JPH1099040A - Manufacture of freezable tofu and frozen tofu - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacture of tofu and frozen tofu with excellent freezing preservability by suppressing the freezing denaturation of soybean protein at the time of freezing by the action of a gelatinizer and dextrines and/or oligosaccharides. SOLUTION: In this manufacture of the freezable tofu, after heating the dilute liquid of the pasty grinded material containing the gelatinizer and the dextrines and/or the oligosaccharides, tofu refuse is separated, soymilk is obtained, a tofu coagulant is added to the soymilk and it is solidified. Also, the frozen tofu is formed by freezing the tofu. In the manufacture of the freezable tofu, a manufacture operation is facilitated since the dilute liquid of the pasty grinded material containing the gelatinizer and the dextrines and/or the oligosaccharides is used and the effect of improving the freezing resistance of the tofu or the like is demonstrated since the obtained tofu does not contain excessive water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a tofu that can be frozen and a method for producing a frozen tofu. More specifically, the present invention relates to a method for producing a frozen tofu having excellent freezing preservability, a method for producing a freezerable tofu as a material thereof, and a method for producing soymilk as a raw material thereof.

[0002]

2. Description of the Related Art Tofu is a food containing soybean protein having an excellent amino acid balance, and has been used for a long time since it has an excellent texture and flavor. Tofu is usually prepared by immersing washed soybeans in water overnight, then adding a small amount of water to a grinder to make a grind of muddy (referred to as raw gou). The soybean milk is manufactured by diluting the soybean milk and then heating the soybean soybean milk to obtain a soybean milk by filtering the hot soybean milk while removing the soybean milk, and adding a tofu coagulant to the soybean milk to coagulate it. Although tofu has excellent properties as a food, it is a food having a high moisture content and a poor shelf life, and it is difficult to store it in a refrigerated state for a long period of time. Therefore, frozen tofu has been studied in order to improve the preservability of tofu and enhance convenience. However, when tofu is frozen, the protein freeze-denatures, and when it is thawed, a lot of drip is generated. In addition, "su" enters and becomes a sponge-like Takano tofu. Such tofu loses the texture of tofu, and it is difficult to obtain frozen tofu that can reproduce the original taste and texture of tofu by simply freezing the tofu.

Due to such problems, conventionally, trehalose, guar gum, locust bean gum, sodium alginate, methylcellulose, curdlan, tamarind gum, indigestible dextrin, polydextrose, lactitol, palatinit, fructooligosaccharide, etc. are added to soymilk. A method and a method of treating soymilk with transglutaminase to prevent drip and improve texture have been proposed (for example, JP-A-7-31399, JP-A-7-510).
No. 17, JP-A-7-223161, JP-A-7-217661
-265030, JP-A-6-46784,
JP-A-6-113777 and JP-A-6-15384
0, JP-A-6-181729, JP-A-6-181729
217729, JP-A-6-217730,
JP-A-6-245727, JP-A-6-25379
No. 8, JP-A-6-26957, JP-A-5-4
9430, JP-A-5-18421, JP-A-5-316984, JP-A-5-336916, etc.).

[0004]

As described above, generally, when tofu is frozen, a lot of drip is generated at the time of thawing, so that it becomes a sponge containing so-called "su" and the original texture of the tofu is lost. For this reason, many methods have been proposed to solve such a problem by adding an anti-drip agent or a substance imparting freeze resistance. But,
The conventional method has a certain effect on the freezing resistance of tofu, but it often causes water separation during thawing, and as a result, the tofu often shrinks or becomes a hard tofu without elasticity. Is different from In addition, some types of additives exhibit high viscosity and coagulation at high temperatures, and there is a problem that the timing of adding the additives to soymilk, the temperature adjustment, and the addition operation become complicated.

Further, when additives are directly added to soymilk,
Usually, additives are added to soymilk in a state of being dissolved or dispersed in water, because they cause lump or a state in which additives are unevenly dispersed. As a result, the soymilk is diluted, and the water content of the obtained tofu increases. When such tofu is frozen, the amount of drip at the time of thawing becomes extremely large, and it is not possible to obtain tofu having a good texture. In order to solve such a problem, it is necessary to reduce the amount of water added to the raw gou to prepare a high-concentration soymilk, but since the amount of water added is small, the yield of soymilk is deteriorated, and the cost increases. There's a problem. The present inventors have studied to improve these disadvantages, and as a result, by adding a gelling agent and dextrins and / or oligosaccharides to raw gou or a diluent thereof,
It has been found that the complexity of operation and the problem of dilution of soymilk can be avoided; and that the obtained tofu has excellent freezing resistance and can be suitably used as a material for frozen tofu. The present invention has been made based on such findings, and an object of the present invention is to provide a method for easily and efficiently producing tofu having excellent freezing resistance, a method for producing a frozen tofu by freezing the tofu, and a method for producing the tofu. It is intended to provide a method for producing soymilk used for production.

[0006]

Means for Solving the Problems The gist of the present invention made to solve the above-mentioned problems is to provide a method for producing tofu, comprising the steps of: preparing a soybean diluent containing a gelling agent and dextrins and / or oligosaccharides; After heating, okara is separated to obtain soymilk, and a method of producing tofu that can be frozen, comprising coagulating a soymilk by adding a tofu coagulant; wherein the gelling agent is gelatin, agar, carrageenan, xanthan gum, A method for producing the above-mentioned freezeable tofu, which is locust bean gum, guar gum, tamarind gum, cod gum, syllium seed gum and / or pectin; the oligosaccharide is maltose, isomaltose, cellobiose, trehalose, raffinose, maltotriose, isoform The frozen tofu of the above or the above which is maltotriose and / or stachyose A method for producing a freezing tofu according to any of the above-mentioned items, wherein a tofu coagulant is added after cooling the soymilk obtained by separating the okara, and the mixture is heated and solidified. A method for producing frozen tofu, comprising freezing the obtained tofu; heating a gelling agent and a dilute solution containing dextrins and / or oligosaccharides; separating the okara from the okara; A method for producing soymilk, characterized by obtaining soymilk containing dextrins and / or oligosaccharides.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has the above-mentioned constitution, and the method for producing soymilk of the present invention comprises the steps of heating a raw gou dilute solution containing a gelling agent and dextrins and / or oligosaccharides, followed by heating. To separate the gelling agent and dextrins and / or
Or a method for producing a freezing tofu of the present invention, comprising adding a tofu coagulant to the above-mentioned soy milk and coagulating it; and producing the frozen tofu of the present invention. The method comprises freezing the tofu obtained above. According to the standard method, the above raw soybeans are ground (or pulverized) while adding a small amount of water to soybeans (such as round soybeans, half-cut soybeans, and pressed defatted soybeans) soaked in water overnight.
However, the present invention is not limited to this, and a dispersion in which full-fat soybean powder, dehulled soybean powder, and the like are dispersed in water can also be used.

Examples of gelling agents include gelling proteins (eg, gelatin, casein, etc.), thickening polysaccharides (eg, agar, carrageenan, xanthan gum, locust bean gum, guar gum, alginic acid, gellan gum, tamarind gum, Pectin, cod gum, syllium seed gum, konjac, etc.), and gelatin, carrageenan, xanthan gum and locust bean gum are preferably used from the viewpoint of the effect. Such gelling agents may be used in combination of two or more. In the present invention, the gelling agent is a substance capable of forming a gel when cooled, and exhibits an effect by suppressing protein denaturation and imparting water retention to the tofu and enhancing the binding of the tofu tissue when the tofu is frozen. Thus, it is possible to improve the texture when the frozen tofu is thawed and to prevent the generation of drip and "su".

[0009] Dextrins and oligosaccharides are also substances having an effect of preventing freezing and denaturation of tofu. When used in combination with the above-mentioned gelling agent, the freezing resistance of tofu is synergistically improved. At least one of dextrins and oligosaccharides is used, and it is more preferable to use both. Examples of the above dextrins include dextrins and cyclodextrins having various molecular weights. In addition, two or more dextrins may be used in combination. Conventional oligosaccharides (including oligosaccharide alcohols) can be used, such as lactose, maltose, isomaltose, cellobiose, trehalose, raffinose, maltotriose, isomaltotriose, stachyose and the like. Is exemplified. In addition, two or more oligosaccharides may be used in combination.

[0010] The method for preparing the Niku gou dilution containing the gelling agent and dextrins and / or oligosaccharides is not particularly limited. For example, a gelling agent and dextrins may be added after adding a predetermined amount of dilution water to Niku. And / or a method of adding oligosaccharides; a method of adding a predetermined amount of dilution water after adding a gelling agent and dextrins and / or oligosaccharides to raw gou; a method of adding a gelling agent and dextrins and / or oligosaccharides For example, a method of adding a fixed amount of dilution water and adding this to raw gou is exemplified. The amount of dilution water used for the raw gou can be appropriately adjusted according to the desired soymilk concentration and the like, but water of about 3 to 6 times, usually about 5 times the weight of the raw go is used.

The concentration of the gelling agent, dextrins and oligosaccharides in the raw gou diluent is appropriately adjusted depending on the protein concentration in the raw gou diluent, the freezing temperature and speed of the tofu, and the like. And the total concentration of oligosaccharides is about 0.5 to 10% by weight (hereinafter, unless otherwise specified,% means% by weight), preferably 1 to 7% by weight.
%, More preferably 2 to 5%. If the concentration of these additives is less than 0.5%, it is difficult to impart freezing resistance to the obtained tofu, and if it exceeds 10%, the texture of the tofu may be impaired, which is not preferable. .

The thus-prepared gelling agent and the dilute solution containing dextrins and / or oligosaccharides are then usually boiled in a kettle or blown with heated steam according to a conventional method. It is heated for about 40 minutes to prepare go. By this heat treatment, the gelling agent and the dextrins and / or oligosaccharides are dissolved in the go, so that the go which uniformly dissolves the gelling agent and the dextrins and / or the oligosaccharides can be obtained. Therefore, in the method of the present invention, it is possible to prevent lumps and non-uniform distribution of the additive, and there is an advantage that the operation of adding the additive is facilitated. The produced go is filtered using a conventional filter medium such as cotton cloth while hot, and okara is removed to obtain soymilk containing a gelling agent and dextrins and / or oligosaccharides. The protein content in the soymilk is appropriately adjusted depending on the use of the tofu, but is usually adjusted to about 1 to 15%.

Next, a tofu coagulant is added to the obtained soy milk to coagulate, thereby preparing tofu. As the tofu coagulant used here, a conventional tofu coagulant can be used. For example, glucono delta lactone (hereinafter, referred to as glucono delta lactone)
GDL), magnesium chloride, calcium chloride,
Examples thereof include calcium sulfate and bittern. The amount of the tofu coagulant added to the soy milk is appropriately adjusted depending on the protein content in the soy milk, etc., but is preferably 0.1 to 1%, preferably 0.2 to 1%.
It is adjusted to about 0.7%, more preferably about 0.3 to 0.5%.

As a method of adding a tofu coagulant to soy milk and a method of forming tofu, a method of adding a tofu coagulant to hot soy milk obtained by filtering go and coagulating to obtain tofu; A method of obtaining tofu by cooling the soybean milk, adding a tofu coagulant thereto, and then heating to solidify the soymilk to obtain tofu. In the method using the above-mentioned cooled soymilk, the temperature of the cooled soymilk is adjusted to such an extent that the coagulation reaction does not immediately proceed even if a tofu coagulant is added to the soymilk.
Cool to about 50 ° C, preferably about 20-40 ° C. Further, the heating after adding the tofu coagulant to the cooled soy milk may be performed by heating to a temperature at which coagulation of the soy milk is caused by the tofu coagulant or more, and is heated to about 70 to 90 ° C., generally about 80 to 85 ° C. . The heating time is appropriately adjusted according to the protein concentration in the soymilk, the amount of the tofu coagulant used, the heating temperature, and the like. Coagulation is completed in about 10 to 60 minutes, usually about 25 to 45 minutes.

In the above-mentioned heating, it is preferable that the cooled soymilk is heated after being degassed. If the degassing process is not performed, the gas component dissolved in the cooled soy milk is gasified, and air bubbles may be generated in the soy milk during heat coagulation, which may result in tofu having "su" . The above deaeration treatment may be performed before or after the addition of the tofu coagulant to the cooled soy milk. If necessary, other components may be added to the soy milk. Examples of such components include starches (for example, corn starch, waxy starch, potato starch, sweet potato starch, tapioca starch, wheat starch and the like). Starch derived from natural products, chemical conversion of starch,
Processed starch obtained by physical or enzymatic treatment),
Soy protein (for example, isolated soy protein, concentrated soy protein, etc.), legume powder (for example, pea powder, green bean powder, kinto bean powder, broad bean powder, etc.), citron, lemon, shiso, matcha, spinach, moloheiya, etc. And fruit and vegetable powders, fruit juice extracts, flavors, seasonings and the like. The tofu obtained by coagulation in this way is allowed to cool or is cooled by forced cooling using a cooling bath (preferably about 5 ° C).
Then, the frozen tofu of the present invention is produced.

[0016] The tofu obtained above has freezing resistance and can be suitably used as a material for frozen tofu. The tofu freezing step is not particularly limited as long as the tofu can be frozen, and can be performed by various methods. For example, a method of cutting the tofu solidified in a coagulation container into small pieces of a suitable size, placing it on a belt conveyor, moving the conveyor and passing it through a freezer compartment and freezing; cut tofu small pieces Is put in a vat and frozen in a freezer. The shape and size of the cut tofu can be adjusted appropriately according to the use of the thawed frozen tofu, etc. When eating the thawed tofu as it is or using it as a food material, a die of appropriate size Alternatively, in the case of using the thawed tofu as a fried or fried material, the cut tofu may be cut into an appropriately sized piece. Further, in the production of tofu, a plastic bag such as polyethylene is filled with the mixture of the cooled soy milk and the tofu coagulant, and the mixture is heated and cooled to produce a bag tofu, and the bag tofu is stored in a freezer. A method of obtaining frozen tofu by freezing may be used.

The freezing temperature of the tofu may be any temperature at which the tofu can be frozen, and is about -20 to -80 ° C, preferably -40.
Freeze in a freezer at about ℃. The freezing time can be appropriately adjusted according to the freezing temperature, the size of the tofu to be frozen, and the like. The thus-obtained frozen tofu of the present invention has a characteristic that the original flavor and texture of the tofu are maintained without causing "su" or drip even when thawed. Therefore, the tofu obtained by thawing the frozen tofu of the present invention can be eaten as it is, can be used as a cooking material, and can be used as a deep-fried or oil-fried dough.

[0018]

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. Example 1 A small amount of water (80 in total) was added to 80 kg of water-soaked soybean by a conventional method.
Liter) was added to grind the raw go, and 70 liters of water was added to this raw go to prepare a raw go dilute solution. After adding 2 kg / 100 liters of gelatin, 1 kg / 100 liters of dextrin and 1 kg / 100 liters of isomaltose to this raw dilute solution, 9
Heat at 8 ° C for 10 minutes to make wu, immediately filter with cotton cloth,
Soy milk was obtained (protein content: about 7.5%). After cooling the obtained soy milk to about 30 ° C. to obtain cooled soy milk, 100 liters of the cooled soy milk is put into a coagulation container, and GDL is added to 0.3% to this, and heated at 85 ° C. for 40 minutes. After coagulation, the mixture was cooled in a cooling bath at 5 ° C. to obtain the tofu of the present invention.

The cooled tofu was cut into dice each having a size of about 2 cm, placed in a vat, transferred to a freezer at -40 ° C. and frozen to obtain a frozen tofu of the present invention. As a control, a solution prepared by heating and dissolving 2 kg of gelatin, 1 kg of dextrin and 1 kg of isomaltose in 8 liters of water was added to 100 liters of chilled soymilk (protein content: about 5%) produced by a conventional method. Then, tofu was obtained in the same manner as described above, and then frozen tofu was prepared.

The obtained frozen tofu of the present invention and the frozen tofu of the control were stored in a freezer at -18 ° C. for one month, then thawed with hot water to obtain tofu, and the flavor, texture and drip amount were examined. . Table 1 shows the results. As shown in Table 1, in the tofu obtained by thawing the frozen tofu of the present invention, "su" was hardly recognized, and had a texture similar to that of the tofu produced by a conventional method. Further, upon thawing, the occurrence of dripping was significantly reduced. On the other hand, the tofu obtained by thawing the control product had a large amount of drip, so that the thawed tofu was slightly deformed. From this result, it was clarified that the frozen tofu produced from the tofu containing an excessive amount of water, such as the control product, was inferior to the storage stability of the product of the present invention.

[0021]

[Table 1]

Example 2 Gelatin was added at 2 kg / 100 to the raw gou dilute solution obtained in Example 1.
After adding liters and maltose to 1.5 kg / 100 liters, the mixture was heated at 98 ° C. for 10 minutes to make go, and immediately filtered with a cotton cloth to obtain soy milk. After cooling the obtained soy milk to about 15 ° C. to obtain cooled soy milk, the cooled soy milk 100
After adding 0.3% of GDL to 1 liter and deaeration under reduced pressure, the mixture was coagulated by heating at 85 ° C for 40 minutes, and then cooled in a cooling bath at 5 ° C to obtain the tofu of the present invention. The cooled tofu was cut into dice having a size of about 2 cm and placed on a belt conveyor. The conveyor was moved, passed through a freezer at -40 ° C, and frozen to obtain the frozen tofu of the present invention.

Examples 3 to 8 The gelling agents shown in Table 2 were added to the raw gou diluent obtained in Example 1
A dextrin and an oligosaccharide are added to a predetermined concentration, and other components shown in Table 2 are added to the cooled soy milk to a predetermined concentration, if necessary, in the same manner as in Example 2, except that the dextrins and the oligosaccharide are added to the cooled soymilk to a predetermined concentration. To produce frozen tofu. All of the obtained frozen tofu were excellent in the freezing preservability, the amount of drip at the time of thawing was small, and "su" was hardly recognized.

[0024]

[Table 2]

Example 9 Kure was prepared in the same manner as in Example 1, and immediately filtered with a cotton cloth to obtain hot soymilk (about 90 ° C.). 100 liters of the obtained hot soy milk is put into a coagulation container, and GDL is added to the coagulation container so as to have a concentration of 0.3%. After allowing to stand and coagulate, the mixture is cooled in a cooling bath at 5 ° C. I got The cooled tofu was cut into pieces of about 2 cm in dice, placed in a vat, transferred to a freezer at −40 ° C., and frozen to obtain the frozen tofu of the present invention.

[0026]

According to the method of the present invention for producing a tofu that can be frozen, a dilute solution containing a gelling agent and dextrins and / or oligosaccharides is heated to uniformly dissolve the additives. Therefore, the operation of adding the additive is easy. Further, since the soymilk is not diluted, the obtained tofu does not contain excessive moisture. Further, since high-concentration soymilk is not required, the yield of soymilk does not decrease. The obtained tofu contains a gelling agent having a function of imparting freezing resistance to the tofu and dextrins and / or oligosaccharides, and thus has extremely good freezing resistance. The method for producing a frozen tofu of the present invention is a method in which the above-mentioned tofu is frozen, and the gelling agent and dextrins and / or oligosaccharides suppress the freezing and denaturation of the soybean protein during freezing, so that the frozen tofu is excellent in refrigeration preservability. In addition, even if it is thawed, the generation of drip and the generation of "su" are small, so that a thawed tofu having the original texture and flavor of tofu can be obtained. Therefore,
According to the present invention, while maintaining good texture and flavor,
Frozen tofu that can be stored for a long period of time can be obtained, and distribution and management costs of tofu can be significantly reduced.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuo Takatsuji 7-139 Ikejiri, Itami-shi, Hyogo Tajimaya Foods Co., Ltd.

Claims (6)

[Claims] 1. A method for producing tofu, comprising heating a raw gou diluent containing a gelling agent and dextrins and / or oligosaccharides, separating okara from soybean milk, and adding a tofu coagulant to the soymilk. A process for producing tofu that can be frozen, characterized by adding and coagulating. 2. The gelling agent is gelatin, agar, carrageenan, xanthan gum, locust bean gum,
2. The method according to claim 1, which is guar gum, tamarind gum, cod gum, syllium seed gum and / or pectin. 3. The method according to claim 1, wherein the oligosaccharide is maltose, isomaltose, cellobiose, trehalose, raffinose, maltotriose, isomalttriose and / or stachyose. 4. The method for producing a freezeable tofu according to any one of claims 1 to 3, wherein the soymilk obtained by separating the okara is cooled, a tofu coagulant is added, and the mixture is coagulated by heating. 5. A method for producing frozen tofu, comprising freezing the tofu obtained in any one of claims 1 to 4. 6. A gelling agent and dextrins and / or
Alternatively, a method for producing soymilk, comprising heating a raw soybean diluent containing oligosaccharides and separating okara to obtain soymilk containing a gelling agent and dextrins and / or oligosaccharides.