JP2888066B2 - Method of making rice in a container - Google Patents

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 in a container, and in particular, it can provide cooked rice with excellent texture and is simpler and easier to produce aseptic condition than conventional methods for producing aseptic rice. The present invention relates to a method for producing cooked rice in a container, which is capable of producing a variety of cooked cooked rice products.

[0002]

2. Description of the Related Art Conventionally, there is a method of producing cooked rice in which raw rice or half-boiled rice is filled together with water in a retort pouch, sterilized by heating with steam or other means, and the rice in a bag is cooked. is there.

[0003] In this method, cooking and sterilization are carried out at once, but it is simple, but the amount of water filled together with rice is smaller than the amount used for cooking rice, so that the water content of cooked rice is reduced. However, the amount of cooked rice grains is tightly adhered to each other in a container with a small thickness and a large area like a retort pouch, so that rice cannot be made plump. Discoloration point of rice (106-107 ° C)
Because retort sterilization is performed at a high temperature of about 120 ° C., which is higher than that, cooked rice is easily discolored.

[0004] For this reason, cooked rice containing a retort pouch is inevitably inferior in texture and appearance to cooked rice cooked at home.

At present, a widely used method of producing cooked rice in a container is to continuously perform a rice cooking process and a sterile packaging process. In this method, rice and water are cooked in a rice cooker, steamed, then the cooked rice is loosened, the amount to be filled into individual containers such as trays is measured, and each container is filled and sealed. According to the method, rice cooked in a container can be obtained which is comparable in texture and appearance to cooked rice cooked at home.

[0006]

The above-mentioned conventional method for producing aseptic cooked rice involves a step of subdividing the rice cooked in the rice cooker into small containers and refilling the same, but this step is performed under a sufficient sterile atmosphere. Requires special equipment and strict control to create a sufficient sterile atmosphere.
In addition, a step of sterilizing a container such as a tray used for aseptic packaging and a lid before filling with cooked rice is required. The process of aseptically filling the cooked rice into individual containers in this way is troublesome and costly, and there is a problem that the measurement of the rice in the individual containers is not uniform due to the temperature of the cooked rice and the like. . It is extremely difficult to correct the amount of cooked rice filled in the container by uneven metering by the conventional aseptic filling method. Furthermore, in the conventional aseptic filling method, it is the best to fill trays, cups, and other containers having a relatively easy shape for filling rice, such as round and rectangular shapes, with complicated shapes such as floral designs that have many bends. It is impossible to uniformly fill cooked rice in a container having a small area to be filled, such as a container having a small area or a container for storing diapers and sushi one by one. In terms of the type of cooked rice, in the conventional aseptic filling method, rice porridge and porridge cannot be accurately measured and filled because rice grains and water are separated.

[0007] The present invention has been made in view of the problems of the above-described conventional method for producing cooked rice in a container, and provides a cooked rice having a plump texture and appearance similar to cooked rice cooked at home. Another object of the present invention is to provide a novel method of producing cooked rice in a container, which does not have the above-mentioned disadvantages peculiar to the conventional method of refilling cooked rice in individual containers under an aseptic atmosphere.

[0008]

Means and Actions for Solving the Problems The inventors of the present invention have conducted research and experiments in order to achieve the above object of the present invention, and as a result, filled a container with rice and water or a seasoning liquid and opened the container. Well, when heating by steam heating etc. while appropriately adjusting the heating temperature, surprisingly rice with the same plump texture and appearance as rice cooked at home can be obtained,
The present inventors have found that the above problems of the conventional method of producing aseptic cooked rice can be solved at once, and have reached the present invention.

In other words, the method for producing cooked rice in a container according to the present invention, which achieves the above objects, comprises filling a container with rice soaked in advance in water, a calculated amount of water or a seasoning solution, and, if necessary, an appropriate ingredient and seasoning; The method is characterized in that rice is cooked and sterilized at the same time by heating while the container is opened, and then the container is sealed.

According to the present invention, since rice is cooked by heating the container in an opened state, there is no need to limit the amount of water to be filled together with the rice in the container, unlike rice cooked in a retort pouch. You can add as much water as you need to get the cooked rice. In addition, by sealing the container immediately after the completion of the rice cooking and sterilization process, the container can be sealed while the sterilization temperature is still maintained, so the container can be sealed under milder conditions compared to the conventional aseptic filling method. It can be performed in an atmosphere and can simplify equipment and management for achieving aseptic conditions. If the container is sealed under the same aseptic conditions as the conventional aseptic filling method, the sterility in the container can be made better than the conventional method, and the storage period of the product is longer than before Things.

According to the present invention, it is possible to omit the step of dividing the cooked rice into small portions and refilling each container as in the conventional aseptic filling method, and to provide both the lid and the container as in the conventional method. It is not necessary to sterilize, and even if sterilizing, only the lid needs to be sterilized. Also, since the measurement of rice in each container is performed at the stage of raw rice, accurate measurement can be performed, and there is no variation in measurement as in the conventional method.

Further, according to the present invention, the rice is filled into the container at the stage of raw rice, so that the container can be easily filled with any shape. Therefore, rice can be easily filled even in a container having a small area to be filled, such as a container having a complicated shape such as a flower pattern and a lot of bending or a container for storing diapers and sushi one by one. According to the present invention, porridge, porridge, etc., which could not be produced because accurate measurement was impossible in the past, can be easily produced according to the present invention.

[0013] As the raw rice in the present invention, glutinous rice,
It does not matter what kind of rice is used, such as glutinous rice, soft rice, or hard rice, and the quality. In addition, these seven-divided rice, polished rice and the like can be widely used.

The raw rice is polished and immersed in water according to a conventional method, then a predetermined amount is measured and filled into a container together with the calculated amount of water.
Since the physical properties of the rice itself vary depending on the rice production place, type, harvest time, water content, etc., the polishing rice, water immersion time, etc. are appropriately adjusted according to these. Instead of water, an appropriate seasoning liquid may be filled in a container together with rice.

In the container, besides rice and water or seasoning liquid,
Appropriate ingredients and seasonings may be added as needed.
Ingredients include beans such as red beans and green peas, vegetables such as wild vegetables, bamboo shoots, meat such as chicken meat, processed fishery products such as kamaboko, and seasonings such as soy sauce, vinegar,
Examples include but not limited to mirin, sake, salt, sugar, curry powder, chemical seasonings, and the like.

The container used in the present invention is not particularly limited, such as a plastic container, a food can, a glass bottle, and a plastic bag, as long as it has heat resistance of 100 ° C. or higher and has moisture resistance to moisture such as steam.

As the plastic container, for example, a container such as a cup, a tray, a bottle, or the like molded using a resin such as high-density polyethylene, polypropylene, PET, PBT, or polycarbonate, or a barrier material for the intermediate layer using the resin. , A coloring material, etc. can be used.

When a plastic container is used, when the plastic container is sealed immediately after cooking, the temperature of the product is high and it is filled with water vapor. Need to be prevented. As a method of preventing such decompression deformation,
In the case of a tray-shaped container having a large bottom area, the shape is as shown in FIG. 1 so that the bottom becomes a panel that absorbs reduced pressure. FIG. 1A is a cross-sectional view of the tray 1 and the lid 2 before sealing, and 3 shows cooked rice. The tray 1 has a small convex portion 1a, 1b in the longitudinal direction and a central convex portion 1c at the bottom. When the lid 2 is put on the tray 1 and the tray 1 is sealed, the central convex portion 1c at the bottom of the tray 1 is deformed so as to be depressed as shown in FIG. Absorb the reduced pressure to prevent abnormal deformation of the container.

In order to absorb the reduced pressure, instead of deforming the bottom of the tray as described above, as shown in a sectional view before sealing in FIG. 2a, 2b and a central convex portion 2c are provided,
After sealing, the convex portion 2c at the center of the lid 2 may be deformed so as to be recessed as shown in FIG. 2B so as to absorb the reduced pressure in the head space.

Further, the container may be prevented from being deformed by selecting a material of the cover material having good spreadability. Examples of such a material include a laminated product using a film such as undrawn nylon, vinylon, polyvinylidene chloride, and polyethylene terephthalate, a co-extruded product, and a coated product such as a heat seal lacquer. It is also possible to prevent deformation due to reduced pressure by using a rigid material for the container body, bottom, etc., or by giving the container rigidity with the thickness and shape of the container. Further, liquid nitrogen is dropped just before the hermetic seal to balance the amount of volumetric shrinkage due to vaporization and expansion of liquid nitrogen and vapor liquefaction and cooling of rice, thereby preventing pressure-induced deformation of the container.

When a food can is used, a steel can that is resistant to reduced pressure, such as a steel can, does not deform without taking any special measures. However, it is preferable to consider the combined use of the liquid nitrogen dropping method as described above. When aseptic filling is taken into consideration, it is necessary to use liquid nitrogen used after filtering.

The rice cooking / sterilizing treatment is preferably carried out by steam heating, and it is also possible to use this together with electromagnetic wave heating. Rice cooking time, steaming time, etc.
Considering the type, harvest time, moisture content, etc., the cooked rice is set to be in the best condition.

It is not necessary to sterilize the container in advance, but it is preferable to sterilize the lid in advance by UV sterilization or the like. In addition, in the step of cooking and sterilizing the rice in the container in the opened state, the lid is placed on the container, and immediately after the rice cooking and sterilization process is completed, the lid is put on the container and sealed, so that the lid is sterilized in advance. You don't have to.

[0024]

【Example】

Example 1 A mixture of 94 g of rice (including moisture) and 112 g of water previously immersed in water for 10 hours was prepared by mixing vertical x horizontal x depth = 120 mm x 90 mm x 3
It was weighed and filled into a 0 mm plastic molded container (Lamicone tray). One hundred containers were prepared and cooked and sterilized by the method of the present invention. The rice cooking and sterilization treatment was performed using a steam heating sterilizer equipped with a heater.

One hundred containers filled with the rice and water were placed in the sterilizer without a lid. The temperature before rice cooking and sterilization is 20 ° C inside sterilizer, 21 ° C inside container (product temperature)
Met. Steam was supplied into the sterilizer at the same time as the start. Three minutes after the supply, the temperature in the sterilizer increased to 98 ° C on average, and the product temperature at that time was 49 ° C. 10 minutes after the steam was supplied, the conveyor was set so that the container could pass above the heater incorporated under the conveyor. The heater temperature of this part is 130 ° C, and the steam passing through this heater is installed so as to hit the container.
Steam is also supplied from the top and side of the sterilizer. The temperature in the sterilizer at this time was 105 ° C on average, and the product temperature was 96 → 10
The time required to reach 4 ° C. is about 2 minutes.
The steam was introduced for 5 minutes, then the steam introduced from the surroundings was stopped, and only the steam supply at the lower part of the heater was carried out, and the process of evaporating excess steam and steaming was carried out simultaneously for 10 minutes, thereby completing the rice cooking / sterilizing process.

Immediately after the rice cooking and sterilizing treatment, the UV-sterilized lid material was sealed and sealed in a clean environment of NASA standard class 100. The remaining 50 pieces were taken out as they were, and the temperature was lowered to room temperature. The temperature of cooked rice immediately after sealing is 86 ° C
Met.

The average moisture content of the cooked rice was 62%, and the variation in the moisture content on the container wall side and the vertical position from the center was very small, 60 to 65%. Unlike the heating of the lower part of the cooking of the rice box, the effect of the repetition was not so great because the whole surface was heated, but the repetition improved the moisture uniformity a little. After storing 70 of these at 37 ° C. for one month, the appearance was inspected. All of the results showed no swelling or discoloration, and no deterioration or deterioration by bacteria, mold, yeast, etc. was observed. The water content after heating at 37 ° C. for one month in a microwave oven was stable at 55 to 60%, but the cup wall portion had a slightly higher water content.

Example 2 The same container as in Example 1 was used, filled with the same amount of rice and water, and cooked and sterilized by steam heating in the opened state in the same manner as in Example 1. Twenty-five minutes after the supply of steam, electromagnetic wave heating was performed from a cooking / sterilization room under a NASA standard class 100 clean environment. An electromagnetic wave having a frequency of 2450 MHz is guided to a clean room through a waveguide, and is irradiated to cooked rice for one minute.
The cycle of stopping for 1 minute is repeated 3 times, and after the third irradiation, 1
After a minute the seal was sealed. Cooking rice temperature just before sealing is 70-7
At 8 ° C., the water content was 55-62%. Inspection of 50 of them at 37 ° C. for 1 month showed no deterioration, swelling, etc. due to bacteria, mold, yeast and the like.

Example 3 This example concerns the production of a 7-minute porridge in a container. Using 20 bowl-shaped C-PET containers having a diameter of 120 mm and a depth of 70 mm, 50 g of rice preliminarily immersed in water for 10 hours, and 280 g of hot water at about 60 ° C.
Using the apparatus used in Example 1, the rice was cooked and sterilized in an opened state. After heating the contents for a further 30 minutes after the temperature of the contents reaches the steam temperature by steam heating at 101 to 105 ° C., take out the steam without taking the steaming step as in Example 1 and in a sterile room of NASA class 100. The headspace was flushed with nitrogen gas through a sterilizing filter, and the film lid was heat-sealed and sealed. 3
As a result of observation at 7 ° C. for one week, no decay, generation of mold, change in taste, and the like were observed, and a porridge that was not different from a 7-minute porridge made in a normal home was obtained.

Example 4 150 g of rice preliminarily immersed in water and 185 g of water were put into 50 cans of a food can (No. 4 can, 74 mm in inner diameter, 453 ml in inner volume), and steam injection time was performed in exactly the same manner as in Example 1. 25 →
Rice was cooked in the open state for 30 minutes, with the steaming heating time being changed from 10 to 15 minutes. After removing from the sterilizer, the can lid was immersed in a hydrogen peroxide solution (20% concentration) and dried with hot air in a drier at 100 to 110 ° C., and the can lid was tightly wound in a NASA class 100 clean environment. As a result of observation after storage at 37 ° C. for 2 weeks, no decay, mold, etc. occurred.

[0031]

As described above, according to the present invention, rice is cooked by heating in a state where the container is opened, so that the amount of water to be filled together with rice into the container like rice with a retort pouch is reduced. There is no need to set a limit, and the necessary amount of water can be added to obtain the desired cooked rice. Further, since the product temperature in the rice cooking / sterilization process does not rise to 105 ° C. or more, discoloration of rice does not occur. Therefore, cooked rice having a plump texture and appearance similar to cooked rice cooked at home can be obtained.

Further, by sealing the container immediately after the completion of the rice cooking / sterilizing step, the container can be sealed while the sterilizing temperature is still maintained. Therefore, the sealing of the container is gentler than the conventional aseptic filling method. It can be performed in a sterile atmosphere under the conditions, and the apparatus and management for realizing the sterile conditions can be simplified. Also, if the container is sealed under the same aseptic conditions as the conventional aseptic filling method, the aseptic condition in the container can be made better than the conventional method, and the shelf life of the product can be longer than before. It can be long.

According to the present invention, it is possible to omit the step of dividing the cooked rice into small portions and refilling each container as in the conventional aseptic filling method, and to dispose both the lid and the container as in the conventional method. It is not necessary to sterilize, and even if sterilizing, only the lid needs to be sterilized. Also, since the measurement of rice in each container is performed at the stage of raw rice, accurate measurement can be performed, and there is no variation in measurement as in the conventional method.

Further, according to the present invention, since the container is filled at the stage of raw rice, the container can be easily filled whatever the shape of the container. Therefore, rice can be easily filled even in a container having a small area to be filled, such as a container having a complicated shape with many bends such as a flower pattern or a container for storing diapers or sushi one by one. According to the present invention, porridge, porridge, etc., which could not be produced because accurate measurement was impossible in the past, can be easily produced according to the present invention. Therefore, according to the present invention, a wide variety of cooked rice products, which were impossible or extremely difficult to manufacture with the conventional aseptic filling method, can be easily manufactured with relatively simple equipment.

[Brief description of the drawings]

FIG. 1 shows a plastic container 1 used in the method of the present invention.
It is sectional drawing which shows an example.

FIG. 2 is a sectional view showing another example of a plastic container used in the method of the present invention.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-40866 (JP, A) JP-A-63-207356 (JP, A) JP-A-57-39746 (JP, A) JP-A-5-39746 176696 (JP, A) JP-A-6-22711 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A23L 1/10

Claims (2)

(57) [Claims] 1. A pre-water soaked rice and calculated amount of water or optionally liquid seasoning and suitable ingredients and seasonings, bottom
Tray-shaped tray with convex portions at the front, back, and center
Fill in a plastic container and heat with the container opened
And, in sealing the container after rice and sterilization at the same time
The container is further deformed so that the central convex portion at the bottom of the container is recessed.
A method for producing cooked rice in a container , wherein the reduced pressure in the headspace is absorbed . 2. Rice pre-soaked in water and a calculated amount of water or water
Put the taste liquid and the appropriate ingredients and seasonings as needed
A concave part is provided before and after the lid and a convex part is provided in the center.
Into a tray-shaped plastic container, and the container is opened.
And then cook and sterilize at the same time.
By sealing, the convex part at the center of the lid is changed to be concave.
Shaped to absorb decompression of container headspace
Production method of cooked rice in a container.