A portable impedance sensing device and method for meat quality detection

Abstract

The application provides a portable impedance sensing device and method for meat quality detection, comprising: a shell, the end of the shell is provided with an inner thread for contact with the surface of a meat sample to be detected, and an outer thread of a replaceable electrode is matched with the inner thread; the outer thread of the replaceable electrode is provided with two conductive convex points, and the two conductive convex points are in conductive connection with two conductive concave points arranged at the end of the inner thread of the shell; and the inside of the shell is provided with a control circuit for measuring the impedance of the meat sample to be detected, and the control circuit is connected with the two conductive concave points at the end of the inner thread of the shell through wires. The technical scheme of the application effectively expands the application range of meat sample detection, improves the detection efficiency, reduces the detection cost, reduces food loss, and provides a practical means for food traceability and quality control.

Description

A portable impedance sensing device and method for meat quality detection Technical Field

[0001] This invention belongs to the field of food testing technology, specifically relating to a portable impedance sensing device and method for meat quality testing. Background Technology

[0002] Under improper handling or storage conditions, meat is prone to quality decline and even spoilage, resulting in significant resource waste and economic losses. Currently, meat testing largely focuses on its biochemical indicators. These tests often rely on expensive, large-scale instruments and cumbersome sample pretreatment, which is significantly destructive to meat samples and makes simple, rapid on-site assessment difficult. Existing research has confirmed that the impedance characteristics of meat tissue can reflect its composition (such as fat or moisture content) and structure (such as muscle texture or fiber orientation), serving as parameters for assessing the structural state of meat and thus analyzing its quality grade, freshness changes, and freeze-thaw cycle count. Therefore, developing and applying an impedance-based meat testing device as a supplement or alternative to traditional meat testing techniques is essential.

[0003] Impedance testing (IBT) is a technique that analyzes changes in tissue condition by utilizing the electrical properties and their changing patterns of a sample. It is characterized by its simplicity, speed, low cost, and minimal damage to the sample. With the deepening of impedance research, the application of IBT has expanded to fields such as the analysis of physiological parameters in plants and animals, the maturity of fruits and vegetables, and the quality of meat. However, current impedance testing largely relies on relatively expensive and bulky equipment such as electrochemical workstations and LCR meters. The output of the test results is not simple and intuitive enough, making it difficult to achieve convenient and rapid on-site impedance testing. Therefore, to realize the application of impedance testing technology in practical production and daily life, and to adapt to the fast-paced commodity production and distribution model, it is essential to develop compact, portable impedance testing devices with wireless communication capabilities and long battery life.

[0004] Meat encompasses multiple categories, including livestock meat, poultry meat, and aquatic animal products. It is stored, processed, and distributed in various forms, such as fresh, chilled, and frozen, resulting in a diverse range of properties and forms. In impedance testing, the material and structure of the electrodes significantly impact detection sensitivity. Common impedance testing devices often use only a single, fixed impedance testing electrode, making it difficult to match the structural characteristics of different meat products and thus hindering accurate and sensitive impedance detection for a wide variety of meat products. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a portable impedance sensing device and method for meat quality testing. This is of great significance for simple and efficient food quality testing, effectively expanding the scope of application for meat sample testing, improving testing efficiency, reducing testing costs, minimizing food loss, and providing a practical means for food traceability and quality control.

[0006] A portable impedance sensing device for meat quality testing includes: a housing, the end of which is provided with an internal thread adapted to the external thread of a replaceable electrode for contacting the surface of a meat sample to be tested;

[0007] The replaceable electrode has two conductive protrusions at the end of its external thread, which are conductively connected to two conductive recesses at the end of its internal thread in the housing.

[0008] The housing contains a control circuit for measuring the impedance of the meat sample to be tested. The control circuit is connected to two conductive recesses at the end of the internal thread of the housing via wires.

[0009] Preferably, the control circuit includes an impedance measurement module, a controller module, a power supply module, and a communication module;

[0010] The impedance measurement module is connected to two conductive recesses at the end of the internal thread of the housing via an excitation wire and a receiving wire. The excitation wire outputs an excitation signal to the replaceable electrode, and the receiving wire receives and processes the response signal collected by the replaceable electrode.

[0011] The controller module is connected to the impedance measurement module via an integrated circuit bus, and is used to set parameters for the excitation signal and calculate the impedance of the meat sample to be tested based on the response signal processed by the impedance measurement module.

[0012] The power supply module is used to supply power to the impedance measurement module, the controller module, and the communication module;

[0013] The communication module is used to transmit the impedance of the meat sample to be tested, calculated by the controller module, to the smart terminal.

[0014] Preferably, the impedance measurement module includes:

[0015] The filtering unit is used to amplify, filter, and suppress noise in the response signal to obtain a denoised response signal.

[0016] An analog-to-digital conversion unit is used to sample, hold, quantize, and encode the denoised response signal based on the analog-to-digital converter to obtain a digital response signal.

[0017] The Fourier transform unit is used to perform a discrete Fourier transform on the digital response signal based on the digital signal processor to obtain the real and imaginary parts at each frequency point.

[0018] Preferably, the replaceable electrode further includes an electrode tip, which is replaced with a double-needle stainless steel electrode when the meat sample to be tested is a non-frozen meat sample.

[0019] Preferably, when the meat sample to be tested is a frozen meat sample, the electrode ends are replaced with two semi-annular thin stainless steel sheet electrodes with fixed spacing and fixed area, and an elastic insulating material is added between the insulating shell of the replaceable electrode and the semi-annular thin stainless steel sheet electrodes.

[0020] Preferably, the controller module includes:

[0021] An amplitude calculation unit is used to calculate the amplitude of the impedance of the meat sample to be tested based on the real and imaginary parts at each frequency point.

[0022] The gain coefficient calculation unit is used to obtain the gain coefficient based on the real and imaginary parts of each frequency point, combined with the resistor of known impedance connected at the preset scanning frequency;

[0023] An impedance calculation unit is used to calculate the impedance of the meat sample to be tested based on the gain coefficient and the amplitude.

[0024] The present invention also provides a portable impedance sensing method for meat quality detection, wherein the device comprises:

[0025] The electrode tip of the replaceable electrode is selected based on whether the meat sample to be tested is frozen, and the replaceable electrode is connected to the housing of the portable impedance sensing device by threads. The electrode tip of the replaceable electrode is pressed tightly against the surface of the meat sample to be tested, so that the portable impedance sensing device and the meat sample to be tested form a circuit.

[0026] The intelligent terminal and communication module send instructions to the controller module, and the controller module controls the impedance measurement module to generate an excitation signal to provide electrical signal excitation to the meat sample to be tested.

[0027] The response signal is acquired using replaceable electrodes, and the response signal is processed using an impedance measurement module to obtain the real and imaginary parts at each frequency point;

[0028] The controller module calculates the impedance of the meat sample to be tested based on the real and imaginary parts of each frequency point, and sends it to the smart terminal through the communication module.

[0029] Preferably, the method for calculating the impedance of the meat sample to be tested includes:

[0030] The amplitude of the impedance of the meat sample to be tested is calculated based on the real and imaginary parts at each frequency point;

[0031] Based on the real and imaginary parts of each frequency point, and combined with the resistor of known impedance connected at the preset scanning frequency, the gain coefficient is obtained.

[0032] The impedance of the meat sample to be tested is calculated based on the gain coefficient and the amplitude.

[0033] Compared with existing technologies, the advantages of this invention are as follows: This invention integrates an impedance measurement module, a controller module, a communication module, a power supply module, and a smart terminal to realize a food impedance detection system. Due to its miniaturization and applicability with the assistance of a smart terminal, it is simple and portable. The device allows the controller module to control the output control signal of the impedance detection module, adjusting the output excitation signal according to sample detection needs, thus improving detection sensitivity and accuracy. The system is equipped with multiple replaceable electrodes, achieving good contact with different target meat surfaces, improving detection stability and accuracy. Using this method, the portable device can accurately detect the impedance of different meat samples, offering advantages such as ease of use, speed, and long battery life. Based on these advantages, the device and method of this invention are widely applicable for detecting impedance changes in food during production and storage, and for food quality evaluation. Attached Figure Description

[0034] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 is a structural diagram of a portable impedance sensing device for meat quality detection provided in an embodiment of the present invention;

[0036] Figure 2 is a cross-sectional view of the connection between the portable impedance sensing device and the replaceable electrode provided in an embodiment of the present invention.

[0037] Figure 3 is a structural diagram of the device with replaceable electrodes provided in an embodiment of the present invention;

[0038] Figure 4 is a schematic diagram of the implementation method of the portable impedance sensing device for meat quality detection provided in an embodiment of the present invention;

[0039] Figure 5 is a functional block diagram of the control circuit in the portable impedance sensing device for meat quality detection provided in an embodiment of the present invention.

[0040] Figure 6 is a schematic diagram of the output sinusoidal excitation waveform of the portable impedance sensing device for meat quality detection provided in an embodiment of the present invention.

[0041] Figure 7 shows a comparison of the impedance detection results of the portable impedance sensing device for meat quality testing provided in the embodiments of the present invention and the LCR tester.

[0042] Figure 8 shows the impedance measurement curve of the portable impedance sensing device for meat quality detection provided in the embodiment of the present invention for the equivalent circuit model of biological tissue.

[0043] Figure 9 shows the detection results of impedance changes of four different meat samples during storage using a portable impedance sensing device for meat quality testing provided in an embodiment of the present invention.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1-Housing, 2-Replaceable electrode, 3-Control circuit, 4-Impedance measurement module, 5-Controller module, 6-Communication module, 7-Power supply module, 8-Internal thread, 9-Conductive dimple, 10-Excitation wire, 11-Receiver wire, 12-Replaceable electrode external thread, 13-Conductive bump, 14-Double needle stainless steel electrode, 15-Semi-annular thin stainless steel sheet electrode, 16-Replaceable electrode internal wire, 17-Insulating housing, 18-Elastic insulating sponge for replaceable electrode, 19-Smart terminal. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Example 1

[0049] As shown in Figure 1, a portable impedance sensing device for meat quality detection includes: a housing 1, and an internal thread 8 at the end of the housing 1 for contacting the surface of a replaceable electrode 2 with an external thread 12 adapted to the internal thread 8.

[0050] As shown in Figure 2, in order to facilitate electrode replacement and ensure good electrical connection, the replaceable electrode 2 has two conductive protrusions 13 at the end of the external thread 12, which are conductively connected to the two conductive recesses 9 at the end of the internal thread 8 of the housing 1.

[0051] The housing 1 is equipped with a control circuit 3 for measuring the impedance of the meat sample to be tested. The control circuit 3 is connected to two conductive recesses 9 at the end of the internal thread 8 of the housing 1 via wires.

[0052] A further embodiment includes an impedance measurement module 4, a controller module 5, a power supply module 7, and a communication module 6; this effectively improves the portability of the detection device and meets the requirements for miniaturization and lightweighting of testing devices in on-site food testing, as shown in Figure 5.

[0053] Impedance measurement module 4 is connected to two conductive recesses 9 at the end of the internal thread 8 of housing 1 via excitation wire 10 and receiving wire 11. It outputs an excitation signal to replaceable electrode 2 using excitation wire 10 and processes the response signal collected by replaceable electrode 2 using receiving wire 11. In this embodiment, impedance measurement module 4 can be constructed using Analog Devices' AD5933 or AD5940, Texas Instruments' AFE4300, or Maxim Integrated's MAX30001 or MAX30009 impedance measurement chips as the main components. It has low power consumption, adjustable excitation frequency, large detection range, and high measurement accuracy.

[0054] The controller module 5 is connected to the impedance measurement module 4 via an integrated circuit bus. It is used to set parameters for the excitation signal and calculate the impedance of the meat sample to be tested based on the response signal processed by the impedance measurement module 4. The controller module 5 is constructed using the MSP430FR2433 mixed-signal microcontroller from Texas Instruments as the main component. It has the advantages of fast writing, flexibility and durability and non-volatile flash memory.

[0055] Power module 7 is used to power impedance measurement module 4, controller module 5 and communication module 6;

[0056] The communication module 6 transmits the impedance of the meat sample to be tested, calculated by the controller module 5, to the smart terminal 19. The communication module 6 uses the WH-BLE103 Bluetooth chip from Wenheng Electronics Technology Co., Ltd. as its main component, ensuring strong compatibility and reliable connection, enabling communication with a smartphone app developed according to the BLE protocol. The power module 7 can be constructed using the TP4056 charging module from Tuowei Integrated Circuit Co., Ltd. and the TLV627432 step-down converter from Texas Instruments as its main components. This results in a simple peripheral circuit, efficient step-down conversion, and a stable operating voltage for the impedance measurement module 4, controller module 5, and communication module 6. The chips used in each module are small in size and low in power consumption, contributing to the miniaturization, portability, and long battery life of the devices, thus facilitating their application in on-site meat sample testing.

[0057] A further embodiment is that the impedance measurement module 4 includes:

[0058] The filtering unit is used to amplify, filter, and suppress noise in the response signal to obtain a denoised response signal.

[0059] The analog-to-digital conversion unit is used to sample, hold, quantize, and encode the denoised response signal based on the analog-to-digital converter to obtain the digital response signal;

[0060] The Fourier transform unit is used to perform discrete Fourier transform on the digital response signal based on the digital signal processor to obtain the real and imaginary parts at each frequency point.

[0061] A further embodiment is that the replaceable electrode 2 also includes an electrode tip, which is replaced with a double needle-shaped stainless steel electrode 14 when the meat sample to be tested is a non-frozen meat sample.

[0062] A further embodiment involves replacing the electrode tip with two fixed-spaced, fixed-area semi-annular thin stainless steel sheet electrodes 15, and adding an elastic insulating material between the insulating shell 17 of the replaceable electrode 2 and the semi-annular thin stainless steel sheet electrodes 15.

[0063] Specifically, as shown in Figures 3 and 4, in this embodiment, there are two main types of replaceable electrodes: the electrode ends that contact the surface of the food sample can be double needle-shaped stainless steel electrodes 14 with a fixed spacing of 1 cm and a length of 1.5 cm, which can effectively control the insertion depth and electrode spacing in the sample during detection, thereby improving the effectiveness and accuracy of the detection; or they can be two semi-annular thin stainless steel sheet electrodes 15 with an inner diameter of 3 cm, an outer diameter of 6 cm, and a spacing of 2 cm. The electrode sheet 15 is connected to the conductive protrusion 13 at the other end of the electrode through an internal electrode wire 16, and a layer of 0.5 cm thick elastic insulating sponge 18 is added between the electrode sheet 15 and the insulating shell 17 of the electrode, so that the electrode can produce a certain deformation to achieve a tight fit with the hard sample surface, thereby improving the stability and accuracy of the detection.

[0064] In one possible implementation, the smart terminal application software (smart terminal 19) running on the Android platform of a smartphone is developed using the Android Studio development tool for sample type selection, sending instructions, result presentation, and displaying relevant information for user reference.

[0065] A further embodiment is that the controller module 5 includes:

[0066] The amplitude calculation unit is used to calculate the amplitude of the impedance of the meat sample to be tested based on the real and imaginary parts at each frequency point; specifically, the impedance measurement module further calculates the real part R and the imaginary part I through discrete Fourier transform, and calculates the amplitude |Z| and phase measurement value θ' of the sample impedance according to the following formula:

[0067]

[0068] The gain coefficient calculation unit is used to obtain the gain coefficient based on the real and imaginary parts of each frequency point, combined with the resistor of known impedance connected at a preset scanning frequency; specifically, the gain coefficient G is obtained by calculation and calibration using a resistor R0 of known impedance connected at a certain scanning frequency.

[0069]

[0070] Impedance calculation unit is used to calculate the impedance of the meat sample to be tested based on the gain coefficient and amplitude.

[0071] Specifically, the smart terminal 19 can transmit data with the portable impedance sensing device used for meat quality detection via the communication module, and after modulation by the communication module 6, the data is transmitted to the controller module 5. After the controller module 5 starts working, it sends a command to the impedance measurement module 4. Upon receiving the command, the impedance measurement module 4 sends an electrical excitation signal of a specific frequency to the replaceable electrode via the excitation wire 10. The adjustable excitation signal frequency range is 1-500kHz, typically 30kHz, as shown in Figure 6, which is a schematic diagram of the 30kHz sinusoidal excitation signal waveform output by the device. The detection signal is transmitted back to the impedance measurement module 4 via the receiving wire 11. The impedance measurement module 4 amplifies, filters, and suppresses noise in the received electrical signal, then samples, holds, quantizes, and encodes it into a digital signal via an analog-to-digital converter, and inputs it to a digital signal processor for discrete Fourier transform, outputting the real and imaginary parts of each frequency point, and transmitting the results to the controller module 5. The controller module 5 calculates the sample impedance based on the formula and the gain coefficient G, where the gain coefficient G for chilled meat is... 1k The gain coefficient G of frozen meat was obtained through calculation and calibration by connecting a resistor with a known impedance of 1kΩ at a certain scanning frequency. 10k It was obtained through calculation and calibration by connecting a resistor with a known impedance of 10kΩ at a certain scanning frequency, combined with the gain coefficient G. 1k / G 10k The impedance Z of the sample is calculated using the following formula:

[0072]

[0073] The phase θ of the system30k The phase θ of the sample impedance was obtained through phase calculation calibration with a pure resistor connected at 30kHz. The phase θ was calculated using the following formula:

[0074] θ=θ'-θ 30k .

[0075] The controller module 5 transmits the results to the smart terminal 19 for display via the communication module 6.

[0076] To evaluate the accuracy of the meat impedance detection system, a biological tissue equivalent circuit model (R1 and R2 are pure resistors of 1kΩ and 10kΩ respectively, and C is a 10nF ceramic capacitor) was used to simulate meat tissue, and the amplitude and phase information of the equivalent circuit model at different frequencies were collected. As shown in Figure 7, the detection results of the portable impedance sensing device for meat quality detection provided in this embodiment of the invention are basically the same as those of the LCR tester. This device can achieve accurate measurement of the impedance of biological tissue. Figure 8 shows the impedance measurement curve of the portable impedance sensing device for meat quality detection of this invention on the biological tissue equivalent circuit model.

[0077] Example 2

[0078] The present invention also provides a portable impedance sensing method for meat quality detection, using the apparatus of Embodiment 1, comprising:

[0079] Based on whether the meat sample to be tested is frozen, select the electrode end of the replaceable electrode 2, and connect the replaceable electrode 2 to the housing 1 of the portable impedance sensing device through a thread, so that the electrode end of the replaceable electrode 2 is in close contact with the surface of the meat sample to be tested, so that the portable impedance sensing device and the meat sample to be tested form a circuit.

[0080] The intelligent terminal 19 and the communication module 6 send instructions to the controller module 5, and the controller module 5 controls the impedance measurement module 4 to generate an excitation signal to provide an electrical signal excitation to the meat sample to be tested.

[0081] The response signal is acquired using replaceable electrode 2, and processed using impedance measurement module 4 to obtain the real and imaginary parts of each frequency point.

[0082] The controller module 5 calculates the impedance of the meat sample to be tested based on the real and imaginary parts at each frequency point, and sends it to the smart terminal 19 via the communication module 6. Specifically, based on the real and imaginary part results returned by the impedance measurement module, the controller module calculates the sample impedance detection data based on the formula and the gain coefficient G, saves it in real time, and sends it to the smart terminal via the communication module; the smart terminal 19 analyzes, records, and displays the real-time saved detection data, and provides corresponding reference standard tables for users to query.

[0083] During storage, meat undergoes continuous biochemical reactions, leading to changes such as loosening of muscle tissue structure and leakage of tissue fluid. These changes alter the impedance properties of the meat, typically manifesting as a decrease in impedance amplitude and an increase in phase. Therefore, by accumulating test data, a correlation can be established between the quality of different meats under specific storage conditions and their impedance amplitude and phase, allowing for the assessment of meat quality through impedance measurement results.

[0084] As shown in Figure 7, the portable impedance sensing detection device and LCR meter provided in this embodiment of the invention were used to test various meat samples, and the detection results were compared. The results show that the detection results of the device and method provided in this embodiment of the invention are basically consistent with the results of the LCR meter, which can realize accurate and convenient detection of the impedance of various meat samples.

[0085] As shown in Figure 9, the portable impedance sensing detection device provided in this embodiment of the invention was used to detect the impedance changes of various meat samples, such as pork, chicken, shrimp, and fish, during storage at room temperature. The results show that the device and method provided in this embodiment of the invention can detect the impedance of various meat samples, and the changes in impedance (amplitude and phase) can reflect the quality decline of meat as storage time increases. The portable impedance sensing detection device provided in this embodiment of the invention is expected to be used in actual production for rapid assessment of meat quality.

[0086] A further implementation method involves calculating the impedance of the meat sample to be tested, including:

[0087] The amplitude of the impedance of the meat sample to be tested is calculated based on the real and imaginary parts at each frequency point;

[0088] Based on the real and imaginary parts of each frequency point, and combined with the resistor of known impedance connected at the preset scanning frequency, the gain coefficient is obtained.

[0089] The impedance of the meat sample to be tested is calculated based on the gain coefficient and amplitude.

[0090] Compared to traditional impedance-based meat detection devices, this invention combines integrated circuits and replaceable electrodes, significantly simplifying the hardware structure compared to traditional detection devices such as LCR meters. This allows for greater miniaturization and integration of the system. Simultaneously, a battery and low-power chip are integrated into the system, greatly improving portability and extending the device's independent operating time. The replaceable electrode structure allows the detection device to closely fit various meat samples, including fresh, chilled, and frozen meats. Impedance-based detection enables in-situ, real-time testing of different meat samples, facilitating product quality assessment. Based on these advantages, this invention can be widely applied to on-site impedance-based quality detection and assessment of meat during processing and storage, demonstrating broad application prospects.

[0091] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A portable impedance sensing device for meat quality detection, characterized in that, The device includes: a housing, the end of which has an internal thread adapted to the external thread of a replaceable electrode for contact with the surface of a meat sample to be tested; the external thread of the replaceable electrode has two conductive protrusions that are conductively connected to two conductive recesses at the end of the internal thread of the housing; the housing contains a control circuit for measuring the impedance of the meat sample to be tested, the control circuit being connected to the two conductive recesses at the end of the internal thread of the housing via wires; the control circuit includes an impedance measurement module, a controller module, a power supply module, and a communication module; the impedance measurement module is connected to the two conductive recesses at the end of the internal thread of the housing via an excitation wire and a receiving wire, outputting an excitation signal to the replaceable electrode using the excitation wire, and using and processing the response signal collected by the replaceable electrode received by the receiving wire; The controller module is connected to the impedance measurement module via an integrated circuit bus, and is used to set parameters for the excitation signal and calculate the impedance of the meat sample to be tested based on the response signal processed by the impedance measurement module; the power supply module is used to supply power to the impedance measurement module, the controller module, and the communication module. The communication module is used to transmit the impedance of the meat sample to be tested calculated by the controller module to the smart terminal; the impedance measurement module includes: a filtering unit, used to amplify, filter and suppress noise in the response signal to obtain a denoised response signal; an analog-to-digital conversion unit, used to sample, hold, quantize and encode the denoised response signal based on the analog-to-digital converter to obtain a digital response signal; a Fourier transform unit, used to perform a discrete Fourier transform on the digital response signal based on a digital signal processor to obtain the real and imaginary parts of each frequency point; the replaceable electrode also includes electrode terminals, when the meat sample to be tested is a non-frozen meat sample, the electrode terminals are replaced with double needle-shaped stainless steel electrodes; when the meat sample to be tested is a frozen meat sample, the electrode terminals are replaced with two semi-annular thin stainless steel sheet electrodes with fixed spacing and fixed area, and an elastic insulating material is added between the insulating shell of the replaceable electrode and the semi-annular thin stainless steel sheet electrodes.

2. The apparatus according to claim 1, characterized in that, The controller module includes: an amplitude calculation unit for calculating the amplitude of the impedance of the meat sample to be tested based on the real and imaginary parts of each frequency point; a gain coefficient calculation unit for obtaining the gain coefficient based on the real and imaginary parts of each frequency point, combined with the resistance of the known impedance connected at a preset scanning frequency; and an impedance calculation unit for calculating the impedance of the meat sample to be tested based on the gain coefficient and the amplitude.

3. A portable impedance sensing method for meat quality detection, using the device described in any one of claims 1-2, characterized in that, include: The electrode tip of a replaceable electrode is selected based on whether the meat sample to be tested is frozen. The replaceable electrode is connected to the housing of the portable impedance sensing device via a thread, and the electrode tip of the replaceable electrode is pressed tightly against the surface of the meat sample to form a circuit between the portable impedance sensing device and the meat sample. Instructions are sent to the controller module via a smart terminal and a communication module. The controller module controls the impedance measurement module to generate an excitation signal to provide electrical excitation to the meat sample to be tested. The replaceable electrode is used to acquire the response signal, and the impedance measurement module processes the response signal to obtain the real and imaginary parts at each frequency point. Based on the real and imaginary parts at each frequency point, the controller module calculates the impedance of the meat sample to be tested and sends it to the smart terminal via the communication module.

4. The method according to claim 3, characterized in that, The method for calculating the impedance of a meat sample to be tested includes: calculating the amplitude of the impedance of the meat sample to be tested based on the real and imaginary parts at each frequency point; obtaining a gain coefficient based on the real and imaginary parts at each frequency point, combined with the resistance of a known impedance connected at a preset scanning frequency; and calculating the impedance of the meat sample to be tested based on the gain coefficient and the amplitude.

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