A method for preventing mold growth on bamboo products

Abstract

This invention discloses a method for preventing mold growth on bamboo products, comprising the following steps: S1, pretreatment of bamboo units: for bamboo strips, hot water soaking combined with steam treatment; for flattened bamboo boards, layering treatment; S2, impregnation treatment with anti-mold agent: the bamboo units treated in S1 are immersed in a composite system containing carvacrol and laccase, so that the anti-mold agent is loaded into the bamboo; S3, preparation of bamboo tableware: the bamboo units treated in S2 are processed into shapes to obtain bamboo tableware products. This invention combines "wet heat pretreatment" with "high-efficiency fixation of plant-derived anti-mold agent" technology to achieve green and long-lasting anti-mold treatment of bamboo.

Description

Technical Field

[0001] This invention relates to the field of bamboo processing technology, specifically to a method for preventing mold growth on bamboo products. Background Technology

[0002] Against the backdrop of increasingly severe global plastic pollution, the large-scale production and inefficient disposal of plastic products have become prominent threats to the ecological environment. Bamboo, with its high toughness, ease of processing, and complete biodegradability, is an ideal plastic substitute. In recent years, disposable tableware such as bamboo knives, forks, spoons, and straws has become increasingly popular with consumers. However, because bamboo is rich in nutrients such as starch, protein, and sugars, these tableware items are prone to mold growth during storage and transportation, especially during export by sea. Existing mature anti-mold technologies mainly target industrial products such as furniture and building materials. The anti-mold agents used in these products generally have high toxicity, are difficult to degrade, and can easily harm human health, making them unsuitable for bamboo food products that come into direct contact with the human body. To overcome the shortcomings of anti-mold agents used in industrial products, new environmentally friendly, efficient, and low-toxic bamboo anti-mold agents have become the research and development direction, mainly including nano-metal anti-mold agents and plant-derived extract anti-mold agents.

[0003] Nanomaterials, due to their strong bactericidal properties, low toxicity, and good stability, exhibit excellent anti-mold effects against common mold-causing fungi on bamboo. However, nanomaterial anti-mold agents rely solely on electrostatic adsorption, resulting in poor mechanical stability and easy loss and migration within bamboo, posing potential biosafety risks and environmental hazards. Natural plant-derived anti-mold agents, with their wide availability, good biocompatibility, and non-toxicity, have become an ideal alternative to traditional chemical anti-mold agents. Carvacrol, a natural phenolic compound widely used in food preservation and flavoring, shows significant inhibitory effects against common bamboo molds such as Aspergillus niger and Penicillium citrinum. However, carvacrol is highly volatile and has weak interfacial bonding with bamboo, making it prone to loss during use and cleaning, thus hindering long-term anti-mold efficacy. Furthermore, natural plant-derived anti-mold agents typically require a large loading to achieve optimal anti-mold effects, leading to higher processing costs. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] Therefore, the purpose of this invention is to provide a method for preventing mold growth on bamboo products, so as to improve the mold resistance of bamboo tableware.

[0006] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0007] A method for preventing mold growth on bamboo products, comprising the following steps:

[0008] S1. Bamboo unit pretreatment: For bamboo strips, hot water soaking combined with steaming is used; for flattened bamboo boards, layered treatment is carried out.

[0009] S2, Anti-mold agent impregnation treatment: The bamboo unit treated with S1 is impregnated into a composite system containing carvacrol and laccase, so that the anti-mold agent is loaded into the bamboo.

[0010] S3. Bamboo tableware preparation: The bamboo units treated in S2 are processed and shaped to obtain bamboo tableware products.

[0011] As a preferred embodiment of the anti-mildew treatment method for bamboo products described in this invention, step S1 specifically includes the following pretreatment of bamboo strips: soaking the bamboo strips in hot water at 60-80℃ for 1-3 hours to partially dissolve the nutrients inside the bamboo, and then transferring them to a pressure tank and steaming them with saturated steam at 120-160℃ for 0.5-2 hours to degrade some of the nutrients.

[0012] As a preferred embodiment of the anti-mildew treatment method for bamboo products described in this invention, step S1 specifically includes the following pretreatment for flattened bamboo boards: after the bamboo is softened and flattened and the temperature is not lower than 80°C, it is cut into 2-4 layers along the thickness direction to obtain thin flattened bamboo with a thickness of 1.0-3.0 mm.

[0013] As a preferred embodiment of the anti-mildew treatment method for bamboo products according to the present invention, in step S2, the anti-mildew agent impregnation treatment adopts a two-step method, specifically including: first, immersing the bamboo unit pretreated in step S1 into a carvacrol solution, draining the residual solution on the surface after impregnation, and then vacuum drying to a moisture content of 6-10%;

[0014] The bamboo units that have been impregnated with carvacrol are then immersed in laccase solution for a second impregnation. After impregnation, the residual solution on the surface is drained, and the bamboo is vacuum dried again until the moisture content is 6-8%.

[0015] In a preferred embodiment of the anti-mildew treatment method for bamboo products according to the present invention, the concentration of the carvacrol solution is 7.5-17.5 mg / mL, and the concentration of the laccase solution is 0.3-0.7 mol / L.

[0016] As a preferred embodiment of the anti-mildew treatment method for bamboo products described in this invention, in step S2, the anti-mildew agent impregnation treatment adopts a one-step method, that is, carvacrol and laccase are premixed evenly in a certain proportion, and then the bamboo unit pretreated in step S1 is placed in a pressure tank and impregnated by vacuum pressure method.

[0017] As a preferred embodiment of the anti-mildew treatment method for bamboo products according to the present invention, the vacuum pressure impregnation pressure is 0.2-0.6 MPa and the impregnation time is 2-4 h.

[0018] In a preferred embodiment of the anti-mildew treatment method for bamboo products described in this invention, the vacuum drying temperature is 30-50℃.

[0019] As a preferred embodiment of the anti-mildew treatment method for bamboo products according to the present invention, the specific steps of step S3 are as follows: the bamboo strip unit obtained in S2 is planed and layered to prepare thin bamboo strips;

[0020] Bamboo tableware products are made by milling, molding, and shaping thin bamboo strips or thin, flattened bamboo that has already been layered.

[0021] Compared with existing technologies, the advantages of this invention are as follows: This invention combines "moist heat pretreatment" with "high-efficiency fixation of plant-derived antifungal agents" technology to achieve green and long-lasting antifungal properties for bamboo. On the one hand, moist heat treatment degrades and dissolves organic substances such as starch, sugars, and proteins in bamboo, reducing the nutrient source for mold. On the other hand, through the catalysis of carvacrol by *Rubus lacquers*, carvacrol binds tightly to bamboo components, improving the antifungal agent's resistance to leaching and achieving long-lasting antifungal properties. Simultaneously, the synergistic effect of "moist heat pretreatment" and "high-efficiency fixation of plant-derived antifungal agents" reduces the amount of antifungal agent used, saving costs. This invention has a simple process, good compatibility with existing production processes, low cost, simple equipment, and is easy to industrialize, possessing broad application prospects. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. 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. Wherein:

[0023] Figure 1 These are comparative images showing the Penicillium citrinum mold growth state of bamboo after 28 days of mold culture under different treatment methods in Example 1 and Comparative Examples 1-2 of the present invention. Figure 1 a is a diagram showing the state of Penicillium citrinum mold growth on untreated bamboo. Figure 1b is a diagram showing the mold growth state of Penicillium citrinum on bamboo treated in Comparative Example 1. Figure 1 c is a diagram showing the mold growth state of Penicillium citrinum on bamboo, as described in Comparative Example 2. Figure 1 d is a diagram showing the mold growth state of Penicillium citrinum on bamboo treated in Example 1;

[0024] Figure 2 These are comparative images showing the green Trichoderma mold growth state of bamboo after 28 days of mold culture under different treatment methods in Example 1 and Comparative Examples 1-2 of the present invention. Figure 1 Image a shows the state of green Trichoderma on untreated bamboo. Figure 1 b shows the state of green Trichoderma mildew on bamboo treated in Comparative Example 1. Figure 1 c is a diagram showing the green mold growth state of bamboo as described in Comparative Example 2. Figure 1 d is a diagram showing the state of green Trichoderma mildew on bamboo treated in Example 1;

[0025] Figure 3 These are comparative images showing the Aspergillus niger mold growth status of bamboo after 28 days of mold culture under different treatment methods in Example 1 and Comparative Examples 1-2 of the present invention. Figure 1 Image a shows the state of Aspergillus niger mold growth on untreated bamboo. Figure 1 b is a diagram showing the mold growth state of Aspergillus niger on bamboo treated in Comparative Example 1. Figure 1 c is a diagram showing the mold growth state of Aspergillus niger on bamboo, as described in Comparative Example 2. Figure 1 d is a diagram showing the mold growth state of bamboo treated with Aspergillus niger in Example 1;

[0026] Figure 4 This is a comparison of the anti-mold effect of bamboo tableware prepared in Example 2 of the present invention and untreated bamboo tableware under long-term storage conditions;

[0027] Figure 5 The bar chart shows the test results of the anti-leakage performance of the antifungal agent in aqueous solution under different pretreatment methods provided by the present invention. Detailed Implementation

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0030] To verify the technical effect of the anti-mildew treatment method for bamboo products of the present invention, the following Examples 1-2 and Comparative Examples 1-2 are provided.

[0031] Example 1

[0032] This embodiment provides a bamboo material that combines hydrothermal-steam pretreatment and antifungal agent impregnation. The preparation steps are as follows:

[0033] S1. Bamboo strip pretreatment: The bamboo tubes are split and planed into regular bamboo strips with a length of 1.5m, a width of 3mm, and a thickness of 6mm; the bamboo strips are soaked in water at a temperature of (63±3)℃ for 3 hours, and then treated under saturated steam at 130℃ for 1.5 hours.

[0034] S2. Antifungal agent impregnation treatment: A two-step method is adopted. The bamboo strips obtained in S1 are first immersed in a 7.5 mg / mL carvacrol solution at a pressure of 0.7 MPa for 2 hours. After impregnation, the residual solution on the surface is blotted off, and the bamboo strips are vacuum dried at 35°C to a moisture content of about 10%. Then, the bamboo strips are immersed in a 0.5 mol / mL laccase solution for a second impregnation treatment at a pressure of 0.7 MPa for 2 hours. After impregnation, the residual solution on the surface is blotted off, and the bamboo strips are vacuum dried at 35°C to a moisture content of about 8%.

[0035] Example 2

[0036] This embodiment provides a method for processing bamboo tableware into finished products after anti-mildew treatment, the steps of which are as follows:

[0037] S1. Bamboo strip pretreatment: The bamboo tubes are split and planed into regular bamboo strips with a length of 1.5m, a width of 3mm, and a thickness of 6mm; the bamboo strips are soaked in water at a temperature of (63±3)℃ for 3 hours, and then treated under saturated steam at 130℃ for 1.5 hours.

[0038] S2, Anti-mildew agent impregnation treatment: The bamboo strips obtained in S1 are first impregnated in a 7.5 mg / mL carvacrol solution at a pressure of 0.7 MPa for 2 hours. After impregnation, the residual solution on the surface is blotted off, and the bamboo strips are vacuum dried at 35°C until the moisture content is about 10%. Then, the bamboo strips are impregnated in a 0.5 mol / mL laccase solution for a second impregnation treatment at a pressure of 0.7 MPa for 2 hours. After impregnation, the residual solution on the surface is blotted off, and the bamboo strips are vacuum dried at 35°C until the moisture content is about 8%.

[0039] S3. Bamboo tableware preparation: The bamboo strip unit obtained in S2 is planed to prepare a thin bamboo strip with a thickness of 2mm. The thin bamboo strip is then milled and cut to produce bamboo knife products.

[0040] Comparative Example 1

[0041] The bamboo material is only boiled, including the following steps:

[0042] S1. Bamboo strip pretreatment: The bamboo tubes are split and planed into regular bamboo strips with a length of 1.5m, a width of 3mm, and a thickness of 6mm; the bamboo strips are soaked in water at a temperature of (63±3)℃ for 3 hours.

[0043] S2. Bamboo strip drying: After pretreatment, the bamboo strips are dried at 50℃ until the moisture content is about 8%.

[0044] Example 2

[0045] The bamboo is treated only by boiling and steaming, including the following steps:

[0046] S1. Bamboo strip pretreatment: The bamboo tubes are split and planed into regular bamboo strips with a length of 1.5m, a width of 3mm, and a thickness of 6mm; the bamboo strips are soaked in water at a temperature of (63±3)℃ for 3 hours, and then treated under saturated steam at 130℃ for 1.5 hours.

[0047] S2. Bamboo strip drying: After pretreatment, the bamboo strips are dried at 50℃ until the moisture content is about 8%.

[0048] The anti-mildew performance of the samples prepared in Comparative Examples 1-2 and Examples 1-2 was tested, and the results are shown in Table 1 below. Figures 1-3 .

[0049]

[0050] As shown in Table 1 and Figures 1-3 As shown, by testing untreated bamboo, comparative examples 1-2, and bamboo obtained in Example 1, the results of mold infection showed that after 28 days, the infection level of the three molds on untreated bamboo reached level 4; the hydrothermal treatment group could delay the mold growth process but had limited anti-mold ability, and after 28 days, the infection values ​​of Penicillium citrinum and Aspergillus niger reached level 4; the combined hydrothermal and steam treatment could inhibit the infection of Penicillium citrinum and Trichoderma viride, but the inhibitory effect on Aspergillus niger was average; while the anti-mold effect was optimal after hydrothermal-steam pretreatment combined with carvacrol-laccase treatment; after 28 days, the Penicillium citrinum (PC) group only showed a very small amount of light white mold spots on the edge of the bamboo block, and the main texture and structure remained intact, with no large-area mold growth; the Trichoderma viride group showed no obvious mold spots throughout the process, and only a small amount of hyphae appeared on the surface of the culture medium; the Aspergillus niger group maintained a uniform color and intact structure throughout, with no mold layer coverage or structural damage, and only slight color changes.

[0051] Furthermore, the disposable bamboo products prepared in Example 2 and untreated disposable bamboo products were placed in an environment of 25°C and 70±5% humidity, simulating a relatively humid indoor environment such as a bathroom, to observe their antibacterial and antifungal properties over a long period. Figure 4As shown, by 90 days, a large area of ​​dense mold layer had formed on the serrated edge and central texture area of ​​the untreated bamboo knife blade, with mold spots ranging from dark gray to dark brown, and mycelium intertwined and covering it. In Example 2, the mold growth process of the bamboo was significantly slowed down. At 90 days, only a few scattered light yellowish-brown mold spots appeared on the surface of the knife. By 130 days, the mold spots only slowly expanded in local areas of the knife blade and did not form a continuous coverage. The original color and structural integrity of the bamboo were basically maintained, which met the storage and transportation time requirements of disposable tableware products.

[0052] Meanwhile, the bamboo materials pretreated with different anti-mildew agents from Example 1 and Comparative Examples 1-2 were impregnated in an aqueous solution, and their resistance to leaching was tested. Figure 5 As shown, the loss rate of the antifungal agent was minimal after hydrothermal-steam pretreatment and carvacrol-laccase impregnation treatment, indicating that the pretreatment and laccase played a synergistic fixation role, thereby improving the anti-loss of carvacrol.

[0053] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for preventing mold growth on bamboo products, characterized in that, Includes the following steps: S1. Bamboo unit pretreatment: For bamboo strips, hot water soaking combined with steaming is used; for flattened bamboo boards, layered treatment is carried out. S2, Anti-mold agent impregnation treatment: The bamboo unit treated with S1 is impregnated into a composite system containing carvacrol and laccase, so that the anti-mold agent is loaded into the bamboo. S3. Bamboo tableware preparation: The bamboo units treated in S2 are processed and shaped to obtain bamboo tableware products.

2. The method for preventing mold growth on bamboo products according to claim 1, characterized in that, In step S1, the pretreatment of bamboo strips specifically includes: soaking the bamboo strips in hot water at 60-80℃ for 1-3 hours to partially dissolve the nutrients inside the bamboo, and then transferring them to a pressure tank and steaming them with saturated steam at 120-160℃ for 0.5-2 hours to degrade some of the nutrients.

3. The method for preventing mold growth on bamboo products according to claim 1, characterized in that, In step S1, the pretreatment of the flattened bamboo board specifically includes: after the bamboo is softened and flattened and the temperature is not lower than 80℃, it is cut into 2-4 layers along the thickness direction to obtain thin flattened bamboo with a thickness of 1.0-3.0mm.

4. The method for preventing mold growth on bamboo products according to claim 1, characterized in that, In step S2, the anti-mold agent impregnation treatment adopts a two-step method, specifically including: first, immersing the bamboo unit pretreated in step S1 into a carvacrol solution, draining the residual solution on the surface after impregnation, and then vacuum drying to a moisture content of 6-10%; The bamboo units that have been impregnated with carvacrol are then immersed in laccase solution for a second impregnation. After impregnation, the residual solution on the surface is drained, and the bamboo is vacuum dried again until the moisture content is 6-8%.

5. The method for preventing mold growth on bamboo products according to claim 4, characterized in that, The concentration of the carvacrol solution is 7.5-17.5 mg / mL, and the concentration of the laccase solution is 0.3-0.7 mol / L.

6. The method for preventing mold growth on bamboo products according to claim 1, characterized in that, In step S2, the anti-mold impregnation treatment is carried out in one step, that is, carvacrol and lacquer mold are mixed evenly in a certain proportion beforehand, and then the bamboo unit after the pretreatment in step S1 is placed in a pressure tank and impregnated by vacuum pressure method.

7. A method for preventing mold growth on bamboo products according to claim 4 or 6, characterized in that, The vacuum pressure impregnation pressure is 0.2-0.6 MPa, and the impregnation time is 2-4 hours.

8. The method for preventing mold growth on bamboo products according to claim 4, characterized in that, The vacuum drying temperature is 30-50℃.

9. A method for preventing mold growth on bamboo products according to claim 1, characterized in that, The specific steps of step S3 are as follows: the bamboo strip units obtained in S2 are planed and layered to prepare thin bamboo strips; Bamboo tableware products are made by milling, molding, and shaping thin bamboo strips or thin, flattened bamboo that has already been layered.

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