Long-acting preservation method and intelligent control system for agricultural products and meat based on biological preservative

Abstract

The application discloses a long-acting preservation method and an intelligent control system for agricultural product meat based on a biological preservative, and belongs to the field of agricultural product meat preservation technology. The microorganism response triggering unit comprises a plurality of biological sensor arrays distributed in the interior or on the surface of the preservation material. The biological preservative loading unit comprises a porous biological-based high-molecular skeleton and a biological preservative compound. The intelligent control unit comprises a data acquisition module, a spoilage kinetics model module and an instruction output module. The application constructs a microorganism response triggering mechanism, so that the release of the preservative depends on the metabolic activity of spoilage bacteria. When the amount of microorganisms is low in the early stage of storage, the characteristic response layer is maintained intact to block the release. When the microorganisms proliferate rapidly in the middle and late stages of spoilage, the metabolic products secreted by the microorganisms specifically trigger the degradation of the response layer, enabling the on-demand release mode, and through the intelligent instruction, the application starts the intensified pulse release in the peak period of spoilage, so as to ensure that the concentration of the bacteriostatic component is matched with the spoilage intensity in real time, and the utilization efficiency of the preservative is improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural product storage and preservation technology, specifically to a long-term preservation method and intelligent control system for agricultural products and meat based on biological preservatives. Background Technology

[0002] Fresh meat and agricultural products, due to their rich nutritional content and high water content, are highly susceptible to microbial contamination and spoilage during storage and transportation. Traditional meat preservation technology mainly relies on a combination of low-temperature cold chain and chemical preservatives. However, chemical preservatives such as sodium dehydroacetate are facing increasingly stringent regulatory restrictions, and consumers' strong demand for "clean labels" is prompting the industry to seek safer alternatives.

[0003] Biological preservatives have become a research hotspot due to their natural and safe properties. However, current application methods mainly involve slow release through soaking, spraying, or composite packaging materials, which suffers from uncontrollable release rates of active ingredients and a mismatch between the duration of action and the microbial spoilage process. Specifically, conventional slow-release systems release large amounts of preservatives in the early stages of storage when microbial biomass is low, leading to premature depletion of effective ingredients. Conversely, in the later stages of spoilage when microorganisms proliferate rapidly, the release rate decreases, failing to form a long-lasting antimicrobial barrier. Furthermore, existing preservation systems lack the ability to perceive and adaptively regulate changes in the storage environment and meat quality in real time, hindering the technological leap from static protection to intelligent response. Summary of the Invention

[0004] To address this issue, the present invention provides a method and intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives, in order to solve the problem that conventional slow-release systems in the prior art release a large amount of preservatives when the microbial population is low in the early stage of storage, resulting in the premature depletion of effective components; while in the later stage of spoilage when microorganisms proliferate rapidly, the release rate decreases, making it impossible to form a long-term antibacterial barrier.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives includes:

[0007] A microbial response triggering unit includes multiple biosensor arrays distributed inside or on the surface of the preservation material. The biosensor arrays are used to detect the concentration of metabolic markers of specific spoilage microorganisms on the surface of meat in real time, and generate a trigger signal when the concentration reaches a preset threshold. The metabolic markers include proteases, lipases, volatile basic nitrogen, or organic acids secreted during microbial proliferation.

[0008] A biopreservative loading unit comprises a porous bio-based polymer framework and a biopreservative complex encapsulated within its porous structure. The porous bio-based polymer framework is constructed by cross-linking at least one of chitosan, sodium alginate, gelatin, or zein, and has an interconnected microporous channel network. The biopreservative complex contains at least one plant-derived extract and at least one microbial-derived bacteriocin. The surface of the biopreservative complex is modified with a characteristic responsive layer sensitive to the metabolic marker. In an untriggered state, the characteristic responsive layer blocks the release of the biopreservative. Upon receiving the trigger signal, it undergoes structural degradation or conformational change, thereby opening the release channel.

[0009] The intelligent control unit, connected to the microbial response triggering unit and the biopreservative loading unit, includes a data acquisition module, a spoilage kinetics model module, and an instruction output module. The data acquisition module receives real-time data from the biosensor array. The spoilage kinetics model module has a built-in predictive model for the growth of spoilage microorganisms under different meat types and storage temperatures, used to dynamically estimate the remaining shelf life based on real-time data. The instruction output module sends an enhanced release instruction to the biopreservative loading unit when the estimated remaining shelf life is lower than a set safety threshold, thereby regulating the degradation rate of the characteristic response layer or triggering an additional physical release mechanism.

[0010] Preferably, the microbial response triggering unit further includes a pH-sensitive sensing element and a temperature compensation element; the pH-sensitive sensing element is used to monitor pH changes on the surface of meat due to microbial metabolism, and the temperature compensation element is used to collect storage environment temperature data in real time and perform temperature correction on the measured values ​​of the metabolic marker concentration; the biosensor array uses immobilized enzyme electrodes or molecularly imprinted electrochemical sensors to specifically detect dominant spoilage bacterial populations of Pseudomonas, Thermonas thermophilus, or Lactobacillus sensing signal molecules.

[0011] Preferably, in the biopreservative loading unit, the characteristic response layer is constructed using a layer-by-layer self-assembly technique, including an inner enzyme-sensitive protein layer and an outer polysaccharide shielding layer; the enzyme-sensitive protein layer is a thin film prepared from gelatin or casein, which can be specifically degraded by proteases secreted by microorganisms;

[0012] The polysaccharide shielding layer is a thin film made of alginate or pectin. When the polysaccharide shielding layer is not degraded, it maintains structural integrity to prevent the leakage of the biopreservative. When microorganisms proliferate and secrete proteases, the enzyme-sensitive protein layer is preferentially degraded, causing the polysaccharide shielding layer to fall off or break, thereby initiating the release. The release rate of the biopreservative complex is preset by regulating the degree of cross-linking of the enzyme-sensitive protein layer. The degree of cross-linking is negatively correlated with the release rate. The formula for calculating the degree of cross-linking is: degree of cross-linking (%) = (amount of free amino group reduced after reaction / total amount of amino group before reaction) × 100%.

[0013] Preferably, in the biopreservative loading unit, the biopreservative complex comprises 30-50% by weight of tea tree oil or cinnamaldehyde microcapsules, 20-40% by weight of nisin or penicillin, 10-20% by weight of lysozyme, and 5-15% by weight of vitamin E or tea polyphenols as antioxidant synergists; the wall material of the microcapsules is β-cyclodextrin or gum arabic, prepared by spray drying, with an average particle size of 1-10 μm; the porous bio-based polymer framework has a porosity of 60-85%, an average pore size of 50-200 μm, and active functional groups that form chemical bonds with the characteristic response layer are grafted onto the pore surface.

[0014] Preferably, the intelligent control unit further includes an adaptive algorithm module, which is connected to the spoilage kinetics model module and the instruction output module. The adaptive algorithm module uses recursive least squares to correct the spoilage kinetics model parameters online based on the difference between historical data and actual sensor monitoring data. When the actual spoilage rate of a batch of meat products deviates significantly from the model's predicted value, the adaptive algorithm module automatically adjusts the maximum specific growth rate or lag period parameters in the model to make the subsequent remaining shelf life projections closer to reality. The instruction output module recalculates the release strategy based on the corrected model and sends adjustment instructions to the biopreservative loading unit. These adjustment instructions include a pulsed release mode or a continuous low-dose release mode. Specifically, the pulsed release mode involves initiating a high-intensity release pulse lasting 30-60 minutes when the daily growth rate of volatile basic nitrogen concentration exceeds 15%, with the pulse intensity being 3-5 times the baseline release rate, and the pulse interval dynamically adjusted according to the spoilage rate. The continuous low-dose release mode is suitable for the early stages of spoilage, with the release rate maintained at 0.1-0.5 μg / cm²·h.

[0015] Preferably, the system further includes a self-repair monitoring and feedback unit, which includes a fluorescent probe layer and an optical detection module. The fluorescent probe layer is coated on the outer surface of the biopreservative loading unit and contains liposomes or polymer vesicles encapsulating specific dyes. When the characteristic response layer degrades, causing changes in the local microenvironment, the liposomes or polymer vesicles rupture and release the dye, generating a fluorescent signal. The optical detection module includes an ultraviolet light source and a photoelectric sensor, used to periodically irradiate and detect changes in the fluorescence intensity of the fluorescent probe layer. When the detected fluorescence intensity exceeds twice the background value, it is determined that the characteristic response layer has degraded and the preservative release is initiated, while the distribution of the release area is recorded. If the fluorescence intensity in a certain area is abnormally increased beyond a set upper limit threshold, it is determined that the response layer has undergone excessive local degradation, and the intelligent control unit sends a compensation release command to the biopreservative loading units in adjacent untriggered areas to maintain the uniformity of the preservation effect.

[0016] To achieve the above objectives, the present invention also provides the following technical solution:

[0017] The intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives includes the following steps:

[0018] Step S1: Prepare a porous bio-based polymer framework loaded with bio-preservative complex into a preservation film, preservation pad or preservation coating, and attach it to the surface of meat products or the inner wall of the packaging.

[0019] Step S2: The concentration of volatile basic nitrogen or the concentration of specific spoilage bacteria community sensing signal molecules on the surface of meat are monitored in real time through the microbial response triggering unit, and the monitoring data is transmitted to the intelligent control unit in real time.

[0020] Step S3: The spoilage kinetics model module built into the intelligent control unit uses the modified Gompertz equation to extrapolate the remaining shelf life based on the initial colony count, storage temperature and real-time monitoring data; when the concentration of the monitored metabolic markers reaches the first preset threshold, the instruction output module issues a primary release instruction, inducing the partial opening of the characteristic response layer, so that the biological preservative seeps out at the first release rate.

[0021] Step S4: When the concentration of the monitored metabolic markers reaches a second preset threshold that is higher than the first preset threshold, the instruction output module issues an enhanced release instruction to accelerate the degradation of the characteristic response layer through electrical stimulation or local micro-heating, so that the biopreservative is released at a second release rate that is higher than the first release rate, thereby inhibiting the rapid proliferation of spoilage microorganisms.

[0022] Step S5: The intelligent control unit continuously monitors meat quality indicators. When the concentration of volatile basic nitrogen falls below the safety limit or the spoilage rate decreases to the set level, the instruction output module issues an inhibition release command. By changing the direction of the electric field or interrupting micro-heating, the characteristic response layer stops further degradation, and the release of biological preservatives is paused or slowed down.

[0023] Preferably, the modified Gompertz equation in step S3 is used to describe the growth dynamics of putrefactive microorganisms, and its specific form is as follows:

[0024] ,

[0025] Where N(t) is the number of microorganisms at time t, N0 is the initial number of microorganisms, Nmax is the maximum number of microorganisms, μ is the maximum specific growth rate, λ is the lag period, and e is the natural constant; the intelligent control unit updates the μ and λ parameters online based on real-time monitoring data using a λ nonlinear fitting method. When the goodness of fit R 2 When the value is below 0.9, the adaptive algorithm module is triggered to adjust the parameters; the first release rate is 0.2-0.8 μg / cm³. 2 The second release rate is 1.5-5.0 μg / cm³. 2 •h; The first preset threshold is when the volatile basic nitrogen concentration reaches 15-20 mg / 100g, and the second preset threshold is when the volatile basic nitrogen concentration reaches 25-30 mg / 100g or the increment per unit time exceeds 5 mg / 100g·h.

[0026] This invention has the following advantages: It constructs a microbial response triggering mechanism, making the release of preservatives dependent on the metabolic activities of spoilage bacteria. In the early stage of storage when the amount of microorganisms is low, the characteristic response layer maintains complete barrier release, avoiding ineffective consumption of preservatives. In the middle and late stages of spoilage, when microorganisms proliferate rapidly, their secreted metabolites specifically trigger the degradation of the response layer, opening the on-demand release mode. During the peak of spoilage, enhanced pulse release is initiated through intelligent commands to ensure that the concentration of antibacterial components matches the spoilage intensity in real time, thereby improving the utilization efficiency of preservatives.

[0027] By using a spoilage dynamics model and adaptive algorithms, the remaining shelf life can be dynamically estimated and model parameters can be corrected online. Based on quality feedback, the release strategy can be automatically adjusted, thus completing the technological leap from static protection to intelligent response. Attached Figure Description

[0028] To more intuitively illustrate the prior art and this application, exemplary drawings are provided below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0029] Figure 1 A block diagram of an intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives, provided in an embodiment of this application.

[0030] Figure 2 A flowchart illustrating a long-term preservation method for agricultural products and meat based on biological preservatives, provided in this application embodiment. Detailed Implementation

[0031] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these embodiments are merely for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Technical engineers in the field can make some non-essential improvements and adjustments to the present invention based on the above-described content. 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.

[0032] Please see Figure 1 A smart control system for long-term preservation of agricultural products and meat based on biological preservatives includes:

[0033] A microbial response triggering unit includes multiple biosensor arrays distributed inside or on the surface of the preservation material (the biosensor arrays should be checked for inactivation before each transport, and replaced promptly if inactivated). The biosensor arrays are used to detect the concentration of metabolic markers of specific spoilage microorganisms on the surface of meat in real time, and generate a trigger signal when the concentration reaches a preset threshold. The metabolic markers include proteases, lipases, volatile basic nitrogen, or organic acids secreted during microbial proliferation.

[0034] A biopreservative loading unit comprises a porous bio-based polymer framework and a biopreservative complex encapsulated within its porous structure. The porous bio-based polymer framework is constructed by cross-linking at least one of chitosan, sodium alginate, gelatin, or zein, and has an interconnected microporous channel network. The biopreservative complex contains at least one plant-derived extract and at least one microbial-derived bacteriocin. The surface of the biopreservative complex is modified with a characteristic responsive layer sensitive to the metabolic marker. In an untriggered state, the characteristic responsive layer blocks the release of the biopreservative. Upon receiving the trigger signal, it undergoes structural degradation or conformational change, thereby opening the release channel.

[0035] The intelligent control unit, electrically connected to the microbial response triggering unit and the biopreservative loading unit, can be powered by a refrigeration system. It includes a data acquisition module, a spoilage kinetics model module, and an instruction output module. The data acquisition module receives real-time data from the biosensor array. The spoilage kinetics model module has a built-in predictive model for the growth of spoilage microorganisms under different meat types and storage temperatures, used to dynamically estimate the remaining shelf life based on real-time data. The instruction output module sends an enhanced release instruction to the biopreservative loading unit when the estimated remaining shelf life is lower than a set safety threshold, regulating the degradation rate of the characteristic response layer or triggering an additional physical release mechanism.

[0036] When implementing this invention, it has the following characteristics (taking a cold chain logistics company that needs to transport a batch of chilled pork over long distances, with a shelf life requirement of more than 15 days as an example):

[0037] The system consists of a disposable flexible biosensor patch integrated on the surface of the inner liner film of the packaging (containing a molecularly imprinted electrochemical sensor for population sensing signal molecules (such as acyl homoserine lactones, AHLs) of Pseudomonas (the main spoilage bacteria of chilled fresh meat), and a miniature temperature compensation element), which monitors the metabolic activity intensity of specific spoilage bacteria on the surface of pork in real time.

[0038] The porous preservation pad, which adheres closely to the surface of meat, comprises a porous framework, a biopreservative complex, and a responsive layer. The porous framework is a sponge-like material with interconnected micropores (average pore size approximately 100 μm), constructed from chitosan and sodium alginate through a cross-linking reaction. The biopreservative complex, encapsulated within the framework pores, contains cinnamaldehyde microcapsules (40% for broad-spectrum antibacterial activity) and nisin (30% for inhibiting Gram-positive bacteria). The responsive layer is a double-layered film coated on the surface and inner walls of the pores of the preservation pad using a layer-by-layer self-assembly technique. The inner layer is a gelatin layer (enzyme-sensitive protein layer) that can be specifically degraded by proteases, while the outer layer is a water-insoluble alginate layer (polysaccharide shielding layer). In the untriggered state, the outer alginate layer blocks the release of the internal preservatives.

[0039] The intelligent control unit is a disposable low-power microprocessor installed on the outside of the packaging box. It is connected to the internal sensors through flexible circuits and has a built-in data acquisition module, a microchip preloaded with a spoilage dynamics model of chilled pork (spoilage dynamics model module), and an instruction output module.

[0040] Early stage of storage: The pork is fresh, with few microorganisms and weak metabolic activity. Pseudomonas has not yet secreted a large amount of protease, and the volatile basic nitrogen (TVB-N) value is less than 12mg / 100g.

[0041] The microbial response triggering unit continuously monitors, but the AHLs concentration is far below the preset threshold, and no trigger signal is generated. The alginate layer on the outer layer of the biopreservative loading unit remains intact, firmly sealing the internal cinnamaldehyde and nisin, with almost no release (the release rate approaches 0). During this stage, the intelligent control unit is only in a low-power listening state and does not issue release commands.

[0042] Initiation of spoilage: On the 5th day of storage, with temperature fluctuations, Pseudomonas begins to enter the logarithmic growth phase and starts to secrete large amounts of proteases to break down meat protein for its own growth. The TVB-N value rises to 18 mg / 100g.

[0043] The microbial response triggering unit detects that the AHLs concentration has reached the first preset threshold (corresponding to approximately 15-20 mg / 100g of TVB-N) and immediately generates a trigger signal. Upon receiving the signal, the intelligent control unit recalculates the remaining shelf life using the spoilage kinetics model module, determines that the spoilage initiation phase has begun, and the command output module issues a primary release command. This command acts as a microcurrent on the biopreservative loading unit.

[0044] In the characteristic response layer, proteases secreted by the microorganisms begin to corrode and specifically degrade the inner gelatin layer from the outside. After the gelatin layer is degraded, the outer alginate layer loses its substrate and subsequently undergoes localized rupture or detachment. The biopreservatives (cinnamaldehyde, nisin) encapsulated in the pores begin to slowly seep out at an initial release rate (approximately 0.5 μg / cm²·h).

[0045] Peak spoilage period: On the 10th day of storage, microorganisms proliferated too rapidly in some areas, and the TVB-N concentration rose sharply to 28 mg / 100g, exceeding the second preset threshold.

[0046] The microbial response trigger unit detected a daily growth rate of TVB-N exceeding 15%. The spoilage kinetic model built into the intelligent control unit calculated that the remaining shelf life would be below the safety threshold, and the command output module issued an enhanced release command. This command activated a pulsed release mode: by using micro-heating elements (physical release mechanism) to instantaneously raise the local temperature, accelerating the physical disintegration of the characteristic response layer, while simultaneously using electrical stimulation to promote mass transfer within the porous framework.

[0047] Upon receiving the command, the biopreservative loading unit abruptly increased its release rate to the second release rate (approximately 4.0 μg / cm²·h), delivering a high-intensity pulse lasting 45 minutes. High concentrations of cinnamaldehyde and nisin rapidly diffused onto the meat surface, effectively inhibiting the explosive growth of spoilage bacteria.

[0048] Inhibition and decline phase: After enhanced release, microbial activity was significantly inhibited. The TVB-N concentration gradually declined and stabilized at 22 mg / 100 g, and the putrefaction rate decreased.

[0049] The microbial response triggering unit detected that the TVB-N concentration had fallen below the second preset threshold and its growth had ceased. The intelligent control unit determined that the risk of spoilage had decreased, and the command output module issued a release inhibition command. The system interrupted micro-heating, the release mode switched from pulsed to baseline level, the release rate decreased to 0.3 μg / cm²·h, or even stopped.

[0050] The microbial response triggering unit also includes a pH-sensitive sensing element and a temperature compensation element; the pH-sensitive sensing element is used to monitor pH changes on the surface of meat caused by microbial metabolism (such as acid production by lactic acid bacteria and ammonia production by protein spoilage), and the temperature compensation element is used to collect storage environment temperature data in real time and perform temperature correction on the measured values ​​of the metabolic marker concentration; the biosensor array uses immobilized enzyme electrodes or molecularly imprinted electrochemical sensors to specifically detect the dominant spoilage bacterial population sensing signal molecules of Pseudomonas, Thermonas thermophilus, or Lactobacillus.

[0051] In the biological preservative loading unit, the characteristic response layer is constructed using a layer-by-layer self-assembly technology, including an inner enzyme-sensitive protein layer and an outer polysaccharide shielding layer. The enzyme-sensitive protein layer is a thin film made of gelatin or casein, which can be specifically degraded by proteases secreted by microorganisms. When microorganisms multiply in large quantities and secrete proteases, the inner layer is preferentially degraded, causing the outer layer to lose support and fall off or rupture, thereby opening the release channel.

[0052] The polysaccharide shielding layer is a thin film made of alginate or pectin. When the polysaccharide shielding layer is not degraded, it maintains structural integrity to prevent the leakage of the biopreservative. When microorganisms proliferate and secrete proteases, the enzyme-sensitive protein layer is preferentially degraded, causing the polysaccharide shielding layer to fall off or break, thereby initiating the release. The release rate of the biopreservative complex is preset by regulating the degree of cross-linking of the enzyme-sensitive protein layer. The degree of cross-linking is negatively correlated with the release rate. The formula for calculating the degree of cross-linking is: degree of cross-linking (%) = (amount of free amino group reduced after reaction / total amount of amino group before reaction) × 100%.

[0053] In the biological preservative loading unit, the biological preservative complex contains 30-50% by weight of tea tree oil or cinnamaldehyde microcapsules, 20-40% by weight of nisin or penicillin, 10-20% by weight of lysozyme, and 5-15% by weight of vitamin E or tea polyphenols as antioxidant synergists.

[0054] The wall material of the microcapsules is β-cyclodextrin or gum arabic, prepared by spray drying, with an average particle size of 1-10 μm; the porous bio-based polymer framework has a porosity of 60-85%, an average pore size of 50-200 μm, and active functional groups that form chemical bonds with the characteristic response layer are grafted onto the pore surface.

[0055] In practical applications, the prediction accuracy of a fixed mathematical model decreases when used to predict meat products of different varieties, seasons, and initial colony counts. To address this technical problem, the following technical solution is implemented: the intelligent control unit further includes an adaptive algorithm module, which is connected to the spoilage kinetics model module and the instruction output module. The adaptive algorithm module uses a recursive least squares method to correct the spoilage kinetics model parameters online based on the differences between historical data and actual sensor monitoring data. When the actual spoilage rate of a batch of meat products deviates significantly from the model's predicted value, the adaptive algorithm module automatically adjusts the maximum specific growth rate in the model. Alternatively, a delay period parameter can be used to make the subsequent estimated remaining shelf life more closely resemble the actual situation. The instruction output module recalculates the release strategy based on the corrected model and sends adjustment instructions to the biopreservative loading unit. The adjustment instructions include a pulsed release mode or a continuous low-dose release mode. Specifically, the pulsed release mode involves initiating a high-intensity release pulse that lasts for 30-60 minutes when the daily growth rate of volatile basic nitrogen concentration exceeds 15%. The pulse intensity is 3-5 times the baseline release rate, and the pulse interval is dynamically adjusted according to the spoilage rate. The continuous low-dose release mode is suitable for the early stage of spoilage, with the release rate maintained at 0.1-0.5 μg / cm²·h.

[0056] The system also includes a self-repair monitoring and feedback unit, which comprises a fluorescent probe layer and an optical detection module. The fluorescent probe layer is coated on the outer surface of the biopreservative loading unit and contains liposomes or polymer vesicles encapsulating specific dyes. When the characteristic response layer degrades, causing changes in the local microenvironment, the liposomes or polymer vesicles rupture and release the dye, generating a fluorescent signal. The optical detection module includes an ultraviolet light source and a photoelectric sensor, used to periodically irradiate and detect changes in the fluorescence intensity of the fluorescent probe layer. When the detected fluorescence intensity exceeds twice the background value, it is determined that the characteristic response layer has degraded and the preservative release is initiated, while the distribution of the release area is recorded. If the fluorescence intensity in a certain area is abnormally increased beyond a set upper limit threshold, it is determined that the response layer has undergone excessive local degradation, and the intelligent control unit sends a compensation release command to the biopreservative loading units in adjacent untriggered areas to maintain the uniformity of the preservation effect.

[0057] like Figure 2 As shown, the intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives includes the following steps:

[0058] Step S1, deployment of preservation medium and interface construction: a porous bio-based polymer framework loaded with bio-preservative complex is prepared into a preservation film, preservation pad or preservation coating and attached to the surface of meat products or the inner wall of packaging.

[0059] Step S2, Real-time monitoring and data transmission of spoilage markers: The concentration of volatile basic nitrogen or the concentration of specific spoilage bacteria community sensing signal molecules on the surface of meat are monitored in real time through the microbial response triggering unit, and the monitoring data is transmitted to the intelligent control unit in real time.

[0060] Step S3, Primary Response Triggering and On-Demand Release: The spoilage kinetics model module built into the intelligent control unit uses the modified Gompertz equation to extrapolate the remaining shelf life based on the initial colony count, storage temperature, and real-time monitoring data; when the monitored concentration of metabolic markers reaches the first preset threshold, the instruction output module issues a primary release instruction, inducing the partial opening of the characteristic response layer, so that the biopreservative can seep out at the first release rate.

[0061] Step S4, Enhanced intervention during peak spoilage period: When the concentration of the monitored metabolic markers reaches a second preset threshold higher than the first preset threshold, the instruction output module issues an enhanced release instruction to accelerate the degradation of the characteristic response layer through electrical stimulation or local micro-heating, so that the biopreservative is released at a second release rate higher than the first release rate, thereby inhibiting the rapid proliferation of spoilage microorganisms.

[0062] Step S5, Intelligent Feedback and Release Inhibition: The intelligent control unit continuously monitors meat quality indicators. When the concentration of volatile basic nitrogen falls below the safety limit or the spoilage rate decreases to the set level, the instruction output module issues a release inhibition command. By changing the direction of the electric field or interrupting micro-heating, the characteristic response layer stops further degradation, and the release of the biological preservative is paused or slowed down.

[0063] The modified Gompertz equation in step S3 is used to describe the growth dynamics of putrefactive microorganisms, and its specific form is as follows:

[0064] ,

[0065] Where N(t) is the number of microorganisms at time t, N0 is the initial number of microorganisms, Nmax is the maximum number of microorganisms, μ is the maximum specific growth rate, λ is the lag period, and e is the natural constant; the intelligent control unit updates the μ and λ parameters online based on real-time monitoring data using a λ nonlinear fitting method. When the goodness of fit R 2 When the value is below 0.9, the adaptive algorithm module is triggered to adjust the parameters; the first release rate is 0.2-0.8 μg / cm³. 2 The second release rate is 1.5-5.0 μg / cm³. 2 •h; The first preset threshold is when the volatile basic nitrogen concentration reaches 15-20 mg / 100g, and the second preset threshold is when the volatile basic nitrogen concentration reaches 25-30 mg / 100g or the increment per unit time exceeds 5 mg / 100g·h.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives, characterized in that, include: A microbial response triggering unit includes multiple biosensor arrays distributed inside or on the surface of the preservation material. The biosensor arrays are used to detect the concentration of metabolic markers of specific spoilage microorganisms on the surface of meat in real time, and generate a trigger signal when the concentration reaches a preset threshold. The metabolic markers include proteases, lipases, volatile basic nitrogen, or organic acids secreted during microbial proliferation. A biopreservative loading unit comprises a porous bio-based polymer framework and a biopreservative complex encapsulated within its porous structure. The porous bio-based polymer framework is constructed from at least one of chitosan, sodium alginate, gelatin, or zein through a cross-linking reaction and has an interconnected microporous channel network. The biopreservative complex contains at least one plant-derived extract and at least one microbial-derived bacteriocin, and the surface of the biopreservative complex is modified with a characteristic responsive layer sensitive to the metabolic markers. The intelligent control unit is electrically connected to the microbial response triggering unit and the biopreservative loading unit, and includes a data acquisition module, a spoilage kinetics model module, and an instruction output module. The data acquisition module is used to receive real-time data from the biosensor array. The spoilage kinetics model module has a built-in predictive model for the growth of spoilage microorganisms based on different types of meat and different storage temperatures, which is used to dynamically extrapolate the remaining shelf life based on real-time data. The instruction output module is used to send an enhanced release instruction to the biopreservative loading unit when the extrapolated remaining shelf life is lower than a set safety threshold.

2. The intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives according to claim 1, characterized in that, The microbial response triggering unit also includes a pH-sensitive sensing element and a temperature compensation element; the pH-sensitive sensing element is used to monitor pH changes on the surface of meat due to microbial metabolism, and the temperature compensation element is used to collect storage environment temperature data in real time and perform temperature correction on the measured values ​​of the metabolic marker concentration.

3. The intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives according to claim 1, characterized in that, In the biological preservative loading unit, the characteristic response layer is constructed using a layer-by-layer self-assembly technology, including an inner enzyme-sensitive protein layer and an outer polysaccharide shielding layer. The enzyme-sensitive protein layer is a thin film made of gelatin or casein, which can be specifically degraded by proteases secreted by microorganisms. The polysaccharide shielding layer is a thin film made of alginate or pectin. When the polysaccharide shielding layer is not degraded, it maintains structural integrity to prevent the leakage of biological preservatives. When microorganisms proliferate and secrete proteases, the enzyme-sensitive protein layer is preferentially degraded, causing the polysaccharide shielding layer to fall off or break. The release rate of the biopreservative complex is preset by regulating the cross-linking degree of the enzyme-sensitive protein layer. The cross-linking degree is negatively correlated with the release rate, and the formula for calculating the cross-linking degree is as follows: Degree of crosslinking = (reduction of free amino groups after reaction / total amino group amount before reaction) × 100%.

4. The intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives according to claim 1, characterized in that, In the biopreservative loading unit, the biopreservative complex comprises 30-50% by weight of tea tree oil or cinnamaldehyde microcapsules, 20-40% by weight of nisin or penicillin, 10-20% by weight of lysozyme, and 5-15% by weight of vitamin E or tea polyphenols as antioxidant synergists; the wall material of the microcapsules is β-cyclodextrin or gum arabic, prepared by spray drying, with an average particle size of 1-10 μm; the porous bio-based polymer framework has a porosity of 60-85%, an average pore size of 50-200 μm, and active functional groups that form chemical bonds with the characteristic response layer are grafted onto the pore surface.

5. The intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives according to claim 3, characterized in that, The intelligent control unit also includes an adaptive algorithm module, which is electrically connected to the putrefaction kinetics model module and the command output module. The adaptive algorithm module uses the recursive least squares method to correct the putrefaction kinetics model parameters online based on the difference between historical data and actual sensor monitoring data.

6. The intelligent control system for long-term preservation of agricultural products and meat based on biological preservatives according to claim 1, characterized in that, The system also includes a self-healing monitoring and feedback unit, which includes a fluorescent probe layer and an optical detection module. The fluorescent probe layer is coated on the outer surface of the biopreservative loading unit and contains liposomes or polymer vesicles encapsulating specific dyes. When the characteristic response layer degrades, causing changes in the local microenvironment, the liposomes or polymer vesicles rupture and release the dye, generating a fluorescent signal. The optical detection module includes an ultraviolet light source and a photoelectric sensor, used to periodically irradiate and detect changes in the fluorescence intensity of the fluorescent probe layer.

7. A method for long-term preservation of agricultural products and meat based on biological preservatives, characterized in that, Includes the following steps: Step S1: Prepare a porous bio-based polymer framework loaded with bio-preservative complex into a preservation film, preservation pad or preservation coating, and attach it to the surface of meat products or the inner wall of the packaging. Step S2: The concentration of volatile basic nitrogen or the concentration of specific spoilage bacteria community sensing signal molecules on the surface of meat are monitored in real time through the microbial response triggering unit, and the monitoring data is transmitted to the intelligent control unit in real time. Step S3: The spoilage kinetics model module built into the intelligent control unit uses the modified Gompertz equation to extrapolate the remaining shelf life based on the initial colony count, storage temperature and real-time monitoring data; when the concentration of the monitored metabolic markers reaches the first preset threshold, the instruction output module issues a primary release instruction, inducing the partial opening of the characteristic response layer, so that the biological preservative seeps out at the first release rate. Step S4: When the detected concentration of metabolic markers reaches a second preset threshold that is higher than the first preset threshold, the instruction output module issues an enhanced release instruction to accelerate the degradation of the characteristic response layer through electrical stimulation or local micro-heating, so that the biopreservative is released at a second release rate that is higher than the first release rate. Step S5: The intelligent control unit continuously monitors meat quality indicators. When the concentration of volatile basic nitrogen falls below the safety limit or the spoilage rate decreases to the set level, the instruction output module issues a release inhibition command. By changing the direction of the electric field or interrupting micro-heating, the characteristic response layer stops further degradation, thereby pausing or slowing down the release of the biopreservative.

8. The method for long-term preservation of agricultural products and meat based on biological preservatives according to claim 7, characterized in that, The modified Gompertz equation in step S3 is used to describe the growth dynamics of putrefactive microorganisms, and its specific form is as follows: ， Where N(t) is the number of microorganisms at time t, N0 is the initial number of microorganisms, Nmax is the maximum number of microorganisms, μ is the maximum specific growth rate, λ is the lag period, and e is the natural constant.

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