JP2003333997A - Method for production of hydrolysate of soy protein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for production of hydrolysate of soy protein achieving both quality and productivity, having emulsifying property and foaming property equal or more than that of a product obtained in a fractionation process, without requiring the fractionation process in producing the polypeptide containing both hydrolysates obtained by separated hydrolysis of 7S component (β-conglycinin) and 11S component (glycinin) of the soy protein. <P>SOLUTION: The method produces the hydrolysate of protein originating from 7S component (β-conglycinin) and 11S component (glycinin) by selectively hydrolyzing (a first hydrolyzing step) either one of the 7S component (β- conglycinin) and 11S component (glycinin) of the soy protein, and then hydrolyzing (a second hydrolyzing step) without fractionating the hydrolyzed fraction and the unhydrolyzed fraction to obtain the both hydrolysates, and then subjecting them to a heating process under ≤pH 4.3 and ≥100°C of temperature. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a functional soybean protein hydrolyzate having high emulsifying ability and foaming ability, and particularly, to efficiently obtain a hydrolyzate having high emulsifying ability and foaming ability. The present invention relates to a method for producing a protein hydrolyzate.

[0002]

2. Description of the Related Art In recent years, consumers have become increasingly interested in natural materials in foods, and there is a strong demand for the development of natural materials that replace synthetic emulsifiers and foaming agents. Soybean protein as a natural material has been studied as a raw material for emulsifiers and foaming agents from the past. (JP-A-56-26171, JP-A-57-16674, JP-A-6-197788)
JP-A-49-109551 and JP-A-53
-58982, JP-A-58-36347,
JP-A-60-176549, JP-A-60-184
372, JP 61-216646, JP 4-311354, US-2502482, US-381.
4816, US-4409248, US-4370267, US-463290
3) However, it was difficult to satisfy all of the functional characteristics, workability (simpleness of the process), and yield of the product obtained by either method.

On the other hand, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 2001-069.
No. 920, a polypeptide that separately hydrolyzes the 7S component (β-conglycinin) and the 11S component (glycinin) in soybean protein and contains both hydrolysates (hereinafter referred to as “both hydrolysates”). It is sometimes referred to as "a thing".) Has excellent properties of emulsifying power and foaming power, and proposes natural materials replacing synthetic emulsifiers and foaming agents and a method for producing the same. However, while the polypeptide obtained by this technique is characterized by significantly superior emulsifying power and foaming ability as compared with the product obtained by the previous method, its quality and yield are not so high. It was greatly affected by the conditions, and there was still room for improvement before being completely satisfied in terms of quality, yield, and workability. Specifically, in the production method of the publication, in the non-separation preparation method, which is the most efficient in terms of workability and yield, the functional characteristics are easily influenced by the concentration used, and the concentration is reduced under a low concentration condition of less than 3%. There is a drawback that the functionality tends to decrease with the decrease, and in order to obtain a polypeptide having excellent emulsifying power and foaming power even under low concentration conditions, in order to obtain a polypeptide, it is difficult to obtain A fractionation operation for removing the fraction was required. Therefore, when a polypeptide having a high function even in a low concentration condition is sought, there are problems such as a decrease in yield due to fractionation, a decrease in productivity due to the inclusion of a fractionation step, a treatment problem of a separation residue generated as a bipro in fractionation operation, etc. Since they are derived, it is desired to solve these problems.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a soybean protein hydrolyzate excellent in emulsifying property and foaming property,
7S component (β-conglycinin) in soybean protein and 11
With respect to the production of a polypeptide that separately hydrolyzes the S component (glycinin) and that contains both hydrolysates, unless the fractionation operation is performed in each hydrolysis, the emulsifying and foaming functions are high. Where a degradable product is difficult to obtain, a method for producing an improved soybean protein hydrolyzate having excellent emulsifying power and foaming power equivalent to or better than the conventional fractionated processed product, regardless of the presence or absence of a fractionation operation, is provided. To provide.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that 7S in soybean protein is
Selectively hydrolyze either the component (β-conglycinin) or the 11S component (glycinin), and then further hydrolyze the undecomposed fraction to prepare a “both hydrolyzate”, and carry out the main hydrolysis By subjecting the product to a heat treatment under acidic conditions, it was found that a protein hydrolyzate having extremely excellent emulsifying property and foaming property can be obtained regardless of the presence or absence of a fractionation operation of the hydrolyzate, and the present invention Has been completed.

That is, the present invention selectively hydrolyzes either the 7S component (β-conglycinin) or the 11S component (glycinin) in soybean protein to obtain a hydrolyzed fraction and an undegraded fraction. The unhydrolyzed fraction is further hydrolyzed with or without being separated once to obtain a "both hydrolyzate".
A method for producing a soybean protein hydrolyzate, which comprises performing an acidic heat treatment at 0 ° C. or higher.

In the present invention, the phytase can be used to reduce the phytic acid in the soybean protein before the heat treatment of the hydrolyzate in the above production method, or alternatively, the hydrolyzate before the heat treatment. 0.1 to the solid weight of
It is also possible to add 10% chitosan.

Further, in the present invention, the low-denaturation soybean protein is used as a raw material to selectively hydrolyze the 11S component within a reaction time of 4 hours at a reaction pH of 3.0 or less and a reaction temperature of 45 ° C. or less, and then undecomposed Minutes, temperature over 45 ℃, pH
Is a method of producing a soybean protein hydrolyzate at a pH higher than 3.0.

On the other hand, the present invention uses low-denaturation soybean protein as a raw material, and selectively hydrolyzes the 7S component within a reaction time of 2 hours,
It is a method for producing a protein hydrolyzate, which is carried out at pH 3.0 to 8.0 at a reaction temperature of 50 ° C. or higher, and then hydrolyzing the undecomposed fraction at 45 ° C. or lower and pH 3.0 or lower.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention selectively hydrolyzes either 7S component (β-conglycinin) or 11S component (glycinin), which is a constituent of soybean protein, to obtain a hydrolyzed fraction. Separate the undegraded fraction or leave it as it is and further hydrolyze the undegraded fraction to prepare a "both hydrolyzate".
The manufacturing method is characterized by including a step of subjecting to an acidic heat treatment at 100 ° C or higher at 4.3 or lower. And as a further preferred embodiment, in the process of preparing both of the above-mentioned hydrolysates, after performing a treatment process of reducing phytic acid mixed phytic acid with phytase and / or a process of adding chitosan, this is adjusted to pH 4.3. Hereinafter, it is preferable to perform an acidic heat treatment at 100 ° C. or higher.

The steps for preparing both hydrolysates derived from 7S and 11S will be described. This is soy protein that contains both 7S and 11S components, which are the main constituents of soybean protein, is used as a substrate, and a proteolytic enzyme acts to select the 11S component in the first-stage decomposition reaction (selective decomposition). Specifically, the undecomposed 7S component is hydrolyzed by the second-stage decomposition reaction, or conversely, the 7S component is selectively hydrolyzed by the first-stage decomposition reaction, and the undecomposed 11S component is hydrolyzed by the second-stage decomposition reaction. It consists of a decomposition process. In the present invention, after the first-stage decomposition reaction, the decomposed product is not fractionally collected, and the second-stage decomposition reaction is subsequently performed to prepare “both hydrolysates”, but the fraction is also fractionated after the first-stage reaction. A hydrolyzate having no difference in emulsifying property and foaming function from the case of performing the second-step reaction can be obtained. Therefore, when the fractionation is not performed, it is not necessary to incorporate the fractionation operation of the first-stage decomposed product by centrifugation or the like in the second-stage decomposition, so that the production process is efficient and the loss in yield does not occur.

The raw soybean protein used in the present invention is preferably undenatured or low-denatured. Low-denaturation defatted soybeans that have been defatted with a solvent such as whole soybeans or hexane, or soybean milk or defatted soybean milk obtained by extracting them with water, and isoelectric focusing using an acid to this to recover a precipitated fraction Examples thereof include isolated soybean protein and isolated soybean protein obtained by removing okara from a low-denaturation concentrate obtained by removing whey components from defatted soybean. The low-denaturation defatted soybean used is N
It is SI60 or more, preferably NSI80 or more. Whether these proteins have been denatured by heating, etc.
DSC (Differential Scanning Calorimetry) of protein
It can be determined by analysis. (Nagano et al., J. Agric.Fo
od Chem., 40,941-944 (1992))

When the 11S component is selectively hydrolyzed by the first-step decomposition reaction, 1% of the soybean protein is used as a substrate.
Proteolytic enzyme is added to the solution having a protein concentration of ˜30% in an amount of 0.001-1% with respect to the substrate solid content, preferably 0.0.
It is added in the range of 1 to 0.5%, and at 45 ° C. or lower, preferably 30 to 40 ° C., pH 3.0 or lower, preferably pH
The reaction time is 1.8 to 2.5, and the reaction time is within a short period of 4 hours, preferably 10 minutes to 50 hours at a solubility of 0.22 MTCA in 2 hours.
It is good to react until it becomes. If the reaction temperature exceeds 45 ° C., the 7S component as well as the 11S component is susceptible to decomposition at the same time, making it difficult to selectively decompose the 11S component.
Since the decomposed product of the S component itself has a lower molecular weight, the functions of emulsifying property and foaming property are deteriorated. When the reaction pH is higher than 3.0, the selectivity of decomposition is lowered and a large amount of low molecular weight compounds and high molecular weight substances deviating from the proper molecular weight in terms of molecular weight are generated, and the functions of emulsification and foaming are deteriorated, which is not preferable. If the pH is too low, the selectivity is lowered and the salt is increased in the subsequent neutralization, which is not preferable. Further, if the reaction time is too long, the degradation product of the 11S component becomes lower in molecular weight, and the quality is deteriorated as described above, which is not preferable.

The proteolytic enzyme used here has a pH of
All protein hydrolases that show activity at 3.0 or less are suitable, and a series of aspartic proteases derived from animal-derived pepsin and capssin and microorganisms, such as "Neulase F" and "Protease M" (Amano Pharmaceutical Co., Ltd. Commercially available enzyme preparations such as "Company", "Sumiteam LP", "Sumiteam AP" (produced by Shin Nippon Kagaku Co., Ltd.) can be used.
Of these, pepsin is preferable.

In order to selectively hydrolyze the 7S component by the first-step decomposition reaction, the above soybean protein substrate is used, and 0.5% to 2% is used.
Proteolytic enzyme is added to the solution having a protein concentration of 0% in an amount of 0.001 to 0.5%, preferably 0.0 to 0.1%, based on the solid content of the substrate.
It is added in the range of 1 to 0.5%, and at a reaction temperature of 50 ° C. or higher, preferably 55 to 85 ° C., the pH is higher than 3.0.
H, preferably pH 3.5-8.0, reaction time within a short time of 2 hours, preferably about 10-30 minutes, 0.2.
It can be carried out by reacting until the solubility of 2MTCA becomes 10 to 50%. If the reaction temperature and pH are outside this range,
The selective decomposability of 7S decreases, and the decomposition of 11S also occurs, which is not preferable. Further, even if the reaction time becomes long, hydrolysis proceeds more than necessary and the function of the hydrolyzate is deteriorated, which is not preferable. The protein hydrolase used here is more than 50 ° C and less than 90 ° C, preferably 55 to 85 ° C.
It is necessary that the enzyme agent has proteolytic activity. The origins of these are commercially available enzyme agents of plant or animal organs or microbial origin, and the origin is not particularly limited.

The undecomposed fraction of the first-stage decomposition reaction is subjected to the second-stage decomposition in the state of containing the first-stage decomposed product without collecting the fraction by centrifugation or the like. For example, after the first-stage decomposition reaction of the 11S component, a reaction temperature higher than 45 ° C. in an arbitrary pH range, or a pH higher than 3 at a reaction temperature, a fraction rich in the 7S component is obtained. Second stage decomposition reaction. Above all, it is efficient and convenient to carry out the reaction at a temperature of 50 ° C. or higher and a pH of 3.0 or lower. After the 7S component is subjected to the first stage decomposition reaction, the 11S component-rich fraction is subjected to the second stage decomposition reaction. In this case, it is particularly preferable to carry out at a pH of 3.0 or lower and a reaction temperature of 45 ° C. or lower. The proteolytic enzyme used in the second-step decomposition reaction may be judged to be necessary in consideration of the residual activity of the enzyme used in the first-step decomposition. In addition, the above-mentioned enzyme is exemplified as long as it has activity at the reaction pH. The reaction time is as short as 2 hours or less, preferably about 10 to 30 minutes and 0.22 MTCA.
It is decomposed to have a solubility of about 30 to 90%, preferably 40 to 65%. In this way, "both hydrolysates"
It prepares and heat-processes this decomposition product under acidic condition.

The condition of acidic heating is that the solution of "both hydrolysates" has a solid content of 5 to 20% by weight, preferably 7% by weight.
-14% by weight concentration, pH 2-4.3, preferably p
H range from 2.5 to 3.8, 100 ℃ ~ 160 ℃,
Preferably, heating is performed at 105 ° C. to 140 ° C. for several seconds to 5 minutes. When the solid content is less than 5% by weight, the heating effect is obtained but the work efficiency is poor and it is not suitable. On the other hand, 20
When the content is more than 5% by weight, the viscosity of the protein solution increases excessively in the treatment of a protein hydrolyzate having a low decomposition rate, and there is a risk of deterioration of workability due to deterioration of fluidity, which is not preferable. If the pH during heating is less than 2, the protein hydrolyzate will be further subjected to acid hydrolysis during heating, leading to a reduction in the functions of emulsification and foamability. Moreover, the above-mentioned function may be deteriorated in the heat treatment under the condition that the pH exceeds 4.3. When the heating temperature is lower than 100 ° C, the function of the protein hydrolyzate is insufficiently expressed. When the heating temperature is higher than 160 ° C, acid hydrolysis during heating is likely to occur, which leads to deterioration of the function. The heating time is adjusted depending on the heating temperature and the degree of acid hydrolysis. Specifically, the higher the heating temperature, the easier the acid hydrolysis progresses, so the heating time must be shorter. If it is a steam injection type continuous direct heat sterilizer, it is possible to instantaneously perform high-temperature heat treatment at 100 ° C. or higher, and it can be exemplified as a suitable heating device.

In the present invention, it is important to heat under acidic conditions at a pH of 4.3 or less, and the reason for this is that the pH is 4.3.
In a pH environment above 3, the protein hydrolyzate becomes more susceptible to hydrophobic interaction and interaction between the hydrolyzates due to SS exchange reaction due to heating, leading to a decrease in solubility due to an increased degree of association. While the emulsifying and foaming functions of are reduced, in a pH environment lower than pH 4.3,
Since the SS exchange reaction is not promoted and the association of degradation products is suppressed, it is presumed that the high solubility is maintained and the functionality is not deteriorated.

Further, it is effective to carry out the treatment steps described below at any stage before the acidic heat treatment in order to further enhance the emulsifying power and foaming power of the finally prepared protein hydrolyzate. , And preferably incorporated.

One of the operations is to remove or decompose the mixed phytic acid derived from soybean. As a method for removing phytic acid, electrodialysis, membrane separation, treatment with an ion exchange resin, etc. can be exemplified. For the decomposition of phytic acid, an enzymatic reaction by phytase (enzyme having a phytic acid decomposing activity in a broad sense) is used. This is a method of hydrolyzing phytic acid. In particular, the latter enzymatic decomposition treatment using phytase is the most advantageous method from the viewpoint of production cost. As the phytase to be used, it is preferable to select an enzyme or enzyme agent having a low protease activity in order to avoid affecting the physical properties of the soybean protein hydrolyzate. The phytase treatment may be carried out at any stage before the decomposition of the raw material, after the selective decomposition, and after the decomposition of the undecomposed fraction. However, the reaction conditions are to avoid heat denaturation of 7S and 11S when carried out with a soy protein substrate,
The reaction should be below 50 ° C, preferably below 40 ° C.

The reaction pH of the phytase treatment can be any pH condition as long as it has enzymatic activity, but since the heat treatment is performed at pH 4.3 or less later, the pH adjustment operation and the ash content Considering the increase, it is preferable to treat at pH 4.3 or less. It is desirable to reduce the level of removal or decomposition of phytic acid to 0.5% by weight or less, preferably 0.3% by weight or less, based on the weight of protein.

Another preferred operation is 7S and 11
Before the heat treatment of both hydrolyzates derived from S, chitosan is added in an amount of 0.1 to 10% by weight, preferably 0.5 to 3% by weight, based on the solid weight of the protein hydrolyzate. Is effective. Chitosan is preferably a deacetylated product of chitin produced from shells of crustaceans such as shrimp and crab, and usually contains a water-soluble glucosamine polymer as a main component. If the amount of chitosan added is less than 0.1% by weight, the expected improvement in physical properties can be obtained only slightly. On the contrary, if it exceeds 10% by weight, the solution viscosity of the product becomes high, leading to a decrease in foamability. This is not preferable because it causes a decrease.
The chitosan used has a molecular weight of 3000 or more, preferably 1
A grade of 10,000 or more types with a deacetylation degree of 80% or more is suitable, and the addition time may be any time as long as it is a stage before acid heating, similar to the phytase treatment. However, chitosan has low solubility above pH 5 and is difficult to dissolve, so pH 5
It is preferable to add and dissolve in the decomposed product solution under the following acidic conditions.

As described above, performing phytase treatment or chitosan addition, preferably both phytase treatment and chitosan addition, in the stage before the acidic heat treatment brings out the effect of the heat treatment under acidic conditions more, The emulsifying power and foaming power of the prepared protein hydrolyzate are further enhanced.

The reason why the phytase treatment or the addition of chitosan is added before the acidic heat treatment is that these operations contribute to the improvement of the solubility of the protein hydrolyzate in the acidic region, and that the protein hydrolyzate in the subsequent acidic heat treatment is It is presumed that the interaction is further reduced and the effect of obtaining a highly functional hydrolyzate is enhanced. 7S and 11S acid-heat-treated in this way
Both derived hydrolyzate solutions can be commercialized as a powder as a liquid or by drying such as spray drying.

The protein hydrolyzate obtained by the present invention is
As described above, the emulsifying property and the foaming property are excellent, and it is used for foods using these functions, but the product of the present invention has these functions remarkably even in the acidic range, and is suitable for acidic emulsified foods. Is particularly preferably used.

[0026]

EXAMPLES Hereinafter, the embodiments of the present invention will be specifically described with reference to Examples, but the technical scope of the present invention is not limited by these Examples.

(Preparation of isolated soybean protein curd) 10 times amount of warm water at 40 ° C. was added to low-denaturation defatted soybean flakes (NSI: 90) manufactured by Fuji Oil Co., Ltd., and NaOH solution was added thereto to adjust the pH. Adjusted to 7.0. This was gently stirred, extracted for 1 hour, and separated by centrifugation into an insoluble fraction of okara and a soluble fraction of defatted soymilk. Hydrochloric acid was added to the defatted soymilk thus obtained to adjust its pH to 4.5, and the resulting protein precipitate was recovered by centrifugation to obtain a separated soybean protein curd. In this isolated soy protein curd, the solid content was 40%.
% By weight, and the crude protein purity in this solid content is 9%.
It was 5% by weight. In addition, as a result of DSC analysis, 7S
Endothermic peaks derived from the component and the 11S component were observed.

[Production Example 1] Water and phosphoric acid were added to the isolated soybean protein curd to adjust the pH to 2.5 and the isolated soybean protein concentration to 10% by weight, and 2 L of this solution was mixed with phytase (manufactured by Shin Nippon Chemical Industry Co., Ltd.). "Sumiteam PHY") 1g,
Phytase treatment was performed at 37 ° C. for 30 minutes. Then 3
800 mg of pepsin (manufactured by Nippon Biocon Co., Ltd.) was added at 7 ° C. and pH 2.5, and hydrolysis was carried out for 1 hour (first stage decomposition: selective decomposition). As a result of analyzing the reaction solution by electrophoresis, only the 11S component in soybean protein was selectively hydrolyzed.
The mobility band corresponding to the S component disappeared. Then, without separating the first-stage reaction solution,
In this state, only the solution temperature is raised to 70 ° C, and the 7S component that remains undecomposed during the heating process is enzymatically hydrolyzed (second stage decomposition).
Then, “both hydrolysates” were prepared. The solubility of 0.22M TCA in the first-step reaction solution was 33%, and the solubility of 0.22M TCA in the second-step reaction solution was 44%.

The protein hydrolyzate solution prepared above was divided into two equal parts, one was left as it was, and 1 g of chitosan (“Chitosan LL” manufactured by Yaizu Suisan Chemical Co., Ltd.) was added to the other solution to completely After stirring and dissolving until dissolved, each solution was subjected to heat treatment at 120 ° C. for 7 seconds in a continuous direct heat sterilizer, and then spray-dried as it was, soybean protein hydrolyzate containing no chitosan (T-1a). ) And chitosan were added to prepare a soybean protein hydrolyzate (T-1b). In addition,
In both cases, the solution pH before heating is pH 3, which is 0.2
The 2M TCA solubility was 51%.

[Production Example 2] Water and phosphoric acid were added to the isolated soybean protein curd to adjust the pH to 2.5 and the isolated soybean protein concentration to 10% by weight, and 800 mg of pepsin (manufactured by Nippon Biocon) was added to 2 L of this solution. Was added and the mixture was hydrolyzed at 37 ° C. for 1 hour (first stage decomposition). As a result of analyzing the reaction solution by electrophoresis, only the 11S component in soybean protein was selectively hydrolyzed. Then, without separating the first reaction liquid, only the solution temperature is raised to 70 ° C. in the same pH state,
The 7S component that remained undecomposed during the temperature rising process was enzymatically hydrolyzed (second-stage decomposition) to prepare a “both hydrolyzate”. The solubility of 0.22 M TCA in the first-stage decomposition reaction solution was 30%,
The second-stage decomposition reaction solution had a solubility of 0.22 M TCA of 40%.

The prepared solution containing protein hydrolyzate was divided into two equal parts, one was left as it was, and the other was added with 1 g of chitosan (“Chitosan LL” manufactured by Yaizu Suisan Chemical Co., Ltd.), It was stirred and dissolved until completely dissolved. The chitosan-free solution and the chitosan-containing solution were directly subjected to heat treatment at 120 ° C. for 7 seconds in a continuous direct heat sterilizer, which was then atomized and dried. As a result, a soybean protein hydrolyzate containing no chitosan (T-2a) and a soybean protein hydrolyzate containing chitosan (T-2b) were obtained. In both cases, the solution pH before heating was pH 3, and the T2a and b solubility of 0.22M TCA was 48%.

Comparative Production Example 1 Water and phosphoric acid were added to the isolated soybean protein curd to obtain a pH of 2.
5. The isolated soybean protein concentration was adjusted to 10% by weight, and 1.5 g of phytase (“Sumiteam PHY” manufactured by Shin Nippon Chemical Industry Co., Ltd.) was added to 3 L of this solution, and phytase treatment was performed at 37 ° C. for 30 minutes. . Next, 1.2 g of pepsin (manufactured by Nippon Biocon Co., Ltd.) was added at 37 ° C. and pH 2.5, and hydrolysis was carried out for 1 hour (first stage decomposition). As a result of analyzing the reaction solution by electrophoresis, only the 11S component in soybean protein was selectively hydrolyzed, and the mobility band corresponding to the 11S component disappeared. Then, without separating the first reaction liquid, only the solution temperature is raised to 70 ° C. in the same pH state, and the 7S component that remains undecomposed during the temperature raising process is enzymatically hydrolyzed (second stage decomposition). "Both hydrolysates" were prepared. In addition,
The solubility of 0.22M TCA in the first reaction solution was 33%, and the solubility of 0.22M TCA in the second reaction solution was 45%.

The prepared protein hydrolyzate solution was divided into three equal parts, and 1 g of chitosan (“Chitosan LL” manufactured by Yaizu Suisan Kagaku Kogyo Co., Ltd.) was added to each solution and dissolved by stirring until completely dissolved. . After that, one is pH 3 as it is, and the other two are pH 4.5 and pH 6 with NaOH solution.
Adjusted to 5. Each solution is adjusted to pH 3 with a continuous direct heat sterilizer at 95 ° C for 1 minute.
And for the pH 6.5 adjusted solution, after heat treatment at 120 ° C. for 7 seconds, spray drying is performed as it is, and the pH is adjusted to 3
Heat-treated soy protein hydrolyzate (C-1a), pH 4.
5 Heat-treated soybean protein hydrolyzate (C-1b) and p
H6.5 heat-treated soybean protein hydrolyzate (C-1c) was prepared. The solubility of C-1a at 0.22M TCA was 5
3%, C-1b, C-1C 0.22M TCA solubility is 5
It was 0%.

[Comparative Production Example 2] Water and hydrochloric acid were added to the isolated soybean protein curd to adjust the pH to 2.0 and the isolated soybean protein concentration to 10.
The concentration was adjusted to 200% by weight, 200 mg of pepsin (manufactured by Nippon Biocon Co., Ltd.) was added to 1 L of this solution, and the mixture was hydrolyzed at 37 ° C. for 30 minutes (first stage decomposition). As a result of analyzing the reaction solution by electrophoresis, only the 11S component in soybean protein was selectively hydrolyzed. The first reaction solution was adjusted to pH 4.5 with NaOH, and the resulting precipitate was centrifuged to separate a supernatant fraction containing a degradation product of the 11S component and a precipitation fraction containing an undegraded 7S component. Separated. In addition, 0.22M of the reaction solution of the first step reaction
The TCA solubility was 24%. The precipitated fraction was adjusted to pH 2.0 and solid content 7% by weight with water and hydrochloric acid, 100 mg of pepsin was added to 1 L of this solution, and the mixture was stirred at 60 ° C for 2 hours.
Hydrolysis was performed again for 0 minutes (second step reaction). The solubility of 0.22 M TCA in the reaction solution was 44%. The second-step reaction solution was mixed with the supernatant fraction of the first-step reaction, 3% by weight of Ca hydroxide was added to the solid content of the mixed solution, and NaOH was added.
The solution was adjusted to pH 6.5, subjected to heat treatment at 120 ° C. for 7 seconds in a continuous direct heat sterilizer, and then cooled to room temperature. After cooling, the insoluble component was removed by centrifugation at 5000 G for 10 minutes to obtain a supernatant fraction containing "both hydrolysates", which was spray-dried and the insoluble component was removed to remove the soy protein hydrolyzate (C -2) was prepared. The solubility of C-2 in 0.22M TCA was 73%, and the solid content recovery rate was 70%.

Comparative Production Example 3 Water and phosphoric acid were added to the isolated soybean protein curd to adjust the pH to 2.5 and the isolated soybean protein concentration to 1
Adjusted to 0% by weight, 1 liter of this solution at 37 ° C, pH
As it is 2.5, pepsin (manufactured by Nippon Biocon) 400 mg
Was added for hydrolysis for 1 hour (first stage decomposition). As a result of analyzing the reaction solution by electrophoresis, only the 11S component in soybean protein was selectively hydrolyzed, and the mobility band corresponding to the 11S component disappeared. Then, without separating the first-step reaction solution, the solution temperature is kept at 70 without changing the pH.
The temperature was raised to 0 ° C., and the 7S component that remained undecomposed during the temperature raising process was enzymatically hydrolyzed (second-stage decomposition) to prepare a “both hydrolyzate”. The solubility of 0.22M TCA in the first-stage reaction solution was 3
1% and the 0.22M TCA solubility of the second stage reaction solution was 4%.
It was 3%.

The prepared protein hydrolyzate solution was adjusted to pH 6.5 with a NaOH solution. This solution was heat-treated at 120 ° C. for 7 seconds with a continuous direct heat sterilizer, and then spray-dried to prepare a soybean protein hydrolyzate (C-3). The solubility of C-3 of 0.22M TCA was 46.
%Met.

[Comparative Production Example 4] Water and phosphoric acid were added to the isolated soybean protein curd to adjust the pH to 2.5 and the isolated soybean protein concentration to 1
Adjusted to 0% by weight, 1 liter of this solution at 60 ° C, pH
200 mg as it is 200 mg of pepsin (manufactured by Nippon Biocon)
Was added and hydrolyzed for 2 hours. As a result of analyzing the reaction solution by electrophoresis, both the 11S component and the 7S component in soybean protein were hydrolyzed. PH of this reaction solution with NaOH solution
The solution was adjusted to 6.5, and this solution was heat-treated at 120 ° C. for 7 seconds by a continuous direct heat sterilizer, and then spray-dried to prepare a soybean protein hydrolyzate (C-4). In addition,
C-4 had a solubility of 0.22 M TCA of 56%.

The trial production conditions of the production example and the comparative production example are shown in the table.
Summarized in 1.

[Table 1]

[Functional Evaluation] (Evaluation of Foaming Power and Emulsifying Power of Each Soybean Protein Hydrolyzate) (Evaluation of Foaming Power) The evaluation in the present invention is based on the foaming capacity in an oil system and its stability. . The foam quality (foaming stability) was evaluated by the method described below for the purpose of clarifying the difference in foaming power between the production examples of the present invention and the comparative production examples. That is, a 3 wt% aqueous solution was adjusted to pH 4 and pH 7, 5 ml of soybean oil was added to 100 ml of this, and this was treated with a homogenizer (manufactured by Nippon Seiki Co., Ltd.) at 10,000 rpm for 1 minute. The foam volume (ml) was measured after transfer. The stability was evaluated from the amount of change in the foam volume (ml) immediately after foaming and after standing for 1 hour.

(Evaluation of emulsifying power) Functional evaluation of the product of the present invention
It was evaluated by measuring the emulsifying activity. Emulsifying activity is pH
1 ml of soybean oil was added to 3 ml of the sample solution (1% by weight) adjusted to 4, 5.5, and pH 7 to prepare an emulsion with an ultrasonic disperser, which was diluted 1000 times with a 0.1% SDS solution. The solution turbidity (absorbance at 500 nm) was measured. In the evaluation, the higher the turbidity value, the higher the emulsifying power.

The foaming power evaluation results of each soybean protein hydrolyzate prepared in each Production Example and Comparative Production Example are shown in Table-2, and the emulsification power evaluation results are shown in Table-3.

[Table 2]

[0042]

[Table 3]

As shown in the results of Tables 2 and 3, the "both hydrolysates" described in the present invention were subjected to acidic heat treatment at a specific condition, that is, pH 4.3 or less and 100 ° C or more ( T group), an effective improvement effect of the foaming force is obtained,
Regarding the emulsifying power, it can be seen that the emulsifying power from the weakly acidic range (pH 5.5) to the acidic range (pH 4) is improved. Further, it can be seen that it is effective to further improve quality by performing phytase treatment, addition of chitosan, and both of these operations before the acidic heat treatment. The foaming power and emulsifying power of T-1a to 2b are equivalent to or higher than those of C-2, and the production method of the present invention provides excellent quality without sacrificing product yield. It has become possible to give it.

[Application Example 1] (Mayonnaise-Like Dressing) An attempt was made to prepare a mayonnaise-like dressing using each of the soybean protein hydrolysates prepared in Production Examples 1-2 and Comparative Production Examples 1-2, and the particle size was further determined. Evaluation was performed by measuring. The dressing was prepared by mixing and dissolving the following ingredients except salad oil, and then emulsifying with a homogenizer (manufactured by Nippon Seiki Co., Ltd.) while adding salad oil thereto (7
000 rpm) to prepare a mayonnaise-like dressing. The emulsified particle size of each preparation was measured using a laser particle size distribution meter (SALD-2000A manufactured by Shimadzu Corporation).

The composition of the mayonnaise-like dressing is as follows (exemplified parts are by weight). Salad oil: 74 parts, vinegar:
13 parts, protein degradation product sample: 2 parts, seasoning: 2 parts, spice: 1 part, water: 8 parts.

[0046]

[Table 4]

Emulsions having a mayonnaise-like structure could be prepared from all the preparations of Production Examples and Comparative Production Examples. Above all, Production Examples T-1 to T-4 of the present invention were excellent in quality in an emulsified particle size state substantially similar to Comparative Production Example C-4. This result suggests that the emulsifying power under acidic conditions is further improved. In addition, Production Examples T-1 to 4 of the present invention
The mayonnaise-like emulsion obtained in Example 1 had less bitterness and improved flavor in comparison with the mayonnaise-like emulsion obtained in Comparative Production Example C-4. The reason for this is that T-1 ~
It is considered that this is because the content of the low-molecular-weight peptide exhibiting a bitterness is small because the decomposition degree of 4 is lower. Therefore, by using the production method of the present invention, it is possible to further improve the quality of a soybean protein hydrolyzate as an emulsifier for a mayonnaise-like dressing.

[Application Example 2] (Sponge cake) A sponge cake was prepared by the all-in-mix method using each of the soybean protein hydrolysates prepared in Production Examples 1-2 and Comparative Production Examples 1-2 as a foaming agent. The composition of the cake dough (the example part is based on the weight) is as follows. Soft flour: 100 parts,
Sugar: 100 parts, whole egg: 200 parts, salad oil: 20 parts, sorbitol: 15 parts, salt: 1 part, protein hydrolyzate sample: 8 parts.

To prepare the sponge cake, all the raw materials except the salad oil were first uniformly dispersed, and the salad oil was added to the dough to adjust it to the dough, and then the temperature of the product was adjusted to 25 ° C., using a whipper blade to make Kenwood. Use a mixer ("Pro KM-230" manufactured by Aikosha Seisakusho Co., Ltd.) to set the scale 6 to 4
It was whipped for a minute to prepare a cake dough. After 280 g of the obtained dough was baked at 160 ° C. for 30 minutes and allowed to cool to room temperature, the volume, texture and flavor of the sponge cake were evaluated. The flavor and texture of the cake are ◎
It is shown as (very good), ◯ (good), Δ (slightly inferior), and x (inferior).

[0050]

[Table 5]

Although only T-3 of Production Example 2 had a slightly low foaming power, the other T-1, T-2, and T-4 exhibited good foaming power under the conditions of this trial production, and the all-in-mix method was used. The foaming agent was of a quality-satisfactory level. Above all
T-2 had an excellent foaming power, and the texture of the prepared sponge cake was also the best. In addition, C- of Comparative Production Example
1-3, the specific gravity of the dough is 0.55 even if the whipping time is extended.
It fell only to a certain degree. As described above, by using the production method of the present invention, it is possible to prepare a soybean protein hydrolyzate in which the function of the foaming agent for sponge cake is improved as compared with the conventional product.

Application Example 3 (Flower Paste) Using each of the soybean protein hydrolysates prepared in Production Examples 1 and 2 and Comparative Production Examples 1 and 2, the acid type was evaluated for suitability for flower paste. For the formulation, set the simple model formulation shown below, and the pH of the formulation with a sample concentration of 1% and oil content of 30%.
Prepare 4 acidic paste dough. After leaving overnight, squeeze 5 g of paste dough onto a filter paper using a squeezing bag and add 1 g of water to it.
Filter paper, put in a closed container, heat treated in an oven at 200 ° C for 10 minutes, and evaluate the oil separation state and shape retention of the paste dough after heating to evaluate acid type flower paste suitability. did. Paste preparation is 55
After dissolving raw materials other than oil with warm water at ℃, add oil to pre-emulsify, adjust the solution pH to 4 and continue pre-emulsification, emulsify this with a high pressure homogenizer (100 Kg / cm2), A paste dough was prepared by stirring and heating 300 g of this dough solution to a dough temperature of 85 ° C. using a lab kneader (“TK-03 type” manufactured by Tokushu Kika Kogyo Co., Ltd.). (Stirring speed: 120 rpm Jacket temperature: 120 ° C)

Simple model formulation (examples are based on weight) Sample: 1 part, rapeseed oil: 30 parts, sugar: 10 parts, dextrin: 6 parts, modified starch: 7 parts, water: 46 parts * For pH 4 preparation Was prepared with citric acid.

[0054]

[Table 6]

As shown in the evaluation results, T-1a to T2 of the production example
b was obtained with good results in terms of shape retention and oil-off evaluation, and was judged to be a suitable material as an emulsifier for acidic type flower paste. One Comparative Example C-1
In cases a to c, oil separation occurs during heating and stirring during paste preparation, and the paste itself cannot be prepared (C
-1b, c), the firing resistance of the paste is low (C-1a)
The function as an emulsifier for acidic type flower paste was poor.

[0056]

INDUSTRIAL APPLICABILITY According to the present invention, 7S component (β-conglycinin) and 11S component (glycinin) in soybean protein
Regarding the production of protein hydrolyzate (polypeptide) derived from soybean, a soybean protein hydrolyzate having excellent emulsifying power and foaming power equal to or higher than that of the fractionated product is prepared without the need for fractionation It has become possible to significantly improve yield and productivity.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Eiji Iwaoka             4-3 Kinindai, Taniwahara Village, Tsukuba-gun, Ibaraki Prefecture               Fuji Oil Co., Ltd. Tsukuba Research and Development Center             -In

Claims (9)

[Claims] 1. When hydrolyzing soybean protein, first, the 7S component (β-conglycinin) or 1 in soybean protein is used.
By selectively hydrolyzing any of the 1S component (glycinin) and then further hydrolyzing the undegraded fraction, 7S
A method for producing a soybean protein hydrolyzate, characterized in that a hydrolyzate of both the ingredient and the 11S ingredient is obtained, and this is subjected to heat treatment under conditions of pH 4.3 or lower and 100 ° C or higher. 2. The method for producing a soybean protein hydrolyzate according to claim 1, wherein a phytase is used to reduce the phytic acid mixed with phytic acid derived from soybean before the heat treatment of the hydrolyzate. 3. The soybean protein according to claim 1 or 2, wherein before the heat treatment of the hydrolyzate, 0.1 to 10% by weight of chitosan is added to the solid weight of the hydrolyzate and then the heat treatment is performed. Method for producing hydrolyzate. 4. The production method according to claim 1, wherein the low-denaturation soybean protein is used as a raw material, and the selective hydrolysis is selective hydrolysis of the 11S component in the soybean protein. 5. The selective hydrolysis is carried out within a reaction time of 4 hours,
The method according to claim 4, which is carried out at pH 3.0 or lower and 45 ° C. or lower. 6. The process according to claim 4, wherein the hydrolysis of the undegraded fraction is carried out at a temperature above 45 ° C. or at a pH higher than pH 3.0. 7. The method according to claim 1, wherein the low-denaturation soybean protein is used as a raw material, and the selective hydrolysis is selective hydrolysis of the 7S component in the soybean protein. 8. The selective hydrolysis is carried out within a reaction time of 2 hours,
The method according to claim 7, which is carried out at a pH higher than pH 3.0 and at 50 ° C. or higher. 9. The method according to claim 8, wherein the hydrolysis of the undecomposed fraction is carried out at a temperature of 45 ° C. or lower and a pH of 3.0 or lower.