Preparation method of tobacco flavor capable of reducing harmful substance residues and application of tobacco flavor in cigarettes

Abstract

The invention discloses a preparation method of a tobacco flavor capable of reducing harmful substance residues, which comprises the following steps: adding an aqueous solution or an ethanol solution with the mass concentration of 10-80% into a tobacco raw material, carrying out hot reflux extraction at 30-100 DEG C, and filtering to obtain a tobacco extracting solution. And carrying out vacuum concentration on the tobacco extracting solution at 30-100 DEG C until the density is 1.0-1.1 g / cm < 3 >, so as to obtain the tobacco concentrated solution. Standing the tobacco concentrated solution, and filtering to obtain an external water phase solution; the preparation method comprises the following steps: mixing a surfactant, a carrier and an oil phase, adding an internal water phase solution, and stirring in an emulsification container to prepare a stable W / O / W type emulsion; uniformly mixing an external water phase solution with the W / O / W emulsion, stirring, standing for 10-60 minutes, layering, separating an emulsion phase from a water phase, collecting the water phase, adding propylene glycol with the mass ratio of 10%-20%, and performing vacuum concentration at the temperature of 30-70 DEG C until the density is 1.1-1.3 g / cm < 3 >, so as to obtain the tobacco flavor capable of reducing harmful substance residues. The tobacco flavor obtained by the method disclosed by the invention can effectively reduce the content of harmful substances such as heavy metals, and is very suitable for industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco flavors and fragrances production, and specifically relates to a preparation method of tobacco flavors for reducing residual harmful substances and an application thereof in cigarettes. Background Art

[0002] Studies have shown that heavy metals in tobacco are another type of harmful substance after nicotine, tar and pesticide residues. When people smoke cigarettes, heavy metals enter the human body through mainstream smoke and cause potential harm. The residues of harmful substances such as heavy metals in cigarettes have become a global problem, and smoking has become one of the important ways for smokers to suffer from certain heavy metal hazards. With the increasing awareness of health and safety, pollution of harmful substances such as heavy metals in cigarettes has received widespread attention, and the control technology related to it has become a hot topic for many scholars in recent years.

[0003] It is difficult to completely avoid heavy metal pollution in tobacco cultivation, and tobacco has the function of absorbing and accumulating heavy metals in the soil. Relevant research reports that the heavy metal content in the test soil exceeded the standard by 2.5 times, and the heavy metal content in discarded tobacco leaves was higher than that in the soil, up to 11 times. Tobacco flavors and fragrances are mostly extracted and processed from waste tobacco leaves, tobacco dust, tobacco leaf fragments, tobacco stems and other tobacco waste. Heavy metals in tobacco are often enriched in tobacco flavors and fragrances during the extraction and extraction process. Since a large amount of tobacco extracts are added to cigarettes, the risk of cigarettes being contaminated by harmful substances such as heavy metals during the processing stage is increased.

[0004] At present, there is no standard for the limit of heavy metal content in flue-cured tobacco in China. However, my country's tobacco industry standard "Tobacco Flavors YC / T 164-2012" clearly stipulates the maximum limit of As and Pb in tobacco flavors and fragrances: heavy metals (in terms of Pb) ≤ 10.0 mg / Kg, As ≤ 3.0 mg / Kg. Therefore, conducting relevant research on the reduction of harmful substances such as heavy metals in tobacco flavors and fragrances has become an important way to achieve safe production of cigarettes.

[0005] The existing methods for separating and recovering metal ions from liquids mainly include solid adsorption, ion exchange, chemical precipitation, electrolysis, and oxidation-reduction methods. However, these methods are complex and expensive, and require the addition of a large amount of chemical agents when recovering metal ions from flavors and fragrances, which destroys the original flavors and fragrances. They are not suitable for the reduction of harmful substances such as heavy metal residues in tobacco flavors and fragrances.

[0006] Liquid membrane technology is a new type of membrane separation method that emerged in the 1960s. It enriches the target substance components contained in one of the two mutually soluble phases into the other phase through the liquid membrane, and realizes the separation operation technology of one or a class of target substances through the selective permeation phenomenon. Due to its simple operation, fast separation, good selectivity, and economic energy saving, this separation technology has been widely used in hydrometallurgy, environmental protection, medicine, chemical industry, wastewater treatment and other technical fields. The use of this separation technology to treat waste liquid containing metal ions has attracted the attention of scholars at home and abroad. However, the current technology of recovering heavy metal ions in waste liquid using emulsion liquid membrane technology is for the purpose of recovering metal ions, regardless of whether the original liquid can continue to be used. Therefore, a large amount of toxic organic solvents and acids or alkalis for adjusting the pH value need to be added to the flavors and fragrances during separation, which will greatly destroy the original fragrance of the flavors and fragrances. Adding flavors and fragrances to cigarettes will cause obvious irritation to the mouth, nose, and throat, obvious impurities, and residual aftertaste. There are also safety risks, making it difficult to apply in cigarettes. Therefore, the current emulsion liquid membrane separation method is not suitable for use in reducing the residual harmful substances such as heavy metals in tobacco flavors and fragrances, which limits the application of this method in cigarette flavors and fragrances.

[0007] In order to solve the above problems, the present invention is proposed. Summary of the invention

[0008] The present invention discloses a method for preparing tobacco flavoring for reducing residual harmful substances, comprising the following steps:

[0009] (1) Adding an aqueous solution or an ethanol solution with a mass concentration of 10% to 80% to a tobacco raw material, performing heat reflux extraction at 30 to 100° C., and filtering to obtain a tobacco extract.

[0010] (2) The tobacco extract obtained in step (1) is vacuum concentrated at 30-100° C. to a density of 1.0-1.1 g / cm 3 , and obtain tobacco concentrate.

[0011] (3) The tobacco concentrated liquid obtained in step (2) is allowed to stand and then filtered, and the obtained filtrate is the external aqueous phase solution.

[0012] (4) The surfactant, carrier and oil phase are mixed, added to the internal aqueous phase solution, and placed in an emulsification container for stirring to obtain a stable W / O / W emulsion.

[0013] (5) The external aqueous phase solution of step (3) and the W / O / W type emulsion obtained in step (4) are mixed evenly, stirred, and allowed to stand for 10-60 minutes before stratification to separate the emulsion phase and the aqueous phase.

[0014] (6) Collect the aqueous phase obtained in step (5), add 10%-20% by mass of propylene glycol, and vacuum concentrate at 30-70° C. to a density of 1.1-1.3 g / cm 3 , that is, obtaining tobacco flavors with reduced residual harmful substances.

[0015] Preferably, the specific conditions for stirring in step (4) are: stirring speed of 3000-10000 r / min, stirring time of 10-20 min; the specific conditions for stirring in step (5) are: stirring speed of 100-400 r / min, stirring time of 10-120 min.

[0016] Preferably, the method further comprises the steps of: demulsifying the emulsion phase obtained in step (5) under high voltage electrostatic conditions of 15 kV and 0.02 mA for 30 min, allowing the emulsion to stand for stratification, and recovering the oil phase for reuse in the next preparation of the W / O / W emulsion.

[0017] Preferably, the tobacco raw material described in step (1) is selected from one or more waste tobacco raw materials with high heavy metal content such as discarded tobacco leaves, tobacco dust, tobacco leaf fragments, discarded tobacco stems, etc.; the mass ratio of the waste tobacco raw material to the solution is 1:1-1:25, and the hot reflux extraction adopts a repeated process for multiple extractions, the number of extractions is 2, and the time of each extraction is 1-6 hours.

[0018] Preferably, the specific conditions for standing in step (3) are: cooling and standing at 4°C for 6-8h, the filtering method in step (3) can be filter cloth filtration and / or membrane filtration, the filter cloth specification is 400-500 mesh, the membrane filtration is ultrafiltration, and the specific steps of ultrafiltration are: standing the tobacco concentrate obtained in step (2) and separating it through an ultrafiltration membrane assembly, filtering once or combining filtration multiple times with an ultrafiltration membrane with a molecular weight cutoff of 30KDa-5KDa at room temperature, and collecting the filtrate, and the obtained filtrate is the external aqueous phase solution.

[0019] Preferably, in step (4), the surfactant is sucrose ester and / or octanoic acid glyceride, the carrier is pentanedione and tributyl phosphate, and the mass ratio of pentanedione to tributyl phosphate is 1:10-10:1; the oil phase is one or more of corn oil, peanut oil, almond oil, coconut oil, and olive oil, the pH of the inner aqueous phase solution is 1-3, specifically one or more of lactic acid, malic acid, and citric acid, and the volume ratio of the oil phase: surfactant: carrier: inner aqueous phase solution is (30-40):(1-5):(1-5):(30-40).

[0020] Another aspect of the present invention provides the use of the tobacco flavor obtained by the above preparation method, wherein the tobacco flavor is diluted by one half with a 75-100% by mass ethanol solution and then added to cigarette shreds.

[0021] Preferably, the mass ratio of the tobacco flavor to the cigarette tobacco is 1:1000-10:1000.

[0022] The above technical solutions can be freely combined under the premise of no contradiction.

[0023] The present invention has the following beneficial effects:

[0024] 1. The present invention provides a method for preparing tobacco flavors for reducing harmful substance residues. The emulsion liquid membrane technology is used for the first time. The inner water phase, outer water phase, oil phase, surfactant and carrier are made into an emulsion liquid membrane system. The heavy metals in the flavors extracted from tobacco raw materials are selectively extracted and reduced. Through specific extraction, concentration, ultrafiltration, emulsion liquid membrane and other process steps, the heavy metal residues (such as lead, arsenic, etc.) in the tobacco flavors can be significantly reduced. Compared with the traditional extraction method and the existing emulsion liquid membrane method that do not use the harmful substance reduction technology of the present invention, the heavy metal content in the tobacco flavors prepared by the present invention is significantly reduced, and the heavy metal residues meet the industry standards. The combined separation effect of the inner water phase, membrane phase and outer water phase of the emulsion liquid membrane can combine the heavy metal extraction and back extraction into one. The oil phase extracts heavy metals from the outer water phase and the inner water phase back extracts heavy metals from the oil phase at the same time. Therefore, when extracting and reducing heavy metals such as As and Pb with relatively low content in tobacco flavors, it has advantages that cannot be matched by ordinary extraction and separation. The entire process is close to complete extraction, with high extraction yield, fast rate and high selectivity, overcoming the problems existing in traditional enrichment processes.

[0025] 2. In the preparation method of tobacco flavoring for reducing residual harmful substances provided by the present invention, the oil phase can be recovered and reused for the next preparation of emulsion, the amount of reagents required is small, the product cost is low, and the separation is carried out at room temperature and the separation time is short, which avoids the impact on the original tobacco flavoring to the greatest extent. It is a green and environmentally friendly method with high economic benefits.

[0026] 3. The present invention provides a method for preparing tobacco flavors for reducing residual harmful substances. The selected emulsion system uses reagents: oil phase, surfactant, and internal aqueous phase solution, which are all non-toxic and safe additives, meeting tobacco safety requirements. At the same time, these additives themselves also contribute to the aroma of cigarettes. The selected carriers use neutral complex carrier pentanedione and chelate carrier tributyl phosphate. The use of composite carriers can improve the extraction efficiency of the liquid membrane system, and the reduction of heavy metal ions can be achieved without additional adjustment of the pH value of flavors and fragrances.

[0027] 4. The heavy metal index of the tobacco flavor obtained by the unique extraction method to reduce the residual harmful substances meets the relevant requirements of the tobacco industry standard "Tobacco Flavor YC / T 164-2012". Adding the tobacco flavor obtained by the preparation method of the present invention to cigarettes not only does not destroy the sensory characteristics of the original tobacco flavor, but also significantly improves the original aroma, aroma quality and aroma volume of the tobacco, improves the aftertaste and impurities, and improves the overall quality of the cigarette. The harmful substance reduction technology of the present invention does not have a negative impact on the sensory quality of the tobacco flavor, but enhances it. This effect is unpredictable by technicians in this field. At the same time, the method of the present invention can greatly improve the added value of the utilization of waste tobacco raw materials with high heavy metal content, which is in line with the environmental protection concept of waste utilization.

[0028] 5. Cigarettes added with tobacco flavors prepared by the present invention have significantly reduced irritation in the oral cavity, nasal cavity, throat, etc., and the dryness and astringency are also improved, and the overall smoking comfort is significantly improved. This further proves that the present invention not only retains the original advantages of tobacco flavors, but also improves the smoking experience of cigarettes by reducing the residual harmful substances such as heavy metals. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is specifically described below in conjunction with embodiments, but the embodiments of the present invention are not limited thereto.

[0030] The operating methods without specific conditions in the examples are usually carried out according to conventional conditions and conditions described in technical manuals, or according to conditions recommended by manufacturers. The general equipment and materials used are all commercially available unless otherwise specified.

[0031] Example 1

[0032] A method for preparing tobacco flavoring for reducing residual harmful substances comprises the following steps:

[0033] (1) Take 1 kg of waste tobacco raw material, add 7 kg of 60% ethanol, perform hot reflux extraction twice at 65° C., extract for 2 h, filter the extract with 400 mesh gauze, and obtain tobacco extract.

[0034] (2) The tobacco extract obtained in step (1) was concentrated under vacuum at 60°C until the density reached 1.1 g / cm 3 , obtaining tobacco concentrate;

[0035] (3) The tobacco concentrate obtained in step (2) was cooled to 4° C. and allowed to stand for 8 h, and then separated by an ultrafiltration membrane assembly. At room temperature, the ultrafiltration membranes with molecular weight cutoffs of 20 KDa, 10 KDa, and 5 KDa were used to filter the filtrates, and the filtrates obtained were the external aqueous phase solution.

[0036] (4) Coconut oil, sucrose ester, pentanedione and tributyl phosphate are mixed, and a lactic acid solution with a pH of 1.5 is added and placed in an emulsifying container. The volume ratio of coconut oil, sucrose ester, pentanedione, tributyl phosphate and lactic acid solution is 30:1:1:2:30. The mixture is stirred at a high speed of 9000 r / min for 10 min to obtain a stable W / O / W emulsion.

[0037] (5) The filtrate obtained in step (3) and the W / O / W emulsion obtained in step (4) were mixed evenly, stirred at a speed of 300 r / min for 40 min, and after standing for 30 min, the emulsion phase and the aqueous phase were separated.

[0038] (6) Collect the aqueous phase obtained in step (5), add 15% by mass of propylene glycol, and vacuum concentrate at 60°C to a density of 1.3 g / cm 3 , that is, obtaining tobacco flavors with reduced residual harmful substances.

[0039] (7) The emulsion phase obtained in step (5) is demulsified under high voltage electrostatic conditions of a voltage of 15 kV and a current of 0.02 mA for 30 minutes, and after standing and stratification, the oil phase is recovered and reused in the next preparation of a W / O / W emulsion.

[0040] Example 2

[0041] A method for preparing tobacco flavoring for reducing residual harmful substances comprises the following steps:

[0042] (1) Take 1 kg of the discarded tobacco mixture, add 8 kg of water; perform heat reflux extraction twice at 80° C. for 3 hours, and filter the extract with 400-mesh gauze to obtain a tobacco extract.

[0043] (2) The tobacco extract obtained in step (1) was concentrated under vacuum at 65°C until the density reached 1.1 g / cm 3 , obtaining tobacco concentrate;

[0044] (3) The tobacco concentrate obtained in step (2) was cooled and allowed to stand at 4° C. for 6 hours, and then filtered through a 500-mesh filter cloth to obtain an external aqueous phase solution.

[0045] (4) Olive oil, octanoic acid glyceride, pentanedione and tributyl phosphate are mixed, and a citric acid solution with a pH of 2 is added and placed in an emulsifying container. The volume ratio of olive oil, octanoic acid glyceride, pentanedione, tributyl phosphate and lactic acid solution is 35:2:1:1:30. The mixture is stirred at a high speed of 7000 r / min for 15 min to obtain a stable W / O / W emulsion.

[0046] (5) The filtrate obtained in step (3) and the W / O / W emulsion obtained in step (4) were mixed evenly, stirred at a speed of 300 r / min for 50 min, and after standing for 30 min, the emulsion phase and the aqueous phase were separated.

[0047] (6) Collect the aqueous phase obtained in step (5), add 10% by mass of propylene glycol, and vacuum concentrate at 65°C to a density of 1.2 g / cm 3 , that is, obtaining tobacco flavors with reduced residual harmful substances.

[0048] (7) The emulsion phase obtained in step (5) is demulsified under high voltage electrostatic conditions of a voltage of 15 kV and a current of 0.02 mA for 30 min. After standing and stratification, the oil phase is recovered and reused in the next preparation of a W / O / W emulsion.

[0049] Comparative Example 1

[0050] A method for preparing tobacco flavor without using harmful substance residue reduction technology, comprising adding 9 times 60% ethanol to waste tobacco leaf fragments, performing heat reflux extraction twice at 60°C, and evaporating and concentrating the extract to 1.3 g / cm 3 , get tobacco flavor.

[0051] Comparative Example 2

[0052] A method for preparing tobacco flavors by using conventional emulsion liquid membrane technology to recover heavy metal ions has been reported. Compared with Example 1, in step 3, H2SO4 solution is added to the tobacco concentrate to adjust the pH to 2 as the external aqueous phase. In step 4, sulfonated kerosene is used as the oil phase, Span80 is used as the surfactant, and di(2-ethylhexyl) phosphate is used as the mobile carrier. After mixing several reagents, 4% NaOH is added as the internal aqueous phase solution and placed in an emulsification container. The volume ratio of oil phase: surfactant: carrier: internal aqueous phase solution is 31:1:1:32. Tobacco flavors are obtained.

[0053] Example 3

[0054] In order to compare the effects of different processes on the residual harmful substances such as heavy metals in tobacco flavors, the tobacco flavors prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention were respectively tested and analyzed for the content of heavy metals mainly arsenic and lead according to "YC / T 294-2009 Determination of arsenic, lead, cadmium, chromium and nickel in tobacco flavors and liquids by graphite furnace atomic absorption spectrometry". The results are shown in Table 1:

[0055] Table 1 Detection results of heavy metal content in different samples

[0056]

[0057] The results show that the content of heavy metals (in terms of Pb) and arsenic (in terms of As) in the tobacco flavor obtained by the method for preparing tobacco flavors for reducing harmful substance residues of the present invention, such as Example 1 and Example 2, is significantly reduced compared to before reduction, and is significantly lower than the traditional extraction method (i.e., Comparative Example 1) that does not use harmful substance reduction technology. The content of heavy metals (in terms of Pb) and arsenic (in terms of As) in the tobacco flavor obtained by Example 1 and Example 2 is reduced to a greater extent than the currently available emulsion liquid membrane method (i.e., Comparative Example 2), indicating that the preparation method for reducing heavy metal residues of the present invention can effectively reduce the residues of harmful substances such as heavy metals in tobacco flavors.

[0058] Example 4

[0059] Sensory evaluation of cigarettes: The tobacco flavors and spices obtained in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 of the present invention were diluted by half with 75% alcohol and injected into cigarettes at an addition amount of 1% of tobacco shreds per cigarette using an injection machine, respectively, to obtain Cigarette-Example 1 (20 cigarettes), Cigarette-Example 2 (20 cigarettes), Cigarette-Comparative Example 1 (20 cigarettes), and Cigarette-Comparative Example 2 (20 cigarettes). Blank cigarettes without added spices (50 cigarettes) were used as controls. All the above cigarettes were placed in a constant temperature and humidity chamber (temperature 22±1°C, humidity 60±2%) for 48 hours of equilibrium, and were evaluated by experts with cigarette evaluation qualifications in accordance with "GB5606.4-2005 Cigarette Part 4 Sensory Technical Requirements" and "YC / T497-2014 Cigarette Chinese Cigarette Style Sensory Evaluation Method". The evaluation results are shown in Tables 2, 3, and 4:

[0060] Table 2 Cigarette smoking evaluation results

[0061]

[0062] Table 3 Evaluation results of cigarette comfort characteristics

[0063]

[0064] Table 4 Cigarette smoke characteristics evaluation results

[0065]

[0066] The results show that the tobacco flavor obtained by the method for preparing tobacco flavor for reducing residual harmful substances of the present invention, when added to cigarettes, significantly increases the original aroma of tobacco, improves the smoke concentration, improves the aroma quality and aroma quantity, and has a significant improvement effect on aftertaste and miscellaneous odors.

[0067] It can be seen from Tables 2, 3 and 4 that the cigarettes added with the tobacco flavoring prepared by the present invention have an efficacy close to that of Comparative Example 1 and are better than that of Comparative Example 1 when smoked, which indicates that the harmful substance reduction technology adopted by the present invention can reduce harmful substances such as heavy metals in tobacco flavorings without destroying the sensory characteristics and efficacy of the original tobacco flavorings. What is more worth mentioning is that the technology has been improved in reducing irritation and improving aftertaste.

[0068] Comparative Example 2 uses the existing emulsion liquid membrane method. Although it can reduce harmful substances such as heavy metals in spices, the solvents used are sulfonated kerosene, Span80, di(2-ethylhexyl) phosphate, and H2SO4. These solvents are toxic and irritating. After being added to cigarettes, they will cause obvious irritation to the mouth, nose, and throat, and there will be a residual aftertaste on the tongue.

[0069] In summary, the tobacco flavor obtained by the method for preparing tobacco flavors for reducing harmful substance residues of the present invention not only reduces harmful substances such as heavy metals, improves the safety of flavors, and meets the safety requirements of the tobacco industry, but also greatly improves the added value of waste tobacco raw materials with high content of harmful substances such as heavy metals. When added to cigarettes, it significantly increases the original aroma of tobacco, increases smoke concentration, improves the aroma quality and aroma volume, and has a significant improvement effect on aftertaste and miscellaneous odors. The harmful substance reduction technology used in the present invention provides a new method and new model for the research on the reduction of harmful substances such as heavy metals in natural flavors, which can be promoted and applied to different natural flavors.

[0070] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. The above technical solutions can be freely combined without contradiction. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing tobacco flavor for reducing residual harmful substances, characterized in that: The following steps are involved: (1) adding an aqueous solution or an ethanol solution with a mass concentration of 10% to 80% to a tobacco raw material, performing heat reflux extraction at 30 to 100° C., and filtering to obtain a tobacco extract; (2) The tobacco extract obtained in step (1) is vacuum concentrated at 30-100° C. to a density of 1.0-1.1 g / cm 3 , obtaining tobacco concentrate; (3) allowing the tobacco concentrate obtained in step (2) to stand and then filtering, whereby the obtained filtrate is the external aqueous phase solution; (4) mixing a surfactant, a carrier and an oil phase, adding the inner aqueous phase solution, placing the mixture in an emulsifying container and stirring the mixture to obtain a stable W / O / W emulsion; (5) mixing the external aqueous phase solution of step (3) and the W / O / W type emulsion obtained in step (4) uniformly, stirring, standing for 10-60 minutes, and then separating the emulsion phase and the aqueous phase; (6) Collect the aqueous phase obtained in step (5), add 10%-20% by mass of propylene glycol, and vacuum concentrate at 30-70° C. to a density of 1.1-1.3 g / cm 3 , that is, obtaining tobacco flavors with reduced residual harmful substances.

2. The preparation method according to claim 1, characterized in that: The specific conditions for stirring in step (4) are: stirring speed of 3000-10000 r / min, stirring time of 10-20 min; the specific conditions for stirring in step (5) are: stirring speed of 100-400 r / min, stirring time of 10-120 min.

3. The preparation method according to claim 1, characterized in that: The method further comprises the steps of: demulsifying the emulsion phase obtained in step (5) under high voltage electrostatic conditions of 15 kV and 0.02 mA for 30 minutes, allowing the emulsion phase to stand for stratification, and recovering the oil phase for reuse in the next preparation of the W / O / W emulsion.

4. The preparation method according to claim 1, characterized in that: The tobacco raw material described in step (1) is selected from one or more waste tobacco raw materials with high heavy metal content such as discarded tobacco leaves, tobacco dust, tobacco leaf fragments, and discarded tobacco stems; the mass ratio of the waste tobacco raw material to the solution is 1:1-1:25, and the hot reflux extraction adopts a repeated process for multiple extractions, the number of extractions is 2, and the time of each extraction is 1-6 hours.

5. The preparation method according to claim 1, characterized in that: The specific conditions for standing still in step (3) are: cooling and standing at 4°C for 6-8 hours. The filtering method in step (3) can be filter cloth filtration and / or membrane filtration, the filter cloth specification is 400-500 mesh, the membrane filtration is ultrafiltration, and the specific steps of ultrafiltration are: standing the tobacco concentrate obtained in step (2) and separating it through an ultrafiltration membrane assembly, filtering once or combining filtration multiple times with an ultrafiltration membrane with a molecular weight cutoff of 30KDa-5KDa at room temperature, and collecting the filtrate. The obtained filtrate is the external aqueous phase solution.

6. The preparation method according to claim 1, characterized in that: The surfactant described in step (4) is sucrose ester and / or octanoic acid glyceride, the carrier is diacetyl and tributyl phosphate, and the mass ratio of diacetyl to tributyl phosphate is 1:10-10:1; the oil phase is one or more of corn oil, peanut oil, almond oil, coconut oil, and olive oil, the pH of the inner aqueous phase solution is 1-3, specifically one or more of lactic acid, malic acid, and citric acid, and the volume ratio of the oil phase: surfactant: carrier: inner aqueous phase solution is (30-40):(1-5):(1-5):(30-40).

7. Use of the tobacco flavor obtained by the preparation method according to any one of claims 1 to 6, characterized in that: The tobacco flavor is diluted to half with 75-100% by mass ethanol solution and then added into cigarette shreds.

8. The use according to claim 7, characterized in that The mass ratio of the tobacco flavor to the cigarette tobacco is 1:1000-10:1000.

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