JP7422097B2 - Cooker and cooking method - Google Patents

Description

The present invention relates to a cooking device and a cooking method.

2. Description of the Related Art Cooking devices have been known in which food and cooking liquids (water, seasonings) are placed in a cooking tank and heated to a boiling state of approximately 100° C. for cooking (boiling, stewing, steaming, etc.). Furthermore, in order to shorten the cooking time, there are also known cooking devices such as pressure cookers that cook at a high temperature of about 120° C. by keeping the inside of the cooking tank in a high pressure state. Patent Document 1 listed below describes, as an example of a heating cooker, a device that heats and cooks food by supplying steam into a cooking tank in which food is stored.

Cooking at high temperatures causes problems such as thermal denaturation of the proteins contained in the food, making the food hard, destroying nutrients contained in the food, and loss of the original flavor and color of the food due to oxidation. Furthermore, when using a pressure cooker, there is a risk of accidents such as the pot lid flying off due to incorrect usage or malfunction of the equipment. On the other hand, a method is known in which food is cooked at a lower temperature so as not to deteriorate the quality of the food.

JP2011-085318A

While conventional low-temperature cooking can prevent food quality deterioration such as thermal denaturation of proteins, there is a problem in that the cooking time is longer than when cooking by boiling the cooking liquid using high-temperature heating. Furthermore, in steam cooking, there is a problem in that the temperature distribution within the cooking tank becomes uneven, resulting in uneven heating.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a cooking device and a cooking method that can shorten cooking time and reduce uneven heating in low-temperature cooking. .

A cooking device according to one aspect of the present invention includes a sealable cooking tank in which foodstuffs and cooking liquid are stored, and a heating coil that heats the cooking tank by electromagnetic induction. A pressure reducing means for reducing the pressure in the cooking tank, and a control section controlling the temperature increasing means and the pressure reducing means. The control unit controls the pressure reducing means so that the pressure inside the cooking tank is reduced to a saturated steam pressure of a predetermined cooking temperature, and supplies current to the heating coil to heat the cooking tank by electromagnetic induction. The heating means is controlled so that the temperature of the cooking tank is raised toward the cooking temperature, and the cooking tank is maintained at the cooking temperature in the reduced pressure state.

In the above cooker, the pressure inside the cooking tank is reduced from atmospheric pressure to the saturated vapor pressure of the cooking temperature, and the cooking tank is maintained at the cooking temperature, thereby making it possible to boil the cooking liquid even during low-temperature cooking. can. This promotes convection of the cooking liquid within the cooking tank and speeds up heat transfer to the food. In addition, when cooking under reduced pressure, the internal thermal conductivity of the food increases, so the center temperature of the food can quickly approach its surface temperature. As a result, cooking time can be further shortened. Furthermore, by generating saturated steam, the temperature distribution within the cooking tank can be made uniform, so that uneven heating of foodstuffs can be further reduced.

The term "cooking liquid" is a concept that includes not only seasoning liquids but also non-seasoning liquids such as water.

The cooking device may further include a tank temperature detection section that detects the temperature of the cooking tank. The control section may control the temperature raising means so that the temperature detected by the tank temperature detection section is maintained at the cooking temperature.

According to the results of intensive research by the present inventors, when the pressure inside the cooking tank is reduced to the saturated vapor pressure of the cooking temperature and maintained at the cooking temperature, even if the cooking temperature remains stable after a certain period of time has elapsed from the start of heating. For example, the temperature of the cooking tank, the temperature of the cooking liquid, and the temperature of the food become approximately the same. Therefore, by detecting the temperature of the cooking tank, which is relatively easy to detect, and maintaining it at the cooking temperature, if the temperature is stable, the temperature of the food can be determined from the temperature of the cooking tank without having to directly detect the temperature of the food. can be estimated.

The cooking device may further include a food temperature detection section that detects the temperature of the food material.

As described above, under saturated steam pressure, the cooking tank and the food stabilize at approximately the same cooking temperature after a certain period of time, but there is a difference in the time it takes to reach the cooking temperature. For this reason, when only the tank temperature detection section is used, it becomes difficult to accurately grasp the food temperature until the cooking temperature is stabilized. On the other hand, by providing a food temperature sensor separate from the tank temperature sensor, the food temperature can be accurately determined even before the food temperature stabilizes at the cooking temperature.

In the above cooking device, the control section may include a time measurement section that starts measuring the cooking time when the temperature detected by the food temperature detection section reaches the cooking temperature.

This makes it possible to more accurately manage the time for maintaining the food at the cooking temperature.

Here, "the detected temperature of the food temperature sensor reaches the cooking temperature" means not only when the detected temperature completely matches the cooking temperature, but also when it falls within a predetermined error range due to device performance. include.

In the above cooking device, the pressure reduction means may include a pressure reduction pump whose operation is controlled by the control unit and which reduces the pressure inside the cooking tank by sucking air in the cooking tank. The control unit stops the operation of the pressure reducing pump after the pressure inside the cooking tank is reduced to the saturated steam pressure, and controls the temperature increasing means so that the cooking tank reaches the cooking temperature after the stop. You can.

According to the above configuration, by stopping the operation of the pressure reducing pump before the cooking tank reaches the cooking temperature and boiling starts, moisture is prevented from being sucked into the pressure reducing pump when sucking air in the cooking tank. It can be prevented. Therefore, there is an advantage that there is no need to provide a trap mechanism to prevent moisture from being sucked into the vacuum pump.

The cooking device may further include an input section into which set values for the cooking temperature and cooking time of the food material can be input.

According to the above configuration, the food can be reliably cooked under the conditions of the set cooking temperature and cooking time.

The cooking appliance may be configured to be controllable by the control unit and further include an atmosphere introducing means for introducing air into the cooking tank. The control unit may control the pressure reduction means and the atmosphere introducing means so as to repeat pressure reduction and pressure restoration in the cooking tank.

Thereby, the cooking device can be used not only for heating under reduced pressure but also for impregnation, drying, etc. Specifically, during impregnation, by repeatedly reducing and restoring the pressure in the cooking tank, the food can be impregnated with the seasoning liquid (seasoning) in a short time. In addition, during drying, by reducing the pressure inside the cooking tank, the moisture in the food can be evaporated at a lower temperature.

A cooking method according to another aspect of the present invention is a cooking method in which food is cooked in a sealable cooking tank in which food and cooking liquid are stored. The cooking method includes the steps of setting a cooking temperature for the food material, and cooking the food material at the cooking temperature. In the cooking step, the pressure inside the cooking tank is reduced to the saturated vapor pressure of the cooking temperature, and the temperature of the cooking tank is raised toward the cooking temperature by electromagnetic induction heating, so that the inside of the cooking tank reaches the cooking temperature. The cooking tank is maintained at the cooking temperature in a state where the pressure is reduced to the saturated steam pressure.

In the above cooking method, the pressure inside the cooking tank is reduced from atmospheric pressure to the saturated vapor pressure of the cooking temperature, and the cooking temperature is maintained in the cooking tank, so that the cooking liquid remains boiling even during low-temperature cooking. can be heated and cooked. This promotes convection of the cooking liquid within the cooking tank and speeds up heat transfer to the food. In addition, when cooking under reduced pressure, the internal thermal conductivity of the food increases, so the center temperature of the food can quickly approach its surface temperature. As a result, cooking time can be further shortened. Moreover, since the temperature distribution within the cooking tank can be made uniform by the convection of the cooking liquid, uneven heating can be further reduced.

In the above cooking method, in the cooking step, the temperature of the cooking tank detected by a tank temperature detection section provided in the cooking tank may be maintained at the cooking temperature.

As mentioned above, when the pressure inside the cooking tank is reduced to the saturated vapor pressure of the cooking temperature and maintained at the cooking temperature, if the cooking tank is in a stable state after a certain period of time has passed from the start of heating, the temperature of the cooking tank is The temperature of the cooking liquid and the temperature of the food become approximately the same. Therefore, by using a tank temperature sensor to monitor the temperature of the cooking tank, which is relatively easy to detect, and maintaining it at the cooking temperature, cooking can be done without directly detecting the temperature of the food if it is in a stable state. The temperature of the food can be estimated from the temperature of the tank.

In the above cooking method, in the step of heating and cooking, measurement of the cooking time may be started from the time when the temperature of the food material reaches the cooking temperature.

As mentioned above, under saturated steam pressure, the cooking tank and the food stabilize at approximately the same cooking temperature after a certain period of time, but the cooking tank takes a shorter time to reach the cooking temperature. Therefore, when the cooking tank reaches the cooking temperature, the food has not yet reached the cooking temperature, and if you start measuring the cooking time at this point, the food will be reliably cooked for the predetermined cooking time. becomes difficult to do. On the other hand, by starting measuring the cooking time when the food temperature reaches the cooking temperature, the food can be reliably cooked for a predetermined cooking time.

In the above cooking method, in the step of heating and cooking, the pressure inside the cooking tank may be reduced by sucking the air inside the cooking tank using a pressure reducing pump. Further, in the cooking step, the operation of the pressure reducing pump may be stopped after the inside of the cooking tank is reduced to the saturated steam pressure, and the cooking tank may reach the cooking temperature after the stop.

According to the above method, by stopping the operation of the pressure reducing pump before the cooking tank reaches the cooking temperature and boiling starts, moisture is not sucked into the pressure reducing pump when sucking the air in the cooking tank. can be prevented. Therefore, there is an advantage that there is no need to prepare a trap mechanism for preventing moisture from being sucked into the vacuum pump.

The cooking method may further include a step of setting a cooking time for the food material before the step of heating and cooking.

According to the above method, the food can be reliably cooked under the set cooking time conditions.

According to the present invention, it is possible to provide a cooking device and a cooking method that can shorten the cooking time in low-temperature cooking and reduce uneven heating.

1 is a schematic diagram showing the configuration of a cooking device according to Embodiment 1 of the present invention. It is a flow chart which shows the procedure of the cooking method using the above-mentioned cooking appliance. It is a timing chart for explaining temperature control and pressure control in the above-mentioned cooking method. It is a schematic diagram showing the composition of the cooker concerning Embodiment 2 of the present invention. It is a schematic diagram showing the composition of the cooker concerning Embodiment 3 of the present invention. It is a functional block diagram showing the composition of the control part in the above-mentioned cooking appliance. It is a timing chart for demonstrating temperature control and pressure control in the cooking method using the said cooker. It is a graph showing temperature changes in general heating cooking. It is a graph showing temperature changes during cooking under normal pressure using a food core temperature sensor. It is a graph showing temperature changes during cooking under saturated steam pressure using a food core temperature sensor. It is a timing chart for explaining temperature control and pressure control during execution of impregnating concentration mode. It is a graph showing the measurement results of heat transfer time to foodstuffs.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

(Embodiment 1)
<Cooker configuration>
First, the configuration of a cooking device 1 according to Embodiment 1, which is one embodiment of the present invention, will be described with reference to FIG. FIG. 1 shows the overall configuration of a cooking device 1 according to this embodiment.

The cooking device 1 is a cooking device that immerses food 90 in a cooking liquid 91 (water, seasoning liquid) and performs heating cooking such as boiling or stewing. The cooking device 1 mainly includes a cooking tank 10, a temperature increasing means 20, a pressure reducing means 30, an atmosphere introducing means 40, a tank temperature detecting section 50, and a control section 60.

The cooking tank 10 includes a tank main body 11 in which an internal space for storing food 90 and a cooking liquid 91 is formed, and an opening 11A formed in the upper part, and a tank main body 11 that covers the opening 11A. It has a lid part 12 attached so as to be openable and closable.

The tank body 11 has a pot shape and includes a bottom portion 14 and a side wall portion 15 erected from the bottom portion 14 . The tank body 11 has an internal space deep enough to accommodate food 90 and cooking liquid 91. The tank body 11 is mainly made of a metal material such as aluminum or copper that has good thermal conductivity. Further, the tank body 11 is a multilayer pot in which the outer surface (bottom surface 16) of the bottom portion 14 is constituted by a heating element made of a magnetic metal such as ferritic stainless steel. The tank body 11 may be made entirely of aluminum or copper, or may be made entirely of ferritic stainless steel.

The lid portion 12 is made of a heat-resistant material such as glass or polycarbonate material. The lid 12 is opened when putting the food 90 and the cooking liquid 91 into the tank body 11, and during cooking, the lid 12 is closed so as to cover the entire opening 11A as shown in FIG.

The cooking tank 10 may further include a lid packing (not shown) that seals the gap between the tank body 11 and the lid part 12. This lid packing is made of an elastic member such as silicone resin. Thereby, the inflow of air from the outside to the inside of the cooking tank 10 is suppressed, and the cooking tank 10 has a structure that can be sealed. Note that the cooking tank 10 may have a structure that can be sealed not only by the lid packing but also by other means.

The temperature raising means 20 is for raising the temperature of the cooking tank 10. The temperature raising means 20 has a placing part 21 arranged below the cooking tank 10 and a heating coil 22 arranged inside the placing part 21.

The placing portion 21 includes a flat placing surface 21A on which the cooking tank 10 is placed, as shown in FIG. The cooking tank 10 is removable from the placing part 21. For example, the cooking tank 10 is removed from the mounting portion 21 when putting food 90 or cooking liquid 91 into the cooking tank 10 or when cleaning the inside of the tank.

The heating coil 22 heats the vicinity of the bottom 14 of the cooking tank 10 by electromagnetic induction by supplying current. More specifically, the heating coil 22 generates an eddy current in the heating element or the tank body 11 in the cooking tank 10 by a magnetic field generated by the supply of current, and the bottom of the cooking tank 10 is heated by the Joule heat generated by the eddy current. Increase the temperature around 14. Note that the temperature raising means 20 is not limited to one that raises the temperature of the cooking tank 10 by an induction heating method as in this embodiment, but may be one using other means (heater) such as a resistance heating method.

The pressure reducing means 30 is for reducing the pressure inside the cooking tank 10 by sucking the air inside the cooking tank 10 . The pressure reduction means 30 includes a pressure reduction pipe 31, a pressure detection section 32, a pressure reduction valve 33, and a pressure reduction pump 34.

The pressure reduction pipe 31 has a flow path through which air sucked from inside the cooking tank 10 flows. As shown in FIG. 1, the pressure reduction pipe 31 is connected at one end to the upper surface of the lid portion 12 and is arranged to communicate with the inside of the cooking tank 10.

The pressure detection unit 32 is a pressure sensor for detecting the pressure inside the cooking tank 10. The pressure detection unit 32 is attached in the middle of the pressure reduction pipe 31, as shown in FIG.

The pressure detection unit 32 may be provided at other positions (lid, pot body, valve, etc.) as long as it can detect the pressure inside the cooking tank 10.

The pressure reduction valve 33 is a control valve that switches between circulating and blocking air within the pressure reduction pipe 31. When the pressure detection unit 32 is attached to the pressure reduction pipe 31 as in this embodiment, the pressure reduction valve 33 is connected to the pressure reduction pipe 31 on the side opposite to the cooking tank 10 when viewed from the pressure detection unit 32, as shown in FIG. It is located in

The pressure reduction pump 34 is a vacuum pump, and reduces the pressure inside the cooking tank 10 by sucking the air inside the cooking tank 10 through the pressure reduction pipe 31. In the case where the pressure detection section 32 is attached to the pressure reduction piping 31 as in this embodiment, the pressure reduction pump 34 connects the pressure reduction piping 31 to the pressure reduction piping 31 on the side opposite to the pressure detection section 32 when viewed from the pressure reduction valve 33, as shown in FIG. It is located in

According to the pressure reducing means 30, by operating the pressure reducing pump 34 with the pressure reducing valve 33 open, the air inside the cooking tank 10 can be sucked through the pressure reducing pipe 31 and the pressure inside the cooking tank 10 can be reduced. can.

The air introducing means 40 is for allowing air to flow into the cooking tank 10 to restore the reduced pressure inside the cooking tank 10 to atmospheric pressure. The air introduction means 40 has an air introduction pipe 41 and an air introduction valve 42.

The air introduction pipe 41 has a flow path through which air is supplied into the cooking tank 10. As shown in FIG. 1, the atmospheric air introduction pipe 41 is arranged alongside the pressure reduction pipe 31 so that one end thereof is connected to the upper surface of the lid portion 12 and communicates with the inside of the cooking tank 10. At least a portion of the atmospheric air introduction pipe 41 may be integrally used with the decompression pipe 31.

The air introduction valve 42 is a control valve that switches between circulating and blocking air in the air introduction pipe 41. The atmosphere introduction valve 42 is arranged in the middle of the atmosphere introduction pipe 41, as shown in FIG.

According to the air introduction means 40, by allowing air to flow into the cooking tank 10 through the air introduction pipe 41 with the air introduction valve 42 open, the depressurized inside of the cooking tank 10 is restored to atmospheric pressure. can be done.

The tank temperature detection section 50 includes a temperature sensor that detects the outer surface temperature of the cooking tank 10. As shown in FIG. 1, the tank temperature detection section 50 is attached near the bottom 14 on the outer surface 13 (outer surface), and detects the temperature of this portion. As the tank temperature detection section 50, a temperature sensor such as a thermocouple or a thermistor can be exemplified, but is not limited thereto.

Although the tank temperature detection unit 50 is not limited to being attached to the outer surface 13 near the bottom 14 as in this embodiment, it is preferably attached to a portion where the temperature is mainly raised by the temperature raising means 20. For example, the tank temperature detection section 50 may be attached to the bottom surface 16 (outer surface) to detect the temperature of this portion. Further, the tank temperature detection section 50 can be attached to any position in the tank body 11 as long as the temperature is approximately the same as that of the bottom surface 16 during heating by the temperature raising means 20. Further, the tank temperature detection section 50 is not limited to one that detects the outer surface temperature of the cooking tank 10, and may be arranged inside the cooking tank 10 to detect the inner surface temperature of the cooking tank 10. It may be embedded in the cooking tank 10 to detect the internal temperature of the cooking tank 10, or it may be one that measures the temperature of the cooking liquid 91 in the cooking tank 10 and treats it as the tank temperature. Further, the tank temperature detection section 50 is not limited to a single temperature sensor, and may include a plurality of temperature sensors.

The control unit 60 is a controller that controls the operation of each of the temperature increasing means 20, the pressure reducing means 30, and the atmosphere introducing means 40.

The control unit 60 controls the temperature raising means 20 to supply current to the heating coil 22 to heat the bottom part 14 of the cooking tank 10 by electromagnetic induction. The control unit 60 is connected to the tank temperature detection unit 50, and the detection result (measurement result of the external surface temperature of the cooking tank 10) by the tank temperature detection unit 50 is input.

The control unit 60 is connected to each of the pressure reducing valve 33 and the pressure reducing pump 34. The control unit 60 controls the opening/closing operation of the pressure reducing valve 33 and also controls the operating state (on/off) of the pressure reducing pump 34. The control unit 60 is connected to the pressure detection unit 32, and the detection result (pressure inside the cooking tank 10) by the pressure detection unit 32 is input.

The control unit 60 is connected to the atmosphere introduction valve 42 and controls the opening/closing operation of the atmosphere introduction valve 42.

The cooking device 1 further includes an input section 70. The input unit 70 is a part that allows the user to input set values for cooking temperature and cooking time according to the type of food material 90, cooking method, and the like. The input unit 70 transmits the input setting values to the control unit 60.

The control section 60 has a storage section (not shown) for storing the above setting values. Further, the control section 60 further includes a calculation section (not shown) for calculating the value of the saturated steam pressure at the set cooking temperature, and stores the calculated value in the storage section.

The cooking device 1 further includes a display section 80. The display unit 80 is a display and displays the cooking status, such as the external temperature of the cooking tank 10 and the pressure inside the cooking tank 10, which are input to the control unit 60.

<Cooking steps>
Next, the procedure of the cooking method (reduced pressure heating mode) according to one embodiment of the present invention will be explained with reference to FIGS. 1 to 3. This cooking method is carried out using the above-mentioned cooking device 1 (see FIG. 1), and is a method of heating cooking such as boiling or stewing in a sealable cooking tank 10 in which foodstuff 90 and cooking liquid 91 are stored. FIG. 2 is a flowchart showing the procedure of the above cooking method. FIG. 3 is a timing chart showing the method of temperature control and pressure control of the cooking tank 10 in the above cooking method. In FIG. 3, (1) shows the change in the outer surface temperature of the cooking tank 10 detected by the tank temperature detection section 50, (2) shows the on/off switching of the temperature raising means 20, and (3) shows the pressure The pressure inside the cooking tank 10 detected by the detection unit 32 is shown, (4) shows the on/off switching of the pressure reduction pump 34, (5) shows the open/closed state of the pressure reduction valve 33, and (6) shows the open/closed state of the pressure reduction valve 33. The open/closed state of the air introduction valve 42 is shown. Further, in FIG. 3, the horizontal direction indicates the passage of time.

First, a step of setting the cooking temperature of the food material 90 is performed (FIG. 2: S1). In this step S1, the cooking temperature T1 is set according to the type of food material 90, the cooking method, etc. The cooking temperature T1 is set to a low temperature below 100° C. (for example, 60° C.) from the viewpoint of preventing thermal denaturation of proteins contained in the foodstuff 90 during cooking. The cooking temperature T1 is set based on a set value input into the input unit 70 by the user.

Next, a step of setting the cooking time of the food material 90 is performed (FIG. 2: S2). In this step S2, the cooking time t0 is similarly set according to the type of food material 90, the cooking method, etc. The cooking time t0 is similarly set based on a setting value input into the input unit 70 by the user.

Next, a step of cooking the food material 90 at the set cooking temperature T1 and cooking time t0 is performed (FIG. 2: S3). In this step S3, the food 90 is heated and cooked while the pressure inside the cooking tank 10 and the temperature of the cooking tank 10 are adjusted as described below.

First, the pressure adjustment inside the cooking tank 10 will be explained. The pressure reducing pump 34 is turned on by the control unit 60, and the pressure reducing valve 33 is opened (FIG. 2: S31, FIG. 3: t1). At this time, the air introduction valve 42 is closed. As a result, the air inside the cooking tank 10 is sucked by the pressure reduction pump 34 via the pressure reduction pipe 31, and the pressure inside the cooking tank 10 is reduced.

When the pressure inside the cooking tank 10 is reduced from the atmospheric pressure P0 to the saturated steam pressure P1 at the cooking temperature T1 (FIG. 2: S33, FIG. 3: t2), the operation of the pressure reduction pump 34 is stopped by the control unit 60, and the pressure is reduced. The valve 33 is closed (FIG. 2: S34). On the other hand, the air introduction valve 42 remains closed. Thereby, the inside of the cooking tank 10 is maintained in a state where the pressure is reduced to the saturated steam pressure P1 at the cooking temperature T1.

Next, temperature adjustment of the cooking tank 10 will be explained. First, the temperature increasing means 20 is turned on by the control unit 60 (FIG. 2: S32, FIG. 3: t1). As a result, the bottom 14 side of the cooking tank 10 is heated by electromagnetic induction by the heating coil 22, and the outer surface temperature of the cooking tank 10 increases from the initial temperature T0 toward the cooking temperature T1. Here, as shown in FIG. 3, the pressure inside the cooking tank 10 reaches the saturated vapor pressure P1 before the outer surface temperature of the cooking tank 10 reaches the cooking temperature T1, and the operation of the pressure reducing pump 34 is stopped.

Thereafter, the inside of the cooking tank 10 is further heated while being reduced to the saturated steam pressure P1, and the outer surface temperature of the cooking tank 10 reaches the cooking temperature T1 (FIG. 2: S35, FIG. 3: t3). Here, when the pressure inside the cooking tank 10 is reduced to the saturated steam pressure P1, heat transfer within the tank becomes faster, so the external surface temperature of the cooking tank 10, the temperature of the cooking liquid 91, and the temperature of the food material 90 are It will be almost the same. Therefore, at the time when the outer surface temperature of the cooking tank 10 reaches the cooking temperature T1, the cooking liquid 91 also reaches a temperature that is substantially the same as the cooking temperature T1. Further, since the pressure inside the cooking tank 10 is reduced to the saturated steam pressure P1, the cooking liquid 91 boils in a low temperature state, and the food 90 is heated and cooked in a low temperature boiling state.

During cooking, the inside of the cooking tank 10 is maintained at a reduced pressure to the saturated steam pressure P1, and the outer surface temperature of the cooking tank 10 is maintained at the cooking temperature T1. Specifically, as shown in FIG. 3, the temperature raising means 20 is repeatedly turned on and off by the control unit 60, thereby maintaining the outer surface temperature of the cooking tank 10 at the cooking temperature T1. In this way, the food material 90 is heated and cooked for the cooking time t0 under the conditions of the saturated steam pressure P1 and the cooking temperature T1 (FIG. 2: S36).

Next, a step of opening the inside of the cooking tank 10 to the atmosphere is performed (FIG. 2: S4). In this step S4, after the cooking time t0 has elapsed, the temperature raising means 20 is turned off by the control section 60, and the air introduction valve 42 is opened. As a result, air flows into the cooking tank 10 through the atmosphere introduction pipe 41, and the pressure inside the cooking tank 10 is restored to atmospheric pressure P0. By sequentially executing steps S1 to S4 as described above, the cooking method according to the present embodiment is completed.

<Effect>
Next, the effects of the cooking device 1 and cooking method will be explained.

The cooking device 1 includes a cooking tank 10 in which foods 90 and cooking liquid 91 are stored, a temperature raising means 20 for raising the temperature of the cooking tank 10, a pressure reducing means 30 for reducing the pressure inside the cooking tank 10, and a control section 60. , is equipped with. The control unit 60 controls the pressure reducing means 30 so that the pressure inside the cooking tank 10 is reduced to the saturated steam pressure P1 at the cooking temperature T1, and increases the pressure so that the cooking tank 10 is maintained at the cooking temperature T1 in the reduced pressure state. The heating means 20 is controlled.

The cooking method described above includes a step S1 of setting a cooking temperature T1 of the food material 90, and a step S3 of heating and cooking the food material 90 at the cooking temperature T1. In Step S3 of heating and cooking, the cooking tank 10 is maintained at the cooking temperature T1 in a state where the pressure inside the cooking tank 10 is reduced to the saturated steam pressure P1 at the cooking temperature T1.

According to the above-mentioned cooking device 1 and cooking method, the cooking tank 10 is maintained at the cooking temperature T1 in a state where the pressure inside the cooking tank 10 is reduced to the saturated steam pressure P1 at the cooking temperature T1. In contrast, the cooking liquid 91 can be boiled even during cooking at a low temperature of 95° C. or lower. This promotes convection of the cooking liquid 91 within the cooking tank 10 and speeds up heat transfer to the food material 90. Furthermore, since the thermal conductivity within the food 90 increases during cooking under reduced pressure, the center temperature of the food 90 can quickly approach its surface temperature. As a result, cooking time can be further shortened. Furthermore, by cooking at a low temperature, it is possible to prevent thermal denaturation of proteins and destruction of nutrients contained in the food material 90.

The cooking device 1 includes a tank temperature detection section 50 that detects the outer surface temperature of the cooking tank 10. The control unit 60 controls the temperature raising means 20 so that the temperature detected by the tank temperature detection unit 50 (outer surface temperature of the cooking tank 10) is maintained at the cooking temperature T1.

When the inside of the cooking tank 10 is maintained at the cooking temperature T1 in a state where the pressure inside the cooking tank 10 is reduced to the saturated steam pressure P1 of the cooking temperature T1, the temperature of the cooking tank 10 and The temperature of the cooking liquid 91 and the temperature of the food material 90 become approximately the same. Therefore, by detecting the outer surface temperature of the cooking tank 10, which is relatively easy to detect, and maintaining it at the cooking temperature T1, the temperature of the cooking tank can be maintained even if the temperature of the food 90 is not directly detected in a stable state. The temperature of the food can be estimated from

In addition, by maintaining the temperature so as not to exceed the cooking temperature T1, even when the food 90 comes into direct contact with the surface of the cooking tank 10, such as during boiling or simmering, the food 90 does not exceed the cooking temperature T1. It can prevent heating.

In the cooking device 1 described above, the pressure reducing means 30 includes a pressure reducing pump 34 that reduces the pressure inside the cooking tank 10 by sucking air inside the cooking tank 10 . As shown in FIG. 3, the control unit 60 stops the operation of the pressure reducing pump 34 after the pressure inside the cooking tank 10 is reduced to the saturated steam pressure P1, and controls the cooking tank 10 to reach the cooking temperature T1 after the stop. The temperature increasing means 20 is controlled.

As a result, by stopping the operation of the pressure reducing pump 34 before the cooking tank 10 reaches the cooking temperature T1 and boiling starts, moisture is not sucked into the pressure reducing pump 34 when sucking air in the cooking tank 10. It can be prevented. Therefore, there is an advantage that there is no need to provide a trap mechanism for preventing moisture from being sucked into the decompression pump 34. Note that the trap mechanism may not be omitted and may be provided immediately before the decompression pump 34.

<Modified example>
In the above embodiment, a case has been described in which the decompression pump 34 is stopped before the cooking tank 10 reaches the cooking temperature T1, but the present invention is not limited to this. The pressure reduction pump 34 may be stopped after the cooking tank 10 reaches the cooking temperature T1 (the cooking temperature T1 is reached before the pressure reduction pump 34 is stopped), or the pressure reduction pump 34 may be stopped at the same time as the cooking temperature T1 is reached. Good too. That is, the timing before and after the timing when the cooking tank 10 reaches the target temperature and the timing when the inside of the cooking tank 10 reaches the target pressure is not particularly limited, and either timing may be first or may be simultaneous.

In the embodiment described above, in order to keep the pressure inside the cooking tank 10 constant, the pressure may be adjusted by reducing the pressure or introducing atmospheric air. Further, the pressure in the cooking tank 10 is not limited to being held constant after reaching the saturated steam pressure P1, and the pressure in the cooking tank 10 may be adjusted even after moving to the heating cooking step.

In the above-mentioned embodiment, one cooking temperature T1 is set and heating cooking in which this is maintained has been described, but the present invention is not limited to this. A plurality of cooking temperatures may be set, and heating cooking may be performed in which each cooking temperature is maintained in stages. In this case, the pressure within the cooking tank 10 is adjusted to the saturated steam pressure at each cooking temperature.

(Embodiment 2)
Next, Embodiment 2, which is another embodiment of the present invention, will be described. The cooking device 2 according to the second embodiment basically has the same configuration as the cooking device 1 according to the first embodiment. However, the cooking device 2 according to the second embodiment differs from the cooking device 1 according to the first embodiment in the configuration of the cooking tank 10.

As shown in FIG. 4, the cooking device 2 according to the second embodiment, like the cooking device 1 according to the first embodiment, includes a sealable cooking tank 10 in which food 90 and cooking liquid 91 are stored. . Here, the cooking device 2 includes a porous plate 92 disposed within the cooking tank 10 at a predetermined height from the bottom portion 14 . A support portion 11B that supports the end of the porous plate 92 is provided on the inner wall surface of the cooking tank 10.

Foodstuffs 90 are placed side by side on a porous plate 92. The cooking liquid 91 is contained so that the liquid level is located below the porous plate 92, as shown in FIG.

In the cooking device 2, the cooking liquid 91 (water) is evaporated by raising the temperature of the cooking tank 10 by the heating means 20, and the food 90 can be steamed using the steam (dashed line arrow in the figure). Here, as in Embodiment 1, the food 90 can be heated with saturated steam by maintaining the cooking temperature T1 in a state where the pressure inside the cooking tank 10 is reduced to the saturated steam pressure P1. Therefore, the temperature distribution within the cooking tank 10 becomes uniform, and uneven heating of the food material 90 can be further reduced.

<Modified example>
In the above embodiment, it is sufficient that the food material 90 can be heated and cooked by applying steam, and is not limited to the case where the porous plate 92 and the support portion 11B are provided. For example, a food support part (pedestal) including a support plate (not limited to a porous plate) located at a predetermined height from the bottom 14 of the cooking tank 10 and legs extending downward from the support plate is a food support part (pedestal) in the cooking tank. 10, and a food product 90 may be placed on the support plate. The cooking liquid 91 may be accommodated in the cooking tank 10 such that the liquid level is located below the support plate. In this case, the food 90 can be placed at a predetermined height from the bottom 14 and steamed and cooked without providing the support part 11B on the inner wall surface of the cooking tank 10 as in the above embodiment.

In the above embodiment (or modified example), the cooking device 2 having the configuration shown in FIG. 4 is not limited to steam cooking, and heating cooking such as boiling or stewing may be performed as in the first embodiment. . In this case, the cooking liquid 91 is stored in the cooking tank 10 so that the liquid level is located above the porous plate 92 (or the support plate) (so that the food material 90 is immersed in the cooking liquid 91). . In this way, heating cooking such as boiling or stewing is not limited to the case where the food 90 is placed on the bottom part 14 of the cooking tank 10 as in the first embodiment (FIG. 1), but also when the food material 90 is placed on the bottom part 14 of the cooking tank 10 as shown in FIG. The food material 90 may be placed on a porous plate 92 (or a support plate) located at a predetermined height from the porous plate 14.

(Embodiment 3)
Next, Embodiment 3, which is still another embodiment of the present invention, will be described. The cooking device 3 according to the third embodiment basically has the same configuration as the cooking device 1 according to the first embodiment. However, the cooker 3 according to the third embodiment is different in that it further includes a food temperature detection section 51 that detects the temperature of the food material 90.

<Cooker configuration>
As shown in FIG. 5, the cooking device 3 includes a main body housing 81 consisting of a rectangular parallelepiped or cylindrical case, a main body portion 82 placed on the bottom surface of the main body housing 81, and a main body portion 82 arranged within the main body portion 82. The cooking tank 10 mainly includes a cooking tank 10, a temperature raising means 20, a pressure reducing means 30, an atmosphere introducing means 40, a tank temperature detection section 53, a food temperature detection section 51, and a control section 88.

The main body housing 81 constitutes an exterior part of the cooking device 3, and accommodates each component of the cooking device 3, such as the main body portion 82 and the cooking tank 10, inside. The main body housing 81 may be made of a metal that does not rust, such as stainless steel or aluminum, or may be made of a resin that has heat resistance of 100° C. or higher, such as polypropylene.

The main body portion 82 is provided with a recess having a shape that matches the outer shape of the cooking tank 10, and the cooking tank 10 can be installed in the recess. The main body part 82 has a heat insulating part 82A that surrounds the cooking tank 10 so as to insulate it from the outside, and a mounting part 82B that is placed on the bottom surface of the main body housing 81. The heat insulating portion 82A may be made of a resin having heat resistance of 100° C. or higher, such as polypropylene, and the mounting portion 82B may be made of a rust-free metal such as stainless steel or aluminum.

The cooking tank 10 has a tank main body 11 and a lid part 12 that have a pot shape that can accommodate food 90 and cooking liquid 91, and is arranged in a recess provided in the main body part 82. The cooking tank 10 can be removed from the main body 82 when placing food 90 or cleaning. The tank body 11 is mainly made of aluminum, copper, or the like having excellent thermal conductivity, and has a heating element 11C bonded to its outer surface. The heating element 11C is made of a magnetic metal plate such as ferritic stainless steel, and has a shape that follows the shape of the tank body 11. The heating element 11C constitutes a part of a temperature raising means 20 that raises the temperature of the cooking tank 10 as described later.

The lid portion 12 is made of a transparent resin material such as glass that has heat resistance of 120° C. or higher, and is arranged at the upper end of the tank body 11 with the lid packing 83 interposed therebetween. The lid packing 83 is made of an elastic member such as silicone, and is in airtight contact with the upper end surface of the tank body 11 and the lower surface of the lid portion 12. As a result, the cooking tank 10 has a hermetically sealed structure, and air circulation inside and outside the tank is blocked. Note that the cooking tank 10 is provided with a pressure detection section (not shown) that detects the pressure inside the interior 11A.

The temperature raising means 20 raises the temperature of the cooking tank 10, and includes a heating element 11C and a plurality of heating coils 84. The heating coil 84 is arranged inside the heat insulating section 82A, and is in contact with the heating element 11C joined to the bottom outer surface of the tank body 11. By passing a high frequency current through this heating coil 84, the heating element 11C generates heat due to electromagnetic induction, and as a result, the temperature of the cooking tank 10 can be raised. Further, the heating coil 84 may be arranged so as to be in contact with the heating element 11C joined to the outer side surface of the tank body 11. Further, the temperature raising means 20 is not limited to one that raises the temperature of the cooking tank 10 by an induction heating method, and may be other heating means such as a resistance heating type heater.

The pressure reducing means 30 reduces the pressure inside the cooking tank 10, and includes a pressure reducing pump 85, a pressure reducing valve 87A, and a pressure reducing pipe 87B. The decompression pump 85 is arranged at a bottom corner of the main body housing 81 . The pressure reducing valve 87A is placed on a support plate 85A located above the pressure reducing pump 85. One end of the pressure reduction pipe 87B is fixed to the upper surface of the lid 12 by a fixing member 87C so as to communicate with the pressure reduction port 87 that penetrates the lid 12 in the thickness direction. Although not shown, a pressure reduction pump 85 is connected to the other end of the pressure reduction pipe 87B, and a pressure reduction valve 87A is provided in the middle of the pressure reduction pipe 87B. Thereby, by operating the pressure reduction pump 85 with the pressure reduction valve 87A open, the air inside the cooking tank 10 is sucked through the pressure reduction pipe 87B, and the pressure inside the cooking tank 10 is reduced to below atmospheric pressure. Can be done.

The air introduction means 40 introduces air into the cooking tank 10, and includes an air introduction valve 86A and an air introduction pipe 86B. The air introduction valve 86A is arranged on the support plate 85A in line with the pressure reduction valve 87A. One end of the air introduction pipe 86B is fixed to the upper surface of the lid 12 by a fixing member 86C so as to communicate with the air introduction port 86 that penetrates the lid 12 in the thickness direction. Further, an air introduction valve 86A is provided in the middle of the air introduction pipe 86B. By opening the air introduction valve 86A when the pressure inside the cooking tank 10 is in a reduced pressure state, air is allowed to flow into the cooking tank 10 through the air introduction pipe 86B, and the pressure inside the cooking tank 10 is restored to atmospheric pressure. Can be done.

The tank temperature detection section 53 includes a temperature sensor that detects the outer surface temperature of the cooking tank 10. The tank temperature detection unit 53 is a thermocouple, thermistor, or the like, and is arranged in the vicinity of the heating coil 84 so as to be in contact with the bottom outer surface of the tank body 11 . More specifically, the heating coil 84 is in contact with the bottom outer surface of the tank body 11 by being inserted into a hole formed in the heating element 11C. Thereby, the temperature at the bottom of the tank body 11, which is mainly heated by the heating coil 84, can be detected. During cooking, the temperature raising means 20 is controlled so that the outer surface temperature of the tank body 11 detected by the tank temperature detection section 53 is maintained at the set cooking temperature.

Further, the tank temperature detection unit 53 is not limited to being in contact with the bottom outer surface of the tank body 11, but may be arranged so as to be in contact with the side outer surface. Further, the tank temperature detection unit 53 is not limited to a configuration that detects the external temperature of the tank body 11, and is arranged in the interior 11A of the tank body 11 so as to be in contact with the bottom inner surface or the side inner surface of the tank body 11. A configuration may be adopted in which the inner surface temperature of the main body 11 can be detected. Further, the tank temperature detection section 53 may be embedded in the tank main body 11 and configured to be able to detect the internal temperature of the tank main body 11.

The food temperature detection section 51 is constituted by a temperature sensor that detects the temperature of the food material 90. The food temperature detection section 51 is a rod-shaped sensor that is provided with a sensor section that detects the temperature of the food material 90 at a tip end 51A, and is inserted into the inside 11A of the tank body 11 through an insertion hole 52 that penetrates the lid section 12 in the thickness direction. It has been inserted. A rear end portion 51B of the food temperature sensing portion 51 opposite to the tip portion 51A is located above the top surface of the lid portion 12 and is held by a holding member 52A. The holding member 52A holds the food temperature sensing portion 51 so that the tip portion 51A is at a predetermined height position from the bottom surface of the tank body 11. Further, the height position of the tip portion 51A can be adjusted by moving the food temperature sensing portion 51 up and down while being held by the holding member 52A. Further, the holding member 52A has a width larger than the diameter of the insertion hole 52, and is arranged on the upper surface of the lid portion 12 so as to close the insertion hole 52. This can prevent outside air from flowing into the interior 11A of the tank body 11 through the insertion hole 52.

The tip portion 51A has a shape that is sharp enough to pierce the surface of the food material 90. As shown in FIG. 5, by piercing the tip 51A to the center of the food 90, the center temperature (core temperature) of the food 90 can be detected. During cooking, measurement of the cooking time is started when the core temperature of the food 90 detected by the food temperature detection unit 51 reaches the set cooking temperature. Further, the tip portion 51A has a bendable structure, so that the position of the tip portion 51A in the interior 11A of the tank body 11 can be finely adjusted.

The food temperature detection unit 51 is not limited to detecting the center temperature of the food material 90, and may detect the surface temperature of the food material 90 by bringing the tip portion 51A into contact with the surface of the food material 90. Alternatively, the temperature of the cooking liquid 91 may be detected by immersing the tip 51A in the cooking liquid 91 without contacting the food 90, or by positioning the tip 51A above the liquid level of the cooking liquid 91. The steam temperature of the cooking liquid 91 may also be detected. Further, in the present embodiment, a case has been described in which the temperature of the food material 90 is detected by bringing the tip portion 51A into direct contact with the food material 90, but the food material temperature detection section 51 may be constituted by a non-contact type temperature sensor.

The control unit 88 is a controller that controls the operation of each of the temperature increasing means 20, the pressure reducing means 30, and the atmosphere introducing means 40. As shown in FIG. 6, the control section 88 includes an operation control section 88A, a time measurement section 88B, an input section 88C, a display section 88D, and a warning generation section 88E. Further, the control unit 88 is configured to receive the temperatures detected by each of the tank temperature detection unit 53 and the food temperature detection unit 51.

The operation control unit 88A is a function for controlling the operation of each device in the CPU, and controls the operation of each device so as to execute various programmed sequence controls. Specifically, the operation control unit 88A controls the heating coil 84 and the pressure reducing pump 85 to be turned on and off, and also controls the pressure reducing valve 87A and the air introduction valve 86A to be opened and closed. The time measurement unit 88B is a timer and starts measuring the cooking time when the temperature detected by the food temperature detection unit 51 reaches the set cooking temperature. The input unit 88C is an operation button or the like for the user to perform various operations on the cooking device 3, and can input the cooking temperature, cooking time, cooking mode, etc. of the food material 90. The display section 88D is a display, and displays the temperature of the cooking tank 10 and the food material 90 detected by the tank temperature detection section 53 and the food temperature detection section 51 during cooking, and the temperature of the cooking tank detected by a pressure detection section (not shown). 10 and the cooking time measured by the time measuring section 88B. The warning generating section 88E is a section that sounds an alarm sound, and notifies the user of the elapsed cooking time by sounding an alarm when the cooking time has elapsed in the time measuring section 88B.

<Cooking steps>
Next, the procedure of the cooking method (reduced pressure heating mode) according to Embodiment 3 of the present invention will be explained with reference to the timing chart of FIG. 7. In FIG. 7, (1) shows the change in the core temperature of the food 90 detected by the food temperature detection unit 51, (2) shows the open/closed state of the pressure reduction valve 87A, and (3) shows the open/closed state of the air introduction valve 86A. (4) shows switching on/off of the pressure reducing pump 85, and (5) shows switching on/off of energization to the heating coil 84. Further, in FIG. 7, the horizontal direction indicates the passage of time.

First, the user inputs the cooking temperature T and cooking time t0 of the food material 90 into the input section 88C. The cooking temperature T is set within a range of 55 to 95°C (for example, 60°C). Further, the cooking time t0 is set within a range of 0 to 199 minutes.

In the standby state (FIG. 7: t1 to t2), the air introduction valve 86A is open and the pressure reduction valve 87A is closed, and both the pressure reduction pump 85 and the heating coil 84 are in the OFF state. Then, the operation control unit 88A turns on the pressure reduction pump 85 and the heating coil 84, opens the pressure reduction valve 87A, and closes the air introduction valve 86A (FIG. 7: t2). As a result, the air inside the cooking tank 10 is sucked by the pressure reducing pump 85 and the pressure inside the cooking tank 10 is reduced, and the temperature of the cooking tank 10 is raised, so that the temperature of the food material 90 is increased. Then, when the inside of the cooking tank 10 reaches a pressure from the atmospheric pressure to the saturated steam pressure +3% of the cooking temperature T (FIG. 7: t3), the operation control unit 88A closes the pressure reducing valve 87A. Then, after a certain period of time has elapsed, the pressure reducing pump 85 is turned off (FIG. 7; t4). In this way, the pressure reduction pump 85 can be protected by operating the pressure reduction pump 85 for a certain period of time even after the pressure reduction valve 87A is closed.

Next, when the core temperature of the food 90 (detected value by the food temperature detection unit 51) reaches -2°C of the cooking temperature T (FIG. 7: t5), the time measurement unit 88B measures the cooking time t0. will be started. At this time, the temperature of the cooking liquid 91 has already reached the cooking temperature T because the temperature of the cooking liquid 91 rises faster than the core temperature of the food 90. Moreover, since the pressure inside the cooking tank 10 is reduced to near the saturated vapor pressure, the cooking liquid 91 boils, and the food 90 is cooked in a low-temperature boiling state. During cooking, the amount of electricity applied to the heating coil 84 is adjusted so that the outer surface temperature of the cooking tank 10 detected by the tank temperature detection unit 53 is maintained at the cooking temperature T, as in the first embodiment. Ru.

Then, when the cooking time t0 has elapsed from the start of measurement (FIG. 7: t6), an alarm sounds in the warning generator 88E, and the power supply to the heating coil 84 is stopped. Then, the process automatically moves to the storage process while maintaining the reduced pressure state in the cooking tank 10. Thereafter, when the cook presses the cooking end key, the atmosphere introduction valve 86A is opened, and the pressure inside the cooking tank 10 is restored to atmospheric pressure (FIG. 7: t7). In this way, by opening the air to the atmosphere at the timing when the cooking end key is pressed, the inside of the cooking tank 10 can be maintained in a reduced pressure state even if the cook does not notice the end of cooking, and the food 90 and cooking liquid 91 can be kept in a reduced pressure state. can be prevented from coming into contact with air. The cooking method (reduced pressure heating mode) according to the third embodiment is completed by the above steps.

<Effect>
Next, the effects of the cooking device 3 and the cooking method according to the third embodiment will be explained. FIG. 8 is a graph showing temperature changes over time during cooking under normal pressure in which a food core temperature sensor is not used. FIG. 9 is a graph showing temperature changes over time during cooking under normal pressure using a food core temperature sensor. FIG. 10 is a graph showing a change in temperature over time during cooking under saturated steam pressure using the cooker 3 according to the third embodiment. In the graphs in Figures 8 to 10, the "T1" curve shows the time change in the temperature of the cooking tank, the "T2" curve shows the time change in the center temperature of the food, and the "T3" curve shows the time change in the temperature of the cooking liquid. The curve "T4" shows the time change of the surface temperature of the food material. In addition, in FIG. 8, since neither the center temperature nor the surface temperature of the food material is measured, the lines indicated by "T2, T4" in the graph indicate the estimated temperature values. In addition, the "T2" line is used when the center temperature of the food has not reached the target heating temperature at the end of cooking (T2'), and when the center temperature of the food exceeds the target heating temperature at the end of cooking. Two wires are shown in the case of overheating (T2'').

First, in heating cooking under normal pressure where a food core temperature sensor is not used, as shown in the graph of FIG. heated to a higher temperature. Moreover, measurement of cooking time is started at the same time as heating starts. In this case, it is not possible to confirm whether the center temperature T2 of the food has reached the target heating temperature after the predetermined cooking time has elapsed, and the food cannot be reliably cooked for the predetermined cooking time at the target heating temperature. Can not do it.

Next, in heating cooking under normal pressure using a food core temperature sensor, as shown in the graph of FIG. It is heated so that By starting measuring the cooking time when the center temperature T2 of the food reaches the target heating temperature, the food can be reliably cooked for a predetermined cooking time at the target heating temperature. However, in this case, the surface temperature T4 of the food material becomes higher than the target heating temperature, resulting in an overheated state.

On the other hand, in cooking under saturated steam pressure using the cooker 3 according to Embodiment 3, the temperature rise rate of the food is faster than under normal pressure, and the heat conduction from the surface to the center of the food increases. Since the heating rate increases, there is no need to heat the cooking tank to a temperature higher than the target heating temperature of the food. Further, as shown in the graph of FIG. 10, each of the temperatures T1 to T4 stabilizes at the same cooking temperature after a certain period of time. Therefore, it is possible to prevent the food from becoming overheated as under normal pressure.

Furthermore, as shown in the graph of FIG. 10, the time taken for each of the temperatures T1 to T4 to reach the target heating temperature is different. Specifically, T1 is the shortest time to reach the target heating temperature, T3 is the next shortest, T4 is the next shortest, and T2 is the longest. Therefore, when T1 reaches the target heating temperature, the center temperature T2 of the food has not reached the target heating temperature, and if you start measuring the cooking time at this point, the food will be heated at the target heating temperature for a predetermined cooking time. It cannot be cooked reliably. On the other hand, the cooking device 3 is equipped with a food temperature detection section 51 to directly measure the center temperature of the food, and starts measuring the cooking time when this center temperature reaches the target heating temperature. , it is possible to more accurately manage the time to maintain the food at the target heating temperature.

(Embodiment 4)
Next, Embodiment 4, which is still another embodiment of the present invention, will be described. The cooking device according to the fourth embodiment has not only the reduced pressure heating mode in which cooking is performed at a low temperature under saturated steam pressure as described in the third embodiment, but also the control unit 88 that controls the pressure reducing means 30 and the atmospheric introduction means 40. This makes it possible to further execute an impregnating concentration mode in which the pressure inside the cooking tank 10 is repeatedly reduced and restored.

FIG. 11 shows a timing chart in the impregnation concentration mode. In FIG. 11, (1) shows the change in the core temperature of the food 90 detected by the food temperature detection unit 51, (2) shows the open/closed state of the pressure reduction valve 87A, and (3) shows the open/closed state of the air introduction valve 86A. (4) shows switching on/off of the pressure reducing pump 85, and (5) shows switching on/off of energization to the heating coil 84. Further, in FIG. 11, the horizontal direction indicates the passage of time.

First, the user inputs conditions such as the cooking temperature T, the pressure reduction time t0, and the number of repetitions of pressure reduction and pressure recovery into the input section 88C. The cooking temperature T is set within the range of 0 to 60°C, the pressure reduction time t0 is set within the range of 2 to 20 minutes, and the number of repetitions is set to 1 to 20 times.

In the standby state (FIG. 11: t1 to t2), the pressure reduction valve 87A is closed, the atmosphere introduction valve 86A is open, and both the pressure reduction pump 85 and the heating coil 84 are in the OFF state.

Next, the process moves to a pressure reduction step (FIG. 11: t2 to t3). In this pressure reduction process, the operation control unit 88A turns on the electricity to the pressure reduction pump 85 and the heating coil 84, opens the pressure reduction valve 87A, and closes the atmospheric air introduction valve 86A. As a result, the air inside the cooking tank 10 is sucked by the pressure reducing pump 85 to reduce the pressure inside the cooking tank 10, and the temperature of the cooking tank 10 is raised, thereby increasing the temperature of the food 90. This pressure reduction process continues for a pressure reduction time t0 inputted in advance. Further, after the temperature of the food material 90 reaches the cooking temperature T, the cooking temperature T is maintained by repeatedly turning on and off the electricity to the heating coil 84, as shown in FIG.

Next, the process moves to a pressure recovery step (FIG. 11: t3 to t4). In this pressure recovery step, the operation control unit 88A opens the atmospheric air introduction valve 86A. As a result, air flows into the cooking tank 10 from the atmosphere introduction port 86, and the pressure inside the cooking tank 10 increases. This pressure restoration step is carried out for a shorter time than the pressure reduction step, for example, for one minute.

Then, the pressure reduction step and the pressure return step are repeated a preset number of times. As a result, air enters and exits the food 90 repeatedly, and in the process, the cooking liquid 91 impregnates the food 90 in a short time. Thereafter, when the repetition of the pressure reduction process and the pressure recovery process is completed a set number of times, the pressure reduction valve 87A is closed while the atmospheric air introduction valve 86A is open, and the pressure reduction pump 85 and heating coil 84 are turned off (Fig. 11 :t4). The impregnation/concentration mode is completed in the above manner. Further, this mode can be used not only for impregnating the food material 90 but also for drying it, and the food material 90 can be dried in a short time.

(Other embodiments)
Next, other embodiments of the present invention will be described.

In the third embodiment, in addition to the reduced pressure heating mode and the impregnating concentration mode, a manual cooking mode may be possible. In the manual cooking mode, sequence control such as the reduced pressure heating mode and the impregnation concentration mode is not performed, and the user can manually perform various operations such as turning on reduced pressure, turning off reduced pressure, and releasing reduced pressure.

In the third embodiment described above, the timing of starting measurement of the cooking time t0 is not limited to being controlled based on the temperature detected by the food temperature detection unit 51, and the measurement of the cooking time t0 is performed based on the temperature detected by the tank temperature detection unit 53. The timing of the start may be controlled. In this case, the food temperature detection unit 51 can be used as a means for monitoring the temperature inside the food 90 and the cooking tank 10. This monitor value may be displayed on the display section 88D provided in the cooking device 3, or may be displayed on a display section provided on another device.

In the third embodiment, the food temperature detection section 51 may be omitted, and only the temperature of the cooking tank 10 may be detected by the tank temperature detection section 53. In this case, the amount of electricity applied to the heating coil 84 is controlled so that the temperature of the cooking tank 10 is maintained at the set cooking temperature T, and when the temperature of the cooking tank 10 reaches the cooking temperature T, the time measuring unit 88B starts measuring the cooking time t0. Further, the time measuring section 88B may start measuring the cooking time t0 when the heating coil 84 starts being energized. Alternatively, the above control may be performed by detecting the temperature of the cooking liquid 91 instead of directly measuring the temperature of the cooking tank 10.

Further, in the third embodiment, the tank temperature detection section 53 may be omitted and only the food temperature detection section 51 may be configured. As shown in the graph of FIG. 10, the temperature T1 of the cooking tank 10 and the temperature T3 of the cooking liquid 91 are approximately the same when stable. Therefore, the temperature of the cooking liquid 91 is detected by the food temperature detection unit 51, and the amount of electricity applied to the heating coil 84 is controlled so that the temperature of the cooking liquid 91 is maintained at the cooking temperature T, thereby detecting the tank temperature. Heating control similar to that when using the section 53 becomes possible.

Further, in the third embodiment, both the tank temperature detection section 53 and the food temperature detection section 51 are arranged in the interior 11A of the tank main body 11, and the tank temperature detection section 53 detects the temperature of the cooking liquid 91, and the food temperature detection section 51 detects the temperature of the cooking liquid 91. The center temperature of the foodstuff 90 may be detected by. Then, the amount of electricity applied to the heating coil 84 may be controlled based on the temperature of the cooking liquid 91, and the timing of starting measurement of the cooking time t0 may be controlled based on the center temperature of the food material 90.

Furthermore, in the first and second embodiments described above, a food temperature sensing section may be further provided. Further, in the first and second embodiments described above, in addition to the reduced pressure heating mode, an impregnation concentration mode and a manual cooking mode may be executable.

(Experiment example)
An experiment was conducted to measure the temperature changes of the ingredients, seasoning liquid, and cooking tank when the ingredients and seasoning liquid were placed in the cooking tank and heated. Chicken breast was used as the ingredient. The food and seasoning liquid were heated by increasing the temperature of the cooking tank while the pressure inside the cooking tank was reduced from atmospheric pressure (approximately 101 kPa). Temperature measurements were performed on the food (center and surface), seasoning liquid, and outer surface of the cooking tank using a thermometer. Temperature measurement started from the time the food was immersed in the seasoning liquid. As a comparative example, temperature measurements were also conducted when heated under atmospheric pressure.

FIG. 12 shows temporal changes in temperature in each of the ingredients (center and surface), seasoning liquid, and outer surface of the cooking tank. In the graph of FIG. 12, the horizontal axis indicates elapsed time (minutes), and the vertical axis indicates temperature (° C.). In addition, in the graph of Figure 12, (A) shows the temperature change on the outer surface of the cooking tank under reduced pressure, (B) shows the temperature change on the food surface under reduced pressure, and (C) shows the temperature change on the surface of the food under reduced pressure. It shows the temperature change in the center of the food, and (D) shows the temperature change in the seasoning liquid under reduced pressure. In addition, in the graph of FIG. 12, (a) shows the temperature change of the outer surface of the cooking tank under atmospheric pressure, (b) shows the temperature change of the seasoning liquid under atmospheric pressure, and (c) shows the temperature change of the seasoning liquid under atmospheric pressure. (d) shows the temperature change at the food surface under atmospheric pressure.

Table 1 shows the time it takes for the temperature at the center of the food to reach the target temperature, the total cooking time, and the maximum and minimum values of the difference between the center temperature and the surface temperature of the food under reduced pressure and atmospheric pressure, respectively. and average values are shown, respectively.

As is clear from Figure 12, the food temperature under reduced pressure (B, C) takes longer to reach near the target set temperature than the food temperature under atmospheric pressure (c, d). It was short. Specifically, as shown in Table 1, the time required for the center temperature of the food to reach the target temperature was 34 minutes under atmospheric pressure, but 6 minutes under reduced pressure. Furthermore, under reduced pressure, the difference between the center temperature and surface temperature of the food (all of the maximum value, minimum value, and average value) was smaller than under atmospheric pressure.

The embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

1, 2, 3 Cooker 10 Cooking tank 20 Temperature raising means 30 Pressure reducing means 34, 85 Depressurizing pump 40 Atmospheric introduction means 50, 53 Tank temperature detection section 51 Food temperature detection section 60, 88 Control section 70 Input section 88B Time measurement section 90 Foodstuffs 91 Cooking liquid P1 Saturated vapor pressure T, T1 Cooking temperature t0 Cooking time

Claims (2)

a sealable cooking tank in which ingredients and cooking liquid are stored;
Temperature raising means for raising the temperature of the cooking tank;
a pressure reducing means for reducing the pressure inside the cooking tank;
A control unit that controls the temperature increasing means and the pressure reducing means,
The control unit controls the pressure reducing means so that the pressure inside the cooking tank is reduced to a saturated vapor pressure of a predetermined cooking temperature, and controls the temperature increase so that the temperature of the cooking tank is raised toward the cooking temperature. The temperature of the food is the same as the outer surface temperature of the cooking tank after a certain period of time has elapsed from the start of heating with the pressure reduced to the saturated vapor pressure of the cooking temperature and maintained at the cooking temperature by controlling the means. Based on the premise that the cooking tank reaches the cooking temperature, after the certain period of time has elapsed from the start of heating in a state where the inside of the cooking tank is depressurized to the saturated vapor pressure of the cooking temperature, the external surface temperature of the cooking tank reaches the cooking temperature. A cooking device that heats and cooks the food by controlling the temperature raising means so that the temperature is maintained. A cooking method in which food is cooked in a sealable cooking tank containing food and cooking liquid, the method comprising:
setting a cooking temperature for the food;
Cooking the food at the cooking temperature,
In the cooking step, the pressure inside the cooking tank is reduced to the saturated vapor pressure of the cooking temperature, and the temperature of the cooking tank is raised toward the cooking temperature, so that the inside of the cooking tank reaches the saturated vapor pressure of the cooking temperature. The inside of the cooking tank is based on the premise that the temperature of the food will be the same as the outer surface temperature of the cooking tank after a certain period of time has passed from the start of heating under reduced pressure and maintained at the cooking temperature. cooking the food by heating so that the external surface temperature of the cooking tank is maintained at the cooking temperature after the predetermined period of time has elapsed from the start of heating in a state where the food is reduced in pressure to the saturated vapor pressure of the cooking temperature; Method.

Images