Dynamic low-temperature plasma sterilization and preservation method
By using dynamic low-temperature plasma sterilization, combined with non-contact detection and ultra-low oxygen packaging, the problem of sterilization and preservation of fresh products has been solved, achieving efficient and safe preservation and maintaining product quality.
Patent Information
- Application Number
- CN202511787013.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-01
- Publication Date
- 2026-02-27
AI Technical Summary
Existing technologies cannot effectively kill the initial microbial contamination of fresh products such as salmon and tuna, and traditional methods will damage the product structure and sensory quality. Chemical preservatives pose safety hazards, and static low-temperature plasma technology lacks adaptability.
The dynamic low-temperature plasma sterilization method is adopted. By non-contact detection of the initial bacterial count of the material and dynamic adjustment of plasma parameters, combined with closed-loop control of ozone concentration and ultra-low oxygen packaging, precise sterilization and preservation are achieved.
It achieves efficient sterilization and preservation of fresh products, extends shelf life, maintains product quality and nutritional value, and provides product quality transparency and safety assurance.
Smart Images
Figure CN121569842A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of preservation technology, in particular to a dynamic low-temperature plasma sterilization and preservation method. BACKGROUND
[0002] With the improvement of living standards and the upgrading of consumption concept, raw seafood (such as salmon, tuna, etc.) is increasingly favored by the market due to its rich nutrition and unique taste. However, such products are rich in water and protein, and are extremely susceptible to microbial contamination and spoilage. At the same time, they are extremely heat-sensitive, and traditional heat sterilization techniques can severely damage their cell structure and sensory quality, resulting in a loss of nutritional value, poor taste, and dull color, and therefore cannot be applied.
[0003] Currently, the industry mainly uses physical refrigeration, chemical preservative treatment, modified atmosphere packaging (MAP) or static low-temperature plasma technology for the preservation of raw seafood. Physical refrigeration is a simple low-temperature storage method that can slow down microbial growth, but cannot effectively kill the initial microbial population, has a short preservation period, and has a high safety risk. Chemical preservative treatment generally uses chlorine-containing disinfectants or organic acids for soaking or spraying. This method can cause chemical residues, cause consumers to worry about health and safety, and may also cause odors that affect the natural flavor of the product. Modified atmosphere packaging (MAP) can inhibit microorganisms by changing the gas composition in the package (such as increasing CO2 and reducing O2). This method can only inhibit microbial reproduction and cannot effectively kill the initial high microbial count. It is a passive preservation method with limited effect. Static low-temperature plasma technology has shown potential in food surface sterilization, but lacks adaptability to different types and different initial contamination levels of materials, which can easily lead to insufficient or excessive treatment. Therefore, a new dynamic low-temperature plasma sterilization and preservation method that can dynamically adapt to material characteristics, precisely control the reaction process, and seamlessly integrate with advanced packaging technology is needed. SUMMARY
[0004] In view of the deficiencies of the prior art, the present application provides a dynamic low-temperature plasma sterilization and preservation method to solve the problems raised in the background art.
[0005] To achieve the above purpose, the present application is implemented by the following technical solution: a dynamic low-temperature plasma sterilization and preservation method, comprising the following steps: S1, material loading: placing the raw seafood to be treated in the treatment chamber of the modular low-temperature plasma generating device; S2, non-contact detection: scanning the surface of the raw seafood by the multispectral imaging unit integrated in the chamber to non-contact estimate the initial microbial count based on image data; S3, adaptive plasma sterilization: the central controller calls the dynamic power regulation algorithm, based on the S2 obtained raw seafood species, thickness and estimated initial bacterial colony data, to calculate and set the initial voltage and frequency parameters of the high-frequency pulse power supply; start the power supply to generate low-temperature plasma at the porous electrode, which acts on the surface of raw seafood in a dynamic diffusion manner for sterilization; S4, closed-loop regulation of ozone concentration: the ozone concentration in the treatment chamber is monitored in real time by an ozone concentration sensor, and the data is fed back to the central controller; the controller compares the real-time concentration with the preset safety threshold range and dynamically adjusts the working parameters of the power supply or the ventilation system in the chamber to stabilize the ozone concentration within the safety threshold range; S5, surface recovery treatment before packaging: after sterilization, filtered low-temperature high-humidity air or inert gas is introduced into the treatment chamber to treat the surface of raw seafood for a short time to eliminate residual ozone and restore the surface to near the initial fresh color; S6, ultra-low oxygen packaging and process data recording: raw seafood treated in step four is immediately transferred to an ultra-low oxygen environment with an oxygen content of less than 1% for sealing and packaging; at the same time, the species of the batch of raw seafood, the power supply parameter change curve, the ozone concentration fluctuation curve and the total processing time data during processing are packaged to generate a unique quality traceability code and are associated with the package.
[0006] According to the above technical solution, in step five, the temperature of the gas introduced is 2-6℃, the relative humidity is 85%-95%, and the treatment time is 30-120 seconds.
[0007] According to the above technical solution, in step two, the multispectral imaging unit captures the light intensity signal of the raw seafood surface in a specific fluorescence band and compares it with the built-in microbial quantity prediction model to estimate the initial bacterial colony count.
[0008] According to the above technical solution, in step six, the quality traceability code is attached to the package in the form of a two-dimensional code or an RFID tag; by scanning the code, the process data can be accessed and visualized.
[0009] According to the above technical solution, the specific execution process of the dynamic power regulation algorithm in step three includes: establishing a mapping relationship database of seafood species, thickness, initial bacterial colony count and optimal power supply parameters; calling the database to calculate the optimal initial voltage and frequency; and during the processing, the feedback data of the plasma intensity is obtained according to the preset time interval, and the power supply parameters are fine-tuned.
[0010] According to the above technical solution, the safety threshold range in step three is 50ppm to 200ppm of ozone concentration.
[0011] According to the technical solution, the ultra-low oxygen packaging in the fifth step is achieved by nitrogen filling packaging or vacuum packaging.
[0012] The application provides a dynamic low-temperature plasma sterilization and preservation method. (1) The sterilization and preservation method can accurately apply the most suitable intensity of plasma treatment according to the characteristics of the material through the synergistic effect of the dynamic power adjustment algorithm and the ozone concentration closed-loop control system, completely kills the surface microorganisms (including pathogenic bacteria and spoilage bacteria), and maximizes the prevention of protein denaturation, fat oxidation and flavor deterioration caused by excessive treatment, and perfectly retains the original color, taste and nutritional value of raw seafood.
[0013] (2) The sterilization and preservation method has a synergistic preservation system of "dynamic plasma sterilization" and "ultra-low oxygen packaging", the plasma treatment provides instant and powerful surface sterilization effect, and the subsequent ultra-low oxygen environment effectively inhibits the regrowth of residual microorganisms and enzyme activity, and the combination of the two produces a "1+1>2" effect, thereby extending the preservation period of raw seafood to more than twice that of traditional methods.
[0014] (3) The sterilization and preservation method introduces a non-contact multi-spectral detection and process data tracing system, changes the product quality control from "post-detection" to "process intelligent control", realizes real-time evaluation of raw material quality and full-process accurate recording and feedback of production parameters, reduces the dependence on human experience, guarantees the stability and consistency of the quality of different batches of products, and provides a solid data foundation for quality tracing and continuous process optimization.
[0015] (4) The sterilization and preservation method converts the invisible sterilization and preservation process into visual data assets through the "one product one code" quality tracing system, provides consumers with unprecedented product quality transparency, can query detailed production processing information by scanning the two-dimensional code, greatly enhances the consumers' confidence in food safety, establishes a high-tech and high-quality market image for the brand, and thus improves the core competitiveness and added value of the product. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 The figure is a schematic diagram of the sterilization and preservation process of the application. DETAILED DESCRIPTION
[0017] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described, obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.
[0018] Please refer to Figure 1 An embodiment of the present application is: a dynamic low-temperature plasma sterilization and preservation method, comprising the following steps: S1, material loading: placing raw food seafood to be processed in a processing chamber of a modular low-temperature plasma generating device; S2, non-contact detection: scanning the surface of the raw food seafood by a multi-spectral imaging unit integrated in the chamber, and non-contact estimating the initial microbial colony count based on image data; S3, adaptive plasma sterilization: the central controller calls a dynamic power regulation algorithm, calculates and sets the initial voltage and frequency parameters of the high-frequency pulse power supply based on the type, thickness and estimated initial colony count data of the raw food seafood obtained in S2; starting the power supply to generate low-temperature plasma at the multi-hole medium electrode, and the plasma acts on the surface of the raw food seafood in a dynamic diffusion manner for sterilization; S4, closed-loop regulation of ozone concentration: the ozone concentration in the processing chamber is monitored in real time by an ozone concentration sensor, and the data is fed back to the central controller; the controller compares the real-time concentration with the preset safe threshold range, and dynamically adjusts the working parameters of the power supply or the ventilation system in the chamber to stabilize the ozone concentration within the safe threshold range; S5, surface recovery treatment before packaging: after sterilization, filtered low-temperature and high-humidity air or inert gas is introduced into the processing chamber to treat the surface of the raw food seafood for a short time to eliminate residual ozone and restore the surface to near the initial fresh color; S6, ultra-low oxygen packaging and process data recording: the raw food seafood treated in step five is immediately transferred to an ultra-low oxygen environment with an oxygen content of less than 1% for sealing and packaging; at the same time, the type of the batch of raw food seafood, the power supply parameter change curve, the ozone concentration fluctuation curve and the total processing time data in the processing process are packaged to generate a unique quality traceability code and associated to the package. By providing a whole-process controllable, intelligent and non-thermal preservation process, the shelf life of raw food seafood is significantly prolonged, and quality decline caused by over-treatment or insufficient treatment is avoided by dynamic adjustment.
[0019] In the fourth step, the temperature of the gas is 2-6℃, the relative humidity is 85%-95%, and the processing time is 30-120 seconds. The recovery environment is controlled to ensure the optimal effect of eliminating ozone and restoring color. Low temperature prevents material temperature fluctuations, high humidity effectively supplements surface moisture, avoids dry weight loss, and short processing time ensures production efficiency. Ultimately, the product presents the best appearance and taste.
[0020] In the first step, the multispectral imaging unit captures the light intensity signal of the surface of the raw seafood in a specific fluorescence band, and compares it with the built-in microbial quantity prediction model to estimate the initial bacterial colony count. Through non-contact detection, biochemical information (microbial quantity) is converted into real-time measurable physical optical information, achieving second-level, non-destructive, online detection of the initial contamination level. This provides real-time data input for subsequent "dynamic power regulation", enabling the entire system to change from "open loop" to "closed loop", greatly improving the accuracy and reliability of sterilization.
[0021] In the fifth step, the quality traceability code is attached to the package in the form of a two-dimensional code or an RFID tag. By scanning the code, process data can be accessed and visualized, converting intangible processing into tangible, queryable data assets and attaching them to the product. This greatly enhances product quality transparency and consumer trust, establishing a "high-quality, traceable" image for the brand. It also provides valuable data for process optimization and problem tracing for producers, enhancing product added value and market competitiveness.
[0022] The specific execution process of the dynamic power regulation algorithm in the second step includes: establishing a mapping relationship database of seafood species, thickness, initial bacterial colony count, and optimal power parameters; calling the database to calculate the optimal initial voltage and frequency values; and during processing, obtaining feedback data on plasma intensity at preset time intervals to fine-tune power parameters, achieving intelligent and adaptive fine control. This achieves consistent and optimal sterilization and preservation effect for different batches and states of materials, reducing reliance on human operational experience and improving the standardization and intelligent level of the production line.
[0023] The safety threshold range in the third step is 50ppm to 200ppm of ozone concentration. By defining a safe window for ozone concentration, a best balance point is found between effective sterilization and avoiding oxidative flavor deterioration, which can fully utilize the sterilization ability of ozone and effectively constrain its side effects, ensuring that raw seafood retains its original fresh flavor and nutritional ingredients after sterilization.
[0024] The ultra-low oxygen packaging in step five is achieved by nitrogen filling or vacuum packaging, cutting off the oxygen source for microbial growth and fat oxidation, providing a long-term stable storage environment for the plasma sterilization effect, and at the same time producing a synergistic effect with the plasma sterilization technology, together extending the preservation period to more than twice that of the traditional method, and effectively preventing secondary corruption and oxidation deterioration in the circulation link.
[0025] While the embodiments of the application have been illustrated and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the spirit and scope of the application, which is defined by the appended claims and their equivalents.
Claims
1. A dynamic low-temperature plasma sterilization and preservation method, characterized in that, Includes the following steps: S1. Material loading: Place the raw seafood to be processed into the processing chamber of the modular low-temperature plasma generator; S2. Non-contact detection: The surface of raw seafood is scanned by a multispectral imaging unit integrated in the warehouse, and the initial number of microbial colonies is estimated non-contactly based on the image data. S3, Adaptive Plasma Sterilization: The central controller calls the dynamic power adjustment algorithm, and calculates and sets the initial voltage and frequency parameters of the high-frequency pulse power supply based on the raw seafood type, thickness and estimated initial colony count data obtained in S2; the power supply is started, and low-temperature plasma is generated at the porous dielectric electrode. The plasma acts on the surface of the raw seafood in a dynamic diffusion manner to sterilize it. S4. Closed-loop control of ozone concentration: The ozone concentration in the treatment chamber is monitored in real time by an ozone concentration sensor and the data is fed back to the central controller; the controller compares the real-time concentration with the preset safety threshold range and dynamically adjusts the power supply operating parameters or the ventilation system in the chamber to keep the ozone concentration stable within the safety threshold range. S5. Surface restoration treatment before packaging: After sterilization, low-temperature, high-humidity air or inert gas that has been filtered for bacteria is introduced into the treatment chamber to treat the surface of raw seafood for a short time to eliminate residual ozone and restore its surface to a near-original fresh color. S6. Ultra-low oxygen packaging and process data recording: The raw seafood processed in step four is immediately transferred to an ultra-low oxygen environment with an oxygen content of less than 1% for sealed packaging; at the same time, the type of raw seafood in this batch, the power parameter change curve during the processing, the ozone concentration fluctuation curve, and the total processing time data are packaged to generate a unique quality traceability code and associated with the packaging.
2. The dynamic low-temperature plasma sterilization and preservation method according to claim 1, characterized in that: In step four, the temperature of the introduced gas is 2-6℃, the relative humidity is 85%-95%, and the processing time is 30-120 seconds.
3. The dynamic low-temperature plasma sterilization and preservation method according to claim 2, characterized in that: In step one, the multispectral imaging unit captures the light intensity signal of the surface of raw seafood in a specific fluorescence band and compares it with the built-in microbial quantity prediction model to estimate the initial colony count.
4. The dynamic low-temperature plasma sterilization and preservation method according to claim 3, characterized in that: In step five, the quality traceability code is attached to the packaging in the form of a QR code or an RFID tag; the process data can be accessed and visualized by scanning the code.
5. The dynamic low-temperature plasma sterilization and preservation method according to claim 4, characterized in that: The specific execution process of the dynamic power adjustment algorithm in step two includes: establishing a database of mapping relationships between seafood type, thickness, initial colony count and optimal power parameters; calling the database to match and calculate the optimal initial values of voltage and frequency; and during the processing, obtaining feedback data of plasma intensity according to a preset time interval to fine-tune the power parameters.
6. The dynamic low-temperature plasma sterilization and preservation method according to claim 5, characterized in that: The safety threshold range in step three is an ozone concentration of 50 ppm to 200 ppm.
7. The dynamic low-temperature plasma sterilization and preservation method according to claim 6, characterized in that: The ultra-low oxygen packaging in step five is achieved using nitrogen-filled packaging or vacuum packaging.