KR20120124950A - A method containing starch gelatinization for manufacturing bean curd and the bean curd - Google Patents

Abstract

PURPOSE: A producing method of soft bean curd using the gelatinization reaction of starch, and the soft bean curd are provided to improve the firmness, the quality, and the elasticity of the soft bean curd. CONSTITUTION: A producing method of soft bean curd using the gelatinization reaction of starch comprises the following steps: producing soymilk using soybeans, and firstly heating the soymilk; inserting the starch and a coagulating agent into the soymilk, and stirring the mixture; and secondly heating the mixture at the temperature greater than the gelatinization temperature of the starch. The starch is modified tapioca starch. 0.1-3wt% of starch is mixed with the total amount of soymilk mixture. [Reference numerals] (AA) Surface temperature; (BB) Central temperature; (CC) Heating bath; (DD) Cooling; (EE) At 5:15 p.m.; (FF) At 5:30 p.m.; (GG) At 5:45 p.m.; (HH) At 6:00 p.m.; (II) At 6:15 p.m.; (JJ) At 6:30 p.m.; (KK) At 6:45 p.m.; (LL) At 7:00 p.m.; (MM) At 7:15 p.m.; (NN) At 7:30 p.m.

Description

A method containing starch gelatinization for manufacturing bean curd and the bean curd}

The present invention relates to a method for producing soft tofu, and a method for preparing soft tofu, and a method for producing soft tofu including a step of adding starch to soymilk and a heating step of gelatinizing starch.

Tofu is a food rich in minerals and protein, including calcium, and is frequently eaten in a variety of dishes due to its light taste and soft texture. However, tofu is rich in moisture and nutrients, and not only is prone to decay, but also has a disadvantage in that storage and distribution are difficult because the strength of tissues is reduced. Therefore, a method of drying the tofu has been proposed as a method for solving the storage and portability of the tofu at the same time.

As a technique related to the method of drying tofu, Korean Tofu No. 2000-53766 dry tofu and a method of manufacturing the same, a method of drying the tofu for 18 to 20 hours at a temperature of 60 ℃ after depressurizing the tofu in a vacuum dryer The method for drying the tofu has been proposed, and the tofu is placed in a freezer and subjected to pre-cooling for about 1 hour until immediately before freezing, that is, until a freezing phase occurs on the surface of the tofu. Put the dried tofu in a vacuum freeze dryer and depressurize it so that the temperature of the tofu reaches 40 ° C., and then vacuum freeze the step, which is not only cumbersome and complicated, but also takes a long time and denatures the protein. The taste and aroma of tofu are deformed so that the taste of fresh tofu cannot be fully restored when the tofu is restored. Since tissue is destroyed there is a limit not to revive the texture of tofu.

An object of the present invention is to provide a method of drying a tofu that can restore the taste and texture of the state before drying by providing a method of vacuum freezing the tofu to minimize the denaturation of protein in the tofu without preliminary freezing process. do.

In addition, the present invention provides a method for producing a soft tofu comprising the step of adding starch to soy milk and heating the starch in the production of soft tofu, compared to conventional soft tofu in the physical properties such as hardness of the tofu An object of the present invention is to provide a high-quality soft tofu and a method for producing the same, which have high strength and elasticity.

In addition, an object of the present invention is to provide a stirring method for uniformly dispersing starch in soy milk by using starch in the form of a starch dispersion liquid during the step of stirring the soymilk and starch during the manufacturing process of tofu.

In addition, the present invention provides a method for producing a dried tofu suitable for adding dried starch and gelatinizing it to dry dried tofu in the production of tofu and vacuum freeze-drying such dried tofu to prepare a dried tofu. The purpose.

According to one embodiment of the present invention, there is provided a method for producing soft tofu comprising the steps of adding starch to soymilk and heating the starch in a method for producing soft tofu.

According to one embodiment of the present invention, the starch added to the soft tofu undergoes a gelatinization reaction during the manufacturing process of the tofu, resulting in higher strength and elasticity than the conventional soft tofu in physical properties such as hardness of the tofu. Is provided.

According to one embodiment of the present invention, a method of stirring soymilk and starch in the manufacturing process of tofu provides a stirring method for uniformly dispersing starch in soymilk by using starch in the form of a starch dispersion.

According to an embodiment of the present invention, in the method of drying the tofu to provide a method for drying the tofu to provide a method of vacuum freeze drying the tofu without preliminary freezing process to restore the taste and texture of the state before drying as it is .

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

Specifically, the present invention relates to a method for manufacturing a dry soybean curd that is different from the conventional method and a method for drying the same, so that the dry soybean soup has a texture similar to that of the original after restoration.

The present invention is a manufacturing process of soy milk, a step of adding dilution water, modified starch, antioxidant and coagulant to soy milk, and then stirring it, packaging the soy milk mixture in a soft tofu pouch, heating the packaged soft tofu, solidified soft tofu It may include a step of cooling the cooled tofu tofu, a step of freezing the cut tofu vacuum freezing process and a freeze drying process of the frozen tofu.

The present invention is a soft tofu which has higher quality in physical properties such as hardness of tofu, which is not only excellent for use as a dry tofu for producing dried tofu, but also has its own texture even if it is not produced as dry tofu. In order to provide excellent soft tofu, during the tofu manufacturing process, the step of adding starch to the soy milk and gelatinizing it. The starch is preferably a modified starch, for example, a modified starch such as tapioca modified starch, rice modified starch, sweet potato modified starch, potato modified starch, corn modified starch, more preferably using a tapioca modified starch. The starch is preferably added to 0.1 to 3% by weight, more preferably 1% by weight based on the total weight of the soy milk mixture.

When the starch is mixed with soymilk, the starch and the dilution water are firstly stirred in a starch dispersion form using a known homomixer in order to uniformly disperse the starch in the soymilk, and then it is soaked with soymilk. It is preferred to put it in a tank and proceed with the second stirring step. In the first stirring step, an antioxidant may be additionally added and stirred.

In the coagulant added to the second stirred soymilk mixture, it is preferable not to use a glutono deltalactone which decomposes the functional groups of the starch and hinders the action of the starch, more preferably a mixed coagulant and magnesium chloride containing no GDL. It is preferable to use prepared coagulant as a coagulant, and most preferably to use calcium sulfate as a coagulant.

In heating the secondary stirred soymilk mixture, it is preferable to induce a gelatinization reaction of starch by heating to a temperature above the gelatinization temperature of the starch added to the soymilk. In one embodiment of the present specification, when the starch added to the soy milk is tapioca modified starch, considering that the gelatinization temperature is 70 ~ 75 ℃, so that the product temperature of tofu is about 80 ~ 100 ℃ or more, preferably 83 The temperature of the heating bath is heated to about 80 to 100 ° C, preferably at least 86 ° C, preferably at least 40 minutes, more preferably at least 1 hour, so that the starch is gelatinized so as to be at least C. It is preferable to make the said heating process into hot water treatment.

The composition of the soft tofu prepared by the above method is preferably 9 to 12 brix soy milk, more preferably 10.5 brix soy milk, preferably 0.1 to 3 wt%, more preferably starch based on the total weight of the soy milk. May comprise 1% by weight, preferably 0.1 to 1% by weight, more preferably 0.3% by weight, and additionally 0.01 to 1% by weight, more preferably 0.15% by weight of an antioxidant It can be included as.

The soft tofu prepared by the above method provides a harder, more firm texture of the tofu in the physical properties of the tofu, such as hardness, gumminess, chewiness, and the like of the conventional tofu.

Specifically, as in one embodiment (Comparative Test Examples 2-1, 3-2) of the present specification, the soft tofu prepared according to the above-described manufacturing method was subjected to physical property analyzer (Texture Analyzer-Model: TA-XT) under the following conditions. Plus, 'MHK Corporation') can measure the properties of soft tofu.

Probe: cylindrical shape 2 cm in diameter;

Pre-test speed at which the probe descends to sample: 1.00 mm / sec;

Test speed of penetration of the probe into the sample after it reached the sample surface: 5.00 mm / sec;

Post-test speed at which the probe has penetrated the sample (post-test speed): 5.00 mm / sec;

Target mode of the probe: distance;

A distance at which the probe recognizes the surface of the sample and penetrates the sample: 5.000 mm;

A trigger type for the probe to recognize the sample: force; And

Minimum trigger force for the probe to recognize the presence of the sample: 5.0 g

As a result of measuring the physical properties of the soft tofu, the hardness was 120 ~ 160g, and it was harder when compared with the control group (without starch or starch added but no gelatinization reaction) showing a distribution of 30 ~ 100g. It was confirmed that elastic properties were shown (see Tables 2 and 3).

The tofu used in the manufacturing method of the following dried tofu of this invention is not specifically limited, A well-known tofu may be used. That is, when it is made to dry by the manufacturing method of the dried tofu of this invention using the well-known known tofu which is commercially available, the dried soft tofu which is excellent in quality compared with the conventional method of manufacturing the dry tofu can be obtained. However, in order to obtain the soft tofu which is almost the texture of the raw material after restoration, in the best quality, it is more preferable to use the soft tofu prepared by the above method as the dry tofu.

In the method of manufacturing a dried soybean curd according to the present invention, the prepared soybean curd is put into a device used for freezing and drying in a state of being only cooled without preliminary freezing. The freezing process of the tofu tofu is a vacuum freezing process performed under reduced pressure, and in one embodiment of the present specification, the passage time when the vacuum degree drops from 4 tor to 2.5 torr (absolute pressure) is preferably within 30 minutes, more preferably. The rapid vacuum freezing is adjusted to within 15 minutes. As a result, when the product temperature of the soft tofu is lowered from 0 to -5 ° C, the transit time is preferably within 30 minutes, more preferably within 15 minutes, thereby minimizing protein denaturation in the tofu, thereby obtaining high-quality soft tofu. In other words, by the vacuum freezing method, the ice growth rate is remarkably faster than the freezing method stored in the conventional freezer (-18 ° C.-70 ° C.), thereby minimizing protein denaturation in the tofu. It becomes possible.

In the freeze-drying process of the soft tofu after the vacuum freezing process, in one embodiment of the present specification, preferably in the range of vacuum degree 2.5torr to 0.5torr (absolute pressure), q more preferably in the range of vacuum degree 1.5torr to 0.5torr The product temperature of the tofu is preferably 40 ° C, more preferably while the drying is performed and the temperature of the hot plate in the apparatus used for the lyophilization is preferably 10 to 80 ° C, more preferably 20 to 75 ° C. Do not exceed 35 ° C to minimize denaturation of protein in the tofu.

After completing the drying process, the tofu is preferably vacuum packaged and distributed for preservation of quality.

The dried soft tofu prepared by the above drying process is closer to the texture of the raw material before drying in the physical properties of the tofu such as firmness, guminess and chewiness of the tofu after restoration as compared to the conventional general dry tofu. It is more firm and provides a soft tofu with excellent texture. Specifically, after restoring the dried tofu prepared according to the above-described manufacturing method as in one embodiment of the present specification (Comparative Test Example 3-2), the physical properties of the tofu prepared by the method of preparing the tofu of the present application were measured. As a result of measuring the properties of the soft tofu which was restored after drying under the same conditions as the same, the control group showed a distribution of 50 to 90 g of solidity and a distribution of 30 to 50 g (without starch or starch added but no gelatinization reaction occurred) When compared with), it was confirmed that the harder and more elastic physical properties (see Table 3).

The present invention has the advantage of providing a method of drying the tofu to provide a method for vacuum freeze-drying the tofu without preliminary freezing process to restore the taste and texture of the state before drying.

The present invention provides a method for producing a soft tofu comprising the steps of adding starch to soy milk and heating the starch to produce a soft tofu, so that the tofu having higher quality in physical properties such as hardness of the tofu and There is an advantage to providing a method of preparation thereof.

The present invention has an advantage of providing a stirring method for uniformly dispersing starch in soy milk by using starch in the form of a starch dispersion during the step of stirring the soymilk and starch during the manufacturing process of tofu.

The present invention has the advantage of providing a method for producing a dry tofu suitable for making starch by adding starch in the preparation of tofu, and drying it to dry, and a method for producing a dry tofu by vacuum freeze-drying such dry tofu .

Specifically, the present invention is superior to use as a soft tofu for the production of dry tofu as a soft tofu having higher quality in physical properties such as hardness of the tofu, and of course, even if it is not manufactured as dry tofu In order to provide a soft tofu with an excellent texture, during the manufacturing process of the tofu, the step of adding starch to soy milk and gelatinizing it. By adding starch and heating soymilk at the temperature condition to induce its gelatinization reaction, it improves the softness of the soft tofu and provides a more firm texture. To prepare dried tofu using this, the firm texture lost after drying It provides dry soft tofu with excellent physical properties after restoration, which helps to save sponge texture after drying.

Starch added in the above process is preferably modified starch, more preferably tapioca modified starch to maximize the effect of the starch. In addition, 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, so that cracking and bursting of the tofu by the vacuum freeze-drying process during the manufacturing of the dried tofu is performed. Can be prevented.

When the starch is mixed with soymilk, the starch and the dilution water are firstly stirred in a starch dispersion form using a known homomixer in order to uniformly disperse the starch in the soymilk, and then it is soaked with soymilk. It is preferred to put it in a tank and proceed with the second stirring step. In the first stirring step, preferably, an antioxidant, for example, vitamin E, vitamin C, tocopherol, green tea extract, rosemary extract, and the like may be further added and stirred, and when the antioxidant is further added and stirred, It prevents fat rancidity in the head and provides the effect of extending the head's shelf life relatively long. When starch is directly added to soymilk, the starch is unevenly dispersed in soymilk and the grain size of the starch increases, which adversely affects the extension of the stirring time and the tofu properties, resulting in a difference in the quality of the tofu. When using the first stirred starch dispersion as described above, the stirring time of the soymilk and starch dispersion is shortened, there is an advantage that can be obtained tofu of uniform properties.

In the coagulant added to the second stirred soymilk mixture, gluconodeltalactone (GDL) is preferably not used because it decomposes the functional groups of starch and interferes with the action of starch, and more preferably calcium sulfate is used as a coagulant. Is suitable.

The soft tofu prepared by the above method provides a harder, more firm texture of the tofu in the physical properties of the tofu, such as hardness, gumminess, chewiness, and the like of the conventional tofu.

In the manufacturing method which produces a dry tofu, Preferably, the tofu produced by the said method is used as a drying tofu. The present invention has the advantage of providing a method for producing dried tofu to prevent the deterioration of texture by preventing the denaturation of the protein in the tofu caused by the preliminary freezing step, in the manufacturing of dried tofu. In addition, the freezing process of the soft tofu is a vacuum freezing process performed under reduced pressure, in one embodiment of the present specification, the passage time when the vacuum degree is lowered from 4 tor to 2.5 tor (absolute pressure) is preferably within 30 minutes, more preferably Preferably, by adjusting the temperature to within 15 minutes and rapid vacuum freezing, the passage time when the temperature of the soft tofu falls from 0 to -5 ° C is preferably within 30 minutes, more preferably within 15 minutes, It provides a method for obtaining high quality tofu by minimizing protein denaturation. In other words, by the vacuum freezing method, the ice growth rate is remarkably faster than the freezing method stored in the conventional freezer (-18 ° C.-70 ° C.), thereby minimizing protein denaturation in the tofu. It becomes possible.

Furthermore, in the freeze-drying step of the tofu tofu after the vacuum freezing step, the present invention, in one embodiment of the present specification, preferably proceeds with drying in the range of vacuum degree 1.5torr to 0.5torr (absolute pressure), and the freeze-drying The temperature of the hot plate is preferably 10 to 80 ° C, more preferably 20 to 75 ° C, while the product temperature of the soft tofu is preferably not higher than 40 ° C, more preferably 35 ° C. There is an advantage to minimize denaturation of the protein.

The dried soft tofu prepared by the above drying process is closer to the texture of the raw material before drying in the physical properties of the tofu such as firmness, guminess and chewiness of the tofu after restoration as compared to the conventional general dry tofu. And, it is more firm and has the advantage of providing a soft tofu excellent texture.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a graph measuring the temperature change of the surface and the center of the tofu which occurs when the tofu to which tapioca modified starch is added is heated to a temperature higher than the gelatinization temperature of the tapioca modified starch.
FIG. 2 is a graph measuring the temperature change of the surface and the center of the tofu during the boiling treatment of the conventional general tofu which does not undergo starch gelatinization in the heating step of the tofu in the tofu production method.
Figure 3 is a photograph showing the difference in physical properties of the tofu in accordance with the temperature of the center of the tofu during the boiling water treatment of the tofu in the method of manufacturing starch tofu added starch.
4 is a photograph showing the difference in physical properties of the tofu in accordance with the temperature of the center of the tofu during the boiling water treatment of the tofu in the method of manufacturing a tofu with starch, together with FIG. 3.
Figure 5 is a photograph showing the difference in the physical properties of the tofu according to the type of coagulant used in the tofu added starch.
Figure 6 is a photograph showing the difference in freezing quality of the frozen tofu and frozen in the conventional way tofu frozen in the freezer.
7 and 8 are graphs showing the difference in physical properties after restoration of dried tofu prepared by adding tapioca modified starch and dried starch prepared by adding other starches, gums, sugars and enzymes, respectively.
9 is a photograph showing the difference in physical properties of dried tofu according to the type of coagulant used in the tofu to which starch is added.
10 is a photograph showing the difference between the case where the starch is added to the soymilk in the form of a starch dispersion and stirred, and the case where the starch is directly added and stirred.
11 and 12 are graphs showing the difference between the backscattering degree of soymilk stirred by adding starch and starch in the form of starch dispersion in the process of adding starch to soymilk and immediately stirring the starch.

Hereinafter, the present invention will be described 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 content of the present invention is not limited thereto.

Example

Example 1

Manufacturing method (purifying method of dry tofu for drying) which undergoes gelatinization reaction of starch

(1) Step 1: Soymilk Manufacturing Process

After removing the foreign matter by washing the received soybeans, distilled water was added to the washed soybeans and soaked for 12 hours at room temperature. Distilled water was added to the soaked soybeans again, and the blend was pulverized with a blender so that the brix of soy milk was 11 brix.

The pulverized soybean was filtered through a filter to separate the soy and soy milk, and then the separated soy milk was heated and sterilized for 20 minutes while gradually increasing the temperature from 100 ° C to 105 ° C. The heat treated final soymilk was adjusted to 10.5 brix, and the soymilk was cooled to 10 ° C or lower.

(2) step 2: adding dilution water, modified starch, antioxidant and coagulant to soymilk, followed by stirring

476 kg of the cooled soymilk was charged from the bottom of the stirring tank so as not to produce a bubble. Dissolve starch dispersion by dissolving 5 kg of tapioca modified starch (HT2X, manufactured by Abebe) in 24 kg of distilled water, and homogenizing 1 kg of antioxidant (SD-20, Tocopherol MIX, manufactured by Deferred Chemical) for 10 minutes with a homomixer. Made with.

The starch dispersion was placed in a stirring tank containing 476 kg of the 10.5brix soymilk and sufficiently stirred for 10 minutes. As a coagulant, 1.45 kg of calcium sulfate was well dissolved in 7.25 kg of distilled water, placed in the stirring tank, and stirred with the soymilk mixture.

(3) Step 3: Packaging Soymilk Mixture in Soft Tofu Pouch

508.7 kg of the soymilk mixture solution added with the coagulant was added to the 1 kg soft tofu pouch while stirring and packed.

(4) Step 4: heating the packaged tofu

The packaged soft tofu was heated in a hot water bath set at 86 ° C. for 1 hour to coagulate so that the temperature of the center of the soft tofu was 83 ° C. or more.

(5) step 5: cooling the solidified tofu

The solidified tofu was cooled for 5 hours in a cold water of 5 ° C so that the center temperature of the tofu is 10 ° C or less and then refrigerated.

It was confirmed that the tofu prepared by the above method exhibits the physical properties of Test Example 2 below.

Test Example 1

Temperature change of the surface and central part of soft tofu heated to a temperature higher than the gelatinization temperature of starch added to soymilk

The soft tofu with the addition of tapioca modified starch (HT2X, manufactured by Abebe) is considered to have a sufficient gelatinization process up to the center of the tofu, taking into account that the denatured temperature of the modified starch is 70 to 75 ° C. Hot water treatment was performed for 60 minutes in the 86 degreeC hot water bath so that the temperature (product temperature) may be 80 degreeC or more. The temperature change of the surface and center part of a tofu head at this time is shown in FIG.

In the case of soft tofu heated to a temperature higher than the gelatinization temperature of the tapioca modified starch through the graph of FIG. 1, as a result of the gelatinization process of the starch, the temperature of the center increases relatively slowly during heating, and the temperature of the center rapidly increases after heating. We could confirm the descent. When the hot water bath was heated at 86 ℃ for 30 minutes, the central temperature did not reach 60 ℃ and the tapioca-modified starch was not enough to be gelatinized. When heated for about 1 hour, the center temperature exceeded 80 ℃. Gelatinization reaction of starch became possible.

Comparative Test Example 1

Temperature Changes at the Surface and Core of Conventional Soft Tofu without Starch

The conventional general tofu with no added starch (clear soy tofu, manufactured by 'Clear Water') was obtained, and the temperature change of the surface and the center of the tofu during hot water treatment of the tofu was measured.

Referring to FIG. 2, which shows the measurement results, it was confirmed that the temperature of the center of the tofu head increased relatively sharply during heating, and that the temperature of the center gradually decreased after heating.

Test Example 2

Example  Measurement of physical properties of soft tofu prepared by 1

After preparing tofu according to the manufacturing method of Example 1, the physical properties of the tofu were measured using a physical property analyzer (Texture Analyzer-Model: TA-XT Plus, manufactured by MHK Corporation). Physical properties were measured under the following conditions.

Probe: cylindrical shape 2 cm in diameter;

Pre-test speed at which the probe descends to sample: 1.00 mm / sec;

Test speed of penetration of the probe into the sample after it reached the sample surface: 5.00 mm / sec;

Post-test speed at which the probe has penetrated the sample (post-test speed): 5.00 mm / sec;

Target mode of the probe: distance;

A distance at which the probe recognizes the surface of the sample and penetrates the sample: 5.000 mm;

A trigger type for the probe to recognize the sample: force; And

The trigger force for the probe to recognize the presence of the sample: a condition set to 5.0 g.

Under the above conditions, the physical properties of the tofu prepared by the manufacturing method of Example 1 are as shown in Table 1 below.

Center temperature
(℃) Firmness
(Hardness (g)) Stickiness
(Adhesiveness (gs)) Cohesive
(Cohesiveness) Sword
(Gumminess) Chewiness
(Chewiness) This quantity (%) 83.22 128.04 0.97 0.85 76.58 73.52 7.01

In Table 1, the hardness indicates the force required for the sample to reach the desired deformation, and the tackiness indicates the force required for the probe to penetrate the sample and then separate again. Bury. Cohesiveness is a force that tries to maintain the shape of an object, and if it is larger than sticky, no sample will appear on the probe. Probability is the property of making a semisolid sample unswallowable and is calculated by the product of firmness and cohesiveness. Chewability is the property of making a sample in a solid state swallowable.

Comparative Test Example 2-1

Measurement of Properties of Soft Tofu without Starch Gelatinization

The composition of the tofu is the same as that of Example 1, but in order to find out the properties of the tofu which is not subjected to gelatinization of starch in the fourth step of Example 1, the six time points at which the temperature of the center of the tofu is different in the fourth step of Example 1 Sampling was carried out in order to measure the physical properties of each sample under the same conditions as in Test Example 2. The measured value thereof is shown in Table 2 below together with the data of Test Example 2.

Center temperature
(℃) Firmness
(Hardness (g)) Stickiness
(Adhesiveness (gs)) Cohesive
(Cohesiveness) Sword
(Gumminess) Chewiness
(Chewiness) Completion
(%) Primary 47.57 25.96 0.88 0.55 14.5 12.76 18.02 Secondary 51.28 26.51 0.905 0.56 14.97 13.54 20.58 Third 55.82 33.69 0.91 0.56 18.95 17.25 11.10 4th 64.9 53.46 0.945 0.69 37.04 35 9.44 5th 74.3 62.85 0.96 0.77 48.39 46.45 7.49 6th 83.22 128.04 0.97 0.85 76.58 73.52 7.01 Correlation coefficient 0.93 0.97 0.99 0.99 0.98 0.87

Considering that the gelatinization temperature of tapioca starch, which is the starch added to the tofu tofu, is 70 to 75 ° C, sufficient gelatinization reaction of the starch may occur when the temperature of the center of the tofu is about 80 ° C or higher. Only the sixth sample, with a central temperature of 83.22 ° C, is a soft tofu that has undergone gelatinization of starch.

Looking at Table 2, it can be seen that the physical properties of the prepared tofu has a significant correlation with the starch gelatinization, in particular, the hardness, cohesiveness, gumminess and chewiness of the soft tofu showed a great correlation.

In addition, the amount of completion is to measure the amount of water coming out of the tofu during the same time after the production of tofu cut into a uniform size divided by the initial weight expressed as a percentage, the overall degree of completion is reduced depending on the degree of luxury of the core It was confirmed. It is believed that this resulted in reducing the amount of water required by starch becoming gelatinous and holding water present in the tofu.

In other words, the starch added to the soft tofu causes a gelatinization reaction, which makes it harder and more elastic than the soft tofu prepared without undergoing the gelatinization reaction. , It was confirmed that it is made of high quality soft tofu.

3 and 4 show photographs of the first and sixth samples during and after measurement of physical properties.

Comparative Test Example 2-2

Comparison of Properties of Soft Tofu according to the Types of Coagulants Used for Starch-Added Soft Tofu

After the same manufacturing method as in Example 1, but by varying the type of coagulant used to prepare a tofu and compared the properties of each. Specifically, 8: 2: 4 pure tofu prepared using calcium sulfate 1kg as a coagulant, calcium sulfate, magnesium chloride and GDL in soymilk added with 5 kg of tapioca modified starch (HT2X, manufactured by Abbe) The physical properties of soft tofu prepared using 1 kg of mixed coagulant mixed at a ratio of were compared. The test results thereof are shown in FIG. 5.

As a result of the test, the tofu using calcium sulfate as a coagulant was prepared as the tofu having the physical properties of Test Example 2, but the tofu using the complex coagulant did not contain starch or starch was added in step 4 of Example 1 Like soft tofu that has not been heated to temperatures above the gelatinization temperature, soft tofu with properties similar to those of conventional soft tofu has been produced. More specifically, the soft tofu using calcium sulfate is significantly less diuretic, the firmness of the tofu is visible from the outside, the strength is stronger than the conventional tofu, and the texture is softer. The soft tofu using was a lot of yellowish water, and it had a soft texture and weak strength similar to that of normal soft tofu without starch. The appearance of such physical properties in soft tofu using a complex coagulant was judged to be a result of GDL contained in the coagulant, which lowers the pH and degrades the functional groups of starch added to the soymilk, thereby inhibiting the effect of starch.

Example 2

Drying of soft tofu by vacuum freeze drying method

With the soft tofu manufactured by the manufacturing method of Example 1, the drying process of the soft tofu was performed.

(1) Step 1: Cutting of Tofu

In Example 1, the chilled tofu stored in the pouch was peeled off from the pouch, and the first, second, and third cuts were cut through a cutter, and pretreatment was performed so that the width, length, and height of the soft tofu were about 5 cm or less.

(2) step 2: vacuum freezing process of the cut tofu

After cutting the tofu, divided into 4kg each pan into a drying pan and spread well to avoid overlapping tofu. Then, the product was put into a lyophilized tube while maintaining the temperature of the soft tofu at 10 ° C. or lower. In order to proceed with the vacuum freezing, the vacuum pump was operated so that the time of vacuum drop from 4torr to 2torr was less than 15 minutes, and the rapid freezing was performed to shorten the time when the product temperature of the tofu to fall from 0 ℃ to -5 ℃ as possible. It was.

(3) Step 3: freeze drying process of the soft frozen tofu

Freeze-drying was carried out in the range of vacuum 2torr ~ 0.5torr while adjusting the temperature of the hot plate to 10 ~ 75 ℃ based on -15 ℃ where the freezing was completed. After 30 hours, drying was completed, and the mixture was depansed and packed.

Comparative Test Example 3-1

Freezing Quality Comparison of Tofu Frozen in Vacuum Freeze and Traditionally Frozen Tofu

Tofu frozen by the two-stage vacuum freezing method of Example 2 and put into the freezer was tested to compare the freezing quality of the frozen tofu in the conventional manner.

A comparison of freezing quality is shown in FIG. 6.

In the case of vacuum frozen tofu, the protein was slightly denatured in several places with yellow staining, but the tofu frozen in the -70 ℃ freezer was generally yellowish and the frozen tofu in the -18 ℃ freezer was very yellow. In comparison, it was judged that only a small amount of protein denaturation occurred only in a very localized region, and that the degeneration was not so different from the original in texture after restoration. When comparing the quality of each frozen tofu when the raw tofu texture score was 5 out of 5, the sensory evaluation of sensory evaluation after thawing vacuum frozen tofu was 5 points, which was almost no difference from the original. Tofu frozen in a -70 ° C freezer was evaluated to have 2.5 points and tofu frozen in a -18 ° C freezer.

These results indicate that the vacuum freezing method rapidly removes heat from the water in the tofu as the water vaporizes, resulting in a significantly faster ice growth rate than the conventional freezing method stored in a freezer. It is judged to be due to relatively little degeneration of the protein in the head.

Comparative Test Example 3-2

Measurement of physical properties before and after drying starch tofu and starch tofu

The tofu was prepared by the manufacturing method of Example 1, but the sample was sequentially sampled at six different time points at different temperatures of the center of the tofu in Step 4 of Example 1 as in Comparative Test Example 2-1. The physical properties of each sample were measured under the same conditions as described above, and the six samples were prepared as dry tofu by the method of Example 2. Measured under the same conditions. Its measured value is shown in Table 3 below.

Primary Secondary Third 4th 5th 6th relation
Coefficient control
Starch free Center temperature
(℃) 27.72 30.51 35.44 46.87 59.97 83.12 Sample time (minutes) 12 14 17 24 34 60 0.98



Properties of Soft Tofu Before Drying Firmness
(Hardness (g)) 25.61 34.44 53.87 88.09 100.56 143.28 0.98 91.95 Stickiness
(Adhesiveness
(g · s)) 0.82 0.86 0.95 0.93 0.97 1.01 0.85 0.96 cohesion
(Cohesiveness) 0.61 0.61 0.79 0.79 0.85 0.83 0.76 0.83 Sword
(Gumminess) 15.63 21.16 42.50 69.24 85.66 118.41 0.98 76.58 Chewiness
(Chewiness) 12.82 18.30 40.58 64.74 83.51 120.19 0.99 73.52



Properties of Soft Tofu after Restoration Firmness
(Hardness (g)) 36.99 40.19 44.16 50.46 57.30 60.06 0.96 47.70 Stickiness
(Adhesiveness
(g · s)) 0.91 0.83 0.92 0.91 0.85 0.87 0.24 0.85 Cohesive
(Cohesiveness) 0.74 0.68 0.70 0.71 0.73 0.67 0.39 0.73 Sword
(Gumminess) 27.41 27.36 30.77 35.85 42.05 40.06 0.88 43.63 Chewiness
(Chewiness) 24.80 22.71 28.30 32.62 35.53 34.85 0.86 29.44

As shown in Table 3, in the case of soft tofu (in particular, in the case of the fifth sample) in which the starch was added but the heat of the center of the tofu was not heated to a temperature higher than the gelatinization temperature of the starch, the control group before and after drying It was confirmed that the same properties as the soft tofu of starch-free starch tested in the control).

In the case of the sixth sample heated to a temperature higher than the gelatinization temperature of the starch, it was confirmed that it showed the hardest (hardness) and the strongest texture (gum, chewability) not only before drying but also in the soft tofu which was restored after drying. It was confirmed that the tofu was prepared with.

Comparative Test Example 3-3

tapioca  Soft tofu prepared by adding modified starch, and other Starch , Galvanic, sugar and Enzymes  Comparison of Properties after Restoration of Dried Tofu Prepared by Addition

The physical properties of the soft tofu prepared by adding the tapioca-modified starch to the preparation method of Examples 1 and 2 and the other starches, gums, sugars and enzymes, respectively, were compared. For other starch, powder was used, curdlan and cellulose gum were used as gum, trehalose, sorbitol, maltodextrin, poly dextrose as sugar, and transglutaminase (TG) as enzyme. Used. In addition, hydroxy propyl methyl cellulose was used as a food additive, and dried soybean curd was prepared by the preparation method of Examples 1 and 2 using soymilk SD powder and hyaluronic acid. For each of the prepared dried tofu, the texture and cracking properties of the tofu after restoration were evaluated based on a perfect score of 5 points.

Comparison and evaluation of the physical properties are shown in Table 4, FIG. 7 and FIG.

Texture offshoot Tapioca Starch 4.9 4 Powder 2.5 3 Curdlan 3 4.5 Cellulose sword 4 One Trehalose 3 One Sorbitol 3 2 Maltodextrin 3.5 3 Poly dextrose 4 3 Transglutaminase (TG) 3.5 2 Hyaluronic acid One 2 Soymilk SD Powder 3 1.5 Hydroxy Proryl Methyl Cellulose (HPMC) 2 3

[Texture Index]

Comparing the properties of each soft tofu, the soft tofu prepared using tapioca modified starch was evaluated as the highest score of almost 5 points in the texture of tofu. In the splitting of the tofu, the tofu made using curdlan received the highest score, but the curdlan had a problem that the texture of the tofu was considerably inferior.

As a result of comparing the appearance preference and cut preference, the tofu using tapioca modified starch was evaluated as the best.

Comparative Test Example 3-4

Comparison of Properties of Dried Soft Tofu by Starch-Added Coagulants in Soft Tofu

Through the same manufacturing method as in Example 1 and Example 2, dry tofu was prepared by varying the type of coagulant used therein and the physical properties were compared. Specifically, according to the manufacturing method of Example 1, tofu soymilk added with 5 kg of tapioca modified starch (HT2X, product of 'Abebe') was prepared using pure tofu prepared using 1 kg of calcium sulfate as a coagulant, and 1 kg of GDL. One tofu was dried according to the method of Example 2 to compare the properties of dried tofu first, and then the properties of the tofu cured by pouring water were also compared. Comparative results are shown in FIG. 9.

In the comparison, the size of the soft tofu was prepared with the width, length, and height of 1 cm and 3 cm and 5 cm, and there was no difference in physical properties according to the size of the soft tofu.

As shown in FIG. 9, when GDL is used as a coagulant, the tofu is slightly soured by the sour taste originating from the GDL itself, so it is not sensually good, and the pH is lowered to decompose the functional group of the starch. Since the effect is canceled, it can be confirmed that not only gives a rich texture but also internal cracking after restoration.

Sensory comparison test

With conventional dry tofu Example  1 and Example  Sensory Comparison of Dried Tofu Prepared by the Manufacturing Method of 2

Commercially available dried tofu (Tonglim Foods tofu products per second) was obtained and a test was conducted to compare the sensory properties after restoration of dried tofu prepared by the production methods of Examples 1 and 2 above.

Donglim Food's pure tofu products per second are manufactured by conventional methods, i.e., by a manufacturing method that does not include the step of inducing a gelatinization reaction of starch, and dried by conventional methods, i.e. preliminary freezing (up to just before freezing). Freeze-dried dried tofu by the method of freeze-drying the soft tofu through.

The sensory test was conducted on 50 housewives aged 25-49 years, using instant cup soft tofu stew which is a finished product of dried soft tofu. In the case of the Dongrim food per second tofu is composed of dried tofu, dried soup and liquid soup, it was marketed, hot water was poured into the sensory test, prepared by the production method of Examples 1 and 2 of the present specification In the case of dried tofu which had been dried, the tofu stew sauce (made by 'Dadam') was added to the dried tofu, and hot water was poured to perform a sensory test.

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

Dongrim Foods Tofu Soft Tofu Soft tofu according to Example 1 and Example 3 Symbol of overall tofu 3.04 4.15 Symbol map of tofu appearance 2.88 4.04 Tofu size symbol 2.87 4.03 Tofu taste sign 3.21 4.04 Symbol of tofu texture 3.05 4.11 Symbol of tofu tenderness 2.80 4.29 Symbol of the flavor of the whole soup 3.14 3.71 Symbol of soup taste 2.98 3.61 Symbol of overall stew 3.15 3.92 Exterior sign of stew 2.86 4.00

As a result of the sensory test, evaluation of the dried tofu produced by the manufacturing method of the said Example 1 and Example 2 of this specification showed higher in all the items. In particular, in view of the high degree of sensory evaluation of the dried soft tofu prepared by the manufacturing method of Example 1 and Example 2 of the present specification in the degree of acceptability of the texture of tofu and the softness of tofu, said Example 1 of the present specification And when manufacturing the dried tofu prepared by the manufacturing method of Example 2, it was confirmed that the product having an excellent texture can be produced closer to the texture of the raw material before drying than the conventional method.

Example 3

Method of Making Starch Dispersion

In the preparation of tofu, starch and antioxidants were added to soymilk to prepare starch dispersion so that the starch was more evenly dispersed in soymilk.

5 kg of tapioca modified starch (HT2X, manufactured by Abebe) was dissolved in 24 kg of distilled water, and 1 kg of antioxidant (SD-20, manufactured by Deferred Chemical, Inc.) was sufficiently homogenized with a homomixer for 10 minutes to form a starch dispersion. .

When the starch dispersion was added to the soymilk and stirred, it was confirmed that not only the shortening of the stirring time but also the starch was uniformly dispersed in the soymilk to obtain tofu having uniform physical properties.

Comparative Test Example 4

Apply starch directly to soymilk Stirring  If and by applying starch dispersion Stirring  Comparison of the degree of dispersion of cases

In the step of adding starch to soymilk and stirring, in order to compare the degree of dispersion of starch in soymilk when the starch is directly applied and the starch dispersion is stirred, the comparative test is carried out under the following experimental conditions. Was carried out.

470 g of commercial 10brix soy milk was obtained and placed in two beakers, and then one beaker was added with 30 g of starch dispersion (5 g of tapioca-modified starch + 25 g of dilution) in the same manner as in Example 3 to obtain 500 g of the final soymilk mixture 9.5 g. Brix, 1% by weight starch, and another beaker was added 5g tapioca modified starch and 25g dilution water directly to the soy milk, similarly 500g of the final soymilk mixture to 9.5 brix, 1% by weight starch, each of the stirring device It was carried out by stirring for 10 minutes at a rotation speed of 100rpm.

In each case, the comparison of starch dispersion in soymilk was measured by the Turbiscan LAB (Leanon Tech, Inc.) measuring the extent to which light was transmitted and reflected (backscattering) when the light was shot on both beakers. By measuring the position, size and degree of insoluble particles in the liquid phase. The measurement of the reflected and transmitted light was carried out by scanning at 2 minute intervals for a total of 60 minutes.

The comparison of the photograph which added the starch dispersion liquid to soymilk and the photograph which added the starch immediately is shown in FIG.

Backscattering results measured using a Turbiscan LAB instrument are shown in FIG. 11. The enlarged comparison result of FIG. 11 is shown in FIG.

As shown in Figure 10, in the case of soymilk added with starch dispersion, a starch sedimentation layer was formed near the lower end of the beaker (about 2 mm high from the bottom of the beaker), and in the case of soymilk added with starch immediately, at the bottom of the beaker It was confirmed that the starch precipitate layer was formed at a height of about 8 mm. This means that the size of starch particles in soymilk is much larger when starch is added immediately.

Looking at the Backscattering results measured using a Turbiscan LAB instrument, as shown in FIG. 11, for soymilk with starch dispersion (FIG. 11, graph above), the starch was directly placed at a point approximately 2 mm above the bottom of the beaker. In the case of the added soy milk (Fig. 11, the graph below), the backscattering was recorded at a height of about 8 mm from the bottom of the beaker, indicating that a starch precipitate layer was formed around each of them. This means that when starch is directly added as described above, starch is not evenly dispersed in the soymilk and starch particles are entangled to form particles having a larger particle size.

Referring to FIG. 12, which is an enlarged comparison of FIG. 11, when the starch dispersion is added (FIG. 12, the graph above), the backscattering value is noticeable after about 18 minutes of scanning using a Turbiscan LAB apparatus. It was measured differently by making peaks at the bottom of the beaker, but when starch was added immediately (Fig. 12, the graph below), peaks began to form after about 10 minutes of scanning. This means that when starch is added immediately, the dispersion of starch in soymilk remains uneven and starch particles remain large, so that the precipitation rate of starch particles is faster than when starch dispersion is added.

Therefore, from the above results, it was confirmed that adding and stirring the starch dispersion liquid in the soymilk was more uniformly dispersed in the soymilk with the starch particles smaller than when the starch was added directly.

Claims (11)

Preparing soymilk from raw soybeans;
Primary heating the prepared soymilk;
Stirring by adding starch and a coagulant to the first heated soymilk; And
Secondary heating the stirred soymilk mixture
The method of manufacturing a soft tofu comprising the method of claim 2, wherein the second heating step is a heating step of gelatinizing starch by heating to a temperature higher than the gelatinization temperature of the starch. The method of claim 1, wherein the starch is modified starch. The method for producing soft tofu according to claim 2, wherein the modified starch is tapioca modified starch. The method of claim 1, wherein the starch is added to be 0.1 to 3% by weight based on the total weight of the soymilk mixture. The method of claim 1, wherein the coagulant is not gluconodelta-lactone (GDL). 6. The method for producing soft tofu according to claim 5, wherein the coagulant is calcium sulfate. The method of claim 1, wherein the starch is a starch dispersion liquid in which the starch is stirred with a dilution water by a homogener. The method of claim 3, wherein the secondary heating step is a step of heating tofu so that the product temperature of tofu is 80 ℃ ~ 100 ℃. The method of claim 8, wherein the secondary heating step is a step of heating soybean curd, characterized in that for heating the temperature of the heating bath is 80 ℃ ~ 100 ℃. 10. The method of claim 9, wherein the secondary heating step is a step of heating for more than 40 minutes characterized in that the step of heating. A soft tofu prepared by the method of any one of claims 1 to 10.

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