JP2001000126A - Production of frozen bean curd for freeze-dried bean curd - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing frozen bean curd for freeze-dried bean curd, by which the frozen bean curd can be produced at a low cost, wherein the frozen bean curd does not generate cracks in a freeze-drying process and in a process for the water-adding restoration of the freeze-dried bean curd, can be rapidly restored with water, thereby permits the production of large freeze-dried bean curd, and gives freeze-dried bean curd having a texture equal to that of conventional raw bean curd after restored. SOLUTION: This method for producing frozen bean curd 16 for freeze-dried bean curd comprises injecting air into high temperature bean milk 7 to bubble the bean milk, adding gelatin and a saccharide such as maltose, oligotose or trehalose as gelling agents, and calcium sulfate singly or a composite coagulant consisting mainly of the calcium sulfate, a lactic acid-based composite coagulant, or the like, as a coagulant to the bubbled bean milk before the temperature of the bean milk is lowered, thereby coagulating the bubbled bean curd under a temperature condition of 65 to 85 deg.C, and then quickly freezing the coagulated bean curd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing frozen tofu for freeze-dried tofu.

[0002]

2. Description of the Related Art In recent years, freeze-dried tofu has been developed,
It is used as an ingredient in instant foods such as instant miso soup. Freeze-dried tofu has been developed from the manufacturing technology of frozen tofu (highly preserved tofu that is frozen so as not to form a sponge and thawed when needed). A step of adding a gelling agent and a coagulant, rapidly freezing the coagulated tofu to produce frozen tofu, and drying the frozen tofu by FD drying (keeping the temperature at a low temperature in a vacuum to remove moisture to dry the food) Lyophilization process).

In conventional frozen tofu for freeze-dried tofu, starch and gums (xanthan gum, tamarind gum, gum arabic, guar gum, etc.) are used as gelling agents.
Locust bean gum), curdlan (trade name) and the like were used.

[0004] However, frozen tofu for freeze-dried tofu produced using these gelling agents is liable to crack in the FD drying step, and has a water-recovery property of commercialized freeze-dried tofu (in hot water). Is poor, the faster the restoration, the worse the texture, and the better the texture,
There is a strong tendency that the restoration is slow, and the texture and taste of the restored tofu are considerably different from ordinary tofu produced by a traditional method.

Therefore, freeze-dried tofu has a size limit of about 5 mm square, and even if it is indicated as instant miso soup containing tofu, tofu of about 5 mm square has little meaning as an ingredient. At present, the product is visually and tastefully different from ordinary tofu.

Further, in the conventional frozen tofu for freeze-dried tofu, since starch, gums, curdlan and the like are used as a gelling agent, there is a problem that the production cost is high.

[0007] In other words, soy milk is generally produced through steps of soy milk immersion, weighing and grinding, boiling, and separation of soy milk (discharge from okara) by filtration. When starch, gums, curdlan, etc. are added to the soy milk in the state, the reaction immediately proceeds, and the soy milk solidifies before these gelling agents are uniformly dispersed in the tofu tissue.

[0008] For this reason, hot soy milk immediately after production is specifically cooled, the temperature of the soy milk is once lowered to about 10 to 40 ° C, and a gelling agent such as starch, gums, curdlan and the like is added. Stir well and after adding coagulant, again 65-85 °
Heating to about C required coagulation of the tofu.

Therefore, a soymilk cooler or a tank for cooled soymilk is required as a production facility, and the processing time from the production of soymilk to the production of frozen tofu is long. Will be higher. In particular, when a card run is used, the tendency is remarkable because the price of the card run itself is high.

[0010]

SUMMARY OF THE INVENTION In view of the above situation, the present invention does not cause any cracks during the FD drying step or the reconstitution with water, and can be rapidly reconstituted with water.
For example, it is possible to produce freeze-dried tofu of a size suitable for roasted tofu, hot pot tofu, etc., and furthermore, the frozen taste is comparable to that of normal raw tofu after restoration. An object of the present invention is to provide a method for producing frozen tofu for freeze-dried tofu from which dry tofu can be obtained at low cost.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, in the present invention, in summary, air is injected into hot soymilk to contain air bubbles. As a gelling agent, instead of starch, gums, curdlan, etc., gelatin and
Saccharides such as maltose, oligotose and trehalose are used. A so-called high temperature soy milk coagulation method is adopted. It has taken the technical measures. That is, the method for producing a frozen tofu for freeze-dried tofu according to the present invention comprises, as described in claim 1, injecting air into soy milk in a high temperature state to contain air bubbles, and before the soy milk temperature falls. To this soy milk, gelatin as a gelling agent, and sugars such as maltose, oligotose, and trehalose are added, and as a coagulant, calcium sulfate alone, a complex coagulant containing calcium sulfate as a main component, lactic acid-based By adding a complex coagulant or the like, the soymilk containing air bubbles is 65-85 °
The method is characterized by coagulating under a temperature condition of C and rapidly freezing the coagulated tofu to produce a frozen tofu for freeze-dried tofu.

According to the above-mentioned constitution, instead of using starch, gums, curdlan or the like as a gelling agent, gelatin and sugars such as maltose, oligotose and trehalose are used. In addition to obtaining frozen tofu for freeze-dried tofu, cracking does not occur, air is injected, and soymilk is allowed to contain air bubbles. By coagulating underneath, the rehydration property of the freeze-dried tofu commercialized through the FD drying step is improved, cracks during rehydration are eliminated, and rapid rehydration is possible.

Therefore, it is possible to produce freeze-dried tofu of any size, and it is possible to produce freeze-dried tofu much larger than conventional products. It is also possible to manufacture it. Furthermore, by using gelatin and sugars such as maltose, oligotose and trehalose instead of starch, gums, curdlan, etc. as gelling agents,
The taste and texture of the commercialized freeze-dried tofu after restoration are improved, and the taste is comparable to that of ordinary raw tofu,
The texture is obtained.

Also, the higher the content of air bubbles by air injection, the faster the reconstitution of the freeze-dried commercialized tofu-dried tofu becomes. It is possible to adjust the water resilience of the tofu. For example,
When producing freeze-dried tofu used as an ingredient for instant miso soup or sashimi soup with low viscosity, by reducing the amount of air injection, water absorption can be suppressed and the time required for restoration can be adjusted. In the case of producing freeze-dried tofu for marbo tofu and other freeze-dried tofu used for other high-viscosity soups that need to be impregnated with thick juice to make it compatible with the taste, use a large amount of air injection. Then, restoration can be accelerated by improving water absorption.

Further, instead of using starch, gums, curdlan, etc. as a gelling agent, gelatin and sugars such as maltose, oligotose and trehalose are used,
As a coagulant, calcium sulfate alone, which has a wider reaction temperature range than bittern and magnesium chloride, a composite coagulant containing calcium sulfate as a main component, a lactic acid-based composite coagulant, etc. Certain soymilk can be coagulated by a so-called high-temperature soymilk coagulation method without cooling once, and the manufacturing cost can be reduced in combination with omitting expensive curdlan.

The soymilk in the present invention includes not only soymilk alone but also soymilk mixed with powders or flavor liquids such as citrus fruits such as yuzu, mushrooms such as matsutake, and seaweeds such as seaweed and kelp. It does not do.

When air is injected into soy milk in a high-temperature state to contain air bubbles, the upstream side of a pump for pumping soy milk from a soy milk tank to a measuring bucket as in the second aspect of the present invention. It is desirable to inject air into the soymilk flow path by utilizing the negative pressure generated by the flow of the soymilk.

With such a configuration, the air injection amount is automatically adjusted according to the flow rate of the soymilk flowing in the soymilk flow path, and the pump for feeding the soymilk serves as a stirring device, and the dedicated stirring device is used. This is because the injected air and the soymilk can be sufficiently agitated and fine bubbles can be contained in the entire soymilk without providing an apparatus.

The coagulated tofu may be cut into desired dimensions in advance and then rapidly frozen, or sent to the next step without cutting, and then cut into desired dimensions after quick freezing or FD drying. Good.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An example of a method for producing a frozen tofu for freeze-dried tofu according to the present invention will be described with reference to FIGS. 1 to 3. A soymilk 7 is manufactured through the steps of immersion 1, weighing and grinding 2, boiling 4, and separation of soymilk by filtration (okara discharge 6) 5. In the process of the weighing and grinding 2, for example, an antifoaming agent 3 such as monoglyceride and silicon is added.

The defoaming agent is added for the purpose of preventing large bubbles from being generated on the surface of soy milk, as in a general method for producing tofu. In, it is not necessary to use an antifoaming agent, even if an antifoaming agent is added, so as not to deteriorate the reconstituting ability of the commercialized freeze-dried tofu,
It is desirable to minimize the amount of addition. In particular,
In this example, about 0.5 g of an antifoaming agent is added per liter of soymilk.

In the boiling step 4, it is desirable to remove the green odor of soybeans by sufficiently boiling, for example, boiling at 120 ° C. for 3 minutes. Also,
The concentration of soymilk 7 is about 12% in a normal method for producing tofu, but in a method for producing frozen tofu for freeze-dried tofu, taking into account the amount of the gelling agent, for example,
It is desirable to have a soymilk concentration of 10 to 11.5%.

Next, the soymilk 7 in a high temperature state immediately after production is prepared.
Then, after injecting air 8 to contain air bubbles, the addition of the gelling agent 9 and the addition of the coagulant 10 are carried out before the temperature of the soymilk is lowered so much.

As the gelling agent, starch, gums, curdlan and the like are not used, and only gelatin and saccharides (for example, any one or more of maltose, oligotose and trehalose) are used. As the coagulant, any one of a simple substance of calcium sulfate having a wider reaction temperature range than that of bittern or magnesium chloride, a composite coagulant containing calcium sulfate as a main component, or a lactic acid-based composite coagulant is used.

As gelatin, it is desirable to use effervescent gelatin having better solubility than ordinary gelatin. The addition amount of the gelling agent is 15 per liter of soy milk.
About 21 g (gelatin 5-6 g, sugars 10-15
g), the amount of coagulant added is 3 to
It is about 5 g.

If the amount of the gelling agent is not more than 15 g per liter of soy milk, the coagulated tofu tends to separate, that is, the water retention of the tofu deteriorates, water easily escapes from the tofu, and the FD increases. Cracks are likely to occur during the drying process and during the reconstitution of the commercialized freeze-dried tofu with water. Conversely, if the amount is 21 g or more, the freeze-dried tofu that has been commercialized has poor water reconstituting properties, and the time until reconstitution is prolonged. By the way, in instant foods such as instant miso soup, it is desired to restore within 10 seconds when put in boiling water,
If the amount of the gelling agent exceeds 21 g per liter of soymilk, it takes 10 seconds or more to recover, and this request cannot be met.

Then, before the temperature of the soymilk decreases, the so-called high-temperature soymilk coagulation method is used.
Under the temperature condition of 65 to 85 ° C, soymilk 7 containing air bubbles
At a high temperature. Although the reheating 12 shown in FIG. 1 is not an indispensable step as a method for producing a frozen tofu for freeze-dried tofu, a gelling agent and a coagulant are added in consideration of a decrease in the temperature of soymilk due to heat radiation to the atmosphere. Soy milk 7 to 8
Reheat 12 to 5 ° C to promote solidification,
It is desirable to perform sterilization. Even if the reheating 12 is performed, the temperature of the soymilk 7 to be reheated 12 is much higher than the conventional production method in which the soymilk was actively cooled prior to the addition of the gelling agent. Short heating time is enough,
Less heat is required.

Then, in the step of cooling 13, the solidified tofu is pre-cooled, cut into pieces of an arbitrary size 14, and then rapidly frozen 15 to produce frozen tofu 16 for freeze-dried tofu. The pre-cooling of the solidified tofu is performed in order to prevent the generation of steam in the step of quick freezing 15 and to increase the water retention of the tofu.

Thereafter, the frozen tofu 16 for freeze-dried tofu is passed through a step of FD drying 17 to be commercialized as freeze-dried tofu.

When air is injected into the soymilk 7 in a high-temperature state to contain air bubbles, a pump P for pumping the soymilk 7 from the soymilk tank 18 to the measuring bucket 19 as shown in FIGS. A drain cock 21 is provided in the soymilk flow path 20a on the upstream side of the soybean milk.
It is preferable that air be injected by utilizing a negative pressure generated by the flow of air.

With this configuration, the soymilk flow paths 20a, 20a, 2 can be provided without providing a high-precision air injection amount control device.
0b, the air injection amount is automatically adjusted according to the flow rate of the soymilk 7, and the pump P for soymilk pressure feeding functions as a stirring device, so that the injection was performed without providing a dedicated stirring device. The air and soy milk 7 are sufficiently stirred, soy milk 7
This is because fine bubbles can be contained throughout.

Further, by adjusting the degree of opening of the drain cock 21, the amount of air injected (the content of air bubbles) can be adjusted to adjust the water resilience of the commercialized freeze-dried tofu. In other words, the higher the content of air bubbles due to air injection, the faster the water-based restoration of the commercialized freeze-dried tofu, and the lower the speed, the slower the recovery.
By controlling the degree of opening by controlling the air injection amount, it is possible to adjust the water resilience of the commercialized freeze-dried tofu. For example, when producing freeze-dried tofu used as an ingredient for instant miso soup or sashimi juice with low viscosity, by reducing the amount of air injection, water absorption can be suppressed and the time required for restoration can be adjusted. Conversely, when manufacturing freeze-dried tofu for marbo tofu or other high-viscosity soups that need to be impregnated with thickened soup to make it taste-friendly, air injection volume The restoration can be accelerated by increasing the water absorption and improving the water absorption.

When the soymilk 7 pumped by the pump P reaches the set amount, the measuring bucket 19 shown in FIG. It is configured to supply to the coagulation tray 23. In FIG. 2, 24 is a gelling agent tank, 25 is a coagulant tank, and 26 is a conveyor. Prior to the soy milk 7, the gelling agent and the coagulant are charged from the gelling agent tank 24 and the coagulating agent tank 25 to the coagulating tray 23 placed on the conveyor 26, and then the measuring bucket 19 is supported. Rotate around the shaft 22 to remove the soy milk 7 inside the tray 2 for coagulation.
Filling and stirring are performed by supplying vigorously to 3.

Further, in order to prevent the bubbles contained in the soymilk 7 from separating and falling out, the length of the soymilk flow path 20b on the downstream side of the pump P, the discharge pressure of the pump P, the capacity of the measuring bucket 19, etc. Is set to 0 so that the process from when the soymilk 7 passes through the pump P to when the soymilk 7 to which the gelling agent and the coagulant is added is filled in the coagulation tray 23 is quickly completed.

When cutting the coagulated tofu to an arbitrary size, it may be cut artificially or automatically using a wire rod or another cutter, as shown in FIGS. 4 (a) and 4 (b).
As shown in Fig. 7, after filling the coagulation tray 23 with the soymilk 7 to which the gelling agent and the coagulant have been added, the grid-shaped partition frame 2 is formed.
7 is set in the coagulation tray 23, coagulated in this state, and then the partition frame 27 is taken out, so that the coagulated tofu is cut into an aligned state at an interval corresponding to the plate thickness of the partition frame 27. Is desirable.

With such a configuration, the solidified tofu is arranged at intervals corresponding to the thickness of the partition frame 27, so that a large number of cut tofu can be arranged around the periphery without artificially arranging. This is because the tofu is placed in a state where there is a gap S, and individual tofu is efficiently cooled from the surrounding gap S in the subsequent step of quick freezing 15.

Although not shown, the coagulation tray 23 is filled with the soymilk 7 to which the gelling agent and the coagulant have been added, and then a grid-like partition frame 27 is fitted into the coagulation tray 23 and coagulated in this state. , Without taking out the partition frame 27,
The partition frame 27 may be taken out after rapid cooling and FD drying.

According to such a procedure, although the cooling efficiency is reduced, there is an advantage that the volume of the tofu is reduced by the FD drying, and the partition frame 27 can be easily taken out.

According to the above-mentioned constitution, instead of using starch, gums, curdlan or the like as the gelling agent, gelatin and sugar (any one or more of maltose, oligotose and trehalose) are used. ), Not only the frozen tofu 16 for freeze-dried tofu which does not cause cracking in the step of FD drying 17 is obtained, but also air-injection 8 is carried out so that the soy milk 7 contains bubbles.
By solidifying the soymilk 7 under a temperature condition of 65 to 85 ° C. without cooling once, the freeze-dried tofu commercialized through the step of FD drying 17 is improved in the water-recovery property, and cracks at the time of water-recovery are improved. And water can be quickly reconstituted.

Accordingly, it is possible to produce freeze-dried tofu of any size, for example, freeze-dried tofu of a size suitable for roasted tofu, tofu for hot pot cooking, and the like. Instead of starch, gums, curdlan, etc., gelatin and maltose, oligotose, by using sugars such as trehalose,
The taste and texture of the commercialized freeze-dried tofu after restoration are improved, and the taste is comparable to that of ordinary raw tofu,
The texture is obtained.

Instead of using starch, gums, curdlan or the like as a gelling agent, gelatin and sugars such as maltose, oligotose and trehalose are used,
As a coagulant, calcium sulfate alone, which has a wider reaction temperature range than bittern and magnesium chloride, a composite coagulant containing calcium sulfate as a main component, a lactic acid-based composite coagulant, etc. Some soy milk 7,
It is possible to coagulate by a so-called high-temperature soymilk coagulation method without cooling, and it is possible to reduce the production cost in combination with omitting expensive curd runs.

In the above-described embodiment, the soymilk 7 immediately after the production is used as the soymilk 7 in the high temperature state. However, the soymilk previously produced and stored at a low temperature is sterilized by reheating to a high temperature. It is also possible to carry out using soy milk in a state.

[0043]

As described above, according to the present invention, cracks do not occur during the FD drying process and the reconstitution with water, and the reconstitution can be carried out promptly with water, so that freeze-dried tofu of any size can be produced. It is possible to produce large freeze-dried tofu suitable for roasted tofu and hot pot tofu, etc., and the freeze-dried tofu has the same taste and texture after restoration as normal raw tofu. The resulting frozen tofu for freeze-dried tofu can be produced at low cost.

[Brief description of the drawings]

FIG. 1 is a process diagram illustrating a method for producing a frozen tofu for freeze-dried tofu according to the present invention.

FIG. 2 is a schematic diagram illustrating a main part of a facility for producing frozen tofu for freeze-dried tofu.

FIG. 3 is a diagram illustrating a main part of FIG. 3;

FIG. 4 is a diagram illustrating an example of a method of cutting solidified tofu.

[Explanation of symbols]

7: soy milk, 8: air injection, 11: high temperature coagulation, 13: cooling, 14: cutting, 15: quick freezing, 16: frozen tofu for freeze-dried tofu.

Claims (2)

[Claims] 1. After air is injected into soy milk in a high temperature state to contain air bubbles, gelatin and maltose, oligotose, trehalose and the like are added to the soy milk as a gelling agent before the temperature of the soy milk is lowered. With sugars, and
By adding a simple substance of calcium sulfate, a complex coagulant containing calcium sulfate as a main component, a lactic acid-based complex coagulant, or the like as a coagulant, soy milk containing air bubbles is reduced to 65 to 85.
A method for producing frozen tofu for freeze-dried tofu, comprising coagulating under temperature conditions of ° C., and rapidly freezing the solidified tofu to produce frozen tofu for freeze-dried tofu. 2. A method for injecting air into a soymilk flow path on the upstream side of a pump for pumping soymilk from a soymilk tank to a measuring bucket using negative pressure generated by the flow of soymilk. A method for producing a frozen tofu for freeze-dried tofu according to claim 1.