JP2001069927A - Production of sterile packed rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing sterile packed rice aiming at decreasing possibility of its secondary pollution and also shortening rice-cooking time. SOLUTION: This method for producing sterile packed rice comprises such processes that a given quantity of rice after washed and soaked is packed into an individual meal tray, the rice thus packed in the individual meal tray is intermittently flushed with high-pressure and hightemperature saturated steam in a sealed chamber for sterilization treatment, and at the same time, the rice is preliminary pregelatinized and then hot water is poured thereinto as cooking water so as to advance its pregelatinization; the individual meal tray is capped with a covering material to firmly seal it followed by cooking the rice with far-infrared radiation. Such kinds of rice can be provided as packed rice directly eatable at once by regulation of the far-infrared radiation ricecooking conditions, or as so-called quick cooked rice capable of becoming eatable by heating in a short time, and also, when such rice-cooking processes are omitted, as water- containing rice or water-absorbing rice capable of becoming eatable by user's cooking without cooking water.

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 packed rice in a sterilized condition.

[0002]

2. Description of the Related Art The applicant of the present invention has conducted research and development on a method capable of substantially completely killing not only general living bacteria but also heat-resistant living bacteria in the production of so-called packed rice, and as a result, the rice washing was immersed. The filled rice is fixedly filled into individual food trays, sterilized by intermittently flashing high-pressure, high-temperature saturated steam on the rice fixedly filled into individual food trays in a sealed chamber, and at the same time the rice is pregelatinized and then cooked It has been found that complete sterilization can be achieved by a method for producing aseptic packed cooked rice, which is characterized in that a lid is put on an individual food tray and hermetically sealed after water is poured and cooked. This method has already been patented (Japanese Patent No. 291876).

[0003]

This method is sufficiently practical and has the advantages that rice with good taste can be obtained and complete sterilization can be achieved without enclosing an oxygen scavenger or adjusting pH. However, as a result of subsequent research and development, it became clear that there were some problems to be solved.

[0004] One is the problem associated with cross-contamination. According to the above method, cooked rice in a tray is conveyed to a hermetically sealed machine by a conveyor, but during this time, in order to prevent secondary contamination due to exposure to the outside air, a rice cooker is used. It is necessary to surround the area from the outlet of the above to the hermetic sealing machine with a clean booth having a degree of cleanness of about 100 to 1,000. In order to prevent secondary pollution, steam may be steamed with hot water after sealing and sealing, instead of or in combination with the installation of a clean booth.

[0005] Further, in the above method, rice cooking time of about 30 minutes was required, but it is desired to shorten the time as much as possible for improving yield.

Furthermore, means for a clean booth and a steaming step required for preventing the above-mentioned secondary contamination, and further, when steaming with hot water, means for cooling thereafter (such as a cold water tank). Since the apparatus for performing the above method tends to be large-sized with the installation, it is desired that the apparatus be simplified as much as possible to improve the space efficiency and reduce the cost.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems in the above-mentioned method and to provide a more improved method for producing aseptic packed cooked rice or rice.

[0008] That is, the present invention is to sterilize the rice soaked in washed rice in an individual tray by intermittently flushing the rice filled in the individual tray with high-pressure high-temperature saturated steam in a sealed chamber. Preliminarily pregelatinized rice at the same time as processing, then further pregelatinized by pouring hot water as cooking water, after covering the individual food tray with a lid material and sealing completely sealed, using far infrared rays A method for producing aseptic packed rice characterized by cooking rice.

The present invention also provides sterilization by filling a fixed quantity of the rice soaked and immersed in the individual food tray, and intermittently flushing the rice filled with the fixed quantity in the individual food tray with high-pressure, high-temperature saturated steam in a sealed chamber. Preliminarily pregelatinized rice at the same time as processing, then further pregelatinized by pouring hot water as cooking water, after covering the individual food tray with a lid material and sealing completely sealed, using far infrared rays A method for producing sterile packed rice that can be eaten as it is, characterized in that rice is substantially completely pregelatinized by cooking rice.

[0010] The present invention also provides sterilization by filling a fixed quantity of the rice soaked and immersed in the individual food tray, and intermittently flushing the rice filled in the individual food tray with high-pressure, high-temperature saturated steam in a sealed chamber. Preliminarily pregelatinized rice at the same time as processing, then further pregelatinized by pouring hot water as cooking water, after covering the individual food tray with a lid material and sealing completely sealed, using far infrared rays A method for producing aseptic packed rice obtained as fast-cooked rice, characterized by further pregelatinizing rice to a state where rice can be eaten by heating for a short time by cooking rice.

[0011] The present invention also provides sterilization by filling a fixed quantity of the rice soaked and immersed in the individual food tray, and intermittently flushing the rice filled with the fixed quantity in the individual food tray with high-pressure, high-temperature saturated steam in a sealed chamber. Preliminary pregelatinization of rice at the same time as processing, and then further pregelatinization by injecting boiling water as cooking water, and providing the product as a completely sealed and sealed cover with individual food trays covered A method for producing aseptic packed rice that is ready to be eaten after cooking without the need for cooking water.

[0012] The present invention also provides sterilization by filling a fixed quantity of the rice soaked and immersed in a single food tray and intermittently flushing high-pressure, high-temperature saturated steam with respect to the rice fixedly filled in the single food tray in a sealed chamber. At the same time as the treatment, the rice is preliminarily pregelatinized, then hot water is poured as cooking water to further pregelatinize, and the individual food tray is covered with a lid material and completely sealed and sealed, and then controlled temperature conditions And cooked rice using far-infrared light under cooking time,
Aseptic, characterized by selectively providing rice in a state that can be eaten by heating for a short time or rice that can be eaten after cooking without the need for cooking water This is a method for producing pack rice.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The production process of a sterile pack rice according to the present invention is shown in the chart of FIG. 1 and will be described below based on the chart.

Rice (milled rice) milled by a milling machine is stored in a storage. The rice is washed and immersed in a conventional manner using degassed water, and pretreated so that the water content is about 10 to 30%.
To a fixed amount.

[0015] The tray filled with rice in a fixed amount is subjected to a surface smoothing treatment as required, and then sent to a sealed chamber, where the container and the rice are sterilized under high pressure and high temperature conditions.
Thereby, not only general living bacteria but also heat-resistant living bacteria can be killed.

The sterilization treatment in the sealed chamber is 100
By using pressurized steam at a high temperature of 120 ° C. or higher, preferably 120 ° C. to 140 ° C., the process can be performed collectively on a large number of trays housed in a sealed chamber within a short time of several tens of seconds. Steam pressure is 2.7-3.0kgf / cm
The pressure is preferably about 2 and is press-fitted into the sealed chamber from the steam generator.

By performing the sterilization treatment under such high pressure and high temperature conditions, the rice in each tray (more precisely, the starch in the rice, hereinafter the same) is preliminarily pregelatinized, and the rice cooked is shortened. It is possible to complete in time. At this stage, the rice is preliminarily pregelatinized.

The sterilization is performed by intermittently flushing the rice filled in the individual food tray with saturated steam of high pressure and high temperature. For example, the high-pressure high-temperature saturated vapor flash treatment for 5 to 10 seconds is repeated about 6 to 8 times as one cycle.

Such an intermittent pressurized heat sterilization treatment
Enables effective sterilization without sacrificing the taste of rice, and advances the individual trays from the rice filling station to the rice cooker during the non-processing interval without steam flushing Therefore, the efficiency and speed of operation of the production line can be increased.

A method and an apparatus for performing such a sterilization treatment are described in Japanese Patent No. 283819 by the present applicant.
No. 8, please refer to it.

After the sterilization treatment, each tray is filled with, for example, boiling water of 80 ° C. or higher as cooking water necessary for cooking rice. It is preferable to use degassed water as the hot water, and it is preferable that the hot water has been sterilized in advance. The tray adjusted to a predetermined pH value may be filled in the tray. In the case of manufacturing packed rice and red rice, the tray is filled with necessary seasoning liquid, coloring liquid, ingredients and the like at the same time as boiling water.

The use of hot water as the cooking water is extremely important in the present invention, and this further promotes the pregelatinization of rice, so that the rice cooking time can be further reduced.

Further, in the present invention, since rice is cooked after hermetically sealing, if water at normal temperature is used as the cooking water, the cooking water will evaporate due to the heat of the rice cooking, and the air will expand in the sealed tray to cause a puncture phenomenon. Will happen. To prevent this, it is indispensable to fill and enclose hot water.

Filling with hot water also exerts an effect of further increasing the sterilizing effect.

After filling with hot water, a UV-sterilized lid is applied and hermetically sealed. After flushing the tray with an inert gas, the tray may be hermetically sealed.

Next, the rice in the tightly sealed tray is cooked using far-infrared rays. Far-infrared rays radiate from ceramics heated by electricity or gas 5-25 μm in wavelength
It has excellent heating efficiency, has less heating unevenness, is easy to control the temperature, and is a heating method using radiant heat, which can be heated without directly contacting the heating medium with the food, so that the taste is not impaired. In recent years, it has been widely used for heating food.

As a rice cooking technique using far-infrared rays, Japanese Patent Application Laid-Open Nos. Hei 6-243965 and Hei 7-280
Various types have already been proposed in Japanese Patent Application Laid-Open No. 279, Japanese Patent Application Laid-Open No. Hei 10-257966, and the like, and any of these technologies may be employed in the present invention.

Rice in trays can be completely pregelatinized by far-infrared rice cooking. However, since pregelatinization has progressed to some extent during high-pressure high-temperature sterilization and filling with hot water, rice cooking time is significantly longer than in the past. Can be shortened. In an experiment by the present applicant, rice cooking time, which conventionally required about 30 minutes, was reduced to about 10 minutes.

After far-infrared rice cooking, the obtained sterile packed rice is subjected to surface drying treatment, printing of the date of manufacture and expiration date,
Pinhole inspection, weight inspection, etc. are required through post-processing steps,
It is packed in a predetermined case and shipped. According to the present invention, the steaming step after rice cooking can be omitted, and a sufficient cooling effect can be obtained by natural cooling while being conveyed on the conveyor, so that no special device is required.

According to the present invention, a sufficient sterilizing effect can be obtained by sterilizing under high pressure and high temperature conditions and filling hot water into the tray, and floating in the air or a worker is required until the subsequent sealing. Even if germs attached to the hands or clothes are mixed, it is sterilized by the heat of rice cooking, and since it is already completely sealed at the time of rice cooking, there is no secondary contamination after rice cooking, A sterilized packed rice is obtained. Therefore, it is not necessary to use a clean booth in the hermetic sealing process, and the equipment can be simplified and the cost can be reduced.

In the above, the present invention has been described as providing packed rice which can be immediately eaten as it is or by simply warming it by completely pregelatinizing rice in the rice cooking process. Because the rice cooking process is performed using a far-infrared heating method that can be easily performed,
By controlling the temperature at the time of cooking rice, the degree of alpha conversion can be controlled. For example, by finishing the rice cooking process with a relatively low degree of pregelatinization, so-called fast-cooked rice in a sterile pack (can be eaten for about several minutes in a microwave oven and for several ten minutes in boiling water) Rice). Further, the product produced at the stage of hermetically sealing (ie, one that does not perform far-infrared rice cooking at all) corresponds to what is called hydrated rice or so-called water-absorbed rice, but conventional hydrated rice and water-absorbed rice have insufficient storage stability. On the other hand, the product according to the present invention is completely sterilized, and is completely sealed and packed, so that it can be stored for several months or more even at room temperature, and the taste hardly decreases even after long-term storage. It has the advantage that.

[0032]

According to the present invention, since a certain amount of rice is filled in the tray and then sterilized under high-pressure and high-temperature conditions, and then the tray is filled with hot water, a sufficient sterilizing effect can be obtained.

Moreover, since rice is cooked in a state in which the tray is completely sealed and sealed after filling with hot water, even if germs are mixed in between the filling of the hot water and the completion of the sealing, the germs are removed at a high temperature during the subsequent cooking of rice. Since it can be completely killed, it is possible to provide a hermetically sealed rice in a completely sterilized state.

Therefore, it is not necessary to use a clean booth in the hermetic sealing process, and steaming with hot water after cooking rice is not necessary, so that the equipment can be greatly simplified and the cost can be reduced.

Further, since the present invention employs a far-infrared ray system in which the temperature can be easily adjusted in the rice cooking process, it is easy to adjust the degree of alpha of rice required as a product and commercialize the product. In other words, when cooked at a sufficient temperature for a sufficient time, it is substantially completely pregelatinized,
Provided as so-called fast-cooked rice, which can be provided as packed rice that can be eaten immediately as it is, and can be eaten with a short time of heating if alpha is limited to a certain level When the rice cooking step is omitted, the rice can be provided as so-called hydrated rice or water-absorbed rice which can be eaten by the user cooking without cooking water. In other words, by appropriately selecting the temperature and the time as the rice cooking conditions, the rice in any one of the above states can be provided as a completely sterile packed rice.

[Brief description of the drawings]

FIG. 1 is a chart showing a manufacturing process of a sterile pack rice according to the present invention.

Claims (5)

[Claims] Claims 1. A fixed quantity of rice washed and immersed in a single food tray is sterilized by intermittently flashing high-pressure, high-temperature saturated steam on the rice fixedly filled in the individual food tray in a sealed chamber. Preliminarily pregelatinize rice and then further advance it by pouring boiling water as cooking water, cover the individual food tray with a lid material, seal it completely sealed, and cook rice using far infrared rays A method for producing aseptic packed rice, comprising 2. A fixed quantity of rice washed and immersed in a single food tray is filled in the individual food tray, and sterilized by intermittently flushing the rice filled in the individual food tray with high-pressure, high-temperature saturated steam in a sealed chamber. Preliminarily pregelatinize rice and then further advance it by pouring boiling water as cooking water, cover the individual food tray with a lid material, seal it completely sealed, and cook rice using far infrared rays A method for producing sterile packed rice that can be consumed as it is, characterized in that rice is substantially completely pregelatinized. 3. The rice soaked and immersed rice is fixedly filled in an individual food tray and sterilized by intermittently flushing the rice filled in the individual food tray with high pressure and high temperature saturated steam in a sealed chamber. Preliminarily pregelatinize rice and then further advance it by pouring boiling water as cooking water, cover the individual food tray with a lid material, seal it completely sealed, and cook rice using far infrared rays Characterized in that the rice is further pregelatinized to a state where the rice can be eaten by heating for a short time, thereby producing a sterile packed rice obtained as quickly cooked rice. 4. The present invention also provides a method for filling a fixed quantity of the rice soaked and immersed in the individual food tray, and intermittently flushing the rice filled with the fixed quantity into the individual food tray in a sealed chamber with high-pressure, high-temperature saturated steam. Preliminarily pregelatinized rice at the same time as pre-sterilization and then further pregelatinized by injecting hot water as cooking water, and provided as a product in a completely sealed and sealed state with a lid material attached to the individual food tray A method for producing aseptic packed rice that can be eaten after cooking without the need for cooking water. 5. A fixed quantity of the rice soaked and soaked in the individual food tray is filled in the individual food tray, and the rice filled in the fixed quantity of the individual food tray is sterilized by intermittently flashing high pressure and high temperature saturated steam in the sealed chamber. Rice is preliminarily pregelatinized, and then further pregelatinized by pouring hot water as cooking water.After covering the individual food tray with a lid material and sealing completely tightly, controlled temperature conditions and rice cooking time Rice that can be eaten as it is, cooked by heating for a short time, or cooked without cooking water by cooking rice using far infrared rays under A method for producing aseptic packed rice, characterized by selectively providing rice in any one of the states in which rice can be prepared.