JPH06343406A - Production of boiled rice - Google Patents

Abstract

PURPOSE:To obtain sterile boiled rice having reduced unevenness of water content between the upper and lower parts of a container and an excellent taste by packing rice grain and carbonated water into a closed packing container, sealing the container, simultaneously sterilizing by heating under pressure and boiling. CONSTITUTION:Polished rice is washed with water, immersed in water and allowed to stand for one hour to give water-soaked rice. The water-soaked rice is packed into a polypropylene container, carbonated water having a volume ratio of a carbon dioxide gas of 0.85 is supplied to the container, which is hermetically sealed with a plastic lid. Then the packed container filled with the rice grain and carbonated water is arranged under a given pressure condition, irradiated with microwave under 2.1kg/cm<2> pressurizing condition, the temperature of the contents is rapidly raised and heating is continued until the temperature of the contents reaches 125 deg.C. The container is maintained at the given temperature for 10 minutes and sterilized by heating under pressure and boiled to give sterile boiled rice having reduced unevenness of water content between the upper and lower parts of the container and an excellent taste.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of producing cooked rice with good flavor and sterilization by subjecting it to pressure heat sterilization under a constant pressure condition.

[0002]

2. Description of the Related Art In the case of cooking rice using a generally popular rice cooker such as a conventional electric kettle or a gas kettle, after washing raw rice, the rice is filled in a predetermined kettle and the lid is closed by adding an appropriate amount of water. After absorbing water for a while, heat it.

At this time, rice grains float in a large amount of water in the initial stage of heating and are vigorously stirred up and down. Even after the water absorption progresses and the stirring motion of rice grains is gradually suppressed, the water accumulated in the lower part of the kettle changes to steam by heating from the bottom, and at the upper part of the kettle steam Are condensed and become water drops and move to the lower part.

By repeatedly convectively moving the water up and down as described above, the water in the kettle was made uniform, and the resulting cooked rice had no water unevenness and had a very good flavor.

However, in the above method, it takes a considerable time to cook rice, and it is impossible to supply aseptic cooked rice according to the Food Sanitation Law on a commercial scale. It is necessary to perform the pressure heat sterilization treatment used.

[0006] In the raw rice filling method in the method for producing cooked rice by the pressure heat sterilization treatment, rice grains are filled in a dedicated container in the presence of water, and the container is filled with 120 from the outside.
By heating under pressure with steam or hot water of around ° C or microwave, the hydrogen bond of the rice starch granules is broken, the starch granules are swollen and gelatinization is promoted to obtain cooked rice.

[0007]

However, in the above-mentioned method, vigorous convection movement of water does not occur due to the small ambient temperature distribution, and therefore the rice grains are not agitated,
No vertical movement of the rice grain can be seen.

Therefore, the water staying in the lower part of the container hardly moves upward, the lower rice grain continues to be dipped in the liquid, and the upper rice grain is not supplied with sufficient water, so that the entire rice grain has uneven water content. Remarkably occurs.

[0009] Along with this, even when the cooked rice is ready, the upper part is hard due to lack of water, and conversely the lower part becomes pasty or rice cake-like due to excess water, and the state of the cooked rice in the upper and lower parts varies. Conspicuously, the texture of cooked rice was not satisfactory.

Therefore, in the present invention, in view of the above problems,
When rice is cooked in a specified container, the unevenness of water in the upper and lower parts of the container is reduced, and the same fluffy texture and texture as rice cooked with a normal rice cooker can be obtained, and aseptic cooked rice on a commercial scale. It is an object to provide a manufacturing method of

[0011]

The present invention takes the following technical means in order to achieve the above object.

That is, after filling a predetermined closed type packaging container with rice grains and carbonated water, the container is hermetically sealed, and thereafter, it is subjected to pressure heat sterilization treatment and rice cooking.

[0013]

In the method for producing cooked rice according to the present invention, by using rice grains and carbonated water in which carbon dioxide gas is dissolved, carbon dioxide gas dissolved in water is foamed during sterilization under heating under pressure. Even if the rice grains are agitated and the water absorption progresses and the agitation movement of the rice grains is gradually suppressed, the water convection state continues, so there is little moisture unevenness even at the top and bottom of the container, and therefore, a normal rice cooker It is possible to obtain the same fluffy texture and texture as rice cooked.

[0014]

EXAMPLE An example of the method for producing cooked rice according to the present invention will be described below. First, after filling the microwave-permeable closed type packaging container with rice grains and carbonated water in which carbon dioxide gas is dissolved,
The container is sealed, and then microwave irradiation treatment is performed in a microwave heating device in which the pressurizing condition is adjusted to 1.5 to 2.5 kg / cm ² according to the predetermined content heating temperature. This makes it possible to produce sterilized cooked rice. The contents heating temperature condition is 115 to 12
It can be exemplified at 5 ° C for 10 to 30 minutes, but there is no particular limitation.

The pressurizing conditions are adjusted so that the contents do not bump and the packaging container does not deform or burst, and the pressure difference between the container internal pressure and the processing tank internal pressure is within a certain range. It is necessary to keep within.

As the method for producing cooked rice, a method of performing sterilization treatment by performing the microwave irradiation treatment is mentioned, but the method is not limited to this method, and for example,
Any method such as normal retort sterilization using steam or hot water, or pressure heat sterilization treatment equivalent thereto may be used.

The rice grains according to the present invention are not particularly limited, and include, for example, polished rice, seven-minute mashed rice, half-polished rice, brown rice,
It is possible to use germ rice etc.

Further, as the carbonated water, the volume of carbon dioxide gas in the volume ratio of 0.5 to 1.5 is exemplified.
The conditions are not particularly limited, and can be appropriately adjusted according to the air content in the packaging container, the pressure resistance, and the like.

Since the packaging container needs to have pressure resistance and heat resistance in accordance with pressure and heating conditions, its material is polyethylene, polyester, polypropylene, polyethylene terephthalate, etc., or a monolayer body thereof, or It is possible to use a laminate, or a laminate in which a gas barrier material such as an ethylene vinyl acetate copolymer is further laminated as an intermediate layer.

In the present invention, when filling the packaging container with rice grains and carbonated water, washed raw rice grains may be washed with rice and then immersed in water to leave water-immersed rice and carbonated water may be filled. ,
Raw rice grains after washing may be filled with carbonated water as they are. In the following description, both raw rice grains and water-immersed rice are simply referred to as rice grains.

The packaging container filled with rice grains and carbonated water can be sealed by a known means such as heat sealing.

Hereinafter, the method for producing cooked rice of the present invention will be described.
This will be described in detail with reference to some examples.

<First Example> 88 g of polished rice was washed and then 1
After soaking for time, 111 g of water-soaked rice was obtained. After filling the water-immersed rice in a polypropylene container having a capacity of 350 cc, 89 g of carbonated water having a volume ratio of carbon dioxide of 0.85 was filled and hermetically sealed with a plastic lid.

Then, the packaging container filled with the rice grains and carbonated water was placed under the predetermined pressure condition to obtain 2.1 kg.
Microwave irradiation was performed under a pressure condition of / cm ² to rapidly raise the temperature of the content and heat treatment was performed so that the temperature of the content reached 125 ° C.

Next, a mottled step was performed by adjusting the amount of heat so that the predetermined temperature could be maintained for about 10 minutes, and further cooling was performed to obtain 200 g of aseptic cooked rice.

<Second Embodiment> 88 g of polished rice and 112 g of carbonated water having a volume ratio of carbon dioxide gas of 0.91 are 3 parts.
After filling a polypropylene container having a capacity of 50 cc, 200 g of aseptic cooked rice was obtained in the same manner as in the first embodiment.

<Comparative Example 1> 450 g of polished rice was cooked in a commercially available electric rice cooker, and subjected to a mulling process and a loosening process to obtain 1040 g of cooked rice.

Second Comparative Example Under the pressurized condition of the first example, conventional tap water was used in place of the carbonated water, and other conditions were the same, and 200 g of aseptic cooked rice was obtained.

<Third Comparative Example> Under the pressurized condition of the second example, conventional tap water was used in place of the carbonated water, and other conditions were the same, and 200 g of aseptic cooked rice was obtained.

Regarding the aseptic cooked rice obtained in each of the first and second embodiments and the second and third comparative examples, the surface portion (upper portion) and the bottom portion (lower portion) of the cooked rice cooked in the predetermined container The water content of and was measured by a conventional method. The results are shown in Table 1.

For the measurement of the water content, 2 g of each cooked rice on the surface and bottom was weighed by a weighing tube, left for 3 hours in a constant temperature dryer adjusted to 135 ° C., and then a desicator 30 Allow to cool for a minute and weigh to determine water content.

[0032]

[Table 1]

The cooked rice obtained by the method in each of the above-mentioned examples was stored for one day, and the appearance, aroma, taste,
The variation of rice grains and comprehensive evaluation were conducted by a sensory evaluation test (method according to the method of the Food Agency). The results are shown in Table 2.

In the sensory evaluation method, the same level of evaluation as that of the cooked rice obtained in the first comparative example was set to "0", and the evaluation was divided into 6 levels from -1 to -5, and then evaluated. The evaluation “0” of the first comparative example is set to 100 points (highest evaluation value),
The other values are converted into evaluation values of 80 to 0, respectively.

[0035]

[Table 2]

From the results shown in Tables 1 and 2 above, the cooked rice obtained using the carbonated water of the first and second examples has a surface portion that is higher than that of cooked rice obtained using conventional tap water. The difference in water content between the bottom and the bottom is extremely small, and accordingly, in relative evaluation, cooked rice cooked by the method of the present invention is compared in appearance, aroma, taste, texture and variation. The evaluation was good, and in particular, a very high evaluation was obtained regarding texture and variation.

Therefore, the use of carbonated water in the method for producing cooked rice of the present invention makes it possible to obtain cooked rice which is very good in total, as compared with the conventional method using tap water or the like. Can be said.

[0038]

According to the method for producing cooked rice of the present invention, after filling a predetermined closed type packaging container with rice grains and carbonated water, the container is sealed and then subjected to pressure heat sterilization and cooking. During the heating and sterilization under pressure, carbon dioxide gas dissolved in water is foamed, whereby the rice grains filled in the container are agitated at the beginning of heating, and the stirring motion of the rice grains is gradually suppressed. , The convection state is continuing in the container.

The cooked rice produced by the above method has little unevenness in water even in the upper and lower parts of the container, and it is possible to obtain the same fluffy texture and texture as rice cooked by an ordinary rice cooker. .

Therefore, by using the method for producing cooked rice from rice grains and carbonated water according to the present invention, it is possible to easily obtain aseptic cooked rice which is extremely good even at a commercial level.

From the above, the method for producing cooked rice of the present invention makes it possible to produce a completely new type of cooked rice having both good quality and simplicity on a commercial scale.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichiro Komatsu 463 Kagasuno, Kawauchi Town, Tokushima City, Tokushima Prefecture Otsuka Chemical Co., Ltd.Food Research Institute (72) Inventor Ryo Nakakita 463 Kagasuno, Kawauchi Town, Tokushima City, Tokushima Prefecture Gaku Co., Ltd.Food Research Institute (72) Inventor Tomoyuki Nakamura 463 Kagasuno, Kawauchi-cho, Tokushima Prefecture Otsuka Chemical Co., Ltd. Food Research Institute (72) Inventor Masanori Watanabe 463 Kagasuno, Kawauchi-cho, Tokushima Prefecture Otsuka Chemical Shares Company Food Research Institute (72) Inventor Kimio Hirota 463 Kagasuno, Kawauchi-cho, Tokushima City, Tokushima Prefecture Otsuka Chemical Co., Ltd. (72) Inventor Kazuma Suzuka Okamoto 463, Kagasuno, Tokushima City, Tokushima Prefecture Inside the Food Research Center

Claims (1)

[Claims] 1. A method for producing cooked rice, which comprises filling a predetermined closed type packaging container with rice grains and carbonated water, sealing the container, and then sterilizing by heating under pressure and cooking rice.