JPWO2010092778A1 - Acid-soluble soybean protein material and method for producing the same - Google Patents

Abstract

An acidic soluble soy protein material with reduced astringency and bitterness and excellent flavor for use in acidic foods and drinks is obtained. In gel filtration using 1 wt% SDS-containing buffer (pH 7.0), the content of the fraction with mass of 150 kDa or more detected at 220 nm is 18% or less, and the TCA (0.22M) solubilization rate is 45%. The following acidic soluble soybean protein material is used. In addition, in the production of acid-soluble soybean protein material that is subjected to phytase treatment and acidic heat treatment above 100 ° C, protease treatment is started at pH 3.4 or lower, so that the acid-soluble soybean protein material having the above characteristics Can be manufactured. [Selection] Figure 1

Description

  The present invention relates to an acid-soluble soybean protein material useful for, for example, acidic food and drink.

Acidic foods and drinks are characterized by their refreshing flavor, and are typically acidic beverages such as fruit juices, jelly, and yogurts. Conventionally, when preparing highly transparent protein foods and drinks, whey protein, which is a main component of milk whey and has high solubility under acidic conditions, has been exclusively used.
Separated soy protein, which is a soy protein material obtained by separating from soy, has a very low solubility in the pH range around pH 4.5, which is its isoelectric point from around pH 3. Therefore, various attempts have been made to increase the solubility of soy protein containing soy protein in acidic water. Patent Document 1 increases the solubility of soy protein in acidity by heating the soy protein to 250 to 320 ° F. (121 to 160 ° C.) under an acid pH of 2.0 to 4.2. Patent Document 2 greatly improves the solubility of the soy protein material in the acidic region by a treatment such as phytase treatment of the separated soybean protein followed by high-temperature heat treatment under acidity.

  Acidic aqueous solutions of these protein materials that dissolve at pH 3.5, such as whey protein and acidic soluble soy protein material, have a problem of feeling astringency in the mouth when ingested (Non-patent Document 1). This astringency is induced by isoelectric precipitation of the protein in the mouth, and can be avoided by reducing the molecular weight of the protein. However, protein hydrolysis under weak acidity reduces astringency, but has a problem of bitterness. Both astringency and bitterness could not be reduced to a level used for food and drink.

  Therefore, in order to reduce astringency while suppressing the occurrence of bitterness, a method of performing acid solubilization treatment by adjusting to weak acidity after performing hydrolysis under neutrality has also been studied (Patent Document 3). In this neutral decomposition method, a bitterness was hardly generated and astringency was considerably reduced, but further improvement is desired. An acidic soluble soybean protein material that has reduced astringency and bitterness and has reached a level that can be used for acidic foods such as beverages or jelly-like foods is desired.

Japanese Patent Publication No. 53-19669 WO02 / 067690 Brochure WO2008 / 136326 Brochure

Abstracts of Annual Meeting of the Japanese Society of Agricultural Chemistry 58 (2J13p04), 2006

  An object of the present invention is to provide an acid-soluble soybean protein material that is reduced in astringency and bitterness and excellent in flavor for use in acidic foods and drinks.

As a result of diligent research to solve the above-mentioned problems, the present inventors have not so far carried out protease degradation of a soy protein-containing solution to a certain degree of degradation when preparing an acidic soluble soybean protein material. It was found that by starting the reaction at pH 3.4 or less, astringency and bitterness are greatly reduced, and this discovered that the content of fractions of 150 kDa or more in gel filtration described later was significantly low, This invention was completed.
That is, the present invention
(1) In gel filtration using 1 wt% SDS-containing buffer solution (pH 7.0), the content of the fraction with mass number of 150 kDa or more detected at 220 nm is 18% or less and TCA (0.22M) is solubilized. Acid soluble soy protein material with a rate of 45% or less.
(2) A method for producing an acidic soluble soybean protein material, characterized in that protease treatment is started at pH 3.4 or less, and the TCA (0.22M) solubilization rate is 10% or more and 45% or less.
(3) The method for producing an acid-soluble soybean protein material according to (2), wherein the production of the acid-soluble soybean protein material is based on a phytase treatment and an acidic heat treatment exceeding 100 ° C.
(4) Acidic food and drink using the acidic soluble soybean protein material according to claim 1.

  According to the present invention, it is possible to obtain an acidic soluble soybean protein material suitable for acidic foods and drinks which has little astringency and bitterness and is excellent in flavor.

Comparison by gel filtration The product (C) of the present invention is a gel filtration chromatogram showing that the fraction of 150 kDa or more is very small compared to the conventional product (F). Comparison by electrophoresis Not only the product of the present invention (C) but also the conventional product (F) is an SDS polyacrylamide gel electrophoresis pattern showing that 7S globulin and 11S globulin bands do not remain.

(Acid-soluble soy protein material)
Hereinafter, the present invention will be specifically described. In the present specification, an acidic soluble soybean protein material is a protein-rich fraction extracted from soybean raw material and separated from okara, and is defined as a dilute acid NSI modified method of 90% or more. . Furthermore, one form of the present invention is an acidic soluble soybean protein material, which exhibits a molecular weight distribution described later, has a TCA (0.22M) solubilization rate of 45% or less, and 40% or less. Further preferred. When the TCA (0.22M) solubilization rate exceeds 45%, a lot of bitterness may occur. Further, when the dilute acid NSI is less than 90%, roughness and the like occur, and it is difficult to use as a protein material for acidic foods and drinks.

(Molecular weight distribution)
In one embodiment of the present invention, the content of a fraction having a mass number of 150 kDa or more detected at 220 nm in gel filtration using a 1 wt% SDS-containing buffer (pH 7.0) is 18% or less, preferably 14%. The following acidic soluble soybean protein materials. An acidic soluble soybean protein material having a mass fraction of more than 150 kDa with a content of more than 18% has a large unpleasant astringency and cannot be used for acidic foods. On the other hand, if it is 18% or less, the astringency is reduced to an unpleasant level or less, and if it is 14% or less, the astringency is almost not felt. Only protein materials that meet the above conditions are the present invention and are suitable for acidic foods and drinks.

  This gel filtration can be performed as follows. That is, a column of “TSK gel G3000SWXL” (φ7.8 mm × 300 mm) (manufactured by Tosoh Corporation) was used, and a 50 mM phosphate buffer (pH 7.0) containing 1% SDS and 1.17% NaCl was used as an eluent. The flow rate is 0.8 ml / min and the column oven temperature is 40 ° C.

  From the results of gel filtration obtained at a measurement wavelength of 220 nm, the peak area of the elution time earlier than the elution time of the molecular weight marker γ-globlin (molecular weight 150 kDa) is measured, and the mass number is 150 kDa as a percentage of the total peak area of the sample. Obtain the content of the above fractions.

  The acidic soluble soybean protein material of the present invention uses soybean-derived raw materials. The preparation method of the acid-soluble soybean protein raw material using the raw material derived from soybean is illustrated below.

(Soy protein material)
The production of the above-mentioned acidic soluble soybean protein material can be prepared by acid solubilizing the soybean protein material, for example, as follows. First, a soy material that can be extracted with soy protein, including okara (insoluble fiber content), such as defatted soybeans and concentrated soybean protein that has undergone a defatting process. Degreasing is performed by pressing or solvent extraction. Generally, defatted soybeans obtained by low-temperature extraction using n-hexane as an extraction solvent are suitable as a starting material. Extracting soluble components from such soybean raw materials with water or hot water to remove insoluble Okara, and adjusting the pH of the defatted soymilk to the vicinity of the isoelectric point of soy protein, protein components that are insoluble components The separated soybean protein obtained by separating and recovering can be used as a soybean protein material in the subsequent steps. In the present invention, a separated soybean protein containing a large amount of 7S globulin or 11S globulin obtained by fractionating separated soybean protein or using soybean rich in specific components can also be used. In the present specification, “soy protein” means a protein derived from soybean or a molecule of a hydrolyzate thereof. In contrast, non-fat soy, concentrated soy protein and other okaras (insoluble fiber content) are separated from “soy raw material”, and protein components are extracted from the soy raw material and the defatted soy milk or defatted soy milk is isoelectric. The neutralized product of point precipitation (separated soy protein) or a hydrolyzate thereof is expressed and distinguished as “soy protein material”. The acidic soluble soybean protein material of the present invention is preferably a separated soybean protein having a crude protein content of 85% or more.
Furthermore, if it is used for foods and drinks that do not require transparency, soybeans and processed soybean products that are not defatted, such as whole soybeans and soybean flour, are used as “soy raw materials”, and the “soy protein material” Can also be used.

(Acid addition treatment)
Subsequently, it is important in preparing the product of the present invention that the soybean protein material described above is treated with protease under stronger acidity than before. That is, a soybean protein material aqueous solution having a pH of 3.4 or less, preferably pH 3 or less is prepared, and protease treatment is started. The acid used here is an acid used in foods, and for example, mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid are preferable, and two or more acids may be mixed and used. In addition, organic acids such as citric acid, malic acid, tartaric acid, lactic acid, gluconic acid, fumaric acid, succinic acid, acetic acid, and oxalic acid can be used in combination with the mineral acid. If the pH exceeds 3.4, the present invention cannot be achieved. If the pH is too low, it is difficult to react depending on the type of protease, and the ash content of the system increases, which is not preferable. Usually, a pH of 2.5 or higher is preferable.

(Protease treatment)
Protease is added to this solution and reacted. The protease used in the present invention is preferably a protein in which amino acids are bound in a chain or an endo-type protease that is an enzyme that hydrolyzes peptide bonds inside the peptide to form several peptides. It is also possible to combine one or more exo-type proteases, which are enzymes that sequentially cleave amino acids and peptides from the amino terminus and carboxy terminus present at the ends of proteins and peptides. These endo-type proteases and exo-type proteases can be used as long as they have activity in an environment of pH 3.4 or lower, but those derived from microorganisms such as Aspergillus genus and Rhizopus genus, and those derived from plants. It can be preferably used. Among these, those derived from microorganisms are preferable, those derived from the genus Aspergillus are particularly preferable, and those derived from Aspergillus oryzae are most preferable. As proteases derived from the genus Aspergillus, "Sumiteam ACP" (manufactured by Shin Nippon Chemical Co., Ltd.), "Protease M (Amano) G" (manufactured by Amano Enzyme) (from Aspergillus oryzae), "Orientase 20A" (H. And "Denapsin 2P" (manufactured by Nagase Chemtech) (from Aspergillus niger).

  Although the reaction temperature depends on the type of enzyme used, the reaction is generally carried out at 20 ° C or higher and 70 ° C or lower. If it is less than 20 ° C, the protease activity is low and it may be industrially undesirable because it is necessary to increase the amount of enzyme added. If it exceeds 70 ° C, it may be inactivated by heat denaturation depending on the type of protease. The degree of degradation in the above-described gel filtration containing SDS is that the content of the fraction having a mass number of 150 kDa or more is 18% or less, and the TCA (0.22M) solubilization rate is 10% or more and 45%. It is essential that: Further, it is preferably 15% or more and 40% or less. If it exceeds 45%, the molecular weight will decrease, and the use will be limited due to the occurrence of bitterness, both in terms of physical properties and taste, and if it is less than 10%, astringency cannot be improved, both of which are for the purpose of the present invention. Does not match. Although the pH of the system is slightly increased by the treatment with acidic protease, the pH at the start of protease treatment is important for the present invention.

(Acid solubilization treatment)
In order to make the soybean protein material described above into an acidic soluble soybean protein material, an acid solubilization treatment is required. For the acid solubilization treatment in the present invention, for example, a method disclosed in WO2002 / 67690 can be used. Above all, phytase treatment for removing phytic acid derived from the raw material protein in the solution containing soy protein, and heating the solution containing soy protein at a temperature exceeding 100 ° C in an acidic region from the pH of the isoelectric point of the protein. The method by performing the treatment is preferable because it can efficiently increase the dissolution rate of soy protein under acidity.

(Phytase treatment)
The origin of the phytase used in the present invention is not particularly limited as long as it is an enzyme or enzyme agent having phytic acid hydrolysis activity. The temperature, time, pH, and amount added can be appropriately set depending on the phytase used. The order in which the phytase treatment and the protease treatment are performed is not particularly limited, and can be performed before the protease treatment, after the protease treatment, or simultaneously. By simultaneously reacting phytase in the protease reaction, the process is simplified and the productivity can be improved.

(Heat treatment)
The heat treatment in the present invention is adjusted to a pH lower than the isoelectric point of soybean protein, preferably pH 2.3 to 4.3, and a temperature exceeding 100 ° C., preferably 180 ° C. or less, more preferably 105 ° C. to 160 ° C. Heat with. At a pH exceeding the isoelectric point or at a temperature below 100 ° C., acid solubilization does not proceed, and an acid-soluble soybean protein material that meets the present invention cannot be obtained. When the temperature exceeds 180 ° C., peptide bonds are partially decomposed, and the quality may be deteriorated. If the pH is too low, the amount of acid to be used is remarkably increased, which is not preferable in terms of flavor and workability of the resulting product. The heating time is preferably 1 second to 1 hour. When heating for less than 1 second, acid solubilization is not sufficiently performed, and when heating for 1 hour or more, there is a possibility of affecting the quality such as flavor. The concentration of the solution containing soy protein is preferably 3 to 30% by weight of solid content, more preferably 8 to 16% by weight of solid content. If the solid content is less than 3% by weight, there is no problem in quality, but the working efficiency tends to decrease. If the solid content exceeds 30% by weight, the viscosity of the solution containing the protein increases remarkably, and the subsequent workability deteriorates. It tends to make it. However, when decomposition of the soy protein to be heated is advanced, the effect of thickening is small and the concentration can be increased.

  Although a heating method is not ask | required, the continuous direct heating sterilizer of a steam injection system can be illustrated as a desirable system. This apparatus is a system in which steam is blown into a liquid flowing in a pipe, and can be instantaneously heated to a high temperature exceeding 100 ° C. If the protease and phytase treatments are performed in advance, it is preferable that acidic solubilization treatment and sterilization by heating can be performed simultaneously by subsequent acidic heating.

(Dry)
The solution containing the acid-soluble soy protein material that has been subjected to the acid solubilization treatment can be used as it is, but can also be pulverized in order to enhance the convenience of use. . The drying method is not particularly limited, and a spray drying apparatus or the like is suitable. The acidic soluble soybean protein material obtained according to the present invention can provide a solution having a pH of 3 to 4.5, which is low in solubility in ordinary separated soybean protein. In this drying, it is preferable to carry out the drying treatment while maintaining the acidity without performing neutralization or the like.

(Acid food and drink)
Usually, a protein under weak acidity has a pH near the isoelectric point, the protein aggregates, and it is difficult to obtain an acidic protein food or drink having a good texture without roughness. By using the acidic soluble soybean protein material obtained in the present invention, an acidic food and drink having a good taste in the acidic region, a good texture without causing protein precipitation, and a good storage stability can be obtained. Examples of acidic foods and drinks include acidic protein beverages. Seasoning at the time of beverage preparation is selected according to tastes such as sugars and fragrances. The protein content is preferably in the range of 1 to 20% by weight, although it depends on the degree of protein intake. In addition, an acidic jelly-like food can be prepared by using an acidic soluble soybean protein material obtained by the present invention in combination with an appropriate gelling agent together with sugars, flavors and the like.
Moreover, since it has high solubility while being acidic and good in flavor, it is also suitable for use in swallowing foods, acidic whipped creams and the like.

The analysis method used in the present invention is described below.
● Crude protein content: The nitrogen content was determined based on the Kjeldahl method, multiplied by a coefficient of 6.25 to obtain the crude protein content, and the result was shown in anhydrous conversion.
● NSI (water-soluble nitrogen index): Based on the official analysis method BA-11-65 NSI of AOCS (American Oil Chemist Society), the following was performed. Weighed 3.5 g of protein material, added 100 ml of water, stirred with propeller (500 rpm) for 10 minutes, and sampled nitrogen (measured by Kjeldahl method) in the filtrate filtered with No. 5A filter paper. Expressed as a percentage of nitrogen.
Dilute acid NSI modified method: In the above NSI measurement method, after stirring the propeller, the pH was 3.5 and the dissolved protein was quantified.
-TCA (0.22M) solubilization ratio: An equal amount of 0.44M trichloroacetic acid (TCA) was added to a 2% by weight aqueous solution of protein material, and the proportion of soluble protein was measured by the Kjeldahl method. As protein degradation proceeds, the TCA solubilization rate increases.
● pH: pH was measured at 25 ° C.

  Examples are described below. Unless otherwise specified, the following parts and% are all parts by weight and% by weight.

(Comparative Example 1) Preparation of protease-degraded / acid-soluble soybean protein material at pH 3.5 Low-denatured defatted soybean obtained by pressing soybean, extracting and removing oil using n-hexane as an extraction solvent ( NSI: 91) Add 7 parts by weight of water to 1 part by weight, extract with stirring at room temperature for 1 hour while adjusting to pH 7 with dilute sodium hydroxide solution, then centrifuge at 4,000 xg to separate okara and insoluble matter. And defatted soy milk was obtained. After adjusting this skimmed soymilk to pH 4.5 with phosphoric acid, it is centrifuged at 2,000 × g using a continuous centrifuge (decanter) to obtain an insoluble fraction (acid precipitation card) and a soluble fraction (whey). It was. The acid precipitation curd was watered to a solid content of 10% by weight to obtain an acid precipitation curd slurry. This acid precipitation curd slurry was also used in the following examples, comparative examples, and experimental examples.

  The acid precipitation curd slurry having a solid content of 10% by weight was adjusted to pH 3.5 with a phosphoric acid solution and then heated to 50 ° C. To this solution, 0.1 wt% protease derived from Aspergillus oryzae (“Sumiteam ACP” manufactured by Shin Nippon Chemical Co., Ltd., 1,000 U / g) at a solid content was added and hydrolyzed for 60 minutes. After the reaction, the enzyme was inactivated by heating at 85 ° C. for 20 minutes. This hydrolyzate was adjusted to pH 3.5, phytase equivalent to 8 units per 100 g of solid content (“Phytase Novo” manufactured by Novozymes) was added and allowed to act for 30 minutes. Heated at 140 ° C for 10 seconds in a continuous direct heat sterilizer. This was spray-dried to obtain a powdery acidic soluble soybean protein material (A) (crude protein content 91%).

(Example 1) Preparation of protease-degrading / acid-soluble soybean protein material at pH 3.3 After adjusting the acid precipitation curd slurry of Comparative Example 1 having a solid content of 10% by weight to pH 3.3 with phosphoric acid, 50 ° C It was heated to become. To this solution, 0.1% by weight of “Sumiteam ACP” per solid content was added and hydrolyzed for 60 minutes. After the reaction, the enzyme was inactivated by heating at 85 ° C. for 20 minutes. This hydrolyzate was adjusted to pH 3.5, “phytase novo” corresponding to 8 units per solid was added, and the enzyme reaction was carried out for 30 minutes. After the reaction, it was heated at 140 ° C. for 10 seconds in a continuous direct heat sterilizer. This was spray-dried to obtain a powdery acidic soluble soybean protein material (B) (crude protein content 90%).

(Example 2) Preparation of protease-degrading / acid-soluble soy protein material at pH 3.0 After adjusting the acid precipitation curd slurry of Comparative Example 1 having a solid content of 10% by weight to pH 3.0 with phosphoric acid, 50 ° C It was heated to become. To this solution, 0.1% by weight of “Sumiteam ACP” per solid content was added and hydrolyzed for 60 minutes. After the reaction, the enzyme was inactivated by heating at 85 ° C. for 20 minutes. To this hydrolyzate, “phytase novo” corresponding to 8 units per solid was added, and an enzyme reaction was carried out for 30 minutes. After the reaction, it was heated at 140 ° C. for 10 seconds in a continuous direct heat sterilizer. This was spray-dried to obtain a powdery acidic soluble soybean protein material (C) (crude protein content 90%).

(Comparative Example 2) Preparation of undegraded / acid-soluble soy protein material After adjusting the acid precipitation curd slurry having a solid content of 10% by weight of Comparative Example 1 to pH 3.5 with a phosphoric acid solution, “Phytase Novo” equivalent to 8 units was added and allowed to act for 30 minutes. Heated at 140 ° C for 10 seconds in a continuous direct heat sterilizer. These were spray-dried to obtain a powdery acidic soluble soybean protein material (D) (crude protein amount 92%).

(Comparative Example 3) Preparation of plant protease degradation / acid-soluble soybean protein material at pH 3.5 After adjusting the acid precipitation curd slurry having a solid content of 10% by weight of Comparative Example 1 to pH 3.5 with phosphoric acid, 50 Heated to 0 ° C. To this solution, 0.1% by weight of “papain W-40” (400,000 U / g, manufactured by Amano Enzyme) per solid content was added, and hydrolysis was performed for 60 minutes. After the reaction, the enzyme was inactivated by heating at 85 ° C. for 20 minutes. The hydrolyzate was adjusted to pH 3.5, “phytase novo” corresponding to 8 units per solid was added, and the enzyme reaction was carried out at pH 3.5 for 30 minutes. After the reaction, it was heated at 140 ° C. for 10 seconds in a continuous direct heat sterilizer. This was spray-dried to obtain a powdery acidic soluble soybean protein material (E) (crude protein content 91%).

Comparative Example 4 Preparation of Neutral Protease Decomposition / Acid Soluble Soy Protein Material After adjusting the acid precipitation curd slurry having a solid content of 10% by weight of Comparative Example 1 to pH 6.5 with dilute sodium hydroxide solution, continuous Heated at 140 ° C for 10 seconds in a direct heat sterilizer. This solution was adjusted to 50 ° C., and 0.1 wt% of protease derived from the genus Bacillus (“Protamex” 1.5 AU (Anson unit) / g, manufactured by Novozyme) per solid content was added, followed by hydrolysis for 60 minutes. After the reaction, the enzyme was inactivated by heating at 85 ° C. for 20 minutes. After adding phosphoric acid to this hydrolyzate and adjusting to pH 3.5, "phytase Novo" corresponding to 8 units per solid was added and allowed to act for 30 minutes. Heated at 140 ° C for 10 seconds in a continuous direct heat sterilizer. These were spray-dried to obtain a powdery acidic soluble soybean protein material (F) (crude protein amount 80%).

(Comparative Example 5) Preparation of acid-soluble soybean protein material having a high degree of decomposition After adjusting the acid precipitation curd slurry having a solid content of 10% by weight of Comparative Example 1 to pH 3.0 with a phosphoric acid solution, the temperature becomes 50 ° C. Warmed to. To this solution, 0.5% by weight of “Sumiteam ACP” per solid content was added and hydrolyzed for 60 minutes. After the reaction, the enzyme was inactivated by heating at 85 ° C. for 20 minutes. To this hydrolyzate, “phytase novo” corresponding to 8 units per 100 g of solid content was added and allowed to act for 30 minutes. Heated at 140 ° C for 10 seconds in a continuous direct heat sterilizer. This was spray-dried to obtain a powdery acidic soluble soybean protein material (G) (crude protein content 90%).

(Example 3) Preparation of protease-degrading / acid-soluble soybean protein material at pH 3.0 2
Preparation was carried out in the same manner as in Example 2 to obtain a powdery acidic soluble soybean protein material (H) (crude protein content 90%). However, “Sumiteam ACP” was added to the solution at a concentration of 0.25 wt% per solid, and hydrolysis was performed for 60 minutes.

(Sensory evaluation and quality comparison)
Sensory evaluation and quality measurement were carried out on the acid-soluble soybean protein materials (A) to (H) (Table 1). Sensory evaluation prepared 5 weight% aqueous solution, and evaluated "astringency" and "bitterness". For each item, based on "1 point" that you do not feel, "2 points" that you hardly feel, "3 points" that you feel but are uncomfortable, "4 points" that you feel (discomfort), "5 points" that you feel strongly, Sensory evaluation was performed by 20 panelists, and the average value was shown.

  In (B) and (C) where decomposition was started at pH 3.4 or lower, both astringency and bitterness were reduced, which was suitable for use in acidic foods and drinks. Undegraded (D) felt a very strong astringency. (A) (E), which started degrading at a pH exceeding 3.4, has a bitter taste compared to (D) but cannot be reduced to a level that is not unpleasant, and bitterness is felt uncomfortable. Had occurred at the level. Neutral degradation (F) was slightly less astringent than (E), but had some problems and felt a soy odor. Therefore, (A), (D), (E), and (F) did not reach the level that can be preferably used for acidic foods and drinks. For (G) and (H), which increased the amount of enzyme and increased the degree of degradation, in (G), the TCA solubilization rate exceeded 45% and increased to a level at which bitterness was felt uncomfortable. Although it did not meet the purpose, a TCA solubilization rate of 45% or less (H) had a good flavor.

(Table 1) Sensory evaluation and comparison of each quality

(Experimental example 1) Molecular weight distribution by gel filtration Moreover, the comparison by gel filtration was performed about (B)-(F). The results are shown in Table 1 and FIG. No astringency was observed (B), (C), and (H), and the fractions with a mass number of 150 kda or more were all low values of 18% or less. It was found to have. For gel filtration measurement, the ratio of the peak area of elution time earlier than 8.1830 minutes was measured for the molecular weight marker γ-globlin (MP Biomedicals, Inc. molecular weight 150 kDa) using the system described above, and the mass number was 150 kDa or more. It was set as the content of the fraction. The sample was dissolved in the eluent so as to be 0.1% by weight as protein, passed through a cellulose acetate type membrane filter (DISMIC-13CP 0.20 μm, manufactured by Advantec), the precipitate was removed, and 20 μl was injected.

  The HPLC main unit uses equipment manufactured by JASCO Corporation, “PU-2089 Plus” as the liquid feed pump, “UV-2077 Plus” as the detector, “CO-2,065 Plus” as the column oven, and “LC” as the system controller. -Net II / ADC "and" ChromNAV "as analysis software. The chromatogram waveform processing was ChromNAV with a slope sensitivity of 10.00 μV / sec, a slope width of 0.1 min, a minimum area of 10,000 μV · sec, a minimum height of 1000 μV, a drift of 0.000 μV / min, and a slope width doubling time of 0.0000 min.

(Experimental example 2) Comparison by SDS electrophoresis About (C)-(F), it used for SDS-polyacrylamide electrophoresis, and investigated the behavior of the protein. Electrophoresis was in accordance with the Laemmli method [Nature, Vol. 227, 680-685 (1970)]. That is, 10 μL of a 5% by weight aqueous solution of a sample and 90 μL of Tris-SDS-β-ME sample treatment solution (manufactured by Cosmo Bio) were mixed and heated at 100 ° C. for 5 minutes, and SDS-Tris-Glycine running buffer (Cosmo Bio) 10-20% gradient gel was used for 1 hour at a constant flow of 25 mA. After electrophoresis, the gel was stained with Page Blue 83 (CBB R-250) staining solution (manufactured by Cosmo Bio).

  As shown in FIG. 2, the undegraded (D) and the decomposition started at pH 3.5 (E), where astringency was felt strongly, compared to the decomposition started at pH 3.0 (C). Components such as 7S globulin and 11S globulin were not degraded and bands were observed. In addition, since the content of fractions of 150 kda or more by gel filtration is high (Table 1), (D) and (E), it is assumed that these undegraded 7S and 11S proteins are involved in astringency. (E) Under the conditions where the decomposition was started at pH 3.5, it was found that the 7S globulin and 11S globulin were not properly decomposed even though the TCA solubilization rate was high. On the other hand, (F) of neutral degradation has a thinner band observed by electrophoresis than (C), and even though it has a high degree of degradation, the content of fractions of 150 kda or higher by gel filtration is as high as 21.8% ( Compared with Table 1, FIG. 1), (C), astringency was still felt, and also the amount of crude protein was lower than others. From the above examination, it was confirmed that the polymerized product due to SS bond or the like cannot be dissociated by simply performing hydrolysis under the decomposition conditions that do not cause bitterness, and it does not lead to a decrease in astringency.

(Example 4) Preparation of acidic soluble soybean protein material by decomposition at pH 3.0 using 11S globulin as a raw material 11S globulin from isolated soybean protein was prepared by the production method described in International Publication WO2006 / 129647. To obtain 11S globulin-enriched material. That is, 1 kg of low-denatured defatted soybean was mixed while spraying 100 g of 70 wt% hydrous alcohol, and the outside of the sealed container was heated so that the product temperature of the defatted soybean was 70 ° C. and maintained for 30 minutes. 7 parts by weight of water is added to 1 part by weight of the processed defatted soybeans, extracted with stirring at room temperature for 30 minutes while adjusting to pH 7.5 with dilute sodium hydroxide solution, centrifuged at 1,000 xg, and okara and insoluble. Minutes were separated to obtain defatted soymilk A. 5 parts by weight of water was added to okara and insoluble matter, extracted while stirring at room temperature for 30 minutes, and centrifuged at 1,000 × g to separate okara and insoluble matter to obtain defatted soymilk B. Skim soymilk A and B were mixed, adjusted to pH 5.8 using hydrochloric acid, and centrifuged at 1,000 × g to obtain an 11S globulin-enriched material that was an insoluble fraction. The 11S globulin concentrated material was added with water to a solid content of 10% by weight, adjusted to pH 3.0, 0.1% by weight of “Sumiteam ACP” was added to the solid content, and hydrolysis was performed at 50 ° C. for 60 minutes. After the reaction, the enzyme was inactivated by heating at 85 ° C. for 20 minutes. This hydrolyzate was adjusted to pH 3.5, “phytase Novo” corresponding to 8 units per 100 g of solid content was added, and allowed to act for 30 minutes. Heated at 140 ° C for 10 seconds in a continuous direct heat sterilizer. This was spray-dried to obtain powdered acidic soluble soybean protein material (I) (crude protein content 90%).

(Comparative Example 6) Preparation of undegraded acidic soluble soybean protein material using 11S globulin as a raw material The 11S globulin concentrated material having a solid content of 10% by weight described in Example 4 was adjusted to pH 3.0, and 140 ° C. , Heated for 10 seconds and spray-dried to obtain an 11S globulin undegraded product (J) (crude protein amount 92%) subjected to acid solubilization treatment.

(Comparative Example 7) Preparation of acid-soluble soybean protein material by neutral decomposition using 11S globulin as a raw material The 11S globulin concentrated material having a solid content of 10% by weight described in Example 4 was adjusted to pH 7.0. The solution was adjusted to 50 ° C. and 0.1% “Protamex” per solid content was added, followed by hydrolysis for 60 minutes. After the reaction, the enzyme was inactivated by heating at 85 ° C. for 20 minutes. After adding phosphoric acid to this hydrolyzate and adjusting to pH 3.5, "phytase Novo" corresponding to 8 units per solid was added and allowed to act for 30 minutes. The mixture was heated at 140 ° C. for 10 seconds in a continuous direct heat sterilizer and then spray-dried to obtain an acidic soluble soybean protein material (K) (crude protein content 80%).

(Example 5) Preparation of acidic soluble soy protein material by decomposition at pH 3.0 using 7S globulin as a raw material 7S globulin from separated soy protein was produced using the production method described in International Publication WO2002 / 28198 And 7S globulin-enriched material was obtained. That is, 10 parts by weight of water is added to 1 part by weight of low-denatured defatted soybeans, extracted with stirring for 1 hour at room temperature while adjusting to pH 7.0 with dilute sodium hydroxide solution, and centrifuged at 1,000 xg for okara and insoluble. Minutes were separated to obtain defatted soymilk. The defatted soymilk was adjusted to pH 4.2 using hydrochloric acid, heated to 40 ° C., cooled, adjusted to pH 5.8 and centrifuged to obtain a soluble fraction. The soluble fraction was adjusted to pH 4.9 with hydrochloric acid and centrifuged at 1,000 × g to obtain a 7S globulin-enriched material that was a precipitate. The 7S globulin concentrate was hydrated to a solid content of 10% by weight, adjusted to pH 3.0, 0.1% “Sumiteam ACP” was added per solid content, and hydrolysis was performed at 50 ° C. for 60 minutes. After the reaction, the enzyme was inactivated by heating at 85 ° C. for 20 minutes. “Phytase Novo” corresponding to 8 units per 100 g of solid content was added to this hydrolyzate and allowed to act for 30 minutes. Heated at 140 ° C for 10 seconds in a continuous direct heat sterilizer. This was spray-dried to obtain powdered acidic soluble soybean protein material (L) (crude protein content 90%).

(Sensory evaluation and quality comparison)
Sensory evaluation and quality measurement were performed on the acid-soluble soybean protein materials (C) and (I) to (L) (Table 2). The 11S globulin-rich material started to decompose at pH 3.4 or lower (I), which has a slightly higher content of 15.5% of the fraction of 150 kda or higher, but slightly astringent compared to (C), but uncomfortable. It wasn't enough to feel. Moreover, the bitterness was reduced and it was suitable for using for acidic food and drink. Undecomposed (J) felt strong astringency. Neutral degradation (K) was less astringent than (J), but felt uncomfortable. In addition, (L) prepared from a material rich in 7S globulin has low astringency and bitterness, and can be used for acidic foods. From the above, even when using a material rich in 11S globulin and 7S globulin as a raw material, as in Example 2, by starting enzymatic degradation at pH 3.4 or lower, acidic soluble soybean protein to a level that can be used for acidic foods and drinks. The astringency of the material could be reduced.

(Table 2) Sensory evaluation and comparison of each quality

(Example 6) Preparation of acidic powder beverage 66.7 parts of powdered acidic soluble soybean protein material (C) prepared in Example 2, 18.6 parts of granulated sugar, 12.4 parts of grapefruit powder juice (made by Yaizu Suisan Chemical Co., Ltd.) , Grapefruit fragrance (manufactured by Takasago Fragrance Co., Ltd.) 2.1 parts and sweetener (Sucralose, Saneigen FFI Co., Ltd.) 0.2 part were mixed well to obtain a protein-containing acidic powder drink. 15 g of this powder was added to 185 g of water and mixed well with a shaker to obtain a beverage. Although this beverage was evaluated by sensory evaluation, it has an appropriate acidity, does not feel the astringent taste peculiar to conventional acidic soluble soybean protein materials, does not feel bitterness, does not feel soybean odor, and feels good over the throat It was excellent in palatability.

(Example 7) Preparation of acidic jelly-like food 5.0 parts by weight of powdered acid-soluble soybean protein material (C) prepared in Example 2, 8.0 parts of fructose glucose liquid (manufactured by Cornstarch Japan), 5-fold concentrated pineapple Mixing fruit juice (Food Material Co., Ltd.) 2.5 parts, agar (Ina Agar Co., Ltd.) 0.3 parts, pineapple fragrance (Takasago Fragrance Co., Ltd.) 0.2 parts, water 84.0 parts. The mixture was adjusted to pH 3.6, sterilized by heating at 95 ° C., mixed with agar liquid swollen by heating at high temperature, filled in a cheer pack, and gelled by refrigeration overnight to prepare a jelly beverage. The obtained jelly beverage did not feel astringent and had a good texture.

(Example 8) Preparation of acidic swallow food Powdered acidic soluble soybean protein material prepared in Example 2 (C) 4.3 parts by weight, granulated sugar 12.5 parts by weight, fermented lactate dolomite (Meiji Dairies) 1.25 parts by weight, Vitamin fortifier 0.125 parts by weight, tartaric acid 0.1 parts by weight, mineral yeast preparation “Mix Mineral Yeast C” 0.1 part by weight, “Mix Mineral Yeast M” 0.025 part by weight (manufactured by LS Corporation), stevia preparation 0.06 part by weight The powder was mixed and dispersed and dissolved in 46.04 parts by weight of water. A high-speed emulsification disperser was used for dissolution. Next, 4.3 parts by weight of hardened rapeseed oil was added little by little and stirred so that the oil was not separated (solution 1).
1.3 parts by weight of an agar preparation “Agar Mix # 24” (manufactured by Aoba Kasei) was dispersed in 25 parts by weight of water and dissolved by heating in a hot water bath for 10 minutes (solution 2). Solution 2 was mixed while solution 1 was stirred. Thereto, 4.0 parts by weight of transparent concentrated mango juice, 0.1 part by weight of the dye “β-carotene 10C” (manufactured by Mitsubishi Chemical Foods) and 0.9 part by weight of fragrance were added and mixed, and filled into a standing pouch. This was sterilized by heating at 85 ° C. for 30 minutes and cooled with running water to obtain a jelly-like swallowed food (pH 3.90).
It contains protein, lipid, and sugar, which are the three major nutrients, and can consume 1.2kcal in 1g, and other nutrients necessary for the body: calcium, magnesium, trace element minerals, vitamins, and dietary fiber. Including soft jelly with a soft and smooth texture, and a soft jelly with little stickiness in the pharynx, it was able to be eaten by an elderly person or a patient who had difficulty in swallowing without aspiration.

(Example 9) Preparation of acidic whipped cream To 2.0 parts by weight of powdered acidic soluble soybean protein material (C) prepared in Example 2, 0.2 parts by weight of sucrose fatty acid ester S-570 (manufactured by Mitsubishi Chemical Foods) Then, 52.6 parts by weight of water was added and dissolved, and an aqueous phase was prepared at a pH of 3.5. Separately, 23 parts by weight of a middle melting point fraction of palm oil, 22 parts by weight of hardened coconut oil, and 0.2 parts by weight of soybean lecithin (manufactured by Sakai Oil Co., Ltd.) were mixed to prepare an oil phase. The aqueous phase and the oil phase were mixed, stirred with a homomixer at 70 ° C. for 15 minutes and pre-emulsified, then homogenized at a pressure of 1 MPa, and then sterilized by direct steam heating at 144 ° C. for 4 seconds. Subsequently, the mixture was homogenized at a pressure of 4 MPa, immediately cooled, and kept at 5 ° C. for 24 hours to prepare an acidic cream. When this cream was whipped, it showed a high overrun of 90% at a whipping time of 3 minutes, the structure was smooth, and a refreshing sour taste was also obtained.

  According to the present invention, it is possible to produce a protein material that has little astringency and bitterness, excellent flavor, and satisfies the physicochemical properties such as low viscosity, high solubility, and high stability required for acidic foods and drinks. . By using this acidic soluble soybean protein material, protein-containing acidic foods and drinks that have a better flavor than before can be produced.

Claims (4)

In gel filtration using a buffer solution (pH 7.0) containing 1% by weight SDS, the content of a fraction having a mass number of 150 kDa or more detected at 220 nm is 18% or less, and the TCA (0.22M) solubilization rate is 45. Less than% acidic soluble soy protein material. A method for producing an acidic soluble soybean protein material, characterized in that protease treatment is started at pH 3.4 or lower, and TCA (0.22M) solubilization rate is 10% or more and 45% or less. The method for producing an acid-soluble soybean protein material according to claim 2, wherein the production of the acid-soluble soybean protein material is performed by a phytase treatment and an acidic heat treatment exceeding 100 ° C. Acidic food and drink using the acid-soluble soybean protein material according to claim 1.

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