JP2017093947A - Cooker and cooking method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooker that can shorten cooking time in low temperature cooking and that can also reduce uneven heating.SOLUTION: A cooker 1 includes: a hermetically sealable cooking tank 10 in which food materials 90 and cooking liquid 91 are housed; heating means 20 for raising temperature of the cooking tank 10; depression means 30 for reducing pressure inside the cooking tank 10; and a controller 60 for controlling the heating means 20 and the decompression means 30. The controller 60 controls the decompression means 30 so that the cooking tank 10 is decompressed inside down to the saturation vapor pressure of a set cooking temperature, and also controls the heating means 20 so that, under the decompressed state, the cooking tank 10 is maintained at the cooking temperature.SELECTED DRAWING: Figure 1

Description

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

  2. Description of the Related Art Conventionally, there is known a cooking device in which ingredients and cooking liquid (water, seasoning liquid) are put in a cooking tank and cooked (boiled, boiled, steamed, etc.) in a boiling state of about 100 ° C. In order to shorten the cooking time, a cooking device such as a pressure cooker that cooks at a high temperature of about 120 ° C. with the cooking tank in a high pressure state is also known. In Patent Document 1 below, as an example of a heating cooker, an apparatus for cooking by heating by supplying steam into a cooking tank in which ingredients are stored is described.

  In cooking at a high temperature, there is a problem that the protein contained in the food is thermally denatured to harden the food, the nutrient contained in the food is broken, and the original flavor and color of the food are impaired by oxidation. In addition, when a pressure cooker is used, there is a risk that an accident such as a pan lid flying due to an error in usage or a malfunction of the equipment may occur. On the other hand, a method of cooking food at a lower temperature so as not to deteriorate the quality of the food is known.

JP 2011-085318 A

  Conventional low-temperature cooking can prevent deterioration of food quality such as heat denaturation of protein, but has a problem that cooking time becomes longer compared to cooking by boiling the cooking liquid by high-temperature heating. In steam cooking, there is also a problem that the temperature distribution in the cooking tank becomes non-uniform and uneven heating occurs.

  This invention is made | formed in view of the said subject, The objective is to provide the cooking device and cooking method which can shorten cooking time in low-temperature heat cooking, and can reduce a heating nonuniformity. .

  A cooker according to one aspect of the present invention includes a sealable cooking tank in which ingredients and cooking liquid are stored, a temperature raising means for raising the temperature of the cooking tank, a pressure reducing means for reducing the pressure in the cooking tank, And a controller for controlling the temperature raising means and the pressure reducing means. The control unit controls the decompression unit so that the inside of the cooking tank is decompressed to a saturated vapor pressure at a predetermined cooking temperature, and the cooking tank is maintained at the cooking temperature in the decompressed state. Control the temperature raising means.

  In the above cooking device, the cooking liquid can be boiled even in low temperature cooking by maintaining the cooking tank at the cooking temperature in a state where the inside of the cooking tank is depressurized from the atmospheric pressure to the saturated vapor pressure of the cooking temperature. it can. Thereby, the convection of a cooking liquid is accelerated | stimulated in a cooking tank, and the heat transfer to a foodstuff becomes quick. Moreover, since the heat conductivity inside a foodstuff becomes high in the cooking under reduced pressure, the center temperature of a foodstuff can be brought close to the surface temperature rapidly. As a result, the cooking time can be further shortened. Moreover, since the temperature distribution in a cooking tank can be made uniform by generating saturated steam, the heating unevenness of a foodstuff can be reduced more.

  “Cooking liquid” is a concept that includes not only seasoning liquids but also non-seasoning liquids such as water.

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

  According to the results of the diligent research conducted by the present inventors, when the cooking tank is maintained at the cooking temperature with the pressure reduced to the saturated vapor pressure of the cooking temperature, it should be in a stable state after a certain time has elapsed since the start of heating. For example, the temperature of the cooking tank, the temperature of the cooking liquid, and the temperature of the ingredients are substantially the same. Therefore, by detecting the temperature of the cooking tank that is relatively easy to detect the temperature and maintaining it at the cooking temperature, the temperature of the food can be determined from the temperature of the cooking tank without detecting the temperature of the food directly if it is stable. Can be estimated.

  The cooker may further include a food temperature detection unit that detects the temperature of the food.

  As described above, under the saturated vapor pressure, the cooking tank and the food are stabilized at substantially the same cooking temperature after a certain period of time, but there is a difference in the time until the cooking temperature is reached. For this reason, when only a tank temperature detection part is used, it becomes difficult to grasp | ascertain food material temperature correctly until it stabilizes at cooking temperature. On the other hand, by providing the food temperature detector separately from the bath temperature detector, the food temperature can be accurately grasped even before the cooking temperature is stabilized.

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

  Thereby, the time which maintains a foodstuff at cooking temperature can be managed more correctly.

  Here, “the temperature detected by the food temperature detection unit reaches the cooking temperature” is not only when the detected temperature completely matches the cooking temperature, but also within a predetermined error range caused by the device performance. Including.

  In the cooking device, the decompression unit may have a decompression pump whose operation is controlled by the controller and decompressing the cooking tank by sucking air in the cooking tank. The control unit stops the operation of the decompression pump after the cooking tank is depressurized to the saturated vapor pressure, and controls the temperature raising means so that the cooking tank reaches the cooking temperature after the stop. May be.

  According to the above configuration, by stopping the operation of the vacuum pump before the cooking tank reaches the cooking temperature and starts boiling, moisture is sucked into the vacuum pump when the air in the cooking tank is sucked. Can be prevented. Therefore, there is an advantage that it is not necessary to provide a trap mechanism for preventing moisture from being sucked into the decompression pump.

  The cooker may further include an input unit capable of inputting set values of the cooking temperature and cooking time of the ingredients.

  According to the said structure, a foodstuff can be reliably heat-cooked on the conditions of the set cooking temperature and cooking time.

  The cooker may be configured to be controllable by the control unit, and may further include air introduction means for introducing air into the cooking tank. The control unit may control the decompression unit and the air introduction unit so as to repeat decompression and return pressure in the cooking tank.

  Thereby, the said cooker can be utilized also for impregnation, drying, etc. besides pressure reduction heating. Specifically, in the impregnation, the impregnation of the seasoning liquid (seasoning) into the food can be performed in a short time by repeating the decompression and the return pressure in the cooking tank. In drying, the moisture content of the food can be evaporated at a lower temperature by reducing the pressure in the cooking tank.

  The cooking method which concerns on the other situation of this invention is a cooking method which heat-cooks in the sealable cooking tank in which a foodstuff and a cooking liquid are accommodated. The cooking method includes a step of setting a cooking temperature of the food material and a step of cooking the food material at the cooking temperature. In the heating cooking step, the cooking tank is maintained at the cooking temperature in a state where the inside of the cooking tank is depressurized to the saturated vapor pressure of the cooking temperature.

  In the above cooking method, the cooking tank is maintained at the cooking temperature in a state where the inside of the cooking tank is depressurized from the atmospheric pressure to the saturated vapor pressure of the cooking temperature, so that the cooking liquid is boiled even in low temperature cooking. Can be cooked. Thereby, the convection of a cooking liquid is accelerated | stimulated in a cooking tank, and the heat transfer to a foodstuff becomes quick. Moreover, since the heat conductivity inside a foodstuff becomes high in the cooking under reduced pressure, the center temperature of a foodstuff can be brought close to the surface temperature rapidly. As a result, the cooking time can be further shortened. Moreover, since the temperature distribution in a cooking tank can be made uniform by the convection of a cooking liquid, a heating nonuniformity can be reduced more.

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

  As described above, when the cooking tank is maintained at the cooking temperature with the pressure reduced to the saturated vapor pressure of the cooking temperature, the temperature of the cooking tank is The temperature of the cooking liquid and the temperature of the ingredients are substantially the same. For this reason, the temperature of the cooking tank, which is relatively easy to detect temperature, is monitored using the tank temperature detection unit, and this is maintained at the cooking temperature, so that cooking can be performed without detecting the temperature of the ingredients directly in a stable state. The temperature of the food can be estimated from the temperature of the tank.

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

  As described above, under the saturated vapor pressure, the cooking tank and the food are stabilized at substantially the same cooking temperature after a lapse of a certain time, but the cooking tank has a shorter time until reaching the cooking temperature. For this reason, when the cooking tank reaches the cooking temperature, the food has not reached the cooking temperature, and when the cooking time measurement is started at this time, the food is surely cooked for the predetermined cooking time. It becomes difficult to do. On the other hand, by starting the measurement of the cooking time when the food temperature reaches the cooking temperature without fail, the food can be reliably cooked for a predetermined cooking time.

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

  According to the above method, by stopping the operation of the vacuum pump before the cooking tank reaches the cooking temperature and starts boiling, moisture is sucked into the vacuum pump when the air in the cooking tank is sucked. Can be prevented. Therefore, there is an advantage that it is not necessary to prepare a trap mechanism for preventing water suction into the decompression pump.

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

  According to the said method, a foodstuff can be reliably heat-cooked on the conditions of the set cooking time.

  ADVANTAGE OF THE INVENTION According to this invention, the cooking time and cooking method which can shorten cooking time in low-temperature heat cooking and can reduce a heating nonuniformity can be provided.

It is the schematic which shows the structure of the cooking appliance which concerns on Embodiment 1 of this invention. It is a flowchart which shows the procedure of the cooking method using the said cooking appliance. It is a timing chart for explaining temperature control and pressure control in the above-mentioned cooking method. It is the schematic which shows the structure of the cooking appliance which concerns on Embodiment 2 of this invention. It is the schematic which shows the structure of the cooking appliance which concerns on Embodiment 3 of this invention. It is a functional block diagram which shows the structure of the control part in the said cooker. It is a timing chart for demonstrating the temperature control and pressure control in the cooking method using the said cooking appliance. It is a graph which shows the temperature change in general cooking. It is a graph which shows the temperature change in the heating cooking under the normal pressure using the core temperature sensor of a foodstuff. It is a graph which shows the temperature change in the heat cooking under saturated vapor pressure using the core temperature sensor of a foodstuff. It is a timing chart for explaining temperature control and pressure control during execution of impregnation concentration mode. It is a graph which shows the measurement result of the heat transfer time to a foodstuff.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
<Composition of cooker>
First, the structure of the cooking appliance 1 which concerns on Embodiment 1 which is one Embodiment of this invention is demonstrated with reference to FIG. FIG. 1 shows the overall configuration of a cooking device 1 according to the present embodiment.

  The cooking device 1 is a cooking device that immerses the ingredients 90 in a cooking liquid 91 (water, seasoning liquid) and performs cooking such as cooking or boiling. The cooker 1 mainly includes a cooking tank 10, a temperature raising means 20, a decompression means 30, an air introduction means 40, a tank temperature detection unit 50, and a control unit 60.

  The cooking tank 10 is formed with respect to the tank main body 11 so as to cover the tank main body 11 in which an internal space in which the ingredients 90 and the cooking liquid 91 are stored is formed and an opening 11A is formed on the upper side, and the opening 11A. And a lid portion 12 that can be freely opened and closed.

  The tank body 11 has a pan shape including a bottom portion 14 and a side wall portion 15 erected from the bottom portion 14. The tank body 11 is formed with an internal space having a depth enough to accommodate the food 90 and the cooking liquid 91. The tank body 11 is composed mainly of a metal material such as aluminum or copper having good thermal conductivity. Moreover, the tank main body 11 is a multilayer pan comprised by the heat generating body which the outer surface (bottom surface 16) of the bottom part 14 consists of magnetic metals, such as ferritic stainless steel. The tank body 11 may be entirely constituted of aluminum or copper, or may be entirely constituted of ferritic stainless steel.

  The lid 12 is made of a heat resistant material such as glass or polycarbonate material. The lid 12 is opened when the food 90 and the cooking liquid 91 are put into the tank body 11, and the lid 12 is closed so as to cover the entire opening 11A as shown in FIG. 1 during cooking.

  The cooking tank 10 may further include a lid packing (not shown) that seals a gap between the tank body 11 and the lid portion 12. The lid packing is made of an elastic member such as silicone resin. Thereby, inflow of the air from the outside to the inside of the cooking tank 10 is suppressed, and the cooking tank 10 has a sealable structure. In addition, 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 includes a placement portion 21 disposed below the cooking tank 10 and a heating coil 22 disposed within the placement portion 21.

  As shown in FIG. 1, the placement unit 21 includes a flat placement surface 21 </ b> A on which the cooking tank 10 is placed. The cooking tank 10 is removable with respect to the mounting part 21. For example, the cooking tank 10 is removed from the mounting portion 21 when the food 90 or the cooking liquid 91 is put into the cooking tank 10 or when the inside of the tank is washed.

  The heating coil 22 electromagnetically heats the vicinity of the bottom 14 in the cooking tank 10 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 supplying current, and the bottom of the cooking tank 10 by Joule heat generated by the eddy current. 14 vicinity is heated up. Note that the temperature raising means 20 is not limited to the one that raises the temperature of the cooking tank 10 by the induction heating method as in this embodiment, and may be another means (heater) such as a resistance heating method.

  The decompression means 30 is for decompressing the inside of the cooking tank 10 by sucking the air in the cooking tank 10. The decompression means 30 includes a decompression pipe 31, a pressure detector 32, a decompression valve 33, and a decompression pump 34.

  The decompression pipe 31 has a flow path through which air sucked from the cooking tank 10 flows. As shown in FIG. 1, the decompression pipe 31 is arranged so that one end thereof is connected to the upper surface of the lid 12 and communicates with the inside of the cooking tank 10.

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

  The pressure detector 32 may be provided at another position (lid, pan body, valve, etc.) as long as the pressure in the cooking tank 10 can be detected.

  The pressure reducing valve 33 is a control valve that switches between air flow and shutoff in the pressure reducing pipe 31. When the pressure detector 32 is attached to the decompression pipe 31 as in the present embodiment, the decompression valve 33 is located on the opposite side of the cooking tank 10 as viewed from the pressure detector 32 as shown in FIG. Is arranged.

  The decompression pump 34 is a vacuum pump, and decompresses the inside of the cooking tank 10 by sucking air in the cooking tank 10 through the decompression pipe 31. When the pressure detector 32 is attached to the decompression pipe 31 as in the present embodiment, the decompression pump 34 is located on the opposite side of the pressure detector 32 from the decompression valve 33 as shown in FIG. Is arranged.

  According to the decompression means 30, by operating the decompression pump 34 with the decompression valve 33 opened, the air in the cooking tank 10 can be sucked through the decompression pipe 31 to decompress the cooking tank 10. it can.

  The air introduction means 40 is for returning the pressure in the reduced-pressure cooking tank 10 to atmospheric pressure by flowing air into the cooking tank 10. 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 supplied into the cooking tank 10 flows. As shown in FIG. 1, the air introduction pipe 41 is arranged so that one end of the air introduction pipe 41 is connected to the upper surface of the lid portion 12 along with the decompression pipe 31 and communicates with the inside of the cooking tank 10. The air introduction pipe 41 may have a configuration in which at least a part is used together with the decompression pipe 31.

  The air introduction valve 42 is a control valve that switches between air flow and blockage in the air introduction pipe 41. The air introduction valve 42 is arranged in the middle of the air introduction pipe 41 as shown in FIG.

  According to the air introduction means 40, the air is introduced into the cooking tank 10 through the air introduction pipe 41 with the air introduction valve 42 opened, so that the decompressed cooking tank 10 is restored to atmospheric pressure. Can be made.

  The tank temperature detection unit 50 is configured by a temperature sensor that detects the outer surface temperature of the cooking tank 10. As shown in FIG. 1, the bath temperature detector 50 is attached to the outer surface 13 (outer surface) in the vicinity of the bottom 14 and detects the temperature of this portion. Examples of the bath temperature detection unit 50 include temperature sensors such as thermocouples and thermistors, but are not limited thereto.

  Although the tank temperature detection part 50 is not restricted to the case where it is attached to the outer surface 13 in the vicinity of the bottom part 14 as in this embodiment, it is preferable that the tank temperature detection part 50 is attached to a part mainly heated by the temperature raising means 20. For example, the tank temperature detection unit 50 may be attached to the bottom surface 16 (outer surface) and detect the temperature of this portion. Moreover, the tank temperature detection part 50 can be attached to arbitrary positions in the tank main body 11, if it is a part used as the temperature substantially the same as the bottom face 16 during the heating by the temperature rising means 20. FIG. Furthermore, the tank temperature detection part 50 is not limited to what detects the outer surface temperature of the cooking tank 10, It may be arrange | positioned inside the cooking tank 10 and may detect the inner surface temperature of the cooking tank 10, or the cooking tank 10 The temperature of the cooking liquid 91 in the cooking tank 10 may be measured and treated as the tank temperature. Moreover, the tank temperature detection unit 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 operations of the temperature raising means 20, the pressure reducing means 30, and the air introduction means 40.

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

  The controller 60 is connected to each of the pressure reducing valve 33 and the pressure reducing pump 34. The controller 60 controls the opening / closing operation of the pressure reducing valve 33 and 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 a detection result (pressure in the cooking tank 10) by the pressure detection unit 32 is input.

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

  The cooker 1 further includes an input unit 70. The input unit 70 is a part where the user can input the set values of the cooking temperature and cooking time according to the type of food 90, the cooking method, and the like. The input unit 70 transmits the input set value to the control unit 60.

  The control unit 60 has a storage unit (not shown) for storing the set value. Moreover, the control part 60 further has a calculating part (not shown) for calculating the value of the saturated vapor pressure at the set cooking temperature, and stores the calculated value in the storage part.

  The cooker 1 further includes a display unit 80. The display unit 80 is a display, and displays the cooking state such as the outer surface temperature of the cooking tank 10 and the pressure in the cooking tank 10 input to the control unit 60.

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

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

  Next, the step which sets the cooking time of the foodstuff 90 is performed (FIG. 2: S2). In step S2, the cooking time t0 is similarly set in accordance with the type of food 90, the cooking method, and the like. The cooking time t0 is similarly set based on the set value input to the input unit 70 by the user.

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

  First, the pressure adjustment in the cooking tank 10 will be described. The decompression pump 34 is turned on by the controller 60, and the decompression valve 33 is opened (FIG. 2: S31, FIG. 3: t1). At this time, the air introduction valve 42 is closed. Thereby, the air in the cooking tank 10 is sucked by the decompression pump 34 through the decompression pipe 31, and the inside of the cooking tank 10 is decompressed.

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

  Next, temperature adjustment of the cooking tank 10 will be described. First, the temperature raising means 20 is turned on by the control unit 60 (FIG. 2: S32, FIG. 3: t1). Thereby, the bottom 14 side of the cooking tank 10 is electromagnetically heated by the heating coil 22, and the outer surface temperature of the cooking tank 10 rises from the initial temperature T0 toward the cooking temperature T1. Here, as shown in FIG. 3, before the outer surface temperature of the cooking tank 10 reaches the cooking temperature T1, the pressure in the cooking tank 10 reaches the saturated vapor pressure P1, and the operation of the decompression pump 34 is stopped.

  Thereafter, the cooking tank 10 is further heated with the pressure reduced to the saturated vapor pressure P1, and the outer surface temperature of the cooking tank 10 reaches the cooking temperature T1 (FIG. 2: S35, FIG. 3: t3). Here, in the state where the inside of the cooking tank 10 is reduced to the saturated vapor pressure P1, heat transfer in the tank is accelerated, so that the outer surface temperature of the cooking tank 10, the temperature of the cooking liquid 91, and the temperature of the ingredients 90 are as follows. It becomes almost the same. Therefore, when the outer surface temperature of the cooking tank 10 reaches the cooking temperature T1, the cooking liquid 91 also reaches substantially the same temperature as the cooking temperature T1. Moreover, since the cooking tank 10 is depressurized to the saturated vapor pressure P1, the cooking liquid 91 boils in a low temperature state, and the food 90 is cooked in a low temperature boiling state.

  During cooking, the state where the inside of the cooking tank 10 is reduced to the saturated vapor pressure P1 is maintained, and the outer surface temperature of the cooking tank 10 is maintained at the cooking temperature T1. Specifically, as shown in FIG. 3, the controller 60 repeatedly turns the temperature raising means 20 on and off, so that the outer surface temperature of the cooking tank 10 is maintained at the cooking temperature T1. In this manner, the food 90 is cooked over the cooking time t0 under the conditions of the saturated vapor pressure P1 and the cooking temperature T1 (FIG. 2: S36).

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

<Effect>
Next, the effect by the said cooking appliance 1 and a cooking method is demonstrated.

  The cooking device 1 includes a cooking tank 10 in which ingredients 90 and a 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 in the cooking tank 10, and a control unit 60. It is equipped with. The controller 60 controls the pressure reducing means 30 so that the inside of the cooking tank 10 is reduced to the saturated vapor pressure P1 of the cooking temperature T1, and the cooking tank 10 is increased so that the cooking tank 10 is maintained at the cooking temperature T1 in the reduced pressure state. The temperature means 20 is controlled.

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

  According to the cooking device 1 and the cooking method described above, the cooking tank 10 is maintained at the cooking temperature T1 in a state where the inside of the cooking tank 10 is reduced to the saturated vapor pressure P1 of the cooking temperature T1, and thus the case where the cooking tank 10 is under atmospheric pressure. In contrast, the cooking liquid 91 can be boiled even in low temperature cooking at 95 ° C. or lower. Thereby, the convection of the cooking liquid 91 is promoted in the cooking tank 10, and heat transfer to the food 90 is accelerated. Moreover, since the heat conductivity in the foodstuff 90 becomes high in the cooking under reduced pressure, the center temperature of the foodstuff 90 can be brought close to the surface temperature quickly. As a result, the cooking time can be further shortened. Moreover, the heat denaturation of the protein contained in the foodstuff 90 and the destruction of nutrients can be prevented by cooking at low temperature.

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

  If the cooking tank 10 is maintained at the cooking temperature T1 with the pressure reduced to the saturated vapor pressure P1 of the cooking temperature T1, the temperature of the cooking tank 10 is determined as long as it is in a stable state after a certain period of time from the start of heating. The temperature of the cooking liquid 91 and the temperature of the foodstuff 90 become substantially the same. Therefore, by detecting the outer surface temperature of the cooking tank 10 whose temperature is relatively easy to detect and maintaining this at the cooking temperature T1, the temperature of the cooking tank can be detected without directly detecting the temperature of the ingredients 90 in a stable state. From the above, the temperature of the food can be estimated.

  Moreover, by maintaining the temperature so as not to exceed the cooking temperature T1, even when the food 90 is in direct contact with the surface of the cooking tank 10, such as cooking with boiled food or boiled food, the food 90 is excessively exceeded the cooking temperature T1. Heating can be prevented.

  In the cooking device 1, the decompression means 30 has a decompression pump 34 that decompresses the inside of the cooking tank 10 by sucking air in the cooking tank 10. As shown in FIG. 3, the control unit 60 stops the operation of the decompression pump 34 after the inside of the cooking tank 10 has been reduced to the saturated vapor pressure P1, and the cooking tank 10 reaches the cooking temperature T1 after the stop. The temperature raising means 20 is controlled.

  Thus, by stopping the operation of the decompression pump 34 before the cooking tank 10 reaches the cooking temperature T1 and starts boiling, the suction of moisture into the decompression pump 34 when the air in the cooking tank 10 is sucked. Can be prevented. Therefore, there is an advantage that it is not necessary to provide a trap mechanism for preventing moisture from being sucked into the decompression pump 34. The trap mechanism may be provided immediately before the decompression pump 34 without being omitted.

<Modification>
Although the said embodiment demonstrated the case where the decompression pump 34 was stopped before the cooking tank 10 reaches | attains cooking temperature T1, it is not restricted to this. The decompression pump 34 may be stopped after the cooking tank 10 reaches the cooking temperature T1 (the cooking temperature T1 is reached before the decompression pump 34 is stopped), or the decompression pump 34 is stopped simultaneously with reaching the cooking temperature T1. Also good. That is, before and after the timing at which the cooking tank 10 reaches the target temperature and the timing at which the inside of the cooking tank 10 reaches the target pressure are not particularly limited, either timing may be earlier or at the same time.

  In the said embodiment, in order to keep the pressure in the cooking tank 10 constant, pressure adjustment by pressure reduction or air introduction may be performed. Moreover, it is not restricted to the case where the pressure in the cooking tank 10 is kept constant after reaching the saturated vapor pressure P1, and the pressure in the cooking tank 10 may be adjusted even after the heating cooking step is started.

  In the said embodiment, although one cooking temperature T1 was set and heat cooking by which this was maintained was demonstrated, it is not restricted to this. A plurality of cooking temperatures may be set, and cooking may be performed in which each cooking temperature is maintained in stages. In this case, the pressure in the cooking tank 10 is adjusted so as to be the saturated vapor pressure at each cooking temperature.

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

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

  The food material 90 is installed side by side on the porous plate 92. As shown in FIG. 4, the cooking liquid 91 is stored so that the liquid level is located below the porous plate 92.

  In the cooking device 2, the cooking liquid 91 (water) is evaporated by raising the temperature of the cooking tank 10 by the temperature raising means 20, and the cooking of the food 90 can be performed by the steam (broken arrows in the figure). Here, the foodstuff 90 can be heated with saturated steam by maintaining the cooking tank 10 at the cooking temperature T1 in a state where the inside of the cooking tank 10 is reduced to the saturated steam pressure P1 as in the first embodiment. Therefore, the temperature distribution in the cooking tank 10 becomes uniform, and the heating unevenness of the food 90 can be further reduced.

<Modification>
In the said embodiment, what is necessary is just to be able to cook by applying steam to the foodstuff 90, and it is not limited to the case where the porous board 92 and the support part 11B are provided. For example, a food support section (pedestal) having 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 cooking tank. 10 on the bottom part 14 and the foodstuff 90 may be arrange | positioned on the said support plate. And the cooking liquid 91 may be accommodated in the cooking tank 10 so that a liquid level may be located below the said support plate. In this case, steam cooking can be performed by arranging the food 90 at a predetermined height from the bottom portion 14 without providing the support portion 11B on the inner wall surface of the cooking tank 10 as in the above embodiment.

  In the said embodiment (or modification), it is not limited to the case where steam cooking is performed with the cooking appliance 2 of the structure shown in FIG. 4, and cooking such as cooking or cooking may be performed as in the above-described first embodiment. . In this case, the cooking liquid 91 is accommodated 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 90 is immersed in the cooking liquid 91). . Thus, cooking such as boiled or stewed is not limited to the case where the ingredients 90 are arranged on the bottom 14 of the cooking tank 10 as in the first embodiment (FIG. 1), but the bottom as shown in FIG. The food material 90 may be disposed on a porous plate 92 (or a support plate) located at a predetermined height from 14.

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

<Composition of cooker>
As shown in FIG. 5, the cooking device 3 is arranged in a main body housing 81 formed of a rectangular parallelepiped or cylindrical housing, a main body portion 82 placed on the bottom surface of the main body housing 81, and the main body portion 82. The cooking tank 10, the temperature raising means 20, the decompression means 30, the air introduction means 40, the tank temperature detection unit 53, the food material temperature detection unit 51, and the control unit 88 are mainly provided.

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

  The main body portion 82 is provided with a recess having a shape suitable for the outer shape of the cooking tank 10, and the cooking tank 10 can be installed in the recess. The main body part 82 includes a heat insulating part 82 </ b> A that surrounds the cooking tank 10 so as to insulate the outside from the outside, and a mounting part 82 </ b> B that is mounted on the bottom surface of the main body housing 81. The heat insulating part 82A may be made of a resin having heat resistance of 100 ° C. or higher such as polypropylene, and the mounting part 82B may be made of a metal that does not generate rust such as stainless steel or aluminum.

  The cooking tank 10 includes a tank body 11 and a lid part 12 having a pan shape capable of accommodating the ingredients 90 and the cooking liquid 91, and is disposed in a recess provided in the body part 82. The cooking tank 10 can be detached from the main body 82 when the food 90 is installed or cleaned. The tank body 11 is mainly composed of aluminum, copper, or the like excellent in thermal conductivity, and a heating element 11C is joined to the outer surface thereof. The heating element 11 </ b> C is made of a magnetic metal plate such as ferritic stainless steel and has a shape along the shape of the tank body 11. The heating element 11C constitutes a part of the temperature raising means 20 for raising the temperature of the cooking tank 10 as will be described later.

  The lid portion 12 is made of a transparent resin material having a heat resistance of 120 ° C. or higher such as glass, and is disposed on 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. Thereby, the cooking tank 10 becomes a structure which can be sealed, and the distribution | circulation of the air inside and outside the tank is interrupted | blocked. The cooking tank 10 is provided with a pressure detection unit (not shown) that detects the pressure in the interior 11A.

  The temperature raising means 20 raises the temperature of the cooking tank 10 and includes a heating element 11 </ b> C and a plurality of heating coils 84. The heating coil 84 is disposed inside the heat insulating part 82 </ b> A and is in contact with the heating element 11 </ b> C joined to the bottom outer surface of the tank body 11. By supplying a high frequency current to the heating coil 84, the heating element 11C generates heat by electromagnetic induction, and as a result, the cooking tank 10 can be heated. Moreover, the heating coil 84 may be arrange | positioned so that the heat generating body 11C joined to the side part outer surface of the tank main body 11 may be contacted. Further, the temperature raising means 20 is not limited to the one that raises the temperature of the cooking tank 10 by the induction heating method, and may be other heating means such as a resistance heating type heater.

  The decompression means 30 decompresses the cooking tank 10 and includes a decompression pump 85, a decompression valve 87A, and a decompression pipe 87B. The decompression pump 85 is disposed at a corner on the bottom surface side in the main body housing 81. The decompression valve 87A is placed on a support plate 85A located above the decompression pump 85. One end of the decompression pipe 87B is fixed to the upper surface of the lid 12 by a fixing member 87C so as to communicate with the decompression port 87 penetrating the lid 12 in the thickness direction. Although not shown, a decompression pump 85 is connected to the other end of the decompression pipe 87B, and a decompression valve 87A is provided in the middle of the decompression pipe 87B. Thus, by operating the pressure reducing pump 85 with the pressure reducing valve 87A opened, the air in the cooking tank 10 is sucked through the pressure reducing pipe 87B, and the pressure in the cooking tank 10 is reduced to less than atmospheric pressure. Can do.

  The air introduction means 40 is for introducing 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 side by side with the pressure reducing valve 87A on the support plate 85A. One end of the air introduction pipe 86 </ b> B is fixed to the upper surface of the lid 12 by a fixing member 86 </ b> C so as to communicate with the atmosphere introduction port 86 that penetrates the lid 12 in the thickness direction. 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 inside of the cooking tank 10 is in a decompressed state, air is caused to flow into the cooking tank 10 through the air introduction pipe 86B, and the inside of the cooking tank 10 is restored to atmospheric pressure. Can do.

  The tank temperature detection unit 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, a thermistor, or the like, and is disposed in contact with the bottom outer surface of the tank body 11 in the vicinity of the heating coil 84. 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 of the bottom part of the tank main body 11 mainly heated by the heating coil 84 can be detected. During heating 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 unit 53 is maintained at the set cooking temperature.

  Moreover, the tank temperature detection part 53 is not limited to the case where it contacts the bottom outer surface of the tank body 11, and may be disposed so as to contact the side outer surface. The tank temperature detection unit 53 is not limited to the configuration for detecting the outer surface temperature of the tank body 11, and is disposed in the inside 11 </ b> A of the tank body 11 so as to contact the bottom inner surface or the side inner surface of the tank body 11. It is good also as a structure which can detect the internal surface temperature of the main body 11. FIG. The tank temperature detection unit 53 may be configured to be embedded in the tank body 11 and to detect the internal temperature of the tank body 11.

  The food temperature detection unit 51 is configured by a temperature sensor that detects the temperature of the food 90. The food material temperature detection unit 51 is a rod-shaped sensor provided with a sensor unit that detects the temperature of the food material 90 at the tip 51A, and is inserted into the interior 11A of the tank body 11 through the insertion hole 52 that penetrates the lid 12 in the thickness direction. Has been inserted. The rear end portion 51B opposite to the front end portion 51A in the food material temperature detection unit 51 is located above the upper surface of the lid portion 12, and is held by the holding member 52A. The holding member 52 </ b> A holds the food temperature detector 51 so that the tip 51 </ b> A is at a predetermined height from the bottom surface of the tank body 11. Moreover, the height position of 51 A of front-end | tip parts can also be adjusted by moving the foodstuff temperature detection part 51 up and down in the state hold | maintained by 52 A of holding members. The holding member 52 </ b> A has a width larger than the diameter of the insertion hole 52, and is disposed on the upper surface of the lid portion 12 so as to close the insertion hole 52. Thereby, it is possible to prevent outside air from flowing into the inside 11 </ b> A of the tank body 11 through the insertion hole 52.

  51 A of front-end | tip parts have a sharp shape which can be stabbed into the foodstuff 90 surface. As shown in FIG. 5, the center temperature (core temperature) of the food 90 can be detected by piercing the tip 51 </ b> A to the center of the food 90. During cooking, measurement of cooking time is started when the core temperature of the food 90 detected by the food temperature detector 51 reaches the set cooking temperature. Further, the distal end portion 51A has a bendable structure, whereby the position of the distal end portion 51A in the interior 11A of the tank body 11 can be finely adjusted.

  The food temperature detector 51 is not limited to detecting the center temperature of the food 90, and may detect the surface temperature of the food 90 by bringing the tip 51A into contact with the surface of the food 90. Moreover, you may detect the temperature of the cooking liquid 91 by making the front-end | tip part 51A immersed in the cooking liquid 91, without contacting the foodstuff 90, or positioning the front-end | tip part 51A above the liquid level of the cooking liquid 91. Thus, the steam temperature of the cooking liquid 91 may be detected. Moreover, although this embodiment demonstrated the case where the front-end | tip part 51A was made to contact the foodstuff 90 directly and the temperature of the foodstuff 90 was detected, the foodstuff temperature detection part 51 may be comprised by the non-contact-type temperature sensor.

  The controller 88 is a controller that controls the operations of the temperature raising means 20, the pressure reducing means 30, and the atmosphere introducing means 40. As shown in FIG. 6, the control unit 88 includes an operation control unit 88A, a time measurement unit 88B, an input unit 88C, a display unit 88D, and a warning generation unit 88E. Moreover, the control part 88 is comprised so that the temperature detected by each of the tank temperature detection part 53 and the foodstuff temperature detection part 51 may be input.

  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 performs control so as to switch the heating coil 84 and the decompression pump 85 on and off, and performs control so as to switch the opening and closing of the decompression valve 87A and the air introduction valve 86A. The time measuring unit 88B is a timer and starts measuring the cooking time when the temperature detected by the food temperature detecting 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, and the like of the food 90. The display unit 88D is a display, and during cooking, the temperature of the cooking tank 10 and the food 90 detected by the tank temperature detection unit 53 and the food temperature detection unit 51, and the cooking tank detected by the pressure detection unit (not shown). The pressure in 10 and the cooking time measured by the time measuring unit 88B are displayed. The warning generation unit 88E is a part 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 measurement unit 88B.

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

  First, the cooking temperature T and cooking time t0 of the food 90 are input to the input unit 88C by the user. The cooking temperature T is set within a range of 55 to 95 ° C. (for example, 60 ° C.). 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 opened and the pressure reducing valve 87A is closed, and the pressure reducing pump 85 and the heating coil 84 are both turned off. Then, the operation controller 88A turns on the decompression pump 85 and the heating coil 84, opens the decompression valve 87A, and closes the air introduction valve 86A (FIG. 7: t2). Thereby, while the air in the cooking tank 10 is attracted | sucked by the decompression pump 85, the inside of the cooking tank 10 is pressure-reduced, and the temperature of the foodstuff 90 rises because the cooking tank 10 is heated up. When the inside of the cooking tank 10 reaches from atmospheric pressure to the saturated steam pressure + 3% pressure of the cooking temperature T (FIG. 7: t3), the pressure reducing valve 87A is closed by the operation control unit 88A. Then, after a predetermined time has elapsed, the decompression pump 85 is turned off (FIG. 7; t4). Thus, the decompression pump 85 can be protected by operating the decompression pump 85 for a certain period of time even after the decompression valve 87A is closed.

  Next, when the core temperature of the food 90 (detected value of the food temperature detector 51) reaches a temperature of −2 ° C. of the cooking temperature T (FIG. 7: t5), the time measuring unit 88B measures the cooking time t0. Be started. At this time, the temperature of the cooking liquid 91 has reached the cooking temperature T because the temperature of the cooking liquid 91 is higher than the core temperature of the food 90. Moreover, since the inside of the cooking tank 10 is depressurized to near the saturated vapor pressure, the cooking liquid 91 boils and the food 90 is cooked in a low-temperature boiling state. During heating cooking, as in the first embodiment, the energization amount 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. The

  And when cooking time t0 passes since the measurement start (FIG. 7: t6), an alarm will sound in the warning generation part 88E, and the electricity supply to the heating coil 84 will be stopped. And it transfers to a preservation | save process automatically, with the pressure reduction state in the cooking tank 10 maintained. Thereafter, when the cook presses the cooking end key, the air introduction valve 86A is opened, and the pressure in the cooking tank 10 is restored to atmospheric pressure (FIG. 7: t7). As described above, when the cooking end key is released to the atmosphere when the cooking end key is pressed, the cooking tank 10 can be kept in a decompressed state when the cook does not notice the end of cooking. Can be prevented from touching the air. The cooking method (reduced pressure heating mode) according to the third embodiment is completed by the procedure as described above.

<Effect>
Next, the effect by the cooking appliance 3 and the cooking method which concern on the said Embodiment 3 is demonstrated. FIG. 8 is a graph showing a temporal change in temperature during cooking under normal pressure where the core temperature sensor for food is not used. FIG. 9 is a graph showing a temporal change in temperature in cooking under normal pressure using a core temperature sensor for food. FIG. 10 is a graph showing a change with time of temperature in heating cooking under saturated steam pressure using the cooking device 3 according to the third embodiment. In the graphs of FIGS. 8 to 10, the curve “T1” indicates the time change of the temperature of the cooking tank, the curve “T2” indicates the time change of the center temperature of the ingredients, and the curve “T3” indicates the temperature of the cooking liquid. The curve of “T4” shows the time change of the surface temperature of the foodstuff. In FIG. 8, since neither the center temperature nor the surface temperature of the food is measured, the lines indicated by “T2, T4” in the graph indicate the estimated temperature values. The line “T2” indicates that the center temperature of the food has not reached the target heating temperature at the end of cooking (T2 ′), and the center temperature of the food exceeds the target heating temperature at the end of cooking. Two cases of overheating (T2 ″) are shown.

  First, in cooking under normal pressure where the food core temperature sensor is not used, as shown in the graph of FIG. 8, the temperature T1 of the cooking tank is set to the target heating temperature of the food in order to shorten the temperature rise time of the food. It is heated to a higher temperature. Moreover, the measurement of cooking time is started simultaneously with the start of heating. In this case, it is not possible to confirm whether or not the center temperature T2 of the food has reached the target heating temperature when the predetermined cooking time has elapsed, and the food is reliably cooked for the predetermined cooking time at the target heating temperature. Can not do it.

  Next, in cooking under normal pressure using the core temperature sensor of the food, as shown in the graph of FIG. 9, the temperature T1 of the cooking tank is higher than the target heating temperature of the food as in the above case. It is heated to become. Then, by starting the measurement of the cooking time when the center temperature T2 of the food reaches the target heating temperature, the food can be reliably cooked for the predetermined cooking time at the target heating temperature. However, in this case, the surface temperature T4 of the food becomes higher than the target heating temperature, resulting in an overheating state.

  On the other hand, in the cooking under the saturated vapor pressure using the cooking device 3 according to the third embodiment, the temperature rise rate of the food is larger than that under normal pressure, and the heat conduction from the surface of the food to the center is performed. Since the rate increases, it is not necessary 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, the temperatures T1 to T4 are stabilized at the same cooking temperature after a predetermined time has elapsed. Therefore, it can prevent that a foodstuff will be in an overheating state like normal pressure.

  Further, as shown in the graph of FIG. 10, the time until each temperature T1 to T4 reaches the target heating temperature is different. Specifically, T1 is the shortest time to reach the target heating temperature, T3 is short, T4 is short, T2 is the longest. Therefore, when T1 reaches the target heating temperature, the center temperature T2 of the food does not reach the target heating temperature, and when the measurement of the cooking time is started at this time, the food is kept at the target heating temperature for the predetermined cooking time. It cannot be cooked reliably. On the other hand, the cooking device 3 directly measures the center temperature of the food by providing the food temperature detector 51, and starts measuring the cooking time when the center temperature reaches the target heating temperature. The time for maintaining the food material at the target heating temperature can be managed more accurately.

(Embodiment 4)
Next, Embodiment 4 which is still another embodiment of the present invention will be described. As described in the third embodiment, the cooker according to the fourth embodiment controls the decompression means 30 and the air introduction means 40 by the control unit 88 as well as the decompression heating mode in which cooking is performed at a low temperature under saturated vapor pressure. Thus, it is possible to further execute the impregnation concentration mode in which the decompression and the decompression in the cooking tank 10 are repeated.

  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 detector 51, (2) shows the open / close state of the decompression valve 87A, and (3) shows the air introduction valve 86A. (4) shows on / off switching of the decompression pump 85, and (5) shows on / off switching of energization to the heating coil 84. 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 times the pressure reduction / recovery is repeated to the input unit 88C. The cooking temperature T is set within the range of 0 to 60 ° C., the decompression 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 decompression valve 87A is closed and the air introduction valve 86A is opened, and both the decompression pump 85 and the heating coil 84 are in the off state.

  Next, the process proceeds to a decompression step (FIG. 11: t2 to t3). In this decompression step, the operation controller 88A turns on the power to the decompression pump 85 and the heating coil 84, opens the decompression valve 87A, and closes the atmosphere introduction valve 86A. Thereby, the air in the cooking tank 10 is sucked in by the decompression pump 85 and the inside of the cooking tank 10 is decompressed, and the cooking tank 10 is heated to increase the temperature of the food 90. This decompression step is continued for a decompression time t0 inputted in advance. Moreover, after the temperature of the foodstuff 90 reaches the cooking temperature T, the cooking temperature T is maintained by repeating ON / OFF of the energization to the heating coil 84 as shown in FIG.

  Next, the process proceeds to a decompression step (FIG. 11: t3 to t4). In the return pressure process, the air introduction valve 86A is opened by the operation control unit 88A. Thereby, air flows into the cooking tank 10 from the air introduction port 86, and the pressure in the cooking tank 10 rises. This decompression step is performed for a shorter time than the decompression step, for example, for one minute.

  Then, the decompression step and the decompression step are repeated a preset number of times. Thereby, the entrance / exit of air in the ingredients 90 is repeated, and the cooking liquid 91 is impregnated in the ingredients 90 in a short time in the process. After that, when the repetition of the decompression process and the decompression process is completed a set number of times, the decompression valve 87A is closed with the atmosphere introduction valve 86A opened, and the decompression pump 85 and the heating coil 84 are turned off (FIG. 11). : T4). The impregnation / concentration mode is completed as described above. Further, this mode can be used not only for impregnation of the food material 90 but also for drying, 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 Embodiment 3, in addition to the reduced pressure heating mode and the impregnation concentration mode, the manual cooking mode may be executable. 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 operations such as reduced pressure on, reduced pressure off, and reduced pressure release.

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

  In the said Embodiment 3, the foodstuff temperature detection part 51 may be abbreviate | omitted and the temperature of the cooking tank 10 may be detected by the tank temperature detection part 53. FIG. In this case, the amount of current supplied 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 The measurement of cooking time t0 by 88B is started. Moreover, you may start the measurement of the cooking time t0 by the time measurement part 88B at the time of the energization start to the heating coil 84. FIG. Moreover, it is good also as a structure which does not measure the temperature of the cooking tank 10 directly, but detects the temperature of the cooking liquid 91 and performs the said control.

  Moreover, in the said Embodiment 3, the tank temperature detection part 53 is abbreviate | omitted and it is good also as a structure only of the foodstuff temperature detection part 51. FIG. 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 substantially the same when stable. For this reason, the temperature of the cooking liquid 91 is detected by the food material temperature detection unit 51, and the temperature of the cooking liquid 91 is controlled at the cooking temperature T so that the temperature of the cooking coil 91 is maintained at the cooking temperature T. Heating control similar to that when the unit 53 is used is possible.

  In the third embodiment, the tank temperature detection unit 53 and the food temperature detection unit 51 are both arranged in the interior 11A of the tank body 11, and the temperature of the cooking liquid 91 is detected by the tank temperature detection unit 53 and the food temperature detection unit 51 is detected. Thus, the center temperature of the food 90 may be detected. And while controlling the energization amount to the heating coil 84 based on the temperature of the cooking liquid 91, you may control the measurement start timing of the cooking time t0 based on the center temperature of the foodstuff 90.

  In the first and second embodiments, a food temperature detector may be further provided. In the first and second embodiments, in addition to the reduced pressure heating mode, the impregnation concentration mode and the manual cooking mode may be executable.

(Experimental example)
An experiment was conducted to measure each temperature change of the ingredients, the seasoning liquid and the cooking tank when the ingredients and the seasoning liquid were put in the cooking tank and heated. As an ingredient, chicken breast meat was used. In the state where the inside of the cooking tank was depressurized from atmospheric pressure (about 101 kPa), the ingredients and the seasoning liquid were heated by raising the temperature of the cooking tank. Temperature measurement was performed using the thermometer about foodstuffs (center part and surface), seasoning liquid, and the outer surface of a cooking tank. The temperature measurement was started when the food was immersed in the seasoning liquid. As a comparative example, temperature measurement was also performed when heated under atmospheric pressure.

  FIG. 12 shows the time variation of the temperature of each of the food (center and surface), seasoning liquid, and outer surface of the cooking tank. In the graph of FIG. 12, the horizontal axis represents elapsed time (minutes), and the vertical axis represents temperature (° C.). Moreover, in the graph of FIG. 12, (A) shows the temperature change of the outer surface of a cooking tank under pressure reduction, (B) shows the temperature change of the foodstuff surface under pressure reduction, (C) is under pressure reduction. The temperature change at the center of the food is shown, and (D) shows the temperature change of the seasoning liquid under reduced pressure. Moreover, in the graph of FIG. 12, (a) shows the temperature change of the outer surface of a cooking tank under atmospheric pressure, (b) shows the temperature change of the seasoning liquid under atmospheric pressure, (c) is atmospheric pressure. The temperature change of the foodstuff center at the bottom is shown, and (d) shows the temperature change of the foodstuff surface under atmospheric pressure.

  Table 1 shows the time until the temperature at the center of the food reaches the target temperature, the total cooking time, the maximum value and the minimum value of the difference between the center temperature of the food and the surface temperature for each of the reduced pressure and the atmospheric pressure. And average values are shown respectively.

  As is clear from FIG. 12, the food temperature (B, C) under reduced pressure is longer than the food temperature (c, d) under atmospheric pressure until it reaches the target set temperature. It was short. Specifically, as shown in Table 1, the time until the central temperature of the food reaches the target temperature was 34 minutes under atmospheric pressure, but 6 minutes under reduced pressure. Moreover, the difference (all the maximum value, minimum value, and average value) between the center temperature and the surface temperature of the foodstuff became smaller under reduced pressure than under atmospheric pressure.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1, 2, 3 Cooker 10 Cooking tank 20 Temperature raising means 30 Pressure reducing means 34, 85 Pressure reducing pump 40 Air introduction means 50, 53 Tank temperature detecting part 51 Food temperature detecting part 60, 88 Control part 70 Input part 88B Time measuring part 90 Food 91 Cooking liquid P1 Saturated steam pressure T, T1 Cooking temperature t0 Cooking time

Claims (12)

A sealable cooking tank in which ingredients and cooking liquid are stored;
A temperature raising means for raising the temperature of the cooking tank;
Decompression means for decompressing the inside of the cooking tank;
A controller for controlling the temperature raising means and the pressure reducing means,
The control unit controls the decompression unit so that the inside of the cooking tank is decompressed to a saturated vapor pressure at a predetermined cooking temperature, and the cooking tank is maintained at the cooking temperature in the decompressed state. A cooker that controls the heating means. Further comprising a tank temperature detection unit for detecting the temperature of the cooking tank,
The said control part is a cooking appliance of Claim 1 which controls the said temperature rising means so that the temperature detected by the said tank temperature detection part is maintained at the said cooking temperature.   The cooking device according to claim 2, further comprising a food temperature detector that detects a temperature of the food.   The said control part is a cooking appliance of Claim 3 containing the time measurement part which starts the measurement of cooking time, when the temperature detected by the said food material temperature detection part reaches | attains the said cooking temperature. The decompression means is controlled by the control unit, and has a decompression pump that decompresses the cooking tank by sucking air in the cooking tank.
The controller stops the operation of the decompression pump after the cooking tank is depressurized to the saturated vapor pressure, and controls the temperature raising means so that the cooking tank reaches the cooking temperature after the stop. The cooking device according to any one of claims 1 to 4.   The cooker of any one of Claims 1-5 further provided with the input part which can input the setting value of the cooking temperature and cooking time of the said foodstuff. It is configured to be controllable by the control unit, further comprising an air introduction means for introducing air into the cooking tank,
The said control part is a cooking appliance of any one of Claims 1-6 which controls the said pressure reduction means and the said air introduction means so that the pressure_reduction | reduced_pressure and return pressure in the said cooking tank may be repeated. A cooking method of cooking by heating in a sealable cooking tank in which ingredients and cooking liquid are stored,
Setting the cooking temperature of the ingredients;
Cooking the ingredients at the cooking temperature, and
In the cooking step, the cooking tank is maintained at the cooking temperature in a state where the inside of the cooking tank is depressurized to the saturated vapor pressure of the cooking temperature.   The cooking method according to claim 8, wherein in the heating cooking step, a temperature of the cooking tank detected by a tank temperature detection unit provided in the cooking tank is maintained at the cooking temperature.   The cooking method according to claim 9, wherein in the heating and cooking step, measurement of cooking time is started from the time when the temperature of the food material reaches the cooking temperature. In the cooking step,
The inside of the cooking tank is decompressed by sucking the air in the cooking tank by a decompression pump,
The operation of the decompression pump is stopped after the inside of the cooking tank is reduced to the saturated vapor pressure, and the cooking tank reaches the cooking temperature after the stop. The cooking method described.   The cooking method according to any one of claims 8 to 11, further comprising a step of setting a cooking time of the food before the step of cooking by heating.

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