Yak meat fresh-keeping treatment method capable of intelligently regulating and controlling high-voltage pulse electric field

Abstract

The invention provides a yak meat fresh-keeping treatment method capable of intelligently regulating and controlling a high-voltage pulse electric field, and relates to the technical field of food processing.The yak meat fresh-keeping treatment method comprises the steps that a dielectric spectrum sensor is used for monitoring the conductivity value of extracellular fluid in real time, the field intensity of a composite waveform high-voltage pulse electric field is adjusted based on the conductivity value, and the yak meat fresh-keeping treatment method is obtained through the composite waveform high-voltage pulse electric field; accelerating the precursor loading liquid to enter muscle fibers and generate oxidative polymerization to form an endogenous preservative, and spraying a nanocrystallized natural antibacterial peptide solution, so that the antibacterial peptide instantly enters cytoplasm to deeply kill by virtue of an electroporation channel, and a layer of physical exogenous protective agent barrier is formed on the surface of the meat product; according to the method, yak meat is taken as a raw material, after-ripening maintenance is performed in a low-temperature and high-humidity environment of a high-voltage electrostatic field, storage and transportation are performed in cooperation with directional modified atmosphere packaging, a four-in-one long-acting fresh-keeping system with an internal chemical barrier, a surface biological barrier, an external physical barrier and a whole-course low-temperature barrier is formed, and stable, controllable and long-acting maintenance of the yak meat quality is achieved.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a method for preserving yak meat using intelligent regulation of a high-voltage pulsed electric field. Background Technology

[0002] Yak meat has coarse muscle fibers and low fat content, making it prone to problems such as juice loss, darkening of color, and microbial growth during storage and transportation. This makes it more difficult to preserve than regular beef. Current technologies typically use high-voltage pulsed electric fields to tenderize or sterilize meat, such as CN107467149A, which discloses a method for tenderizing beef using high-voltage pulsed electric field coupling technology; and CN120323500A, which discloses a method for preserving fresh meat at electric field coupled storage temperatures, which sets different fixed electric field intensities and times for fresh meat preservation. However, existing technologies for preserving fresh meat or beef still have the following problems: Problem 1: When applying a high-voltage pulsed electric field to preserve fresh meat, fixed electric field parameters or ranges are usually selected. It is impossible to intelligently and dynamically adjust the parameters according to the condition of the meat. Since the quality of different batches of fresh meat or beef is different, and the parameters change continuously during the processing, the fixed electric field parameters cannot meet the optimal preservation requirements and may also cause damage to the fresh meat or beef. The low level of intelligence leads to the final preservation quality failing to meet the requirements. Question 2: When high-voltage pulse electric fields are used to sterilize and preserve fresh meat or beef, sterilization is instantaneous and there is no sustained antibacterial ability after the treatment. It cannot provide long-term protection throughout the storage and transportation process. The treatment of a single high-voltage pulse electric field cannot meet the needs of long-term preservation. Moreover, fresh meat or beef itself cannot preserve itself. After the external influence is removed, fresh meat or beef still cannot reach the optimal preservation requirements, resulting in a significant reduction in preservation time, which is not conducive to long-term storage and preservation. Question 3: For fresh meat or beef treated with a high-voltage pulse electric field, direct refrigeration or freezing is generally chosen for preservation. At this time, the fresh meat or beef is in an unstable state after treatment, and its endogenous activity and ionic environment have changed. If it is directly refrigerated, its quality will still deteriorate quickly and its stability is not high. There is a lack of maintenance treatment for the treated fresh meat or beef. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides the following technical solution: a method for preserving yak meat using intelligent regulation of a high-voltage pulsed electric field, the method comprising: S100. Soak yak meat in the precursor loading solution to obtain soaked yak meat; S200: Apply a composite waveform high-voltage pulse electric field to the soaked yak meat; S300: Obtain the conductivity value of the extracellular fluid of yak meat in S200, generate a feedback signal based on the conductivity value, adjust the parameters of the composite waveform high voltage pulse electric field based on the feedback signal, and spray the natural antimicrobial peptide solution onto the surface of yak meat. S400: The yak meat processed by S200 and S300 is transferred to a post-maturation environment superimposed with a high-voltage electrostatic field for post-maturation. S500: Take the yak meat that has been post-aged and aged, and then perform directional modified atmosphere packaging. Store and transport the directional modified atmosphere packaged yak meat in a cold chain.

[0004] Furthermore, the step of soaking yak meat in a precursor loading solution to obtain soaked yak meat includes: After preparing a sodium lactate solution with a concentration of 0.5%-2.0%, bamboo leaf extract was added to prepare an aqueous solution with a concentration of 0.05%-0.2% as the precursor loading solution; After being cut, the yak meat was completely immersed in the precursor loading solution at an ambient temperature of 4-10℃. Evacuate the precursor loading liquid environment to a vacuum level of -0.05 to -0.08 MPa, and tumble at a rate of 5-15 revolutions per minute for 15-30 minutes. After tumbling, restore normal pressure, remove the yak meat from the pre-loaded liquid and drain off the excess liquid on the surface to obtain soaked yak meat.

[0005] Furthermore, applying a composite waveform high-voltage pulsed electric field to the soaked yak meat includes: The soaked yak meat is placed in a composite waveform high-voltage pulse electric field. Each cycle of the composite waveform high-voltage pulse electric field generates a nanosecond-level pulse and a microsecond-level pulse. The electric field strength parameter of the nanosecond-level pulse is 30-50 kV / cm, and the pulse width parameter is 100-300 nanoseconds. The electric field strength parameter of the microsecond-level pulse is 5-15 kV / cm, and the pulse width parameter is 10-50 microseconds. The pulse repetition frequency of the composite waveform high-voltage pulse electric field is controlled to be 50-200Hz, so that the soaked yak meat leaves the composite waveform high-voltage pulse electric field after being treated with 100-500 pulses.

[0006] Furthermore, the step of obtaining the conductivity value of the extracellular fluid of yak meat in S200 and generating a feedback signal based on the conductivity value includes: The conductivity of the extracellular fluid of yak meat was measured in real time. The conductivity value is compared with the preset upper and lower threshold values, and a feedback signal is generated based on the conductivity value.

[0007] Furthermore, the step of adjusting the parameters of the composite waveform high-voltage pulse electric field based on feedback signals and spraying the natural antimicrobial peptide solution onto the surface of yak meat includes: If the conductivity value exceeds the upper limit threshold, a first feedback signal is generated. Based on the first feedback signal, the electric field strength of the microsecond-level pulse of the composite waveform high-voltage pulse electric field is reduced by 10%-20%. If the conductivity value is lower than the lower threshold, a second feedback signal is generated. Based on the second feedback signal, the electric field strength of the nanosecond-level pulse of the composite waveform high-voltage pulse electric field is increased by 10%-20%. If the conductivity value is between the upper and lower thresholds, a third feedback signal is generated, and the natural antimicrobial peptide solution is evenly sprayed onto the surface of the yak meat based on the third feedback signal.

[0008] Furthermore, the natural antimicrobial peptide solution is a nano-sized aqueous suspension of nisin, the mass-volume concentration of the natural antimicrobial peptide solution is 0.02%-0.08%, and the particle size distribution of the nisin is 100-500 nanometers.

[0009] Furthermore, the natural antimicrobial peptide solution is stored at a temperature of 4-8°C, and the atomized particle size during spraying is 20-100 micrometers, with a spray pressure of 0.2-0.6 MPa.

[0010] Furthermore, the step of transferring the yak meat treated with S200 and S300 into a post-maturation environment superimposed with a high-voltage electrostatic field for post-maturation includes: The yak meat processed with S200 and S300 was transferred to a post-maturation environment, with the temperature adjusted to 0-4℃ and the relative humidity range to 85%-95%. A high-voltage electrostatic field is applied to the post-curing environment, with the electric field strength ranging from 200 to 500 kV / m, and the post-curing time is 12 to 72 hours.

[0011] Furthermore, the yak meat that has undergone post-ripening and conditioning is subjected to directional modified atmosphere packaging, and the directional modified atmosphere packaged yak meat is then stored and transported via cold chain, including: After the yak meat is removed from the high-voltage electrostatic field, it is placed inside a packaging bag and vacuum-sealed. The packaging bag is filled with a specified proportion of mixed gas to complete the directional modified atmosphere packaging; The directional modified atmosphere packaged yak meat is then transferred to a cold chain environment at 0-4℃ for storage and transportation.

[0012] Furthermore, random samples were taken from the yak meat before S100 treatment to determine the initial total bacterial count. If the initial total bacterial count was less than the specified threshold, one cycle from S100 to S200 was executed. If the initial total bacterial count was greater than or equal to the specified threshold, two cycles from S100 to S400 were executed. In the second cycle, S200, the electric field intensity of both nanosecond-level pulses and microsecond-level pulses was increased by 5%-10% based on the first cycle.

[0013] This invention provides a method for preserving yak meat using intelligent regulation of a high-voltage pulsed electric field. It offers the following advantages: 1. This invention employs a dielectric spectrum sensor to monitor the extracellular fluid conductivity in real time during high-voltage pulsed electric field treatment of yak meat. Based on the conductivity value, the field strength of the composite waveform high-voltage pulsed electric field is adjusted, and nanosecond-level pulses and microsecond-level pulses are combined for processing. When the conductivity is below the lower threshold, the electric field strength of the nanosecond pulse or the width of the microsecond pulse is automatically increased to improve perforation efficiency and sterilization thoroughness. When the conductivity is above the upper threshold, the intensity of the microsecond pulse is automatically weakened to reduce thermal damage to muscle fibers. This allows the processing parameters of the composite waveform high-voltage pulsed electric field to be dynamically maintained at a balance point of sufficient sterilization and minimal damage, according to different initial qualities and batches of yak meat. This improves the stability and reliability of sterilization efficiency, maximizes the preservation of water-holding capacity and muscle fiber structure of yak meat, and avoids juice loss and textural deterioration caused by over-processing, thereby ensuring the freshness and edibility of the final product from the source.

[0014] 2. This invention employs a synergistic mechanism of endogenous and exogenous preservatives in yak meat. Utilizing a composite waveform high-voltage pulsed electric field, a precursor loading solution containing sodium lactate solution and bamboo leaf extract is accelerated to enter the muscle fibers and undergo oxidative polymerization, forming an endogenous preservative that can effectively scavenge free radicals and inhibit lipid oxidation. Based on the electroporation of microbial cell membranes created by the composite waveform high-voltage pulsed electric field, a nano-sized natural antimicrobial peptide solution is intelligently sprayed. This allows the antimicrobial peptides to instantly enter the cytoplasm through the electroporation channels, achieving deep killing. Simultaneously, a physical exogenous protective barrier is formed on the surface of the meat, continuously inhibiting subsequent contamination by microorganisms. Through the synergy of the internal chemical barrier and the surface biological barrier, the preservation effect no longer relies on a single instantaneous electric field, but is transformed into a stable state that combines internal and external factors, and instantaneous and long-term effects. This provides continuous, full-cycle preservation protection for yak meat throughout its storage, transportation, and even sales processes.

[0015] 3. This invention involves treating yak meat with a composite waveform high-voltage pulsed electric field and a natural antimicrobial peptide solution, then introducing it into a low-temperature, high-humidity environment with a superimposed high-voltage electrostatic field for post-maturation. This provides a stable environment for the unstable yak meat. The ion wind continuously generated by the high-voltage electrostatic field forms an oxygen-isolated barrier on the surface of the meat, inhibiting oxidation. Furthermore, the electrostatic field guides the orderly migration of intracellular charged particles released during electrotreatment, promoting their binding with myofibril proteins. This consolidates and enhances the tenderizing and preservation effects brought about by the high-voltage pulsed electric field. It inhibits microbial regeneration and enzyme activity, prevents moisture evaporation, and maintains the tenderness of the meat. Simultaneously, it is combined with directional modified atmosphere packaging for storage and transportation, forming a four-in-one long-lasting preservation system consisting of an internal chemical barrier, a surface biological barrier, an external physical barrier, and a continuous low-temperature barrier. This results in a more stable meat structure, optimized flavor and texture, and stronger resistance to deterioration. It ensures the uniformity and stability of product quality throughout the entire chain from processing to the consumer, achieving stable, controllable, and long-term maintenance of yak meat quality. Attached Figure Description

[0016] Figure 1 This is a flowchart of a method for preserving yak meat using intelligent regulation of a high-voltage pulsed electric field, according to the present invention. Detailed Implementation

[0017] 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. Example 1:

[0018] like Figure 1 As shown, a method for preserving yak meat using intelligent control of a high-voltage pulsed electric field is described, the method comprising: S100. Soak yak meat in the precursor loading solution to obtain soaked yak meat; S101. After preparing a sodium lactate solution with a concentration of 0.5%-2.0% (w / v), bamboo leaf extract is added to prepare an aqueous solution with a concentration of 0.05%-0.2% (w / v) as the precursor loading solution. Sodium lactate, as a safe moisture retainer and preservative, can form a protective film on the surface of yak meat and inhibit microbial growth by reducing water activity. Bamboo leaf extract is rich in antioxidant bamboo leaf polyphenols, such as flavonoids. As a natural antioxidant, bamboo leaf polyphenols can effectively remove free radicals generated during the storage of yak meat, inhibit lipid oxidation, and delay the rancidity and color deterioration of yak meat. The synergistic effect of sodium lactate and bamboo leaf extract lays the material basis for the in-situ reaction triggered by the composite waveform high-voltage pulse electric field. S102. After cutting the yak meat, completely immerse it in the precursor loading liquid, allowing the precursor loading liquid to penetrate into the surface layer of the yak meat and the intercellular spaces of the muscle fibers. The ambient temperature of the precursor loading liquid is 4-10℃. Vacuum the environment of the precursor loading liquid, with a vacuum degree in the range of -0.05 to -0.08MPa, and tumble at a rate of 5-15 revolutions per minute for 15-30 minutes. The vacuum treatment creates a vacuum environment, which can effectively remove air from the intercellular spaces of the muscle fibers, facilitating the rapid penetration of the precursor loading liquid. The mechanical action of tumbling assists the precursor loading liquid to diffuse from the surface layer to the deep layer of the muscle fibers, carrying out physical penetration, so that sodium lactate and bamboo leaf extract are pre-attached and partially penetrate into the muscle fiber network and intercellular spaces of the yak meat, forming an initial distribution barrier for endogenous preservatives. In actual production, near-infrared spectroscopy online detection technology is used to assess whether the precursor loading liquid has effectively penetrated the yak meat. An online near-infrared spectroscopy probe is installed at the location where S102 is completed. The online near-infrared spectroscopy probe emits near-infrared light to irradiate the surface of the yak meat that has completed S102 treatment for penetration detection. Since bamboo leaf polyphenols in bamboo leaf extract have specific absorption characteristic peaks in the near-infrared region, a calibration model is established between the intensity or area of ​​the characteristic absorption peak of bamboo leaf polyphenols and the penetration depth. The calibration model is established through experiments before production. Through this calibration model, the penetration of bamboo leaf polyphenols can be quickly and non-destructively judged. When the intensity of the characteristic absorption peak of bamboo leaf polyphenols reaches or exceeds the preset qualified threshold, it is determined that the penetration of the precursor loading liquid of this batch of yak meat has met the standard and is allowed to enter the S200 treatment. If it is lower than the threshold, an alarm is generated or the material is returned for reprocessing. S103. After tumbling, restore normal pressure, remove the yak meat from the precursor loading liquid and drain the excess liquid on the surface to obtain soaked yak meat. This avoids the residual precursor loading liquid causing current conduction or arc interference during subsequent high-voltage pulse electric field treatment, ensuring uniform treatment effect. S200. Apply a composite waveform high-voltage pulse electric field to the soaked yak meat. The composite waveform high-voltage pulse electric field is used to kill microorganisms, trigger the precursor loading liquid to undergo an in-situ reaction inside the yak meat to generate endogenous preservatives, and provide a channel for the entry of natural antimicrobial peptide solution as an exogenous preservative. Among them, the in-situ reaction refers to the oxidation and polymerization of bamboo leaf polyphenols under the influence of a composite waveform high voltage pulse electric field, forming polyphenol polymers or oligomers with larger molecular weights and more complex conjugated systems. Due to the driving force of the composite waveform high voltage pulse electric field, the generated polyphenol polymers or oligomers usually have stronger free radical scavenging ability and metal ion chelating ability than monomers, thus exhibiting stronger antibacterial and antioxidant activities. To ensure the in-situ reaction, the yak meat extract after treatment was analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). Compared with the yak meat soaked in a composite waveform high voltage pulse electric field without treatment, the peak area of ​​the original bamboo leaf polyphenol monomers in the yak meat treated with S200 was reduced. At the same time, new and broad chromatographic peak groups appeared in the high molecular weight region, representing polyphenol polymers or oligomeric substances. The improved free radical scavenging rate of the treated meat sample was directly detected by electron paramagnetic resonance (EPR) technology, which functionally verified the successful generation of endogenous preservative. S201. The soaked yak meat is placed in a composite waveform high-voltage pulsed electric field. Each cycle of the composite waveform high-voltage pulsed electric field sequentially generates a nanosecond-level pulse and a microsecond-level pulse. The electric field strength parameter of the nanosecond-level pulse is 30-50 kV / cm, and the pulse width parameter is 100-300 nanoseconds. The electric field strength parameter of the microsecond-level pulse is 5-15 kV / cm, and the pulse width parameter is 10-50 microseconds. The nanosecond-level pulse, utilizing its extremely short pulse width and high electric field strength, targets and treats the microbial cell membrane, utilizing the high electric field strength... The instantaneous action of the pressure gradient creates nanoscale electroporation on the microbial cell membrane while causing minimal structural damage to the larger myofibers. The microsecond-level pulse is applied immediately after the nanosecond-level pulse, utilizing the long pulse width and low field strength to thoroughly inactivate the perforated microorganisms through the Joule heating effect. Simultaneously, the resulting local thermal and electrochemical effects act as in-situ reaction triggers, accelerating the reaction and polymerization of sodium lactate and bamboo leaf extract in the precursor loading solution within the myofibers, thereby generating and enriching endogenous preservatives with stronger antibacterial and antioxidant activities. S202. Control the pulse repetition frequency of the composite waveform high-voltage pulse electric field to 50-200Hz, so that the soaked yak meat leaves the composite waveform high-voltage pulse electric field after being treated with 100-500 pulses. By controlling the total number of pulses and the repetition frequency, ensure that the cumulative application of electric field energy is accurate, balance the sterilization effect and meat quality preservation, and avoid over-treatment that could lead to muscle fiber damage. S300: Obtain the conductivity value of the extracellular fluid of yak meat in S200, generate a feedback signal based on the conductivity value, adjust the parameters of the composite waveform high voltage pulse electric field based on the feedback signal, and spray the natural antimicrobial peptide solution onto the surface of yak meat. S301. After electroporation of the cell membrane, the integrity of the semipermeable membrane is disrupted, allowing high concentrations of intracellular ions (such as potassium) to escape. + Na + Cl - Electroporation can lead to leakage into the extracellular fluid, increasing the ion concentration. Since conductivity is positively correlated with the type and concentration of ions, the higher the degree of electroporation, the higher the ion concentration leaked into the extracellular fluid, resulting in increased conductivity. The real-time upward trend and absolute value of conductivity can directly and sensitively reflect the severity of cell membrane perforation and the total amount of cell contents leaked. By monitoring changes in the conductivity of the extracellular fluid, the degree of perforation and damage to microbial membranes and myofibril membranes can be indirectly characterized. A dielectric spectrum sensor is used to monitor changes in the conductivity of the extracellular fluid flowing out of yak meat, allowing for real-time measurement of the extracellular fluid conductivity of yak meat. S302. Compare the conductivity value with the preset upper and lower threshold values. Generate a feedback signal based on the conductivity value. The upper threshold represents the risk boundary of muscle fiber damage, and the lower threshold represents the boundary of insufficient microbial inactivation effect. The upper and lower threshold values ​​are set based on a large amount of experimental data, taking into account factors such as the initial quality of yak meat (e.g., pH value, water holding capacity) and the target shelf life of the treated batch. The experiment finds the range of conductivity values ​​that achieves the best preservation effect, i.e., the microbial treatment meets the standard and muscle damage is minimal. The upper boundary of this range is the upper threshold, and the lower boundary is the lower threshold. For example, the lower threshold corresponds to a conductivity in the range of 2.5-3.5 mS / cm, indicating that the treatment has begun to take effect; the upper threshold corresponds to a conductivity in the range of 6.0-8.0 mS / cm, indicating an increased risk of muscle fiber damage. A comparison table was constructed to correlate changes in conductivity with adjustments to the electric field of the composite waveform high-voltage pulse. This table, based on data from previous experiments, shows the range of conductivity changes and the specific adjustment parameters for microsecond and nanosecond pulses of the composite waveform high-voltage pulse electric field. This facilitates rapid response to feedback signals and improves processing efficiency. For example, if the conductivity value exceeds the upper threshold by 5%, the microsecond pulse electric field intensity is reduced by 10%; if it exceeds 10%, it is reduced by 15%. If the conductivity value exceeds the upper limit threshold, it indicates excessive electroporation of the myofiber membrane, resulting in a large amount of intracellular fluid leaking into the extracellular fluid. This indicates an increased risk of myofiber damage and generates a first feedback signal. Based on the first feedback signal, the electric field strength of the microsecond-level pulse of the composite waveform high-voltage pulse electric field is reduced by 10%-20%, or the pulse width of the microsecond-level pulse is reduced, in order to reduce the thermal effect and electrochemical impact on the myofiber during subsequent microsecond-level pulse processing. If the conductivity value is below the lower threshold, it indicates insufficient electroporation of the microbial cell membrane, indicating insufficient microbial inactivation. A second feedback signal is generated, and based on this signal, the electric field strength of the nanosecond-level pulse of the composite waveform high-voltage pulse electric field is increased by 10%-20%, or the pulse width of the microsecond-level pulse is increased, enhancing the perforation efficiency and killing effect on the microbial cell membrane. By increasing the intensity of the nanosecond-level pulse electric field, the transmembrane potential can be increased, increasing the perforation density and pore size on the microbial cell membrane. Increasing the microsecond-level pulse width prolongs the Joule heating effect and electrochemical action time, ensuring more thorough killing of perforated microorganisms. The two work synergistically to overcome the bottleneck of insufficient sterilization and ensure food safety. If the conductivity value is between the upper and lower thresholds, it is determined that the microbial cell membrane has formed effective electroporation, and the myofiber damage is still within a controllable range. A third feedback signal is generated, and based on this signal, the natural antimicrobial peptide solution is evenly sprayed onto the surface of the yak meat. The atomized droplets collide, wet, and spread on the surface of the meat, forming a very thin liquid film rich in natural antimicrobial peptides. Through precise delivery of the exogenous natural antimicrobial peptide solution, the solution diffuses and enters the cytoplasm of the microbial cells through electroporation generated by the composite waveform high-voltage pulse electric field. Nisin binds to specific lipid II on the cell membrane, specifically... Lipid II is a key intermediate in the bacterial cell wall synthesis process, including lipid anchors embedded in the cell membrane and peptidoglycan precursor units connecting the lipid anchors. Nisin binds to specific lipid II to form pores in the cell membrane, causing leakage of cell contents and achieving instantaneous killing of residual microorganisms. Some antimicrobial peptides that fail to immediately enter the cytoplasm of microorganisms form a biomolecular barrier with continuous antibacterial effect on the surface of yak meat, namely exogenous preservatives. The exogenous preservatives and the internally generated endogenous preservatives work together to form a dual preservation defense line, achieving instantaneous and deep synergy between physical fields and biological preservatives, which greatly improves the instantaneous sterilization efficiency. The natural antimicrobial peptide solution is an aqueous suspension of nisin that has undergone nano-processing. The mass-volume concentration of the natural antimicrobial peptide solution is 0.02%-0.08%, and the particle size distribution of nisin ranges from 100 to 500 nanometers. The natural antimicrobial peptide solution is stored at a temperature of 4-8℃, and the atomized particle size during spraying is 20-100 micrometers, with a spray pressure of 0.2-0.6 MPa.

[0019] S400: Yak meat treated with S200 and S300 is transferred to a post-maturation environment with a superimposed high-voltage electrostatic field for post-maturation. The high-voltage electrostatic field generates ion wind, which is used to work synergistically with endogenous and exogenous preservatives to inhibit oxidation and microbial regeneration, thereby stabilizing the quality of yak meat. S401. Transfer the yak meat treated with S200 and S300 into the post-maturation environment. Adjust the temperature of the post-maturation environment to 0-4℃ and the relative humidity range to 85%-95%. Low temperature inhibits microbial regeneration and enzyme activity, while high humidity prevents excessive evaporation of moisture from the yak meat and maintains its tenderness. S402. Apply a high-voltage electrostatic field to the post-ripening environment, with the electric field strength ranging from 200-500 kV / m and the post-ripening time being 12-72 hours. The high-voltage electrostatic field is generated by an externally connected high-voltage electrostatic field generator. The non-uniform field design can continuously generate ion wind. The high-voltage electrostatic field works synergistically with the internal preservation barrier formed by the endogenous preservatives in steps S100 to S300 and the surface preservation barrier formed by the exogenous preservatives. The ion wind generated by the high-voltage electrostatic field can form an air barrier on the surface of the meat, effectively isolating oxygen and providing a stable working environment for the natural antimicrobial peptide solution attached to the surface. At the same time, the high-voltage electrostatic field can guide the orderly migration of charged particles such as calcium ions released into the extracellular fluid due to the treatment of the composite waveform high-voltage pulse electric field in S200, promoting their binding with myofibrils, thereby consolidating the tenderizing effect. It also works synergistically with the polyphenolic antioxidants generated in situ inside to further inhibit fat oxidation, together forming a long-lasting preservation system that combines external protection and internal repair. After soaking in S100, the yak meat is treated with S200 within 30 minutes. S200 and S300 are carried out simultaneously. After S200 and S300 are completed, S400 is carried out within 10 minutes. Random samples were taken from yak meat before S100 treatment, and the initial total bacterial count was determined. If the initial total bacterial count is less than the specified threshold, the initial contamination level of this batch of yak meat is determined to be relatively light, falling within the scope of routine preservation. In this case, one cycle from S100 to S200 will be executed to achieve the expected preservation and quality improvement goals. If the initial total bacterial count is greater than or equal to the specified threshold, the batch of yak meat is determined to have a relatively high initial contamination level and falls under the category of enhanced preservation. In this case, two cycles, S100 to S400, are executed. In S200 of the second cycle, in order to overcome the resistance of microorganisms and ensure complete eradication, the electric field intensity of both nanosecond-level pulses and microsecond-level pulses needs to be increased by 5%-10% based on the first cycle. The specified threshold is determined comprehensively based on the microbial limits for chilled meat in national food safety standards, the specific spoilage bacteria characteristics of yak meat, and the internal control standards set by enterprises to ensure the shelf life of the products; for example, if the national standard requires that the total bacterial count of chilled meat be less than 1×10⁻⁶... 6 For CFU / g, to allow for a safety margin, companies can set the internal control threshold to 5 × 10⁻⁶. 5 CFU / g, the specific value needs to be determined through experiments based on the product positioning and expected shelf life; S500, take the yak meat that has been aged and preserved and then perform directional modified atmosphere packaging, and store and transport the directional modified atmosphere packaged yak meat in the cold chain. S501. After removing the yak meat from the high-voltage electrostatic field, place it inside a packaging bag and vacuum process it. The packaging bag is made of a high-barrier composite packaging material, usually a vacuum packaging bag or modified atmosphere packaging tray with PA / PE or PET / AL / CPP structure. The packaging bag made of composite packaging material must meet the following requirements: oxygen permeability is less than 50 mm / m²•day•atm, and water vapor permeability is less than 10 g / m², to ensure effective isolation of oxygen and prevention of moisture loss. S502. Fill the packaging bag with a specified proportion of mixed gas to complete the directional modified atmosphere packaging. The composition of the mixed gas is: carbon dioxide (CO2) concentration of 30%-50% (v / v), nitrogen (N2) concentration of 50%-70% (v / v), and residual oxygen (O2) concentration strictly controlled below 0.5% (v / v). Carbon dioxide is used to inhibit the growth of aerobic microorganisms, and nitrogen is used as a filling gas to prevent the packaging from collapsing and further isolate oxygen. The low-oxygen environment continues and consolidates the gas barrier generated by the high-voltage electrostatic field in step S400, completely blocking the oxidation reaction pathway of fat and myoglobin. S503. The directional modified atmosphere packaged yak meat is transferred to a cold chain environment of 0-4℃ for storage and transportation. Throughout the storage, transportation and sales process, temperature sensors must be used to monitor the temperature in real time to ensure that the core temperature of the yak meat remains stable within this range. The low temperature environment is seamlessly connected with the post-ripening temperature of S401 to maximize the inhibition of the regeneration of residual microorganisms and the activity of endogenous enzymes in the meat. By using directional modified atmosphere packaging and a low-temperature environment, the antioxidant components such as polyphenol polymers inside the packaging achieve higher efficiency and longer lifespan in scavenging free radicals and inhibiting lipid oxidation under continuous low-oxygen conditions. The natural antimicrobial peptides on the surface have a more significant inhibitory effect on anaerobic and facultative anaerobic bacteria in low-oxygen and high-carbon dioxide environments. The low-temperature cold chain consolidates the tenderizing and preservation effect brought about by the high-voltage pulse electric field, preventing juice loss and textural deterioration caused by temperature fluctuations. The low-temperature environment, the modified atmosphere environment composed of mixed gases inside the packaging, the endogenous preservative barrier already formed inside the yak meat, and the exogenous preservative barrier on the surface work synergistically to form a four-in-one long-lasting preservation system consisting of an internal chemical barrier, a surface biological barrier, an external physical barrier, and a full-process low-temperature barrier, thereby achieving stable, controllable, and long-term maintenance of the quality of yak meat.

[0020] In this embodiment, the thresholds, models, and judgment methods used in the processing are all set after extensive laboratory experiments and verification before production use. For example, the upper and lower thresholds, the calibration model between the intensity or area of ​​the characteristic absorption peak of bamboo leaf polyphenols and the penetration depth, the detection and judgment of whether the in-situ reaction has occurred, and the comparison table between the change of conductivity value and the adjustment of the composite waveform high voltage pulse electric field, etc., are all obtained through extensive laboratory experiments. In this embodiment, the following is further included in actual use: Case 1: Long-distance cold chain transportation of high-quality yak meat; High-end yak meat producers need to transport their products across multiple climate zones via cold chain to supply first-tier cities. The entire process is expected to take 21 days. Without using traditional freezing (to avoid damaging the taste), they ensure that the beef maintains a high level of sensory and hygienic quality at the end of the transportation route, achieving undamaged preservation and stable quality to meet the demands of the high-end market. The method of this application is used to process yak meat, including: S100, Precursor loading solution soaking: Use 1.5% (w / v) sodium lactate and 0.1% (w / v) bamboo leaf extract to prepare a precursor loading solution, and tumble it for 20 minutes at 6℃ and -0.06MPa vacuum to ensure effective penetration. Use near-infrared spectroscopy for online detection, and use the characteristic absorption peak of bamboo leaf polyphenols as an indicator to ensure that the penetration meets the standard before proceeding to the next process. S200, Composite Waveform High Voltage Pulse Electric Field Processing: Initial parameters are set as follows: nanosecond pulse 40kV / cm, 200ns; microsecond pulse 10kV / cm, 30μs; total number of pulses 300; S300, intelligent feedback and natural antimicrobial peptide spraying: The conductivity value of the extracellular fluid is monitored in real time by a dielectric spectrum sensor. The conductivity of this batch of beef is stable at 4.8 mS / cm, which is within the preset upper and lower thresholds. A third feedback signal is automatically generated. Based on the third feedback signal, 0.05% nano-sized nisin solution is atomized and sprayed onto the surface of the meat at a pressure of 0.4 MPa. S400, post-curing and packaging: Curing for 48 hours at 2℃, 90% relative humidity, and with a superimposed 300kV / m high-voltage electrostatic field, followed by modified atmosphere packaging with a gas ratio of 40%CO2 and 60%N2, and cold chain transportation at 0-4℃.

[0021] Compared with conventional 4°C refrigeration, the shelf life using the processing method of this application is extended by at least 2 times, juice loss is reduced, and weight loss is reduced by 5.33%–6.94% compared with conventional direct freezing. The meat remains tender, and through intelligent feedback of high-voltage pulse electric field, sterilization is achieved while protecting muscle fibers to the greatest extent. The color and texture of the beef are close to that of fresh beef.

[0022] Case 2: Enhanced treatment of yak meat with excessive initial microbial contamination; A batch of yak meat had an initial total bacterial count of 8.0 × 10⁻⁶ due to equipment malfunction during the pre-cooling process after slaughter. 5 The CFU / g level exceeded the company's internally set safety threshold (5.0 × 10⁻⁶). 5 (CFU / g) Through enhanced processing, the microbiological indicators of beef not only meet national standards, but also have sufficient safety margin for preservation, avoiding economic losses caused by returns; The method of this application is used to process yak meat, including: Because the initial total bacterial count exceeded the standard, the system automatically activated the dual-cycle enhanced preservation program. First cycle treatment: The parameters for soaking the precursor loading liquid are the same as in Case 1; the composite waveform high-voltage pulse electric field uses the basic parameters (same as in Case 1). Monitoring revealed that the conductivity value was 2.8 mS / cm, which was below the lower threshold. A second feedback signal was generated, which automatically increased the nanosecond-level pulse field strength by 15% to 46 kV / cm. Second cycle treatment: According to the procedure, the pulse field strength of the second cycle is increased by 8% on the basis of the adjustment in the first cycle, that is, the nanosecond pulse is set to 50kV / cm and the microsecond pulse is set to 11kV / cm. After this treatment, the conductivity rises to 5.5mS / cm, which is within the safe range, and the natural antimicrobial peptide spraying is performed. The subsequent high-voltage electrostatic field curing and modified atmosphere packaging process is the same as in Case 1; After processing, sampling and testing showed that the total bacterial count decreased by more than 6 log units, reaching <10²CFU / g, which is far below the national safety standard. Through parameter adaptive enhancement and dual-cycle treatment, a batch of potentially substandard products was successfully transformed into safe and high-quality products, demonstrating a strong ability to correct deviations in the face of unexpected situations.

[0023] Case 3: Synergistic preservation through supercooled storage for export; To expand into overseas markets with extremely high requirements for shelf life, a preservation solution is needed that can achieve ultra-long-term storage without deep freezing, in order to save transportation costs and maintain the best taste of meat, extending the storage period of yak meat to more than 45 days, while maintaining its texture like fresh meat after thawing without loss of juice. The method of this application is used to process yak meat, including: This application deeply integrates the intelligent pulse electric field processing with the high-voltage electrostatic field subcooling storage technology.

[0024] Pretreatment and pulsed electric field treatment: The process is basically the same as in Case 1, ensuring the internal generation of endogenous preservatives and the formation of an initial barrier. Supercooling storage in a high-voltage electrostatic field: The post-ripening environment is set to -2.5℃ (lower than the ice core temperature of yak meat but higher than the eutectic point), and a DC high-voltage electrostatic field of 350kV / m is applied. The ion wind generated by the field is used to suppress ice crystal formation and achieve supercooling storage. Under these conditions, the food is stored for 45 days. After storage, no ice crystals formed on the meat, successfully avoiding tissue damage caused by traditional freezing. The beef had good color and texture, and the total number of bacteria and the degree of protein decomposition were inhibited. After thawing and cooking, the juice retention rate was extremely high, and the taste was not significantly different from fresh yak meat, fully meeting the stringent requirements of the high-end export market.

[0025] In this embodiment, when treating yak meat with a high-voltage pulsed electric field, a dielectric spectrum sensor is used to monitor the conductivity of the extracellular fluid in real time. Based on the conductivity value, the field strength of the composite waveform high-voltage pulsed electric field is adjusted, and nanosecond-level pulses and microsecond-level pulses are set for composite treatment. When the conductivity is lower than the lower threshold, the electric field strength of the nanosecond pulse or the width of the microsecond pulse is automatically increased to improve the perforation efficiency and sterilization thoroughness. When the conductivity is higher than the upper threshold, the intensity of the microsecond pulse is automatically weakened to reduce thermal damage to the muscle fibers. This allows the processing parameters of the composite waveform high-voltage pulsed electric field to be dynamically maintained at a balance point of sufficient sterilization and minimal damage according to different initial qualities and different batches of yak meat. This improves the stability and reliability of sterilization efficiency, maximizes the preservation of water-holding capacity and muscle fiber structure of yak meat, and avoids juice loss and textural deterioration caused by over-processing, thereby ensuring the freshness and edibility of the final product from the source.

[0026] This study employs a synergistic mechanism of endogenous and exogenous preservatives in yak meat. A composite waveform high-voltage pulsed electric field accelerates the entry of a precursor loading solution containing sodium lactate solution and bamboo leaf extract into muscle fibers, where it undergoes oxidative polymerization. This forms an endogenous preservative that effectively scavenge free radicals and inhibits lipid oxidation. Based on the electroporation of microbial cell membranes created by the composite waveform high-voltage pulsed electric field, a nano-sized natural antimicrobial peptide solution is intelligently sprayed. This allows the antimicrobial peptides to instantly enter the cytoplasm through the electroporation channels, achieving deep killing. Simultaneously, a physical exogenous protective barrier is formed on the meat surface, continuously inhibiting subsequent contamination by microorganisms. Through the synergy of the internal chemical barrier and the surface biological barrier, the preservation effect no longer relies on a single instantaneous electric field but is transformed into a stable state that combines internal and external factors, with both instantaneous and long-term effects complementing each other. This provides continuous, full-cycle preservation protection for yak meat throughout its storage, transportation, and even sales processes.

[0027] Yak meat treated with a composite waveform high-voltage pulsed electric field and a natural antimicrobial peptide solution is then introduced into a low-temperature, high-humidity environment with a superimposed high-voltage electrostatic field for post-maturation. This provides a stable environment for the unstable yak meat. The ion wind continuously generated by the high-voltage electrostatic field forms an oxygen-isolated barrier on the surface of the meat, inhibiting oxidation. The electrostatic field also guides the orderly migration of intracellular charged particles released during electrotreatment, promoting their binding with myofibrils. This consolidates and enhances the tenderizing and preservation effects brought about by the high-voltage pulsed electric field. It inhibits microbial regeneration and enzyme activity, prevents moisture evaporation, and maintains the tenderness of the meat. Combined with directional modified atmosphere packaging for storage and transportation, this forms a four-in-one long-lasting preservation system consisting of an internal chemical barrier, a surface biological barrier, an external physical barrier, and a continuous low-temperature barrier. This results in a more stable meat structure, optimized flavor and texture, and stronger resistance to deterioration. It ensures the uniformity and stability of product quality throughout the entire chain from processing to the consumer, achieving stable, controllable, and long-term maintenance of yak meat quality. Example 2:

[0028] This application also provides an electronic device. The electronic device may include one or more processors and one or more memories. The memories store computer-readable code, which, when executed by the one or more processors, can perform the intelligent control of a high-voltage pulsed electric field for yak meat preservation as described above.

[0029] The method or system according to the embodiments of this application can also be implemented using the architecture of the electronic device shown in this application. The electronic device may include a bus, one or more CPUs, ROM, RAM, a communication port connected to a network, input / output, a hard disk, etc. The storage device in the electronic device, such as a ROM or hard disk, may store the intelligent control method for preserving yak meat using a high-voltage pulse electric field provided in this application. Furthermore, the electronic device may also include a user interface. Of course, the architecture shown in this application is merely exemplary; when implementing different devices, one or more components in the electronic device shown in this application may be omitted according to actual needs. Example 3:

[0030] One embodiment of this application discloses a computer-readable storage medium. The computer-readable storage medium stores computer-readable instructions. When the computer-readable instructions are executed by a processor, a method for preserving yak meat by intelligently controlling a high-voltage pulsed electric field, as described in the above-described embodiments of this application, can be performed. The storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and cache memory. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc.

[0031] Furthermore, according to embodiments of this application, the processes described in the above-referenced flowcharts can be implemented as computer software programs. For example, this application provides a non-transitory machine-readable storage medium storing machine-readable instructions that can be executed by a processor to perform instructions corresponding to the method steps provided in this application, such as a method for preserving yak meat by intelligently controlling a high-voltage pulsed electric field. When this computer program is executed by a central processing unit (CPU), it performs the functions defined in the method of this application.

[0032] A method system for preserving yak meat using a smart high-voltage pulsed electric field includes a processor and a machine-readable storage medium connected to the processor. The machine-readable storage medium is used to store programs, instructions, or code, and the processor is used to execute the programs, instructions, or code in the machine-readable storage medium to implement the above-mentioned method.

[0033] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a reference structure" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preserving yak meat using intelligent regulation of a high-voltage pulsed electric field, characterized in that, The method includes: S100. Soak yak meat in the precursor loading solution to obtain soaked yak meat; S200: Apply a composite waveform high-voltage pulse electric field to the soaked yak meat; S300: Obtain the conductivity value of the extracellular fluid of yak meat in S200, generate a feedback signal based on the conductivity value, adjust the parameters of the composite waveform high voltage pulse electric field based on the feedback signal, and spray the natural antimicrobial peptide solution onto the surface of yak meat. S400: The yak meat processed by S200 and S300 is transferred to a post-maturation environment superimposed with a high-voltage electrostatic field for post-maturation. S500: Take the yak meat that has been post-aged and aged, and then perform directional modified atmosphere packaging. Store and transport the directional modified atmosphere packaged yak meat in a cold chain.

2. The method for preserving yak meat using intelligent control of a high-voltage pulsed electric field according to claim 1, characterized in that, The process of soaking yak meat in a precursor loading solution to obtain soaked yak meat includes: After preparing a sodium lactate solution with a concentration of 0.5%-2.0%, bamboo leaf extract was added to prepare an aqueous solution with a concentration of 0.05%-0.2% as the precursor loading solution; After being cut, the yak meat was completely immersed in the precursor loading solution at an ambient temperature of 4-10℃. Evacuate the precursor loading liquid environment to a vacuum level of -0.05 to -0.08 MPa, and tumble at a rate of 5-15 revolutions per minute for 15-30 minutes. After tumbling, restore normal pressure, remove the yak meat from the pre-loaded liquid and drain off the excess liquid on the surface to obtain soaked yak meat.

3. The method for preserving yak meat using intelligent regulation of a high-voltage pulsed electric field according to claim 2, characterized in that, The process of applying a composite waveform high-voltage pulsed electric field to the soaked yak meat includes: The soaked yak meat is placed in a composite waveform high-voltage pulse electric field. Each cycle of the composite waveform high-voltage pulse electric field generates a nanosecond-level pulse and a microsecond-level pulse. The electric field strength parameter of the nanosecond-level pulse is 30-50 kV / cm, and the pulse width parameter is 100-300 nanoseconds. The electric field strength parameter of the microsecond-level pulse is 5-15 kV / cm, and the pulse width parameter is 10-50 microseconds. The pulse repetition frequency of the composite waveform high-voltage pulse electric field is controlled to be 50-200Hz, so that the soaked yak meat leaves the composite waveform high-voltage pulse electric field after being treated with 100-500 pulses.

4. The method for preserving yak meat using intelligent control of a high-voltage pulsed electric field according to claim 3, characterized in that, The step of obtaining the conductivity value of the extracellular fluid of yak meat in S200 and generating a feedback signal based on the conductivity value includes: The conductivity of the extracellular fluid of yak meat was measured in real time. The conductivity value is compared with the preset upper and lower threshold values, and a feedback signal is generated based on the conductivity value.

5. The method for preserving yak meat using intelligent control of a high-voltage pulsed electric field according to claim 4, characterized in that, The process of adjusting the parameters of the composite waveform high-voltage pulse electric field based on feedback signals and spraying the natural antimicrobial peptide solution onto the surface of yak meat includes: If the conductivity value exceeds the upper limit threshold, a first feedback signal is generated. Based on the first feedback signal, the electric field strength of the microsecond-level pulse of the composite waveform high-voltage pulse electric field is reduced by 10%-20%. If the conductivity value is lower than the lower threshold, a second feedback signal is generated. Based on the second feedback signal, the electric field strength of the nanosecond-level pulse of the composite waveform high-voltage pulse electric field is increased by 10%-20%. If the conductivity value is between the upper and lower thresholds, a third feedback signal is generated, and the natural antimicrobial peptide solution is evenly sprayed onto the surface of the yak meat based on the third feedback signal.

6. The method for preserving yak meat using intelligent control of a high-voltage pulsed electric field according to claim 5, characterized in that, The natural antimicrobial peptide solution is an aqueous suspension of nisin that has undergone nano-processing. The mass-volume concentration of the natural antimicrobial peptide solution is 0.02%-0.08%, and the particle size distribution of the nisin is in the range of 100-500 nanometers.

7. The method for preserving yak meat using intelligent control of a high-voltage pulsed electric field according to claim 6, characterized in that, The natural antimicrobial peptide solution is stored at a temperature of 4-8℃, and the atomized particle size during spraying is 20-100 micrometers, with a spray pressure of 0.2-0.6 MPa.

8. The method for preserving yak meat using intelligent regulation of a high-voltage pulsed electric field according to claim 7, characterized in that, The process of transferring yak meat treated with S200 and S300 into a post-fermentation environment superimposed with a high-voltage electrostatic field for post-fermentation includes: The yak meat processed with S200 and S300 was transferred to a post-maturation environment, with the temperature adjusted to 0-4℃ and the relative humidity range to 85%-95%. A high-voltage electrostatic field is applied to the post-curing environment, with the electric field strength ranging from 200 to 500 kV / m, and the post-curing time is 12 to 72 hours.

9. The method for preserving yak meat using intelligent regulation of a high-voltage pulsed electric field according to claim 1, characterized in that, The yak meat, after being harvested and aged, undergoes directional modified atmosphere packaging, followed by cold chain storage and transportation, including: After the yak meat is removed from the high-voltage electrostatic field, it is placed inside a packaging bag and vacuum-sealed. The packaging bag is filled with a specified proportion of mixed gas to complete the directional modified atmosphere packaging; The directional modified atmosphere packaged yak meat is then transferred to a cold chain environment at 0-4℃ for storage and transportation.

10. The method for preserving yak meat using intelligent control of a high-voltage pulsed electric field according to claim 1, characterized in that, Random samples were taken from yak meat before S100 treatment to determine the initial total bacterial count. If the initial total bacterial count was less than the specified threshold, one cycle from S100 to S200 was executed. If the initial total bacterial count was greater than or equal to the specified threshold, two cycles from S100 to S400 were executed. In S200 of the second cycle, the electric field intensity of the nanosecond-level pulse and the microsecond-level pulse were increased by 5%-10% based on the first cycle.

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