Passive smart label for meat food detection and meat food freshness detection method

Abstract

The invention provides a passive smart tag for meat food detection and a meat food freshness detection method. The passive smart tag for meat food detection comprises a transducer, a sensitive element, an analog front end, a microprocessor, an NFC chip and an antenna, the sensitive element is used for adsorbing the biogenic amine volatilized during meat decay, and the transducer converts the concentration of the biogenic amine into an electrical impedance signal; the analog front end collects an electrical impedance signal output by the sensitive element and converts the electrical impedance signal into a digital signal; the microprocessor obtains the nitrogen content in the meat food according to the digital signal and the mapping relation between the total nitrogen content of the volatile basic group of the meat and the impedance variable quantity; the NFC chip sends the nitrogen content in the meat food to a client side through the antenna, the freshness degree of the meat food under various storage conditions and various transportation conditions is detected, the freshness index is quantified through the nitrogen content, and technical support is provided for detecting whether food materials and dishes are fresh or not.

Description

Technical Field

[0001] The present invention relates to the technical field of food safety detection, and in particular to a passive smart tag for meat food detection and a meat food freshness detection method. Background Art

[0002] In the actual detection of the freshness of meat samples, the existing food evaluation method is based on empirical methods, that is, judgment through vision, smell, taste and touch, etc., but it cannot detect the early stages of deterioration, and the results vary greatly due to people's subjective judgment. The Kjeldahl method determines the freshness of meat products by measuring the content of volatile basic total nitrogen (TVB-N), but this detection method is a destructive test, involving complex sample preparation and a long analysis cycle, and requires professional testers to use expensive large-scale precision instruments for measurement. In related technologies, near-infrared (NIR) spectroscopy and Fourier transform infrared (FTIR) spectroscopy are used, but this method is greatly affected by temperature and environment, and cannot be used for detection under the storage and transportation conditions of meat products, and cannot accurately quantify the freshness index of meat. Summary of the Invention

[0003] The present invention provides a passive intelligent tag for meat food detection and a meat food freshness detection method, which is used to solve the defects of traditional meat food detection methods that are unable to perform detection under storage and transportation conditions of meat products and cannot accurately quantify the freshness index of meat.

[0004] The present invention provides a passive smart tag for meat food detection, comprising: Sensitive components, transducers, analog front-ends, microprocessors, NFC chips, and antennas; The sensitive element is a biogenic amine sensitive membrane, which is used to characteristically adsorb biogenic amines volatilized during meat spoilage; The transducer is a gold interdigital electrode, which converts the concentration of the biogenic amine into an electrical impedance signal of the interdigital electrode; The analog front end is used to collect the electrical impedance signal output by the sensitive element and convert it into a digital signal; The microprocessor is used to obtain the nitrogen content in the meat product according to the digital signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and send the nitrogen content in the meat product to the NFC chip; The NFC chip sends the nitrogen content in the meat product to the client through the antenna.

[0005] According to the passive smart tag for meat food detection provided by the present invention, the analog front end includes: Operational amplifier circuit, filter circuit, voltage regulator circuit and analog-to-digital conversion circuit; The operational amplifier circuit is used to amplify the electrical impedance signal; The filtering circuit is used to remove noise signals from the amplified electrical impedance signal; The voltage stabilizing circuit is used to regulate the input voltage to supply power to the microprocessor and other circuits of the analog front end; The analog-to-digital conversion circuit is used to convert the de-noised electrical impedance signal into a digital format for processing and converting it into a digital signal.

[0006] According to the passive smart tag for meat food detection provided by the present invention, the microprocessor is further used for: Compensating the digital signal to correct sensor drift and obtain a compensated signal; The nitrogen content in the meat product is obtained according to the compensation signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and the nitrogen content in the meat product is transmitted to the NFC chip through a communication protocol.

[0007] According to the passive smart tag for meat food detection provided by the present invention, the NFC chip is connected to the antenna, and the NFC chip includes: capture circuits, rectifiers, and voltage regulators; The capture circuit is used to capture the induced alternating current generated when the antenna approaches the active device; The rectifier is used to convert the induced alternating current into a direct current voltage; The voltage regulator is used to adjust the DC voltage to a preset voltage range.

[0008] The passive smart tag for meat food detection provided by the present invention further includes: The sensitive element, analog front end, microprocessor, NFC chip and antenna are printed as a stretchable circuit and integrated with nanowires, and the integrated circuit is attached to a flexible substrate.

[0009] The present invention also provides a meat freshness detection method, which is applicable to the passive smart tag for meat detection described above, comprising: The passive smart tag for meat food detection is powered by capturing energy from active devices through the antenna and NFC chip in the passive smart tag for meat food detection; The biogenic amine-sensitive membrane was used to modify the interdigital electrode to adsorb the biogenic amines volatilized during meat spoilage, and the concentration of the biogenic amines was converted into an electrical impedance signal of the interdigital electrode. Converting the electrical impedance signal into a digital signal, obtaining the nitrogen content in the meat product based on the digital signal and a mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and sending the nitrogen content in the meat product to the NFC chip; The nitrogen content in the meat product is sent to the client through the NFC chip and the antenna.

[0010] The meat product freshness detection method according to the present invention also includes: The volatile basic total nitrogen content in the meat product is measured using the Kjeldahl method, and the nitrogen content in the meat product obtained by the passive smart tag for meat product detection is linearly fitted with the volatile basic total nitrogen content in the meat product measured using the Kjeldahl method to obtain the freshness of the meat product. The freshness includes freshness grade, sub-freshness grade and corruption grade, and is displayed synchronously on the client through text and color.

[0011] The present invention also provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any of the above-described meat product freshness detection methods when executing the program.

[0012] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements any of the above-mentioned meat product freshness detection methods.

[0013] The present invention provides a passive smart tag for meat food detection and a method for detecting the freshness of meat food. The passive smart tag for meat food detection includes a sensitive element, a transducer, an analog front end, a microprocessor, an NFC chip, and an antenna. The sensitive element is a biogenic amine sensitive membrane, and the transducer is a gold interdigital electrode, which converts the concentration of the biogenic amine into an electrical impedance signal of the interdigital electrode. The analog front end is used to collect the electrical impedance signal output by the sensitive element and convert it into a digital signal. The microprocessor is used to obtain the nitrogen content in the meat food based on the digital signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and send the nitrogen content in the meat food to the NFC chip. The NFC chip sends the nitrogen content in the meat food to a client via the antenna. The present invention can realize rapid detection of the freshness of meat food under various storage conditions and various transportation conditions, and quantify the freshness index by nitrogen content, providing technical support for detecting the freshness of ingredients and dishes. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 Schematic diagram of the functional structure of the meat product freshness detection method provided by an embodiment of the present invention; Figure 2 Schematic diagram of the detection principle provided by an embodiment of the present invention; Figure 3 Schematic diagram of the structure of the biogenic amine sensing system provided by an embodiment of the present invention; Figure 4 This is a schematic diagram of the process of a passive smart tag for meat food detection provided by an embodiment of the present invention; Figure 5 Schematic diagram of an application scenario of the meat food freshness detection method provided by an embodiment of the present invention; Figure 6 It is a functional structure diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0016] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0017] Figure 1 The functional structure diagram of the passive smart tag for meat food detection provided by the embodiment of the present invention is as follows: Figure 1 As shown, the passive smart tag for meat food detection provided by the embodiment of the present invention includes: Sensitive components, transducers, analog front-ends, microprocessors, NFC chips, and antennas; The sensitive element is a biogenic amine sensitive membrane, which is used to characteristically adsorb biogenic amines volatilized during meat spoilage. The transducer is a gold interdigital electrode, which converts the concentration of the biogenic amines into an electrical impedance signal of the interdigital electrode. The analog front end is used to collect the electrical impedance signal output by the sensitive element and convert it into a digital signal; The microprocessor is used to obtain the nitrogen content in the meat product according to the digital signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and send the nitrogen content in the meat product to the NFC chip; The NFC chip sends the nitrogen content in the meat product to the client through the antenna.

[0018] In an embodiment of the present invention, the sensitive element, analog front end, microprocessor, NFC chip and antenna are printed as a stretchable circuit and integrated with nanowires, and the integrated circuit is attached to a flexible substrate.

[0019] Traditional meat freshness detection uses near-infrared spectroscopy and Fourier transform infrared spectroscopy. This method is greatly affected by temperature and environment, cannot be used for detection under the storage and transportation conditions of meat products, and cannot accurately quantify the freshness indicators of meat.

[0020] The passive smart tag for meat food detection provided by an embodiment of the present invention includes a sensitive element, a transducer, an analog front end, a microprocessor, an NFC chip and an antenna; the sensitive element is a biogenic amine sensitive membrane for characteristically adsorbing biogenic amines volatilized during meat spoilage; the transducer is a gold interdigital electrode that converts the concentration of the biogenic amine into an electrical impedance signal of the interdigital electrode; the analog front end is used to collect the electrical impedance signal output by the sensitive element and convert it into a digital signal; the microprocessor is used to obtain the nitrogen content in the meat food based on the digital signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and send the nitrogen content in the meat food to the NFC chip; the NFC chip sends the nitrogen content in the meat food to the client via the antenna. The present invention can realize the rapid detection of the freshness of meat food under various storage conditions and various transportation conditions, and quantify the freshness index by nitrogen content, providing technical support for detecting the freshness of ingredients and dishes.

[0021] Based on any of the above embodiments, the analog front end includes: Operational amplifier circuit, filter circuit, voltage regulator circuit and analog-to-digital conversion circuit; The operational amplifier circuit is used to amplify the electrical impedance signal; The filtering circuit is used to remove noise signals from the amplified electrical impedance signal; The voltage stabilizing circuit is used to regulate the input voltage to supply power to the microprocessor and other circuits of the analog front end; The analog-to-digital conversion circuit is used to convert the de-noised electrical impedance signal into a digital format for processing and converting it into a digital signal.

[0022] In an embodiment of the present invention, a passive smart tag for meat food testing, namely a biogenic amine sensor, uses an analog front-end chip to convert the analog signal generated by the sensor into a digital signal suitable for wireless transmission. Biogenic amine sensors typically generate weak analog signals that require amplification for accurate detection and analysis. An operational amplifier circuit amplifies the weak analog signal generated by the biogenic amine sensor to a detectable level while maintaining its integrity. A filtering circuit removes unnecessary noise and interference from the sensor signal, thereby improving the sensor's signal-to-noise ratio and ensuring that the subsequent digital conversion accurately represents the biogenic amine concentration. A voltage regulator circuit precisely regulates the input voltage and outputs a stable voltage (approximately 2-3V) to the load, which is used to power the microprocessor and analog front-end for electrochemical sensing. After conditioning, the analog signal must be converted to a digital format for processing and wireless transmission. The analog-to-digital conversion circuit performs this conversion and ensures that the digital output accurately reflects the analog input of the biogenic amine sensor.

[0023] Based on any of the above embodiments, the microprocessor is further configured to: Compensating the digital signal to correct sensor drift and obtain a compensated signal; The nitrogen content in the meat product is obtained according to the compensation signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and the nitrogen content in the meat product is transmitted to the NFC chip through a communication protocol.

[0024] In an embodiment of the present invention, a microprocessor chip is a key component of the wireless passive biogenic amine sensor, primarily responsible for data processing, control, and communication. First, the microprocessor processes the data collected by the biogenic amine sensor. After the analog front-end chip converts the analog signal into a digital signal, the microprocessor interprets and analyzes the data to determine the concentration of the biogenic amine. The microprocessor further processes the data to optimize the sensor's output, including compensating for environmental factors and correcting for sensor drift. Second, the microprocessor controls the overall operation of the biogenic amine sensor system, including sending commands, calibrating the sensor, and controlling the timing of data acquisition and transmission. Finally, the microprocessor transmits the data to the NFC chip via its own communication protocol.

[0025] Based on any of the above embodiments, the NFC chip is connected to the antenna, and the NFC chip includes: capture circuits, rectifiers, and voltage regulators; The capture circuit is used to capture the induced alternating current generated when the antenna approaches the active device; The rectifier is used to convert the induced alternating current into a direct current voltage; The voltage regulator is used to adjust the DC voltage to a preset voltage range.

[0026] In this embodiment of the present invention, an NFC chip is connected to an antenna coil, responsible for powering the entire sensor, storing data, and wireless communication with the smartphone. Power is provided by the NFC chip's energy capture circuit. When the antenna is in proximity to the electromagnetic field generated by an active device, inductive coupling occurs, generating an induced alternating current (AC) in the NFC chip's antenna coil. However, this induced AC current cannot be directly used by the sensor's circuitry. Therefore, the energy capture circuit converts the AC voltage to a direct current (DC) voltage using a rectifier. The rectified DC voltage can be unstable, varying with the strength of the electromagnetic field and the distance between the NFC devices. To provide a stable power supply, the energy capture circuit typically includes a voltage regulator to ensure that the voltage remains within a specific range, powering the sensor's internal components (analog front end and microprocessor). The microprocessor transfers the processed data to the NFC chip's memory unit (EEOROM) via the I2C communication protocol. The data is then transmitted to the smartphone via NFC based on the ISO / IEC 14443A communication protocol.

[0027] The embodiment of the present invention mainly utilizes the combination of electrochemical impedance spectroscopy and wireless radio frequency identification to achieve rapid detection of the freshness of food ingredients and dishes. The sensitive element mainly realizes the specific recognition of volatile amines, while the NFC chip is responsible for capturing the electromagnetic field energy generated by the mobile phone and wireless data transmission. By combining the two, the gas sensor, antenna, circuit and chip are integrated on a flexible substrate (PET or PDMS) using inkjet printing and nanowires to produce a wireless passive smart tag sensor. The specific detection principle is as follows: Figure 2 shown.

[0028] In some embodiments of the present invention, before the biogenic amine sensor performs actual sample measurements, it is necessary to calibrate the sensor using a standard volatile biogenic amine gas (primarily ammonia). The gas sensing system used can be configured with standard gases of varying concentration gradients. The system consists of a pressure gauge, a commercial ammonia sensor, a sealed gas detection chamber, a voltage transformer module, an AC-DC converter module, a fan, and a gas metering device. The entire device is airtight, and the structure is as follows: Figure 3As shown in the figure, the AC-DC module performs rectification, converting 220V AC power into 24V DC power, while the transformer module converts the 24V DC voltage into 12V DC power suitable for various electrical appliances. Before configuring the standard gas, nitrogen is introduced to purge the entire device to expel air. After calculating the required volume of ammonia gas (all experimental gas cylinders are 99.999% high-purity gas), a handwheel is used to adjust the gas constant volume device, which consists of a sealed gas container and a multi-stage gear transmission system to precisely control the container volume. Ammonia gas is then introduced into the constant volume device and injected into the closed chamber for mixing, completing the gas configuration. The sensitive material is then placed in the closed chamber, and the response values ​​are measured under different concentration gradients. Throughout the entire process, pressure sensors and ammonia concentration sensors are used to monitor the pressure and concentration within the container to ensure the accuracy of the measurement results.

[0029] The passive smart tag for meat food testing provided by the present invention enables rapid, real-time detection of the freshness of ingredients and dishes. First, the sensor uses an antenna coil and an energy capture circuit in the NFC chip to collect energy generated by an active NFC device (smartphone) to power the entire device. Next, an impedance-type gas sensor is constructed by modifying interdigital electrodes with a biogenic amine-sensitive membrane. This element specifically adsorbs biogenic amines volatilized during meat spoilage and converts the concentration of the biogenic amines into an electrical impedance signal at the interdigital electrodes. Next, an analog front end, consisting of an operational amplifier, filter circuit, and voltage regulator circuit, collects and processes the impedance signal from the gas sensor. The processed analog signal is then converted to a digital signal by a digital-to-analog conversion circuit and transmitted to a microprocessor. The data is then sent to the memory in the NFC chip. Finally, a smartphone is used to read the digital signal from the memory via NFC wireless communication technology, determining the relationship between the volatile basic nitrogen content of meat and the impedance change. This ultimately establishes a basis for determining freshness, providing a basis and reference for healthy eating practices.

[0030] The meat freshness detection method provided by the present invention is described below. The meat freshness detection method described below and the passive smart tag for meat detection described above can be referenced to each other.

[0031] Figure 4 Flowchart of the meat product freshness detection method provided by the embodiment of the present invention, such as Figure 4 As shown, the meat food freshness detection method provided by the embodiment of the present invention includes: Step 401: Capture energy from active components through the antenna and NFC chip in the passive smart tag for meat food detection to power the passive smart tag for meat food detection. Step 402: using a biogenic amine sensitive membrane to modify an interdigital electrode to adsorb biogenic amines emitted during internal decay, and converting the concentration of the biogenic amines into an electrical impedance signal of the interdigital electrode; Step 403: Convert the electrical impedance signal into a digital signal, obtain the nitrogen content in the meat product based on the digital signal and a mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and send the nitrogen content in the meat product to the NFC chip; Step 404: Send the nitrogen content in the meat product to the client via the NFC chip and the antenna.

[0032] In an embodiment of the present invention, the meat product freshness detection method further includes: The volatile basic total nitrogen content in the meat product is measured using the Kjeldahl method, and the nitrogen content in the meat product obtained by the passive smart tag for meat product detection is linearly fitted with the volatile basic total nitrogen content in the meat product measured using the Kjeldahl method to obtain the freshness of the meat product. The freshness includes freshness grade, sub-freshness grade and corruption grade, and is displayed synchronously on the client through text and color.

[0033] In an embodiment of the present invention, the biogenic amines in actual meat samples are measured. Because in actual measurements, very few biogenic amines are volatilized from meat, the meat product and the sensor are encapsulated in the same package and left to stand for a period of time to enrich the volatilized biogenic amines to a concentration sufficient to be detected by the sensor. Afterwards, a smartphone with NFC function is used to scan the NFC antenna to obtain the impedance change of the sensitive material in the sensor due to the binding of the biogenic amines, and the data is recorded. Subsequently, the Kjeldahl nitrogen determination method in the national standard is used to measure the content of volatile basic total nitrogen in the meat sample, and the impedance parameters are correlated with the content of volatile basic total nitrogen, and a linear fit is performed on the two. The accuracy of the sensor can reach the ppm level, and it can be used in a series of applications from slaughterhouse to dining table, such as freezers, cold chain transport vehicles, refrigerators, and food inner packaging, etc. Figure 5 Finally, the biogenic amine content is correlated with the freshness index in the national standard to determine the corresponding meat freshness level, which is used as the basis for the sensor's freshness judgment. Freshness is divided into three levels: fresh, sub-fresh, and spoiled, and displayed synchronously on the phone using text and color.

[0034] The meat freshness detection method provided by the embodiment of the present invention captures the energy of the active device through the antenna and NFC chip in the passive smart tag to power the passive smart tag used for meat detection; uses a biogenic amine sensitive film modified interdigital electrode to adsorb biogenic amines volatilized during meat spoilage, and converts the concentration of the biogenic amines into an electrical impedance signal of the interdigital electrode; converts the electrical impedance signal into a digital signal, and obtains the nitrogen content in the meat based on the digital signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and sends the nitrogen content in the meat to the NFC chip; and transmits the nitrogen content in the meat to the client via the NFC chip and the antenna. This method can realize rapid detection of the freshness of meat under various storage conditions and various transportation conditions, and quantifies the freshness index by nitrogen content, providing technical support for detecting the freshness of ingredients and dishes.

[0035] Figure 6 An example of a physical structure diagram of an electronic device is shown below. Figure 6 As shown, the server may include: a processor 610 , a communications interface 620 , a memory 630 and a communication bus 640 , wherein the processor 610 , the communications interface 620 and the memory 630 communicate with each other via the communication bus 640 . The memory 630 includes a computer program, an operating system, and acquired data. The processor 610 can call the logic instructions in the memory 630 to execute a passive smart tag for meat food detection. The method includes: capturing the energy of the active device through the antenna and NFC chip in the passive smart tag to power the passive smart tag for meat food detection; using a biogenic amine sensitive film to modify the interdigital electrode to adsorb the biogenic amine volatilized during meat spoilage, and converting the concentration of the biogenic amine into an electrical impedance signal of the interdigital electrode; converting the electrical impedance signal into a digital signal, obtaining the nitrogen content in the meat food based on the digital signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and sending the nitrogen content in the meat food to the NFC chip; and sending the nitrogen content in the meat food to the client via the NFC chip and the antenna.

[0036] In addition, the logic instructions in the aforementioned memory 630 can be implemented in the form of a software functional unit and, when sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the relevant art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0037] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the passive smart tag for meat food detection provided by the above-mentioned methods, the method comprising: capturing energy of active devices through the antenna and NFC chip in the passive smart tag to power the passive smart tag for meat food detection; using biogenic amine-sensitive membrane-modified interdigital electrodes to adsorb biogenic amines volatilized during meat spoilage, and converting the concentration of biogenic amines into an electrical impedance signal of the interdigital electrodes; converting the electrical impedance signal into a digital signal, obtaining the nitrogen content in the meat food based on the digital signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and sending the nitrogen content in the meat food to the NFC chip; and sending the nitrogen content in the meat food to the client via the NFC chip and the antenna.

[0038] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0039] Through the description of the above embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the relevant technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A passive smart tag for meat food detection, characterized in that: include: Sensitive components, transducers, analog front-ends, microprocessors, NFC chips, and antennas; The sensitive element is a biogenic amine sensitive membrane, which is used to characteristically adsorb biogenic amines volatilized during meat spoilage; The transducer is a gold interdigital electrode, which converts the concentration of the biogenic amine into an electrical impedance signal of the interdigital electrode; The analog front end is used to collect the electrical impedance signal output by the sensitive element and convert it into a digital signal; The microprocessor is used to obtain the nitrogen content in the meat product according to the digital signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and send the nitrogen content in the meat product to the NFC chip; The NFC chip sends the nitrogen content in the meat product to the client through the antenna.

2. The passive smart tag for meat food detection according to claim 1, characterized in that: The analog front end comprises: Operational amplifier circuit, filter circuit, voltage regulator circuit and analog-to-digital conversion circuit; The operational amplifier circuit is used to amplify the electrical impedance signal; The filtering circuit is used to remove noise signals from the amplified electrical impedance signal; The voltage stabilizing circuit is used to regulate the input voltage to supply power to the microprocessor and other circuits of the analog front end; The analog-to-digital conversion circuit is used to convert the de-noised electrical impedance signal into a digital format for processing and converting it into a digital signal.

3. The passive smart tag for meat food detection according to claim 1, characterized in that: The microprocessor is further configured to: Compensating the digital signal to correct sensor drift and obtain a compensated signal; The nitrogen content in the meat product is obtained according to the compensation signal and the mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and the nitrogen content in the meat product is transmitted to the NFC chip through a communication protocol.

4. The passive smart tag for meat food detection according to claim 1, characterized in that: The NFC chip is connected to the antenna, and the NFC chip includes: capture circuits, rectifiers, and voltage regulators; The capture circuit is used to capture the induced alternating current generated when the antenna approaches the active device; The rectifier is used to convert the induced alternating current into a direct current voltage; The voltage regulator is used to adjust the DC voltage to a preset voltage range.

5. The passive smart tag for meat food detection according to claim 1, characterized in that: Also includes: The sensitive element, analog front end, microprocessor, NFC chip and antenna are printed as a stretchable circuit and integrated with nanowires, and the integrated circuit is attached to a flexible substrate.

6. A method for detecting the freshness of meat products, applicable to the passive smart tag for meat product detection according to any one of claims 1 to 5, characterized in that: include: The passive smart tag for meat food detection is powered by capturing energy from active devices through the antenna and NFC chip in the passive smart tag for meat food detection; The biogenic amine-sensitive membrane was used to modify the interdigital electrode to adsorb the biogenic amines volatilized during meat spoilage, and the concentration of the biogenic amines was converted into an electrical impedance signal of the interdigital electrode. Converting the electrical impedance signal into a digital signal, obtaining the nitrogen content in the meat product based on the digital signal and a mapping relationship between the volatile basic total nitrogen content of the meat and the impedance change, and sending the nitrogen content in the meat product to the NFC chip; The nitrogen content in the meat product is sent to the client through the NFC chip and the antenna.

7. The method for detecting the freshness of meat products according to claim 6, wherein: Also includes: The volatile basic total nitrogen content in the meat product is measured using the Kjeldahl method, and the nitrogen content in the meat product obtained by the passive smart tag for meat product detection is linearly fitted with the volatile basic total nitrogen content in the meat product measured using the Kjeldahl method to obtain the freshness of the meat product. The freshness includes freshness grade, sub-freshness grade and corruption grade, and is displayed synchronously on the client through text and color.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the meat product freshness detection method according to claim 6 or 7 is implemented.

9. A non-transitory readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the meat product freshness detection method according to claim 6 or 7 is implemented.

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