Tobacco endogenous biomass-based material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of tobaccos, and discloses a preparation method of a tobacco endogenous biomass-based material, which comprises the following steps: S1, carrying out dipping treatment and solid-liquid separation on a tobacco waste raw material, then carrying out defibering, and then carrying out alkali pretreatment and alkali liquor cooking treatment to obtain tobacco slurry; s2, bleaching and decolorizing the tobacco pulp to obtain bleached tobacco pulp; s3, carrying out enzyme treatment on the bleached tobacco pulp; s4, the tobacco pulp obtained after enzyme treatment is subjected to pulp grinding and high-pressure homogenization treatment, and the tobacco endogenous biomass-based material is obtained. The invention further discloses the tobacco endogenous biomass-based material and application thereof.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco, and in particular relates to a tobacco endogenous biomass-based material, a preparation method and use thereof. Background Art

[0002] In the context of the dual carbon goals and resource shortages, tobacco stems and broken tobacco leaves are important agricultural wastes in the tobacco industry. Using them as raw materials to prepare tobacco endogenous biomass-based materials is of great significance for the efficient utilization of waste tobacco resources and environmental protection. Since tobacco and broken tobacco leaves have similar chemical compositions to other lignocellulose resources, waste tobacco resources can also be used as one of the sources for preparing new biomass-based materials (nanocellulose).

[0003] There are usually chemical, mechanical and biological methods for preparing nanocellulose materials using lignocellulose resources. The chemical method usually refers to the acid hydrolysis method, which has a low yield and causes certain pollution to the environment, limiting its industrial application; the single mechanical method has the disadvantage of high energy consumption and is difficult to industrialize; the single biological enzyme method has a long treatment time, which is not conducive to rapid production. Therefore, the combination of biological enzyme treatment and mechanical method can reduce energy consumption, has good development prospects, and is a green, environmentally friendly and efficient method for preparing biomass-based materials. In addition, since components such as lignin and hemicellulose are wrapped on the surface of cellulose to form a natural barrier, it is difficult for biological enzymes to act on the glycosidic bonds of cellulose, so it needs to be delignified.

[0004] The present invention is proposed for this purpose. Summary of the invention

[0005] In order to improve the efficiency of biological enzymes and improve the efficient utilization rate of waste tobacco resources, the preparation method of the present invention performs pre-impregnation, alkali pretreatment, alkaline cooking, bleaching, enzyme pretreatment, mechanical treatment and other processes on the waste tobacco raw materials, further improving the preparation efficiency of tobacco endogenous biomass-based materials. The tobacco endogenous biomass-based materials obtained by the present invention have a diameter of less than 100nm and a length range of 500nm-several microns, have a high specific surface area and good biocompatibility, can be used for the development of tobacco endogenous biomass-based related materials, and can meet the needs of high-value utilization of waste tobacco resources.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The first aspect of the present invention discloses a method for preparing a tobacco endogenous biomass-based material, comprising the following steps:

[0008] S1, impregnating the tobacco waste raw material, performing decomposition after solid-liquid separation, and then performing alkali pretreatment and alkali solution cooking to obtain tobacco slurry;

[0009] S2, taking the above tobacco pulp and performing bleaching and decolorization treatment to obtain bleached tobacco pulp;

[0010] S3, subjecting the bleached tobacco pulp to enzyme treatment;

[0011] S4. The tobacco slurry obtained after the enzyme treatment is subjected to pulping and high-pressure homogenization treatment to obtain the tobacco endogenous biomass-based material.

[0012] Preferably, in step S1, the impregnation conditions are: solid-liquid ratio of 1: (1-6), temperature of 50°C-100°C, pH value of 5-7, and impregnation time of 1h-4h; the impregnated tobacco fibers are deflaked, and the speed of the deflaker is not less than 10000rpm to destroy its structure and squeeze out the black liquor.

[0013] Preferably, in step S1, the alkali pretreatment conditions are: the amount of NaOH in the alkali solution is 1-6wt% of the absolute dry tobacco pulp, the temperature is 80°C-100°C, the solid-liquid ratio is 1:(1-10) (g / mL), and the treatment time is 20min-60min.

[0014] Preferably, in step S1, the alkali cooking conditions are: the amount of NaOH added to the alkali solution is 1-4wt% of the absolute dry tobacco pulp, the temperature is 100°C-155°C, the solid-liquid ratio is 1:(1-5) (g / mL), and the alkali cooking time is 20min-60min.

[0015] Preferably, in step S2, the bleaching and decolorizing treatment of tobacco pulp comprises the following steps: (1) oxygen delignification bleaching: the tobacco pulp concentration is 10%, the amount of alkali is 2-5wt% of the absolute dry tobacco pulp (i.e., the water-free tobacco raw material initially added), the amount of magnesium sulfate is 0.5wt% of the absolute dry tobacco pulp, the oxygen pressure is 0.7MPa, the temperature is 80℃-100℃, and the time is 20min-60min; (2) hydrogen peroxide bleaching: the tobacco pulp concentration is 10%, H 2 O 2 The dosage is 1-3wt% of the absolute dry tobacco pulp, the dosage of magnesium sulfate is 0.1wt% of the absolute dry tobacco pulp, the dosage of sodium silicate is 3% of the absolute dry tobacco pulp, the dosage of diethylenetriaminepentaacetic acid (DTPA) is 0.3wt% of the absolute dry tobacco pulp, the pH value is 11, the temperature is 70℃-90℃, and the time is 20min-60min; (3) Chlorine dioxide bleaching: the tobacco pulp concentration is 10%, ClO 2 The dosage is 1-5wt% of the absolute dry tobacco pulp, the temperature is 50°C-70°C, and the time is 20min-60min.

[0016] Preferably, in step S3, the enzyme treatment conditions are: cellulase dosage 100U / g-1000U / g, pH value 6.0-8.0, temperature 40℃-60℃, tobacco pulp concentration 5wt%, treatment time 1h-3h; adding the tobacco slurry obtained after enzyme treatment into boiling water to inactivate the enzyme, separating and washing; such as centrifuging to remove the supernatant and adding deionized water to thoroughly wash to remove the residual enzyme solution.

[0017] Preferably, in step S4, PFI refining is used; in the high-pressure homogenization treatment, the slurry concentration is (0.1-0.15) wt%, and the treatment steps are: first stabilize the slurry suspension under a relatively low pressure such as 500 bar, and then pressurize it to 1000 bar; collect samples after 30 cycles to obtain the tobacco endogenous biomass-based material; and store it at 4°C for future use.

[0018] The second aspect of the present invention discloses a tobacco endogenous biomass-based material obtained by the preparation method, which has a diameter of less than 100nm, a length of 500nm-10μm, and a specific surface area of ​​not less than 230m 2 / g; its cytotoxicity was determined by MTT method, and the cell survival rate was not less than 80%; the Zeta potential was -20~-40mV.

[0019] The third aspect of the present invention discloses the use of the tobacco endogenous biomass-based material for preparing tobacco materials, such as for preparing tobacco microcapsules, flavor-retaining cigarette papers, flavor-retaining granular materials, etc.; it can also be directly added to tobacco leaves / tobacco shreds to improve their aroma sustained-release effect, while having a moisturizing effect; it can also be used as a tobacco additive to improve the aroma sustained-release ability of flavors and fragrances; if applied to cigarette products, it can prolong the persistence of cigarette aroma and improve the fullness and moisturizing characteristics of cigarette aroma.

[0020] Beneficial effects of the present invention:

[0021] The method of the present invention uses tobacco waste as raw material, and obtains tobacco endogenous biomass-based materials by steaming, bleaching, bio-enzyme treatment and mechanical treatment. The method of the present invention has the characteristics of being green, environmentally friendly, high yield, and environmentally friendly, and can reduce energy consumption. The tobacco endogenous biomass-based materials obtained by the method of the present invention have a diameter of less than 100nm and a length of 500nm-10μm; and a specific surface area of ​​not less than 230m 2 / g; its cytotoxicity was determined by MTT method, and the cell survival rate was not less than 80%; the Zeta potential was -20~-40mV. It has a high specific surface area, good biocompatibility and stability. It can be used in the development of tobacco endogenous biomass-based related materials, such as the preparation of tobacco microcapsules, flavor-preserving cigarette papers, and flavor-preserving granular materials, and can meet the needs of high-value utilization of waste tobacco resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 1 is the particle size distribution of the tobacco endogenous biomass-based material of the present invention (a: Example 1; b: Example 2).

[0023] Figure 2 This is the infrared analysis of the tobacco endogenous biomass-based material of the present invention.

[0024] Figure 3 SEM analysis of materials obtained in the examples and comparative examples (a: Example 1; b: Example 2; c: Example 3; d: Example 4; e: Comparative Example 1; f: Comparative Example 2).

[0025] Figure 4 Physical pictures of tobacco endogenous biomass-based materials obtained in Example 1 and Example 2.

[0026] Figure 5 This is a picture of dead cells and living cells observed under a confocal laser microscope (CLSM) of cells treated with tobacco endogenous biomass-based materials obtained in Example 3. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below in conjunction with specific embodiments, but is not limited thereto.

[0028] Example 1: Preparation of tobacco endogenous biomass-based materials, the steps are:

[0029] (1) The tobacco raw material is first impregnated, and the solid-liquid ratio in the impregnation conditions is 1:6, the temperature is 100°C, the pH is 6, and the treatment time is 4 hours. The extracted tobacco fiber is placed in a deflaker at a speed of 10,000 rpm to destroy its structure and squeeze out the black liquor. After solid-liquid separation, the tobacco slurry is prepared by alkali pretreatment and alkali cooking. Among them, the alkali pretreatment conditions are: the addition amount of NaOH is 6wt% (equivalent to absolute dry tobacco slurry), the temperature is 100°C, the solid-liquid ratio is 1:5 (g / mL), and the treatment time is 60 minutes. The alkali cooking conditions are: the addition amount of NaOH is 2wt% (equivalent to absolute dry tobacco slurry), the temperature is 155°C, the solid-liquid ratio is 1:3 (g / mL), and the treatment time is 60 minutes.

[0030] (2) The above tobacco pulp is subjected to bleaching and decolorization treatment to obtain bleached tobacco pulp. Oxygen delignification bleaching: the tobacco pulp concentration is 10wt%, the alkali amount is 5wt% (equivalent to absolute dry tobacco pulp), the magnesium sulfate amount is 0.5wt%, the oxygen pressure is 0.7MPa, the temperature is 100°C, and the time is 60min. Hydrogen peroxide bleaching: the tobacco pulp concentration is 10wt%, H 2 O 2The dosage is 2wt% (equivalent to absolute dry tobacco pulp), the dosage of magnesium sulfate is 0.1wt%, the dosage of sodium silicate is 3wt%, the dosage of DTPA is 0.3%, the pH is 11, the temperature is 80℃, and the time is 60min. Chlorine dioxide bleaching: ClO 2 The dosage is 5wt% (equivalent to absolute dry tobacco pulp), the tobacco pulp concentration is 10wt%, the temperature is 70°C, and the time is 60min.

[0031] (3) The bleached tobacco pulp is subjected to an enzyme treatment process. The enzyme treatment conditions include a cellulase dosage of 500 U / g, a treatment at a constant speed (300 rpm) for 1 hour at a pH value of 7.0, a temperature of 60° C., and a tobacco pulp concentration of 5 wt%. The tobacco pulp obtained after the enzyme treatment is then added to boiling water for 10 minutes to inactivate the enzyme. The supernatant is then removed by centrifugation and deionized water is added for thorough washing to remove the residual enzyme solution.

[0032] (4) The tobacco slurry obtained after the enzyme treatment is subjected to PFI refining and high-pressure homogenization to obtain tobacco endogenous biomass-based materials. In the high-pressure homogenization, the slurry concentration is 0.1wt%, and the paper pulp suspension is first stabilized under a relatively low pressure (500 bar), and then gradually pressurized to 1000 bar, and the sample is collected after 30 cycles; finally, the tobacco endogenous biomass-based materials are obtained; stored at 4°C, and then the tobacco endogenous biomass-based materials are characterized.

[0033] Example 2: Preparation of tobacco endogenous biomass-based materials, the steps are:

[0034] (1) The tobacco raw material is first impregnated, and the solid-liquid ratio in the pre-impregnation conditions is 1:5, the temperature is 100°C, the pH is 6, and the treatment time is 3h. The extracted tobacco fiber is placed in a deflaker at a speed of 10,000 rpm to destroy its structure and squeeze out the black liquor. After solid-liquid separation, the tobacco slurry is prepared by alkali pretreatment and alkali cooking. Among them, the alkali pretreatment conditions are: the addition amount of NaOH is 5wt% (equivalent to absolute dry tobacco slurry), the temperature is 95°C, the solid-liquid ratio is 1:6 (g / mL), and the treatment time is 50min. Alkali cooking conditions: the addition amount of NaOH is 2wt% (equivalent to absolute dry tobacco slurry), the temperature is 155°C, the solid-liquid ratio is 1:3 (g / mL), and the treatment time is 60min.

[0035] (2) Take an appropriate amount of the above tobacco pulp and perform bleaching and decolorization treatment to obtain bleached tobacco pulp. Oxygen delignification bleaching: tobacco pulp concentration is 10wt%, alkali amount is 3wt% (equivalent to absolute dry tobacco pulp), magnesium sulfate amount is 0.5wt%, oxygen pressure is 0.7MPa, reaction temperature is 100℃, and reaction time is 60min. Hydrogen peroxide bleaching: tobacco pulp concentration is 10wt%, H 2 O 2Dosage 1wt% (equivalent to absolute dry tobacco pulp), magnesium sulfate 0.1wt%, sodium silicate 3wt%, DTPA 0.3%, pH 11, temperature 80℃, 60min. Chlorine dioxide bleaching: ClO 2 The dosage is 4wt% (equivalent to absolute dry tobacco pulp), the tobacco pulp concentration is 10wt%, the temperature is 70°C, and the time is 60min.

[0036] (3) The bleached tobacco pulp was subjected to an enzyme pretreatment process. The enzyme treatment conditions were 500 U / g of cellulase, and the reaction was carried out at a constant speed (300 rpm) for 1 hour under the conditions of pH (6.8), temperature (60°C) and concentration of 5 wt%. At the end of the pretreatment, the reaction mixture was added to boiling water for 10 minutes to inactivate the enzyme. Then, the supernatant was removed by centrifugation and deionized water was added to thoroughly wash to remove the residual enzyme solution.

[0037] (4) The tobacco slurry obtained after enzyme pretreatment is subjected to PFI refining and high-pressure homogenization to obtain tobacco endogenous biomass-based materials. The slurry concentration in high-pressure homogenization is 0.1-0.15wt%, and the paper pulp suspension is first stabilized under a relatively low pressure (500 bar), and then gradually pressurized to 1000 bar, and samples are collected after 30 cycles. The tobacco endogenous biomass-based materials obtained are finally stored at 4°C, and then the tobacco endogenous biomass-based materials are characterized.

[0038] Example 3: Preparation of tobacco endogenous biomass-based materials, the steps are:

[0039] (1) The tobacco raw material is first impregnated, and the solid-liquid ratio in the pre-impregnation conditions is 1:4, the temperature is 90°C, the pH is 6, and the treatment time is 4h. The extracted tobacco fiber is placed in a deflaker, and the speed is adjusted to 10000r to destroy its structure and squeeze out the black liquor. After solid-liquid separation, the tobacco slurry is prepared by alkali pretreatment and alkali cooking. Among them, the alkali pretreatment conditions are: the addition amount of NaOH is 4wt% (equivalent to absolute dry tobacco slurry), the temperature is 100°C, the solid-liquid ratio is 1:5 (g / mL), and the treatment time is 50min. Alkali cooking conditions: the addition amount of NaOH is 3wt% (equivalent to absolute dry tobacco slurry), the temperature is 145°C, the solid-liquid ratio is 1:4 (g / mL), and the treatment time is 60min.

[0040] (2) Take an appropriate amount of the above tobacco pulp and perform bleaching and decolorization treatment to obtain bleached tobacco pulp. In the oxygen delignification bleaching stage, the pulp concentration is 10%, the amount of alkali is 4wt% (equivalent to absolute dry tobacco pulp), the amount of magnesium sulfate is 0.5%, the oxygen pressure is 0.7MPa, the reaction temperature is 100℃, and the reaction time is 60min. In the hydrogen peroxide bleaching stage, the pulp concentration is 10%, H 2 O 2The dosage is 2.5wt% (equivalent to absolute dry tobacco pulp), the dosage of magnesium sulfate is 0.1%, the dosage of sodium silicate is 3%, the dosage of DTPA is 0.3%, the pH is 11, the reaction temperature is 80℃, and the reaction time is 60min. 2 The dosage is 3wt% (equivalent to absolute dry tobacco pulp), the pulp concentration is 10%, the reaction temperature is 70°C, and the reaction time is 60min.

[0041] (3) The bleached tobacco pulp was subjected to an enzyme pretreatment process. The enzyme treatment conditions were 400 U / g of cellulase, and the reaction was carried out at a constant speed (300 rpm) for 1 hour under the conditions of pH (6.8), temperature (60°C) and concentration of 5 wt%. At the end of the pretreatment, the reaction mixture was added to boiling water for 10 minutes to inactivate the enzyme. Then, the supernatant was removed by centrifugation and deionized water was added to thoroughly wash to remove the residual enzyme solution.

[0042] (4) The tobacco slurry obtained after enzyme pretreatment was subjected to PFI refining and high-pressure homogenization to obtain tobacco endogenous biomass-based materials. The slurry concentration in high-pressure homogenization was 0.1-0.15wt%, and the paper pulp suspension was first stabilized under a relatively low pressure (500 bar), and then gradually pressurized to 1000 bar. After 30 cycles, the samples were collected, and the tobacco endogenous biomass-based materials were finally stored at 4°C. The tobacco endogenous biomass-based materials were then characterized and cell compatibility experiments were performed.

[0043] Example 4: Preparation of tobacco endogenous biomass-based materials, the steps are:

[0044] (1) The tobacco raw material is first impregnated, and the solid-liquid ratio in the pre-impregnation conditions is 1:3, the temperature is 80°C, the pH is 6, and the treatment time is 4h. The extracted tobacco fiber is placed in a deflaker, and the speed is adjusted to 10000r to destroy its structure and squeeze out the black liquor. After solid-liquid separation, the tobacco slurry is prepared by alkali pretreatment and alkali cooking. Among them, the alkali pretreatment conditions are: the addition amount of NaOH is 2wt% (equivalent to absolute dry tobacco slurry), the temperature is 80°C, the solid-liquid ratio is 1:5 (g / mL), and the treatment time is 50min. Alkali cooking conditions: the addition amount of NaOH is 2wt% (equivalent to absolute dry tobacco slurry), the temperature is 115°C, the solid-liquid ratio is 1:5 (g / mL), and the treatment time is 60min.

[0045] (2) Take an appropriate amount of the above tobacco pulp for bleaching and decolorization to obtain bleached tobacco pulp. Among them, the pulp concentration in the oxygen delignification bleaching stage is 10%, the amount of alkali is 2wt% (equivalent to absolute dry tobacco pulp), the amount of magnesium sulfate is 0.5%, the oxygen pressure is 0.7MPa, the reaction temperature is 100℃, and the reaction time is 60min. The pulp concentration in the hydrogen peroxide bleaching stage is 10%, the amount of H2O2 is 1wt% (equivalent to absolute dry tobacco pulp), the amount of magnesium sulfate is 0.1%, the amount of sodium silicate is 3%, the amount of DTPA is 0.3%, the pH is 11, the reaction temperature is 80℃, and the reaction time is 60min. The amount of ClO2 in the chlorine dioxide bleaching stage is 1.5wt% (equivalent to absolute dry tobacco pulp), the pulp concentration is 10%, the reaction temperature is 70℃, and the reaction time is 60min.

[0046] (3) The bleached tobacco pulp was subjected to an enzyme pretreatment process. The enzyme treatment conditions were 100 U / g of cellulase, and the reaction was carried out at a constant speed (300 rpm) for 1 hour under the conditions of pH (6.8), temperature (60°C) and concentration of 5 wt%. At the end of the pretreatment, the reaction mixture was added to boiling water for 10 minutes to inactivate the enzyme. Then, the supernatant was removed by centrifugation and deionized water was added to thoroughly wash to remove the residual enzyme solution.

[0047] (4) The tobacco slurry obtained after enzyme pretreatment is subjected to PFI refining and high-pressure homogenization to obtain tobacco endogenous biomass-based materials. The slurry concentration in high-pressure homogenization is 0.1-0.15wt%, and the paper pulp suspension is first stabilized under a relatively low pressure (500 bar), and then gradually pressurized to 1000 bar, and samples are collected after 30 cycles. The tobacco endogenous biomass-based materials obtained are finally stored at 4°C, and then the tobacco endogenous biomass-based materials are characterized.

[0048] Comparative Example 1: There is no alkaline cooking step and only a hydrogen peroxide bleaching step.

[0049] (1) Same as Example 1.

[0050] (2) Take an appropriate amount of the above tobacco pulp and perform bleaching and decolorization treatment to obtain bleached tobacco pulp. Use hydrogen peroxide bleaching: tobacco pulp concentration is 10wt%, H2O2 dosage is 2wt% (equivalent to absolute dry tobacco pulp), magnesium sulfate dosage is 0.1wt%, sodium silicate dosage is 3wt%, DTPA dosage is 0.3%, pH is 11, temperature is 80°C, and time is 60min.

[0051] (3) and (4) are the same as in Example 1. The tobacco endogenous bio-based material was characterized.

[0052] The results were as follows: the slurry was not completely decolorized, and high-pressure homogenization could not be performed. The prepared material was still in the form of large fibers, and did not reach the nano state, and the preparation was not successful.

[0053] Comparative Example 2: Only oxygen delignification and bleaching step.

[0054] (1) Same as Example 1.

[0055] (2) Take an appropriate amount of the above tobacco pulp and perform bleaching and decolorization treatment to obtain bleached tobacco pulp. Oxygen delignification bleaching: tobacco pulp concentration is 10wt%, alkali amount is 5wt% (equivalent to absolute dry tobacco pulp), magnesium sulfate amount is 0.5wt%, oxygen pressure is 0.7MPa, temperature is 100℃, and time is 60min.

[0056] (3) and (4) are the same as in Example 1. The tobacco endogenous bio-based material was characterized.

[0057] The results were as follows: the slurry was not completely decolorized, and high-pressure homogenization could not be performed. The prepared material was still in the form of large fibers, and did not reach the nano state, and the preparation was not successful.

[0058] The test items are as follows:

[0059] 1. Morphology observation: Scanning electron microscopy (SEM) was used to observe tobacco endogenous biomass-based materials; Figure 3 shown.

[0060] 2. Potential analysis: The prepared tobacco endogenous biomass-based material sample was diluted to 0.01wt% to 0.5%, ultrasonically dispersed for 5 min (50kHz, 200W), and the potential of the sample was measured using a Zeta potential analyzer. Potential can characterize the stability of tobacco endogenous biomass-based materials to a certain extent. As shown in Table 1.

[0061] 3. Particle size distribution: Use a nanoparticle size analyzer to measure the particle size, and the dispersion medium is water. Each sample is measured three times in parallel and the average value is taken. Figure 1 shown.

[0062] 4. Infrared analysis: Use potassium bromide tableting method to prepare samples. Take about 1 mg of cold-dried sample and 0.1 g of potassium bromide powder and put them in a mortar, grind and mix them thoroughly. Put the ground powder in a grinder and press it into a transparent and uniform thin sheet. Use Fourier transform infrared spectrometer to measure the FT-IR spectrum of the samples respectively. The measured wavelength range is 4000 cm -1 ~400cm -1 .like Figure 2 shown.

[0063] 5. Biocompatibility analysis: The cytotoxicity of tobacco endogenous biomass-based materials was determined using the MTT method (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, trade name: Thiazole Blue). Figure 5 shown.

[0064] 6. Specific surface area analysis: The specific surface area of ​​tobacco endogenous biomass-based materials was determined using a specific surface area and porosity analyzer and the nitrogen adsorption-desorption principle. Before testing, the sample was heat treated at 110°C for two hours, mainly to remove impurity gases in the sample. See Table 1.

[0065] The analysis results are as follows:

[0066] Table 1 Zeta potential, cell viability and specific surface area analysis of tobacco endogenous biomass-based materials

[0067]

[0068] Table 1 shows the Zeta potential, cell viability, and specific surface area analysis data of the tobacco endogenous biomass-based materials obtained in Table 1. It can be seen from Table 1 that the potentials of the tobacco endogenous biomass-based materials obtained in Examples 1, 2, 3, and 4 are -39.69 mV, -31.56 mV, -29.8 mV, and -21.5 mV, indicating that under suitable conditions, the prepared tobacco endogenous biomass-based materials have a higher electronegativity, that is, have better stability. It can also be seen from Table 1 that the cell viability of the tobacco endogenous biomass-based materials obtained in Examples 1, 2, 3, and 4 is greater than 80%, indicating that the tobacco endogenous biomass-based materials obtained by this method have good biocompatibility. In addition, the specific surface area of ​​the tobacco endogenous biomass-based materials obtained in Examples 1, 2, 3, and 4 is distributed in the range of 200-300 m 2 / g, indicating that the tobacco endogenous bio-based material obtained by this method has a larger specific surface area.

[0069] Figure 1 The particle size distribution of the tobacco endogenous biomass-based material of the present invention (a: Example 1; b: Example 2). The particle size distribution of the tobacco endogenous biomass-based material obtained in Examples 1 and 2 is about 100 nm, and the distribution is relatively concentrated, indicating that the tobacco endogenous biomass-based material has a good particle size distribution.

[0070] Figure 2 This is the infrared analysis of the tobacco endogenous bio-based material obtained in Examples 1, 2, 3, and 4. Figure 2 It can be seen that the tobacco endogenous bio-based materials obtained by the method of the present invention all exhibit a special absorption peak of cellulose (1376cm -1 , 1062 cm -1 and 890 cm -1 There are no new absorption peaks, which means that this method does not modify the endogenous bio-based materials of tobacco.

[0071] Figure 3SEM analysis of the materials obtained in the examples and comparative examples (a: Example 1; b: Example 2; c: Example 3; d: Example 4; e: Comparative Example 1; f: Comparative Example 2). Figure 3 (ad) It can be seen that the length of the tobacco endogenous bio-based materials obtained in Examples 1, 2, 3, and 4 is in the range of several microns; Figure 3 As can be seen from e-3f, the materials prepared in comparative examples 1 and 2 are still in the form of large fibers and have not reached the nano state, indicating that the preparation was not successful.

[0072] Figure 4 Physical pictures of tobacco endogenous biomass-based materials obtained in Example 1 and Example 2. Figure 4 It can be seen that the tobacco endogenous bio-based materials obtained in Examples 1 and 2 have good stability.

[0073] Figure 5 This is a picture of the dead cells and living cells observed under a confocal laser microscope (CLSM) of the cells treated with tobacco endogenous biomass-based materials obtained in Example 3. Figure 5 It can be seen that a small number of cells are dead. Combined with the cell survival rate in Table 1, it can be concluded that the tobacco endogenous bio-based material obtained by the method of the present invention has good biocompatibility.

[0074] The tobacco endogenous bio-based material obtained by the method of the present invention can be used for the development of tobacco endogenous biomass-based related materials, such as for the preparation of tobacco microcapsules, flavor-retaining cigarette papers, flavor-retaining granular materials, etc., to achieve good results, and can meet the demand for high-value utilization of waste tobacco resources. The applicant has separately applied for patent protection for the application of the tobacco endogenous bio-based material obtained by the present invention.

[0075] Those skilled in the art should understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for preparing tobacco endogenous biomass-based materials, characterized in that: The steps include: S1, impregnating the tobacco waste raw material, performing decomposition after solid-liquid separation, and then performing alkali pretreatment and alkali solution cooking to obtain tobacco slurry; S2, taking the above tobacco pulp and performing bleaching and decolorization treatment to obtain bleached tobacco pulp; S3, subjecting the bleached tobacco pulp to enzyme treatment; S4. The tobacco slurry obtained after the enzyme treatment is subjected to pulping and high-pressure homogenization treatment to obtain the tobacco endogenous biomass-based material.

2. The preparation method according to claim 1, characterized in that: In step S1, the impregnation conditions are: solid-liquid ratio of 1: (1-6), temperature of 50°C-100°C, pH value of 5-7, and impregnation time of 1h-4h; the impregnated tobacco fibers are deflaked, and the speed of the deflaker is not less than 10000rpm.

3. The preparation method according to claim 1, characterized in that: In step S1, the alkali pretreatment conditions are: the amount of NaOH in the alkali solution is 1-6wt% of the dry tobacco pulp, the temperature is 80°C-100°C, the solid-liquid ratio is 1:(1-10) (g / mL), and the treatment time is 20min-60min.

4. The preparation method according to claim 1, characterized in that: In step S1, the alkali cooking conditions are: the amount of NaOH added to the alkali solution is 1-4wt% of the dry tobacco pulp, the temperature is 100°C-155°C, the material-liquid ratio is 1:(1-5) (g / mL), and the alkali cooking time is 20min-60min.

5. The preparation method according to claim 1, characterized in that: In step S2, the bleaching and decolorization treatment of tobacco pulp includes the following steps: (1) oxygen delignification bleaching: the tobacco pulp concentration is 10%, the alkali dosage is 2-5wt% of the dry tobacco pulp, the magnesium sulfate dosage is 0.5wt% of the dry tobacco pulp, the oxygen pressure is 0.7MPa, the temperature is 80℃-100℃, and the time is 20min-60min; (2) hydrogen peroxide bleaching: the tobacco pulp concentration is 10%, the H2O2 dosage is 1-3wt% of the dry tobacco pulp, the magnesium sulfate dosage is 0.1wt% of the dry tobacco pulp, the sodium silicate dosage is 3% of the dry tobacco pulp, the DTPA dosage is 0.3wt% of the dry tobacco pulp, the pH value is 11, the temperature is 70℃-90℃, and the time is 20min-60min; (3) chlorine dioxide bleaching: the tobacco pulp concentration is 10%, the ClO2 dosage is 1-5wt% of the dry tobacco pulp, the temperature is 50℃-70℃, and the time is 20min-60min.

6. The preparation method according to claim 1, characterized in that: In step S3, the enzyme treatment conditions are: cellulase dosage 100U / g-1000U / g, pH value 6.0-8.0, temperature 40℃-60℃, tobacco pulp concentration 5wt%, treatment time 1h-3h; then the tobacco pulp obtained after enzyme treatment is enzyme inactivated, separated and washed.

7. The preparation method according to claim 1, characterized in that: In step S4, PFI is used for pulping; in the high-pressure homogenization treatment, the slurry concentration is (0.1-0.15) wt%, and the treatment steps are: first stabilize the slurry suspension under 500 bar conditions, and then pressurize it to 1000 bar; collect samples after 30 cycles to obtain the tobacco endogenous biomass-based material.

8. The tobacco endogenous biomass-based material obtained by the preparation method according to any one of claims 1 to 7, wherein the diameter is less than 100 nm, the length is 500 nm-10 μm, and the specific surface area is not less than 230 m 2 / g; its cytotoxicity was determined by MTT method, and the cell survival rate was not less than 80%; the Zeta potential was -20~-40mV.

9. Use of the tobacco endogenous biomass-based material according to claim 8 for preparing tobacco materials.

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