JPS59106260A - Instant boiled rice - Google Patents

Abstract

PURPOSE:Instant boiled rice having the same whiteness, gloss, and pleasantness to the palate as those of boiled rice prepared by a pan or pot, by subjecting rice grains which are washed with water, immersed in water and dehydrated to internal induction heating so that the rice grains are adjusted to a given water content, subjecting it to vacuum packaging. CONSTITUTION:A given amount of polished rice having about 15wt% water preserved in the tank 1 is weighed, sent to the rice washing machine 4 by pressure, and washed with water by pressure of the jetting water 4a and the agitator 4b for about 3min. The rice grains K adjusted to about 24wt% water content are sent to the water immersion device 6 by the pipe 5, immersed in water for about 30min, the rice grains K reaching about 32wt% water content are put in the netlike container 8a of the dehydrating packing device 8, dehydrated fully, and a fixed amount of the rice grains is continuously packed 8b into the containers C made of PP, arranged at a constant interval, traveling in the arrow direction. While the packing containers C are passed through the microwave irradiation device 11, they are irradiated with microwave, heated to 100 deg.C or a little higher than it and the rice grains are boiled. The boiled rice grains are subjected to vacuum packaging by the vacuum device 12, and cooled to about 4 deg.C by the cooler 13, to give an instant boiled rice product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to instant rice that has the same white color, gloss, texture, and taste as rice cooked in a pot or pot by a simple rice cooking process.

Rice has been the staple food of Japanese people for a long time, and the cooking methods include washing the rice, draining the water (so that water can be added accurately),
Processing methods such as adding water, immersion, heating, and unevenness are also well established.

However, the actual rice cooking process relies heavily on human experience and intuition, such as determining the level of rice washing and the amount of water added, making it difficult to control the degree of cooking.Furthermore, each processing step requires an appropriate amount of time. It takes more than 70 minutes to cook, and there was a need to simplify the process.

Therefore, automatic rice cookers and recently various instant rice and simple rice cooking methods that simplify the rice cooking process have been proposed, and these are commercially available as retort food. Although this kind of instant rice is mainly intended for home use, simplification of the rice cooking process is more in demand in the food service industry such as restaurants and cafeterias. hand,
Simplifying the rice cooking process, that is, shortening the working time by omitting pre-processing of rice cooking, is an important business issue. Furthermore, the problem of processing contaminated water from rice washing, which is part of the pre-processing for rice cooking, is a major problem.

This is because in the near future, restaurants and other food service industries may be designated as business establishments subject to the Water Pollution Control Act, and in that case, although their scale is relatively small, they will discharge relatively large amounts of highly polluted wastewater. This problem becomes a very big problem for the restaurant industry, which has many stores and offices.

Most of the various instant rice or rice cooked by instant rice methods that have been proposed in the past involve milling the raw rice, soaking it in water, and then steaming it to a moisture content of about 65%, and then weighing out a certain amount. It is packaged and subjected to retort sterilization to extend its shelf life, then cooled, packaged, and shipped to the market.

Most of this type of instant rice is eaten by putting it in boiling water or heating it in a microwave oven while still packaged, and then removing the packaging after heating. When I tried cooking the rice, I found that the white discoloration had disappeared and the color was slightly brownish, and the individual rice grains were separated. I notice that it is inferior. Because rice has been a staple food for many people for a long time, they are particularly sensitive to its luster, texture, and taste, and it is a fact that many people have experienced that traditional instant rice is inferior to regular rice in these respects. However, even with his talent, he hasn't made any improvements. For this reason, there is currently no tendency for ordinary households to use instant cooked rice instead of regular cooked rice.

In consideration of the above points, the present invention proposes an instant rice that can obtain cooked rice with the same whiteness, gloss, texture, and taste as regular cooked rice through a simple rice cooking process. internal induction heating to reduce the moisture content to approximately 32-35%
The product is then vacuum packaged to produce instant cooked rice.

The present invention will be explained below based on the drawings.

FIG. 1 is a schematic diagram of an instant cooked rice manufacturing apparatus according to the present invention.

1 is a tank that stores raw rice, and this tank has a moisture content of 15%.
The polished rice before and after is stored. Reference numeral 2 denotes a pneumatic rice feeder having a measuring device, which measures a certain amount of polished rice stored in a tank 1 and pressure-feeds it through a conduit 3 to a rice washing machine 4. In the rice washing machine 4, polished rice is stirred by an agitator 4b driven by the pressure of water ejected from a nozzle 4a and a motor M. The water pressure is about 4 to 9/c++f, which is enough to prevent polished rice from cracking.
Do the following for about 3 minutes. If the soaking time is less than 3 minutes, the rice bran and dirt cannot be removed sufficiently, and if the soaking time is longer than 3 minutes, the rice grains K may be cracked although the rice grains K can be removed sufficiently.

Rice grains begin to absorb water during this washing process, and the water content after washing reaches approximately 24%. The soaked rice grains are sent to conduit 5 along with the water.
The container is then transported to a submergence container 6 filled with water in advance, where it is submerged in water for about 30 minutes.

Water is poured into the water immersion container 6 from the injection lower. The moisture content of rice grains decreases to around 30% after soaking for about 30 minutes, and rises to about 3.2% after soaking for 120 minutes, but does not increase after that, so considering work efficiency, the soaking time is about 30 minutes. is sufficient. On the other hand, if the soaking time is less than 30 minutes, water will not be able to spread between the individual crystals of the rice grains, so water will not be able to spread between the molecules in the subsequent microwave irradiation process, and the center of the rice grains will not be completely absorbed after cooking. It does not gelatinize and becomes powdery and has a core, which causes a decrease in taste.

Reference numeral 8 denotes a drainer and filler, in which the soaked rice grains K are placed in a net-like container 8a, drained for about 10 minutes, and then filled into container C in a fixed amount. If you don't drain the water sufficiently, the contact surface with Yoneyoshi water will turn into a paste-like surface when irradiated with microwaves, which is undesirable.On the other hand, if you drain the rice for a long time (more than 10 minutes), it will become too dry and the moisture in the rice grains will be lost. This transpiration causes cracks in the rice grains. The moisture content of the rice grains after being soaked in water is about 32%. Note that if a plurality of colander fillers 8 are arranged side by side, work efficiency will be improved.

The container C is manufactured by passing a rolled wrapping sheet 9 made of polypropylene, polyester, nylon or the like through a molding machine 10 and heat-forming it there. While the containers C lined up at regular intervals move in the direction of the arrow at a slow speed, when each container C reaches the position number of the filling port 8b at the lower end of the drainer filling device 8, a certain amount of rice grains are released from the filling port 8b. Filled.

The filling container C is equipped with a microwave irradiation device (for example, a frequency 24
50 MH, output 200-600 W) 11, it is heated by microwave irradiation and its moisture content changes depending on the irradiation time as shown in Figure 2 (A in the figure is the inside of the solid rice, B is the inside of the solid rice). shape is the external moisture content of rice). The temperature of the rice grains immediately after leaving the microwave irradiation device 11 is 100° C. or slightly higher. The rice grains heated in this way are vacuum packed in a vacuum device 12, and then packed in a cooling device 13 for about 40 minutes.
cooled to ℃. The purpose of cooling here is to prevent the starch from gelatinizing due to the heat held by the rice grains.

The packaged rice thus obtained is separated one by one for each container. Reference numeral 14 denotes a humidity adjustment chamber for keeping the moisture content of the rice grains unchanged during the processing from microwave irradiation to subsequent vacuum packaging.

Processing conditions such as temperature, amount of water, water temperature, etc. in each processing step of the above-mentioned production apparatus are not limited, and can be arbitrarily changed depending on production capacity, amount of rice per container, etc.

However, during the above processing steps, the order of the microwave irradiation, vacuum treatment, and cooling treatment may be changed. Furthermore, although microwave irradiation was used to internally induction heat the rice grains in the above embodiments, other internal induction heating means may of course be used.

The rice produced using the above production equipment has white discoloration, gloss, taste,
In terms of elasticity, it is superior to conventional instant cooked rice of this type, but this is thought to be due to the microwave irradiation, and the reason for this is thought to be as follows. The white discoloration is due to the intense movement of the rice grain molecules due to microwave irradiation, which causes sufficient moisture to be trapped between each molecule, and the white discoloration is more pronounced than in normal rice. The luster is due to the fact that the molecules of the rice grains vibrate and generate heat, which keeps the cell membranes of the rice grains healthy and gives them a glossy appearance. The taste of cooked rice is determined by the degree of starch gelatinization, but microwave irradiation keeps the water content at about 32 to 35%, and the subsequent rice cooking process further promotes starch gelatinization. It is thought that this is why the taste is so strong.

In the conventional instant rice manufacturing process, the water content of rice grains is reduced to about 65% by steaming after soaking in water. Also,
Because the gelatinization of starch progresses uniformly through microwave irradiation, the elasticity becomes almost the same as that of regular rice.

When we investigated the white discoloration, gloss, and taste of the cooked rice obtained by cooking the instant cooked rice according to the present invention, we found that it changed depending on the length of the irradiation time.

Figures 3 (a), (b), and (c) show changes in white discoloration, gloss, and taste when microwave irradiation time was varied for cooked instant rice that had been refrigerated at 4℃ for 5 days after production. show.

As can be seen from this graph, an irradiation time of around 10 minutes produces good results. The irradiation time also affects the moisture content and shelf life of the rice grains. Figure 4 shows a test in which the rice grains were immersed in water before irradiation and the p115 was reduced to less than p115 to suppress the growth of bacteria. In the example shown in b), if the irradiation time is 8 minutes or less, the
Rice that has been stored for days will develop a bad odor due to bacterial growth, and if the irradiation time is longer than 12 minutes, the moisture content will decrease, and if the irradiation time is extended, the rice grains may even burn. (A in the figure is the inside of the rice grain, and B is the outside of the rice grain.) Regarding shelf life, the results of a constant temperature test at a room temperature of 35°C after production revealed that if the irradiation time was less than 10 minutes, the shelf life would be extremely poor, reaching 20 days or less. Ta.

To cook the instant rice prepared in this way, the packaged rice is torn open and the solid cooked rice is taken out, placed in a container such as a pot or kettle, and water is measured, added, and heated.

The rice takes about 15 minutes to cook, and the rice cooks for about 15 minutes unevenly, for a total of about 30 minutes. The cooked rice is exactly the same as hand-cooked rice in terms of white discoloration, gloss, taste, and texture, and the taste is far superior to that of conventional instant rice. The present invention can be applied not only to the cooking of polished rice but also to the cooking of brown rice, which is convenient because a pressure cooker or the like is not required in this case.

As explained above, in the present invention, rice grains that have been washed, soaked in water, and drained are internally heated by induction heating to reduce the water content to about 32%.
~ 35% and then vacuum-packed it to produce instant cooked rice, which significantly shortened the time required for cooking to about half of the conventional method, and the cooked rice did not turn white, had a glossy texture, and had a similar taste to that of conventional instant cooked rice. It has been experimentally confirmed that it is far superior to retort food such as boiled rice and instant brown rice, and even better than hand-cooked rice, and has been well received by tasters. The microwave irradiation in the process of producing instant cooked rice according to the present invention corresponds to both the conventional heating and sterilization processes, so the process can be simplified.

When the instant cooked rice according to the present invention is used in the food service industry such as a restaurant, there is no need for pre-treatment for rice cooking, so there is no problem with disposing of contaminated water, which is extremely advantageous in terms of equipment, operation, maintenance, etc. Needless to say.

[Brief explanation of the drawing]

Figure 1 is a route map of the instant cooked rice manufacturing device according to the present invention, Figure 2 is a diagram showing changes in the moisture content of rice depending on the microwave irradiation time, and Figures 3 (A), (B), and (C). Figure 4 (A) shows the relationship between the irradiation time and the moisture content of rice. Figure, (b) is a diagram showing the relationship between microwave irradiation time and shelf life. 1... Tank 2... Air rice feeder 3, 5... Conduit 4... Rice washer 4a... Nozzle 4b... Stirrer 6... Water immersion container 7... Inlet 8 ...Drainer filling device 8a...Container 8b...Filling port 9...
Packaging sheet 10... Molding machine 11... Microwave irradiation device 12... Vacuum device 13... Cooling device 1
4...Humidity Control Room Patent Applicant: Ichikawa Co., Ltd. Attorney, Hiroo Tsuchi Suzuki Figure 2 Figure 3 JP-A-59-1062 GO (5) Figure 3 Procedural Amendments March 10, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Indication of the case, Patent Application No. 214659 filed in 1982, 2, Name of the invention, instant rice 3, Name of the person making the amendment: Ichikawa Co., Ltd. 4, Agent address: 3-4 Shiba, Minato-ku, Tokyo No. 1 @ Tomowa Building 6, Detailed Description of the Invention Column 7 of the Specification Subject to Amendment, Contents of the Amendment The specification of the present application is amended as follows. (1) After "Filling" in the third line of page 6, there is a message that says, "At this time, the surface of the filled rice grains should be flattened to prevent them from becoming mounds. (2) Add “It is a humidity control room.” on page 7, line 13.
Instead of using the vacuum device 12, if a portion of the rice grains is left in the charged container C and temporarily sealed, the water contained in the rice grains will turn into steam while being heated by microwave irradiation. The remainder of the coke is passed through with the air to the outside (as this leaks out, the inside of the container is in a vacuum state, so it can be degassed and a vacuum device is not required. In this case, the main seal of container C is removed after heat treatment by microwave irradiation. (3) In the 9th line of page 7, amend ``To prevent'' to ``To prevent and equalize quality.'' From the bottom of the same page. From the 4th line to the 2nd line, “Also...
・Moyoi. ” to be deleted. 1-(4) After "Of course it's good." in the second line of page 8 (ko, [
Containers C may be made separately in advance and stacked in a predetermined position* and then taken out one by one by a robot or the like, or they may be automatically strained so that they are supplied one by one. ” to join. (5) Page 10, line 15 [...It's convenient. '' followed by ``In addition, in the case of brown rice, of the pericarp, seed coat, ectosperm, aleurone layer, and starch from the surface that makes up brown rice, only the pericarp is removed during rice polishing to improve water absorption during cooking. Of course, in the case of rice cakes, it is necessary to boil the koazuki or cowpeas separately from the glutinous rice treatment, and then mix and stir the glutinous rice that has been soaked in water. Since this is well known, I will not elaborate further." 2- Procedural amendment July 1980/P Japan Patent Office Commissioner Kazuo Wakasugi 1. Indication of the case 1982 Patent Application No. 214659 2. Name of the invention Instant rice 3. Person making the amendment Related Patent Applicant Address: 430, Kanagawa Prefecture, Chiyogihogaku; Address: 4, Ichikawa Act Co., Ltd.; Agent Address: 5, Shiba City Building, 3-4-11 Shiba, Minato-ku, Tokyo; Date of Amendment Order: 6; 7. Contents of the amendment The specification of the present application will be amended as follows. (1) In the second line from the bottom of the third page, ``-1 is corrected to ``-1. ``7. Contents of correction (correction made with ljl [In this case...preferable.'') Next to -1, ``The height of the rice grains placed in the container 8a should be adjusted so that the entire surface is heated uniformly by microwave irradiation, which will be described later.'' 10 to 30, preferably 20 to 2
It is best to set the height to 5. If the height is below this range, the moisture content of the rice grains will decrease during heating, and if it exceeds this range, the surface will tend to burn before the inside is heated. There is almost no need to change this height even if the diameter of the container 8a changes. ” to join. (3) Correct “through-1” on page 6, line 13 to “through-1”, and correct “through-1” on line 14 to “through-1”. (4) on page 7 In the fifth line, "Slightly high. -1"
- Zukkami is low. Correct it to -1, and in the 7th line of the same page, [It will be cooled. Correct -I with "The lower the cooling temperature, the better the taste." -1 [Next, for your reference, the shelf life of the instant cooked rice produced from this book was tested using a standard agar medium using a standard agar medium using a homogenizer, and was heated to 48± in a 37°C incubator. As a result of 3 hours of culture, refrigerated storage (3°C ± 2°C)
For samples stored at 10811 days after production, both white rice and brown rice were below 300/g, and for samples stored in a thermostatic chamber (35°C), 63 days after production, both white and brown rice were at 300/g.
Less than /ri, after 73 days, 1.2XIO/Q for white rice
, 2.0 x 102/9 Bacillus bacteria were detected in brown rice. The number of bacteria of this level is the number of bacteria immediately after cooking ordinary rice, and it shows how long the instant rice prepared by the method of the present invention has. July 2, 1958 Director General of the Japan Patent Office Kazuo Wakasugi1, Indication of the case, Patent Application No. 214659 of 19822, Title of the invention Instant rice3, Person making the amendment/Relationship with the case Patent application Person name: Ichikawa Act Co., Ltd. 4, agent address: Shiba City Building 6, 3-4-11 Shiba, Minato-ku, Tokyo
, Column 7 of detailed explanation of the invention in the specification subject to amendment, Contents of amendment

Claims (2)

[Claims] (1) Instant cooked rice, characterized in that a predetermined amount of rice grains that have been washed, soaked in water, and drained are heated internally to a moisture content of about 32 to 355 I6, and then vacuum packaged. (2) The instant cooked rice according to claim 1, wherein internal induction heating of rice grains is performed by irradiating microwaves.