above (1) to (4), the step of adding any one or a combination of lactic acid bacteria, bifidobacteria, and yeast to the formula In the present invention, step (5) is performed as necessary. Accordingly, this is a step of adding one or a combination of lactic acid bacteria, bifidobacteria, and yeast to the formula milk in any of steps (1) to (4). The types of lactic acid bacteria, bifidobacteria, and yeast are not limited and can be selected as appropriate. Further, the concentrations and amounts of lactic acid bacteria, bifidobacteria, and yeast to be added are not limited, and can be determined as appropriate to obtain the desired fermented milk or fermented milk-like acidic gel.
In the present invention, fermented milk refers to milk that contains more than a certain number of viable bacteria and non-fat milk solids, and includes those defined in the "Ministerial Ordinance on Ingredient Standards for Milk and Dairy Products (Ministerial Ordinance on Milk, etc.)". , "Any milk containing non-fat milk solids of 8.0% or more and the number of lactic acid bacteria (or yeast) of 10 million or more per ml is included in the fermented milk of the present invention."
Note that if the fermented milk is not produced, lactic acid bacteria, bifidobacteria, and yeast may not be added. In the present invention, the fermented milk-like acidic gel refers to the fermented milk defined above that does not contain the specified number of viable lactic acid bacteria (or yeast number) or does not contain it at all.
As described above, in the production method of the present invention, fermented milk or fermented milk-like acidic gel can be produced in the same way as fermented milk or fermented milk-like acid gel that has undergone a fermentation process using lactic acid bacteria (or yeast) without going through a fermentation process.

The manufacturing method of the present invention basically includes the steps described above, but other steps performed in food manufacturing may be interposed between the above steps, or additional steps may be added before or after the above steps. Needless to say, it can be done.
Such steps include a sterilization step, a container filling step, a homogenization step, etc., and can be performed either at the raw material stage or at the produced acidic gel stage.

The fermented milk and fermented milk-like acidic gel obtained by the production method of the present invention can be used as is as a food. In particular, since the hardness of the gel can be controlled by controlling pH and temperature, it is possible to freely produce gel-like foods with desired hardness. In addition, it can be further processed into other foods in the same way as known fermented milk. Examples of foods include desserts and milk drinks.

Examples of the present invention will be described in detail below, but the present invention is not limited thereto.

[Acidic gel evaluation method]
A method for evaluating acidic gels produced in the following Examples and Comparative Examples will be described.
(Method of measuring hardness)
A texture analyzer (TA-XT plus, manufactured by Stable Micro Systems) was used to measure the hardness of the acidic gel. A cylinder with a diameter of 16 mm was used as the jig, and the jig was penetrated 10 mm into the acid gel at a speed of 1 mm/sec, and the load applied to the acid gel was measured using a load cell.

(sensory evaluation)
The sensory evaluation of the acidic gel was carried out by a panel specializing in sensory evaluation. Four panelists specialized in sensory evaluation evaluated the smoothness of the acidic gel at a temperature of 10°C in two grades: "○: Smooth" and "×: Not smooth." The tabulated results are shown in Table 1 below as "〇" when the number of people who answered "〇" is 3 or more, and as "×" when the number of people who answered "〇" is 2 or less.

[Example 1] Acidic gels were prepared under various conditions, and hardness measurements and sensory evaluations were performed.
1. Method for producing acidic gel An acidic gel was produced according to the following procedure.
(i) Homogenization Milk homogenized at a pressure of 15 MPa was immersed in hot water and sterilized at 90° C. for 10 minutes to prepare formula milk. Next, the sterilized formula was immersed in ice-cold water and cooled to 10°C for adjustment. The solid content and casein:whey ratio of the formula milk were as shown in Table 1.
(ii) 50 g of formula milk was weighed into a 100 g cup-shaped container and cooled to 3°C.
(iii) The pH of the formula was adjusted to 4.7 using lactic acid (20 wt%).
(iv) The pH-adjusted formula was left at 10° C. for 20 hours.
2. The hardness of the acidic gel obtained as a result of the evaluation was 11.7 gf when penetrated 10 mm. The sensory evaluation of the smoothness of the obtained acidic gel was "○".

[Example 2]
1. Methods for producing acidic gel (i) to (iii) Same as Example 1.
(iv) The pH-adjusted formula was left at 30° C. for 20 hours.
2. The hardness of the acidic gel obtained as a result of the evaluation at the time of 10 mm penetration was 37.5 gf, and an acidic gel harder than that of Example 1 was obtained. Therefore, it was found that the hardness of the acidic gel can be controlled by controlling the temperature after adjusting the pH. The sensory evaluation of the smoothness of the obtained acidic gel was "○".

[Example 3]
1. Methods for producing acidic gel (i) to (ii) Same as Example 1.
(iii) The pH of the formula was adjusted to 4.7 using acetic acid (50 wt%) for pH adjustment.
(iv) Same as Example 1.
2. The hardness of the acidic gel obtained as a result of the test was 11.0 gf when penetrated 10 mm.
Furthermore, an acidic gel having almost the same hardness as in Example 1 was obtained, and it was found that the difference in organic acid had almost no effect on the hardness of the acidic gel. The sensory evaluation of the smoothness of the obtained acidic gel was "○".

[Comparative example 1]
1. Methods for producing acidic gel (i) to (iii) Same as Example 1.
(iv) The pH-adjusted formula was allowed to stand at 5°C for 20 hours.
2. Evaluation results The formula remained liquid even after being left to stand, and did not gel.

[Comparative example 2]
1. Methods for producing acidic gel (i) to (iii) Same as Example 1.
(iv) The pH-adjusted formula was left at 40° C. for 20 hours.
2. The hardness of the acidic gel obtained as a result of the evaluation was 78.7 gf when penetrated 10 mm. The sensory evaluation of the smoothness of the obtained acidic gel was "x".

[Comparative example 3]
1. Acidic gel manufacturing method (i), (ii) Same as Example 1.
(iii) pH was adjusted to 5.5 using lactic acid (20 wt%).
(iv) The pH-adjusted formula was left at 30° C. for 20 hours.
2. Evaluation results The formula remained liquid even after being left to stand, and did not gel.

[Consideration]
Table 1 summarizes the manufacturing conditions for each of the above acidic gels and the evaluation results of the acidic gels.
Comparison of Example 1 and Example 2 revealed that hardness can be controlled by temperature control after pH adjustment, and that increasing the control temperature tends to yield an acidic gel with higher hardness.
Furthermore, from Comparative Examples 1 and 2, gelation does not occur at 5°C and it lacks smoothness at 40°C, so the temperature range for step (4) of the present invention is greater than 5°C and less than 40°C. , 10°C to 35°C was found to be preferable.
Furthermore, it was found from Example 3 that the same effect could be obtained even if the type of organic acid used to adjust the pH in step (3) was changed.
Furthermore, according to Comparative Example 3, gelation cannot be achieved when the pH of the formula is set to 5.5, so the pH range adjusted in step (3) of the present invention needs to be around the isoelectric point. It was found that 4.0 to 5.2 is desirable.
It has also been found that step (2) is desirably 10° C. or lower from the viewpoint of reducing the aggregation rate of milk proteins and preventing immediate coagulation even at pH near the isoelectric point.

According to the production method of the present invention, fermented milk with desired hardness and fermented milk-like acidic gel can be provided by adjusting the milk to near its isoelectric point and controlling the temperature within a predetermined range after the adjustment. I can do it. Furthermore, if lactic acid is used to adjust the isoelectric point, fermented milk and fermented milk-like acidic gel can be provided without impairing the original flavor of fermented milk.

Claims (8)

A method for producing fermented milk and fermented milk-like acidic gel, comprising the following steps:
(1) Step of providing the formula milk (2) Step of controlling the temperature of the above formula milk at 0 to 10°C (3) Step of adjusting the pH of the above formula milk to 4.0 to 5.2 (4) ) The production method includes the step of leaving the pH-adjusted formula at a temperature of 10 to 35°C. The production according to claim 1, wherein the step of providing the formula milk in step (1) is a step of providing raw milk, skim milk, reconstituted milk, reconstituted skim milk, or milk obtained by adding auxiliary materials to these milks. Method. The manufacturing method according to claim 1 or 2, further comprising the following step (5).
(5) In (1) to (4) above, the step of adding any one or a combination of lactic acid bacteria, bifidobacteria, and yeast to the formula milk. The step of adjusting the pH of the formula milk in the step (3) to 4.0 to 5.2,
The manufacturing method according to any one of claims 1 to 3, which is a step of adjusting using an organic acid. The manufacturing method according to any one of claims 1 to 4, which does not include a fermentation step. Fermented milk and fermented milk-like acidic gel produced by the production method according to any one of claims 1 to 5. A method for gelling milk, the method comprising the step of adjusting the pH of formula milk at 0 to 10°C to 4.0 to 5.2, and then controlling the temperature of the formula milk. The milk gelling method according to claim 7, wherein the step of controlling the temperature is a step of controlling the temperature within a range of 10 to 35°C.