JP2004016228A - Method for heating packaged food product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for heating a packaged food product in view of the fact that a previously exposed method using electric heating has an advantage of heating in a short time but is not acceptable for a production site such as a factory because of making the shape of a package and the finish of a product extremely different from those produced by a conventional method using a smokehouse. <P>SOLUTION: This method for heating the packaged food comprises putting electrodes for electric heating and a food material in a packaging bag and sealing the product to form the packaged food. The electric heating is performed by electrical contact through pressure-welding a feeding part to the electrode in the packaged food from the outside of the packaged bag. When electrically heating the packaged food, heat is released from the surface of the packaged food. A temperature control part performs heat insulation and warming so as to prevent temperature drop by the heat radiation. When electrically heating the packaged food, generation of heat at the contact surface of the electrode with the food material becomes larger than that of other parts due to contact resistance at the contact surface. The temperature control part performs heat radiation or cooling so as to prevent excessive temperature rise by the generation of heat. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for heating packaged foods such as ham and sausage using fish meat, animal meat, etc., in which heating is carried out by applying an alternating current directly to the packaged foods so as to generate heat and increase the temperature uniformly in a short time. It is about technology.
[0002]
[Prior art]
When heating packaged foods such as ham and sausage using fish meat, animal meat, etc., conventionally, collagen meat filled with fish meat and animal meat is allowed to stand in a smoke house and matured by setting the temperature and humidity of the smoke house. → Drying → smoking → steaming. For the time required for heating, hams manufactured in factories with a diameter of about 10 cm and a length of about 100 cm satisfy the sterilization conditions under the Food Sanitation Law of “63 ° C. for 30 minutes”. It takes 5 to 8 hours for the entire heating process.
[0003]
A current-carrying heating technique has been disclosed in which current is applied to fish and animal meat packed in a packaging bag to generate heat so that the heating step can be performed in a short time.
[0004]
As a means for energizing the packaged food, a method in which the packaged food is brought into close contact by pressing an electrode plate against the opposite surface of the packaged food is described in, for example, JP-A-63-207371 and is well known.
[0005]
Further, as a means for energizing the packaged food, a method in which a conductive fiber body containing a high concentration of salt is brought into close contact with the opposite surface of the packaged food to bring the electrode plate into close contact is described in, for example, Japanese Patent Publication No. 49-45570. And are known.
[0006]
Further, as a form of the packaged food for electric heating, a form in which an electrode plate is put inside the package and a projection as a part of the electrode is put out of the package is described in, for example, JP-A-63-207369. It is.
[0007]
A production method in which a large number of packages having different shapes are subjected to submergence in a conductive liquid and heated by energization in order to treat them at once is described in, for example, JP-A-61-132137.
[0008]
For example, Japanese Patent Application Laid-Open No. 6-169738 discloses a method for producing a food with a flavor of scent by conducting an electric heating by setting a smoking process included in a process of producing ham and the like to a submerged state in a conductive liquid to which a sap has been added. It is described and known.
[0009]
[Problems to be solved by the invention]
The method using electric heating that has already been released has the advantage that heating can be performed in a short time, but the form of the packaged product and the finished state of the product are significantly different from the conventional manufacturing method using a smoke house, At present, it is not accepted by manufacturing sites such as factories.
[0010]
In the method described in JP-A-63-207371, in which a packaged food is brought into close contact by pressing an electrode plate, an electric current flows through a packaging film between the electrode plate and the food. The packaging film generally has a higher resistance value than the electrode plate, even if it is a film having moisture permeability. Therefore, when an electric current is applied, heat generation at the contact surface with the electrode plate, the packaging film, and the food increases, and the temperature rise near the electrode plate is accelerated. Therefore, it is difficult to uniformly heat the packaged food. A similar problem occurs when a conductive fiber body moistened with a high concentration of salt described in JP-B-49-45570 is adhered through a packaging film.
[0011]
In a packaged food described in JP-A-63-207369, in which an electrode plate is placed inside a package and a projection that is a part of an electrode is taken out of the package, the contact state between the food material and the electrode plate is limited. The method described in JP-A-63-207371 is improved and the heat generation at the contact surface is reduced. However, since the electrode plate has protrusions, the conventional fasteners and tools for sealing the packaging bag cannot be used. In addition, titanium that does not easily corrode is often used for an electrode plate heated by electricity, but there is a problem that it is difficult to manufacture an electrode plate having projections having a complicated shape with titanium.
[0012]
In the manufacturing method described in JP-A-61-132137 and JP-A-6-169938, in which a conductive liquid is submerged and energized and heated, the product must be dried in order to finish it in a wet state. . In addition, since there is no evaporation from the surface of the packaged food during heating, there is a problem that a product having a different moisture value from a conventional product is completed. In the production of ham, there is a problem that a method different from the conventional smoke process using a smoke house is completed in a method of adding a smoke liquid and heating in a flooded state.
[0013]
[Means for Solving the Problems]
The present invention provides a method of heating a packaged food that can be heat-treated in a short time without changing the packaging form or the finished condition when producing a conventional smokehouse product.
[0014]
An electrode body for electric heating and food are put in a packaging bag and sealed to form a packaged food. For example, in a conventional smoked ham product, in order to eliminate useless portions of the protrusions on both ends, a plate called a "spacer" made of resin is sealed at both ends and both ends of the packaged food are molded flat. ing. In the present invention, the resin spacer is replaced with a metal electrode body, and the form of the conventional product and the packaged food is not changed. For this reason, the same fastening fitting as that used in the conventional heating method using a smoke house can be used as a fastening fitting for sealing the packaging bag at both ends like a ham product.
[0015]
Electrical connection to the electrode body inside the packaged food is made through the film of the packaging bag. In the case of a moisture-permeable film, the film is electrically conductive by wetting the film, so that an electrical connection is made by pressing the power supply unit. In the case of an insulating film, an electrical connection is made by making a through hole in the film and bringing the electrode body inside the package into direct contact with the power supply section. The through-hole is generally pierced with a thermocouple or other thermometer to measure the temperature of the food material in the packaged food, but the through-hole may become larger or the bag may break. Does not cause any problem in the present heating method.
[0016]
When the packaged food is electrically heated, the heat escapes from the surface of the packaged food. In order to prevent a decrease in temperature due to the heat radiation, heat retention or heating is performed by a temperature control unit.
[0017]
When the packaged food is heated by electric current, heat is generated more than other parts due to the contact resistance of the contact surface between the electrode body and the food material. In order to prevent an excessive rise in temperature due to this heat generation, heat is radiated or cooled by the temperature control unit.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
A pair of electrode bodies is put together with a conductive food material in a packaging bag and sealed to form a packaged food. The power supply unit is electrically connected to the electrode body inside the packaging bag by pressing the power supply unit from the outside of the packaging bag. A temperature control unit capable of independently controlling the temperature is disposed on the two end surfaces of the packaging bag and the surfaces other than the two end surfaces that come into contact with the electrode body inside the packaged food.
[0019]
An embodiment for carrying out the method for heating a packaged food of the present invention will be described with reference to an external view showing components in FIG. 1 and a cross-sectional view of components in FIG. 1 and 2, reference numeral 1 denotes a packaging bag made of a moisture-permeable packaging film or an insulating packaging film, and a pair of electrode bodies 2a and 2b are arranged in contact with the end surface of the inner packaging bag. Is filled with a food material 3 having conductivity. The electrode bodies 2a and 2b and the food material 3 are hermetically sealed by a packaging bag. 5a and 5b are power supply units for supplying power to the electrode bodies 2a and 2b inside the packaging bag. Reference numerals 4a and 4b denote temperature control units for controlling the temperatures of the two end faces of the packaging bag with which the electrode bodies 2a and 2b inside the packaging bag are in contact. Reference numeral 4c denotes a temperature control unit for controlling the temperature of the surface of the packaging bag except for the two end surfaces of the packaging bag in contact with the electrode bodies 2a and 2b. FIG. 1 shows a state before the power supply units 5a and 5b and the temperature control units 4a, 4b and 4c are arranged at predetermined positions so that each component can be easily understood. Arrows in the figure indicate the moving direction when the arrangement is performed. FIG. 2 shows a state in which the components are arranged. The temperature of each part of the packaged food is measured by a thermometer (not shown).
[0020]
1 and 2, the packaged food has a columnar shape, but is not limited to this shape. In addition, the electrode body, the temperature control section, and the power supply section have been described as being adapted to the cylindrical packaged food, but the shape is not limited to this.
[0021]
The power supply units 5a and 5b for supplying power to the electrode bodies 2a and 2b inside the packaging bag are pressed against the electrode bodies 2a and 2b from outside the packaging bag 1 by a movable pressing mechanism (not shown). The power supply units 5a and 5b in FIG. 2 show a state where they are pressed against each other. FIG. 3 and FIG. 4 are cross-sectional views showing, in an enlarged manner, a pressure-contact portion when the electrode unit 2 is pressed against the power supply unit 5 from outside the packaging bag 1 or 1a. FIG. 3 shows a case where the packaging bag is made of the moisture-permeable packaging film 1a, and FIG. 4 shows a case where the packaging bag is made of the insulating or moisture-permeable packaging film 1.
[0022]
In the case of the moisture-permeable packaging film in FIG. 3, since the packaging film is wet by the moisture of the conductive food material 3, power can be supplied to the electrode body 2 by pressing the power supply unit 5 against the packaging material.
[0023]
In the case of the insulating packaging film or the moisture-permeable packaging film shown in FIG. 4, by providing a through hole 6 in the packaging film, the electrode body 2 and the power supply unit 5 can contact and supply power. The through-hole 6 may be opened before the power supply unit 5 is pressed, or may be formed by piercing the packaging film when the power supply unit 5 is pressed.
[0024]
When power is supplied from the power supply bodies 5a and 5b to the electrode bodies 2a and 2b inside the packaged food, a current flows through the food material 3 to generate heat. The contact surfaces between the electrode bodies 2a and 2b and the food material 3 generate more heat than other parts due to contact resistance. In order to prevent an excessive rise in temperature due to this heat generation, heat is radiated or cooled by the temperature control sections 4a, 4b arranged on the end faces where the electrode bodies 2a, 2b are in contact. The contact resistance may be different at the two contact surfaces, in which case the calorific value will also be different. Since the temperature controllers 4a and 4b can independently control the temperature, the temperature controllers 4a and 4b perform the adjustment according to the respective heat values. Further, the heat escapes as the food material 3 generates heat from the surface of the packaged food except for the end surfaces where the electrode bodies 2a and 2b are in contact, so that the temperature controller 4c keeps or warms the heat.
[0025]
【Example】
Embodiments of an apparatus for carrying out the method for heating packaged food according to the present invention will be described with reference to FIGS. FIG. 5 is an external view, and FIG. 6 is a sectional view. FIGS. 5 and 6 show a case where the packaging bag 1a is made of a moisture-permeable packaging film. The pair of electrode plates 10a and 10b arranged in contact with the inner end surface of the packaging bag shows a case where a disk-shaped electrode plate is used as an electrode body. The inside of the electrode plates 10a and 10b is filled with a food material 3 having conductivity. In this embodiment, the open portion of the packaging bag is closed by the fastening members 7a and 7b. The power supply units 8a and 8b for supplying power to the electrode plates 10a and 10b inside the packaging bag are pressed against the electrode plates 10a and 10b from outside the packaging bag 1a by a movable pressing mechanism (not shown). 7 shows a state in which the power supply unit 8b on the right side of FIG. 6 is pressed. This state is the state shown in FIG. 8a and 8b in FIG. 5 and 8a in FIG. 6 show a state before being pressed. In the arrangement of this embodiment, the operation of improving the contact state between the electrode plates 10a and 10b and the food material 3 to reduce the value of the contact resistance and the operation of pressing the electrode plate and the power supply unit against each other are performed by a one-way pressing operation. There is an advantage that it can be realized at the same time.
[0026]
5 and 6, the power supply unit 8a serves as a temperature control unit on the end surface of the packaging bag where the electrode plates 10a and 10b are in contact so that the power supply units 8a and 8b do not come into close contact with the end surface of the packaging bag where the electrode plates 10a and 10b are in contact. , 8b have a shape having four projections, and a space in which air can move is provided. Since this space can move air, it can also move heat and has a heat radiation effect. Since the electric heating is performed in the room, a temperature gradient is generated between the contact surface between the electrode plates 10a and 10b and the food material 3 and the room air, and the heat moves to the room air side. Excessive heat generated by contact resistance between the electrode plates 10a and 10b and the food material 3 is radiated from the surfaces of the electrode plates 10a and 10b that are not in contact with the food material 3 and diffuses into the air. As a result, the temperature near the contact surface between the electrode plates 10a and 10b and the food material 3 decreases.
[0027]
The surfaces other than the two end surfaces of the packaging bag in contact with the electrode plates 10a and 10b in FIGS. 5 and 6 are covered with the heat insulating material 9. The heat insulating material 9 is arranged as a temperature control section, and functions to prevent heat escaping from the surface of the packaging bag 1a from diffusing into the outside air and to prevent a temperature drop on the surface.
[0028]
FIG. 7 shows an example of the voltage value at each position of the food material when a voltage of 10 V is applied between the electrode plates 10a and 10b in the packaged food. The horizontal axis indicates the distance from the electrode plate 10a. The distance between the electrode plates 10a and 10b is 280 mm. For simplicity, a picture of the electrode plate is shown at the position where the electrode plate is arranged in the graph. The vertical axis indicates the voltage value between the electrode plate 10a and each part of the food material 3. The change in the voltage value at the contact portion between the food material 3 and the electrode plates 10a and 10b showed a large value, but was a substantially constant change value in the food material 3. This indicates that the contact resistance between the food material 3 and the electrode plates 10a and 10b is large. When the electric heating is performed, the calorific value in this portion becomes larger than that in the other portions.
[0029]
The contact resistance varies depending on the contact state between the food material 3 and the electrode plates 10a and 10b, the applied voltage value, and the conductivity of the food material 3. The tendency shown in FIG. 7 can be seen in the food material 3 having a degree of electrical conductivity that can be electrically heated. Generally, when the conductivity of the food material 3 is high, when the applied voltage value is large, or when the food material 3 and the electrode plates 10a and 10b are not in close contact, this tendency is likely to appear. When there is a moisture-permeable film between the food material 3 and the electrode plates 10a and 10b, the contact resistance value increases.
[0030]
FIG. 8 shows how the temperature difference between the end surface temperature of the food material 3 in contact with the electrode plates 10a and 10b and the central temperature of the center of the food material 3 during the electric heating. The horizontal axis shows the above-mentioned end face temperature, and the vertical axis shows the value obtained by subtracting the center temperature from the end face temperature. FIG. 8 shows a conventional example in which a moisture permeable film is provided between an electrode plate and a food material and no temperature control unit is provided (indicated by a black square), and the electrode plates 10a and 10b of the present embodiment are shown. The case where the food material 3 is in direct contact with the food material 3 and has a temperature control part (indicated by ●) is shown. In the conventional example, when the electric heating is started, the end face temperature becomes higher than the center temperature, and even if the center temperature is 55 ° C., the end face temperature rises to nearly 90 ° C. In the present embodiment, it can be seen that the temperature difference is at most about 5 degrees, and the temperature difference between the end face and the center of the food material 3 is very small.
[0031]
FIG. 9 shows the difference in the heat retaining effect depending on the presence or absence of the heat retaining material 9. The vertical axis in FIG. 9 shows a temperature difference which is a value obtained by subtracting the surface temperature from the center temperature of the food material 3 during the heating by energization. The horizontal axis indicates the center temperature of the food material 3 during the heating by energization.
[0032]
When the heat insulating material 7 was not provided (indicated by a black square), the amount of heat radiation from the surface of the packaging film 1 increased as the center temperature increased, and the temperature difference between the center temperature and the surface temperature increased. Even if the center temperature is 80 ° C., the surface temperature is 55 ° C., 25 degrees lower than that.
[0033]
When there is the heat insulating material 7 shown in the present embodiment (indicated by ●), heat radiation from the surface of the packaging film 1 is suppressed, and the temperature difference between the center temperature and the surface temperature is 10 degrees or less. Understand. As in the case of using the heat insulating material 7 in the present embodiment, disposing the temperature control unit on the surface other than the two end surfaces of the packaging bag in contact with the electrode plates 10a and 10b can be achieved by heating the central temperature of the packaged food at the time of heating. This has the effect of equalizing the temperature.
[0034]
If the packaged food uses livestock meat such as ham, the temperature may be raised to a predetermined temperature, and then immediately transferred to the next manufacturing step, for example, a smoke treatment step, for processing. The form of the packaged food does not differ from the form of the packaged food by the conventional smoke house, and the surface state of the packaged food becomes a dry state, which is also the same as the state of the packaged food by the conventional smoke house. Therefore, as in the related art, a smoke process using a smoke house can be performed as a post process. The finished product is sliced ham by removing the electrode plate and cutting it thinly in parallel to the surface where the electrode plate was in contact.
[0035]
In the present embodiment, the example in which the electrode plates 10a and 10b have a disk shape is shown, but it is needless to say that the electrode plates 10a and 10b may have a polygonal shape such as a square.
[0036]
In this embodiment, the packaging bag has a cylindrical shape with both ends opened, and the open ends of both ends are sealed with the fastening members 7a and 7b. It may be sealed with a fitting, and the sealing means may be other than the fastening fitting, for example, by heat fusion or an adhesive. The shape of the bag is not limited to the cylindrical shape.
[0037]
In the present embodiment, the shape of the power supply portions 8a and 8b is a disk shape having four protrusions, but the number of protrusions and the shape of the power supply portion are not limited. In addition, the tip shape of the projection is shown as a column, but the shape is not limited to this.
[0038]
In the present embodiment, in the example in which the temperature control unit is provided by the heat radiation and the heat retaining action, it is shown that the temperature difference between the respective units can be reduced. However, if the temperature control unit using the heater or the cooling device is provided, the food material can be further reduced. This is because the temperature difference between the parts can be reduced.
[0039]
【The invention's effect】
The use of electric heating to heat packaged foods has the advantage that the temperature can be raised quickly.However, when used to heat actual packaged foods in the conventional method, the form of the packaging bag is the same as that of the conventional manufacturing method. And the finished state of the product has changed, making it difficult to spread. ADVANTAGE OF THE INVENTION According to the heating method of this invention, since the uniform heating is attained without changing the form of the conventional packaged food, there exists an effect that electric heating becomes easy to use.
[0040]
[Brief description of the drawings]
FIG. 1 is an external view showing an example of an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of an embodiment of the present invention. FIG. Example of case)
FIG. 4 is an enlarged cross-sectional view of a pressure contact portion (an example of an insulating or moisture-permeable film).
FIG. 5 is an external view showing an embodiment of the present invention. FIG. 6 is a cross-sectional view showing an embodiment of the present invention. FIG. 7 is a view showing each of food materials when a voltage is applied between electrode plates in packaged food. FIG. 8 is a graph showing an example of a voltage value at a position. FIG. 8 is a graph showing an example of a temperature difference between an end surface temperature of a food material in contact with an electrode plate and a central temperature of the food material during energization and heating. FIG. 9 is a graph showing a temperature difference between a central temperature and a surface temperature of a food material during electric heating, and showing a difference in a heat retaining effect depending on the presence or absence of a heat retaining material.
DESCRIPTION OF SYMBOLS 1 Insulating or moisture-permeable packaging film 1a Moisture-permeable packaging film 2, 2a, 2b Electrode body 3 Food material 4a, 4b, 4c Temperature control part 5, 5a, 5b Power supply part 6 Through-holes 7a, 7b Fastener 8a, 8b Power supply unit 9 having four protrusions 9 Heat insulator 10a, 10b Electrode plate

Claims (2)

A packaging bag made of an insulating film or a moisture-permeable film is filled into a space between a pair of electrode bodies arranged in parallel in contact with two opposite end surfaces inside the bag and the electrode body. There is a packaged food sealed with a wet food material having conductivity, and a pair of power supply units are pressed against the pair of electrodes inside the packaged food from outside the package, respectively, and are pressed against each other, and opened on the film of the pressed portion. The power is supplied to the electrode body by electrically connecting through the through hole or through a moist and permeable film, and a current is passed through the food material between the electrode bodies to generate heat. How to heat the packaged food. Each of the two end surfaces of the packaging bag in contact with the electrode body inside the packaging bag, and the surface of the packaging bag except for the two end surfaces, has a temperature control unit capable of independently controlling the temperature, The method for heating packaged food according to claim 1.

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