Method for adsorbing tobacco-specific nitrosamines, tobacco extract and atomizing matrix

Abstract

A method for adsorbing tobacco-specific nitrosamines from a tobacco extract. The method comprises: 1) diluting a tobacco extract with a solvent; 2) adding activated carbon to the diluted tobacco extract, followed by static adsorption; 3) subjecting the tobacco extract, which has been adsorbed by activated carbon, to first centrifugation and then first filtration to obtain a first filtrate; 4) adding a molecular sieve to the first filtrate for stirring and adsorption; 5) subjecting the tobacco extract, which has been adsorbed by the molecular sieve, to second centrifugation and then second filtration to obtain a second filtrate; and 6) concentrating the second filtrate under reduced pressure into a tobacco extract that has been concentrated under reduced pressure having the same solid content as the tobacco extract, wherein the content of tobacco-specific nitrosamines in the tobacco extract that has been concentrated under reduced pressure is less than 70000 ng / g. In addition, a tobacco extract obtained by the method and an atomizing matrix comprising the tobacco extract are provided.

Description

Methods for adsorbing tobacco-specific nitrosamines, tobacco extract, and atomization substrate

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202410982363.3, filed on July 19, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the field of electronic atomization technology, in particular to a method for adsorbing tobacco-specific nitrosamines in tobacco extract, a tobacco extract, and an atomization substrate. BACKGROUND

[0004] Tobacco-specific nitrosamines (TSNAs) are a class of N-nitrosamine compounds that exist only in tobacco and smoke. They are generated by the nitrosation of secondary and tertiary amine alkaloids with nitrate or nitrite during the curing, fermentation, and combustion of tobacco. There are four important TSNAs, including nitrosonornicotine (NNN), nitrosanatabine (NAT), nitrosanabasine (NAB), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). TSNAs can induce various cancers in experimental animals, and the carcinogenicity of NNN and NNK has been verified. Therefore, it is generally believed that the content and composition of TSNAs directly affect the safety of tobacco products.

[0005] Therefore, it is necessary to remove TSNAs from tobacco extract. SUMMARY

[0006] In view of the above, the main purpose of the present disclosure is to provide a method for effectively adsorbing TSNAs in tobacco extract without affecting the taste of electronic cigarettes. The method also has the advantages of energy saving, time saving, cost reduction, significant economic and social benefits. The further purpose of the present disclosure is to provide a tobacco extract obtained by the method and an atomization substrate containing the tobacco extract.

[0007] To achieve the above-mentioned purposes, the present disclosure provides the following technical solutions.

[0008] The first aspect of the present disclosure provides a method for adsorbing tobacco-specific nitrosamines in tobacco extract, comprising:

[0009] 1) diluting the tobacco extract with a solvent;

[0010] 2) adding activated carbon to the diluted tobacco extract for static adsorption;

[0011] 3) subjecting the tobacco extract adsorbed by the activated carbon to a first centrifugation, and then to a first filtration to obtain a first filtrate;

[0012] 4) adding molecular sieves to the first filtrate and stirring to adsorb;

[0013] 5) subjecting the tobacco extract adsorbed by the molecular sieves to a second centrifugation, and then to a second filtration to obtain a second filtrate; and

[0014] 6) concentrating the second filtrate under reduced pressure to a solid content equal to that of the tobacco extract concentrated under reduced pressure, and the content of tobacco-specific nitrosamines in the tobacco extract concentrated under reduced pressure is less than 70,000 ng / g; preferably, less than 60,000 ng / g; more preferably, less than 50,000 ng / g.

[0015] In some embodiments, the mass ratio of the activated carbon, the molecular sieves, and the tobacco extract is (2-3) : (1-2) : 10, preferably 3:2:10.

[0016] In some embodiments, the pore size of the molecular sieves is to preferably to more preferably

[0017] In some embodiments, the silica-alumina ratio of the molecular sieves is 12.5 to 25, preferably 25.

[0018] In some embodiments, the molecular sieves are selected from the group consisting of HZSM-5, NaZSM-5, NaY, CaA, preferably HZSM-5.

[0019] In some embodiments, the mesh number of the activated carbon is 100 to 500 mesh, preferably 200 to 300 mesh, more preferably 200 mesh.

[0020] In some embodiments, the solvent is selected from the group consisting of water, ethanol, or a mixture of the two, and the mass ratio of the solvent to the tobacco extract is 10:1 to 1:1, preferably 5:1 to 1:1, more preferably 3:1.

[0021] In some embodiments, the static adsorption is carried out at 20 to 50°C, preferably 25°C, for 10 to 20 hours, preferably for 15 hours.

[0022] In some embodiments, the stirring adsorption is carried out at 20 to 50°C, preferably 25°C, for 1 to 3 hours, preferably for 2 hours.

[0023] In some embodiments, the first centrifugation and the second centrifugation are performed at 4°C at 4000 rpm to 6000 rpm, preferably 5000 rpm, for 10 to 15 minutes.

[0024] In some embodiments, the first filtration is performed using a 200 to 600 mesh, preferably 600 mesh, filter.

[0025] In some embodiments, the second filtration is performed using a 200 to 600 mesh, preferably 600 mesh, filter.

[0026] In some embodiments, the concentration under reduced pressure is performed at 45°C to 65°C, 60 mbar to 120 mbar, preferably at 60°C, 60 mbar.

[0027] A second aspect of the present disclosure provides a tobacco extract obtained by the method of the present disclosure.

[0028] A third aspect of the present disclosure provides an aerosol substrate comprising the tobacco extract of the present disclosure, wherein the mass percentage of the tobacco extract in the total mass of the aerosol substrate is 0.2% to 5%, preferably 0.2% to 2%, more preferably 0.5%.

[0029] In the present disclosure, by using activated carbon powder and molecular sieve as adsorbents to adsorb the tobacco extract, TSNAs in the tobacco extract can be effectively removed while the tobacco aroma is taken into account. For tobacco extract with very high TSNAs content, the method of the present disclosure reduces the TSNAs content to below 70000 ng / g, with a removal rate of up to 99.1%, so that the aerosol substrate containing the tobacco extract greatly reduces the harm to human health and the pollution to the environment caused by TSNAs in tobacco products, and the taste is close to that of traditional tobacco, and the satisfaction is improved. Moreover, the method of using activated carbon powder and molecular sieve for adsorption is time-saving, low-cost, and has significant economic and social benefits. DETAILED DESCRIPTION

[0030] The following detailed description discusses exemplary implementations. The detailed description included herein should not be interpreted as a limitation on the disclosure. Further, although specific language maybe used herein, the claims should not be limited to the specific language used. One skilled in the art will understand that other implementations, including modifications, are within the spirit and scope of the present disclosure.

[0031] Throughout this specification, unless specifically stated otherwise, the terms used herein are to be interpreted as generally used in the art. Thus, 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 disclosure belongs.

[0032] It should be noted that in the embodiments of the present disclosure, the terms "comprising", "containing" or any other variants thereof are intended to cover non-exclusive inclusion, so that a method or device comprising a series of elements not only includes the elements explicitly listed, but also includes other elements not explicitly listed, or further includes elements inherent in the implementation of the method or device. Without more limitation, the element defined by the sentence "comprising a" does not exclude the presence of other related elements in the method or device comprising the element.

[0033] In the present disclosure, the words "aerosol for user inhalation", "aerosol" or "smoke" can include, but are not limited to, aerosol, suspension liquid, low-temperature vapor and volatile gas.

[0034] TSNAs do not exist in fresh tobacco leaves, and they are generated in the process of tobacco curing, processing and smoking. The process of tobacco extraction and processing can enrich TSNAs, resulting in a higher content of TSNAs in the extract. The current removal methods for TSNAs are divided into two categories: pretreatment and post-treatment. The pretreatment is to remove or control the content of TSNAs precursors (nitrate, nitrite, alkaloid, etc.) to reduce TSNAs, mainly including tobacco source removal and improvement of tobacco curing method. The post-treatment method is to treat the TSNAs already present in the tobacco leaves, mainly including physical adsorption and microbial fermentation. For the TSNAs already present in the tobacco extract, the liquid phase adsorption method can be used to remove the tobacco extract, but the composition of the tobacco extract is more complex than that of the tobacco extract, containing more aroma substances and higher density. How to effectively remove TSNAs while ensuring the aroma of tobacco extract in electronic cigarettes is a big difficulty in the research of removing TSNAs in tobacco extract.

[0035] Therefore, the first aspect of the present disclosure provides a method for adsorbing tobacco-specific nitrosamines in tobacco extract. In the method of the present disclosure, low-cost activated carbon and molecular sieve are mainly used as adsorption materials, and liquid phase adsorption is used to adsorb TSNAs in tobacco extract, forming a new technology for removing TSNAs in electronic cigarette oil and other tobacco products, reducing the harm of TSNAs in tobacco products to human health.

[0036] Specifically, the method of the present disclosure comprises:

[0037] 1) diluting the tobacco extract with a solvent;

[0038] 2) adding activated carbon to the diluted tobacco extract for static adsorption;

[0039] 3) performing a first centrifugation on the tobacco extract adsorbed by the activated carbon, and then performing a first filtration to obtain a first filtrate;

[0040] 4) adding molecular sieves to the first filtrate for stirring adsorption;

[0041] 5) performing a second centrifugation on the tobacco extract adsorbed by the molecular sieves, and then performing a second filtration to obtain a second filtrate; and

[0042] 6) concentrating the second filtrate under reduced pressure to a reduced-pressure-concentrated tobacco extract having the same solid content as the tobacco extract, and the content of tobacco-specific nitrosamines in the reduced-pressure-concentrated tobacco extract is less than 70,000 ng / g; preferably, less than 60,000 ng / g; more preferably, less than 50,000 ng / g.

[0043] The method of the present disclosure is suitable for tobacco extract for electronic cigarettes. It should be understood that the method of the present disclosure is also suitable for other tobacco extracts. In some embodiments, the tobacco extract comprises one or more of a burley water extract, a burley alcohol extract, a flue-cured water extract, and a flue-cured alcohol extract.

[0044] In some embodiments, the dilution step described above is performed by using water, ethanol, or a mixture of the two as the solvent. In a specific embodiment, ethanol is used as the solvent.

[0045] In some embodiments, in the dilution step described above, the mass ratio of the solvent used to the tobacco extract is 10:1 to 1:1, such as 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, or 1:1. In a specific embodiment, the mass ratio of the solvent used to the tobacco extract is 3:1.

[0046] In some embodiments, the standing adsorption step described above is performed using activated carbon. It should be understood that activated carbon powder has a large specific surface area and strong adsorption capacity, and can achieve effective adsorption by relying on the interaction between the activated carbon and the adsorbed molecules.

[0047] In a specific embodiment, the activated carbon is coconut shell activated carbon, which is commercially available from China Carbon Industry Co., Ltd., or is prepared by a method of burning coconut shells at high temperature and activating the charcoal at high temperature.

[0048] In some embodiments, the activated carbon used in the standing adsorption step described above has a mesh size of 100 to 500 mesh, such as 100 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, 350 mesh, 400 mesh, 450 mesh, or 500 mesh. In a specific embodiment, the activated carbon used in the standing adsorption step described above has a mesh size of 200 mesh.

[0049] In some embodiments, the mass ratio of activated carbon to tobacco extract is 2:10 to 3:10, such as 2.2:10, 2.4:10, 2.6:10, 2.8:10. In a specific embodiment, the mass ratio of activated carbon to tobacco extract is 3:10.

[0050] If the ratio of activated carbon to tobacco extract is too low, the corresponding adsorption effect cannot be achieved, so that the content of TSNAs in the tobacco extract is still relatively high. If the ratio of activated carbon to tobacco extract is too high, the loss of tobacco aroma caused by activated carbon is high, and the loss rate is large.

[0051] It has been verified that, within the scope of the present disclosure, the mass ratio of activated carbon to tobacco extract is such that, after adsorbing TSNAs by the method of the present disclosure, the content of TSNAs in the obtained extract is low, and the sensory evaluation after being formulated into an atomization substrate is basically consistent with that of untreated tobacco extract.

[0052] In some embodiments, the above standing adsorption step is carried out at 20 to 50°C for 10 to 20 hours. In a specific embodiment, the above standing adsorption step is carried out at 25°C for 15 hours.

[0053] In some embodiments, the above first centrifugation is carried out at 4°C at 4000 rpm to 6000 rpm for 10 to 15 minutes. In a specific embodiment, the above first centrifugation is carried out at 5000 rpm for 10 minutes.

[0054] In some embodiments, the above first filtration is carried out using a filter screen of 200 to 600 mesh. There is no particular limitation on the filter screen as long as it can achieve the effect of filtration. For example, gauze or nylon screen can be used. In a specific embodiment, the above first filtration is carried out using a 600 mesh gauze.

[0055] In some embodiments, the above stirring adsorption step is carried out using a molecular sieve. It is understood that a molecular sieve is a crystalline material with ordered pore structure, which is commonly used in catalysis, separation and adsorption processes. Their structural feature is composed of silicon-aluminum oxide tetrahedral units, which are connected by oxygen bridges to form a three-dimensional network. The molecular sieve can adsorb TSNAs because it has a pore structure and a high specific surface area. The cations in the molecular sieve channel attract the negatively charged O in the N-NO functional group of TSNAs through electrostatic attraction, causing the N-NO functional group to insert into the molecular sieve channel, and then adsorb the whole or part of the N-NO functional group into the molecular sieve channel. The present disclosure selectively adsorbs NNK and other TSNAs by using a molecular sieve with a pore size similar to the size of NNK and other TSNAs.

[0056] In some embodiments, the pore size of the molecular sieve used in the above stirring adsorption step is To such as 3, 4, 5, 6, 7, 8, In an embodiment, the molecular sieve used in the stirring and adsorbing step has a pore size of 5-7 A.

[0057] The molecular sieve with the pore size in the above range is similar in size to the TSNAs molecules, and thus can selectively adsorb the TSNAs.

[0058] In some embodiments, the molecular sieve used in the stirring and adsorbing step has a silica-alumina ratio of 12.5-25. In an embodiment, the molecular sieve used in the stirring and adsorbing step has a silica-alumina ratio of 25.

[0059] The surface morphology, crystal structure, hydrophilic-hydrophobic property and adsorption performance of molecular sieves with different silica-alumina ratios are significantly different: as the silica-alumina ratio of the molecular sieve decreases, the hydrophilic property of the molecular sieve is better, and the adsorption effect is worse.

[0060] In some embodiments, the molecular sieve used in the stirring and adsorbing step is selected from the group consisting of HZSM-5, NaZSM-5, NaY, CaA. In an embodiment, the molecular sieve used in the stirring and adsorbing step is HZSM-5 with a silica-alumina ratio of 25, which is available from Shanghai Titan Technology Co., Ltd.

[0061] The inventors have found that the molecular sieves HZSM-5, NaZSM-5, NaY, CaA have good adsorption effect on TSNAs. It has been further found that the molecular sieve HZSM-5 has particularly superior selective adsorption effect on TSNAs. The reason is that the molecular size is most similar to the size of the NNK molecule.

[0062] In some embodiments, the mass ratio of the molecular sieve to the tobacco extract is 1:10-2:10, such as 1.2:10, 1.4:10, 1.6:10, 1.8:10. In an embodiment, the mass ratio of the molecular sieve to the tobacco extract is 2:10.

[0063] If the ratio of the molecular sieve to the tobacco extract is too low, the corresponding adsorption effect cannot be achieved, so that the content of TSNAs in the tobacco extract is still relatively high. If the ratio of the molecular sieve to the tobacco extract is too high, the loss of tobacco aroma caused by the activated carbon is high, and the loss rate is large.

[0064] It has been verified that when the mass ratio of the molecular sieve to the tobacco extract is within the range of the present disclosure, the content of TSNAs in the obtained extract after adsorbing TSNAs by the method of the present disclosure is low, and the sensory evaluation after being formulated into an atomization substrate is basically consistent with that of the untreated tobacco extract.

[0065] In some embodiments, the stirring and adsorbing step is performed at 20-50°C for 1-3 hours. In a specific embodiment, the stirring and adsorbing step is performed at 25°C for 2 hours.

[0066] In some embodiments, the second centrifugation is performed at 4°C at 4000-6000 rpm for 10-15 minutes.

[0067] In a specific embodiment, the second centrifugation is performed at 4°C at 5000 rpm for 10 minutes.

[0068] In some embodiments, the second filtration is performed using a filter with a mesh size of 200-600. The mesh size is not particularly limited as long as the filter can achieve the effect of filtration. For example, gauze or nylon mesh can be used. In a specific embodiment, the second filtration is performed using a gauze with a mesh size of 600.

[0069] In some embodiments, the reduced pressure concentration is performed at 45-65°C under 60-120 mbar. The reduced pressure concentration method is not particularly limited, and for example, a rotary evaporator can be used to perform the reduced pressure concentration, such as concentrating to the original concentration (60-70% solid content) of the extract. In a specific embodiment, the reduced pressure concentration is performed at 60°C under 60 mbar.

[0070] The method of the present disclosure uses activated carbon and molecular sieves as adsorption materials at a low cost, and uses liquid phase adsorption to treat tobacco extract for TSNAs adsorption, which can effectively remove TSNAs in tobacco extract, while saving costs, reducing environmental pollution, and achieving significant economic and social benefits.

[0071] The present disclosure also provides a tobacco extract obtained by the method of the present disclosure. In the tobacco extract of the present disclosure, the content of TSNAs is less than 70000 ng / g; preferably, less than 60000 ng / g; more preferably, less than 50000 ng / g.

[0072] The present disclosure also provides an aerosol substrate comprising the tobacco extract of the present disclosure. In some embodiments, the mass percentage of the tobacco extract in the aerosol substrate is 0.2%-5%, such as 0.2%, 0.3%, 0.4%, 0.5%, 1%, 1.5%, 2%, 3%, 4%, or 5%, relative to the total mass of the aerosol substrate. In a specific embodiment, the mass percentage of the tobacco extract in the aerosol substrate is 0.5%, relative to the total mass of the aerosol substrate.

[0073] In addition to the tobacco extract of the present disclosure, the aerosol substrate can comprise other additional components, such as solvents and additives.

[0074] The solvent in the atomization base is used to dissolve various components in the atomization base and generate aerosol when atomized, so as to give the consumer the feeling of swallowing cloud and spitting mist. For example, the solvent is at least one selected from water, ethanol, ethylene glycol, propanol, propylene glycol, glycerol, butanol, butanediol, butanetriol, benzyl alcohol, triethyl citrate, glyceryl triacetate, and glyceryl octyl decanoate. The disclosure does not have special restrictions on the addition amount and proportion of the solvent, and any addition amount and proportion of the solvent commonly used in the atomization base can be used in the atomization base of the disclosure.

[0075] The additives in the atomization base can include at least one of a sweetener, a cooling agent, and an organic acid. The cooling agent and the sweetener can further provide different flavoring mouthfeel. The organic acid can further reduce the irritation to the throat and also improve the satisfaction to a certain extent. The disclosure does not have special restrictions on the types of the sweetener, the cooling agent, and the organic acid, and those commonly used can be used in the atomization base. By way of example, the cooling agent can be WS-3, WS-5, WS-12, WS-14, WS-23, WS-25, WS-27, menthol, menthyl ether, and menthyl ester, but is not limited thereto. By way of example, the organic acid can be acetic acid, butyric acid, 2-methylbutyric acid, lactic acid, levulinic acid, malic acid, tartaric acid, benzoic acid, and citric acid, but is not limited thereto. By way of example, the sweetener can be neotame, advantame, sucralose, acesulfame potassium, glucosylated steviol glycoside, aspartame, hesperidin dihydrochalcone, neohesperidin dihydrochalcone, and naringin dihydrochalcone, but is not limited thereto. The disclosure does not have special restrictions on the addition amount of the sweetener, the cooling agent, and the organic acid.

[0076] It should be understood that the disclosure does not have special restrictions on the preparation method of the atomization base, and generally can include the step of uniformly mixing the components. According to some embodiments, the components can be heated and mixed, for example, heated at about 30°C to 50°C for 10 to 20 minutes.

[0077] The disclosure is described in more detail below by way of examples, and it should be understood that the examples described below are exemplary and are only used to explain the disclosure, and cannot be understood as a limitation on the disclosure. If no specific technology or condition is specified in the examples, the technology or condition described in the literature in the art or according to the product instruction is used.

[0078] Examples

[0079] Experimental methods

[0080] Collection method of TSNAs in tobacco extract: 0.1 g of tobacco extract sample was weighed into a centrifuge tube, and 2 mL of 0.1 mol / L ammonium acetate solution containing internal standard (the internal standard was 40.0 ng / ml of NNK-d4, NNN-d4, NAB-d4 and NAT-d4) was added. The sample was ultrasonically extracted for 30 min, and then an appropriate amount of the extract was filtered through a 0.22 μm water phase filter membrane, and transferred to a chromatographic analysis bottle for HPLC-MS / MS analysis.

[0081] Preparation method of aerosol substrate containing tobacco extract: the addition amount of burley tobacco extract was 0.5%, and the addition amount of propylene glycol and glycerol mixed solution (6:4 to 1:1, w / w) was 99.5%.

[0082] Collection method of TSNAs in smoke of aerosol substrate containing tobacco extract: the raw material sample was prepared into a cartridge, and the smoke was extracted according to the standard of GB-41770, with the extraction parameters being 55 mL, 30 s, 3 s, 100 puffs. Then, the smoke was collected by using two 44 mm glass fiber filters, and placed in a conical flask, and 15 mL of 0.1 mol / L ammonium acetate solution containing internal standard (the internal standard was 40.0 ng / mL of NNK-d4, NNN-d4, NAB-d4 and NAT-d4) was added. The sample was shaken on a shaker for 30 min for complete extraction, and then an appropriate amount of the extract was filtered through a 0.22 μm water phase filter membrane, and transferred to a chromatographic analysis bottle for HPLC-MS / MS analysis.

[0083] Determination method of TSNAs content in sample: the determination of TSNAs was performed on HPLC-MS / MS (model: Thermo Orbitrap Exploris 120), with the specific parameters being as follows: the chromatographic column was Hypersil GOLDTM aQ 18 column (1.9 μm, 2.1 mm x 100 mm); the mobile phase was A phase 0.1% formic acid and B phase 100 mmol ammonium acetate solution; the flow rate was 0.2 mL / min; the column temperature was 35°C; the injection volume was 2 μL each time; the ion source was electrospray ionization source (ESI), with the electrospray voltage being 5000 V; the scanning mode was positive ion scanning, and the detection mode was multiple reaction detection mode (MRM). The final solution was quantified by internal standard method. NNN, NNK, NAT and NAB standard substances (purity ≥98%) were configured into a series of standard working solutions (the concentration gradient of NNN, NNK, NAT and NAB was 1.0, 2.0, 8.0, 20.0, 40.0, 80.0, 200 and 400 ng / mL, and the concentration of the four internal standards was 40.0 ng / mL), and then injected in turn to draw the standard working curve, with the correlation coefficient being greater than or equal to 0.99. The working curve calculation result was taken as the quantitative result.

[0084] Sensory evaluation method:

[0085] The treated tobacco extract was added to a mixed solvent (solvent ratio 98%) of PG:VG = 6:4 according to a 2% addition amount to obtain an atomization base. The atomization base was loaded into an electronic atomizer, and 7 evaluators were used to perform sensory evaluation of smoking, including comfort, richness, stimulation, tobacco aroma, and offensive odor, etc. The sensory evaluation was mainly based on GB5606.4-2005 as the evaluation standard, and the sensory evaluation was given in combination with the sensory characteristics of the electronic cigarette. The sensory evaluation scoring standard is shown in Table 1.

[0086] Table 1: Sensory evaluation scoring standard

[0087] Example 1

[0088] 1) 300 g of 95% ethanol was added to 100 g of white burley extract (solid content 65%) for dilution.

[0089] 2) 30 g of activated carbon powder (200 mesh) was added to the obtained dilution, and then adsorbed at 25°C for 15 hours.

[0090] 3) Transferred to a centrifuge, centrifuged at 5000 rpm for 10 minutes, and then filtered with 600 mesh gauze to obtain a first filtrate.

[0091] 4) 20 g of molecular sieve (pore size 4A, Si / Al ratio 25, type HZSM-5) was added to the obtained first filtrate, and then stirred and adsorbed at 25°C for 2 hours.

[0092] 5) Transferred to a centrifuge, centrifuged at 5000 rpm for 10 minutes, and then filtered with 600 mesh gauze to obtain a second filtrate.

[0093] 6) The solvent was recovered by rotary evaporation under reduced pressure at 60°C and 60 mbar, and concentrated to the original concentration of the tobacco neat oil (solid content 65%) to obtain the treated tobacco extract.

[0094] Then, the obtained tobacco extract was tested by the above-described determination method of TSNAs content and sensory evaluation method. The test results are shown in Tables 2 and 3.

[0095] Wherein the removal rate (%) = (TSNAs before treatment - TSNAs after treatment) / TSNAs before treatment x 100%;

[0096] Loss rate (%) = (1 - m after treatment sample / m before treatment sample) x 100%.

[0097] Example 2 ​

[0098] The same method as in Example 1 was conducted except that the activated carbon was added in an amount of 20 g.

[0099] Example 3

[0100] The same method as in Example 1 was conducted except that the molecular sieve was added in an amount of 10 g.

[0101] Example 4

[0102] The same method as in Example 3 was conducted except that the activated carbon was added in an amount of 20 g.

[0103] To investigate the difference in the effect of the combination of activated carbon and molecular sieve and the use of one of the substances alone, the following comparative examples were prepared.

[0104] Comparative Example 1

[0105] The same method as in Example 1 was conducted except that the 100 g of the white burley extract (solid content 65%) was not treated.

[0106] Comparative Example 2

[0107] The same method as in Example 1 was conducted except that 50 g of activated carbon was used alone without using the molecular sieve.

[0108] Comparative Example 3

[0109] The same method as in Example 1 was conducted except that 50 g of molecular sieve was used alone without using the activated carbon.

[0110] Comparative Example 4

[0111] The same method as in Example 1 was conducted except that 30 g of activated carbon was used alone without using the molecular sieve.

[0112] Comparative Example 5

[0113] The same method as in Example 1 was conducted except that 20 g of molecular sieve was used alone without using the activated carbon.

[0114] The test results of the above examples and comparative examples are shown in Table 2, and the sensory evaluation results are shown in Table 3.

[0115] Table 2: TSNAs test results of Examples 1 to 4 and Comparative Examples 1 to 5

[0116] Table 3: Sensory evaluation results of Examples 1 to 4 and Comparative Examples 1 to 5

[0117] From the above results, it can be seen that the effect of removing TSNAs by using two kinds of adsorbents for combined treatment is better than that of adding the same mass of a single kind of adsorbent. It can also be seen that when two kinds of substances are used for combined treatment, the optimal addition ratio of activated carbon is 30%, the optimal addition ratio of molecular sieves is 20%, the highest removal rate can reach 99.1%, and the addition of activated carbon and molecular sieves has little effect on the loss of tobacco aroma of tobacco extract, so that effective adsorption of TSNAs can be achieved without excessive influence on tobacco aroma. After being prepared into an atomized substrate, the content of TSNAs in smoke is reduced to undetectable, ensuring the safety of the atomized substrate. Thus, the method of the present disclosure has low cost, good effect, and good economic and social benefits.

[0118] Although the present disclosure has been described with reference to specific exemplary embodiments thereof, many different alterations, modifications and the like will become apparent to those skilled in the art.

[0119] Variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the present disclosure, from a study of the disclosure and the appended claims.

Claims

1. A method for adsorbing tobacco-specific nitrosamines in a tobacco extract, comprising: 1) diluting the tobacco extract with a solvent; 2) adding activated carbon to the diluted tobacco extract for static adsorption; 3) performing a first centrifugation on the activated carbon adsorbed tobacco extract, followed by a first filtration to obtain a first filtrate; 4) adding molecular sieves to the first filtrate for stirring adsorption; 5) performing a second centrifugation on the molecular sieve adsorbed tobacco extract, followed by a second filtration to obtain a second filtrate; and 6) concentrating the second filtrate under reduced pressure to a reduced pressure concentrated tobacco extract having the same solid content as the tobacco extract, and the tobacco-specific nitrosamines content in the reduced pressure concentrated tobacco extract is less than 70000 ng / g; preferably, less than 60000 ng / g; more preferably, less than 50000 ng / g. The mass ratio of the activated carbon, the molecular sieves, and the tobacco extract is (2-3) : (1-2) : 10, preferably 3 : 2 :

10.

2. The method of claim 1, wherein, The silica-alumina ratio of the molecular sieves is 12.5 to 25, preferably 25; 3. The method of claim 1 or 2, wherein, The pore size of the molecular sieve is from 4.0 to 4.5 A preferably from 4.1 to 4.4 A more preferably from 4.2 to 4.3 A even more preferably from 4.3 to 4.4 A The molecular sieves are selected from the group consisting of HZSM-5, NaZSM-5, NaY, CaA, preferably HZSM-5. The mesh number of the activated carbon is 100 to 500 mesh, preferably 200 to 300 mesh, more preferably 200 mesh.

4. The method of any one of claims 1 to 3, wherein, The solvent is selected from the group consisting of water, ethanol, or a mixture of the two, and the mass ratio of the solvent to the tobacco extract is 10: 1 to 1: 1, preferably 5: 1 to 1: 1, more preferably 3:

1.

5. The method of any one of claims 1 to 4, wherein, The static adsorption is performed at 20 to 50°C, preferably 25°C, for 10 to 20 hours, preferably 15 hours; and / or 6. The method of any one of claims 1 to 5, wherein, The stirring adsorption is performed at 20 to 50°C, preferably 25°C, for 1 to 3 hours, preferably 2 hours. The first and second centrifugations are performed at 4000 rpm to 6000 rpm, preferably 5000 rpm, at 4°C for 10 to 15 minutes; 7. The method of any one of claims 1 to 6, wherein, The first filtration is performed using a 200 to 600 mesh, preferably 600 mesh, filter screen; The second filtration is performed using a 200 to 600 mesh, preferably 600 mesh, filter screen; The reduced pressure concentration is performed at 45°C to 65°C, 60 mbar to 120 mbar, preferably at 60°C, 60 mbar.

8. A tobacco extract obtained by the method of any one of claims 1 to 7.

9. An aerosol substrate comprising the tobacco extract of claim 8. The mass percentage of the tobacco extract relative to the total mass of the aerosol substrate is 0.2% to 5%, preferably 0.2% to 2%, more preferably 0.5%.

10. The aerosolizing substrate of claim 9 wherein, 10. A method for reducing the content of tobacco-specific nitrosamines in a tobacco extract, comprising: 1) diluting the tobacco extract with a solvent; 2) adding activated carbon to the diluted tobacco extract for static adsorption; 3) performing a first centrifugation on the activated carbon adsorbed tobacco extract, followed by a first filtration to obtain a first filtrate; 4) adding molecular sieves to the first filtrate for stirring adsorption; 5) performing a second centrifugation on the molecular sieve adsorbed tobacco extract, followed by a second filtration to obtain a second filtrate; and 6) concentrating the second filtrate under reduced pressure to a reduced pressure concentrated tobacco extract having the same solid content as the tobacco extract, and the tobacco-specific nitrosamines content in the reduced pressure concentrated tobacco extract is less than 70000 ng / g; preferably, less than 60000 ng / g; more preferably, less than 50000 ng / g. The mass ratio of the activated carbon, the molecular sieves, and the tobacco extract is (2-3) : (1-2) : 10, preferably 3 : 2 :

10. The silica-alumina ratio of the molecular sieves is 12.5 to 25, preferably 25; The molecular sieves are selected from the group consisting of HZSM-5, NaZSM-5, NaY, CaA, preferably HZSM-5. The mesh number of the activated carbon is 100 to 500 mesh, preferably 200 to 300 mesh, more preferably 200 mesh. The solvent is selected from the group consisting of water, ethanol, or a mixture of the two, and the mass ratio of the solvent to the tobacco extract is 10: 1 to 1: 1, preferably 5: 1 to 1: 1, more preferably 3:

1. The static adsorption is performed at 20 to 50°C, preferably 25°C, for 10 to 20 hours, preferably 15 hours; and / or The stirring adsorption is performed at 20 to 50°C, preferably 25°C, for 1 to 3 hours, preferably 2 hours. The first and second centrifugations are performed at 4000 rpm to 6000 rpm, preferably 5000 rpm, at 4°C for 10 to 15 minutes; The first filtration is performed using a 200 to 600 mesh, preferably 600 mesh, filter screen; The second filtration is performed using a 200 to 600 mesh, preferably 600 mesh, filter screen; The reduced pressure concentration is performed at 45°C to 65°C, 60 mbar to 120 mbar, preferably at 60°C, 60 mbar.

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