JPH0576280A - Preparation of milk curd - Google Patents

Abstract

PURPOSE:To provide a milk curd having a palatability close to that of bean curd, holding the preferable taste and flavor of milk and capable of containing a large amount of milk component. CONSTITUTION:Liquid milk is subjected to ultrafiltration to obtain a concentrated milk having a whole milk protein content of 5-12%. The concentrated milk is sterilized with heat, added with a milk clotting enzyme and coagulated by reaction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a food (hereinafter referred to as "milk tofu") obtained by coagulating milk in a tofu-like manner.

[0002]

2. Description of the Related Art Milk, as it is called "complete food",
It is a food rich in nutrition that was used as a medicine in ancient times.
Even in Japan, where the introduction of milk into the diet was significantly delayed compared to Western countries, the daily milk consumption per person exceeds 100 ml, and the role of milk in nutritional supplementation is increasing. Especially in connection with the lack of calcium intake of Japanese people, which was revealed in the National Nutrition Survey in 1989, the calcium content in milk, which has a very high body absorption efficiency, is important for improving such nutritional imbalance. It is well known that it is expected to play a role and that active expansion of use is being promoted at the national government level.

However, about 15% of people hardly drink milk because of their constitution such as lactose intolerance and taste preference.
(National Milk Dissemination Association, March 1988 survey), which is a major obstacle to promotion of use. Therefore, as a means of overcoming this obstacle, milk that changes the form of "drinking milk" to "eating milk" and also aims to fuse it with Japanese food to change the taste of milk and thereby contribute to promoting the utilization of milk. Several methods for producing tofu or foods similar thereto have been conventionally known.

For example, apricot kernel tofu obtained by melting apricot kernel powder with milk and solidified with agar, a method of mixing a small amount of cow's milk or powdered milk with soybean milk as a main raw material and adding a coagulating agent to coagulate it, and a weak acid in milk To form a coagulation precipitate of milk protein, collect and shape it, and to make a tofu-like coagulum containing milk components by utilizing the heat gel forming ability of egg white or soybean protein isolate, etc. Is.

[0005]

[Problems to be Solved by the Invention] The technical problems to be solved when producing so-called milk tofu, which is obtained by coagulating milk in a tofu-like manner, are that the texture is similar to that of tofu and that the desirable flavor of milk is alive. In addition, it is possible to minimize loss of nutritional components in milk due to syneresis during production or during storage of products, and to contain milk components as much as possible.

[0006] In order to obtain a tofu-like coagulum by forming a uniform gel while milk containing one of its components, water, milk can be roughly classified into two methods, that is, heating or coagulating protein components in milk. A method of making a gel by adding a gelling agent or the like or by adding a gelling agent or a food material having gel forming ability is considered. The method of forming a coagulation precipitate of milk protein by adding weak acid to milk and collecting and molding it corresponds to the former, and although it is a simple method, there is a large loss of milk components that do not coagulate and it is called effective use of nutritional components. There is a side problem. On the other hand, almond tofu, which is obtained by solidifying milk with agar, corresponds to the latter, but it has a different texture from ordinary tofu using soymilk, and can be said to be a dessert food having a jelly-like texture. Similarly, the latter egg white,
For the method of producing milk tofu utilizing the heat-gel forming ability of the isolated soybean protein, inventions such as Japanese Patent Publication No. 62-42571 can be seen. However, in order to develop the shape retention of gel comparable to tofu, these heating The required amount of the material having the gel forming ability to be added is relatively large, so that the flavor peculiar to each material such as egg odor has a considerable adverse effect on the preferable milk flavor of the product. Milk soybean milk made from the soybean milk of the main ingredient by adding a small amount of milk or milk powder, the milk tofu made by the same method as the normal tofu has low nutritional value derived from milk components, and should be called "milky soybean tofu". It is of a degree, and it is hard to say that it is a full-scale tofu-like food using milk. Furthermore, in a known method, an existing dairy product such as milk powder is used as a means for strengthening the milk component of milk tofu. For example, when a large amount of milk powder is used, the concentration of salt components originally present in milk is increased, The salty taste of the product is increased to cause a taste problem, and the lactose concentration is also increased, which is an inconvenient product for the above-described lactose-intolerant consumer.

The present invention has been made in view of the above-mentioned problems, and has a texture similar to tofu, and makes the best use of the preferable flavor of milk. It is an object of the present invention to provide a method for producing milk tofu capable of minimizing loss of nutritional components and containing milk components as much as possible.

[0008]

Means for Solving the Problems As a result of various studies on a method for producing milk tofu, the present inventor has concentrated milk obtained by ultrafiltration of liquid milk (hereinafter abbreviated as “UF concentrated milk”). A method of reacting a milk-clotting enzyme with a milk (invention according to claim 1), and egg white solid or soluble whey protein
F milk can be used in a larger amount than in the prior art, and a coagulant such as calcium sulfate can be used as an essential component by two methods, that is, a method of adding a small amount to F-concentrated milk and coagulating with heat (the invention according to claim 2). It was found that a good gel comparable to tofu can be obtained without doing so. At the same time, by using UF-concentrated milk as a milk component source, a large amount of nutritionally important components such as proteins and calcium that are concentrated in the ultrafiltration membrane are contained, and conversely salts and lactose in milk. Since it is hardly concentrated, it has become possible to produce milk tofu that has been given the aforementioned salty taste and effectiveness as a measure against lactose intolerance.

That is, according to the first aspect of the present invention, concentrated milk having a total milk protein content of 5 to 12% obtained by ultrafiltration of liquid milk is sterilized by heating and then reacted by adding a milk-clotting enzyme. This is a method of producing milk tofu by solidifying.

The first aspect of the present invention uses the UF-concentrated milk instead of whole milk or skim milk for the remarkable water separation phenomenon of the gel that occurs when the milk-clotting enzyme is applied to the whole milk or skim milk. It is a method of obtaining a gel-like food which is almost eliminated and is very similar to tofu.

In the first aspect of the present invention, the "liquid milk" which is the undiluted solution to be subjected to the ultrafiltration treatment includes whole milk, skimmed milk, partially skimmed milk, and dairy products such as condensed milk, powdered milk, butter, cream or casein. So-called reconstituted milk prepared by dissolving or dispersing is also included. If necessary, a small amount of dairy products such as the above-mentioned cream may be additionally added to the prepared UF concentrated milk.

The milk protein content, which represents the degree of concentration of UF-concentrated milk, is difficult to unambiguously define depending on the taste and physical properties required for milk tofu, but it is usually 5-12%. The total milk solid content corresponding to this is, for example, about 12 to 23% in UF concentrated milk obtained from skim milk. However, if the amount is too small or too large, defects such as water separation and texture may occur, and the amount is preferably 6 to 10%. The type of ultrafiltration membrane used in the preparation of UF-concentrated milk may be any type as long as it has the ability to sufficiently block fats and proteins in milk and allow low-molecular lactose and soluble inorganic components to permeate. The filtering operation may be performed as usual.

The curdling enzyme to be used can be arbitrarily selected as long as it is an enzyme having a property of gelling milk protein, but an enzyme for cheese production, which has almost no off-taste or off-flavor associated with the enzymatic reaction, so-called animal origin, Rennet of microbial origin or plant origin is preferable, and the amount of addition may be a conventional method in cheese production. Before adding the enzyme, the pH of the UF-concentrated milk, which is the substrate for the enzyme reaction, is adjusted to a range in which the enzyme is sufficiently active. At that time, if the pH is too low, precipitation of milk protein occurs immediately. And a uniform gel may not be obtained, and the sourness becomes strong, which is not preferable in terms of taste.
Various organic acids are used for pH adjustment, but acidic food materials such as fruit juice and vinegar, which contain various organic acids as one component such as lemon juice, can of course be used.
The blending ratio may be arbitrarily determined in consideration of the taste and the effect on the physical properties of the milk protein gel.

In addition to the above-mentioned essential components, various additives or food materials as exemplified below can be added to the UF concentrated milk as needed. That is, the physical properties of the product can be varied by using a small amount of a thickening polysaccharide and the like, and it is also free to enhance the palatability with various seasonings, flavors, colorants, spices, fruit juices and the like. If necessary, an emulsifier may be added for the purpose of homogenizing the raw materials, or an antifoaming agent may be added for the purpose of defoaming.

The above raw materials are mixed and homogenized except for the enzyme and the raw material for pH adjustment, and then heat sterilized and cooled to PH.
Adjust and add enzyme. The enzyme reaction is usually carried out in a container, but only the enzyme is previously added to the container,
You may pour the mixture of other raw materials in it. The reaction temperature is
Although it is determined in consideration of the range in which the above-mentioned various enzymes exhibit activity, it is usually about 20 to 45 ° C.

The above is the first aspect of the present invention, and the second aspect of the present invention will be described below. The second aspect of the present invention is to obtain a total milk solid content of 12 to 12 obtained by ultrafiltration of liquid milk with the physical strength of 1 part by weight of soluble whey protein and 1 part by weight of egg white solid being 1 and 3 units, respectively. This is a method for producing milk tofu by adding 3 to 10 titer units of at least one of soluble whey protein and egg white solids to 100 parts by weight of 35% concentrated milk and heating and coagulating the mixture.

The second aspect of the present invention is a method utilizing the gel forming ability of soluble whey protein or egg white solid by heating, wherein the amount of soluble whey protein, egg white solid, or both is minimized, In addition, UF concentrated milk is used for coagulating a large amount of milk solids into tofu.

In the second aspect of the present invention, it is difficult to uniquely define the total milk solid content, which represents the degree of concentration of UF concentrated milk, depending on the taste and physical properties required for milk tofu, but 42% or less. It is necessary to be. However, if the milk solids are too much, the nutritional value is increased, but the flavor and texture are thickened, and the taste is slightly deviated from the palatability as a tofu-like food. Therefore, the total milk solids is preferably 35%. In the following, if the total milk solid content is too small, it is necessary to use a large amount of soluble whey protein or egg white solid material in terms of physical properties. Milk solids range from 12 to 35%. The method for preparing UF concentrated milk and the definition of "liquid milk" excluding the degree of concentration are the same as in the case of the above-described first present invention.

Comparing the physical properties of the soluble whey protein and the egg white solid mainly with respect to the gel forming ability, the present inventor found that the former is 3 parts by weight and the latter is 1 part by weight, and thus the former is almost equivalent to the former. It finds that it can exert its function. That is, in the second aspect of the present invention, the physical strength of each of the soluble whey protein and the egg white solid is set to 1 and 3 units, and U
The amount of the former, the latter, or both added to 100 parts by weight of F-concentrated milk is 11 units or less, preferably 3 to 10 units. Furthermore, if the use amount of these gel-forming components is further minimized and a tofu-like food product containing a large amount of milk solids and making good use of the original flavor of milk is expected, use egg white solids alone. However, in this case, the texture peculiar to the heat gel of the egg white, that is, the good crispness tends to be slightly excessive, and it can be improved by using a soluble whey protein in combination, which gives a slight stickiness to the texture depending on taste. Also, the use of soluble whey protein alone gives physical properties similar to tofu, but since the required amount is relatively large, the peculiar whey odor affects the flavor of the product.

The soluble whey protein used in the second aspect of the present invention is unmodified whey protein produced by concentrating cheese whey or casein whey by a known method such as ultrafiltration or reverse osmosis. , Concentrated solutions or dry powders are used. An example of a dry powder composition is 70% protein, 16 lactose
%, Fat 5%, ash 4%, and water 5%. The egg white solid is usually a dry powder, but raw egg white or concentrated egg white can also be used.

Incidentally, in addition to the above-mentioned essential components, various additives or food materials can be added to the UF concentrated milk, if necessary, as in the case of the above-mentioned first aspect of the present invention.

After all the above raw materials are mixed and heated and solidified, the raw material mixture is usually dispensed into a container and the whole container is heated. The heating conditions are a temperature of 70 to 100 ° C., and a heating time is about 30 to 60 minutes, although it depends on the volume and shape of the container. When mixing the raw materials, make sure that each raw material is sufficiently dispersed and dissolved.
It is preferable to perform heating and homogenizing operations at 55 ° C or lower.

[0023]

EXAMPLES Examples of the present invention will be described below. In the examples, the first and second examples are the first example of the present invention,
The third to fifth embodiments are embodiments of the second invention.

<< First Example >> Non-fat milk was concentrated to a concentration ratio of about 2.5 times by using an ultrafiltration device equipped with a polysulfone membrane having a cut-off molecular weight of about 20,000 to concentrate UF with a milk protein content of 7.5%. Got milk This UF-concentrated milk is sterilized at 80 ° C for 15 minutes, cooled to below 10 ° C, and then vinegar with acidity of 4.5% and acidity
Add an equal amount of 4.5% citric acid aqueous solution little by little, and add P
The H was adjusted to 6. Next, adjust the pH and adjust the temperature to 10 ° C.
Dissolve 1 g of rennet powder for cheese production (main components rennin and pepsin) in 10 kg of UF concentrated milk held below, dissolve in a small amount of water and stir, then immediately dispense it into a 100 ml capacity molding container. The sample was stored in a constant temperature oven at 35 ° C. for enzymatic reaction. After confirming the completion of solidification of the contents, the product was rapidly cooled to 10 ° C or lower to obtain the intended product.

The product obtained has almost no syneresis, a silky tofu-like texture and a light flavor with a light milk flavor, and is a very good match for soy sauce, soup sauce and other Japanese-style seasonings. there were. In terms of nutrition, it contains 210 mg of calcium per 100 g, which is about twice as much as milk, and 7.1% of milk protein, and it is extremely valuable as a nutritionally balanced food to supplement calcium deficiency.

<Second Embodiment> The same procedure as in the first embodiment was carried out except that UF concentrated milk (milk protein content: 7.5%) prepared by replacing skim milk with whole milk was used. And got the product to. The product had a slightly thick milk flavor with a slight cheese-like flavor and a textured texture.

In this example, milk protein 4% was also used.
(Comparative Example 1) and 13% (Comparative Example 2) of two types of UF concentrated milk were prepared, and the same procedure was followed except that
In Comparative Example 1, the product was significantly water-separated, and the gel strength was insufficient as a tofu-like food, and in Comparative Example 2, on the contrary, the gel was too hard, and the texture was rich and the melt in the mouth was poor. Neither of them was of good quality as milk tofu.

<< Third Embodiment >> Using the same ultrafiltration apparatus as in the first embodiment, a mixture of equal amounts of skim milk and whole milk was concentrated to a concentration ratio of about 2.5 times to obtain a total milk solid content of 20. % UF concentrated milk was obtained. To 10 kg of this UF concentrated milk, add 200 g of dried egg white powder and a small amount of silicon as an antifoaming agent to make a total of about 10.2 kg, 40
The mixture was thoroughly mixed and dissolved using a homomixer while heating to -50 ° C. Dispense the mixed solution into a 100 ml heat-resistant container,
After heating at 80 to 90 ° C for 45 minutes, it was cooled to obtain the desired milk tofu. The obtained product had a slightly crunchy texture, but had physical properties similar to silken tofu, no water separation, and almost no egg white odor, and thus the original flavor of milk was utilized.

The same procedure as in this Example was carried out except that the amount of the dried egg white powder added was 50 g (Comparative Example 3) or 450 g (Comparative Example 4). In Comparative Example 4, on the contrary, in Comparative Example 4, the gel is a little too hard as a tofu-like food, and the texture and flavor are close to the whiteness of boiled eggs, and it can be said that the physical properties of milk tofu are appropriate. Was not.

<Fourth Example> 100 kg of soluble whey protein concentrate powder, 200 g of dried egg white powder, and defoaming were added to 10 kg of UF-concentrated milk prepared by the same method as in the third example by blending raw materials. Milk tofu was prepared in the same manner as in the third example except that a small amount of silicon was added as an agent to make the total amount about 10.3 kg. The obtained product had good physical properties such that the texture with too good a crispness characteristic when using the egg white alone as in the third example was improved.

<Fifth Embodiment> In a raw material mixture, 10 g of UF concentrated milk prepared by the same method as in the third embodiment was added with 600 g of soluble whey protein concentrate powder and a small amount of silicon as an antifoaming agent. Milk tofu was prepared in the same manner as in Example 3 except that the total amount was about 10.6 kg. The obtained product had no syneresis and had a slightly sticky texture, but the physical properties as milk tofu were comparable.

[0032]

As described above, according to the method of the present invention, it is possible to add a large amount of a specific nutritionally useful milk component such as milk protein and calcium, which has never existed before, and moreover, the original milk It is possible to provide milk tofu having a desirable flavor and an excellent texture similar to that of ordinary tofu. The milk tofu obtained by the first method of the present invention is
It is a milk protein gel with a uniquely fine texture and a soft texture obtained by an enzymatic reaction. For example, it can be tasted by adding seasonings such as soy sauce and soup sauce to a cold chicken flavor. The milk tofu obtained by the method of the second aspect of the present invention can be cooked by heating in addition to eating cold soy sauce, so it can be used as a miso soup ingredient, and various cooking materials such as simmered and stir-fried foods. Widely available as. By expanding the fields of use in this way, it will greatly contribute to promoting the use of milk.

Claims (2)

[Claims] 1. A method in which concentrated milk having a total milk protein content of 5 to 12% obtained by ultrafiltration of liquid milk is sterilized by heating and then reacted by adding a milk-clotting enzyme to coagulate it. Milk tofu manufacturing method. 2. A total milk solid content of 12 to 35% obtained by ultrafiltration of liquid milk with a physical strength of 1 part by weight of soluble whey protein and 1 part by weight of egg white solid, respectively. A method for producing milk tofu, comprising adding 3 to 10 titer units of at least one of soluble whey protein and egg white solids to 100 parts by weight of concentrated milk, and heating and coagulating this.