JPH08193A - Polished rice having improved taste and its production - Google Patents

Abstract

PURPOSE:To improve the palatability of cooked rice such as glutinousness, stiffness and chewability and the gloss and color of the cooked rice grain by treating the surface of polished rice with an aqueous solution containing an enzyme and a water-soluble dietary fiber such as decomposed polysaccharide. CONSTITUTION:Polished rice is surface-treated with an aqueous solution containing (A) a water-soluble dietary fiber such as decomposed polysaccharide (e.g. gum guaiac or locust bean gum) or pullulan and (B) an enzyme (e.g. amylolytic enzyme or cellulolytic enzyme). The aqueous solution is preferably sprayed on the rice and the sprayed rice is preferably aged to uniformize the distribution of water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to polished rice with improved taste and a method for producing the same. More specifically, the present invention relates to milled rice characterized by surface-treating an aqueous solution containing a decomposed product of a polysaccharide and an enzyme to milled rice and a method for producing the same.

[0002]

2. Description of the Related Art As a method for processing and processing polished rice, a method of conditioning and processing the polished rice after polishing (Japanese Patent Application Laid-Open No. 56-4405).
1), (JP-A-60-25548), a method in which rice bran powder is mixed and stirred, and friction-polished (JP-A-61-17948),
(JP-A-61-265060), a method of removing surface fats and oils that cause deterioration of taste and applying rice bran oil (JP-A-59-259).
120064), a method of adding starch syrup, dextrin or the like to rice and drying (Japanese Patent Laid-Open No. 63-319057) and the like have been proposed. Further, a method has also been proposed in which only a water-soluble dietary fiber such as a decomposed product of a polysaccharide or pullulan is sprayed on the surface of milled rice and then dried (Japanese Patent Publication No. 26507/1994). However, although these methods are expected to have the effects of finishing the appearance of polished rice beautifully, preventing the deterioration of flavor during storage of the polished rice, the change of water content, the change of quality, etc. No consideration was given to the improvement of the rice cooking characteristics and taste when the rice was cooked, and the effect was not satisfactory.

[0003]

Generally, when rice is stored after harvesting, it deteriorates peculiarly to so-called old rice after about half a year and the flavor is remarkably lowered. When cooked rice, the peculiar taste to old rice is deteriorated. It will be cooked rice. For this reason, development of a technique for improving the flavor of stored rice has become an important issue for increasing the consumption of rice. On the other hand, some rice has a bad taste even if it is not necessarily old rice, depending on the variety and production area.
There are so-called low-quality rice and exotic rice such as Thai-made rice and Chinese-made rice, and it is desired to improve the quality of these as well as the taste improvement of old rice. An object of the present invention is to improve the rice cooking characteristics and taste of polished rice by surface-treating the polished rice after polishing or after polishing, and to provide high-quality polished rice with stable quality.

[0004]

Means for Solving the Problems As a result of earnest studies on improvement of rice quality, the present inventors have found that polysaccharides such as guar gum, locust bean gum, tamarind gum, on the surface of milled rice or milled rice subjected to post-harvest polishing. One or more water-soluble dietary fibers selected from the group of pectin, xanthan gum, and pullulan, and a starch-degrading enzyme,
The inventors have found that the above-mentioned problems can be solved by homogenizing water after surface treatment of an aqueous solution containing one or more of protein degrading enzymes and cellulose degrading enzymes, and completed the present invention. The degradation product of the polysaccharide in the present invention,
It refers to a substance obtained by decomposing a polysaccharide with an enzyme or an acid. Specifically, guar gum and locust bean gum are preferably decomposed by the enzyme galactomannanase produced by the genus Aspergillus, and pectin is Aspergil.
Degradation products by the enzyme pectinase produced by the genus lus are preferred. The decomposition limit of the polysaccharide in the present invention may be 50% by weight or more when measured by a measurement method that conforms to the definition of dietary fiber, that is, an enzyme gravimetric method. Incidentally, the enzyme gravimetric method referred to here is that after the dehydrated and defatted sample is decomposed with an enzyme such as amylase, protease, amyloglucosidase,
It refers to a method of precipitating and collecting with about 80% alcohol.
(Comment on hygiene test method, 1990, 294-296) Furthermore, the viscosity of a 5 wt% aqueous solution is a B-type viscometer, 25 ° C., 30 rp.
100 cps or less, preferably 50 cps under measurement conditions of m
The following are good: The enzyme used in the present invention can be used without particular limitation as long as it contains one or more starch degrading enzymes, protein degrading enzymes and cellulose degrading enzymes. It is convenient to use commercially available enzyme products for these enzymes, but it is also possible to use a treated product obtained by treating an animal, plant or microbial tissue containing each of these enzymes by an appropriate method. For example, a ground product, an extract, or a dried product of these tissues, which is purified to the extent that it does not adversely affect the flavor of cooked rice, can be appropriately used. Among these enzymes, starch-degrading enzymes include α-amylase and β
-Amylase, glucoamylase, etc. are available. As α-amylase, those derived from Bacillus genus, Aspergillus genus, etc. can be used, and β-amylase can be wheat, soybean, Aspe
Sources such as Rgillus spp. can be used, and glucoamylases derived from Rhizopus spp., Aspergillus spp. can be used. In the present invention, a glucoamyase produced by Rhizopus is particularly desirable. The protein degrading enzymes include acid protease, neutral protease, basic protease, etc. Acid protease is Asperg
Those of origin such as illus spp., Penicilluum spp. can be used, and neutral proteases are Bacillus spp., Aspergillus spp.
It is possible to use those of origin such as genus bacteria, and basic protease is
Those derived from Bacillus can be used. In the present invention, a neutral protease produced by Bacillus is particularly desirable. In addition, cellulolytic enzymes include cellulase, hemicellulase, etc. Cellulase is Aspergillus spp., T
Those of origin such as ricoderma can be used, and those of origin such as Aspergillus can be used as hemicellulases. Furthermore, with this glucoamylase produced by Rhizopus
The one containing a neutral protease produced by the genus Bacillus is more optimal. Examples of the method for surface-treating the milled rice in the present invention include a method of dipping in an aqueous solution containing one or more kinds of water-soluble dietary fiber and an enzyme, a method of applying, a method of spraying, etc. Considering this, the method of spraying is preferable. In the present invention, after the surface treatment, the step of aging may be carried out for homogenizing the water content, and the aging method is not particularly limited. A closed container that suppresses the evaporation of is desirable. For example, a container capable of homogenizing water by circulating hot air, a container having no water permeation, a vinyl chloride container, a polyethylene container, a tank and the like can be mentioned. The optimum temperature is 35 to 40 ° C., and the suitable aging period is 3 to 5 days, but 3 days is sufficient in consideration of workability. Further, it is desirable to stir the rice from time to time during ripening to make the rice even. For improving the taste of the present invention, as described above, after surface-treating rice with a specific amount of an aqueous solution of water-soluble dietary fiber and enzyme,
It is carried out by equalizing the water content and aging.

The amount of water-soluble dietary fiber in the aqueous solution is about 1.0.
~ 30.0% by weight, preferably 9.0-20.0% by weight
Is. The amount of enzyme in the aqueous solution is about 0.01-1.
50% by weight, specifically determined by the type and titer of the enzyme. For example, in the case of a starch degrading enzyme having a titer of about 300 U / g, about 0.01 to 0.30% by weight, and in the case of a protein degrading enzyme having a titer of about 1000 U / g, about 0.
05 to 1.50% by weight is used, and in the case of a cellulolytic enzyme having a titer of about 10,000 U / g, about 0.01 to 0.30% by weight is used. Hereinafter, even for enzymes having various titers, the amount used can be appropriately selected based on the above-mentioned titer and amount used. The amount of the aqueous solution containing the above components is about 1% by weight to 5% based on the rice polished before cooking.
Weight percent is preferred. Next, the present invention will be specifically described with reference to test examples and examples.

[0006]

【Example】

Test Example 1 An aqueous solution was prepared by dissolving glucoamylase and guar gum degradation products produced by Rhizopus in the amounts shown in Table 1,
"Yukihikari" produced in Hokkaido in 1992 by polishing this aqueous solution
It was sprayed at a rate of 10 g per 1 kg. Then, the mixture was aged for 3 days by refluxing in a circulating air duct at 35 to 40 ° C. to obtain processed rice with a water content of 15%. 300 g of each of the obtained processed milled rice and the untreated milled rice used for this treatment were sharpened and washed four times, drained, 480 g of water was added thereto, and the rice was cooked by a conventional method using an electric kettle. And panelist 1
A taste test was conducted by 0 people. The taste test results are shown in Table 1.
Shown in The guar gum decomposition product used in this test example was prepared by the following method. (Preparation of guar gum decomposition product) The pH was adjusted to 3.0 by adding citric acid to 900 parts of water. To this, 0.2 part of the enzyme galactomannanase produced by Aspergillus and 100 parts of guar gum powder were added and mixed, and the enzyme was allowed to act at 40 to 45 ° C for 24 hours. After the reaction, the enzyme was destroyed by heating at 95 ° C for 15 minutes. The transparent solution obtained by filtering and removing impurities was lyophilized to obtain a guar gum decomposition product 70.
Got a part. The dietary fiber content (by enzyme gravimetry) of this guar gum decomposition product was 90%, and the viscosity of a 5% by weight aqueous solution was 42 cps.

[0007]

[Table 1]

Test Example 2 After preparing an aqueous solution containing 0.07% by weight of glucoamylase produced by the genus Rhizopus and 9.93% by weight of a guar gum decomposition product, this aqueous solution was refined to produce "Yukihikari" produced in Hokkaido in 1992. Spraying was carried out at a rate of 10 g per 1 kg. Then, by circulating hot air at 35 to 40 ° C, Table 2
Aged for the period described in 1), the obtained processed rice and the unprocessed rice used for this treatment are each 300 g, and are sharpened and washed 4 times,
After draining the water, 480 g of water was added thereto, and the rice was cooked by a conventional method using an electric kettle. Then, a taste test was conducted by 10 panelists. The results of the taste test are shown in Table 2.

[0009]

[Table 2]

Test Example 3 An aqueous solution containing 0.07% by weight of various enzymes and 9.93% by weight of a guar gum decomposition product and a guar gum decomposition product 9.9.
After preparing an aqueous solution containing only 3% by weight as a component, 10 g of this aqueous solution was spray-sprayed to 1 kg of "Yukihikari" produced in Hokkaido in 1992. Then 35-40 ° C
The rice was aged for 3 days by circulating warm air to obtain processed rice with a water content of 15%. 300 g of each of the processed milled rice and the untreated milled rice used in the main treatment were sharpened and washed four times, drained, 480 g of water was added thereto, and the rice was cooked by an ordinary method using an electric kettle. Then, a taste test was conducted by 10 panelists. The results of the taste test are shown in Table 3.

[0011]

[Table 3]

Test Example 4 0.07% by weight of glucoamylase produced by the genus Aspergillus dissolved in the amount shown in Table 4, various polysaccharide hydrolysates or pullulan in an aqueous solution was purified from an aqueous solution in 1992 "Yukihikari" 1 kg Was sprayed at a rate of 10 g. Then, the rice was aged for 3 days by circulating hot air at 35 to 40 ° C. to obtain processed milled rice having a water content of 15%. 300 g of each of the processed milled rice and the untreated milled rice used in the main treatment were sharpened and washed four times, drained, 480 g of water was added thereto, and the rice was cooked by an ordinary method using an electric kettle. And the panelist 10
A human taste test was conducted. Table 4 shows the results of the taste test.

[0013]

[Table 4]

The pullulan used in the test examples had a dietary fiber content of 84% (by the enzyme gravimetric method), and a 5% by weight aqueous solution had a viscosity of 13 cps. Decomposition products of various polysaccharides were prepared by the following method. (Preparation of Locust Bean Gum Decomposition Product) Citric acid was added to 900 parts of water to adjust the pH to 3.0. Asperg
Add and mix 0.2 part of the enzyme galactomannanase produced by the illus genus and 100 parts of locust bean gum powder 4
The enzyme was allowed to act for 6 hours at 0 to 45 ° C. 95 ° C after reaction,
The enzyme was destroyed by heating for 15 minutes. The impurities were removed by filtration and the resulting solution was freeze-dried to obtain 64 parts of a locust bean gum decomposition product. The dietary fiber content (by enzyme gravimetric method) of this locust bean gum decomposition product is 9
The viscosity of the 1% and 5% by weight aqueous solution was 92 cps. (Preparation of Pectin Degradation Product) The pH was adjusted to 3.0 by adding citric acid to 900 parts of water. To this, 0.1 part of pectinase produced by Aspergillus spp. And 100 parts of pectin powder (esterification degree 70%) were added and mixed, and the mixture was stirred at 30 to 35 ° C for 8 hours.
The enzyme was made to act for a time. After the reaction, the enzyme was destroyed by heating at 95 ° C for 15 minutes. Then, the transparent solution obtained by filtering and removing impurities was lyophilized to obtain a pectin decomposition product 64.
Got a part. The dietary fiber content of this guar gum breakdown product (by the enzyme gravimetric method) is 84%, and the viscosity of a 5% by weight aqueous solution is 13%.
It was cps.

Example 1 An aqueous solution containing 0.07% by weight of glucoamylase produced by the genus Rhizopus and 9.93% by weight of a guar gum degradation product was prepared, and then this aqueous solution was refined to produce "Yukihikari" produced in Hokkaido in 1992. 10 g was sprayed for 1 kg. Then, the water content was homogenized by refluxing in a circulating air passage at 35 to 40 ° C., and processed rice having a water content of 15% was obtained. 300 g of each of the processed milled rice and the untreated milled rice used for this treatment were added.
After scouring and draining, add 480g of water to this,
Rice was cooked in the usual manner using an electric kettle. When a taste test was conducted by 10 panelists, the taste of rice such as luster, stickiness, hardness, and taste was significantly superior to that of the rice treated with the examples than the untreated rice. Example 2 10 g of the same aqueous solution as in Example 1 was spray-sprayed on blended rice in which 500 g of "Yukihikari" produced in Hokkaido in 1992 and 500 g of Thai rice were mixed. Then 35-40
Aged for 3 days by refluxing the circulating air at ℃, water content 15%
I got processed rice. The processed milled rice and the untreated milled rice used for the main treatment were each sharpened and washed 300 times, dried 4 times, added with 480 g of water, and cooked in a conventional manner using an electric kettle. When a taste test was conducted by 10 panelists, the taste of rice such as luster, stickiness, hardness, and taste was significantly superior to that of the rice treated with the examples than the untreated rice. Example 3 100% of blended rice (moisture content 13.3%, whiteness 43.2%) consisting of 70% Thai non-glutinous rice and 30% Hitomebore
Using a rotary drum type coating device (cylindrical rotary drum; length 3,250 mm, diameter 1,000 mm, rotation speed; 8.5 rpm), glucoamylase 0.0
1 kg of an aqueous solution containing 7% by weight and a guar gum decomposition product of 9.93% by weight was added. After that, it was dried for 2 days by circulating hot air at 35 to 40 ° C. to homogenize the water content to obtain processed rice. 800 processed and untreated rice obtained
g, the water content was 1.8 times, and the rice was washed with an electric rice cooker for 2-3 minutes. Table 5 shows the results of the taste test by 10 panelists.
Shown in

[0016]

[Table 5]

Uchichi rice from Thailand 70% and Hitomebore 30
Compared to untreated products, the ones that have been blended with 100% are “glossy”, “taste”, “stickiness”, and “comprehensive evaluation”.
There was a significant difference in terms of. Embodiments of the present invention and target products are as follows. (1) A milled rice and a method for producing the same, wherein the milled rice is surface-treated with an aqueous solution containing a decomposition product of a polysaccharide or pullulan and an enzyme. (2) Polished rice and a method for producing the same, wherein the rice is surface-treated with an aqueous solution containing a decomposition product of a polysaccharide or pullulan and an enzyme and then aged. (3) The method according to (1) or (2) above, wherein the polysaccharide is guar gum. (4) The above (1), wherein the polysaccharide is locust bean gum.
Alternatively, the manufacturing method of (2). (5) The method according to (1) or (2) above, wherein the polysaccharide is tamarind gum. (6) The above (1) or (2), wherein the polysaccharide is pectin
Manufacturing method. (7) The method according to (1) above, wherein the polysaccharide is xanthan gum. (8) The above-mentioned (1) to which the decomposed product is a decomposed product by an enzyme.
The manufacturing method of (7). (9) The above (1) to which the decomposed product is a decomposed product with an acid.
The manufacturing method of (7). (10) The above (1) to which the enzyme is a starch-degrading enzyme
The manufacturing method of (9). (11) The above (1) to which the enzyme is a protein-degrading enzyme
The manufacturing method of (9). (12) The above (1) to which the enzyme is a cellulolytic enzyme
The manufacturing method of (9). (13) The above (1) to which the surface treatment is a dipping method
The manufacturing method of (12). (14) The above (1) to which the surface treatment is a coating method
The manufacturing method of (12). (15) The above (1) to which the surface treatment is a spraying method.
The manufacturing method of (12). (16) The production method according to the above (2) to (10), wherein the aging is carried out in a container in which water can be equalized by a circulation air passage. (17) The above (2), wherein the aging is carried out in a vinyl chloride container.
~ The manufacturing method of (15). (18) The production method according to the above (2) to (15), wherein aging is carried out in a polyethylene container.

(19) The production method according to the above (2) to (18), wherein the aging temperature is 35 to 40 ° C. (20) The aging period of 3 to 5 days (2) to
The manufacturing method of (19). (21) The production method of (10), wherein the starch-degrading enzyme is α-amylase. (22) The method according to (10) above, wherein the starch-degrading enzyme is β-amylase. (23) The method according to (10) above, wherein the starch-degrading enzyme is glucoamylase. (24) The method according to (11) above, wherein the protein-degrading enzyme is an acidic protease. (25) The method according to (11) above, wherein the protein-degrading enzyme is a neutral protease. (26) The method according to (11) above, wherein the protein degrading enzyme is a basic protease. (27) The method according to (12) above, wherein the cellulolytic enzyme is cellulase. (28) The method according to (12) above, wherein the cellulolytic enzyme is hemicellulase. (29) The production method according to the above (21), wherein the origin of the α-amylase is the genus Bacillus. (30) The production method according to the above (21), wherein the α-amylase originates from the genus Aspergillus. (31) The origin of β-amylase is wheat (2)
2) Manufacturing method. (32) The production method according to (23) above, wherein the origin of glucoamylase is the genus Rhizopus. (33) The production method according to (23), wherein the origin of glucoamylase is the genus Aspergillus. (34) The production method of (24), wherein the origin of the acidic protease is of the genus Aspergillus. (35) The production method of (25), wherein the origin of the neutral protease is of the genus Bacillus. (36) The method according to (25) above, wherein the origin of the neutral protease is the genus Aspergillus. (37) The method according to (26) above, wherein the basic protease is of the genus Bacillus. (38) The production method according to the above (27), wherein the origin of the cellulase is the genus Aspergillus. (39) The production method according to the above (27), wherein the cellulase originates from the genus Trichoderma. (40) The method according to (28) above, wherein the origin of hemicellulase is the genus Aspergillus.

[0019]

The processed rice mill obtained according to the present invention has the following features. (1) When rice is cooked, the taste such as stickiness, hardness, and chewyness is significantly improved compared to untreated rice. (2) The rice grain surface has improved luster and color, resulting in polished rice with a glossy appearance. (3) The coating of water-soluble dietary fiber prevents a decrease in water content during storage, so that cracking of rice grains due to a decrease in water content can be prevented. (4) Oxidation that causes off-taste and off-odor is prevented by blocking contact of oils and fats in the raw material water with air, resulting in stable rice milling with stable quality for a long time. (5) The starch is decomposed by the action of the enzyme to give the rice sweetness.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Tsuda 9-5 Akahori Shinmachi, Yokkaichi-shi, Mie Taiyo Kagaku Co., Ltd. (72) Inventor Kim Takehisa 9-5 Akahori-shinmachi, Yokkaichi, Mie Gaku Co., Ltd. (72) Inventor Masato Kobayashi 3-3-5 Kojimachi, Chiyoda-ku, Tokyo (72) Inventor Toshio Masuda 23-3 Nakada, Kidakata, Fukushima City, Fukushima Prefecture

Claims (3)

[Claims] 1. A surface treatment of polished rice with an aqueous solution containing one or more kinds of water-soluble dietary fibers selected from the group of decomposed products of polysaccharides and pullulan and one or more kinds of enzymes. Rice mill and its manufacturing method. 2. The milled rice and the method for producing the same according to claim 1, wherein the polysaccharide is guar gum, locust bean gum, tamarind gum, pectin or xanthan gum. 3. The milled rice according to claim 1, wherein the enzyme is one or more of a starch degrading enzyme, a protein degrading enzyme, and a cellulolytic enzyme, and a method for producing the same.