JPH0779639B2 - Quality improver for creamy dairy products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to coffee whitener, whipped cream,
The present invention relates to a quality improver for creamy dairy products such as ice cream.

(B) Conventional technology Creamy foods such as coffee whitener, whipped cream, ice cream, etc. are all processed milk products containing milk and fat milk and other solid components, oils and water as the main constituents. It is said that an O / W type emulsion is formed by the complex action of each of these components.

In such creamy dairy products, it is desirable in terms of quality that the emulsion is maintained as stable as possible, that the cream retains well, and that it has an appropriate viscosity according to the purpose. . Furthermore, in coffee whiteners, so-called feathering (a phenomenon in which a feather-like coagulated material floats on the coffee liquid surface) that may occur when added to coffee and the formation of an oil film on the surface are desired as much as possible.

In order to impart or improve such quality, an emulsion stabilizer has been conventionally added to these creamy milk products. And, as such an emulsion stabilizer, a safe one is desired because the addition target is a food, and from this viewpoint, glycerin fatty acid ester, sucrose fatty acid ester, propylene glycol fatty acid ester, sorbitan fatty acid ester, etc. So-called polyhydric alcohol fatty acid ester type surfactants, lecithin, etc. are widely used (Japanese Patent Publication No. 55-43739, Japanese Patent Publication No. 51-6161, Japanese Patent Publication No. 54-39459, Japanese Patent Publication No. 51-9823, Japanese Patent Publication No. 9823). 55-42617
No. 58-44347, 59-41689, 59-55
-34052, JP-A-56-42546, JP-B-58-26309, etc.).

(C) Problems to be Solved by the Invention However, although the above-mentioned surfactants such as polyhydric alcohol fatty acid ester are recognized as food additives, they are chemical synthetic products themselves, and thus they are anxious in terms of toxicity. Is what remains. Further, these surfactants are not always satisfactory in terms of cost and quality improvement effect.

The present invention has been made under such circumstances, in particular, a new creamy dairy processed product which can be replaced by a surfactant such as a polyhydric alcohol fatty acid ester which has been widely used conventionally, is safe and inexpensive, and has an excellent quality improving effect. It is intended to provide an additive for use.

(D) Means for Solving the Problems From the above viewpoints, the present inventors have conducted various researches and studies, and as a result, have made alkaline decomposition treatment essential, and added acid, enzyme,
The specific protein partial hydrolyzate obtained by the sequential multi-step decomposition treatment in combination with the decomposition treatment with an oxidizing agent or a reducing agent is (i) a novel substance whose properties and the like are completely different from those of a normal protein partial hydrolyzate. (Ii) It has been found that the quality improvement effect of the creamy dairy processed product is superior to the above-mentioned conventional surfactants, simple alkali decomposed products, enzymatic decomposed products, oxidative decomposed products and the like.

Thus, according to the present invention, a grain protein partially decomposed product having the following physical properties: (a) weight average molecular weight (by gel filtration method) of 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. Yes, (d) pH buffering property (the pH of 100 ml of a 5 wt% aqueous solution of this product is 6%
To require 2 to 25 ml of 1N-hydrochloric acid to reduce to 2), (e) Soluble in water and insoluble in methanol, ethanol, acetone, ether, (f) Appearance is pale yellow It is a nice reddish brown powder. (G) Color develops by xanthoprotein reaction and ninhydrin reaction. (H) Strong surface tension lowering ability (By adding 0.1% by weight of this product to pure water at 25 ° C, The surface tension of pure water is 50 dyne / c
m or less (measured with Dunui's surface tensiometer)
(I) Strong emulsifying ability (completely emulsifying 100 g of a water-soybean oil mixture containing at least 30% by weight of soybean oil by the use of 1 g of this product (a uniform emulsified state for at least 10 minutes, preferably 1 hour). There is provided a quality improver for creamy dairy products, which comprises a substance characterized by:

The protein partial hydrolyzate specified above is a novel substance that has not been described in the literature prior to the filing of the present application, and in particular, the grain protein portion which has been conventionally known in terms of the surface tension lowering ability (h) and the emulsifying ability (i). Distinguished products are distinguished.

The quality improving agent of the present invention is used by adding it during the production of a creamy dairy processed product, and exhibits various quality improving effects by adding a necessary amount.

For example, fresh cream and milk obtained from milk,
Milk processed products mainly composed of milk solid components such as skimmed milk, fats and oils and water are used as they are as coffee whiteners, and they can be used as whipped cream by stirring them and allowing air to be included. However, it is possible to easily provide a coffee whitener in which the feathering phenomenon and the occurrence of a fat and oil film on the surface are suppressed by adding the former to the coffee whitener. In the latter case, a foam (whipped), which is stable and has excellent shape retention, can be easily provided. Further, ice cream also exhibits various quality improving effects such as stabilization of shape retention.

All of these various effects are superior to conventional general-purpose surfactants and normal grain protein partially decomposed products.

The creamy milk processed product to be the subject of the present invention is typically the above-mentioned coffee whitener, whipped cream, ice cream or the like, but in addition to this, at least a milk solid component, fats and oils and water are essential constituent components. The liquid and foam foods are as follows.

In the present invention, the grain protein means a protein contained in grains, where grains include wheat (eg wheat),
Examples include corn and beans (eg, soybean). Of the proteins contained in such grains, for example, wheat protein contains glutenin and gliadin as main components,
Usually called wheat gluten. Further, corn protein contains zein as a main component and is usually called corn gluten. These are all known substances, and can be obtained by separating or extracting from grains by a conventional method. For example, when obtaining wheat protein (wheat gluten), a small amount of water is added to wheat flour and kneaded firmly, and then this is kneaded in a large amount of water, the starch is suspended in the water, and the gluten-containing component becomes a sticky mass. Remain. If this operation is repeated several times while changing water, a grayish brown viscous mass can be obtained. For the preparation of the partially degraded product of this invention,
Although such a lump can be used as it is,
The dried product may be used, or a further purified product or a partially modified product may be used. For example, wheat gluten is commercially available as a dried product and can be easily obtained. In addition, commercially available corn gluten and soybean protein can be easily used.

Although such a protein may be a crude product or a purified product, it is preferable to use a protein containing 70% or more of the protein.

The partially decomposed product of the present invention is obtained by subjecting a grain protein to a multistage decomposition treatment in which hydrolysis treatment with an alkali and decomposition treatment with an acid, an enzyme, an oxidizing agent or a reducing agent are combined. That is, it can be obtained by combining the alkali decomposition treatment and the other decomposition treatments.

The above-mentioned hydrolysis treatment with alkali is suitably performed by heating in a dilute aqueous alkali solution. Usually, an aqueous solution or aqueous dispersion of a substance to be hydrolyzed is added in the presence of an alkali agent such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate to about 60 to 180.
It is suitable to perform the stirring under a temperature of about 10 to 600 minutes. Here, the aqueous solution or dispersion of the hydrolysis target is 2 to 40
It is preferable to use one by weight, and the amount of the alkaline agent used is preferably 0.1 to 6 g based on 20 g of the substance to be hydrolyzed.

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. Generally, it is suitable to stir an aqueous solution or aqueous dispersion of the decomposition target in the presence of an inorganic acid such as hydrochloric acid or sulfuric acid or an organic acid such as acetic acid at about 60 to 120 ° C for about 10 to 600 minutes. . Here, the quantitative conditions are preferably the same as the above-mentioned conditions for the alkaline hydrolysis.

Similarly, it is suitable to perform the decomposition treatment with an enzyme in a dilute aqueous solution of an enzyme having a protease activity. Usually, a small amount of an enzyme such as pepsin, alkaline protease, papain is present in an aqueous solution or aqueous dispersion of the decomposition target. In this state, it is carried out under the optimum pH condition of this enzyme at about 10 to 60 ° C for 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 performed 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 treated with a sulfite, a thiol compound, or erythorbic acid. , A reducing agent such as hydrazine or a small amount of hydrogen peroxide or an oxidizing agent such as hypochlorite is present at about 10 to 100 ° C. for 10 to 600 minutes. 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 alkaline hydrolysis treatment (A), and then decomposed using the above-mentioned acid, enzyme, reducing agent and oxidizing agent (B) (decomposition treatment other than alkali)
Any one of them or two or more thereof may be subjected to the treatment, or the decomposition treatment may be performed in the reverse order. 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 the present invention, a more excellent effect is recognized when the weight average molecular weight is in the range of 500 to 80,000. These molecular weights are
It can be appropriately controlled by adjusting the conditions of the partial decomposition treatment described above.

The molecular weight of these substances is 1600,6500,16 as a standard substance.
It is a value measured by a gel filtration method using sodium polystyrene sulfonate having a molecular weight of 000,65,000,88000 and Sephadex G-75 or G-100 manufactured by Falmachine Co., Ltd. as a carrier.

The partial hydrolyzate of the protein thus obtained can be used as it is in the form of an aqueous solution after decomposition as it is as a quality improving agent for a creamy dairy processed product, but can also be used as a powder after drying. Further, for example, a purified product obtained by desalting treatment such as ultrafiltration or decolorization treatment can be favorably used.

The quality improving agent of the present invention may be added directly to a commercially available fresh cream and used, or may be added and used in the process of producing a creamy product. For example, oil and fat are mixed with water, skim milk or dried products thereof in water, and if necessary, an additive such as casein is added to prepare a creamy product, which is added to any process or raw material to be used. be able to.
The amount added at this time is based on the milk product material (total solid content)
Suitable is 0.02 to 5% by weight, 0.1 to 2% by weight
Is preferred. Here, if the addition amount is less than 0.02% by weight, the quality improving effect is insufficient, and if it exceeds 5% by weight, the effect commensurate with the increase in the addition amount cannot be obtained, which is not suitable.

The quality improving agent of the present invention may contain other quality improving components in addition to the above-mentioned partially decomposed protein products. In particular, it is a preferred embodiment to use in combination with a polyhydric alcohol fatty acid ester type surfactant such as sucrose fatty acid ester or glycerin fatty acid ester. At this time, the mixing ratio of the partially decomposed protein and the surfactant is 1: 6 to 6: 1 (weight ratio).
((Preferably 1: 4 to 4: 1) is more preferable because a synergistic quality improving effect can be obtained.

Further, a commonly used preservative such as ethanol, propionic acid, lactic acid, sorbic acid, dehydroacetic acid, and sodium salt may be used in combination, and this is also one preferable mode of use.

(E) Examples The present invention will be described in detail with reference to Examples and Test Examples.

Examples 1 to 10 (Preparation of Degradation Products by Partial Decomposition of Wheat Gluten with Acid and Subsequent Partial Decomposition with Alkali) Hydrochloric acid aqueous solution equivalent to 0.5 g, 1 g, 2 g and 4 g in terms of hydrogen chloride
20 g of wheat gluten (reagent product) manufactured by Wako Pure Chemical Industries, Ltd. was added to each flask containing 100 g, and the mixture was heated and stirred at 80 ° C. and 100 ° C. for 60 minutes. Then, the total amount of pure water to neutralize with caustic soda to 200g, to prepare a 10% aqueous solution of the partial decomposition product of wheat gluten acid, 100g of each put into a flask or 10 autoclaves, caustic soda or sodium carbonate 0.5 Add an amount in the range of ~ 2g each, 80
The mixture was heated and stirred at 30 ° C to 150 ° C for 30 minutes to 360 minutes. Then, the mixture was neutralized with hydrochloric acid and the total amount was 200 g with pure water to obtain invention products No. 1 to 10 which were partially decomposed products of the present invention.

Table 1 shows the decomposition conditions and the average molecular weight of the decomposition products.

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

Examples 11 to 14 (Preparation of corn gluten and soybean protein by partial decomposition with acid and subsequent partial decomposition with alkali carried out) Preparation of corn gluten manufactured by Nippon Shokuhin Kako Co., Ltd. as raw material and under the same conditions as in Examples 6 and 1. Inventive products Nos. 11 and 12 were obtained by sequentially carrying out partial decomposition with acid and alkali. The average molecular weights were 11800 and 27100, respectively.

In addition, the soybean protein obtained by defatting commercially available yuba with acetone was used as a raw material, and the partial decomposition was sequentially carried out using an acid and an alkali under the same conditions as in Examples 6 and 1 to obtain invention products No. 13 and 14. .

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

Examples 15 and 16 (Preparation of Decomposition Products by Partial Decomposition of Wheat Gluten with Alkali and Partial Decomposition with Acid Performed Then) Examples 1 to 1 were added to 100 g of an aqueous solution in which 2 g or 4 g of caustic soda was dissolved.
After adding 20 g of wheat gluten used in 10 and stirring at 100 ° C. for 60 minutes, the mixture was neutralized with hydrochloric acid, and a 10% aqueous solution of partially decomposed product of wheat gluten with alkali was prepared in a total amount of 200 g with pure water. Hydrochloric acid corresponding to 0.5 g and 1 g in terms of hydrogen chloride was separately added to 100 g of the mixture, and the mixture was heated with stirring at 100 ° C. for 60 minutes. After that, neutralize with caustic soda and make a total amount of 200 g with pure water.
I got o.15,16. Table 2 shows the decomposition conditions and the average molecular weight of the decomposed products.

Example 17 (Preparation of Degradation Products by Partial Decomposition of Wheat Gluten by Enzyme and Subsequent Partial Decomposition by Alkali) 20 g of wheat gluten used in Examples 1 to 10 was dissolved in 0.1N hydrochloric acid solution 1
It was added to a flask containing 50 g to obtain a pH 1.5 aqueous solution. 0.2 g of pepsin was added to this, and it was made to react at 37 degreeC for 90 minutes. After that, neutralize with caustic soda and make the total amount to 200 g with pure water to prepare a 10% aqueous solution of the partial decomposition product of wheat gluten by the enzyme,
1 g of caustic soda was added to 100 g of the mixture, and the mixture was heated and stirred in the flask for 60 minutes. After that, the product was neutralized with hydrochloric acid to obtain 200 g of pure water to obtain Inventive Product No. 17.

The average molecular weight was 29,000.

Example 18 (Preparation of Decomposition Product by Partial Decomposition of Wheat Gluten with Reducing Agent and Subsequent Partial Decomposition with Alkali) Examples 1 to 1 were added to 100 g of an aqueous solution containing 4 g of sodium sulfite.
20 g of wheat gluten used in 10 was added, and after stirring for 60 minutes at 30 ° C., a total amount of 200 g was prepared with pure water to prepare a 10% aqueous solution of a partial decomposition product of the reducing agent of wheat gluten, and 1 g of caustic soda was added to 100 g of the solution. In addition, the mixture was heated and stirred in a flask at 100 ° C for 60 minutes. Then, a total amount of 200 g was obtained with pure water neutralized with hydrochloric acid to obtain Invention Product No. 18. The average molecular weight was 39500. Example 19 (Preparation of Degradation Product by Partial Decomposition of Wheat Gluten with Alkali and Partial Decomposition with Enzyme Performed Next (Sequential Reverse of Example 17)) Used in Examples 1 to 10 in 100 g of an aqueous solution in which 2 g of caustic soda was dissolved. After adding 20 g of wheat gluten and heating and stirring at 100 ° C. for 60 minutes, the mixture was neutralized with hydrochloric acid to make a total amount of 200 g with pure water to prepare a 10% aqueous solution of partially decomposed product of wheat gluten with alkali,
The reagent hydrochloric acid was added to 100 g of the solution to obtain an aqueous solution having a pH of 1.5, and 0.1 g of pepsin was added to the solution in the flask and reacted at 37 ° C. for 90 minutes. After this, neutralize with caustic soda and add a total of 20
Inventive product No. 19 having 0 g was obtained.

The average molecular weight was 24500.

Example 20 (Preparation of Decomposition Product by Partial Decomposition of Wheat Gluten with Alkali and Partial Decomposition with Oxidizing Agent Performed Next) To 100 g of an aqueous solution in which 2 g of caustic soda was dissolved, 20 g of wheat gluten used in Examples 1 to 10 was added, and 100 ° C was added. After heating and stirring for 60 minutes, neutralize with hydrochloric acid, make a total amount of 200 g with pure water to prepare a 10% aqueous solution of partially decomposed wheat gluten with alkali,
Hydrogen peroxide corresponding to 0.5 g in terms of H ₂ O ₂ was added to 100 g of the mixture, and the mixture was heated and stirred at 40 ° C. for 60 minutes. Then remains
Add H ₂ O ₂ and an equivalent amount of sodium thiosulfate, and add 20
Inventive product 20 was obtained with 0 g.

The average molecular weight was 37,000.

Various physical properties and particle dispersing action of the partially decomposed protein of the present invention obtained in Examples 1 to 20 are shown in Table 3 below, and the results of measuring surface tension and emulsion duration are shown in Table 4.

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.
Sephadex G-75 manufactured by Pharmacia Co., Ltd. using sodium polystyrene sulfonate having a molecular weight of 000,88,000.
Alternatively, it is a value measured by a gel filtration method using G-100 as a carrier.

[Isoelectric point]

Each of the invention products 1 to 20 obtained in the examples of the present invention was placed in a beaker.
100 g of each was taken, 1N-HCl was added in 1 ml portions with stirring at room temperature, and the pH was measured. The pH value at which the slope of the obtained pH curve becomes gentle was taken as the isoelectric point.

(Buffer capacity) From the pH curve obtained in the same manner as the isoelectric point measuring method,
The buffering capacity was defined as the amount of 1N hydrochloric acid required to reduce the value from 6 to 2. Incidentally, the pH neutralization curve at this time, invention product No. 1, No.
7, No. 11 and No. 13 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) ・ A total of 25 invention products and tap water in National MI type mixer
Add 0 g and add 250 g of calcium carbonate (light calcium carbonate manufactured by Takehara Chemical Industry Co., Ltd.) and mix for 2 minutes to prepare a 50 wt% slurry. Immediately thereafter, the slurry is transferred to a beaker, and the viscosity (cps) is measured with a DVH-B type viscometer manufactured by Tokyo Keiki Co., Ltd. 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 invention is 0.3 with respect to the total amount of 500 g.
% By weight.

(Kaolin slurry) -In a National MI type mixer, 200 g of the partially decomposed product of the present invention and tap water are added, and 300 g of kaolin [manufactured by Tsuchiya Kaolin Industry Co., Ltd.] powder is added and mixed for 2 minutes to prepare a 60 wt% slurry. To do. 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,
Viscosity is measured with rotor Nos. 3-5. 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.

The methods for measuring the surface tension and the duration of emulsification are as follows.

[Measurement of Surface Tension] The surface tension of the invention products prepared in the examples was measured at a temperature of 25 ° C. using pure water as a solvent with a surface tension meter manufactured by Dunui.

[Measurement of emulsification duration] The emulsification duration of the invention products prepared in the examples was measured by the following test method.

《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 left at room temperature, and the time until the start of separation is defined as the emulsification duration 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.

Comparative Example 1 (Preparation of Wheat Gluten) The wheat gluten used in Examples 1 to 10 was used as a comparative product No. 1 without being decomposed.

Comparative Example 2 (Preparation of partially decomposed product of wheat gluten with alkali) 20 g of wheat gluten used in Examples 1 to 10 was added to 100 g of an aqueous solution in which 2 g of caustic soda was dissolved, and the mixture was heated with stirring at 100 ° C. for 60 minutes and then neutralized with hydrochloric acid. Comparative product No. 2 was obtained with pure water in a total amount of 200 g.

The average molecular weight was 47,000.

Comparative Example 3 (Preparation of partially decomposed product of wheat gluten by acid) 20 g of wheat gluten (reagent product) manufactured by Wako Pure Chemical Industries, Ltd. was added to a flask containing 100 g of hydrochloric acid aqueous solution corresponding to 4 g in terms of hydrogen chloride, The mixture was heated and stirred at 100 ° C for 60 minutes. afterwards,
Comparative product No. 3 neutralized with caustic soda and made up to 200 g with pure water
Got The average molecular weight of the partial hydrolyzate was 47,000.

Comparative Example 4 (Preparation of partially decomposed product of wheat gluten by enzyme) 20 g of wheat gluten used in Examples 1 to 10 was dissolved in 0.1N hydrochloric acid solution 1
It was added to a flask containing 50 g to obtain a pH 1.5 aqueous solution. 0.2 g of pepsin was added to this, and it was made to react at 37 degreeC for 90 minutes. Then, neutralize with caustic soda and use pure water for a total amount of 200 g.
got o.4. The average molecular weight of the partially decomposed product was 60,000.

Inventive products No. 1 to 20 of the embodiment of the present invention, Comparative product N of the comparative example
o.1 to 4 and sucrose fatty acid ester which is a known quality improving agent [Daiichi Kogyo Seiyaku Co., Ltd., trade name: DK ester F
-160 (HLB15), Comparative product No. 5] Palmitic acid monoglyceride [manufactured by Taiyo Kagaku Co., Ltd., trade name: Sunsoft No. 800]
The following test examples were carried out for the comparative product No. 6].

Test Example 1 (Quality improvement effect of coffee whitener) 1 to 3 g of each test sample and 30 g of skim milk powder (Skim milk manufactured by Snow Brand Milk Products Co., Ltd.) were dispersed or dissolved in warm water at 65 ° C to obtain a total amount of 700.
Solution A was prepared as g. Separately, 0.1 g of palmitic acid monoglyceride (Sunsoft No. 8001: Taiyo Kagaku Co., Ltd.) was dissolved in 700 g of soybean hydrogenated oil at 70 ° C (increasing melting point 36 ° C) to the above A
The solution was gradually added with stirring, and the mixture was stirred at 70 ° C for 10 minutes. Then, it homogenized at 50 kg / cm ² using a high pressure homogenizer to obtain a coffee whitener.

The quality of this coffee whitener was tested in the following manner.

<Test method> 13g of roasted coffee beans "Brazil" was weighed and hot water 85
The coffee liquor extracted at 100 ℃ was kept warm at 80 ℃, 100 ml of the above coffee whitener was added, and after stirring, there was feathering (a phenomenon in which a feather-like coagulated substance floats on the coffee liquor) (+) With (±) without (−) and time until film formation were measured.

[Test Results] As a result of performing the above tests on the invention products Nos. 1 to 20 prepared by the respective examples as test samples, the feathering phenomenon did not occur and it took 10 minutes or more to form the film. The test results of the representative examples are shown in Table 5 together with the comparative examples.

Table 6 shows the results of the combined use of the partially decomposed product of Inventive Product No. 7 and sucrose fatty acid ester (Comparative Example No. 5).

It can be seen that the feathering phenomenon and the film formation phenomenon are remarkably suppressed by using the invention product as described above. It is also found that such effects are synergistically increased by the combined use with sucrose fatty acid ester.

Test Example 2 (Effect of improving quality of whipped cream) 45 parts of soybean hydrogenated oil (increasing melting point 36 ° C.) and 65 parts of raw milk to which each sample was added were stirred with a homomixer at a temperature of 70 ° C. for 15 minutes. After that, the mixture was homogenized at 80 kg / cm ² using a homogenizer and the emulsified state was observed. Then, it was sterilized by heating at 70 ° C for 10 minutes and then rapidly cooled to 10 ° C. A creamy fat composition was obtained by aging for 12 hours in a refrigerator at 5 ° C. This creamy composition was stirred with an electric hand whipper at a speed of 600 rpm to obtain a whipped cream. The quality of this whipped cream was evaluated by conducting tests on the following items.

<Evaluation item and method> (1) Viscosity: Rion BO-2 type viscometer is used (2) Overrun: Increased volume ratio when the optimum foaming state calculated by the following formula is reached (3) Foaming time: 600 with electric hand whipper
Time to reach the optimum foaming state when foaming 500 ml of cream-like composition at the speed of rotation (4) Width of foaming end point: optimum foaming when foaming in the same manner as above Time to maintain state.

(5) Shape retention, texture: A ... good, AB ... some good, B ...
… Evil, not practical.

[Test Results] The above-mentioned tests were conducted on the invention products No. 1 to 20 prepared by the respective examples as the test products. A representative example is shown in Table 7 together with a comparative example. The table also shows the results of the combined use of the invention product No. 7 and the sucrose fatty acid ester (comparative product No. 5).

As described above, it is understood that the whipped cream excellent in shape retention can be easily produced by using the invention product.

(F) Effect of the invention The quality improving agent of the present invention has an excellent quality improving effect on various creamy dairy products. Since the partially decomposed product of grain protein as an active ingredient is a food or a food-like product, it is extremely advantageous in that it is not toxic, has improved safety as a food additive, and is inexpensive.

Therefore, the stabilizer of the present invention is extremely useful as an additive for emulsified oily foods.

[Brief description of drawings]

FIGS. 1 (a) to 1 (d) are graphs separately illustrating pH neutralization curves for the partial hydrolyzate used in the present invention.

Claims (9)

[Claims] 1. A partially degraded product of grain protein, which has the following physical properties: (a) a weight average molecular weight (by gel filtration method) of 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. Yes, (d) pH buffering property (the pH of 100 ml of a 5 wt% aqueous solution of this product is 6%
To require 2 to 25 ml of 1N-hydrochloric acid to reduce to 2), (e) Soluble in water and insoluble in methanol, ethanol, acetone, ether, (f) Appearance is pale yellow It is a nice reddish brown powder. (G) Color develops by xanthoprotein reaction and ninhydrin reaction. (H) Strong surface tension lowering ability (By adding 0.1% by weight of this product to pure water at 25 ° C, The surface tension of pure water is 50 dyne / c
m or less (measured with Dunui's surface tensiometer)
(I) Strong emulsifying ability (completely emulsifying 100 g of a water-soybean oil mixture containing at least 30% by weight of soybean oil by the use of 1 g of this product (a uniform emulsified state for at least 10 minutes, preferably 1 hour). A creamy dairy product quality improver comprising a substance characterized by: 2. The partially decomposed product is a combination of (A) an alkali hydrolysis treatment of grain protein and (B) one or more decomposition treatments using an acid, an enzyme, an oxidizing agent or a reducing agent. The quality improving agent according to claim 1, which is a substance obtained by subjecting to a multistage partial decomposition treatment by combination. 3. The quality improving agent according to claim 2, wherein the partially decomposed product is obtained by a two-step partial decomposition treatment by a combination of a hydrolysis treatment with an alkali and a hydrolysis treatment with an acid. . 4. The quality improver according to claim 1, wherein the grain is wheat gluten, corn gluten, or soybean protein. 5. The quality improving agent according to any one of claims 1 to 4, wherein the creamy dairy product is coffee whitener, whipped cream or ice cream. 6. The quality improving agent according to claim 1, which further comprises a polyhydric alcohol fatty acid ester type surfactant. 7. The quality improving agent according to claim 6, wherein the protein partial degradation product and the polyhydric alcohol fatty acid ester type surfactant are mixed in a weight ratio of 1: 6 to 6: 1. 8. The quality improving agent according to claim 7, wherein the polyhydric alcohol fatty acid ester type surfactant is sucrose fatty acid ester and / or glycerin fatty acid ester. 9. From 0.02 to the creamy dairy product material
The quality improver according to claim 1, which is used by adding 5% by weight.