JPH06245743A - Production of hermetically packaged food - Google Patents

Abstract

PURPOSE:To provide a process for the preparation of a hermetically packaged food, capable of preventing the deformation of the vessel to be filled with a heating object and effective for reducing the cost and improving the quality. CONSTITUTION:The production process comprises a packaging step A to fill and seal a heating object food 14 in a microwave transmitting packaging vessel 15, a transfer step B to supply at least one of the hermetically packaged food 17 to a transfer line 8, a heating step C to irradiate the food 14 in the package 17 with microwave from the upper and lower waveguides 10, 11 above the transfer line 8 under a pressure of <=2.8kg/cm<2> and raise the temperature of the food to 110-130 deg.C, a temperature-maintaining step D to keep the food at the above temperature in dry-heat atmosphere having a relative humidity of 0-30% and a temperature of 110-130 deg.C for a prescribed period and a cooling step E to cool the treated food 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to continuous sterilization or cooking and sterilization of a hermetically sealed food to be heated without deformation of the packaging container, which can be stored at room temperature for a long period of time and is simple and convenient. The present invention relates to an improvement in a method for producing a sealed packaged food that can be eaten by re-cooking.

[0002]

2. Description of the Related Art Generally, heating food by microwave is different from heating using steam, hot water, etc., because the object to be heated is directly heated from the inside, so that the thermal efficiency is extremely high and the object to be heated is very good. It is possible to raise the temperature rapidly.

Therefore, when microwaves are used for sterilizing foods, it is said that higher quality products can be obtained as compared with conventional retort sterilization and the like. Sterilization is possible, and when the sterilization standard stipulated by the Food Sanitation Law is achieved (low-acid foods (pH 4.6 or more) that are used for normal temperature distribution), the cold point of the food to be heated in the heat treatment is 120 ° C for 4 minutes. The above must be maintained).

However, the container filled with the object to be heated was significantly deformed depending on the pressure conditions in the temperature rising stage by microwave irradiation, the sterilization temperature maintaining stage, and the cooling stage.

[0005]

As a measure for preventing the deformation of the container, it is conceivable to increase the container strength of the container itself or to heat it for a long time under a low pressure that does not cause deformation. It has become a factor of rise in quality and deterioration of quality.

Further, in the above method, the sterilization standard stipulated by the Food Sanitation Law is achieved while minimizing the deformation of the container,
Moreover, it has been quite difficult to supply products continuously on a commercial scale.

Therefore, in the present invention, in view of the above problems,
To provide a method for producing a hermetically sealed packaged food, which can prevent deformation of a container filled with an object to be heated and can achieve cost reduction and quality improvement because it can be continuously produced on a commercial scale. It is an issue.

[0008]

The present invention takes the following technical means in order to achieve the above object.

That is, a packaging step A for filling and sealing the heated food 14 in the microwave permeable packaging container 15, and a transportation step B for supplying at least one hermetically packaged food packaging body 17 onto the transportation line 8. , 2.8 kg / cm ² or less under pressure, the upper and lower waveguides 10, 1 provided on the transfer line 8
A temperature raising step C of irradiating microwaves from 1 to raise the temperature of the food 14 in the package 17 to 110 to 130 ° C .;
The temperature under the pressure conditions, and relative humidity 0 ~ 30%,
The temperature increasing step C includes a temperature maintaining step D for maintaining a predetermined time in a dry heat atmosphere with an ambient temperature of 110 to 130 ° C. and a cooling step E for cooling the processed food 14.
, Temperature maintenance process D, cooling process E
It is characterized in that it heats and sterilizes by heating, or heat-cooked and sterilized foods are manufactured while adjusting the pressure to a pressure condition of 2.8 kg / cm ² or less.

[0010]

In the method for producing a hermetically packed food according to the present invention, the pressure adjusting units 4,5 interposed between the temperature raising step C, the temperature maintaining step D, and the cooling step E respectively apply pressure in each step. Since the condition can be appropriately adjusted to 2.8 kg / cm ² or less, the temperature increasing step C to the temperature maintaining step D sequentially increase the pressure within the range of the pressurizing condition, and the temperature maintaining step D to the cooling step E. Is set to decrease the pressure sequentially,
It is possible to reliably prevent the deformation of the container.

[0011]

Examples The present invention is an instant food that can be stored at room temperature for a long period of time and can be eaten by simple re-cooking,
A method for producing a sealed packaged food by sterilizing by microwave, or cooking and sterilizing while keeping the food to be heated such as food for microwave oven in the packaging container, and as one example thereof, continuous microwave heating The steps of manufacturing using the pressure sterilizer S will be sequentially described along the manufacturing line with reference to the drawings.

As shown in FIG. 1, in the continuous microwave heating and pressure sterilizing apparatus S, a microwave irradiating section 1, a dry heat heating section 2 and a cooling section 3 are respectively provided with a second pressure adjusting section 4 and The third pressure adjusting section 5 is provided continuously, and the first pressure adjusting section 6 is provided at the inlet of the microwave irradiating section 1.
Also, a fourth pressure adjusting unit 7 is provided at the outlet of the cooling unit 4, and a transfer line 8 can pass between the respective units.

The continuous microwave heating and pressure sterilizer S
Each part (first to fourth pressure adjusting parts 5, 6, 7, 8, microwave irradiating part 1, dry heat heating part 2, cooling part 3) is provided with a pressure adjusting pipe 9 for manufacturing. It can be adjusted according to the process.

The microwave irradiator 1 is provided with a pair of upper waveguide 10 and lower waveguide 11 above and below the carrier line 8, respectively. And the lower waveguide 11 is arranged such that the distance to the object to be irradiated is shorter than or the same as the wavelength of the microwave. Has been done. The number of the waveguides 10 and 11 is not limited to one as in the above-described embodiment, but can be appropriately increased according to the type of food or container.

A hot air circulation type heater 12 is further provided in the dry heat heating section 2, and a cooler 13 is provided in the cooling section 3.
Is provided.

In the case of producing a sealed packaged food with the continuous type microwave heating and pressure sterilizer S constructed as described above, first, the uncooked or cooked heated food 14 is
For example, it is filled in a microwave permeable packaging container 15 made of polypropylene, ethylene-vinyl alcohol copolymer or the like, and hermetically sealed with a lid 16. The above is the packaging process A
And

Next, the sealed packaged food package 17 is opened by using the conveyor 18 or the like to open the first pressure adjusting section 6 of the continuous microwave heating and pressure sterilizing apparatus S, and at least 1 is placed inside the package. Transport and supply one by one. The above is transportation process B.

The continuous microwave heating and pressure sterilizer S
When using, the pressure inside the microwave irradiation unit 1 should be adjusted in advance.
^{0.5kg / cm 2 ~2.0kg / cm 2} , preferably to 1.5 kg / cm ^2,
Also, the pressure in the dry heat heating unit 2 is 1.0 kg / cm ^{2 to} 2.8 kg / cm.
² , preferably 2.2 kg / cm ² , and the pressure in the cooling unit 3
^{0.5kg / cm 2 ~2.0kg / cm 2} , preferably previously adjusted respectively to 0.5 kg / cm ^2. The pressure condition is appropriately adjusted within the range of 2.8 kg / cm ² or less in accordance with the type of food, container, sterilization condition and the like.

When adjusting the pressure in each of the above parts, the pressure in the first pressure adjusting part 6 is adjusted to 0 kg / cm ² to 1.5 kg / cm ^2.
To the same pressure as the microwave irradiation part 1 in advance.

Next, the microwave irradiation unit 1 is opened and the food package 17 is conveyed into the microwave irradiation unit 2.

Next, microwaves are radiated from the upper and lower waveguides 10 and 11 of the microwave radiating section 1 whose pressure is adjusted to 1.5 kg / cm ² in advance, and the hermetically sealed food package is packaged. Increase the internal temperature of 17 to 110-130 ° C.

At this time, the pressure in the first pressure adjusting section 6
While reducing the pressure from 1.5 kg / cm ² to 0 kg / cm ² , the pressure inside the second pressure adjusting unit 4 is increased from 0 kg / cm ² to 1.5 kg / cm ² , and the pressure inside the microwave irradiation unit 1 is Set to the same pressure. The above is the temperature increasing step C.

Next, the second pressure adjusting section 4 is opened, the food package 17 is conveyed into the second pressure adjusting section 4, and
Adjust the pressure in the second pressure adjusting unit 4 from 1.5 kg / cm ² to 2.2 kg / cm
Pressurize up to ² and adjust to the same pressure as the inside of the dry heat heating unit 2.

Next, the dry heat heating unit 2 is opened, the food package 17 is conveyed into the dry heat heating unit 2, and the dry heat heating unit 2 is heated.
The temperature in 2 is relative humidity 0 to 30%, ambient temperature 110 to 130
The temperature is adjusted to a dry heat atmosphere of ° C and maintained for a predetermined time.

At this time, the pressure in the second pressure adjusting section 4 is
While reducing the pressure from 2.2 kg / cm ² to 1.5 kg / cm ² , the pressure inside the third pressure adjusting unit 5 is increased from 0 kg / cm ² to 2.2 kg / cm ² , and inside the dry heat heating unit 2. Make the same pressure as.
The above is the temperature maintaining step D.

Next, the third pressure adjusting section 5 is opened, the food package 17 is conveyed into the third pressure adjusting section 5, and
Adjust the pressure in the third pressure adjusting unit 5 from 2.2 kg / cm ² to 0.5 kg / cm ^2.
The pressure is reduced to ² and adjusted to be the same as the pressure inside the cooling unit 3.

Next, the cooling unit 3 is opened, and the cooling unit 3 is opened.
The food package 17 is conveyed into the inside and is cooled in the cooling section 3.

At this time, the pressure in the third pressure adjusting section 5 is
While increasing the pressure from 0.5 kg / cm ² to 2.2 kg / cm ² , the pressure in the fourth pressure adjusting unit 7 is increased from 0 kg / cm ² to 0.5 kg / cm ² , and the pressure in the cooling unit 3 is Adjust to the same pressure.

Next, the fourth pressure adjusting section 7 is opened, the food package 17 is conveyed into the fourth pressure adjusting section 7, and the pressure in the fourth pressure adjusting section 7 is 0.5 kg / cm ² to 0 kg /
Reduce the pressure to cm ² . The above is the cooling step E.

Finally, the sealed packaged food 19 discharged from the fourth pressure adjusting unit 7 and sterilized by heating under pressure or cooked and sterilized in this way is completed.

In the temperature increasing step C, the distance between the upper waveguide 10 and the hermetically sealed food package 17 is longer than the wavelength of the microwave, while the lower waveguide 11 and the hermetically sealed food package 17 are hermetically sealed. By making the interval with the food package 17 shorter than the wavelength of the microwave, the central portion of the food 14 in the packaging container 15 by the microwave radiated from the lower waveguide 11 installed at the short position, Further, the microwaves emitted from the upper waveguide 10 installed at the long position can heat the peripheral portions of the food 14 respectively, and the internal temperature of the food 14 can be rapidly increased by 110 to 130 ° C. Can be raised to.

Further, in the temperature maintaining step D, the food package 17 that has been hermetically packaged is subjected to a pressure condition of 2.8 kg / cm ² or less, a relative humidity of 0 to 30%, and an ambient temperature of 110 to 130 °.
Since it is maintained in the dry heating atmosphere of C for a predetermined time, the internal temperature of the food package 17 can be stably maintained,
It is possible to manufacture foods with very little uneven heating.

Incidentally, FIG. 2 shows an explanatory view of the steps following the carrying step B in the above-mentioned manufacturing. FIG. 2 shows a case where five sealed packaged foods 19 are successively manufactured.

In this case, when the food package 17 is conveyed into the second pressure adjusting unit 4 by opening the second pressure adjusting unit 4, the second package 17 is heated by the continuous microwave heating. When the first wrapping body 17 is conveyed into the pressure sterilization device S, and the first wrapping body 17 is conveyed into the third pressure adjusting section 5, the third wrapping body 17 is conveyed into the device S and one more When the second package 17 is conveyed into the fourth pressure adjusting unit 7, the fourth package 17 is conveyed into the device S and the second package 17 is conveyed into the fourth pressure adjusting unit 7. The fifth package 17 is transported into the apparatus S when it is transported to.

As in the above embodiment, the pressure adjusting portion (first to
Since the fourth pressure adjusting unit 5, 6, 7, 8) is interposed between each process and the pressurizing condition in each process can be appropriately adjusted, it becomes possible to successively and successively overlap the processes, It can be manufactured inexpensively on a commercial scale.

Specific examples of the method for producing the sealed packaged food 17 of the present invention will be described below with reference to test examples and comparative examples.

<Test Example> First, as a packaging step A, 360 g of extremely high-viscosity potage soup was filled in a polypropylene microwave permeable packaging container 15 having a capacity of 600 ml, and then,
The lid 16 made of plastic is hermetically sealed.

Next, after the carrying step B, the temperature rising step C
In the microwave irradiation unit 1, the pressure inside the hermetically sealed package 17 is adjusted to 1.5 kg / cm ² , and the microwave irradiation output is 0.5 kw and the upper waveguide 10 and the microwave irradiation. Microwaves are radiated from the lower waveguide 11 whose output is 1.0 kw for a predetermined time.

Next, as a temperature maintaining step D, a dry heat heating unit is used.
The pressure inside 2 is adjusted to 2.2 kg / cm ² , the temperature is adjusted to 122 ° C, and the relative humidity is adjusted to 0% in a dry heat atmosphere, and the temperature is maintained for a predetermined time.

Further, in the cooling step E, the packaging body 17 was transported into the cooling section 3 and cooled at a pressure of 0.5 kg / cm ^{2 in the} cooling section 3 to manufacture.

During the progress of each of the above steps, the packaging container
The temperature change of the peripheral portion and the central portion of the potage soup in 15 was measured. The result is shown in FIG. As is clear from the measurement results, almost no temperature difference was observed in the peripheral portion and the central portion of the potage soup, the container 15 was not deformed, and the F ₀ value according to the Food Sanitation Law was about 8.5. A food with no quality problems was produced.

<Comparative Example> In the same manner as in the first embodiment, after the packaging step A, in the transportation step B, the microwave irradiation part
1, the dry heat heating unit 2 and the cooling unit 3 are transferred into a continuous continuous microwave heating and pressure sterilizer (not shown) that is continuous without a pressure adjusting unit, and the temperature rising process C After adjusting the pressurization and microwave irradiation output conditions in the same manner, the temperature maintaining step D 1 and the cooling step E 2 were allowed to proceed under the same conditions as above, and the same production was performed thereafter.

During the progress of each of the above steps, the package 12
The change in the product temperature of the peripheral portion and the central portion of the potage soup inside was measured. The measurement result, F ₀ value according to the Food Sanitation Law is about
Although it was 8.9, the container 15 was deformed, and the partial browning that was considered to be caused by overheating was also generated and the product had no commercial value.

[0044]

EFFECT OF THE INVENTION In the method for producing a hermetically sealed food according to the present invention, the packaging step, the carrying step, and the temperature raising step are performed to
Irradiate microwaves from the upper and lower waveguides provided on the transportation line under a pressurized condition of 5 to 2.8 kg / cm ² to rapidly raise the temperature of the food to 110 to 130 ° C, and In the temperature maintaining step, the temperature is set under the pressure condition and the relative humidity is set.
It was sterilized by heating under pressure, or cooked and sterilized by keeping it in a dry heat atmosphere of 0 to 30% and an ambient temperature of 110 to 130 ° C for a predetermined time, and finally cooling the food in a cooling step. A sealed packaged food can be manufactured.

At this time, in the pressure adjusting section, pressure is applied between the temperature raising step and the temperature maintaining step and depressurized between the temperature maintaining step and the cooling step, and the pressurizing condition in each step is adjusted appropriately. Since it is possible to prevent the deformation of the container sufficiently, it is possible to achieve the sterilization standard stipulated in the Food Sanitation Law, and it is also possible to successively and sequentially repeat the process, thus reducing the cost. It has become possible to improve the quality on a commercial scale.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a production process of a hermetically sealed food product of the present invention.

FIG. 2 is an explanatory table showing the manufacturing process of the hermetically sealed food of the present invention.

FIG. 3 is a graph showing changes in internal component temperature according to the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microwave irradiation part 2 Dry heat heating part 3 Cooling part 4 2nd pressure adjustment part 5 3rd pressure adjustment part 6 1st pressure adjustment part 7 4th pressure adjustment part 8 Conveyance line 9 Pressure adjustment pipe 10 Upper waveguide Tube 11 Lower waveguide 14 Food to be heated 15 Microwave permeable packaging container A Packaging process B Conveying process C Temperature increasing process D Temperature maintaining process E Cooling process

Claims (1)

[Claims] 1. A packaging process (A) for filling and sealing a microwave-permeable packaging container (15) with a food to be heated (14) and a food package (17) which has been hermetically packaged on a transfer line (8). In the carrying step (B) of supplying at least one to the upper and lower waveguides (10), (11) provided on the carrying line (8) under a pressure condition of 2.8 kg / cm ² or less. ) From the microwave,
A temperature raising step (C) of raising the temperature of the food (14) in (17) to 110 to 130 ° C, and the temperature under the pressurized condition, relative humidity of 0 to 30%, and ambient temperature of 110 to Temperature maintenance process (D) of maintaining for a predetermined time in a dry heat atmosphere of 130 ° C
And a cooling step (E) for cooling the processed food (14), the temperature increasing step (C), the temperature maintaining step (D),
A hermetically sealed package characterized by producing heat-pressurized sterilized or heat-cooked and sterilized food while constantly adjusting the pressure to 2.8 kg / cm ² or less during each step of the cooling step (E). Food manufacturing method.