A microbial fermentation device for low-salt cured meat products and a method thereof

Abstract

The application discloses a kind of microbial fermentation device and method of low salt cured meat product, it is related to fermentation device technical field.The microbial fermentation device of low salt cured meat product is collected by being arranged air microorganism sampler air sample in fermentation chamber in real time and exports the detection signal of characterizing miscellaneous bacteria pollution risk, by comparing detection signal with at least two levels of miscellaneous bacteria risk threshold value and exporting corresponding fence control instruction by multistage response control module, corresponding fence control action is executed according to control instruction by fence factor execution unit, realizes the real-time perception of miscellaneous bacteria pollution risk in the fermentation process of low salt cured meat product, grading judgment and dynamic intervention closed-loop control, solve the technical problem that existing fermentation equipment lacks miscellaneous bacteria real-time detection capability and dynamic prevention and control capability.

Description

Technical Field

[0001] This invention relates to the field of fermentation equipment technology, specifically to a microbial fermentation device and method for low-salt cured meat products. Background Technology

[0002] Fermented flavored cured meat products refer to meat products with special flavor and texture formed by the fermentation of microorganisms or enzymes under artificially controlled conditions, which causes a series of biochemical and physical changes in the meat. With the increasing demand of consumers for healthy food, low-salt cured meat products have gradually become an important direction for industry research and development. Low-salt fermentation can reduce the sodium content in the product. There are various fermentation equipment for cured meat products in the existing technology. For example, Chinese patent CN202211378087 discloses an automatic fermentation equipment for flavored cured meat based on microbial fermentation. The equipment is equipped with a cured meat hanging mechanism in the fermentation tank, and an inoculation liquid nozzle is set below the hanging mechanism. The nozzle is driven to rise and fall by a lifting mechanism to achieve uniform inoculation of the cured meat. The inner wall of the fermentation tank is also fixedly connected with an electric heating component, a temperature sensor, and a humidity sensor. The fermentation temperature in the fermentation tank is maintained within a preset range by the temperature sensor and the electric heating component.

[0003] However, the existing technologies still have the following shortcomings. First, the monitoring targets of existing fermentation equipment are concentrated on physicochemical environmental parameters such as temperature, humidity, pressure, and pH value, lacking the ability to detect the concentration of microorganisms in the air inside the fermentation chamber in real time. Under low-salt conditions, the antibacterial effect of salt is weakened, and the risk of contamination by miscellaneous bacteria (especially molds and putrefactive bacteria) increases. Since the risk of miscellaneous contamination cannot be detected in real time, by the time miscellaneous bacteria invade, they have already developed to a certain scale, making intervention difficult and ineffective. Second, in the process design stage, existing technologies usually set parameters such as temperature and humidity within a preset range, and do not dynamically adjust them according to the real-time changes in the risk of miscellaneous contamination during fermentation. This parameter control method is difficult to cope with the sudden and gradual characteristics of miscellaneous contamination during low-salt fermentation. Finally, the miscellaneous control methods of existing fermentation equipment are relatively simple, usually performing a one-time sterilization treatment before fermentation, lacking the ability to control miscellaneous bacteria during fermentation. Once miscellaneous bacteria invade in the middle of fermentation, there is a lack of intervention methods. Therefore, how to achieve real-time perception and control of the risk of miscellaneous contamination during the fermentation of low-salt cured meat products is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a microbial fermentation apparatus and method for low-salt cured meat products, thereby solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a microbial fermentation device for low-salt cured meat products, comprising:

[0006] Fermentation chamber, used to hold cured meat products to be fermented;

[0007] An air microbial sampler is installed in the fermentation chamber to collect air samples from the fermentation chamber and output a detection signal characterizing the risk of contamination by miscellaneous bacteria.

[0008] A multi-level response control module is connected to the air microbial sampler for receiving the detection signal and outputting corresponding fence control commands based on the comparison results of the detection signal with at least two preset microbial risk thresholds.

[0009] The fence factor execution unit is connected to the multi-level response control module and is used to receive the fence regulation instructions and execute the corresponding fence regulation actions. The fence regulation actions include at least one of physical fence regulation, chemical fence regulation and biological fence regulation.

[0010] Preferably, the airborne microbial sampler comprises:

[0011] The sampling pipeline has one end inserted into the fermentation chamber and the other end connected to a vacuum pump;

[0012] A rapid detection culture medium carrier is installed on the sampling pipeline to carry the rapid detection culture medium to capture airborne microorganisms;

[0013] An image acquisition module is installed at the rapid detection culture medium carrier and is used to periodically acquire colony images on the rapid detection culture medium.

[0014] The image analysis module is connected to the image acquisition module and is used to perform image recognition processing on the colony image, count the number of colonies and identify the colony morphology to generate the detection signal.

[0015] Preferably, the fence control commands include control commands to maintain normal fermentation, first-level response control commands, second-level response control commands, and third-level response control commands;

[0016] The fence factor execution unit includes an ultraviolet circulation air assembly, which is disposed on the inner wall of the fermentation chamber. It is used to increase the ultraviolet power to a preset power level when the first-level response control command is received, and to run continuously for a preset time.

[0017] Preferably, the fence factor execution unit further includes a natural antibacterial agent atomizing spray assembly, the natural antibacterial agent atomizing spray assembly comprising:

[0018] An antibacterial agent storage tank is located outside the fermentation chamber;

[0019] Atomizing nozzle is located at the top of the inside of the fermentation chamber and is connected to the antibacterial agent storage tank via a liquid supply pipeline.

[0020] A metering pump, installed on the liquid supply pipeline, is used to atomize and spray the natural antibacterial agent solution in the antibacterial agent storage tank into the fermentation chamber through the atomizing nozzle when the secondary response control command is received.

[0021] Preferably, the natural antibacterial agent solution is a tea polyphenol solution or a nisin solution with a mass percentage concentration within a preset range.

[0022] Preferably, the fence factor execution unit further includes:

[0023] A fresh air duct is connected to the fermentation chamber and is used to introduce fresh air into the fermentation chamber.

[0024] A shut-off valve is installed on the fresh air duct to cut off the fresh air duct when the level 3 response control command is received;

[0025] A carbon dioxide supply component, connected to the fermentation chamber, is used to introduce carbon dioxide into the fermentation chamber when the three-level response control command is received, thereby reducing the oxygen concentration in the fermentation chamber.

[0026] A high-concentration bacterial solution spraying component is installed inside the fermentation chamber and is used to spray the dominant fermentation bacterial solution onto the surface of the cured meat product when the three-level response control command is received.

[0027] Preferably, the multi-level response control module further includes a fence strength index calculation unit, which is used to calculate the fence strength index based on the control actions of each currently active fence factor execution unit.

[0028] When the fence strength index reaches the preset safety fence strength threshold, the multi-level response control module inhibits the activation of the natural antibacterial agent atomizing spray component.

[0029] This invention also discloses a microbial fermentation method for low-salt cured meat products, using the aforementioned microbial fermentation device for low-salt cured meat products, comprising the following steps:

[0030] Step S1: Hang the cured meat products to be fermented in the fermentation chamber to start fermentation;

[0031] Step S2: Periodically collect air samples from the fermentation chamber using an air microbial sampler installed in the fermentation chamber, rapidly culture the collected air samples, and obtain detection signals characterizing the risk of contamination by miscellaneous bacteria through image acquisition and recognition;

[0032] Step S3: The multi-level response control module receives the detection signal and compares the detection signal with at least two preset levels of contamination risk thresholds;

[0033] Step S4: Based on the comparison results, the multi-level response control module outputs corresponding fence adjustment commands;

[0034] Step S5: The fence factor execution unit receives the fence regulation instruction and executes the corresponding fence regulation action, wherein the fence regulation action includes at least one of physical fence regulation, chemical fence regulation and biological fence regulation.

[0035] Step S6: Repeat steps S2 to S5 until fermentation is complete.

[0036] Preferably, the preset contaminant risk threshold in step S3 includes a safety threshold, a warning threshold, and a danger threshold, wherein the safety threshold is less than the warning threshold, and the warning threshold is less than the danger threshold;

[0037] In step S4

[0038] When the detection signal is less than the safety threshold, the multi-level response control module outputs a control command to maintain normal fermentation.

[0039] When the detection signal is greater than or equal to the safety threshold and less than the warning threshold, the multi-level response control module outputs a first-level response adjustment command.

[0040] When the detection signal is greater than or equal to the warning threshold and less than the danger threshold, the multi-level response control module outputs a two-level response adjustment command;

[0041] When the detection signal is greater than or equal to the danger threshold, the multi-level response control module outputs a three-level response control command.

[0042] Preferably, the multi-level response control module further includes a fermentation stage adaptive unit, which is used to dynamically adjust the values ​​of the safety threshold, warning threshold and danger threshold according to the current fermentation stage of the fermentation process;

[0043] In the early stage of fermentation, the warning threshold is lowered to a first set value; in the middle and late stages of fermentation, the warning threshold is raised to a second set value, wherein the first set value is less than the second set value.

[0044] The technical effects and advantages of this invention are as follows:

[0045] 1. This microbial fermentation device for low-salt cured meat products collects air samples from the fermentation chamber in real time using an air microbial sampler and outputs a detection signal characterizing the risk of contamination by miscellaneous bacteria. A multi-level response control module compares the detection signal with at least two preset contamination risk thresholds and outputs corresponding fence control commands. The fence factor execution unit executes the corresponding fence control action according to the control commands, realizing a closed-loop control of real-time perception, graded judgment, and dynamic intervention of the risk of contamination by miscellaneous bacteria during the fermentation process of low-salt cured meat products. This solves the technical problem that existing fermentation equipment lacks real-time detection and dynamic control capabilities for miscellaneous bacteria.

[0046] 2. This microbial fermentation device for low-salt cured meat products constructs a multi-level progressive barrier control system that combines physical, chemical, and biological barriers. This system is achieved by setting up an ultraviolet circulating air component to increase ultraviolet power during the first-level response, a natural antibacterial agent atomizing spray component to spray natural antibacterial agents during the second-level response, and a carbon dioxide supply component and a high-concentration bacterial liquid spray component to synergistically perform operations such as cutting off fresh air, reducing oxygen, and biological occupancy during the third-level response. This allows the device to progressively increase the intervention intensity according to the risk level of contamination by miscellaneous bacteria, avoiding interference with normal fermentation during sterilization and providing a combination of intervention methods superior to existing technologies in the event of a miscellaneous bacteria outbreak.

[0047] 3. The microbial fermentation device for low-salt cured meat products calculates the fence strength index based on the control actions of the execution units of each currently active fence factor through the fence strength index calculation unit. When the fence strength index reaches the preset safe fence strength threshold, the activation of the natural antibacterial agent atomizing spray component is suppressed, avoiding excessive intervention caused by the superposition of multiple fence factors. At the same time, the fermentation stage adaptive unit dynamically adjusts the value of the contamination risk threshold according to the current fermentation process. The threshold is tightened in the early stage of fermentation to achieve prevention, and the threshold is relaxed in the middle and late stages of fermentation to avoid excessive and frequent intervention. This achieves refined and adaptive adjustment of contamination control throughout the fermentation process, improving the device's adaptability to different fermentation stages. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0050] Figure 2 This is a schematic diagram of the internal structure of the fermentation chamber of the present invention;

[0051] Figure 3 This is the front view of the present invention;

[0052] Figure 4 This is a top view of the present invention;

[0053] Figure 5 This is a side view of the present invention;

[0054] Figure 6 This is a diagram showing the internal structure of the air microbial sampler of the present invention;

[0055] Figure 7 This is a diagram illustrating the architecture of the multi-level response control module of the present invention.

[0056] Figure 8 This is a multi-level response logic judgment diagram of the present invention;

[0057] Figure 9 This is a schematic diagram of the method flow of the present invention.

[0058] In the diagram: 100, Fermentation chamber; 200, Air microbial sampler; 210, Sampling pipeline; 220, Air pump; 230, Rapid detection culture medium carrier; 240, Image acquisition module; 250, Image analysis module; 300, Multi-level response control module; 310, Fence strength index calculation unit; 320, Fermentation stage adaptive unit; 400, Fence factor execution unit; 410, Ultraviolet circulating air assembly; 420, Natural antibacterial agent atomizing spray assembly; 421, Antibacterial agent storage tank; 422, Atomizing nozzle; 423, Liquid supply pipeline; 424, Metering pump; 430, Fresh air pipeline; 431, Sealing valve; 440, Carbon dioxide supply assembly; 450, High-concentration bacterial solution spray assembly. Detailed Implementation

[0059] 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.

[0060] This embodiment discloses a microbial fermentation device for low-salt cured meat products, according to the attached... Figure 1 To be continued Figure 9 As shown, it includes a fermentation chamber 100, an air microbial sampler 200, a multi-level response control module 300, and a fence factor execution unit 400. The air microbial sampler 200 is disposed in the fermentation chamber 100. The multi-level response control module 300 is signal-connected to the air microbial sampler 200, and the fence factor execution unit 400 is control-connected to the multi-level response control module 300.

[0061] Fermentation chamber 100 is a sealed box structure used to hold cured meat products to be fermented. A closable, sealed door is provided on one side of fermentation chamber 100 for taking out and placing the cured meat products. A hanging mechanism is provided at the top of the interior of fermentation chamber 100, consisting of multiple parallel hanging beams with hooks spaced apart on each beam for hanging the cured meat products to be fermented. The walls of fermentation chamber 100 are made of food-grade stainless steel, with an insulation layer sandwiched inside to maintain a stable temperature inside the fermentation chamber 100. Fermentation chamber 100 also includes a temperature control component and a humidity control component. The temperature control component includes an electric heating element and a cooling coil installed on the inner wall of fermentation chamber 100, and the humidity control component includes a humidifier and a dehumidifier installed inside fermentation chamber 100 to maintain the temperature and humidity within the preset fermentation process parameters.

[0062] An air microbial sampler 200 is installed inside the fermentation chamber 100 to collect air samples from the fermentation chamber 100 and output a detection signal characterizing the risk of contamination by miscellaneous bacteria. The air microbial sampler 200 includes a sampling pipeline 210, an air pump 220, a rapid detection culture medium carrier 230, an image acquisition module 240, and an image analysis module 250.

[0063] Furthermore, one end of the sampling tube 210 extends into the interior of the fermentation chamber 100, and the other end of the sampling tube 210 is connected to an air pump 220. The inlet end of the sampling tube 210 is located inside the fermentation chamber 100 near the suspension mechanism, at the center height of the hanging area of ​​the cured meat products, enabling the collection of air samples from the environment surrounding the meat products. A rapid detection culture medium carrier 230 is provided on the sampling tube 210. The rapid detection culture medium carrier 230 is used to carry the rapid detection culture medium to capture microorganisms in the air. The rapid detection culture medium carrier 230 includes a culture medium tray and a rapid detection culture medium placed on the culture medium tray. The rapid detection culture medium is preferably a selective chromogenic culture medium for common contaminants, including molds and putrefactive bacteria. This culture medium can make the captured contaminant colonies chromogenic within 4 to 6 hours, so as to facilitate subsequent image recognition. The air pump 220 has a pumping flow rate of 2.5 L / min to 3.5 L / min, and each sampling time is 3 to 5 minutes to ensure that a sufficient amount of air sample passes through the surface of the rapid detection culture medium so that microbial particles are captured.

[0064] Furthermore, the image acquisition module 240 is located at the rapid detection culture medium carrier 230. The image acquisition module 240 includes a high-resolution industrial camera and a supplementary light source, and is used to periodically acquire colony images on the rapid detection culture medium. The acquisition cycle of the image acquisition module 240 is once every 1 hour. The image analysis module 250 is signal-connected to the image acquisition module 240. The image analysis module 250 has a built-in image recognition algorithm, which is used to perform image recognition processing on the colony images, count the number of colonies and identify the colony morphology to generate a detection signal. The detection signal includes total number of miscellaneous bacteria data and miscellaneous bacteria type characteristic data. The image analysis module 250 transmits the detection signal to the multi-level response control module 300 via wired or wireless means.

[0065] The image analysis module 250's built-in image recognition algorithm performs image recognition processing on the colony images, specifically including the following steps:

[0066] The first step is image preprocessing: After receiving the original colony image acquired by the image acquisition module 240, the image analysis module 250 first performs grayscale processing on the original image, converting the color image into a grayscale image; then, the median filtering algorithm is used to denoise the grayscale image to remove noise interference introduced during the image acquisition process; finally, the histogram equalization method is used to enhance the image contrast, making the grayscale difference between the colony area and the culture medium background area more significant.

[0067] The second step is image segmentation: an adaptive threshold segmentation algorithm, such as the Otsu algorithm, is used to binarize the preprocessed image, separating the foreground of the colony region from the background of the culture medium region to generate a binary image. For cases where colonies are stuck together, the watershed algorithm is used to segment the stuck colonies, separating the contacting colonies into independent connected regions.

[0068] The third step is feature extraction and colony counting: each connected region in the segmented binary image is marked, and the morphological parameters such as area, perimeter, and circularity of each connected region are counted. The number of connected regions is used as the total number of colonies. Connected regions with an area smaller than a preset minimum colony area threshold are removed as noise. In this embodiment, the minimum colony area threshold is preferably 50 pixels. Connected regions with an area larger than a preset maximum single colony area threshold are counted according to the area ratio. In this embodiment, the maximum single colony area threshold is preferably 500 pixels.

[0069] The fourth step is colony morphology recognition and classification: The image analysis module 250 also stores a database of colony morphology features of common contaminants, including Aspergillus, Penicillium, and bacterial colonies. This database contains feature parameters such as colony color, edge morphology, surface texture, and colony diameter range after various contaminants have been cultured on rapid detection media for 4 to 6 hours. The image analysis module 250 extracts the HSV color space features (hue, saturation, brightness), shape features (circularity, elongation, rectangularity), and texture features (energy and entropy based on the gray-level co-occurrence matrix) of each connected region. The extracted feature vectors (such as contrast, correlation, etc.) are input into a pre-trained support vector machine (SVM) classifier for classification and recognition. The SVM classifier uses thousands of manually labeled images of miscellaneous bacteria colonies collected in the early stage as a training sample set. The radial basis function (RBF) is used as the kernel function, and the kernel parameters are optimized by cross-validation. The classifier outputs the category label of each colony. The image analysis module 250 counts the number and proportion of each type of miscellaneous bacteria based on this, generates a detection signal containing the total number of miscellaneous bacteria and the characteristic data of miscellaneous bacteria species, and transmits it to the multi-level response control module 300.

[0070] The multi-level response control module 300 is connected to the air microbial sampler 200 to receive detection signals and output corresponding fence control commands based on the comparison results of the detection signals with at least two preset microbial risk thresholds. The multi-level response control module 300 is a programmable logic controller (PLC) or an embedded industrial control computer, which stores preset microbial risk thresholds and corresponding fence control strategies.

[0071] Furthermore, the multi-level response control module 300 presets three risk thresholds for miscellaneous bacteria: a safety threshold, a warning threshold, and a danger threshold. The safety threshold < the warning threshold < the danger threshold. In this embodiment, the safety threshold is preferably 10 CFU / m³, the warning threshold is preferably 50 CFU / m³, and the danger threshold is preferably 100 CFU / m³. These thresholds are determined based on experimental data on the risk of miscellaneous bacteria contamination during the fermentation of low-salt cured meat products. When the concentration of miscellaneous bacteria in the air inside the fermentation chamber 100 is below 10 CFU / m³, the risk of contamination of meat products by miscellaneous bacteria is extremely low and can be considered a safe state. When the concentration of miscellaneous bacteria reaches 10 to 50 CFU / m³, miscellaneous bacteria begin to proliferate actively, and preventive measures need to be taken. When the concentration of miscellaneous bacteria reaches 50 to 100 CFU / m³, the risk of miscellaneous bacteria contamination increases, and enhanced intervention measures need to be taken. When the concentration of miscellaneous bacteria exceeds 100 CFU / m³, miscellaneous bacteria contamination is in an outbreak state, and emergency control measures need to be taken.

[0072] When the detection signal is less than the safety threshold, the multi-level response control module 300 outputs a control command to maintain normal fermentation, that is, the fence factor execution unit 400 maintains the operation state under normal fermentation mode.

[0073] When the detected signal is greater than or equal to the safety threshold and less than the warning threshold, the multi-level response control module 300 outputs a first-level response control command.

[0074] When the detected signal is greater than or equal to the warning threshold and less than the danger threshold, the multi-level response control module 300 outputs a two-level response control command.

[0075] When the detected signal is greater than or equal to the danger threshold, the multi-level response control module 300 outputs a three-level response control command.

[0076] Furthermore, the multi-level response control module 300 also includes a fence strength index calculation unit 310. The fence strength index calculation unit 310 is used to calculate the fence strength index based on the control actions of the currently active fence factor execution units 400. The calculation formula for the fence strength index is: Fence strength index = Σ antibacterial contribution coefficient of each active fence factor × weight factor. The antibacterial contribution coefficient and weight factor of each fence factor are determined through pre-experimentation and stored in the multi-level response control module 300. When the fence strength index reaches the preset safe fence strength threshold, the multi-level response control module 300 inhibits the activation of the natural antibacterial agent atomizing spray component 420. The safe fence strength threshold is preferably 80%, that is, when the superimposed antibacterial effect of the physical fence and the biological fence has reached more than 80%, the chemical fence will no longer be activated to avoid the excessive addition of antibacterial agents from having an adverse effect on the product flavor.

[0077] The fence strength index calculation unit 310 stores the antibacterial contribution coefficient and corresponding weighting factor of each fence factor. The antibacterial contribution coefficient and weighting factor of each fence factor are obtained through prior experimental determination. The specific determination method is as follows:

[0078] Each barrier factor, including the ultraviolet circulating air component 410, temperature control component, natural antibacterial agent atomizing spray component 420, and high-concentration bacterial solution spray component 450, was individually applied to a simulated culture medium for cured meat products inoculated with standard test bacteria, such as typical contaminants like Aspergillus, Penicillium, and spoilage bacteria. After running for a preset time under standard fermentation conditions in a fermentation chamber of 100°C, samples were taken to test the survival rate of contaminants in each group. The antibacterial rate of each barrier factor was calculated based on the survival rate of the control group without any barrier factors. This antibacterial rate is the basic value of the antibacterial contribution coefficient of the barrier factor.

[0079] The weighting factors of each barrier factor are determined comprehensively based on the actual controllability, duration of action, and degree of influence on product quality during the fermentation process of low-salt cured meat products. The ultraviolet circulating air component 410 has a short duration of action, can be quickly started and stopped, and does not directly contact the product, so its weighting factor is set to 0.3; the temperature regulation component has a wide range of action but a slow response, so its weighting factor is set to 0.2; the natural antibacterial agent atomizing spray component 420 has a direct antibacterial effect but may have a certain impact on the surface flavor of the product, so its weighting factor is set to 0.25; the high-concentration bacterial liquid spray component 450 inhibits miscellaneous bacteria through biological competition, has a mild effect but a relatively slow onset of action, so its weighting factor is set to 0.25. The sum of the above weighting factors is 1.0.

[0080] Fence strength index calculation unit 310 calculates the current fence strength index according to the following formula:

[0081] ;

[0082] Wherein, FSI is the fence strength index, expressed as a percentage; The antibacterial contribution coefficient of the i-th currently active fence factor; is the weight factor corresponding to the i-th currently effective fence factor; n is the total number of currently effective fence factors. When the fence strength index reaches the preset safety fence strength threshold of 80%, the multi-level response control module 300 inhibits the activation of the natural antibacterial agent atomizing spray component 420.

[0083] Furthermore, the multi-level response control module 300 also includes a fermentation stage adaptive unit 320. The fermentation stage adaptive unit 320 is used to dynamically adjust the values ​​of the safety threshold, warning threshold, and danger threshold according to the current fermentation stage. In the early stage of fermentation, that is, within 0 to 12 hours after fermentation starts, miscellaneous bacteria are most likely to invade, so the warning threshold is lowered to the first set value, which is preferably 5 CFU / m³. In the middle and late stages of fermentation, that is, after 12 hours of fermentation starts until the end of fermentation, the dominant bacteria have taken the lead, so the warning threshold is raised to the second set value, which is preferably 20 CFU / m³. The first set value is less than the second set value. Through the above dynamic adjustment, a differentiated prevention and control strategy is realized.

[0084] The fence factor execution unit 400 is connected to the multi-level response control module 300 for receiving fence regulation instructions and executing corresponding fence regulation actions. The fence regulation actions include at least one of physical fence regulation, chemical fence regulation, and biological fence regulation.

[0085] Furthermore, the fence factor execution unit 400 includes an ultraviolet (UV) circulating air assembly 410, which is disposed on the inner wall of the fermentation chamber 100. The UV circulating air assembly 410 includes a UV lamp and a circulating fan. The UV lamp is a low-pressure mercury lamp that emits ultraviolet light with a wavelength of 253.7 nm. The circulating fan is disposed behind the UV lamp and is used to circulate the air in the UV lamp irradiation area to all parts of the fermentation chamber 100. The UV circulating air assembly 410 is used to increase the UV power when a first-level response control command is received. The UV power is increased to twice that of the regular fermentation mode and runs continuously for 30 minutes. In the regular fermentation mode, the UV circulation fan component 410 runs for 15 minutes every 2 hours with a UV power of 15W. In the first-level response mode, the UV power is increased to 30W and runs continuously for 30 minutes to enhance the killing effect on airborne bacteria. The 30-minute running time is determined based on the killing kinetic curve of common bacteria by the UV lamp at 30W power. Under this power and duration conditions, the killing rate of airborne bacteria can reach more than 99%.

[0086] Furthermore, the fence factor execution unit 400 also includes a natural antibacterial agent atomizing spray assembly 420. The natural antibacterial agent atomizing spray assembly 420 includes an antibacterial agent storage tank 421, an atomizing nozzle 422, a supply pipeline 423, and a metering pump 424. The antibacterial agent storage tank 421 is located outside the fermentation chamber 100, with a filling port at the top and an outlet at the bottom. The atomizing nozzle 422 is located at the top of the interior of the fermentation chamber 100 and connects to the antibacterial agent storage tank via the supply pipeline 423. The outlet of the liquid tank 421 is connected, and the atomizing nozzle 422 is a pressure atomizing nozzle with an atomizing particle size of 10μm to 50μm, which can uniformly atomize and distribute the antibacterial agent solution inside the fermentation chamber 100. The metering pump 424 is installed on the liquid supply pipeline 423 to accurately control the spray volume of the antibacterial agent solution. The natural antibacterial agent atomizing spray assembly 420 is used to atomize and spray the natural antibacterial agent solution in the antibacterial agent storage tank 421 into the fermentation chamber 100 through the atomizing nozzle 422 when a secondary response control command is received.

[0087] Furthermore, the natural antibacterial agent solution is a tea polyphenol solution or a nisin solution with a mass percentage concentration of 0.05% to 0.15%. The determination of the above concentration range is based on the following: when the concentration is below 0.05%, the antibacterial effect is not significant and cannot effectively inhibit the growth of miscellaneous bacteria; when the concentration is above 0.15%, although the antibacterial effect is enhanced, it will have an adverse effect on the flavor of cured meat products and may remain on the product surface. Experimental verification shows that the concentration range of 0.05% to 0.15% can minimize the impact on the flavor of the product while ensuring effective antibacterial action. In this embodiment, the natural antibacterial agent solution is preferably a tea polyphenol solution with a mass percentage concentration of 0.10%.

[0088] Furthermore, the fence factor execution unit 400 also includes a fresh air duct 430, a shut-off valve 431, a carbon dioxide supply component 440, and a high-concentration bacterial solution spraying component 450. The fresh air duct 430 is connected to the fermentation chamber 100 and is used to introduce fresh air into the fermentation chamber 100 to maintain oxygen supply and gas exchange within the fermentation chamber 100. The shut-off valve 431 is installed on the fresh air duct 430 and is either an electric butterfly valve or an electric ball valve, used to cut off the flow when a level-three response control command is received. The fresh air duct 430 switches the fermentation chamber 100 to a fully enclosed circulation state. The carbon dioxide supply assembly 440 is connected to the fermentation chamber 100. The carbon dioxide supply assembly 440 includes a carbon dioxide cylinder, a pressure reducing valve, and a supply pipeline. One end of the supply pipeline is connected to the carbon dioxide cylinder, and the other end extends into the fermentation chamber 100. The carbon dioxide supply assembly 440 is used to introduce carbon dioxide into the fermentation chamber 100 upon receiving a level-three response control command, reducing the oxygen concentration in the fermentation chamber 100 from 21%. The rationale for reducing the oxygen concentration to 10% to 12% is that most aerobic bacteria, such as molds, require a minimum oxygen concentration of 5% to 10% for growth. Controlling the oxygen concentration at 10% to 12% effectively inhibits the growth of aerobic bacteria without completely eliminating oxygen, which could lead to the proliferation of anaerobic putrefactive bacteria. Furthermore, this oxygen concentration range does not significantly inhibit the normal metabolism of the dominant fermenting bacteria. The high-concentration bacterial solution spraying component 450 is installed inside the fermentation chamber 100. 50 includes a bacterial solution storage tank, a bacterial solution delivery pipeline, and a spray head. The spray head is located at the top of the fermentation chamber 100, arranged adjacent to or integrated with the atomizing nozzle 422. The high-concentration bacterial solution spraying assembly 450 is used to spray the dominant fermentation bacterial solution onto the surface of the cured meat product when a three-level response control command is received. The concentration of the dominant fermentation bacterial solution is 2.5 to 3.5 times that of the conventional fermentation bacterial solution. The dominant fermentation bacterial solution is a mixed bacterial solution containing Lactobacillus plantarum and Staphylococcus aureus. The concentration of the conventional fermentation bacterial solution is 1.0 × 10⁻⁶. 8 CFU / mL, bacterial concentration increased to 2.5 × 10⁻⁶ under Level 3 response mode. 8 Up to 3.5×10 8 The rationale for increasing the bacterial concentration to 2.5 to 3.5 times the conventional level (CFU / mL) is that this concentration range enables the dominant bacteria to competitively exclude other bacteria under conditions of bacterial overgrowth, i.e., the biological occupancy effect. At the same time, it avoids excessive fermentation or abnormal product flavor caused by excessively high bacterial concentrations. Experiments have verified that when the bacterial concentration is less than 2.5 times the conventional level, the competitive exclusion effect is insufficient and cannot effectively inhibit other bacteria; when the bacterial concentration is more than 3.5 times the conventional level, the metabolic products of the dominant bacteria accumulate too quickly, which may lead to an excessively low product pH value and affect product quality.

[0089] The workflow of this embodiment will be described in detail below with reference to specific examples:

[0090] Example 1: This example uses a scenario where the risk of contamination by miscellaneous bacteria in low-salt cured meat products during conventional fermentation is at a safe level. (See attached...) Figure 1 To be continued Figure 9 Detailed workflow description:

[0091] Step S1: The operator opens the sealed door of the fermentation chamber 100, hangs the cured meat products to be fermented on the hooks of the hanging mechanism at the top of the fermentation chamber 100, closes the sealed door, and starts the fermentation program. The temperature and humidity control components in the fermentation chamber 100 adjust the temperature and humidity in the fermentation chamber 100 to the preset fermentation process parameters, and the cured meat products begin to ferment in the fermentation chamber 100.

[0092] Step S2: The air microbial sampler 200 starts sampling according to the preset sampling cycle. The air pump 220 starts and draws air from inside the fermentation chamber 100 through the sampling pipeline 210. When the air flows through the rapid detection medium carrier 230, the microbial particles in the air are captured on the surface of the rapid detection medium. After sampling, the rapid detection medium on the rapid detection medium carrier 230 is used to cultivate the captured microorganisms for 4 to 6 hours. After cultivation, the image acquisition module 240 acquires colony images on the surface of the rapid detection medium. The image analysis module 250 performs image recognition processing on the colony images, counts the number of colonies and identifies the colony morphology, generates a detection signal characterizing the risk of contamination by miscellaneous bacteria, and transmits the detection signal to the multi-level response control module 300.

[0093] Step S3: The multi-level response control module 300 receives the detection signal and compares it with the preset three-level bacterial risk thresholds: a safety threshold of 10 CFU / m³, a warning threshold of 50 CFU / m³, and a danger threshold of 100 CFU / m³. If the detection signal shows that the bacterial concentration is 5 CFU / m³, which is less than the safety threshold of 10 CFU / m³, then the current bacterial contamination risk is determined to be at a safe level.

[0094] Step S4: The multi-level response control module 300 outputs a control command to maintain conventional fermentation to the fence factor execution unit 400 based on the comparison results. After receiving the control command, the fence factor execution unit 400 operates the ultraviolet circulating air component 410 in the conventional fermentation mode, that is, it runs for 15 minutes every 2 hours with an ultraviolet power of 15W. The natural antibacterial agent atomizing spray component 420, the carbon dioxide gas supply component 440, and the high-concentration bacterial liquid spray component 450 are all kept in the off state.

[0095] Step S5: Repeat steps S2 to S4 until fermentation ends. Throughout the fermentation process, the air microbial sampler 200 continuously monitors the concentration of miscellaneous bacteria in the fermentation chamber 100, and the multi-level response control module 300 continuously judges the risk level of miscellaneous bacteria contamination and outputs corresponding control commands to ensure that the concentration of miscellaneous bacteria in the fermentation chamber 100 is always maintained at a safe level.

[0096] Example 2: This example uses a scenario where the risk of contamination by miscellaneous bacteria in low-salt cured meat products gradually escalates to different levels during fermentation, combined with the attached... Figure 1 To be continued Figure 9 Detailed workflow description:

[0097] Step S1: The operator opens the sealed door of the fermentation chamber 100, hangs the cured meat products to be fermented on the hooks of the hanging mechanism at the top of the fermentation chamber 100, closes the sealed door, and starts the fermentation process.

[0098] Step S2: The air microbial sampler 200 starts sampling every hour. The air pump 220 starts at a flow rate of 3.0 L / min and draws air from inside the fermentation chamber 100 through the sampling pipeline 210. The sampling time is 4 minutes. When the air flows through the rapid detection medium carrier 230, the microbial particles in the air are captured on the surface of the rapid detection medium. After sampling, the rapid detection medium on the rapid detection medium carrier 230 is used to culture the captured microorganisms for 5 hours. After the culture is completed, the image acquisition module 240 acquires colony images on the surface of the rapid detection medium. The image analysis module 250 performs image recognition processing on the colony images, counts the number of colonies and identifies the colony morphology, generates a detection signal and transmits it to the multi-level response control module 300.

[0099] Step S3: The multi-level response control module 300 receives the detection signal and compares it with the preset three-level miscellaneous bacteria risk threshold. If the detection signal of a certain sampling period shows that the miscellaneous bacteria concentration is 30 CFU / m³, which is greater than or equal to the safety threshold of 10 CFU / m³ and less than the warning threshold of 50 CFU / m³, the multi-level response control module 300 determines that the current miscellaneous bacteria contamination risk is at the warning level and outputs a first-level response control command to the fence factor execution unit 400. After receiving the first-level response control command, the fence factor execution unit 400 increases the ultraviolet power of the ultraviolet circulation air component 410 from the conventional 15W to 30W, which is twice the conventional power, and runs continuously for 30 minutes to enhance ultraviolet sterilization of the air in the fermentation chamber 100. The natural antibacterial agent atomizing spray component 420, the carbon dioxide gas supply component 440 and the high-concentration bacterial liquid spray component 450 remain in the closed state. After 30 minutes, the ultraviolet circulation air component 410 resumes normal fermentation mode operation.

[0100] If the detection signal in subsequent sampling cycles shows that the concentration of miscellaneous bacteria continues to rise to 70 CFU / m³, which is greater than or equal to the warning threshold of 50 CFU / m³ but less than the danger threshold of 100 CFU / m³, then the multi-level response control module 300 determines that the current risk of miscellaneous bacteria contamination is at a dangerous level and outputs a secondary response control command to the barrier factor execution unit 400. After receiving the secondary response control command, the barrier factor execution unit 400 starts the natural antibacterial agent atomizing spray assembly 420, and the metering pump 424 starts, supplying a 0.10% (w / w) concentration of tea polyphenol solution from the antibacterial agent storage tank 421. Liquid is delivered to atomizing nozzle 422 via pipeline 423. Atomizing nozzle 422 atomizes the tea polyphenol solution into droplets of 10μm to 50μm and sprays them into the fermentation chamber 100. The spraying duration is 30 minutes. At the same time, fence strength index calculation unit 310 calculates the fence strength index of each fence factor that is currently active. If the fence strength index after the superposition of the antibacterial contribution of the ultraviolet circulating wind component 410 and the antibacterial contribution of tea polyphenol atomization has reached more than 80% of the safe fence strength threshold, the multi-level response control module 300 can terminate the atomization spray of natural antibacterial agent in advance to avoid excessive addition of antibacterial agent.

[0101] If the detection signal in subsequent sampling cycles shows that the concentration of miscellaneous bacteria continues to rise to 150 CFU / m³, which is greater than or equal to the danger threshold of 100 CFU / m³, then the multi-level response control module 300 determines that the current risk of miscellaneous bacteria contamination is at the outbreak level and outputs a three-level response control command to the barrier factor execution unit 400. After receiving the three-level response control command, the barrier factor execution unit 400 simultaneously performs the following three actions: First, the sealing valve 431 is closed, the fresh air duct 430 is cut off, and the fermentation chamber rotates at 100 rpm. To ensure a fully enclosed circulation system, preventing the continued entry of external airborne bacteria; secondly, the carbon dioxide supply component 440 is activated, introducing carbon dioxide into the fermentation chamber 100 to reduce the oxygen concentration from 21% to 10%-12%, utilizing the low-oxygen environment to inhibit the growth of aerobic bacteria; thirdly, the high-concentration bacterial solution spraying component 450 is activated, spraying the surface of the cured meat products with the dominant fermentation bacterial solution, whose bacterial concentration is 3.0 times that of conventional fermentation bacterial solution, i.e., 3.0 × 10⁻⁶. 8 The CFU / mL concentration suppresses other bacteria through competitive exclusion of dominant bacteria. The Level 3 response continues until the detection signal falls below the warning threshold, at which point the Level 3 response is gradually deactivated, and the system returns to Level 2 or Level 1 response mode.

[0102] Step S4: Throughout the fermentation process, the fermentation stage adaptive unit 320 dynamically adjusts the values ​​of the three-level thresholds according to the current fermentation stage. In the early stage of fermentation, within 0 to 12 hours after fermentation starts, the warning threshold is lowered from 50 CFU / m³ to 5 CFU / m³, so that the device can start responding when the concentration of miscellaneous bacteria is low, thus achieving early prevention. In the middle and late stages of fermentation, after 12 hours of fermentation starts, the warning threshold is adjusted from 50 CFU / m³ to 20 CFU / m³, avoiding excessively frequent interventions that may affect the normal fermentation process, thus achieving relaxation in the later stage.

[0103] Step S5: Repeat steps S2 to S4 until fermentation is complete.

[0104] Example 3: This example uses the collaborative control logic of the fence strength index calculation unit 310 as an example, combined with the attached... Figure 1 To be continued Figure 9 Detailed workflow description:

[0105] Steps S1 to S3 are the same as in Example 2.

[0106] Step S4: When the multi-level response control module 300 outputs the secondary response control command, the fence strength index calculation unit 310 starts the calculation. The fence strength index calculation unit 310 obtains the control action information of each fence factor execution unit 400 that is currently in effect. For example, if the ultraviolet circulating wind component 410 is currently running in the primary response mode, the ultraviolet power is 30W, the antibacterial contribution coefficient is experimentally determined to be 35%, and the temperature in the fermentation chamber 100 has been adjusted to a process range that is conducive to inhibiting miscellaneous bacteria by the temperature regulation component, and the antibacterial contribution coefficient is 15%, then the current fence strength index = 35% + 15% = 50%. This value is less than the preset safety fence strength threshold of 80%. Therefore, the multi-level response control module 300 allows the activation of the natural antibacterial agent atomizing spray component 420 to supplement the antibacterial effect of the chemical fence.

[0107] If the UV circulation air component 410 is currently running with an antibacterial contribution coefficient of 35%, the temperature has been adjusted with an antibacterial contribution coefficient of 15%, and the high-concentration bacterial liquid spray component 450 is running in the third-level response mode with an experimentally determined antibacterial contribution coefficient of 40%, then the current fence strength index = 35% + 15% + 40% = 90%. This value has reached the safe fence strength threshold of 80%. At this time, even if the multi-level response control module 300 outputs a second-level response control command, the fence strength index calculation unit 310 will send an inhibition signal to the multi-level response control module 300. The multi-level response control module 300 will inhibit the start-up of the natural antibacterial agent atomizing spray component 420 according to the inhibition signal, so as to avoid the excessive intervention of the chemical fence from having an adverse effect on the product flavor.

[0108] Step S5: Repeat the above steps until fermentation is complete.

[0109] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A microbial fermentation device for low-salt cured meat products, characterized in that, include: Fermentation chamber (100) is used to contain cured meat products to be fermented; An air microbial sampler (200) is installed in the fermentation chamber (100) to collect air samples in the fermentation chamber (100) and output a detection signal characterizing the risk of contamination by miscellaneous bacteria; A multi-level response control module (300) is connected to the air microbial sampler (200) for receiving the detection signal and outputting a corresponding fence control command based on the comparison result of the detection signal with at least two preset levels of contaminant risk thresholds. The fence factor execution unit (400) is controlled and connected to the multi-level response control module (300), and is used to receive the fence regulation command and execute the corresponding fence regulation action. The fence regulation action includes at least one of physical fence regulation, chemical fence regulation and biological fence regulation.

2. The microbial fermentation device for low-salt cured meat products according to claim 1, characterized in that, The airborne microbial sampler (200) includes: The sampling pipeline (210) extends into the fermentation chamber (100) at one end and is connected to a vacuum pump (220) at the other end. A rapid detection culture medium carrier (230) is disposed on the sampling pipeline (210) and is used to carry the rapid detection culture medium to capture microorganisms in the air; An image acquisition module (240) is disposed at the rapid detection culture medium carrier (230) and is used to periodically acquire colony images on the rapid detection culture medium; The image analysis module (250) is connected to the image acquisition module (240) by signal, and is used to perform image recognition processing on the colony image, count the number of colonies and identify the colony morphology to generate the detection signal.

3. The microbial fermentation device for low-salt cured meat products according to claim 1, characterized in that, The fence control commands include control commands to maintain normal fermentation, first-level response control commands, second-level response control commands, and third-level response control commands; The fence factor execution unit (400) includes an ultraviolet circulation air assembly (410), which is disposed on the inner wall of the fermentation chamber (100) and is used to increase the ultraviolet power to a preset power level when the first-level response control command is received, and to run continuously for a preset time.

4. The microbial fermentation device for low-salt cured meat products according to claim 3, characterized in that, The fence factor execution unit (400) further includes a natural antibacterial agent atomizing spray assembly (420), which includes: An antibacterial agent storage tank (421) is located outside the fermentation chamber (100); Atomizing nozzle (422) is located at the top of the inside of the fermentation chamber (100) and is connected to the antibacterial agent storage tank (421) through a liquid supply pipeline (423); A metering pump (424) is installed on the liquid supply pipeline (423) and is used to atomize and spray the natural antibacterial agent solution in the antibacterial agent storage tank (421) into the fermentation chamber (100) through the atomizing nozzle (422) when the secondary response control command is received.

5. The microbial fermentation device for low-salt cured meat products according to claim 4, characterized in that, The natural antibacterial agent solution is a tea polyphenol solution or a nisin solution with a mass percentage concentration within a preset range.

6. The microbial fermentation device for low-salt cured meat products according to claim 4, characterized in that, The fence factor execution unit (400) further includes: The fresh air duct (430) is connected to the fermentation chamber (100) and is used to introduce fresh air into the fermentation chamber (100); A shut-off valve (431) is installed on the fresh air duct (430) to shut off the fresh air duct (430) when the three-level response control command is received. A carbon dioxide supply assembly (440) is connected to the fermentation chamber (100) and is used to introduce carbon dioxide into the fermentation chamber (100) when the three-level response control command is received, thereby reducing the oxygen concentration in the fermentation chamber (100). A high-concentration bacterial solution spraying component (450) is installed inside the fermentation chamber (100) and is used to spray the dominant fermentation bacterial solution onto the surface of the cured meat product when the three-level response control command is received.

7. The microbial fermentation device for low-salt cured meat products according to claim 6, characterized in that, The multi-level response control module (300) also includes a fence strength index calculation unit (310), which is used to calculate the fence strength index based on the control actions of each currently active fence factor execution unit (400). When the fence strength index reaches the preset safety fence strength threshold, the multi-level response control module (300) suppresses the activation of the natural antibacterial agent atomizing spray component (420).

8. A method for microbial fermentation of low-salt cured meat products, using the microbial fermentation apparatus for low-salt cured meat products as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step S1: Hang the cured meat products to be fermented in the fermentation chamber (100) to start fermentation; Step S2: Periodically collect air samples from the fermentation chamber (100) using an air microbial sampler (200) installed in the fermentation chamber (100), rapidly culture the collected air samples, and obtain detection signals characterizing the risk of contamination by miscellaneous bacteria through image acquisition and recognition; Step S3: The multi-level response control module (300) receives the detection signal and compares the detection signal with at least two preset levels of contamination risk thresholds; Step S4: Based on the comparison results, the multi-level response control module (300) outputs the corresponding fence control command; Step S5: The fence factor execution unit (400) receives the fence regulation instruction and executes the corresponding fence regulation action, wherein the fence regulation action includes at least one of physical fence regulation, chemical fence regulation and biological fence regulation. Step S6: Repeat steps S2 to S5 until fermentation is complete.

9. The microbial fermentation method for low-salt cured meat products according to claim 8, characterized in that, The preset contaminant risk threshold in step S3 includes a safety threshold, a warning threshold, and a danger threshold. The safety threshold is less than the warning threshold, and the warning threshold is less than the danger threshold. In step S4 When the detection signal is less than the safety threshold, the multi-level response control module (300) outputs a control command to maintain normal fermentation; When the detection signal is greater than or equal to the safety threshold and less than the warning threshold, the multi-level response control module (300) outputs a first-level response control command; When the detection signal is greater than or equal to the warning threshold and less than the danger threshold, the multi-level response control module (300) outputs a two-level response control command; When the detection signal is greater than or equal to the danger threshold, the multi-level response control module (300) outputs a three-level response control command.

10. The microbial fermentation method for low-salt cured meat products according to claim 9, characterized in that, The multi-level response control module (300) further includes a fermentation stage adaptive unit (320), which is used to dynamically adjust the values ​​of the safety threshold, warning threshold and danger threshold according to the fermentation stage of the current fermentation process. In the early stage of fermentation, the warning threshold is lowered to a first set value; in the middle and late stages of fermentation, the warning threshold is raised to a second set value, wherein the first set value is less than the second set value.

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