A low-nicotine tobacco extract and its preparation method and application

Abstract

This invention relates to the field of tobacco flavoring and fragrance technology, and particularly to a low-nicotine tobacco extract, its preparation method, and its application. The preparation method includes the following steps: S1. Extracting tobacco raw materials with a solvent to obtain a tobacco extract; S2. Adsorbing nicotine from the tobacco extract with a hygroscopic adsorbent in a heated, closed environment with a relative humidity of 30%-60%, removing the hygroscopic adsorbent after adsorption to obtain the low-nicotine tobacco extract. This application utilizes heating and relative humidity conditions, which not only cause the hygroscopic adsorbent to form a water film on its pore walls after absorbing moisture, making it easier to adsorb nicotine but less likely to adsorb aroma substances; but also makes nicotine more easily volatilized and released compared to aroma substances; thereby achieving the purpose of effectively adsorbing nicotine while reducing the adsorption of aroma substances.

Description

Technical Field

[0001] This invention relates to the field of tobacco flavoring and fragrance technology, and in particular to a low-nicotine tobacco extract, its preparation method, and its application. Background Technology

[0002] Tobacco extracts have long been considered the most effective and least harmful natural flavoring agent for cigarettes, playing an irreplaceable role in enhancing the natural aroma of tobacco and improving smoking satisfaction. They are widely used in tobacco flavorings, new tobacco products, and tobacco sheet flavorings. However, tobacco extracts contain a significant amount of nicotine. When used in cigarettes, new tobacco products, or tobacco sheets, a slightly larger amount can result in a harsh aroma, increased throat impact, and increased irritation; a smaller amount, on the other hand, fails to achieve the desired flavor enhancement. Therefore, selectively separating nicotine from tobacco extracts while minimizing the loss of other aroma-enhancing substances solves these problems when used in the flavoring of cigarettes and other tobacco products.

[0003] The patent document with publication number CN107149161A discloses a low-nicotine tobacco extract and its preparation method. First, a tobacco extract with a relatively low nicotine content is prepared by extraction with ketone or ester solvents. Then, a certain amount of nicotine is removed by washing with water, the solvent is removed by concentration, and finally, the nicotine is removed relatively completely by molecular distillation, thereby preparing a tobacco extract flavoring with very low nicotine content and good aroma quality.

[0004] The above methods still result in tobacco extracts containing a significant amount of nicotine after treatment. This is because: 1. When extracted with ketone or ester solvents, nicotine and aroma compounds dissolve simultaneously in the extractant, making it impossible to prepare a tobacco extract with a relatively low nicotine content; 2. Nicotine is soluble in water, ethanol, chloroform, ether, and oils, and washing the extract with water can only separate a small amount of nicotine; 3. Molecular distillation cannot remove large quantities of nicotine from the extract. Furthermore, the aforementioned treatment methods are complex and costly, making them unsuitable for industrial application.

[0005] Meanwhile, it uses smoking evaluation to prove that the aroma substances in the extract are preserved. However, in reality, firstly, it extracts esters or ketones from tobacco leaves using ketone or ester solvents. However, the aroma components with relatively high content in cigarette tobacco leaves are mainly alcohols, hydrocarbons, and heterocyclic compounds. The aroma components of esters or ketones in tobacco leaves are relatively low, which makes the aroma component content in the extract actually low as well. Secondly, molecular distillation also leads to the loss of esters or ketones as aroma components. This is because the principle of molecular distillation is to separate light and heavy molecules by utilizing the difference in their free paths. Nicotine has a molecular weight of around 162 and a boiling point of around 247°C. Many esters or ketones in tobacco have molecular weights and boiling points that are lower than or very similar to those of nicotine. For example, representative ester compounds include γ-butyrolactone (86 molecular weight, 200°C), γ-valerolactone (100 molecular weight, 207°C), and methyl phenylacetate (150 molecular weight, 216°C). Representative ketone compounds include megastigmatrienone (190 molecular weight, 289°C), damascone (190 molecular weight, 271°C), and methylheptenone (126 molecular weight, 173°C). Therefore, when removing light components, molecular distillation inevitably removes a significant amount of aroma substances.

[0006] Therefore, the above methods are difficult to effectively reduce nicotine content while maintaining the content of aroma components. Summary of the Invention

[0007] The present invention aims to solve the above problems by providing a low-nicotine tobacco extract, its preparation method, and its application.

[0008] The technical solution to the problem of this invention is, firstly, a method for preparing a low-nicotine tobacco extract, comprising the following steps:

[0009] S1. Extract tobacco raw materials with a solvent to obtain tobacco extract;

[0010] S2. The tobacco extract is subjected to nicotine adsorption using a hygroscopic adsorbent in a closed environment with heating and a relative humidity of 30%-60%. After adsorption, the hygroscopic adsorbent is removed to obtain a low-nicotine tobacco extract.

[0011] In this application, nicotine is removed primarily through physical adsorption separation, utilizing its water solubility. Specifically: Firstly, in a humid environment, after absorbing moisture, the pore walls of the hygroscopic adsorbent form a water film. Since nicotine is water-soluble, while most aroma compounds are insoluble, the hygroscopic adsorbent effectively adsorbs nicotine but not aroma compounds. Secondly, under heating and humidity conditions, water-soluble nicotine in the tobacco extract is more readily volatilized and dispersed in the water molecules of the environment, thus being adsorbed by the hygroscopic adsorbent. However, most aroma compounds in the tobacco extract are insoluble or poorly soluble in water; in a water-saturated environment, the volatilization of these aroma compounds is hindered, making them difficult to volatilize. Based on this, an extract with low nicotine content and high aroma compound content is obtained.

[0012] Furthermore, the hygroscopic adsorbent that has completed adsorption can be washed off with water and freeze-dried to obtain nicotine, which can be used in pharmaceuticals, e-cigarette liquids, etc., thus improving the utilization rate of nicotine and hygroscopic adsorbent.

[0013] Generally, selectable hygroscopic adsorbents include one or more of bentonite, cross-linked polyvinylpyrrolidone, and cyclodextrin. However, in the above adsorption process, the hygroscopic adsorbent is easily saturated, affecting the sustained adsorption effect of nicotine. Therefore, as a preferred embodiment of the present invention, the hygroscopic adsorbent includes a hygroscopic swelling material and / or a hygroscopic and breathable material.

[0014] In embodiments where a single hygroscopic expansion material is used as the hygroscopic adsorbent, based on the expansion effect of the hygroscopic expansion material, after adsorbing a certain amount of water molecules dissolved in nicotine, it can expand to generate more pores, thereby further and continuously adsorbing nicotine and water molecules dissolved in nicotine, ensuring long-term adsorption effect and improving adsorption efficiency.

[0015] The hygroscopic swelling material should be selected from materials insoluble in the solvent used during extraction to facilitate the subsequent separation of tobacco extract and adsorbent. Preferably, the hygroscopic swelling material includes one or both of bentonite and cross-linked polyvinylpyrrolidone. Bentonite is insoluble in water and common organic solvents and has strong hygroscopic and swelling properties, capable of adsorbing 8-15 times its own volume of water. Cross-linked polyvinylpyrrolidone is insoluble in water, alkalis, acids, and common organic solvents, and also has strong swelling properties and the ability to complex with various substances.

[0016] In embodiments where a single moisture-absorbing and breathable material is used as the hygroscopic adsorbent, once the moisture-absorbing and breathable material becomes saturated with moisture, the water molecules containing dissolved nicotine will rapidly permeate from the saturated water vapor end to the unsaturated vapor end along the channels provided by the moisture-absorbing and breathable material. This allows the originally saturated end to re-adsorb water molecules containing dissolved nicotine, ensuring a long-lasting adsorption effect.

[0017] The moisture-absorbing and permeable material is preferably a film-forming material that facilitates the separation of tobacco extract and adsorbent. Preferably, the moisture-absorbing and permeable material includes a cyclodextrin-polyurethane blend. The cyclodextrin-polyurethane blend refers to a membrane structure obtained by dissolving polyurethane resin into a polyurethane solution, adding β-cyclodextrin, or a complex of β-cyclodextrin and polytetrahydrofuran, stirring until homogeneous, and then coating the solution. In the cyclodextrin-polyurethane blend, the hydroxyl and ether oxygen groups of β-cyclodextrin and polytetrahydrofuran provide more channels and adsorption sites for water molecules to enter the polyurethane membrane, improving the moisture absorption effect. When water molecules reach saturation in the polyurethane membrane, they will permeate from the saturated water vapor end to the unsaturated vapor end along the channels provided individually or jointly by β-cyclodextrin and polytetrahydrofuran, improving the membrane's moisture permeability.

[0018] In embodiments employing both hygroscopic expansion materials and hygroscopic permeable materials, the combined use of the two can further synergistically improve the adsorption effect. When used in combination, it is preferable to load the hygroscopic expansion material onto one side of the hygroscopic permeable material. While improving the hygroscopic performance of the hygroscopic permeable material alone, the hygroscopic expansion material also stretches the hygroscopic permeable material through expansion, increasing the micropores of the membrane and accelerating the permeation of the membrane, thereby improving the adsorption efficiency.

[0019] In S1, the choice of solvent is unrestricted. It can be commonly used water, alcohol, ketone, or ester solvents. These solvents can be used for extraction in sequence or mixed together.

[0020] In order to extract the aroma components from the tobacco raw material as much as possible, the extraction solid-liquid ratio, extraction temperature and time should be limited. As a preferred embodiment of the present invention, the mass ratio of tobacco raw material to solvent is 1:(5-10); more preferably, the extraction temperature is 50℃-90℃ and the extraction time is 1h-4h.

[0021] Since the adsorbent is a hygroscopic material, to reduce the influence of the solvent in the extract on the adsorbent, as a preferred embodiment of this invention, the extract is concentrated to a specific gravity of 1.1-1.3 (20°C) after extraction to obtain the tobacco extract. Specific gravity refers to the ratio of the weight of a completely dry and compacted substance to the weight of an equal volume of pure water; here, it can be understood as the mass ratio of the absolutely dry substance to the solvent. At this point, the tobacco extract is in the form of a paste. This application aims to minimize the amount of solvent in the tobacco extract, but should not completely remove the solvent, to ensure the subsequent release of nicotine and facilitate the separation and removal of the adsorbent.

[0022] In S2, the heating temperature affects the evaporation rate. Since physical adsorption is used, the evaporation rate should not be too fast. Preferably, adsorption is performed at 20℃-45℃. The adsorption time should also not be too long or too short. Too long a time may lead to adsorbent saturation, while too short a time may result in insufficient adsorption. The specific adsorption time is related to the temperature and the amount of adsorbent used. Preferably, under the conditions of 20℃-45℃ and a ratio of adsorbent to tobacco extract of 0.5g / L-1.6g / L, adsorption is performed for 30min-80min.

[0023] Another objective of this invention is to provide a low-nicotine tobacco extract prepared by the above method, wherein the nicotine content is relatively low and the content of other aroma components is relatively high.

[0024] Another objective of this invention is to provide an application of a low-nicotine tobacco extract in cigarettes. This extract, which has a significant difference in nicotine and aroma substance content, can significantly enhance the aroma and flavor of cigarettes, harmonize the tobacco aroma, increase the aroma quantity, and improve the quality of cigarettes, without significantly increasing the strength or irritation.

[0025] In application, as a preferred embodiment of the present invention, the amount of the low-nicotine tobacco extract used is 0.04%-0.08% of the mass of cigarette tobacco. Preferably, it is 0.06%.

[0026] The beneficial effects of this invention are:

[0027] 1. This application provides a method for preparing a low-nicotine tobacco extract. By using heating and relative humidity conditions, not only does the hygroscopic adsorbent form a water film on the pore walls after absorbing moisture, making it easier to adsorb nicotine but less likely to adsorb aroma substances; it also makes nicotine more easily volatilized and released compared to aroma substances; thereby achieving the purpose of effectively adsorbing nicotine while reducing the adsorption of aroma substances; nicotine can be removed by up to 88.35%, while other aroma components are lost by 10.11%.

[0028] 2. This application provides a low-nicotine tobacco extract with a significant difference in nicotine and aroma substance content. When applied to cigarettes, it can significantly increase the aroma concentration of cigarettes, reduce off-flavors, and does not increase irritation or throat discomfort. Compared with ordinary tobacco extracts, the dosage can be increased to compensate for the lack of aroma in low-tar cigarettes without causing other side effects. Furthermore, the nicotine can also be used in electronic cigarettes, pharmaceuticals, and other fields. Attached Figure Description

[0029] Figure 1 This is the total ion chromatogram of the tobacco extract from Example 1, analyzed by GC-MS.

[0030] Figure 2 This is a graph showing the integral results of nicotine content in tobacco extracts from Example 1;

[0031] Figure 3 These are GC-MS analysis diagrams before and after adsorption treatment in Example 1. Detailed Implementation

[0032] The following are specific embodiments of the present invention, and the technical solution of the present invention will be further described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments. Example 1

[0033] A low-nicotine tobacco extract is prepared by the following steps:

[0034] S1. Cut the tobacco raw material into 1mm wide shreds, add water to the shreds (the water mass is 8 times the mass of the tobacco shreds), and then heat to extract at 65℃ for 3 hours. After extraction, filter out impurities, and distill the filtrate under reduced pressure to concentrate it to a ratio (20℃) of 1.2, obtaining a relatively viscous tobacco extract.

[0035] GC-MS analysis of tobacco extracts yielded the following results: Figure 1 As shown in the figure, it has a high content of nicotine. Furthermore, the results of integrating each component are as follows: Figure 2 As shown, the tobacco extract contains 31.8% nicotine and 68.2% other aroma substances.

[0036] S2. The tobacco extract and crospyrrolidone were placed separately in a sealed environment at 30°C and 50% relative humidity and allowed to stand for 1 hour. Then, still in a sealed environment at 30°C and 50% relative humidity, crospyrrolidone was added to the tobacco extract at a ratio of 1 g / L. After stirring evenly, the mixture was allowed to stand for adsorption for 60 minutes. After adsorption was complete, the crospyrrolidone was removed by filtration to obtain a low-nicotine tobacco extract.

[0037] GC-MS analysis of low-nicotine tobacco extract yielded the following results: Figure 3 As shown, the nicotine content was significantly reduced after adsorption, while the content of other substances decreased only slightly. Specifically, based on the GC-MS integration results, the nicotine removal rate was 88.36%, and the aroma-producing substance removal rate was 10.11%. Example 2

[0038] This embodiment is basically the same as that of Embodiment 1, except that in step S2, cross-linked polyvinylpyrrolidone is replaced with an equal mass of bentonite. Example 3

[0039] This embodiment is basically the same as that of Embodiment 1, except that in step S2, cross-linked polyvinylpyrrolidone is replaced with an equal mass of cyclodextrin. Example 4

[0040] This embodiment is basically the same as that of Embodiment 1, except that in step S2, cross-linked polyvinylpyrrolidone is replaced with an equal mass of cyclodextrin-polyurethane blend.

[0041] The cyclodextrin-polyurethane blend was prepared by the following steps: β-cyclodextrin was dissolved in DMAc to prepare a 20% (w / w) solution. Polytetrahydrofuran was then added to the solution at a molar ratio of β-cyclodextrin to polytetrahydrofuran of 1:0.5. After stirring for 1 hour, the mixture was dried at 90°C. Sufficient ethanol was then added to the dried sample to wash away any polytetrahydrofuran that had not formed a stable complex with β-cyclodextrin. The sample was then vacuum filtered and washed with ethanol to obtain the complex. Polyurethane resin was dissolved in DMAc to prepare a 13% (w / w) polyurethane solution. 4% (w / w) of the above-mentioned complex was added to the solution, and the mixture was stirred evenly at 65°C. After standing to remove bubbles, the mixture was dropped onto a glass plate, scraped into a film using a glass rod, and dried at 80°C to obtain the cyclodextrin-polyurethane blend.

[0042] In this procedure, the tobacco extract and the cyclodextrin-polyurethane blend were placed separately in a sealed environment at 30°C and 50% relative humidity and allowed to stand for 1 hour. Then, still in a sealed environment at 30°C and 50% relative humidity, the tobacco extract was coated onto the bottom of a sealed glass dish to a thickness of 1 mm. The glass dish was connected to a vibrating motor, and a cyclodextrin-polyurethane blend film was then placed on top of the tobacco extract, with a cyclodextrin-polyurethane blend to tobacco extract ratio of 1 g / L. Adsorption was carried out under vibration for 60 minutes. After adsorption was complete, the cyclodextrin-polyurethane blend film was removed to obtain a low-nicotine tobacco extract. Example 5

[0043] This embodiment is basically the same as Embodiment 1, except that in step S2, cross-linked polyvinylpyrrolidone is replaced with an equal mass of cyclodextrin-polyurethane blend loaded with cross-linked polyvinylpyrrolidone.

[0044] In the first step, the tobacco extract, cross-linked polyvinylpyrrolidone (XLPE), and cyclodextrin-polyurethane blend were placed in a sealed environment at 30°C and 50% relative humidity and allowed to stand for 1 hour. Then, still in a sealed environment at 30°C and 50% relative humidity, XLPE was added to the tobacco extract at a ratio of 0.5 g / L, and the mixture was stirred until homogeneous. This mixture was then coated onto one side of a cyclodextrin-polyurethane blend film with a thickness of 1 mm, maintaining a cyclodextrin-polyurethane blend-to-total-extract ratio of 0.5 g / L. The mixture was allowed to stand for 60 minutes for adsorption. After adsorption was complete, the cyclodextrin-polyurethane blend film was removed, and XLPE was filtered out to obtain a low-nicotine tobacco extract. Example 6

[0045] This embodiment is basically the same as Embodiment 1, except that in step S2, cross-linked polyvinylpyrrolidone is replaced with an equal mass mixture, which is a mixture of cross-linked polyvinylpyrrolidone and bentonite in equal mass ratio. Example 7

[0046] This embodiment is basically the same as embodiment 1, except that the relative humidity is 30% in step S2. Example 8

[0047] This embodiment is basically the same as embodiment 1, except that in step S2, the relative humidity is 60%. Example 9

[0048] This embodiment is basically the same as Example 1, except that in step S2, the ratio of cross-linked polyvinylpyrrolidone to tobacco extract is 0.5 g / L, and it is adsorbed for 80 min in a closed environment with a temperature of 20°C and a relative humidity of 50%. Example 10

[0049] This embodiment is basically the same as that of Example 1, except that in step S2, the ratio of cross-linked polyvinylpyrrolidone to tobacco extract is 1.6 g / L, and it is adsorbed for 30 min in a closed environment with a temperature of 45°C and a relative humidity of 50%. Example 11

[0050] This embodiment is basically the same as Embodiment 1, except that in step S1, after extraction, impurities are filtered out, and the filtrate is concentrated by vacuum distillation to a specific gravity (20°C) of 1.1 to obtain tobacco extract. Example 12

[0051] This embodiment is basically the same as Embodiment 1, except that in step S1, after extraction, impurities are filtered out, and the filtrate is concentrated by vacuum distillation to a specific gravity (20°C) of 1.3 to obtain tobacco extract. Example 13

[0052] This embodiment is basically the same as Embodiment 1, except that in step S1, the tobacco raw material is cut into 1mm wide tobacco shreds, water is added to the obtained tobacco shreds, and the mass of water is 5 times the mass of tobacco shreds; then heating and extraction are carried out at a temperature of 50°C for 1 hour. Example 14

[0053] This embodiment is basically the same as Embodiment 1, except that in step S1, the tobacco raw material is cut into 1mm wide tobacco shreds, water is added to the obtained tobacco shreds, and the mass of water is 10 times the mass of tobacco shreds; then heating and extraction are carried out at a temperature of 90°C for 4 hours.

[0054] Comparative Example 1

[0055] This comparative example is basically the same as Example 1, except that the relative humidity is 10% in step S2.

[0056] Comparative Example 2

[0057] This comparative example is basically the same as Example 1, except that the relative humidity is 80% in step S2.

[0058] Comparative Example 3

[0059] This comparative example is basically the same as Example 1, except that in step S2, cross-linked polyvinylpyrrolidone is replaced with an equal mass of expanded graphite adsorbent.

[0060] Adsorption evaluation

[0061] The tobacco extracts and low-nicotine tobacco extracts obtained in Examples 1-14 and Comparative Examples 1-3 were analyzed by GC-MS, and the results are shown in Table 1 below.

[0062] Table 1.

[0063]

[0064] As shown in Table 1, by comparing Examples 1, 7-8, and Comparative Examples 1-2, it can be seen that the relative humidity of the adsorption environment has a significant impact on the adsorption effect. Under the condition of using cross-linked polyvinylpyrrolidone hygroscopic adsorbent, an environmental humidity of 30%-60% can effectively improve the adsorption effect of cross-linked polyvinylpyrrolidone on nicotine, while reducing the adsorption of other aroma substances. When the environmental humidity is too low, the water film on the pores of the hygroscopic adsorbent is incomplete, and other aroma substances that are insoluble in water are easily volatilized and released, resulting in a decrease in the adsorption effect on nicotine and an increase in the adsorption effect on other aroma substances. When the environmental humidity is too high, the hygroscopic adsorbent becomes saturated with water, and the adsorption effect on nicotine and other aroma substances is reduced.

[0065] By comparing Examples 1-6 and Comparative Example 3, it can be seen that the performance of the adsorbent has a significant impact on the adsorption effect. In Comparative Example 3, expanded graphite is an oleophilic adsorbent and is difficult to absorb moisture, thus reducing the adsorption effect on nicotine but improving the adsorption effect on other aroma substances. Example 15

[0066] The application of a low-nicotine tobacco extract in cigarettes includes the following steps:

[0067] The low-nicotine tobacco extract obtained in Example 1 was diluted with water to a mass concentration of 1.2% to obtain a flavoring agent. The flavoring agent was sprayed onto the tobacco shreds at a mass ratio of 0.06% of the low-nicotine tobacco extract to the tobacco shreds. After spraying, the tobacco shreds were sealed and stored for 2 hours, then dried to a moisture content of 12.5% ​​to obtain flavored cigarettes. Example 16

[0068] This embodiment is basically the same as embodiment 15, except that the flavoring is sprayed onto the tobacco shreds at a mass ratio of 0.04% for low nicotine tobacco extract to tobacco shreds. Example 17

[0069] This embodiment is basically the same as embodiment 15, except that the flavoring is sprayed onto the tobacco shreds at a mass ratio of 0.08% for low nicotine tobacco extract to tobacco shreds.

[0070] Comparative Example 4

[0071] The tobacco extract obtained in step S1 of Example 1 was diluted with water to a mass concentration of 1.2% to obtain a flavoring agent. The flavoring agent was sprayed onto the tobacco shreds at a mass ratio of 0.06% for the low-nicotine tobacco extract to the shredded tobacco. After spraying, the tobacco shreds were sealed and stored for 2 hours, then dried to a moisture content of 12.5% ​​to obtain flavored cigarettes.

[0072] Comparative Example 5

[0073] Take deionized water of the same mass as the amount of flavoring used in Example 15, spray it onto the tobacco shreds, and after spraying, seal the tobacco shreds and store them for 2 hours. Then dry them until the moisture content is 12.5% ​​to obtain flavored cigarettes.

[0074] Suction Evaluation

[0075] The flavored cigarettes prepared in Example 15 and Comparative Examples 4-5 were evaluated by smoking, and the results are shown in Table 2 below.

[0076] Table 2.

[0077]

[0078] As shown in Table 2, it can be seen that after adding the tobacco extract with 88% nicotine separated by PVPP adsorption in Example 15, the aroma and aftertaste scores increased significantly, the harmony was significantly enhanced, the off-flavors were slightly reduced, and the gloss, irritation and strength did not change significantly. In contrast, the samples with tobacco extract without nicotine removal showed an increase in aroma and aftertaste scores, a smaller reduction in off-flavors, no significant changes in harmony, gloss and irritation, and a slight increase in strength.

[0079] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for preparing a low-nicotine tobacco extract, characterized in that: Includes the following steps: S1. Extract the tobacco raw material with water, and then concentrate the extract to a specific gravity of 1.1-1.3 to obtain the tobacco extract; S2. The tobacco extract is subjected to nicotine adsorption using a hygroscopic adsorbent in a closed environment with heating and a relative humidity of 30%-60%. After adsorption, the hygroscopic adsorbent is removed to obtain a low-nicotine tobacco extract. The dosage of the hygroscopic adsorbent is 0.5 g / L-1.6 g / L, and the adsorption is carried out at 20℃-45℃ for 30 min-80 min; The hygroscopic adsorbent is a hygroscopic swelling material and / or a hygroscopic and breathable material; The moisture-absorbing and expanding material is one or both of bentonite and cross-linked polyvinylpyrrolidone. The moisture-absorbing and breathable material is a cyclodextrin-polyurethane blend.

2. The method for preparing a low-nicotine tobacco extract according to claim 1, characterized in that: In step S1, the mass ratio of tobacco raw material to water is 1:(5-10), the extraction temperature is 50℃-90℃, and the extraction time is 1h-4h.

3. A low-nicotine tobacco extract prepared by the preparation method according to any one of claims 1-2.

4. The application of the low-nicotine tobacco extract as described in claim 3 in cigarettes.

5. The application of the low-nicotine tobacco extract according to claim 4 in cigarettes, characterized in that: The amount of the low-nicotine tobacco extract used is 0.04%-0.08% of the mass of cigarette tobacco.

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