JP2001095682A - Method and apparatus for heating food based on electrical resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for heating food based on electrical resistance for thermally solidified food wherein uniform heating effect is obtained, and maintain a close contact between electrodes and food to obtain favorable heating effect even if the thermally solidified fool is shrunk during the heating process. SOLUTION: The heating method and apparatus comprise a case in specific shape, thermally solidified food, and a pair of plate-like electrodes, each having a food contact face formed, and the pair of the electrodes and food are placed in the case. The face of the food to be in contact with the electrodes and the food contact faces of the electrodes are brought into a uniform and close contact with each other. The apparatus is connected with a power supply, and power is applied for a specified period of time with the electric field strength between the electrodes kept at a specified value. The apparatus includes the pair of the electrodes having the food contact faces and power supply connecting terminals and the case. A moisture-retaining material is added to food to prevent shrinkage of the food due to heat during a heating process and maintain a favorable contact between the food and the electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of heating food and an apparatus therefor, and more particularly to a method of applying an electric current to food by applying the property of poor conductivity of the food itself. The present invention relates to an exothermic food heating method and apparatus using electric resistance to generate cooking by electric resistance of the food.

[0002]

2. Description of the Related Art A dish called "radish mochi" or "chawan mochi", which belongs to Chinese cuisine, is made by coagulating flour such as cereals with water, mixing ingredients and steaming. is there. This kind of food is cooked for a long time, and when heating the solid food, the steaming method using steam is applied as a traditional method to achieve the purpose of heating. However, in the traditional steaming method described above, the amount of heating is directly proportional to the height of the contact area temperature and time, but inversely proportional to the thickness of the object to be heated. Therefore, as the volume or thickness of the heated object increases,
The time required to transfer heat to the center of the object and raise the temperature is increased. For this reason, in the traditional heating method, the degree to which heat is received between the surface of the food and the central point becomes uneven, and the quality of food heating may be reduced.

[0003] As for the heating technique for foods, there has been proposed a method for heating solid foods such as Frankfurt, for example, by using an electric current. In other words, this is an application of the same property as electric resistance and the principle that electric energy is converted to heat energy by resistance, which has poor conductivity while having the conductivity of food itself. . The means is such that the electrode plate is brought into contact with both ends of the food, an electric current is passed through the food through the electrode plate, the food is heated, and the fire is passed.

Hereinafter, this method is referred to as an electric resistance type food heating method. In the heating method, the following equation is satisfied. Thermal energy generation = conductivity x (voltage gradient) ² proportional conductivity = length / (cross-sectional area x resistance)

Therefore, the conductivity of each part of the food is uniform,
In addition, when the current distribution density is the same, a uniform and rapid heating effect can be obtained.

However, the electrode is unlikely to come into close contact with food,
There are some inconveniences in implementing the food heating method. That is, when the solid food has an irregular shape, a part of the food is not located between the electrodes or the food does not come into close contact with the electrodes, so that the current distribution density inside the food is irregular. It becomes uniform and the heating becomes locally uneven.

[0007] In view of these circumstances, many improvements have been filed as patents. For example, USP. 2,083,717 and
In 2,152,314, a heating method was proposed in which the electrodes were inserted into Frankfurt. USP. In 4,016,301 and 4,016,297, the paint applied to the surface of the electrode was modified to be designed to come into close contact with food. USP. 2,094,814 and Taiwan Patent 27
No. 5,566, disclose a method in which foods are put into containers each filled with salt water and an electric resistance type food heating method is applied.

[0008] However, the means disclosed in these patents are:
None of them has the expected effect on the uniformity of heating, and these are rarely implemented and commercialized.

Further, an example in which the electric resistance type food heating method is applied to a food in a flowing state has been proposed. In this method, food in a flowing state is continuously poured into a pipe body having a plurality of electrodes provided therein, and the food is heated according to the above principle when passing through the electrodes. Although this method solves the problem of uneven heating, it cannot be applied to solid food that does not flow in the pipe. In addition, no method has been proposed for a so-called hot solid food which is a semi-solid which flows when not heated and which becomes a solid state once heated and put through a fire. This is partly because the shape of the object changes during the heating process, and the continuous pouring heating method or the solid heating method cannot be applied. This is because the food shrinks during the heating process, causing a problem in contact between the electrode and the food.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art, and has been made in consideration of the above-mentioned drawbacks. It is intended to provide the device.

Another object of the present invention is to provide an electric resistance-type food heating method and a device thereof that can provide a uniform heating effect in a method for heating a heat-solidified food.

It is another object of the present invention to provide an electric resistance type food heating method and apparatus capable of maintaining a good heated state of a hot solid food product in which a shrinkage phenomenon occurs in a heating process. And

[0013]

In order to achieve the above object, an electric resistance type food heating method according to the present invention comprises a container having a specific shape and a fluid (paste) which solidifies when heated. And a thermosolid food having an appropriate electrical conductivity, and a pair of plate-shaped electrodes each having a food contact surface formed therein, and the pair of electrodes and the food are placed in a container. In this case, the pair of electrodes are provided at positions where the food contact surfaces face each other, the food is inserted therebetween, and the surfaces of the respective foods that contact the electrodes and the food contact surfaces of the electrodes are uniformly and tightly contacted. Then, it is connected to a power supply to load electricity on the electrodes for a predetermined time, and the electric field strength between the electrodes is maintained at a predetermined strength.

In order to achieve the above object, an electric resistance type food heating apparatus according to the present invention comprises a food contact surface,
Including a pair of electrodes and a container having a power connection terminal,
A pair of electrodes are placed in the container so as to face each other, food is put between the electrodes, and the electrode contact surface of the food and the food contact surface of the electrode are uniformly and tightly contacted with each other.

[0015] By blending the food with a material having a water retention property, the food is prevented from shrinking due to heating in the heating process, good contact between the food and the electrode is maintained, and heat is generated in the most preferable energized state.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A box-shaped container 5 having a rectangular bottom surface and an open top surface, and a pair of electrodes 2, 3 having food contact surfaces 2a, 3a and power connection terminals 2b, 3b, An electric resistance-type food heating apparatus is constituted by the above-mentioned method, and the electrodes 2, 3 and a heat-solid fluid (paste-like) food which is heated and solidified are put into the container 5 and electricity is supplied to the container, and heat is generated by electric resistance. The food is heated by applying the principle described above.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to explain the technical idea of the present invention in detail, preferred embodiments will be described below, provided that the embodiments are preferred examples for carrying out the present invention. It does not limit the invention. FIG. 1 is a perspective view of an electric resistance type food heating apparatus according to the present invention, and FIG. 2 discloses a cross-sectional view for explaining a use mode. As shown in FIG. 1, a food heating apparatus according to the present invention basically includes a pair of electrodes 2, 3 and a container 5 for storing the electrodes 2, 3 and food.
In this embodiment, both ends of the container 5 have a rectangular shape with a flat surface, and the upper surface is an open surface. However, actually, any other specific shape may be used. In addition, as disclosed in FIG. 2, a lid 5a may be provided (the lid 5a has an effect of preventing evaporation of water contained in food).

The food 4 is a fluid (paste-like) liquid before being heated, and is a heat-solid food that solidifies when heated. For example, "radish mochi", which belongs to the Chinese cuisine in a broad sense,
It is a food made by dissolving cereals such as "potato mochi" and "chawan mochi" in water, adding ingredients and seasoning, and then heating, or heating and coagulating fish meat surimi.

The electrodes 2 and 3 are preferably made of titanium,
A metal material such as 316L or 304 stainless steel is formed in a plate shape. Each of the electrodes 2, 3 forms a food contact surface 2a and 3a, and furthermore, a power connection terminal 2
b and 3b are provided. The food contact surfaces 2a and 3a are formed to have substantially the same size as the inner side surfaces at both ends of the container 5, and are provided between the food contact surfaces 2a and ab of the electrodes 2 and 3 provided at positions where the food to be heated faces. Put in.

The method of using the above-described food heating apparatus and the effects thereof will be described below together with the food heating method according to the present invention. A food heating method according to the present invention includes the container 5, the food 4, and the electrodes 2, 3, and puts the electrodes 2, 3 and the food 4 (uncooked, paste-like) into the container 5 as shown in FIG. The food 4 is placed between the food contact surfaces 2a and 3a of the electrodes 2 and 3, and a contact surface (not shown) of the food 4 with the electrode;
The electrodes are brought into close contact with the food contact surfaces 2a, 3a. Then, an AC or DC power supply 1 is connected by a lead wire 6.
(Preferably AC) and the power supply connection terminals 2b of the electrodes 2 and 3;
3b, and is energized for a predetermined time, and maintains the electric field strength between the electrodes 2 and 3 at a predetermined strength. In such a state, the food 4 contains moisture but is an unsatisfactory conductor, so that it has the same effect as electric resistance,
During this time, heat is generated by the action of the electric current and the electric resistance and is heated. Moreover, the food 4 is the food contact surfaces 2a and 3a of the electrodes.
Are uniformly and intimately contacted by an electrode contact surface (not shown) having substantially the same width as that of the food 4, each portion of the food 4 has substantially the same conductivity, and a current of the same density is loaded.
For this reason, it is heated uniformly. However, the container 5 may be formed into any shape as long as a uniform current density is obtained in the process of applying electricity to the food 4 and heating the food 4, and therefore, a food of any shape can be produced.

An experiment was conducted to compare the effect of the above-described heating method according to the present invention with the effect of the heating method according to the conventional traditional manufacturing method. The results are disclosed below. In the experiment, the container had a length of 14 cm, a width of 7 cm and a height of 7 cm as standard. Food is `` radish mochi (food that has been milled from rice, mixed with water, seasoned, heated and solidified) ''
Was used as an experimental control, and 0 to 65 kg of paste before heating was used.

A metal electrode having a width of 7 cm is placed on each of both end surfaces in the container (substantially the same as the area of both end surfaces in the container), and the paste-like food is injected between the electrodes.
/ 60 Hz AC electricity was applied. As a result, the pasty food is 5
It took 4 minutes to heat from 0 ° C to 110 ° C to solidify and form.

According to the conventional traditional cooking method, it is necessary to steam at least 70 minutes when a similar weight of pasty "radish mochi" is steamed in a metal container of the same size and shape to achieve the same result. Is done.

As can be seen from the above results, when the heating method according to the present invention is used in place of the conventional heating method for the conventional hot solid food, the heating time can be shortened and energy can be saved. In addition, it is important to point out that the degree of heating of the food becomes uniform because the electric conductivity of the food is uniform and the electric density of each part is uniform. Therefore, not only can heating of the food be completed in a short time, but also a food having a uniform condition like a fire can be obtained.

Further, the relationship between the electric field intensity and the heating rate was compared, and a comparative experiment was separately conducted to obtain the most preferable heating method. In this experiment, the distances between the electrodes 2 and 3 were set to 30 cm, 20 cm, and 10 cm, and the AC voltages were set to 60 V, 120 V, 180 V, and 240 V, respectively. However, the electric field strength is 20
0V / M, 300V / M, 400V / M, 600V / M, 800V / M, 900V /
M, 1200V / M, 2400V / M, etc. That is, the combinations disclosed in Table 1.

[0026]

[Table 1]

FIG. 3 discloses the relationship between the electric field strength and the average temperature rise rate obtained from the above-described experimental results.

As can be seen from the results of the above experiments, the rate of temperature rise is 0.007 when the electric field strength is 200 V / M.
° C / sec, and about 3 seconds for the temperature to rise to 62 ° C.
Need time. That is, the temperature rises very slowly, the surface temperature is low, and the temperature gradient is too large. Electric field strength of 2400
In the case of V / M, the temperature rise rate is 1.133 ° C./sec. However, when the temperature is 80 ° C. or more, a large amount of water vapor and smoke are generated, and the taste is scorched. This is because the heating rate is clearly too high. When the electric field strength is the same, the heating rate is almost the same.

Therefore, when food is heated by the heating method according to the present invention, the quality of the finished radish must be close to that obtained by the traditional production method, and a reasonable heating rate must be provided. In addition, it is preferable to set the electric field strength between 600 V / M and 1000 V / M separately from the above. Naturally, an electric field strength of 400
Even if it is set between V / M and 600 V / M, or between 1000 V / M and 2400 V / M, it can still be accepted. In other words, if the elasticity of the electric field is applied, the uniformity of the current density at the section of the food during the energization process is insufficient and the uniformity of the heating is insufficient even if the uniformity of the heating is insufficient. The purpose of heating or heating within the time is achieved.

Further, when the present invention is carried out, for example, foods which tend to shrink and cause cracks in the food during the heating process such as "radish mochi", the food contact surface 2a of the electrode of the food 4 And a water-retaining compound material in proportion to the food so that the surface receiving electricity when contacting with 3a maintains good contact with the food contact surfaces 2a and 3a of the electrode during the process of solidification by heating. Alternatively, a compound material that expands due to heat may be added. Such compounding materials include, for example, sugars such as trehalose, modified starch, colloids, proteins such as soybean separated proteins,
Phosphates such as sodium metaphosphate or potassium dihydrogen phosphate. However, it is not necessary to add such a compounding material to foods that expand when heated.

That is, for example, food 4 such as "radish mochi"
About rice flour, corn starch,
An appropriate water retention rate can be obtained by separately adding and mixing the above-mentioned compounding materials before and after solidifying basic materials such as salt and processed radish into the container 5 or before solidifying. According to the results of the experiment, 0.4% of soy protein isolate was used.
% (W / w) can increase the water retention by 2.9%, and when trehalose is added by 1.08% (w / w), increase the water retention by 2.2%. 0.4
% Of soybean separated protein and 1.08% of trehalose were added and mixed at the same time, and it was found that the water retention could be increased by 6.7%. Therefore, in an embodiment of the present invention, by adding an appropriate amount of a water-retaining or swelling compounding material to a food to be cooked, the paste of fluid starch before cooking is coagulated by heat. The shrinkage phenomenon due to evaporation of water can be prevented, and uniform, close and good contact between the food and the food contact surfaces 2a, 3a of the electrodes can be maintained. For this reason,
The energy from the power supply can be efficiently applied to the food 4 and converted to heat energy.

Next, in order to obtain good contact between the electrode and the food during the heating process, mechanical elasticity may be applied in addition to the above-described method of adding the water-retention compounding material. That is, the electrode is pressed by the mechanical elasticity to make close contact with the food. In order to implement this method, various methods known to those skilled in the art can be applied. For example, a spring and an adjustment screw are provided between the surface opposite to the food contact surface of the electrode and the inner wall surface of the container, or only the adjustment screw is provided, and as time elapses and heating progresses, the position of the adjustment screw is changed. It moves step by step and presses the electrodes into intimate contact with the food. That is, the object of pressing the electrode against food by applying mechanical elasticity or the like is achieved.

Experimental examples of the application of the mechanical elastic force will be described below. In the experiment, the weight of the specimen was fixed, and no mechanical elasticity was applied (the distance between the electrodes was 10 cm), and a constant mechanical elasticity was applied (the distance between the electrodes was 9.6 cm). ) And applying a larger mechanical elasticity (the distance between the electrodes is 9.8 cm). As a result of the experiment, the temperature rise rate when no mechanical elasticity was applied was 0.566 ° C./sec.
Met. The temperature rise rate when a constant mechanical elasticity was applied was 0.645 ° C./sec. The temperature rise rate when a larger mechanical elasticity is applied is 0.655 ° C / sec.
Met. From the above results, in the process of heating, to apply a mechanical pressing force after the food is solidified and solidified, or when applying a step and mechanical pressing force as the solidification,
Maintain better contact between the electrode and the food,
Clearly, the rate of temperature rise is increased.

The above embodiments are merely examples relating to the technical idea of the present invention, and do not limit the present invention.
Therefore, any modifications or diversions that can be easily made by those skilled in the art are included in the claims of the present invention.

[0035]

According to the electric resistance type food heating method of the present invention and the heating method to which the apparatus is applied, the energy from the power source is efficiently converted into heat energy and applied to the food, so that the heating time In turn, which in turn translates into energy savings.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electric resistance heating device according to the present invention.

FIG. 2 is an explanatory view of an embodiment of an electric resistance heating method according to the present invention.

FIG. 3 is a diagram showing the relationship between the electric field strength and the rate of temperature rise when a test sample is cooked by an electric resistance heating method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply 2, 3 Electrode 2a, 3a Food contact surface 4 Food 5 Container 6 Lead wire

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yang Bin Huai Barry Taiwan 300 Sinchu, Khun-Fu Road, Section 2, Number 305-7F Road, Section 2, Rain 155, No. 52, 3 Floor (72) Inventor Lee Siping Taiwan Kaosun Xian, Chi San, Nan Chow Li, Chi Nan Second Road, No. 95 ( 72) Inventor Tsai Wei Chung, Taiwan Shinchu, Pao San Road, Lane 93, Array 2, No. 11 F-term (reference) 4B055 AA26 AA50 BA63 CA61 CA71 CB01 CC01 DB02 FA20 FB03 FB05 FC07 GD04

Claims (10)

[Claims] 1. A method for heating a food, wherein the food is heated by electric resistance. The container has a specific shape, a fluid before being heated, a solidified body when heated, and a heat-solid having appropriate conductivity. Food, and a pair of electrode plates having a plate-shaped food contact surface in contact with the heat-solidified food,
Wherein the electrode is provided in the container at a position where the food contact surface with the heat-solidified food is opposed, the heat-solidified food is placed so as to be located between the two electrodes, and electrodes at both ends of the solidified food are provided. Providing the contact surface and the food contact surface of the electrode in close contact with each other, applying a certain amount of electricity to the pair of electrodes from a power supply for a certain period of time, and maintaining the electric field intensity between the pair of electrodes at a specific intensity. An electric resistance type food heating method characterized by the above-mentioned. 2. The heat-solidified food is mixed with a water-retention compounding material to prevent the food from shrinking in the process of generating heat by passing an electric current, and thereby receiving electricity at both ends of the food. The electrical resistance type food heating method according to claim 1, wherein a close contact between the electrode and the surface of the electrode is maintained. 3. A manufacturing process in which a mechanical elastic force gradually acts on the pair of electrodes to press the heat-solidified food and maintain close contact between the electrodes and the food. The method of heating an electric resistance food according to claim 1, wherein the food is heated. 4. The electric field strength is from 400 V / M to 240 V.
The method of claim 1, wherein the method is between 0 V / M. 5. The method of heating an electric resistance food according to claim 2, wherein the water-retaining compounding material is a soybean separated protein. 6. The method for heating an electric resistance food according to claim 2, wherein the compound having water retention is a saccharide. 7. The electric resistance type food according to claim 1, wherein the pair of electrodes have a uniform current density in a process of applying a current to each part of the heat-solidified food. Heating method. 8. The food contact surface of the pair of electrodes with food is substantially parallel to each other, and the food is located at a position lower than the contact surface of the electrode between the pair of electrodes. The method for heating an electric resistance food according to claim 7, wherein the food is placed relatively in the direction of. 9. An electric resistance type food heating device having a pair of plate-shaped electrodes and a container, wherein each of the pair of electrodes has a food contact surface with food and a power input terminal. And, in contact with the food, the electric energy is appropriately conducted to the food, the container stores the food to be heated and the pair of electrodes,
In addition, when the food to be heated is placed between the pair of electrodes, the food contact surface of the electrode and the surface receiving the electricity of the food are respectively uniform. An electric resistance type food heating device characterized in that it is configured to be in close contact with the food heating device. 10. The container holds the food contact surfaces of the pair of electrodes substantially parallel to each other, and the food is located between the pair of electrodes at a position lower than the width of the electrode contact surfaces. 10. The apparatus according to claim 9, wherein each portion of the food to be heated has a uniform current density so that each portion of the food to be heated is positioned relatively in the direction of the electrodes.
An electric resistance-type food heating device according to item 1.