JPS5814813B2 - Foaming agent and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foaming agent that uses soybean protein and has excellent foaming properties and foam stability, good storage stability, and is also desirable in terms of flavor, and a method for producing the foaming agent.

More specifically, the present invention relates to a foaming agent with extremely superior foam stability compared to conventional products, and a simple method for producing the foaming agent.

Methods for obtaining foaming substances by hydrolyzing plant proteins such as soybean proteins with enzymes have been known, for example, as described in US Pat. No. 2,489,1. 7 3, 3,814,8
There is a 16th mag.

That is, the dedigitated soybeans are extracted with alkali, followed by acid precipitation to obtain separated proteins, and the acid-precipitated curd is dispersed in water.
This method includes hydrolysis with pepsin, filtration, and spray drying of the filtrate.

The foamable substances obtained by these methods also have problems with foam stability and solubility, and also have the disadvantage of having a taste, so they are not satisfactory.

Although some improvement methods are available, they are not always sufficient.

Although conventional products have these drawbacks, they have been widely used as materials for making confectionery such as frappes, nougat, sponge cakes, and meringues, but there has been a strong demand for improvements.

The present inventor conducted research on the foaming properties of soybean protein and found that the molecular weight of the decomposed protein greatly influences the expression of physical properties, and in particular, the molecular weight is 1,000 to 6,000, preferably 1,000 to 6,000, preferably 1, Through research using gel chromatography, etc., the inventors discovered that the foaming property and foam stability are high in the 500 to 6,000 range, and have completed the present invention.

That is, the foaming agent according to the present invention has a molecular weight of substantially 1,
000 to 6,000, more preferably 1,500 to 6,000, it is made of soy protein hydrolyzed peptide, and there are various methods for producing it. It is efficient to partially hydrolyze the peptide with an autolytic enzyme and separate the peptide having a molecular weight substantially within the above range.

The raw material soybean protein is not particularly limited, and soybean proteins such as defatted soybeans, concentrated proteins or isolated proteins obtained therefrom, or products containing the same can be used.

It may be in any form, for example heat-denatured or alcohol-denatured.

However, this method is not suitable for obtaining foamable proteins other than soybean protein.

On the other hand, the enzyme may be any enzyme such as hefsin, papain, morsin, etc., and proteolytic enzymes of animal, plant or microbial origin are used.

The first step of the method of the present invention is to partially hydrolyze the soybean protein or its containing material in an aqueous solvent using a proteolytic enzyme.

Hydrolysis is carried out so that the APL (average peptide chain length) is approximately 4 to 25.

The hydrolysis conditions are not particularly different from conventional ones, and the pH is in the optimum range for the enzyme used, and the range where the enzyme acts most efficiently can be determined while taking into account the spoilage of the raw material, and it is usually between 5° and 60°C, preferably 20° to 50°C is selected.

Although the hydrolysis time varies depending on the enzyme activity and amount used, it is preferable to set it within 24 hours in terms of yield and product quality.

If the pE changes more widely than the optimum range during this hydrolysis reaction, it is effective to adjust the pH during the reaction.

Next, the reaction is stopped by inactivating the enzyme activity as in general enzymatic reactions, and heat inactivation is effective for this purpose.

Usually, deactivation is completed by heating to 70°C or higher for 5 to 30 minutes.

The second step of this method is to separate a peptide having the desired molecular weight from the reaction solution thus obtained.

If there are polymeric impurities derived from raw soy protein, such as fibrous substances (so-called okara), it is desirable to remove these substances from the reaction solution first in order to improve the efficiency of the subsequent reaction. It is advantageous to adjust the pH of the solution to 7-8 and remove insoluble matter.

Next, low-molecular weight parts and high-molecular weight parts such as proteins and peptides are removed.For polymers, the pH of the enzyme reaction solution is adjusted to 4 to 5, and insoluble parts are removed by filtration, centrifugation, decantation, etc. This can be achieved mostly by removing things.

If this operation is insufficient, the accuracy can be improved by ultrafiltration or the like.

On the other hand, the removal of low molecular weight portions can be carried out by ultrafiltration or other suitable means, but ultrafiltration is the most efficient.

The filtration membrane used for this ultrafiltration has a molecular weight cutoff of 1.0.
00 to 10,000, especially 1,000 to 5,000
For example, commercially available filtration membranes such as Amicon UM2 and Diaflow Membrane DM5 manufactured by Amicon Corporation of America are sufficient.

The optimal values for membrane treatment conditions such as pH 1 pressure and temperature vary depending on the properties of the membrane and protein solution used, but usually the pH is 3 to 8 and the pressure is 0.5 kg/ffl to 7 kg/C.
r? L and waterfall are within the range of 0'C to 50°C.

Decomposition of peptides, etc. may become a problem during this treatment, but in this case, alcohol may be added within the capacity of the membrane used, or a preservative such as sorbic acid may be added in advance. It is also effective to subject it to treatment.

The substantially molecular weight obtained in this way is 1,000 to 6,
000, more preferably 1,500 to 6,000, a peptide-containing solution is prepared by adding an alkali or acid such as sodium hydroxide to pH around neutrality, more specifically 6 to 7.
After adjusting the composition, it can be made into a product as a concentrate or dried by freeze-drying or the like.

This product has excellent foaming properties and foam stability, especially the latter stability, and has almost no taste, with no so-called soybean odor or bitter taste.

Furthermore, the dried product has low hygroscopicity and has excellent storage stability.

For reference, FIG. 1 shows the results of examining the relationship between molecular weight categories, foaming properties, and foam stability using gel filtration.

The foaming properties and foam stability were measured using the methods described below, and gel filtration was performed using Pharmacia Se.
Phadex G-50 was used.

As is clear from FIG. 1, it is clear that peptides with a molecular weight of 1,000 to 6,000, particularly 1,500 to 6,000, are suitable for foaming properties and foam stability.

In particular, it is clear that bubble stability is greatly affected by the presence of low molecular weight substances.

Therefore, the foaming agent according to the present invention has a molecular weight of substantially 1,000.
0 to 6,000, preferably 1.5000 to 6,000
However, it is particularly desirable that the presence of low molecular weight substances be as small as possible;
It is important that the substance having a molecular weight of 0.00 or less, more preferably 1,500 or less, accounts for 5% or less, more preferably 3% or less of the total weight.

On the other hand, the presence of high molecular weight substances has less influence than low molecular weight substances, but as a high quality foaming agent it is still desirable to have as little as possible, and the upper limit is 20% of the total weight.
% or less.

As is clear from the above explanation, the foaming agent according to the present invention has various properties required for a foaming agent to a high degree, and its manufacturing method is also easy.

Therefore, the present invention makes a significant contribution to the field of foaming agent use.

The present invention will be explained in more detail with reference to Examples below.

The methods for measuring foamability and foam stability in Examples are as follows.

Foaming property: 100 ml of a sample solution with a degree of 1% was placed in a syringe for measuring foaming property (inner diameter 82 mm, capacity 1,000 mA), and a constant speed stirrer (C manufactured by Tokyo Rika Co., Ltd.) was used.
hemystirrer, B-100 rotation speed 2.80O
After 10 minutes, the rotation is stopped and the volume A of the foam is measured after 5 minutes.

This volume A and the volume of the initial solution (100ml) The foaming property is defined as the ratio of

Foam stability: After measuring the foamability using the above method, the product is left to stand for 2 hours, and the volume B of the foam is measured again.

The foam stability is defined as the foam reduction rate (A-B/A×100) determined from this volume B and the foam volume A at the time of foamability measurement.

Example 1 100g of defatted soybeans for brewing (nitrogen content 7.9%)
It was dispersed in twice the amount of water and adjusted to pH 1.5 with hydrochloric acid.

To this was added pepsin (1:10,000) at 1% (w/w) based on defatted soybean, hydrolyzed at 40°C for 4 hours, and then heated at 70°C for 30 minutes to inactivate the enzyme.

Thereafter, the pH of the solution was adjusted to 7.0 with sodium hydroxide, insoluble matter was removed by centrifugation, and the supernatant was adjusted to pH 4.0 with hydrochloric acid.
The proteinaceous precipitate formed in step 5 was removed by centrifugation to obtain a clear solution.

This solution was subjected to ultrafiltration using Amicon UM10 (ultrafiltration membrane with a molecular weight cutoff of 10,000) manufactured by Amicon, USA, and the filtration residue was freeze-dried to obtain 27 g of a product.

Compounds with a molecular weight of 1,000 or less in this product are 3%, 1,
4% had scores below 500, and about 10% had scores above 6,000.

The foamability and foam stability of this product were 4.7 and 7, respectively.
At 2%, both properties were excellent, and it was almost tasteless and odorless, which was preferable from the standpoint of taste.

On the other hand, when the clear liquid obtained in the above method was directly freeze-dried without ultrafiltration, the foamability and foam stability were 4.6% and 45%, respectively. It was bad, and had a very bitter taste.

Example 2 Isolated soybean protein obtained from defatted soybeans (nitrogen content 13.8%)
) 100g was dispersed in 20 times the amount of water, and sodium hydroxide l-I
The pH was adjusted to 7.0 with Jum.

Add 1 g of cysteine and 1 g of papain to this, and
Hydrolysis was carried out at C for 8 hours.

During this time, the pH was adjusted every 2 hours with sodium hydroxide.

After hydrolysis, the enzyme was inactivated by heating at 70°C for 30 minutes, and the pH was adjusted to 4.5 with hydrochloric acid, followed by centrifugation, and insoluble materials were removed.
(An ultrafiltration membrane with a molecular weight cutoff of 1,000) was used to perform ultrafiltration, and the residual liquid was freeze-dried to obtain 54 g of a product.

Compounds with a molecular weight of 1,000 or less in this product are 2%, 1,
8% had scores below 500, and 15% had scores above 6,000.

This product has foaming properties and foam stability of 4.8 and 7, respectively.
At 1%, both properties were excellent, and it was almost tasteless and odorless, which was preferable from the standpoint of taste.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the molecular weight, foaming property (solid line), and foam stability (broken line) of soybean protein autolytic peptide.

Claims (1)

[Scope of Claims] 1. A foaming agent consisting essentially of a soybean protein hydrolyzed peptide having a molecular weight of 10 million to 6,000. 2 The molecular weight of the peptide is substantially 1,500 to 6,0
The foaming agent according to claim 1, which is 00. 3. Partially hydrolyze soybean protein or its contents with a proteolytic enzyme, and then reduce the molecular weight to substantially 1,000. to 6
A method for producing a foaming agent, which comprises separating a peptide consisting of ,000. 4 The molecular weight of the peptide is substantially 1,500 to 6,0
00. The manufacturing method according to claim 3.