JP2009189276A - Soybean peptide-containing liquid food - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid food suppressed in browning caused by heat treatment or long preservation, in spite of containing peptide. <P>SOLUTION: This liquid food comprises a soybean protein thermolysin hydrolyzate. The liquid food is suppressed in browning caused by heat treatment or long preservation by containing a soybean protein thermolysin hydrolyzate as peptide in the liquid food without the need of specifying peptide component, further mixing specific additives or performing specific treatment. The phenomenon is the same in a liquid food containing sugar or sugar alcohol. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid food containing soybean peptide. More specifically, the present invention relates to a liquid food containing a thermolysin hydrolyzate of soy protein.

  In recent years, peptide-containing foods have attracted attention because peptides are more readily absorbed by the body than proteins and thus are more effective. In particular, the demand for liquid food is increasing from the viewpoint of ease of consumption. However, the peptide has a problem that when it is subjected to a high-temperature heat treatment in an aqueous system or left for a long time even at a low temperature, it is colored brown and changes its color tone.

  On the other hand, the peptide of Patent Document 1 is characterized in that the browning reaction is suppressed and coloring deterioration is caused by specifying the content of sugar and free amino acid contained as impurities in the peptide obtained by hydrolyzing the protein. There are few things. Patent Document 2 discloses a technique for preventing or delaying peptide browning by adding high ester pectin to a peptide in an acidic environment. In Patent Document 3, browning is prevented by reacting a food containing protein, peptide or amino acid and reducing sugar with an enzyme having an action of oxidizing a reducing group of reducing sugar.

Patent Document 4 discloses a technique of using deesterified pectin for protein stabilization in an acidic environment.
JP 04-297500 A JP 2005-192557 A International Publication No. 02/39828 Pamphlet International Publication No. 97/03574 Pamphlet

  However, the disclosure of Patent Document 1 relates to browning suppression by specifying the content of components contained in the peptide itself, and when the peptide is contained in foods, particularly foods containing saccharides, the above effect is obtained. It is not necessarily obtained. Moreover, since the method of patent documents 2-4 has a restriction | limiting in an additive and a manufacturing method, there exists a subject that application is restricted.

  The subject of this invention is providing the liquid food by which browning in heat processing and long-term storage is suppressed, even if it contains a peptide.

  As a result of repeated investigations to solve the above problems, the present inventors have identified a peptide component or a specific additive by adding a thermolysin hydrolyzate of soy protein as a peptide to a liquid food. It was found that browning during heat treatment and long-term storage is suppressed without the need for further blending or specific treatment. Furthermore, it has been confirmed that the phenomenon is the same for liquid foods containing sugar or sugar alcohol, and the present invention has been completed.

That is, the present invention
(1) A liquid food comprising a thermolysin hydrolyzate of soy protein,
(2) The food according to (1), further comprising at least one selected from the group consisting of sugar and sugar alcohol,
(3) The food according to (1) or (2), wherein the content of the thermolysin hydrolyzate of soy protein is 0.01 to 40% by weight,
About.

  Even if the liquid food of this invention contains a peptide, since the browning in heat processing and long-term storage is suppressed, there exists the outstanding effect that the quality degradation by coloring is suppressed. Moreover, such an effect is remarkably exhibited also when the liquid food contains sugar or sugar alcohol.

  The liquid food of the present invention is greatly characterized in that it contains a thermolysin hydrolyzate of soybean protein (hereinafter referred to as thermolysin hydrolyzate) as a peptide. In the present specification, the “liquid food” means a food in a liquid, emulsion or paste state, not in a gel state.

  The thermolysin hydrolyzate is obtained by hydrolyzing soy protein with thermolysin. Such a hydrolyzate contains a wide variety of peptides, but specifically contains a peptide represented by Leu-Glu-His-Ala (hereinafter referred to as LEHA). In the present invention, although the detailed reason is unknown, since this LEHA has a structure for chelating a metal compound such as iron ion or copper ion contained in a trace amount in the food, the peptide-containing liquid food It is presumed that the browning reaction is suppressed by inactivating the metal compound that catalyzes the browning reaction. Moreover, since LEHA is stable even in a high temperature state, even if the liquid food of the present invention is subjected to heat treatment or long-term storage, the above-mentioned action of LEHA is not reduced, and the quality deterioration due to coloring of the liquid food of the present invention is not caused. Presumed to be suppressed.

  Below, the preparation method of a thermolysin hydrolyzate, ie, the method of hydrolyzing soybean protein with thermolysin, is demonstrated.

  The soybean protein is not particularly limited as long as it is a protein derived from a soybean plant, but is preferably a protein derived from the seed of a soybean plant.

  Therefore, in the present invention, the soybean plant itself, the seed of the soybean plant itself, or the crushed or crushed product of the plant or the seed may be used as the soybean protein, but preferably from all components in the soybean plant. What isolate | separated and refine | purified the protein component, More preferably, what isolate | separated and refine | purified the protein component from all the components in the seed of a soybean plant is used. The soy protein obtained by separation and purification in this way may contain substantially all kinds of proteins contained in soybean plants or soybean plant seeds, and also contains some kinds of proteins. It may be.

  As the soy protein, commercially available products can also be suitably used. For example, Nisshin Cosmo Foods Co., Ltd., ADM Far East Co., Ltd., Showa Sangyo Co., Ltd., Fuji Oil Co., Ltd., Koyo Shokai Co., Ltd., etc. Readily available from other manufacturers or suppliers.

  In the present specification, the seeds of soybean plants not only refer to the whole structure commonly referred to as soybean seeds but also include, for example, dehulled soybean seeds, defatted soybean seeds (powder), and snow flora (Okara) obtained from the whole soybean seeds. ) Etc.

  Thermolysin (EC3.4.24.27) is a heat-resistant protease produced by a heat-resistant bacterium called Bacillus thermoproteolyticus. Thermolysin is generally known to cleave a peptide bond on the amino group side of a hydrophobic amino acid residue having a large side chain (for example, isoleucine, leucine, valine, phenylalanine, methionine, alanine, etc.).

  Commercially available thermolysin can be suitably used, and is easily available from manufacturers such as Daiwa Kasei Co., Ltd. In the present invention, a protease known in the art as a protease having peptide cleavage characteristics (such as cleavage sequence specificity) equivalent to thermolysin can be used as thermolysin.

  In the present invention, when hydrolyzing soybean protein, a protease other than thermolysin may be used as long as the effects of the present invention are not impaired. Other proteases are not particularly limited, and examples include papain, bromelain, trypsin, chymotrypsin, pancreatin, and subtilin. These may be used alone or in combination of two or more with thermolysin.

  The reaction conditions used when hydrolyzing soy protein with thermolysin are not particularly limited and may be appropriately selected by those skilled in the art according to common general technical knowledge. For example, when using commercially available thermolysin, it can be used according to the instruction manual. As a specific example, soy protein or a soy protein concentration in a solvent such as water is preferably 0.1 to 30% (w / v), more preferably about 1 to 10% (w / v). A raw material containing soy protein is suspended, and thermolysin is added to this suspension so that it is preferably about 0.001 to 3% (w / v), more preferably about 0.01 to 0.125% (w / v). The aspect which performs reaction is mentioned. As reaction temperature, 30-80 degreeC is preferable, 40-70 degreeC is more preferable, 50-60 degreeC is further more preferable. The reaction time is preferably 2 to 30 hours, more preferably 3 to 24 hours, further preferably 10 to 20 hours, and further preferably 12 to 18 hours. The pH of the reaction solution is preferably around pH 7.0 to 8.5, which is the optimum pH for thermolysin.

  The means for stopping the reaction is not particularly limited, and known means can be used. Examples of such means include heat treatment. Specifically, the reaction product may be heat-treated at a temperature of about 80 to 100 ° C., preferably for 3 to 20 minutes, more preferably 5 to 15 minutes, and at 85 ° C. for 15 minutes or at 100 ° C. for 5 minutes. Thermolysin contained in the reaction product can be inactivated by heat treatment for minutes.

  The thermolysin hydrolyzate obtained by the hydrolysis reaction as described above can be further processed by any method known to those skilled in the art, if necessary. For example, it is preferable to remove large solid particles in the hydrolyzate by a treatment such as filtration. Filtration conditions and the like are not particularly limited and may be appropriately selected by those skilled in the art according to common general technical knowledge. For example, when the filter paper is likely to be clogged, a filter aid or the like can be suitably used.

  Alternatively, the hydrolyzate can be pulverized by concentration under reduced pressure and then freeze-drying. The conditions and equipment used for concentration under reduced pressure and lyophilization are not particularly limited, and can be appropriately selected by those skilled in the art according to common technical knowledge. The hydrolyzate thus powdered can be used as it is or after being dissolved in a solvent such as water.

  As long as the thermolysin hydrolyzate contains LEHA, the thermolysin hydrolyzate may contain substantially all of a wide variety of peptides generated by hydrolyzing soy protein with thermolysin, or Such a wide variety of peptides may be a part obtained by further fractionation and purification by a known method. Examples of peptides other than LEHA contained in the thermolysin hydrolyzate include LEH and LEHAF. However, for convenience, the soy protein is used as it is in a state containing substantially all of a wide variety of peptides including LEHA obtained by hydrolysis with thermolysin. In addition, LEHA can be identified and quantified by the method described in Examples described later.

  The average molecular weight of the thermolysin hydrolyzate in the present invention is preferably 300 to 10,000. From the viewpoint of obtaining a higher effect, the average molecular weight is more preferably 400 to 5000, further preferably 500 to 3500, and still more preferably 550 to 3200. The average molecular weight of the thermolysin hydrolyzate can be measured by any method known to those skilled in the art, for example, gel permeation chromatography (GPC). In this specification, the average molecular weight measured by the GPC method means “peak average molecular weight”, and “peak average molecular weight” is the molecular weight corresponding to the elution time of the peak top (the strongest peak) of the chromatogram. Means.

  The LEHA content in the thermolysin hydrolyzate is preferably 0.05 to 0.2% by weight, more preferably 0.1 to 0.2% by weight.

  The total content of free amino acids in the thermolysin hydrolyzate is preferably 0.01 to 0.5% by weight, more preferably 0.01 to 0.3% by weight, and still more preferably 0.01 to 0.2% by weight. The total content of free amino acids in the thermolysin hydrolyzate can be measured by any method known to those skilled in the art, and can be easily measured by, for example, automatic amino acid analysis.

In the present invention, as the thermolysin hydrolyzate, “Colaplus ^™ N” which is a commercial product (peak average molecular weight: 711, LEHA content: 0.14% by weight, free amino acid total content: 0.14% by weight, ROHTO Pharmaceutical Co., Ltd. Can be used.

  The content of the thermolysin hydrolyzate in the liquid food is preferably 0.01 to 40% by weight, more preferably 0.1 to 20% by weight, and still more preferably 0.5 to 10% by weight from the viewpoint of ease of processing and palatability. .

  The LEHA content in the liquid food is preferably 0.000005 to 0.08% by weight, more preferably 0.00005 to 0.08% by weight, and still more preferably from the viewpoint of inactivating the metal compound contained in a trace amount in the liquid food. 0.01 to 0.08% by weight.

  As long as the liquid food of the present invention contains a thermolysin hydrolyzate, there are no particular limitations on the constituent components and the production method. For example, even a liquid food processed and manufactured using a thermolysin hydrolyzate as a raw material Alternatively, it may be a liquid food containing a thermolysin hydrolyzate.

  Moreover, since thermolysin hydrolyzate contains LEHA which inactivates the catalyst of a peptide browning reaction, the browning of thermolysin hydrolyzate itself is suppressed. Therefore, the liquid food of the present invention can be conventionally blended with additives that are difficult to blend due to the browning of the peptide. That is, the liquid food of the present invention may further contain at least one selected from the group consisting of sugar and sugar alcohol.

  Examples of the sugar include monosaccharide, disaccharide, and oligosaccharide. Examples of monosaccharides include glucose, fructose, mannose, arabinose, xylose, fucose, psicose, ribose, glucosamine, N-acetylglucosamine, and glucuronic acid. Examples of the disaccharide include sucrose, lactose, maltose, isomaltose, trehalose, cellobiose, cordobiose, and nigerose. Examples of the oligosaccharide include dairy oligosaccharide, soybean oligosaccharide, galactooligosaccharide, fructooligosaccharide, isomaltoligosaccharide, xylo-oligosaccharide, raffinose, chitin oligosaccharide, and chitosan oligosaccharide.

  Examples of the sugar alcohol include sorbitol, maltitol, erythritol, xylitol, mannitol, lactitol, and reduced palatinose.

  These sugars and sugar alcohols may be contained alone or in combination of two or more.

  The total content of sugar and sugar alcohol in the liquid food is preferably 0.01 to 20% by weight, more preferably 0.1 to 15% by weight, from the viewpoint of imparting a preferable sweetness and not impairing the taste of the food. 10% by weight is more preferred.

  In addition to the thermolysin hydrolyzate, sugar and sugar alcohol, the liquid food of the present invention is a high-grade sweetener (aspartame, acesulfame potassium, sucralose, stevia, erythritol, trehalose, maltose, as long as the effects of the present invention are not impaired. Licorice extract, rakan fruit extract, saccharin, etc.), acidulants (citric acid, malic acid, succinic acid, tartaric acid, etc.), vitamins (vitamin B, vitamin C, vitamin A, vitamin E, etc.), fruit juice, milk Ingredients, fats and oils, cosmetic ingredients (hyaluronic acid or its salts, chondroitin sulfate, collagen, methylsulfonylmethane, ceramide, elastin, silk peptide, placenta extract, coenzyme Q10, lipoic acid, astaxanthin, isoflavone, pine bark extract, olive leaf extract Etc.), mineral salts (lactic acid) Calcium, magnesium chloride, potassium chloride, etc. ferric ammonium citrate), perfumes, thickeners, flavorings, dispersing agents, stabilizing agents, preservatives, may also contain additives such as an antioxidant.

  The pH of the liquid food of the present invention is preferably 2.5 to 7.5, more preferably 3.0 to 6.0, and still more preferably 3.5 to 5.0 from the viewpoint of allowing the thermolysin hydrolyzate to be stably present in the food. In addition, there is no limitation in particular as a method of adjusting pH, It can carry out according to a well-known method suitably so that it may become desired pH.

  Examples of the liquid food of the present invention include tea, coffee, cocoa, soft drinks, lactic acid bacteria drinks, alcoholic drinks, milk, soy milk, soup, fruit puree, vegetable puree, yam paste, livestock meat paste, fish paste, livestock meat extract, Examples include chicken extract, shellfish extract, crustacean extract, fish extract, seaweed extract, pasty curry roux, ice cream, whipped cream, butter cream, custard cream, chocolate cream, white sauce and the like.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, a comparative example, and a reference example, this invention is not limited at all by these Examples.

[Peak average molecular weight of soybean peptide]
Soybean peptide is dissolved in 25 mM Tris-HCl buffer (containing 150 mM NaCl, pH 7.5) to prepare a 1 mg / mL test solution. HPLC column Superdex peptide HR (10 mm ID × 30 cm, manufactured by Amersham Biosciences) is equilibrated with the same buffer, and 100 μL of the test solution is injected into this column. The column flow rate is 0.5 mL / min, the column temperature is room temperature, the peptide is detected at 214 nm, and the peak average molecular weight is estimated from the elution time. As peptide preparations with known molecular weights, Cytochrome C (Sigma, molecular weight 12327), Aprotinin (Sigma, molecular weight 6518), Hexaglycine (Sigma, molecular weight 360), Triglycine (Sigma, molecular weight 189) Glycine (manufactured by Sigma, molecular weight 75) was used.

[Identification and quantification of LEHA in soybean peptide]
Soy peptide was dissolved in 0.05% trifluoroacetic acid (TFA) aqueous solution to a concentration of 1 mg / mL, and then filtered through a 0.45 μm membrane filter. The filtrate was used as a sample for LC-MS / MS, and the following LC- According to MS / MS conditions, LEHA is identified and quantified. The peaks used for identification and quantification are LEHA molecular ion peak (m / z 469.1) and product ion peak (m / z 227.2), and synthetic LEHA aqueous solutions with concentrations of 0, 10, 100, and 1000 ppb were used as preparations. A calibration curve was prepared and the LEHA concentration in the sample was determined. Moreover, the detection limit of LEHA in this test was 0.01 mg in 1 g of soybean peptide.

<LC-MS / MS conditions>
Device: Q-TRAP (Applied Biosystems)
Ion source: ESI, positive detection mode: SRM
Turbo gas temperature: 500 ℃
Spray voltage: 3000V
HPLC column: Unison UK-C18 (2.1mmφ × 50mm) (manufactured by Intact Corporation)
Column temperature: 40 ° C
Elution solvent: 0.05% TFA aqueous solution (solvent A), acetonitrile containing 0.05% TFA (solvent B)
Elution gradient:
0 min Solvent A 100%, Solvent B 0%
8.0 minutes Solvent A 30%, Solvent B 70%
8.1 minutes Solvent A 5%, Solvent B 95%
10.0 minutes Solvent A 5%, Solvent B 95%
Flow rate: 0.2mL / min
Injection volume: 10μL
Analysis time: 10 minutes

[Total content of free amino acids in soybean peptide]
Various free amino acids in soybean peptides are quantified by an amino acid automatic analysis method, and the total content of free amino acids is determined by adding them.

[Identification and quantification of LEHA in liquid food]
The liquid food was diluted with 0.05% TFA aqueous solution so that the soy peptide concentration would be 1 mg / mL, then filtered through a 0.45 μm membrane filter, or obtained by centrifugation (3000 r / min, 10 minutes) Using Kiyoshi as a sample for LC-MS / MS, LEHA is identified and quantified according to the LC-MS / MS conditions used when identifying and quantifying LEHA in the soybean peptide. Moreover, the detection limit of LEHA in this test was 1.0 mg in 1 g of liquid food.

Examples 1-A to G and Comparative Examples 1-A to G, 2-A to G
1 g of the peptide shown in Table 1 and 10 g of the additive shown in Table 1 were dissolved in an appropriate amount of purified water, adjusted to pH 3.5 with citric acid, and then adjusted to a total volume of 100 mL with purified water. Liquid foods of G (Example 1 group), Comparative Examples 1-A to G (Comparative Example 1 group) and Comparative Examples 2-A to G (Comparative Example 2 group) were obtained. In addition, LEHA content of Example 1 group was 0.0014 weight%, and LEHA content of Comparative Examples 1 and 2 group was below the detection limit.

Test Example 1 [storage stability]
About the liquid foodstuff of each Example group and the comparative example group, after storing for 2 weeks in a 60 degreeC thermostat, the light absorbency (420nm) was measured. The results are shown in Table 1. It should be noted that the absorbance before storage is not different if the same peptide is used even if the additives are different. Examples 1 group is 0.03 to 0.06, Comparative Examples 1 and 2 are 0.05 to 0.10. The liquid food was also colorless and transparent. In addition, if the absorbance after storage is 0.13 or more, the liquid food is browned, and the degree of browning is judged to have a difference in appearance if the absorbance difference is 0.04 or more, and the lower absorbance after storage is better It shows a good storage stability.

  From the above, the liquid foods of Examples 1-A to G containing the thermolysin hydrolyzate have lower absorbance after storage than those of Comparative Examples 1-A to G and Comparative Examples 2-A to G, and the browning reaction Is suppressed, and it can be seen that the storage stability is good. Moreover, since the liquid foodstuffs of Examples 1-A to G are stable even at high temperature storage at 60 ° C., it is estimated that long-term storage at room temperature or low temperature is also good. In addition, all the liquid foods after storage were clear with no formation of precipitates.

Test Example 2 [LEHA stability in liquid food]
About the liquid foodstuff of Example 1 group, LEHA content was measured after preserve | saving for 2 weeks in a 60 degreeC thermostat. In addition, since the LEHA content of the liquid food of Comparative Examples 1 and 2 was below the detection limit, the test was not performed.

  As a result, Example 1-A (without sugar addition) 1.3 mg / 100 mL, Example 1-B (glucose) 1.1 mg / 100 mL, Example 1-C (fructose) 1.2 mg / 100 mL, Example 1-D Sugar) LEHA content of 1.2 mg / 100 mL, Example 1-E (sorbitol) 1.4 mg / 100 mL, Example 1-F (maltitol) 1.4 mg / 100 mL, Example 1-G (erythritol) 1.3 mg / 100 mL Met. Since the LEHA content of the liquid food before storage is 1.4 mg / 100 mL, it has been found that LEHA is stable even at high temperature storage.

Formulation Examples 1-7 Thermolysin Hydrolyzate-Containing Liquid Food Using the raw materials shown in the following Formulation Examples 1-7, according to a method known to those skilled in the art, as a soy protein thermolysin hydrolyzate, “Colaplus ^™ N” (peak average A liquid food containing a molecular weight of 711, a LEHA content of 0.14% by weight, a free amino acid total content of 0.14% by weight, manufactured by Rohto Pharmaceutical Co., Ltd.) can be prepared. The unit is% by weight.

Formulation Example 1: Beverage Sodium Hyaluronate 0.01
Thermolysin hydrolyzate 1.0
Royal Jelly Extract 1.0
Lemon juice 1.0
Vitamin B2 0.005
Vitamin B6 0.05
Vitamin C 0.5
Erythritol 5.0
Reduced maltose starch syrup 5.0
Water soluble dietary fiber 5.0
Stabilizer (pectin) 0.2
Sweetener (acesulfame potassium, sucralose) 0.008
Calcium lactate 0.05
Magnesium chloride 0.015
Potassium chloride 0.015
Perfume 0.025
Preservatives (sodium benzoate, butylparaben) Appropriate amount Acidulant Appropriate amount (adjusted to pH 3.5)
Purified water remaining
Total 100.0% by weight

Formulation Example 2: Beverage Thermolysin Hydrolyzate 2.0
Honey 6.0
Maltitol 4.0
Sweetener (acesulfame potassium, sucralose) 0.02
Shark cartilage extract (contains 40% chondroitin sulfate) 0.8
Methylsulfonylmethane 2.0
Fish collagen 0.1
Glucosamine 1.0
Calcium gluconate 0.3
Preservatives (sodium benzoate, butylparaben) 0.05
Antioxidant (extract of bayberry, enzyme-treated rutin) 0.04
Stabilizer (propylene glycol alginate) 0.5
Vitamin B2 0.005
Perfume 0.025
Suitable amount of acidulant (adjusted to pH 3.6)
Purified water remaining
Total 100.0% by weight

Formulation Example 3: Oolong Tea Oolong Tea Extract 3.0
Thermolysin hydrolyzate 0.5
Sodium L-ascorbate 0.01
Maltitol 0.05
Fragrance 0.2
Purified water 96.24
Total 100.0% by weight

Formulation Example 4: Potato Soup Potato Powder 2.0
Thermolysin hydrolyzate 3.0
Milk cheese powder 7.0
Butter 0.8
Potato starch 2.5
Chicken extract powder 0.5
Salt 1.0
Sugar 1.0
Spice 0.01
Purified water 82.19
Total 100.0% by weight

Formulation Example 5: Yam paste yam 86.9
Thermolysin hydrolyzate 3.0
Antioxidant (Vitamin C) 0.1
Dextrin 10.0
Total 100.0% by weight

Formulation Example 6: Pasty curry beef tallow 6.0
Flour 2.5
Seasoning (amino acid) 1.0
Thermolysin hydrolyzate 5.0
Salt 1.4
Sugar 1.6
Fragrance 0.1
Spice 2.0
Seasoning 0.4
Onion powder 1.0
Beef extract 0.5
Starch 2.0
Powdered milk 1.0
Purified water 75.5
Total 100.0% by weight

Formulation Example 7: Whipped cream refined palm oil 50.0
Thermolysin hydrolyzate 0.75
Granulated sugar 8.0
Salt 0.05
Nonfat dry milk 4.0
Stabilizer 0.5
Purified water 36.7
Total 100.0% by weight

Formulation examples 8 to 71 Thermolysin hydrolyzate-containing liquid food Using the raw materials shown in Tables 2 to 5, according to a method known to those skilled in the art, as a thermolysin hydrolyzate of soy protein, “Colaplus ^TM N” (peak average molecular weight: 711, LEHA content: 0.14% by weight, free amino acid total content: 0.14% by weight, manufactured by Rohto Pharmaceutical Co., Ltd.). The unit is% by weight.

  Even if the liquid food of the present invention contains a peptide, quality deterioration due to coloring is suppressed, so that the liquid food is suitably used in the food field.

Claims (3)

  A liquid food comprising a thermolysin hydrolyzate of soy protein.   The food according to claim 1, further comprising at least one selected from the group consisting of sugar and sugar alcohol.   The food according to claim 1 or 2, wherein the content of the thermolysin hydrolyzate of soy protein is 0.01 to 40% by weight.