Food cooking control method and device

1. A food cooking process control method, wherein the food is arranged in a cooking heat energy supply enclosure, supported on a reference surface or on a cooking surface, inserting a temperature detection device into said food, the method comprising:

determining the thickness of the food and positioning, based on said thickness, at least one temperature detection device inside said food in a detection zone to a pre-determined insertion depth and/or at a distance from a surface through which the food absorbs cooking heat energy, by means of the aid of positioning means;

obtaining during cooking a temperature TC in said detection zone by means of said temperature detection device at various times of the cooking process;

processing during cooking the data of said temperature TC and the data of the temperature of one or more surfaces through which the food receives the cooking heat energy or of a detected temperature in a zone close to said cooking heat energy receiving surface TP, and estimating, for each of said times of the cooking process, a temperature gradient between the zone through which it receives the cooking heat energy and the center of the food; and

stopping the heat energy supply when the mentioned TC plus the thermal inertia allow reaching a desired final equilibrium food temperature, result of the homogenization of said temperature gradient between the zone or zones through which the food receives the cooking heat energy and the center of the food, as a consequence of the heat energy accumulated in the food and provided by said gradient.

2. The method according to claim 1 , wherein the food receives the heat energy through a surface on which it is supported, by the application of a cooking heat energy source under said food, wherein said cooking process includes at least one turn-over or cooking step to reach said desired equilibrium food temperature comprising:

determining the time of said turn-over which will be at least one in number and which can be predefined by the user according to:

said temperature TC of the detection device at the time prior to each turn-over;

the evolution of the temperature of said detection zone, determined by said processing including at least one first derivative of the temperature TC; and

said temperature gradient between the outside of the food in contact with the cooking surface and said detection zone, inside the food, and

positioning said detection device after each turn of the food, based on the thickness of the food, to a pre-determined insertion depth and/or at a distance from a surface through which the food absorbs cooking heat energy, by means of the aid of said positioning means.

3. The method according to claim 2 , wherein the temperature at the end of at least one cooking step, or calculated central temperature TCC, is determined by means of the following expression

TCC=TC +(( TP−TC )× F )+ D 1 +D 2

wherein:

TC=central temperature measured at all times,

TP=temperature close to the cooking surface,

F=correction factor depending on the physical characteristics of the food, on the type of food and on the interrelation between the time derivatives of the TC and the TP, which express the value of the absorption of the heat energy received at each of the points in time and which comprise at least the thickness of said food, the water content thereof and the direction of its fibers,

D1=correction factor depending on the value of the first derivative of TC,

D2=correction factor depending on the value of the variation of the first derivative of TC or second derivative.

4. The method according to claim 2 , further comprising:

inserting into the food at least two of said temperature detection devices, by means of the aid of said positioning means, placing them inside the food at a pre-determined distance which is a percentage of the thickness and/or an absolute pre-determined distance with respect to a food support surface or from the opposite food surface; and

controlling the temperature and evolution of the temperature of each of said detection devices analyzing with a certain frequency the data or readings from said temperature detection devices to know the detected central temperature TC and the calculated central temperature TCC of the food over time.

5. The method according to claim 1 , further comprising detecting the temperature of said cooking surface of the food and/or detecting the room temperature of the cooking enclosure and/or detecting at least one zone of the food by means of at least one temperature detection device positioned inside said food at an absolute distance or a distance which is a percentage of the thickness with the aid of the positioning means.

6. The method according to claim 2 , further comprising comparing the values of said detected central temperature TC with the value of a target central temperature TCO predefined by the user depending on the cooking point required for the food, controlling said heat source according to the result of said comparisons.

7. The method according to claim 2 , further comprising:

measuring the elapsed time t 1 between said application of said heat source under the food and the time at which a signal S 1 has been generated, and once said food has been turned over, maintaining the application of said heat source under the food for an application time t 2 according to said measured time t 1 ; and

controlling said heat source to apply a same or different heating power during the measured time t 1 before turning over the food and during the application time t 2 once the food has been turned over,

wherein said control of the heat source is carried out by means of a series of pre-defined successive increments or decrements of the heating power taking into account an initial central temperature TCI of the food and the evolution of the TP or of the estimated TP.

8. The method according to claim 2 , further comprising analyzing the variation of said values of the detected central temperature TC and of the detected temperature close to the cooking surface TP over time, by means of a series of readings, as well as calculating a heat absorption function of the food with respect to time, which is a slope function TP or TC obtained as a result of the evolution of the values of the temperature which are coherent over time, to establish:

that said evolution is or is not coherent according to the difference of values between every two of said readings; and

that the central temperature TC and the detected temperature close to the cooking surface TP are increasing or decreasing according to the sign of the difference between successive values and in that:

if it is established that the evolution of the values of the detected central temperature TC is not coherent, the method comprises considering the results of said comparisons of the detected central temperature TC with said target central temperature TCO as invalid until it is established that the evolution is coherent; and

if it is established that the evolution of the values of the detected central temperature TC is coherent and that the evolution of said slope function PC is negative, but that the result of said function of the calculated central temperature TCC is greater than the value of the calculated target central temperature TCCO for a consecutive number of readings, the method comprises indicating that the food is cooked;

if it established that the evolution of the values of the detected central temperature TC, after the detection of at least one turn-over of the food, is not coherent or whether or not it is coherent, the values are increasing in a number of successive readings, and greater than the value of the target central temperature TCO, the method comprises indicating that the food is cooked; and

if the detected central temperature TC reaches the value of the target central temperature TCO and the evolution of said slope function PC is positive or equal to zero for a consecutive number of prior readings and a consecutive number of readings after the time at which both temperatures TC, TCO coincide or TC>TCO, the method comprises indicating that the food is cooked.

9. The method according to claim 2 , further comprising:

calculating a function of the calculated target central temperature TCCO of the food, obtained by adding to the target central temperature TCO a safety factor due to the heat loss experienced by the food when the cooking process ends:

placing said food on a surface at a temperature less than said temperature TCO, comparing the values of said calculated central temperature TCC with the value of said calculated target central temperature TCCO; and

controlling said heat source according to the result of said comparisons.

10. The method according to claim 2 , further comprising calculating at least one heat absorption coefficient function of the food with respect to time, which relates the values of the detected temperature close to the cooking surface TP with an optimal heat absorption coefficient function P optimal and a certain constant heating power, allowing fine-tuning the heating power to be supplied by the heat source, said function or functions having two characteristics:

they are exponential equations; and

for a value of the temperature TP of 100° C., the value of the optimal heat absorption coefficient P optimal is equal to or close to zero

and in that:

said calculated heat absorption coefficient function of the food with respect to time is at least one slope function PP obtained as a result of the evolution of the coherent values of the detected temperature close to the cooking surface TP over time; or

said calculated heat absorption coefficient function of the food with respect to time is an average function PPM of a slope function PP obtained as a result of the evolution of the values of the detected temperature close to the cooking surface TP over time,

such that if the heating power is known said heat absorption function allows calculating the time the TP will last the food between an initial TP and another final TP.

11. The method according to claim 8 , further comprising:

calculating a function of the calculated target central temperature TCCO of the food, obtained by adding to the target central temperature TCO a safety factor due to the heat loss experienced by the food when the cooking process ends:

placing said food on a surface at a temperature less than said temperature TCO, comparing the values of said calculated central temperature TCC with the value of said calculated target central temperature TCCO; and

controlling said heat source according to the result of said comparisons.

12. The method according to claim 3 , further comprising calculating at least one heat absorption coefficient function of the food with respect to time, which relates the values of the detected temperature close to the cooking surface TP with an optimal heat absorption coefficient function P optimal and a certain constant heating power, allowing fine-tuning the heating power to be supplied by the heat source, said function or functions having two characteristics:

they are exponential equations; and

for a value of the temperature TP of 100° C., the value of the optimal heat absorption coefficient P optimal is equal to or close to zero

and in that:

said calculated heat absorption coefficient function of the food with respect to time is at least one slope function PP obtained as a result of the evolution of the coherent values of the detected temperature close to the cooking surface TP over time; or

said calculated heat absorption coefficient function of the food with respect to time is an average function PPM of a slope function PP obtained as a result of the evolution of the values of the detected temperature close to the cooking surface TP over time,

such that if the heating power is known said heat absorption function allows calculating the time the TP will last the food between an initial TP and another final TP.