JPH06133711A - Production of cooked rice put in container - Google Patents

Abstract

PURPOSE:To produce cooked rice put in a container having excellent texture and appearance, simplifying a device for aseptically reparking cooked rice and a method therefore, eliminating variability of metering and providing a product with diversity. CONSTITUTION:Raw rice and water or a seasoning solution are packed into a container and heated in a closed state of the container. Rice cooking and sterilization are simultaneously carried out and then the container is closed.

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, which can provide cooked rice with a particularly excellent texture and is simpler and easier to obtain a sterile condition than conventional sterile cooked rice manufacturing methods. The present invention relates to a method for producing cooked rice in a container capable of producing various cooked rice products in a container.

[0002]

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

Although this method is simple in that rice is cooked and sterilized at the same time, the amount of water filled with rice is smaller than the amount used for normal rice cooking, so the water content of cooked rice is increased. However, it is less than normal cooked rice. Therefore, cooked cooked rice grains stick to each other firmly and form a mochi in a container with a small thickness and a large area, such as a retort pouch, which makes it impossible to make fluffy cooked rice. Discoloration point of rice (106-107 ℃)
Since the retort sterilization is performed at a high temperature of about 120 ° C, which is higher than 120 ° C, the cooked rice is easily discolored.

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

Currently, a widely used method for producing cooked rice in a container is to carry out a rice cooking step and an aseptic packaging step in succession. In this method, rice and water are cooked in a rice cooker, steamed, and then the cooked rice is loosened, and each container such as a tray is weighed and sealed in each container. According to the method, it is possible to obtain cooked rice in a container that is comparable in texture and appearance to cooked rice cooked at home.

[0006]

The conventional method for producing aseptic cooked rice described above includes a step of subdividing the cooked rice cooked in the rice cooker into each container and refilling it. However, this step is performed under a sufficiently sterile atmosphere. Therefore, special equipment and strict control are necessary to create a sufficiently sterile atmosphere.
Further, a step of sterilizing a container such as a tray used for aseptic packaging and a lid in advance before filling the cooked rice is required. As described above, the process of aseptically filling cooked cooked rice into individual containers is tedious and costly, and the amount of cooked rice in each container is uneven due to the temperature of cooked rice and other problems. . It is extremely difficult to correct the amount of cooked rice filled in the container by non-uniform weighing by the conventional aseptic filling method. Furthermore, in the conventional aseptic filling method, it is the best to fill rice in a container such as a tray or cup that is relatively easy to fill with rice such as a circular shape or a rectangular shape. It is impossible to uniformly fill the cooked rice in a container having a small filling area, such as the above-mentioned container or a container for inserting mussubi or sushi one by one. Regarding the type of cooked rice, in the conventional aseptic filling method, it is impossible to measure and fill an accurate amount in rice gruel and porridge since the rice grains and water are separated.

The present invention has been made in view of the problems of the above-mentioned conventional method for producing cooked rice in a container, and a cooked rice having a plump texture and appearance similar to cooked rice cooked at home is obtained. Further, it is an object of the present invention to provide a novel method for producing cooked cooked rice in a container which does not have the above-mentioned drawbacks peculiar to the conventional method of refilling cooked cooked rice in individual containers under a sterile atmosphere.

[0008]

Means and Actions for Solving the Problems The inventors of the present invention have conducted research and experimentation in order to achieve the above-mentioned object of the present invention, and as a result, filled a container with rice and water or a seasoning liquid, and opened the container. By heating with steam heating while adjusting the heating temperature appropriately, surprisingly, cooked rice with a plump texture and appearance similar to cooked rice cooked at home is obtained,
The inventors have found that the above-mentioned problems of the conventional aseptic cooked rice manufacturing method can be solved at once, and arrived at the present invention.

That is, the method for producing cooked rice in a container of the present invention which achieves the above object is to fill a container with rice soaked in water in advance and a calculated amount of water or seasoning liquid and, if necessary, appropriate ingredients and seasonings, It is characterized in that the container is sealed after the rice is cooked and sterilized at the same time by heating the container in the opened state.

According to the present invention, the rice is cooked by heating the container in the opened state. Therefore, it is not necessary to set the amount of water to be filled in the container together with the rice unlike the cooked rice with the retort pouch, and it is desired. You can add as much water as you need to get the cooked rice. Also, by sealing the container immediately after the rice cooking / sterilization process is completed, the container can be sealed while the sterilization temperature is still maintained, so that the container is sterilized under milder conditions than the conventional aseptic filling method. It can be performed in an atmosphere, and the equipment and control for achieving aseptic conditions can be simplified. If the container is hermetically sealed under the same aseptic conditions as the conventional aseptic filling method, the aseptic condition in the container can be made better than that of the conventional method, and the shelf life of the product is longer than before. Can be one.

Further, according to the present invention, it is possible to omit the step of dividing the cooked rice into small pieces and refilling each container as in the conventional aseptic filling method, and, in addition to the conventional method, both the lid and the container are removed. It is not necessary to sterilize, and even if it sterilizes, only the lid needs to be sterilized. Further, since the rice in each container is weighed at the stage of raw rice, it can be accurately weighed, and there is no variation in the weighing 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 with any shape. Therefore, it is possible to easily fill rice even in a container having a small filling area such as a container having a complicated shape with a lot of bending such as a flower pattern or a container for putting diaper and sushi one by one. Further, according to the present invention, even porridge, porridge, etc. which could not be manufactured in the past because accurate measurement is impossible can be easily manufactured by the present invention.

The raw rice in the present invention is glutinous rice,
It does not matter what kind or quality of rice such as non-glutinous rice, soft rice, hard rice, etc. In addition, these seven-minute rice, polished rice, etc. can be widely used.

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

In the container, in addition to rice and water or seasoning liquid,
Appropriate ingredients and seasonings may be added if necessary.
Examples include azuki beans, beans such as green peas, vegetables such as edible wild plants and bamboo shoots, meat such as chicken meat, and processed marine products such as kamaboko, and seasonings such as soy sauce, vinegar,
Examples thereof include mirin, sake, salt, sugar, curry powder, and chemical seasonings, but are not particularly limited thereto.

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

As the plastic container, for example, a container such as a cup, a tray or a bottle formed by using a resin such as high density polyethylene, polypropylene, PET, PBT or polycarbonate, or a barrier material for the intermediate layer using the above resin. It is possible to use a multi-layer container or the like using a coloring material, or the like.

When a plastic container is used, the product temperature is high when sealing the plastic container immediately after cooking rice and it is filled with water vapor, so that the inside may be deformed due to a reduced pressure after sealing. Need to be prevented. As a method of preventing such reduced pressure deformation,
In the case of a tray-shaped container having a large bottom area, the shape as shown in FIG. FIG. 1A is a sectional view of the tray 1 and the lid 2 before sealing, and 3 shows cooked rice. The tray 1 has small front and rear small convex portions 1a and 1b and a central convex portion 1c at the bottom in the longitudinal direction. When the lid 1 is covered with the lid 2 and the tray 1 is sealed, the central convex portion 1c at the bottom of the tray 1 is deformed so as to be recessed as shown in FIG. 1B due to the pressure reduction of the head space of the tray 1 due to the condensation of water vapor. Absorbs the reduced pressure to prevent abnormal deformation of the container

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

It is also possible to prevent the container 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 of non-stretched nylon, vinylon, polyvinylidene chloride, polyethylene terephthalate, a coextruded product, or 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 providing the container with rigidity depending on the thickness and shape of the container. Further, it is possible to prevent liquid from being deformed under reduced pressure by dropping liquid nitrogen immediately 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.

When food cans are used, those that are resistant to reduced pressure, such as steel cans, will not deform even if no special measures are taken, but those that undergo reduced pressure deformation such as aluminum cans. It is preferable to consider the combined use of the liquid nitrogen dropping method as described above. If aseptic filling is taken into consideration, it is necessary to use the liquid nitrogen used after filtering.

The rice cooking / sterilization treatment is preferably carried out by steam heating, and it is also possible to use this together with electromagnetic wave heating. Rice production time, steaming time, etc.
Set the cooked rice so that it is in the best condition, taking into consideration the type, harvest time, water content, etc.

Although it is not necessary to sterilize the container in advance, it is preferable that the lid is sterilized by UV sterilization or the like in advance. In addition, in the process of cooking and sterilizing 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 to sterilize the lid in advance. No need to leave.

[0024]

【Example】

Example 1 94 g of rice (including water) and 112 g of water that had been previously dipped in water for 10 hours were added to a length × width × depth = 120 mm × 90 mm × 3.
It was weighed and filled into a 0 mm plastic molding container (Lamicon tray). 100 containers were prepared and cooked and sterilized by the method of the present invention. Rice cooking and sterilization treatment were performed using a steam heating type sterilizer equipped with a heater.

Into this sterilizer, 100 containers filled with the rice and water were loaded without a lid. The temperature before cooking and sterilization is 20 ° C inside the sterilizer and 21 ° C inside the container (product temperature).
Met. Simultaneously with the start, steam was supplied into the sterilizer, and the temperature inside the sterilizer rose to 98 ° C. on average 3 minutes after the supply, and the product temperature at that time was 49 ° C. It was set so that the container would pass 10 minutes after the steam was supplied by the conveyor to the upper part of the heater incorporated under the conveyor. The heater temperature of this part is 130 ° C, and it is installed so that the steam passing through this heater hits the container.
Steam is also supplied from the top and sides of the sterilizer. At this time, the temperature inside the sterilizer is 105 ° C on average, and the product temperature is 96 → 10
It takes about 2 minutes to reach 4 ° C.
It was kept for 5 minutes, then the steam introduced from the surroundings was stopped, only the steam supply at the lower part of the heater was carried out, and the steps of vaporizing excess water and steaming were carried out simultaneously for 10 minutes, and the rice cooking / sterilization step was completed.

Immediately after the rice is cooked and sterilized, the lid material that has been UV sterilized in advance is sealed and sealed in a NASA standard class 100 clean environment, and the 50 pieces are immediately turned upside down and cooled to room temperature. The remaining 50 pieces were taken out as they were, and the temperature was lowered to room temperature to make them. The temperature of the cooked rice immediately after sealing is 86 ° C.
Met.

The moisture content of cooked rice was 62% on average, and the variation in the moisture content on the side of the wall surface of the container and in the vertical position from the center was 60 to 65%, which was very small. The effect of repeated repeated heating was different from heating only the lower part of the rice cooked with rice, and no significant effect was observed, probably because it was heated over the entire area, but repeated repeated operation improved the water uniformity a little. 70 pieces of this product were stored at 37 ° C. for 1 month, and then the appearance was inspected. All the results showed no swelling or discoloration, and no deterioration or deterioration due to bacteria, mold, yeast, etc. The one stored for one month at 37 ° C had a stable water content of 55 to 60% after being heated in a microwave oven, but the cup wall surface portion had a slightly higher water content.

Example 2 Using the same container as in Example 1, the same amounts of rice and water were filled, and cooking and sterilization by steam heating were performed in the opened state in the same manner as in Example 1. Twenty-five minutes after steam supply, electromagnetic wave heating was performed from the cooking / sterilization room in a clean environment of NASA standard class 100. Guide the electromagnetic wave of frequency 2450MHz to the clean room through the waveguide and irradiate the rice for 1 minute.
Repeat the cycle of stopping for 3 times 3 times after the third irradiation
Sealed and sealed after a minute. The rice cooking temperature just before sealing is 70 to 7
The water content was 8 ° C. and 55 to 62%. 50 pieces of this product were stored at 37 ° C. for 1 month, and after the storage test, no deterioration or swelling due to bacteria, mold, yeast, etc. was observed.

Example 3 This example concerns the manufacture of a 7 minute porridge in a container. Using 20 C-PET containers with a diameter of 120 mm and a depth of 70 mm in a bowl shape, put 50 g of rice that had been immersed in water in advance for 10 hours and 280 g of warm water at about 60 ° C.,
Using the apparatus used in Example 1, the rice was cooked and sterilized in the opened state. After the temperature of the contents reaches the vapor temperature by steam heating at 101 to 105 ° C, the contents are heated for another 30 minutes, and then taken out as they are, without taking the steaming step as in Example 1, in a NASA class 100 sterile room. The headspace was flushed with a nitrogen gas through a sterilization filter, and the film lid was heat-sealed and sealed. Three
As a result of observation after storage at 7 ° C. for 1 week, no spoilage, generation of mold, change in taste and the like were observed, and 7-minute porridge made in a normal household was obtained.

Example 4 150 cans of rice and 185 g of water, which had been previously immersed in water, were put into 50 cans of 4 food cans (74 mm in inner diameter, 453 ml in internal capacity), and steam injection time was completely the same as in Example 1. 25 →
Rice was cooked in the opened state for 30 minutes with the steaming heating time changed from 10 to 15 minutes. After being taken out from the sterilizer, the can lid which was immersed in hydrogen peroxide water (20% concentration) and dried with warm air in a dryer at 100 to 110 ° C. was wound and fastened in a NASA class 100 clean environment. As a result of observation after storage at 37 ° C. for 2 weeks, no decay or mold was observed.

[0031]

As described above, according to the present invention, since rice is cooked by heating the container in an opened state, the amount of water to be filled with rice in a container like rice cooked with a retort pouch is adjusted. There is no need to set restrictions, and the amount of water required to obtain the desired cooked rice can be added. Also, since the product temperature in the rice cooking / sterilization process does not rise above 105 ° C, discoloration of rice does not occur. Therefore, a cooked rice having a fluffy texture and appearance similar to cooked rice cooked at home is obtained.

Further, by sealing the container immediately after the rice cooking / sterilization process is completed, the container can be sealed while the sterilization temperature is still maintained, so that the container is sealed more slowly than the conventional aseptic filling method. It can be performed in an aseptic atmosphere of conditions, and the equipment and management for achieving aseptic conditions can be simplified. If the container is hermetically sealed under the same aseptic conditions as in the conventional aseptic filling method, the aseptic condition in the container can be made superior to that in the conventional method, and the shelf life of the product is longer than that of the conventional method. It can be long.

Further, according to the present invention, it is possible to omit the step of dividing the cooked rice into small pieces and refilling each container as in the conventional aseptic filling method, and, in addition to the conventional method, both the lid and the container are removed. It is not necessary to sterilize, and even if it sterilizes, only the lid needs to be sterilized. Further, since the rice in each container is weighed at the stage of raw rice, it can be accurately weighed, and there is no variation in the weighing 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 with any shape. Therefore, rice can be easily filled even in a container having a complicated shape with many bends such as a flower pattern or a container having a small filling area such as a container for inserting diaper and sushi one by one. Further, according to the present invention, even porridge, porridge, etc. which could not be manufactured in the past because accurate measurement is impossible can be easily manufactured by the present invention. Therefore, according to the present invention, a wide variety of cooked rice products, which are difficult or extremely difficult to manufacture by the conventional aseptic filling method, can be easily manufactured by a relatively simple apparatus.

[Brief description of drawings]

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

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

Claims (1)

[Claims] 1. Cooking rice and sterilizing by preliminarily immersing rice in water and a calculated amount of water or seasoning liquid and, if necessary, appropriate ingredients and seasonings in a container and heating the container in an opened state. A method for producing cooked rice in a container, which comprises simultaneously sealing and then sealing the container.