JPS63226268A - Thawing and cooking of frozen food by electronic oven and frozen food retainer therefor - Google Patents

Abstract

PURPOSE:To carry out thawing and cooking uniformly without causing heat unevenness, by covering the whole side wall face of a retainer with a material to reflect microwave but not transmit and packing a frozen food in the retainer made of a material to transmit microwave. CONSTITUTION:The inner wall face of a side wall 3 to divide a storage part 2 of a retainer 1 having such a depth that a frozen food 6 will not protrude itself from the top is covered with a material 4 to reflect microwave but not transmit. When the frozen food is placed on a heating chamber of an electronic oven having no turntable, the frozen food 6 is heated by microwave coming in the vertical direction and the peripheral part will not more rapidly heated than the central part.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to thawing and cooking of frozen foods in a microwave oven, and more particularly, to thawing and cooking of frozen foods by uniform heating in a microwave oven. This invention relates to thawing and cooking of frozen foods by uniform heating in a microwave oven that does not have a turntable for horizontally rotating the foods.

The thawing and cooking of frozen foods according to the present invention is suitable for thawing and cooking of frozen foods in a microwave oven without a turntable, and pre-cooked frozen foods in the restaurant industry can be used in a high-output microwave oven without a turntable. ,
It is suitable for thawing and cooking and is efficiently utilized in the restaurant industry.

[Technical background and explanation of conventional technology]

2. Description of the Related Art It is widely used to heat and cook food using a microwave oven and to warm the cooked food. Heating by a microwave oven is dielectric heating, and food is heated by dielectric heating of water contained in the food.

Water has two states: solid water and liquid water, and the dielectric heating coefficient for each state [(
dielectric system) x (dielectric constant)] is 1
1.55, whereas water in a solid state has a value of 0.
003, water in a liquid phase is heated very quickly by microwaves in a microwave oven,
Water in a solid state does not heat up as quickly.

When heating frozen food using microwaves in a microwave oven, uneven heating may occur where some parts of the frozen food are heated strongly and others are not heated as strongly. However, since water is heated faster than water, the uneven heating caused by this is more significant. Furthermore, for water to metamorphose into water, 80
It requires 1g of heat of fusion, but 80% of this water
Since the amount of heat per 1g corresponds to the amount of heat required to raise the temperature of water at 06°C to 80°C, the uneven heating that occurs when heating frozen foods using a microwave oven is significantly amplified. Become something.

On the other hand, it has been proposed to place aluminum foil around the periphery of a flat packaged food to prevent the periphery of the packaged food from overheating when heated with microwaves. (Utility Application No. 57-85452) The present inventor has been conducting research for many years on manufacturing technology such as food freezing processing and cooking processing. Occasionally, uneven heating often occurs, but if frozen foods are placed in a retainer with aluminum foil attached to the entire side wall and heated in a microwave oven, uneven heating is less likely to occur. If you hold this retainer containing frozen food at an appropriate height in the heating chamber of a microwave oven,
It was discovered that the heating unevenness was further reduced, and based on these findings, the present invention was achieved.

[Object of the invention and summary of the invention]

An object of the present invention is to provide a method for heating frozen foods in a microwave oven to defrost them.
To provide a method for uniformly thawing and cooking frozen foods by uniformly heating the frozen foods by using an electronic one without causing uneven heating.

Another object of the present invention is to provide a retainer for frozen foods that can be thawed and cooked uniformly in a microwave oven without causing uneven heating.

In the present invention, when thawing and cooking frozen food by heating in a microwave oven, the entire inner wall surface of the frozen food is coated with a material that reflects microwaves without transmitting them.
This is a method for thawing and cooking frozen food, which is characterized by placing the frozen food in a retainer made of a material that transmits microwaves and heating it uniformly, thereby thawing and cooking the frozen food.

When heating frozen foods according to the present invention in a microwave oven, aluminum foil or an aluminum plate can be used as the material that reflects microwaves without transmitting them, which covers all side walls of the inner wall of the retainer, and constitutes the retainer. The retainer can be made of polystyrene foam, acrylic, plastics with low dielectric constants such as polycarbonate or polytetrafluoroethylene, glass, or ceramics.
The underside of the retainer can be fitted with legs of sufficient height to hold frozen food in a retainer in sufficient position for even heating; Microwave ovens for heating frozen foods may be of high power and do not have a turntable to horizontally rotate the heated food. can be used.

The present invention has sufficient depth to accommodate frozen food;
A frozen food product characterized in that the entire side wall surface of the inner wall has a frozen food accommodating portion covered with a material that reflects microwaves without transmitting them, and is made of a material that transmits microwaves. This is a retainer for heating with a microwave oven.

In the retainer for heating frozen foods in a microwave oven of the present invention, aluminum foil or an aluminum plate is used as the material that reflects microwaves without transmitting them and covers all side walls of the inner wall of the frozen food storage section. The microwave-transparent materials that make up the retainer include expanded polystyrene, acrylic resin,
Plastics with low dielectric potential such as polycarbonate or polytetrafluoroethylene, glass, or ceramics can be used.

The retainer for heating frozen food in a microwave oven of the present invention has a height sufficient to uniformly heat the frozen food without uneven heating during heating of the frozen food in the microwave oven. You can attach the necessary legs to maintain it.

[Detailed description of the invention]

FIG. 1 is a perspective view of an example of a retainer used for defrosting and cooking frozen foods in a microwave oven according to the present invention;
FIG. 2 is a partially cutaway side view of an example of the implementation of the retainer in a state where frozen food is accommodated, and FIG. 3 is a heating chamber of a microwave oven with the retainer placed in the heating chamber of the microwave oven. FIG. 3 is a side view of the inside of the heating chamber, and FIG. 3 shows the state of the heating chamber in an embodiment of the present invention.

] is a retainer for frozen food, the upper part of which is the side wall 3
The inner wall surface of the storage section 2 of the side wall 3 is covered with a material 4 that reflects microwaves without transmitting them. 5 is a leg portion on the lower surface of the retainer 1, and 6 is a frozen food. 10 is the heating chamber of the microwave oven, 11 is the heating chamber】0
12 is an antenna on the ceiling of the heating chamber 10, and microwaves are radiated from the antennas 11 and 12 to the entire heating chamber 10. And 13 is a glass tray on which objects to be heated in the microwave oven are placed.

To thaw and cook frozen foods according to the present invention, frozen foods 6
The retainer 1 containing the frozen food 6 is placed on the glass tray 13 of the heating chamber 10 of the microwave oven, and microwaves are emitted from the antennas 11 and 12. , the frozen food 6 accommodated in the storage part 2 of the retainer 1 is heated, thereby thawing and cooking the frozen food 6.

The retainer 1 has a depth that prevents the frozen food 6 stored therein from protruding upward, and the inner wall surface of the side wall 3 that partitions the storage section 2 is made of a material that reflects microwaves without transmitting them. covered by 4. When the retainer 1 containing the frozen food 6 in the storage section 2 is heated in the heating chamber 10 of the microwave oven, the frozen food 6 in the storage section 2 is heated by the microwaves that enter from above and below. The microwaves that are supposed to be reflected on the wall surface of the heating chamber 1O and enter the retainer 1 from the horizontal direction are reflected by the material 4 that covers the inner wall surface of the side wall 3 and reflects without transmitting the microwaves. Housing part 2 of retainer 1
It doesn't even reach. If there were no material a4 that does not transmit microwaves but reflects them, which covers the inner wall surface of the side wall 3 that partitions this storage section 2, the peripheral edge of the frozen food 6 in the storage section 2 would be Since the center of the frozen food 6 is heated by both the microwaves entering from above and the microwaves entering from the horizontal direction, the temperature rises faster than the center of the frozen food 6, which is heated only by the microwaves entering from above and below. The frozen food 6 is supposed to be heated unevenly, but the inner wall surface of the side wall 3 that partitions the housing section 2 of the retainer l is coated with a material 4 that reflects microwaves without transmitting them. Since the microwaves entering from the horizontal direction are blocked, the entire frozen food 6 stored in the storage section 2 is heated only by the microwaves entering from above and below, thereby uniformly heating the entire frozen food 6. It is.

The retainer 1 has leg parts 5 on the lower surface of the retainer 1 with a height necessary to maintain the accommodating part 2 of the retainer 1 at an appropriate height in the heating chamber 10 of the microwave oven 4. Since the height necessary to hold the housing part 2 in the heating chamber 10 of the microwave oven is unique to each microwave oven, the height of the leg part 5 is determined experimentally for each microwave oven. Should. However, as described in the discussion of the Examples and Comparative Examples, the uneven heating of the frozen food 6 caused by the fluctuation of the legs 5 is not so large.

Any material 4 that reflects microwaves without transmitting them can be used as long as it has the performance shown here, but aluminum foil or an aluminum plate is preferably used. is simple and economical. The material constituting the main body, side wall 3, and leg portion 5 of the retainer 1 may be any material that transmits microwaves.
Although any material can be used, it is preferred to use expanded polystyrene, acrylic resin, polycarbonate or polytetrafluoroethylene or polyester. However, only the side wall 3 can be made of a material that reflects microwaves without transmitting them, and when the side wall 3 is made of a material that reflects microwaves without transmitting them, the inner wall surface of Covering with material 4 that reflects microwaves without transmitting them can be omitted.

Further, the microwave oven used for thawing frozen food according to the present invention is a household microwave oven equipped with a turntable for horizontally rotating the object to be heated, or a commercial microwave oven without this turntable. Although any of these can be used, it is most effective when a commercial high-output microwave oven without a turntable is used.

Further, the frozen food that is thawed and cooked according to the present invention may be packaged with a material that transmits microwaves, such as a polyester film.

〔Example〕

Example Frozen pilaf (27
0 Jil) 2 bags were attached to the legs 5 of a height of 50++ m, and the inner wall surface of the side wall 3 of the storage section 2 was covered with aluminum foil in a foamed polystyrene retainer [Dimensions of the storage section 2: 12? +m (ltG) x 180mm (length) x 2511III+ (depth)],
This retainer was installed in a commercial microwave oven without a turntable (MR-1400, Hitachi product, heating chamber dimensions: 365 mm (Ilii) x 405 m+
I + (depth) x 245 (height), micro pumping crab
1400 W/700 W) and heated for 3 minutes at an output of 1400 W to defrost and cook the frozen pilaf.

After thawing and cooking, the pilaf is heated evenly throughout.
It was ready for consumption.

Comparative Example 1 (Example without using retainer) Frozen pilaf was thawed and cooked in the same manner as in Example except that the expanded polystyrene retainer of Example was not used.

After heating the pilaf for 3 minutes, the part directly above the antenna was overheated and almost dry, while the other parts away from the antenna were moderately cooked. was occurring.

Comparative Example 2 (Example corresponding to the case where there is no aluminum foil on the inner wall of the housing part 2 of the retainer) In Comparative Example 1, the plastic tray to which the periphery of height 50III11 was attached was placed in the heating chamber of a microwave oven, and the plastic tray was placed on top of it. Place the frozen pilaf and do the same as in Comparative Example 1.
Thawed and cooked frozen pilaf.

After heating for 3 minutes, the pilaf had uneven heating, with the center part of the package being moderately cooked, but the peripheral part of the package being almost dry due to overheating. .

Comparative Example 3 (In Comparative Example 2, the frozen food was placed farther away from the antenna) In Comparative Example 1, a plastic tray with legs attached in order of height 100 was placed in the heating chamber of a microwave oven, and frozen pilaf was placed on top of it. The frozen pilaf was then thawed and cooked in the same manner as in Comparative Example 1.

After heating for 3 minutes, the pilaf had uneven heating, with the center part of the package being moderately cooked, but the peripheral part of the package being almost dry due to overheating. .

Comparative Example 4 (Example in which the accommodating part of the retainer was brought closer to the antenna) Using the retainer of the example with the legs 5 removed, frozen pilaf was thawed and cooked in the same manner as in the example. .

After thawing and cooking, the part directly above the antenna is almost dry due to overheating, while the other parts away from the antenna are undercooked due to insufficient heating. It was uneven.

Comparative Example 5 (Example in which the accommodating part of the retainer was placed far away from the antenna) Frozen pilaf was stored in the same manner as in the example except that the retainer of the example was attached with legs of a height of 100+++m. Thawed and cooked.

Although the pilaf after thawing and cooking did not have such large heating unevenness, there was a portion of the periphery of the package that was insufficiently cooked.

[Consideration of Examples and Comparative Examples]

The microwave oven used in the example has rotating antennas 11 and 12 on the ceiling and floor of the heating chamber 10, each of which radiates microwaves of 700 W. This is a high-power microwave oven that does not have a table.

In a microwave oven, microwaves are radiated radially into the heating chamber from the antenna, but the walls of the heating chamber of the microwave oven are made of a material (i.e., metal) that reflects the microwaves without transmitting them. According to the angle of reflection of the microwave on the wall surface of the heating chamber, microwaves are generated in the horizontal direction within the heating chamber. (Microwaves in the horizontal direction inside the heating chamber) Also, depending on the angle of reflection of the microwave on the wall surface of the heating chamber, microwaves that travel around a certain path inside the heating chamber are generated. (Microwaves settled in the heating chamber) Comparative Example 2 is an example that differs from the example in that the inner wall of the retainer accommodating part 2 used in the example is not coated with aluminum foil. It can be seen that the retainer used in the example can prevent uneven heating of the frozen pilaf due to overheating of the peripheral edge of the pilaf package by providing an aluminum foil coating on the inner wall of the accommodating part 2.

Comparison of the results of Comparative Example 2 and Example shows that when the inner wall of the housing part 2 of the retainer used in Example is not coated with aluminum foil (Comparative Example 2), the periphery of the frozen pilaf packaging is Although part B of the frozen pilaf packaging is heated by both vertical microwaves and horizontal microwaves inside the heating chamber, part B is only heated by the vertical microwaves inside the heating chamber. , uneven heating occurs at the center and periphery of the package of frozen pilaf, whereas in the case where the inner wall of the housing part 2 of the retainer is covered with aluminum foil (example), the horizontal microwave in the heating chamber is blocked by this aluminum foil,
As a result, both the center and the periphery of the frozen pilaf are only heated by the microwaves in the vertical direction within the heating chamber, so it is thought that the entire frozen pilaf is heated evenly, thereby preventing uneven heating. .

Comparative Example 4 is an example different from the example in that the legs 5 on the lower surface of the retainer used in the example were removed (that is, the frozen food storage section 2 of the retainer was moved closer to the antenna on the floor). It can be seen from the above that the retainer used in the example can prevent uneven heating of the frozen pilaf caused by overheating of the center of the pilaf by attaching the legs 5 to the lower surface thereof.

As mentioned above, microwaves are radiated radially from the antenna into the heating chamber of a microwave oven, but when microwaves are radiated radially, as they approach the radiation source, the density of the microwaves in the area near the radiation source increases. becomes larger, whereas
Since the density of microwaves is smaller in the area away from the radiation source, in the case of Comparative Example 4, uneven heating in the frozen pilaf occurred due to the difference in the distance from the antenna to the frozen food and the resulting difference in the density of the microwaves. it is conceivable that.

Comparative Example 5 differs from the example in that the height of the legs of the retainer used in the example was increased (that is, the frozen food storage section 2 of the retainer was moved away from the antenna on the floor). Therefore, it can be seen that uneven heating of frozen pilaf can be prevented by attaching a suitable height 1111 part 5 to the lower surface of the retainer used in the example.

As mentioned above, inside the heating chamber of a microwave oven, there are microwaves that are stationary within the heating chamber and are circulating repeatedly over a certain path. There are no places. The example is a case where frozen pilaf is placed in a place that is not affected by microwaves that are stationary in the heating chamber, and Comparative Example 5 is a case where the frozen pilaf is placed in a place that is not affected by microwaves that are stationary in the heating chamber (i.e., the frozen pilaf is placed in a place that is not affected by microwaves that are stationary in the heating chamber). This is thought to be the case when a frozen pilaf is placed in the microwave passageway.

The path of the microwaves that settle in the heating chamber is thought to vary depending on the type of microwave oven and the shape of the metal wall of the heating chamber. Although it is thought that it should be determined experimentally for each individual item or type, the heating unevenness of frozen pilaf caused by the microwaves stationed in the heating chamber is not that large.

Comparative Examples 1 and 3 correspond to the retainers used in Comparative Examples 4 and 5, in which the aluminum foil coating on the inner wall surface of the accommodating part 2 was removed, so the results are similar to the results and trends of Comparative Examples 4 and 5. The fact that they are the same shows that what was thought from the results of Comparative Examples 4 and 5 is correct.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an example of an implementation of a retainer used for defrosting and cooking frozen foods using a microwave oven according to the present invention, and FIG. 2 is a partially cutaway side view of an example of an implementation of the retainer in a state where frozen foods are accommodated. 3 and 3 are side views of the inside of the heating chamber of the microwave oven with the retainer placed in the heating chamber of the microwave oven.

Claims (13)

[Claims] (1) When thawing and cooking frozen food by heating in a microwave oven, the frozen food is coated with a material that reflects microwaves without transmitting them to the entire inner wall surface of the frozen food, and is made of a material that transmits microwaves. A method for thawing and cooking frozen food, which is characterized by placing the frozen food in a retainer, heating the frozen food uniformly, and thereby thawing and cooking the frozen food. (2) The method for thawing and cooking frozen food according to claim 1, wherein the material that reflects microwaves without transmitting them is aluminum foil or an aluminum plate. (3) Claim 1, characterized in that the material that transmits microwaves is foamed polystyrene, acrylic resin, polycarbonate, or polytetrafluoroethylene.
A method for thawing and cooking a frozen food according to item 1 or 2. (4) The retainer has legs attached to its lower surface that are necessary to hold the frozen food contained in the retainer at a height sufficient to uniformly heat it during heating in a microwave oven. A method for thawing and cooking a frozen food according to any one of claims 1 to 3, characterized in that: (5) Thawing and cooking the frozen food according to any one of claims 1 to 4, characterized in that the frozen food is packaged with a film made of a material that transmits microwaves. Method. (6) The method for thawing and cooking frozen food according to claim 5, wherein the material that transmits microwaves is polyester. (7) The refrigerator according to any one of claims 1 to 6, wherein the microwave oven is a high-power microwave oven that does not have a turntable that horizontally rotates the food to be heated. How to defrost and cook food. (8) having a frozen food accommodating portion having a depth sufficient to accommodate the frozen food, and whose inner wall is coated with a material that reflects microwaves without transmitting them;
A retainer for heating frozen foods in a microwave oven, the main body of which is made of a material that transmits microwaves. (9) The retainer for heating frozen foods in a microwave oven according to claim 8, wherein the material that reflects microwaves without transmitting them is an aluminum foil or an aluminum plate. (10) The electronic frozen food according to claim 8 or 9, wherein the material that transmits microwaves is foamed polystyrene, acrylic resin, polycarbonate, or polytetrafluoroethylene. Retainer for microwave heating. (11) The retainer can hold frozen food on its lower surface during heating in a microwave oven without causing uneven heating.
The frozen food according to any one of claims 8 to 10, wherein the frozen food is equipped with legs necessary to maintain a high temperature sufficient for uniform heating. Retainer for microwave heating. (12) Claim 1, characterized in that the legs are made of a material that transmits microwaves.
A retainer for heating frozen food in a microwave oven according to item 1. (13) A microwave oven for frozen food according to claim 12, wherein the material that transmits microwaves is foamed polystyrene, acrylic resin, polycarbonate, polytetrafluoroethylene, or polyester. Retainer for heating by.