JP2012231781A - Method for producing bean curd, including starch gelatinization reaction and the gelatinized bean curd - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide bean curd having higher qualities in physical properties such as the hardness of the bean curd, and to provide a method for producing the same.SOLUTION: The method for producing the bean curd, including a step of producing soybean milk from soybeans; a primary heating step of heating the soybean milk in a heating tank; a step of adding and stirring starch and a coagulation agent to the soybean milk on primary heating to produce a soybean milk mixture liquid; and a secondary heating step of heating the stirred soybean mixture liquid, is characterized in that the secondary heating step is a heating step of heating at temperature not less than the starch gelatinization temperature to gelatinize the starch; and the bean curd produced by the method.

Description

  The present invention provides a method for producing rag tofu comprising a step of adding starch to soy milk and a heating step of gelatinizing starch in producing rag tofu, and has higher quality in physical properties such as hardness of tofu. Oboro tofu and a method for producing the same are provided.

  Tofu is a food rich in calcium, minerals and proteins, and is often selected from menus for various dishes because of its light flavor and soft texture. However, since tofu is rich in moisture and nutrients, it is not only susceptible to spoilage, but also has a drawback that it is difficult to store and distribute due to its low tissue strength. Therefore, it has been proposed to dry tofu as a method for simultaneously solving the storage and portability of tofu.

  According to the technology related to the method for drying tofu, the dried tofu disclosed in Korean Patent No. 2000-53766 and the method for producing the same, the tofu is put in a vacuum dryer and depressurized, and then the tofu is applied at a temperature of 60 ° C. for 18 to 20 hours. A method of drying was proposed. In the method of drying tofu according to Korean Patent No. 10-0891445, it was pre-cooled for about 1 hour until the tofu was put in a freezer and immediately before it was frozen, that is, until frozen frost was generated on the surface of the tofu. Thereafter, the cooled tofu was put in a vacuum freeze dryer and the pressure was reduced so that the temperature of the tofu reached 40 ° C., followed by a step of vacuum freezing. Therefore, the stage is not only complicated and complicated, but also takes a long time, so it induces considerable protein denaturation, changes the original flavor and aroma of tofu, and when the tofu is restored, the flavor of raw tofu is perfect There is a limit that the texture of tofu cannot be restored because the structure is destroyed during the freezing process.

  The present invention provides a drying method that vacuum-freezes the tofu tofu without a preliminary freezing process and minimizes the denaturation of the protein in the tofu, so that the flavor and texture of the state before drying can be almost restored as it is. It aims to provide a method.

  The present invention also provides a method for producing rag tofu having a step of adding starch to soy milk and a heating step for gelatinizing starch in the production of rag tofu, and has a hardness higher than that of existing rag tofu in physical properties such as hardness of tofu. An object of the present invention is to provide a high quality rag tofu having high elasticity and elasticity and a method for producing the same.

  Another object of the present invention is to provide a stirring method in which starch is uniformly dispersed in soy milk by using starch in the form of a starch dispersion at the stage of stirring soy milk and starch during the production process of tofu. And

  Furthermore, the present invention relates to a method for producing a dry rag tofu suitable for the production of dried tofu tofu by adding starch in the production of tofu, and vacuum lyophilizing the dried rag tofu to dry torn tofu. An object of the present invention is to provide a method of producing

  In an embodiment of the present invention, there is provided a method for producing rag tofu having a step of adding starch to soy milk and a heating step of gelatinizing starch in the method of producing rag tofu.

  In one embodiment of the present invention, the starch added to the tofu tofu is subjected to a gelatinization reaction in the tofu production process, so that the physical properties such as the hardness of the tofu (Hardness) are higher than the existing tofu tofu and have elasticity. A high quality rag tofu is provided.

  In an embodiment of the present invention, in the method of stirring soy milk and starch in the tofu production process, the starch is used in the form of a starch dispersion to provide a stirring method capable of uniformly dispersing starch in soy milk. .

  In one embodiment of the present invention, in a method for drying rag tofu, a method for vacuum lyophilization of tofu without a pre-freezing process is provided, and the method for drying rag tofu can restore the flavor and texture of the state before drying as it is. Is provided.

  The following specific examples are merely illustrative of the present invention, and the contents of the present invention should not be construed as being limited by the following specific examples.

  Specifically, the present invention relates to a method for producing a drying rag tofu different from the existing method and a drying method thereof in order to give a texture similar to the original after the dried rag tofu is restored. It is.

  The present invention is a process for producing soymilk, a step of adding solubilized water / modified starch / antioxidant and a coagulant to the soymilk, stirring the soymilk mixture, and packaging the soymilk mixture with a rag tofu pouch. The process, the process of heating the packaged tofu, the process of cooling the solidified tofu, the cutting of the cooled tofu, the freezing of the cut tofu and the freeze-drying of the frozen tofu Steps may be included.

  The present invention relates to rag tofu having higher quality in physical properties such as hardness of tofu. It has excellent properties for use as a dry rag tofu for the production of dry rag tofu, and provides a rag tofu with an excellent texture even when not produced as a dry rag tofu . Therefore, the step of adding starch to the soymilk and making it gelatinize is included in the tofu production process. The starch is preferably a modified starch such as tapioca-modified starch, rice-modified starch, sweet potato-modified starch, potato-modified starch, or corn-modified starch, and more preferably tapioca-modified starch. The starch is preferably added in an amount of 0.1 to 3% by weight, more preferably 1% by weight, based on the total weight of the soymilk mixture.

  In order to uniformly disperse the starch in soy milk when the starch is mixed with soy milk, first, the starch and dilution water are first stirred using a known homomixer (Homomixer) to produce a starch dispersion. After that, it is preferable to put into a stirring tank containing soy milk and proceed to the secondary stirring stage. In the primary stirring step, an antioxidant may be further added and stirred.

  As the coagulant to be added to the secondary stirred soymilk mixture, it is preferable not to use glutanodelta lactone (GDL), which degrades the functional group of starch and interferes with the action of starch, and more preferably contains GDL. It is better to use a mixed coagulant, magnesium chloride, or prepared bitter juice as a coagulant, and most preferred to use calcium sulfate as a coagulant.

  In heating the secondary-stirred soymilk mixture, it is preferable to heat the starch at a temperature equal to or higher than the starch gelatinization temperature added to the soymilk to induce starch gelatinization. In one specific example of the present specification, when the starch added to soy milk is tapioca-modified starch, considering that the gelatinization temperature is 70 to 75 ° C, the product temperature of tofu is about 80 to 100 ° C. The starch is gelatinized by heating at a temperature of about 80 to 100 ° C., preferably 86 ° C. or more, preferably 40 minutes or more, more preferably 1 hour or more, so that the temperature is higher than 80 ° C., preferably 83 ° C. The heating step is preferably hot water treatment.

  The composition of the tofu prepared by the above method is preferably 9-12 brix soymilk, more preferably 10.5 brix soymilk, and starch is preferably 0.1-3 wt%, more preferably 1 wt% based on the total weight of soymilk. % Can be included. The coagulant can preferably contain 0.1 to 1% by weight, more preferably 0.3% by weight. Further, an antioxidant may be further contained in an amount of 0.01 to 1% by weight, more preferably 0.15% by weight.

  Oboro tofu produced by the above-mentioned method has higher hardness and better texture in terms of tofu physical properties such as tofu hardness, gumminess, chewiness, etc. Offer taoboro tofu.

Specifically, as shown in certain specific examples of the present specification (Comparative Test Examples 2-1 and 3-2), the odor tofu produced by the above production method was analyzed under the following conditions. (Texture Analyzer-Model name: TA-XT Plus, 'MHK Trading Company' product) can be used to measure the physical properties of rag tofu.
Probe: cylindrical shape with a diameter of 2 cm Pre-test speed of the probe descending to the sample: 1.00 mm / sec;
The speed at which the probe penetrates into the sample after it touches the sample surface (test speed): 5.00 mm / sec;
Post-test speed after the probe penetrates the sample (post-test speed): 5.00 mm / sec;
Target mode of the probe: distance;
The probe recognizes the surface of the sample and penetrates through the sample distance: 5.000 mm;
The condition for the probe to recognize the sample (trigger type): force; and the minimum force for the probe to recognize the presence of the sample: 5.0 g

  As a result of measuring the physical properties of Oboro Tofu, the control group showed a distribution of hardness of 120 to 160 g and a distribution of 30 to 100 g (no starch added or starch was added but no gelatinization reaction occurred) Compared with Tofu), it was confirmed that it had harder and more elastic properties (see Tables 2 and 3).

  In the invention of the present application, the tofu used in the following method for producing dried tofu is not particularly limited, and a known tofu may be used. That is, when drying with the manufacturing method of the dry rag tofu of this invention using the publicly known rag tofu which is marketed, the dry rag tofu excellent in quality compared with the manufacturing method of the existing dry rag tofu can be obtained. However, in order to obtain the best quality and almost the same texture as the original after restoration, it is more preferable to use the rag tofu produced by the above method as the drying rag tofu.

  In the dry rag tofu production method of the present invention, the prepared rag tofu is put into an apparatus used for freezing and drying in a state in which it is cooled only without pre-freezing. The freezing process of the tofu tofu is a vacuum freezing process performed under reduced pressure, and in one specific example of the present specification, the elapsed time when the degree of vacuum drops from 4 torr to 2.5 torr (absolute pressure), The temperature is adjusted to be preferably within 30 minutes, more preferably within 15 minutes, followed by rapid vacuum freezing. With this, the elapsed time when the product temperature of the tofu tofu falls from 0 to -5 ° C is preferably within 30 minutes, more preferably within 15 minutes, minimizing protein denaturation in the tofu, and high quality Oboro tofu can be obtained. That is, in the case of the vacuum freezing method, the ice growth rate is remarkably faster than the freezing method stored in an existing freezer (-18 ° C to -70 ° C). It becomes possible to minimize the denaturation.

  After the vacuum freezing step, in the lyophilization process of the tofu tofu, in one specific example of the present specification, preferably the vacuum degree is 2.5 torr to 0.5 torr (absolute pressure), more preferably the vacuum degree is 1.5 torr to 0.5 torr. Drying is allowed to proceed in the range of torr. The temperature of the hot plate in the apparatus used for the lyophilization is preferably adjusted to 10 to 80 ° C., more preferably 20 to 75 ° C., and the product temperature of the tofu is preferably 40 ° C., more preferably more than 35 ° C. Minimize protein denaturation in rag tofu.

  Oboro tofu that has been subjected to the drying step is preferably distributed in a vacuum package for quality preservation.

  The dried boro tofu produced by the above drying process is an original material before drying in terms of the physical properties of tofu such as hardness, gumminess, chewiness, etc. of the tofu after restoration compared to the existing dried rag tofu It provides a rag tofu that is closer, harder, more chewy and has a better texture. Specifically, as shown in a specific example of the present specification (Comparative Test Example 3-2), after restoring the dry rag tofu produced by the above production method, the boro tofu production method of the present invention described above is used. As a result of measuring the physical properties of the boro tofu restored after drying under the same conditions as the physical properties of the prepared boro tofu, the control showed a hardness distribution of 50 to 90 g and a distribution of 30 to 50 g. When compared with the group (no added starch or tofu with added starch but no gelatinization reaction), it was confirmed that it showed harder and more elastic properties (see Table 3).

  The present invention has an advantage of providing a method for vacuum-freeze-drying rag tofu without a preliminary freezing process, and providing a method for drying rag tofu that can restore the flavor and texture of the state before drying as it is.

  The present invention provides a method for producing rag tofu comprising a step of adding starch to soy milk and a heating step of gelatinizing starch in producing rag tofu, and more in physical properties such as hardness of tofu (Hardness). There is an advantage in providing a rag tofu having a high quality and a method for producing the same.

  The present invention has an advantage of providing a stirring method in which starch can be uniformly dispersed in soy milk by using the starch in a starch dispersion state when performing the step of stirring soy milk and starch during the production process of tofu.

  In the production of tofu, the present invention relates to a method for producing a drying rag tofu suitable for adding starch to gelatinize it to make a dry rag tofu, and to dry such a rag tofu for vacuum drying and drying. There is an advantage of providing a method for producing tofu.

  Specifically, the present invention relates to tofu tofu having higher quality in physical properties such as hardness of tofu, and of course it is excellent for use as a drying tofu tofu for the production of dried tofu tofu. In order to provide a tofu that has an excellent texture even if it is not manufactured as a dry tofu, it includes a step of adding starch to soy milk to gelatinize it in the tofu production process. To. By heating the soy milk under a temperature condition that induces a gelatinization reaction by adding starch, the moisturizing power of the rag tofu is increased, so that it provides a more crunchy texture and uses this In the production of dried rag tofu, a dry texture that is not crunchy after drying is utilized, and there is no spongy texture that occurs after drying.

  The starch added in the above step preferably uses modified starch, more preferably tapioca modified starch to maximize the effect of the starch. The starch is preferably added in an amount of 0.1 to 3% by weight, more preferably 1% by weight, based on the total weight of the soy milk mixture, and when the dry rag tofu is produced, And cracking phenomenon can be prevented.

  When the starch is mixed with soy milk, in order to uniformly disperse the starch in the soy milk, the starch and dilution water are first stirred first using a known homomixer (Homomixer) to form a starch dispersion. After making it into a state, it is preferable to put it into a stirring tank containing soy milk to advance the secondary stirring stage. In the primary stirring step, an antioxidant such as vitamin E, vitamin C, tocopherol, green tea extract, rosemary extract and the like can be added and stirred. In addition, when an antioxidant is additionally added and stirred, there is an effect of preventing the fat spoilage in tofu and extending the shelf life of tofu relatively long. When starch is added directly to soy milk, starch is non-uniformly dispersed in soy milk, resulting in an increase in the size of starch particles, which has an adverse effect on the prolonged stirring time and the physical properties of tofu. When the starch dispersion liquid subjected to primary stirring as described above is used, the stirring time of soy milk and starch dispersion liquid can be shortened, and tofu with uniform physical properties can be obtained. There are advantages you can do.

  In the coagulant to be added to the secondary agitated soymilk mixture, glucono delta lactone (GDL) is preferably not used because it degrades the functional group of starch and hinders the action of starch, more preferably calcium sulfate. It is better to use it as a coagulant.

  Oboro tofu produced by the above method is harder, more chewy, and textured in terms of tofu hardness, gumminess, chewiness and other tofu properties compared to existing general rag tofu. Provides an excellent rag tofu.

  In the production method for producing dry rag tofu, preferably the rag tofu produced by the above method is used as the dry rag tofu. In the present invention, when producing dried rag tofu, it does not go through the existing pre-freezing step, prevents denaturation of the protein in the tofu induced by the pre-freezing, and prevents the powdery and crumbly texture. There is an advantage of providing a method for producing rag tofu. In addition, the freezing process of the tofu tofu is a vacuum freezing process performed under reduced pressure, and in one specific example of the present specification, the elapsed time when the degree of vacuum drops from 4 torr to 2.5 torr (absolute pressure). However, preferably, the elapsed time when the product temperature of the tofu tofu falls from 0 to -5 ° C. is preferably adjusted by quick vacuum freezing within 30 minutes, more preferably within 15 minutes. Provided is a method capable of obtaining high-quality rag tofu within 30 minutes, more preferably within 15 minutes, by minimizing protein denaturation in tofu. That is, in the case of the vacuum freezing method, the ice growth rate is remarkably faster than the freezing method stored in the existing freezer (-18 ° C to -70 ° C). Denaturation can be minimized.

Furthermore, the present invention is a specific example of the present specification, preferably in the range of a vacuum degree of 1.5 torr (absolute pressure), in the freeze-drying step of the above-mentioned tofu tofu after the vacuum freezing step. The temperature of the hot plate in the apparatus used in the freeze-drying is preferably adjusted to 10 to 80 ° C, more preferably 20 to 75 ° C, and the product temperature of the tofu is preferably 40 ° C, more preferably 35 There is the advantage of minimizing the denaturation of the protein in the rag tofu not to exceed ℃.
The dried boro tofu produced by the drying process is an original material before drying in terms of the physical properties of tofu such as hardness, gumminess and chewiness of tofu after restoration compared to the existing general dried rag tofu There is an advantage of providing a rag tofu that is closer to the texture of, harder and more chewy.

FIG. 1 is a graph obtained by measuring the temperature change of the surface and the central part of the garlic tofu, which is generated when the garlic tofu to which tapioca-modified starch is added is heated at a temperature equal to or higher than the gelatinization temperature of the tapioca-modified starch. Fig. 2 is a graph showing the temperature change of the surface and the central part of the rag tofu during hot water treatment of the existing general rag tofu which has not undergone starch gelatinization process in the heating process of rag tofu . FIG. 3 is a photograph showing the difference in physical properties of borotofu according to the temperature of the center of borotofu during hot water treatment of borotofu in the method for producing borotofu containing starch. FIG. 4 is a photograph together with FIG. 3 showing a difference in physical properties of the rag tofu according to the temperature of the center of the rag tofu during the hot water treatment of the rag tofu in the method for producing the rag tofu added with starch. FIG. 5 is a photograph showing the difference in physical properties of the tofu depending on the type of coagulant used in the tofu to which the starch is added. FIG. 6 is a photograph showing the difference in freezing quality between tofu frozen in a vacuum and tofu frozen in an existing method in a freezer. FIG. 7 is a graph showing the difference in physical properties after restoration between boro tofu produced by adding tapioca-modified starch and dried boro tofu produced by adding other starches, gums, sugars and enzymes, respectively. It is. FIG. 8 is a graph showing the difference in physical properties after restoration between garlic tofu produced by adding tapioca-modified starch and dried garlic tofu produced by adding other starches, gums, sugars and enzymes, respectively. It is. FIG. 9 is a photograph showing the difference in physical properties of dried rag tofu depending on the type of coagulant used in rag tofu with added starch. FIG. 10 is a photograph showing the difference when adding starch in the state of starch dispersion and stirring in the step of adding starch to soy milk, and when adding starch and stirring directly. FIG. 11 is a graph showing the difference in the degree of backscattering of soymilk that has been added and stirred in the state of starch dispersion and soymilk that has been directly added and stirred in the step of adding starch to soymilk. . FIG. 12 is a graph showing the difference in the degree of backscattering of soy milk that has been added and stirred in the state of starch dispersion and soy milk that has been directly added and stirred in the step of adding starch to soy milk. .

  The present invention will be described below by describing the following examples, test examples and comparative test examples. However, the following examples, test examples and comparative test examples are merely examples of the present invention, and the contents of the present invention are not limited thereto.

(Example)
Example 1
Production method of boro tofu through gelatinization reaction of starch (production method of boro tofu for drying)
(1) Stage 1: Soy milk production process

The introduced soybean was washed to remove foreign substances, and then distilled water was added to the washed soybean and immersed for 12 hours at room temperature. Distilled water was also added to the soaked soybean so that the soymilk concentration (brix) was adjusted to 11brix and pulverized with a blender.
The pulverized soybean was filtered through a filter to separate it into okara and soy milk, and then the separated soy milk was heated and sterilized for 20 minutes if the temperature was gradually increased from 100 ° C to 105 ° C. The heat-treated final soymilk was adjusted to 10.5brix, and the soymilk was cooled to 10 ° C or lower.

(2) Stage 2: Step of adding diluted water, modified starch, antioxidant and coagulant to soy milk and then stirring it From the bottom of the stirring tank so that 476 kg of the cooled soy milk does not generate internal bubbles Thrown to fill. Dissolve 5 kg of tapioca-modified starch (HT2X, 'Abebe') in 24 kg of distilled water, and thoroughly homogenize 1 kg of antioxidant (SD-20, Tocopherol MIXk, Iyon Chemical) with a homomixer (homomixer) for 10 minutes. To produce a starch dispersion.
The starch dispersion was put into a stirring tank containing 476 kg of the 10.5brix soy milk and stirred sufficiently for 10 minutes. As a coagulant, 1.45 kg of calcium sulfate was well dissolved in 7.25 kg of distilled water and placed in the stirring tank and stirred with the soymilk mixture.

(3) Step 3: Packaging the soymilk mixture into a rag tofu pouch 508.7 kg of the soymilk mixture to which the coagulant was added was divided into 1 kg rag tofu pouches, filled and packaged.

(4) Four stages: the process of heating the packaged tofu tofu The temperature of the center of the tofu tofu is 83 ° C while the packaged tofu tofu is solidified by hot water treatment for 1 hour in a hot water bath set at 86 ° C. It was made to become above.

(5) Step 5: Step of cooling the solidified tofu tofu The above solidified tofu tofu was cooled with cold water at 5 ° C. for 1 hour so that the center temperature of the tofu was 10 ° C. or less, and then stored refrigerated.
Oboro tofu produced by the above method was confirmed to exhibit the physical properties of Test Example 2 below.

Test example 1
Temperature change of the surface and the center of Oboro Tofu heated above the gelatinization temperature of starch added to soy milk

  Oboro tofu added with tapioca-modified starch (HT2X, 'Abebe' company product) is sufficiently gelatinized to the center of tofu considering that the gelatinization temperature of the modified starch is 70-75 ° C Then, hot water treatment was performed in a hot water bath at 86 ° C. for 60 minutes so that the temperature (article temperature) of the above-mentioned tofu tofu was 80 ° C. or higher. FIG. 1 shows the temperature change of the surface and the center of the rag tofu at this time.

  In the graph of Fig. 1, in the case of rag tofu heated at a temperature higher than the gelatinization temperature of tapioca-modified starch, since the starch gelatinization process is involved, the temperature at the center rises relatively slowly during heating, and after heating It was confirmed that the temperature at the center dropped sharply. When the temperature of the hot water bath was 86 ° C and heated for about 30 minutes, the temperature at the center did not rise to about 60 ° C, so the tapioca-modified starch was not gelatinized sufficiently, and the center temperature when heated for about 1 hour Became over 80 ° C, and the gelatinization reaction of starch became possible.

Comparative test example 1
Surface and center temperature of existing general rag tofu without added starch

  Obtain existing general rag tofu without modified starch (Korean margunkon corn tofu, product of Margunmure Co., Ltd.) and measure the temperature change of the surface and center of rag tofu during hot water treatment did.

    As shown in FIG. 2, which shows the measurement results, the temperature of the center part of the rag tofu rises relatively rapidly during heating compared to FIG. 1, and the temperature of the center part gradually decreases after heating. It could be confirmed.

Test Example Physical property measurement of Oboro tofu produced in Example 2

After producing the rag tofu by the production method of Example 1, the physical properties of the rag tofu are measured using a physical property analyzer (Texture Analyzer-model name: TA-XT Plus, 'MHK Trading Company' product). did. The physical properties were measured under the following conditions.
Probe: cylindrical shape with a diameter of 2 cm;
The speed at which the probe descends to the sample (pre-test speed): 1.00 mm / sec;
The speed at which the probe penetrates into the sample after it touches the sample surface (test speed): 5.00 mm / sec;
Post-test speed after the probe penetrates the sample (post-test speed): 5.00 mm / sec;
Target mode of the probe: distance;
The probe recognizes the surface of the sample and penetrates through the sample distance: 5.000 mm;
The condition for the probe to recognize the sample (trigger type): force; and the minimum force for the probe to recognize the presence of the sample: 5.0 g Conditions to set

Table 1 below shows the physical properties of the rag tofu produced by the production method of Example 1 under the above conditions.

  In Table 1 above, hardness indicates the force required to reach a certain level of deformation, and stickiness indicates the force required for the probe to separate again after it has penetrated the sample, which is greater than cohesiveness. In some cases, a portion of the sample sticks to the probe. Cohesiveness is a force that maintains the shape of the object as it is, and if it is larger than the stickiness, the sample will not stick to the probe. Gum properties indicate the property of making a semi-solid sample unswallowable and is calculated by multiplying hardness and cohesiveness. Chewability indicates the property of making a solid sample swallowable.

Comparative Test Example 2-1
Measurement of physical properties of oboro tofu without starch gelatinization reaction

The composition of the rag tofu was the same as in Example 1, and in order to investigate the physical properties of the rag tofu that had not undergone starch gelatinization reaction in the four stages of Example 1, the four steps of Example 1 were used. Sampling was sequentially performed at six different temperatures in the center of the boro tofu, and the physical properties of each sample were measured under the same conditions as in Test Example 2. The measured values are shown in Table 2 below together with the data of Test Example 2 described above.

  Tapioca of starch added to boro tofu Taking into account that the gelatinization temperature of starch is 70-75 ° C, if the temperature of the center of boro tofu does not exceed about 80 ° C, sufficient gelatinization reaction of starch will occur In the comparative test example 2 described above, only the sixth sample in which the temperature of the center portion of the rag tofu is 83.22 ° C. is recognized as the rag tofu that has undergone starch gelatinization reaction.

  Looking at Table 2 above, the physical properties of the garlic tofu produced have a significant correlation with the gelatinization of starch, and in particular, the garlic tofu has a high correlation in hardness, cohesiveness, gum and chewing properties. It was.

  In addition, the amount of water separation is a figure that is cut in a uniform size after tofu production, measures the amount of water coming out of the tofu at a fixed time, and is divided by the initial weight and displayed as a percentage. It was confirmed that the degree of water separation decreased in proportion to the degree of gelatinization at the center. This is because starch is gelatinized, and it plays a role of catching moisture present in tofu, resulting in a decrease in water separation.

  That is, the starch added to the tofu tofu causes a gelatinization reaction, so that it becomes harder and more elastic than the tofu tofu produced without undergoing the gelatinization reaction, and the maintainability of the form is strong. It was confirmed that a high-quality rag tofu was produced, which is advantageous for transportation and storage, but has a crunchy texture and improved texture.

  3 and 4 show the photographs when the physical properties of the first to sixth samples were measured and after the measurement.

Comparative Test Example 2-2 Comparison of physical properties of Oboro Tofu according to the type of coagulant used in Oboro Tofu with added starch

  Although the same production method as in Example 1 was used, rag tofu was produced by changing the type of coagulant used for this, and the physical properties were compared. Specifically, tapioca modified starch (HT2X, 'Abebe' product) added 5 kg of soy milk to each 1 kg of tofu prepared with calcium sulfate as a coagulant, calcium sulfate, magnesium chloride and GDL in order 8: 2 The physical properties of boro tofu produced using 1 kg of mixed coagulant mixed at a ratio of 4 were compared. The test results are shown in FIG.

  As a result of the test, the rag tofu using calcium sulfate as the coagulant produced the rag tofu having the physical properties of Test Example 2, but the rag tofu using the composite coagulant was not added with starch, Or even if starch is added, physical properties similar to existing general rag tofu with no starch properties, such as rag tofu that was not heated at a temperature higher than the gelatinization temperature of starch in the four stages of Example 1. Oboro tofu was produced. More specifically, the rag tofu with calcium sulfate has much less water separation, the elasticity of the tofu can be seen from the appearance, the strength is stronger than the existing rag tofu, and the texture is softer and higher quality The physical properties of tofu tofu were shown. Contrary to this, the rag tofu using the complex coagulant had a lot of light yellow water separation, and it was similar to the general rag tofu without starch and showed a chewy texture and low strength.

  Oboro tofu using a complex coagulant exhibits such physical properties because GDL contained in the complex coagulant degrades the functional group of starch added to soy milk by lowering the pH and inhibits the effect of starch It was judged to be the result of doing.

Example 2
Drying of tofu tofu by vacuum freeze-drying method

  Using the rag tofu produced by the production method of Example 1, the rag tofu drying step was performed.

(1) 1st stage: cutting process of rag tofu The rag tofu that has been refrigerated in Example 1 above is separated from the pouch, and is subjected to primary, secondary and tertiary cutting through a cutting machine. Then, pretreatment was performed so that the height was about 5 cm or less.

(2) Stage 2: Vacuum freezing process of the cut chopped tofu After cutting the chopped tofu, it was divided into 4kg pieces and put into dry bread and spread well so that the tofu did not overlap. Thereafter, the product of the above-mentioned tofu tofu was put into a freeze-dried tube while maintaining the product temperature at 10 ° C. or lower. Operate the vacuum pump to perform vacuum freezing so that the time required for the vacuum to drop from 4 torr to 2 torr is within 15 minutes, thereby reducing the time for the product temperature of the tofu to fall from 0 ° C to -5 ° C. Rapid freezing was performed as short as possible.

(3) Three stages: freeze-drying process of taro tofu that has been frozen in a vacuum range of 2 torr to 0.5 torr while adjusting the temperature of the hot plate to 10 to 75 ° C based on -15 ° C when the above freezing is completed And freeze-dried. After 30 hours, the drying was completed and the bread was taken out and packaged.

Comparative Test Example 3-1
Comparison of frozen quality of tofu frozen in vacuum and tofu frozen in existing method in freezer

A test was conducted to compare the freezing quality of the tofu frozen in the two-stage vacuum freezing method of Example 2 and the tofu frozen in the existing method in a freezer.
A comparison of frozen quality is shown in FIG.

  In the case of tofu that had been frozen in a vacuum, the protein was slightly denatured in some places, but this was due to the fact that the tofu that had been frozen in the -70 ° C freezer generally turned pale yellow and the -18 ° C freezer. Comparing that the tofu frozen in a very yellow color, it was judged that a small amount of protein denaturation occurred only in a very localized part, which is not much different from the original in the texture after restoration It was determined that The score of the texture of the original tofu was 5 points, and when comparing the quality of each frozen tofu, the score of the sensory evaluation of the frozen tofu after thawing was 5 points after thawing. The tofu frozen in the -70 ° C freezer was evaluated with a frozen quality of 2.5 points, and the tofu frozen in the -18 ° C freezer was evaluated with a frozen quality of about 1 point.

  Such a result shows that in the case of the vacuum freezing method, heat is instantaneously taken away from the moisture in the tofu while the water is vaporized, so the ice growth rate (ice growth rate) compared to the freezing method stored in the existing freezer. rate) is remarkably fast, and it is judged that there is relatively little protein modification in the tofu.

Comparative Test Example 3-2
Measurement of physical properties before and after drying of starch saponified tofu and starch saponified tofu

Oboro tofu is manufactured by the manufacturing method of Example 1 described above, but in the four stages of Example 1 as in Comparative Test Example 2-1, the temperature of the center of Oboro Tofu is different in order at 6 locations. Sampling and measuring the physical properties of each sample under the same conditions as in Test Example 2 above, and after preparing the above six samples by the method of Example 2, dry rag tofu was added to the sample. The rag tofu that was put in and restored and the physical properties of each were measured under the same conditions as in Test Example 2. The measured values are as shown in Table 3 below.

  As shown in Table 3 above, starch is added, but the temperature of the center of tofu is not heated to a temperature equal to or higher than the gelatinization temperature of starch (especially in the case of the fifth sample), It was confirmed that before and after drying, all of the physical properties were similar to those of the starch-free borotofu tested in the control group.

  In the case of the sixth sample heated at a temperature higher than the gelatinization temperature of starch, it is the hardest (hardness) and most chewy (gum and chewing properties), not only before drying, but also with rag tofu restored after drying. ) Was confirmed, and it was confirmed that it was produced as an otofu tofu having higher quality properties.

Comparative Test Example 3-3
Comparison of physical properties after reconstitution of dried rag tofu made by adding tapioca-modified starch and dried rag tofu made by adding other starches, gums, sugars and enzymes

  Physical properties of garlic tofu produced by adding the tapioca-modified starch and the above-mentioned production method of Example 1 and Example 2, and taro tofu produced by adding other starches, gums, sugars and enzymes, respectively. Compared. As other starches, long powder was used, curdlan and cellulose gum were used as gums, trehalose, sorbitol, maltodextrin and polydextrose were used as sugars, and transglutaminase (TG) was used as enzymes. In addition, hydroxypropylmethylcellulose used as a food additive was used, and dried rag tofu was produced by the production method of Example 1 and Example 2 using soymilk SD powder and hyaluronic acid. The texture of the tofu after restoration and the physical properties of the cracks were evaluated on the basis of a maximum of 5 points for each of the produced dry rag tofu.

The comparison and evaluation of the above physical properties are shown in Table 4, FIG. 7 and FIG.

  Comparing the physical properties of each tofu, the tofu produced using tapioca-modified starch was evaluated as the highest score of bean corrosion near 5 points. For tofu cracks, the tofu made with curdlan received the highest score, but when curdlan was used, there was a problem that the texture of tofu dropped significantly. It was evaluated as not suitable for use.

  As a result of comprehensive comparison of appearance and texture, tofu using tapioca-modified starch was evaluated as the best.

Comparative Test Example 3-4
Comparison of physical properties of dried taro tofu according to the type of coagulant used in taro tofu with added starch

  Although it was manufactured by the same manufacturing method as in Example 1 and Example 2, dried rag tofu was manufactured using different types of coagulants and the physical properties were compared. Specifically, by the production method of Example 1, tapioca modified starch (HT2X, 'Abebe' company product) 5 kg of soymilk, each of which was prepared using 1 kg of calcium sulfate as a coagulant and 1 kg of GDL. The rag tofu produced by drying was dried according to the method of Example 2 and the physical properties of the dried boro tofu were compared. Then, the physical properties of the boro tofu restored by pouring water were compared again. The comparison results are shown in FIG.

In the above comparison, the size of the rag tofu was 1 cm in width, length, and height, and 3 cm and 5 cm in height, and the difference in physical properties depending on the size of the rag tofu was also compared at the same time.
As shown in Fig. 9, when GDL is used as a coagulant, first the tofu becomes slightly sour due to the acidity from the GDL itself, it is not functionally good, the pH is lowered and the functional group of starch is degraded. As a result, the gelatinization effect of starch was offset, and it was confirmed that a texture that was crushed after restoration and that many internal cracks occurred.

Sensory comparison test
Sensory comparison of existing dried rag tofu and dried rag tofu produced by the production method of Example 1 and Example 2

  Obtained commercially available dried rag tofu (Donim food chodan rag tofu product) and the sensory function after restoration of the dried rag tofu produced by the production method of Example 1 and Example 2 of the present specification. A comparative test was performed.

  Donnim food chodan boro tofu products are manufactured in an existing manner, i.e. manufactured by a manufacturing method that does not include a step of inducing the gelatinization reaction of starch and dried in an existing manner, i.e. pre-frozen (or frozen). It is a dried rag tofu that has been freeze-dried by a method of freeze-drying the rag tofu that has been cooled to the previous state.

  The sensory test was conducted for 50 housewives aged 25-49 years old by instantly producing and tasting instant cup rag tofu chige in the form of a finished product of dry rag tofu. In the case of the above-mentioned donnim food chodan rag tofu, it is composed of dried tofu, ingredient soup and liquid soup and is marketed, hot water is poured into this to conduct a sensory test, and Example 1 and In the case of the dried boro tofu produced by the production method of Example 2, the dried tofu was poured with tangy tofu chige condiment (Dadam Co., Ltd.) and hot water was poured into it to conduct a sensory test.

The sensory test results are shown in Table 5 below. The score was evaluated based on a maximum of 5 points.

  As a result of the sensory test, the evaluation of the dried rag tofu produced by the production method of Example 1 and Example 2 of the present specification was highly evaluated in all items. In particular, the dry rag tofu produced by the production method of Example 1 and Example 2 of the present specification received a high sensory evaluation with the degree of preference for tofu corrosion and the degree of preference for tofu softness. From this, when producing the dried rag tofu produced by the production method of Example 1 and Example 2 of the present specification, it is closer to the texture of the original before drying than the existing method, and excellent It was confirmed that a product having a texture could be produced.

Example 3
Method for producing starch dispersion

  In the production of tofu, starch and an antioxidant were added to soy milk. In order to disperse starch uniformly in soy milk, it was produced as a starch dispersion.

  Dissolve 5 kg of tapioca-modified starch (HT2X, 'Abebe') in 24 kg of distilled water, and thoroughly homogenize 1 kg of antioxidant (SD-20, 'Yeon Chemical') with a homomixer (homomixer) for 10 minutes. To produce a starch dispersion.

  When the above starch dispersion was put into soy milk and stirred, not only the stirring time was shortened, but also starch was uniformly dispersed in soy milk, and it was confirmed that tofu with uniform physical properties was obtained.

Comparative test example 4
Comparison of dispersion degree when starch is directly added to soy milk and stirred using starch dispersion

  In the step of adding starch to soy milk and stirring, the following experimental conditions were used to compare the degree of starch dispersion in soy milk when starch was added directly and stirred using the starch dispersion. A comparative test was conducted.

  After putting 470 g of commercially available 10brix soy milk in two beakers, add 30 g of starch dispersion (5 g tapioca modified starch + 25 g of diluted water) to one beaker in the same manner as in Example 3. Specifically, 500 g of the soymilk mixture was combined with 9.5 brix and 1% by weight of starch. In another beaker, add 5g tapioca modified starch and 25g diluted water directly to the soy milk. Similarly, adjust the final soymilk mixture 500g to 9.5 brix and starch to 1% by weight, and then use a stirrer for each. Then, it was carried out by stirring for 10 minutes at a rotation speed of 100 rpm.

  The comparison of the degree of starch dispersion in soy milk in each case is reflected when the light is transmitted to both beakers using a Turbiscan LAB (Leanontech's product) device. The degree (Backscattering) was measured to measure the position, size and degree of insoluble particles in the liquid. The reflected light and transmitted light were measured with a total of 60 minutes skewed at intervals of 2 minutes.

FIG. 10 shows a comparison between a photograph in which the starch dispersion was added to soy milk and a photograph in which the starch was directly added.
The results of Backscattering measured using a Turbiscan LAB instrument are shown in FIG. The result of enlarging and comparing FIG. 11 is shown in FIG.

  As shown in FIG. 10, in the case of soymilk to which a starch dispersion is added, a starch precipitation layer is formed on the bottom of the lower part of the beaker (about 2 mm from the bottom of the beaker), and the soymilk to which starch is added directly is formed. In this case, it was confirmed that a starch precipitation layer was formed at a height of about 8 mm from the bottom of the beaker. This means that when the starch is added directly, the size of the starch particles in the soymilk is much larger.

  Looking at Backscattering results measured using a Turbiscan LAB instrument, as shown in Fig. 11, in the case of soy milk with added starch dispersion (Fig. 11, upper graph), a point about 2 mm from the bottom of the beaker. In the case of soymilk with added starch directly (Fig. 11, lower graph), Backscattering was high at a point about 8mm from the bottom of the beaker. I understand. This means that, as described above, when starch is added directly, starch cannot be uniformly dispersed in soy milk, and the starch particles are solidified and formed with a larger size. is there.

  Looking at FIG. 12 in which the above FIG. 11 is enlarged and compared, when starch dispersion is added (FIG. 12, upper graph), about 18 minutes have passed since scanning using the Turbiscan LAB instrument. After that, the Backscattering price markedly formed a peak in the lower part of the beaker and began to show different measured values, but when starch was added directly (Figure 12, lower graph), the peak was observed at about 10 minutes after scanning. Began to form. This means that when the starch is added directly, the dispersion of the starch in the soymilk is not uniform and the starch particles remain large, and the precipitation rate of the starch particles is faster than when the starch dispersion is added.

  Therefore, taking the above results together, it can be confirmed that the starch dispersion added to the soymilk and stirred more uniformly in the soymilk with the starch particles being smaller than when the starch is added directly. It was.

Claims (11)

Producing soymilk from beans;
A primary heating step of heating the soy milk in a heating tank;
A step of adding starch and a coagulant to the primary heated soy milk and stirring to produce a soy milk mixed solution; and a secondary heating step of heating the stirred soy milk mixed solution. In the method
The method for producing rag tofu, wherein the secondary heating step is a heating step in which the starch is gelatinized by heating at a temperature equal to or higher than the gelatinization temperature of the starch.   2. The method for producing rag tofu according to claim 1, wherein the starch is a modified starch.   3. The method for producing a rag tofu according to claim 2, wherein the modified starch is a tapioca-modified starch.   The method for producing a tofu according to claim 1, wherein the starch content is 0.1 to 3% by weight based on the total weight of the soymilk mixture.   The rag tofu according to claim 1, wherein the coagulant is not glucono delta lactone (GDL).   6. The method for producing a rag tofu according to claim 5, wherein the coagulant is calcium sulfate.   The method of claim 1, wherein the starch is used in the form of a starch dispersion obtained by stirring the starch with dilution water and a homomixer.   4. The method for producing a rag tofu according to claim 3, wherein the second heating step is performed such that the product temperature of the rag tofu is 80 to 100 ° C.   9. The method for producing rag tofu according to claim 8, wherein in the secondary heating step, the heating tank is heated to a temperature of 80 to 100 ° C.   10. The method for producing a rag tofu according to claim 9, wherein the secondary heating step is performed for 40 minutes or more.   The rag tofu manufactured by the method of any one of Claims 1 thru | or 10.