JPH07327618A - Quality improver for cooked rice and method for improving quality - Google Patents

Abstract

PURPOSE:To obtain a quality improver for cooked rice, containing a polydextrose as an active ingredient, capable of approximating the texture of a cooked raw material rice such as Indica-type rice, blended or low-grade rice to that of Japonica-type rice and suppressing the occurrence of a dry feeling and excellent in properties of preventing starch from retrograding. CONSTITUTION:This quality improver for cooked rice contains a polydextrose and further an amylase as active ingredients. The amounts of the active ingredients based on the weight of raw rice are preferably 0.1-2wt.% polydextrose and 0.005-0.5wt.% amylase. Furthermore, this method for improving the quality of the cooked rice is to preferably cook a foreign rice or a low-grade rice raw material in the presence of the quality improver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quality improving agent for cooked rice and a method for improving quality of cooked rice using the same.

[0002]

2. Description of the Related Art There are low quality rice that has a bad taste due to its quality, production area, etc., and improvement of its quality has been a research subject for many years. In recent years, foreign rice including Indica rice has begun to be widely used due to market opening of agricultural products, diversification of food culture, lack of rice, and the like. Among them, compared to Japonica rice, Indica rice has a small amylopectin content, a large amount of cellulose contained in the cell wall, and has peculiar properties such as containing glucomannan that is hardly contained in Japonica rice. Therefore, the water absorption is poor, the cooked rice has no stickiness (stiffness), and there are many problems such as a tingling sensation due to the aging of starch due to cooling (cooling). Domestic low-quality rice also has the same problem, and various methods are being studied in various fields to improve the texture to the same quality as high-quality rice, but it is currently reported that satisfactory research results were obtained. Is not now.

That is, conventionally, as a rice quality improving agent,
For example, methods have been proposed in which enzymes such as amylase, protease, cellulase and the like, oils and fats, surfactants such as glycerin fatty acid ester and the like are used, but the texture improving effect is not yet satisfactory. In particular, for indica rice and blended rice containing the same, even if an enzyme agent such as amylase is used, the effect of preventing the aging of starch accompanying cooling after cooking rice is not substantially recognized, and the texture is similar to that of high quality rice. There is almost no expectation that the effect of improving it can be expected.

In view of the above situation, the present inventor also obtained by adding some additive (quality improving agent) to these when cooking low quality rice including outside rice such as the above-mentioned indica rice. As a result of conducting various studies to improve the texture of cooked rice, the addition of polydextrose or amylase and polydextrose, which has never been added to this type of cooked rice, is surprisingly obtained. Rice has a sticky texture that closely resembles the quality of domestic Japonica rice,
It was further discovered that after cooling the indica rice, cooked rice of improved quality can be obtained without causing a dry feeling due to aging of starch. The present invention has been completed based on this new finding.

[0005]

That is, the present invention relates to a quality improving agent for cooked rice characterized by containing polydextrose or amylase and polydextrose as active ingredients, and a method for improving the quality of cooked rice using the same.

In the quality improver for cooked rice of the present invention, the polydextrose used as an essential active ingredient is a polysaccharide found by Pfizer Central Research Laboratories, for example, as an acid and a plasticizer. It is produced by thermally polymerizing glucose in the presence of the polyol, and the product is already commercially available as dietary fiber (indigestible sugar). Therefore, the use of the quality improver for cooked rice according to the present invention can, of course, also provide the effects of supplementing and strengthening the dietary fiber which is the original polydextrose.

The quality improving agent of the present invention may contain not only the above polydextrose as an active ingredient, but also a combination of the polydextrose and amylase.
In this case, not only the amount of polydextrose used can be reduced, but also a more excellent quality improving effect can be achieved. The α-amylase used in combination here may be any of various commercially available preparations.

The amount of the quality improving agent of the present invention used with respect to the raw rice is 0.0% of the polydextrose based on the weight of raw rice.
It is preferably selected from the range of 5 to 5% by weight, preferably 0.1 to 2% by weight, and when amylase is used in combination, the combined amount is usually about 0.001 with respect to the weight of raw rice.
It is suitable to be in the range of ˜1 wt%, preferably 0.005 to 0.5 wt%. By utilizing each component in this range, the effect of improving quality of cooked rice expected by the present invention is exhibited.

The improving agent of the present invention can be easily prepared in a powder form by using the above-mentioned active ingredient (polydextrose) alone or by mixing it with amylase, and it is not necessary to add any other additives. Of course, other additives conventionally proposed as a quality improving agent for this type of cooked rice, for example, other enzymes such as protease and cellulase, proteolytic products such as gelatin, edible oils and fats, and surfactants for foods. It is also possible to add a mixture of polysaccharides such as guar gum and starch or starch decomposition products such as waxy corn starch. It is also possible to prepare a solution form or the like using an appropriate diluent or the like.

The quality improving agent of the present invention thus prepared is
When cooking raw rice such as indica rice, blended rice, and low-quality rice, by adding and blending it in the raw rice soaking water to cook the rice, the cooked rice is similar to the sticky Japonica rice or high-quality cooked rice of the present invention. Rice can be obtained, and the aging of starch that accompanies the cooling of the cooked rice can be prevented, and the occurrence of dryness can be suppressed.

Therefore, the present invention also provides a method for improving the quality of cooked rice using the above quality improving agent.

The method of the present invention comprises:
It is indispensable to add rice to the raw rice (fresh rice) to cook the rice, and the others can follow the usual method for producing this kind of cooked rice. For example, in the case of using Indica rice as raw material rice, generally, the washed raw rice is immersed in about 1.4 to 2.0 times by weight of water and left for a suitable time, usually several tens of minutes to several hours, and then, Under the conditions specified for generally used rice cookers,
It may be cooked for about 15 to 40 minutes depending on the amount of raw rice. The quality improver of the present invention may be added at any time during the cooking of the raw rice, that is, as long as the improver can act on the raw rice at an appropriate time after the raw rice is puffed and before it is gelatinized. It is suitable that the raw material rice is added and blended in the raw material rice soaking water at the time of immersion in water after washing or immediately before cooking rice. When low quality rice is used as a raw material, the above-mentioned rice cooking conditions for Indica rice can be used.

The raw material rice to which the method of the present invention can be applied is not limited to foreign rice such as the above-mentioned indica rice, but low quality domestic rice, blended rice such as rice, and blended rice obtained by further blending high quality rice. Etc. may be used.

[0014]

EXAMPLES Examples will be given below to explain the present invention in more detail.

[0015]

Example 1 300 g of indica rice was washed with water, added with water so that the total amount was 840 g, and soaked at room temperature for 1 hour, and then 1% by weight of polydextrose as a quality improving agent of the present invention immediately before cooking rice. (Weight of raw rice, the same applies hereinafter) (Sample 1 of the present invention) or 1% by weight of polydextrose
And 0.02% by weight of α-amylase (sample 2 of the present invention) were added, respectively, and an electric kettle (manufactured by Matsushita Electric Industrial Co., Ltd., S
Rice was cooked using R-102 type, 1.0 liter cooked).

For comparison and control, the same rice was cooked without adding the quality improving agent of the present invention (control sample 1). Further, in place of the quality improving agent of the present invention, α-amylase 0.02
A comparative sample 1 is prepared by adding rice in the same weight% and cooking the rice in the same manner.

100 g of each cooked rice sample thus obtained
Each of the rice balls was placed in a rice ball mold to prepare a rice ball, and the hardness of each rice ball was measured immediately after preparation and after standing at 25 ° C. for 24 hours using a rheometer.

At the same time, the texture of each rice ball was evaluated by a sensory test using a panel of 10 people. In this evaluation, the texture of a rice ball made by using the cooked rice of Japonica rice (Akitakomachi) in the same manner was evaluated as 1
0 (reference value) and the above comparative sample 1 (no quality improver added)
The value was evaluated as 1 (control value), and the average value of evaluation values of each panel obtained by 10-level evaluation was used.

The results obtained are also shown in Table 1.

[0020]

[Table 1]

From Table 1 above, it is clear that according to the method of the present invention, indica cooked rice having a good texture similar to Akitakomachi can be obtained.

[0022]

[Example 2] 300 g of blended rice of Indica rice (20 parts by weight of Indica rice, 80 parts by weight of Japonica rice (Akitakomachi)) was washed with water, drained, and then added with water so that the total amount became 750 g, and immersed at room temperature for 1 hour. Immediately before cooking, 0.5 g of polydextrose / 100 g of rice (inventive sample 1) or 0.5 g of polydextrose / 100 g of rice and α-amylase 0.0 as the quality improving agent of the present invention.
1 g / 100 g of rice (inventive sample 2) was added, and an electric kettle (manufactured by Matsushita Electric Industrial Co., Ltd., SR-102) was added.
The rice was cooked using the mold.

For comparison and control, the same rice was cooked without adding the above-mentioned quality improving agent of the present invention (control sample 1). Further, in place of the quality improving agent of the present invention, α-amylase 0.01
Comparative sample 1 is prepared by adding 100 g of rice per 100 g of rice and cooking the rice in the same manner.

100 g each of the thus-prepared cooked rice is put into a rice ball mold to prepare a rice ball, and immediately after preparation and 2
The hardness of each rice ball after standing at 5 ° C. for 24 hours was measured using a rheometer, and the texture was evaluated by a sensory test using a panel of 10 persons in the same manner as in Example 1. .

The results obtained are shown in Table 2.

[0026]

[Table 2]

From Table 2 above, it is clear that, according to the method of the present invention, similar to Example 1, blended cooked rice having a good texture similar to that of Japonica rice can be obtained.

[0028]

[Example 3] 300 g of low-quality rice (produced in Hokkaido) was washed with water, drained, water was added so that the total amount became 750 g, and the mixture was immersed at room temperature for 1 hour. Dextrose 0.5 g / rice 100 g (Inventive Sample 1) or polydextrose 0.5 g / rice 100
g and 0.01 g of α-amylase / 100 g of rice (sample 2 of the present invention) were added, and rice was cooked using an electric kettle (SR-102 type, manufactured by Matsushita Electric Industrial Co., Ltd., 1.0 liter cooked rice).

For comparison and control, the same rice was cooked without adding the quality improving agent of the present invention (control sample 1). Further, in place of the quality improving agent of the present invention, α-amylase 0.01
Comparative sample 1 is prepared by adding 100 g of rice per 100 g of rice and cooking the rice in the same manner.

100 g each of the thus-prepared cooked rice is put in a rice ball mold to prepare a rice ball, immediately after preparation and 2
The hardness of each rice ball after standing at 5 ° C. for 24 hours was measured using a rheometer, and the texture was evaluated by a sensory test using a panel of 10 persons in the same manner as in Example 1. .

The results obtained are shown in Table 3.

[0032]

[Table 5]

From Table 3 above, it is clear that according to the method of using the quality improving agent of the present invention, cooked rice with significantly improved texture can be obtained even in the case of low quality rice, as in the above-mentioned Examples. Is.

Claims (3)

[Claims] 1. A quality improver for cooked rice, which comprises polydextrose as an active ingredient. 2. A quality improving agent for cooked rice, which comprises polydextrose and amylase as active ingredients. 3. A method for improving the quality of cooked rice, which comprises cooking raw rice or low-quality rice raw material in the presence of the quality improving agent according to claim 1 or 2.