JPH07327615A - Production of cooked rices - Google Patents

Abstract

PURPOSE:To produce glossy cooked rices, improved in taste, hardly causing the collapse thereof without a dry feeling and capable of providing a puffy texture and viscosity from milled rice having a high amylose content such as Indica-type rice simply in aspect of operating efficiency. CONSTITUTION:This method for producing cooked rices comprises using milled nonglutinous rice having >=20wt.% amylose content in starch contained in the milled rice to be cooked, adding pregelatinized waxy corn starch and/or pregelatinized glutinous rice flour and, as necessary, an alpha-amylase thereto in cooking the rice or adding the waxy corn starch and/or glutinous rice flour and alpha-amylase in cooking the rice or using water containing the waxy corn starch and/or glutinous rice flour as water for cooking the rice, previously dipping the milled rice in water and then starting the cooking of rice.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing cooked rice using glutinous rice containing 20% by weight or more of amylose in starch contained therein. More particularly, the present invention relates to a method for cooking Indica rice with improved taste, in which the cooked rice does not crumble, is glossy, has no dryness, and has a plump texture and stickiness. "Boiled rice" of the present invention
Means cooked rice, cooked rice under pressure / heat sterilization, and cooked rice including prepared cooked rice.

[0002]

2. Description of the Related Art The deliciousness of cooked rice is determined in part by how to cook it, and it is necessary to cook it according to the type and characteristics of the rice. Indica rice compared to Japonica rice,
Generally, starch has a high amylose content and protein content that are said to have a great relationship with the taste of rice, and its texture is harder when cooked normally, as compared to Japonica cooked rice,
The characteristic is that there is no stickiness. Although rice porridge and fried rice have the characteristic that they are not sticky, stickyness is an essential component of deliciousness when eating with cooked rice such as white rice, and rice cooked with indica rice has improved dryness and flavor. There are many points to do. There is a need for a cooking method that allows tasty indica rice with low stickiness.

Conventionally, the texture improving method for indica rice has been
It is known to prolong the time of immersion in water, increase the amount of water added, treat with various enzymes (protease, amylase, cellulase, etc.), and use additives such as gelatin, agar, emulsifiers, thickeners, etc. There is. However, for example, when rice is cooked with an increased amount of water, it simply becomes soft and does not have stickiness, and when a thickener is added, the cooked rice has an extraordinary stickiness, which greatly differs from the original texture of rice. In both cases, it is difficult to improve the texture significantly.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing cooked rice using so-called long-grain rice polishing, which is less sticky to eat with white rice. In detail, the present invention uses milled rice with a high amylose content such as indica rice to reduce the collapse of cooked rice, to make it glossy, and to give it a fluffy texture and stickiness, and to improve the taste. It is intended to provide a method for producing cooked rice.

[0005]

[Means for Solving the Problems] The present invention has developed a rice cooking method for the purpose of bringing the taste of Indica cooked rice closer to that of Japonica cooked rice.

[0006] The polished rice targeted by the present invention is non-glutinous rice polished in which the content of amylose in the contained starch is 20% by weight or more. Indica rice is exemplified as the non-glutinous rice having an amylose content of 20% or more in the present invention. Indica rice is called long grain rice because of its grain shape.

Based on the results of analysis by the present inventor of various kinds of Japanese rice and foreign rice, for example, Japonica rice Koshihikari has a starch content of 78.4% by weight, of which amylose is 15.0% by weight and amylopectin is 85. Indica rice has a starch content of 7% compared to 0% by weight.
9.1% by weight, of which amylose is 27.0% by weight,
Amylopectin is 73.0% by weight, and one of the characteristics is that the ratio of amylose is high. The non-glutinous rice containing 20% by weight or more of amylose in the starch contained is
It is not preferable to eat it with white rice due to lack of stickiness.

[0008] First, when the present inventor cooks rice using indica rice, various additives (eg, gelatin, agar, xanthan gum, powdered indica rice, horse starch, tapioca starch,
White ball flour, cellulase, xylanase, amylase preparation,
Experiments were carried out on the effects of papain and actinase), and it was first found that shiratama powder was better in terms of stickiness and the condition of disassembling was better than the control product without additives. Based on this finding, we conducted a keen study of a rice cooking method in which starch with a high content of amylopectin, such as shiratama powder and waxy corn starch, was added.

[0009] Waxy cornstarch is characterized in that it is 100% amylopectin starch that does not contain any amylose component. It is also resistant to aging and is rich in viscoelasticity, swelling power, water retention, and gloss. The reason is that when rice is cooked with rice having a small ratio of, that is, a large ratio of amylose, it is considered that the starch has properties effective for improving the quality.

However, in order to significantly improve the taste of Indica rice, it was necessary to add the amount of starch to the extent that rice cannot be cooked under ordinary rice cooking conditions such as household electric or gas rice cookers. It is impossible to make the taste of Indica rice close to that of Japonica rice with the amount of starch added that can be cooked by the usual rice cooking method using a commercially available electronic jar rice cooker or gas rice cooker. On the other hand, when white starch powder, waxy cornstarch high-concentration starch liquid is added, or when a large amount of starch is added as powder, heat convection and conduction do not occur during heating of rice, so a uniform temperature rise can be prevented. With the so-called core remaining in the center, the bottom of the pot is burnt and rice cannot be cooked.

[0011] Therefore, the present inventor has developed a method of not only simply adding starch having a high content of amylopectin, but also a method of cooking rice by adding a starch solution having a concentration which cannot be cooked under ordinary conditions and conditions. went. Starch with high amylopectin content, which is effective for improving the texture of indica rice, has almost 100% amylopectin content such as waxy corn starch, pregelatinized waxy cornstarch, white fluff, and pregelatinized white fluff.
The effect was low with starches having a little amylopectin content, such as tapioca starch and glutinous flour.

[0012] These waxy corn starch and / or shiratama powder can be added in an amount of 5% by weight or more with respect to the raw rice due to the gelatinization, that is, the decomposition in the gelatinized starch manufacturing process which is the processed starch. By using pregelatinized starch, rice can be cooked by utilizing a slight decrease in the molecular weight when producing pregelatinized starch. Also, while maintaining the properties of waxy cornstarch, which are suitable as a quality improver for cooked rice, such as viscoelasticity, swelling power, water retention, and gloss, heat convection and conduction occur during cooking. is there.

Therefore, in the method for producing cooked rice according to the present invention, α-waxed waxy cornstarch and / or α-oxidized white fluff flour is used in cooking rice of non-glutinous rice containing 20% by weight or more of amylose in the starch contained therein. It is characterized by

In the method for producing cooked rice of the present invention, when the non-glutinous rice is Indica rice, the present invention preferably uses 5 to 10% by weight of pregelatinized waxy cornstarch and / or pregelatinized relative to the Indica rice. It is a rice cooking method of Indica rice that has a soft texture and stickiness, with little crushing of rice, no stickiness, and no dryness by adding shiratama powder.

As mentioned above, the α-waxed waxy cornstarch and / or the α-wasted shiratama powder is contained in an amount of 5 to 10 relative to raw rice.
% Weight addition is preferred. When the amount added is 5% or more, the texture is more effective, but when the amount added is more than 10%, the texture of rice cake becomes strong and the rice becomes too sticky.

On the other hand, in the present invention, α-amylase is added at the same time when the amount of starch that is difficult to cook with a normal rice cooker is added to reduce the molecular weight of starch, and heat convection and conduction occur during cooking rice. I also discovered that it is possible to cook rice. This utilizes the effect that α-amylase enzymatically decomposes starch to reduce the molecular weight.
The α-amylase may be any enzyme already used for cooking rice.

Therefore, according to the method for producing cooked rice of the present invention, waxy cornstarch and / or shiratama powder and α are used for cooking rice of non-glutinous rice containing 20% by weight or more of amylose in the starch contained therein.
-Characterized by the use of amylase. As the waxy cornstarch and / or white syrup, α-waxed cornstarch and / or pregelatinized shiratama can be used.

Similarly, α- possessed by indica rice itself
Utilizing the amylase activity, rice can be cooked even if waxy corn starch and shiratama powder are added. That is, the indica rice is immersed in a starch solution, and the α-amylase activity of the indica rice is utilized to reduce the viscosity of the starch solution. Although α-amylase possessed by Indica rice has not been specified, the action of enzymatically degrading waxy corn starch from the decrease in viscosity of waxy corn starch solution,
That is, α-amylase activity was confirmed.

Therefore, according to the method for producing cooked rice of the present invention, when the non-glutinous rice of non-glutinous rice containing 20% by weight or more of amylose in the starch contained therein is cooked, the milled rice and the milled rice are treated with waxy corn starch and / or Alternatively, it is characterized in that a mixture of water containing shiratama powder is soaked in advance before cooking rice.

Also in the above-mentioned production method, the waxy corn starch and / or shiratama powder is preferably added to the raw rice in an amount of 5 to 10% by weight. When the amount added is 5% or more, the texture is more effective, but when the amount added is more than 10%, the texture of rice cake becomes strong and the rice becomes too sticky.

[0021]

EXAMPLES The present invention will be described with reference to examples. The invention is in no way limited by this example.

In the examples, the physical properties of cooked rice were measured by Leoner (manufactured by Yamadensha). Using the 3-grain method by the chewing test, the S / H value (S;
Stickiness, H; hardness) was determined. The measurement conditions are as follows. Plunger: 30 mm circular disc Clearance: 0.3 mm Stage speed: 0.5 mm / sec A high S / H value means that it is soft and tenacious, that is, the texture that Japanese people like. Generally, it is said that the S / H value of cooked rice, which is preferred by Japanese people, is 0.18 to 0.25. The S / H value of indica rice was also in good agreement with the result of sensory evaluation.

Example 1 After washing 300 g of Indica rice, the rice was immersed in water for 1 hour.
The weight of the indica rice after soaking and draining was 390 g. To this indica rice was added 480 g of 5.7% pregelatinized waxy cornstarch solution, and after further immersion for 1 hour,
Rice was cooked with a commercially available electronic jar rice cooker. The above-mentioned usage ratio corresponds to pregelatinized waxy corn starch with a weight ratio of 8 to raw rice and water with a weight ratio of 150 to 100 solids.
The obtained cooked rice was excellent in hardness, stickiness, and flavor as compared with the one without the addition of pregelatinized waxy corn starch, and the cooked rice had less collapse and was glossy. The S / H value at this time is 0.0
84 ± 0.036 (Control product; 0.013 ± 0.011)
Met.

Example 2 The cooked rice obtained in Example 1 was subjected to a sensory test according to the following criteria (n = 29). The appearance, texture, and overall were compared with untreated Indica rice, based on the α-waxy cornstarch added product. As shown in Table 1, the untreated Indica rice was significantly distinguished (risk rate 1%), and was inferior in all of the appearance, texture, and overall, as compared with the pregelatinized waxy corn starch-added product.

[0025]

[Table 1]

Example 3 Using the cooked rice obtained in Example 1, frozen pilaf was prepared with the seasoning composition shown in Table 2. The obtained frozen pilaf had less collapse of the cooked rice, was glossy, had no dryness, and had a plump texture and stickiness as compared with the one to which the pregelatinized waxy corn starch was not added.

[0027]

[Table 2]

Example 4 300 g of Indica rice was washed and gelatinized at 75 ° C.
It was immersed for 2 hours in 486 g of a 9% waxy corn starch solution (that is, waxy corn starch in a weight ratio of 8 to 100 fresh rice and water in a weight ratio of 150 to 100 of solids). After the immersion, rice was cooked with a commercially available electronic jar rice cooker.
The obtained cooked rice was the same as the cooked rice shown in Example 1. The S / H value at this time was 0.088.

Example 5 300 g of Indica rice was washed and then immersed in water for 1 hour.
The weight of the indica rice after soaking and draining was 390 g. 420 g of a 5.7% waxy corn starch solution gelatinized at 75 ° C. and 3 units of α-amylase (manufactured by Hankyu Bio Industry; liquefying enzyme T) to this indica rice
Was added and cooked with a commercially available electronic jar rice cooker. After cooking rice, the same rice as that shown in Example 2 was obtained (S
/ H value: 0.050 ± 0.025).

Comparative Example 1 300 g of Indica rice was washed and then immersed in water for 1 hour.
The weight of the indica rice after soaking and draining was 390 g. This indica rice was heat-gelatinized at 75 ° C. for 5.7.
% Of waxy cornstarch solution was added (that is, waxy cornstarch with a weight ratio of 8 to 100 of raw rice and water with a weight ratio of 150 to 100 of solid amount) and cooked in a commercially available electronic jar rice cooker. After the rice was cooked (the rice cooker switch was turned off), the cooked rice had a layer of paste on the bottom of the kettle, and the cooked rice in the center of the kettle had a core.

Example 6 After washing 300 g of Indica rice, 486 g of a 4.9% white pearl powder solution gelatinized by heating to 75 ° C. (that is, weight of white pearl powder with a weight ratio of 8 to 100 of raw rice and 100 with respect to the solid amount) It was immersed in water (ratio of 100) for 2 hours. After the immersion, rice was cooked with a commercially available electronic jar rice cooker. The obtained cooked rice was the same as the cooked rice shown in Example 1. The S / H value at this time was 0.063 ± 0.039 (control product; 0.013 ± 0.0
11).

Example 7 After washing 300 g of Indica rice, it was immersed in water for 1 hour.
The weight of the indica rice after soaking and draining was 390 g. To this indica rice, 420 g of 5.7% gelatinized shiratama powder solution and 3 units of α-amylase (manufactured by Hankyu Bio Industry; liquefying enzyme T) were added, and cooked in a rice cooker with a commercially available electronic jar. did. After cooking rice, the same rice as that shown in Example 1 was obtained.

[0033]

EFFECT OF THE INVENTION From milled rice with a high amylose content such as indica rice, in terms of workability, there is little collapse of the cooked rice, it is glossy, and there is no dryness, giving a plump texture and stickiness. It is possible to produce cooked rice having an improved taste.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ikuo Kimura 559-6 Kitano-cho, Hachioji-shi Central Research Institute of Japan Fisheries Stock Company (72) Inventor Tsuyoshi Koriyama 559-6 Kitano-cho, Hachioji-shi Central Research Institute of Japan Fisheries Co., Ltd. In-house

Claims (5)

[Claims] 1. A method for producing cooked rice, which comprises adding pregelatinized waxy corn starch and / or pregelatinized white syrup flour to the rice cooked of nonglutinous rice containing 20% by weight or more of amylose in the starch contained therein. Method. 2. The method for producing cooked rice according to claim 1, further comprising adding α-amylase. 3. Cooked rice of waxy corn starch and / or shiratama powder, and α-amylase are added to the cooked rice of nonglutinous rice containing 20% by weight or more of amylose in the starch contained therein. Manufacturing method. 4. When cooking non-glutinous rice of non-glutinous rice containing 20% by weight or more of amylose in the starch contained therein, waxy cornstarch and // as water for cooking rice is used.
Alternatively, a method for producing cooked rice is characterized in that water containing shiratama powder is used, and the rice is first pre-soaked and then cooked. 5. The non-glutinous rice is indica rice.
5. The method for producing cooked rice according to claim 4.