JPH0739329A - Preparation of packaged cooked rice - Google Patents

Abstract

PURPOSE:To prepare an aseptically packaged cooked rice having excellent preservability, palatability, color and flavor and high commercial value with decreased number of preparation steps in high productivity at a low cost. CONSTITUTION:This process for the preparation of a packaged cooked rice comprises the filling of rice and water necessary for cooking in a vessel provided with an inner layer 6 and an outer layer 2 made of a thermoplastic resin, a 1st intermediate layer 4 made of a gas-barrier resin and positioned to the side of the outer layer and a 2nd intermediate layer 5 made of a resin composition containing a deoxidation agent and positioned to the side of the inner layer, the sealing of the vessel after substituting oxygen in the vessel, the heating of the sealed package in an autoclave at <=110 deg.C and the maintenance of the oxygen concentration in the vessel to <=0.3% after cooking.

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 sterilized packaged cooked rice, and more particularly, to produce packaged cooked rice excellent in preservability, texture, color and flavor of the cooked rice as a content. Well, it relates to a method of manufacturing at low cost.

[0002]

2. Description of the Related Art In recent years, packaged cooked rice filled with cooked cooked rice for one to several meals and sealed has been receiving attention. These packaged cooked rice can be distributed and stored at room temperature without freezing, and at meal time, it can be heated in a microwave oven or the like after opening.

It is already known to attach a deoxidizer in a small bag to the inside of the package in order to prevent rancidity and microbial growth of cooked rice during storage (for example, JP-A-63-248359). Japanese Patent Laid-Open No. 3-98542).

[0004]

However, in the method of attaching the oxygen absorber contained in a small bag before sealing the container, a special operation for attachment is required, the number of steps is increased, and filling and sealing is performed. It is necessary to have an extremely high level of control in order to prevent the bacteria from jumping in between, and in some cases, the consumer may accidentally put the oxygen absorber in his mouth. Not a method.

Further, in the above-mentioned known method, it is necessary to fill the inside of the container with the rice cooked outside the container, and not only the steps of rice cooking and filling are required, but also the equipment for performing the filling under a highly sterile condition. Is also required, which requires a large amount of cost for the equipment, and also has the drawback of increasing the number of steps.

Further, in the case where the individual cooked one meal is inverted and filled in the container, the surface of the cooked rice in the container has a shiny gloss, and the commercial value is low in terms of texture and appearance.

[0007] Therefore, the object of the present invention is to preserve,
It is an object of the present invention to provide a method capable of producing sterilized packaged cooked rice excellent in color and flavor and having high commercial value in a small number of steps with high productivity and at low cost.

[0008]

According to the present invention, an inner layer and an outer layer made of a thermoplastic resin, a first intermediate layer of a gas barrier resin located on the outer layer side and a resin containing an oxygen scavenger located on the inner layer side. In a container with a second intermediate layer of the composition,
Water necessary for rice and cooked rice is filled, oxygen in the container is replaced and sealed, and the sealed package is heated at 110 ° C in a pressure heating pot.
Provided is a method for producing sterilized packaged cooked rice, which comprises heating and cooking rice at a temperature not exceeding 10%, and maintaining the oxygen concentration in the container after the completion of rice cooking at 0.3% or less.

[0009]

In the present invention, the inner and outer layers made of a thermoplastic resin, the first intermediate layer of the gas barrier resin located on the outer layer side, and the second intermediate layer of the resin composition containing the oxygen scavenger located on the inner layer side. Use a container equipped with.

The inner layer and the outer layer of the thermoplastic resin impart moldability and heat resistance to a tray, a cup-shaped container or a bag-shaped container. Further, the inner layer is for providing the heat sealability with the inner surface material of the lid and the heat sealability itself. The intermediate layer (first intermediate layer) of the gas barrier resin located on the outer layer side is for suppressing the permeation of oxygen into the container through the container wall. On the other hand, the intermediate layer (second intermediate layer) of the oxygen scavenger-containing resin composition located on the inner layer side is for absorbing oxygen in the container and for absorbing oxygen entering through the container wall or the lid material. is there.

This specific container is filled with water required for rice and rice, the oxygen in the container is replaced, and the container is sealed with a lid, and the sealed package does not exceed 110 ° C. in a pressure heating pot. Boil the rice at the temperature and set the oxygen concentration in the container to 0.3 after the rice is cooked.
Maintaining below% is a salient feature of the present invention.

According to the present invention, the packaging container is filled with rice and water, sealed, and then heated and cooked, so that the oxygen and oxygen in the second intermediate layer are utilized by utilizing the heat and steam at the time of cooked rice. Is significantly activated, and oxygen in the container and oxygen that enters through the wall or lid is effectively absorbed, and the oxygen concentration in the container is suppressed to 0.3% or less for a long period after the completion of rice cooking. You can

That is, the rate of absorption of oxygen by the oxygen absorber is
Under the condition that water coexists, the temperature becomes remarkably large at a high temperature of about 100 ° C. compared to room temperature. Further, although a moisture-resistant thermoplastic resin such as a polyolefin originally has a permeability to oxygen, at a high temperature of about 100 ° C., a permeability to water vapor becomes considerably larger than that at room temperature. Therefore, in the multi-layered container according to the present invention, during heating and cooking, moisture is supplied to the second intermediate layer through the inner and outer thermoplastic resin layers, and oxygen is effectively absorbed and removed by the oxygen scavenger through the second intermediate layer. Will be done.

Further, according to the present invention, since the rice is cooked in a sealed state and the sealed state is maintained even after the rice is cooked, the cooked rice comes into contact with the outside air or the microorganisms in the outside air are mixed into the cooked rice. Since such a situation is avoided and rice is cooked in the packaging container, there is an advantage in manufacturing that a special rice cooking device and an aseptic filling device are unnecessary, and the number of steps is reduced.

In the method of the present invention, the heating and cooking temperature is set to 1
It is specified that the temperature is 10 ° C or lower, because at high temperatures such as 110 ° C or higher, the texture of rice is destroyed during rice cooking.
This is because the texture (deliciousness) is impaired. On the other hand, the rice is cooked for each package in a pressure heating pot. By heating the atmosphere under pressure, deformation of the package due to vapor pressure is prevented. At the same time, it is possible to easily perform operations such as entering and exiting the heating device.

In rice cooking at the above temperature, the degree of sterilization or sterilization does not become perfect as in so-called retort sterilization, but according to the present invention, since rice is cooked at a temperature of 110 ° C. or less in a short time, rice is cooked. The tissue is not destroyed and the oxygen absorbent activated during rice cooking suppresses the oxygen concentration after the rice is cooked to 0.3% or less, whereby the growth of bacteria can be completely prevented.

The packed cooked rice according to the present invention is in a satisfactory state in which rice grains stand like so-called cooked cooked rice, and this tendency tends to occur especially when reverse cooked rice is cooked for steaming on the way. Is remarkable.

[0018]

Preferred Embodiment of the Invention

[Packaging Container] In FIG. 1 showing an example of a packaging container used in the present invention, a container 1 of this packaging container 10 is made of a thermoplastic resin outer layer 2, an adhesive resin layer 3a, and a gas barrier resin. It comprises an intermediate layer 4, an adhesive resin layer 3b, a second intermediate layer 5 made of a resin composition containing an oxygen scavenger, and an inner layer 6 of a thermoplastic resin. It should be noted that the second intermediate layer 5 contains a deoxidizer, the first intermediate layer 4 is provided on the outer surface side of the container, and the second intermediate layer 5 is provided on the inner side.

In the present invention, as the thermoplastic resins 2 and 6 provided on both sides of the container, low-, medium- or high-density polyethylene, isotactic polypropylene,
Ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer,
Ethylene-vinyl acetate copolymers, ion-crosslinking olefin copolymers (ionomers) or olefin resins such as blends thereof, and the like, polystyrene, styrene-butadiene copolymer, styrene-isoprene copolymer, It may be a styrene resin such as an ABS resin, a thermoplastic polyester such as polyethylene terephthalate or polytetramethylene terephthalate, or a polycarbonate. Among these, from the viewpoint of hygiene, olefin resin is preferable, and from the viewpoint of heat resistance,
Propylene resins are preferred.

As the gas barrier resin constituting the first intermediate layer 4, a thermoformable thermoplastic resin having a small oxygen permeability coefficient is used. The most suitable example of the gas barrier resin may include an ethylene-vinyl alcohol copolymer, for example, an ethylene content of 2
Copolymer saponification obtained by saponifying an ethylene-vinyl acetate copolymer having a content of 0 to 60 mol%, particularly 25 to 50 mol% so as to have a saponification degree of 96 mol% or more, particularly 99 mol% or more. Compounds are used. The saponified ethylene-vinyl alcohol copolymer should have a molecular weight sufficient to form a film, and is generally 0.01 dl as measured at 30 ° C. in a mixed solvent of 85:15 by weight of phenol: water. It is desirable to have a viscosity of not less than / g, especially not less than 0.05 dl / g.

Further, as another example of the gas barrier resin having the above characteristics, polyamides having 5 to 50, especially 6 to 20, amide groups per 100 carbon atoms; eg, nylon 6, nylon 6,6, nylon 6 / 6,6 copolymer, metaxylylene adipamide, nylon 6,10, nylon 11, nylon 12, nylon 13 and the like are used. These polyamides should also have a molecular weight sufficient to form a film, in concentrated sulfuric acid.
It is desirable that the relative viscosity (η _rel ) measured at a concentration of 1.0 g / dl and a temperature of 30 ° C. is 1.1 or more, particularly 1.5 or more.

As the oxygen scavenger to be contained in the second intermediate layer 5 of the present invention, all oxygen scavengers conventionally used for this kind of use can be used, but they are generally reducing and substantially insoluble in water. Preferred examples thereof include metal powders having reducing properties such as reducing iron, reducing zinc, reducing tin powders; low metal oxides such as ferrous oxide and ferric oxide, and Reducing metal compounds such as iron carbide, silicon iron, iron carbonyl, iron hydroxide; and the like, which are mainly composed of one kind or a combination thereof, may be used, if necessary, of alkali metal or alkaline earth metal. It can be used in combination with hydroxides, carbonates, sulfites, thiosulfates, tertiary phosphates, secondary phosphates, organic acid salts, halides and the like.

Further, a polymer compound having a polyhydric phenol in the skeleton, for example, a polyhydric phenol-containing phenol / aldehyde resin and the like can be mentioned.

These oxygen scavengers generally have an average of 100 μm.
It is preferable to have a particle size of m or less, especially 50 μm or less.

The oxygen scavenger may be used in combination with a water absorbing agent. As the water absorbing agent, a deliquescent inorganic salt, a deliquescent organic compound, a water absorbing resin or the like is used.
Examples of deliquescent substances include inorganic salts such as sodium chloride, calcium chloride, zinc chloride, ammonium chloride, ammonium sulfate, sodium sulfate, magnesium sulfate, disodium hydrogen phosphate, sodium diphosphate, potassium carbonate, sodium nitrate; glucose. , Low-molecular or high-molecular organic compounds such as fructose, sugar, gelatin, modified casein, modified starch, tragacanth gum, polyvinyl alcohol (PVA), and water-soluble cellulose derivatives.

The above-mentioned deoxidizing material may be used in combination with a water-absorbing resin in order to activate the oxygen-absorbing effect, and it may be used in combination with many water-soluble resins or essentially water-insoluble and dozens of its own weight. A resin is used which has the ability to absorb double to several hundred times the amount of water. What is called a super absorbent resin generally has an ionizable group that contributes to water absorption,
It has a net-like or cross-linked structure or a gel-like structure for making this resin insoluble in water.

Examples of the water absorbent resin include acrylic acid (salt) -grafted starch, acrylonitrile-grafted hydrolyzate of starch, acrylic acid (salt) -grafted cellulose and starch- or cellulose-based graft derivatives, and crosslinked polyacryl. Copolymers of acids (salts), especially acrylic acid (salts), with polyfunctional monomers such as divinylbenzene or with hydrophobic monomers such as styrene and acrylates;
Vinyl alcohol-acrylic acid (salt) block copolymer produced by saponification of copolymer of vinyl acetate and acrylic ester; polyvinyl alcohol and / or acid anhydrides such as maleic anhydride and phthalic anhydride There is a modified polyvinyl alcohol in which a carboxyl group and a crosslinked structure are simultaneously introduced into the side chain by reacting with.

The water-absorbing agent and the water-absorbing resin are
It is preferably used in an amount of 1 to 10% by weight, especially 3 to 8% by weight.

As the thermoplastic resin containing the oxygen scavenger, any of the above-mentioned thermoplastic resins and gas barrier resins can be used. Of course, mixtures of these resins can be used, and resins other than these can also be used. In terms of adhesiveness with the thermoplastic resin 6, it is preferable to use the same resin as the resin 6. From the viewpoint of adhesiveness, it is preferable to use the same type of gas barrier resin.

The oxygen scavenger is 1 to 30% by weight based on the resin,
Particularly, it is preferable to use it at a concentration of 5 to 28% by weight. If the content of the oxygen scavenger is lower than the above range, it becomes difficult to suppress the oxygen concentration in the container to a concentration suitable for the growth of microorganisms or lower, while even if the concentration is higher than the above range, the decrease in oxygen concentration In terms of points, there is no particular effect, and it is rather disadvantageous in terms of molding workability and price.

As in the case of the ethylene-vinyl alcohol copolymer, sufficient adhesion is obtained between the gas barrier resin 4 used and the thermoplastic resin layer 2 and the oxygen absorber-containing resin layer 5 during lamination. In some cases, the adhesive resin layers 3a and 3b are interposed between them.

Examples of such an adhesive resin include carbonyl (--CO) based on carboxylic acid, carboxylic acid anhydride, carboxylic acid salt, carboxylic acid amide, carboxylic acid ester and the like.
-) Group in the main chain or side chain, 1 to 700 milliequivalent (meq) / 100 g resin, especially 10 to 500 meq
/ 100 g of the resin contained in the concentration of the resin. Suitable examples of adhesive resins include ethylene-acrylic acid copolymers, ionically cross-linked olefin copolymers, maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, acrylic acid grafted polyolefins, ethylene-vinyl acetate copolymers, copolymers. One or a combination of two or more of polymerized polyester, copolyamide and the like.
These resins are useful for lamination by coextrusion or sandwich lamination. In addition, an isocyanate-based or epoxy-based thermosetting adhesive resin is also used for adhesive lamination of the preformed gas barrier resin film and the thermoplastic resin film.

The oxygen scavenger-containing resin layer generally varies depending on the amount of oxygen allowed in the container, but is generally 30 to 150.
It is desirable to have a thickness of μm, especially 50 to 120 μm.

The thickness of the gas barrier resin layer is generally 5
The thickness is preferably from 50 to 50 μm, particularly from 8 to 40 μm.

On the other hand, the thermoplastic resin layer for the inner and outer layers is generally 3
It is preferable that the inner layer has a thickness of 0 to 1000 μm, particularly 50 to 400 μm. Among them, the inner layer has a thickness of 40 to 110 μm in order to effectively activate the oxygen scavenger and oxygen. The outer layer preferably has a relatively large thickness of 150 to 400 μm so that the permeation of water vapor is suppressed as much as possible.

The packaging container used in the present invention is molded into a cup, tray or the like by a method known per se except that it has the above-mentioned layer structure.

Multilayer coextrusion is advantageous for the production of a laminate, and after melt-kneading with an extruder corresponding to each resin layer, T
-Extrusion into a predetermined sheet or film shape through a multi-layer multi-layer die such as a die or a circular die. Further, a lamination method such as dry lamination, sandwich lamination, and extrusion coating may be adopted.

By subjecting this film or sheet to means such as vacuum forming, pressure forming, bulging forming, and plug assist forming, a semi-rigid packaging container such as a cup or tray can be obtained. Furthermore, in a multi-layer film,
It is also possible to stack or fold this in a bag shape and heat seal the periphery to form a bag-shaped container (pouch).

In a cup-shaped or tray-shaped semi-rigid packaging container, a flexible heat seal lid is used to seal the container. This heat-seal lid is composed of a laminate of an inner surface layer made of a heat-sealable resin, an oxygen barrier layer made of a gas barrier resin or a metal foil, and a protective resin layer. Between layers,
Sealing by heat sealing is performed.

[Manufacture of Package] In FIG. 2 for explaining the manufacturing process of the sterilized packed cooked rice according to the present invention, first,
In step A, the packaging container 10 is sterilized by, for example, irradiation with ultraviolet rays (UV). In step B, this container 10 is filled with polished rice, washed rice 11 which has been dipped in deoxidized / filtered sterile water after polishing, and sterile water 12 necessary for cooking rice. After filling, process C
The air on the liquid surface is replaced with an inert gas such as nitrogen or carbon dioxide, or water vapor 13 to eliminate the air on the container as much as possible, and then predicted in step D, for example, ultraviolet (UV) irradiation. The lid 14 which has been sterilized by is applied and sealed by heat sealing.

In step E, the obtained hermetically sealed package 15 is packed in a pressure heating pot 16 and hot water and a pressurizing gas are supplied into the pressure heating pot to cook rice at a predetermined temperature and pressure. . In the middle of the rice cooking process, that is, in the process F, the pressure heating pot 16 can be inverted to perform the reverse steaming similar to the cooked rice.
After the rice cooking process is completed, the cooked packaged cooked rice 17 is cooled and taken out to obtain a product.

The sterilization of the packaging container or the lid can be performed using, for example, a sterilizing ultraviolet (UV) lamp, or can be performed using hydrogen peroxide, peracetic acid, ozone water, or the like. Further, the water used for cooking rice or washing rice must be sterilized in advance by filter filtration or the sterilizing means. The ratio of rice to be filled and water is preferably in the range of 0.5 to 1.5 times the weight ratio of water to rice.

In order to keep the oxygen in the container after cooking rice at a low level, it is advantageous to control the oxygen concentration in the headspace to 0.5% or less, which is performed by inert gas replacement or steam replacement. Be seen. Simultaneously with the nitrogen replacement, it is preferable to enclose water vapor and give the lid a slight tension.

In the case of white rice, the rice is cooked at 98 to 110 ° C.
Especially at a temperature of 102 to 107 ° C. for 15 to 30 minutes,
In particular, it is preferable to perform it for about 20 to 25 minutes. In the case of mixed rice, the temperature may be slightly higher as long as the structure of the cooked rice is not broken. The degree of pressurization inside the retort is such that deformation of the container can be prevented, and it is preferable that the pressure inside the container and the pressure outside the container are substantially equal.

By heating and cooking rice in a pressure heating pot, the oxygen scavenger present in the second intermediate layer of the container wall is activated, and the oxygen concentration in the container is 0.3. Reach a level within%. Inverting the kettle while it is warming up and / or cooling will result in a satisfying state of rice grain.

[0046]

The present invention will be described in the following examples.

Example 1 Polypropylene resin (MI 0.5 g / 10 min, 23
(0 ° C.), an iron-based oxygen absorbent having an average particle size of 30 μm was mixed at a ratio of 75:25 by weight using a batch type high speed stirring blade mixer. This mixture is then added to 5
Pelletizing was performed by a pelletizer composed of an extruder / strand die / blower cooler / cutter with a built-in 0 mm diameter screw. A mixture (POA) of the above pelletized polypropylene and oxygen absorber was used as a second intermediate layer, and an ethylene vinyl alcohol copolymer (ethylene content 32 mol%, saponification degree 99.6 mol%, EVO) was used.
H) as the first intermediate layer and a melt index of 0.5
g / 10min (230 ℃) polypropylene (PP)
As the inner and outer layers, and melt index 1.0 g / 10 mi
n-type (230 ° C) maleic anhydride-modified PP (ADH) 4-layer 6-layer sheet with adhesive layer (total thickness 0.5 mm, composition ratio PP / POA / ADH / EVOH / ADH / PP
= 7: 10: 1: 2: 1: 29).

After heating the obtained sheet to about 190 ° C., a rectangular tray-shaped container having a depth of 25 mm, a long axis of 135 mm, and a short axis of 105 mm in which the POA layer was located inside the EVOH layer was formed by a vacuum forming machine.

As the flexible heat-sealing lid, nylon 6,66 copolymer outer layer 15 μm / ethylene-vinyl alcohol copolymer (the same as above) intermediate layer 12 μm
m / Linear low density polyethylene (LLDPE) inner layer 50μ
m laminate was used.

The tray-shaped container and the inner surface of the lid were sterilized by irradiation with ultraviolet rays (UV). This container was filled with 110 g of washed rice that had been soaked in flowing water after polishing and 90 g of sterilized water. As the washed rice, 10% of the outer skin was removed, and as the water, dechlorinated and filter-sterilized sterile water was used.

After the filling, the air on the liquid surface was replaced with nitrogen and a small amount of carbon dioxide gas was filled, and the lid and the container flange were sealed with a heat seal bar at a temperature of about 175 ° C.

The sealed package is placed in a rotary oven for isothermal hot water, heated from 40 ° to 100 ° C. in 20 minutes, kept at 100 ° C. for 25 minutes, cooled to 40 ° C. in 15 minutes, and then 5 It was taken out after cooling to the water temperature in minutes. The inversion of the kettle was performed once during the temperature increase (5 minutes before reaching 100 ° C.) and during the cooling (5 minutes before reaching 40 ° C.).

When the oxygen concentration in the taken out package was measured, it was confirmed to be 0.3% or less. Also,
When the elution of iron in cooked rice was measured by an atomic absorption method, it was below the detection limit of 0.1 ppm.

The heat-sealing lid of the cooked rice package was opened by peeling, and the whole container was placed in a microwave oven and heated. No deformation or foaming was observed in the container after heating. It was confirmed that the rice grains in the container stood up and that the rice was cooked well. In the flavor test by the 1: 2 point identification method using the general panel, there was no significant difference from the ordinary tray cooked rice.

[0055]

According to the present invention, the innermost layer and outermost layer made of a thermoplastic resin, the first intermediate layer of the gas barrier resin located on the outer layer side, and the oxygen scavenger-containing resin composition located on the inner layer side. Using a container equipped with the second intermediate layer, the water required for rice and rice is filled in this specific container, the oxygen in the container is replaced, and the container is sealed with a lid. By heating and cooking rice in a pressure cooker at a temperature not exceeding 110 ° C for a short time, the degree of sterilization or sterilization is not perfect like so-called retort sterilized cooked rice, but the texture of rice is not destroyed and the texture is improved. Along with being excellent, the oxygen scavenger in the second intermediate layer is activated during rice cooking, the absorption of oxygen in the container is effectively performed, and the oxygen concentration in the container after completion of rice cooking is suppressed to 0.3% or less. Proliferation can be effectively suppressed.

Further, according to the present invention, since the rice is cooked in a sealed state and the sealed state is maintained even after the rice is cooked, the cooked rice comes into contact with the outside air or the microorganisms in the outside air are mixed into the cooked rice. Since such a situation is avoided and rice is cooked in the packaging container, there is an advantage in manufacturing that a special rice cooking device and an aseptic filling device are unnecessary, and the number of steps is reduced.

The packaged cooked rice according to the present invention is in a satisfactory state in which rice grains stand like so-called cooked cooked rice, and this tendency tends to occur especially when reverse cooked rice is cooked for steaming on the way. Is remarkable. Further, according to the method of the present invention, there is no elution of iron into cooked rice and the flavor of cooked rice is extremely good.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a multilayer structure of a container of the present invention.

FIG. 2 is a process drawing for explaining a manufacturing process of packaged cooked rice according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 container wall 2 outer layer of thermoplastic resin 3a and 3b adhesive resin layer 4 first intermediate layer composed of gas barrier resin 5 second intermediate layer composed of resin composition containing oxygen scavenger 6 inner layer of thermoplastic resin 10 Packaging container 11 Washed rice 12 Water necessary for cooking rice 13 Inert gas or steam 14 Lid 15 Sealed package 16 Pressurized heating pot 17 Cooked packed rice

Front page continued (72) Inventor Yasuhiro Oda 25 Sachigaoka, Asahi-ku, Yokohama-shi, Kanagawa (72) Inventor Masayasu 1-2-7 Kotsubo, Zushi-shi, Kanagawa

Claims (1)

[Claims] 1. An inner layer and an outer layer comprising a thermoplastic resin, a first intermediate layer of a gas barrier resin located on the outer layer side, and a second intermediate layer of a resin composition containing an oxygen scavenger located on the inner layer side. Fill the container with water required for rice and rice,
After replacing the oxygen in the container, it is sealed and the sealed package is heated and cooked in a pressure cooker at a temperature not exceeding 110 ° C, and the oxygen concentration in the container after completion of cooking is maintained at 0.3% or less. A method for producing packaged cooked rice, which comprises: