JP7575882B2 - Solid soybean food, method for producing solid soybean food, and method for reducing the yellow color of solid soybean food - Google Patents

Description

The present invention relates to a solid soy food, a method for producing a solid soy food, and a method for reducing the yellow color of a solid soy food. More specifically, the present invention relates to a solid soy food that uses soy powder and has a reduced yellow color derived from the soy powder by adding a specific emulsifier to the solid soy food, a method for producing the same, and a method for reducing the yellow color of a solid soy food.

Soy foods have long been familiar to people as tofu, soy milk, natto, etc., but in recent years, due to the growing health consciousness, the components contained in soybeans have been attracting attention. The nutrients contained in okara are also expected to have health benefits, and soy milk and tofu containing okara, which are made from soybean powder, are being sold.
Incidentally, soybean powder (hereinafter also referred to as soybean flour) obtained by dehulling and grinding soybeans has a yellowish appearance, and is known to become darker yellow when heated. This yellow coloring is believed to be due to polyphenols contained in large amounts in soybean pulp. Therefore, soy milk and tofu produced from soybean powder are yellowish compared to conventional soy milk and tofu that do not contain soybean pulp, and there has been a demand for products with the same whiteness as conventional products.

To date, a method for producing tofu with a vivid white color and luster has been reported, using soybeans stored for a specified period at 0° C. or below and at a temperature above freezing (Patent Document 1). Also, a method for producing a white tofu-like gel has been reported, using a method for producing a soy protein gel in which a divalent metal salt is added to soy protein in an aqueous system and then a high-pressure treatment is performed to form a gel (Patent Document 2).
However, there is room for investigation into a simpler method for improving the yellowish color of soybean foods made from soybean powder as a raw material.

JP 2008-142053 A Japanese Patent Application Publication No. 06-022701

In view of the above problems, the present invention aims to provide a solid soy food, a method for producing a solid soy food, and a method for reducing the yellow color of a solid soy food.

The inventors discovered that the yellow color of a solid soy food containing soy powder and a coagulant can be lightened by adding a specific emulsifier to the solid soy food, and thus completed the present invention. Specifically, the present invention provides the following:

(1) A solid soybean food product containing 5 to 40% by mass of soybean powder, 0.1 to 2% by mass of a coagulant, and 0.4 to 4% by mass of one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides.
(2) The solid soybean food according to (1), wherein the average particle size of the soybean powder is 10 to 60 μm.
(3) A solid soybean food according to (1) or (2), in which the HLB of the polyglycerol fatty acid ester having an average degree of polymerization of 3 or more and/or the sucrose fatty acid ester is 10 or more.
(4) A method for producing a solid soybean food, comprising the steps of: preparing a solution containing 5 to 40% by mass of soybean powder, 0.1 to 2% by mass of a coagulant, and 0.4 to 4% by mass of one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides; and coagulating the solution.
(5) A method for lightening the yellow color of a solid soybean food containing soybean powder by adding one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides.
(6) A method for lightening the yellow color of a solid soybean food by adding 0.4 to 4 mass% of one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides to a solid soybean food containing 5 to 40 mass% soybean powder and 0.1 to 2 mass% of a coagulant.

According to the present invention, by adding a specific emulsifier to a solid soy food product containing soy powder and a coagulant, the yellow color derived from the soy powder can be lightened.

Specific embodiments of the present invention are described in detail below, but the present invention is not limited to the following embodiments and can be modified as appropriate within the scope of the invention.

[Solid soybean food]
The solid soybean food of the present invention contains 5-40% by mass of soybean powder, 0.1-2% by mass of a coagulant, and 0.4-4% by mass of one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides, and is characterized in that the yellow color derived from the soybean powder of the solid soybean food is lighter. Here, lighter yellow color refers to a visual confirmation that the yellow color is lighter than that of a solid soybean food that does not contain the sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides.
The solid soybean food of the present invention is a food in which a solution containing the above-mentioned soybean powder, a coagulant, and an emulsifier is coagulated by the coagulant. The solid soybean food of the present invention is not particularly limited as long as it is a food in a state in which it has lost fluidity (including a semi-solid state) at room temperature (1 to 30°C), and examples of the solid soybean food include tofu, tofu-like foods, jelly-like foods, etc.

[Soybean powder]
Specifically, the soybean powder used in the present invention can be one or more types of soybean flour selected from full-fat soybean flour obtained by grinding dehulled whole soybeans, defatted soybean flour obtained by grinding defatted soybeans, and deodorized full-fat soybean flour obtained by heating and deodorizing full-fat soybean flour. If the soybean powder used in the present invention is full-fat soybean flour, the effect of the coagulant can be easily obtained during the production of the solid soybean food of the present invention, which is preferable.
The content of the soybean powder in the solid soybean food of the present invention is preferably 7 to 35% by mass, more preferably 10 to 30% by mass, and most preferably 15 to 25% by mass. When the content of the soybean powder is within the above range, the effect of the coagulant is more easily obtained during the production of the solid soybean food of the present invention.

The soybean powder used in the present invention has an average particle size of preferably 10 to 60 μm, more preferably 15 to 50 μm, and most preferably 20 to 40 μm. When the average particle size is within the above range, a solid soybean food with physical properties that are easy to eat can be obtained.
In the present invention, the average particle size means a particle size at 50% of the cumulative value in the particle size distribution obtained by the laser diffraction/scattering method. In addition, the soybean powder used in the present invention is preferably such that the cumulative value of 10% is 0.3 times or more of the average particle size and the cumulative value of 90% is 3 times or less of the average particle size when measured by the above-mentioned measurement method, and more preferably such that the cumulative value of 10% is 0.4 times or more of the average particle size and the cumulative value of 90% is 2.6 times or less of the average particle size.

[Coagulant]
The coagulant used in the present invention is not particularly limited as long as it coagulates (makes the fluidity of) the solution containing the soybean powder and coagulant used in the present invention, as well as one or more selected from sucrose fatty acid ester, polyglycerol fatty acid ester having an average degree of polymerization of 3 or more, propylene glycol fatty acid ester, and citric acid monoglyceride, but gelling agents, bittern, etc. can be used. Examples of the gelling agent include carrageenan, locust bean gum, agar, deacylated gellan gum, native gellan gum, glucomannan, xanthan gum, alginate, etc., and mixtures thereof. Examples of the bittern include crude seawater magnesium chloride, magnesium chloride, glucono delta lactone, etc., and mixtures thereof. It is preferable to use bittern as the coagulant used in the present invention.
The content of the coagulant in the solid soybean food of the present invention is preferably 0.1 to 1.5% by mass, more preferably 0.2 to 1% by mass, and most preferably 0.2 to 0.6% by mass. When the content of the coagulant is within the above range, it is easier to obtain a solid soybean food with physical properties that are easy to eat.

[Sucrose fatty acid ester]
The sucrose fatty acid ester used in the present invention is one in which a fatty acid is ester-bonded to sucrose, and a commercially available sucrose fatty acid ester may be used, or a sucrose fatty acid ester produced by a conventionally known method may be used. The sucrose fatty acid ester used in the present invention is preferably a straight-chain fatty acid having 12 to 24 carbon atoms as a constituent fatty acid (e.g., lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, erucic acid, etc.), and more preferably one or two selected from palmitic acid and stearic acid. Preferred examples of the sucrose fatty acid ester include sucrose palmitate, sucrose stearate, etc.
The sucrose fatty acid ester used in the present invention preferably has an HLB of 10 or more, more preferably 12 or more, and most preferably 12 to 16. Here, HLB indicates the balance between hydrophilic groups and lipophilic groups in an emulsifier, and is a value determined by a known measurement method. For example, the HLB value of the emulsifier can be calculated using the Atlas method. The Atlas method is as follows:
HLB=20×(1-S/A)
S: Saponification value A: This refers to a method for calculating the HLB value from the neutralization value of the fatty acid in the ester.

[Polyglycerol fatty acid ester with average polymerization degree of 3 or more]
The polyglycerol fatty acid ester having an average degree of polymerization of 3 or more used in the present invention is a glycerol polymer (polyglycerol) to which a fatty acid is esterified. Commercially available polyglycerol fatty acid esters may be used, or polyglycerol fatty acid esters produced by a conventionally known method may be used. The polyglycerol is obtained as a mixture having various degrees of polymerization. The polyglycerol fatty acid ester having an average degree of polymerization of 3 or more used in the present invention may be one that has been highly purified by molecular distillation or the like, but since it is generally difficult to isolate polyglycerol having a degree of polymerization of 4 or more, a mixture of polyglycerol fatty acid esters having various degrees of polymerization is acceptable. The average degree of polymerization is preferably 3 to 30, more preferably 4 to 12, and most preferably 5 to 10. Here, the average degree of polymerization is expressed as follows, where n is the average degree of polymerization of the raw material polyglycerol, m is the average molecular weight, and OHV is the hydroxyl value of the raw material polyglycerol:
m = 74n + 18
OHV=56110(n+2)/m
Therefore, the OHV can be determined using the Standard Method for Analysis of Fats, Oils and Related Compounds (2,3,6,2-1996 Hydroxyl Value (Pyridine-Acetic Anhydride Method)) and the average degree of polymerization of polyglycerol can be calculated from the above formula.
The polyglycerol fatty acid ester having an average degree of polymerization of 3 or more used in the present invention is preferably a straight-chain fatty acid having 12 to 24 carbon atoms (e.g., lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, erucic acid, etc.), more preferably one or two selected from stearic acid and oleic acid. Preferred examples of the polyglycerol fatty acid ester having an average degree of polymerization of 3 or more include pentaglycerol stearate (average degree of polymerization 5), decaglycerol oleate (average degree of polymerization 10), etc.
The polyglycerol fatty acid ester having an average degree of polymerization of 3 or more used in the present invention preferably has an HLB of 10 or more, more preferably 12 or more, and most preferably 12-14.

[Propylene glycol fatty acid ester]
The propylene glycol fatty acid ester used in the present invention is a monoester or diester of a fatty acid and propylene glycol, and a commercially available propylene glycol fatty acid ester may be used, or a propylene glycol fatty acid ester produced by a conventionally known method may be used.
The propylene glycol fatty acid ester used in the present invention is preferably a straight-chain fatty acid having 12 to 24 carbon atoms (e.g., lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, erucic acid, etc.), more preferably stearic acid. A preferred example of the propylene glycol fatty acid ester is propylene glycol stearate.

[Citrate monoglyceride]
The citric acid monoglyceride used in the present invention is one in which citric acid and a fatty acid are ester-bonded to glycerin, and a commercially available citric acid monoglyceride may be used, or a citric acid monoglyceride produced by a conventional method may be used.
The citrate monoglyceride used in the present invention is preferably a straight-chain fatty acid having 12 to 24 carbon atoms (e.g., lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, erucic acid, etc.), more preferably oleic acid. A preferred example of the citrate monoglyceride is citrate oleic acid monoglyceride.

The content of one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides in the solid soybean food of the present invention is preferably 0.5 to 3 mass%, more preferably 0.6 to 2 mass%, and most preferably 0.7 to 1.5 mass%. When the content of one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides is within the above range, the effect of fading the yellow color of the solid soybean food is more easily obtained.
Incidentally, if the content of the emulsifier exceeds 4% by mass, the flavor of the solid soybean food of the present invention deteriorates, and therefore it is not preferable.

The solid soybean food of the present invention preferably contains one or two selected from sucrose fatty acid esters and polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, and more preferably contains one or two selected from sucrose fatty acid esters having an HLB of 10 or more and polyglycerol fatty acid esters having an average degree of polymerization of 3 or more and an HLB of 10 or more.

[Other ingredients]
The solid soybean food of the present invention may contain ingredients other than those mentioned above, as long as the ingredients do not impair the effects of the present invention or do not color the food as a whole, such as sugars, acidulants, vitamins, amino acids, salt, flavorings, oils and fats.

The solid soybean food product of the present invention preferably contains water. There are no particular limitations on the water used in the present invention, and tap water, well water, purified water, ion-exchanged water, etc. can be used. The water content in the solid soybean food product of the present invention is preferably 50 to 92% by mass, more preferably 55 to 90% by mass, even more preferably 60 to 88% by mass, and most preferably 70 to 85% by mass.

[L*a*b* color system]
In the present invention, the L*a*b* (L-star, A-star, B-star) color system represents the color characteristics of the solid soybean food of the present invention. *The indices of the color system are lightness (L* value) and chromaticity (a* value, b* value), and can be measured by known methods. The measuring device is, for example, a color difference meter (Konica A CHROMA METER CR-5 manufactured by Minolta Co., Ltd. can be used.
In the L*a*b* color system, the b value represents the saturation of yellow. The higher the b value, the higher the saturation of yellow. The lower the b value, the lower the saturation of yellow. Therefore, in the present invention, the yellowish appearance of the solid soybean food originating from the soybean powder is suppressed by the emulsifier (sucrose fatty acid ester, polyglycerin fatty acid ester having an average polymerization degree of 3 or more, propylene glycol fatty acid ester, The thinning effect of adding one or more types of citric acid monoglycerides can be confirmed by a decrease in the b value.
Specifically, the solid soybean food of the present invention is prepared by removing the emulsifier (one or two selected from sucrose fatty acid ester, polyglycerol fatty acid ester having an average degree of polymerization of 3 or more, propylene glycol fatty acid ester, and citric acid monoglyceride). The difference (b1-b2) between the b value (b1) of the food produced excluding the soybean extract (or more than one kind) and the b value (b2) of the solid soybean food of the present invention is preferably 0.30 or more, more preferably The difference in b value is preferably 0.70 or more, and most preferably 1.20 or more. When the difference in b value is within the above range, the effect of the present invention can be clearly confirmed even by visual inspection.

[Method for producing solid soybean food]
The method for producing a solid soybean food of the present invention includes the steps of preparing a solution containing 5 to 40% by mass of soybean powder, 0.1 to 2% by mass of a coagulant, and 0.4 to 4% by mass of one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides, and coagulating the solution.
The process for preparing the solution is not particularly limited as long as it is a process that can obtain a solution in which soybean powder, a coagulant, and one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides are uniformly dispersed and dissolved.
When a gelling agent is used as the coagulant, it is preferable to heat the mixture to a temperature at which the gelling agent is completely dissolved to obtain a homogeneous solution. When bittern is used as the coagulant, it is preferable to stir the solution in which the soybean powder and the emulsifier are uniformly dispersed and dissolved at 70 to 95°C (product temperature) for 15 to 60 minutes, add bittern, and stir to obtain a homogeneous solution.
It is also preferable to replenish the water that has evaporated during the heating and stirring.

The step of solidifying the solution is not particularly limited as long as the solidifying agent (gelling agent and/or bittern) in the solution can solidify the solution (make it lose fluidity). Specifically, when a gelling agent is used as the solidifying agent, the solution in which the gelling agent is dissolved is solidified by bringing the product temperature to a value equal to or lower than the gelling temperature of the gelling agent. When bittern or the like is used as the solidifying agent, the solution in which the bittern is dissolved is brought to 75 to 90°C (product temperature) and then cooled to solidify.
The preferred embodiments of the solid soybean food are the same as those described above for the solid soybean food of the present invention.

[Method for reducing the yellow color of solid soy foods]
The method for lightening the yellow color of a solid soybean food of the present invention is a method for incorporating one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides into a solid soybean food containing soybean powder. Here, lightening the yellow color in the present invention refers to a visual confirmation that the yellowish color derived from soybean powder is lighter than that of a solid soybean food that does not contain the sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides.

The method of lightening the yellow color of the solid soybean food of the present invention can be confirmed by a decrease in the b value of the L*a*b* color system. Specifically, the difference (b1-b2) between the b value (b2) of the solid soybean food of the present invention and the b value (b1) of a food produced by removing an emulsifier (one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters with an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides) from the solid soybean food of the present invention is preferably 0.30 or more, more preferably 0.70 or more, and most preferably 1.20 or more. When the difference in b value is as above, the effect of the present invention can be clearly confirmed.

The method for lightening the yellow color of the solid soybean food of the present invention is preferably a method in which a solid soybean food containing 5 to 40% by mass of soybean powder and 0.1 to 2% by mass of a coagulant is added with 0.4 to 4% by mass of one or more selected from sucrose fatty acid esters, polyglycerol fatty acid esters having an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides.
The preferred embodiments of the solid soybean food are the same as those described above for the solid soybean food of the present invention.

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

[Tofu production]
Tofu was produced using the formulations in Tables 1 to 3 in the following manner.
1. Full fat soy flour (trade name: Soya Flower NSA, manufactured by Nisshin Oillio Group Co., Ltd., average particle size: 29.0 μm (accumulated value 10%: 13.2 μm, accumulated value 90%: 72.2 μm), defoamer (trade name: Asahi Silicone AF105, manufactured by Asahi Chemical Industry Co., Ltd.), emulsifier, and water were uniformly mixed using a homomixer (3000 rpm, 5 minutes).
2. The prepared mixture was heated and stirred with a propeller for 30 minutes while being kept at 90° C. The amount of water evaporated during the heating and stirring was replenished, and then bittern (product name: magnesium chloride, manufactured by Kanto Chemical Co., Ltd.) was added and dissolved by stirring.
3. The mixture containing the bittern was filled into a 100 mL container, cooled, and then refrigerated to solidify the mixture. As a control, tofu containing no emulsifier was also produced using the same procedure as above.
The emulsifiers used in the table are as follows:
Emulsifier-1: Sucrose palmitate (Ryoto Sugar Ester P-1670, manufactured by Mitsubishi Chemical Foods Co., Ltd.), HLB 16
Emulsifier-2: Sucrose stearate (Ryoto Sugar Ester S-370, manufactured by Mitsubishi Chemical Foods Co., Ltd.), HLB 3
Emulsifier-3: Decaglycerin oleate (Poem J-0381V, manufactured by Riken Vitamin Co., Ltd.), HLB 12
Emulsifier-4: Pentaglycerin stearate (Sunsoft A-186E, Taiyo Kagaku Co., Ltd.), HLB 4
Emulsifier-5: Propylene glycol stearate (Rikemal PS-100, manufactured by Riken Vitamin Co., Ltd.), HLB 3.7
Emulsifier-6: Citrate oleate monoglyceride (Poem K-37V, manufactured by Riken Vitamin Co., Ltd.), HLB 6
Emulsifier-7: Succinic acid stearic acid monoglyceride (Poem B-30, manufactured by Riken Vitamin Co., Ltd.), HLB 5.5
Emulsifier-8: Diglycerol stearate (Poem J-2081V, manufactured by Riken Vitamin Co., Ltd.), HLB 6
Emulsifier-9: Sorbitan acid oleate (Poem O-80V, manufactured by Riken Vitamin Co., Ltd.), HLB 4.9
Emulsifier-10: Polyglycerol condensed ricinoleic acid ester (Sunsoft No. 818H, Taiyo Kagaku Co., Ltd.), HLB 1-2
Emulsifier-11: Enzymatically decomposed lecithin (Reshimal EL, manufactured by Riken Vitamin Co., Ltd.)

[Evaluation of tofu color]
The degree of yellowness of the tofu produced above was evaluated visually and using the b value of the L*a*b* color system.
(Visual Evaluation)
A panel of five experts visually evaluated the degree of yellowness of the tofu surface according to the following evaluation criteria. The evaluation was based on the consensus of the five experts. The results are shown in Tables 1 to 3.
(Evaluation Criteria)
○: Yellow or white color obviously lighter than the control ×: Yellow color equivalent to the control, or yellow color darker than the control, or color other than yellow

(Evaluation using the b value of the L*a*b* color system)
The tofu produced above was placed in a solid cell of a color difference meter (CHROMA METER CR-5, manufactured by Konica Minolta, Inc.) and measured to determine the b value. Next, the difference (b1-b2) between the b value (b1) of the control example and the b value (b2) of the example or comparative example was determined and evaluated according to the following criteria. The results are shown in Tables 1 to 3.
(Evaluation Criteria)
◎: 0.70 or more ○: 0.30 or more and less than 0.70 ×: Less than 0.30 or a negative value

The above results confirmed that the tofu of the present invention (solid soybean foods: Examples 1 to 8) containing 0.5 to 2.0% by mass of any of sucrose fatty acid esters, polyglycerol fatty acid esters with an average degree of polymerization of 3 or more, propylene glycol fatty acid esters, and citric acid monoglycerides was lighter in yellow color than the tofu of the control example.

Claims (4)

A solid soybean food product containing 5 to 40% by mass of soybean powder, 0.1 to 2% by mass of a coagulant, and 0.4 to 4% by mass of citric acid monoglyceride . The solid soybean food product according to claim 1, wherein the average particle size of the soybean powder is 10 to 60 μm. A method for producing a solid soybean food, comprising the steps of preparing a solution containing 5 to 40% by mass of soybean powder, 0.1 to 2% by mass of a coagulant, and 0.4 to 4% by mass of citric acid monoglyceride , and coagulating the solution . The method for lightening the yellow color of a solid soybean food comprises adding 0.4 to 4 mass% of citric acid monoglyceride to the solid soybean food, the solid soybean food containing 5 to 40 mass% of soybean powder and 0.1 to 2 mass% of a coagulant .