JPH0446545B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for producing calcium-enriched aseptic tofu,
More specifically, we use a new calcium hydroxide-sucrose complex, which has never been used as a tofu coagulant, as a tofu coagulant, and it has excellent long-term storage stability, structure, flavor, and texture. The present invention also relates to a method for producing calcium-enriched aseptic tofu containing a large amount of calcium, in which the calcium complex as a coagulant is used as a calcium-enriching agent.

[Prior art]

In the past, the coagulant for tofu used was calcium sulfate or a mixture of magnesium chloride, magnesium sulfate, etc., but recently glucono delta-lactone (hereinafter abbreviated as "GDL") has been used as a coagulant. ), so-called bagged tofu or blown tofu began to be produced. However, these known tofus are insufficiently sterilized and cannot be stored for long periods of time.

Therefore, in order to improve this point, soy milk was added.
A method for producing aseptic tofu in containers was developed by sterilizing it using the VTIS or UHT method, adding a coagulant (GDL) under aseptic conditions, aseptic blow molding, filling and sealing, and then heating and coagulating it (Tokuko Sho). 56−
23574, Special Publication No. 56-23577). In addition, a method was also developed in which a coagulant (GDL) was continuously added in proportion to the mixture in the above method (Japanese Patent Publication No. 39865/1983).

However, these prior art methods use a coagulant (GDL) that coagulates soymilk when heated, so if it is added to soymilk before sterilization using the VTIS or UHT method, it will not be sterilized. These conventional coagulants cannot be added to soymilk before the sterilization process, as it would be theoretically possible to coagulate it due to the heat of the soybean milk. Therefore, even in the above prior art documents,
For example, in section b of the claims of Japanese Patent Publication No. 56-29574, the object to which a coagulant is added is "obtained sterilized soymilk" or "the sterilized soymilk," and the coagulant is added after sterilization. It is clearly stated that

However, adding a large amount of coagulant after sterilization in this way tends to cause problems in aseptic control of the process, and a sterilizing filtration device such as a Millipore filter is required as described in the above-mentioned known literature.

Furthermore, in the current diet where calcium intake is decreasing, it is recommended to fortify various foods with calcium, and tofu is one of the foods for which calcium fortification is desired.

However, in the above prior art, only GDL is specifically disclosed as a coagulant.
There is no suggestion of calcium fortification. Even if an attempt is made to strengthen calcium by adding a large amount of a coagulant made of a calcium salt other than GDL after the sterilization process, it is technically difficult to add a large amount of calcium sulfate, which has been used conventionally, because it has low solubility in water. Calcium chloride causes uneven coagulation and deterioration of flavor, so both are not preferred.

However, although water-soluble calcium salts such as calcium lactate can be added in large quantities after sterilization, the lactic acid moiety in the molecule of calcium lactate has a large weight, so this salt cannot be used for the purpose of calcium fortification. Must be used in large quantities. In this case, the resulting bitter taste and other off-flavors remain and the flavor is significantly deteriorated and reduced. Moreover, since calcium lactate is expensive, the cost of the resulting product is also very problematic.

In this way, when producing aseptic tofu, flavor,
Not only from a cost perspective, but also from a quality perspective,
Adding a large amount of calcium was extremely difficult.

[Means to solve the problem]

The present invention was made in order to solve these drawbacks all at once, and it is possible to reduce the cost by adding a large amount of calcium-containing coagulant in the process before sterilization without degrading the flavor. This was done in order to develop a completely new coagulation system that can simultaneously satisfy the objectives of strengthening.

After considering various aspects to achieve this objective, we came to the conclusion that the desired objective could not be achieved with the conventionally known types of coagulants that are related to heat, so we developed a new coagulant that is heat resistant. We learned that it is necessary to do so.

Therefore, various calcium compounds were screened in search of a material that has such heat resistance, calcium fortification, and coagulation of soybean protein, but no success was achieved. Then, we changed our thinking and focused on complexes and conducted further screening. We arrived at a calcium hydroxide-sucrose complex among the complexes of calcium hydroxide and sugar, and as a result of considering more detailed processing conditions, we hereby present the present paper. The invention was completed.

That is, the present invention relates to a method for producing calcium-enriched aseptic tofu, which uses a calcium hydroxide-sucrose complex as a novel coagulant.

The complex itself is a known substance (Journal of the Chemical Society of Japan, 1972, No. 12, P2287-2291), but its application to food is unknown, much less its use as a coagulant for tofu. In fact, it has not even been suggested. In other words, the application of this composite to a coagulant is a novel one that has not been described in any literature. in this way,
The present invention has newly developed a novel use of the composite as a coagulant, and the present invention should be highly evaluated based on this point alone. The coagulation mechanism of this composite is a new one that is completely different from conventionally known ones, resulting in very soft and flavorful tofu (hereinafter, this will also be referred to as "coagulation" to distinguish it from conventional coagulation). ), the present invention will be highly evaluated in terms of the development of a completely new type of coagulant that was previously unknown.

In carrying out the present invention, a calcium hydroxide-sucrose complex is added to soymilk produced by a conventional method, and if necessary, magnesium sulfate and/or salt may be added to improve firmness and flavor. It's okay. However, when the amount of calcium hydroxide-sucrose complex added is 50 mg% or more in terms of calcium in the product, 0.05 to 0.1% of sodium hexametaphosphate is added to the product to prevent thickening during pH adjustment. Since the pH of the mixture thus obtained is tilted toward the alkaline side, the pH is adjusted to around 7.0 using an aqueous solution of an organic acid such as citric acid.

Therefore, ultra-high temperature sterilization is performed. For this purpose, various systems can be used freely, for example, VTIS system etc.
It is best to process for about 60 seconds. If necessary,
Magnesium sulfate and salt may be added after sterilization. This sterilization process kills all fungi, including spores, contained in soybean milk, calcium hydroxide-sucrose complexes, etc., rendering them sterile and imparting preservability.

In the present invention, calcium hydroxide-sucrose complex is used as a novel coagulant, so
It is fundamentally different from conventional heat-coagulating coagulants such as GDL, calcium sulfate, and calcium chloride.
It is truly revolutionary in that it does not coagulate even during the above-mentioned high temperature sterilization process.

Next, an organic acid aqueous solution is aseptically added to the sterilized mixture to adjust the pH to weakly acidic. This PH value is
It is preferably 5.7 to 5.9; if it is less than that, the soymilk will thicken and workability will deteriorate, or the gel structure will become rough and syneresis will increase. If it is more than that, the structure will become soft, which is undesirable. As an organic acid,
All organic acids may be used alone or in combination as long as they do not adversely affect the raw materials, products, or coagulation process. Examples of organic acids include citric acid, gluconic acid, malic acid, fumaric acid, and ascorbic acid. Among these, citric acid or ascorbic acid is particularly preferred from the viewpoint of taste, etc., but since natural fruit juices generally contain abundant of the above acids, they can be substituted with them, and various flavorings can be made. Acidic fruit juice lowers the pH of soymilk and causes protein precipitation, so it was difficult with conventional methods to add enough juice to fully develop the flavor, but the production method of the present invention does not change the production process. It is possible.

Calcium enrichment is one of the important objectives of the present invention, and if the calcium hydroxide-sucrose complex used as a coagulant is insufficient for calcium enrichment, for example, pH adjustment may be necessary after sterilization. Sometimes calcium compounds may be added aseptically.
As the calcium compound, it is preferable to use calcium lactate in terms of taste. When adding calcium hydroxide-sucrose complex alone as a calcium component, the amount added is calculated as the amount of calcium in the product.
It is preferably 30 to 50 mg%. If it is less than 30mg%, the tofu will be soft, and if it exceeds 50mg, sodium hexametaphosphate will be added to the product.
If 0.05 to 0.1% is not added, the soymilk will thicken, the texture of the tofu will deteriorate, and no decrease in water retention will be observed, all of which are unfavorable.

The addition rate of sodium hexametaphosphate is between 50 and 100 mg% of calcium equivalent in the product.
It increases proportionally from 0.05 to 0.1%, but if it exceeds 0.1%, an adverse effect on flavor may occur.
Also, as a calcium component, calcium hydroxide
When calcium lactate is added in addition to the sucrose complex, it is preferable that the amount of both added is 15 to 30 mg% in terms of calcium in the product. Calcium enrichment treatment and organic acid addition treatment are performed under known aseptic conditions such as aseptic indoor treatment.

The container is then filled and sealed using known equipment such as aseptic filling machines. Then, the tofu is heat-treated for 20 to 60 minutes by a known method such as using a heating coagulation tank at 75 to 95°C to coagulate the tofu product.

One of the important points of the present invention is to use a calcium hydroxide-sucrose complex as a novel coagulant. This method is fundamentally different in that it yields tofu with an excellent flavor that is extremely soft, creamy, and has a completely new texture. The new structure shown here is not only based on the results of sensory tests, but also as shown in the schematic diagram in Figure 1, when protein particles are heated in the presence of a large amount of calcium, several groups of particles first coagulate. This is explained by the fact that the grains form a loosely spaced lattice structure using these particles as a material (References J. Food Sci 43, 79).
(1978). On the other hand, according to the conventional method, as shown in the schematic diagram in Figure 2, several protein particles do not aggregate in advance, but instead combine individually at narrow intervals to form a very dense structure. Therefore, the organization becomes hard and not soft.

As described above, the method of the present invention has a completely different coagulation system from the conventional method, and is a new coagulation system, which will be referred to as coagulation.
The details of this mechanism will require further research, but it is estimated as follows. In other words, the calcium hydroxide-sucrose complex becomes a chelate compound under high temperature sterilization conditions near neutrality, and the calcium is not ionized, so it is in a form that is difficult to react with proteins. , protein destabilization and decrease in heat resistance in the presence of calcium are avoided. Next, when the pH is lowered, the complex is destroyed and calcium is ionized at this stage, where it comes into contact with proteins, causing protein coagulation, and it is presumed that a phenomenon called coagulation occurs.

〔Effect of the invention〕

As described above, in the present invention, by using a calcium complex as a novel coagulant, we can industrially produce sterile tofu that is creamy and has an excellent flavor and has an extremely soft and mild texture that has never been seen before. It can be produced in an advantageous manner. Moreover, by using calcium complex alone or in combination with calcium lactate, it is possible to improve
It is also possible to fortify foods with calcium five times as much, and the present invention can achieve the remarkable effects of calcium fortification, imparting a soft and creamy flavor, low cost, and long-term storage all at once. be.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Calcium hydroxide-sucrose complex 71 in 2400 kg of soy milk
Kg, 30 Kg of 10% saline solution, and 30 Kg of 5% sodium hexametaphosphate solution were added, and then 81 Kg of 10% citric acid aqueous solution and 170 Kg of water for line extrusion were added to adjust the pH to 7.1.

Then, using the VTIS device manufactured by Alfa Arraval
High-temperature sterilization was performed by VTIS treatment at 140°C for 30 seconds, followed by cooling. Thereafter, 36 kg of 10% citric acid aqueous solution was added under aseptic conditions to adjust the pH to 5.75.

Next, the tofu was aseptically filled and sealed in a conventional manner using a Tetrabrik aseptic filling device, and then placed in a heating coagulation tank and coagulated at 85° C. for 40 minutes to obtain product tofu. The resulting tofu has a mild and creamy texture, with little syneresis.
A very good gel was formed. In addition, regarding the calcium fortification rate, the calcium equivalent value in the product is
The content was extremely high at 110mg%, making it an excellent calcium-fortified food.

The composition of the soy milk used here is: total solids: 12.0%, protein: 5.8%, calcium:
The 30 mg% calcium hydroxide-sucrose complex solution was obtained by dissolving 5.0 kg of calcium hydroxide and 23.3 kg of sucrose in 43.0 kg of water and stirring and mixing.

Example 2 To 2400 kg of soymilk with the same composition as in Example 1, 24 kg of calcium hydroxide-sucrose complex solution and 30 kg of 10% saline were added, and then 18.8 kg of 10% citric acid aqueous solution and 200 kg of water were added to adjust the pH to 7.0. Adjusted to.

Then, using the VTIS device manufactured by Alfa Arával.
High-temperature sterilization was performed by VTIS treatment at 140°C for 30 seconds, followed by cooling. Next, 5 to this
A mixed solution of 60 kg of % calcium lactate aqueous solution, 65 kg of 10% citric acid aqueous solution, and 200 kg of water was added under aseptic conditions.
The pH at that time was 5.8. Then, 6.0 kg of water was added.

Next, the tofu was filled and sealed aseptically in a conventional manner using a Tetrabrik aseptic device, and then placed in a heated coagulation tank and treated at 85°C for 40 minutes to coagulate to obtain product tofu. The obtained tofu had a mild and creamy texture as in Example 1, and was excellent with little syneresis. In addition, the amount of calcium equivalent in the product was 58 mg%, making it an outstanding calcium-fortified food.

The calcium hydroxide-sucrose complex solution used here contains 1.67 kg of calcium hydroxide and 7.66 kg of sucrose.
Kg in 14.67 Kg of water and stirred and mixed.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a coagulation protein according to the present invention, and FIG. 2 is a schematic diagram of a coagulation protein according to a conventional method.

Claims (1)

[Scope of Claims] 1. After adding a calcium hydroxide-sucrose complex as a coagulant to soymilk, heat sterilization is performed, the pH thereof is adjusted to weak acidity, and after being aseptically filled into a container, the container is sealed, A method for producing calcium-enriched sterile tofu, which is characterized by heating and coagulating the tofu. 2. The method for producing calcium-enriched aseptic tofu according to claim 1, wherein the amount of the calcium hydroxide-sucrose complex added is 30 to 100 mg% in terms of calcium in the product. 3. When the amount of calcium hydroxide-sucrose complex added is 50 mg% or more as calcium equivalent in the product, sodium hexametaphosphate is added to the product from 0.05 to 50 mg%.
The method for producing aseptic tofu enriched with calcium according to claim 2, characterized in that 0.1% of calcium is added. 4. The method for producing calcium-enriched sterile tofu according to claim 1, wherein the adjusted pH is 5.7 to 5.9. 5. The method for producing calcium-enriched aseptic tofu according to claim 1, characterized in that the pH is adjusted by adding an organic acid aseptically. 6. The method for producing calcium-enriched aseptic tofu according to claim 1, wherein the organic acid is citric acid or ascorbic acid. 7. The method for producing calcium-enriched aseptic tofu according to claim 6, characterized in that citric acid or ascorbic acid as the organic acid is added in the form of natural fruit juice.