JP5887714B2 - Soy emulsified composition, reduced-fat soy milk, and production method thereof - Google Patents

Description

  The present invention relates to a reduced-fat soymilk and a soybean-emulsified composition obtained using fat-containing soybeans as raw materials, and methods for producing them. Specifically, from the fat-containing soybeans that are the starting material, the technology for providing the reduced fat soy milk in which the neutral lipids and also the polar lipids are reduced without passing through the degreasing step with an organic solvent, and from the fat-containing soybeans that are the starting materials The present invention relates to a soybean emulsified composition enriched with neutral lipids and polar lipids.

  As a method for industrially producing soybean oil and defatted soybean from soybean, a solvent extraction method in which extraction is performed using an organic solvent such as hexane is common. When protein is extracted from soybean with water to produce defatted soymilk, the defatted soybean obtained by this organic solvent extraction method is used for water extraction. The obtained defatted soymilk is filled after sterilization to obtain a liquid product, or dried after sterilization and processed into a powdered product. Furthermore, when producing a separated soy protein obtained by separating and concentrating protein from defatted soymilk, the protein is isoelectrically precipitated by adjusting the obtained defatted soymilk to an acidic pH, and the precipitate is recovered and neutralized and sterilized. Dried and processed into a powdered product.

  However, recent reports point out that the solvent released during production affects the destruction of the ozone layer and the like. In addition, although defatted soybeans after solvent extraction are solvent-removed, the consumer's negative image of using organic solvents as food ingredients is not zero. Under these circumstances, the press extraction method is known as a safer and more environmentally friendly degreasing method, but there is a problem that it is difficult to increase the lipid recovery rate as compared with the solvent extraction method.

On the other hand, a method has been studied in which soy milk extracted from whole fat soybeans is centrifuged to float an emulsion (cream) rich in lipids in the upper layer and separated into soy milk and emulsions with less lipids ( Patent Documents 1 and 2).
Furthermore, the oil body is agglomerated by a method of demulsifying soymilk using a demulsifier or a proteolytic enzyme and separating lipids from the soymilk (Patent Document 3, Non-Patent Document 1) or by adding salts such as sodium ascorbate and sodium chloride. Methods (Patent Documents 4, 5, and 6) are disclosed.
Further, in Patent Documents 7 and 8, after adding water to soybean and grinding, heat treatment is performed either before or after separating the ground product into soymilk and okara, and the resulting soymilk is centrifuged at high centrifugal force to obtain lipids. It is divided into soy milk and oil body that have fallen to some extent.

Special table 2009-528847 Special table 2010-519928 US Pat. No. 6,548,102 Japanese Patent Laid-Open No. 11-56248 JP 2002-20781 A Japanese National Patent Publication No. 11-506619 WO2002 / 26788 pamphlet JP 2002-101820 A

J. Am. Oil Chem. Soc. (2009) 86: 283-289

In the method of Patent Document 1 and the like, lipids emulsified in soymilk have a small particle size and require a high centrifugal force (G) for separation, and are not suitable for mass production. Actual separation efficiency is low, and it is difficult to highly separate lipids in soy milk.
In the method of Patent Document 3 for demulsifying soymilk, the flavor of the demulsifier is easily produced in the product. Regarding the interaction between the protein and the lipid that are strongly emulsified, the separation of the lipid is limited even with the demulsifier. It will be something like that.
In the methods of Patent Documents 4 to 6 in which salt is added to soy milk, the amount of sodium increases as the salt concentration increases, and the flavor of the salt itself is imparted to the product. To reduce this, protein is insolubilized. In addition, it is necessary to perform water washing or dialysis, and the use of a large amount of water increases the environmental load. In addition, the flavor inherent in soybeans is impaired, and oligosaccharides having an intestinal regulating action and isoflavones having physiological functions are reduced.
The methods of Patent Documents 7 and 8 are methods in which most of the lipid in soybean is transferred to soy milk, and then the lipid is separated by heat treatment and high centrifugal force. It is difficult to separate efficiently, and the reduction of extracts (neutral lipids and polar lipids) extracted with a mixed solvent of chloroform / methanol is limited.
As described above, none of the methods was sufficiently satisfactory because the separation efficiency of lipid from soy milk was low.
In view of such circumstances, the present invention efficiently separates lipids from fat-containing soybeans without relying on organic solvents such as hexane, thereby reducing not only neutral lipids but also polar lipids. It is an object of the present invention to provide a novel processed fat-reduced soybean material and to provide a new soybean material enriched with neutral lipids and polar lipids.
In the following description, unless otherwise specified, lipid refers to the total lipid composed of neutral lipid and polar lipid extracted with a mixed solvent of chloroform / methanol.

In order to solve the above-mentioned problems, the present inventor has made various studies, but when full-fat soybean is extracted with water, most of the lipid moves to the soymilk side and is finely emulsified, as in Patent Documents 3-6. Even with the use of various additives, it was very difficult to easily remove lipids from soy milk efficiently.
Therefore, as the present inventors are further diligently studying, the present inventors do not use low-denatured soybeans (usually NSI 90 or more) that are generally used as raw materials for soybean materials, but NSI has a specific range. Attempts were made to use processed soybeans that had been previously modified until. According to conventional common sense, when soybean is extracted with water, most of the lipid is emulsified and transferred to the water-soluble fraction. However, when the processed soybean is suspended in water as a raw material and centrifuged to separate into a water-soluble fraction and an insoluble fraction, unexpectedly, most of the lipids including polar lipids are water-soluble fractions. Instead, it was concentrated on the insoluble fraction (dietary fiber) side. It has been found that the component composition of the insoluble fraction is new and unprecedented and can be used as a useful soybean emulsified composition having flavor and physical properties suitable for use in foods and drinks. On the other hand, the lipids including polar lipids are also significantly reduced in the water-soluble fraction, the composition is new, and the flavor suitable for use in foods and drinks, without the degreasing process with organic solvents, and the remaining fats and oils It has been found that it can be provided as a soy protein material such as reduced-fat soymilk, which has the characteristic of less flavor deterioration over time.
The present invention has been completed on the basis of the above knowledge, and thereby the above-mentioned problems have been solved.

That is, the present invention for solving the above problems
(1) The protein content per dry matter is 25% by weight or more, and the lipid content (referred to as the content of chloroform / methanol mixed solvent extract, the same in the following) is 100% by weight or more with respect to the protein content. A soybean emulsified composition, wherein the lipoxygenase protein content per protein is 4% or more,
(2) The soybean emulsified composition according to (1), wherein the dietary fiber content per dry matter is 10% by weight or less,
(3) Using fat-containing soybeans whose lipid content per dry matter is 15% by weight or more and whose NSI is processed in the range of 20 to 77,
1) A step of preparing a suspension by adding water to the oil-containing soybean,
2) Solid-liquid separation of the suspension, transfer of neutral lipid and polar lipid to the insoluble fraction, removal of the water-soluble fraction containing protein and carbohydrate, and recovery of the insoluble fraction;
A method for producing a soybean emulsified composition, comprising:
(4) The soybean according to (3), wherein the recovered insoluble fraction is further homogenized, and then the homogenized liquid is subjected to solid-liquid separation to remove dietary fiber, and the supernatant is recovered. Production method of emulsified composition,
(5) Using fat-containing soybeans whose lipid content per dry matter is 15% by weight or more and whose NSI is processed in the range of 20 to 77,
1) A step of preparing a suspension by adding water to the oil-containing soybean,
2) a step of solid-liquid separation of the suspension, removing neutral lipids and polar lipids by transferring them to an insoluble fraction, and collecting a water-soluble fraction containing proteins and carbohydrates;
A method for producing a reduced-fat soy protein material, comprising:
(6) Using fat-containing soybeans with a lipid content of 15% by weight or more per dry matter and NSI of 20 to 77, suspending the fat-containing soybeans in water to obtain a suspension, the suspension Separating the liquid into solid and liquid, removing the water-soluble fraction, and collecting the insoluble fraction;
(7) A fat-containing soybean having a lipid content per dry matter of 15% by weight or more and an NSI of 20 to 77 is obtained by suspending the fat-containing soybean in water to obtain a suspension. Separating the liquid into solid and liquid, removing the insoluble fraction, and collecting the water-soluble fraction;
It is.

According to the reduced-fat soy protein material of the present invention, there is provided a reduced-fat soy protein material such as a new reduced-fat soymilk that has a low lipid content and a high plant sterol content while also being sufficiently reduced in neutral lipids and polar lipids. can do. At the same time, it is possible to provide a reduced-fat soy protein material having a clean soybean flavor that has no blue odor compared to the prior art, and has a high flavor stability over time.
On the other hand, according to the soybean emulsified composition of the present invention, a novel soybean emulsified composition that contains abundant polar lipids together with soybean neutral lipids, and has a blue-flavored taste and a rich flavor like soybeans as a food material. Can be provided.
In addition, according to the method for producing a reduced-fat soy protein material or a soybean emulsified composition of the present invention, the reduction in lipids from soybeans containing a large amount of lipids can be efficiently performed with a simple operation without using an organic solvent such as hexane. A soy emulsified composition enriched with a reduced-fat soy protein material or lipid such as soy milk can be separated and provided.

<Soy emulsified composition>
The soybean emulsified composition of the present invention is derived from soybean and has a particularly high ratio of lipophilic proteins other than glycinin and β-conglycinin (or lipoxygenase protein as another index) among proteins, and neutral lipids and polar lipids. The protein content per dry matter is 25% by weight or more, and the lipid content per dry matter (referred to as a chloroform / methanol mixed solvent extract) is 100% of the protein content per dry matter. The lipoxygenase protein content per protein is 4% or more by weight. Hereinafter, the soybean emulsified composition of the present invention and the production method thereof will be described.

(Lipid)
In general, the lipid content is measured by an ether extraction method, but the soy emulsion composition of the present invention contains many polar lipids that are difficult to extract with ether in addition to neutral lipids. : Using a mixed solvent of methanol 2: 1 (volume ratio) and the amount of extract extracted at the normal pressure boiling point for 30 minutes as the total lipid amount, the lipid content is calculated. As the solvent extraction device, “Soxtec” manufactured by FOSS can be used. That is, the lipid content in the present invention refers to the total lipid content as the chloroform / methanol mixed solvent extract content. The above measurement method is referred to as “chloroform / methanol mixed solvent extraction method”.

  The soybean emulsified composition of the present invention is characterized by containing a lipid having a value higher than the ratio of lipid content / protein content of the soybean flour, and particularly rich in polar lipids. The lipid is a lipid derived from soybean as a raw material.

  The lipid content of the soybean emulsified composition of the present invention is 100% by weight or more, preferably 120 to 250% by weight, more preferably 120 to 200% by weight, based on the protein content per dry matter, and more lipid than protein. It is a feature. Although not essential for the constitution, when the lipid content is expressed in absolute amount, it is appropriate that it is 35% by weight or more, preferably 40% by weight or more per dry matter. If the soybean emulsified composition is one from which fibers and the like are removed, the lipid content can be increased to 50% by weight or more per dry matter. The upper limit of the lipid content is not limited, but is preferably 75% by weight or less, more preferably 70% by weight or less.

(protein)
The protein content of the soybean emulsified composition of the present invention is 25% by weight or more, preferably 30% by weight or more per dry matter. The upper limit of the protein content is not limited, but is preferably 50% by weight or less, more preferably 40% by weight or less.

Analysis of protein content The protein content in the present invention is measured as the amount of nitrogen by the Kjeldahl method, and is obtained by multiplying the amount of nitrogen by a nitrogen conversion factor of 6.25.

O Composition analysis of each component of protein The composition of each component of protein such as soybean emulsified composition in the present invention can be analyzed by SDS polyacrylamide gel electrophoresis (SDS-PAGE).
Hydrophobic interactions, hydrogen bonds, and intermolecular disulfide bonds between protein molecules are cleaved by the action of the surfactant SDS and the reducing agent mercaptoethanol, and negatively charged protein molecules follow their intrinsic molecular weight. By showing the electrophoretic distance, it exhibits a migration pattern characteristic of proteins. After electrophoresis, after staining the SDS gel with Coomassie Brilliant Blue (CBB), calculate the ratio of the density of bands corresponding to various protein molecules to the density of all protein bands using a densitometer. It can be obtained by the method of

(Lipoxygenase protein)
The soybean emulsified composition of the present invention is characterized in that it contains a specific amount or more of lipoxygenase protein which is generally hardly contained in the oil body in soybean, and contains at least 4% or more per total protein in the soybean emulsion composition. And preferably 5% or more.
When normal undenatured (NSI 90 or higher) soybeans are used as the raw material, the lipoxygenase protein exists in a soluble state, and therefore when extracted with water, it is extracted to the water-soluble fraction side. On the other hand, in the present invention, the lipoxygenase protein remains in the insoluble fraction side because it is inactivated and insolubilized in the raw soybean by heat treatment.
The increase in the proportion of lipoxygenase protein in the protein not only stabilizes the emulsified state of fats and oils, but also provides a smooth texture that cannot be obtained with a normal soy protein composition mainly composed of globulin proteins. In addition, a rich flavor is added to the material.

  In the case of a lipoxygenase protein, there are usually three types, L-1, L-2 and L-3, and the content can be calculated from the intensity of these bands corresponding to the lipoxygenase protein by the above-described electrophoresis method.

(Lipophilic protein)
The soybean emulsified composition of the present invention is characterized in that among the types of proteins, more lipophilic proteins are contained than general soybean materials. Lipophilic protein refers to a group of minor acid-precipitating soybean proteins other than glycinin (7S globulin) and β-conglycinin (11S globulin) among the major acid-precipitating soybean proteins of soybean, such as lecithin and glycolipids. It accompanies many polar lipids. Hereinafter, it may be simply abbreviated as “LP”.
LP is a mixture of miscellaneous proteins, so it is difficult to identify each protein and measure the LP content precisely, but by calculating the following LCI (Lipophilic Proteins Content Index) value Can be estimated. According to this, the LCI value of the protein in the soybean emulsified composition is usually 60% or more, preferably 63% or more, more preferably 65% or more.
When normal undenatured soybeans (NSI 90 or higher) are used as raw materials, LP exists in a soluble state, so when extracted with water, it is extracted to the water-soluble fraction. On the other hand, in the present invention, LP remains in the insoluble fraction side because it has been deactivated and insolubilized by heat treatment in the raw soybean.
The increase in the proportion of LP in the protein not only stabilizes the emulsified state of the fats and oils, but also provides a smooth texture that cannot be obtained with a normal soy protein composition mainly composed of globulin proteins. In addition, a rich flavor is imparted to the material.

[LP content estimation / LCI value measurement method]
(a) As the main protein in each protein, 7S selects α subunit and α ′ subunit (α + α ′), 11S selects acidic subunit (AS), LP selects 34 kDa protein and lipoxygenase protein (P34 + Lx), The staining ratio of each protein selected by SDS-PAGE is determined. Electrophoresis can be performed under the conditions shown in Table 1.
(b) X (%) = (P34 + Lx) / {(P34 + Lx) + (α + α ′) + AS} × 100 (%) is obtained.
(c) Since the LP content of the separated soybean protein prepared from low-denatured defatted soybean is measured by the fractionation method of methods 1 and 2 before heat sterilization, it is about 38%, so X = 38 (%). (P34 + Lx) is multiplied by the correction coefficient k * = 6.
(d) That is, the estimated LP content (Lipophilic Proteins Content Index, hereinafter abbreviated as “LCI”) is calculated by the following equation.

(Table 1)

(Dry matter content)
The soybean emulsified composition of the present invention usually has a fresh cream-like property, and the usual dry matter is about 20 to 30% by weight, but is not particularly limited. That is, it may be a liquid having a low viscosity by water addition, a cream having a higher viscosity by concentration processing, or a powder having been processed by powder.

(Production aspect of soybean emulsified composition)
The soybean emulsified composition of the present invention has a water-soluble nitrogen index (Nitrogen Solubility Index, hereinafter referred to as “NSI”) of 20 to 77, preferably 20 to 70, and a total lipid content of 15% by weight or more per dry matter. After the step of preparing a suspension by adding water to fat-containing soybeans such as fat soybeans, the suspension is solid-liquid separated, and neutral lipids and polar lipids are transferred to the insoluble fraction to produce protein. And a carbohydrate-containing water-soluble fraction is removed, and an insoluble fraction is recovered. Hereinafter, this production mode will be described.

-Raw soybean and its processing As soybean which is the raw material of the soybean emulsified composition, fat-containing soybean such as full fat soybean or partially defatted soybean is used. Examples of partially defatted soybeans include those obtained by partially defatting whole fat soybeans by physical extraction treatment such as compression extraction. Generally, about 20 to 30% by weight of lipid per dry matter is contained in whole fat soybeans, and there are some special soybean varieties with lipids of 30% by weight or more, although there is no particular limitation, A material containing at least 15% by weight or more, preferably 20% by weight or more of lipid is suitable. The form of the raw material may be in the form of half cracked soybeans, grits, powder. If it is excessively defatted and the lipid content is too low, it will be difficult to obtain the lipid-rich soybean emulsion composition of the present invention. In particular, defatted soybeans extracted with an organic solvent such as hexane and having a neutral lipid content of 1% by weight or less are not preferable because the good flavor of soybeans is impaired. Therefore, this invention has the characteristics also as a degreasing technique which does not use an organic solvent from soybean.

In the above-mentioned fat-containing soybean, most of the protein is in an unmodified and soluble state in the natural state, and NSI is usually over 90, but in the present invention, NSI is 20 to 77, preferably 20 to 70. It is appropriate to use processed soybeans that have been treated. A more preferable lower limit of NSI can be 40 or more, more preferably 41 or more, still more preferably 43 or more, and most preferably 45 or more. A more preferable upper limit of NSI can be less than 75, more preferably less than 70, and a lower NSI of less than 65, alternatively less than 60, or less than 58 can be used.
Such processed soybeans are obtained by performing processing such as heat treatment or alcohol treatment. The processing means is not particularly limited, and for example, heat treatment such as dry heat treatment, steam treatment, superheated steam treatment, microwave treatment, hydrous ethanol treatment, high pressure treatment, and combinations thereof can be used.

If the NSI is too low, the protein ratio in the soybean emulsified composition tends to be high, and if it is too high, the protein recovery rate on the reduced-fat soymilk side will be low. Moreover, miscellaneous taste such as roasting odor due to overheating tends to occur. Conversely, when the NSI is a high value of 80 or more, for example, the protein ratio in the soybean emulsified composition decreases, and the lipid recovery rate from soybean tends to decrease. In addition, the flavor has a strong blue odor.
For example, when performing heat treatment with superheated steam, the treatment conditions are affected by the production environment, so it can not be said unconditionally, but the NSI of processed soybeans is used in about 5 to 10 minutes using superheated steam at about 120 to 250 ° C. The processing conditions may be selected as appropriate so that the value falls within the above range, and no particular difficulty is required for the processing. For convenience, commercially available soybeans with NSI processed in the above range can also be used.

NSI can be expressed as a ratio (% by weight) of water-soluble nitrogen (crude protein) in the total amount of nitrogen based on a predetermined method. In the present invention, NSI is a value measured based on the following method. .
That is, 100 ml of water is added to 2.0 g of a sample, followed by stirring and extraction at 40 ° C. for 60 minutes, followed by centrifugation at 1400 × g for 10 minutes to obtain supernatant 1. 100 ml of water is added again to the remaining precipitate, followed by stirring and extraction at 40 ° C. for 60 minutes, and centrifugation at 1400 × g for 10 minutes to obtain supernatant 2. Supernatant 1 and supernatant 2 are combined, and water is further added to make 250 ml. After filtering with No. 5A filter paper, the nitrogen content of the filtrate is measured by Kjeldahl method. At the same time, the nitrogen content in the sample is measured by the Kjeldahl method, and the ratio of the nitrogen recovered as filtrate (water-soluble nitrogen) to the total nitrogen in the sample is expressed as weight%, which is NSI.

  The processed soybean is preferably subjected to a tissue destruction treatment such as pulverization, crushing, and pressure bias by dry or wet in advance before water extraction. In tissue destruction treatment, it may be swollen in advance by water immersion or steaming, thereby reducing the energy required for tissue destruction, and eluting and removing components with unpleasant taste such as whey protein and oligosaccharides, as well as water retention The extraction ratio of globulin proteins (especially glycinin and β-conglycinin) having a high ability to gel and gelling ability, that is, the ratio of transfer to a water-soluble fraction can be further increased.

-Water extraction from raw soybeans Water extraction is performed by adding 3 to 20 times, preferably 4 to 15 times, the amount of water to the fat-containing soybeans and suspending the fat-containing soybeans. The higher the rate of hydrolysis, the higher the extraction rate of the water-soluble component and the better the separation. However, if it is too high, concentration is required and costs increase. Further, when the extraction process is repeated twice or more, the extraction rate of the water-soluble component can be further increased.

  There is no particular restriction on the extraction temperature, but the higher the extraction rate of the water-soluble component, the more easily the oil and fat is solubilized, the soy emulsion composition has low lipid, and conversely the reduced fat soy milk has high lipid. Therefore, it is good to carry out at 70 degrees C or less, Preferably it is 55 degrees C or less. Or it can also carry out in the range of 5-80 degreeC, Preferably it is 50-75 degreeC.

  The higher the extraction pH (the pH of the soy suspension after water addition), the higher the temperature, the higher the extraction rate of water-soluble components. The fat of soy milk tends to be high. Conversely, if the pH is too low, the protein extraction rate tends to be low. Specifically, the lower limit can be adjusted to pH 6 or higher, pH 6.3 or higher, or pH 6.5 or higher. The upper limit can be adjusted to pH 9 or lower, pH 8 or lower, or pH 7 or lower from the viewpoint of increasing lipid separation efficiency. Alternatively, from the viewpoint of increasing the protein extraction rate, it is possible to adjust the pH to 9 to 12 more alkaline.

-Solid-liquid separation after water extraction After water extraction, the suspension of fat-containing soybeans is subjected to solid-liquid separation by centrifugation, filtration or the like. At this time, most of the lipids including not only neutral lipids but also polar lipids are not eluted in the water extract, but transferred to the insolubilized proteins and dietary fibers and recovered as the precipitation side (insoluble fraction). This is very important. Specifically, 70% by weight or more of the lipid of the fat-containing soybean is transferred to the precipitation side. In addition, a small amount of lipid is also eluted on the supernatant side during extraction, but it is not finely emulsified like the lipid in soy milk, and it is centrifuged at 15,000 xg or less, or about 5,000 xg or less. In this respect, it is preferable to use a centrifuge. Depending on the equipment used, the centrifugal separator can be used for ultracentrifugation of 100,000 × g or more, and in the case of the present invention, it can be carried out without using an ultracentrifuge.
It is also possible to add a demulsifier during or after water extraction to promote lipid separation from soy milk. The demulsifier is not particularly limited, but for example, the demulsifier disclosed in Patent Document 2 is used. do it. However, in the case of the present invention, it can be carried out without using a demulsifier.

  When centrifugation is used as the solid-liquid separation, either a two-layer separation method or a three-layer separation method can be used. In the case of the two-layer separation method, an insoluble fraction that is a precipitation layer is collected. When using the three-layer separation method, (1) floating layer (cream fraction with the smallest specific gravity containing lipid), (2) intermediate layer (water-soluble fraction containing a small amount of protein and carbohydrate), (3) It is divided into three-layer fractions: a sediment layer (insoluble fraction rich in lipids and dietary fibers). In this case, the intermediate layer (2) of the water-soluble fraction having a low lipid content is removed or recovered, and the floating layer (1) or the precipitated layer (3) is recovered as an insoluble fraction, or (1) and (3 ).

  The obtained insoluble fractions (1) and (3) can be used as they are, or, if necessary, through a concentration step, a heat sterilization step, a powdering step, etc. to obtain the soybean emulsified composition of the present invention.

・ Removal of dietary fiber When the obtained insoluble fraction contains dietary fiber, for example, when it is the fraction of (3) or (1) and (3) above, water is added if necessary, and a high-pressure homogenizer or jet cooker heater After homogenization by means of, etc., through the process of further solid-liquid separation of the homogenized liquid and collecting the supernatant, dietary fiber (ocara) can also be removed, and the rich flavor is further concentrated A soybean emulsified composition can be obtained. Proteins can be more easily extracted by adding a heat treatment step, an alkali treatment step or the like, if necessary, before or after the homogenization. In this case, the dietary fiber content per dry matter is 10% by weight or less, and more preferably 5% by weight or less. In the present invention, the dietary fiber content can be measured by the enzyme-weight method (modified Prosky method) according to the “Fiveth Amendment Japanese Food Standard Component Table” (Ministry of Education, Culture, Sports, Science and Technology, 2005).

(Characteristics and utilization of soybean emulsified composition)
The soybean emulsified composition of the present invention is an emulsified composition that contains lipids (neutral lipids and polar lipids) and proteins in a specific range, has a particularly high LP content of proteins, and also contains fibers as necessary. The natural deliciousness inherent in soybeans is concentrated, and there is no or very little unpleasant taste such as blue odor, astringent taste, and astringency, which has been considered as a conventional problem, and it has a very rich flavor. It can be used as a food for various foods.
It is possible to add water and oil to normal soy flour and isolated soy protein to make an emulsified composition similar to this soy emulsified composition, but it is difficult to equalize lipoxygenase protein content or LCI value It is. Therefore, the soybean emulsified composition prepared by the present technology has a feature that it is much better in flavor than such an assembled product and is highly usable as a food material.

<Low-fat soy protein material>
The reduced-fat soy protein material such as reduced-fat soy milk of the present invention has been found from the same technical idea as the above-mentioned soybean emulsified composition, and has a corresponding technical relationship with the soybean emulsified composition. Proteins derived from soybean and mainly composed of glycinin and β-conglycinin are the main constituents, and soy milk contains a relatively large amount of water-soluble components such as carbohydrates and ash. On the other hand, dietary fiber is removed, and both lipids are reduced in neutral lipids and polar lipids, and the amount of LP such as lipoxygenase protein is low. Examples of soy protein materials other than soy milk include soy protein materials in which the protein purity is further increased using the soy milk as a raw material. Typically, protein purity is obtained by removing water-soluble components such as sugar and ash from soy milk. And a soy milk or a fractionated soy protein in which the purity of glycinin or β-conglycinin is increased by further fractionating the protein of the soy milk or the separated soy protein. These isolated soybean protein and fractionated soybean protein can be produced by a known method.
Although the reduced-fat soy protein material such as this reduced-fat soymilk is made from fat-containing soybeans, the defatted soymilk and isolated soy protein obtained by water extraction from defatted soybeans defatted using an organic solvent such as hexane The protein content is equivalent to, specifically, the protein content per dry matter is at least 30% by weight or more, preferably a high protein content of 50% by weight or more. However, other component compositions are significantly different from those of conventional reduced-fat soy protein materials such as defatted soymilk.
Hereinafter, the reduced-fat soybean protein material such as reduced-fat soymilk of the present invention and the production method thereof will be described.

(carbohydrate)
The reduced-fat soy protein material of the present invention is the main component in which saccharides and protein occupy most of the dry matter, and the content of carbohydrate (excluding lipid, protein and ash from dry matter) is expressed as the total content with protein. And 80% by weight or more per dry matter, preferably 85% by weight or more. The residual component of the dry matter is almost composed of ash and a small amount of lipid, and the ash is usually 15% by weight or less, preferably 10% by weight or less per dry matter. Although dietary fiber is contained in carbohydrates, the reduced-fat soy protein material of the present invention has a dietary fiber content removed, so the amount is 3% by weight or less, preferably 2% by weight or less per dry matter.

(protein)
The protein content of the reduced-fat soybean protein material of the present invention can be in the range of 30 to 99% by weight per dry matter. Here, the protein content is measured as a nitrogen amount by the Kjeldahl method in the same manner as in the soybean emulsion composition, and is obtained by multiplying the nitrogen amount by a nitrogen conversion factor of 6.25. When the soy protein material is soy milk, the lower limit is usually 45% by weight or more, or 50% by weight or more, or 55% by weight or more per dry matter, and the upper limit can be 70% by weight or less, or 65% by weight or less. Depending on the processing method, such as protein fractionation and the addition of other components, it can be in the range of 30 wt% or more and less than 45 wt%. In addition, when the soy protein material is isolated soy protein obtained by further purifying soy milk to increase protein purity, the lower limit is more than 70% by weight, or 80% by weight or more, and the upper limit is 99% by weight or less, or 95% by weight or less. It can be.

(Lipoxygenase protein)
The reduced-fat soy protein material of the present invention is also characterized in that the lipoxygenase protein that is generally water-soluble and easily extracted is very small, and it is 1% or less, preferably 0.5% or less per total protein in the reduced-fat soy protein material. It is.
When normal undenatured (NSI 90 or higher) soybeans are used as the raw material, the lipoxygenase protein exists in a soluble state, and therefore when extracted with water, it is extracted to the water-soluble fraction side. On the other hand, in the present invention, the lipoxygenase protein remains in the insoluble fraction side because it is inactivated and insolubilized in the raw soybean by heat treatment.
Since the ratio of the lipoxygenase protein in the protein of the reduced-fat soy protein material is extremely small, there is an advantage that it is possible to obtain soy milk that keeps the lipid content at an extremely low level.

  The protein content and protein component composition of the reduced-fat soy protein material of the present invention can be analyzed in the same manner as the soybean emulsified composition.

(Lipophilic protein: LP)
The reduced-fat soy protein material of the present invention is characterized in that the content of LP is less than the general soy material among the types of proteins.
The LP content can be estimated as the LCI value as in the case of the soybean emulsified composition. According to this, the LCI value of the protein in the reduced-fat soybean protein material is usually 40% or less, more preferably 38%. Hereinafter, it is more preferably 36% or less.
When normal undenatured soybeans (NSI 90 or higher) are used as raw materials, LP exists in a soluble state, so when extracted with water, it is extracted to the water-soluble fraction. On the other hand, in the present invention, LP remains in the insoluble fraction side because it has been deactivated and insolubilized by heat treatment in the raw soybean.
There is an advantage that it is possible to obtain soy milk that keeps the lipid content at a very low level by the low ratio of LP in the protein of the reduced-fat soy protein material.

(Lipid)
The reduced-fat soy protein material of the present invention, such as reduced-fat soymilk, contains only a value lower than the lipid content / protein content ratio of the raw soybean powder, and the content of polar lipids as well as neutral lipids is low. It is a feature. The lipid here refers to total lipid (neutral lipid and polar lipid) derived from soybean as a raw material. On the other hand, general reduced-fat soymilk is obtained by water-extracting defatted soybeans obtained by defatting soybeans with hexane, but the reduced-fat soymilk is still abundant because polar lipids are not removed.
That is, the reduced-fat soy protein material of the present invention, such as reduced-fat soymilk, has a lipid content of less than 10% by weight, preferably less than 9% by weight, more preferably less than 8% by weight, and even more preferably 5% by weight relative to the protein content. %, More preferably 4% by weight or less, and may be 3% by weight or less. That is, one important feature is that the total lipid including neutral lipids and polar lipids is much less than protein. This lipid content is expressed as the content of a chloroform / methanol mixed solvent extract. The defatted soymilk extracted from defatted soybeans defatted using a normal organic solvent is almost free of neutral lipids, but because some of the polar lipids are extracted, the lipid content of the protein is approximately 5-6% by weight. is there. That is, the reduced-fat soy protein material of the present invention has oils and fats, particularly polar lipids, reduced to the same level or higher than that of defatted soymilk using ordinary organic solvents.
Furthermore, the lipid content per dry matter is 5% by weight or less, preferably 3% by weight or less, more preferably 2% by weight or less, and further preferably 1.5% by weight or less.

(Plant sterol)
The reduced-fat soy protein material of the present invention is characterized in that the content of plant sterols relative to lipids is significantly higher than that of ordinary defatted soymilk.
Plant sterols are contained in soybean seeds in an amount of about 0.3% by weight and mainly contain sitosterol, campesterol, stigmasterol and the like. Since plant sterols contained in these soybeans have low polarity, when extracting soybean oil with an organic solvent such as hexane, most of the plant sterols migrate to the soybean oil side. Removed. Therefore, the amount of plant sterol is very small in defatted soybean.
On the other hand, in the reduced-fat soybean protein material of the present invention, campesterol and stigmasterol, which are plant sterols that have high affinity for lipids and are insoluble in water, despite the low content of both neutral lipids and polar lipids, In particular, they found that many remained. Thus, it is extremely difficult to increase the content of plant sterols relative to lipids in the reduced-fat soy protein material, except for a method of adding separately, and the present invention provides a soy protein material containing a large amount of plant sterols with almost no lipid. Has the advantage of being able to.
The total content of campesterol and stigmasterol is about 40 to 50 mg per 100 g of fat in the reduced-fat soy protein material prepared from defatted soybeans defatted with an organic solvent such as hexane. The reduced-fat soybean protein material of the present invention has a high content of at least 200 mg per 100 g of lipid, preferably 230 mg or more, more preferably 400 mg or more, still more preferably 450 mg or more, and even more preferably 500 mg or more.

The content of these plant sterols can be obtained by a general method such as obtaining the ratio of the peak area to the standard product by chromatography after extraction with an organic solvent.
For example, it can be analyzed according to the sterol quantitative method (No. 11014761-attached analysis method flowchart) of the Japan Food Analysis Center. Specifically, 1.2 g of a sample was collected, dispersed in 50 ml of 1 mol / L potassium hydroxide ethanol solution, saponified, 150 ml of water and 100 ml of diethyl ether were added, and unsaponifiable matter was extracted into the ether layer. Add 50 ml of diethyl ether twice and extract. The extracted unsaponified diethyl ether layer is washed with water, dehydrated and filtered, and the solvent is removed by volatilization. Thereafter, the extract is washed with 10 ml of diethyl ether: hexane (8:92) solution by column chromatography (silica cartridge column) and eluted with 25 ml of diethyl ether: hexane (20:80) solution. To the solution is added 0.5 mg of 5α-cholestane as an internal standard, and the solvent is removed by volatilization. 5 ml of hexane is added to this sample, and the target plant sterol is detected by gas chromatography (hydrogen flame ion detector). The conditions of the gas chromatographic method can be performed as follows.

<Gas chromatograph operating conditions>
Model: GC-2010 [Shimadzu Corporation]
Detector: FID
Column: DB-1 [J & W SCIENTIFIC] φ0.25mm × 15m, film thickness 0.25μm
Temperature: Sample inlet 290 ° C, detector 290 ° C
Column 240 ℃ → 3 ℃ / min temperature rise → 280 ℃
Sample introduction system: Split (split ratio 1:30)
Gas flow rate: Helium (carrier gas) 2.3ml / min
Helium (makeup gas) 30ml / min
Gas pressure: Hydrogen 40ml / min, Air 400ml / min

(Isoflavones)
The reduced-fat soybean protein material of the present invention is also characterized by a relatively high content of isoflavones. Specifically, the content per dry matter is preferably 0.10% by weight or more. The content of isoflavones is determined by the analytical method described in “Soy Isoflavone Food Quality Standards (Public Notice No. 50, Revised Review)” (Japan Health and Nutrition Food Association, issued on March 6, 2009). Can be quantified according to In the present invention, the content of isoflavones represents an equivalent as a glycoside.

(Dry matter content)
When the reduced-fat soy protein material of the present invention is reduced-fat soymilk and the property is liquid, the dry matter is usually about 3 to 20% by weight, but is not particularly limited. In other words, it may be hydrated to give a low-viscosity liquid, or it may be made highly viscous by concentration processing such as vacuum concentration or freeze concentration, or powdered by powder processing such as spray drying or freeze drying. It may be.

(Manufacturing mode of reduced-fat soy protein material)
In the method for producing reduced-fat soymilk and other soy protein materials of the present invention, the suspension is prepared after adding water to a fat-containing soybean having a lipid content of 15% by weight or more per dry matter. This is a method of solid-liquid separation of a turbid liquid to remove an insoluble fraction and recovering a water-soluble fraction, and further using a fat-containing soybean having an NSI of 20 to 77, preferably 20 to 70 as a raw soybean. The reduced fat soymilk having the above composition is obtained by transferring the functional lipid and the polar lipid to the insoluble fraction side.

  More specifically, in the same production aspect as the soybean emulsified composition, solid lipid separation after the water extraction step transfers not only the neutral lipid but also the polar lipid to the insoluble fraction, and the other water-soluble fraction It can be obtained by collecting. In the case of the two-layer separation method, the supernatant is recovered as a water-soluble fraction, and in the case of the three-layer separation method, the intermediate layer (2) may be recovered as a water-soluble fraction.

-Raw material soybean and its processing The raw material soybean can use what was processed similarly to what is used by manufacture of the said soybean emulsified composition. If it is excessively defatted and the lipid content is too low, it will be difficult to obtain a reduced-fat soy milk containing a large amount of plant sterols while the lipid of the present invention is low.
In the processing of raw soybeans, if the NSI is too high, the separation efficiency of lipids and proteins decreases, the lipid content of the reduced-fat soy protein material tends to increase, and the flavor has a strong blue odor.

-Water extraction from raw soybeans and solid-liquid separation Water extraction from raw soybeans can also be performed under the same temperature and pH conditions as in the method for producing the soybean emulsion composition. Solid-liquid separation after water extraction can also be performed in the same manner as described above.

○ Reduced-fat soymilk The obtained water-soluble fraction can be used as the reduced-fat soymilk of the present invention as it is or after undergoing a concentration step, a heat sterilization step, a powdering step, and the like.

○ Isolated soy protein High protein purity by removing soy whey components such as whey protein and oligosaccharide from the reduced-fat soymilk of the present invention and concentrating the protein, neutralizing, sterilizing, drying and pulverizing if necessary. Isolated soy protein can be prepared. Any known method can be used to remove the soy whey component. For example, the most common reduced-fat soymilk is adjusted to an acidic pH (about pH 4 to 5) near the isoelectric point, and the protein has an isoelectric point. In addition to a method of precipitating and removing the whey from the supernatant by centrifugation or the like and collecting the precipitate, a method of removing a relatively low molecular weight whey by membrane separation or the like can be applied.

(Characteristics and use of reduced-fat soy protein material)
The reduced-fat soy protein material of the present invention has a low content of lipids, particularly polar lipids and low calories, compared to reduced-fat soy milk or isolated soy protein extracted from defatted soybeans defatted with hexane, etc. Since no organic solvent is used, the environmental load is small, and it is not denatured by the organic solvent and has a very good flavor. In addition, it is characterized by high oxidation stability due to the low amount of LP together with polar lipids, and very little deterioration of flavor over time.
Taking advantage of these characteristics, when the soy protein material is soy milk, the obtained water-soluble fraction can be used as it is as a reduced-fat soy milk after sterilization.
Further, when dried and used as a powdery material, the storage stability of the flavor is remarkably excellent because the lipid is not oxidized unlike ordinary soymilk powder or powdered soy protein.

<Method of concentrating lipids of soybean material>
The lipid concentration method of the soybean material of the present invention uses fat-containing soybeans having a lipid content per dry matter of 15% by weight or more and NSI of 20 to 77, preferably 20 to 70. Suspend in water to obtain a suspension, solid-liquid separate the suspension, remove the water-soluble fraction containing protein and lipid, and collect the insoluble fraction into which neutral lipid and polar lipid have migrated It is characterized by doing.
Specifically, in the production mode of the soybean emulsified composition which is the soybean material described above, the neutral lipid and the polar lipid are concentrated by collecting the insoluble fraction by solid-liquid separation after the water extraction step. can do. Without adding oil and fat separately, the lipid content per dry matter can be increased to 100% by weight or more, preferably 100 to 250% by weight, more preferably 120 to 200% by weight with respect to the protein content. The lipid transfer rate from fat soybean can be made 80% or more.
As a result, a very rich flavor can be imparted to the soybean material, and the suitability for use can be expanded.

<Method of reducing lipids in soybean material>
The method for reducing lipids in a soybean material of the present invention uses a fat-containing soybean having a lipid content per dry matter of 15% by weight or more and an NSI of 20 to 77, preferably 20 to 70. Suspended in water to obtain a suspension, the suspension is solid-liquid separated, neutral lipids and polar lipids are transferred to the insoluble fraction to be removed, and a water-soluble fraction containing proteins and carbohydrates It is characterized by collect | recovering.
Specifically, in the production mode of the reduced-fat soy protein material that is the soy material described above, by recovering the water-soluble fraction to which the protein and sugar have been transferred by solid-liquid separation after the water extraction step, soy Neutral lipids and polar lipids can be reduced. Specifically, the lipid content per dry matter can be reduced to 5% by weight or less, and the lipid transfer rate from fat-containing soybeans can be made 10% or less.
This makes it possible to obtain a soybean material with reduced lipids without using defatted soybeans defatted using an organic solvent such as hexane. In addition to conventional defatted soymilk and isolated soybean protein, β-conglycinin, glycinin, etc. It can also be used to produce fractionated soy protein.

  Examples of the present invention will be described below. Hereinafter, “%” means “% by weight” unless otherwise specified. Analysis of lipids was performed according to the chloroform / methanol mixed solvent extraction method unless otherwise specified.

(Example 1) Preparation of soybean emulsified composition and reduced-fat soymilk 4.5 times the amount of soybean powder made into NSI 59.4 by wet heat treatment was added to a suspension by adding water at 50 ° C. and 30 ° C. Stir for minutes and extract with water. The pH at this time was 6.7. Centrifugation of a three-layer separation method was continuously performed at 6,000 × g, and separated into (1) a floating layer, (2) an intermediate layer, and (3) a precipitation layer. Then, 6.3 kg of the soybean emulsified composition including the floating layer and the precipitated layer was recovered, and 12 kg of reduced-fat soymilk was recovered as the intermediate layer. Freeze-dry each fraction and measure dry matter as a general ingredient, and protein per dry matter (by Kjeldahl method), lipid (by chloroform / methanol mixed solvent extraction method) and ash content, and further lipoxygenase protein content by SDS-PAGE The LCI value was analyzed as an estimate of the LP content. In addition, when the dry matter, protein, and lipid content of soybean powder was 100%, the percentage of each component transferred to the reduced-fat soymilk and soybean emulsified composition was determined (Table 2). reference).

(Table 2)

As shown in Table 2, fat in low-fat soymilk is 2.3% or less in dry matter at 5% or less, and even in protein, 3.6% is hardly contained, and lipids are significantly reduced from soy milk without using organic solvent from soy flour. I was able to. Most of the lipid (89%) contained in the soybean powder was transferred to the soybean emulsion composition, and a soybean emulsion composition enriched with lipid was obtained. The protein content per dry matter of this soybean emulsified composition was 25% or more (32%), the lipid content was 35% or more (43%), and the ratio of the lipid content to the protein content was 1 or more (about 1.3). .
Lipoxygenase protein is contained in more than 4% (6.2%) of the protein in the soybean emulsified composition, and more than soy flour, while reduced-fat soymilk contains almost 1% (0.3%) of the protein. It was. The LCI value was 60% or more (67%) in the soybean emulsified composition, which was higher than 57% of soybean flour.
The obtained reduced-fat soymilk and soybean emulsified composition were heat-sterilized in a boiling water bath for 10 minutes to confirm the flavor. As a result, the soybean emulsion composition was concentrated with a rich flavor like soybeans. The reduced-fat soymilk had a strong sweetness and both had a good flavor different from conventional soymilk and reduced-fat soymilk.

(Example 2)
The soybean emulsified composition prepared in Example 1 was added 0.5 times by weight and further homogenized with a high-pressure homogenizer at 13 MPa, and then the homogenized solution was heat-treated at 142 ° C. for 7 seconds in a steam direct blowing system. Then, the insoluble fiber was separated and removed at 6,000 × g with a continuous centrifuge to obtain a supernatant fraction, which was again used as a soybean emulsified composition. After freeze-drying, the general components, lipoxygenase protein content, and LCI were analyzed in the same manner as in Example 1 (see Table 3).

(Table 3)

  In the soybean emulsified composition of Example 1, carbohydrates were 20.5% per dry matter, whereas carbohydrates in the supernatant fraction were 5% per dry matter and dietary fiber was 2% per dry matter. In the supernatant fraction, the dietary fiber is removed, and the lipid content per dry matter is further increased from 43% to 59%. The ratio of the lipid content to the protein content is 1.8, and the rich flavor of soy is further concentrated. The soybean emulsified composition with very good quality was obtained.

(Examples 3 and 4 and Comparative Example 1)
300g of water is added to each 20g of three types of soybean flour (NSI: 59.5, 66.8, 94.9) with different NSI depending on heating conditions, adjusted to pH 7.5 with 20% NaOH, and 30 minutes at 50 ° C. Extracted with stirring. Separation was performed at 1,400 × g for 10 minutes using a centrifuge, and separated into a cream layer, an intermediate layer, and a precipitate layer (Okara). Furthermore, the cream layer and the precipitation layer were combined to make a soybean emulsified composition, and the remaining intermediate layer was made soy milk. After freeze-drying, general components were analyzed for each fraction in the same manner as in Example 1 (see Table 4).

(Table 4)

When soybean powder of NSI 59.5 (Example 3) and NSI 66.8 (Example 4) is used as a raw material, the transfer rate of lipid in the total lipid in the intermediate layer (soy milk) is 10% or less (0.7% and 3.4%) Thus, the lipid content was sufficiently reduced to 5% or less (0.5% and 2.3%) in the dry matter, and good separability was exhibited. The soybean emulsified compositions of Examples 3 and 4 all have a protein content of 25% or more (34% and 30%) per dry matter, and the lipid content per dry matter of 100% or more (130% and 156%).
On the other hand, when soybean protein of NSI 94.9 (Comparative Example 1), in which the soybean protein is unmodified, is used as a raw material, 15% of the total lipid is transferred to the intermediate layer, and the lipid content per dry matter is 8.1%. Separability was not sufficient. In addition, the soybean emulsified composition of Comparative Example 1 had a protein content per dry matter of less than 25% (18%), and the flavor was blue and the rich taste was not felt.

(Analysis example 1) Comparison with commercially available soybean emulsified composition The composition per dry matter of a commercially available soybean emulsion composition “Soy Supreme Kreme” (manufactured by SunOpta Grains and Foods Group) was analyzed. there were.

Protein 32.0%
Lipid 54.5% (170% per protein)
Carbohydrate 10.4%
Ash content 4.5%
Dietary fiber 5.7%
LCI value 49.6%
Lipoxygenase protein content per protein 2%

This commercial product is presumed to have been produced by the method described in Patent Document 3 (US Pat. No. 6,548,102), and a demulsifier is used as an essential additive. This composition was significantly different from the composition of Example 2 according to the present invention in terms of LCI value or lipoxygenase protein content. That is, it was shown that the soybean emulsified composition of the present invention has a significantly higher LP content than the conventional product. When the flavors of the product of the present invention and the commercial product were compared, the flavor of the product of the present invention was particularly rich and characteristic and good.

<Flavor comparison of reduced-fat soy protein material>
About four points of the soybean emulsified composition obtained in Examples 1 and 2 and Comparative Example 1 and the commercially available soybean emulsified composition used in Analysis Example 1, each flavor (kokumi, blue odor, astringent taste) The relative evaluation was performed. The evaluation results are shown in Table 5.

(Table 5)

(Examples 5 to 8 and Comparative Examples 2 and 3) Preparation of various reduced-fat soymilk In the same manner as in Example 1, the raw material form, NSI, hydrolysis rate, extraction temperature, extraction time, and pH during extraction are shown in Table 6. Various changes were made to the described conditions to prepare various reduced-fat soymilk (Examples 5 to 8, Comparative Examples 2 and 3). The pH of Example 7 and Comparative Example 3 was adjusted by adding caustic soda. About the obtained various reduced-fat soymilk, recovered amount, dry matter concentration (%), protein content per dry matter (%), LCI value, lipid per protein (extract with chloroform: methanol = 2: 1 solvent) content ( %), The analytical data of the plant sterol content (sum of campesterol and stigmasterol content) (mg) per 100 g of lipid are summarized in Table 6. Table 6 also shows the data of Example 1 prepared on the same manufacturing scale for data comparison.

(Table 6)

The conventional defatted soymilk of Comparative Example 2 had a lipid content of almost 0% by the ether extraction method, but the lipid content by the chloroform / methanol mixed solvent extraction method contained 5.2% per protein. That is, it shows that a considerable amount of polar lipids not extracted with hexane remain in conventional defatted soymilk. Moreover, the plant sterol content with respect to lipid was clearly lower than the Example.
In Comparative Example 3, it is understood that the fat content from the soybean is poor because the NSI of the raw material soybean is high, the lipid content is extremely high with respect to the protein. On the other hand, the reduced-fat soymilk of the Examples had a low lipid content of 10% or less with respect to the protein even though the whole fat soybean with a high lipid content was the raw material.
Even in comparison with Comparative Example 2, many Examples had lipid contents equal to or less than that, showed high values of plant sterol content with respect to lipids, and exhibited an unprecedented characteristic composition. Also, the LCI values of the examples were generally lower than those of Comparative Example 2.
The total content of isoflavones contained in the reduced-fat soymilk obtained in Example 5 was analyzed and found to be 0.266% per dry matter.

(Analysis example 2) Analysis of commercially available reduced-fat soymilk About 3 commercially available separated soy protein products (manufactured by Specialty Protein Producers) presumed to be produced by the methods of Patent Documents 1 and 2, protein content, lipid The content, plant sterol content and LCI value were analyzed. The analytical values are shown below.

(Table 7)

The commercial product is isolated soy protein prepared from soybeans without using defatted soybeans defatted with organic solvents, but the lipid content is more than 12% of protein, and the separation of polar lipids from soy milk is insufficient It can be seen that it is. The plant sterol was also about 134 to 165 mg per 100 g of lipid, which was much lower than the reduced-fat soy protein material of the present invention. Moreover, all LCI values are 43 or more, and it turns out that many LPs are contained.
As for “ECO-Ultra Gel SPI 6500”, the total content of isoflavones was analyzed and found to be 0.186% per dry matter.
As described above, these commercial products were completely different in composition from the reduced-fat soy protein material of the present invention.

(Comparative example 4) Additional test of patent document 8 (Unexamined-Japanese-Patent No. 2002-101820) Patent document 8 is describing the technique which heats the soymilk obtained from the soybean seed, and isolate | separates a cream layer by centrifugation. Therefore, this technology was further tested, and the protein content, lipid content, and LCI value of the resulting reduced-fat soymilk were analyzed.
After washing 40 g of soybean seeds, it was put into a 200 ml beaker, water was added to a scale of 150 ml, and it was immersed in a refrigerator (4 ° C.) overnight. Water was added to the water-absorbing soybean to give a total weight of 300 g, ground with a mixer for 2 minutes, and further ground for 2 minutes. The cut cotton was spread on a Buchner funnel, and the ground product was suction filtered to obtain unheated soy milk. It was transferred to an Erlenmeyer flask and heated in boiling water. After reaching 75 ° C., the mixture was heated for 10 minutes while maintaining 75 ° C., and cooled to room temperature (about 25 ° C.) with cold water to obtain soy milk. Next, the soymilk was centrifuged at 6,200 × g for 30 minutes, and the floating fraction (cream) was removed. Furthermore, soy milk considered to have a low oil content in the lower layer was collected and freeze-dried so that the cream was not mixed. This was used as a sample of reduced-fat soymilk heated at 75 ° C.
Furthermore, only the heating temperature was set to 95 ° C., and other conditions were carried out in the same manner, and soy milk was collected. This was used as a sample of reduced-fat soymilk heated at 95 ° C. Analytical values of the obtained samples are shown below.

(Table 8)

  The lipid content for the protein exceeded 29% in all cases, which was considerably higher than the reduced-fat soy protein material of the present invention. Since the lipid content does not decrease even when the heating temperature is increased from 75 ° C. to 95 ° C., it is understood that the separation of polar lipids from soy milk is insufficient even by the heat treatment. Also, the LCI value was as high as 49 or more. These additional samples of Patent Document 8 were completely different in composition from the reduced-fat soy protein material of the present invention.

(Example 8) Preparation of isolated soybean protein
300 kg of water was added to 20 kg of soybean powder adjusted to NSI of 55, adjusted to pH 6.5 with an aqueous sodium hydroxide solution, and extracted with stirring at 50 ° C. for 30 minutes. Separation was carried out at 1,400 × g for 10 minutes with a centrifuge, and separated into a cream layer, an intermediate layer, and a precipitation layer (Okara). After concentrating soymilk as an intermediate layer to a dry matter amount of 12%, an appropriate amount of hydrochloric acid was added to adjust the pH to 4.5. Further, separation was performed at 3,000 × g for 15 minutes using a centrifuge, and the precipitate was recovered.
Water was added to the separated precipitate to a dry matter amount of 18%, and an aqueous sodium hydroxide solution was added to adjust the pH to 7.5. After drying under pressure and heat, spray drying was performed to prepare isolated soy protein.
The analysis results of the obtained isolated soybean protein were 96.0% dry matter, 82.1% protein per dry matter, 1.90% total fat (2.31% per protein), 6.57% ash, and 5.43% carbohydrate. Moreover, the plant sterol was 10.7 mg per 100 g dry matter (564 mg per 100 g lipid), and the total content of isoflavones was 0.301% per dry matter.
The flavor of the obtained isolated soy protein was clearly superior to that of commercially available isolated soy protein produced from defatted soybean defatted with hexane, with less astringency such as blue odor and astringency. It was.

<Flavor comparison of reduced-fat soy protein material>
The reduced-fat soymilk of the present invention obtained in Example 5, the reduced-fat soymilk of Comparative Example 2 prepared from hexane-defatted defatted soybeans, the isolated soy protein (SPI) of the present invention obtained in Example 8 and analysis The flavors of the commercially available SPI “GPF Meat SPI 6500” in Example 2 and the conventional commercially available SPI “Fujipro F” (produced by Fuji Oil Co., Ltd.) manufactured from defatted soybeans defatted with hexane were compared. Relative evaluation was performed. The evaluation results are shown below.

(Table 9)

  The reduced-fat soymilk and soybean emulsified composition of the present invention can be produced without using an organic solvent, there is no fear of air pollution and ozone layer destruction, and a step of evaporating the organic solvent from defatted soybean is not necessary. Therefore, it can contribute to energy saving, and can provide soybean materials that are friendly to the natural environment. In other words, it can contribute to the realization of a sustainable society that is friendly to the natural environment.

Claims (10)

The protein content per dry matter is 25% by weight or more, the lipid content as a chloroform / methanol mixed solvent extract is 100% by weight or more with respect to the protein content, and the lipoxygenase protein content per protein is 4% or more. A soy emulsified composition. The soybean emulsified composition according to claim 1, wherein the dietary fiber content per dry matter is 10% by weight or less. The soybean emulsified composition according to claim 1 or 2, wherein the lipid content of the chloroform / methanol mixed solvent extract is 120 to 250% by weight based on the protein content. The soybean emulsified composition according to any one of claims 1 to 3, wherein a lipid content of the chloroform / methanol mixed solvent extract is 35 wt% or more and 75 wt% or less per dry matter. Using fat-containing soybeans having a lipid content of 15% by weight or more as a chloroform / methanol mixed solvent extract per dry matter and processed into a water-soluble nitrogen index of 40 to 77,
1) A step of preparing a suspension by adding water to the oil-containing soybean,
2) The suspension was subjected to solid-liquid separation, neutral lipids and polar lipids were transferred into an insoluble fraction containing a dietary fiber, to remove the water-soluble fraction containing the protein and carbohydrates, the insoluble fraction Recovering process,
A method for producing a soybean emulsified composition, comprising: 6. The soybean emulsified composition according to claim 5, wherein the recovered insoluble fraction is further homogenized, and then the homogenized liquid is subjected to solid-liquid separation to remove dietary fiber, and the supernatant is recovered. Manufacturing method. The method for producing a soybean emulsified composition according to claim 5 or 6, wherein the water-soluble nitrogen index of the fat-containing soybean is 40 or more and less than 75. The method for producing a soybean emulsified composition according to claim 5 or 6, wherein the fat-containing soybean has a water-soluble nitrogen index of 40 or more and less than 70. The method for producing a soybean emulsified composition according to claim 5 or 6, wherein the fat-containing soybean has a water-soluble nitrogen index of 40 or more and less than 65. The method for producing a soybean emulsified composition according to claim 5 or 6, wherein the fat-containing soybean has a water-soluble nitrogen index of 40 or more and less than 60.