JP6765753B2 - Method for producing carboxymethylated starch with suppressed swelling - Google Patents

Description

The present invention relates to a method for producing carboxymethylated starch in which swelling is suppressed.

Carboxymethylated starch is a modified starch in which the hydroxyl groups of amylose and amylopectin constituting the starch are replaced with carboxymethyl groups. For example, it can be obtained by adding sodium monochloroacetate to a starch slurry adjusted to pH 10 with sodium hydroxide and reacting. Carboxymethylated starch is widely used as a disintegrant for direct tableting in pharmaceutical applications because of its good grain fluidity, and is also used as a thickener and emulsion stabilizer in food and beverage and cosmetic applications. .. Furthermore, it is also used in industrial applications such as textile printing glue and papermaking. However, there is room for further improvement in physical properties such as thickening of ordinary carboxymethylated starch.

Conventionally, various processing treatments for improving the physical properties of starch have been known, and one of them is a treatment for suppressing swelling of starch, and the physical properties of starch can be significantly modified. That is, since the starch granules can be strengthened by the swelling suppressing treatment, the thickening effect of the starch paste can be strengthened by applying a low degree of swelling suppressing treatment, and the viscosity stability is obtained by applying a high degree of swelling suppressing treatment. A high starch paste solution can be obtained. As a swelling suppressing treatment, a method of introducing a crosslinked structure into starch is known, and crosslinked starch having an adipic acid crosslinked or a phosphoric acid crosslinked is widely used mainly in the food field (Non-Patent Document 1). ..

Therefore, although attempts to use such a method can be considered, carboxymethylated starch (sodium starch glycolate) having adipic acid cross-linking or phosphate cross-linking introduced is not recognized as a food additive under the provisions of the Food Sanitation Law. Therefore, there was a big problem that it could not be used for food. In addition, since the above-mentioned cross-linking treatment uses various chemicals, there are problems in terms of manufacturing cost and environmental load.

On the other hand, the physical processing process of heating starch under acidic conditions is commonly used for the purpose of decomposing and reducing the molecular weight of starch. Since the starch is reduced in molecular weight by the above treatment, the viscosity of the paste solution is lowered. Is known (Non-Patent Document 2, Patent Document 1).

Encyclopedia of starch science, published by Asakura Shoten Co., Ltd., March 2003, p. 403-406 Encyclopedia of starch science, published by Asakura Shoten Co., Ltd., March 2003, p. 410

JP 2011-130696

An object of the present invention is to improve the physical properties of carboxymethylated starch by a simpler physical processing process that does not involve the introduction of functional groups.

As a result of intensive studies to solve the above problems, the present inventors have unexpectedly performed a process of suppressing swelling of starch by adjusting the pH of carboxymethylated starch and heat-treating it. , It was found that it leads to the improvement of the physical properties, and the present invention was completed.

That is, the first aspect of the present invention provides a method for producing swelling-suppressing carboxymethylated starch, which comprises adjusting the raw material carboxymethylated starch to pH 8 or less and heat-treating it.

In the method for producing swelling-suppressing carboxymethylated starch, it is preferable that the heat treatment is performed under dry conditions of 30 to 200 ° C.

Further, it is preferable that the heat treatment is carried out under wet conditions at 25 ° C. or higher and at a temperature lower than the gelatinization temperature of the carboxymethylated starch as a raw material.

Further, it is preferable to add an acid to the carboxymethylated starch to adjust the pH to 8 or less. In this case, the acid preferably contains, for example, one or more acids selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, citric acid, lactic acid, and phosphoric acid.

Further, it is preferable to obtain a carboxymethylated starch whose swelling is suppressed so as to be 0.7 times or less as a relative value with respect to the degree of heat swelling of the carboxymethylated starch which is the raw material.

A second aspect of the present invention is the production of a food product, wherein the swelling-suppressing carboxymethylated starch obtained by the production method of the first aspect is contained in the food product in an amount of 0.1 to 10% by mass. It provides a method. In this case, for example, a method for producing a food selected from bakery foods, food sauces, food pastes, and frozen desserts is preferable.

A third aspect of the present invention provides a method for improving the texture of foods, which comprises adding the swelling-suppressing carboxymethylated starch obtained by the production method of the first aspect described above.

According to the present invention, swelling can be suppressed by a very simple method of adjusting the pH of carboxymethylated starch and heating it, so that the environmental load is less than that of a normal cross-linking treatment, and the cost is simple and low. It is possible to obtain carboxymethylated starch in which swelling is suppressed, and it can be advantageously used in pharmaceutical applications, cosmetic applications, and industrial applications such as textiles and papermaking. Further, since the starch is a carboxymethylated starch that has been subjected to a physical processing treatment (acid treatment), it can be added to food as a food additive.

It is a chart which shows the RVA analysis result of the starch sample of Comparative Example 2 and Example 2. FIG. It is a chart which shows the RVA analysis result of the starch sample of Comparative Example 3 and Example 5.

The present invention provides a method for producing swelling-suppressing carboxymethylated starch, which comprises adjusting the pH of carboxymethylated starch as a raw material to 8 or less and heat-treating it. It is generally known that when an acid is added to starch and heat-treated, the starch is hydrolyzed by the acid, the molecular weight is lowered, and the viscosity of the paste solution is lowered. However, in carboxymethylated starch, the addition of an acid or the like causes When the pH was adjusted to 8 or less and heat-treated, it was surprisingly found that a process for suppressing swelling of starch was performed, and for example, a remarkable thickening effect was exhibited depending on the degree of swelling suppression. The mechanism is unknown, but it is presumed that the carboxyl groups are intramolecularly associated to form a rigid structure on the surface of the starch particles.

As used herein, carboxymethylated starch means modified starch in which the hydroxyl groups in the starch are replaced with carboxymethyl groups. There is no particular limitation on the metal or salt coordinated to starch, and sodium, calcium, potassium and the like can be used, but sodium is coordinated in that it can be suitably used for foods ( Sodium starch glycolate) is preferably used.

As the carboxymethylated starch used in the production method of the present invention, commercially available starch may be used, but the starch is carboxymethyled by a conventionally known method such as adding sodium monochloroacetate to a starch suspension under alkaline conditions. It can also be obtained by making it. More specifically, for example, to a starch suspension adjusted to pH 9 to 13 by adding an acid agent such as hydrochloric acid or an alkaline agent such as sodium hydroxide, 0.1 to 100 parts by mass of the dry mass of the starch. It can be obtained by adding 50 parts by mass of sodium monochloroacetate and holding and stirring at 10 to 60 ° C. for 1 to 48 hours. The type and origin of the starch as a raw material are not particularly limited, and any starch generally used for foods, pharmaceuticals, cosmetics, industrial products, etc. may be used. Examples thereof include corn starch, tapioca, rice starch, wheat starch, horse belly starch, sweet potato starch, green bean starch, potato starch, kudzu starch, sardine starch, sago starch, pea starch, and Oobayuri starch. Of these, tapioca, cornstarch, rice starch, and potato starch are particularly preferable because they are inexpensive and easily available in large quantities. Further, in any starch, in addition to ordinary starch, those improved by breeding method or genetic engineering method such as Uruchi species, Waxy species, and Hyamylose species may be used. Commercially available starches can be used.

In order to adjust the pH of the carboxymethylated starch to 8 or less, the pH environment in contact with the carboxymethylated starch as a raw material may be adjusted to pH 8 or less, and more preferably to pH 7 or less. In a pH environment higher than pH 8, the effect of performing the swelling suppressing treatment becomes poor, which is not preferable. The means is not particularly limited, but can be typically carried out by adding an acid or the like. The acid may be any acid such as an inorganic acid or an organic acid, and two or more kinds may be used in combination. In addition. In order to use the obtained swelling-suppressing carboxymethylated starch in foods, it is preferable to use an acid recognized as a food additive. Examples of such an acid include hydrochloric acid, sulfuric acid, nitric acid, acetic acid, citric acid, lactic acid, phosphoric acid and the like. Of these, hydrochloric acid is preferable from the viewpoint of the amount of addition, odor, coloring and the like.

The mode of heat treatment is not particularly limited, and heat energy may be applied to the carboxymethylated starch as a raw material. The heat treatment may be performed under dry conditions or wet conditions. Here, the dry condition means that the heat treatment is performed with a water content of less than 25% by mass, and in the present specification, it may be referred to as a dry reaction. Further, the wet condition means that a cake or slurry having a water content of 25% by mass or more is prepared and heat-treated, and may be referred to as a wet reaction in the present specification.

The heat treatment can be performed under dry conditions of, for example, 30 to 200 ° C. The temperature condition at the time of the dry reaction is more preferably 50 to 180 ° C. Further, the pH environment at the time of the dry reaction is more preferably pH 0.5 to 7.5. Compared with the wet reaction, the dry reaction can be heat-treated at a high temperature without worrying about gelatinization of starch, and the reaction can proceed efficiently because the water content is small. Therefore, it is suitable for performing the swelling suppressing treatment in a short time, and also suitable for performing a strong swelling suppressing treatment.

As another mode, the heat treatment may be carried out under wet conditions of, for example, 25 ° C. or higher and a temperature lower than the gelatinization temperature of the raw material carboxymethylated starch (temperature not reaching the gelatinization temperature). .. That is, in the case of a wet reaction, from the viewpoint of workability, it is preferable to carry out the reaction under conditions below the gelatinization temperature of the raw material carboxymethylated starch (conditions under which the gelatinization temperature is not reached). The gelatinization temperature varies depending on the origin of the source starch and the degree of introduction (substitution) of the carboxymethyl group. For example, observe the carboxymethylated starch as a raw material with a microscope and measure the temperature at which the polarized cross of the starch granules disappears. Etc., it can be determined as appropriate. The temperature condition at the time of the wet reaction is more preferably 25 to 55 ° C. Further, the pH environment at the time of the wet reaction is more preferably 2.5 or less. In the wet reaction, the swelling suppression is slower than that in the dry reaction, and it is easy to control the desired degree of swelling suppression.

In the production method of the present invention, the timing of the heat treatment described above and the pH adjustment (or addition of acid) described above is not particularly limited. For example, the heat treatment may be performed after the desired acid has been added to the carboxymethylated starch, or the heat treatment may be performed at the same time while adding the desired acid of the carboxymethylated starch.

In the production method of the present invention, the lower the pH during the heat treatment, the stronger the swelling suppression treatment, the higher the heating temperature, the stronger the swelling suppression treatment, and the longer the heating time, the stronger the swelling suppression treatment. Can be processed. That is, carboxymethylated starch having a desired degree of suppression of swelling can be obtained by appropriately adjusting the three elements of pH, heating temperature and heating time.

In the production method of the present invention, it is preferable to obtain carboxymethylated starch whose swelling is suppressed so as to be 0.7 times or less as a relative value with respect to the degree of heat swelling of the carboxymethylated starch as a raw material. From the viewpoint of its effect, the heat swelling degree is suppressed so that the relative value is 0.2 or more and 0.7 times or less with respect to the heat swelling degree of the raw material carboxymethylated starch. It is preferable that the swelling is suppressed so that the relative value is 0.2 or more and 0.5 times or less.

The degree of heat swelling can be measured by, for example, the following method.

Weigh 0.1 g (solid content equivalent) of a starch sample adjusted to pH 8 into a 15 mL conical tube, and add a 2% (w / w) ammonium sulfate aqueous solution to a total volume of 10 g. Heat in a boiling water bath for 5 minutes and cool in running water for 5 minutes. After cooling, the mixture is centrifuged at 2,060 × g for 15 minutes with a centrifuge, and the volume of the precipitated starch paste layer (sedimented product, mL) is defined as the degree of heat swelling.

The degree of heat swelling of carboxymethylated starch that is not suppressed in swelling varies depending on the origin of the source starch and the degree of introduction (substitution) of carboxymethyl groups, but the degree of swelling suppression obtained by the production method of the present invention. In the carboxymethylated starch, the degree of suppression of swelling is objectively defined as the relative value. In general, carboxymethylated starch is easily heated and swells, and the degree of heat swelling cannot be measured in pure water. However, the above measurement conditions are conditions in which starch is difficult to swell, and the degree of heat swelling is measured under these conditions. By doing so, it is possible to appropriately measure the degree of suppression of swelling even in carboxymethylated starch that easily swells by heating. The swelling-suppressing carboxymethylated starch provided by the production method of the present invention typically has an absolute value (precipitation volume, mL) of the degree of heat swelling measured under the above measurement conditions of 0.1 or more. It is preferably 5 or less, more preferably 0.2 or more and 4.0 or less, and even more preferably 0.3 or more and 3.5 or less.

In a typical case, the swelling-suppressing carboxymethylated starch obtained by the production method of the present invention retains starch granule particles and is insoluble in cold water. Therefore, the starch may be used as it is for various purposes, or may be used for various purposes after being solubilized in cold water by a pregelatinization treatment or the like.

The swelling-suppressing carboxymethylated starch provided by the production method of the present invention is excellent in the effect of improving the texture of food. Specifically, for example, in bakery foods, it is possible to have both a moist feeling and a melt-in-the-mouth texture, and it is possible to obtain a soft and elastic texture, and in a food source, it is possible to obtain a pleasant texture, which is suitable for foods. In the paste, the texture can be made to melt in the mouth, and in the cold confectionery, the texture can be made smooth and have a good texture in the mouth. In addition, it is possible to improve the flavor release of foods and enhance the flavor.

On the other hand, from another viewpoint of the present invention, it is possible to provide a food containing the swelling-suppressing carboxymethylated starch described above. Foods include, for example, bakery foods, sauces, pastes, frozen desserts, Western confectionery, Japanese confectionery, noodles, fried food clothing, seasonings, processed egg foods, soups, aquatic paste products, jams. Kind and so on. More specifically, since the effect of improving the texture can be more effectively exerted, bread, roll bread, brioche, steamed bread, nan, denish, pie, tart, pancake, chiffon cake, hot cake, sponge cake, castella, and biscuits.・ Bakery foods such as cookies and pastries, food sauces such as pasta sauce, meat sauce, tomato sauce, white sauce, demiglas sauce, curry sauce, hayashi sauce, gravy sauce, hamburger sauce, salsa sauce, steak sauce, flower paste, peanuts Food pastes such as pastes, fruit pastes, chocolate pastes, butter creams, custard creams, ice creams, ice candy, sherbets, shaved ice, frappe, frozen yogurt, jelly, puddings, bavarois, cold confectionery such as sardines, etc. ..

The content of the swelling-suppressing carboxymethylated starch described above in food is not particularly limited, but is typically, for example, 0.1 to 10% by mass, preferably 0.1 to 2% by mass. It is more preferable to do so.

On the other hand, from still another viewpoint of the present invention, it is provided a composition for improving the texture of a food containing swelling-suppressing carboxymethylated starch, or a method for improving the texture of a food containing swelling-suppressing carboxymethylated starch. Can be done. That is, it provides a composition and a method for using the swelling-suppressing carboxymethylated starch described above for improving the texture of foods. The texture-improving composition may contain components other than swelling-suppressing carboxymethylated starch as long as its effect is not impaired. Further, in the texture improving method, components other than swelling-suppressing carboxymethylated starch may be used in combination as long as the effect is not impaired. Examples of other components include flours / starches, thickening polysaccharides, inorganic salts, fats and oils, sugars, emulsifiers, enzymes and the like.

The details of the present invention will be described below with reference to examples, but the technical scope of the present invention is not limited to the following examples. The degree of thermal swelling of each starch sample and the measurement of amylogram were carried out as follows.

(Measurement of heat swelling degree)
0.1 g (solid content equivalent) of each starch sample adjusted to pH 8 was weighed into a 15 mL conical tube, and a 2% (w / w) ammonium sulfate aqueous solution was added up to a total amount of 10 g. It was heated in a boiling water bath for 5 minutes and cooled in running water for 5 minutes. After cooling, the mixture was centrifuged at 2,060 × g for 15 minutes with a centrifuge, and the volume (sedimented product, mL) of the precipitated starch paste layer was taken as the degree of heat swelling.

(Measurement of amylogram)
30 g of a 6 mass% suspension of each starch sample was held in a paddle at 50 ° C. for 1 minute while stirring at a rotation speed of 50 rpm, and a continuous heating state from 50 ° C. to 95 ° C. was maintained in 4 minutes. Rapid Visco Analyzer (manufactured by Perten Instruments) under the condition that 95 ° C. is held for 1 minute and 30 seconds, then a continuous cooling state up to 50 ° C. is given in 4 minutes, and the temperature is kept at 50 ° C. for 2 minutes. Perform RVA analysis by. The maximum viscosity measured in the analysis was taken as the peak viscosity.

<Test 1>
[Comparative Example 1] (Production of raw material carboxymethylated starch)
Water was added to the waxy cornstarch in advance to form a slurry of 30 to 40% by mass. After heating to 45 ° C., 20 parts by mass of sodium sulfate was dissolved in 100 parts by mass of the dry mass of starch. After adjusting the pH to 11 to 12 by adding an alkaline agent consisting of sodium hydroxide, 10 parts by mass of sodium monochloroacetate was added to 100 parts by mass of the dry mass of the starch and reacted for 20 hours. After completion of the reaction, the sample was washed with water, dehydrated and dried to prepare a sample of Comparative Example 1.

[Comparative Example 2] (Production of carboxymethylated starch that only adjusts pH)
Waxy cornstarch was subjected to carboxymethylation treatment in the same manner as in Comparative Example 1, and after completion of the reaction, an acid consisting of hydrochloric acid was added to adjust the pH to 8, washed with water, dehydrated, and dried to prepare a sample of Comparative Example 2.

[Example 1] (Production of carboxymethylated starch that suppresses swelling by wet reaction 1)
Water was added in advance to the carboxymethylated starch prepared in Comparative Example 2 to form a slurry of 30 to 40% by mass. After heating to 35 ° C., an acid composed of hydrochloric acid was added to adjust the pH to 2, and the reaction was carried out at 35 ° C. for 3 hours. After completion of the reaction, sodium hydroxide was added to adjust the pH to 8, washed with water, dehydrated, and dried to prepare a sample of Example 1.

[Example 2] (Production of carboxymethylated starch that suppresses swelling by wet reaction 2)
Water was added in advance to the carboxymethylated starch prepared in Comparative Example 2 to form a slurry of 30 to 40% by mass. After heating to 45 ° C., an acid composed of hydrochloric acid was added to adjust the pH to 0.7, and the reaction was carried out at 45 ° C. for 1 hour. After completion of the reaction, sodium hydroxide was added to adjust the pH to 8, washed with water, dehydrated, and dried to prepare a sample of Example 2.

[Example 3] (Production of carboxymethylated starch that suppresses swelling by wet reaction 3)
Water was added in advance to the carboxymethylated starch prepared in Comparative Example 2 to form a slurry of 30 to 40% by mass. After heating to 45 ° C., an acid composed of hydrochloric acid was added to adjust the pH to 0.7, and the reaction was carried out at 45 ° C. for 3 hours. After completion of the reaction, sodium hydroxide was added to adjust the pH to 8, washed with water, dehydrated, and dried to prepare a sample of Example 3.

[Example 4] (Production of swelling-suppressing carboxymethylated starch by dry reaction)
The sample of Example 4 was prepared by dispersing the carboxymethylated starch prepared in Comparative Example 2 in an aluminum vat and heating it in a blow dryer at 130 ° C. for 5 hours.

Table 1 shows the measurement results of the degree of heat swelling and the peak viscosity (maximum viscosity in RVA analysis) of each sample. Moreover, the comparison of the RVA analysis result of Comparative Example 2 and Example 2 is shown in FIG.

As shown in Table 1, the degree of heat swelling of the carboxymethylated starch (Examples 1 to 4) adjusted to pH 8 or less and heat-treated by a wet or dry method is the carboxymethylated starch of Comparative Example 1 which is a raw material. It was significantly reduced compared to the above, and swelling was clearly suppressed. Moreover, the peak viscosity of the carboxymethylated starch of Examples 1 to 4 was higher than that of the carboxymethylated starch of Comparative Example 1. On the other hand, the carboxymethylated starch (Comparative Example 2) in which only pH adjustment was performed had a slightly higher peak viscosity than Comparative Example 1, but the degree of heat swelling hardly changed. That is, the carboxymethylated starch (Examples 1 to 4) heat-treated by adding an acid to pH 8 or less is the untreated raw material carboxymethylated starch (Comparative Example 1) and carboxymethyl obtained by adjusting the pH only. It was confirmed that the swelling-suppressing treatment was stronger than that of the methylated starch (Comparative Example 2), and that a remarkable thickening effect was exhibited.

<Test 2>
[Comparative Example 3] (Production of raw material carboxymethylated starch)
Water was added to tapioca starch in advance to form a slurry of 30 to 40% by mass. After heating to 45 ° C., 20 parts by mass of sodium sulfate was dissolved in 100 parts by mass of the dry mass of starch. After adjusting the pH to 11 to 12 by adding an alkaline agent consisting of sodium hydroxide, 10 parts by mass of sodium monochloroacetate was added to 100 parts by mass of the dry mass of starch, and the mixture was reacted for 20 hours. After completion of the reaction, the sample was washed with water, dehydrated and dried to prepare a sample of Comparative Example 3.

[Example 5] (Production of swelling-suppressing carboxymethylated starch by wet reaction)
Water was added in advance to the carboxymethylated starch prepared in Comparative Example 3 to form a slurry of 30 to 40% by mass. After heating to 45 ° C., an acid composed of hydrochloric acid was added to adjust the pH to 0.7, and the reaction was carried out at 45 ° C. for 6 hours. After completion of the reaction, sodium hydroxide was added to adjust the pH to 8, washed with water, dehydrated, and dried to prepare a sample of Example 5.

Table 2 shows the measurement results of the heat swelling degree and the peak viscosity of each sample. Further, FIG. 2 shows a comparison of the RVA analysis results of Comparative Example 3 and Example 5.

As shown in Table 2, the degree of heat swelling of the carboxymethylated starch (Example 5) adjusted to pH 8 or less and heat-treated in a wet manner was lower than that of the carboxymethylated starch of Comparative Example 3 which was a raw material. And swelling was suppressed. Further, the viscosity of the carboxymethylated starch of Example 5 was higher than that of the carboxymethylated starch of Comparative Example 3, and as shown in FIG. 2, the viscosity breakdown (viscosity decrease due to the collapse of starch granules). ) Was not observed, so the viscosity stability of the paste solution was improved.

In the following tests 3 to 6, the texture improving effect of the swelling-suppressing carboxymethylated starch was examined. The following samples were prepared for that purpose.

[Sample preparation]
(Sample 1)
The carboxymethylated starch of Sample 1 was obtained in the same manner as in Comparative Example 2 above.

(Sample 2)
The carboxymethylated starch of Sample 2 was obtained in the same manner as in Example 1 above.

(Sample 3)
The carboxymethylated starch of Sample 3 was obtained in the same manner as in Example 2 above.

(Sample 4)
The carboxymethylated starch of Sample 4 was obtained in the same manner as in Example 3 above.

(Sample 5)
The carboxymethylated starch of Sample 5 was obtained in the same manner as in Example 4 above.

(Sample 6)
"NEWGELIN XGT" (trade name of xanthan gum, manufactured by Mitsubishi Chemical Foods Co., Ltd.) was used as sample 6.

(Sample 7)
"Maps # 306" (trade name of acetylated adipic acid cross-linked starch, manufactured by Nihon Shokuhin Kako Co., Ltd.) was used as sample 7.

(Sample 8)
“Sunvest NN-153” (trade name of a stabilizer consisting of guar gum and carrageenan, manufactured by Saneigen FFI Co., Ltd.) was used as sample 8.

<Test 3> (Sponge cake)
A sponge cake was prepared as follows with the formulations shown in Table 3. That is, whole eggs, white sugar, and salt were put into a mixer bowl and stirred, and then emulsified fat, salad oil, and tap water were added, and the mixture was stirred for 2 minutes and 30 seconds. Next, the cake flour, any of the samples 1 to 7 and the baking powder were added, and the mixture was stirred for 2 minutes and 30 seconds or more until the dough specific gravity reached 0.45. After dispensing 350 g of the dough into an 18 cm diameter round cake mold, it was baked in an oven set at 170 ° C. at the top and 180 ° C. at the bottom for 30 minutes. The sponge cake was taken out from the oven into a net on the pan, allowed to cool for 30 minutes, covered, and stored in a refrigerator.

The obtained sponge cake was subjected to a sensory evaluation by eight panelists 4 days after refrigerated storage. In the sensory evaluation, the additive-free group (test group in which the sample was replaced with soft flour) was used as the standard (0 points), and it melted in the mouth (the better the mouthfeel, the higher the evaluation), the moist feeling (the stronger the moist feeling, the higher the evaluation), and the softness. (The softer the higher the evaluation) and the elasticity (the stronger the elasticity, the higher the evaluation) were evaluated with ± 3 points, and the average score was calculated. The results are shown in Table 4.

As a result, as shown in Table 4, the moist feeling and softness were improved in the group to which Sample 2 (carboxymethylated starch subjected to swelling suppression treatment) was added. In the group to which Samples 3 to 5 (carboxymethylated starch subjected to swelling suppression treatment) were added, melting in the mouth, moist feeling, softness and elasticity were improved. On the other hand, in the group to which Sample 6 (xanthan gum) or Sample 7 (acetylated adipic acid cross-linked starch) was added, no remarkable effect of improving the texture was observed. In the addition group of Sample 6, the texture was unfavorable because the dough was crushed. On the other hand, in the group to which sample 1 (normal carboxymethylated starch not suppressed in swelling) was added, the melting in the mouth and the elasticity were inferior to those in the group without addition.

<Test 4> (tomato sauce)
Tomato sauce was prepared as follows with the formulation shown in Table 5. That is, tap water and any of the samples 1 to 6 were weighed in a 1 L plastic container, stirred with a stirrer (350 rpm), and dispersed. In order to keep the viscosity of the sauce at the same level, the starch sample (Samples 1 to 5) had an addition amount of 2.0%, and the xanthan gum sample (Sample 6) had an addition amount of 0.5%. Then, white sugar, salt, white pepper, tomato paste, and 10% consomme chicken were added and mixed by stirring. The obtained solution was subjected to heat treatment by subjecting it to a viscograph (manufactured by Brabender). The heating conditions were maintained at 75 rpm from 35 ° C. to 90 ° C. at a rate of 1.5 ° C. per minute for 10 minutes. Then, it was cooled from 90 ° C. to 40 ° C. at a rate of 2 ° C. per minute. Olive oil was added to the resulting sauce and mixed well. 100 g of the sauce was filled in a pouch bag and refrigerated at 5 ° C.

The obtained tomato sauce was subjected to sensory evaluation by 7 panelists 10 days after refrigerated storage. In the sensory evaluation, shape retention (higher evaluation as the shape retention of the sauce is higher), smoothness (higher evaluation as the texture is smoother), and tomato flavor (flavor is higher) based on the addition group of sample 1 (0 points). The stronger the evaluation, the higher the evaluation) was evaluated with ± 3 points, and the average score was calculated. The results are shown in Table 6.

As a result, as shown in Table 6, shape retention, smoothness and tomato flavor were improved in the group to which Samples 2 to 5 (carboxymethylated starch subjected to swelling suppression treatment) were added. In the addition group of Sample 2 and Sample 3, the tomato flavor was particularly strong. On the other hand, in the group to which Sample 6 (xanthan gum) was added, the shape retention property was lowered and the tomato flavor was reduced.

<Test 5> (Flower paste)
A flower paste was prepared as follows with the formulations shown in Table 7. That is, first, undiluted solutions for all test categories were prepared. Tap water was weighed in a pan, and premixed skim milk powder, whole milk powder, milk protein, white sugar and sugar solution were added and dissolved by stirring with a whipper. Further, salt, citric acid, locust bean gum and gellan gum mixed in advance were added and dissolved by stirring with a whipper, and then frozen 20% sweetened egg yolk and frozen egg white which had been thawed in running water and mixed in advance were added. The above steps were carried out under 30 ° C. conditions while heating. Further heating was performed, and when the temperature reached 50 ° C., the heating was stopped to prepare a stock solution. This undiluted solution was dispensed into a plastic container, flour, any of the samples 1 to 5 and 7 and rapeseed oil were added, and the mixture was stirred with a homogenizer (TK HOMOMIXER MARK2) at 5,000 rpm for 5 minutes. The resulting solution was transferred to a pan and heated to 90% by weight. It was filled in a pouch bag, allowed to cool, vacuum packed, and heated in a boiling water bath for 10 minutes to obtain a flower paste.

The obtained flower paste was subjected to a sensory evaluation by 7 panelists. In the sensory evaluation, the mouthfeel (higher evaluation as the mouthfeel is better) and body feeling (higher evaluation as the body feeling is stronger) are evaluated with ± 3 points based on the addition group of sample 1 (0 points), and the average score thereof. Was calculated. The results are shown in Table 8.

As a result, as shown in Table 8, in the group to which Samples 2 to 5 (carboxymethylated starch subjected to swelling suppression treatment) were added, the mouthfeel and body feeling were improved. On the other hand, in the group to which Sample 7 (acetylated adipic acid cross-linked starch) was added, the mouthfeel was poor.

<Test 6> (ice cream)
Ice cream was prepared as follows with the formulation shown in Table 9. That is, first, in order to gelatinize the starch samples for the samples 1 to 5 and 7, the starch samples of any of the samples 1 to 5 and 7 are prepared in advance by diluting the starch samples 20 times with tap water and heating to 90 ° C. The 5% by mass paste solution used was prepared. In order to make the viscosity of the ice cream mix solution about the same, the solid content addition rate was set to 1.0% for these starch samples (samples 1 to 5 and 7), and for the other samples 8 (stabilizer). The addition amount was 0.3%. Tap water (43%) was weighed in a 2 L pan, skim milk powder was added, and the mixture was heated and stirred to 50 ° C., and then stored at 5 ° C. overnight. Unsalted butter, vegetable solid fat, emulsifier, granulated sugar (7%), and the remaining tap water were added to the obtained skim milk powder solution, and the mixture was heated and stirred while boiling in hot water using a stirrer (500 rpm). After reaching 80 ° C., the amount of evaporated water was added. After stirring with a first homogenizer (TK HOMOMIXER MARK2) at 5,000 rpm for 5 minutes, the solution was applied to a second homogenizer (manufactured by SPX Flow Technology Japan) and homogenized at 150 bar. To the obtained homogenizing solution, add the 5% paste solution prepared by using any of the starch samples of Samples 1 to 5 and 7 or Sample 8 (stabilizer) and the remaining granulated sugar, and mix them with a stirrer. A mixed solution was obtained. The obtained mixed solution was filled in a pouch bag and boiled in hot water until it reached 80 ° C. After cooling with ice to lower the product temperature, it was cooled in a refrigerator at 5 ° C. overnight. After adding and mixing the vanilla fragrance to the mixed solution, the mixture was cooled and stirred using an ice creamer until the target overrun value became 45. The ice cream was dispensed into a 120 mL plastic container and frozen in a quick freezer at -30 ° C.

The obtained ice cream was stored at −30 ° C. for 1 month and then subjected to sensory evaluation by 7 panelists. In the sensory evaluation, the smoothness (the smoother the higher the evaluation) and the melting in the mouth (the better the melting in the mouth, the higher the evaluation) are evaluated with ± 3 points based on the addition group of the sample 1 (0 points), and the average score is calculated. did. The results are shown in Table 10.

As a result, as shown in Table 10, the melting in the mouth was improved in the group to which Sample 2 (carboxymethylated starch subjected to swelling suppression treatment) was added. In the group to which Samples 3 to 5 (carboxymethylated starch subjected to swelling suppression treatment) were added, smoothness and melting in the mouth were improved. On the other hand, in the group to which Sample 7 (acetylated adipic acid cross-linked starch) was added, the mouthfeel was poor and the texture was heavy and unfavorable. Further, in the sample 8 (stabilizer) addition group, the smoothness was low.

From the results of Samples 3 to 6, it is clear that the carboxymethylated starch subjected to the swelling-suppressing treatment has a more advantageous texture improving effect than the carboxymethylated starch not swelling-suppressed. became. It was also clarified that it has a better texture improving effect as compared with the thickening polysaccharide widely used as a texture improving agent and the existing crosslinked starch.

As described above, carboxymethylated starch with swelling suppression is obtained by adjusting the pH of carboxymethylated starch and heat-treating, and the carboxymethylated starch has remarkable viscosity and viscosity stability depending on the degree of swelling suppression. Etc. can be demonstrated. By the above manufacturing method, it is possible to obtain carboxymethylated starch whose swelling is suppressed by a simple and low-cost method with less environmental load than existing chemical methods such as cross-linking treatment, so that it can be used for pharmaceuticals, cosmetics and fibers. -Can be used advantageously for industrial applications such as papermaking. In addition, the carboxymethylated starch is a food additive and has a good texture improving effect, so that it can be advantageously used for food applications.

Claims (9)

A method for producing swelling-suppressing carboxymethylated starch, which comprises adjusting the raw material carboxymethylated starch to pH 8 or less and heat-treating it (however, the raw material carboxymethylated starch is adjusted to pH 8 or less under nitrogen injection conditions. Except for the method having a step of adjusting and the method having a step of treating the carboxymethylated starch as a raw material with an acidic gas after adjusting the pH) . The swelling-suppressing carboxymethylation according to claim 1, wherein a carboxymethylated starch whose swelling is suppressed so as to be 0.7 times or less as a relative value with respect to the heat swelling degree of the carboxymethylated starch as the raw material is obtained. How to make starch. The method for producing swelling-suppressing carboxymethylated starch according to claim 1 or 2 , wherein the heat treatment is performed under dry conditions of 30 to 200 ° C. The production of swelling-suppressing carboxymethylated starch according to claim 1 or 2 , wherein the heat treatment is carried out under wet conditions at a temperature of 25 ° C. or higher and lower than the gelatinization temperature of the raw material carboxymethylated starch. Method. The method for producing a swelling-suppressing carboxymethylated starch according to any one of claims 1 to 4 , wherein an acid is added to the carboxymethylated starch to adjust the pH to 8 or less. Production of the swelling-suppressing carboxymethylated starch according to claim 5 , wherein the acid contains one or more acids selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, citric acid, lactic acid, and phosphoric acid. Method. A method for producing a food product, wherein the swelling-suppressing carboxymethylated starch obtained by the production method according to any one of claims 1 to 6 is contained in the food product in an amount of 0.1 to 10% by mass. The method for producing a food according to claim 7, which is a method for producing a food selected from bakery foods, food sauces, food pastes, and frozen desserts. A method for improving the texture of a food, which comprises adding the swelling-suppressing carboxymethylated starch obtained by the production method according to any one of claims 1 to 6.