JPS61231981A - Method for sterilizing packaged food with microwave - Google Patents

Abstract

PURPOSE:To heat sterilize a packaged food without uneven quality, by putting the packaged food containing filled and sealed food heatable with microwaves in a support consisting of a material pervious to microwaves, and reversing the packaged food upside down at least once during the application of the microwaves. CONSTITUTION:A packaged food filling and sealing a food heatable with microwaves is put into a support 4, having a volume for containing the packaged food and a storing part 41 of almost the same shape, and consisting of a material pervious to the microwaves and the packaged food is reversed upside down at least once during the application of the microwaves. Thus, the uniform heat sterilization can be carried out without causing drying or scorching of the food.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for sterilizing food packages using microwaves, and in particular to a method for sterilizing food packages continuously under normal pressure and preventing uneven quality of food products. The present invention relates to a method for microwave sterilization of food packages that does not cause sterilization.

[Conventional technology]

Sterilization by microwave irradiation is already well known, and food packaging? Japanese Patent Publication No. Sho 5B-26949 also describes a method of sealing the inside of a pressure-resistant container made of a microwave-permeable material and sterilizing it by irradiating it with microwaves from outside the pressure-resistant container.

[Problem that the invention seeks to solve]

In the above method, since the pressure container is integrally formed with the microwave irradiation device, food packages cannot be continuously sterilized, and the method has the following drawbacks.

In other words, if the food consists of solid matter and liquid water,
The liquid accumulates at the bottom of the package, and the solids at the top and bottom of the package are outside the liquid and in the liquid, respectively, so even if the solids outside the liquid become dry or burnt due to heating,
Furthermore, the phenomenon that solid matter in the liquid was not sufficiently sterilized tended to occur.

Furthermore, even if a food consists only of solids, if the food contains water, heating will cause the water to evaporate and form droplets (
A similar phenomenon was likely to occur as the liquid was dripping.

The present invention was developed in view of the above circumstances, and it is possible to continuously sterilize food packages, and it also prevents uneven heating, drying or burning of some parts as described above, and incomplete sterilization of other parts. The purpose of the present invention is to provide a sterilization method that does not cause unevenness in quality.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a food package filled with a food that can be heated with microwaves and sealed, with a volume that can accommodate the food package and a microwave-transmissive container having a storage part of approximately the same shape. Provided is a method for sterilizing a food package by microwaves, which is characterized in that the food package is housed in a flexible support and turned upside down at least once during microwave irradiation. By the way, does this reversal mean that the food inside the package is dry, burnt, etc.? This is to prevent such a phenomenon from occurring, so it is necessary to turn it over and spread the water or cup evenly over the solid matter before such a phenomenon occurs.

[For production]

According to this method, the package is turned upside down at least once during microwave irradiation and is turned over before the food becomes dry or burnt, so the food can be heated evenly without drying or burning. It also becomes possible to heat for a long time.

In addition, since the food package is kept in a horizontal state and remains horizontal even after being turned over, it is possible to prevent the food from falling into the lower part of the package.

Furthermore, according to this method, since the inside of the package is sealed, even air-containing packages can be heated and sterilized without causing degassing, and there is no escape of moisture or water vapor, so there is no need to dry the food. There is even less room for blemishes to occur.

〔Example〕

Food packaging bodies that can be used in this method are shown in Figure 4 1a) (bl
Alternatively, it is as shown in FIGS. 5(a) and 5(b).

That is, FIG. 4 fal is a plan view showing the sealed bag (2) containing the food (11fjr), and FIG. 4 fbl is a cross-sectional view thereof. A perspective view of the tray (3), and FIG. 5 (6) is a sectional view thereof.

The food 111 may be any food that can be sterilized by microwaves, but a mixture of solid and liquid or food that produces drips when heated is compatible with the spirit of the present invention. Examples include beefsteak, grilled fish, red rice, white rice, tofu, sweet natto, hamburger steak, meatballs, and grilled eel.

In addition, the bag (2) and the tray (3) are made of a material that can transmit microwaves. Specifically, in the case of the bag 12), a laminated film of stretched nylon/unstretched polypropylene, stretched nylon/unstretched nylon/unstretched A laminated film of Bo-11 propylene, a laminated film of stretched nylon/saponified ethylene-vinyl acetate copolymer/unstretched Bo-11 propylene,
It is # scrap film of Bo-11 ester/unstretched Bo-11 propylene.

In addition, in the case of tray f: J, l, the lid material is the above bag (2
) Any of the laminated films listed as materials can be used, as well as poly-11 ester/stretched nylon/unstretched poly-11
Laminated films of propylene can also be used, and the container body can be made of unstretched polypropylene sheets, unstretched nylon/unstretched polypropylene laminate sheets, unstretched polypropylene/
Saponified ethylene-vinyl acetate copolymer/unstretched bottle 11
Laminated sheet of propylene, unstretched polypropylene/unstretched nylon/saponified ethylene-vinyl acetate copolymer/
This is a laminated sheet of unstretched polypropylene drawn by drawing.

In addition, whether it is a bag or a tray,
From the viewpoint of efficiency of heating by microwave transmission, the thickness is preferably 35+ m or less, and the packaging form may be vacuum packaging or air-containing packaging, but it must be completely sealed to prevent gas from entering or exiting.

The outline of the sterilizer used in this method is shown in FIG. That is, the support body (4) containing the food package moves endlessly through the heating section (6), the holding section (7), and the cooling section (81) by the two guide rails (51. Naturally, the cooling section (8
) and the heating section (6:).

The support (41 has a shape as shown in FIG. 2 (al (bl) or FIG. 3. That is, FIG. (bl is its cross-sectional view, and FIG. 3 is a cross-sectional view of the support when the food package is a tray.

As is clear from these countries, the support (4) consists of two upper and lower holding plates having a storage part (4υ) that has approximately the same external shape as the food package, and at least one of the holding plates is heated. The reason why the support body (41) has a storage part with approximately the same shape as the outer shape of the food package is that the food package is stored here, and This is to prevent the food package from opening even if it expands due to heating.

The support (4) is made of a heat-resistant, pressure-resistant, and microwave-transparent material, specifically, polycarbonate, Teflon, ceramics, wood, or a material obtained by mixing glass fiber with the polycarbonate or Teflon.

As mentioned above, the support containing the food package is transferred along the two guide rails (51) and is irradiated with microwaves and heat sterilized in the heating section (6). At this time, the support body containing the food package is The support (41) is turned upside down once. This turning is done before the food becomes dry or burnt. This inversion ensures that the liquid and lumps are evenly distributed inside the package and prevents the food from drying or burning. If heating is allowed for a long time, the heating should be reversed again for the same reason.

The heating temperature varies depending on the food, but the maximum temperature for high temperature sterilization is 1.
30℃, 85-100℃ for pasteurization, heating section (
61 to reach the set temperature within about 10 minutes.

After the support body (4) leaves the heating section (6), it enters the holding section (7) as it is. The holding part (71) does not have heating equipment, and the surrounding band' is covered with a heat insulating material such as glass wool or asbestos. Make sterilization more effective.

After this, the support (4) is cooled in the cooling section (8). Cooling can be done by water cooling or air cooling (if the package is vacuum packed, the food package must be cooled to below 100°C; if the package contains gas, it must be cooled to about 706C or below, and then the food package must be removed from the support (4). .At this time, do 1) generated during cooling.
In order to spread the liquid evenly, it is necessary to turn the support (4) upside down again during cooling. This reversal during cooling is necessary when the food is likely to have uneven quality due to toppings, such as boiled rice.

〔effect〕

The present invention is a method as described above, and has the effect that microwave sterilization can be performed without causing unevenness in the quality of solids.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory diagram of a sterilizer, FIG. 2 is a plan view and a sectional view of a support when the food package is a bag, and FIG. is a sectional view in the case of a tray, FIG. 4 (bl is a plan view and a sectional view of a food packaging body (bag), and FIG. 5 is a perspective view and a sectional view of a food packaging body (tray). (11...food (2)...bag (3)...
Tray (4)...Support (4υ...Storage section (
4...Measurement opening (51...Guide roll (
6: Heating part (71... Holding part (
8) Cooling section Figure 1 Figure 2 (Q) Figure 4 (0) Figure 95 (O-machi Figure 5 (b)

Claims (1)

[Claims] 1) A food package filled and sealed with a food that can be heated by microwaves is made of a microwave-transmissible material having a volume that can be accommodated by the food package and a storage section of approximately the same shape. A method for sterilizing a food package using microwaves, the method comprising storing the package in a support and turning it upside down at least once during microwave irradiation. 2) The sterilization method according to claim 1, wherein the food package is turned upside down at least once during cooling after microwave irradiation.