JPH0349546B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for producing containerized tofu, and more particularly, to a method for automatically producing containerized soft-boiled tofu.

Prior Art As a method for automatically producing tofu in containers, an invention as described in Japanese Patent Publication No. 56-23574 has already been proposed. The method for producing packaged tofu according to this proposed invention roughly consists of the steps of heat sterilizing soy milk and then cooling it to room temperature, filtering the glucono delta lactone aqueous solution with a Millipore membrane filter to make it sterile, and pouring it into a sterile mixing tank together with the soy milk. a step of aseptically forming a container from a heat-resistant and water-resistant sheet-like material, filling it with soymilk and glucono delta-lactone, and sealing the container; The process consists of immersing the water in a heated water tank.

Problems to be Solved by the Invention In the tofu manufacturing method according to the proposed invention, glucono delta-lactone is used as a coagulant. However, glucono-delta-lactone is more expensive than bittern, which has traditionally been used as a coagulant, and has the disadvantage that it gives tofu a sour taste that impairs its flavor. The reason why glucono delta lactone is used as a coagulant instead of bittern when producing tofu automatically is as follows.
This is because bittern reacts and coagulates immediately when mixed with tofu, whereas glucono delta-lactone rapidly reacts with soy milk and coagulates when heated.

The purpose of this invention is to provide a method for producing packaged tofu with good flavor using a coagulant and inexpensive bittern, especially bittern with magnesium chloride purity of 99.5% or more, which is completely safe as a food additive. .

Means for Solving the Problems In order to achieve the above object, the method for producing tofu in a container according to the present invention maintains the soymilk at a temperature below 20°C when supplying the soymilk to a filling device via a conduit. Mix magnesium chloride with bittern with a purity of 99.5% or higher, which was previously cooled to below 20℃ in a conduit, fill the mixed liquid into a container, seal the container, and heat the sealed container to cool the mixed liquid in the container. It is characterized in that it is coagulated to obtain tofu.

As bittern, the purity of magnesium chloride is 99.5
% or more was used for the following reason. Ordinary bittern has low purity magnesium chloride and may contain harmful magnesium bromide. Therefore, the most desirable bittern as a food additive is 100% pure magnesium chloride. However, since magnesium chloride is deliquescent, it still contains 0.5% water even when dried. In the end, in practical terms, the best material for tofu production is one that consists of 99.5% magnesium chloride and the rest, with no other impurities. Of course, if the water content can be reduced to less than 0.5%, it would be no problem.

A heat exchanger is used as a means for cooling the soymilk and bittern. The cooling temperature should be 20°C or less, but 15 to 17°C is particularly suitable. In order to sterilize soymilk and bittern, it is best to heat both to 128°C for at least 1 second before cooling. After cooling, the soy milk and bittern are stored in a sterile tank. It is preferable to use a pipe mixer to mix soymilk and bittern.
The container may be of any shape, but in order to prevent the tofu from spoiling, it is best to use a box-shaped container and lid made of a material with oxygen barrier properties, such as polypropylene, polypropylene, etc. Synthetic resins such as nylon can be used, and in some cases, composite materials may also be used. Steam or hot water is used to heat the sealed container, and the heating temperature is preferably 95° C. or higher and the holding time is preferably 20 minutes or longer. To prevent tofu from deteriorating during storage, it is best to quickly cool the sealed container after heating.

Effects The method for producing packaged tofu according to the present invention achieves the ideal purity for bittern from the viewpoint of food additives.
Since 99.5% or more of magnesium chloride is used, on the other hand, the reaction rate when mixed with soy milk is extremely fast, and in conventional methods, the mixture would solidify before being filled into containers.

Therefore, according to the present invention, when soymilk is supplied to the filling device via a conduit, the soymilk is kept at a temperature below 20°C, and the bittern mixed with the soymilk is also kept at 20°C. It is slow and does not solidify immediately. Furthermore, since this mixing is performed in the conduit immediately before filling, it is possible to fill the container with the soymilk after mixing and before it solidifies.

Example Soy milk obtained by a conventional method is first passed through a deaeration tank to remove air bubbles contained in the soy milk. The soymilk after air bubbles are removed is passed through a heating heat exchanger and a cooling heat exchanger, and stored in a sterile tank. Steam is used as the heat medium. The heating temperature of soybean milk was 135°C, and the passage time through the heat exchanger was 2 seconds. Cooling water is used as the refrigerant. The cooling temperature is 15.5°C.

Bittern is also heated and cooled using the same method and conditions as soy milk and stored in a sterile tank. Magnesium chloride with a purity of 99.5% was used as bittern.

Sterilized soymilk is supplied from the tank to the filling device via a conduit. A pipe mixer is placed in the conduit near the connection with the filling device, and the bittern conduit is connected to the soy milk conduit at the part where the pipe mixer is located, and this conduit allows the soy milk to be mixed. A predetermined amount of bittern is supplied from the tank to a pipe mixer, where the soymilk and bittern are instantaneously mixed.

The filling device is placed on the top wall of the sterile chamber and its inlet with a valve opens into the sterile chamber. A conveyor carrying a large number of containers runs directly below the injection port. The inside of the sterile chamber, including the internal equipment, is sterilized by hydrogen peroxide spray, then the existing air is replaced with hot air, and then the temperature is returned to normal temperature.
Maintained in a sterile atmosphere. The box-shaped container is filled by the weight of the soymilk and bittern mixture, and the filling time is 20 seconds, which is controlled by opening and closing a valve. The container and lid are made of colorless and transparent polypropylene. After filling, the container is mechanically capped and heat sealed in the same sterile chamber.

The sealed container that is automatically discharged from the sterile chamber is placed in a hot water bath and heated to 96°C for 30 minutes to solidify the liquid mixture in the sealed container and obtain Kinugoshi tofu.

Transfer the heated sealed container from the hot water tank to the cooling tank.
The tofu is packaged in a container and does not deteriorate in quality.

Effects According to this invention, the purity is 99.5, which is completely acceptable as a food additive, which was thought to be impossible to use as bittern because the coagulation reaction with soy milk is too fast.
% of magnesium chloride, it is now possible to provide packaged tofu with better flavor to consumers at a lower cost and with peace of mind, compared to tofu obtained by the conventional manufacturing method using glyconodelta-lactone. I can do it.

Claims (1)

[Claims] 1. When soymilk is supplied to the filling device through a conduit, the soymilk is kept at 20℃ or less, and the purity of the magnesium chloride that is kept at 20℃ or less in the conduit immediately before filling is 99.5.
% or more of bittern, filling the mixed liquid into a container, sealing the container, and heating the sealed container to solidify the mixed liquid in the container to obtain tofu. .