JP2016002010A - Method for producing dehydrated tofu and smoked tofu - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a dehydrated soybean curd causing no collapse of shape, maintaining both of a fresh taste and a smooth texture inherent to soybean curd.SOLUTION: In a preparation step, a soybean curd is prepared. In an accommodation step, the soybean curd is wrapped with a piece of cloth and accommodated in a molding box. In a squeezing step, the soybean curd accommodated in the molding box maintained at temperature higher than the solidification point of the water component in the soybean curd and 35°C or lower is compressed with a pressing lid with pressure gradually increasing. A dehydrated soybean curd is thereby obtained. Since the soybean curd is maintained at the temperature higher than the solidification point of the water component in the soybean curd and 35°C or lower in the squeezing step, solidification of the water component in the soybean curd or hardening of the soybean curd is avoided, so that the resultant dehydrated soybean curd can maintain a smooth texture inherent to soybean curd. Since the soybean curd is compressed with pressure gradually increasing in the squeezing step, the resultant dehydrated soybean curd is free from collapse of shape. Furthermore, since the soybean curd is compressed with pressure gradually increasing in the squeezing step, the time required for the squeezing step is reduced, so that the resultant dehydrated soybean curd can maintain the fresh taste of soybean curd.

Description

  The present invention relates to a method for producing dehydrated tofu and smoked tofu produced using the dehydrated tofu obtained by the production method as an ingredient.

  The dehydrated tofu obtained by squeezing tofu can be eaten as it is, and can also be used as a food for producing processed tofu products such as smoked tofu. However, since the tofu is brittle and soft, applying a strong pressing force to the tofu during pressing may cause the tofu to lose its shape. On the other hand, if you try to obtain dehydrated tofu by pressing the tofu so that the tofu does not lose its shape, it is difficult for the resulting dehydrated tofu to maintain both the fresh taste and the original smooth texture of the tofu. .

  For example, if the tofu is pressed while keeping the tofu at a temperature of 35 ° C. or lower and applying a certain pressing pressure so that the tofu does not lose its shape, the pressing takes too much time, so the fresh taste from the dehydrated tofu is impaired. . When tofu is squeezed while maintaining the tofu at a temperature higher than 35 ° C., the evaporation rate of water increases due to the high temperature, and the squeezing can be completed in a short time. The feeling is impaired.

In the method for producing smoked tofu described in Patent Document 1, tofu is prepared by adding 0.2 to 1.2% by mass of calcium chloride as a coagulant to soy milk. After that, the mold box laid with cotton cloth is filled with tofu that has been broken into pieces sufficiently, spread with a push lid, and pressed under pressure until the tofu has a water content of about 75% by weight. The conditions for applying a pressing pressure, 10 to 20 g / cm ² at 5 to 30 minutes, conditions are illustrated as 100 to 200 g / cm ² at 10 to 60 minutes.

  However, Patent Document 1 does not describe the temperature condition of tofu during pressing. Moreover, since the manufacturing method of patent document 1 has completed the pressing of tofu within 90 minutes in total, the time required for pressing is extremely short. For this reason, in the manufacturing method of patent document 1, it is thought that tofu is exposed to the high temperature in the case of pressing. Therefore, according to the manufacturing method described in Patent Document 1, it is considered that the resulting dehydrated tofu is hardened and the smooth texture is impaired from the dehydrated tofu.

JP 2007-111037 A

  An object of the present invention is to provide a method for producing dehydrated tofu that retains both a fresh taste and a smooth texture inherent to tofu without losing its shape. Furthermore, this invention aims at providing the smoked tofu which manufactured the dehydrated tofu obtained by the manufacturing method as a foodstuff.

  In order to achieve the above object, a method for producing dehydrated tofu according to the present invention includes a preparation step of preparing tofu, a storage step of wrapping the tofu with a cloth and storing it in a mold box, A pressing step of pressing the tofu with a pressing lid while gradually increasing the pressing pressure while keeping the tofu higher than the freezing point of water of the tofu and 35 ° C. or less.

  Moreover, in the manufacturing method of the dehydrated tofu which concerns on this invention, the said pressing process is performed, keeping the said tofu stored in the said mold box at 3 to 6 degreeC.

  In the method for producing dehydrated tofu according to the present invention, the push lid is a bamboo basket.

Further, in the method for manufacturing a dewatering tofu according to the present invention, the pressing step, the tofu is housed in the mold box, in its first stage, 30 g / cm ² or more 70 g / cm ² less pressing force Pressing for 30 minutes or more and 120 minutes or less, and in the second stage, pressing at a pressing pressure of 100 g / cm ² or more and 160 g / cm ² or less for 30 minutes or more and 240 minutes or less, and in the third stage, 300 g / cm ² or more. The pressing is performed for 420 minutes or more and 660 minutes or less with a pressing pressure of 400 g / cm ² or less.

  In the method for producing dehydrated tofu according to the present invention, the tofu prepared in the preparation step is cotton tofu prepared from soy milk having a bittern concentration of 0.20% by mass or more and 0.25% by mass or less.

  In the method for producing dehydrated tofu according to the present invention, the soy milk is Brix 12.0 or more and 12.7 or less.

  The smoked tofu according to the present invention is a smoked tofu obtained by smoke-treating the dehydrated tofu produced by the method for producing dehydrated tofu.

  In the method for producing dehydrated tofu according to the present invention, the pressing step is performed while keeping the tofu at a temperature higher than the freezing point of the water of tofu and not higher than 35 ° C. Since the temperature is higher than the freezing point of the tofu moisture, the tofu moisture does not become ice in the pressing process. Therefore, ice does not break the internal structure of tofu. Moreover, since it is 35 degrees C or less, in a pressing process, tofu is not exposed to high temperature and the crosslinking reaction etc. of soybean protein progresses too much, and tofu does not become hard. Therefore, dehydrated tofu that exhibits the original smooth texture of tofu can be produced.

  Furthermore, in the pressing step, the pressing pressure applied to the tofu via the push lid is increased stepwise. In the first stage of the pressing process, since the pressing pressure applied to the tofu is low, water can be extracted from the tofu without causing the tofu to lose its shape. Compared with the tofu immediately before starting the pressing process, the tofu that has completed the first stage of the pressing process has a lower moisture content and is less likely to lose its shape. For this reason, after the 2nd stage of a pressing process, the pressing pressure higher than the pressing pressure added in the 1st stage can be applied to tofu. Therefore, when the pressing pressure applied to the tofu is increased stepwise, a higher pressing pressure can be applied to the tofu without causing the tofu to lose its shape in the second and subsequent steps. Thereby, since the time required for dehydration of tofu can be greatly shortened, a fresh taste is maintained with dehydrated tofu. Therefore, dehydrated tofu with a fresh taste can be produced without losing shape.

  Therefore, according to the present invention, there is provided a method for producing dehydrated tofu that maintains both the fresh taste and the original smooth texture of tofu without losing its shape.

[Manufacturing Method According to Embodiment 1]
The method for producing dehydrated tofu according to Embodiment 1 includes a preparation process, a storage process, and a pressing process.

  In the preparation step, tofu is prepared as a raw material for dehydrated tofu. The tofu used as a raw material is not limited to soybeans, and may be tofu produced using black beans or the like as a raw material. The tofu as a raw material is preferably cotton tofu. The tofu as a raw material is preferably a tofu that is produced by a conventional method, soaked in hot water at about 80 ° C. for 30 minutes and sterilized, and then soaked in water at 5 to 10 ° C. and cooled.

  In the storage process, the tofu is wrapped in a cloth and stored in a mold box. The fabric is preferably wetted with a cotton bleached fabric. The mold box is a box-shaped mold box having an opening on the upper surface, which is used for molding tofu by pressing the soy milk coagulum. It is preferable that the mold box has a large number of micropores formed on its side and bottom surfaces in order to discharge water squeezed from tofu. The material of the mold box is preferably a material selected from the group consisting of aluminum, stainless steel, wood, bamboo, and mixtures thereof. In the storing step, the tofu may be wrapped with a cloth outside the mold box, and the tofu wrapped in the cloth may be stored in the mold box. Alternatively, in the storing step, a mold box with cloth on the inside may be prepared, tofu may be placed on the cloth in the mold box, and the tofu may be wrapped with the cloth in the mold box.

  In the pressing step, the tofu contained in the mold box is pushed with the push lid while gradually increasing the pressing pressure while maintaining the temperature above 35 ° C. above the freezing point of the tofu moisture. By pressing the tofu, water is squeezed out of the tofu and the tofu is dehydrated. After dehydrating the tofu, the dehydrated tofu can be taken out of the mold box and the cloth to obtain dehydrated tofu.

  Since the water of tofu is an aqueous solution in which a coagulant is dissolved, the freezing point is less than 0 ° C. due to the freezing point depression. Depending on the concentration of the coagulant, for example, if the tofu does not cool to about −3 ° C. or less, the moisture of the tofu may not coagulate. On the other hand, the pressing process is performed while keeping the tofu at a temperature higher than the freezing point of the tofu moisture. Thereby, since the water | moisture content of tofu does not solidify during a pressing process, it can avoid that the internal structure of tofu is destroyed by ice. Therefore, with the resulting dehydrated tofu, the original smooth texture of tofu is maintained.

  If the squeezing process is performed while keeping the tofu at a temperature higher than 35 ° C., the cross-linking reaction of the soy protein proceeds too much, and the tofu becomes hard, so the dehydrated tofu that is produced will impair the original smooth texture of the tofu. End up. On the other hand, if the pressing process is performed while keeping the tofu at 35 ° C. or lower, the tofu is not exposed to a temperature higher than 35 ° C., so that the cross-linking reaction of the soy protein is difficult to proceed and the tofu is suppressed from becoming hard. be able to. Therefore, when the pressing process is performed while keeping the tofu at 35 ° C. or lower, the original dehydrated tofu and the original smooth texture of the tofu are maintained.

  More preferably, the pressing step is performed while keeping the tofu contained in the mold box at a temperature higher than 0 ° C. and 20 ° C. or lower. If the pressing process is performed while keeping the tofu at a temperature higher than the freezing point of tofu and below 0 ° C., the tofu's moisture will coagulate unintentionally due to a slight temperature change or vibration, etc. Internal structure may be destroyed. On the other hand, when the pressing process is performed while keeping the tofu at a temperature higher than 0 ° C., there is no possibility that the moisture of the tofu is solidified due to a slight temperature change or vibration. Therefore, the internal structure of the tofu can be further prevented from being broken by ice, so that the original smooth texture of the tofu can be maintained with the resulting dehydrated tofu.

  Compared to the case where the pressing step is performed while keeping the tofu higher than 20 ° C. and not higher than 35 ° C., the case where the pressing step is performed while maintaining the tofu higher than 0 ° C. and not higher than 20 ° C. is performed during the pressing step. The cross-linking reaction of soy protein is further suppressed. Therefore, with the resulting dehydrated tofu, the original smooth texture of the tofu is further maintained.

  Further, the pressing step is more preferably performed while keeping the tofu at a temperature higher than 0 ° C and not higher than 10 ° C. Compared to the case where the pressing step is performed while keeping the tofu higher than 10 ° C. and not higher than 20 ° C., the case where the pressing step is performed while maintaining the tofu higher than 0 ° C. and not higher than 10 ° C. is the completed dehydrated tofu, The fresh taste and the smooth texture inherent to tofu are further preserved. In addition, the range higher than 0 ° C. and not higher than 10 ° C. is a temperature range assuming that the squeezing process is performed in a refrigerator compartment or the like. In general, the target set temperature of a refrigerator compartment or the like is often set to around 4 ° C., and the temperature in the refrigerator compartment temporarily rises by several degrees by opening or closing the door. For this reason, when the pressing process is performed while maintaining the tofu at a temperature higher than 0 ° C. and not higher than 10 ° C., it is easy to control the temperature of the tofu when performing the pressing process in a refrigerator.

  The push lid is a push lid having a plate shape or the like, which is used for the purpose of squeezing soymilk coagulum and molding tofu. It is preferable that the push lid is provided with a large number of minute holes for discharging water squeezed from tofu. The material of the push lid is preferably a material selected from the group consisting of aluminum, stainless steel, wood, bamboo, and mixtures thereof. Moreover, it is preferable that a push lid is a shape according to opening of a mold box, and is a dimension which hardly produces a clearance gap between mold boxes.

  In the pressing step, a pressing lid is placed on a cloth wrapped in tofu stored in a mold box, and the pressing lid is pressed from above, whereby pressing pressure is applied to the tofu through the pressing lid. By using the push lid, it becomes easy to apply a pressing pressure to the tofu, and it is possible to avoid applying a pressing pressure locally to a part of the tofu. Thereby, for example, it is possible to avoid the occurrence of mold deformation such as lack of tofu corners or a large depression of the tofu surface.

  The means for applying pressure to the tofu in the pressing step may be a method of placing a weight such as a weight on the push lid, or a method of pressing the tofu from above the push lid with a press device. . In the pressing process, it is more preferable to place a plate on the push lid. When tofu is pressed from the top of the plate placed on the push lid, compared to the case where the tofu is pushed from the top of the push lid without placing the plate, a part of the tofu is pressed locally. Can be avoided.

General cotton tofu has a moisture content of about 87 to 88% by weight and a certain gel strength. For this reason, it is easy to squeeze out moisture by applying pressure to general cotton tofu. On the other hand, the tofu prepared in the present invention is, for example, cotton tofu with a water content of 89.2 wt% or more and 89.5 wt% or less. Thus, tofu with a high water content has a low gel strength. For example, when a pressing pressure of about 130 g / cm ² is applied as it is, the mold becomes out of shape.

  The inventor of the present application has made extensive studies on a method for producing dehydrated tofu by squeezing out moisture from cotton tofu having a low gel strength and having a water content of 89.2% by weight or more and 89.5% by weight or less. As a result, the inventor of the present application has found that the pressing pressure applied to tofu is increased step by step in the pressing process as a means for solving the problem.

For example, when cotton tofu with a low gel strength having a moisture content of 89.2 wt% or more and 89.5 wt% or less is prepared in the preparation process, the tofu contained in the mold box is used in the first stage of the pressing process. The pressing force is as low as 30 g / cm ² or more and 70 g / cm ² or less for 30 minutes or more and 120 minutes or less. Thereby, even if it is tofu with low gel intensity | strength, a water | moisture content can be squeezed out from the said tofu, without making the said tofu lose shape.

The tofu that has completed the first stage of the pressing process has a lower moisture content than the tofu immediately before the pressing process is started, so the gel strength is increased and the mold becomes difficult to lose its shape. For this reason, in the second stage of the pressing process, the tofu contained in the mold box is higher than the pressing pressure in the first stage, for example, at a pressing pressure of 100 g / cm ² or more and 160 g / cm ² or less, You can press for more than 240 minutes. Compared to the tofu immediately after the first stage, the tofu that has undergone the second stage has a lower moisture content and is thus less likely to lose its shape. Therefore, if the pressing force applied to tofu is increased stepwise, a higher pressing pressure can be applied to the tofu without causing the tofu to lose its shape in the second and subsequent steps.

In the third stage of the pressing process, the tofu stored in the mold box is pressed for 420 minutes or more and 660 minutes or less with a pressing force of 300 g / cm ² or more and 400 g / cm ² or less, for example. When a high pressing pressure is applied to the tofu in the third stage, the time required for pressing the tofu can be greatly shortened, so that the fresh taste is maintained with the dehydrated tofu. Therefore, dehydrated tofu with a fresh taste can be produced without losing shape.

  The stage of increasing the pressing pressure in the pressing process is not limited to three stages, and may be two stages. For example, if a general cotton tofu having a moisture content of about 87 to 88% by weight is prepared in the preparation process, the tofu has a certain gel strength. There is no need to perform steps. In this case, the first stage of the above-described pressing process may be omitted, and only the second stage and the third stage of the above-described pressing process may be performed. Alternatively, the step of increasing the pressing pressure in the pressing process may be four or more steps.

  In the pressing step, it is preferable to squeeze water from the tofu by pressing the tofu so that the water content of the tofu is 70 wt% or more and 75 wt% or less when the final stage is completed. When the moisture content of the resulting dehydrated tofu is less than 70% by weight, since the dehydrated tofu is excessively dehydrated, the smooth texture is impaired from the dehydrated tofu. When the moisture content of the dehydrated tofu is higher than 75% by weight, the gel strength of the dehydrated tofu is low, so that the dehydrated tofu becomes soft and the elastic texture unique to the dehydrated tofu does not stand out. Moreover, even if processed tofu processed foods, such as smoked tofu, are manufactured using soft dehydrated tofu as a foodstuff, the processed tofu processed foods will not be crunchy. Furthermore, when the moisture content is high, the shelf life of dehydrated tofu is shortened.

  When the moisture content of the resulting dehydrated tofu is 70 wt% or more and 75 wt% or less, the dehydrated tofu maintains the original smooth texture of tofu and has a unique elastic texture. Presents.

  More preferably, in the pressing step, when the last step is completed, the tofu is pressed to press the moisture from the tofu so that the water content of the tofu is 73 wt% or more and 75 wt% or less. Is good. The dehydrated tofu with a moisture content of 73 wt% or more and 75 wt% or less retains the original smooth texture of tofu more than the dehydrated tofu with a moisture content of 70 wt% or more and less than 73 wt%. The tofu has a unique and unique texture.

  Therefore, according to the manufacturing method which concerns on Embodiment 1, the manufacturing method of the dehydrated tofu which maintained both the fresh taste and the smooth smooth texture of tofu without shape loss is provided.

  In addition, as a method of squeezing water from tofu in a short time without making the tofu into a mold, prepare tofu with a thickening agent and tofu filled in an edible container, and compress these tofu It is possible to apply the method. However, tofu added with the thickening agent no longer exhibits the original smooth texture of tofu. Moreover, when the tofu filled in the edible container is pressed in the pressing process, the taste component of the container penetrates into the tofu and becomes a tofu exhibiting the taste of the container. For this reason, when the tofu added with the thickening agent or the tofu filled in the edible container is subjected to the pressing process, the resulting dehydrated tofu does not show the original smooth texture of tofu.

[Manufacturing Method According to Embodiment 2]
About the manufacturing method which concerns on Embodiment 2, only the matter different from the manufacturing method which concerns on Embodiment 1 is demonstrated. In the manufacturing method which concerns on Embodiment 2, the tofu stored in the type | mold box is kept in the state of 3 to 6 degreeC in the case of a pressing process.

  In a refrigerated room or the like where the target set temperature is set to be higher than 0 ° C and lower than 3 ° C, there is a possibility that a location where the temperature is locally below 0 ° C may occur near the vent hole. When the process is performed, the tofu moisture may solidify and the internal structure of the tofu may be broken. In addition, when the tofu is kept at 3 ° C. or more and 6 ° C. or less than when the tofu is kept at a temperature higher than 6 ° C. and kept at 10 ° C. or less, the resulting dehydrated tofu The fresh taste stands out especially. Furthermore, when the pressing process is performed in a state where the tofu is kept at 3 ° C. or more and 6 ° C. or less, the shelf life of the resulting dehydrated tofu can be set long. For this reason, it becomes easy to manufacture tofu processed foods, such as smoked tofu, from the dehydrated tofu and distribute the said tofu processed food.

[Manufacturing Method According to Embodiment 3]
About the manufacturing method which concerns on Embodiment 3, only the matter different from the manufacturing method which concerns on Embodiment 1, 2 is demonstrated. In the manufacturing method which concerns on Embodiment 3, a bamboo basket is used as a pushing lid | cover at a pressing process.

  The bamboo basket is bent following the uneven shape of the surface of the tofu. Therefore, when the bamboo basket is used, it is possible to particularly avoid the tofu from being deformed due to local pressing pressure on the tofu. In addition, when bamboo baskets are used, the quality of the dehydrated tofu becomes easier than when a wooden push lid is used because there is less risk of bamboo fragments being mixed into the tofu. Further, the gap between the bamboos constituting the bamboo basket acts as an outlet for discharging water squeezed from the tofu and as an outlet for deriving water vapor evaporated from the tofu out of the mold box. For this reason, when bamboo basket is used, the time required for dehydration of tofu can be further shortened in the pressing step. Therefore, when bamboo shoots are used, the original dehydrated tofu and the original fresh taste of tofu are further preserved.

[Pressing pressure in pressing process]
A method for applying the pressing force in the pressing step, which is common to the manufacturing methods according to the first to third embodiments, will be described. The expression step, tofu, housed in the mold box, pressed by a lid press while increasing stepwise pushing pressure, in its first stage, 30 g / cm ² or more 70 g / cm ² 30 minutes or more following pressing force Press for 120 minutes or less, and in the second stage, press for 30 minutes or more and 240 minutes or less with a pressing pressure of 100 g / cm ² or more and 160 g / cm ² or less, and in the third stage, 300 g / cm ² or more and 400 g / cm ² Press from 420 minutes to 660 minutes with the following pressure.

When the pressing pressure is less than 30 g / cm ² in the first stage of the pressing process, the pressing pressure is too low, so it takes a long time to dehydrate the tofu, and the efficiency of dehydration of the tofu is poor. For this reason, it is not preferable that the pressing pressure is less than 30 g / cm ² from the viewpoint of shortening the time of the pressing process. For example, if the tofu prepared in the preparation process is a tofu with low gel strength having a water content of 89.2 wt% or more and 89.5 wt% or less, the pressing pressure is 70 g / g in the first stage of the pressing process. When it is higher than cm ² , the tofu may be out of shape.

  When the length of the pressing time is less than 30 minutes in the first stage of the pressing process, water has not been sufficiently squeezed from the tofu. For example, if the tofu prepared in the preparation step is a low gel strength tofu with a water content of 89.2% by weight or more and 89.5% by weight or less, if the pressing time is less than 30 minutes, Since the gel strength remains low, the tofu may lose its shape when the process proceeds to the second stage of the pressing process. When the length of the pressing time exceeds 120 minutes in the first stage of the pressing process, a certain amount of water has already been squeezed out of tofu, so the flow rate of water squeezed out of tofu has decreased. For this reason, it is not preferable that the length of time for pressing in the first stage exceeds 120 minutes from the viewpoint of shortening the time of the compression process because the efficiency of dehydration of tofu deteriorates.

In the first stage of the pressing step, by pressing 30 g / cm ² or more 70 g / cm ² or less of pushing pressure over 30 minutes 120 minutes or less, for example, tofu is prepared in the preparing step moisture content 89.2 wt% or more 89 Even if the tofu has a low gel strength of less than 5% by weight, water is appropriately squeezed out of the tofu and the gel strength of the tofu is increased. For this reason, even if it transfers to the 2nd stage of a pressing process as it is, tofu does not lose shape.

  Even in the second stage of the pressing process, the upper limit value and the lower limit value of the height of the pressing pressure and the length of time are determined for the same reason as in the first stage described above. Even in the third stage of the pressing process, the upper limit value and the lower limit value of the height of the pressing force are determined for the same reason as in the first stage described above. In the third stage of the pressing process, pressing for 420 minutes or more and 660 minutes or less is a suitable length of time for adjusting the water content of the resulting dehydrated tofu to 70% by weight or more and 75% by weight or less. Because it is.

  As described above, for example, tofu prepared in the preparation process has a water content of 89.2% by weight or more and 89.5% by weight when the pressing process is performed while increasing the pressing pressure in stages from the first stage to the third stage. Even if the tofu has a low gel strength of not more than%, water can be squeezed out of the tofu in as short a time as possible without causing the tofu to lose its shape. Further, when the tofu is kept at 3 ° C. or more and 6 ° C. or less when performing the pressing step, the time required for squeezing water from the tofu until the water content of the tofu becomes 70% by weight or more and 75% by weight or less is 12 Less than time.

  In addition, the ease of squeezing out the water from tofu varies greatly depending on the variety and quality of the soybean that is the raw material of tofu. In addition, the variety and quality of soybeans that can be obtained as raw materials are not constant because they change every moment according to climate change and soybean price changes every year. For this reason, when the production method of the present invention is carried out and dehydrated tofu having a water content of 70% by weight or more and 75% by weight or less is stably obtained every time, depending on the variety and quality of the soybean that is the raw material of tofu. From the first stage to the third stage of the pressing process, it is necessary to adjust the conditions flexibly at each stage. In order to cope with such circumstances, in the first to third stages of the above-described pressing process, a certain width is provided for the height of the pressing pressure and the length of time for which the pressing pressure is applied in each stage. ing.

[Coagulant]
Depending on the concentration of the coagulant contained in the soymilk, the tofu prepared from the soymilk has a greatly different gel strength. For example, cotton tofu prepared from soy milk having a bittern concentration of about 0.40% by mass has a sufficiently high concentration of coagulant contained in soy milk. High gel strength. If cotton tofu with high gel strength is prepared, it can be compressed by applying a high pressing pressure of about 200 g / cm ² to the cotton tofu as it is, so that the pressing can be easily completed in a short time. However, in this case, since the cotton tofu is hardened by the coagulant, the resulting dehydrated tofu has a poor smooth texture.

On the other hand, cotton tofu prepared from soymilk having a bittern concentration of 0.20% by mass or more and 0.25% by mass or less has a low gel strength of cotton tofu because the concentration of the coagulant contained in the soymilk is low. It is difficult to squeeze cotton tofu with low gel strength without causing it to lose its shape. On the other hand, the inventor of the present application, in the process of completing the present invention, to cotton tofu prepared from soybean milk having a bittern concentration of 0.20% by mass or more and 0.25% by mass or less, from the beginning to the end of pressing. When a test was applied to a low pressing pressure of about 50 g / cm ² , the cotton tofu could be squeezed without causing it to lose its shape. At this time, the inventor of the present application discovered that the dehydrated tofu obtained by the test maintained the original smooth texture of cotton tofu. Thereafter, the inventor of the present application diligently studied a method for shortening the time required for the compression step, and as a result, the present invention was completed.

  The conditions of the coagulant common to the manufacturing methods according to Embodiments 1 to 3 will be described. In the production method of the present invention, the tofu prepared in the preparation step is cotton tofu prepared from soy milk having a bittern (magnesium chloride) concentration of 0.20 mass% or more and 0.25 mass% or less.

  If the bittern concentration is less than 0.20% by mass, the soy protein does not sufficiently undergo a cross-linking reaction in soy milk, so that the cotton tofu becomes extremely soft. For this reason, it is very difficult to apply pressure to cotton tofu so that the cotton tofu does not lose its shape in the pressing step. If the bittern concentration is higher than 0.25% by mass, the dehydrated tofu produced through the pressing step will not exhibit a smooth texture.

  Cotton tofu prepared from soy milk having a bittern concentration of 0.20% by mass or more and 0.25% by mass or less has a low gel strength, but when pressed while gradually increasing the pressing pressure in the pressing process, it is dehydrated without losing its shape. There is a degree of gel strength that can be applied. Furthermore, dehydrated tofu prepared from soy milk having a bittern concentration of 0.20% by mass or more and 0.25% by mass or less and having undergone a pressing process exhibits the original smooth texture of cotton tofu. .

  In the production method of the present invention, the tofu prepared in the preparation step is preferably cotton tofu prepared from soy milk having a bittern concentration of 0.21 mass% or more and 0.23 mass% or less. When the bittern concentration is 0.20% by mass or more and less than 0.21% by mass, if the soybean used as the raw material for the cotton tofu is not of a specific variety and of good quality, the tofu will be deformed in the pressing process. It is difficult to apply pressure to cotton tofu so as not to When the bittern concentration is higher than 0.23 mass% and lower than 0.25 mass%, the resulting dehydrated tofu exhibits the original smooth texture of cotton tofu, but lacks its smoothness and delicateness.

  Cotton tofu prepared from soymilk with a bittern concentration of 0.21% by weight to 0.23% by weight is a pressing process unless the variety of soybeans used as a raw material is suitable or the quality is very poor. When cotton tofu is pressed while gradually increasing the pressing pressure, the gel strength is such that it can be dehydrated without losing its shape. Further, such cotton tofu exhibits a smooth texture like silken tofu, although it is cotton tofu. In this case, the resulting dehydrated tofu also exhibits a particularly fine and smooth texture like the prepared tofu.

  The tofu prepared in the preparation step may be cotton tofu prepared from soy milk to which calcium sulfate or glucono delta lactone has been added as a coagulant. If the gel strength of cotton tofu prepared from soy milk having a bittern concentration of 0.20% by mass and the gel strength of tofu prepared by adding calcium sulfate or glucono delta lactone to soy milk, the sulfuric acid in this case The concentration of calcium or glucono delta lactone is the lower limit of the concentration as a coagulant. Similarly, if the bitumen concentration is the same as the gel strength of cotton tofu prepared from soy milk with 0.25% by mass, the concentration of calcium sulfate or glucono delta lactone in this case is the upper limit of the concentration as a coagulant. It becomes. The same applies to a coagulant not mentioned in the present specification and cotton tofu prepared by combining a plurality of types of coagulants and adding them to soy milk.

[Tofu prepared in the preparation process]
The cotton tofu prepared in the preparation step may be prepared by the following methods (1) to (3).
(1) After the soymilk is stirred, a coagulant is added to solidify the soymilk over 15 to 20 minutes.
(2) Put the soymilk coagulum in a mold box covered with a wet cotton bleached cloth and let it dehydrate naturally for 2-5 minutes. After that, the soymilk coagulum is squeezed and "yu" is squeezed out.
(3) The soymilk coagulated product obtained by squeezing “yu” is taken out of the mold box in water and transferred to cold water, and the central temperature of the soymilk coagulated product is lowered to 5 ° C. or lower. Thereby, cotton tofu is obtained.

  The tofu prepared in the preparation step is cotton tofu prepared from soy milk having a brix of 12.0 or more and 12.7 or less. The Brix value of soy milk was measured using a saccharimeter. In addition, the soymilk concentration of Brix 12.0 or more and 12.7 or less corresponds to the soymilk concentration of soybean solid content 10.5% or more and 10.8% or less.

  If the soy milk is less than Brix 12.0 or higher than Brix 12.7, the soy milk concentration is too thin or too thick so that the cotton tofu becomes soft and the resulting dehydrated tofu has an elastic texture. Not present. On the other hand, if soy milk is Brix 12.0 or more and 12.7 or less, cotton tofu will become suitable hardness. As a result, the resulting dehydrated tofu exhibits an elastic texture unique to dehydrated tofu in addition to the smooth texture inherent in cotton tofu. When the dehydrated tofu exhibits an elastic texture, the dehydrated tofu and the processed processed tofu produced from the dehydrated tofu have a unique and crunchy taste.

In particular, a preparation step for preparing cotton tofu prepared from soy milk having a bittern concentration of 0.21% by mass or more and 0.23% by mass or less and Brix 12.0 or more and 12.7 or less, and wrapping the cotton tofu with a cloth, a storage step to fit the mold box, cotton tofu, housed in the mold box, 3 6 ° C. while maintaining the inclusive ° C., in the first stage 30 g / cm ² or more 70 g / cm ² 30 minutes or more following pressing force press 120 minutes or less, press the second stage 100 g / cm ² or more 160 g / cm ² or less in the press pressure more than 30 minutes 240 minutes or less, the third stage 300 g / cm ² or more 400 g / cm ² less pressing force The dehydrated tofu produced by the method of producing dehydrated tofu comprising pressing with bamboo shoots while gradually increasing the pressure so that it is pressed for 420 minutes or more and 660 minutes or less is not deformed and fresh. Taste and silk Exhibits a fine smooth mouthfeel of tofu as corrosion, texture a resilient, has a unique taste that is crunchy.

[Tofu processed foods such as smoked tofu]
The smoked tofu of the present invention is obtained by smoke-treating the dehydrated tofu using the dehydrated tofu produced by the above-described production method as a food material. The smoked treatment may be a hot-boiled method in which dehydrated tofu is poured at a temperature higher than 80 ° C. for 10 to 60 minutes, or a hot-boiled method in which dehydrated tofu is boiled for several hours with smoke at 30 to 60 ° C. Alternatively, the dehydrated tofu may be dipped in a sap and dried. The smoked process gives a smoked odor to the dehydrated tofu and further forms a light brown skin. The smoked tofu thus obtained has a light brown and relatively hard outer skin, a pure white and relatively soft interior, and has a cheese-like appearance and texture.

  When smoke processing is performed by a hot-bath method or a hot-bath method, smoked material is burned by using a device such as a smoke-making kiln (smoker) or an oven to produce dehydrated tofu. Examples of the smoke material include smoke chips, smoke wood, twigs, firewood, and the like containing one or more of walnuts, cherry, oak, hickory, beech, apple, sawdust and the like. From the viewpoint of the flavor imparted to the finished smoked tofu, the smoke material is more preferably a smoked chip containing cherry.

  Moreover, tofu pickles can be produced using the dehydrated tofu produced by the above-described production method as a food material. For example, when the dehydrated tofu produced by the above-described production method is soaked in three cups of vinegar for about 1 to 2 days, three cups of tofu can be pickled. When the dehydrated tofu produced by the above-described production method is soaked in the cocoon bed, the tofu can be pickled. Such tofu pickles can have a long shelf life and are rich in soy protein, so it is considered useful for maintaining health when ingested on a daily basis.

  The processed tofu foods such as smoked tofu according to the present invention are produced using the dehydrated tofu produced by the above-described production method as an ingredient, so that they are not cracked, have a fresh taste, and have a smooth texture.

[Dehydrated tofu as an ingredient for producing smoked tofu]
Since the dehydrated tofu produced by the above-described production method is adjusted to a moisture content of 70 wt% or more and 75 wt%, the smoked tofu produced using the dehydrated tofu as a food material has elasticity like cheese. Presents a texture. For this reason, dehydrated tofu having a moisture content of 70% by weight or more and 75% by weight or less is suitable as a food material in producing smoked tofu that has an elastic texture like cheese.

  When the dehydrated tofu produced by the above-described production method is adjusted to a moisture content of 73 wt% or more and 75 wt% or less, the smoked tofu produced using the dehydrated tofu as a food material has a moisture content of 70 wt% or more and 73 wt%. Compared with smoked tofu produced with less than% by weight of dehydrated tofu as an ingredient, it has a more resilient texture like cheese. Such dehydrated tofu is more suitable as a food material in producing smoked tofu that exhibits an elastic texture like cheese.

  In the preparation step of the manufacturing method described above, cotton tofu prepared from soy milk having a bittern concentration of 0.21% by mass or more and 0.23% by mass or less is prepared, and in the pressing step of the manufacturing method described above, the cotton tofu is prepared. Smoked tofu produced by using dehydrated tofu obtained as a food material at 3 ° C. or more and 6 ° C. or less exhibits a fine and smooth texture. If you eat such smoked tofu, you will feel as if you are eating cheese. Such dehydrated tofu is excellent as a food material in producing smoked tofu with a touch like cheese.

  In the preparation step of the manufacturing method described above, cotton tofu prepared from soy milk having a bittern concentration of 0.21% by mass to 0.23% by mass and Brix of 12.0 to 12.7 is prepared. The smoked tofu produced by using the dehydrated tofu with a moisture content of 73 wt% or more and 75 wt% or less obtained by keeping the cotton tofu at 3 ° C. or more and 6 ° C. or less in the pressing step of the production method is elastic It has a texture with a smooth texture. If you eat such smoked tofu, you will be reminded of eating cheese because of its crunchy texture. Such dehydrated tofu is extremely excellent as a food material for producing smoked tofu with a taste like cheese.

[Pouch]
Processed food products such as dehydrated tofu or smoked tofu obtained by the production method of the present invention are filled in a pouch, sealed, preferably vacuum (degassed), and distributed as a chilled product. The pouch is preferably made of a material having a low oxygen permeability.

  In addition, the tofu processed food such as dehydrated tofu or smoked tofu obtained by the production method of the present invention may be subjected to low temperature heat sterilization for the purpose of extending the shelf life after filling the pouch and vacuum-sealing. When vacuum sealing is performed, heat is efficiently transmitted to dehydrated tofu or processed tofu food, so that the time required for heat sterilization can be shortened and the heating temperature can be low. Thereby, in heat sterilization, it can suppress that dehydrated tofu or tofu processed food becomes hard by heating.

[Comparative Example 1]
In Comparative Example 1, cotton tofu prepared from soy milk of Brix 12.3 having a bittern concentration of 0.24% by mass was prepared in the preparation step. In the storing process, the above-mentioned cotton tofu was wrapped in a cotton wet cloth and stored in a mold box. In the pressing process, while keeping the cotton tofu stored in the mold box at 5 ° C., press the pressure of 130 g / cm ² from the beginning to the end of the pressing and press it with the pressing lid to squeeze out moisture from the cotton tofu. It was.

However, in Comparative Example 1, after the squeezing started, pieces of cotton tofu appeared in the minute holes provided on the side surface of the mold box. For this reason, the test was stopped halfway. The cotton tofu contained in the mold box was crushed. When the bittern concentration is 0.24% by mass and the soymilk is Brix 12.3, the concentration of the coagulant contained in the soymilk is thin, and the cotton tofu prepared from the soymilk has a high water content. As a result, cotton tofu has a low gel strength, so it is considered that the mold was deformed when a pressure of 130 g / cm ² was applied as it was.

[Comparative Example 2]
For Comparative Example 2, only the test conditions different from Comparative Example 1 will be described. In Comparative Example 2, the cotton tofu contained in the mold box in the pressing process was pressed with a pressing lid with a pressing pressure of 70 g / cm ² from the beginning to the end of the pressing while maintaining the temperature at 5 ° C. The water was squeezed out. Thereby, dehydrated tofu was obtained.

  In Comparative Example 2, dehydrated tofu with a water content of 75.0% by weight could be obtained without causing the cotton tofu to lose its shape, but the pressing process required 24 hours or more. Ten evaluators ate the dehydrated tofu obtained in Comparative Example 2 and evaluated its texture. As a result, it was evaluated that dehydrated tofu exhibited the smooth texture inherent in cotton tofu but was not fresh. The fact that it took more than 24 hours for the pressing process is considered to be the cause of the loss of freshness. Some evaluators evaluated that the texture of dehydrated tofu lacked smoothness and subtlety.

[Example 1]
For Example 1, only the test conditions different from those of Comparative Example 1 will be described. In Example 1, the cotton tofu stored in the mold box in the pressing step was pressed at a first stage for 40 minutes with a pressing pressure of 70 g / cm ² while maintaining at 5 ° C., and in the second stage, 160 g / cm press 40 minutes ² push pressure, in a third stage, by pressing 640 minutes press pressure of 400 g / cm ^2, pressing a lid press while increasing stepwise pushing pressure. Thereby, dehydrated tofu was obtained.

  In Example 1, the completed dehydrated tofu was not deformed and its water content was 70.1% by weight. Moreover, in Example 1, the time required for the pressing process was 12 hours. Compared with Comparative Example 2, it can be said that in Example 1, the time required for the pressing process was significantly reduced from 24 hours or more to 12 hours by pressing the cotton tofu while increasing the pressing pressure stepwise.

  Ten evaluators ate the dehydrated tofu obtained in Example 1 and evaluated its texture. As a result, it was evaluated that the dehydrated tofu was fresh and maintained the original smooth texture of cotton tofu. In Example 1, as compared with Comparative Example 2, the time required for the pressing process was significantly shortened, so it is considered that freshness was maintained with dehydrated tofu. Some evaluators evaluated that the dehydrated tofu obtained in Example 1 lacked smoothness and delicacy.

[Example 2]
For Example 2, only the test conditions different from Comparative Example 1 will be described. In Example 2, cotton tofu prepared from soymilk of Brix 12.3 having a bittern concentration of 0.22% by mass was prepared in the preparation step. Furthermore, in the pressing process, the cotton tofu stored in the mold box is pressed at 5 ° C. for 90 minutes with a pressing pressure of 50 g / cm ² in the first stage, and 131 g / cm ² in the second stage. The pressure was pressed for 180 minutes, and in the third stage, the pressure was 345 g / cm ² for 450 minutes. Thereby, dehydrated tofu was obtained.

  In Example 2, since the concentration of the bittern contained in the soymilk was as thin as 0.22% by mass, the cotton tofu prepared from the soymilk exhibited a smooth texture like silken tofu while being a cotton tofu. Since the cotton tofu prepared in Example 2 was prepared from soy milk having a low bittern concentration compared to the cotton tofu prepared in Comparative Examples 1 and 2 and Example 1, the gel strength of the cotton tofu was low.

  In Example 2, the resulting dehydrated tofu was not deformed and its water content was 73.2% by weight. In Example 2, the time required for the pressing process was 12 hours. Ten evaluators ate the dehydrated tofu obtained in Example 2 and evaluated its texture. As a result, dehydrated tofu is fresh and has a fine and smooth texture like cotton tofu like silken tofu. It was.

  INDUSTRIAL APPLICABILITY The present invention is used for a method for producing dehydrated tofu and processed food products such as smoked tofu produced using the dehydrated tofu obtained by the production method as an ingredient.

Claims (7)

A preparation process for preparing tofu;
A storage step of wrapping the tofu with a cloth and storing it in a mold box;
Pressing the tofu contained in the mold box with a push lid while gradually increasing the pressing pressure while keeping the tofu higher than the freezing point of moisture of the tofu at 35 ° C. or less;
A method for producing dehydrated tofu, comprising:   The method for producing dehydrated tofu according to claim 1, wherein the pressing step is performed while maintaining the tofu contained in the mold box at 3 ° C. or more and 6 ° C. or less.   The method for producing dehydrated tofu according to claim 1 or 2, wherein the push lid is a bamboo basket. In the pressing step, the tofu stored in the mold box,
In its first stage, press 30 g / cm ² or more 70 g / cm ² or less in the press pressure of 30 minutes or more and 120 minutes or less,
In the second stage, pressing for 30 minutes or more and 240 minutes or less with a pressing force of 100 g / cm ² or more and 160 g / cm ² or less,
The method for producing dehydrated tofu according to any one of claims 1 to 3, wherein in the third stage, pressing is performed for 420 minutes or more and 660 minutes or less with a pressing force of 300 g / cm ² or more and 400 g / cm ² or less.   The production of dehydrated tofu according to any one of claims 1 to 4, wherein the tofu prepared in the preparation step is cotton tofu prepared from soybean milk having a bittern concentration of 0.20 mass% or more and 0.25 mass% or less. Method.   The method for producing dehydrated tofu according to claim 5, wherein the soy milk is Brix 12.0 or more and 12.7 or less.   Smoked tofu obtained by smoke-treating dehydrated tofu produced by the method for producing dehydrated tofu according to claim 1.