Preparation of copper-based MOFs loaded nano-copper antibacterial material and application of copper-based MOFs loaded nano-copper antibacterial material in tobacco flavoring essence

Abstract

The invention discloses a preparation method of a copper-based MOFs loaded nano-copper antibacterial material and application of the copper-based MOFs loaded nano-copper antibacterial material in tobacco charging essence, and the preparation method comprises the following steps: ultrasonically dispersing 1, 3, 5-benzenetricarboxylic acid in dimethylformamide to form a solution A; adding CuSO4. 5H2O into deionized water, and dissolving to form a solution B; mixing the solution A and the solution B, centrifugally filtering, and drying to obtain a ketone-based MOFs composite material; the preparation method comprises the following steps: adding CuSO4. 5H2O into deionized water, dissolving, and adding a copper-based MOFs material; the preparation method comprises the following steps: dissolving potassium borohydride, potassium hydroxide and hexadecyl trimethyl ammonium bromide in deionized water to prepare a reducing agent / protective agent mixed solution; after the copper sulfate solution is heated to 40-60 DEG C, a reducing agent / protective agent mixed solution is dropwise added, and when the solution becomes brick red, the PH is adjusted to 1-2 with dilute sulfuric acid; and pouring a sodium hypophosphite solution, stirring, centrifuging, and drying to obtain the copper-based MOFs loaded nano-copper material. The copper-based MOFs loaded nano-copper antibacterial material provided by the invention can be used for carrying out rapid cold sterilization treatment on the flavoring essence, so that the shelf life of the flavoring essence is prolonged, and mildew and deterioration are prevented.

Description

Technical Field

[0001] The invention relates to the technical field of tobacco, and in particular to the preparation of a copper-based MOFs-loaded nano-copper antibacterial material and its application in tobacco flavoring. Background Art

[0002] Flavors and fragrances, as the "soul" of cigarette products, are key factors in determining the style and characteristics of cigarette products. Their quality stability directly affects the quality of cigarette products. Improving the stability of flavors and fragrances products is one of the current research hotspots in the tobacco industry. The main ingredients of tobacco flavors are invert sugar and natural extracts. The proportion of water in the solvent system is high, while the content of organic solvents is low. During the use of flavors and fragrances, different brands of flavors are prone to bubbling and deterioration during the shelf life. Research and analysis show that it is a microbial fermentation process. Flavors and fragrances are heat-sensitive products. Excessive temperature will change the color and flavor of the flavors and fragrances. Therefore, non-heating sterilization technology / low-temperature long-time cold sterilization technology is used to ensure the quality of the product without changing the flavor of the product.

[0003] At present, antibacterial materials are mainly divided into natural antibacterial materials, organic synthetic antibacterial materials and inorganic antibacterial materials according to their chemical composition. Among them, inorganic antibacterial agents have a series of advantages such as broad-spectrum antibacterial, high temperature resistance, and strong durability, and are widely used in various fields such as food and medicine. The bactericidal activity of each metal ion in inorganic antibacterial agents decreases in the following order: Ag>Cu>Cd>Cr>Ni>Pd>Co>Zn>Fe. Compared with silver nanoparticles, copper nanoparticles have higher electrical conductivity and thermal conductivity, and lower cost, and are a good substitute for silver.

[0004] However, due to its small particle size and large specific surface area, CuNPs can easily hinder the dispersion of nanopowders and cause them to agglomerate, which makes it unable to exert good antibacterial activity. Therefore, it is necessary to compound nanocopper with a variety of antibacterial agents and carriers through physical adsorption or chemical grafting to improve its dispersibility. MOFs is a porous crystalline material, a grid-structured crystal formed by the coordination of metal ions or metal clusters with organic ligands, so it is also called a porous coordination polymer. It has a higher specific surface area than perforated materials and a larger pore size than microporous materials, and can carry large molecules.

[0005] Therefore, the present invention aims to address the problem that copper ion nanoparticles tend to spontaneously aggregate into large particles and cannot effectively play their role, thus affecting their antibacterial properties. A MOFs-loaded nano-copper antibacterial material and a preparation method thereof are provided, and the antibacterial material is used to perform rapid and continuous sterilization treatment on added flavors to prevent mildew and deterioration and improve the quality stability of the added flavors. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a preparation method of a copper-based MOFs-loaded nano-copper antibacterial material and its application in tobacco flavorings, and to apply the material to tobacco flavorings for sterilization treatment, which has the characteristics of simple operation, high efficiency, greenness, and reusability, and the quality of the flavorings remains unchanged and stable after treatment.

[0007] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0008] A method for preparing a copper-based MOFs-loaded nano-copper antibacterial material comprises the following steps:

[0009] (1) Preparation of copper-based MOFs materials:

[0010] 11) ultrasonically dispersing 1,3,5-benzenetricarboxylic acid in dimethylformamide to form a solution A;

[0011] 12) Add CuSO4.5H2O to deionized water and stir until completely dissolved to form solution B;

[0012] 13) Solutions A and B are stirred uniformly and then mixed, heated in a water bath with low-speed stirring, the water bath temperature is 80-90°C, and the reaction time is 20-24h;

[0013] 14) centrifugally filtering and washing with 95% ethanol, and vacuum drying to obtain a keto-MOFs composite material;

[0014] (2) Preparation of copper-based MOFs loaded nano-copper materials:

[0015] 21) Add CuSO4·5H2O to deionized water, stir rapidly to dissolve it completely, and add copper-based MOFs material and continue stirring;

[0016] 22) Dissolve a certain amount of potassium borohydride (KBH4), potassium hydroxide, and cetyltrimethylammonium bromide (CTAB) in deionized water to prepare a reducing agent / protecting agent mixed solution;

[0017] 23) While stirring at high speed, after the copper sulfate solution in step 21) is heated to a reaction temperature of 40 to 60° C., the reducing agent / protecting agent mixed solution is slowly dripped into the solution until the solution completely turns brick red, and then the pH of the solution is adjusted to between 1 and 2 using dilute sulfuric acid;

[0018] 24) Then, the sodium hypophosphite solution was quickly poured in, and the mixture was heated and stirred for 30 minutes before stopping. The mixture was centrifuged and washed with 95% ethanol, and then vacuum dried to obtain the copper-based MOFs-loaded nano-copper material.

[0019] Preferably, in the above technical solution, in step (1), the molar ratio of CuSO4.5H2O to 1,3,5-benzenetricarboxylic acid is (1-2):1.

[0020] Preferably, in the above technical solution, in step 21), the mass ratio of the copper-based MOFs material to CuSO4·5H2O is (1-3):1.

[0021] Preferably, in the above technical solution, in step 22), the mass ratio of KBH4, potassium hydroxide and CTAB is 1:1:(2-3).

[0022] Preferably, in the above technical solution, the mass ratio of CuSO4·5H2O to sodium hypophosphite is 1:(2-3).

[0023] A copper-based MOFs-loaded nano-copper antibacterial material is prepared according to the above preparation method.

[0024] A method for sterilizing tobacco flavoring essence by using the copper-based MOFs-loaded nano-copper antibacterial material, comprising the following steps:

[0025] S1. Prepare the added flavor according to the formula requirements of the cigarette flavor and fragrance product, pour the prepared added flavor into the stirring kettle and stir continuously for 30 minutes;

[0026] S2, silver-based MOFs loaded nanosilver materials are filled into a homemade filter box, and the filter box is connected to the discharge pipeline port of the stirring tank;

[0027] S3. After the stirring is completed, open the discharge valve at the bottom of the stirring kettle, add the flavoring agent and pour it into the product packaging barrel through the filter box and seal it for storage.

[0028] An application of the copper-based MOFs-loaded nano-copper antibacterial material in tobacco flavoring.

[0029] The above technical solution of the present invention has the following beneficial effects:

[0030] The present application provides a copper-based MOFs-loaded nano-copper antibacterial material, and uses the antibacterial material to perform rapid cold sterilization treatment on added flavors to extend the shelf life of the added flavors and prevent mildew and deterioration; the material has the characteristics of simple operation, high efficiency, greenness, and reusability, and the quality of the added flavors remains unchanged and stable after treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0032] Figure 1 This is a schematic diagram of the usage status of the copper-based MOFs-loaded nano-copper antibacterial material of the present application.

[0033] Figure 2 Comparison of sterilization effects of the products in the examples. DETAILED DESCRIPTION

[0034] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0035] Unless otherwise specified, the reagents used in this application are all commercially available or obtained through commercial channels, or can be prepared by referring to existing chemical methods.

[0036] Example 1

[0037] A method for preparing a copper-based MOFs-loaded nano-copper antibacterial material comprises the following steps:

[0038] (1) Preparation of copper-based MOFs materials:

[0039] 1,3,5-benzenetricarboxylic acid is ultrasonically dispersed in dimethylformamide to form solution A;

[0040] Add CuSO4.5H2O to deionized water and stir until completely dissolved to form solution B;

[0041] Solutions A and B were stirred evenly and then mixed, heated in a water bath with low-speed stirring, the water bath temperature was 80°C, and the reaction time was 24h;

[0042] The mixture was centrifugally filtered and washed with 95% ethanol, and then vacuum dried to obtain a keto-MOFs composite material;

[0043] Wherein, the molar ratio of CuSO4.5H2O and 1,3,5-benzenetricarboxylic acid is 1:1.

[0044] (2) Preparation of copper-based MOFs loaded nano-copper materials:

[0045] Add CuSO4·5H2O to deionized water, stir quickly to make it completely dissolved, add copper-based MOFs material and continue stirring. The mass ratio of copper-based MOFs material to CuSO4·5H2O is 1:1.

[0046] A certain amount of potassium borohydride (KBH4), potassium hydroxide, and cetyltrimethylammonium bromide (CTAB) are dissolved in deionized water to prepare a reducing agent / protecting agent mixed solution, wherein the mass ratio of potassium borohydride (KBH4), potassium hydroxide, and cetyltrimethylammonium bromide (CTAB) is 1:1:2;

[0047] Under high-speed stirring, after the copper sulfate solution is heated to the reaction temperature of 60°C, the reducing agent / protective agent mixed solution is slowly dripped into it until the solution completely turns brick red. Then, dilute sulfuric acid is used to adjust the pH of the solution to between 1 and 2.

[0048] Then, the sodium hypophosphite solution was quickly poured in, with the mass ratio of CuSO4·5H2O to sodium hypophosphite being 1:2. The mixture was heated and stirred for 30 min and then stopped. The mixture was centrifuged and washed with 95% ethanol, and then vacuum dried to obtain the copper-based MOFs-loaded nano-copper material.

[0049] Among them, the mass ratio of copper-based MOFs material and CuSO4.5H2O is 1:1.

[0050] Sterilization treatment in tobacco flavorings:

[0051] S1. The copper-based MOFs loaded nano-copper material is filled into a homemade filter ball box and the filter ball box is placed at the bottom of the flavoring stirring kettle (such as Figure 1 );

[0052] S2. Prepare the Red Flag Canal (mango) flavoring essence (provided by Henan China Tobacco Zhumadian Cigarette Factory) according to the formula requirements of cigarette flavors and fragrances, and pour the prepared flavoring essence into the stirring kettle and continue stirring for 30 minutes;

[0053] S3. After the stirring is completed, open the discharge valve at the bottom of the stirring kettle, pour the added flavor into the product packaging barrel, and seal it for storage. Take a sample and mark it as added flavor 1#.

[0054] Example 2

[0055] A method for preparing a copper-based MOFs-loaded nano-copper antibacterial material comprises the following steps:

[0056] (1) Preparation of copper-based MOFs materials:

[0057] 1,3,5-benzenetricarboxylic acid is ultrasonically dispersed in dimethylformamide to form solution A;

[0058] Add CuSO4.5H2O to deionized water and stir until completely dissolved to form solution B;

[0059] Solutions A and B were mixed after being stirred evenly, heated in a water bath with low-speed stirring, the water bath temperature was 90°C, and the reaction time was 24h;

[0060] The mixture was centrifugally filtered and washed with 95% ethanol, and then vacuum dried to obtain a keto-MOFs composite material;

[0061] Wherein, the molar ratio of CuSO4.5H2O and 1,3,5-benzenetricarboxylic acid is 2:1.

[0062] (2) Preparation of copper-based MOFs loaded nano-copper materials:

[0063] Add CuSO4.5H2O to deionized water, stir quickly to make it completely dissolved, add copper-based MOFs material and continue stirring, the mass ratio of copper-based MOFs material to CuSO4·5H2O is 2:1;

[0064] A certain amount of potassium borohydride (KBH4), potassium hydroxide, and cetyltrimethylammonium bromide (CTAB) are dissolved in deionized water to prepare a reducing agent / protecting agent mixed solution, wherein the mass ratio of potassium borohydride (KBH4), potassium hydroxide, and cetyltrimethylammonium bromide (CTAB) is 1:1:3;

[0065] Under high-speed stirring, after the copper sulfate solution is heated to the reaction temperature of 50°C, the reducing agent / protective agent mixed solution is slowly dripped into it until the solution completely turns brick red, and then dilute sulfuric acid is used to adjust the pH of the solution to between 1 and 2;

[0066] Then, sodium hypophosphite solution was quickly poured in, with a mass ratio of CuSO4·5H2O to sodium hypophosphite of 1:3. After heating and stirring for 30 min, the mixture was centrifuged and washed with 90% ethanol, and vacuum dried to obtain copper-based MOFs loaded with nano-copper materials.

[0067] The mass ratio of copper-based MOFs material and CuSO4·5H2O is 3:1.

[0068] Sterilization treatment in tobacco flavorings:

[0069] S1. The copper-based MOFs loaded nano-copper material is filled into a homemade filter ball box and the filter ball box is placed at the bottom of the flavoring stirring kettle (such as Figure 1 );

[0070] S2. Prepare the Red Flag Canal (mango) flavoring essence (provided by Henan China Tobacco Zhumadian Cigarette Factory) according to the formula requirements of cigarette flavors and fragrances, and pour the prepared flavoring essence into the stirring kettle and continue stirring for 30 minutes;

[0071] S3. After the stirring is completed, open the discharge valve at the bottom of the stirring kettle, pour the added flavor into the product packaging barrel, and seal it for storage. Take a sample and mark it as added flavor 2#.

[0072] Example 3

[0073] A method for preparing a copper-based MOFs-loaded nano-copper antibacterial material comprises the following steps:

[0074] (1) Preparation of copper-based MOFs materials:

[0075] 1,3,5-benzenetricarboxylic acid is ultrasonically dispersed in dimethylformamide to form solution A;

[0076] Add CuSO4.5H2O to deionized water and stir until completely dissolved to form solution B;

[0077] Solutions A and B were mixed after being stirred evenly, heated in a water bath with low-speed stirring, the water bath temperature was 80°C, and the reaction time was 22h;

[0078] The mixture was centrifugally filtered and washed with 95% ethanol, and then vacuum dried to obtain a keto-MOFs composite material;

[0079] Wherein, the molar ratio of CuSO4.5H2O and 1,3,5-benzenetricarboxylic acid is 2:1.

[0080] (2) Preparation of copper-based MOFs loaded nano-copper materials:

[0081] Add CuSO4·5H2O to deionized water, stir rapidly to dissolve it completely, add copper-based MOFs material and continue stirring, the mass ratio of copper-based MOFs material to CuSO4·5H2O is 2:1;

[0082] Dissolve a certain amount of potassium borohydride (KBH4), potassium hydroxide, and cetyltrimethylammonium bromide (CTAB) in deionized water to prepare a reducing agent / protecting agent mixed solution. Dissolve a certain amount of potassium borohydride (KBH4), potassium hydroxide, and cetyltrimethylammonium bromide (CTAB) in deionized water, wherein the mass ratio of potassium borohydride (KBH4), potassium hydroxide, and cetyltrimethylammonium bromide (CTAB) is 1:1:3;

[0083] Under high-speed stirring, after the copper sulfate solution is heated to the reaction temperature of 60°C, the reducing agent / protective agent mixed solution is slowly dripped into it until the solution completely turns brick red. Then, dilute sulfuric acid is used to adjust the pH of the solution to between 1 and 2.

[0084] Then quickly pour in the sodium hypophosphite solution, the mass ratio of CuSO4·5H2O to sodium hypophosphite is 1:2.5, heat and stir for 30 minutes and then stop, centrifuge and wash with 90% ethanol, and vacuum dry to obtain the copper-based MOFs loaded with nano-copper materials.

[0085] The mass ratio of copper-based MOFs material and CuSO4·5H2O is 3:1.

[0086] Sterilization treatment in tobacco flavorings:

[0087] S1. The copper-based MOFs loaded nano-copper material is filled into a homemade filter ball box and the filter ball box is placed at the bottom of the flavoring stirring kettle (such as Figure 1 );

[0088] S2. Prepare the Red Flag Canal (mango) flavoring essence (provided by Henan China Tobacco Zhumadian Cigarette Factory) according to the formula requirements of cigarette flavors and fragrances, and pour the prepared flavoring essence into the stirring kettle and continue stirring for 30 minutes;

[0089] S3. After the stirring is completed, open the discharge valve at the bottom of the stirring kettle, pour the added flavor into the product packaging barrel, and seal it for storage. Take a sample and mark it as added flavor 3#.

[0090] Of course, the added flavors of the present application may also adopt the flavor and fragrance formula of the heated cigarette formula commonly used in the art, and are not limited to the above-mentioned products. The present application only uses this as an example for experimental description.

[0091] Refer to "GB4789.2-2016 National Food Safety Standard Food Microbiology Test Total Colony Count Determination". Use NA medium to culture bacteria and dilute the sample to 1*10 -1 , take 100uL of each sample gradient to the plate, spread it evenly, and culture it at 37℃ for 72h.

[0092] The results are as follows Figure 2 As shown in the figure: after the nano-copper sterilization treatment, the total number of colonies in the flavors 1#, 2# and 3# decreased significantly, while the total number of colonies in the untreated flavors was higher. This shows that the copper-based MOFs loaded nano-copper antibacterial material can effectively eliminate bacteria in the flavors, extend the shelf life of the flavors, and ensure the stable quality of the flavors.

[0093] Although the present invention has been disclosed as above by the embodiments, it is not intended to limit the present invention. Any person skilled in the art may make various choices and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention is limited by the claims and their equivalents.

Claims

1. A method for preparing a copper-based MOFs-loaded nano-copper antibacterial material, characterized in that: The following steps are involved: (1) Preparation of copper-based MOFs materials: 11) ultrasonically dispersing 1,3,5-benzenetricarboxylic acid in dimethylformamide to form a solution A; 12) Add CuSO4.5H2O to deionized water and stir until completely dissolved to form solution B; 13) Solutions A and B are stirred uniformly and then mixed, heated in a water bath with low-speed stirring, the water bath temperature is 80-90°C, and the reaction time is 20-24h; 14) centrifugally filtering and washing with 95% ethanol, and vacuum drying to obtain a keto-MOFs composite material; (2) Preparation of copper-based MOFs loaded nano-copper materials: 21) Add CuSO4·5H2O to deionized water, stir rapidly to dissolve it completely, and add copper-based MOFs material and continue stirring; 22) Dissolve a certain amount of potassium borohydride (KBH4), potassium hydroxide, and cetyltrimethylammonium bromide (CTAB) in deionized water to prepare a reducing agent / protecting agent mixed solution; 23) While stirring at high speed, after the copper sulfate solution in step 21) is heated to a reaction temperature of 40 to 60° C., the reducing agent / protecting agent mixed solution is slowly dripped into the solution until the solution completely turns brick red, and then the pH of the solution is adjusted to between 1 and 2 using dilute sulfuric acid; 24) Then, the sodium hypophosphite solution was quickly poured in, and the mixture was heated and stirred for 30 minutes before stopping. The mixture was centrifuged and washed with 95% ethanol, and then vacuum dried to obtain the copper-based MOFs-loaded nano-copper material.

2. The method for preparing the copper-based MOFs-loaded nano-copper antibacterial material according to claim 1, characterized in that: In step (1), the molar ratio of CuSO4.5H2O to 1,3,5-benzenetricarboxylic acid is (1-2):

1.

3. The method for preparing the copper-based MOFs-loaded nano-copper antibacterial material according to claim 1, characterized in that: In step 21), the mass ratio of the copper-based MOFs material to CuSO4·5H2O is (1-3):

1.

4. The method for preparing the copper-based MOFs-loaded nano-copper antibacterial material according to claim 1, characterized in that: In step 22), the mass ratio of KBH4, potassium hydroxide and CTAB is 1:1:(2-3).

5. The method for preparing the copper-based MOFs-loaded nano-copper antibacterial material according to claim 1, characterized in that: In step 24), the mass ratio of CuSO4·5H2O to sodium hypophosphite is 1:(2-3).

6. A copper-based MOFs-loaded nano-copper antibacterial material, characterized in that: The copper-based MOFs-loaded nano-copper antibacterial material is prepared according to any one of the preparation methods described in claims 1-5.

7. A method for sterilizing tobacco flavorings using the copper-based MOFs-loaded nano-copper antibacterial material of claim 6, characterized in that: The following steps are involved: S1. Prepare the added flavor according to the formula requirements of the cigarette flavor and fragrance product, pour the prepared added flavor into the stirring kettle and stir continuously for 30 minutes; S2, silver-based MOFs loaded with nanosilver materials are filled into a homemade filter box, and the filter box is connected to the discharge pipeline port of the stirring tank; S3. After the stirring is completed, open the discharge valve at the bottom of the stirring kettle, add the flavoring agent and pour it into the product packaging barrel through the filter box and seal it for storage.

8. Use of the copper-based MOFs-loaded nano-copper antibacterial material according to claim 6 in tobacco flavoring.

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