WO2021174641A1

WO2021174641A1 - Method for detecting cooked degree of roast meat in real time

Info

Publication number: WO2021174641A1
Application number: PCT/CN2020/084187
Authority: WO
Inventors: 孙滕谌; 张大华; 曹桂水
Original assignee: 北京他山科技有限公司
Priority date: 2020-03-02
Filing date: 2020-04-10
Publication date: 2021-09-10
Also published as: CN111141786A

Abstract

A method for detecting in real time the degree to which roast meat is cooked: a probe (1) and a controller (2) are used; a detection module (3) is provided on the probe (1); the detection module (3) comprises a signal transmitting electrode (32) and a signal detection electrode (33); and the controller (2) comprises a signal transmitting module (22), a signal detection module (23), a processing module (24) and an output module (4). The method comprises: the probe (1) is inserted into a meat chunk to be roasted; the signal transmitting module (22) sends out a low-frequency AC signal and a high-frequency AC signal in a time-sharing manner by means of the signal transmitting electrode (32); the signal detection electrode (33) detects the low-frequency AC signal and the high-frequency AC signal; and the processing module (24) performs calculations according to the variation amount of at least one of several parameters and outputs a cooked degree result of the roasted meat, wherein the parameters comprise: low-frequency impedance, high-frequency impedance, and low-frequency phase difference. The present method may display the cooked degree of meat in real time and has wide applicability.

Description

A real-time method for detecting the maturity of roasted meat

Technical field

The invention relates to a detection method, in particular to a method for real-time detection of the maturity of roasted meat.

Background technique

Roasting meat is a traditional cooking method. In the process of roasting meat, the protein inside the meat will change. If the roasting temperature is too high or the roasting time is too long, it will spread the protein, which will make the meat lose its tenderness and affect the taste.

There are many factors that affect the maturity of meat, including the type of meat, weight, roasting method, temperature during roasting, roasting time, internal temperature of the meat, and so on. Most of the time, it is necessary to rely on the roaster's own experience to adjust the temperature and time of roasting. Although the griller can use a probe-type thermometer to measure the temperature of the meat center, and then judge the maturity of the meat based on his own experience, this method has the following disadvantages: First, if the griller does not operate properly and does not insert the thermometer into it When the roast is in the center, the maturity of the meat cannot be accurately measured. In addition, when roasting different meats, or when the weight and volume of the meat are different, it is still necessary to rely on the experience of the griller to judge the maturity of the meat based on the core temperature.

The invention patent application with publication number CN109060179 discloses a method for real-time detection of meat maturity. The method only uses a thermometer to detect the temperature and roasting time of the meat. The inventor of the present invention found through experiments that the maturity of the barbecue cannot be accurately detected only by detecting the temperature and time. At the same time, when roasting different meats, the relationship between temperature and roasting time and the maturity of the roast is also different. For this reason, the technical solution of CN109060179 can only give the griller a certain reference function. It still requires a lot of experience of the griller to be able to accurately determine the maturity. Secondly, in the invention application of CN109619121, a method for judging the cookedness of roasted meat by electromagnetic heating is disclosed. However, this method is limited to use in electromagnetic heating grills, and is not suitable for open flames or electric heating ovens. In addition, the detection method uses the energy absorbed by the meat to calculate its rawness and maturity. This calculation will vary due to factors such as the meat, the volume and weight of the meat. Makes the calculated maturity inaccurate. In the invention application of CN107668107, this technical scheme judges the maturity of the meat through the reflectance value of the spectrum. Similarly, the reflection of the spectrum is closely related to the type of meat. And when the meat is marinated, the surface color of the meat will change, and its reflectance to the spectrum will also change. Thirdly, during the roasting process, the heating element in the oven will also have a certain influence on the detection of the spectrum. Therefore, the program cannot accurately detect the maturity of the meat. Finally, CN109977095 discloses a model for predicting the maturity of roasted meat, which is calculated by collecting the color value of the meat and the characteristic peaks generated by the vibration or rotation of hydrogen-containing groups, and combining various protein contents and moisture contents. The calculation method is too complicated, and the requirements for the acquisition accuracy of each parameter are also very high, so that the manufacturing cost is too high and the detection speed is too slow. Users even prefer to use their own experience to judge the maturity of the barbecue.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art and create a detection method that can display the maturity of meat in real time and is widely applicable to the maturity of roasted various meats.

During the roasting of the meat, the meat cells will rupture, causing the water in the cells to overflow. At the same time, the moisture in the meat will evaporate due to the high temperature roasting. The inventors have discovered through a large number of experiments and studies that the change in the moisture in the meat during the roasting process will cause the change in the conductivity of the meat itself. In other words, the meat can be regarded as a resistance-capacitance circuit. The impedance and capacitive reactance in this circuit will change according to the state of the meat being roasted. This patent designs the corresponding detection structure and circuit after the above-mentioned research.

The present invention discloses a method for detecting the maturity of roasted meat in real time. At least one probe for measuring the maturity of meat pieces and a controller are provided. The needle is provided with at least one set of detection modules; the detection module includes: at least a pair of electrodes; the pair of electrodes includes: a signal emission electrode and a signal detection electrode; the controller includes: a power supply, a signal emission module, and a signal detection Module, processing module and output module;

Insert the probe into the piece of meat to be roasted;

The signal transmitting module transmits a low-frequency AC signal and a high-frequency AC signal in a time-sharing manner through the signal transmitting electrode;

The signal detection module detects low-frequency AC signals and high-frequency AC signals through signal detection electrodes;

The processing module calculates the low-frequency, high-frequency impedance and phase difference of the barbecue based on the detected low-frequency AC signal and high-frequency AC signal;

The processing module performs calculations according to the variation of at least one of the following parameters, and outputs the maturity result of the barbecue; the parameters include: low-frequency impedance, high-frequency impedance, and low-frequency phase difference.

The invention also has the following additional features:

The detection range of the aforementioned variation includes the full roasting time or part of the roasting time.

A temperature sensor is also arranged on the above-mentioned probe, and the processing module also performs calculations according to the temperature change amount of the temperature sensor.

The variation of the parameter includes extreme points of high-frequency impedance, extreme points of low-frequency impedance, and extreme points of low-frequency phase difference.

The extreme point is a turning point of the rate of change of the parameter.

The low-frequency AC signal is an AC signal of 1-10 Hz; the high-frequency AC signal is an AC signal greater than or equal to 1 MHz.

There is also a maturity setting module on the controller, which sets the predetermined maturity when the roasting starts.

The processing module in the controller calculates and compares with the predetermined maturity level according to the variation of at least one of the following parameters, and outputs the maturity result of the barbecue; the parameters include: low frequency impedance, high frequency Impedance, low frequency phase difference.

A temperature sensor is also arranged on the probe, and the processing module also performs calculations based on the temperature change of the temperature sensor and the predetermined maturity of the barbecue.

The output result has maturity, and/or the time to reach a predetermined maturity, and the output mode is display and/or alarm and/or data communication.

In the present invention, a signal transmitting electrode and a signal receiving electrode are arranged on the probe, and a low-frequency AC signal and a high-frequency AC signal are emitted to the meat at different times. When a signal is loaded on the meat, a back-induced current is formed inside the meat, which prevents the signal current from passing. In other words, meat can be regarded as a resistance-capacitance network. When the signal is collected by the signal receiving electrode, the signal will have amplitude and phase changes. According to the principle of electricity, the resistance will cause the change of the signal amplitude, and the capacitance will cause the change of the signal phase. For this reason, by detecting the amplitude and phase changes of the signal, it can be converted into the impedance and capacitive reactance of the barbecue. During the roasting of the meat, the moisture in the cells will gradually decrease. As the moisture inside the meat changes, the value of the resistance and capacitance changes, and the collected signals will also have new changes in amplitude and phase, and then the impedance and capacitive reactance values of the roasted meat can be calculated. The signals collected in meats of different maturity levels are also different. The signal processing module calculates the impedance and capacitive reactance values of the meat after different roasting times according to the collected signals; and further combines the temperature changes to calculate the maturity of the barbecue. For this reason, grillers no longer need to use their own experience to confirm the maturity of the meat. In addition, due to the skin effect, high-frequency alternating current will be concentrated on the surface of the conductor, that is, the surface of the meat being roasted. For this reason, the maturity of the surface of the barbecue can be calculated by measuring the impedance of the meat to the high-frequency signal, and the maturity of the meat can be calculated by measuring the impedance of the meat to the low-frequency signal. To make the measurement more accurate, the griller can also better adjust the temperature of the grilled meat according to the maturity of the surface and the inside of the grilled meat.

Description of the drawings

Figure 1 is a block diagram of a prior art method for judging the maturity of barbecued meat.

Fig. 2 is a schematic diagram of a measuring device reflecting the method of the present invention.

Fig. 3 is a structural diagram of a probe of the measuring device.

Figure 4-1 is another structure diagram of the probe of the measuring device.

Figure 4-2 is another structural diagram of the probe of the measuring device.

Figure 4-3 is another structural diagram of the probe of the measuring device.

Fig. 5 is a schematic diagram of the distribution of probes of the measuring device.

Fig. 6 is another schematic diagram of the distribution of probes of the measuring device.

Fig. 7 is the equivalent circuit diagram of the resistance-capacitance network of the barbecue under the low-frequency signal.

Fig. 8 The equivalent circuit diagram of the resistance-capacitance sensing network of the barbecue under the high-frequency signal.

Figure 9 shows the impedance change curve of meat under low-frequency signals during the roasting process.

Figure 10 shows the capacitive reactance curve of meat under low-frequency signals during roasting.

Figure 11 shows the impedance change curve of meat under high-frequency signals during the roasting process.

探针 Probe	11	控制模块 Control module	22
温控模块Temperature control module	21twenty one	信号发射模块Signal transmitter module	22twenty two
信号检测模块Signal detection module	23twenty three	处理模块Processing module	24twenty four
检测模块 Detection module	33	温度传感器 Temperature Sensor	3131
信号发射电极 Signal transmitting electrode	3232	信号检测电极 Signal detection electrode	3333
输出模块 Output module	44	成熟度设定装置 Maturity setting device	55
烹饪腔Cooking cavity	66	加热装置heating equipment	77

Detailed ways

Fig. 2 shows the measuring device used in the method for judging the maturity of the barbecue. The measuring device includes a probe 1 and a controller 2 connected to the probe. The probe 1 and the controller 2 are connected separately, and an insulating protective layer is provided on the wire. The user can insert probe 1 into the meat block, and put the probe 1 meat block into the oven for roasting. At least one set of detection modules 3 is provided on the probe, wherein the detection module 3 includes a temperature sensor 31 and at least a pair of electrodes; the pair of electrodes includes: a signal emitting electrode 32 and a signal detection electrode 33. The controller 2 includes: a power supply 21, a signal transmission module 22, a signal detection module 23, a processing module 24, a maturity setting module 25, and an output module 4. The signal transmitting module 22 is electrically connected to the signal transmitting electrode 32, and the signal detecting electrode 33 is electrically connected to the signal detecting module 23.

2 and 4, the probe 1 is cylindrical, and its end is tapered, which is convenient for the user to insert the probe 1 into the meat to be roasted. Preferably, the signal emitting electrode 32 and the signal detecting electrode 33 are arranged on the surface of the probe 1. In addition, preferably, the signal transmitting electrode 32 is provided at the end of the probe 1. After the user inserts the probe 1 into the meat, the temperature sensor 31 will detect the temperature in the meat. At the same time, the signal transmitting module 22 will send a high frequency AC signal and a low frequency AC signal to the meat through the signal transmitting electrode 32 in a time-division manner. The high-frequency AC signal and the low-frequency AC signal pass through the inside of the meat and are received by the signal detection module 23 through the signal detection electrode 33. Among them, according to the skin effect, high-frequency alternating current will concentrate on the surface of the meat. The low-frequency alternating current passes through the inside of the meat. The presence of moisture in the meat will cause changes in signal amplitude and phase. The processing module 24 calculates the impedance to the high-frequency signal, the impedance to the low-frequency signal, and the capacitive reactance according to the changes in amplitude and phase detected by the signal detection module 23.

Figures 7 and 8 show the equivalent circuits of the resistance-capacitance network of the barbecue for low-frequency signals and high-frequency signals, respectively. Referring to Figure 7, under low-frequency signals, since the back induced current formed inside the meat is small and can be ignored, the meat can be equivalent to an equivalent circuit network containing only resistance and capacitance, regardless of the inductive component of the meat. . Among them, the resistance Re represents the equivalent resistance of the extracellular fluid of the meat organism, and the resistance Ri represents the equivalent resistance of the intracellular fluid of the meat organism. The capacitance Ca represents the equivalent capacitance of the cell membrane of the meat organism. Referring to Fig. 8, when a high-frequency signal is loaded, a back-induced current will be formed in the meat to the high-frequency signal. Therefore, an equivalent inductance element Lc needs to be added to the equivalent circuit. As the meat is roasted, its cells will rupture, overflowing with moisture. In turn, the values of the equivalent resistances Re and Ri, the equivalent capacitance Ca, and the equivalent inductance Lc are constantly changing. The processing module 24 judges the maturity of the barbecue based on these changes.

Referring to FIG. 3, multiple groups of detection modules 3 can be provided on the probe 1, and each group of detection modules 3 includes an independent temperature sensor 31, a signal emitting electrode 32 and a signal detection electrode 33. The detection modules 3 of each group are electrically isolated from each other. Among them, the temperature sensors 31 in each group of detection modules 3 detect each other independently. In one embodiment, the signal emitting electrode 32 and the signal detecting electrode 33 in each group are arranged independently of each other. When the probe 1 is inserted into the meat, each set of signal transmitting electrodes 32 and signal detecting electrodes 33 measure different parts of the meat, thereby solving the problem of roasting poultry (such as whole chickens, ducks, turkeys, etc.). The internal cavity causes the problem of inaccurate detection. In another embodiment, the signal emitting electrode 32 and the signal detecting electrode 33 of each group are connected in parallel, and the processing module 24 determines the position of each group of signal emitting electrode 32 and signal detecting electrode 33 on the probe 1. A set of signal detection results is assigned a certain weight value, and the maturity of the meat is judged after integrating each set of signals.

The controller 2 can also detect the maturity of the meat block in real time through the probe 1. The detection method includes: the temperature sensor 31 detects the temperature in the meat. At the same time, the signal transmitting module 22 sends a high-frequency AC signal and a low-frequency AC signal to the meat through the signal transmitting electrode 32 in a time-division manner. The high-frequency AC signal and the low-frequency AC signal pass through the inside of the meat and are received by the signal detection module 23 through the signal detection electrode 33. Among them, according to the skin effect, high-frequency alternating current will concentrate on the surface of the meat. The low-frequency alternating current passes through the inside of the meat. The presence of moisture in the meat will cause changes in signal amplitude and phase. The processing module 24 calculates the impedance of the meat to the high-frequency signal, the impedance to the low-frequency signal, and the change of the capacitive reactance according to the changes in the amplitude and phase detected by the signal detection module 23. In addition, the processing module 24 will detect in real time the change curve of the impedance and capacitive reactance of the barbecue to the low-frequency signal (as shown in Figs. 9 and 10) and the change curve of the impedance to the high-frequency signal (as shown in Fig. 11). And according to the change curve and the change rate of the curve, the current maturity of the barbecue is calculated in real time. The output module 4 outputs the current maturity of the barbecue. The output module 4 includes, but is not limited to: speakers that emit sound, a display, and transmission of maturity results to other devices through Bluetooth, network or other communication methods, and so on.

In addition, the user can set a predetermined maturity level through the setting module 25 before or during the roasting process according to their own preferences. When the current maturity of the barbecue reaches the maturity set by the user through the setting module 25, the output module 4 will output the result. The user can manually stop the roasting process according to the output result. Preferably, the measuring device can also be connected to the oven. When the current maturity of the barbecue reaches the maturity set by the user through the setting module 25, the output module 4 directly controls the heating power of the heating device in the oven.

Figures 9 and 10 show the change curves of the impedance and capacitive reactance of meat to low-frequency signals obtained by the inventors after many measurements and experiments with the increase of the roasting time. The experiment was performed at the roasting temperature. Set in a roasting environment of 170-200 degrees Celsius, it is obtained by real-time internal detection of meat. The impedance in Figure 9 and Figure 10 is the amplitude ratio of the transmitted signal to the detection signal, and the capacitive reactance is the phase difference between the transmitted signal and the detection signal. Among them, in the initial stage of roasting the meat, the cells in the meat rupture rapidly, and a large amount of water overflows. However, the rate of water evaporation is low, and the rate of water overflow in the meat is greater than the rate of water evaporation. As a result, the low-frequency impedance value of the meat gradually decreases, and the change slope of the low-frequency impedance value is also less than zero. After the meat has been roasted for a period of time, when the temperature in the meat rises to about 65 degrees, the rate of water evaporation between the cells in the meat and the rate of water overflow in the cells are basically the same, so that the low-frequency impedance value of the meat remains basically stable. The change slope of the low-frequency impedance value is also basically equal to zero. When the temperature in the meat is further roasted, the water overflowing from the cells in the meat decreases, and at the same time the water evaporation speeds up, the low-frequency impedance of the meat starts to increase again, and the slope of the low-frequency impedance value is greater than zero. Referring to Fig. 10, the low-frequency capacitive reactance value of meat is basically unchanged during the initial and mid-stage process of roasting, that is, when the rate of water overflow is greater than or equal to the rate of water evaporation. When the overflowing moisture of the cells in the meat decreases and the water evaporation speeds up, the low-frequency capacitive resistance of the meat increases sharply. As the moisture in the meat has basically evaporated, the low-frequency capacitive resistance of the meat will stabilize again.

Figure 11 shows the impedance change curve of meat to high-frequency signals during the roasting process. As described above, due to the skin effect, high-frequency alternating current will intensively pass on the surface of the meat. In the early stage of roasting, the cells on the surface of the meat rupture, overflowing with moisture. In turn, the high-frequency impedance of the meat is gradually reduced, and the slope of the change in the high-frequency impedance is also less than zero. When the roasting reaches a certain level, the water starts to evaporate in a large amount, and the surface layer of the meat is gradually roasted, which increases the resistance. Since the surface of the meat is closer to the heating element, the water overflow rate and the water evaporation rate of the meat surface cells are also faster. So that the change curve of the high-frequency impedance of the meat appears the extreme point earlier, and the change slope of its high-frequency impedance also becomes greater than zero.

The processing module 24 can calculate the maturity of the meat according to the curve of the parameters such as the low-frequency impedance of the meat, the low-frequency capacitive reactance of the meat, and the high-frequency impedance of the meat. Among them, after a large number of experiments by the inventor, since the high-frequency signal is used to detect the maturity of the meat surface, when the high-frequency impedance of the meat is detected, an extreme point appears, that is, when the slope of the high-frequency impedance changes from a negative number When it becomes a positive number, the meat has basically been roasted into a three-mature state. When the rate of change of the low frequency impedance of the meat changes from less than 0 to equal to 0, the meat has basically been roasted into a five-mature state. When the low-frequency capacitive resistance of meat begins to increase sharply, the meat has basically been roasted into a seven-mature state. In the end, when the low-frequency capacitive resistance of the meat stabilizes again, almost all the water in the meat is evaporated. At this time, the meat has basically been grilled and fully cooked.

Referring to Figs. 5 and 6, the measuring device may have a multi-probe 1 structure. Probe 1 contains multiple sub-probes. Each sub-probe is connected in parallel with the controller 2. Users can insert sub-probes in different parts of the meat to detect the maturity of the meat more accurately. Among them, the temperature sensor 31, the signal emitting electrode 32 and the signal detecting electrode 33 in the detection module 3 may be respectively arranged on different sub-probes. Or in a preferred solution, at least one group of detection modules 3 are respectively provided on each sub-probe. The temperature sensors 31 in each group of detection modules 3 are independent of each other. In addition, like the above-mentioned preferred solution, each sub-probe can also be provided with multiple groups of detection modules 3 to improve detection accuracy.

Claims

A method for detecting the maturity of roast meat in real time, which is characterized in that at least one probe for measuring the maturity of meat pieces and a controller are electrically connected between the probe and the controller, and the probe The needle is provided with at least one set of detection modules; the detection module includes: at least a pair of electrodes; the pair of electrodes includes: a signal emission electrode and a signal detection electrode; the controller includes: a power supply, a signal emission module, and a signal detection Module, processing module and output module;

Insert the probe into the piece of meat to be roasted;

The signal transmitting module transmits a low-frequency AC signal and a high-frequency AC signal in a time-sharing manner through the signal transmitting electrode;

The signal detection module detects low-frequency AC signals and high-frequency AC signals through signal detection electrodes;

The processing module calculates the low-frequency, high-frequency impedance and phase difference of the barbecue based on the detected low-frequency AC signal and high-frequency AC signal;

The processing module performs calculations according to the variation of at least one of the following parameters, and outputs the maturity result of the barbecue; the parameters include: low-frequency impedance, high-frequency impedance, and low-frequency phase difference.
The method for real-time detection of the maturity of barbecued meat according to claim 1, wherein the detection range of the change amount includes the entire roasting time or part of the roasting time.
The method for detecting the maturity of barbecue in real time according to claim 1, characterized in that a temperature sensor is also arranged on the probe, and the processing module is also calculated according to the temperature change of the temperature sensor.
The method for detecting the maturity of barbecued meat in real time according to claim 1, 2, or 3, wherein the variation of the parameter includes the extreme point of high-frequency impedance, the extreme point of low-frequency impedance, and the extreme point of low-frequency phase difference. .
The method for real-time detection of the maturity of barbecued meat according to claim 4, wherein the extreme point is a turning point of the rate of change of the parameter.
The method for detecting the maturity of barbecue in real time according to claim 1, wherein the low-frequency AC signal is an AC signal of 1-10 Hz; and the high-frequency AC signal is an AC signal greater than or equal to 1 MHz.
The method for real-time detection of the maturity of barbecued meat according to claim 1, characterized in that there is also a maturity setting module on the controller, and a predetermined maturity is set when the roasting is started.
The method for real-time detection of maturity of barbecued meat according to claim 7, characterized in that the processing module in the controller calculates and compares with the predetermined maturity according to the change of at least one of the following parameters, and outputs the result: The maturity result of the barbecue; the parameters include: low-frequency impedance, high-frequency impedance, and low-frequency phase difference.
The method for real-time detection of the maturity of barbecued meat according to claim 7, characterized in that a temperature sensor is arranged on the probe, and the processing module is also calculated according to the temperature change of the temperature sensor and the predetermined maturity of the barbecue.
The method for real-time detection of maturity of barbecued meat according to claim 1, characterized in that the output result has maturity, and/or the time to reach a predetermined maturity, and the output mode is display and/or alarm and/or data communication.