JPH03195465A - Method for cooking rice - Google Patents

Abstract

PURPOSE:To prevent stickiness of rice and cook rice with excellent gloss and hardly and roughness on the surface of the rice grains in good yield by dipping rice in water, heating the dipped rice with steam, pregelatinizing starch and then cooking the rice. CONSTITUTION:Rice is dipped in water and the dipped rice is then heated with steam to pregelatinize starch. The steamed rice is subsequently cooked to provide cooked rice.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a rice cooking method suitable for various types of cooked rice such as rice, pilaf, and fried rice.

``Conventional technology'' Conventionally, when cooking rice, the rice was soaked in water (soaking process), and then the soaked rice was placed in a rice cooker and water was added to cook it (cooking process). The cooking process consists of a boiling process in which the rice is heated in a rice cooker to swell and gelatinize the rice, and at the same time gelatinizes the starch in the rice, and a baking process in which the rice is cooked once the water in the pot has been absorbed by the rice. The steaming process can then be divided into a steaming process in which the pot is left to steam without removing the lid.

"Problems to be Solved by the Invention" Such conventional rice cooking methods had the following problems.

■ During the cooking process, water absorption and heating proceed simultaneously from the surface side of the rice grain, and gelatinization and swelling of starch proceed simultaneously from the surface side of the rice grain, so the surface side of the rice grain rapidly gelatinizes. ,
For this reason, the path for water to enter the center of the rice grain becomes narrow, making it difficult for water to penetrate into the center of the rice grain, resulting in a problem that a difference in hardness tends to occur between the center and the surface of the cooked rice grain.

In addition, as mentioned above, since the path for moisture to enter the center of the rice grain becomes narrower, it takes time for the center of the rice grain to swell and gelatinize. There is a problem in that the starch on the surface side of the rice grains exposed to water swells excessively and dissolves out, resulting in a sticky texture to the cooked rice.

■ In addition, in the conventional rice cooking method, in order to produce rice with a firm texture, if the amount of water added to the boiling process is reduced, the amount of water that permeates into the center of the rice grain will further decrease. It tends to be in a hard state, so-called a state where the core remains.

For this reason, conventional rice cooking methods have had the problem of not being able to produce hard rice with a good yield.

■ Broken rice and immature rice have small grains, so they swell and gelatinize faster than normal rice. For this reason, when low-grade rice containing defective rice such as broken rice is used, the viscosity of the entire rice becomes too high, resulting in a problem of poor texture.

In addition, when producing hard rice using low-grade rice that contains defective rice such as broken rice, it is necessary to further reduce the amount of water added in the boiling process, which prevents swelling of the center of the rice grain. It becomes increasingly difficult. For this reason, when hard rice is produced using rice containing broken rice or the like using conventional rice cooking methods, there is a problem in that the yield is extremely low.

■ In addition, when using rice with strong bran, such as old rice or ancient rice, there have been complaints that even after thorough washing, the rice retains a strange odor and loses its flavor. .

The present invention was made in view of the above circumstances, and it is possible to cook the center part of the rice grain in the same way as the surface part, and also to cook defective rice such as broken rice and immature rice in the same way as normal rice. To provide a method for cooking rice that can cook rice and also remove rice bran odor.

"Means for Solving the Problems" The rice cooking method of the present invention includes a soaking step of soaking rice in water;
The above object was achieved by inserting a rice steaming process in which the soaked rice is steamed to gelatinize the starch in the rice between the cooking process in which the rice is cooked.

An example of the rice cooking method of the present invention is shown in the order of steps as follows.

1st step (soaking step) Soak the rice in water.

2nd process (steamed rice process) Steam the soaked rice with steam to remove the starch in the rice. Become alpha.

3rd process (cooking process) Steamed rice with hot or cold water Put it in a rice cooker and heat it up.

This cooking process usually involves heating a rice cooker filled with steamed rice and water so that the rice absorbs water, swells, and becomes a paste, and a boiling process in which the water in the rice cooker is absorbed by the rice. It can be divided into three steps: the grilling process, in which the rice grains touching the bottom of the pot are scorched by additional cooking, and the post-steaming process, in which the rice is left to steam after it has been cooked without removing the lid of the pot.

"Function" In the rice cooking method of the present invention, the starch in the rice grains is gelatinized in the rice steaming step, and the rice grains are swollen and gelatinized in the cooking step. During the rice steaming process, gelatinization progresses with almost no moisture being absorbed into the rice grains from the outside, so the rice grains do not swell during the steaming process, and the steamed rice grains keep their water absorption channels open. There is. When these steamed rice grains are then heated with hot water or water in the cooking process, water rapidly permeates into the rice grains through the open water absorption channels and is evenly distributed throughout the rice grains. The center of the rice grain swells and becomes gelatinous almost simultaneously with the surface.

Furthermore, according to the rice cooking method of the present invention, as mentioned above, the steamed rice grains have a water absorption path open, and when these rice grains are heated with hot water or water in the cooking process, they absorb water. Because moisture quickly penetrates into the interior through the channels, the moisture is evenly distributed throughout the rice grain, even if the amount of water added during the cooking process is reduced to produce rice with a firmer texture.

In addition, according to the rice cooking method of the present invention, water rapidly permeates into the center of the rice grain from the open absorption path of steamed rice, so the speed at which water permeates into defective rice such as broken rice and immature rice is fast. The difference in the speed at which water permeates into normal rice and rice is almost eliminated. As a result, defective rice also swells and becomes gelatinous at the same time as normal rice.

In addition, according to the rice cooking method of the present invention, when soaked rice is steamed, the principle of steam distillation is applied, ie, ``even oils with a high boiling point can be distilled out at a temperature lower than the boiling point in the presence of water vapor.'' The rice bran odor is removed by this principle.

Moreover, according to the rice cooking method of the present invention, since the starch in the rice grains is pregelatinized, the time required for the cooking process, which requires large equipment, can be reduced to less than half.

"Example" Hereinafter, an example of the rice cooking method of the present invention will be described along the flowchart shown in FIG.

We weighed 50 kg of polished rice made from 1962 old rice (produced in Kumamoto Prefecture, variety Minaminishiki) for other purposes. This rice was then washed three times using a well-known method (rice washing step 1). Next, transfer the washed rice to a soaking tank, add 75 kg of water, and add 20 kg of water.
℃ for about 1 hour (immersion step 2). After soaking process 2 was completed, the moisture content of the rice was measured and found to be 30-40%.
Met. Rice that has completed soaking process 2 after this (soaked rice)
The rice was put into a vertical rice steamer 20 shown in FIG. And about 10 from the nozzles 21, 21 provided in the middle of the body.
Steam at 0° C. was blown into the rice for 10 to 15 minutes (steamed rice step 3). After that, the steamed rice was taken out from the screw conveyor 22 provided at the bottom of the rice steamer 20. When we examined this rice, we found that the starch in the rice grains had become pregelatinized.
Moisture content was 35-45%.

Next, weigh 5 kg of the steamed rice and start the cooking process.
entered in. In the cooking process 10, first, weighed steamed rice and 8
4.0 kg of hot water adjusted to 0° C. was placed in a round rice cooker 30 with a diameter of 40 cm shown in FIG. 3, and heated over a gas fire for 8 minutes (boiling step 4). When all the moisture in the pot 30 is absorbed by the rice and the surface temperature of the pot 30 rises rapidly, the heat is lowered and heated for 2 minutes (baking step 5), and the extract from the rice is scorched on the inner surface of the pot 30. It has a unique fragrant aroma. After that, I turned off the heat and steamed for 15 minutes without removing the lid and keeping the temperature above 95°C (post-steaming step 6).
. The resulting rice weighed 7.8 kg.

When the cooked rice was examined, it was found that the rice grains were well swollen to the center, the center and the surface were equally hard, and the surface was less sticky. In addition, the rice grains had less surface roughness and good gloss.

When we examined the odor of the cooked rice, we found that the rice bran odor characteristic of old rice had disappeared, and it had the aroma characteristic of pot-cooked rice.

In addition, according to this rice cooking method, boiling step 4 and baking step 5
The cooking process 10 consisting of the steaming process 6 and the steaming process 6 could be completed in less than half the time of the conventional method. From this, it has been found that according to this rice cooking method, the size of the entire equipment including the rice steamer 20 and the like used in the rice steaming process 4 can be made significantly smaller than the conventional rice cooker.

(Example 2) The same polished rice as in Example 1 was prepared, and a portion of it was crushed. In this way, rice containing about 20% by weight of broken rice was prepared, and this was cooked in the same manner as in Example 1.

When the viscosity of the cooked rice was examined, it was found to be on the same level as the rice produced in Example 1. According to this rice cooking method, even if broken rice is mixed in, the rice does not become sticky and has a good texture. We have confirmed that it can be produced.

(Example 3) Using the same polished rice as in Example 1, make 10 hard rice for fried rice.
I cooked it twice. The only difference from the rice cooking method of Example 1 is that the amount of hot water used in the boiling step 4 was 3.5 kg.

When the rice grains of the cooked rice were examined, it was found that both the center and the surface were equally hard. There was also no core left.

Therefore, it was confirmed that rice having a hard texture could be cooked with a good yield according to this rice cooking method.

(Example 4) The polished rice containing 201% by weight of broken rice used in Example 2 was divided into 10 batches and cooked to a firm consistency using the same rice cooking method as in Example 3.

When the obtained rice was examined, it was found that it was not sticky.
The rice was the same hardness. There was also no core left.

(Example 5) When adding hot water in the boiling step 4, ingredients and seasonings were added at the same time to cook rice.

The rice cooked in this manner also had a good texture.

Note that the rice cooking method of the present invention is not limited to the soaking time, steaming time, boiling time, baking time, etc. shown in the above examples. These processing times can be set as appropriate depending on the required quality of the rice.

Further, in the above embodiment, the cooking process 10 is carried out immediately after the rice steaming process.
However, it is not necessary to immediately cook the steamed rice; for example, the cooking process can be carried out after it has been cooled to near room temperature.
You can also do this.

In addition, in the rice cooking method of the present invention, a type of equipment other than the rice steamer 20 and the rice cooker 30 can also be used.

"Effects of the Invention" As explained above, the rice cooking method of the present invention involves soaking rice in water, steaming the soaked rice with steam to pre-gelatinize the starch in the rice, and then pre-gelatinizing the starch in the rice. Because it is a method of cooking rice, during the rice steaming process, almost no water is absorbed into the rice grains from the outside, gelatinization progresses, and the rice grains do not swell.
The steamed rice grains keep their water absorption channels open. When these steamed rice grains are heated with hot water or water during the cooking process, water rapidly permeates into the rice grains through the open water absorption channels and is evenly distributed throughout the rice grains. The center of the rice grain swells and gelatinizes almost simultaneously with the surface.

Therefore, according to the rice cooking method of the present invention, rice grains can be cooked to a uniform hardness both in the center and on the surface.

Furthermore, according to the rice cooking method of the present invention, the center and surface portions of the rice grains are swollen almost simultaneously, so the swelling of the center portion is completed before the starch on the surface side of the rice grains becomes excessively swollen. Therefore, according to the rice cooking method of the present invention, rice can be prevented from becoming sticky.

Further, according to the rice cooking method of the present invention, there is extremely little starch leached from the surface of the rice grains, so the cooked rice grains have less rough surface and are glossy.

Furthermore, according to the rice cooking method of the present invention, the rice grains steamed as described above have water absorption paths open, and when these rice grains are heated together with rice or water in the cooking process, they absorb water. Because moisture quickly penetrates into the interior through the channels, the moisture is evenly distributed throughout the rice grain, even if the amount of water added during the cooking process is reduced to produce rice with a firmer texture. Therefore, according to the rice cooking method of the present invention, even if rice having a hard texture is cooked, the core will not remain, and the rice can be cooked with a high yield.

Furthermore, according to the rice cooking method of the present invention, water rapidly permeates into the center of the rice grain through the open absorption channels of steamed rice, so water permeates into defective rice such as broken rice and immature rice. The difference between the speed and the rate at which water permeates into normal rice is almost eliminated.

As a result, defective rice also swells at the same time as normal rice. Therefore, according to the rice cooking method of the present invention, starch elution from broken rice can be avoided, increase in viscosity of rice can be prevented, and rice with good texture can be produced.

Furthermore, as mentioned above, according to the rice cooking method of the present invention, defective rice such as broken rice swells at the same time as normal rice, and moisture is uniformly distributed both in the center and on the surface. It has the advantage of producing hard rice with good yield even if it is used.

In addition, according to the rice cooking method of the present invention, when soaked rice is steamed, the rice bran odor is removed by the principle of steam distillation. However, it is possible to produce rice with good flavor and no off-odor.

In addition, according to the rice cooking method of the present invention, since the starch in the rice grains is pregelatinized in the rice steaming process, the time for the cooking process, which requires large equipment, can be reduced to less than half. Therefore, according to the rice cooking method of the present invention, the size of the entire equipment including the rice steamer etc. can be made smaller than the conventional rice cooker.

[Brief explanation of drawings]

Fig. 1 is a flowchart showing the working procedure of the rice cooking method of Example 1, Fig. 2 is a schematic configuration diagram showing the vertical rice steamer used in the example, and Fig. 3 shows the rice cooker used in the example. It is a schematic diagram. l... Rice washing process l, 2... Soaking process, 3... Steaming process, 4... Boiling process, 5... Baking process, 6...
Post-steaming process! 0...Steamed rice process.

Claims (1)

[Claims] A rice cooking method characterized by soaking rice in water, steaming the soaked rice with steam to pre-gelatinize the starch, and then cooking the steamed rice.