JPH0734720B2 - Manufacturing method of food by electric heating - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of electrically heating various food materials for processing such as cooking and sterilization, and particularly to a liquid food material and two or more kinds of solid food materials. The present invention relates to a method of electrically heating a mixed food material obtained by mixing.

Conventional technology Generally, retort heating is a typical method for heating solid-liquid mixed food materials for processing such as sterilization or cooking, but retort heating requires a long time for processing and is low in energy efficiency. Therefore, electric heating has recently attracted attention. The electric heating uses what is called Joule heating in which the food material is directly energized to generate heat by the electric resistance of the food material, and in such electric heating, there are advantages such as high energy efficiency and high processing efficiency. There is.

The problem to be solved by the invention is that energization heating is a method of causing the food material to generate heat from the inside by utilizing Joule heat generation due to the current flowing through the food material.
When the food material to be electrically heated is a mixed food material containing multiple types of solid food materials, there is often a difference in the electrical conductivity of each solid food material, in which case there is a difference in the current flowing through each solid material. Occurs, which often causes a difference in the degree of Joule heat generation of each solid food material. If this difference becomes extreme, some solid food materials among the multiple kinds of solid food materials that make up the mixed material will not be sufficiently heated and will not be sterilized sufficiently even if a sufficient current flows as a whole. Or, it may not be processed, or conversely, some solid food materials may be overheated, causing deterioration or deformation. However, in the conventional method of treating food by electric heating, the above-mentioned points have not been sufficiently taken into consideration.

On the other hand, in the case of a mixed food material containing a plurality of kinds of solid food constituent materials, it is often desired that the heating degree of each solid food constituent material is made different. For example, when processing a mixed food material in which a solid food material that can be sufficiently sterilized at a relatively low temperature and a solid food material that requires sterilization at a high temperature are mixed, the taste and shape of each solid food material can be improved. In order to carry out sterilization sufficiently while keeping it, it is desirable that each solid food material is not uniformly heated, but conversely, each solid food material is heated to different temperatures depending on the difficulty of sterilization. When heating a mixed food material that is a mixture of a solid food material that achieves the cooking purpose by heating at a relatively low temperature and a solid food material that does not achieve the cooking purpose unless heating at a high temperature. Also, if each solid food material is heated uniformly, some solid food materials may not be sufficiently cooked, or on the contrary, some solid food materials may be excessively heated and the taste may be impaired. Since the shape may be lost, it is desirable to treat each solid food material so that it is heated at different temperatures according to the optimum cooking temperature of each solid food material. However, in the conventional ordinary food processing method by electric heating, such a point is not particularly considered, so that it is often impossible to sufficiently satisfy the taste and shape of the purpose of sterilization and cooking at the same time. .

The present invention has been made in view of the above circumstances, and is a mixed food material prepared by mixing a plurality of different food constituent materials, particularly a mixed food material prepared by mixing a liquid food material and two or more kinds of solid food materials. A method in which each solid food material can be uniformly heated in the treatment with the material and electric heating, or conversely, the degree of heating of each solid food material can be arbitrarily varied depending on the purpose such as sterilization or cooking. It is intended to provide.

Means for Solving the Problems The inventors of the present invention have conducted intensive experiments and studies to achieve the above-mentioned object, and as a result, about one or more kinds of solid food materials constituting the mixed food material to be electrically heated. The inventors have found that the above-mentioned object can be achieved by performing a pretreatment for adjusting the electric conductivity in advance at the stage before mixing them and heating them by energization, and have completed the invention.

Specifically, the method of the invention of claim 1 heats a mixed food material obtained by mixing a liquid food material and two or more kinds of solid materials with electricity, and Pretreatment is applied to one or more kinds of solid food materials to make their electric conductivity equal to that of other one or more kinds of solid food materials, and then each food material is mixed. It is characterized in that it is electrically heated.

In the method of the invention of claim 2, when electrically heating a mixed food material obtained by mixing a liquid food material and two or more kinds of solid food materials, one or more solid foods of each solid food material are previously heated. For a material, its electrical conductivity is
The present invention is characterized in that a pretreatment is performed to make the electric conductivity of the solid food material of at least one kind different from that of the solid food material, and then each food material is mixed and then heated electrically.

Action In the method of the invention of claim 1, one or more solid food materials among the solid food materials constituting the mixed food material are preliminarily changed in electrical conductivity to any other solid food material. A pretreatment is performed to make it equal to the electric conductivity of the material. If each solid food material is mixed with liquid food material after such pretreatment and the whole (mixed food material) is energized, the electric conductivity of each solid food material will be equal and uniform. Therefore, an electric current flows evenly through each solid food material, and each solid food material can evenly generate Joule heat. Therefore, the heating temperature of each solid food material can be made uniform.

On the other hand, in the method of the invention according to claim 2, for one or more solid food materials among the solid food materials constituting the mixed food material, the conductivity is previously set to any other solid food material. Pre-treatment is applied to make it different from the electric conductivity of the material. If each solid food material is mixed with the liquid food material after such pretreatment and the whole mixed food material is energized, there is a difference in the electrical conductivity of each solid food material. There is also a difference in the current flowing through the material, which results in a different degree of Joule heating of each solid food material, allowing each solid food material to be heated at a different temperature. Then, in this case, by appropriately adjusting the difference in electric conductivity given to each solid food material by the pretreatment, it is possible to give an arbitrary temperature difference according to the purpose such as sterilization or cooking at the time of electric heating.

Example As a mixed food material targeted by the present invention, a material composed of a liquid food material and two or more kinds of solid food materials (solid matter) is used. The liquid food material is typically a seasoning liquid having an appropriate salt content, and the solid food material includes vegetables (including dried vegetables), meat (including dried meat), fish meat (including dried fish meat). ), Fruits (including dried fruits) and the like.

As a specific method of performing pretreatment for adjusting the electric conductivity on such a solid food material, for example, the following methods (a) to (c) may be applied.

(B) A method of immersing in water or boiling with water.

(B) A method of immersing in oil or fat or coating the surface with oil or fat.

(C) Salts (NaCl, KCl, etc.) and acidulants (acetic acid, lactic acid,
A method in which an electrolyte such as citric acid), an amino acid, a nucleic acid, or the like, or a solution thereof, a seasoning containing the same, or a seasoning solution containing the same is used, and is dipped or applied. Alternatively, a method of using these electrolytes or electrolyte solutions, seasonings or seasoning solutions, immersing them in or applying them, and then heating. Alternatively, a method of heating in the electrolyte solution or the seasoning solution. Or, using these electrolytes or electrolyte solutions or seasonings or seasoning solutions, after dipping or coating these,
A method of heating in these electrolyte solutions or seasonings.
Alternatively, a method of injecting these electrolyte solutions or seasonings into a solid food material.

Of these, the method (a) is effective in reducing the electric conductivity of a solid food material having a high salt concentration. Further, the method (b) is effective in increasing the insulating property of the surface of the solid food material by the oil and fat to lower the electric conductivity.
Furthermore, the method (c) can be applied to both cases of decreasing or increasing the electric conductivity by selecting the type of electrolyte or seasoning. Of course, these methods (a) to (c) are used for pretreatment for equalizing the electric conductivity of the solid food materials that make up the mixed food material, and vice versa. Can also be applied.

After mixing the solid food material pretreated as described above with the liquid food material, a specific method for electrically heating is arbitrary, but a container for electrically heating using an electrode made of titanium, for example, It is desirable to fill the container as shown in FIG. 1 and FIG. 2 and conduct electric heating.

In FIGS. 1 and 2, a pair of foil-shaped or thin-plate-shaped titanium electrodes 2A, 2B are provided at positions facing each other inside at least the inside of the container body 1 having an insulating property. These titanium electrodes 2A, 2B are electrically connected to lead terminal portions 3A, 3B provided so as to project outside the container. The mixed food material 4 is filled in the container body 1 and is sealed by a lid member 5 having an electric insulating property.

If the container using the titanium electrode is filled and heated by energization as described above, gas such as hydrogen is generated from the electrode surface during energization and the energization is hindered by bubbles or the container is expanded by gas pressure. In addition, it is possible to prevent rusting or corrosion of the electrode surface even if the electrode is in contact with food for a long time. The electric heating may be performed under atmospheric pressure or under pressure, but under pressure, it can be heated to a high temperature exceeding 100 ° C, so sterilization and cooking are performed at a high temperature of 100 ° C or higher. Perfect for the case.

Specific examples of the method of the present invention will be described below together with reference examples.

Reference Experimental Example 1 Carrot as a solid food material was cut into a size of 20 × 20 × 10 mm, immersed as a pretreatment in a 1.2% NaCl aqueous solution and boiled for 10 minutes. This boiled carrot and 150 g of 5% starch liquid (containing 0.8% NaCl) as a liquid food material were mixed at a ratio of 1: 3 in the electric heating container shown in FIGS. 1 and 2. Filled. 3kg / with compressed air for the entire container
A current of 4.5 A was applied while being pressurized with a pressure of cm ² . Here, the temperature sensor is pierced into the starch liquid portion and the carrot portion, and the temperature of each portion is measured. The results are shown in FIG. 3 (A).

On the other hand, for comparison, carrots (raw carrots) not subjected to the above-mentioned pretreatment are mixed with 5% starch solution and heated by energization in the same manner as above. B).

As shown in FIG. 3 (B), when carrot which was not pretreated was used, the heating temperature of carrot was lower than that of the starch solution because its electric conductivity was lower than that of the starch solution. In addition, in the case of FIG. 3 (A), since the electric conductivity of carrot was almost the same as that of the starch liquid, it was heated to almost the same temperature as the starch liquid.

Reference Example 2 Pork thigh meat as a solid food material was cut into a size of 20 × 20 × 10 mm, and as a pretreatment, it was immersed in a 1.5% NaCl aqueous solution and boiled for 17 minutes. Boiled pork tenderloin and 150 g of 5% starch liquid (containing 0.8% NaCl) as a liquid food material,
Mix in a ratio of 1: 3 and fill a container as in Example 1,
Electrical heating was performed under pressure. The temperature measurement result of each part is shown in FIG.

For comparison, FIG. 4 (B) shows the temperature measurement result of each part in the case of using the pig thigh meat that was not pretreated.

Also in this case, the heating temperature could be made almost equal to that of the starch liquid by increasing the electric conductivity of the pork leg meat to be equal to that of the starch liquid by the pretreatment.

Reference Example 3 Carrot as a solid food material was cut into 20 × 20 × 10 mm pieces, and as a pretreatment, it was immersed in 3% acetic acid and boiled for 10 minutes. This boiled carrot and 150 g of 5% starch liquid (containing 2% acetic acid) as a liquid food material were mixed at a ratio of 1: 3 to prepare a container for electric heating shown in FIGS. 1 and 2. Filled. With the entire container pressurized with compressed air at a pressure of 3 kg / cm ² , 250 V, 0.5 A at the start of heating and 80 V, 0.5 A at the end of heating were energized.

Also in this case, the carrot pretreated with acetic acid had an electric conductivity equivalent to that of the starch liquid, and therefore the carrot could be heated to the same temperature (140 ° C.) as the starch liquid.

Reference Experimental Example 4 Carrot as a solid food material was cut into 20 × 20 × 10 mm pieces, immersed as a pretreatment in a 1.2% NaCl aqueous solution, and boiled for 10 minutes. Carrot after boiling and 5% as a liquid food ingredient
150 g of starch liquid (containing 0.4% NaCl) was mixed at a ratio of 1: 5 and filled in a container similar to the above. An electric current was applied at 60 V while the entire container was pressurized with compressed air at a pressure of 3 kg / cm ² . The result of measuring the temperature of each part is shown in FIG.

From FIG. 5, it is clear that the pretreatment increased the electrical conductivity of carrot and allowed the carrot to be heated to a higher temperature than the starch solution. Here, it is generally considered that a solid substance such as carrot has more microorganisms than a liquid, and therefore heating the solid substance such as carrot to a temperature higher than that of the liquid is considered to be effective for sufficient sterilization.

Reference Experimental Example 5 Carrot as a solid food material is cut into 20 × 20 × 10 mm,
As a pretreatment, it was immersed in a 1.5% NaCl aqueous solution and boiled for 15 minutes. Carrots after boiling and 5% starch liquid (0.4% NaC
150 g (including l) were mixed at a ratio of 1: 5 and filled in a container in the same manner as in Example 4 and electrically heated. The result of measuring the temperature of each part is shown in FIG.

From the results of Reference Experimental Example 4 and Reference Experimental Example 5 described above, it is clear that the temperature difference between the carrot and the starch liquid can be arbitrarily set by adjusting the electric conductivity of the carrot and the starch liquid.

Example As the solid food material, three kinds of carrot, dried shiitake mushroom, and pork were used. Of these, carrots are 20 × 20 × 10
Cut into mm and dip in 1.0% NaCl solution as pretreatment 1
Boiled for 0 minutes. The dried shiitake mushroom was washed with water, immersed in 1.3% saline as a pretreatment, and cut into 20 mm × 20 mm. Pork is cut into 20 x 20 x 10 mm and then 1.2% NaCl as pretreatment
It was immersed in an aqueous solution and boiled for 15 minutes. On the other hand, as liquid food ingredients, 0.5 part of salt, 0.5 part of soy sauce, 5 parts of starch, 0.1 part of sodium glutamate, 0.9 part of sugar, 1 chicken extract.
Part, ginger mince 0.5 part, sesame oil 0.5 part, and water 91 parts were mixed to prepare a seasoning liquid. 150g of this seasoning liquid and 2 pre-treated carrots, shiitake mushrooms, and pork were filled into the electric heating container shown in Figs. 1 and 2 and sealed, and then placed in a pressure container for 3kg / cm. Electrical heating was performed under the pressure of ² . Energize initially at 90V for 100 seconds, then 1.
The power was turned on at 7 A for 20 seconds, and immediately thereafter, cooling water was put in the pressure vessel to cool it. The optimum ultimate temperature and sterilization value (Fo value) of each part at the time of this electric heating were examined. The result is first
Shown in the table.

As shown in Table 1, pork and carrot were able to be heated to almost the same temperature, assuming that their electric conductivities were almost the same (almost the same as the seasoning liquid). On the other hand, shiitake mushrooms usually have a large number of heat-resistant microorganisms. Therefore, they were heated to a temperature higher than those of pork and carrots, and sterilized sufficiently.

After cooling, they were stored in a thermostat at 35 ° C. and 70% (RH) for 2 weeks, and then subjected to a microbe test, which confirmed that they were sterile.

Advantageous Effects of Invention According to the method of the invention of claim 1, when a mixed food material consisting of a liquid food material and two or more kinds of solid food materials is electrically heated for processing such as sterilization or cooking, each solid food material is previously heated. By making the electric conductivity of each of them equal, the heating temperature of each solid food material due to electric heating can be made substantially equal, so that the degree of processing such as sterilization and cooking of each solid food material can be made equal. it can.

Further, according to the method of the invention of claim 2, by positively differentiating the electric conductivity of each solid food material in advance, it is possible to obtain the optimum heating temperature according to the characteristics of each solid food material. it can. That is, when the optimum heating temperature for processing such as sterilization and cooking is different for each solid food material, it is possible to adjust the heating temperature of each solid food material to the optimum temperature, so that excessive heating may damage the taste. It is possible to prevent the shape from being deformed, and it is possible to sufficiently achieve the purpose of processing such as sterilization and cooking.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view showing a container used for electric heating in carrying out the method of the present invention, and FIG. 2 is a vertical sectional view of the container of FIG. 1, FIG. 3 (A), ( B) is a graph showing a temperature measurement chart of Reference Experimental Example 1, FIGS. 4A and 4B are graphs showing a temperature measurement chart of Reference Experimental Example 2, and FIG. 5 is a temperature measurement chart of Reference Experimental Example 4. FIG. 6 is a graph showing a temperature measurement chart of the example.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location A23L 1/212 101 1/31 Z

Claims (2)

[Claims] 1. When electrically heating a mixed food material obtained by mixing a liquid food material and two or more kinds of solid food materials, one or more kinds of solid food materials of each solid food material are previously heated, Pre-treatment is applied to make its electric conductivity equal to that of one or more other solid food materials, and then each food material is mixed and then electrically heated Food manufacturing method. 2. When electrically heating a mixed food material obtained by mixing a liquid food material and two or more kinds of solid food materials, one or more kinds of solid food materials of each solid food material are previously heated, Pre-treatment is applied to make the electric conductivity different from the electric conductivity of one or more other solid food materials, and then each food material is mixed and then electrically heated. Food manufacturing method.