A mold plate protection device for food detection

Abstract

The utility model provides a kind of mould plate protection device for food detection, it includes sealed bag, the sealed bag has bag mouth and is closed using sealing structure, it is characterized by: the sealed bag also has at least 1 opening, the opening is closed by hydrophobic air-permeable composite film, the hydrophobic air-permeable composite film has several micropores, the periphery edge of opening and the periphery edge of hydrophobic air-permeable composite film are sealed connection.The mould plate protection device for food detection of the utility model, by the hydrophobic waterproof performance and air-permeable performance of hydrophobic air-permeable composite film, on the one hand, can block the pollution of external mould spores to the plate in device, on the other hand, can prevent the spores from sample source in device from overflowing outward, to reduce the risk that mould incubator is polluted by different source mould spores, reduce incubator frequent shutdown sterilization times, while avoid moving plate frequently during cultivation and cause inaccurate result.

Description

Technical Field

[0001] This utility model relates to the field of food testing technology, specifically a mold plate protection device for food testing. Background Technology

[0002] Molds refer to multicellular fungi that produce hyphae and spores. The hyphae elongate, branch, and intertwine to form clumps. The genera of fungi that affect food spoilage are mainly *Aspergillus*, *Penicillium*, and *Fusarium*, with *Aspergillus* and *Penicillium* appearing more frequently in most food categories. Mycotoxins produced by molds such as *Aspergillus*, *Fusarium*, and *Penicillium* can cause toxicity, carcinogenicity, and mutagenicity in humans at low concentrations after acute, short-term, and / or long-term exposure. Therefore, the main food microbiological testing methods for molds in China's national food safety standards are GB4789.15 Mold and Yeast Counting Method and GB4789.16 Morphological Examination of Common Toxin-Producing Molds, used to identify and ensure food safety and quality.

[0003] Currently, the mold plate method uses an upright incubation method. The main reason for this is that mold cultures produce a large number of spores, and if the petri dish is inverted, the spores will transfer to the lid. When the dish is turned over, the mold spores on the lid may be released into the air or onto the lab bench, causing serious contamination. Therefore, GB4789.15 and relevant international testing standards all require the upright incubation method.

[0004] However, contamination of mold plates frequently occurs when using the upright culture method. Spores mainly originate from three sources: indoor air conditioning and ventilation systems, the humidifier spray outlet of the mold incubator, and spores generated on the sample plates during the culture process. Common measures to address mold contamination include sterilizing the incubator or sealing the mold spores in the culture with sealing film. However, due to the long mold culture cycle, incubator sterilization presents two main problems: first, the incubator is easily contaminated, requiring frequent shutdowns for sterilization; second, to ensure the stability of culture conditions during the culture process, the plates are usually not moved. When sterilization is initiated, the plates must be moved, which may cause spores to fall and spread, thus affecting the accuracy of mold results (especially plate count results).

[0005] Sealing films, due to their breathability and ability to prevent bacterial contamination, were once used for sealing plates in the purification and identification of molds. However, they are only suitable for small sample sizes. In mold plate counting experiments, each sample needs to be inoculated with two consecutive dilutions, and two plates need to be prepared for each dilution, meaning at least four plates are required for a single sample. When dealing with a large number of plates, manual sealing with sealing films is not only cumbersome but also significantly increases workload and reduces efficiency. Summary of the Invention

[0006] In view of this, and in response to the above-mentioned situation, this utility model proposes a mold plate protection device for food testing to solve the existing problems, ensure the reliability and stability of culture results, and improve work efficiency.

[0007] The objective of this utility model can be achieved through the following technical solutions:

[0008] A mold plate protection device for food testing includes a sealed bag with an opening and a sealing structure for closure. The sealed bag is characterized in that: the sealed bag also has at least one opening, which is closed by a hydrophobic and breathable composite membrane. The hydrophobic and breathable composite membrane has a plurality of micropores, and the four edges of the opening are sealed to the four edges of the hydrophobic and breathable composite membrane.

[0009] Furthermore, a protective sheet is provided on the outer surface of the sealed bag. The protective sheet is located on the outside of the hydrophobic and breathable composite membrane and completely or partially covers the hydrophobic and breathable composite membrane. There is a breathable channel connecting the protective sheet and the hydrophobic and breathable composite membrane to the outside.

[0010] Furthermore, the protective sheet is connected to the outer surface of the sealed bag on both sides, and the top and bottom of the protective sheet have vents respectively. The gap between the protective sheet and the hydrophobic and breathable composite membrane and the two vents form a breathable channel.

[0011] Furthermore, the protective sheet is made of polypropylene.

[0012] In the optimized design, the sealed bag is vertically positioned, with the bag opening located at the top of the sealed bag. The sealed bag has two symmetrical long sides and two symmetrical short sides in its horizontal cross-section. The opening includes two symmetrically arranged openings, each corresponding to one of the two long sides of the horizontal cross-section or one of the two short sides of the horizontal cross-section.

[0013] In the optimized design, the hydrophobic and breathable composite membrane is made of expanded polytetrafluoroethylene (ePTFE).

[0014] In the optimized design, the pore diameter of the micropores in the hydrophobic and breathable composite membrane is less than 3 μm. Further, the pore diameter of the micropores in the hydrophobic and breathable composite membrane is specifically 0.22 μm.

[0015] In the optimized solution, the sealing structure is a sealing clip, which clamps onto the opening of the sealed bag to seal the bag opening.

[0016] This utility model has the following substantial features and advancements:

[0017] 1. The food testing mold plate protection device of this utility model, through the hydrophobic and breathable properties of the hydrophobic and breathable composite membrane, can block the contamination of the plate inside the device by external mold spores on the one hand, and prevent the spores from the sample source inside the device from overflowing outwards on the other hand. This reduces the risk of the mold incubator being contaminated by mold spores from different sources, reduces the number of times the incubator is shut down for disinfection, and avoids inaccurate results caused by frequent movement of the plate during the incubation period.

[0018] 2. The mold plate protection device for food testing of this utility model, through the setting of a hydrophobic and breathable composite membrane, can ensure free air circulation and reduce the rate of moisture evaporation to the external environment, thus avoiding the phenomenon of drying and cracking of the culture medium during long-term cultivation.

[0019] 3. The mold plate protection device for food testing of this utility model can provide a high-throughput channel for the gases produced by the metabolism of microorganisms within the plate, and work in conjunction with the forced airflow of the incubator to promote air circulation. The synergistic effect of the two can maintain the balance of gas exchange within the plate and prevent local gas concentration from affecting the normal growth of microorganisms within the plate.

[0020] 4. The size of the sealing bag of this invention can be designed to perfectly match the requirements of plate stacking, and can hold 10 disposable sterile plastic petri dishes with a diameter of 90mm. The optimal stacking quantity of this device is between 2 and 6, which can meet the sealing requirements of different numbers of petri dishes. In the mold plate counting experiment, stacking and sealing multiple petri dishes of the same sample in this device can avoid cross-contamination between samples and significantly improve work efficiency.

[0021] 5. The mold plate protection device for food testing of this utility model uses materials that can withstand steam sterilization at 121℃ for 30 minutes. Moist heat sterilization before use ensures the sterility of the device. Repeat sterilization is also possible after use, effectively reducing experimental costs. The sealing bag offers flexible and diverse sealing methods, allowing for selection of sealing clips, heat sealing, and other sealing techniques according to actual laboratory conditions. The device, containing the petri dishes, is then placed on a petri dish rack, ensuring adequate spacing between stacked plates without occupying excessive space within the incubator. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the mold plate protection device for food testing in Example 1.

[0023] Figure 2 This is a schematic diagram of the structure of the sealed bag in Example 1.

[0024] Figure 3 This is a schematic diagram of the mold plate protection device for food testing in Example 1.

[0025] Figure 4 This is a schematic diagram of the mold plate protection device for food testing in Example 2.

[0026] Figure 5 This is a schematic diagram of the horizontal cross-section of the mold plate protection device for food testing in Example 2.

[0027] Figure 6 This is a schematic diagram of the horizontal cross-section of the mold plate protection device for food testing in Example 3. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] Example 1

[0030] refer to Figures 1 to 3 A mold plate protection device for food testing includes a sealed bag 1 with a bag opening 11 and a sealing structure for closure. The sealed bag 1 also has at least one opening 12, which is closed by a hydrophobic and breathable composite membrane 2. The hydrophobic and breathable composite membrane 2 has a plurality of micropores, and the four edges of the opening 12 are sealed to the four edges of the hydrophobic and breathable composite membrane 2.

[0031] When using the above structure, please refer to the specific instructions. Figure 3 The mold culture dish 5 is placed inside the sealed bag 1 through the open bag opening 11. Multiple mold culture dishes 5 are stacked sequentially from bottom to top, and then the bag opening 11 is sealed with a sealing structure. The sealed bag 1 is placed in an incubator (not shown in the figure) for cultivation. The hydrophobic and breathable composite membrane 2 has a microporous mesh three-dimensional structure, forming porous channels that allow air to pass freely while blocking mold spores. The entire sealed bag 1 acts as a protective system, isolating the mold culture dish 5 from the external environment, forming an independent micro-cultivation environment. This effectively avoids the risk of contamination, reduces air circulation, and also slows down the rate of water evaporation, mitigating the drying and cracking of the culture medium caused by prolonged cultivation.

[0032] In this embodiment, the sealed bag 1 is specifically arranged vertically, the bag opening 11 is located at the top of the sealed bag 1, the sealed bag 1 has two symmetrical long sides 111 and two symmetrical short sides 112 in the horizontal cross-section, and the opening 12 includes two symmetrically arranged openings, with the two openings 12 respectively corresponding to the two long sides 111 of the horizontal cross-section.

[0033] In the above structure, the sealed bag 1 has an opening 11 at the top, which allows the sealed bag 1 to be fully opened from the top, facilitating the access and observation of the culture dish 5 inside. The opening 12 is located on the long side 111 of the horizontal cross-section, thereby ensuring that the hydrophobic and breathable composite membrane 2 has a large breathable area and ensuring the breathability of the sealed bag 1.

[0034] In this embodiment, the sealing bag 1 is a polypropylene (PP) bag made of polypropylene (PP) material, and the hydrophobic and breathable composite membrane 2 is an expanded polytetrafluoroethylene (e-PTFE) composite membrane made of expanded polytetrafluoroethylene. Both the e-PTFE composite membrane and the polypropylene (PP) bag have high-temperature and high-pressure sterilization resistance, ensuring the sterility of the device after moist heat sterilization before use. The polypropylene (PP) bag serves as the basic container for loading the mold culture dishes 5, and can hold 10 sterile plastic culture dishes with a diameter of 90 mm, meeting the requirements for batch protection of mold plates in food testing.

[0035] In this embodiment, the hydrophobic and breathable composite membrane 2 is firmly fixed to the front and back of the sealing bag 1 using adhesive, ultrasonic waves, or heat fusion. The hydrophobic and breathable composite membrane 2 is positioned as close as possible to the top and bottom of the sealing bag 1 to ensure that it can cover multiple mold culture dishes 5. This ensures that the mold culture dishes 5 stacked at different heights inside the sealing bag 1 have good air permeability and hydrophobicity without affecting the containment and protection function of the mold culture dishes 5.

[0036] In this embodiment, the pore diameter of the hydrophobic and breathable composite membrane 2 is less than 3 μm. Specifically, the pore diameter of the micropores used in this embodiment is 0.22 μm, which can effectively block mold spores with a diameter of 3 to 20 μm from entering and exiting the sealed bag 1.

[0037] In this embodiment, the sealing structure specifically adopts a sealing clip 4, which clamps onto the opening 11 of the sealed bag 1 to seal the opening 11. The structure of the sealing clip 4 facilitates the opening and closing of the bag opening 11.

[0038] Example 2

[0039] refer to Figure 4 and Figure 5 The difference between the mold plate protection device for food testing in this embodiment and that in embodiment 1 is that a protective sheet 3 is also provided on the outer surface of the sealed bag 1. The protective sheet 3 is located on the outside of the hydrophobic and breathable composite membrane 2 and completely covers the hydrophobic and breathable composite membrane 2. There is a breathable channel 10 between the protective sheet 3 and the hydrophobic and breathable composite membrane 2 that connects to the outside.

[0040] In the above structure, the protective sheet 3 is made of polypropylene (PP) material, which covers the outside of the hydrophobic and breathable composite membrane 2 and protects the hydrophobic and breathable composite membrane 2, preventing wear on the outer surface of the hydrophobic and breathable composite membrane 2 after prolonged use. It also ensures air connectivity between the internal space of the sealed bag 1, the micropores of the hydrophobic and breathable composite membrane 2, the air passage 10, and the external environment.

[0041] Furthermore, the protective sheet 3 is connected to the outer surface of the sealing bag 1 on both sides. Specifically, the front and back of the sealing bag 1 are firmly connected to the left and right ends of the protective sheet 3 by means of glue, ultrasonic waves, or heat fusion. The top and bottom ends of the protective sheet 3 are not connected to the sealing bag 1, forming vents 30 respectively. The gap between the protective sheet 3 and the hydrophobic and breathable composite membrane 2 and the two vents 30 form a breathable channel 10.

[0042] Example 3

[0043] refer to Figure 6 The difference between the mold plate protection device for food testing in this embodiment and that in embodiment 2 is that the two openings 12 in this embodiment are respectively located on the two short sides 112 of the horizontal cross-section. The advantage of placing the openings 12 on the short sides 112 in this embodiment is that the hydrophobic and breathable composite membrane 2 is located on the short sides 112. This prevents the mold culture dish 5 inside the sealed bag 1 from contacting the hydrophobic and breathable composite membrane 2 from the inside, thus avoiding wear on the membrane and ensuring the hydrophobic and breathable effect.

Claims

1. A mold plate protection device for food testing, comprising a sealed bag (1), the sealed bag (1) having a bag opening (11) and being sealed by a sealing structure, characterized in that: The sealed bag (1) also has at least one opening (12), which is closed by a hydrophobic and breathable composite membrane (2). The hydrophobic and breathable composite membrane (2) has a plurality of micropores, and the four edges of the opening (12) are sealed to the four edges of the hydrophobic and breathable composite membrane (2).

2. The mold plate protection device for food testing according to claim 1, characterized in that: The outer surface of the sealed bag (1) is also provided with a protective sheet (3). The protective sheet (3) is located on the outside of the hydrophobic and breathable composite membrane (2) and covers all or part of the hydrophobic and breathable composite membrane (2). There is a breathable channel (10) between the protective sheet (3) and the hydrophobic and breathable composite membrane (2) to connect with the outside.

3. The mold plate protection device for food testing according to claim 2, characterized in that: The protective sheet (3) is connected to the outer surface of the sealed bag (1) on both sides. The top and bottom of the protective sheet (3) have vents (30) respectively. The gap between the protective sheet (3) and the hydrophobic and breathable composite membrane (2) and the two vents (30) form a breathable channel (10).

4. A mold plate protection device for food testing according to claim 2 or 3, characterized in that: The protective sheet (3) is made of polypropylene.

5. A mold plate protection device for food testing according to claim 1, 2, or 3, characterized in that: The sealed bag (1) is arranged vertically, and the bag opening (11) is located at the top of the sealed bag (1). The sealed bag (1) has two symmetrical long sides (111) and two symmetrical short sides (112) in a horizontal cross-section. The opening (12) includes two symmetrically arranged openings, which are respectively located on the two long sides (111) of the horizontal cross-section or respectively located on the two short sides (112) of the horizontal cross-section.

6. A mold plate protection device for food testing according to claim 1, 2, or 3, characterized in that: The hydrophobic and breathable composite membrane (2) is made of expanded polytetrafluoroethylene.

7. A mold plate protection device for food testing according to claim 1, 2, or 3, characterized in that: The pore diameter of the micropores in the hydrophobic and breathable composite membrane (2) is less than 3 μm.

8. The mold plate protection device for food testing according to claim 7, characterized in that: The pore diameter of the hydrophobic and breathable composite membrane (2) is 0.22 μm.

9. A mold plate protection device for food testing according to claim 1, 2, or 3, characterized in that: The sealing structure is a sealing clip (4), which clamps onto the opening (11) of the sealed bag (1) to seal the opening (11).

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