Heating appliance and computer program product

Abstract

The present application provides a heating cooker and a program, which can inhibit the variation of internal pressure during pressurization to inhibit the dissolution of nutrient components and make the seasoning liquid in the inner pot sufficiently penetrate into the food material. The heating cooker is a heating cooker capable of cooking food material in an inner pot by heating the inner pot which is closed by a cover portion, and the heating cooker is provided with: a heating portion for heating the inner pot; a pressure detecting portion for detecting the internal pressure in the inner pot; and a control portion for controlling the operation of the heating portion according to the internal pressure detected by the pressure detecting portion, so as to maintain the internal pressure in the inner pot at a pressure value of a control target.

Description

TECHNICAL FIELD

[0001] The present application relates to a heating cooker and a program. BACKGROUND

[0002] A heating cooker such as an electric pressure cooker is provided (Patent Literature 1). In such a heating cooker, a series of processes are implemented in which heating is started after a lid of an inner pot of a pressure-resistant structure is covered to become airtight, and then, after the pressure in the inner pot reaches a prescribed pressure value higher than atmospheric pressure (0 kPa in gauge pressure), a pressurization period in which cooking is performed at a high pressure during a fixed period is set, and after the pressurization period ends, the gas in the inner pot is exhausted to lower the internal pressure to atmospheric pressure.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2020-124291 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, when the pressure in the inner pot during the pressurization period fluctuates greatly, the elution of nutrients cannot be sufficiently suppressed, and in addition, the seasoning liquid in the inner pot cannot sufficiently penetrate the food material.

[0008] Therefore, the present application provides a heating cooker capable of suppressing the fluctuation of the internal pressure during the pressurization period to suppress the elution of nutrients and causing the seasoning liquid in the inner pot to sufficiently penetrate the food material.

[0009] SOLUTION TO PROBLEM

[0010] To achieve the above object, a heating cooker according to one aspect of the present application is a heating cooker capable of cooking food materials in an inner pot by heating the inner pot which is closed by a lid, the heating cooker including: a heating section for heating the inner pot; a pressure detecting section for detecting an internal pressure in the inner pot; and a control section for controlling an operation of the heating section in accordance with the internal pressure detected by the pressure detecting section, wherein the control section is configured to execute: a first process of controlling the heating section to heat the inner pot which is closed, thereby causing the internal pressure in the inner pot to rise to a first pressure value; a second process of controlling the heating section to heat the inner pot after the internal pressure rises to the first pressure value, so as to maintain the internal pressure at the first pressure value; a third process of causing the internal pressure to decrease after the second process is implemented for a prescribed period of time; and a fourth process of controlling the heating section to heat the inner pot so as to maintain a prescribed temperature in the case where the temperature in the inner pot decreases to the prescribed temperature due to the decrease in the internal pressure, wherein in the second process, a process including the following is repeatedly executed: a determination of whether the internal pressure detected by the pressure detecting section decreases by a first prescribed value from the first pressure value; a control of the heating section to perform re-heating for the inner pot in the case where the internal pressure detected by the pressure detecting section decreases by the first prescribed value from the first pressure value; a determination of whether the internal pressure detected by the pressure detecting section after the re-heating rises by a second prescribed value from the first pressure value, the second prescribed value being a prescribed value corresponding to a rate of rise of the internal pressure in the first process; and a control of the heating section to stop the re-heating for the inner pot in the case where the internal pressure detected by the pressure detecting section rises by the second prescribed value from the first pressure value.

[0011] Effects of the Invention

[0012] According to the present application, for example, it is possible to provide a heating cooker capable of suppressing variation in internal pressure during pressurization to suppress elution of nutrients and allowing seasoning liquid in the inner pot to sufficiently penetrate food materials. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 FIG. 1 is a diagram showing an example of an external structure of a heating cooker corresponding to an embodiment.

[0014] Figure 2 FIG. 3 is a diagram showing an example of a hardware structure of a heating cooker corresponding to an embodiment.

[0015] Figure 3 FIG. 6 is a diagram for explaining an example of pressure control in a heating cooker corresponding to an embodiment.

[0016] Figure 4 is a flowchart showing an example of the process in the heating cooker corresponding to the embodiment.

[0017] Figure 5 is a time migration chart corresponding to an example of the process in the heating cooker corresponding to the embodiment.

[0018] Figure 6 is a flowchart showing an example of the heating process in the heating cooker corresponding to the embodiment.

[0019] Figure 7 is a flowchart showing an example of the pressurization process in the heating cooker corresponding to the embodiment.

[0020] Figure 8 is a diagram for explaining an example of the cooking result in the heating cooker. DETAILED DESCRIPTION

[0021] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments are not limited to the invention as recited in the claims, and all combinations of characteristics described in the embodiments are not necessarily essential to the invention. Two or more of the plurality of characteristics described in the embodiments can be arbitrarily combined. In addition, the same reference numerals are given to the same or similar structures, and repetitive description is omitted.

[0022] A heating cooker 100 according to one embodiment of the present invention will be described. Figure 1 is a front perspective view showing an example of the external structure of the heating cooker 100 of the present embodiment as a whole. Figure 1 The state after the cover portion 2 is detached from the main body portion 1 is shown. In addition, here, the X-axis direction is set as the left-right direction of the heating cooker 100, the Y-axis direction is set as the front-rear direction of the heating cooker 100, and the Z-axis direction is set as the up-down direction of the heating cooker 100. In the following description, in the case where it is written as "X-axis direction", it can be defined as including the +X direction and the -X direction. The same applies to the "Y-axis direction" and the "Z-axis direction".

[0023] The heating cooker 100 of the present embodiment is also called a pressure cooker or an electric pressure cooker. The heating cooker 100 is provided with a main body portion 1 that performs heating control of an inner pot 3 according to various heating programs, and a cover portion 2 that is attached to the upper portion of the main body portion 1 in a detachable (detachable) manner. In addition, it is configured to be able to put food as a cooking target object and to cook the food in the inner pot 3 by performing heating control of the inner pot 3 that is closed by the cover portion 2. The heating cooker 100 of the present embodiment is configured to be able to completely detach the cover portion 2 from the main body portion 1, that is, to be able to separate the main body portion 1 and the cover portion 2 from each other.

[0024] The main body 1 can include a housing portion 10 capable of housing the inner pot 3, a heating portion (heater) that heats the inner pot 3 housed in the housing portion 10, and a control portion. The housing portion 10 has a shape of a bottomed cylinder with an upper side open, and is configured to easily take out and put in the inner pot 3 from the upper side open portion in a state where the cover portion 2 is detached from the main body 1. The housing portion 10 is also referred to as an outer pot, and can be formed of metal or the like, for example. Figure 1 The heating portion can also have an induction heating coil for inductively heating the inner pot 3 housed in the housing portion 10, for example. In addition, the control portion has a processor such as a CPU and a memory, for example, and is capable of controlling the heating process of the inner pot 3 (cooking of food materials) by controlling the power supply to the heating portion (induction heating coil) in accordance with a prescribed heating program for cooking food materials in the inner pot 3.

[0025] The heating portion can also have an induction heating coil for inductively heating the inner pot 3 housed in the housing portion 10, for example. In addition, the control portion has a processor such as a CPU and a memory, for example, and is capable of controlling the heating process of the inner pot 3 (cooking of food materials) by controlling the power supply to the heating portion (induction heating coil) in accordance with a prescribed heating program for cooking food materials in the inner pot 3.

[0026] In addition, an operation portion 13 that receives operations by a user is provided on the outer surface of the main body 1. The operation portion 13 is a user interface that the user operates in order to set / adjust the content of the heating process of the inner pot 3 (i.e., the cooking content of food materials put in the inner pot 3), and can be constituted by a button, a dial, a display, or the like, for example.

[0027] The cover portion 2 is installed on the upper portion of the main body 1, and is opened and closed with respect to the housing portion 10 of the main body 1. It can also be understood that the cover portion 2 is installed, arranged, or provided on the upper portion of the main body 1. In the case of the present embodiment, the cover portion 2 has an inner cover, not shown, in addition to the handle portion 15 and the exhaust mechanism 20. The inner cover is configured to cover the upper side open portion of the housing portion 10 (inner pot 3) to make the housing portion 10 (inner pot 3) airtight when the cover portion 2 is installed on the upper portion of the main body 1, and the inner cover can be fixed to the housing portion 10.

[0028] The handle portion 15 is a portion that is held by the user in order to perform the opening and closing operation of the lid portion 2, and can be provided on the upper surface of the lid portion 2 in a manner extending in the left-right direction (X-axis direction). The exhaust mechanism 20 is a mechanism for exhausting gas (vapor) from the inside of the inner pot 3 to the outside (exterior) of the device, and can include an exhaust valve that is opened and closed by the control portion. For example, the exhaust mechanism 20 is configured such that, in the case where the cooking of the food material in the inner pot 3 (heating processing of the inner pot 3) is completed, the exhaust valve 24 is opened by the control of the control portion, and the gas in the inside of the inner pot 3 is automatically exhausted from the exhaust hole 20a provided on the upper surface of the lid portion 2. Thereby, the internal pressure (also simply referred to as "pressure") of the inner pot 3 can be reduced and approach the atmospheric pressure (pressure outside the device). Here, the exhaust mechanism 20 can also be configured such that, in the case where the exhaust button 16 provided on the upper surface of the lid portion 2 is pressed by the user, the exhaust valve is opened in a mechanical manner to exhaust the gas from the inside of the inner pot 3 to the outside of the device (forced exhaust). In addition, it can also be configured such that the exhaust valve 24 is operated by driving the driving portion such as a solenoid, whereby the automatic exhaust is performed. The driving portion operates in a manner to drive the exhaust valve 24 disposed in the lid portion 2 to open (open) the flow path, to exhaust the gas (vapor) from the inside of the inner pot 3 to the outside of the device.

[0029] The lid portion 2 also has a fixing mechanism 30 that can fix the inner lid of the lid portion 2 with respect to the housing portion 10 to maintain the inside of the housing portion 10 of the main body portion 1 as a sealed space. The fixing state of the fixing mechanism 30 is locked by the locking mechanism 40. The locking mechanism 40 can function as a restriction mechanism for restricting the rod of the fixing mechanism 30 from being moved by the user's operation.

[0030] Next, an example of the hardware structure of the heating cooker 100 will be described with reference to Figure 2 The heating cooker 100 is configured to include at least a control portion 201, a heating portion 202, a pressure detecting portion 203, a temperature detecting portion 204, a timer 205, a display portion 206, an exhaust valve driving portion 207, and an operation portion 208.

[0031] The control section 201 controls the operation of the entire heating cooker 100. The control section 201 can be configured by a processor such as a CPU and a memory, and can also be configured as a microcontroller or an MCU (Micro Controller Unit). When the power of the heating cooker 100 is turned on, the control section 201 receives a setting of a cooking method from a user via the operation section 208, and starts cooking in accordance with the received cooking method. The setting of the cooking method can be performed by selecting any one of preset menus, or by manually setting a pressure value, a temperature, a time, and the like. The preset menus include a reservation cooking process corresponding to the present embodiment, and when the reservation cooking process is selected, the operation of the heating section 202, the exhaust valve drive section 207, and the like is controlled in accordance with a process described later, and thus the cooking is performed.

[0032] Next, the heating section 202 is configured to include an induction heating coil, and a control signal is supplied to the heating section 202 in accordance with the control of the control section 201, so that the heating section 202 performs a heating process of the inner pot 3. The pressure detection section 203 detects an internal pressure in the inner pot 3 and notifies the control section 201 of the pressure value. The control section 201 controls the operation of the heating section 202 in accordance with the pressure value notified from the pressure detection section 203. The pressure detection section 203 includes, for example, a pressure sensor for detecting the internal pressure in the inner pot 3, and the pressure sensor is disposed at the bottom of the inner pot 3. Alternatively, the pressure can be calculated from the temperature by arithmetic operation. For example, a temperature sensor can be provided on the lid section 2 side, and the pressure value can be calculated from the temperature output from the temperature sensor. The temperature detection section 204 detects a temperature in the inner pot 3 and notifies the control section 201 of the temperature value. The temperature detection section 204 includes, for example, a temperature sensor configured by a thermistor for detecting the temperature of the inner pot 3, and the temperature sensor can be disposed in contact with the bottom and the side surface of the inner pot 3, or can be disposed on the lid section 2 side. The control section 201 controls the operation of the heating section 202 in accordance with the temperature value notified from the temperature detection section 204.

[0033] The timer 205 is, for example, a time measuring unit that measures the elapsed time of the process when performing a reservation cooking process. The control unit 201 can control the timer 205 to measure the elapsed time. The display unit 206 is configured by an LED, an LCD, or the like, and displays various information such as the cooking elapsed time, the temperature, the pressure, the menu number, the cooking type, and the like in accordance with the control of the control unit 201. The exhaust valve driving unit 207 is configured to include a transmission mechanism using a solenoid, a gear, or the like, and is driven by the control unit 201 to operate the exhaust valve 24, whereby the gas in the inner pot 3 can be exhausted to the outside of the apparatus, and thus the pressure in the inner pot 3 can be decreased. The operation unit 208 is a member for receiving an operation input from the user, and includes a portion integrated with the display unit 206 as a touch panel. The operation unit 208 can include various mechanical operation units such as a button, a switch, or the like in addition to the touch panel.

[0034] Next, a reservation cooking process corresponding to the present embodiment will be described. The reservation cooking process corresponding to the present embodiment can suppress the elution of the nutrient components by maintaining the internal pressure (hereinafter, simply referred to as "pressure") in the inner pot 3 during pressure cooking to be substantially constant, and can cause the seasoning liquid in the inner pot to sufficiently penetrate the food material.

[0035] Figure 3 is a view for explaining a method of pressure control in the past and a method of pressure control in the present embodiment. Figure 3 (A) of shows the past method. In the pressure control of the past method, heating is started from the start of cooking, and the heating is stopped at around 1100 seconds (about 18 minutes). The pressure at this point of time becomes P1 (for example, 70) kPa, and the state where the pressure exceeds the atmospheric pressure is continued for a fixed period. This process is referred to as a pressurization process. At the start of the pressurization process, the heating is stopped, and thus the pressure gradually decreases. Further, when the pressure decreases to about P2 (for example, 25) kPa, re-heating is performed to return the pressure to P3 (for example, 60) kPa. The period from the stop of the heating to the start of the re-heating is about 1100 seconds, and during this period, the pressure decreases from P1 kPa to P2 kPa. After the pressure is recovered and reaches about P3 kPa when the re-heating is performed, the pressurization process ends when the fixed period described above elapses, and thereafter, the pressure gradually decreases to the atmospheric pressure, and the reservation cooking ends.

[0036] As such, in the past method, the pressure in the pressurization process greatly varies. The variation of the pressure is also one of the causes of the elution of the nutrient components from the food material, and in addition, there is a problem that the seasoning liquid does not sufficiently penetrate the food material when the variation of the pressure is large.

[0037] In this regard, in the present embodiment, as Figure 3As shown in (B), it is determined at predetermined time intervals (e.g., 1-second intervals) whether the inner pot 3 should be reheated. For example, in determining the internal pressure at predetermined time intervals, when a change from a negative 1 kPa to a positive 1 kPa (or 2 kPa) in the pressure value of the control target is detected, the heating operation is controlled. Refer to the following paragraphs. Figure 7 This will explain the specific method for controlling the heating action. Therefore, during the pressurization process, the internal pressure of the inner pot 3 can be stably maintained near the target pressure.

[0038] Next, refer to Figure 4 and Figure 5 This will explain the scheduled cooking process corresponding to this embodiment. Figure 4 This is a flowchart of the process corresponding to this embodiment. Controlled by the control unit 201. Figure 2 The actions of each functional block shown are used to implement this process. Figure 5 Showing with Figure 4 The time migration of pressure within the inner pot 3 corresponding to the flowchart ( Figure 5 (A) and the time transition of temperature ( Figure 5 (B) shows the operation waveform of the heating unit 202. Figure 5 (C)).

[0039] First, in S401, for example, when the time set to start cooking arrives, the control unit 201 begins the heating process. Furthermore, it is set that at the start of the heating process, all ingredients to be processed are included in the inner pot 3. During the heating process, such as... Figure 5 As shown in (B), the heating unit 202 is activated to raise the temperature inside the inner pot 3 to a first temperature (Ta). In the heating process of S401, as... Figure 5 As shown in (C), the heater of heating unit 202 is ensured to have a long on-time (high duty cycle) so that the temperature rises from room temperature to a high temperature in a short time. At this time, the first temperature can be set to, for example, approximately 120 degrees (°C). However, 120°C, as an example of the first temperature, is not an exact value, but rather a value around 120°C. At this time, as... Figure 5 As shown in (A), the pressure inside the inner pot 3 rises to the first pressure value (P1). See below for further details. Figure 6 Let's describe the more specific processing in S401.

[0040] Here, the first pressure value can be set to, for example, 95 kPa. Alternatively, the first pressure value can be set to a value within the range of 60 kPa to 100 kPa. In this case, the first pressure value can be set according to the type of food and cooking method. For example, when dry-frying fish, the pressure can be increased to 95 kPa; on the other hand, when boiling radishes, the pressure can be increased to 80 kPa; when dry-frying sardines or pork knuckles, the pressure can be increased to 70 kPa; and when steaming vegetables or making curry, the pressure can simply be increased to 60 kPa.

[0041] Furthermore, in this embodiment, the pressure inside the inner pot 3 is represented by gauge pressure (with atmospheric pressure set to 0 kPa). However, these temperature and pressure values ​​are just one example, and other values ​​can also be used. In particular, the upper limit of the first pressure value can be higher than 100 kPa. Additionally, the lower limit can be set to a value between 60 kPa and 45 kPa.

[0042] In the next step S402, the control unit 201 initiates the pressurization process. During the pressurization process, the heating unit 202 is intermittently activated to maintain the first temperature and first pressure values ​​achieved during the heating process. Figure 5 (C)). The control unit 201 adjusts the control signal that activates the heating unit 202 based on at least one of the pressure value notified from the pressure detection unit 203 and the temperature notified from the temperature detection unit 204, thereby enabling the heating operation of the heating unit 202 to be executed. The main pressurization process is only performed for a predetermined (pre-set) time (hereinafter referred to as...). Figure 7 (As described in connection, T2 = t2 - t1). The duration of the pressurization process varies depending on the cooking content, the type of ingredients placed in the inner pot 3, etc. For example, it can be set to 30 minutes for dry-fried sardines, 15 minutes for pork knuckle stew or curry, 8 minutes for boiled radish, and 30 seconds for steamed vegetables.

[0043] When the elapsed time T2 has elapsed, the processing goes to S403, and the control section 201 implements the pressure reduction process. At this time, the heating section 202 is stopped to naturally reduce the temperature and pressure inside the inner pot 3. Alternatively, the control section 201 can drive the exhaust valve driving section 207 to open the exhaust valve 24, and exhaust the gas from the inside of the inner pot 3 to the outside of the apparatus via the exhaust mechanism 20. Thus, the internal pressure and temperature inside the inner pot 3 can be forcibly reduced. At this time, the internal pressure is reduced to the same degree as the atmospheric pressure (pressure outside the apparatus). Also, the temperature is reduced in correspondence with the reduction of the pressure, but the control section 201 monitors the value of the temperature from the temperature detecting section 204, and in the case where the temperature is determined to be reduced to a prescribed second temperature (Tb, for example, 65 degrees), the holding process is started in S404. In S404, the control section 201 implements the holding process. The control section 201 controls the operation of the heating section 202 based on the value of the temperature from the temperature detecting section 204 to maintain the temperature inside the inner pot at the second temperature.

[0044] Next, details of the processing in the heating process of S401 will be described with reference to Figure 6 Figure 6 is a flowchart showing an example of the processing in the heating process. First, in S601, the control section 201 drives the heating section 202 to start the heating of the inner pot 3. In the following S602, the control section 201 acquires the average pressure value Pav of the pressure inside the inner pot 3 detected by the pressure detecting section 203 for a prescribed time interval. Specifically, the control section 201 acquires the pressure value P from the pressure detecting section 203 in units of 0.1 seconds to calculate the average value Pav for N times. N can be set to 10 times, for example, whereby the average pressure value Pav can be calculated in units of 1 second. The value of N can be arbitrarily set according to the embodiment, and the average pressure value Pav can be calculated for a prescribed time interval corresponding to the value of N. Since the measured value of the pressure greatly fluctuates instantaneously, the average value is used as such to reduce the influence of such instantaneous fluctuations, and thus the change in the actual pressure is observed.

[0045] In the following S603, the control section 201 compares the average pressure value Pav with a first threshold pressure value Pthl (for example, 20 kPa) to determine whether or not Pav≥ Pthl, and in the case where Pav≥ Pthl, the processing goes to S604. On the other hand, in the case where Pav< Pthl, the processing returns to S602 to acquire the pressure value P again, and continues.

[0046] ​In the next S604, the control section 201 drives the timer 205 to start the counting. The counting time Tl is used to measure the time from when the average value Pav of the internal pressure of the inner pot 3 becomes the first threshold pressure value Pthl (20 kPa) to the second threshold pressure value Pth2 (40 kPa). In the present embodiment, the case where Pthl is set to 20 kPa and Pth2 is set to 40 kPa is explained, but this is only an example, and each pressure value can be set to other values. However, it is desirable that Pth2 is set to a value smaller than the minimum value of the pressure that can be set in the pressurization process. For example, in the case where the minimum value is 50 kPa, 40 kPa lower than the minimum value is set. In addition, when the range between Pthl and Pth2 is made too large, the pressure that is the control target can be reached during the determination, and thus it is desirable that the range is set to a size that takes the determination time into consideration. In the present embodiment, the range is set to 20 kPa, but this is only an example, and other values can be set.

[0047] The control section 201 acquires the pressure value P again from the pressure detecting section 203 in the next S605 and calculates the average pressure value Pav, and determines whether or not the average pressure value Pav ≥ Pth2 in S606. In the case where the average pressure value Pav ≥ Pth2, the process proceeds to S607, and in the case where the average pressure value Pav < Pth2, the process returns to S605, and the process is repeated.

[0048] In the next S607, the counting time Tl of the timer 205 is acquired, and the process proceeds to S608. In S608, the control section 201 determines whether or not Tl is a prescribed time threshold value Thl or more. In the case where Tl ≥ Thl, the process proceeds to S609, and in the case where Tl < Thl, the process proceeds to S610. The control section 201 sets the flag value F to 1 in S609 and sets the flag value F to 0 in S610. After that, the process proceeds to S611. The control section 201 acquires the pressure value P again from the pressure detecting section 203 in S611 and calculates the average pressure value Pav, and determines whether or not the pressure value Pav is a prescribed pressure value Pstop or more that ends the pressurization process in S612. If the average pressure value Pav is Pstop or more, the process proceeds to S613, the heating section 202 is stopped, and the process proceeds to the pressurization process of S402. On the other hand, in the case where the average pressure value Pav is less than Pstop, the process returns to S611, and the process is repeated.

[0049] In this way, in the heating process of S401, the control section 201 measures the time (Tl) required for the pressure value in the inner pot 3 to rise from Pthl to Pth2 based on the pressure value notified from the pressure detecting section 203. Further, by comparing this time Tl with a prescribed time threshold Thl, it is possible to determine the rate of rise of the pressure in the inner pot 3. Here, if Tl is less than the time threshold Thl (which can be set to 15 seconds, for example), the flag value (Fl) is set to 0, and if Tl is Thl or more, the flag value (Fl) is set to 1. A flag value of 0 indicates that the rate of rise of the pressure is fast, which corresponds to a case where the moisture content of the seasoning liquid or the like in the inner pot 3 is small. On the other hand, a flag value of 1 indicates that the rate of rise of the pressure is slow, which corresponds to a case where the moisture content of the seasoning liquid or the like in the inner pot 3 is large. The rate of rise of the pressure differs depending on the moisture content, and in addition, the ease with which the pressure in the inner pot 3 fluctuates differs, so in the subsequent pressurization process, the control is switched depending on the value of the flag value. Furthermore, the value of the time threshold Thl is not limited to 15 seconds, and can be set depending on the accuracy of the pressure gauge used, or the like.

[0050] Next, details of the pressure control processing in the pressurization process of S402 will be described with reference to Figure 7 Figure 7 is a flowchart showing an example of the pressure control processing. First, in S701, the control section 201 drives the timer 205 to start the timer. This timer time T2 indicates the implementation time of the pressurization process.

[0051] In the following S702, the control section 201 acquires the flag value (Fl) set in the heating process of S401. Figure 6 ​The flag value F set in S609 and S610 of the S609 and S610 of the above embodiment, and the value of the second parameter p2 of the first parameter p1 and the second parameter p2 used for pressure control is determined according to the value of the flag value F. Further, in the present embodiment, the first parameter p1 is described as a fixed value decided in advance. As a specific example of the second parameter p2, in the case where the flag value F is 0, the value of p2 can be set to 1 (kPa), and in the case where the flag value F is 1, the value of p2 can be set to 2 (kPa), for example. That is, the value of p2 is set to a value that differs according to the rising speed of the internal pressure of the inner pot 3, and the faster the rising speed, the smaller the value of p2. The value of p2 can also be changed according to the embodiment. For example, in the above, p2 is set to 1 in the case where the rising speed is fast, and p2 is set to 2 in the case where the rising speed is slow, but the actual rising speed can be calculated or the value of the measured elapsed time T1 can be standardized, and the like, to be used as p2. In addition, the flag value F corresponds to the water content in the inner pot 3, but can also be set to more than three values instead of the two values of 0 / 1, and different p2s can be assigned for each value. It is also possible to set the value of p2 to change according to the degree of residual heat after the operation of the heating section 202 is stopped. For example, in the case where the residual heat of the heating section 202 is large (in the case where the temperature does not immediately decrease even if the operation of the heating section 202 is stopped, or in the case where the temperature is difficult to decrease), the value of p2 can be set to 0 or a negative value, but is set to a value whose absolute value is not smaller than the value of p1.

[0052] In the following S703, the pressure value P is acquired from the pressure detecting section 203, the average pressure value Pav of the prescribed time interval is calculated as described above, and in S704, it is determined whether the average pressure value Pav has become a value obtained by subtracting p1 (kPa) as the first parameter from the pressure value Pt (kPa) of the control target. Here, the pressure value Pt can be set in advance according to the cooking content, the kind of food material at the cooking start time point. For example, it can be set to 95 kPa, 90 kPa, 70 kPa, or the like.

[0053] In the case where Pav≤Pt-p1 in S704, the processing proceeds to S705. On the other hand, in the case where it is not Pav≤Pt-p1, the processing returns to S703, and is repeated. As described above, the value of p1 can be set to a value decided in advance, and can be set to 1 kPa, for example. The second parameter p2 is a variable value, but the first parameter p1 can be set to a fixed value. Of course, it can also be set to change according to the kind of food material, the amount of seasoning liquid, or the like. For example, in the case where the above flag value F is 1, p1 can be set to 1 kPa, and in the case where the flag value F is 0, p1 can be set to 0.5 kPa, but is not limited thereto.

[0054] In S705, the control section 201 drives the heating section 202 to reheat the inner pot 3. Thereby, the pressure value rises, and thus the pressure value P detected by the pressure detecting section 203 is acquired and the average pressure value Pav is calculated in S706, and it is determined in S707 whether the average pressure value Pav becomes the pressure value obtained by adding the control target pressure value Pt and the parameter p2 set in S702 or more. If the average pressure value Pav ≥ Pt + p2 is established, the processing proceeds to S708. On the other hand, if the average pressure value Pav ≥ Pt + p2 is not established, the processing returns to S706, and the processing is repeated.

[0055] In S708, the control section 201 stops the operation of the heating section 202, and the processing proceeds to S709. In S709, the control section 201 determines whether the implementation time T2 of the pressurization process reaches a predetermined time Th2, and in the case where it is determined that the predetermined time Th2 is reached, the present pressurization process is ended, and the depressurization process of S703 is performed. Here, the time Th2 is a threshold time which is determined in advance and can be different depending on the cooking content and the kind of the material. Further, the determination of S709 can be performed at any time during the pressurization process of S402, and if it is detected that the measured time T2 measured by the timer 205 exceeds Th2, the pressurization process is ended.

[0056] As described above, in the present embodiment, the pressure value at which the re-heating is stopped after the re-heating is started is made different depending on the water content (the value of the flag value F) in the inner pot 3. This is because the degree of the variation of the pressure is different depending on the amount of the water content. Specifically, in the case where the water content is small (F: 0), the pressure rapidly rises after the re-heating, and thus the pressure value at which the heating section 202 is stopped is set low by making the value of p2 low, to suppress the rise of the pressure. On the other hand, in the case where the water content is large, even if the re-heating is performed, the rise of the pressure is more gradual compared to the case where the water content is small, and the value of p2 is set high in order to reliably raise the pressure.

[0057] Further, as an example, the value of p2 is set to 1 in the case where the water content is small, and the value of p2 is set to 2 in the case where the water content is large, but this is only an example. The value of p2 also depends on the accuracy of the followability of the pressure detecting section 203, the size of the inner pot 3, the degree of the residual heat of the heating section 202, and the like, and thus the value of p2 can be arbitrarily determined depending on the embodiment.

[0058] <Embodiment>

[0059] Next, the present application will be made more explicit by the following embodiments, but the following embodiments only indicate typical embodiments of the present application.

[0060] In the embodiment, 70 kPa is set as the control target value of the pressure in the pressurization process described above, and the results obtained by cooking using the conventional control method (A) described above (hereinafter referred to as "control method 1") and the control method (B) corresponding to the present embodiment described above (hereinafter referred to as "control method 2") are analyzed. The effects of the pressure control of the present application are evaluated in the cooking examples of "plum-cooked sardines" and "pork corner cooking" by two evaluation methods, evaluation process 1 and evaluation process 2. Figure 3 Figure 3 The results obtained by cooking using the conventional control method (A) described above (hereinafter referred to as "control method 1") and the control method (B) corresponding to the present embodiment described above (hereinafter referred to as "control method 2") are analyzed. The effects of the pressure control of the present application are evaluated in the cooking examples of "plum-cooked sardines" and "pork corner cooking" by two evaluation methods, evaluation process 1 and evaluation process 2.

[0061] <Plum-cooked sardines>

[0062] Ingredients: sardines, ginger, plums, seasoning liquid (water 200 mL, soy sauce 60 mL, sake 60 mL, Japanese sweet sake 30 mL, refined sugar 14 g)

[0063] Cooking time under 70 kPa: 30 minutes

[0064] <Pork corner cooking>

[0065] Ingredients: pork belly pieces, ginger, green onions, seasoning liquid (blanching water 400 mL, soy sauce 75 mL, sake 75 mL, refined sugar 36 g)

[0066] Cooking time under 70 kPa: 15 minutes

[0067] <Evaluation process 1: comparison of the amount of dissolved nutrients>

[0068] The amount of dissolved zinc, which is relatively easy to detect among the nutrients contained in each ingredient, was analyzed. Specifically, the concentration of zinc (Zn) in the solution was analyzed using a Shimadzu atomic absorption spectrophotometer (AA-7000), and the absolute amount of zinc in the seasoning liquid after cooking was calculated. The mass of the ingredients (sardines, pork) and the amount of the seasoning liquid after cooking were also measured. In addition, the amount of zinc in the seasoning liquid before cooking as a blank was also analyzed.

[0069] In atomic absorption analysis, when a solution containing an element to be measured is sprayed in a mist form toward a high-temperature flame (2000°C) using acetylene / air as fuel, absorption of light at a wavelength specific to the element occurs, so the concentration can be measured based on the degree of absorption. In the present evaluation verification, a zinc-specific cathode lamp (light source wavelength 214 nm) was used. This method is less susceptible to interference from other elements and allows high-sensitivity analysis at the ppb level.

[0070] ​To observe the significant difference in zinc leaching between control methods 1 and 2, three analytical samples were extracted from the cooking liquid after cooking. Additionally, the pre-cooking liquid (standard solution) was analyzed before each extraction, and a standard curve was then calculated based on the data. In the specific analysis, the amount of zinc leached during cooking per 1 kg of food (mg-Zn / kg food) was calculated using the following procedure.

[0071] 1. Dilute the cooked seasoning liquid 50 times.

[0072] 2. Calculate the absorbance of the 50-fold dilution.

[0073] 3. Use a standard curve to convert absorbance into concentration.

[0074] 4. Multiply by 50 to get the concentration before dilution.

[0075] 5. Using the pre-recorded volume of liquid after cooking, calculate the absolute amount of zinc m1 in the liquid after cooking.

[0076] 6. Calculate the absorbance of the seasoning liquid and the zinc concentration in the seasoning liquid.

[0077] 7. Using the pre-recorded volume of liquid before cooking, calculate the absolute amount of zinc m0 originally contained in the seasoning liquid.

[0078] 8. Based on M = m1 - m0, calculate the absolute amount of zinc dissolved from the food during cooking (minus the amount of zinc contained in the seasoning liquid before cooking).

[0079] 9. Calculate the amount of zinc leached per 1 kg of food by dividing the absolute amount M leached by the pre-recorded mass of the food.

[0080] As a result, the amount of zinc dissolved from the plum-cooked sardines and pork trotters cooked using control methods 1 and 2, respectively, is as follows: Figure 8 The results are shown in Figure (A). Here, the following results were obtained regarding both braised sardines with plums and braised pork horns: less zinc was dissolved in the case of cooking using control method 2 compared to the case cooked using control method 1. Furthermore, a significant difference was confirmed at the 99% level (p<0.01) for sardines and at the 95% level (p<0.05) for pork.

[0081] <Evaluation Process 2: Numericalization of Seasoning Liquid Penetration>

[0082] In Evaluation Process 2, using the fact that the more the seasoning liquid penetrates, the more the color of the food material becomes dense, the color density was measured by image analysis, and the penetration degree was numerically evaluated. The specific analysis was performed according to the following procedure.

[0083] 1. Color images were acquired by a digital video camera.

[0084] 2. Grayscale conversion was performed using an application program, ImageJ (manufactured by NIH Image, U.S.A.). The full color was converted into 8-bit grayscale.

[0085] 3. The image was sharpened to make the boundary clear.

[0086] 4. Binary conversion (Otsu Thresholding). The threshold value was determined for the 8-bit grayscale to convert into a black-and-white image.

[0087] 5. The proportion of black in the picture was recognized as the penetration degree (%).

[0088] As a result, the penetration degrees of the plum-cooked sardines and the pork chop boils cooked by Control Method 1 and Control Method 2 were as shown in the graph of (B) of FIG. 9. Here, as to both the plum-cooked sardines and the pork chop boils, the following results were obtained: the penetration degree in the case where cooking was performed by Control Method 2 was higher than that in the case where cooking was performed by Control Method 1. Further, as to the plum-cooked sardines, a significant difference was recognized at the level of 5%, and as to the pork chop boils, a significant difference was recognized at the level of 5%. Figure 8

[0089] Further, as to the pork chop boils, it was recognized that the fibers of the meat were looser in the case where cooking was performed by Control Method 2 than in the case where cooking was performed by Control Method 1. Further, the manner in which the fibers of the meat were loosened at this time was equivalent to that in the case where cooking was performed by Control Method 1 at 95 kPa.

[0090] As described above, in both of these evaluation results, Control Method 2 resulted in a more favorable result. Further, it is considered that the reason for the elution of the nutritional components is that the movement of the nutritional components from the inside of the food material to the outside is likely to occur when the pressure is changed during cooking. Further, it was also possible to grasp from the evaluation results of Evaluation Process 2 that the continuous application of a prescribed pressure is also important for the penetration degree of the seasoning liquid. Further, by performing control to continuously apply a fixed pressure at a low pressure (for example, 70 kPa) as well, it is possible to obtain an effect equivalent to that in the case where a high pressure (for example, 95 kPa) is applied.

[0091] As such, according to the pressure control method in the pressurization process corresponding to the present embodiment, it is possible to suppress the elution of the nutritional components from the food material as a cooking target and increase the penetration degree of the seasoning liquid. ​

[0092] The present application is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present application.

[0093] BRIEF DESCRIPTION OF DRAWINGS

[0094] 1: main body part; 2: lid part; 3: inner pot; 10: housing part; 24: exhaust valve.

Claims

1. A heating cooker capable of cooking food materials in an inner pot by heating the inner pot which is closed by a lid, the heating cooker comprising: a heating section which heats the inner pot; a pressure detecting section which detects an internal pressure in the inner pot; and a control section which controls an operation of the heating section in accordance with the internal pressure detected by the pressure detecting section, the control section being configured to execute the following procedures: a first procedure of controlling the heating section to heat the inner pot which is closed, thereby causing the internal pressure in the inner pot to rise to a first pressure value; a second procedure of controlling the heating section to heat the inner pot after the internal pressure rises to the first pressure value, so as to maintain the internal pressure at the first pressure value; a third procedure of causing the internal pressure to decrease after the second procedure is implemented for a prescribed period; and a fourth procedure of controlling the heating section to heat the inner pot, thereby maintaining a prescribed temperature, in a case where the temperature in the inner pot decreases to the prescribed temperature due to the decrease in the internal pressure, wherein in the second procedure, a procedure including the following procedures is repeatedly executed: a determination of whether the internal pressure detected by the pressure detecting section decreases from the first pressure value by a first prescribed value; a control of the heating section to perform re-heating for the inner pot, in a case where the internal pressure detected by the pressure detecting section decreases from the first pressure value by the first prescribed value; a determination of whether the internal pressure detected by the pressure detecting section after the re-heating rises from the first pressure value by a second prescribed value, the second prescribed value being a prescribed value corresponding to a rate of rise of the internal pressure in the first procedure, wherein the faster the rate of rise of the internal pressure, the smaller the value of the second prescribed value; and a control of the heating section to stop the re-heating for the inner pot, in a case where the internal pressure detected by the pressure detecting section rises from the first pressure value by the second prescribed value.

2. The heating cooker according to claim 1, wherein the second prescribed value has different values corresponding to the rate of rise of the internal pressure in the first procedure.

3. The heating cooker according to claim 1 or 2, wherein the shorter the elapsed time from a second pressure value to a third pressure value which is larger than the second pressure value in the internal pressure in the first procedure, the smaller the value of the second prescribed value.

4. The heating cooker according to claim 3, wherein the third pressure value is a value smaller than a minimum value which is settable as the first pressure value. wherein 5. The heating cooker according to claim 3, wherein the second pressure value is 20 kPa, and the third pressure value is 40 kPa.

6. The heating cooker according to claim 3, wherein the second prescribed value has a first value in a case where the elapsed time is equal to or more than a prescribed time threshold, and the second prescribed value has a second value which is smaller than the first value in a case where the elapsed time is smaller than the prescribed time threshold. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7. The heating cooker according to claim 6, wherein the first value is 2 kPa and the second value is 1 kPa.

8. The heating cooker according to claim 6 or 7, wherein the prescribed time threshold is 15 seconds.

9. The heating cooker according to claim 1 or 2, wherein the pressure detected by the pressure detecting portion is an average of the pressure values detected during a prescribed period.

10. A computer program product including a program for causing a computer to function as a control portion of the heating cooker according to any one of claims 1 to 9.

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