Ohmic heating device, and method for steaming and cooking a leavening food product

Abstract

The present disclosure relates to an ohmic heating device (1) configured for the rising and / or cooking of a leavening food product (PAL) comprising: - a heating enclosure (2) configured to receive a leavening food product; - at least two electrodes comprising a first electrode (3A) and a second electrode (3B) inside the heating enclosure and configured to be in contact with the leavening food product; - a power source (4) configured to produce a difference in voltage between the at least two electrodes (3A, 3B) and a flow of current between the two electrodes and through the leavening food product that heats the leavening food product via Joule heating.

Description

Description Title: Ohmic heating apparatus, and method for steaming and cooking a leavening food product [1] The present disclosure relates to an ohmic heating apparatus. The present disclosure further relates to a method of steaming and cooking a food product, in particular a leavening food product (such as fermented bakery dough) implemented in such an apparatus. [2] The ohmic heating device and the steaming and baking process find a particular application for carrying out, under optimized temperature conditions, the rising of a bakery dough under fermentation, then its baking for the production of bread. Technical field [3] The present disclosure relates to the field of ohmic heating apparatus and method. The ohmic heating technique, also known as Joule heating, consists of generating heat in the product to be heated by passing an electric current through the product then used as an electrical resistor. [4] Ohmic heating methods find particular application for cooking food products. The present disclosure, however, is more particularly concerned with the state of the art of ohmic heating devices used for the proofing and cooking of bakery dough, and more particularly of fermenting dough, typically containing fermentation agents such as yeasts. Prior art [5] The state of the art knows the use of ohmic heating for the operations of rising under fermentation and cooking of bread dough, in particular with the objective of making crustless sandwich bread. [6] An ohmic heating device can thus be configured for the proving and / or cooking of a food product, conventionally comprising: - a heating enclosure configured to receive a food product - at least two electrodes comprising a first electrode and a second electrode, internal to said heating enclosure, configured to be in contact with the rising food product, - an electrical source typically comprising a transformer, the electrical source configured to generate a voltage difference between said at least two electrodes and the circulation of a current flow between the two electrodes, through the rising food product, ensuring heating of the rising food product by Joule effect. [7] It is also known to use this heating technique for the study of the physicochemical properties of bakery dough during baking, in that the rising phase of the dough in fermentation, then the baking of the dough can be carried out, successively in said heating chamber of the ohmic heating device, under optimized temperature conditions. During the proving phase, the heat generated by the circulation of the electric current allows the dough to rise to an optimal temperature, in order to reduce the proving time. [8] However, according to the inventors' findings: - state-of-the-art ohmic heating appliances require significant control of cooking parameters during proving and cooking operations, - this results in particular in the failure to reduce the capacity of operators to carry out a large volume of tests, and more particularly to carry out a large number of simultaneous cooking tests simultaneously, for example in order to simultaneously study a number of different recipes for bakery doughs cooked simultaneously by different heating appliances, or to test different temperature settings during heating for the same food product recipe. Summary [9] This disclosure improves the situation.

[0010] According to a first aspect, there is provided an ohmic heating apparatus configured for proving and / or cooking a rising food product comprising: - a heating enclosure configured to receive a rising food product - at least two electrodes comprising a first electrode and a second electrode, internal to said heating enclosure, configured to be in contact with the rising food product, - an electrical source configured to generate a voltage difference between said at least two electrodes and the circulation of a current flow between the two electrodes, through the rising food product, ensuring heating of the rising food product by Joule effect.

[0011] According to the present disclosure, the electrical source is controllable, said ohmic heating device comprising: - a temperature probe configured to target the temperature of the food product rising inside said heating enclosure, said temperature probe generating a temperature signal, - a level / displacement sensor configured to target a rising height of the food product rising inside the heating enclosure generating a level signal, - a regulation device comprising a processing unit comprising at least one processor having as inputs said temperature signal and said level signal, and as output a control signal for the controllable electrical source.

[0012] The features set out in the following paragraphs may, optionally, be implemented, independently of each other or in combination with each other:

[0013] The level / displacement sensor may be an ultrasonic sensor providing said level signal SN. The level / displacement sensor may also be a time-of-flight camera, also known as a TOF camera, the device comprising software for calculating the height at several points or for calculating the volume of the product during the proving and / or cooking of said product from the measurements taken by said camera to provide said level signal SN.

[0014] According to one embodiment, the processing unit comprises a memory comprising instructions configured to generate a control signal configured to ensure control of the temperature of the rising food product, according to a closed-loop regulation from the temperature signal as feedback, at at least one target temperature by controlling the current flow of the electrical source, and according to at least two setpoint temperature profiles for the food product comprising: - at least a first set temperature profile during a first heating phase, when said level signal corresponds to a rising height of the rising food product lower than a rising threshold value and, - at least one second set temperature profile during a second heating phase, when the level signal corresponds to a rising height of the rising food product greater than said rising threshold value and in which the control device is configured to trigger the transition from the first heating phase to the second heating phase when the level signal reaches the rising threshold value.

[0015] According to one embodiment, the voltage source comprises a voltage variator configured to ensure adjustment of the voltage between said at least two electrodes, according to at least two setpoint voltages comprising a first setpoint voltage and a second setpoint voltage and in which the regulation device is configured to ensure control of the control signal so as to ensure control of the voltage variator according to said at least two setpoint voltages determined and controlled from the level signal of the level sensor.

[0016] According to one embodiment, said at least two setpoint voltages comprise said first setpoint voltage when said level signal corresponds to a rising height of the rising food product lower than said rising threshold value and said second setpoint voltage, higher than the first setpoint voltage, when the level signal corresponds to a rising height of the rising food product higher than said rising threshold value.

[0017] According to one embodiment, said ohmic heating device comprises: - at least one vent of said heating enclosure in communication with an external atmosphere, - a fan, configured to ensure extraction of an atmosphere internal to said enclosure through said at least one vent - a humidity sensor configured to target the humidity of the atmosphere internal to said enclosure of heater generating a humidity signal and wherein the control device is configured to trigger the fan when a humidity signal exceeds a first humidity threshold value and stop the fan when the humidity signal drops or reaches a second, lower humidity threshold value.

[0018] According to one embodiment, said apparatus comprises a user interface configured to provide configuration of: - said at least one target temperature, including said at least one first setpoint temperature profile and said at least one second setpoint temperature profile, and / or - said growth threshold value 3, and / or - said at least two setpoint voltages, including the first setpoint voltage (Uc1) and / or the second setpoint voltage (Uc2), - said first humidity threshold value (VSH).

[0019] According to one embodiment, said apparatus comprises a housing and a lid, the housing forming a bottom wall and side walls of the heating enclosure, defining an upper opening allowing the heating enclosure to be loaded with the rising food product, in a lid-open position, said lid configured to close the upper opening of the housing in a lid-closed position.

[0020] According to one embodiment, said apparatus comprises all or part of the following characteristics: - the two electrodes, including the first and second electrodes, comprise two conductive plates, extending parallel to each other in a vertical direction of the heating enclosure, from or near the bottom wall, and up to the level of the upper opening, - the level / displacement sensor is mounted on the cover, oriented in a reading direction extending between the two electrodes.

[0021] According to one embodiment, said cover comprises an electrical connection device comprising a second housing, secured to an external face of the cover, said connection device connected to the electrical source via an electrical cable comprising an electrical plug, configured to engage with an electrical plug within the second housing, and electrical connections within the second housing connecting said electrical plug of the second housing to said at least two poles, on an internal face of the cover, through the cover, said at least two poles configured to come into contact with the two electrodes in the closed position of the cover, and to release the electrodes in said open position of the cover.

[0022] According to one embodiment, said apparatus comprises a safety system comprising at least a first presence sensor configured to detect the closed position of the cover, said safety system configured to authorize operation of the electrical source and supply of the electrodes when the closed position is detected and to block operation of the electrical source and prohibit the electrical supply when the presence sensor does not detect the closing of the cover.

[0023] According to one embodiment, said safety system comprises a second presence sensor and a third presence sensor, embedded on the cover, the second presence sensor and the third presence sensor configured to detect respectively the presence of the first electrode and the second electrode in said closed position of the cover, and in which said safety system is configured to authorize operation of the electrical source when the second presence sensor and the third presence sensor detect the two electrodes and to block operation of the electrical source when the second presence sensor and the third sensor do not detect the two electrodes.

[0024] According to one embodiment, the cover comprises a first closing portion covering the upper opening of the housing, ensuring the closure of the upper opening of the housing, said first portion incorporating the humidity sensor and at least one second portion in a projecting extension lower than the first portion, ensuring support for the fan, so as to position the fan in line with said at least one vent materialized in one of the side walls of the housing.

[0025] According to one embodiment, the housing is wholly or partly transparent, configured to ensure inspection of the rising food product during heating, in said lid closing position.

[0026] According to a second aspect, the present disclosure further relates to a method of steaming and cooking a rising food product implemented in an ohmic heating apparatus according to the present disclosure, said method comprising: - a loading of a food product rising in said heating enclosure, in contact with the two electrodes comprising the first electrode and the second electrode, - an implementation of a heating cycle by the control device with closed-loop control from the temperature signal as feedback and, according to an automatic sequence comprising at least: - a first heating phase configured to ensure proving of the food product for which the control device ensures heating of the food product according to a first set temperature profile at a maximum temperature up to 45°C when said level signal corresponds to a proving height of the rising food product lower than a proving threshold value - a second heating phase for which the control device ensures heating according to a second set temperature profile, said second phase configured to ensure cooking at a temperature higher than said maximum temperature, when the level signal corresponds to a rising height of the rising food product higher than said rising threshold value and in which the transition from the first heating phase to the second heating phase is ensured by the control device when the level signal reaches the rising threshold value.

[0027] The leavened food product may typically be a fermented bakery dough. Brief description of the drawings

[0028] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analyzing the attached drawings, in which:

[0029] Fig. 1 is a perspective view (partial) of an ohmic heating apparatus comprising: - a heating enclosure, formed by a housing body, preferably transparent, having a lower orifice in the bottom wall for the passage of a temperature probe, intended to be inserted into the food product inside said heating enclosure; - two electrodes comprising a first electrode and a second electrode formed respectively by two parallel, vertical plates, arranged internal to said heating enclosure, configured to be in contact with the food product; - a removable cover in a retracted position, allowing the unloading or loading of the heating enclosure, the cover being carried; - a level / displacement sensor configured to target the height of the dough, and thus measure the rise in the heating chamber; - several presence sensors with a safety system function, with a first sensor configured to detect the closing of the cover, but also two presence sensors arranged to detect the presence of the two electrodes respectively; - an electrical connection device comprising a second housing, integral with an external face of the cover connected to the electrical source by an electrical cable (not shown) and mutually engaging electrical plugs between the second housing and the cable, and electrical connections within the second housing connecting poles of the electrical plug of the second housing to at least two poles on an internal face of the cover, through the cover, said at least two poles configured to come into contact with the two electrodes in the closed position of the cover, and to release the electrodes in said open position of the cover; - a humidity sensor configured to target the humidity of the atmosphere internal to said heating enclosure; - an electric fan secured to the cover and arranged to be placed opposite a vent on one of the side walls of the housing of said heating enclosure.

[0030] Fig. 2 is a view according to Fig. 1, from another angle illustrating the underside of the cover.

[0031] Fig. 3 is a view of the heater in the lid closed position.

[0032] Fig. 4 is a top view of Figure 3.

[0033] Fig. 5 is a view of an apparatus comprising a control device comprising a processing unit, typically a multi-channel industrial programmer / controller, configured to control several heating enclosures in parallel, ensuring regulation according to the sensors, in particular the temperature signal from the temperature probe, the level signal from the level sensor and the humidity signal from the humidity sensor for each of the heating enclosures.

[0034] Fig. 6 is a schematic view of the ohmic heating device comprising said heating enclosure, and the various sensors, the controllable electrical source, and the regulation device ensuring closed-loop regulation typically PID, as well as the user interface comprising a computer.

[0035] Fig. 7 shows from top to bottom, four (fictitious) graphs acquired simultaneously during a heating cycle of a rising food product, and more particularly: - a first graph illustrating the temperature on the ordinate and the time on the abscissa, illustrating a curve illustrating the value of the temperature signal from the temperature probe inserted into the food product, as well as temperature instructions associated with a first rising phase between time to and t s and temperature instructions associated with a second cooking phase between time t sand tf a second graph illustrating, on the ordinate, the rising height and on the abscissa the time, illustrating a curve illustrating the rising height measured by the level sensor over the time between time to and tf, time ts corresponding to the time taken for the rising height to reach a determined rising threshold value VSP; a third graph illustrating the control voltage generated by the controllable electrical source, with a first setpoint voltage, during the rising phase between time to and ts and a second setpoint voltage during the cooking phase between time t sand tf, the transition from the first setpoint voltage to the second setpoint voltage being triggered automatically by the regulation device as soon as the measurement of the level sensor reaches or exceeds the threshold value VSP a fourth graph illustrating the evolution of the humidity in the heating enclosure measured by the humidity sensor, as a function of a regulation implemented by the fan between two humidity thresholds.

[0036] Fig. 7a is a view of the control of the power delivered by the controllable electrical source, at a determined set voltage, which is preferably variable, by a power control by PWM (abbreviated English for "Pulse With Modulation" or in French "pulse width modulation").

[0037] Fig. 7b is a schematic view of the closed-loop PID control comprising a setpoint temperature Te and a temperature control loop according to the signal ST measured by the temperature probe.

[0038] Fig. 8a is a detail of a schematic view of a variant of the ohmic heater including a time-of-flight sensor camera;

[0039] Fig. 8b is a view of the apparatus of Fig. 8a complete with protective cover over the time-of-flight sensor camera. Description of the embodiments

[0040] The present disclosure relates to an ohmic heating apparatus 1 configured for proving and / or cooking a rising food product PAL comprising: - a heating enclosure 2 configured to receive a food product, typically leavening, - at least two electrodes comprising a first electrode 3A and a second electrode 3B, internal to said heating enclosure, configured to be in contact with the rising food product, - an electrical source 4 configured to generate a voltage difference between said at least two electrodes 3A, 3B and the circulation of a current flow between the two electrodes, through the rising food product, ensuring heating of the rising food product by Joule effect.

[0041] With reference to figure 1, and in general, said ohmic heating device may comprise a housing 11 and a cover 12, delimiting a volume of the heating enclosure.

[0042] The housing typically forms a bottom wall 11 a and side walls 11 b, 11 c, 11 d, 11 e of the heating enclosure 2, and defines an upper opening 13 allowing the heating enclosure to be loaded with the rising food product PAL, in an open position PO of the lid. Said lid 12 is configured to close the upper opening 13 of the housing in a lid closing position PF. The housing may be transparent, in whole or in part, at least at the side walls, in order to allow visual inspection by an operator, at least in a lid closing position PF.

[0043] Once the lid is closed, said heating enclosure can be sufficiently sealed to allow the food product to be steamed, making it possible to obtain an internal atmosphere of maximum humidity typically greater than 60%, or even 80% or even 90%, or even greater than 95%.

[0044] Generally, the two electrodes, including the first electrode 3A and the second electrode 3B, may comprise (or consist of) respectively two conductive plates, extending parallel to each other in a vertical direction of the heating enclosure 2, in particular from or near the bottom wall 11a, and up to the level of the upper opening. The dimension of the electrodes is, depending on the height, excessive compared to the volume of the food product dough initially inserted between the two electrodes 3A; 3B.

[0045] When heating is carried out, the food product is inserted into said heating chamber, between the two electrodes 3A, 3B and is brought into contact with the latter, typically on a lower section of the two electrodes 3A and 3B. During ohmic heating, the food product grows upwards along the vertical electrodes, increasing the contact surface between the two electrodes 3A, 3B and the rising food product PAL.

[0046] According to the present disclosure, the electrical source 4 is controllable, and may comprise for this purpose an electrical power transformer which makes it possible to control the electrical power delivered over time.

[0047] The electrical transformer can be used to control the power delivered, at a determined setpoint voltage, which is preferably variable, by PWM power control ("Pulse With Modulation" or "pulse width modulation"). Such control is illustrated in Figure 7a which illustrates the voltage U (constant) versus time, at each period.

[0048] The duty cycle a is a percentage determined as follows: a = (100xAT) / T.

[0049] By decreasing the duty cycle a, the heating is decreased, and by increasing it, the heating is increased.

[0050] Notably, the ohmic heater includes: - a temperature probe 5 configured to target the temperature of the food product rising inside said heating enclosure 2, said temperature probe 5 generating a temperature signal, ST, - a level / displacement sensor 6 configured to target a rising height of the food product rising inside the heating enclosure 2, said sensor generating a level signal, SN, - a regulation device 7 comprising a processing unit 70 comprising at least one processor having as inputs said temperature signal ST and said level signal SN, and as output a control signal SC of the electrical source 4, controllable.

[0051] The temperature probe 5 may typically be a thermocouple, internal to the heating enclosure, said probe configured to be inserted into the food product. The bottom wall 11a may comprise for this purpose an opening OR, intended to be crossed by the temperature probe, or even a cable of the temperature probe.

[0052] The bottom wall 11a may include on an underside protruding Pt legs, allowing the housing to be placed on a flat surface, vertically, in a stable manner, while allowing the temperature probe cable to pass from below between the Pt legs.

[0053] According to one embodiment, the level / displacement sensor 6 may be embedded on the cover, oriented in a reading direction, typically vertical, extending between the two electrodes 3A, 3B. The level sensor 6 may be a contactless distance sensor, for example ultrasonic, comprising a transmitter configured to emit emission radiation which is reflected by the food product, and a receiver configured to receive the radiation reflected by the food product.

[0054] Such a sensor is configured to determine the distance between the food product and the sensor from the time interval between an emission of the emitted radiation and the reception of the reflected radiation. On the other hand, such a sensor is quite directional, that is to say, it measures the distance from a point or a small surface of the dough during rising.

[0055] According to the embodiment of figures 8a and 8b the sensor is a time of flight camera (TOF sensor for time of flight in English) 61 associated with volume calculation software allowing the altitude of the surface of the dough to be mapped during rising and thus the volume of the latter to be known.

[0056] In this embodiment, the device comprises software for calculating the height at several points or for calculating the volume of the product during the proving and / or cooking of said product from the measurements taken by said camera to provide said level signal SN which may for example be a signal representative of the average height of the product or its volume when a TOF camera and its surface calculation software are used.

[0057] The TOF camera makes it possible to avoid measurement errors caused, for example, by bubbles on the surface of the dough which distort a measurement made by an ultrasonic sensor pointed at the location of one of these bubbles.

[0058] The height of the device will be adapted so that the 610 field of the camera takes the total surface of the product during growth.

[0059] When using a TOF camera, one problem is the influence of humidity in the chamber cavity on the measurement. Indeed, the presence of fog in the chamber will disrupt the measurement. It has been determined that activating the fan 9 when the humidity exceeds 50% will sufficiently reduce the presence of fog, which allows for a correct representation of the surface of the dough during rising. In addition, the fan 9 will be placed at the top of the chamber in this embodiment.

[0060] The control device 7 will then be configured to trigger the fan when a humidity signal exceeds a first humidity threshold value VSH1, for example 50% or 55%, and to stop the fan when the humidity signal drops or reaches a second humidity threshold value (VSH2), lower than, for example, 40% or 45%. The control can also be done continuously, the control device adjusting the fan speed according to the humidity.

[0061] According to Figure 8a, the TOF camera 61 is arranged in a groove made in the cover 12 and according to Figure 8b, this camera is covered by a protective plate 62.

[0062] According to one embodiment, in particular that of Figure 3, the cover 12 may comprise an electrical connection device which may comprise a second housing 14, integral with an external face of the cover 12. Said connection device is connected to the electrical source via an electrical cable. The electrical cable comprises a male (resp. female) electrical plug configured to be connected with a female (resp. male) plug F1 integrated into the second housing 14. Electrical connections are provided within the second housing 14 connecting the poles of said electrical plug within the second housing 14 to said at least two poles PL1, PL2, arranged on an internal face of the cover, through the cover.Said at least two poles PL1, PL2 arranged on the internal face of the cover 12 are configured to come into electrical contact with the two electrodes 3A, 3B in the closed position PF of the cover, and to release the electrodes 3A, 3B in said open position PO of the cover.

[0063] According to an advantageous embodiment, said ohmic heating device 1 may comprise a safety system comprising at least one first presence sensor 15 configured to detect the closing position of the cover PF. Said safety system is configured to authorize operation of the electrical source 4 and the supply of the electrodes 3A, 3B, when the closing position PF is detected, and to block the operation of the electrical source and prohibit the electrical supply when the presence sensor does not detect the closing position PF of the cover.

[0064] According to one embodiment, said safety system may comprise a second presence sensor 16 and a third presence sensor 17, embedded on the cover, the second presence sensor and the second presence sensor configured to respectively detect the presence of the first electrode 3A and the second electrode 3B in said closed position PF of the cover. Said safety system is then configured to authorize operation of the electrical source when the second presence sensor 16 and the third presence sensor 17 detect the two electrodes 3A, 3B and to block operation of the electrical source when the second presence sensor and the third sensor do not detect the two electrodes 3A and 3B.

[0065] The processing unit 70 may typically be an industrial regulator or programmer, and in particular based on multiprocessors and multichannel measurement systems, for the implementation of several simultaneous regulations implemented in different heating enclosures 2.

[0066] The electrical source may then typically comprise an isolation transformer connected to the electricity network, and one or more variable transformers (one variable transformer per heating enclosure) connected to the isolation transformer (setting typically between 0V and 220V), the or each variable transformer comprising a rotary adjustment knob controlled by a servomotor of the regulation device 7. These components of the electrical source may be integrated into a casing of the industrial programmer / regulator.

[0067] According to one embodiment, the processing unit 70 may comprise a memory comprising instructions configured to generate a control signal SC configured to ensure control of the temperature of the rising food product, according to a closed-loop regulation from the temperature signal ST as feedback, at at least one setpoint temperature, by controlling the current flow of the electrical source, and according to at least two setpoint temperature profiles for the food product comprising at least: - a first set temperature profile Tc1a, Tc2b during a first heating phase when said level signal SN corresponds to a rising height of the rising food product lower than a rising threshold value VSP, - a second set temperature profile Tc2a, Tc2b, during a second heating phase when the level signal corresponds to a rising height of the rising food product greater than said rising threshold value VSP.

[0068] Generally, closed-loop control is illustrated as an example in Figure 7b and can typically be PID (proportional, integral, derivative) control: - the setpoint value is a setpoint temperature Te (which is typically variable in function of time; see Tc1a, Tc1b for the first heating phase, Tc2a and Tc2b for the second heating phase in particular) - the setpoint value Te is compared with the value of the temperature signal ST of the feedback loop of the PID regulation, resulting in an error s resulting from the difference, - the PID function applied to s generates the control signal SC of the electrical source, - the function of the heating process marked PR applied to the control signal SC generates a temperature of the food product measured by the temperature signal ST.

[0069] According to the present disclosure, the regulation device 7 is configured to trigger the transition from the first heating phase to the second heating phase when the level signal SN reaches the thrust threshold value VSP. The fan is for example used to regulate the humidity in the enclosure around 50% as long as the TOF camera is in operation and the level SN is not reached when such a camera is used.

[0070] The apparatus according to the present disclosure can advantageously allow the implementation of a process for steaming and cooking a leavening food product comprising: - loading a rising food product PAL into said heating enclosure 2 in contact with the two electrodes comprising the first electrode 3A and the second electrode 3B, - an implementation of a heating cycle by the control device with closed-loop control from the temperature signal ST as feedback, according to an automatic sequence comprising at least - a first heating phase configured to ensure a rise of the food product for which the regulation device 7 ensures a heating of the food product, according to a first set temperature profile Tc1a, Tc1b at a maximum temperature up to 45°C when said level signal SN corresponds to a rise height of the rising food product lower than a rise threshold value VSP, - a second heating phase for which the regulation device 7 ensures heating according to a second set temperature profile Tc2a, Tc2b, said second phase configured to ensure cooking at a temperature higher than said maximum temperature, when the level signal NV corresponds to a rising height of the rising food product higher than said rising threshold value VSP.

[0071] The method according to the present disclosure finds a particular application when the leavening food product is a fermented bakery dough.

[0072] The heating appliance 1 according to the present disclosure thus makes it possible to implement a rising of the rising food product, at a temperature optimized to reduce the rising time according to a closed-loop regulation, on the first set temperature profile, always less than or equal to 45°, and cooking, always according to a closed-loop regulation, according to a second set temperature profile.

[0073] According to the present disclosure, the transition from the first heating phase to the second heating phase is advantageously ensured by the regulation device when the level signal SN given by the level / displacement sensor reaches the thrust threshold value VSP.

[0074] The ohmic heating apparatus 1 according to the present disclosure thus advantageously makes it possible to carry out a complete cycle comprising the proving and cooking of the food product, and under conditions optimized for the two phases (namely the first proving phase and the second cooking phase) reducing the time of the complete cycle, and advantageously without control intervention by an operator during the complete cycle, which is fully automated.

[0075] This increases the capacity to implement studies or trials.

[0076] For example, the present disclosure may allow the same operator having several heating enclosures 2, for example four in number as illustrated in Figure 5, to simultaneously launch several complete heating cycles for the proving and cooking of the different rising food products.

[0077] In particular, it may be possible to compare the rising and baking performance of different recipes for food products received in the different heating chambers 2, in particular different recipes for fermented bakery dough, and with a view to comparing them. The different recipes may make it possible to take into account a difference in recipe parameters, for example, in the nature or quantity of yeast, a different water content, a quantity of flour.

[0078] It may also be possible in particular to compare the proving and cooking performance of the same recipe for food products received in the different heating chambers 2, in particular according to different proving and / or cooking temperature profiles, by simultaneously implementing different regulations comprising in particular distinct setpoint temperature profiles.

[0079] Generally, the voltage source, in particular the transformer, may comprise a voltage regulator configured to ensure adjustment of the voltage between said at least two electrodes 3A, 3B, according to at least two setpoint voltages comprising a first setpoint voltage Uc1 and a second setpoint voltage Uc2.

[0080] The regulation device is configured to ensure control of the control signal SC so as to ensure control of the voltage variator according to said at least two setpoint voltages determined and controlled from the level signal SN of the level sensor.

[0081] In particular, said at least two reference voltages may comprise: - a first setpoint voltage Uc1, in particular when said level signal SN corresponds to a rising height of the rising food product lower than said rising threshold value VSP during the first rising phase and, - a second setpoint voltage Uc2, higher than the first setpoint voltage, during the second rising phase, when the VSP level signal corresponds to a rising height of the rising food product greater than said VSP rising threshold value.

[0082] The first set voltage Uc1 is typically optimized for the rising phase of the rising food product, in particular fermented bakery dough, and is typically less than 100V, for example equal to 80V.

[0083] The second setpoint voltage Uc2 is typically optimized for the cooking phase of the rising food product and can typically be greater than or equal to 100V, for example 180V.

[0084] The second setpoint voltage Uc2 is typically higher than the first setpoint temperature Uc2 in order to achieve higher temperatures of the food product during the cooking phase. A higher setpoint voltage also allows for the lower conductivity of the rising food product during the second heating phase to be taken into account. A lower conductivity can be explained by a higher content of unreleased gas pockets from the food product, in particular the fermented dough, due to the development of the fermented dough, during the second heating phase, and in comparison to the gas content of the food product during the first heating phase.

[0085] According to an advantageous embodiment, the ohmic heating device 1 according to the present disclosure can allow regulation of the atmosphere internal to the heating enclosure 2.

[0086] For this purpose, said device may include: - at least one vent 8a, 8b of said heating enclosure in communication with an external atmosphere, - a fan 9, configured to ensure extraction of an atmosphere internal to said enclosure through said at least one vent 8a, 8b, - a humidity sensor 10 configured to target the humidity of the atmosphere internal to said heating enclosure, generating a humidity signal.

[0087] According to such an embodiment, the control device 7 is configured to trigger the fan when a humidity signal exceeds a first humidity threshold value VSH1 and stop the fan when the humidity signal drops or reaches a second, lower humidity threshold value VSH2. The second humidity threshold value can be determined automatically by calculation from the first humidity threshold value VSH1, according to the following formula: VSH2 = VSH1 - p where p is a constant less than VSH1.

[0088] Regulation of the humidity level of the atmosphere inside said enclosure can make it possible to obtain a humidity level high enough to promote the growth of the food product, in humid conditions, favorable to fermentation reactions, in particular the growth of fermented dough, the humidity remaining however lower than the first threshold value VSH1.

[0089] Limiting the humidity level inside the heating enclosure 2, below the first threshold value can advantageously prevent: - the formation of fog which may interfere with a detection part of the sensor level / displacement, especially if it is a TOF camera type sensor, - the accumulation of water by condensation on the electrodes, likely to constitute hot spots which can disrupt heating by the Joule effect, - the formation of fog on the side walls of the housing, which may obstruct transparent viewing, - condensation phenomena on the food product, which can harm the quality of the bread.

[0090] Generally, the cover 12 may comprise a first closure portion 120 covering the upper opening of the housing, ensuring the closure of the upper opening of the housing. Said first closure portion 120 houses the humidity sensor. The cover 12 may comprise at least one second extension portion 121, projecting lower than the first closure portion, in particular forming a bracket providing support for the fan 9, so as to position the fan in line with said at least one vent 8a or 8b materialized in one of the side walls of the housing 11.

[0091] In general, said heating appliance may be provided with a GUI user interface configured to ensure setting of the regulation parameters, and in particular (in whole or in part): - said at least one target temperature, including said first setpoint temperature profile Tel a, Tel b and said at least second setpoint temperature profile Tc2a, Tc2b, and / or - said growth threshold value, and / or - said at least two setpoint voltages, including the first setpoint voltage Uc1 and the second setpoint voltage Uc2, and / or - said first humidity threshold value VSH1.

[0092] The GUI user interface may be a computer implementing a computer program where all or part of the various regulation parameters can be edited. Once the regulation parameters have been edited, said user interface may be connected to the processing unit 70 which implements the heating cycle, with the temperature regulation.

[0093] Once the heating cycle is completed, said GUI user interface can be used to collect the test data (such as temperature, growth height, humidity, energy consumption... as a function of time) in particular from the different sensors, and as illustrated in Figure 7.

[0094] Figure 7 illustrates from top to bottom, four graphs (fictitious here illustrated for the purposes of explanation) which can be acquired simultaneously during a heating cycle of a rising food product, extending between an initial time to and a final time tf, and more particularly: - a first graph illustrating the temperature on the ordinate and the time on the abscissa, illustrating a curve illustrating the profile of the actual temperature TR measured by the temperature probe within the food product, as well as temperature instructions Tc1a and Tc1 b associated with a first rising phase between time to and ts and temperature instructions Tc2a and Tc2b associated with a second cooking phase between time t s and tf, - a second graph illustrating the growth height on the ordinate and the time on the abscissa, illustrating a curve illustrating the growth height measured by the level sensor over time, time t s corresponding to the time taken for the growth height to reach a growth threshold value VSP, - a third graph illustrating the control voltage generated by the controllable electrical source, with a first set voltage during the proving phase between time to and ts and a second set voltage during the cooking phase between time t sand tf, the transition from the first voltage setpoint to the second voltage setpoint being triggered automatically by the regulation device 7 as soon as the measurement from the level sensor reaches or exceeds the thrust threshold value VSP, - a fourth graph illustrating the evolution of the humidity in the heating enclosure, as a function of a regulation implemented by the fan between two humidity thresholds, namely the first humidity threshold value VSH1 and the second, lower humidity threshold value.

[0095] Once the cycle implemented by the processing unit 70 is completed, the data collected as a function of time (such as measured temperatures and / or measured growth height and / or measured humidity value and / or measured energy consumption values) can be saved / downloaded / transferred to a file, for example a spreadsheet data file, typically in a memory of the graphical interface. A program of the graphical interface can allow the visualization of several curves, and in particular of the measured temperature as a function of time (in particular according to graph 1), and / or of the measured growth height as a function of time (in particular according to graph 2), and / or of the set voltages as a function of time (in particular according to graph 3), and / or of the measured humidity value as a function of time (in particular according to graph 4) and / or of the energy consumption value as a function of time. List of reference signs

[0096] - 1. Ohmic heating device, - 2. Heating enclosure, - 3A, 3B. First and second electrodes, - 4. Electrical source, - 5. Temperature probe - ST. Temperature signal (temperature probe), - 6. Level / displacement sensor, - SN. Level signal (level / displacement sensor), - 7. Regulation device, - 70. Processing unit, - SC. Control signal (control device output), - Uc1, Uc2. Respectively first and second set voltage, - VSP. Threshold growth value, - 8a, 8b. Events, - 9. Fan, - 10. Humidity sensor, - SH. Humidity signal, - VSH1. First humidity threshold value, - VSH2. Second humidity threshold value, - 11. Housing, - 11a. Back wall, - OR. Opening (in the back wall for the temperature probe) - 1 b, 11c, 11 d, 11e. Side walls, - 12. Cover. - 13. Upper opening, - 14. Second box, - 15. First presence sensor (cover closing detection) - 16, 17. Second and third presence sensor (respective detections of the second and third electrodes) - PO, PF. Respectively the opening position and closing position of the cover.

Claims

Claims

1. Ohmic heating apparatus (1) configured for proving and / or cooking a rising food product (PAL) comprising: - a heating enclosure (2) configured to receive a rising food product - at least two electrodes comprising a first electrode (3A) and a second electrode (3B), internal to said heating enclosure, configured to be in contact with the rising food product, - an electrical source (4) configured to generate a voltage difference between said at least two electrodes (3A, 3B) and the circulation of a current flow between the two electrodes, through the rising food product, ensuring heating of the rising food product by Joule effect characterized in that the electrical source (4) is controllable, said ohmic heating device comprising: - a temperature probe (5) configured to target the temperature of the food product rising inside said heating enclosure, said temperature probe generating a temperature signal (ST) - a level / displacement sensor (6) configured to target a rising height of the food product rising inside the heating enclosure generating a level signal (SN), - a regulation device (7) comprising a processing unit (70) comprising at least one processor having as inputs said temperature signal (ST) and said level signal (SN), and as output a control signal (SC) of the electrical source (4), controllable.

2. Apparatus according to claim 1 wherein the level / displacement sensor is an ultrasonic sensor providing said level signal (SN).

3. Apparatus according to claim 1 for which the level / displacement sensor is a time-of-flight camera also known as a TOF camera, the apparatus comprising software for calculating height at several points or for calculating the volume of product during the proving and / or cooking of said product from the measurements taken by said camera to provide said level signal (SN).

4. Apparatus according to claim 1, 2 or 3 wherein the processing unit (70) comprises a memory comprising instructions configured to generate a control signal configured to ensure control of the temperature of the rising food product, according to a closed-loop regulation from the temperature signal (ST) as feedback, at at least one target temperature by controlling the current flow of the electrical source, and according to at least two setpoint temperature profiles for the food product comprising: - at least a first set temperature profile (Tc1 a, Tc2b) during a first heating phase, when said level signal (SN) corresponds to a rising height of the rising food product lower than a rising threshold value (VSP) and, - at least a second set temperature profile (Tc2a, Tc2b) during a second heating phase, when the level signal corresponds to a rising height of the rising food product greater than said rising threshold value (VSP) and wherein the regulating device (7) is configured to trigger the transition from the first heating phase to the second heating phase when the level signal (SN) reaches the thrust threshold value (VSP).

5. Ohmic heating apparatus according to one of claims 1 to 4 wherein the voltage source comprises a voltage variator configured to ensure adjustment of the voltage between said at least two electrodes (3A, 3B) according to at least two setpoint voltages comprising a first setpoint voltage (Uc1) and a second setpoint voltage (Uc2) and wherein the regulation device is configured to ensure control of the control signal (SC) so as to ensure control of the voltage variator according to said at least two setpoint voltages determined and controlled from the signal of the level signal (SN) of the level sensor.

6. An ohmic heating apparatus according to claims 4 and 5, wherein said at least two setpoint voltages comprise said first setpoint voltage (Uc1) when said level signal (SN) corresponds to a rising height of the rising food product lower than said rising threshold value (VSP) and said second setpoint voltage (Uc2), higher than the first setpoint voltage, when the level signal (VSP) corresponds to a rising height of the rising food product higher than said rising threshold value (VSP).

7. An ohmic heating apparatus according to one of claims 1 to 6, comprising: - at least one vent (8a, 8b) of said heating enclosure in communication with an external atmosphere, - a fan (9), configured to ensure extraction of an atmosphere internal to said enclosure through said at least one vent (8a, 8b) - a humidity sensor (10) configured to target the humidity of the atmosphere internal to said heating enclosure generating a humidity signal and in which the control device (7) is configured to trigger the fan when a humidity signal exceeds a first humidity threshold value (VSH1) and stop the fan when the humidity signal drops or reaches a second, lower humidity threshold value (VSH2).

8. Heating apparatus according to one of claims 4 to 7 comprising a user interface (GUI) configured to provide a setting of: - said at least one target temperature, including said at least one first setpoint temperature profile (Tc1 a, Tc1 b) and said at least one second setpoint temperature profile (Tc2a, Tc2b) when the apparatus is according to claim 2, and / or - said thrust threshold value (VSP) when the ohmic heating device is according to claim 3, and / or - said at least two setpoint voltages, including the first setpoint voltage (Uc1) and / or the second setpoint voltage (Uc2) when the apparatus is according to claim 4, - said first humidity threshold value (VSH) when said ohmic heating device is according to claim 5.

9. Ohmic heating appliance according to one of claims 1 to 8, comprising a housing (11) and a cover (12), the housing forming a bottom wall (11a) and side walls (11b, 11c, 11d, 11e) of the heating enclosure (2), defining an upper opening (13) allowing the heating enclosure to be loaded with the rising food product (PAL), in an opening position (PO) of the cover, said cover configured to close the upper opening (13) of the housing in a closing position of the cover (PF).

10. An ohmic heating apparatus according to claim 9, having all or part of the following characteristics: - the two electrodes, including the first and second electrodes (3A, AB) comprise two conductive plates, extending parallel to each other in a vertical direction of the heating enclosure (2), from or near the bottom wall (11a), and up to the level of the upper opening, (13), - the level / displacement sensor (6) is mounted on the cover (12), oriented in a reading direction extending between the two electrodes (3A, 3B).

11. An ohmic heating apparatus according to claim 9 or 10, wherein said cover comprises an electrical connection device comprising a second housing (14), integral with an external face of the cover (12), said connection device connected to the electrical source via an electrical cable comprising an electrical plug, configured to engage with an electrical plug within the second housing (14), and electrical connections within the second housing (14) connecting said electrical plug of the second housing (12) to said at least two poles (PL1, PL2), on an internal face of the cover, through the cover, said at least two poles configured to come into contact with the two electrodes (3A, 3B) in the closed position (PF) of the cover, and to release the electrodes (3A, 3B) in said open position (PO) of the cover.

12. Ohmic heating appliance according to one of claims 9 to 11, comprising a safety system comprising at least one first presence sensor (15) configured to detect the closed position of the cover (PF), said safety system configured to authorize operation of the electrical source (3) and the supply of the electrodes (3A, 3B) when the closed position (PF) is detected and to block the operation of the electrical source and prohibit the electrical supply when the presence sensor does not detect the closing (PF) of the cover.

13. Ohmic heating appliance according to claim 12, wherein said safety system comprises a second presence sensor (16) and a third presence sensor (17), embedded on the cover, the second presence sensor (16) and the third presence sensor (17) configured to detect respectively the presence of the first electrode (3A) and the second electrode (3B) in said closing position (PF) of the cover, and wherein said safety system is configured to authorize a operation of the electrical source when the second presence sensor (16) and the third presence sensor (17) detect the two electrodes (3A, 3B) and to block the operation of the electrical source when the second presence sensor and the third sensor do not detect the two electrodes.

14. Ohmic heating appliance according to claim 7 taken in combination with one of claims 9 to 13, in which the cover (12) comprises a first closing portion (120) covering the upper opening of the housing while ensuring the closure of the upper opening of the housing, said first portion embodying the humidity sensor and at least a second extending portion (121) projecting lower than the first portion, ensuring support for the fan (9), so as to position the fan (9) in line with said at least one vent (8a or 8B) materialized in one of the side walls of the housing (11).

15. Heating apparatus according to one of claims 9 to 14, in which the housing is wholly or partly transparent, configured to ensure inspection of the food product rising during heating, in said closed position of the lid (12).

16. Method for steaming and cooking a rising food product implemented in an ohmic heating appliance (1) according to one of claims 1 to 15 comprising: - loading a rising food product (PAL) into said heating enclosure, in contact with the two electrodes comprising the first electrode (3A) and the second electrode (3B), - an implementation of a heating cycle by the control device with closed-loop control from the temperature signal (ST) as feedback and, according to an automatic sequence comprising at least: - a first heating phase configured to ensure a rise of the food product for which the regulation device (7) ensures a heating of the food product according to a first set temperature profile at a maximum temperature up to 45°C when said level signal (SN) corresponds to a rise height of the rising food product lower than a rise threshold value (VSP) - a second heating phase for which the regulation device (7) ensures heating according to a second set temperature profile, said second phase configured to ensure cooking at a temperature higher than said maximum temperature, when the level signal (NV) corresponds to a rising height of the rising food product higher than said rising threshold value (VSP) and in which the transition from the first heating phase to the second heating phase is ensured by the regulation device (7) when the level signal (SN) reaches the rising threshold value (PSP).

17. A steaming and baking process according to claim 16 wherein the leavening food product is a fermented bakery dough.

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