JP2013118841A - Renal function-improving composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a renal function-improving composition having improved flavor.SOLUTION: The renal function-improving composition having a good flavor and a renal function-improving effect contains a soybean emulsion composition having a protein content of ≥25 wt.% based on the dry composition, a lipid content (a content as a chloroform/methanol mixed solvent extract) of ≥100 wt.% based on the protein content, and an LCI value of ≥55%.

Description

The present invention relates to a composition for improving renal function.

  Patent Document 1 describes a soy protein material for nephropathy patients using soybean as a raw material.

International Publication 2009/110504 Pamphlet

An object of the present invention is to provide a composition for improving renal function with improved flavor.

The inventors of the present invention have made extensive studies on the above problems.
Cited Document 1 describes that “non-7S · 11S-acid-precipitating soybean protein” has a strong urinary albumin lowering effect ”. However, since the “non-7S · 11S-acid-precipitating soybean protein” is prepared using defatted soybean as a starting material, a flavor derived from defatted soybean may be included.

  In view of the situation as described above, as a result of further research, the inventor-derived emulsion composition prepared by a specific method without using defatted soybean as a starting material has a very good flavor, and The present invention was completed by finding that it has an action of improving renal function.

That is, the present invention has (1) a protein content per dry matter of 25% by weight or more and a lipid content (referred to as a chloroform / methanol mixed solvent extract) of 100% by weight or more based on the protein content, A composition for improving renal function, comprising a soybean emulsified composition having an LCI value of 55% or more,
(2) A composition for improving renal function, comprising the soybean emulsified composition according to (1), wherein the lipid is unrefined soybean oil;
(3) Using fat-containing soybeans having a lipid content per dry matter of 15% by weight or more and an NSI 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, transferring neutral lipid and polar lipid to the insoluble fraction, removing the water-soluble fraction containing protein and carbohydrate, and collecting the insoluble fraction;
A composition for improving renal function, comprising the soybean emulsified composition according to any one of (1) to (2),
(4) A food using the composition for improving renal function according to (1),
(5) A method for producing a food using the composition for improving renal function according to (4),
It is about.

  The composition for improving renal function according to the present invention has good flavor and renal function improving action, and by using this composition, various foods having excellent flavor and improving kidney function can be easily obtained. it can.

It is a figure which shows the urinary NAG activity at the time of 2-week feeding of a rat.

BEST MODE FOR CARRYING OUT THE INVENTION

The composition for improving renal function of the present invention is characterized by containing a “soy emulsified composition” described below. The content of the soybean emulsified composition in the composition for improving renal function is 1 to 100% by weight, desirably 50 to 100% by weight, more desirably 80 to 100% by weight, and most desirably 100% by weight. %.
The soybean emulsified composition is disclosed in detail in the specification of Japanese application (Japanese Patent Application No. 2011-108598), and will be described below.

<Soy emulsified composition>
The soybean emulsified composition used in the composition for improving renal function of the present invention is derived from soybean, and has a ratio of lipophilic proteins other than glycinin and β-conglycinin (or lipoxygenase protein as another index) among proteins. It is an emulsion composition that is particularly high and contains a large amount of neutral lipids and polar lipids. That is, 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% by weight or more based on the protein content per dry matter, The main characteristic is that the LCI (Lipophilic Proteins Content Index) value is 55% or more.

(Lipid)
In general, the lipid content is measured by an ether extraction method, but the soybean emulsion composition used in the present invention contains many polar lipids that are difficult to extract with ether in addition to neutral lipids. Using a mixed solvent of chloroform: 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. The above measurement method is referred to as “chloroform / methanol mixed solvent extraction method”.

  The soybean emulsified composition used in the present invention is characterized by containing a lipid having a value higher than the ratio of lipid content / protein content of general 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 used in 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. It is characteristic that there are many. 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 used in 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.

-Composition analysis of each component of protein Each component composition of the protein of the soybean emulsified composition used 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 to do.

(Lipoxygenase protein)
The soybean emulsified composition used in the present invention is characterized in that the lipoxygenase protein that is hardly contained in the oil body in soybean is generally contained in a specific amount or more, and at least 4% per total protein in the soybean emulsion composition. It is contained above, 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 used in 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 55% or more, preferably 58% or more, more preferably 60% or more, still more preferably 63% or more, most 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 soybean emulsified composition used in the present invention, LP remains in the insoluble fraction side because LP is deactivated and insolubilized in the raw soybean by heat treatment.
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 used in the present invention usually has a 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 used in 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 lipid content per dry matter of 15% by weight or more. After the step of preparing a suspension by adding water to a fat-containing soybean such as whole fat soybean, the suspension is solid-liquid separated to transfer neutral lipid and polar lipid to the insoluble fraction. It can be obtained by removing the water-soluble fraction containing protein and carbohydrate and recovering the insoluble fraction. 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 small, it will be difficult to obtain a soybean-emulsified composition rich in lipids used in 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.

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.

When NSI is too low, the ratio of the protein in the soybean emulsified composition tends to be high, and the lipid content to the protein is 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.

  The extraction temperature is not particularly limited. However, the higher the extraction rate of the water-soluble component, the more easily the oil and fat are solubilized, and the lower the lipid of the soybean emulsified composition. The following should be done. 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 soybean suspension after the addition of water), the higher the temperature, the higher the extraction rate of the water-soluble component, but the fats and oils also tend to be solubilized, and the lipid in the soybean emulsion composition tends to decrease. . 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, not only neutral lipids but also most of the lipids including polar lipids are not eluted in the water extract, but transferred to the insolubilized protein or dietary fiber to make the precipitation side (insoluble fraction). is 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 xg or more. In the case of the soybean emulsion composition used in the present invention, the centrifugal separator is not used. Is possible.
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, the preparation of the soybean emulsified composition used in the present invention can be carried out without using a demulsifier.

By solid-liquid separation after the water extraction step, not only neutral lipids but also polar lipids are transferred to an insoluble fraction, and a fraction of the soybean emulsified composition can be obtained by collecting this.
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 and the like to obtain a soybean emulsion composition used in 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 of soybean emulsified composition)
The above-mentioned soybean emulsified composition used in the present invention contains a lipid (neutral lipid and polar lipid) and protein in a specific range, has a particularly high LP content of protein, and optionally contains fiber. The natural taste of soy is concentrated, and there is little or no unpleasant taste such as blue odor, astringent taste, astringency, etc. It has a flavor.
It is possible to add water and fat to normal soy flour and isolated soy protein to make an emulsified composition similar to the soy emulsified composition, but adjust the lipoxygenase protein content or LCI value to an equivalent level It is difficult. And the soybean emulsified composition prepared by this technique is characterized by remarkably good flavor and high suitability for use as a food material compared to such an assembled product.

  The lipid in the soybean emulsified composition of the present invention is desirably unrefined soybean oil from the viewpoint of flavor. That is, the lipid in the soybean emulsified composition of the present invention can obtain the most preferable result when derived from the whole soybean, which is the raw material, and the soybean emulsion composition prepared from the whole soybean by a predetermined method, It is most preferable as the main body of action of the composition for reducing serum cholesterol.

  The present inventors have found that the soybean emulsion composition of the present invention has a remarkable effect of improving renal function. The renal function improving effect can be seen by eating an appropriate amount of the soybean emulsified composition of the present invention. That is, the soybean emulsified composition of the present invention can be used as an action body of a composition for improving renal function.

Moreover, the foodstuff which shows a renal function improvement effect | action can be manufactured by making the composition for renal function improvement of this invention contain a predetermined amount in a foodstuff. As described above, the reason why the “food for improving renal function” can be easily prepared is that the composition for improving renal function of the present invention is derived for the first time by having both good flavor and renal function improving action. Yes, this is achieved for the first time by the present invention. In addition, by using the composition for improving renal function of the present invention, a food for specified health and a special-purpose food (food for patients with illness, food for patients with difficulty in swallowing) exhibiting an action for improving kidney function can also be prepared. .
This method for producing a food exhibiting an effect of improving renal function has a technical feature in including the “composition for improving renal function” of the present invention.

  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.

(Production Example 1) Preparation of soybean emulsified composition 1
The suspension was made by adding 4.5 times the amount of water at 50 ° C. to 3.5 kg of soybean powder made to NSI 59.4 by wet heat treatment, and stirred for 30 minutes while keeping warm and extracted 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. And the fraction 6.3kg which combined the floating layer and the precipitation layer was collect | recovered, and the soybean emulsification composition A was prepared.

(Production Example 2) Preparation of soybean emulsified composition 2
The soybean emulsified composition A prepared in Production Example 1 was added 0.5 times by weight and further homogenized with a high-pressure homogenizer at 13 MPa, and then the homogenized liquid was heated at 142 ° C. for 7 seconds by a steam direct blowing method. The insoluble fiber was separated and removed at 6,000 × g with a continuous centrifuge, and a supernatant fraction was obtained.

The soybean emulsified compositions A and B obtained in Production Examples 1 and 2 were partially lyophilized for analysis, dried as general components, protein per dry matter (by Kjeldahl method), lipid (chloroform / methanol mixed solvent) (By an extraction method) and ash content were measured, and further, LCI value was analyzed as an estimated value of lipoxygenase protein content and LP content by SDS-PAGE. For comparison, the soy flour used as a raw material and the commercially available soybean emulsified composition “Soy Supreme Kreme” (SunOpta Grains and Foods Group) presumed to be produced by the method of US Pat. No. 6,548,102 ) And powder type) were similarly analyzed. Each analysis value is shown in Table 2.
Soy emulsified compositions A and B were rich in lipid content relative to protein compared to soybean flour, and the protein composition was significantly different from soybean flour and commercially available soybean emulsified compositions. That is, since the LCI value was as high as 55% or more, LP was concentrated, and the lipoxygenase protein content was also high. The soybean emulsified composition having such a composition is a component composition not found in conventional soymilk or okara. The flavors of these compositions A and B are also concentrated in the natural taste inherent in existing soymilk and soybeans, and unpleasant tastes such as the blue odor, astringent taste, and astringency of soybeans, which were previously considered problems. No, it had a very rich flavor.

(Table 2)
* Figures in parentheses indicate lipid content (%) per protein.

"Urine NAG activity reduction test"
Example 1 and Comparative Example 1
Rats were fed with the diet shown in Table 3, and urinary NAG (β-N-acetyl-D-glucosaminidase) was measured.
NAG is widely distributed in organs, but since it is a fairly large enzyme, serum enzymes rarely appear in urine. By quantifying the amount of NAG in urine, degeneration and destruction of tubular epithelial cells You can know such injuries.

Table 3 Feed formulation
Note) Feed CP = Casein 10% + sample-derived 10%, and the oil content in the feed is adjusted by supplementing the soybean content with 20% of the soy emulsified composition B, supplemented with soybean oil, and the amount of protein Two kinds of baits with the same oil content were prepared.
Casein's CP was 88%.

Test method Animal: Number of Zucker fatty rat animals, Period: n = 6 × 2 groups, 2 weeks Evaluation sample: Casein, soybean emulsified composition B
Operation: <Weight, food intake> Daily measurement
<Blood collection> 2 times in total (on the way, during final dissection)
Analysis: Urinary NAG activity (NAG test Shionogi), urinary protein (Tonein TP)
Test results The urinary NAG activity was significantly lower in the test group using the soybean emulsified composition B than the test group using Casein after 2 weeks of feeding.
The Zucker fatty rat is a mutant exhibiting remarkable obesity, and nephropathy is known to occur as a complication with aging.
In Comparative Example 1, it was shown that the occurrence of nephropathy accompanying aging in Zucker fatty rats was not suppressed at all by Example 1, whereas it was positively suppressed in Example 1.

By using the composition for improving renal function of the present invention, a consumer can improve renal function through eating habits. Therefore, in the food industry, it is possible to develop products that stimulate new demand.

-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, not only neutral lipids but also most of the lipids including polar lipids are not eluted in the water extract, but transferred to the insolubilized protein or dietary fiber to make the precipitation side (insoluble fraction). is 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 xg or more. In the case of the soybean emulsion composition used in the present invention, the centrifugal separator is not used. Is possible.
Further, a demulsifier can be added during water extraction or after water extraction to promote separation of lipids from soy milk, and the demulsifier is not particularly limited . However, the preparation of the soybean emulsified composition used in the present invention can be carried out without using a demulsifier.

The lipid in the soybean emulsified composition of the present invention is desirably unrefined soybean oil from the viewpoint of flavor. That is, the lipid in the soybean emulsified composition of the present invention can obtain the most preferable result when derived from the whole soybean, which is the raw material, and the soybean emulsion composition prepared from the whole soybean by a predetermined method, It is most preferable as the action body of the composition for improving renal function .

Claims (5)

The protein content per dry matter is 25% by weight or more, the lipid content (referred to as the chloroform / methanol mixed solvent extract) is 100% by weight or more with respect to the protein content, and the LCI value is 55% or more. A composition for improving renal function, comprising a soybean emulsified composition. The composition for improving renal function, comprising the soybean emulsified composition according to claim 1, wherein the lipid is unrefined soybean oil. Using fat-containing soybeans having a lipid content per dry matter of 15% by weight or more and an NSI 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, transferring neutral lipid and polar lipid to the insoluble fraction, removing the water-soluble fraction containing protein and carbohydrate, and collecting the insoluble fraction;
The composition for renal function improvement containing the soybean emulsified composition of any one of Claims 1-2 obtained by these. A food using the composition for improving renal function according to claim 1. The manufacturing method of the foodstuff using the composition for renal function improvement of Claim 4.