JP2826088B2 - Method and apparatus for producing aseptic packaged cooked rice - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to sterilizing and packaging rice (white rice, red rice, cooked rice, etc.) for long-term storage. The present invention relates to an improved method and apparatus for producing aseptic packaged cooked rice that can be eaten.

[0002]

2. Description of the Related Art Retort cooked rice is known as a conventional product of this kind. However, this method has a problem in terms of taste because it is excessively heated and the off-flavor cannot be removed. Therefore, in pursuit of taste, recently, sterile cooked rice has been newly released. A typical example of such sterile cooked rice is a small rice cooker that can cook one meal at a time, continuously cook it, supply it to a clean booth, put it in the final container, put a deoxidizer, put a top seal on it, This is a sealing method.

[0003]

Since the above-mentioned conventional sterile cooked rice is cooked under atmospheric pressure, the temperature rises only around 100 ° C., and almost no sterilization effect can be expected. Therefore, in order to control the bacteria, it is necessary to sterilize the rice in the rice washing and water immersion steps, which is a heavy burden on management and economically.

[0004] Further, the transfer from the kettle to the final container,
The operation became complicated and the possibility of cross-contamination was great. Therefore, in order to ensure safety, the pH of water for cooking rice
In general, a method of suppressing the growth of bacteria (including molds and yeasts) during long-term storage by lowering the oxygen content or enclosing a deoxidizer is generally employed.

[0005] In order to lower the pH, an acidulant such as gluconic acid is added, which significantly reduces the flavor and reduces the quality. In addition, strict control of the pretreatment step and encapsulation of the oxygen scavenger have been economically problematic.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for producing aseptic packaged cooked rice that is delicious, highly safe, and economically inexpensive.

[0007]

In order to achieve the above-mentioned object, the production method of the present invention is characterized in that rice is washed and drained, and water-immersed rice is weighed and filled into a final packaging container by a predetermined amount. The water-immersed rice that has been drained while being put in is subjected to steam sterilization for a predetermined time by steam at a predetermined temperature under vacuum degassing in a steaming tank, and then, a predetermined amount of sterilized water is filled in the container. The container is hermetically sealed using a sterilized film, and then heated at a predetermined temperature for a predetermined time, cooked into cooked rice, cooled, dried, and packaged to obtain a product.

As described above, in the production method of the present invention, first, washed and drained water-immersed rice is weighed and filled in a predetermined amount in a final packaging container, and the rice is washed and drained while being kept in the container. The rice is subjected to a steam sterilization treatment for a predetermined time with steam at a predetermined temperature under vacuum degassing in a steaming tank, so that the rice is washed in a normal condition and under a normal condition without strict control of the bacteria in the rice washing stage. Only the rice after draining can be directly steamed and sterilized by steam in a drained state, that is, in a state of being separated as a solid, and thus the rice itself can be quickly cooked using steam at a higher temperature than when cooking rice. Heat sterilization can be performed efficiently. In other words, conventionally,
Since the rice is immersed in water in a rice cooker and cooked under atmospheric pressure, the heating temperature is at most about 100 ° C, which makes it impossible to sufficiently sterilize the rice itself and water, but according to the present invention. For example, since only rice is sterilized by heating while being separated from water, sufficient sterilization can be performed in a short time using steam having a temperature considerably higher than 100 ° C. Moreover, in the present invention, the final packaging container is also put into the rice and sterilized at the same time as the rice, so that the final packaging container is sterilized at the same time, and there is no danger of secondary contamination by the packaging container. In addition, it is possible to save the trouble of transferring to the container after sterilization. on the other hand,
In order to put the water in the final packaging container containing the sterilized rice in a sterilized state separately from the rice,
Unlike the case of sterilizing together with rice, only water alone can be sufficiently sterilized and sterilized. Then, in this state, the container was hermetically sealed with a film sterilized, and then heated at a predetermined temperature for a predetermined time, cooked into cooked rice, cooled, dried, and packaged to produce a product. The heating time for cooking can be shortened, and the heating can be performed at a low temperature. That is, the rice has been swollen to a certain extent by the sterilization treatment using high-temperature steam, and the cooking time and the temperature of the cooked rice can be reduced. In addition, even if there is secondary contamination (falling bacteria) on the way, it is safe because the rice is cooked and cooked at the same time. As described above, according to the production method of the present invention, addition of an acidulant and encapsulation of a deoxidizer can be made unnecessary, so that the flavor at the time of eating can be improved.

Further, the production apparatus of the present invention includes an inlet-side device for weighing and filling a predetermined amount of washed and drained water-immersed rice in a final packaging container, transferring the same to a cassette and carrying it into a steaming tank. The rice in each container of the cassette is steamed and sterilized by steam at a predetermined temperature for a predetermined time under vacuum degassing together with each container, and the cassette after the steam sterilization is carried out from the steaming tank to the clean booth. An outlet-side device that removes the cassette from the cassette, supplies a predetermined amount of sterilized water into each container, and hermetically seals each container with the sterilized film; and rice in each hermetically sealed container. And retort sterilizer that heats and cooks water at a predetermined temperature for a predetermined time, cooks and cools and removes it, and a post-treatment device that dries and packs and cooks the cooked rice that has been removed from the retort sterilizer into a product It made.

[0010] The manufacturing apparatus of the present invention is to wash rice, which is a raw material of cooked rice, drain and sterilize only the rice, at the same time sterilize the final packaging container, and separately sterilize the water after sterilization. In addition to the rice, this is also sealed and sealed with a sterilized film, and cooked with a retort sterilizer to efficiently and inexpensively produce sterilized packaged rice that eliminates the need to add an acidulant or enclose an oxygen scavenger. Can be manufactured. In addition, by putting the container and rice into and out of the steaming tank in a batch by using a cassette, the work efficiency is improved, and when only the rice is separated and sterilized by steaming, put it in the final packaging container. Since it is performed, it is not necessary to transfer to a final packaging container in a clean booth as in the case of cooking in a conventional small rice cooker.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow sheet diagram showing an embodiment of the manufacturing method of the present invention, and FIG. 2 is a plan layout diagram showing an embodiment of the manufacturing apparatus of the present invention. Is supplied to the weighing and filling machine 1, and a predetermined amount, for example, one serving (100 to 110 g) is measured and supplied to the weighing and filling machine 1 separately. The water-immersed rice a filled in the final packaging container b to be drained while being kept in the container b is drained in the steaming tank 2 under vacuum degassing (for example, 30 torr) at a predetermined temperature (for example, 130 ° C.). For a predetermined time (for example, 4 to 7).
Min), and then a predetermined amount (for example, 90 g) of sterilized water c is filled in the container b, and the container b is sterilized by the container sealing device 3 using the film d. And then sealed at a predetermined temperature (for example, 100 to 110) by the retort sterilization apparatus 4.
C) for a predetermined period of time (for example, 20 minutes), cooked into cooked rice e, cooled (for example, to 20 minutes to 45 ° C.), dried in dryer 5, packed in packaging machine 6, and packed with product f. Is what you do.

The final packaging container b may be a heat-resistant plastic container, a metal container, a ceramic container, a lacquer ware, a wooden container, a heat-resistant paper container coated with plastic, a plastic sheet and paper having the same effect as this, or a metal. A container made of a laminated sheet or a composite sheet material such as a foil, a foamed sheet, or the like, or another material, and formed into an appropriate shape (for example, a bowl shape, a cup shape, a dish shape, a pot shape, or any other shape). Things are available. In this embodiment, as shown in FIG. 3D, a bowl shape made of heat-resistant plastic is exemplified.

The weighing and filling machine 1 has a configuration in which the water-immersed rice a, which has been drained and then washed, is automatically measured by a predetermined amount sequentially. And in this weighing and filling machine 1,
The final packaging container b is automatically supplied in synchronization with the measuring operation of the water-immersed rice a, and the measured water-immersed rice a is sequentially charged and filled into the container b.

The inlet-side device 7 for carrying the container b from the metering and filling machine 1 to the steaming tank 2 mainly includes an inlet-side container transfer machine 7a and a cassette loader 7b.

The inlet-side container transfer machine 7a transfers a container b filled with a predetermined amount of water-immersed rice a into a container receiving hole 8a of the cassette 8 as shown in FIG. For example, the illustration of the configuration is omitted, but, for example, a container receiving hole of the cassette 8 which has a gripper for gripping the container b at its tip and receives the container b from the weighing and filling machine 1 and is positioned and held at a predetermined position. 8a.

As shown in FIG. 3A, the cassette 8 has an elongated rectangular parallelepiped box shape with an open upper surface, and a plurality of (for example, eight) container receiving holes 8a. Are provided in a row at equal intervals, and a steam passage hole 8c is appropriately formed in the side wall. And
An openable / closable lid 8d is used in combination. This lid 8d
This is for preventing secondary contamination by falling bacteria during transportation or the like. The cassette 8 and the lid 8d are made of metal such as stainless steel having a rustproof function or made of heat-resistant plastic. The shape of the cassette 8 and the arrangement and number of the container receiving holes 8a can be appropriately changed and implemented.

The cassette loader 7b receives the cassette 8 having a predetermined number of containers b transferred thereon by the inlet-side container transfer machine 7a and having a lid 8d covered on the upper surface, and transporting the cassette 8 toward the inlet of the steaming tank 2. And a belt conveyor, a roller conveyor and the like.

The steaming tank 2 receives the cassette 8 supplied by the cassette loader 7b and drains the water-immersed rice a in each container b while keeping it in the vessel b. As shown in FIGS. 3B and 3C, the cassette 8 is manufactured in a cylindrical shape from a metal material having a rust-proof function such as stainless steel, and the cassette 8 is formed in a longitudinal direction at an inner central portion of the cylindrical shape cross section. Rails 2a and 2a are provided on both sides slightly below the center of the interior to extend along the entire length in the longitudinal direction so as to be movably supported along the inside. A fluororesin material is attached to the cassette sliding surfaces of the rails 2a, 2a, so that the cassette 8 can be easily taken in and out. Further, on the inlet side and the outlet side, valve devices 2b and 2c for hermetically sealing the inside during the steam sterilization treatment are installed. This valve device 2b,
In this embodiment, the ball valve 2c is illustrated as an example, but another type of valve device, for example, a slide type valve device may be used. The opening and closing operations of the valve devices 2b and 2c are performed by an air cylinder or the like. Insertion of the cassette 8 from the cassette loader 7b into the steaming tank 2 can be performed manually by an operator by installing appropriate insertion means. Similarly, the cassette 8 is also sent out to the outlet side of the steaming tank 2. Can be installed. The steaming tank 2 includes a vacuum degassing pipe 2d 'connected to an appropriate vacuum degassing apparatus 2d, a steam supply pipe 2e' connected to an appropriate clean steam generator 2e, and a drain discharge pipe 2f. These are provided with valve devices 2g, 2h, 2i such as ball valves. As the vacuum deaerator 2d, for example, a known water-sealed pump with a single-stage air ejector is used. Also, the clean steam generator 2e
For example, a known apparatus having a configuration in which boiler steam is once blown into water to remove impurities, heated to a predetermined temperature, and supplied is used.

At the outlet side of the steaming tank 2, the cassette 8 after the steam sterilization treatment is taken out from the steaming tank 2.
The container b is taken out of the container and supplied to the container sealing device 3. First, a predetermined amount of sterilized water c is supplied into each container b by the container sealing device 3, and the sterilized film d is supplied.
An outlet side device 9 for hermetically sealing the upper surface of each container b is provided. The outlet-side device 9 mainly includes a cassette unloader 9a including the container sealing device 3, an outlet-side container transfer machine 9b, an aseptic water producing device 9c, a stock conveyor 9d, and reversing devices 9e and 9e '. And

The cassette unloader 9a receives the cassette 8 sent out from the outlet of the steaming tank 2 and conveys it to the outlet side container transfer machine 9b, and is constituted by a belt conveyor or a roller conveyor.

The outlet side container transfer device 9b receives the container b from the container receiving hole 8a of the cassette 8 and receives the container b.
And has substantially the same configuration as the inlet-side container transfer machine 7a. The empty cassette 8 is returned to the entrance-side container transfer machine 7a by the cassette return conveyor 9f.

The container sealing device 3 includes an outlet-side container transfer machine 9.
A predetermined amount of sterilized water c is poured into the container b received from the container b, and this is also a sterilized film d.
Is put on a container b, hermetically sealed by heat sealing or the like, and sent to the next step. The container sealing device 3
When the hermetic sealing of the container b is performed by using the method described above, the container may be filled with nitrogen gas and sealed. The sterilized film d is periodically brought in and set from the outside in a rolled state, fed out by a predetermined length in association with the sealing operation of the container sealing device 3, and trimmed. .

The aseptic water producing apparatus 9c has a configuration in which tap water is sufficiently sterilized by boiling it for a predetermined time, and then, cooled water is supplied to the container b by a predetermined amount.

The hermetically sealed container b sent out of the container sealing device 3 is turned upside down by a reversing device 9e, stays in a stock conveyor 9d for a certain period of time, is steamed, and is turned upside down by another reversing device 9e '. It is returned to the original position, sent to the loader 4a on the side of the retort sterilizer 4 by the communication conveyor 9g, stacked on the tray 10 by the stacker 4c via the carry-in conveyor 4b, and sent to the retort sterilizer 4. Most of the outlet device 9 is a clean room 11
In particular, the outlet-side container transfer device 9b and the container sealing device 3 are arranged in a clean booth 11a.

[0025] The retort sterilizer 4 stacks the steam-sterilized rice a and water c in the containers b stacked on the tray 10 and hermetically sealed with the film d at a predetermined temperature for a predetermined time.
It is heated and cooked on cooked rice e, sterilized by heating at the same time, then cooled and taken out. The retort sterilizing device 4 uses a known device, and its structure is similar to that of the steaming tank 2.

The cooked and sterilized cooked rice e in the retort sterilizing device 4 and cooled in the sealed container b is sent to the unstacker 4e by the unloading conveyor 4d while being stacked on the tray 10, where the tray After being unloaded from 11, it is sent to the dryer 5 via the unloader 4 f, and after being dried, it is sent to the packaging machine 6 to be packaged and made into a product f. The empty tray 10 is returned to the original loader 4a by the tray return conveyor 4g. In FIG. 2, 12 is a compressor, 13 is an air tank, 14 is an aseb tank,
Reference numeral 15 denotes a water tank, 16 denotes an operation / transport line control panel on the steaming tank side, and 17 denotes an operation / transport line control panel on the retort sterilization apparatus side.

[Example] A final packaging container b and rice a soaked in water are supplied to a weighing and filling machine 1. This weighing and filling machine 1
Then, weigh and fill the container b for each serving (100 to 110 g / 1 container). The lid 8d of the cassette 8 returned by the entrance-side container transfer machine 7a is removed, eight containers b are loaded into the cassette 8, and the lid 8d is put on the cassette 8 and sent out to the next step. Six cassettes 8 are carried into the two steaming tanks 2 (two sets are basically operated) by the cassette loader 7b, and the valve devices 2b and 2c at both ends are closed to finish the steam sterilization of the water-immersed rice a. It is carried out together in the state of being put in the packaging container b. After the processing, the cassette unloader 9a (which operates in conjunction with the cassette loader 7b)
Six cassettes 8 are discharged from the two steaming vessels 2 at a time. Even when loading and unloading the cassette 8 to and from the steaming tank 2, the cassette 8 is loaded and unloaded as shown in FIG. 3C on the inner wall surface on the outlet side of the steaming tank 2 so that air leakage is minimized. The air leakage prevention plate 2j is attached so as not to hinder the operation. When discharging the last one (cassette 8), the valve device 2b on the inlet side of the steaming tank 2 is closed to prevent air from leaking from the valve device 2c on the outlet side to the inlet side. The air leaked to the minimum necessary in this manner also contributes to cooling of the rice a in the container b which is the contents of the cassette 8. The cassette 8 which has been subjected to the steam sterilization treatment is transferred from the clean room 11 to the clean booth 1 having the container sealing device 3.
Bring to 1a. Then, the lid 8d of the cassette 8 is removed, the treated container b is taken out, sterilized water c is injected into the container b in a fixed amount (90 g / 1 container), and further, the sterilized film is removed. d is put on the upper surface of the container b to heat the periphery, and the container b is hermetically sealed (top-sealed). In that case, sealing may be performed by filling with nitrogen gas. Thereafter, the sheet is retained for a certain period of time on the stock conveyor 9d, and then inverted by the inverter 9e.
a, stacked on the tray 10 via the stacker 4c, introduced into the retort sterilization apparatus 4, water c and rice a in the container b are cooked and cooked into rice e, and at the same time, sterilized and taken out; The product f is obtained through the dryer 5 and the packaging machine 6.

The material balance in the above embodiment is as follows.

Amount of rice soaked in water: 110 g / container Residual amount of condensed drain during steaming: 10 g / container Injection amount of sterilized water: 90 g / container The total of the above becomes a product: 210 g / container The detailed data of the step of cooking and sterilizing rice a in the steaming tank 2 is as follows. Vacuum deaeration: up to 30 torr with a water seal pump with a single-stage air ejector for 1 to 3 minutes Rise: up to 130 ° C with clean steam supply 0.5 minutes Steaming: keep 130 ° C with clean steam supply for a predetermined time 3 to 7 minutes Pressure: Evacuation until atmospheric pressure (100 ° C.) 0.5 minutes Total of automatic processing operation time 8.5 minutes F value: 8 or more The data of the aseptic water producing apparatus 9c is as follows.

Raw water temperature: 25 ° C. Sterilization temperature: maintained at 130 ° C. for 1 minute Removal temperature after cooling: 35 ° C. F value: 4 or more The data of the retort sterilization apparatus 4 are as follows.

Heating: 15 minutes to 100 to 110 ° C. Bactericidal: Hold at 100 to 110 ° C. 20 minutes Cooling: 20 minutes to 45 ° C. Total automatic operation time: 55 minutes Life test: Rotation and discoloration after 4 months No change in etc.

Although the above embodiment is directed to white rice, the present invention is also applicable to red rice, gomoku rice, and the like. In this case, for example, rice, ingredients and soup are separated into solids and liquids and individually sterilized and cooked. Then, it can be carried out by bringing it into the retort sterilization treatment device.

[0033]

According to the present invention, the bactericidal effect is sufficient and can be evaluated by a scientific numerical value (F value). With conventional rice cooked under atmospheric pressure alone, the F value cannot be achieved. The F value is
In the case of 4, the sterilization degree at which the botulinum is killed is defined, and the higher the numerical value, the higher the sterilization degree. Moreover, the present invention can thoroughly prevent secondary contamination, and even if it is contaminated by falling bacteria in the air, it can be pasteurized (for sterilization other than heat-resistant bacteria) with a retort sterilization treatment device. Safety can be ensured. Therefore, according to the present invention, there is no need to lower the pH by adding an acidulant,
No addition was realized. Also, less heat is applied than conventional products, and rice is exposed during steaming,
Delicious wrapped rice was made without smell. Naturally, the shelf life has improved.

Conventional cooking and sterilizing conditions for cooked rice: 120 ° C. for 40 minutes Cooking and sterilizing conditions for cooked rice of the present invention: water-immersed rice: 130 ° C. for 3 to 7 minutes Added water: 130 ° C. for 1.0 minute After filling and sealing: 100-110 ° C for 20 minutes As is clear from the above comparison results, the heat load is larger in the conventional case.

Further, according to the present invention, the number of initial bacteria does not matter so much, and the pretreatment becomes easy. The oxygen scavenger is no longer needed. In addition, the structure of the machines in the clean room and the clean booth is simpler than before, the management is easy, and an economical production line can be constructed.

[Brief description of the drawings]

FIG. 1 is a flow sheet diagram showing an example of a production method of the present invention.

FIG. 2 is a plan layout view showing an embodiment of the manufacturing apparatus of the present invention.

FIG. 3A is a schematic perspective view of a cassette and a lid, and FIG.
Is a schematic longitudinal sectional front view of the steaming tank, (C) is a schematic longitudinal side view at the outlet side of the steaming tank, (D) is a schematic longitudinal sectional side view of the final packaging container of the present invention filled with water-immersed rice,
(E) is a schematic longitudinal sectional side view of a state in which rice and water which have been sterilized have been filled into a final packaging container and top-sealed with a sterilized film.

[Explanation of symbols]

a: water-immersed rice, b: final packaging container, c: sterile water, d:
Aseptic processing film, e: cooked rice, f: product, 1: weighing and filling machine, 2: cooking tank, 3: container sealing device, 4: retort sterilization processing device, 5: dryer, 6: packaging machine, 7: entrance Side device, 8: cassette, 8d: lid, 9: outlet side device, 10:
Tray, 11: clean room, 11a: clean booth.

Continuation of front page (56) References JP-A-3-155761 (JP, A) JP-A-6-237745 (JP, A) JP-A-6-46770 (JP, A) JP-A-7-155121 (JP, A) JP-A-1-141562 (JP, A) JP-A-8-256709 (JP, A) Tsuneo Kamada, "Meat Processing Handbook", Korin Co., Ltd., May 15, 1985, p. 492-493 (58) Field surveyed (Int. Cl. ⁶ , DB name) A23L 1/10

Claims (2)

(57) [Claims] 1. A rice-washed and drained water-immersed rice is weighed and filled in a final packaging container by a predetermined amount, and the water-immersed rice which has been drained while being kept in the container is vacuum-degassed in a steaming tank under a predetermined condition. Perform steam sterilization treatment for a predetermined time with temperature steam,
Next, the container is filled with a predetermined amount of sterilized water, the container is hermetically sealed with a sterilized film, and then heated at a predetermined temperature for a predetermined time, cooked into cooked rice, and cooled. A method for producing aseptic packaged cooked rice, which is dried, packaged and made into a product. 2. An inlet-side device for weighing a predetermined amount of washed and drained water-soaked rice into a final packaging container, transferring the rice to a cassette and carrying it into a steaming tank, and the inside of each container of the loaded cassette. And a container for carrying out steam sterilization for a predetermined time with steam at a predetermined temperature under vacuum degassing with each container, and transporting the cassette after the steam sterilization to the clean booth from the steamer, taking it out of the cassette, and removing each container An outlet device that supplies a predetermined amount of sterilized water into the container, and seals and seals each container with a sterilized film, and the rice and water in each of the sealed containers at a predetermined temperature. It is characterized by comprising a retort sterilizer that heats it for a predetermined time, cooks it into rice, cools it and takes it out, and a post-processing device that dries and packs the rice cooked in a container taken out of the retort sterilizer into a product. Sterile packaging cooked rice manufacturing apparatus.