JP7665361B2 - Tofu coagulant - Google Patents

Description

The present invention relates to a tofu coagulant and a method for producing tofu.

Tofu is produced by adding a coagulant to soy milk to cross-link proteins and gel them. The network structure formed by cross-linking proteins holds many water molecules, which gives tofu its characteristic elasticity and freshness. Nigari, which is mainly composed of magnesium chloride, has long been used as a coagulant. Magnesium chloride imparts a moderate sweetness to tofu, so by using magnesium chloride, it is possible to produce tofu with a good flavor. On the other hand, magnesium chloride has a fast-acting coagulating action, and the coagulation reaction progresses quickly before it can be uniformly diffused in the soy milk. Therefore, it is said that skilled techniques are required to obtain high-quality tofu with a highly uniform gel structure using magnesium chloride as a coagulant.
As the coagulant, other than magnesium chloride, inorganic salts such as magnesium sulfate, calcium chloride, calcium sulfate, etc. are known to exhibit a coagulating effect on soy milk.

In order to more simply produce tofu having a uniform gel texture using an inorganic salt as a coagulating component, it is known to prepare an inorganic salt sustained-release preparation (slow-release coagulant) and add such a preparation to soy milk to produce tofu.
For example, Patent Document 1 describes a method for producing tofu, in which an emulsifying coagulant containing fats and oils, an emulsifier, water, and an inorganic metal salt and having an average particle size of 0.5 to 5 μm is dispersed in soy milk to form a W/O/W type emulsion state having an average dispersed particle size of 5 to 120 μm after dispersion, and then a coagulation reaction is carried out.
Furthermore, Patent Document 2 describes a W/O type emulsion coagulant using bittern, in which the magnesium chloride concentration in the agent system is 20 to 40% by weight, the magnesium chloride concentration in the aqueous phase is 40 to 70% by weight, the W/O ratio of this emulsion is 40/60 to 65/35, and the blending amount of polyglycerol fatty acid ester in the agent system is 3 to 8% by weight.
Furthermore, Patent Document 3 describes a tofu coagulant consisting of a water-in-oil type emulsion composition having an oil phase containing fats and oils and a lipophilic emulsifier, and an aqueous phase containing potassium, sodium and magnesium chloride, in which the magnesium chloride content in the tofu coagulant is 14.0 to 26.0% by mass, the potassium and sodium content in total is 0.05 to 0.25% by mass, and the potassium content/sodium content is 1/4 to 1/1 in mass ratio.
Furthermore, Patent Document 4 describes a method for producing tofu in which a bittern-dispersed coagulant is dispersed in high-temperature soymilk to carry out a coagulation reaction, in which the temperature of the soymilk used for coagulation is controlled within a range of ±10°C of the coagulation start temperature of the soymilk, and the solubility of the bittern-dispersed coagulant in the soymilk is controlled so that the amount of magnesium chloride dissolved in the soymilk one minute after dispersion is 60% by weight or less, and the amount of magnesium chloride dissolved in the soymilk is 65 to 100% by weight after 10 minutes of dispersion.
Furthermore, Patent Document 5 describes a tofu coagulant composition comprising (a) an inorganic salt-based coagulant, (b) a polyglycerol condensed ricinoleic acid ester, (c) lecithin and/or a glycerol diacetyltartaric acid fatty acid ester, and (d) an oil component.

Japanese Patent Application Publication No. 11-98970 JP 2000-32942 A JP 2019-154440 A Japanese Patent Application Publication No. 11-332497 International Publication No. 2014/208331

In the production of tofu using conventional slow-release coagulants as described in the above Patent Documents 1 to 5, soy milk with a relatively high amount of soluble solids such as proteins (for example, a Brix value of about 12) has been used as the raw material. By using soy milk with a high Brix value (high Brix soy milk), the crosslink density of proteins can be sufficiently increased even with the use of a small amount of slow-release coagulant in which fats and oils and emulsifiers do not significantly affect the flavor of the tofu, and tofu with excellent flavor and texture can be obtained. On the other hand, when soy milk with a low Brix value (low Brix soy milk) is used, it is difficult to achieve both excellent flavor and texture using conventional slow-release coagulants. In other words, if only a small amount of slow-release coagulant is used in which fats and oils and emulsifiers do not substantially affect the flavor of the tofu, a sufficient crosslinking structure cannot be introduced into the soy milk, and as a result, the tofu obtained is difficult to maintain its shape. Even if tofu that maintains its shape is obtained, it will have weak elasticity and an uneven internal structure, resulting in a poor smoothness felt in the mouth when eaten.

The types of soybeans are diverse worldwide, and the Brix value of the resulting soy milk also differs depending on the type of soybean. Therefore, if it were possible to stably coagulate soy milk in tofu production using a small amount of slow-release coagulant, regardless of the Brix value of the soy milk, it would broaden the range of sources for soybeans and soy milk, and would also increase the variety of tofu flavors, which would contribute to the expansion of the tofu market.
There are also attempts to produce tofu with new flavors by adding flavorings to soy milk. In this case, the soy milk is diluted by the incorporation of flavorings, etc. In other words, the same coagulation problems as described above may occur. From this perspective, there is a demand for technology that uses a small amount of coagulant for soy milk with a wide range of Brix values to produce high-quality tofu with excellent elasticity and internal uniformity.

The present invention aims to realize a technology that makes it possible to obtain tofu with excellent elasticity, excellent internal phase uniformity, and a smooth texture, regardless of the Brix value of the soy milk used as the raw material, by using a small amount of a sustained-release coagulant equivalent to that used in the past, from the viewpoint of the composition or characteristics of the sustained-release coagulant, and from the viewpoint of controlling the dispersibility of the sustained-release coagulant in soy milk.

In one aspect, the present invention provides the following tofu coagulant.
A tofu coagulant containing an oily component, a lipophilic emulsifier, and an aqueous component, wherein the total content of the oily component and the lipophilic emulsifier in the tofu coagulant is 52-75% by mass, and the ratio of magnesium chloride in the aqueous component is 30-44% by mass. This invention relating to the tofu coagulant is also referred to as "the invention relating to the first embodiment" or "the coagulant relating to the first embodiment" in this specification.

In another aspect of the present invention, there is provided the following tofu coagulant.
A tofu coagulant containing an oily component, a lipophilic emulsifier, and an aqueous component, wherein the aqueous component contains magnesium chloride, and when the tofu coagulant is dispersed in soy milk under the following dispersion conditions, the tofu coagulant is in the following dispersed state in the dispersion liquid 1 minute after the end of the dispersion treatment.
<Dispersion conditions>
Soy milk with a Brix value of 1 and the tofu coagulant are mixed so that the ratio of magnesium chloride to the total content of the soy milk and the tofu coagulant is 0.14 mass %, and the mixture is subjected to a dispersion treatment using a milder at a temperature of 85°C, a rotation speed of 4000 rpm, and a flow rate of 1 L/min to disperse the tofu coagulant in the soy milk.
<Dispersion state>
The median diameter of dispersed particles of the tofu coagulant is 80 μm or less, and the magnesium chloride concentration in the soy milk is 0.005 mass% or more.
This invention relating to the tofu coagulant is also referred to as "the invention according to the second embodiment" or "the coagulant according to the second embodiment" in this specification.

In yet another aspect of the present invention, there is provided the following method for producing tofu.
A method for producing tofu, comprising dispersing a tofu coagulant containing an oily component, a lipophilic emulsifier, and an aqueous component in soy milk, wherein the aqueous component contains magnesium chloride, and the tofu coagulant is dispersed in the soy milk under the following stirring conditions:
<Mixing conditions>
When soy milk with a Brix value of 1 and the tofu coagulant are mixed so that the ratio of magnesium chloride in the total content of the soy milk and the tofu coagulant is 0.14% by mass, and the mixture is subjected to a dispersion process to disperse the tofu coagulant in the soy milk, the stirring conditions are such that the median diameter of dispersed particles of the tofu coagulant is 80 μm or less in the dispersion liquid one minute after the end of the dispersion process, and the magnesium chloride concentration in the soy milk is 0.005% by mass or more.
This invention relating to a method for producing tofu is also referred to as "the invention according to the third embodiment" or "the production method according to the third embodiment" in this specification.

The tofu coagulant of the present invention is dispersed in soy milk and coagulated, and by using a small amount of the tofu coagulant similar to that of conventional slow-release coagulants, it is possible to obtain tofu with excellent elasticity, excellent internal phase uniformity, and a smooth texture, regardless of the Brix value of the soy milk used as a raw material.
Furthermore, according to the tofu manufacturing method of the present invention, by using a small amount of a sustained-release coagulant similar to that used in the past, it is possible to obtain tofu that has excellent elasticity, excellent internal phase uniformity, and a smooth texture, regardless of the Brix value of the soymilk used as a raw material.

Preferred embodiments of the present invention will be described in the following order: the first embodiment, the second embodiment, and the third embodiment.

The coagulant according to the first embodiment of the present invention contains an oily component, a lipophilic emulsifier, and an aqueous component. The aqueous component contains a specific amount of magnesium chloride as a coagulant component, as described below.

The oil component is a component that is incompatible with water. Incompatible with water means that it is not substantially soluble in water. In other words, when mixed with water, the oil component and water are in a phase-separated state.
Examples of the oily component include fats and oils, and also include polyhydric alcohol fatty acid esters other than triacylglycerol. That is, one or more selected from edible animal fats and oils, edible vegetable fats and oils, and esters of polyhydric alcohols and fatty acids (excluding triacylglycerol and polyglycerol condensed ricinoleic acid ester) can be used as the oily component. Among them, the oily component is preferably a liquid fat at 20°C, and more preferably a liquid fat at 5°C from the viewpoint of the stability of the coagulant. In this specification, "a liquid fat at 20°C" means a fat having a solid fat content of 1% by mass or less at 20°C. In addition, "a liquid fat at 5°C" means a fat having a solid fat content of 1% by mass or less at 5°C. The solid fat content of the fats and oils is measured according to the method described in 2.2.9 Solid Fat Content NMR Method of the Standard Method for Analysis of Fats and Oils established by the Japan Oil Chemists' Association.
Examples of the vegetable oils and fats include soybean oil, rapeseed oil, corn oil, cottonseed oil, safflower oil, olive oil, palm oil, rice oil, sunflower oil, sesame oil, etc., or hardened oils thereof, interesterified oils thereof, or fractionated oils thereof, and one or more types of oils and fats selected from these oils and fats can be used. Examples of the animal oils and fats include lard, beef tallow, etc., and one or more types of oils and fats selected from these oils and fats can be used.
The polyhydric alcohol constituting the ester of the polyhydric alcohol and the fatty acid is preferably one or more selected from propylene glycol, glycerin, polyglycerin, sorbitol and sorbitan.
The ester of the polyhydric alcohol and the fatty acid is preferably a propylene glycol diester compound. The fatty acid constituting the ester of the polyhydric alcohol and the fatty acid is not particularly limited as long as it is a fatty acid originating from edible animal and vegetable fats and oils, and may be, for example, one or more selected from caprylic acid, capric acid, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid, erucic acid, etc. The ester of the polyhydric alcohol and the fatty acid can be prepared by a conventional esterification reaction, etc.

In the coagulant according to the first embodiment, the content of the oily component in the coagulant is preferably 50% by mass or more, more preferably 52% by mass or more, even more preferably 55% by mass or more, and particularly preferably 57% by mass or more, from the viewpoint of improving the texture of the tofu obtained. Also, from the viewpoint of the flavor of the tofu, the content of the oily component in the coagulant is preferably 74% by mass or less, more preferably 72% by mass or less, and even more preferably 70% by mass or less.

The oil component preferably contains the above-mentioned oils and fats. When the oil component contains components other than the above-mentioned oils and fats, the remainder excluding the oils and fats may contain, for example, one or more selected from colorants, antioxidants, seasonings, strengthening agents, and the like.
From the viewpoint of the flavor of tofu, the ratio of the oil or fat in the oily component is preferably 40% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 85% by mass or more, particularly preferably 90% by mass or more, and also preferably 95% by mass or more. It is also preferable that the oily component consists of the oil or fat.

The lipophilic emulsifier is an emulsifier having an HLB of not more than 9, and preferably an emulsifier having an HLB of not more than 8. The HLB value is a value calculated by the Griffin method (W.C. Griffin, J. Soc. Cosmetic. Chemists., 1, 311 (1949)) represented by the following formula.

HLB = 20 x (molecular weight of hydrophilic group portion) / (molecular weight of surfactant)

Examples of the lipophilic emulsifier include polyglycerol condensed ricinoleic acid ester (PGPR), glycerol fatty acid ester, polyglycerol fatty acid ester, organic acid monoglyceride, sorbitan fatty acid ester, propylene glycol fatty acid ester, lecithin, sucrose fatty acid ester, etc. The lipophilic emulsifier preferably contains polyglycerol condensed ricinoleic acid ester from the viewpoint of emulsion stability of the coagulant. The ratio of PGPR in the lipophilic emulsifier is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more. More preferably, all of the lipophilic emulsifiers are PGPR. When the lipophilic emulsifier contains PGPR, it may contain one type of PGPR or two or more types of PGPR.
In the coagulant according to the first embodiment, the content of the lipophilic emulsifier in the coagulant is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and even more preferably 1 to 6% by mass, from the viewpoint of the stability of the coagulant.

PGPR, which is preferred as a lipophilic emulsifier, will be described below. There is no particular limit to the number of glycerin units in the glycerin polymer that constitutes PGPR. In consideration of emulsion stability, it is preferable that the above-mentioned glycerin polymerization degree (average polymerization degree) is 4 to 6. From the same viewpoint, it is also preferable that the condensed ricinoleic acid in PGPR has a structure in which 2 to 5 molecules of ricinoleic acid are condensed.

The degree of glycerol polymerization of polyglycerol is calculated based on the hydroxyl value according to the following formula (3).
MW=74n+18...Formula (1)
OHV=56110(n+2)/MW...Formula (2)
n=(112220-18OHV)/(74OHV-56110)...Formula (3)
MW: average molecular weight of polyglycerol n: degree of polymerization of polyglycerol (average degree of polymerization)
OHV: Hydroxyl value of polyglycerol

The lipophilic emulsifier can be synthesized by a conventional method and is commercially available. For example, commercially available PGPR products include Sunsoft No. 818SK (trade name, manufactured by Taiyo Kagaku Co., Ltd.), Sunsoft No. 818R (trade name, manufactured by Taiyo Kagaku Co., Ltd.), Sunsoft No. 818DG (trade name, manufactured by Taiyo Kagaku Co., Ltd.), SY Glister CR-500 (trade name, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), and Poem PR-300 (trade name, manufactured by Riken Vitamin Co., Ltd.).

In the coagulant according to the first embodiment, the total content of the oily component and the lipophilic emulsifier in the coagulant is 52 to 75% by mass. By setting the content within this range, the dispersibility in soy milk can be improved, the resulting tofu can have excellent elasticity, and the coagulated state can be made more uniform, resulting in a smoother texture. From the viewpoint of the uniformity of the internal phase of the tofu, the total content of the oily component and the lipophilic emulsifier in the coagulant is preferably 55% by mass or more, more preferably 57% by mass or more, and even more preferably 60% by mass or more. In addition, from the viewpoint of the flavor of the tofu, the total content of the oily component and the lipophilic emulsifier in the coagulant is preferably 74% by mass or less, more preferably 73% by mass or less, and even more preferably 72% by mass or less.

The aqueous component means water or a water-soluble component having a solubility in water of 10 g/100 g-H ₂ O or more at 25° C. (the limit amount that can be dissolved in 100 g of water at 25° C. is 10 g). The aqueous component contains magnesium chloride, which is a water-soluble component, and the ratio of magnesium chloride in the aqueous component is 30 to 44 mass %. By setting the ratio of magnesium chloride in the aqueous component within the above range, the coagulation state of the obtained tofu can be made more uniform, and the texture can be made smoother. In the present invention, the content of magnesium chloride is the content calculated as anhydrous. For example, when magnesium chloride is contained by blending MgCl _{2.6H 2} O (magnesium chloride hexahydrate), the content of magnesium chloride is the content of MgCl ₂ , and 6H ₂ O constitutes water in the aqueous component.
In the coagulant according to the first embodiment, the ratio of magnesium chloride in the aqueous component of the coagulant is 30% by mass or more, preferably 32% by mass or more, and more preferably 34% by mass or more, from the viewpoint of the elasticity of the tofu. Also, from the viewpoint of the flavor of the tofu, the ratio of magnesium chloride in the aqueous component of the coagulant is 44% by mass or less, preferably 42% by mass or less, and more preferably 40% by mass or less.
The concentration of magnesium chloride in the aqueous component can be calculated from the blend amount, or can be quantified by the method described in the section on "Magnesium Chloride" in the "8th Edition of the Japanese Standards for Food Additives."

The aqueous component preferably contains water in addition to magnesium chloride. The proportion of water in the aqueous component depends on the form of the coagulant, but is usually 53% by mass or more, and preferably 56% by mass or more. The proportion of water in the aqueous component is usually 70% by mass or less, and preferably 67% by mass or less.
When the aqueous component contains components other than magnesium chloride and water, the remainder of the aqueous component excluding magnesium chloride and water may contain water-soluble components such as inorganic salts having a coagulating effect. The aqueous component is preferably composed of magnesium chloride and water.

The coagulant according to the first embodiment preferably comprises an oil component, a lipophilic emulsifier, and an aqueous component.

The form of the coagulant according to the first embodiment is not particularly limited as long as it is a form in which the oily component, the lipophilic emulsifier, and the aqueous component are mixed. For example, it may be in the form of a composition in which the oily component, the lipophilic emulsifier, and the aqueous component are uniformly mixed, or it is also preferable to have it in the form of a water-in-oil emulsion composition. It is also preferable to have it in a form in which at least a part of the free water, etc. is removed by subjecting the water-in-oil emulsion composition to a drying treatment (such as drying under reduced pressure).

Next, a method for preparing the coagulant according to the first embodiment will be described.
When the coagulant according to the first embodiment of the present invention is obtained as an oil-in-water emulsion composition, the aqueous component and the oil composition containing an oil component and a lipophilic emulsifier are emulsified and dispersed in a water-in-oil type (W/O type) to obtain the coagulant according to the first embodiment. In the obtained emulsion composition, the aqueous component constitutes the aqueous phase, and the oil component constitutes the oil phase. The lipophilic emulsifier functions as an emulsifier that emulsifies and disperses the aqueous component in the oil component. When the coagulant according to the first embodiment is in the form of an oil-in-water emulsion composition, it is emulsified and dispersed in a water-in-oil type by a normal emulsification and dispersion method, except for applying the component composition specified in the present invention, to obtain the coagulant according to the first embodiment consisting of an oil-in-water emulsion composition. In addition, the obtained oil-in-water emulsion composition can be dried, for example, by subjecting it to a reduced pressure treatment, to obtain the coagulant according to the first embodiment.
The coagulant according to the first embodiment can also be prepared by simply mixing the components. That is, it is also preferable to prepare a slurry in which magnesium chloride (preferably magnesium chloride hexahydrate) is dispersed in a solid state in the oil component. Such a slurry-form coagulant is known per se, and the slurry-form coagulant according to the first embodiment (S/O type coagulant) can be obtained by a conventional method, except for applying the component composition specified in the present invention.

The coagulant according to the first embodiment can be uniformly dispersed in soy milk as small dispersed particles at a high particle density (in a state where a large number of dispersed particles are present) even when dispersed in soy milk under relatively mild conditions, and can slowly release magnesium chloride at a moderate release rate. As a result, it is considered that it is possible to obtain tofu that is elastic, has a uniform internal phase, and has a smooth texture regardless of the Brix value, by sufficiently increasing the crosslinking point density of the soy milk. That is, in addition to soy milk with a high Brix value that has been conventionally used as a raw material soy milk, soy milk with a low Brix value (for example, a Brix value of 10 or less, 9 or less, or 8 or less) can also be used as a raw material. Therefore, the range of choices for soybeans or soy milk suppliers is expanded, and it also contributes to the creation of variations in the flavor of tofu. The Brix value of the soy milk to which the coagulant according to the first embodiment is applied can be, for example, 5 to 14, preferably 6 to 13, and also preferably 7 to 13, from the viewpoint of soy milk that has conventionally been used as a raw material. From the viewpoint of soymilk having a low Brix value, the Brix value can be, for example, 5 to 12, preferably 6 to 11, more preferably 7 to 10, and even more preferably 7 to 9.
The production of tofu using the coagulant according to the first embodiment will be described later together with the production of tofu using the coagulant according to the second embodiment.

Next, a coagulant according to a second embodiment of the present invention will be described.
The coagulant according to the second embodiment of the present invention contains an oil component, a lipophilic emulsifier, and an aqueous component. The aqueous component contains magnesium chloride as a coagulant component.
When the tofu coagulant according to the second embodiment is dispersed in soy milk under the following <dispersion conditions>, the tofu coagulant becomes the following <dispersed state> in the dispersion liquid 1 minute after the end of the dispersion treatment.

<Dispersion conditions>
Soymilk with a Brix value of 1 and the tofu coagulant are mixed so that the ratio of magnesium chloride to the total content of the soymilk and the tofu coagulant is 0.14% by mass, and a milder is used to disperse the tofu coagulant in the soymilk by subjecting it to a dispersion process at a temperature of 85°C (this is the temperature of the soymilk with a Brix value of 1 at the start of the dispersion process, and this is the temperature of the soymilk while it is being dispersed by the milder), a rotation speed of 4000 rpm, and a flow rate of 1 L/min (the liquid thus obtained in which the coagulant is dispersed in the soymilk is also referred to as a "dispersion").

The Milder is a device that is widely used for emulsifying and dispersing, and in this invention, we use the MDN303V manufactured by Pacific Machinery Works. In addition, we use three stages of G/M/F rotors and stators.

<Dispersion state>
The median diameter of dispersed particles of the tofu coagulant is 80 μm or less, and the magnesium chloride concentration in the soy milk is 0.005 mass% or more.

The median diameter can be determined by the method described in the Examples below. The magnesium chloride concentration in soymilk is the concentration of magnesium chloride dissolved in soymilk (released into soymilk). The dissolved magnesium chloride concentration can be determined based on electrical conductivity. Details are as described in the Examples below. The same applies to the "magnesium chloride concentration in soymilk" in the production method according to the third embodiment described below.
In the present invention, the "dispersion liquid 1 minute after the end of the dispersion treatment" specifically refers to the dispersion liquid discharged from the outlet of the Milder that is continuously collected for 10 seconds and collected 1 minute after the start of collection (0 seconds after the start of collection). Therefore, the "dispersion liquid 1 minute after the end of the dispersion treatment" actually includes the dispersion liquid from 50 seconds after the end of the dispersion treatment to 1 minute after the end of the dispersion treatment.
The magnesium chloride concentration in soymilk in the "dispersion liquid 1 minute after the end of the dispersion treatment" refers to the ratio (mass %) of the amount of magnesium chloride dissolved from the tofu coagulant into the soymilk in the dispersion liquid from the start of the dispersion treatment (the time of introduction into the inlet of the Milder) to 1 minute after the end of the dispersion treatment. Therefore, the "magnesium chloride concentration in soymilk" in the "dispersion liquid 1 minute after the end of the dispersion treatment" does not include magnesium chloride derived from soymilk, and does not include magnesium chloride remaining in the tofu coagulant without being dissolved into the soymilk, and is determined based on the total amount of magnesium chloride dissolved from the tofu coagulant into the soymilk from the start of the dispersion treatment to the end of the dispersion treatment and from the end of the dispersion treatment to 1 minute after the end of the dispersion treatment. As mentioned above, "1 minute after the end of the dispersion treatment" includes the range from 50 seconds to 1 minute after the end of the dispersion treatment.

The oily component, lipophilic emulsifier, and aqueous component used in the coagulant according to the second embodiment are synonymous with the oily component, lipophilic emulsifier, and aqueous component described in the coagulant according to the first embodiment, respectively, and the preferred composition of each component is also the same. In addition, the ranges of the contents of the oily component, lipophilic emulsifier, and aqueous component in the coagulant can also be preferably applied to the ranges of the contents of each of the oily component, lipophilic emulsifier, and aqueous component described in the coagulant according to the first embodiment.

In the above-mentioned <dispersed state>, the median diameter of the dispersed particles of the tofu coagulant is preferably 80 μm or less, more preferably 70 μm or less, and even more preferably 65 μm or less, from the viewpoint of uniformity of the inner phase of the tofu. Also, in the above-mentioned <dispersed state>, the median diameter of the dispersed particles of the tofu coagulant is usually 20 μm or more, and preferably 40 μm or more.
Considering the relationship between the Brix value of soy milk and the dispersed particle size (median size) of the coagulant, it is considered that the dispersed particle size will be significantly larger when low-protein soy milk with a Brix value of 1 is used compared to when soy milk with a Brix value of 12, which is a common raw material for tofu, is used, since the surfactant (protein) concentration is significantly lower and the viscosity of the soy milk is also low. For example, if the dispersed particle size is 10 μm when soy milk with a Brix value of 12 is used, it is considered that the dispersed particle size will be about 100 to 120 μm when the same coagulant is used to disperse the dispersed particle size in soy milk with a Brix value of 1.

In addition, in the above-mentioned <dispersed state>, the magnesium chloride concentration in the soy milk is 0.005% by mass or more, preferably 0.006% by mass or more, and more preferably 0.007% by mass or more, from the viewpoint of uniformity of the inner phase of the tofu. In addition, from the viewpoint of obtaining more elastic tofu, the magnesium chloride concentration is preferably 0.100% by mass or less, more preferably 0.090% by mass or less, and also preferably 0.085% by mass or less.

The coagulant according to the second embodiment, like the coagulant according to the first embodiment, can be uniformly dispersed in soy milk as small particles with a high particle density even when dispersed in soy milk under relatively mild conditions, and can slowly release magnesium chloride at a moderate release rate. As a result, it is considered that it is possible to obtain tofu that is elastic, has a uniform internal phase, and has a smooth texture, regardless of the Brix value, by sufficiently increasing the crosslinking point density of the soy milk. In other words, in addition to soy milk with a high Brix value that has been used as a raw material soy milk in the past, soy milk with a low Brix value (for example, a Brix value of 10 or less, 9 or less, or 8 or less) can also be used as a raw material, which expands the range of options for sourcing soybeans or soy milk, and also contributes to the creation of variations in the flavor of tofu. As with the coagulant according to the first embodiment, the Brix value of the soy milk to which the coagulant according to the second embodiment is applied can be, for example, 5 to 14, preferably 6 to 13, and also preferably 7 to 13, from the viewpoint of soy milk that has traditionally been used as a raw material. Also, from the viewpoint of soy milk with a low Brix value, the Brix value can be, for example, 5 to 12, preferably 6 to 11, also preferably 7 to 10, and also preferably 7 to 9.

The form of the coagulant according to the second embodiment can be the same as that of the coagulant according to the first embodiment, and the preferred form is also the same. That is, it may be in the form of a composition in which an oily component, a lipophilic emulsifier, and an aqueous component are uniformly mixed, or it is also preferable to have it in the form of a water-in-oil emulsion composition. It is also preferable to have the water-in-oil emulsion composition in a form in which at least a part of free water, etc. is removed by subjecting it to a drying treatment (such as drying under reduced pressure).

Next, the production of tofu using the coagulant according to the first or second embodiment will be described. The production of tofu using the coagulant according to the first or second embodiment can be carried out in a conventional manner, except that the coagulant according to the first or second embodiment is used as the coagulant. That is, the tofu coagulant of the present invention is mixed with soymilk having a desired Brix value, and the mixture is subjected to a dispersion treatment (homogeneous stirring treatment) to disperse the coagulant in the soymilk, and the gradually eluted magnesium chloride acts to form a crosslinked structure in the protein in the soymilk, resulting in gelation, thereby obtaining tofu. This gelation can be promoted by subjecting the dispersion to an aging process at about 80 to 90°C for about 30 to 60 minutes.
When producing tofu, it is preferable to mix and disperse soy milk and a coagulant for tofu so that the magnesium chloride content in the soy milk is about 0.1 to 0.3 mass %.
The dispersion of the coagulant in the soy milk can be carried out by stirring at a desired stirring speed using a stirring device such as a Milder (MDN303V, Rotor-Stator G/M/F, manufactured by Pacific Machinery Works) or a homomixer (TK Homomixer MARKII, manufactured by Primix Corporation). The temperature in this dispersion step can be appropriately adjusted within the range of 20 to 90° C. The dispersion step is preferably carried out at 90° C. or less, more preferably 85° C. or less, and then the above-mentioned high-temperature maturation step is carried out to obtain tofu.
For example, soy milk and a tofu coagulant are mixed at high temperature (about 60 to 90° C.) and stirred for several to several tens of seconds, and then the mixture is filled into a tofu-filled container and a continuous molding machine of a desired shape, and heated at a temperature of about 80 to 90° C. for about 40 to 50 minutes for maturation to produce tofu.

Next, a manufacturing method according to a third embodiment of the present invention will be described.
The manufacturing method according to the third embodiment is a method for manufacturing tofu, which comprises dispersing a tofu coagulant containing an oily component, a lipophilic emulsifier, and an aqueous component in soy milk. The aqueous component contains at least magnesium chloride. In this manufacturing method, specific stirring conditions are applied to the step of dispersing the coagulant in soy milk. The stirring conditions are as follows.

<Mixing conditions>
When soy milk with a Brix value of 1 and the tofu coagulant are mixed so that the ratio of magnesium chloride in the total content of the soy milk and the tofu coagulant is 0.14% by mass, and the mixture is subjected to a dispersion process to disperse the tofu coagulant in the soy milk, the stirring conditions are such that the median diameter of dispersed particles of the tofu coagulant is 80 μm or less in the dispersion liquid one minute after the end of the dispersion process, and the magnesium chloride concentration in the soy milk is 0.005% by mass or more.

The above stirring conditions are stirring conditions that can disperse the coagulant as a specific small particle size in soymilk with a Brix value of 1 in the dispersion liquid 1 minute after the end of the dispersion process, and can make the magnesium chloride concentration in the soymilk 0.005% by mass or more. The invention according to the third embodiment uses the same stirring device (emulsion dispersion device) as the stirring conditions, and adopts the same stirring speed, stirring time, and stirring temperature to obtain tofu through a process of dispersing the coagulant in desired soymilk (for example, soymilk with a Brix value of 7 or more). When using a dispersing machine of a flow type such as a Milder, it is necessary to continuously collect the dispersion discharged from the discharge port for 10 seconds, as explained in the second embodiment. In this case, as explained in the second embodiment, the "dispersion liquid 1 minute after the end of the dispersion process" includes the dispersion liquid 50 seconds after the end of the dispersion process to the dispersion liquid 1 minute after the end of the dispersion process.
In the dispersion treatment in the manufacturing method according to the third embodiment, the soybean species from which the soymilk is derived may be the same as or different from the soybean species from which the soymilk with a Brix value of 1 in the above <Stirring Conditions> is derived. Also, in the dispersion treatment of the coagulant in soymilk in the production of tofu, the mixing ratio of the soymilk and the coagulant may be the same as or different from the mixing ratio of the soymilk with a Brix value of 1 in the above stirring conditions and the coagulant (the magnesium chloride content of the total content of the soymilk and the tofu coagulant is 0.14% by mass). The above can be summarized as follows.

In the manufacturing method according to the third embodiment, the Brix value of the soymilk used for dispersing the coagulant in the soymilk in the tofu production is higher than the Brix value (Brix value is 1) of the soymilk used in determining the above <Stirring conditions>.
In the method according to the third embodiment, the soybean variety from which the soybean milk used for dispersing the coagulant in the soybean milk for tofu production is derived is not limited to the soybean variety having a Brix value of 1 used in determining the above <agitation conditions>.
In the method according to the third embodiment, when dispersing the coagulant in soymilk in the production of tofu, the mixing ratio of the soymilk and the coagulant is not limited to the mixing ratio described in the above <Stirring conditions> (the magnesium chloride content in the total content of soymilk and tofu coagulant is 0.14% by mass). In the production of tofu, it is preferable to mix and disperse the soymilk and the tofu coagulant so that the magnesium chloride content in the soymilk is about 0.1 to 0.3% by mass.

The present inventors have found that, in the production of tofu, when a sustained-release coagulant is dispersed in low Brix soy milk (e.g., soy milk with a Brix value of 7) and the soy milk is coagulated to obtain tofu, if the sustained-release coagulant is dispersed in the soy milk under normal dispersion conditions, even if the soy milk is subsequently subjected to a high-temperature maturation process (e.g., 75 to 95°C), tofu of the desired quality cannot be obtained, but on the other hand, if the sustained-release coagulant is dispersed in the soy milk under special dispersion conditions, such as by significantly increasing the shear force, tofu with excellent elasticity and a smooth texture can be obtained after the subsequent high-temperature maturation process. Based on these findings, the present inventors have further studied the matter, and have found that tofu with excellent elasticity, a uniform internal phase, and a smooth texture can be obtained by determining the stirring conditions for the sustained-release coagulant in the soy milk in the actual production of tofu using the above <stirring conditions> as an index, and have thus completed the manufacturing method according to the third embodiment.

The manufacturing method according to the third embodiment makes it possible to obtain the desired high-quality tofu regardless of the Brix value of the soy milk, and the reasons for this are as explained in the inventions according to the first and second embodiments. In other words, it is considered that the particle density (number of particles) of the coagulant in the soy milk is increased, and the density of cross-linking points in the soy milk is sufficiently increased, making it possible to obtain tofu that is elastic, has a uniform internal phase, and has a smooth texture regardless of the Brix value. In other words, in addition to the soy milk with a high Brix value that has traditionally been used as a raw material soy milk, it is also possible to use soy milk with a low Brix value (for example, a Brix value of 10 or less, or 9 or less, or 8 or less) as a raw material, which expands the range of options for sourcing soybeans or soy milk and also contributes to the creation of variations in the flavor of tofu. In the manufacturing method according to the third embodiment, the Brix value of the soy milk into which the coagulant is dispersed in the production of tofu can be, for example, 5 to 14, preferably 6 to 13, and also preferably 7 to 13, from the viewpoint of soy milk that has traditionally been used as a raw material, similar to the use form of the coagulant according to the first embodiment. Also, from the viewpoint of soy milk with a low Brix value, the Brix value can be, for example, 5 to 12, preferably 6 to 11, also preferably 7 to 10, and also preferably 7 to 9.

The above <agitation conditions> in the production method according to the third embodiment are such that the temperature (the temperature of the soymilk from the start of agitation to the end of agitation) is preferably 90° C. or less, and more preferably 85° C. or less. The agitation temperature is usually 60° C. or more, and preferably 70° C. or more.
That is, in the invention according to the third embodiment, it is preferable that the temperature when dispersing a coagulant in soymilk in the production of tofu (the temperature of soymilk at the start of stirring, that is, the temperature of the soymilk during the stirring treatment) is set to the above temperature.
In addition, the stirring device (emulsifying and dispersing device) used for stirring in the above <Stirring conditions> is not particularly limited, and any homogenizer that can be used in the production of tofu can be appropriately applied.
In addition, in the above <Stirring Conditions>, the dispersion treatment time for dispersing the tofu coagulant in the soy milk is preferably 0.1 to 30 seconds.

In the manufacturing method according to the third embodiment, steps other than the stirring step for dispersing the coagulant in the soy milk can be appropriately adopted from steps in normal tofu manufacturing. For example, the tofu manufacturing method described in the coagulant according to the first and second embodiments can be appropriately applied.

In the coagulant used in the manufacturing method according to the third embodiment, the oil component, the lipophilic emulsifier, and the aqueous component are respectively synonymous with the oil component, the lipophilic emulsifier, and the aqueous component described in the coagulant according to the first embodiment, and the preferred forms are also the same.
However, the content of each component in the coagulant and the ratio of magnesium chloride in the aqueous component are not limited to the ranges described in the first embodiment. This point will be specifically described.

In the coagulant used in the manufacturing method according to the third embodiment, the content of the oily component in the coagulant is preferably 25% by mass or more, more preferably 30% by mass or more, even more preferably 35% by mass or more, even more preferably 40% by mass or more, and even more preferably 45% by mass or more. The content of the oily component in the coagulant is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less.

In the coagulant used in the manufacturing method according to the third embodiment, the content of the lipophilic emulsifier in the coagulant is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and even more preferably 1 to 6% by mass. Thus, the preferred amount of the lipophilic emulsifier used is the same as the amount of the lipophilic emulsifier used in the coagulant of the first embodiment.

In the coagulant used in the manufacturing method according to the third embodiment, the total content of the oily component and the lipophilic emulsifier in the coagulant is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, and even more preferably 45% by mass or more. In addition, the total content of the oily component and the lipophilic emulsifier in the coagulant is preferably 82% by mass or less, more preferably 77% by mass or less, and even more preferably 72% by mass or less.

In the coagulant used in the manufacturing method according to the third embodiment, the proportion of magnesium chloride in the aqueous component is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 28% by mass or more. The proportion of magnesium chloride in the aqueous component is preferably 53% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less, and is also preferably 40% by mass or less, and is also preferably 38% by mass or less.

The coagulant used in the manufacturing method according to the third embodiment preferably comprises an oil component, a lipophilic emulsifier, and an aqueous component.

The form of the coagulant used in the manufacturing method according to the third embodiment may also be in the form of a composition or slurry in which an oily component, a lipophilic emulsifier, and an aqueous component are uniformly mixed, as with the coagulant according to the first embodiment, or it is also preferable to use the coagulant in the form of a water-in-oil emulsion composition. It is also preferable to use the water-in-oil emulsion composition in a form in which at least a portion of free water, etc., has been removed by subjecting it to a drying treatment (such as drying under reduced pressure).

With respect to the above-mentioned embodiment, the present invention further discloses the following tofu coagulant and tofu manufacturing method.

＜1＞
A tofu coagulant comprising an oil component, a lipophilic emulsifier, and an aqueous component,
The tofu coagulant, wherein the total content of the oily component and the lipophilic emulsifier in the tofu coagulant is 52 to 75 mass%, preferably 55 to 74 mass%, more preferably 57 to 73 mass%, and even more preferably 60 to 72 mass%, and the ratio of magnesium chloride in the aqueous component is 30 to 44 mass%, preferably 32 to 42 mass%, and more preferably 34 to 40 mass%.

＜2＞
A tofu coagulant comprising an oil component, a lipophilic emulsifier, and an aqueous component,
the aqueous component comprises magnesium chloride;
When the tofu coagulant is dispersed in soy milk under the following dispersion conditions, the tofu coagulant is in the following dispersed state in the dispersion liquid one minute after the end of the dispersion treatment.
<Dispersion conditions>
Soy milk with a Brix value of 1 and the tofu coagulant are mixed so that the ratio of magnesium chloride to the total content of the soy milk and the tofu coagulant is 0.14 mass %, and the mixture is subjected to a dispersion treatment using a milder at a temperature of 85°C, a rotation speed of 4000 rpm, and a flow rate of 1 L/min to disperse the tofu coagulant in the soy milk.
<Dispersion state>
The median diameter of dispersed particles of the tofu coagulant is 80 μm or less, preferably 70 μm or less, more preferably 65 μm or less, and the magnesium chloride concentration in the soy milk is 0.005 mass% or more, preferably 0.006 mass% or more, more preferably 0.007 mass% or more.
＜3＞
The tofu coagulant according to <2>, wherein in the dispersed state, the median diameter of dispersed particles of the tofu coagulant is preferably 20 μm or more, more preferably 40 μm or more.
＜4＞
The tofu coagulant according to <2> or <3>, wherein in the dispersed state, the median diameter of dispersed particles of the tofu coagulant is preferably 20 to 80 μm, more preferably 20 to 70 μm, and even more preferably 40 to 65 μm.
＜5＞
The tofu coagulant according to any one of <2> to <4>, wherein the magnesium chloride concentration in the soymilk in the dispersed state is preferably 0.100% by mass or less, more preferably 0.090% by mass or less, and even more preferably 0.085% by mass or less.
＜6＞
The tofu coagulant according to any one of <2> to <5>, wherein the magnesium chloride concentration in the soymilk in the dispersed state is preferably 0.005 to 0.100% by mass, more preferably 0.006 to 0.090% by mass, and even more preferably 0.007 to 0.085% by mass.

＜７＞
The tofu coagulant according to any one of <1> to <6>, wherein the oily component contains fats and oils, and the fats and oils are preferably one or more selected from animal fats and oils, vegetable fats and oils, and esters of polyhydric alcohols and fatty acids (excluding polyglycerol condensed ricinoleic acid esters).
＜8＞
The tofu coagulant according to <7>, wherein the ratio of the oil to the oily component is preferably 40% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass.
＜9＞
The tofu coagulant according to <7> or <8>, wherein the animal fat or oil is preferably lard and/or beef tallow.
＜10＞
The tofu coagulant according to any one of <7> to <9>, wherein the vegetable oil is preferably one or more selected from soybean oil, rapeseed oil, corn oil, cottonseed oil, safflower oil, olive oil, palm oil, rice oil, sunflower oil, sesame oil, hardened oils thereof, transesterified oils thereof, and fractionated oils thereof.
<11>
The tofu coagulant according to any one of <7> to <10>, wherein the polyhydric alcohol constituting the ester of the polyhydric alcohol and the fatty acid is preferably one or more selected from propylene glycol, glycerin, polyglycerin, sorbitol and sorbitan.
＜12＞
The tofu coagulant according to any one of <7> to <11>, wherein the fatty acid constituting the ester of the polyhydric alcohol and the fatty acid is preferably one or more selected from the group consisting of caprylic acid, capric acid, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid and erucic acid.
＜13＞
The tofu coagulant according to any one of <1> to <12>, wherein the content of the oily component in the tofu coagulant is preferably 50% by mass or more, more preferably 52% by mass or more, even more preferably 55% by mass or more, and particularly preferably 57% by mass or more.
＜14＞
The tofu coagulant according to any one of <1> to <13>, wherein the content of the oily component in the tofu coagulant is preferably 74% by mass or less, more preferably 72% by mass or less, and even more preferably 70% by mass or less.
＜15＞
The tofu coagulant according to any one of <1> to <14>, wherein the content of the oily component in the tofu coagulant is preferably 50 to 74% by mass, more preferably 52 to 74% by mass, even more preferably 55 to 72% by mass, and particularly preferably 57 to 70% by mass.

＜16＞
The tofu coagulant according to any one of <1> to <15>, wherein the lipophilic emulsifier preferably comprises polyglycerol condensed ricinoleic acid ester, glycerol fatty acid ester, polyglycerol fatty acid ester, organic acid monoglyceride, sorbitan fatty acid ester, propylene glycol fatty acid ester, lecithin, and/or sucrose fatty acid ester, and more preferably comprises polyglycerol condensed ricinoleic acid ester.
＜１７＞
The tofu coagulant according to any one of the above items <1> to <16>, wherein the lipophilic emulsifier contains a polyglycerol condensed ricinoleic acid ester, and the proportion of the polyglycerol condensed ricinoleic acid ester in the lipophilic emulsifier is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more.
＜18＞
The tofu coagulant according to any one of <1> to <17>, wherein the content of the lipophilic emulsifier in the tofu coagulant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more.
＜19＞
The tofu coagulant according to any one of <1> to <18>, wherein the content of the lipophilic emulsifier in the tofu coagulant is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 6% by mass or less.
＜20＞
The tofu coagulant according to any one of <1> to <19>, wherein the content of the lipophilic emulsifier in the tofu coagulant is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and even more preferably 1 to 6% by mass.

＜21＞
The tofu coagulant according to any one of <1> to <20>, wherein the aqueous component contains water, and the proportion of the water in the aqueous component may be 53% by mass or more, and preferably 56% by mass or more.
＜22＞
The tofu coagulant according to any one of <1> to <21>, wherein the aqueous component contains water, and the proportion of the water in the aqueous component is preferably 70% by mass or less, more preferably 67% by mass or less.
＜23＞
The tofu coagulant according to any one of <1> to <22>, wherein the aqueous component contains water, and the proportion of the water in the aqueous component may be 53 to 70% by mass, and preferably 56 to 67% by mass.

＜24＞
A method for producing tofu, comprising applying the tofu coagulant according to any one of the above items <1> to <23> to soymilk having a Brix value of preferably 5 to 14, more preferably 6 to 13, and even more preferably 7 to 13.
＜25＞
A method for producing tofu, comprising applying the tofu coagulant according to any one of the above items <1> to <23> to soymilk having a Brix value of preferably 5 to 12, more preferably 6 to 11, and even more preferably 7 to 9.

＜26＞
A method for producing tofu, comprising dispersing a tofu coagulant containing an oily component, a lipophilic emulsifier, and an aqueous component in soy milk,
the aqueous component comprises magnesium chloride;
The method for producing tofu, comprising applying the following stirring conditions when dispersing the tofu coagulant in the soy milk.
<Mixing conditions>
When soy milk with a Brix value of 1 and the tofu coagulant are mixed so that the ratio of magnesium chloride in the total content of the soy milk and the tofu coagulant is 0.14% by mass, and the mixture is subjected to a dispersion process to disperse the tofu coagulant in the soy milk, the stirring conditions are such that the median diameter of dispersed particles of the tofu coagulant is 80 μm or less in the dispersion liquid one minute after the end of the dispersion process, and the magnesium chloride concentration in the soy milk is 0.005% by mass or more.
＜27＞
The method for producing tofu according to <26>, wherein under the stirring conditions, the median diameter of dispersed particles of the tofu coagulant is preferably 20 μm or more, more preferably 40 μm or more.
＜28＞
The method for producing tofu according to <26> or <27>, wherein under the stirring conditions, the median diameter of dispersed particles of the tofu coagulant is preferably 20 to 80 μm, more preferably 20 to 70 μm, and even more preferably 40 to 65 μm.
＜29＞
The method for producing tofu according to any one of <26> to <28>, wherein under the stirring conditions, a magnesium chloride concentration in the soymilk is preferably 0.100% by mass or less, more preferably 0.090% by mass or less, and even more preferably 0.085% by mass or less.
＜30＞
The method for producing tofu according to any one of <26> to <29>, wherein under the stirring conditions, a concentration of magnesium chloride in the soymilk is preferably 0.005 to 0.100% by mass, more preferably 0.006 to 0.090% by mass, and even more preferably 0.007 to 0.085% by mass.

＜31＞
The method for producing tofu according to any one of <26> to <30>, wherein the stirring conditions are such that the temperature is preferably 90° C. or lower, more preferably 85° C. or lower.
＜32＞
The method for producing tofu according to any one of <26> to <31>, wherein the stirring conditions are such that the temperature is preferably 60° C. or higher, more preferably 70° C. or higher.
＜33＞
The method for producing tofu according to any one of <26> to <32>, wherein a dispersion treatment time for dispersing the tofu coagulant in the soymilk under the stirring conditions is preferably 0.1 to 30 seconds.

＜34＞
The method for producing tofu according to any one of <26> to <33>, wherein the oily component is an oily component according to any one of <7> to <12>.
＜35＞
The method for producing tofu according to any one of <26> to <34>, wherein the content of the oily component in the tofu coagulant is preferably 25% by mass or more, more preferably 30% by mass or more, even more preferably 35% by mass or more, even more preferably 40% by mass or more, and still more preferably 45% by mass or more.
＜36＞
The method for producing tofu according to any one of <26> to <35>, wherein the content of the oily component in the tofu coagulant is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less.
＜３７＞
The method for producing tofu according to any one of <26> to <36>, wherein the content of the oily component in the tofu coagulant is preferably 25 to 80% by mass, more preferably 30 to 80% by mass, even more preferably 35 to 75% by mass, even more preferably 40 to 75% by mass, and still more preferably 45 to 70% by mass.
＜３８＞
The method for producing tofu according to any one of <26> to <37>, wherein the lipophilic emulsifier is the lipophilic emulsifier according to <16> or <17>.
＜３９＞
The method for producing tofu according to any one of <26> to <38>, wherein the content of the lipophilic emulsifier in the tofu coagulant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more.
＜40＞
The method for producing tofu according to any one of <26> to <39>, wherein the content of the lipophilic emulsifier in the tofu coagulant is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 6% by mass or less.
＜41＞
The method for producing tofu according to any one of the above <26> to <40>, wherein the content of the lipophilic emulsifier in the tofu coagulant is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and even more preferably 1 to 6% by mass.
＜42＞
The method for producing tofu according to any one of the above <26> to <41>, wherein the total content of the oily component and the lipophilic emulsifier is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, and still more preferably 45% by mass or more.
＜43＞
The method for producing tofu according to any one of <26> to <42>, wherein the total content of the oily component and the lipophilic emulsifier is preferably 82% by mass or less, more preferably 77% by mass or less, and even more preferably 72% by mass or less.
＜44＞
The method for producing tofu according to any one of the above <26> to <43>, wherein the total content of the oily component and the lipophilic emulsifier is preferably 30 to 82 mass%, more preferably 35 to 82 mass%, even more preferably 40 to 77 mass%, and still more preferably 45 to 72 mass%.

＜45＞
The method for producing tofu according to any one of <26> to <44>, wherein the aqueous component contains water, and the proportion of the water in the aqueous component may be 53% by mass or more, and preferably 56% by mass or more.
＜46＞
The method for producing tofu according to any one of the above items <26> to <45>, wherein the aqueous component contains water, and the proportion of the water in the aqueous component is preferably 70% by mass or less, more preferably 67% by mass or less.
＜47＞
The method for producing tofu according to any one of <26> to <46>, wherein the aqueous component contains water, and the proportion of the water in the aqueous component may be 53 to 70% by mass, and preferably 56 to 67% by mass.
＜48＞
The method for producing tofu according to any one of <26> to <47>, wherein the proportion of the magnesium chloride in the aqueous component is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 28% by mass or more.
＜49＞
The method for producing tofu according to any one of <26> to <48>, wherein a ratio of the magnesium chloride in the aqueous component is preferably 53% by mass or less, more preferably 50% by mass or less, even more preferably 45% by mass or less, even more preferably 40% by mass or less, and even more preferably 38% by mass or less.
＜50＞
The method for producing tofu according to any one of the above <26> to <49>, wherein the ratio of the magnesium chloride in the aqueous component is preferably 20 to 53% by mass, more preferably 25 to 50% by mass, even more preferably 28 to 45% by mass, even more preferably 28 to 40% by mass, and even more preferably 28 to 38% by mass.

＜51＞
The method for producing tofu according to any one of <26> to <50>, comprising dispersing the tofu coagulant in soymilk having a Brix value of preferably 5 or more, more preferably 6 or more, and even more preferably 7 or more, by applying the stirring conditions.
＜52＞
The method for producing tofu according to any one of <26> to <51>, comprising dispersing the tofu coagulant in soymilk having a Brix value of preferably 14 or less, more preferably 13 or less, even more preferably 12 or less, even more preferably 11 or less, and even more preferably 10 or less, by applying the stirring conditions.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these.

[Analysis Method]
<Brix value of soy milk>
The Brix value of the soy milk was measured at 20° C. using a soy milk concentration refractometer (PAL-27S, manufactured by Atago Co., Ltd.).

Preparation Example 1 Preparation of coagulants according to the first and second embodiments A tofu coagulant was obtained by mixing the ingredients (unit: parts by mass) as shown in Table 1. The specific method is described below.

As oily components, corn oil (product name: Nisshin Corn Oil (S), manufactured by Nisshin Oillio Group, Ltd.), medium-chain fatty acid triglyceride (MCT) (product name: Coconard MT, manufactured by Kao Corporation), or propylene glycol diester (manufactured by Nippon Surfactant Industry Co., Ltd.) were used.
As a lipophilic emulsifier, polyglycerol condensed ricinoleic acid ester (PGPR) (product name: Sunsoft No. 818SK, manufactured by Taiyo Kagaku Co., Ltd., glycerol average polymerization degree: 6) was used.
As magnesium chloride hexahydrate (MgCl ₂ .6H ₂ O), Soft Wafer (product name, manufactured by Ako Kasei Co., Ltd.) was used.

Magnesium chloride hexahydrate was dissolved in water at 70°C in the blending ratio shown in Table 1 to prepare an aqueous magnesium chloride solution (aqueous component). The oily component and lipophilic emulsifier were mixed at 70°C in the blending ratio shown in Table 1 to prepare an oil composition. The oil composition at 70°C was stirred at 6000 rpm using a homomixer (product name: TK homomixer MARKII, manufactured by Primix Corporation) and the aqueous solution at 70°C was added to obtain a preliminary emulsion (preliminary emulsification time: 3 minutes). The preliminary emulsion was further emulsified and dispersed by stirring at 9000 to 14000 rpm for 3 to 5 minutes to obtain tofu coagulants (Experimental Examples 1 to 5 and 7 to 13) which are water-in-oil emulsion compositions. The tofu coagulant of Experimental Example 5 was dried under reduced pressure at 60°C and 10 kPa and concentrated to obtain the tofu coagulant of Experimental Example 6. The blend ratios shown in the column for Experimental Example 6 are the component compositions after concentration.

[Test Example 1] Evaluation of uniformity of coagulant The properties of the tofu coagulants obtained in Experimental Examples 1 to 13 were visually observed and evaluated according to the following evaluation criteria. The results are shown in Table 1.

- Evaluation criteria for properties -
◯: The composition is stable and each component is uniformly present.
×: The properties of the coagulant are non-uniform.

[Test Example 2] Median diameter of coagulant in dispersion Soy milk with a Brix value of 1 (commercially available soy milk (product name: Oishii unadjusted soy milk, manufactured by Kikkoman Corporation, Brix value: 10) diluted 8 times) and the tofu coagulant prepared in Preparation Example 1 above (Experimental Examples 1 to 13) were fed using a mono pump at a flow rate of 1 L/min, and treated at 4000 rpm using a Milder (MDN303V, rotor/stator G/M/F, manufactured by Pacific Machinery Works) to disperse the coagulant in the soy milk. The soy milk temperature was set to 85°C during the dispersion treatment using the Milder. The tofu coagulants of Experimental Examples 1 to 13 were fed so that the magnesium chloride concentration in the resulting dispersion was 0.14% by mass.

The dispersion discharged from the Milder outlet was continuously sampled for 10 seconds, and the resulting dispersion was quickly diluted 10-fold with ion-exchanged water (25°C). One minute after the end of the dispersion process (one minute after the start of sampling), the median diameter of the dispersed particles in the diluted solution (corresponding to the volume-based median diameter of the dispersed particles in the dispersion one minute after the end of the dispersion process) was measured using a particle size distribution analyzer (SALD-2100, manufactured by Shimadzu Corporation). The results are shown in Table 1.

[Test Example 3] Release of magnesium chloride 150 ml (80°C) of the dispersion obtained in the same manner as in Test Example 2 was quickly placed in a glass container (screw vial SV-150, manufactured by Nichiden Rika Glass Co., Ltd.), and immediately while stirring (440 rpm) with a stirrer (stirrer bar PTFE coated 8 x 30 mm, manufactured by Tokyo Glass Instruments Co., Ltd.), the electrical conductivity was measured every 5 seconds using a portable multi-purpose water quality meter (MM-42DP, manufactured by DKK-TOA Corporation). During this time, the temperature was kept at 80°C. Based on the obtained measurement results, the magnesium chloride concentration in the soy milk was calculated by the following (Equation 1) using a calibration curve prepared in advance. The magnesium chloride concentration (mass%) in the soy milk was calculated based on the amount of magnesium chloride released into the soy milk from the start of the dispersion treatment to 1 minute after the end of the dispersion treatment (start of collection). The results are shown in Table 1.

Magnesium chloride concentration (mass%)=Magnesium chloride (g)/(Magnesium chloride (g)+Soy milk (g))×100 (Equation 1)

[Preparation Example 2] Tofu production using tofu coagulant Brix 7 soy milk (temperature adjusted to 85°C) and the tofu coagulant of Experimental Examples 1 to 12 were pumped using a mono pump so that the magnesium chloride concentration in the mixed liquid was 0.14%, and the coagulant was dispersed in the soy milk using a Milder (MDN303V, rotor/stator G/M/F, manufactured by Pacific Machinery Works) at 80°C, 4000 rpm, and a flow rate of 1 L/min. These dispersion conditions are general dispersion conditions that are widely adopted in the production of tofu.
150 mL of each of the obtained dispersions was filled into a PP (polypropylene) container (model number: C-150, manufactured by Daiichi Pack Machinery Co., Ltd.), the container was sealed, and then aged at 80° C. for 40 minutes to produce tofu.

[Test Example 4] Compression Breakage Test of Tofu The above tofu stored overnight at 5°C was cut into four cylinders with a diameter of 28 mm and a height of 15 mm, and a compression breakage test was performed using a small tabletop testing machine (Ez-TEST, manufactured by Shimadzu Corporation). The test was performed using a plastic plunger with a diameter of 48 mm. The maximum strength (gf) was calculated when the plunger was lowered to the 60% strain point at a speed of 30 mm/min in the compression breakage test. The average of the four calculated values obtained was taken as the tofu hardness (gf) of the tofu. The results are shown in Table 1.

[Test Example 5] Texture of tofu As in Test Example 4, the texture of tofu stored overnight in a refrigerator (5°C) was evaluated by three expert panelists. Specifically, the tofu was scored according to the following evaluation criteria, and the average scores of the three expert panelists were compared. The evaluation results of the three panelists were all the same. The results are shown in Table 1 below.

-Texture evaluation criteria-
5 points: The tofu has a more uniform internal structure, is more elastic and has a very smooth texture.
4 points: The tofu has a uniform internal structure, is very elastic, and has a smoother texture.
3 points: The internal phase of the tofu is almost uniform, it feels elastic and has a smooth texture.
2 points: The internal phase of the tofu is uneven, it does not feel elastic, and the texture lacks smoothness.
1 point: Cannot be evaluated due to poor clotting.

[Test Example 6] Adhesion of coagulant components to the bottom of the container After tofu production, the container was tilted and the tofu inside was removed, and the adhesion of the coagulant components to the bottom of the container was scored and compared according to the following evaluation criteria. The results are shown in Table 1.

- Evaluation criteria for adhesion condition -
3 points: No coagulant components adhered to the bottom of the container.
2 points: Adhesion of coagulant components to the bottom of the container is observed.
1 point: A larger amount of coagulant component adhered to the bottom of the container.

As shown in Table 1, in Experimental Example 9, in which the ratio of magnesium chloride in the aqueous component was lower than that of the coagulant according to the first embodiment, the release of magnesium chloride did not meet the requirement of the coagulant according to the second embodiment. In this Experimental Example 9, the tofu obtained had poor elasticity, and the internal phase of the tofu was uneven and lacked smoothness in texture. Furthermore, adhesion of the coagulant components to the bottom of the container was also observed.
Experimental Examples 10 and 12, which had a high content of oily components and, as a result, the total content of the oily components and the lipophilic emulsifier was greater than the regulation of the coagulant according to the first embodiment, did not meet the regulation of the coagulant according to the second embodiment in terms of magnesium chloride release. In these cases, tofu could not be obtained due to poor coagulation. In Experimental Examples 10 and 12, the amount of coagulant components adhering to the bottom of the container was greater.
In Experimental Example 11, in which the content of oily components was low and the total content of the oily components and lipophilic emulsifier was less than that of the coagulant specified in the first embodiment, the median diameter of the coagulant in the dispersion (median diameter of dispersed particles) was greater than that of the coagulant specified in the second embodiment. In Experimental Example 11, the tofu had poor elasticity, and the internal phase of the tofu was uneven and lacked smoothness in texture. Furthermore, adhesion of the coagulant components to the bottom of the container was also observed.
In Experimental Example 13, in which the proportion of magnesium chloride in the aqueous component was higher than that specified for the coagulant according to the first embodiment, it was not even possible to obtain a coagulant with a uniform composition.
In contrast, the coagulants according to the first and second embodiments were all in a stable composition state (Experimental Examples 1 to 8), had smaller particle diameters when dispersed in soy milk, and were capable of gradually releasing a sufficient amount of magnesium chloride in soy milk. Furthermore, the tofu obtained using these coagulants had excellent elasticity, and the internal phase of the tofu was in a good condition, giving it a smooth texture. Furthermore, no adhesion of the coagulant components to the bottom of the container was observed.

Preparation Example 3 Preparation of tofu coagulant used in the manufacturing method according to the third embodiment Raw materials were mixed (unit: parts by mass) as shown in Table 2, and emulsified and dispersed in the same manner as in Preparation Example 1 to obtain tofu coagulants (Experimental Examples 14 to 23) that are water-in-oil emulsion compositions. PGPR (Sunsoft 818SK) was used as the lipophilic emulsifier.

[Test Example 7] Evaluation of uniformity of coagulant For the tofu coagulants obtained in Experimental Examples 14 to 23, the uniformity of the coagulant was evaluated in the same manner as in Test Example 1. The results are shown in Table 2.

[Test Example 8] Median diameter of coagulant in dispersion Soy milk with a Brix value of 1 (commercially available soy milk (product name: Oishii unadjusted soy milk, manufactured by Kikkoman Corporation, Brix value of 10) diluted 8 times) and the tofu coagulant prepared in Preparation Example 3 above (Experimental Examples 14 to 21) were fed at a flow rate of 1 L/min using a mono pump, and treated with a Milder (MDN303V, rotor/stator G/M/F, manufactured by Pacific Machinery Works) at a flow rate of 1 L/min under the conditions shown in Table 2 below, "Method of dispersing coagulant in soy milk with a Brix value of 1", to disperse the coagulant in the soy milk. The temperature of the soy milk in the dispersion treatment using the Milder was set to 85°C. The tofu coagulant in Experimental Examples 14 to 21 was fed so that the magnesium chloride concentration in the resulting dispersion was 0.14% by mass.
Also, soy milk with a Brix value of 1 (commercially available soy milk (product name: Oishii unadjusted soy milk, manufactured by Kikkoman Corporation, Brix value of 10) diluted 8-fold) was mixed with the tofu coagulant prepared in Preparation Example 3 above (Experimental Examples 22 and 23), and dispersed for 10 seconds at 5000 rpm using a TK Aji Homo Mixer (manufactured by Primix Corporation, Model 2M-03, shown as "TK Homo Mixer" in Table 2). The soy milk temperature during the dispersion process was set to 85°C. In Experimental Examples 22 and 23, the tofu coagulant was mixed so that the magnesium chloride concentration in the resulting dispersion liquid was 0.14 mass%.

The obtained dispersion was immediately diluted 10-fold with ion-exchanged water (25°C), and 1 minute after the end of the dispersion process, the median diameter of the dispersed particles in the diluted solution (corresponding to the volume-based median diameter in the dispersion 1 minute after the end of the dispersion process) was measured using a particle size distribution measuring device (SALD-2100, manufactured by Shimadzu Corporation). The results are shown in Table 2. When a Milder was used as the disperser, the dispersion discharged from the Milder's outlet was continuously collected for 10 seconds to obtain the dispersion. In other words, when a Milder was used as the disperser, 1 minute after the end of the dispersion process means 1 minute after the start of collection.

[Test Example 9] Release of magnesium chloride The magnesium chloride concentration (mass%) in soy milk was calculated based on the amount of magnesium chloride released into soy milk from the start of dispersion treatment to 1 minute after the end of dispersion treatment, using a dispersion obtained in the same manner as in Test Example 8 above, in the same manner as in Test Example 3 above. The results are shown in Table 2.

Preparation Example 4: Production of tofu using a tofu coagulant Soy milk with a Brix value of 7 (temperature adjusted to 85°C) and the tofu coagulants of Experimental Examples 14, 16 to 21 were pumped using a monopump so that the magnesium chloride concentration in the mixture was 0.14%, and the coagulant was dispersed in the soy milk under the same stirring conditions as those for obtaining the dispersion in Test Example 8 above.
In addition, soy milk with a Brix value of 7 (adjusted to 85°C) and the tofu coagulants of Experimental Examples 22 and 23 were mixed so that the concentration of magnesium chloride in the mixture was 0.14%, and the coagulants were dispersed in the soy milk under the same stirring conditions as those for obtaining the dispersion in Test Example 8 above.
In addition, soy milk with a Brix value of 12 (temperature adjusted to 85°C) and the tofu coagulant in Experimental Example 15 were pumped using a monopump so that the magnesium chloride concentration in the mixed liquid was 0.14%, and the coagulant was dispersed in the soy milk under the same stirring conditions as those for obtaining the dispersion in Test Example 8 above.
150 mL of each of the obtained dispersions was filled into a PP (polypropylene) container (model number: C-150, manufactured by Daiichi Pack Machinery Co., Ltd.), the container was sealed, and then aged at 80° C. for 40 minutes to produce tofu.

[Test Examples 10 to 12] Evaluation of Tofu For each of the obtained tofu, the hardness, texture, and adhesion state of the coagulant components to the bottom of the container were evaluated in the same manner as in the above Test Examples 4 to 6. The results are shown in Table 2.

As shown in Table 2, the coagulant in Experimental Example 19 is the same as the coagulant in Experimental Example 11 in Table 1, and does not satisfy the composition of the coagulant according to the first embodiment. Also, the coagulants in Experimental Examples 20 and 21 have a small amount of oily components, and as a result, the total content of the oily components and lipophilic emulsifier does not satisfy the composition of the coagulant according to the first embodiment. Therefore, even if these coagulants are dispersed in soy milk with a low Brix value under normal dispersion conditions, it is not possible to obtain tofu of the desired high quality.
However, from the results in Table 2, it was found that even when such a coagulant is used, the dispersed particles can be small with a median diameter of 80 μm or less and dispersed at a high particle density in soymilk by significantly improving the stirring conditions in the dispersion process in soymilk with a Brix value of 1. It was also found that by applying such stirring conditions to the dispersion process of the coagulant in soymilk in the tofu production process, tofu with excellent elasticity, a more uniform internal phase and a smoother texture can be obtained, and adhesion of the coagulant components to the bottom of the container can be suppressed.

As with Experimental Example 19, the coagulant in Experimental Example 23 is also the same as the coagulant in Experimental Example 11 in Table 1, and does not meet the composition of the coagulant according to the first embodiment. When such a coagulant is used and the stirring conditions in the dispersion step in soy milk with a Brix value of 1 do not meet the provisions of the third embodiment, it has become clear that tofu exhibiting the desired effects cannot be obtained even if such stirring conditions are applied to the dispersion step of the coagulant in soy milk in the tofu manufacturing process.

Furthermore, experimental examples 14 to 18 and 22 use coagulants that satisfy the composition of the coagulant according to the first embodiment, and by using such coagulants and dispersing the coagulant in soy milk with a Brix value of 1 under stirring conditions that satisfy the provisions of the third embodiment, and applying such stirring conditions to the dispersing step of the coagulant in soy milk during the tofu manufacturing process, it has become clear that tofu with excellent elasticity, a more uniform internal phase and a smoother texture can be obtained, and that adhesion of the coagulant components to the bottom of the container can also be suppressed.

Claims (5)

A tofu coagulant comprising an oil component, a lipophilic emulsifier, and an aqueous component,
The tofu coagulant has a total content of the oily component and the lipophilic emulsifier of 52 to 75% by mass, and a ratio of magnesium chloride to the aqueous component of 30 to 44% by mass. The tofu coagulant according to claim 1, wherein the lipophilic emulsifier comprises a polyglycerol condensed ricinoleic acid ester, and the content of the lipophilic emulsifier in the tofu coagulant is 0.1 to 10% by mass. A tofu coagulant comprising an oil component, a lipophilic emulsifier, and an aqueous component,
the aqueous component comprises magnesium chloride;
the lipophilic emulsifier contains a polyglycerol condensed ricinoleic acid ester, and the content of the lipophilic emulsifier in the tofu coagulant is 0.1 to 10% by mass;
When the tofu coagulant is dispersed in soy milk under the following dispersion conditions, the tofu coagulant is in the following dispersed state in the dispersion liquid one minute after the end of the dispersion treatment.
<Dispersion conditions>
Soy milk with a Brix value of 1 and the tofu coagulant are mixed so that the ratio of the magnesium chloride to the total content of the soy milk and the tofu coagulant is 0.14 mass %, and the mixture is subjected to a dispersion treatment using a Milder at a temperature of 85°C, a rotation speed of 4000 rpm, and a flow rate of 1 L/min to disperse the tofu coagulant in the soy milk .
<Dispersion state>
The median diameter of dispersed particles of the tofu coagulant is 80 μm or less, and the concentration of the magnesium chloride in the soy milk is 0.005 mass % or more. A method for producing tofu, comprising dispersing a tofu coagulant containing an oily component, a lipophilic emulsifier, and an aqueous component in soy milk,
the aqueous component comprises magnesium chloride;
the lipophilic emulsifier contains a polyglycerol condensed ricinoleic acid ester, and the content of the lipophilic emulsifier in the tofu coagulant is 0.1 to 10% by mass;
The method for producing tofu, comprising applying the following stirring conditions when dispersing the tofu coagulant in the soy milk.
<Mixing conditions>
When soy milk having a Brix value of 1 and the tofu coagulant are mixed so that the ratio of the magnesium chloride in the total content of the soy milk and the tofu coagulant is 0.14% by mass, and the mixture is subjected to a dispersion treatment to disperse the tofu coagulant in the soy milk, the stirring conditions are such that the median diameter of dispersed particles of the tofu coagulant is 80 μm or less in the dispersion liquid one minute after the end of the dispersion treatment, and the magnesium chloride concentration in the soy milk is 0.005% by mass or more. The method for producing tofu according to claim 4, further comprising dispersing the tofu coagulant in soy milk having a Brix value of 7 or more by applying the stirring conditions.