JPH0691793B2 - Partially decomposed protein, its production method and use - Google Patents

Description

TECHNICAL FIELD The present invention relates to a partially decomposed protein product, a process for producing the same, and uses thereof. More specifically, it relates to a novel partially decomposed product obtained by decomposing a plant protein of wheat, corn or soybean, a method for producing the same, and a surfactant using the same.

(B) Conventional Technology As a partial hydrolyzate of a vegetable protein, conventionally known are those hydrolyzed with an acid or alkali and those hydrolyzed with an enzyme. Furthermore, such partially decomposed products are
It is also said to be obtained by oxidative decomposition or reductive decomposition using an oxidizing agent or a reducing agent.

For example, Ian L. Batey et al. Made from wheat gluten,
We have reported the physical properties and amino acid composition of a partial hydrolyzate obtained by hydrolyzing this with an alkali or acid (see "Preparat
ion of Salt-Free Protein Products from Acid or Al
kali-Trated Protein ", Food Chemistry No. 12 (1983)
Pp.265-275). On the other hand, AM Hermansson et al. Reported the physical properties of a partial hydrolyzate obtained by hydrolyzing rapeseed oil protein with alkali, acid or enzyme (“Functional Prope
rties of Proteins for Foods-Modification Studies
on Rapeseed Protein Concentrate ", Lebens.−Wiss.u.
-Technol. Vol. 7, No. 3, (1974) pp. 176-181). The partial hydrolyzate obtained is reported here to exhibit some solubility, emulsification and foaming properties.

JP-A-50-95443 discloses that wheat gluten has a pH of 2.0 to 6.0.
It has been shown that the slightly acidic gluten powder obtained by the acidification treatment below is superior as a food material additive to that obtained by treating with a reducing agent. In addition, JP-A-60-237
Japanese Patent No. 939 discloses that partially hydrolyzed wheat gluten obtained by hydrolyzing wheat gluten with oxygen and that it can be used as a substitute for caseinate used in the production of cheese analogs.

(C) Problems to be Solved by the Invention As described above, various research reports have been made on the partial hydrolyzate of plant protein, and the emulsifying ability of the partial hydrolyzate obtained therein is disclosed. There are also cases. However, when the present inventors confirmed the physical properties thereof, wheat, corn, partially decomposed products obtained by any of the above decomposition methods of typical plant proteins such as soybean, can be used as a surfactant. , Its performance is not at a satisfactory level.

On the other hand, sucrose fatty acid ester and lecithin have hitherto been known as the safest surfactants used in the food and medical fields. These are low in toxicity per se, and can be digested into nutrition even if they enter the body, and are excellent as surfactants. However, there is a problem that such sucrose fatty acid ester and lecithin are considerably expensive as compared with other general surfactants.

Under such circumstances, as a result of various studies conducted by the present inventors, the hydrolysis treatment with an alkali in the conventional hydrolysis method was regarded as an essential treatment, and any one of the acid, the enzyme, the oxidizing agent and the reducing agent was decomposed. The hydrolyzate obtained by the decomposition treatment in which two or more steps are combined is a novel hydrolyzate different from the conventional hydrolyzate, and in particular, it is remarkably superior to the conventional product and the sucrose fatty acid ester described above. The present invention has been achieved by discovering the fact that it has excellent emulsifying power and surface active ability such as surface tension lowering ability, etc., which are equal to or higher than those of lecithin, and further has good particle dispersing ability.

(D) Means for Solving the Problems Thus, according to the present invention, a partially decomposed protein is derived from wheat, corn and / or soybean vegetable protein, and has the following physical properties; ) Weight average molecular weight (by gel filtration method) 500-900
In the range of 00, (b) the ultraviolet absorption λmax is around 260 to 280 nm, and the infrared absorption is around 1400, 1630 and 3400 cm ^-1 , (c) the isoelectric point is in the range of 3.9 to 5.0. There is (d) pH buffering property (pH of 100 ml of a 5% by weight aqueous solution of this product at 6
2 to 25 ml of IN-hydrochloric acid is required to reduce from 1 to 2), (e) soluble in water, insoluble in methanol, ethanol, acetone, ether, (f) appearance pale yellow To reddish brown powder, (g) Color is developed by xanthoprotein reaction, ninhydrin reaction, (h) Strong surface tension can be reduced (by adding 0.1 wt% of this product to pure water at 2 ° C, The surface tension of water is 50 dyne / c
m or less (measured with Dunui's surface tensiometer)
(I) having a strong emulsifying ability (with the use of 1 g of this product, 100 g of a water-soybean oil mixture containing at least 30% by weight of soybean oil can be completely emulsified). Will be provided.

The above-mentioned partially decomposed protein product is a novel substance which has not been described in the literature prior to the filing of the present application.

The protein partial hydrolyzate of the present invention has a weight average molecular weight Mw of 500 to 90,000. Here, Mw is a value measured by the gel filtration method.

The most characteristic physical property that distinguishes the protein partial hydrolyzate of the present invention from the conventional protein partial hydrolyzate is its emulsifying property.
That is, the partially decomposed product of the present invention is added and used by 1 g,
Water-soybean oil mixture containing at least 30% by weight soybean oil
It has an excellent emulsifying power capable of completely emulsifying 100 g. "At least" means that soybean oil is 30
This means that 100 g of a mixture containing at least 50% by weight, such as 40% by weight or 50% by weight, can be completely emulsified. The term "complete emulsification" means that, after the emulsification treatment by stirring or the like, the whole uniform emulsified state is maintained for at least 10 minutes or longer, preferably 1 hour or longer, at room temperature. Conventionally known partial decomposed products do not have such a remarkable emulsifying power.
Therefore, the partially decomposed product of the present invention and the conventional partially decomposed product are obviously different at least in this respect.

The partially hydrolyzed protein of the present invention is produced by subjecting wheat protein (wheat gluten), corn protein (corn gluten) or soybean protein as a raw material to a partial decomposition treatment. These may be used as a mixture of two or more kinds. However, it is preferable to use wheat gluten which is usually available.

Partial decomposition treatment includes hydrolysis treatment with alkali, acid,
It is carried out by a multistage decomposition treatment in combination with a decomposition treatment using an enzyme, an oxidizing agent or a reducing agent. That is, the point that the alkali decomposition treatment and the decomposition treatment other than this are combined is the most characteristic point of the manufacturing method of the present invention. Here, it is not possible to obtain the partially hydrolyzed protein of the present invention specified above by only the hydrolysis treatment with alkali. The same applies when the decomposition treatments using an acid, an enzyme, an oxidizing agent and a reducing agent are carried out individually or in combination.

The above hydrolysis treatment with alkali is suitably carried out by heating in a dilute aqueous alkali solution. Normal,
The aqueous solution or aqueous dispersion of the substance to be hydrolyzed is stirred at about 60 to 180 ° C. for about 10 to 600 minutes in the presence of an alkali agent such as sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate. Are suitable. Here, it is preferable to use an aqueous solution or aqueous dispersion of the hydrolysis target of 2 to 40% by weight, and the amount of the alkaline agent used is 0.1 to 0.6 g relative to 20 g of the hydrolysis target. Is preferred.

On the other hand, among other decomposition treatments to be combined with the above-mentioned hydrolysis treatment with alkali, the decomposition treatment with acid is suitably performed by heating in a dilute aqueous acid solution. Usually, it is suitable to stir an aqueous solution or aqueous dispersion of the substance to be decomposed in the presence of an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid or an organic acid such as acetic acid at about 60 to 120 ° C for about 10 to 600 minutes. ing. The quantitative conditions here are preferably the same as the above-mentioned conditions for the alkaline hydrolysis.

Similarly, the decomposition treatment with an enzyme is suitable to be carried out in a dilute aqueous solution of an enzyme having protease activity.
In an aqueous solution or aqueous dispersion of a substance to be decomposed in the presence of a small amount of an enzyme such as pepsin, alkaline protease, papain, etc., under the optimum pH conditions of this enzyme, under about 10 to 60 ° C, about 60 to 600.
Minutes. Here, the quantitative conditions are preferably the same as above except that the amount of enzyme used is 0.02 to 5 g per 20 g of the decomposition target.

Similarly, the decomposition treatment with a reducing agent or an oxidizing agent is preferably carried out in a dilute aqueous solution of a reducing agent or an oxidizing agent. Usually, an aqueous solution or aqueous dispersion of the decomposition target is subjected to a sulfite salt, a thiol compound, or erythorbin. It is carried out at about 10 to 100 ° C. for 10 to 600 minutes in the presence of a small amount of a reducing agent such as acid or hydrazide or an oxidizing agent such as hydrogen peroxide or hypochlorite. The quantitative conditions at this time are preferably the same as those described above except that the amount of the reducing agent or the oxidizing agent used relative to 20 g of the decomposition target is 0.1 to 5 g.

The order of the multistage decomposition process is not particularly limited. That is,
Raw materials such as wheat gluten are first subjected to alkle hydrolysis treatment (A) and then decomposed using the above-mentioned acid, enzyme, reducing agent and oxidizing agent (B) (decomposition treatment other than alkali)
Any of the above or two or more of them may be applied, or vice versa. Alternatively, it can be obtained by first subjecting it to a decomposition treatment other than alkali (B), then subjecting it to alkali hydrolysis treatment (A), and then again subjecting it to a decomposition treatment other than alkali (B). Also,
A neutralization treatment may be appropriately performed between these treatments.

In any case, even if a partial hydrolyzate having an equivalent molecular weight can be obtained by only alkali hydrolysis treatment or only non-alkali decomposition treatment, it is not possible to obtain a hydrolyzate such as the partially hydrolyzed product of the present invention. Although the reason for this is not clear, the site of the protein or polypeptide that is cleaved by alkaline hydrolysis differs from the site of the protein or polypeptide that is cleaved by a decomposition treatment other than alkali, and these decomposition modes are combined. As a result, it is considered that a partially decomposed product having a decomposition form different from the conventional one is generated, and that the specific physical properties are exhibited.

The partially decomposed product of the present invention is obtained by evaporating to dryness from the solution obtained by the decomposition treatment in this way. However, the solution obtained by the decomposition treatment may be used as it is for the required application.

(E) Effect of the Invention The partially decomposed product of the invention thus obtained is high in cost.
Since it has high hydrophilicity in HLB and has excellent emulsifying property and surface tension lowering ability as described above, it can be used as a surfactant. In particular, it is useful as a surfactant because it has a low foaming property despite its excellent emulsifying ability and surface tension reducing ability. Since such a partially decomposed product itself is a kind of modified product of food, it is nontoxic and inexpensive, and is extremely useful as a surfactant in the fields of food and medicine. Among them, those having an average molecular weight of 17,000 to 70,000 are particularly useful because their emulsifying power is superior to that of a conventional sucrose fatty acid ester having low toxicity.

The partially decomposed product of the present invention utilizes various properties such as nontoxicity, low flavor, low foaming property, etc., for example, in the food industry, dairy products such as cream and ice cream, bread such as bread, sponge cake and the like. , Cakes, noodles, tofu, kamaboko,
Starch and protein foods such as ham, sausage and baked pork, processed oils and fats such as margarine, mayonnaise and dressings,
Powdered miso, instant powdered foods such as cocoa, other emulsifiers and dispersants for various beverages and confectionery, as a quality improver,
Further, in the detergent industry, it can be suitably used as a detergent for cleaning foods and dishes, a detergent for cleaning, and also as an emulsifying dispersant for cosmetics, pharmaceuticals, agricultural chemicals, etc. and other edible emulsifying dispersants and frost damage inhibitors. .

When the partially decomposed product of the present invention is used as a surfactant, other known surfactant may be used in combination depending on the purpose. Other surfactants to be combined include relatively lipophilic surfactants such as monoglycerides, sorbitan esters, propylene glycol ethers, lecithin, and sucrose fatty acid esters having various HLB values,
Food fields such as polyglycerin fatty acid ester and cosmetics
Examples include those used in the pharmaceutical field.

Further, such a partially decomposed product further has an excellent particle dispersibility, and exerts a strong viscosity lowering effect based on this. For example
By adding and using 1.5 g, the viscosity and kaolin of 500 g of calcium carbonate slurry containing 50% by weight of calcium carbonate can be obtained.
The viscosity of 500g of kaolin slurry containing 60% by weight is 60
It has the effect of decreasing to below 00 cps. Therefore, the partially decomposed product of the present invention is also useful as a highly stable particle dispersant.

Incidentally, the partial decomposition product of the present invention may be used in combination with other dispersants, as the dispersant used in combination, gum arabic, pectin, CMC, xanthan gum, alginic acid,
Other polysaccharides and the like can be mentioned.

Furthermore, since the above-mentioned partially decomposed product has a buffering capacity as described above, it is also useful as a highly safe buffering agent.

When the partially decomposed product of the present invention is used for various purposes, it may be used in combination with a commonly used preservative such as ethanol, isopropanol, sorbic acid, dehydroacetic acid, sodium chloride and boric acid. This is one of the preferable usage modes.

(F) Examples Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

Comparative Examples 1 to 3 (preparation of partially decomposed product of wheat gluten with acid) 100 g of hydrochloric acid aqueous solution corresponding to 1 g, 2 g and 4 g in terms of hydrogen chloride
Wako Pure Chemical Industries, Ltd. in 3 flasks containing
20 g of wheat gluten (reagent product) manufactured by K.K. After that, neutralize with caustic soda and use pure water for the total amount.
Comparative products Nos. 1 to 3 containing partially decomposed products were obtained in 200 g. Table 1 shows the decomposition conditions and the weight average molecular weight of the decomposition products. The average molecular weight is GP using sodium polystyrene sulfonate as a standard solvent and 1 wt% saline solution.
It is the value measured by the C method. (The same applies to the examples described below.) Comparative Example 4 (Preparation of partially decomposed product of wheat gluten by enzyme) 20 g of wheat gluten used in Comparative Example 1 was added with 150 g of 0.1N hydrochloric acid solution.
Was added to the flask to obtain a pH 1.5 aqueous solution. Wako Pure Chemical Industries, Ltd. reagent pepsin (1: 10,000) 0.2g
Was added and reacted at 37 ° C. for 90 minutes. Then, it was neutralized with caustic soda and the total amount was 200 g with pure water to obtain a comparative product No. 4. The average molecular weight of the partially decomposed product was 60,000.

Comparative Example 5 (Preparation of partially decomposed product of wheat gluten with a reducing agent) 20 g of wheat gluten used in Comparative Example 1 was added to 100 g of an aqueous solution in which 4 g of sodium sulfite was dissolved, and the mixture was stirred at 30 ° C. for 60 minutes and then purified water was used. Comparative product No. 5 was obtained with a total amount of 200 g. The average molecular weight of the partially decomposed product was 79,000.

Comparative Examples 6 to 9 (Preparation of partially hydrolyzed wheat gluten with alkali) 20 g of wheat gluten used in Comparative Example 1 and 0.2 to caustic soda were used.
The mixture was added to 100 g of four aqueous solutions each dissolved within a range of 4 g, and after thorough mixing, heated and stirred in a flask at 80 to 100 ° C. for 30 to 60 minutes in temperature and time. These were neutralized with hydrochloric acid, and the total amount was 200 g with pure water.
Got 9.

Table 2 shows the decomposition conditions and the average molecular weight of the decomposition products.

Examples 1 to 12 (Preparation of Decomposed Products by Partial Decomposition of Wheat Gluten with Acid and Subsequent Partial Decomposition with Alkali) A 10% aqueous solution of partially decomposed product of wheat gluten with acid was prepared under the same conditions as in Comparative Examples 1 to 3. 100 g of each of them was put into a flask or 10 autoclaves, and caustic soda was added thereto in an amount within the range of 0.5 to 2 g, and the mixture was heated and stirred at 100 or 150 ° C. for 60 or 360 minutes. Then, the mixture was neutralized with hydrochloric acid and the total amount was 200 g with pure water to obtain invention products Nos. 1 to 10 containing the partially decomposed product of the present invention. Inventive product No. 1 in the same manner as above except that sodium carbonate was used instead of caustic soda.
Got one. The condition of partial decomposition with acid is 0.5 g of hydrochloric acid added,
Except that the temperature was 80 ° C and the time was 60 minutes, all of Examples 1 to 10
Invention product No. 12 was obtained in the same manner as described above.

Table 3 shows the decomposition conditions and the average molecular weight of the decomposed products.

Inventive product No. 1 was almost saltless and odorless when it was desalted by isoelectric precipitation or dialysis.

Examples 13-16 (Preparation of corn gluten and soybean protein by partial decomposition with acid and then partial decomposition with alkali) Preparation of corn gluten manufactured by Nippon Food Kako Co., Ltd. as a raw material under the same conditions as in Examples 6 and 1. Inventive products Nos. 13 and 14 were obtained by sequentially carrying out partial decomposition with acid and alkali. The average molecular weights were 11800 and 27100, respectively.

Also, using soybean protein obtained by defatting commercially available yuba with acetone as a raw material, the invention products Nos. 15 and 16 were obtained by sequentially partial decomposition using acid and alkali under the same conditions as in Examples 6 and 1. .

The average molecular weights were 12000 and 29,000, respectively.

Examples 17 and 18 (Preparation of Decomposition Products of Wheat Gluten by Partial Decomposition with Alkali and Subsequent Partial Decomposition with Acid) Obtained by carrying out partial decomposition of wheat gluten with alkali under the same conditions as in Comparative Examples 6 and 7. A 10% aqueous solution of the partially decomposed product was prepared, 100 g of each was placed in 2 flasks, 0.5 g of hydrogen chloride equivalent and 1 g of hydrochloric acid corresponding to 1 g were separately added, and the mixture was heated and stirred at 100 ° C. for 60 minutes. . After that, the product was neutralized with caustic soda and the total amount was 200 g with pure water to obtain invention products 17 and 18.

Table 4 shows the decomposition conditions and the average molecular weight of the decomposition products.

Examples 19 and 20 (partial decomposition of wheat gluten with an enzyme and preparation of a decomposed product by partial decomposition with an alkali subsequently carried out) A 10% aqueous solution of the partial decomposition of wheat gluten with an enzyme was prepared under the same conditions as in Comparative Example 4. , 100 g, 2 pieces of them are added, and 1 g and 2 g of caustic soda are added, respectively.
The mixture was heated and stirred for 0 minutes. After that, the product was neutralized with hydrochloric acid to obtain 200 g of pure water to obtain an invention product.

The invention product obtained by adding 1 g of caustic soda was designated as No. 19 and the invention product obtained by adding 2 g was designated as No. 20. The average molecular weight is 29000 and
It was 14,000.

Example 21 (Partial Decomposition of Wheat Gluten with a Reducing Agent and Preparation of Decomposed Product by Partial Decomposition with Alkali Performed Then) A 10% aqueous solution of partial decomposition of wheat gluten with a reducing agent was prepared in the same manner as in Comparative Example 5. 100g of caustic soda
Was added, and the mixture was heated and stirred at 100 ° C. for 60 minutes in the flask. After that, it was neutralized with hydrochloric acid and the total amount was 200 g with pure water.
I got o.21. The average molecular weight was 39500.

Example 22 (Partial decomposition of wheat gluten with alkali and subsequent partial decomposition with enzyme (reverse order from Example 19) by an enzyme) Partial decomposition of wheat gluten with alkali under the same conditions as in Comparative Example 6 A 10% aqueous solution of the product is prepared, and 100 g of the solution is added with a hydrochloric acid reagent to obtain an aqueous solution having a pH of 1.5.
Pepsin was added and reacted at 37 ° C. for 90 minutes. afterwards,
Inventive product No. 22 was obtained by neutralizing with caustic soda and making the total amount to 200 g with pure water. The average molecular weight was 24500.

Decomposition and Preparation of Decomposed Product by Partial Decomposition with Oxidizing Agent Performed Next) A 10% aqueous solution of partially decomposed product of wheat gluten with alkali was prepared under the same conditions as in Comparative Example 6, and 0.5 g thereof was converted into H ₂ O _{2 in} 100 g thereof. Hydrogen peroxide solution corresponding to g was added, and the mixture was heated with stirring at 40 ° C. for 60 minutes. After that, the remaining H ₂ O ₂ and an equivalent amount of sodium thiosulfate were added, and the total amount was 200 g with pure water to obtain Invention product 23.

Various physical properties and particle dispersing action of the partially decomposed plant protein of the present invention obtained in Examples 1 to 23 are shown in Table 5 below.

In the table, W in the raw material column means wheat gluten, C means corn gluten, and B means soy protein. In addition, the blank means that the measurement or the test is not performed.

The measurement methods and test methods for each physical property and particle dispersion action are as follows.

[Average molecular weight]

These molecular weights are 1600,6500,16000,65 as standard substances.
It is the value measured by gel filtration method using sodium polystyrene sulfonate having a molecular weight of 000,88000 as a solvent, 1% by weight saline, and Sephadex G-75 or G-100 manufactured by Pharmacia as a carrier. .

[Isoelectric point]

Each of the invention products 1 to 23 obtained in the examples of the present invention was placed in a beaker.
100 g of each was taken, IN-HCl was added in 1 ml portions at room temperature with stirring, and the pH was measured. The pH value at which the slope of the obtained pH curve was the most gentle was taken as the isoelectric point.

[Buffer capacity]

From the pH curve obtained in the same manner as the isoelectric point measurement method,
The buffering capacity was defined as the amount of IN hydrochloric acid required to reduce the pH from 6 to 2. Incidentally, the pH neutralization curve at this time, invention product No. 1, N
o.7, No. 13, and No. 15 are shown in Fig. 1 (a) to (d).

(UV)

Absorbance in the range of 800 to 200 nm was measured using a Hitachi U-3200 spectrophotometer.

(IR)

It was measured by the KBr method using a Hitachi 260-10 type infrared spectrophotometer.

[Particle Dispersing Power] (Calcium Carbonate Slurry) National M1 type mixer with 250 g of invention product and tap water
Then, 250 g of calcium carbonate (light calcium carbonate manufactured by Takehara Chemical Industry Co., Ltd.) is added and mixed for 2 minutes to prepare a 50 wt% slurry. Immediately after that, the slurry was transferred to a beaker, and using a DVH-B type viscometer manufactured by Tokyo Keiki, the rotation speed was 50 rpm and the rotor N
The viscosity (cps) was measured at o.3 to 5. However, the addition concentration of the partially decomposed product of the invention is 0.3% by weight with respect to the total amount of 500 g.

(Kaolin slurry) -In a National M1 type mixer, 200 g of the partially decomposed product of the present invention and tap water are added, and 300 g of kaolin [Tsuchiya Kaolin Industry Co., Ltd.] powder is added and mixed for 2 minutes to prepare a 60 wt% slurry. To do. Immediately thereafter, the slurry is transferred to a beaker, and the viscosity is measured with a Tokyo Keiki DVH-B type viscometer at a rotation speed of 50 rpm and a rotor No. 3 to 5. However, the addition concentration of the partially decomposed product of the present invention is 0.3% by weight with respect to the total amount of 500 g.

Test Example 1 (Measurement of Surface Tension) The surface tensions of the comparative products prepared in Comparative Examples and Examples, the invention product and sucrose fatty acid ester (comparative product 10) and soybean lecithin (comparative product 11) were measured at a temperature of 25. C. Pure water was used as a solvent, and the measurement was performed by a surface tension meter of Dunui. The results are shown in Table-6. The sucrose fatty acid ester used was Daiichi Kogyo Seiyaku Co., Ltd.'s trade name: DK S-L-160 (HLB is 15), and soybean lecithin is Hosei Oil Co., Ltd.'s trade name: Toyonen Lecithin AY. Is.

Test Example 2 (Measurement of Emulsion Maintenance Time) Comparative Example, Comparative Product Prepared in Examples, Invention Product and Sucrose Fatty Acid Ester Same as Test Example 1 (Comparative Product 10) and Soybean Lecithin (Comparative Product 11) The duration of emulsification was measured by the following test method. The test results are shown in Table-6.

《Test method》 ・ Put a total of 70g of test chemicals and tap water in a beaker, and adjust the pH.
To 7.0. Soybean oil [Reagent manufactured by Kishida Chemical Co., Ltd.] 3
0 g was added and the mixture was mixed with a HV-M type homomixer manufactured by Tokushu Kika Kogyo Co., Ltd. at a rotation speed of 8000 rpm for 5 minutes. Immediately after mixing, the emulsified liquid is transferred to a colorimetric tube and allowed to stand at room temperature, and the time until separation begins is the emulsification maintaining time. The measurement of the duration of emulsification was performed every 10 minutes until 1 hour after the start of standing and thereafter every 1 hour. However, the addition concentration of the partially decomposed product of the present invention is 1.0% by weight based on the total amount.

As described above, the partially decomposed product of the present invention has excellent surface tension lowering ability and emulsifying ability, and in particular, many of the invention products are superior in any point as compared with the conventional sucrose fatty acid ester. It is understood that there is. Further, it is understood that the comparative products 6 to 8 are excellent in the surface tension lowering ability, but the emulsifying ability is remarkably low.

In addition, when the emulsifying ability of Invention Products No. 1, 5 and 6 was repeated using a smaller amount (addition concentration: 0.3% by weight), 24
An emulsification duration of more than an hour was obtained. On the other hand, when sucrose fatty acid ester was additionally tested at an addition concentration of 0.3% by weight, the emulsion duration was 30 minutes, and when it was 0.15% by weight, it was less than 10 minutes.

Test Example 3 (Foamability test) The foaming power of the comparative product, the invention product and the sucrose fatty acid ester (Comparative product 10) prepared in Comparative Examples and Examples was adjusted to a concentration of 0.3% at a temperature of 25 ° C and pure water as a solvent. Los Miles method (JISK-3362)
Measured by The results are shown in Table-7.

(Explanation of Results) The invention product has a very low foaming power as compared with the comparative product. For applications such as cleaning detergents and food or tableware detergents, low-foaming surfactants are required for easy rinsing. However, a highly stable surfactant that can sufficiently satisfy such requirements has not been found so far,
The product of the present invention can be effectively used for those purposes.

Test Example 4 It is known that surfactants influence the viscosity behavior of starch suspensions. As with other surfactants of the product of the present invention, whether it has an effect on gelatinization of starch,
It investigated by the method shown below. Inventor in a beaker
1 g and potato starch (reagent) 20 g were dispersed and dissolved in tap water at 50 ° C., and the volume was adjusted to 500 m1 with tap water at the same temperature. After that, a Viscograph manufactured by Brabender was operated at a rotation speed of 77 rpm. The temperature change conditions were as follows. 50 ° C
Temperature up to 95 ° C at a rate of 1.5 ° C / min,
After holding for 5 minutes, the temperature was again lowered to 50 ° C. at a rate of 1.5 ° C./min, and the viscosity during that time was recorded. Table 8 shows the gelatinization start temperature and the maximum viscosity.

(Discussion of Results) The product of the present invention has the property of increasing the gelatinization start temperature of starch and decreasing the viscosity at the time of gelatinization. Therefore, the product of the present invention can be used as a softener for bread of the product of the present invention or an antioxidant.

Analysis Example Table 9 shows the results of amino acid analysis of the invention products No. 1, No. 7, No. 13 and No. 15. The numerical values in the table indicate the g number of each amino acid per 100 g of the raw material before decomposition.

Similarly, U for invention products No. 1, No. 7, No. 13 and No. 15
V-visible absorption spectrum and IR spectrum
It is shown in FIGS.

[Brief description of drawings]

1 (a) to 1 (d) are graphs respectively illustrating pH neutralization curves for the partial hydrolyzate of the present invention, and FIG.
FIG. 5 similarly illustrates optical characteristics,
(A) in each figure is a UV-visible absorption spectrum diagram,
(B) is an IR spectrum diagram.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08H 1/00 NVD 8215-4J C11D 1/32 C12P 21/06 8214-4B (56) References Kai 63-216437 (JP, A) JP 56-25093 (JP, B2)

Claims (12)

[Claims] 1. A partially hydrolyzed protein, which is derived from wheat, corn and / or soybean vegetable protein, and has the following physical properties: (a) a weight average molecular weight (by gel filtration method) of from 500 to 900
In the range of 00, (b) the ultraviolet absorption λmax is around 260 to 280 nm, and the infrared absorption is around 1400, 1630 and 3400 cm ^-1 , (c) the isoelectric point is in the range of 3.9 to 5.0. There is (d) pH buffering property (pH of 100 ml of a 5% by weight aqueous solution of this product at 6
2 to 25 ml of IN-hydrochloric acid is required to reduce from 1 to 2), (e) soluble in water, insoluble in methanol, ethanol, acetone, ether, (f) appearance pale yellow To reddish brown powder, (g) Color develops by xanthoprotein reaction, ninhydrin reaction, (h) Strong surface tension reducing ability (by adding 0.1 wt% of this product to pure water at 25 ° C, The surface tension of water is 50 dyne / c
m or less (measured with Dunui's surface tensiometer)
(I) having a strong emulsifying ability (with the use of 1 g of this product, 100 g of a water-soybean oil mixture containing at least 30% by weight of soybean oil can be completely emulsified). . 2. The partially hydrolyzed protein according to claim 1, wherein the vegetable protein is wheat gluten. 3. The protein partial hydrolyzate according to claim 1, which has a weight average molecular weight of 17,000 to 70,000. 4. One or more vegetable proteins selected from wheat, corn and soybean are hydrolyzed with (A) alkali and (B) decomposed with an acid, an enzyme, an oxidizing agent or a reducing agent. By subjecting to a partial decomposition treatment by a combination of one or more treatments, the following physical properties are obtained: (a) Weight average molecular weight (by gel filtration method) is 500 to 900
In the range of 00, (b) the ultraviolet absorption λmax is around 260 to 280 nm, and the infrared absorption is around 1400, 1630 and 3400 cm ^-1 , (c) the isoelectric point is in the range of 3.9 to 5.0. There is (d) pH buffering property (pH of 100 ml of a 5% by weight aqueous solution of this product at 6
2 to 25 ml of IN-hydrochloric acid is required to reduce from 1 to 2), (e) soluble in water, insoluble in methanol, ethanol, acetone, ether, (f) appearance pale yellow To reddish brown powder, (g) Color develops by xanthoprotein reaction, ninhydrin reaction, (h) Strong surface tension reducing ability (by adding 0.1 wt% of this product to pure water at 25 ° C, The surface tension of water is 50 dyne / c
m or less (measured with Dunui's surface tensiometer)
(I) having a strong emulsifying ability (with the use of 1 g of this product, 100 g of a water-soybean oil mixture containing at least 30% by weight of soybean oil can be completely emulsified). A process for producing a partially decomposed protein product, which comprises: 5. The partial decomposition treatment is first a hydrolysis treatment (A).
The production method according to claim 4, which is carried out by carrying out the above step and then carrying out the decomposition treatment (B). 6. The method according to claim 4, wherein the partial decomposition treatment is performed by first performing the decomposition treatment (B) and then the hydrolysis treatment (A). 7. The process according to claim 4, wherein the hydrolysis treatment with alkali is carried out in a dilute aqueous alkali solution at about 60 to 180 ° C. for about 10 to 600 minutes. 8. The decomposition treatment with an acid is performed in a dilute aqueous acid solution to about
The method according to claim 4, which is carried out at 60 to 120 ° C. for about 10 to 600 minutes. 9. The process according to claim 4, wherein the decomposition treatment with the enzyme is carried out in a dilute enzyme aqueous solution at about 10 to 60 ° C. for about 60 to 600 minutes. 10. The process according to claim 4, wherein the decomposition treatment with the reducing agent is carried out in a dilute aqueous solution of the reducing agent at about 10 to 100 ° C. for about 10 to 600 minutes. 11. The method according to claim 4, wherein the decomposition treatment with the oxidizing agent is carried out in a dilute aqueous solution of the oxidizing agent at about 10 to 100 ° C. for about 10 to 600 minutes. 12. A partially hydrolyzed protein, which is derived from wheat, corn and / or soybean vegetable protein, and has the following physical properties: (a) a weight average molecular weight (by gel filtration method) of from 500 to 900
In the range of 00, (b) the ultraviolet absorption λmax is around 260 to 280 nm, and the infrared absorption is around 1400, 1630 and 3400 cm ^-1 , (c) the isoelectric point is in the range of 3.9 to 5.0. There is (d) pH buffering property (pH of 100 ml of a 5% by weight aqueous solution of this product at 6
2 to 25 ml of IN-hydrochloric acid is required to reduce from 1 to 2), (e) soluble in water, insoluble in methanol, ethanol, acetone, ether, (f) appearance pale yellow To reddish brown powder, (g) Color develops by xanthoprotein reaction, ninhydrin reaction, (h) Strong surface tension reducing ability (by adding 0.1 wt% of this product to pure water at 25 ° C, The surface tension of water is 50 dyne / c
m or less (measured with Dunui's surface tensiometer)
(I) having a strong emulsifying ability (with the use of 1 g of this product, 100 g of a water-soybean oil mixture containing at least 30% by weight of soybean oil can be completely emulsified). A surfactant containing as an active ingredient.