JP3151341B2 - Manufacturing method of solid milk food - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a solid milk food from a milk protein solution. In particular, the present invention relates to a method for producing a solid milk food by adjusting an acid and a pH to be added to a milk protein solution and gelling the milk protein solution at a lower pressure.

[0002]

[Prior art]

 1) A method in which a protein is thermally denatured and gelled by heating.

[0003] 2) A method of gelling using a gelling agent.

[0004] 3) A method of gelation using an enzyme.

In the above method 1), in order to gel milk protein only by heat in the method 1), a temperature of 100 ° C. or more is required, and even when a gelling agent is added, a temperature of 80 ° C. or more is required. And For this reason, the protein browns and heat-labile physiologically active substances such as vitamins are decomposed or deteriorated.

In the gelling method using the gelling agent of 2), the food to be added may have a chemical odor and impair the flavor.

[0007] Furthermore, the gelation method using an enzyme of 3) involves a loss of dewatering and discarding a whey (whey) portion rich in nutritionally effective ingredients.

As a gelling method other than the above, a method of subjecting milk protein to high-pressure treatment and gelling has recently been reported (Kumeno et al., Abstracts of the Japanese Society of Agricultural Chemistry, p. 14, p. 1992).
Year).

[0009] The high pressure treatment includes denaturation of protein, gelatinization of starch,
It has various advantages such as sterilization of microorganisms, non-destruction of vitamins, and inactivation of enzymes. Among these advantages, gel formation based on protein denaturation has attracted attention as a technique for providing foods with new textures. However, in order to gel by high pressure treatment, it is necessary to perform pressure treatment at a considerably high pressure, and an apparatus for performing such pressure treatment needs to be designed to withstand the applied pressure, and the like. Therefore, it becomes considerably expensive and raises a cost problem. In such a pressure processing apparatus, it is known that as the pressure that can be pressurized increases, the cost of an apparatus particularly exceeding a pressure resistance of 4000 atm dramatically increases. In addition, since the time required to pressurize to a predetermined pressure is directly linked to the production efficiency, there is a need for a method of maintaining the quality of food and gelling at a lower pressure.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to gel milk protein by lower pressure treatment without impairing the flavor and ingredients of food. It is to provide a method.

[0011]

Means for Solving the Problems As a result of diligent studies for solving the above-mentioned object, the present inventors have adjusted the pH of a milk protein solution with an acid and then subjected to pressure treatment to obtain a non-pH-adjusted milk. The present invention has been completed by finding that the milk protein solution gels at a pressure lower than that of the protein solution and that the pH has an optimum range.
In particular, the present inventors impair the flavor and the like by variously examining the acid used for pH adjustment, because the optimal range of pH at which a gel having a high hardness (rupture strength) is obtained varies depending on the type of the acid. It has been found that a food having excellent properties can be provided.

That is, the present invention provides the following (1) to (8)
The manufacturing method shown in FIG.

(1) Production of solid milk food, characterized in that an acid is added to the milk protein solution to adjust the pH to 4.8 to 6.3 and then a gel is formed at a pressure of 1500 to 7000 atm. Method.

(2) The method for producing a solid milk food according to (1), wherein the pH is from 5.0 to 6.1.

(3) When the protein concentration of the milk protein solution is 7
% Or more, the method for producing a solid milk food according to (1) or (2).

(4) The method for producing a solid milk food according to any one of (1) to (3), wherein the acid is acetic acid.

(5) The method for producing a solid milk food according to any one of (1) to (3), wherein the acid is phosphoric acid.

(6) The method for producing a solid milk food according to any one of (1) to (3), wherein the acid is gluconic acid.

(7) The method for producing a solid milk food according to any one of (1) to (3), wherein the acid is ascorbic acid.

(8) The method for producing a solid milk food according to any one of (1) to (3), wherein the acid is citric acid.

In the present invention, the pH of a milk protein solution is adjusted using an acid, and the solution is pressurized to gel to produce a solid milk food.

Examples of the milk protein that can be used in the method of the present invention include milk protein such as skim milk powder, skim concentrated milk, whole fat milk powder, and whole fat concentrated milk, and the like. It can be used by dissolving in water or the like.

The protein concentration in the milk protein solution used in the present invention is preferably at least 7% by weight. If the concentration is lower than this, the milk protein solution becomes difficult to gel, and the breaking strength of the gel decreases.

In the present invention, the breaking strength (N / m ² ) is used to indicate the hardness (hardness) of the gel. A higher value of the breaking strength indicates a harder gel, which means that a harder solid milk product can be produced.

[0025] In the present specification, the term "rupture strength" refers to the hardness (hardness) of a gel.

In the present invention, the pH is adjusted using an acid, but the acid is not particularly limited as long as it is certified as a food additive. However, as described above, the acid used in the present invention is different from the optimum pH range in which a gel having a high breaking strength is obtained by an acid, and the flavor and the like of a food such as sourness are greatly affected by the kind and pH of the acid. Gluconic acid, lactic acid, acetic acid, malic acid, succinic acid, fumaric acid, citric acid,
Phosphoric acid, ascorbic acid, glucono-δ-lactone, tartaric acid, adipic acid and the like are preferred, and particularly preferred acids include acetic acid, phosphoric acid, gluconic acid, ascorbic acid, citric acid and the like.

The acid may be added in such an amount that the milk protein solution is brought to a desired pH. Specifically, in the case of a milk protein solution of 70 g of skim milk powder + 130 g of water, the amount for obtaining a gel having the highest breaking strength is 0.28% by weight (pH 5.78) with citric acid, and gluconic acid with
0.9% by weight (pH 5.90).

The p of milk protein solution prepared by the above acid
The range of H is preferably 4.8 to 6.3, more preferably 5.0 to 6.1. P outside this range
This is because sufficient breaking strength cannot be obtained with H.

The milk protein solution thus adjusted in pH is degassed if necessary, filled in a polyethylene bag or the like, and pressurized.

The pressure range during pressurization is preferably from 1500 to 7000 atmospheres. This means that a gel having a sufficient breaking strength cannot be obtained at a pressure lower than 1500 atm.
On the other hand, if the pressure exceeds 7000 atmospheres, the cost of the pressurizing device becomes large, which causes inconvenience in cost.

The pressurizing time is suitably 30 minutes or less.

As described above, according to the production method of the present invention,
By adjusting the pH of the milk protein solution with an acid, it is possible to obtain a gel having a higher breaking strength than that of an unadjusted one. That is, the production method of the present invention uses a milk protein solution whose pH has been adjusted with an acid, thereby making it possible to obtain a gel having a breaking strength equivalent to that at a lower pressure than that of a non-pH-adjusted one. It is.

Next, the acid used in the present invention will be described in more detail.

In the present invention, various acids can be used as described above, but the optimum pH for giving the highest breaking strength to the gel differs depending on the kind of the acid, and the flavor and the like given to foods also vary greatly. Therefore, when using an acid, it is important to select an acid that meets the purpose.

Here, various acids can be classified into the following three from the viewpoint of the optimum pH that gives the gel the highest breaking strength.

1) An acid which gives the gel the highest breaking strength at around pH 5.8.

Gluconic acid, citric acid, glucono-δ-lactone.

2) An acid that gives the gel the highest breaking strength at around pH 5.6.

Tartaric acid, adipic acid.

3) An acid that gives the gel the highest breaking strength at around pH 5.3.

Phosphoric acid, lactic acid, acetic acid, ascorbic acid, malic acid, succinic acid, fumaric acid.

Acetic acid, ascorbic acid, and the like are examples of the acid that gives the highest breaking strength at an optimum pH under a constant pressure. These acids are also characterized by a wide range of pH having high breaking strength.
Further, citric acid is cited as an acid with the smallest addition amount for achieving the optimum pH.

Having such characteristics, it is possible to select an acid according to various purposes, as described below.

(1) When acetic acid or ascorbic acid is selected, a gel having the highest breaking strength can be obtained. Therefore, in order to obtain a gel having a certain breaking strength at the lowest pressure, it is necessary to select acetic acid or ascorbic acid.

(2) In order to obtain a sour gel under low pressure treatment conditions, it is necessary to select an acid having a low optimum pH. Specifically, it is necessary to select an acid from the group 3), such as phosphoric acid, which can give the gel the highest breaking strength at around pH 5.3.

(3) In order to obtain a gel with low acidity under low pressure treatment conditions, it is necessary to select an acid having a high optimum pH. Specifically, it is necessary to select an acid from the group of 1), such as gluconic acid, which can give the gel the highest breaking strength at around pH 5.8.

(4) In order to obtain a gel having a sour taste and a gel having a low sourness under low pressure treatment conditions by adjusting the pH with the same acid, acetic acid or ascorbic acid having a wide range of pH to impart high breaking strength is used. It is necessary to make a choice.

(5) In order to obtain a gel that is most natural (close to the taste of an untreated product) under low pressure treatment conditions, it is necessary to select a citric acid that can be adjusted to an optimum pH with a small amount of addition. is there.

[0049]

【Example】

Example 1 70 g of skim milk powder was dissolved in 130 g of water while stirring and degassed. Acetic acid, ascorbic acid, and citric acid were added to this solution to adjust the solutions at each pH in Table 1. Each solution was filled in a polyethylene bag, and the bag was heat-sealed so that no air remained in the bag. This was put into Kobe Steel's high pressure processing equipment (diameter 60 mm x 200 mm) and
The gel was formed by pressing at 2,000 atm for 20 minutes. The breaking strength of the obtained gel was measured using a Leonard RE33 manufactured by Yamaden Corporation.
05. The results are shown in Table 1 and FIG.

In the same manner, the breaking strengths of six more acids were measured. Table 1 also shows the maximum value of the breaking strength and the pH value that gives the maximum value.

FIG. 2 shows the relationship between the breaking strength of acetic acid, phosphoric acid and gluconic acid and pH.

From Table 1 it can be seen that acetic acid and ascorbic acid
It can be seen that when adjusted, a harder gel is obtained than when pH is adjusted with another acid.

[0053]

[Table 1] Example 2 70 g of skim milk powder was dissolved in 130 g of water with stirring, deaerated, and filled in a polyethylene bag. This bag
Heat-sealed so that no air remains inside, and put it in a high-pressure processing device (diameter 60 mm x 200 mm) manufactured by Kobe Steel,
Pressure was adjusted at 000 atm for 10 minutes to form a gel without pH adjustment.

On the other hand, 70 g of skim milk powder was dissolved in 130 g of water while stirring, and deaerated. Acetic acid was added to this solution to adjust the pH to 5.28, and a gel was formed in the same manner as in the unadjusted gel. However, the pressure is 2000 atm and 230
The test was performed at two pressures of 0 atm. Similarly, adjust the pH to 5. with fumaric acid.
After adjustment to 30, gel formation was performed at two different pressures, 2200 atm and 2300 atm. The breaking strength of these gels was measured by Leonard RE3305 manufactured by Yamaden Corporation. Table 2 shows the results.

[0055]

[Table 2] When the pH is not adjusted, 2.84 × 10 ⁴ (N / m ² )
6000 atm pressure is necessary to obtain the breaking strength of the steel, whereas when the pH is adjusted with acetic acid, about の of 20
Similar breaking strength can be obtained at 00 atm and at 2200 atm for fumaric acid.

The same test was performed with ten kinds of acids except acetic acid and fumaric acid. Judgment by tactile sensation indicated that a pressure of 2000 to 2800 atm was sufficient to obtain a gel having the same breaking strength as a gel prepared without pH adjustment. From this, as compared with the case where the pH is not adjusted, when the pH is adjusted with an acid, the pressure reducing effect is remarkably recognized with any acid, which leads to a reduction in cost.

Example 3 A milk powder concentration of 35% and a protein concentration of 1 were obtained in the same manner as in Example 2.
A 2.08% pH unadjusted gel was prepared.

On the other hand, 46.4 g of skim milk powder (concentration of milk powder 2
(3.2%, protein concentration 8.0%) was dissolved in 153.6 g of water with stirring and degassed. Acetic acid was added to this solution to adjust the pH to 5.28, and the mixture was pressurized at 6000 atm for 10 minutes to prepare a gel. Similarly, a protein concentration of 7.0%,
The 6.5% and 6.0% milk powder solutions were adjusted to pH 5.28 with acetic acid and pressurized at 6000 atm for 10 minutes. The breaking strength of these gels was measured using a Leonard RE3305 manufactured by Yamaden Corporation.
Was measured. The results are shown in Table 3.

[0059]

[Table 3] From the above results, a gel having the same breaking strength can be prepared by treating a pH adjusted milk powder solution having a concentration corresponding to about 2/3 of the milk powder concentration of a pH adjusted milk powder solution at the same pressure.
From this, about 1/3 of the raw material cost can be saved.

Example 4 A gel without pH adjustment was prepared from whole milk powder in the same manner as in Example 2.

On the other hand, in the same manner as in Example 1, 12 kinds of whole milk powder solutions whose pH was adjusted with 12 kinds of acids were prepared.
H Pressure to obtain the same breaking strength as the gel without preparation (2000
From 2800 atm.
Pressure was applied for 0 minutes to prepare a gel.

A sensory test was conducted by ten panelists to evaluate which of the 13 types of gels had the most refreshing acidity. As a result, it was found that the gel having the refreshing acidity was phosphoric acid. The phosphoric acid has the lowest pH (pH 5.
19) is an acid that gives the highest breaking strength.

Example 5 Full fat-enriched milk (solid content: 36%) was adjusted to pH 60 without pH adjustment.
A high pressure treatment was performed at 00 atm for 10 minutes to prepare a gel.

On the other hand, in the same manner as in Example 1, 12 kinds of full fat concentrated milk (solid content of 3
6%) solution at a pressure (2000 to 2800 atm) to obtain the same rupture strength as a gel without pH adjustment.
The adjusted whole fat concentrated milk solution was pressurized for 10 minutes to prepare a gel.

A sensory test was conducted by 10 panelists to evaluate which of the 13 gels had the least acidity. As a result, it was found that the gel with the least acidity was gluconic acid. This gluconic acid can be
It is the acid that gives the highest breaking strength at the highest pH (pH 5.90) of the two acids.

Example 6 Skim concentrated milk (solid content: 34%) was prepared by
A high pressure treatment was performed at 00 atm for 10 minutes to prepare a gel.

On the other hand, in the same manner as in Example 1, 12 kinds of skim-concentrated milk (solid content: 3
4%) at a pressure (2000 to 2800 atm) to obtain the same breaking strength as the gel without pH adjustment.
The prepared defatted concentrated milk solution was pressurized for 10 minutes to prepare a gel.

A sensory test was conducted by ten panelists to evaluate which of the 13 gels had the least chemical odor. As a result, it was found that the gel with the least chemical smell was citric acid. This citric acid can be
It is an acid that gives the highest breaking strength with the least amount (0.28%) of the two acids.

Example 7 A gel without pH adjustment was prepared from skim milk powder in the same manner as in Example 2.

On the other hand, in the same manner as in Example 1, twelve kinds of skim-concentrated milk (solid content: 3
4%) and a skim milk powder solution in which the pH adjustment range of each acid is shifted by ± 0.2. The 36 kinds of skim milk solutions are pressurized at 2000 to 2800 atm for 10 minutes,
A gel was prepared.

The hardness and flavor of these gels were subjected to a sensory evaluation by 10 panelists. As a result, 12
The gel hardness did not change even when the pH adjustment range was shifted for only ascorbic acid and acetic acid among the various acids.

The gel obtained from the milk powder solution pH-adjusted with ascorbic acid and acetic acid has a sourness (ascorbic acid-
pH 5.2, acetic acid-5.1), slightly sour (ascorbic acid pH 5.4, acetic acid-pH 5.3), and less sour flavor (ascorbic acid-5.6; acetic acid-pH 5.5). . Thus, ascorbic acid or acetic acid alone can provide a wide range of flavors without changing the gel strength.

Example 8 70 g of skim milk powder was dissolved in 130 g of water with stirring. The p that gives the highest breaking strength to this milk protein solution
Acid was added until H, and the amount added was determined. The addition amounts are citric acid 0.28%, fumaric acid, adipic acid and tartaric acid 0.33.
%, Acetic acid 0.4%, succinic acid and malic acid 0.5%, phosphoric acid 0.7%, lactic acid 0.8%, ascorbic acid 0.85
%, Glucono-δ-lactone and 0.9% gluconic acid.

[0074]

According to the method for producing milk food of the present invention,
Since the pH of the milk protein solution is adjusted with various acids, the same breaking strength can be obtained at a lower pressure as compared with the milk protein without pH adjustment.

According to the method for producing milk food of the present invention, the pH of the milk protein solution is adjusted with various acids.
Equivalent breaking strength can be obtained with a milk protein solution having a lower concentration than that of unregulated milk protein.

Further, according to the method for producing a milk food of the present invention, the pH can be adjusted by selecting an acid, so that dairy products having a high acidity, dairy products having a low acidity, and dairy products having almost no treatment can be obtained. Can be prepared at low pressure.

Further, according to the method for producing a milk product of the present invention, the pH of the milk protein solution is adjusted with various acids.
A hard gel which cannot be obtained from the unadjusted gel can be obtained, and a higher quality dairy product can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a change in breaking strength of acetic acid, citric acid and ascorbic acid with respect to a pH change.

FIG. 2 is a diagram showing a change in breaking strength with respect to a change in pH of acetic acid, phosphoric acid, and gluconic acid.

────────────────────────────────────────────────── ─── Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) A23C 9/18 A23J 3/00-3/08 JICST file (JOIS) JAFIC file (JOIS)

Claims (8)

(57) [Claims] 1. An acid is added to a milk protein solution to adjust the pH to 4.8.
A gel at a pressure of 1500 to 7000 atm after adjusting to 6.3. 2. The method for producing a solid milk food according to claim 1, wherein the pH is from 5.0 to 6.1. 3. The method for producing a solid milk food according to claim 1, wherein the protein concentration of the milk protein solution is 7% or more. 4. The method for producing a solid milk food according to claim 1, wherein the acid is acetic acid. 5. The method for producing a solid milk food according to claim 1, wherein the acid is phosphoric acid. 6. The method for producing a solid milk food according to claim 1, wherein the acid is gluconic acid. 7. The method for producing solid milk food according to claim 1, wherein the acid is ascorbic acid. 8. The method for producing a solid milk food according to claim 1, wherein the acid is citric acid.