A single-category food for microwave cooking having two or more divided regions with different dielectric constants, a method for manufacturing the same, and a design method.

Abstract

This application relates to a single category of food for microwave cooking having two or more divided regions with different dielectric constants, a method for manufacturing the same, and a design method for the same. [Solution] This application relates to a food product with excellent heating properties, a method for producing the same, and a design method for producing the same. According to this application, temperature deviations within the food product can be minimized during heating by methods such as microwave irradiation or direct heating.

Description

Technical Field

[0001] The present application relates to a single-category food for microwave cooking having two or more divided regions with different dielectric constants, a manufacturing method thereof, and a design method thereof.

Background Art

[0002] From an electrical perspective, substances can be divided into conductors and dielectrics. A conductor is a substance in which free electrons exist and can conduct electricity well, and a dielectric is a substance through which electricity does not conduct well. The dielectric constant (Permittivity, ε) is a physical description of the reaction pattern of a dielectric to electricity and electromagnetic waves.

[0003] The dielectric constant (Permittivity, ε) is an important characteristic value indicating the electrical properties of a dielectric material, and is a material constant expressing the degree to which the internal + / − moment of a dielectric reacts sensitively to changes in an external electric field. The dielectric constant also indicates the electrical properties with respect to DC current, but in relation to food heating, it is directly related to the properties of AC current, particularly alternating electromagnetic waves. The dielectric constant varies depending on various factors such as the properties of the medium, the frequency of the electromagnetic field applied to the medium, humidity, and temperature. When the frequency is 0 or sufficiently low, the change in the dielectric constant is not large, but when the frequency increases and the phase difference of the reaction to the change in the electric field becomes large, the dielectric constant is defined in the form of a complex number and is expressed by the following mathematical formula.

[0004] From an electrical perspective, substances can be divided into conductors and dielectrics. A conductor is a substance in which free electrons exist and can conduct electricity well, and a dielectric is a substance through which electricity does not conduct well. The dielectric constant (Permittivity, ε) is a physical description of the reaction pattern of a dielectric to electricity and electromagnetic waves.

[0005] Permittivity (ε) is an important characteristic value that indicates the electrical properties of a dielectric material. It is a material constant that expresses the degree to which the dielectric material's internal + / - moment responds sensitively to changes in the external electric field. While permittivity can also indicate the electrical properties with respect to DC current, in the context of food heating, it is directly related to the properties of AC current, particularly AC electromagnetic waves. Permittivity changes depending on various factors such as the properties of the medium, the frequency of the electromagnetic field applied to it, humidity, and temperature. When the frequency is 0 or sufficiently low, the change in permittivity is not large, but when the frequency increases and the phase difference of the response to changes in the electric field becomes large, permittivity is defined in complex number form and is shown by the following formula.

[0006] From an electrical perspective, materials can be divided into conductors and dielectrics. Conductors are materials that have free electrons and can conduct electricity well, while dielectrics are materials that do not conduct electricity well. The dielectric constant (ε) is a physical description of the reaction pattern of a dielectric material to electricity and electromagnetism.

[0007] Permittivity (ε) is an important characteristic value that indicates the electrical properties of a dielectric material. It is a material constant that expresses the degree to which the dielectric material's internal + / - moment responds sensitively to changes in the external electric field. While permittivity can also indicate the electrical properties with respect to DC current, in the context of food heating, it is directly related to the properties of AC current, particularly AC electromagnetic waves. Permittivity changes depending on various factors such as the properties of the medium, the frequency of the electromagnetic field applied to it, humidity, and temperature. When the frequency is 0 or sufficiently low, the change in permittivity is not large, but when the frequency increases and the phase difference of the response to changes in the electric field becomes large, permittivity is defined in complex number form and is shown by the following formula.

[0008] ε = ε'- jε″= ε0ε r = ε0(ε´ r - jε″ r ) ε0 = 8.854 * 10 -12 F / m ε r = Relative Permittivity

[0009] In the above formula, ε' is the real part of the permittivity, called the dielectric constant, and is the part related to the wavelength and propagation of electromagnetic waves. ε'' is the imaginary part of the permittivity, called the loss factor, and is a term related to the energy absorption rate and loss by the medium. Energy loss occurs when ε'' is a positive number at a specific frequency, and this is mainly shown in the form of heat generation. ε0 is the dielectric constant of vacuum, and ε r The relative permittivity is a way of expressing the dielectric constant of a dielectric material as a ratio to the dielectric constant in a vacuum state, and it is a common method of expressing dielectric constant.

[0010] The amount of heat generated due to dielectric constant can be expressed by the following formula. Q = 2πfε″ε0E 2

[0011] Microwave cooking, commonly used for heating food, relies on dielectric constant-based heating as its technical foundation. However, most microwave cooking methods are entirely dependent on the performance and characteristics of the microwave itself. Improvements to cooking quality have been developed only in a "device-centric" manner, such as installing separate devices inside the microwave or attaching accessories that alter the electric field to the packaging. However, these methods are frequently ineffective depending on the product's attributes. Research and development are needed to address these problems from the perspective of the product, which is the actual purpose of microwave heating, and to improve the heating effect. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] U.S. Published Patent US 2016 / 033100 [Overview of the project] [Problems that the invention aims to solve]

[0013] One objective of this application is to provide food that can be uniformly heated when heated by microwave irradiation.

[0014] Another object of this application is to provide a method for producing food that enables uniform heating when heated by microwave irradiation.

[0015] Another object of this application is to provide a method for designing food that can be heated uniformly. [Means for solving the problem]

[0016] In order to achieve the aforementioned objectives, One aspect of this application is a single category of food comprising two or more divided regions having different dielectric constants, wherein the food is uniformly heated by microwave irradiation.

[0017] Other aspects of this application are, (a) The stage of dividing a single-category food into two or more parts; (b) The step of making the components that affect the dielectric constant or the content thereof different in the two or more divided parts such that the two or more divided parts have different dielectric constants; and (c) A method for producing a food product that is uniformly heated by microwave irradiation, comprising the step of producing a single category of food product that includes two or more divided regions having different dielectric constants using two or more portions having different dielectric constants.

[0018] Another aspect of this application is, (a) A step of measuring one or more characteristic values ​​selected from the group consisting of dielectric constant, specific heat, thermal conductivity, density, and porosity of the food; (b) evaluating the non-uniformity of heating of a single-category food using the measured characteristic values and the heating characteristic data of the heating device; and (c) when there is non-uniformity in the heating of the single-category food, determining the number, size, or positional relationship of the divided regions within the food and adjusting the characteristic values of the food within the divided regions; A method for designing the structure of divided regions within the food to improve the heating uniformity of the food is provided.

[0019] Hereinafter, the present application will be specifically described.

[0020] According to one aspect of the present application, there is provided a single-category food including two or more divided regions having different dielectric constants from each other, and the food is uniformly heated by microwave irradiation.

[0021] The present application provides a food that, when the food is heated by microwave irradiation by artificially forming two or more divided regions having different dielectric constants within a single-category food, has the characteristic that the temperature inside the food is uniformly heated.

[0022] The term "dielectric constant" in the present application means a material constant indicating the magnitude of polarization created by a dielectric in response to an external electric field. The larger the dielectric constant, the larger the polarization created by the dielectric, so the electric field inside the dielectric becomes smaller.

[0023] In one embodiment, the two or more divided regions having different dielectric constants from each other can have different dielectric constants or dielectric loss factors.

[0024] The term "dielectric constant" in the present application means the ratio between the dielectric constant of a certain material and the dielectric constant of a vacuum, and is also called relative dielectric constant.

[0025] In this application, the term "dielectric loss factor" is a measure of the magnitude of loss in a dielectric, and refers to the rate of energy loss within a dielectric material through which an electric current passes.

[0026] In one embodiment, the difference in characteristic values ​​between the division area with the highest dielectric constant or dielectric loss rate and the division area with the lowest dielectric constant among division areas having different dielectric constants may be 95% or less of the characteristic value in the division area with the highest dielectric constant or dielectric loss rate.

[0027] The characteristic value in the divided region may be one or more characteristic values ​​selected from the group consisting of dielectric constant, specific heat, thermal conductivity, density, and porosity.

[0028] In this application, two or more divided regions having different dielectric constants may have different components affecting the dielectric constant or different content thereof. Alternatively, even if two or more divided regions having different dielectric constants have the same components affecting the dielectric constant or different content thereof, their dielectric constants may differ because they are manufactured using different methods.

[0029] In one embodiment, the component that affects the dielectric constant may be one or more selected from the group consisting of water, salt, protein, carbohydrates, and fat.

[0030] The salt can be any salt that can be added to food and, when dissolved in water, can form polarization, without limitation. The salt may include, but is not limited to, sodium salts, potassium salts, ammonium salts, magnesium salts, or calcium salts.

[0031] The protein in question is any protein that can be added to food and exhibits specific dielectric properties when mixed with other components and subjected to an electric field, and is therefore not limited to any other protein that can be used. The protein in question may include, but is not limited to, egg white, soy protein, whey protein, insect-derived protein, whey protein concentrate (WPC), whey protein isolate (WPI), albumin, globulin, glutelin, prolamin, albuminoid, histone, or protamine.

[0032] The aforementioned carbohydrates can be any carbohydrate that can be added to food and can exhibit specific dielectric properties when mixed with other components and subjected to an electric field, without any limitations. Examples include polysaccharides, monosaccharides, sugar alcohols, starches, sugars, and dietary fiber, and specifically, D-ribose, trehalose, or sorbitol.

[0033] The aforementioned fat can be used without limitation as long as it is a fat that can be added to food and exhibits specific dielectric properties when mixed with other components and subjected to an electric field. For example, it can include saturated fatty acids or unsaturated fatty acids, and can include animal fats such as pork fat and beef fat, and vegetable oils extracted from plant-based raw materials such as beans, rapeseed, and rice.

[0034] In this application, the term "single-category food" means food that can be recognized as belonging to a single category. More specifically, a single-category food means a portion of food that can be recognized as a single part in terms of food design and is manufactured in the same manner through the same ingredient composition within the food.

[0035] Specifically, a single category of food can be a food product distributed to consumers, or a combination of single category foods can be a food product distributed to consumers, and this can manifest in different ways depending on the type of food.

[0036] More specifically, a single-category food may mean a certain part rather than each individual component. Even more specifically, the meaning of a food manufactured in the same way through the same component composition within the food means that if the final product contains multiple single-category foods, each single-category food is manufactured with its own identical component composition and the same manufacturing method. For example, in the case of fried rice, the entire fried rice may be a single-category food; in the case of dumplings, the dumpling wrapper and the dumpling filling may each be a single-category food; in the case of a hot dog, the bun and the sausage may each be a single-category food; and in the case of a pasta product with sauce, the noodles and the sauce may each be a single-category food. Even if they are the same type of single-category food, the composition and manufacturing method may differ for each single-category food. For example, in the case of a hot dog, the bun and the sausage may each be a single-category food, and even if they are sausages, their respective compositions and manufacturing methods may differ from product to product. In this application, a single-category food can mean each part of a food that can be recognized as a single category in the food industry.

[0037] In this application, a single category of food may be food manufactured by the same method before forming the divided regions described later.

[0038] This application is characterized by the artificial division of a single category of food manufactured using the same method and the same composition of ingredients, so that the divided regions have different dielectric constants. Therefore, in this application, divided regions with different dielectric constants may be formed within a single category of food.

[0039] This application is characterized by artificially creating divided regions with different dielectric constants within a single food category. However, in the case of a food category consisting of two or more items, it does not mean that the dielectric constants of each item in the food category are different from each other. For example, it does not mean that the wrapper and filling of a dumpling have different dielectric constants.

[0040] The form in which two or more divided regions having different dielectric constants are formed in this application is not particularly limited. More specifically, the formation of the divided regions can be modified depending on the type, form, or properties of the food, and the structure is not limited as long as divided regions having different dielectric constants are formed and there is little uneven heating due to microwave irradiation.

[0041] In one embodiment, two or more divided regions having different dielectric constants can be adjacent to each other, forming a layered structure.

[0042] In one embodiment, one of two or more divided regions having different dielectric constants may be scattered within another divided region.

[0043] In one embodiment, a core-shell configuration may be in which one of two or more divided regions having different dielectric constants surrounds another divided region.

[0044] In this application, uniform heating by microwave irradiation means that when a single category of food includes two or more divided regions having different dielectric constants, the thermal deviation, more specifically the coefficient of variation, is reduced compared to when it does not include two or more divided regions having different dielectric constants. The reduction in thermal deviation means that the temperature deviation, more specifically the coefficient of variation, at a specific point becomes smaller when microwave irradiation is performed. More specifically, the coefficient of variation may decrease by 3%, 3.5%, 4%, 4.5%, or 5% or more compared to before the change in dielectric constant.

[0045] According to other aspects of this application, (a) The stage of dividing a single-category food into two or more parts; (b) The step of making the components that affect the dielectric constant or the content thereof different in the two or more divided parts such that the two or more divided parts have different dielectric constants; and (c) A method for producing food that is uniformly heated by microwave irradiation, comprising the step of producing a single category of food including two or more divided regions having different dielectric constants using two or more portions having different dielectric constants.

[0046] In step (a) above, dividing a single-category food into two or more parts can be done in a variety of ways, without limitation depending on the type, form, or properties of the food or the degree of completion of cooking. More specifically, dividing into two or more parts means dividing the structure of a single-category food in order to manufacture a food in which a single-category food portion manufactured in the same way through the same ingredient composition is divided into two or more parts by a designed food structure in order to manufacture a food having two or more parts having two or more parts having different dielectric constants. For example, a single-category food that has been cooked can be divided into two or more parts, food ingredients can be divided into two or more parts before cooking a single-category food, or a semi-finished product in the intermediate stage of cooking a single-category food can be divided into two or more parts.

[0047] In step (b) above, the components that affect the dielectric constant or the content thereof are made different in the two or more divided parts such that the two or more parts have different dielectric constants.

[0048] In one embodiment, the component that affects the dielectric constant may be one or more selected from the group consisting of water, salt, protein, carbohydrates, and fat.

[0049] The salt can be any salt that can be added to food and that can form polarization when dissolved in water, without any limitations. The salt may include, but is not limited to, sodium salts, potassium salts, ammonium salts, magnesium salts, or calcium salts.

[0050] The protein in question is any protein that can be added to food and exhibits specific dielectric properties when mixed with other components and subjected to an electric field, and is therefore not limited to any other protein that can be used. The protein in question may include, but is not limited to, egg white, soy protein, whey protein, insect-derived protein, whey protein concentrate (WPC), whey protein isolate (WPI), albumin, globulin, glutelin, prolamin, albuminoid, histone, or protamine.

[0051] The aforementioned carbohydrates can be any carbohydrate that can be added to food and can exhibit specific dielectric properties when mixed with other components and subjected to an electric field, without any limitations. Examples include polysaccharides, monosaccharides, sugar alcohols, starches, sugars, and dietary fiber, and specifically, D-ribose, trehalose, or sorbitol.

[0052] The aforementioned fats can be added to food and are unrestricted in their use as long as they are substances that can exhibit specific dielectric properties when mixed with other components and subjected to an electric field. For example, they can include saturated or unsaturated fatty acids, and may include animal fats such as pork fat and beef fat, as well as vegetable oils extracted from plant-based raw materials such as beans, rapeseed, and rice.

[0053] In step (c) above, if a single category of food is manufactured using two or more parts having different dielectric constants, the form of the two or more divided regions is not particularly limited.

[0054] In one embodiment, in step (c), a single-category food can be manufactured such that one of two or more parts having different dielectric constants is adjacent to another part and forms a layered structure.

[0055] In other embodiments, in step (c), a single-category food can be manufactured in such a form that one of two or more parts having different dielectric constants is scattered within the other part.

[0056] In other embodiments, in step (c), a single-category food can be manufactured in a core-shell configuration in which one of two or more parts having different dielectric constants surrounds another part.

[0057] Specifically, the food may be manufactured as follows:

[0058] If a single-category food has an unstandardized form, a single-category food containing two or more divided regions having different dielectric constants can be manufactured by producing two or more raw materials, semi-finished products, or parts of food with different dielectric constants, and then alternately stacking the produced raw materials, semi-finished products, or parts of food with different dielectric constants.

[0059] The aforementioned lamination can be carried out using a variety of methods depending on the form of the food. For example, devices such as nozzles, buckets, and auto-scalers can be used, or in the case of food containing a mixture of particles and liquid, an injection method can be used.

[0060] When a single-category food is in the form of a low-viscosity paste, a liquid that solidifies or freezes during processing, or a form that can be mixed during structure formation, a layered structure can be formed using different methods depending on the viscosity of the food raw materials. For example, if the viscosity of the food raw materials is sufficient, a layered structure can be formed using a layered injection nozzle after manufacturing two or more food raw materials with different dielectric constants. If the viscosity of the food raw materials is insufficient, a layered structure can be formed by filling a container with food raw materials manufactured in a certain frame to form a first layer, then freezing or solidifying it, and then filling the first layer with food raw materials with different dielectric constants to form a second layer, which is then frozen or solidified. The process of forming the first and second layers can be repeated two or more times.

[0061] If a single category of food is in a form that makes it difficult to physically form a layered structure, a method can be used to layer two or more types of food obtained by immersing them in an immersion solution with different dielectric constants. Alternatively, a method can be used in which an immersion solution or injection solution, which can be adjusted to have different dielectric constants, is injected into the deep layers of the product, while the surface layer is immersed in the immersion solution. The immersion solution may contain one or more components selected from the group consisting of water, salt, protein, carbohydrates, and fats, which affect the dielectric constant as described above.

[0062] After manufacturing the food containing the two or more divided sections, additional steps may be carried out, such as filling with a filler, freezing, sterilization, or heat treatment.

[0063] According to other aspects of this application, (a) A step of measuring one or more characteristic values ​​selected from the group consisting of dielectric constant, specific heat, thermal conductivity, density, and porosity of a single category of food; (b) A step of evaluating the heating non-uniformity of a single-category food using the measured characteristic values ​​and heating characteristic data of the heating equipment; and (c) If there is heating non-uniformity of the single-category food, the method for designing the structure of divided areas within the food to improve heating uniformity of the single-category food is provided, which includes the steps of determining the number, size, or positional relationship of divided areas within the food and adjusting the characteristic values ​​of the food within the divided areas.

[0064] In one embodiment, the heating characteristic data of the heating device in step (b) above may be heating characteristic data due to electromagnetic, radiation, or convection.

[0065] More specifically, the heating characteristics data refers to data specific to heating equipment, data specific to heating equipment characteristics (e.g., output value, output time, rotation speed of the equipment's fan, wind speed or airflow data based on the fan rotation speed, algorithm for controlling the equipment's heat source, etc.), data specific to food characteristics (e.g., data per salt concentration, data per protein concentration), temperature data for each section or spot within a single food category, temperature change rate data, data for the spot with the highest temperature within a single food category, or data on the movement of the spot with the highest temperature.

[0066] The heating device may be a microwave irradiation device (microwave oven), an electric oven, or a gas oven.

[0067] In one example, the evaluation of the non-uniformity of heating of a single-category food in step (b) can be performed by analyzing the changes or movement of heating spots inside the food.

[0068] In this application, the term "heated spot" refers to a portion of food that shows a higher temperature than the surrounding area when the internal temperature is measured.

[0069] Specifically, the heating spot may be a heating spot formed inside the food when the food is heat-treated using a heating device.

[0070] Non-uniform heating of food can be determined if there are heating spots inside the food, if the heating spots change, or if the heating spots move.

[0071] If it is determined in step (c) above that there is uneven heating of the food, the number, size, or positional relationship of the divided areas within the food is determined, and the characteristic values ​​of the food are adjusted within the divided areas.

[0072] The number, size, positional relationship, and food characteristic values ​​of the aforementioned divided areas can be determined by analyzing the number or location of heating spots.

[0073] The characteristic values ​​of the food to be adjusted within the divided area may be one or more values ​​selected from the group consisting of dielectric constant, specific heat, thermal conductivity, density, and porosity.

[0074] In one embodiment, the adjustment of the characteristic values ​​of the food within the divided area may be done so as to improve the uniformity of heating of the food when it is heated through a heating device.

[0075] In one example, the food may be a food belonging to a single category.

[0076] In one example, the food may be a conventional food or a new food. In the aforementioned aspect of this application, "A method for designing the structure of divided sections within a food to improve the uniformity of heating of the food," the content common to a single category of food and divided sections is the same as the content described in the other aspect of this application mentioned above, and therefore will not be explained again. [Effects of the Invention]

[0077] According to this application, it is possible to manufacture food in which temperature deviations within the food can be minimized when heated by methods such as microwave irradiation or direct heating. According to this application, it is possible not only to provide food that can be heated uniformly when microwaved, but also to design the structure of the food to have heating uniformity when microwaved. However, the effects of this application are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description. [Brief explanation of the drawing]

[0078] [Figure 1] This graph shows the vertical temperature in the center of four samples, each designed with different concentrations of salt and WPC, during microwave irradiation heating. [Figure 2] This graph shows the horizontal temperature in the center of four samples, each designed with different concentrations of salt and WPC, during microwave irradiation heating. [Figure 3] This graph shows the temperature rise at the center of four samples, each designed with different concentrations of salt and WPC, as a result of heating time by microwave irradiation. [Figure 4] This shows the results of confirming the heating patterns of the upper ends of heating elements 1 and 2 in Experimental Example 4 of this application using Thermal Light View. [Figure 5] This is the result of vertically cutting heating elements 1 and 2 of Experimental Example 4 of this application, passing through the center of the upper end to the center of the lower end, and observing them with Thermal Light View. [Figure 6] This graph shows the temperature distribution of the vertical and horizontal portions passing through the center of heating elements 1 and 2 in Experimental Example 4 of this application. [Figure 7] This graph shows the temperature distribution from left to right when heating elements 1 and 2 are cut horizontally in experimental example 4 of this application. [Modes for carrying out the invention]

[0079] The present application will be described in detail below with reference to examples. However, the following examples are for illustrative purposes only, and the content of the present application is not limited to the following examples. [Examples]

[0080] Experimental Example 1: Measurement of the change in dielectric constant due to sodium content Distilled water, salt, D-ribose, WPC (Whey Protein Concentrate), and WPI (Whey Protein Isolate) were mixed in constant ratios, and experimental groups Test1, Test2, and Test3 were prepared by varying the salinity to 0.3%, 0.6%, and 1% (Table 1). Dielectric constants and loss factors were measured using Agilent's Vector Network Analyzer. Dielectric constants (E') and loss factors (E") were measured for two frequencies commonly used in microwave ovens both domestically and internationally: 915 MHz and 2450 MHz.

[0081] [Table 1]

[0082] [Table 2]

[0083] The measurement results confirmed that while the change in dielectric constant is not large when salinity increases, the change in loss factor is relatively large (Table 2).

[0084] Experimental Example 2: Measurement of change in dielectric constant due to protein content (concentrated whey protein) Distilled water, salt, D-ribose, WPC (Whey Protein Concentrate), and WPI (Whey Protein Isolate) were mixed in fixed ratios, with the WPC content differing between 18.9% and 13.9%, to prepare experimental groups Test 1 and Test 2 (Table 3). The dielectric constant and loss factor of the experimental groups were measured using Agilent's Vector Network Analyzer. The dielectric constant (E') and loss factor (E") were measured for two frequencies commonly used in microwave ovens both domestically and internationally: 915 MHz and 2450 MHz.

[0085] [Table 3]

[0086] [Table 4]

[0087] The measurement results showed that the dielectric constant increased in the experimental group with reduced protein content and increased water content, and that there was no significant difference in the loss rate (Table 4).

[0088] Experimental Example 3: Changes in heating patterns due to changes in dielectric constant Model tests were conducted to confirm how differences in dielectric constant and dielectric loss rate, resulting from differences in salinity and protein content, affect the heating temperature of products during microwave irradiation. Four samples were designed in the form of 30mm * 30mm * 30mm hexahedrons, with different concentrations of salt and WPC (Table 5). To minimize variables other than dielectric constant for the designed samples, they were heated for 1 minute without rotation at a power output of 70W in a single-mode 2.45GHz electric field.

[0089] 1. Total energy absorbed by the sample Although all four samples were heated at the same output in the same form and position, they showed differences in the total amount of energy absorbed (Table 5). This is because differences in dielectric constant result in different forms and intensities of electric fields absorbed / reflected from the sample surface and transmitted into the sample's interior. It was found that even under identical conditions, differences in the dielectric constant of the samples lead to differences in the final absorbed energy.

[0090] [Table 5]

[0091] 2. Temperature in the vertical direction of the central part of the sample As shown in the graph in Figure 1, the left side represents the temperature graph as it progresses from the bottom (center) of the product to the top (center) of the product. All shapes share the common characteristic that the temperature at the bottom is relatively higher, but it was found that there is a difference of about 20°C depending on the dielectric constant.

[0092] 3. Temperature of the central part of the sample in the horizontal direction. The graph in Figure 2 shows the temperature distribution penetrating the center of the product from the electromagnetic wave application area (left) to the cavity wall (right), and it can be seen that the temperature distribution differs depending on the dielectric constant. All products were divided into three parts heated from left to right, and it was found that the higher the salinity of the sample, the higher the temperature at the electromagnetic wave application area (left), and the lower the temperature as you move to the right. It can be seen that the lower the salinity and the lower the protein content, the greater the temperature rise in the center, resulting in a difference of up to about 14°C. This is inferred to be due to the dielectric properties in which the electromagnetic waves applied at the electromagnetic wave application area penetrate the left side of the product, and the transmission depth is lower and the heat generation is stronger for samples with a relatively high loss rate, and it is thought to be due to the characteristic that the transmission depth is deeper as the loss rate is lower, and the residual energy is heated at the attenuating wavelength position.

[0093] 4. Changes in sample core temperature due to heating time The graph in Figure 3 shows the temperature rise at the center of each sample while heating it for 60 seconds, and it can be seen that a very large temperature difference occurs at the center due to dielectric properties. As with the previous pattern, it was found that the lower the salinity and protein content, the greater the temperature rise at the center. As can be seen from the above results, it was confirmed that a change at the 5% level of the dielectric constant and a change of about 5-30% in the loss rate show a meaningful difference (15 degrees / minute) in the heating rate and final temperature of the product. Considering that the heating time for typical refrigerated / frozen microwave heated products is about 2-10 minutes, it was confirmed that the difference in dielectric constant can generate a temperature difference at a level that can directly affect the edibility and safety of the product, and that by adjusting this, the heating time and rate with the same microwave can be adjusted. As can be seen from the above experimental results, in the case of electromagnetic wave heating, it was found that even if the irradiation pattern of the electromagnetic wave irradiating device (microwave oven) and the form of the product are all the same, the heating pattern will be completely different depending on the characteristics of the heating element. Furthermore, it was found that as electromagnetic waves are scanned and pass through the surface of the product, electromagnetic energy is consumed as heating progresses, and the more they penetrate, the more energy is lost and the range of temperature rise decreases.

[0094] Experimental Example 4: Heating Pattern When Layers with Different Dielectric Constants Are Artificially Formed 1. Design of the heating element To address the problem of partial and non-uniform heating within the sample, we created divided regions with different dielectric constants within the sample, then heated it by microwave irradiation to confirm whether uniform heating throughout the sample was possible.

[0095] Heating bodies 1 and 2 were designed by dividing the sample used in the above experiment into three vertically divided sections, with each section having a different dielectric constant. The overall size of the heating body was 20 mm * 20 mm * 20 mm, the thickness of each section was the same, and the ratio of the content of the constituent materials included in the sections is shown in Table 6 below.

[0096] Heating elements 1 and 2 were irradiated with a single-mode 300W output from a non-rotating electric field irradiation device for 40 seconds at the upper end of the heating element product.

[0097] [Table 6]

[0098] 2. Heating patterns of the upper end and side of the heated product The heating patterns of the upper ends of heating elements 1 and 2 are shown in Thermal Light View (Figure 4). Heating elements 1 and 2 are shown in Thermal Light View after being vertically cut from the center of the upper end to the center of the lower end (Figure 5). As can be seen in the Thermal Light Views of Figures 4 and 5, it was confirmed that the heating elements in which layers were formed in the divided areas were heated to an even deeper depth.

[0099] 3. Distribution of vertical and horizontal temperatures in the central area The temperatures of the vertical and horizontal sections passing through the centers of heating elements 1 and 2 were observed and displayed in a graph (Figure 6). The temperature distribution is shown from the top (left side of the graph) to the bottom (right side of the graph) when the heating element is cut vertically. The thick line (see separate table) represents heating element 2. The temperature of heating element 2 is almost the same as heating element 1 on the surface of the product, but heating element 1 shows the typical pattern where the temperature decreases as you move towards the bottom. However, heating element 2 shows that the temperature rises further internally, and even at the bottom of the product, it is clear that the temperature is higher than that of heating element 1. The dielectric constant can be increased by forming other layers, and when a high temperature is formed in the center, the internal temperature is conducted uniformly in all directions after heating is complete, resulting in less loss to the outside of the heating element, and an even more uniform and high heating effect can be expected.

[0100] The heating elements 1 and 2 were cut horizontally, and the temperature distribution from left to right is shown (Figure 7). The thick line (see separate table) represents heating element 2, and it can be seen that the temperature rise is generally larger than that of heating element 1, indicating that the internal temperature has risen. As can be confirmed by the experimental results shown in Figure 7, even products with the same shape and the same electromagnetic heating device may show completely different heating patterns due to the formation of other layers by dielectric constant, and it is possible to expect a more uniform and higher temperature in the same heating time.

[0101] Experimental Example 5: Analysis of heating patterns of a multi-part structure containing divided regions with different dielectric constants. One method for generating a multi-part structure through a combination of identical or similar food compositions whose composition is adjusted within a certain range is to incorporate a different composition within a specific composition. Through such a structure, heating uniformity can be improved in the case of food products that are thick or large and cannot be heated sufficiently uniformly by electromagnetic waves and internal heat conduction.

[0102] Experimental Example 5 analyzed whether the heating pattern could be changed or improved when a structure with two or more divided sections is formed by inserting different compositions with adjusted compositions inside products such as frozen rice, frozen fried rice, and frozen bibimbap, or by changing the composition of the external composition.

[0103] The compositions used in the experiment were two types: Composition 2, which is a commercially available instant rice product made by combining rice and water in a fixed ratio; and Composition 1, which is an instant rice product made by mixing 1% refined salt with Composition 2. Four types of products were designed by combining Composition 2 and Composition 1 inside and outside the product. In the case of Composition 2, it may be an instant rice product to be eaten after microwave heating, and in the case of Composition 1, it may be a product with a composition similar to seasoned products such as fried rice or bibimbap.

[0104] The composition ratios of each composition manufactured as described above, and the combinations of compositions in each product, are summarized in Tables 7 and 8 below.

[0105] [Table 7]

[0106] [Table 8]

[0107] The dielectric constants of composition 1 and composition 2 measured at 2.45 GHz are shown in Table 9 below.

[0108] [Table 9]

[0109] The design of the final product, into which the aforementioned compositions are combined, is similar in form to commercially available instant rice, and the structure is designed to have a divided area in which a flat cylindrical composition with a diameter of 4 cm and a height of 1 cm is placed in the center of one of the compositions in the form of a container.

[0110] The manufactured products, from Configuration 1 to Configuration 4, were frozen at -15.5°C and then irradiated with 700W of power for several minutes by positioning them in the center of a turntable structure rotating at approximately 5 RPM in a commercially available 700W consumer microwave oven. After irradiation, the temperature of each product was checked at three locations: the very center, 2cm from the center outwards, and 4cm from the center. The point-by-point temperatures, averages, and deviations for each product from Configuration 1 to Configuration 4 are shown in Table 10 below.

[0111] [Table 10]

[0112] As can be seen from the results shown in Table 10, the product of Composition 4 had the highest average temperature, core temperature, and temperature at Point 1, and the temperature at Point 2 was found to be almost as high as that of Composition 1. Furthermore, the standard deviation of temperature was the lowest, and the coefficient of variation (CV, the value obtained by dividing the standard deviation by the mean, which confirms uniformity in distributions with different means; a smaller number indicates greater uniformity) was also found to be the lowest. In this way, we were able to confirm the effect of improving microwave heating uniformity and heating rate by combining compositions of the same or similar foods with slightly adjusted salt compositions.

[0113] Experimental Example 6: Manufacturing of a product with layers having different dielectric constants Depending on the physical properties of the food, processing methods, and manufacturing process, it may be easy or difficult to create physical layers with different dielectric constants.

[0114] 1. When a laminated structure can be easily formed after manufacturing product parts with different dielectric constants. For foods that can be packaged in a container without being shaped, such as rice or heat-treated grain-based foods, noodles, pasta, and highly viscous curry products, a layered structure can be formed by the following manufacturing method. (a) A semi-finished product is manufactured using two or more formulations with different dielectric constants. (b) Load the first layer onto the container or surface components (using nozzle-type / bucket-type auto-scaler equipment, etc.) (c) Layer 2, which has a different dielectric constant, is placed on top of layer 1. (d) Layer 3, which has a different dielectric constant, is placed on top of layer 2. (e) The above process is carried out for the required number of layers, and after packaging and surface treatment, additional processes (such as freezing / sterilization) are carried out.

[0115] Food products such as dumplings and burritos that have non-molded components containing a mixture of particles and liquids can be formed into a layered structure using the following manufacturing method. (a) Manufacture dumplings / brit fillings using two or more formulations with different dielectric constants. (b) Two or more formulations are injected using a double-fill nozzle or similar to form a layered structure. (c) Filling is applied to the outer shell of dumplings / brittle-type food, and additional processes are carried out after the surface treatment.

[0116] 2. When it is difficult to form a laminated structure after manufacturing product parts with different dielectric constants. Products that exist in standardized forms such as meat / seafood protein, bread / mochi / confectionery, or low-viscosity paste forms, or forms that can be mixed and combined during structure formation, such as when a liquid solidifies / freezes during processing, can be formed into a layered structure using the following manufacturing methods. (a) Manufacture two or more formulations with different dielectric constants. (b) If the viscosity of the compound, dough, etc. is sufficient, a two-layer filling / layered injection nozzle is used to inject compounding materials with different dielectric constants to form a layered structure. If the viscosity is not sufficient, the first layer of compounding is filled into a container, followed by freezing / solidification, and then the process of filling the second layer and freezing / solidifying is repeated to form a layered structure of the product. (c) After the laminated structure is completed, packaging and outer coating are performed, followed by additional processes (sterilization / heat treatment / freezing, etc.).

[0117] 3. When it is difficult to artificially form a physical layered structure. Food products that must maintain their original shape without chain breakage can be formed into a layered structure using the following manufacturing method. (a) In the case of a product in which a layered structure can be formed with thin layers in a mille-feuille style, layers with different dielectric constants can be manufactured by stacking two or more layers that have been immersed in a way that results in different dielectric constants. (b) In cases where it is not possible to form a layered structure, such as with thick meat, layers with different dielectric constants can be manufactured by preparing two or more immersion / injection solutions that can be adjusted to have different dielectric constants, injecting them into the deep layers of the product, and immersing the surface layer.

[0118] Experimental Example 7: Design of a multi-part structure for food that allows for uniform heating. 1. Design of a multi-part structure to solve the problem of uneven heating in conventional products (1) Confirmation of the problem of uneven heating Recognize the problem of uneven heating discovered during cooking tests, such as in response to consumer complaints and verification of mass production deviations.

[0119] (2) Experimental verification We will conduct experimental verification to determine whether the actual problem occurs in a reproducible manner. For example, we will verify whether the problem occurs through reference data that is used when setting the cooking algorithm, such as temperature analysis of the main heating spot, changes in yield after heating, and changes in surface moisture content.

[0120] (3) Measurement of characteristic values If it is determined that improvement is needed for a product's heating non-uniformity problem, measure the characteristic values ​​of the product in question (dielectric constant, specific heat, thermal conductivity, density / porosity, etc.). If characteristic values ​​measured during the initial product design exist, compare them with the currently measured characteristic values ​​to identify the changed characteristic values ​​that caused the change in the heating pattern. Check the history of any changes in the manufacturing process, raw materials, etc., that led to the change in the relevant characteristic value.

[0121] (4) Analytical verification The measured characteristic values ​​and electromagnetic, radiant, and convective heating characteristic data of the heating equipment are used to evaluate the heating non-uniformity characteristics caused by changes in characteristic values. The movement and changes in the main heating spot are analyzed in accordance with the changes in characteristic values.

[0122] (5) Setting of multi-partitioned sections and adjustment of characteristic values The characteristic value adjustment range is set to induce changes in the arrangement pattern of the main heating spots and the intensity changes. In the case of electromagnetic heating, if the intensity of a heating spot in the surface layer falls outside the acceptable range for the specific heat or thermal conductivity of that spot, the characteristic value adjustment is set in a direction that decreases the dielectric loss factor. If the intensity of a specific internal spot is lower than the average value, the characteristic value adjustment is set in a direction that increases the loss factor of that spot.

[0123] Furthermore, the number of divisions is determined by referring to the number and location of the main heating spots.

[0124] Determine whether the number and distribution of divisions in question can be accommodated in the product manufacturing process, and proceed with the integration or separation of division areas at an appropriate level. For example, ensure that the number of adjustments for characteristic values ​​does not exceed a maximum of three, that in the case of a lamination molding process, the number of division areas does not exceed three, mainly by upper / lower divisions, and in the case of multiple injection molding, set the division areas within a range that does not exceed the equipment molding limits.

[0125] The obtained segmented designs are used to predict heating patterns through previously performed analytical verification methods, and a set of verification experiments that are practically applicable is determined.

[0126] (6) Configuration and verification of the verification sample A sample is constructed according to the design described above, and morphological and distribution verification is carried out to ensure that the multi-sectional structure is realized in accordance with the design. The constructed verification sample is then subjected to heating analysis using a target cooking device.

[0127] 2. Design of a multi-part structure to solve heating inconsistencies during new product development (1) Confirmation of the food concept and form Since food products generally have a concept of the form they should have, we limit the list and scope of form-related variables that can be changed while adhering to the guidelines of that concept.

[0128] (2) Measurement of characteristic values If the raw materials and mixing ratios of the product in question are specified to be above a certain level, the physical properties of the relevant proto compound, such as dielectric constant, specific heat, thermal conductivity, density / porosity, etc., will be measured.

[0129] (3) Analytical verification The uniformity of heating is evaluated by combining characteristic values ​​obtained through the execution of the aforementioned analysis and the use of previously analyzed data with the heating characteristics (electric field, radiation, convection, etc.) of the target cooking equipment in question.

[0130] (4) Adjustment of adjustable morphological variables To reduce the deviation prediction obtained through the above analysis, an additional analysis is conducted to see if the deviation can be improved by adjusting the adjustable morphological variables obtained in item (1) above.

[0131] (5) Setting of multi-part structure and setting of adjustment values ​​for characteristic values If the above adjustments are not expected to sufficiently improve the problem of uneven heating, the design of a multi-part structure will proceed. The design method will be the same as the method described in item (5) "Setting of multi-part sections and adjustment of characteristic values" of "1. Design of a multi-part structure for solving uneven heating in conventional products" above.

[0132] (6) Sample configuration for verification and verification The multi-part structure designed above will be verified using the same method as item (6) of "1. Design of a multi-part structure to solve the problem of uneven heating in conventional products".

[0133] 3. Design of a multi-part structure when uniform heating is required in various home appliances. (1) Confirm the list of target cooking appliances Review the list of target cooking equipment that must support the preparation of the product in question. If existing data exists for the equipment on the list, refer to the data for that equipment. If no data exists for the equipment, add the equipment through the equipment addition process or remove it from the support list.

[0134] (2) Measurement of characteristic values Measure the characteristic values ​​of the product in question. If existing measurement data exists, check the product information database to see if there have been any product changes since the time of the measurement. If there have been no changes, use the existing data. If there have been product changes since the time of the existing measurement, display the relevant data as out-date and proceed with new measurements.

[0135] (3) Analytical verification of target cooking equipment Identify the main heating spots of the relevant equipment and identify common heating spots. Check the equipment-specific deviations in the amount of heat that can be transferred in the common heating area and predict the cooking time required for similar heat transfer. During the predicted cooking time, check the amount of heat that can be transferred to the unheated area via conduction and predict whether the specific heat and thermal conductivity of the relevant spot are at a level sufficient to ensure heating uniformity. Through the above process, extract a list of equipment for which similar heating patterns can be ensured and finalize the "List of Supportable Equipment".

[0136] (4) Confirmation of common heating spots and setting of deviation prediction values Based on the transferable heat quantity confirmed in the process described in item (3) above, the expected heating temperature of the relevant spot during product heating is predicted. Additional cooking time settings that can compensate for temperature deviations for each piece of equipment are set, predicted, and determined.

[0137] (5) Setting of multi-part structure and setting of adjustment values ​​for characteristic values Once the above analysis is complete, a decision is made as to whether a multi-part structure is necessary. If it is determined that a multi-part structure is necessary to ensure uniform heating, the process proceeds using the same method as described in item (5) "Setting up multi-part sections and adjusting characteristic values" of "1. Design of a multi-part structure to solve non-uniform heating in conventional products".

[0138] (6) Sample configuration for verification and verification The multi-part structure designed above is verified using the same method as item (6) of "1. Design of a multi-part structure to solve the problem of uneven heating in conventional products".

[0139] While the above has provided illustrative examples of typical embodiments of this application, the scope of this application is not limited to such specific embodiments, and any person with ordinary skill in the art can appropriately modify the claims of this application.

Claims

[Claim 1] A single category of food comprising two or more divided regions having different dielectric constants, wherein the food is uniformly heated by microwave irradiation.

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