Modified tobacco powder, preparation method thereof, aerosol generating substrate and product

Abstract

The invention provides modified tobacco powder and a preparation method thereof, an aerosol generating substrate and a product. The preparation method comprises the following steps: S1, pretreating initial tobacco powder to obtain to-be-reacted tobacco powder; s2, low-temperature plasma is prepared; and S3, contacting the to-be-reacted tobacco powder with low-temperature plasma, and performing surface roughening treatment on the low-temperature plasma to obtain the modified tobacco powder with the active groups. The surface of the tobacco powder is modified through low-temperature plasma to obtain the modified tobacco powder with active groups, so that the surface contact angle of the modified tobacco powder is lower than that of common tobacco powder, and the content of the active groups and the aroma retention rate of the modified tobacco powder are higher than those of the common tobacco powder, so that the modified tobacco powder can be better combined with a binder and essence; the formability and aroma retention capability of a subsequent aerosol generation substrate are improved, so that the taste of an aerosol generation product is improved.

Description

Technical Field

[0001] This patent relates to the field of tobacco processing technology, specifically to a modified tobacco powder and its preparation method, an aerosol generation matrix, and products. Background Technology

[0002] Tobacco sheets, as an important form of reconstituted tobacco, have wide applications in the field of new tobacco products. Tobacco powder, as the basic raw material for tobacco sheet production, directly determines the bonding effect with subsequent binders, flavorings, and other auxiliary materials through its surface properties, thereby affecting the physical strength and sensory quality of the final product.

[0003] In existing tobacco processing technologies, tobacco powder is typically produced by crushing and sieving raw materials such as tobacco fragments and tobacco dust. However, this type of tobacco powder has significant technical drawbacks in practical applications. First, the surface of tobacco powder exhibits typical "inert" characteristics, with a limited number of surface-active groups and a relatively smooth particle morphology, resulting in poor compatibility with functional additives such as binders and flavorings.

[0004] When this type of tobacco powder is used to prepare reconstituted tobacco leaves, structural defects such as shedding and cracking are prone to occur. At the same time, the flavoring components are difficult to adhere firmly, resulting in rapid decay of the product's aroma and difficulty in maintaining sensory quality.

[0005] To address the aforementioned issues, the industry has explored various methods for modifying tobacco powder. Common modification approaches in existing technologies primarily include chemical reagent treatment and high-temperature physical treatment.

[0006] Chemical treatment methods typically involve soaking or spraying tobacco powder with acid or alkali solutions, coupling agents, or surfactants to introduce active groups or alter the surface energy of the tobacco powder. However, these methods inevitably carry the risk of chemical residues, affecting the safety of tobacco products. Furthermore, the wastewater and waste liquid generated during the process increase the burden on environmental protection.

[0007] High-temperature physical processing alters the surface properties of tobacco powder through heating. However, the aroma components and active substances contained in tobacco powder are extremely sensitive to temperature. High-temperature processing often leads to a significant loss of these effective components, making it difficult to balance the modification effect with component retention.

[0008] Furthermore, existing modification methods lack process stability. Even with certain physical modification methods, the lack of precise control over the processing results in significant differences in the surface characteristics of tobacco powder obtained from different batches. Key indicators such as the amount of active groups introduced and surface roughness fluctuate greatly, making it difficult to control the consistency of quality in subsequent industrial production.

[0009] Therefore, there is an urgent need for a method to modify tobacco powder that can effectively enhance the surface activity of tobacco powder, protect the effective components inside the tobacco powder, and has a controllable and environmentally friendly process. This has become a technical problem that needs to be solved in this field. Summary of the Invention

[0010] This patent aims to solve the technical problems of low surface activity and poor compatibility with excipients in existing tobacco powders, as well as the problems of chemical reagent residues, destruction of effective components, and unstable treatment effects in existing modification methods. This patent provides the following technical solutions: In a first aspect, a method for preparing modified tobacco powder is provided, comprising the following steps: Step S1: Pre-treating the initial tobacco powder to obtain the tobacco powder to be reacted; Step S2: Preparing a low-temperature plasma; Step S3: Contacting the tobacco powder to be reacted with the low-temperature plasma and subjecting it to surface roughening treatment by the low-temperature plasma to obtain modified tobacco powder with active groups.

[0011] Furthermore, step S1 includes: step S11: filtering the initial tobacco powder to remove impurities to obtain fine tobacco powder; step S12: drying the fine tobacco powder to obtain the tobacco powder to be reacted.

[0012] Furthermore, in step S11, the initial tobacco powder is filtered through a sieve to obtain fine tobacco powder; the mesh size of the sieve is 150~250 mesh; in step S12, the fine tobacco powder is dried in an oven to obtain tobacco powder to be reacted; the moisture content of the tobacco powder to be reacted is less than 5%; the drying temperature is 58~63℃, 63~68℃ or 68~73℃.

[0013] Furthermore, step S2 includes: step S21: mixing the first gas and the second gas in proportion using a low-temperature plasma processing device to obtain a mixed gas; step S22: applying energy to the mixed gas and partially ionizing it to obtain low-temperature plasma.

[0014] Furthermore, in step S21, the first gas and the second gas are non-polymerizable gases; the volume mixing ratio of the first gas and the second gas is 4:1; in step S22, the processing power of the low-temperature plasma processing device is 70~90W, 90~110W or 110~130W; the processing chamber pressure of the low-temperature plasma processing device is 40~60Pa, 60~80Pa or 80~100Pa.

[0015] Furthermore, step S3 includes: step S31: adding the smoke powder to be reacted into the low-temperature plasma treatment device and contacting it with the mixed gas; step S32: waiting for the smoke powder to be reacted with the low-temperature plasma to obtain modified smoke powder.

[0016] Furthermore, in step S31, the feeding rate of the tobacco powder to be reacted is 1~2 kg / h; in step S32, the reaction temperature is 30~50℃, 50~70℃ or 70~90℃; and the reaction time is 20~40s, 40~60s or 60~80s.

[0017] Secondly, a modified tobacco powder is prepared by the above-described preparation method; the modified tobacco powder has a rough surface and contains active groups; the active groups are one or more of hydroxyl, carboxyl, carbonyl, or hydroperoxy groups; the surface contact angle of the modified tobacco powder is 40~45°, 45~50°, or 50~55°; the content of active groups in the modified tobacco powder is 0.50~0.60 mmol / g, 0.60~0.70 mmol / g, or 0.70~0.80 mmol / g; the aroma retention rate of the modified tobacco powder is greater than or equal to 82%, greater than or equal to 87%, or greater than or equal to 92%.

[0018] Thirdly, an aerosol generating matrix, comprising the aforementioned modified tobacco powder.

[0019] Fourthly, an aerosol generating article, comprising the aforementioned aerosol generating matrix.

[0020] This patent has the following beneficial effects: 1. A modified tobacco powder and its preparation method, aerosol generation matrix and product are provided. The surface of the tobacco powder is modified by low-temperature plasma to obtain modified tobacco powder with active groups. The tobacco powder can better combine with binders and flavorings, improve the formability and aroma retention of the subsequent aerosol generation matrix, thereby improving the taste of aerosol-generated products.

[0021] 2. This patent achieves synergistic physical-chemical modification of the tobacco powder surface by introducing low-temperature plasma treatment technology. At the physical level, high-energy particles in the low-temperature plasma etch the tobacco powder surface, creating a micro-rough structure on the originally smooth surface and significantly increasing the specific surface area. At the chemical level, active free radicals in the low-temperature plasma react with molecules on the tobacco powder surface, introducing oxygen-containing active groups such as hydroxyl, carboxyl, carbonyl, and hydroperoxy groups. This dual modification mechanism of physical roughening and chemical activation transforms the tobacco powder surface from an inert state to a highly active state, providing ideal interface conditions for subsequent bonding with binders, flavorings, and other additives. The rough surface provides physical anchoring points, while the active groups enhance interfacial bonding through hydrogen bonding and chemisorption. The synergistic effect of both fundamentally solves the technical problem of poor compatibility between tobacco powder and additives.

[0022] 3. During the low-temperature plasma treatment, the gas temperature is maintained within a suitable range, with the overall treatment temperature not exceeding 90 degrees Celsius, far below the thermal decomposition temperature of the aroma components in the tobacco powder. Simultaneously, the entire process is carried out in a gaseous environment, without the use of any chemical solvents or reaction reagents, thus avoiding the risk of chemical residues. This low-temperature, solvent-free treatment mode allows the natural aroma components and physiologically active substances in the tobacco powder to be fully preserved. The modified tobacco powder achieves a high level of aroma retention, providing a raw material guarantee for the sensory quality of the final tobacco products.

[0023] 4. In this patent, from the perspective of the overall process layout, the setup of the pretreatment unit, low-temperature plasma treatment unit, post-treatment stabilization unit, and detection unit forms a complete quality control closed loop. The pretreatment unit, through sieving and drying, ensures that the tobacco powder entering the plasma treatment process has uniform particle size and stable moisture content, laying the foundation for subsequent precise processing. The low-temperature plasma treatment unit adopts a continuous processing device, allowing for continuous material feeding and discharging, resulting in significantly higher processing efficiency than intermittent processes. Key process parameters such as processing power, chamber pressure, and residence time can be independently adjusted and precisely controlled, ensuring high consistency in the performance indicators of tobacco powder obtained from different batches, effectively solving the problem of poor batch stability in existing modification methods. The post-treatment stabilization unit, through cooling and sealed storage, effectively fixes the surface active state of the modified tobacco powder, preventing the active groups from becoming inactive or reacting adversely with moisture in the air during storage, ensuring the durability of the modification effect.

[0024] 5. In this patent, the significant reduction in surface contact angle directly reflects the transformation of the tobacco powder from hydrophobic to hydrophilic, meaning that the wettability and compatibility of the tobacco powder with water-based binders and flavoring systems have been substantially improved. The increased content of active groups provides a chemical basis for establishing a strong bond between the tobacco powder and excipients. When the modified tobacco powder is used to prepare an aerosol generating matrix, its bond with the binder is stronger, resulting in a dense sheet structure that is less prone to shedding or cracking; its binding ability with flavorings is enhanced, the retention time of flavorings in the matrix is ​​prolonged, and the aroma release during inhalation is more persistent and uniform. Sensory evaluation verification shows that the aerosol generating products prepared using the modified tobacco powder of this invention have significant improvements in core sensory indicators such as aroma quality, aroma quantity, off-flavors, irritation, and aftertaste, with an overall sensory score higher than the unmodified tobacco powder control sample. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this patent, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this patent and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a flowchart of the preparation method of this patent; Figure 2 This is an electron microscope image of the initial smoke powder in this patent; Figure 3 This is an electron microscope image of the modified smoke powder in this patent. Detailed Implementation

[0027] The detailed features and advantages of this patent are described below in the specific embodiments. The content is sufficient to enable any person skilled in the art to understand the technical content of this patent and implement it accordingly. Based on the specification, claims and drawings disclosed in this specification, a person skilled in the art can easily understand the related objectives and advantages of this patent.

[0028] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not indicate the only possible implementation. The terms "upper," "lower," etc., indicating orientation or positional relationships are defined with reference to the coordinates of the accompanying drawings and are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this patent. The terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this patent belongs. The terminology used herein in the specification of this patent is for the purpose of describing particular embodiments only and is not intended to be limiting of this patent. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] The aerosol-generating articles preferably use a solid matrix, which may include one or more of the following: vanilla leaves, tobacco leaves, homogenized tobacco, expanded tobacco, powder, granules, fragments, strips or sheets; or, the solid matrix may contain additional tobacco or non-tobacco volatile flavor compounds to be released when the matrix is ​​heated.

[0032] "Aerosol generating material" can refer to a substance that produces smoke and / or aerosol or is used for smoking. For example, an aerosol generating material can include tobacco materials. For example, an aerosol generating material can include tobacco leaves, tobacco stems, or substances processed from them. As more specific examples, an aerosol generating material can include pulverized tobacco leaves, pulverized reconstituted tobacco, expanded pipe tobacco, expanded stems, and reconstituted tobacco. However, this disclosure is not limited thereto.

[0033] Preferably, the aerosol generating matrix is ​​a solid aerosol generating matrix. The aerosol generating matrix may simultaneously comprise both solid and liquid components. Preferably, the aerosol generating matrix includes nicotine. In some preferred embodiments, the aerosol generating matrix includes tobacco.

[0034] Alternatively, the solid aerosol generating matrix may contain tobacco volatile aromatic compounds or non-tobacco volatile aromatic compounds released when the solid aerosol generating matrix is ​​heated. The solid aerosol generating matrix may also contain one or more capsules, which include, for example, additional tobacco volatile aromatic compounds or non-tobacco volatile aromatic compounds, and such capsules may melt during heating of the solid aerosol generating matrix.

[0035] Alternatively, the solid aerosol generating matrix can be disposed on or embedded in a heat-stabilized carrier. The carrier can be in the form of powder, granules, pellets, fragments, strips, bars, or sheets. The solid aerosol generating matrix can be arranged on the surface of the carrier, for example, in the form of sheets, foams, gels, or slurries. The solid aerosol generating matrix can be placed on the entire surface of the carrier, or alternatively, it can be patterned to provide uneven fragrance delivery during use.

[0036] The aerosol generating matrix can be in the form of a plug, which includes aerosol generating materials defined by paper or other packaging materials. In the case where the aerosol generating matrix is ​​in the form of a plug, the entire plug comprising any packaging paper is considered to be the aerosol generating matrix.

[0037] Preferably, the aerosol generating matrix includes a plug, which comprises an aggregate of homogeneous tobacco material or other aerosol generating material surrounded by packaging material.

[0038] In this patent, "aerosol generating agent" is used to describe any suitable known compound or mixture of compounds that promotes aerosol formation in use and is substantially resistant to thermal degradation at the operating temperature of the aerosol-generating article.

[0039] Suitable aerosol generating agents are known in the art and include, but are not limited to: polyols, such as propylene glycol, triethylene glycol, 1,3-butanediol, and glycerol; esters of polyols, such as glycerol monoacetate, glycerol diacetate, or glycerol triacetate; and aliphatic esters of mono-, di-, or polycarboxylic acids, such as dimethyl dodecanoate and dimethyl tetradecanoate. Preferred aerosol generating agents are polyols or mixtures thereof, such as propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerol.

[0040] The aerosol generating matrix may include a single aerosol generating agent. Alternatively, the aerosol generating matrix may include a combination of two or more aerosol generating agents.

[0041] Preferably, the aerosol generating matrix has an aerosol generating agent content of more than 5% by dry weight. More preferably, the aerosol generating matrix may have an aerosol generating agent content between about 5% and about 30% by dry weight. In one embodiment, the aerosol generating matrix has an aerosol generating agent content of about 20% by dry weight.

[0042] Tobacco sheets can be manufactured using existing manufacturing processes in the field, such as rolling, slurry processing, and papermaking, to include an aerosol-generating matrix for homogenizing tobacco sheets in aerosol-generating articles.

[0043] In this patent, sheet refers to a layered element having a width and length substantially greater than its thickness.

[0044] In this patent, the aerosol generating matrix comprises a textured sheet of aggregated homogeneous tobacco material.

[0045] In this patent, textured sheet refers to a sheet that has been rolled, embossed, stamped, perforated, or otherwise deformed. The aerosol generating matrix may include an aggregate of textured sheets of homogeneous tobacco material, comprising a plurality of spaced-apart notches, protrusions, perforations, or combinations thereof.

[0046] Preferably, the aerosol-generating matrix comprises aggregated rolled sheets of homogeneous tobacco material. The use of textured sheets of homogeneous tobacco material can advantageously promote the aggregation of the homogeneous tobacco material sheets to form the aerosol-generating matrix.

[0047] In this patent, "curled sheet" refers to a sheet having a plurality of substantially parallel ridges or folds. Preferably, when the aerosol-generating article has been assembled, the substantially parallel ridges or folds extend along or parallel to the longitudinal axis of the aerosol-generating article. This advantageously promotes the aggregation of the curled sheet of homogeneous tobacco material to form an aerosol-generating matrix.

[0048] To make the objectives, technical solutions, and advantages of this patent clearer, the embodiments of this patent will be described in further detail below with reference to the accompanying drawings.

[0049] For a method of preparing modified tobacco powder, please refer to [reference needed]. Figures 1-3 It includes the following steps: Step S1: The initial smoke powder is pretreated to obtain the smoke powder to be reacted.

[0050] Step S11: After filtering and removing impurities from the initial tobacco powder, fine tobacco powder is obtained.

[0051] In step S11, the initial tobacco powder is filtered through a sieve to obtain fine tobacco powder; the mesh size of the sieve is 150~250 mesh.

[0052] Specifically, impurities such as small stones and fiber fragments in the tobacco powder are sieved out, preferably using a 200-mesh sieve to ensure that the tobacco powder is uniform and fine.

[0053] Step S12: Dry the fine smoke powder to obtain the smoke powder to be reacted.

[0054] In step S12, the fine tobacco powder is dried in an oven to form the tobacco powder to be reacted; the moisture content of the tobacco powder to be reacted is less than 5%; the drying temperature is 58~63℃, 63~68℃ or 68~73℃.

[0055] Specifically, the sieved tobacco powder to be reacted is placed in an oven and dried at 60-70°C for 1-2 hours to reduce the moisture content to below 5%. Otherwise, the moisture will affect the reaction between the plasma and the surface of the tobacco powder, resulting in uneven modification.

[0056] Step S2: Prepare low-temperature plasma.

[0057] Specifically, a continuous low-temperature plasma treatment device is used to process mixed gas to generate low-temperature plasma. The device model is NE-DBDN2 from Shenzhen Nanen Technology Co., Ltd. It has an inlet, a processing chamber, and an outlet, and has the advantage of continuous feeding and processing without waiting in batches.

[0058] Step S21: The first gas and the second gas are mixed in proportion using a low-temperature plasma processing device to obtain a mixed gas.

[0059] In step S21, the first gas and the second gas are non-polymerizable gases; the volume mixing ratio of the first gas and the second gas is 4:1.

[0060] Non-polymerizable gases include argon, oxygen, nitrogen, air, and hydrogen, with argon being the preferred first gas and oxygen being the preferred second gas. Argon can make the plasma more stable, while oxygen can help generate more active groups on the surface of the smoke powder.

[0061] Step S22: Apply energy to the mixed gas and partially ionize it to obtain low-temperature plasma.

[0062] In step S22, the processing power of the low-temperature plasma processing device is 70~90W, 90~110W or 110~130W; the processing chamber pressure of the low-temperature plasma processing device is 40~60Pa, 60~80Pa or 80~100Pa.

[0063] Step S3: The tobacco powder to be reacted is contacted with low-temperature plasma and then subjected to surface roughening treatment by low-temperature plasma to obtain modified tobacco powder with active groups.

[0064] Step S31: Add the smoke powder to be reacted into the low-temperature plasma treatment device and contact it with the mixed gas; In step S31, the feed rate of the tobacco powder to be reacted is 1~2 kg / h; Step S32: Wait for the smoke powder to react with the low-temperature plasma to obtain modified smoke powder.

[0065] In step S32, the reaction temperature is 30~50℃, 50~70℃ or 70~90℃; the reaction time is 20~40s, 40~60s or 60~80s.

[0066] Specifically, the pretreated tobacco powder enters the processing chamber through the feed inlet. Under the bombardment of mixed gas plasma, the surface becomes rough and new active groups such as hydroxyl, carboxyl, carbonyl, and hydroperoxy groups are added. The temperature of the entire process is preferably controlled at 40~80℃ to prevent the tobacco powder from heating up and deteriorating.

[0067] After treatment, the smoke powder is discharged from the outlet and allowed to cool naturally to room temperature to prevent the surface active groups from becoming ineffective at high temperatures. After cooling, it is immediately sealed in a bag and stored in a dry environment (humidity ≤50%) to prevent moisture in the air from affecting surface activity and to ensure that the modification effect can be maintained stably for more than 3 months.

[0068] A modified tobacco powder is prepared by the above preparation method; the modified tobacco powder has a rough surface and active groups; the active groups are one or more of hydroxyl, carboxyl, carbonyl or hydroperoxy groups.

[0069] An aerosol generating matrix, comprising the aforementioned modified tobacco powder.

[0070] An aerosol generating article, comprising the aforementioned aerosol generating matrix.

[0071] Example 1

[0072] Take 100g of initial tobacco powder, process it through a 200-mesh sieve, and detect the particle size as 75μm. Place it in a vacuum drying oven and dry it at 60℃ for 1 hour until the moisture content is 5% (≤5%) to obtain the tobacco powder to be reacted. Seal it for later use.

[0073] Plasma parameter setting and processing: Introduce a mixed gas into the processing chamber. The mixed gas is argon:oxygen = 4:1, volume ratio. Set the power to 80W, stabilize the pressure at 60Pa, and set the residence time to 30 seconds.

[0074] The pretreated tobacco powder enters the processing chamber through the feed inlet. Under the bombardment of mixed gas plasma, the surface becomes rough and new active groups are added, resulting in modified tobacco powder A1.

[0075] Finished product collection and testing: After processing, cool for 2 minutes, then remove the modified tobacco powder A1 and seal it for storage.

[0076] Example 2

[0077] Take 100g of initial tobacco powder, process it through a 200-mesh sieve, and the particle size is detected to be 75μm. Place it in a vacuum drying oven and dry it at 65℃ for 1.5h until the moisture content is 4.3% (≤5%) to obtain the tobacco powder to be reacted. Seal it for later use.

[0078] Plasma parameter setting and processing: Introduce a mixed gas into the processing chamber. The mixed gas is argon:oxygen = 4:1, volume ratio. Set the power to 80W, stabilize the pressure at 60Pa, and set the residence time to 30 seconds.

[0079] The pretreated tobacco powder enters the processing chamber through the feed inlet. Under the bombardment of mixed gas plasma, the surface becomes rough and new active groups are added, resulting in modified tobacco powder A2.

[0080] Finished product collection and testing: After processing, cool for 2 minutes, then remove the modified tobacco powder A2 and seal it for storage.

[0081] Comparative Example

[0082] Take 100g of initial tobacco powder from the same batch, process it through a 200-mesh sieve, and the particle size is detected to be 75μm. Place it in a vacuum drying oven and dry it at 62℃ for 1.2h until the moisture content is 4.5% (≤5%) to obtain D1. Do not perform any plasma surface modification treatment and store it in a sealed container.

[0083] Experimental Example 1

[0084] This experimental example was used to prepare an aerosol product containing the modified tobacco powder A1 obtained in Example 1 and to test its performance. 20g glycerol, 10g propylene glycol, 10g tobacco flavoring, and 350g water were mixed and stirred until a liquid was formed.

[0085] Take the sealed and reserved modified tobacco powder A1 and mix it with the above liquid material. Stir thoroughly to ensure that the tobacco powder is evenly dispersed in the liquid material. Place the mixture in a vacuum drying oven and dry it at 105°C for 1 hour to reduce the moisture content to 10%, thus obtaining the aerosol generation matrix.

[0086] The aerosol-generating matrix was processed into cigarettes using conventional cigarette rolling techniques to obtain an aerosol-generated product, labeled Z1, which was used for subsequent performance testing and smoking evaluation experiments.

[0087] Experiment Example 2

[0088] This experimental example was used to prepare an aerosol product containing the modified tobacco powder A2 obtained in Example 2 and to test its performance. 20g glycerol, 10g propylene glycol, 10g tobacco flavoring, and 350g water were mixed and stirred until a liquid was formed.

[0089] Take the sealed and reserved modified tobacco powder A2 and mix it with the above liquid material. Stir thoroughly to ensure that the tobacco powder is evenly dispersed in the liquid material. Place the mixture in a vacuum drying oven and dry it at 105°C for 1 hour to reduce the moisture content to 10%, thus obtaining the aerosol generation matrix.

[0090] The aerosol-generating matrix was processed into cigarettes using conventional cigarette rolling techniques to obtain an aerosol-generated product, labeled Z2, which was used for subsequent performance testing and smoking evaluation experiments.

[0091] Experimental Example 3

[0092] This experimental example was used to prepare an aerosol-generated product containing tobacco powder D1 obtained in the comparative example and to test its performance. 20g glycerol, 10g propylene glycol, 10g tobacco flavoring, and 350g water were mixed and stirred until a liquid was formed.

[0093] Take the sealed and reserved modified tobacco powder D1 and mix it with the above liquid material. Stir thoroughly to ensure that the tobacco powder is evenly dispersed in the liquid material. Place the mixture in a vacuum drying oven and dry it at 105°C for 1 hour to reduce the moisture content to 10%, thus obtaining the aerosol generation matrix.

[0094] The aerosol-generating matrix was processed into cigarettes using conventional cigarette rolling techniques to obtain an aerosol-generated product, labeled Z3, which was used for subsequent performance testing and smoking evaluation experiments.

[0095] Surface contact angle detection

[0096] Core equipment: DSA100 contact angle measuring instrument (Krüss, Germany); Auxiliary equipment: powder tablet press (769YP-15A, Tianjin Keqi), micro-syringe.

[0097] Test method: The main device is a contact angle measuring instrument (Krüz DSA100, Germany); the auxiliary devices include a powder tablet press (769YP-15A), a Φ13-20mm tablet mold, a 1-10μL microsyringe, glass slides, and a desiccator; the reagents are ultrapure water (for testing) and anhydrous ethanol (for cleaning).

[0098] Testing process: 1. Sample pretreatment: Take 2-3g of tobacco powder A1, A2 and D1 that have passed through a 200-mesh sieve, put them into a tableting mold, and press them with a tableting machine at a pressure of 5-8MPa for 30s to make round tablets with a thickness of 1-2mm, a smooth surface and no cracks. Place them in a desiccator for later use.

[0099] 2. Instrument calibration: Turn on the measuring instrument and preheat for 30 minutes. Use a standard glass slide to calibrate the baseline and drop position to ensure stable liquid output from the microsyringe (droplet volume 2μL).

[0100] 3. Sample testing: Fix the tablet on the sample stage, focus clearly, add 1 drop of ultrapure water, let stand for 2 seconds, the instrument automatically takes an image and calculates the contact angle by fitting the Young-Laplace equation.

[0101] 4. Parallel verification: Test 5 times at different positions on the same tablet, remove extreme values ​​and take the average; prepare 3 tablets from the same sample, and take the average of the 3 tablets as the final result.

[0102] 5. Post-processing: After the test, clean the injector and sample stage with anhydrous ethanol, and dry and store them. (Test environment: 25±2℃, 50±5% constant temperature and humidity) The test results are shown in Table 1.

[0103] Note: The tableting pressure should not exceed 8 MPa, otherwise it will easily cause the powder particles to agglomerate and change the surface microstructure. If the powder contains sticky components, a small amount of anhydrous ethanol can be applied to the inner wall of the mold to facilitate demolding.

[0104] Table 1. Surface contact angle detection results of Examples A1, A2 and Comparative Example D1

[0105] in conclusion: The surface contact angles of the modified tobacco powder A1 obtained in Example 1, the modified tobacco powder A2 obtained in Example 2, and the tobacco powder D1 obtained in the comparative example were measured. The test results showed that the tobacco powder D1, which had not undergone low-temperature plasma treatment, had a higher surface contact angle, indicating that its surface exhibited strong hydrophobic properties and poor wettability with water-based excipients.

[0106] The surface contact angles of tobacco powders A1 and A2 modified by the method of this invention are significantly reduced, indicating that the surface of the tobacco powder has changed from hydrophobic to hydrophilic. The enhanced hydrophilicity means that the compatibility of the tobacco powder with water-based binders and fragrance systems has been substantially improved. This improvement in surface wettability is attributed to the active groups introduced into the surface of the tobacco powder by the low-temperature plasma treatment and the surface roughening structure. The two work together to reduce the surface energy of the tobacco powder and improve its affinity for liquids.

[0107] The comparison of modification effects shows that the modified tobacco powder obtained under different process parameters has certain differences in contact angle values, but all of them have achieved significant improvement over the unmodified tobacco powder, verifying the effectiveness of the method of the present invention in controlling the surface wettability of tobacco powder.

[0108] Detection of active group content

[0109] Core equipment: FTIR (Nicolet iS50 / Tensor 27 / IRTracer-100); Auxiliary equipment: tablet press, agate mortar and pestle, electronic balance.

[0110] Detection method: 1. Sample pretreatment: Take tobacco powder A1, A2 and D1 that have passed through a 200-mesh sieve, respectively, and vacuum dry them at 60℃ for 2 hours to remove moisture (to avoid interference with detection), and cool them to room temperature for later use.

[0111] 2. Tablet preparation: Weigh 0.5-1 mg of dry sample and 100-200 mg of dry KBr, grind them thoroughly under an infrared lamp until the particles are <2 μm, transfer them to a mold, and press them at 15-20 MPa for 1 min to make a transparent tablet; at the same time, prepare a blank KBr tablet as a background reference.

[0112] 3. Instrument Calibration and Testing: Turn on the FTIR and warm up for 30 minutes. Set the parameters (scanning range 4000-400cm). - ¹, Resolution 4cm - ¹, Scan 32 times), scan with a blank pellet to subtract the background, then put the sample pellet into the sample chamber for scanning and export the spectral data.

[0113] 4. Qualitative and quantitative analysis: The active groups (-OH, C=O, etc.) are qualitatively identified based on the characteristic wavenumbers. After baseline correction using instrument software, the peak area is calculated. The mass fraction of each group is then quantified by combining the Lambert-Beer law and the standard curve of the standard sample.

[0114] 5. Parallel validation: Three tablets were prepared from the same sample for testing, and the average value was taken as the final result. The test results are shown in Table 2.

[0115] Note: The entire process should be carried out in a dry environment to prevent KBr from absorbing moisture; the sample amount should not exceed 2mg to avoid opaque tablets and excessive absorbance; if the sample contains pigments or tar, it must be removed by Soxhlet extraction with petroleum ether before testing.

[0116] Table 2. Results of active group content detection in Examples A1, A2 and Comparative Example D1

[0117] in conclusion: The content of active groups in the modified tobacco powder A1 obtained in Example 1, the modified tobacco powder A2 obtained in Example 2, and the tobacco powder D1 obtained in the comparative example were tested. The test results showed that the content of active groups in tobacco powder D1, which had not undergone low-temperature plasma treatment, was low, which is consistent with the characteristics of surface inertness. However, the content of active groups in tobacco powders A1 and A2 modified by the method of the present invention was increased.

[0118] The increase in active groups mainly stems from the chemical modification during the low-temperature plasma treatment process, particularly the reaction of oxygen free radicals generated in the plasma state with the surface molecules of the tobacco powder, introducing oxygen-containing functional groups. These newly added active groups provide chemical interaction sites for the bonding of tobacco powder with binders, flavorings, and other auxiliary materials, enhancing interfacial bonding strength through hydrogen bonding, chemisorption, and other mechanisms. Simultaneously, the presence of active groups also improves the surface polarity of the tobacco powder, contributing to enhanced compatibility with polar auxiliary materials.

[0119] The comparison of different embodiments shows that the increase in the content of modified active groups is related to the processing parameters. However, each embodiment has achieved a significant improvement on the unmodified tobacco powder, verifying the effectiveness of the method of the present invention in introducing active groups on the surface of tobacco powder.

[0120] Aroma retention rate test

[0121] Core equipment: Gas chromatography-mass spectrometry (Agilent 7890B-5977B, USA); Auxiliary equipment: including thermal desorption unit (TD-100 / AutoTDS-III), 20mL headspace vials (with PTFE stoppers), constant temperature shaker (THZ-82), 0.1mg electronic analytical balance, and nitrogen blowing device; Reagents include tobacco characteristic aroma standard (purity ≥98%), chromatographic grade dichloromethane / anhydrous ethanol, high-purity nitrogen (99.999%), and Tenax TA adsorbent (60-80 mesh).

[0122] Detection method: 1. Take 5g of tobacco powder A1, A2 and D1 (passed through a 200-mesh sieve) and place them in headspace vials. Add 100μL of aroma standard of known concentration (C0), seal and shake at 25±1℃ and 150r / min for 30min, then let stand for 10min. 2. Preparation of Tenax TA thermal desorption tubes (0.2g adsorbent, activated by nitrogen purging at 300℃ for 30min); 3. Set the coupling parameters (thermal desorption: desorption at 250℃ for 10 min, cold trap -10℃; GC: HP-5MS column, programmed temperature rise, injection port 250℃; MS: EI source, SIM mode quantification). 4. Connect the headspace vial to the thermal desorption instrument, and after enrichment, detect the inlet gas phase to obtain the residual concentration (C1). The retention rate is calculated as (C0-C1) / C0×100%. The detection results are shown in Table 3.

[0123] Note: All glassware must be dried at 100℃ for 2 hours before use; operation must be quick to prevent aroma evaporation, and the headspace bottle must be sealed immediately after capping; the heat desorption tube must be purged and regenerated at high temperature after use to avoid cross-contamination.

[0124] Table 3. Aroma retention rate test results of Examples A1, A2 and Comparative Example D1

[0125] in conclusion: The aroma retention rates of the modified tobacco powder A1 obtained in Example 1, the modified tobacco powder A2 obtained in Example 2, and the tobacco powder D1 obtained in the comparative example were tested. The test results showed that the tobacco powder D1, which had not undergone low-temperature plasma treatment, had a relatively limited ability to retain the aroma standard. However, the aroma retention rates of tobacco powders A1 and A2 modified by the method of this invention were significantly improved.

[0126] This result is due, on the one hand, to the formation of a rough surface structure on the modified tobacco powder, which provides a larger specific surface area and more physical adsorption sites, thus facilitating the adhesion and retention of fragrance molecules; on the other hand, it is due to the introduction of surface-active groups, which can form hydrogen bonds and other interactions with the polar groups in the fragrance molecules, thereby enhancing the adsorption strength.

[0127] It is worth emphasizing that the method of this invention employs low-temperature plasma treatment, with the temperature controlled within a low range throughout the entire process, thus avoiding the destruction of the inherent aroma components in the tobacco powder by high temperatures. Therefore, the modified tobacco powder not only has an improved ability to adsorb added flavorings, but also retains its own natural aroma components intact, which is of great significance for ensuring the sensory quality of the final tobacco product.

[0128] Atmospheric evaluation experiment

[0129] The evaluation was conducted in accordance with the tobacco industry standard YC / T 138-2018 "Sensory Evaluation Method for Cigarettes", using a blind evaluation method, and a new auxiliary evaluation dimension of "aroma retention coordination" was added (related to the finished product aroma retention rate index).

[0130] The evaluation team consisted of seven professionals with advanced tobacco industry evaluation qualifications, all of whom had passed the sensory evaluation calibration assessment. The evaluation environment was a standard tobacco sensory evaluation room, which was odorless, evenly lit, and had stable airflow, meeting the industry's environmental requirements.

[0131] The core sensory evaluation dimensions are: aroma quality (10 points), aroma quantity (10 points), off-flavors (10 points), irritation (10 points), and aftertaste (10 points). A new dimension, aroma retention and harmony, is added (5 points; the higher the score, the better the aroma persistence and integration with the tobacco's natural aroma). The overall sensory score is a weighted average of the scores for each dimension (aroma quality 0.25, aroma quantity 0.25, off-flavors 0.2, irritation 0.2, aftertaste 0.1, aroma retention and harmony 0.1), with a maximum score of 10 points. Sensory evaluation experiments were conducted on the aerosol-generated products Z1-Z3 of Experiments 1-3, and the results are shown in Table 4.

[0132] Table 4 Sensory evaluation results of Examples A1, A2 and Comparative Example D1

[0133] in conclusion: The evaluation results showed that Z3, an aerosol product prepared using unmodified tobacco powder D1, scored low in conventional dimensions such as aroma quality, aroma quantity, off-flavors, irritation, and aftertaste. Its score in the newly added dimension of aroma retention and coordination was also low, resulting in a relatively low overall sensory score. The evaluators specifically noted that the aroma was not full-bodied during puffing, there were off-flavors interfering, the irritation was quite noticeable, the aftertaste was not clean enough, and the aroma decayed quickly, becoming significantly weaker towards the end of the puff.

[0134] The aerosol-generated product Z1, prepared using modified tobacco powder A1 from Example 1, showed significant improvements in all sensory indicators compared to Z3. The aroma was purer, more abundant, with effective suppression of off-flavors and irritation, a cleaner and more comfortable aftertaste, and significantly improved aroma retention and harmony. Evaluators reported that the aroma release was more uniform throughout the vaping process, and the aroma persistence was significantly better than the unmodified sample.

[0135] The aerosol product Z2, prepared using modified tobacco powder A2 from Example 2, exhibits further enhanced sensory performance. It achieves a high level of aroma quality and quantity, with virtually imperceptible off-flavors, mild irritation, a refreshing and comfortable aftertaste, and excellent aroma retention and coordination. The evaluators unanimously agreed that this sample possesses prominent aroma characteristics, blends well with the natural aroma of the tobacco, and delivers a full and lasting aroma during smoking, with overall sensory quality significantly superior to the unmodified sample.

[0136] The comprehensive evaluation results show that the tobacco powder modified by the method of this invention, when used to prepare aerosol-generating products, can improve the sensory quality of the products. This improvement stems from the enhanced surface properties of the modified tobacco powder: the increase in surface-active groups and the formation of a rough structure make the bond between the tobacco powder and the flavoring more robust, the flavoring more persistent in the matrix, and the aroma release more uniformly during inhalation; simultaneously, the bond between the modified tobacco powder and the binder is stronger, resulting in a denser matrix structure, more stable combustion, and reduced generation of impurities.

[0137] The sensory evaluation results, along with the aforementioned physicochemical test results such as surface contact angle, active group content, and aroma retention rate, corroborate each other, jointly verifying the effectiveness of the method of the present invention in improving tobacco powder performance and enhancing the quality of the final product.

[0138] This patent specification uses directional terms such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom" to describe various example structural parts and components of this patent. However, the use of these terms is merely for illustrative purposes and is based on the orientation of the examples shown in the accompanying drawings. Since the embodiments disclosed in this patent can be arranged in different orientations, these directional terms are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or the same as the direction of gravity.

[0139] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this patent will not describe the various possible combinations separately.

[0140] Furthermore, various implementations of this patent can be combined in any way, and as long as they do not violate the spirit of this patent, they should also be regarded as the content disclosed in this patent.

Claims

1. A method for preparing modified tobacco powder, characterized in that, Includes the following steps: Step S1: Pre-treat the initial tobacco powder to obtain the tobacco powder to be reacted; Step S2: Prepare low-temperature plasma; Step S3: The tobacco powder to be reacted is contacted with the low-temperature plasma and subjected to surface roughening treatment by the low-temperature plasma to obtain the modified tobacco powder with active groups.

2. The preparation method according to claim 1, characterized in that, Step S1 includes: Step S11: After filtering and removing impurities from the initial tobacco powder, fine tobacco powder is obtained; Step S12: The fine smoke powder is dried to obtain the smoke powder to be reacted.

3. The preparation method according to claim 2, characterized in that, In step S11, the initial tobacco powder is filtered through a sieve to obtain the fine tobacco powder; The mesh size of the sieve is 150-250 mesh; In step S12, the fine smoke powder is dried in an oven to form the smoke powder to be reacted; The moisture content of the tobacco powder to be reacted is less than 5%; The drying temperature is 58~63℃, 63~68℃ or 68~73℃.

4. The preparation method according to claim 2, characterized in that, Step S2 includes: Step S21: The first gas and the second gas are mixed in proportion using a low-temperature plasma processing device to obtain a mixed gas; Step S22: Apply energy to the mixed gas and partially ionize it to obtain the low-temperature plasma.

5. The preparation method according to claim 4, characterized in that, In step S21, the first gas and the second gas are non-polymerizable gases; The volume mixing ratio of the first gas and the second gas is 4:1; In step S22, the processing power of the low-temperature plasma processing device is 70~90W, 90~110W, or 110~130W; The processing chamber pressure of the low-temperature plasma processing device is 40~60pa, 60~80pa or 80~100pa.

6. The preparation method according to claim 4, characterized in that, Step S3 includes: Step S31: Add the powder to be reacted to the low-temperature plasma treatment device and contact it with the mixed gas; Step S32: Wait for the reactant smoke powder to react with the low-temperature plasma to obtain the modified smoke powder.

7. The preparation method according to claim 6, characterized in that, In step S31, the feeding rate of the tobacco powder to be reacted is 1~2 kg / h; In step S32, the reaction temperature is 30~50℃, 50~70℃, or 70~90℃; The reaction time is 20~40s, 40~60s, or 60~80s.

8. A modified tobacco powder, characterized in that, The modified tobacco powder is prepared by the preparation method according to any one of claims 1 to 7; The modified tobacco powder has a rough surface and contains active groups; The active group is one or more of hydroxyl, carboxyl, carbonyl or hydroperoxy groups; The surface contact angle of the modified tobacco powder is 40~45°, 45~50° or 50~55°; The modified tobacco powder has an active group content of 0.50~0.60 mmol / g, 0.60~0.70 mmol / g, or 0.70~0.80 mmol / g; The aroma retention rate of the modified tobacco powder is greater than or equal to 82%, greater than or equal to 87%, or greater than or equal to 92%.

9. An aerosol generation matrix, characterized in that, The aerosol generating matrix includes the modified smoke powder as described in claim 8.

10. An aerosol-generating product, characterized in that, The aerosol-generating article includes the aerosol-generating matrix as described in claim 9.

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