Method for extracting tobacco flavor components

Abstract

The invention discloses a method for extracting tobacco flavor components, which comprises the following steps: distillation-dry distillation, collection and elution recovery: the distillation-dry distillation comprises the following steps: adding tobacco into a dry distillation device, preheating the dry distillation device, introducing superheated steam into the dry distillation device, and collecting the tobacco flavor components; heating the dry distillation device until the temperature in the kettle is 100-450 DEG C so as to simultaneously perform distillation and dry distillation on the tobacco; the collection comprises collection of distillates distilled in the whole distillation-dry distillation process; the elution recovery comprises the following steps: adding ethanol into the distillate, placing the distillate in refrigeration equipment, carrying out alcohol precipitation, carrying out coarse filtration, and finally carrying out membrane filtration to obtain a solution containing tobacco aroma components. According to the method, the process steps are further optimized, so that the production process is simplified, meanwhile, the yield of the tobacco aroma components is increased, and the pollution to the environment is reduced.

Description

Technical Field

[0001] The invention relates to the field of new tobacco products such as heated cigarettes, and in particular to a process for extracting tobacco flavor components. Background Art

[0002] With the progress of society, the increasingly severe tobacco control environment and the increasing public awareness of personal health protection, new tobacco products are developing rapidly as an important substitute for traditional tobacco, among which heated cigarettes are the most promising development direction of the tobacco industry in the future. The temperature of heated cigarettes is relatively low, and they cannot release enough aroma-causing substances without being burned, resulting in a weak aroma. Usually, tobacco flavor components need to be added to enhance the aroma and strength. At present, tobacco extraction technology generally has a very low extraction rate of about 0.2% to 1%, and the tobacco flavor components obtained lack the characteristic aroma required by tobacco, such as roasted aroma, paste aroma, and baked aroma. Therefore, the development of new tobacco essential oil extraction technology is crucial to the development of tobacco products.

[0003] In patent CN114504119A, a method for extracting tobacco flavor components is disclosed, characterized in that the multifunctional steam distillation-drying integrated equipment is preheated first, and the tobacco raw material is added into the steam distillation-drying device after the temperature is stable; superheated water vapor and nitrogen are passed into the steam distillation-drying device together, and the steam distillation-drying temperature is increased by heating; the distillate of each temperature section is collected according to the temperature; the distillate of each section is extracted with an organic solvent to obtain an extract; the extract is dehydrated, and the solvent is recovered by rotary evaporation to obtain tobacco flavor components that can be used for flavoring new tobacco products. The above-mentioned overall process steps are relatively complicated, especially the additional use of nitrogen, which leads to cumbersome experimental operations. At the same time, a large amount of organic solvents such as ethyl acetate and n-hexane are used in the enrichment and recovery of the final product. The use, recovery and discharge of these highly volatile organic solvents will pollute the social environment and cause harm to human health. Summary of the invention

[0004] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide an improved method for extracting tobacco flavor components, which has a simpler process and can not only improve the yield of tobacco flavor components but also minimize environmental pollution.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] A method for extracting tobacco flavor components, characterized by comprising:

[0007] a) distillation-drying: including adding tobacco into a dry distillation device, preheating the dry distillation device, passing superheated steam into the dry distillation device, and heating the dry distillation device to a kettle temperature of 100-450° C., so as to simultaneously distill and dry distill the tobacco;

[0008] b) Collection: including collecting the distillate distilled during the entire distillation-drying process;

[0009] c) Elution recovery: including adding ethanol to the distillate, placing it in a refrigeration device for alcohol precipitation, then coarse filtration, and finally membrane filtration to obtain a solution containing tobacco flavor components.

[0010] In another aspect, the present invention provides a flavor additive, wherein the flavor additive comprises flavor components directly obtained by the method for extracting tobacco flavor components.

[0011] In another aspect, the present invention provides an aerosol-generating article, comprising the above-mentioned flavor additive.

[0012] Furthermore, the preset temperature for preheating the dry distillation device is 55-65° C. Preheating the dry distillation device helps to remove air from the device and heat the tobacco evenly.

[0013] Preferably, the preset temperature of the dry distillation device is 55-60°C, 60-65°C.

[0014] More preferably, the preset temperature of the dry distillation device is 60°C.

[0015] After the dry distillation device is preheated, the water vapor is passed to the superheated steam device. At this time, the water vapor is heated to 120-200° C. in the superheated steam device, and then the heated water vapor is passed into the dry distillation device.

[0016] Furthermore, the water vapor is heated to 150° C. in a superheated steam device.

[0017] Furthermore, the gas flow rate of the superheated water vapor entering the dry distillation device is 200-450 g·h -1 ,

[0018] Preferably, the gas flow rate of the superheated water vapor entering the dry distillation device is 200-250 g·h -1 , 250-300g·h -1 , 300-350g·h -1 , 350-400g·h -1 or 400-450g·h -1 .

[0019] More preferably, the gas flow rate of the superheated water vapor entering the dry distillation device is 250 g·h -1 、300g·h -1 、350g·h -1 or 400g·h -1 .

[0020] Furthermore, the temperature of the superheated water vapor introduced into the dry distillation device is controlled at 430° C. to achieve extraction of the tobacco raw material.

[0021] Furthermore, the temperature can be segmented according to product requirements and the amount of raw materials, and the temperature in the kettle of the dry distillation device can be set to 100-450°C.

[0022] Preferably, the temperature in the kettle of the carbonization device can be set to 100-150°C, 150-200°C, 200-250°C, 250-300°C, 300-350°C, 350-400°C, 400-450°C.

[0023] More preferably, the temperature in the kettle of the carbonization device can be set to 150°C, 200°C, 250°C, 300°C, 350°C or 400°C.

[0024] Furthermore, the heating rate of the dry distillation device is 0.5-4.5°C·min -1 .

[0025] Preferably, the heating rate of the dry distillation device is 0.5-1°C·min -1 , 1-2℃·min -1 、2-3℃·min -1 、3-4℃·min -1 .

[0026] More preferably, the heating rate of the dry distillation device is 1°C·min -1 , 2℃·min -1 、3℃·min -1 or 4℃·min -1 .

[0027] Furthermore, the collecting step includes collecting distillates in a corresponding temperature range when the dry distillation device is heated to a certain temperature.

[0028] Furthermore, the ethanol concentration is at least 90%, and preferably, the ethanol concentration is 95%.

[0029] Further, at least 1 volume of the ethanol is added to the distillate, preferably, 2-3 volumes of the ethanol are added, and most preferably, 2 volumes of the ethanol are added.

[0030] Furthermore, the temperature of the refrigeration equipment is controlled at -10°C-0°C, and is evenly stirred before being placed in the refrigeration equipment. Preferably, the temperature of the refrigeration equipment is controlled at about -7°C-3°C, and more preferably, the temperature of the refrigeration equipment is controlled at -5°C.

[0031] Impurities such as water-soluble polysaccharides and mucus in the liquid can be removed by placing the liquid in the refrigeration equipment for alcohol precipitation.

[0032] Furthermore, the alcohol precipitation time is at least 10 hours.

[0033] Furthermore, the refrigeration equipment includes a refrigerator, a freezer or other equipment that can maintain a constant low temperature.

[0034] Furthermore, the coarse filtration includes filter paper filtration, and the filter paper includes medium-speed filter paper. Insoluble matter can be removed by using the filter paper.

[0035] The membrane filtration includes inorganic ceramic membrane filtration and solvent-resistant nanofiltration membrane filtration. The membrane material in membrane separation includes at least one polymer material, which is a selective barrier between two phases and a technology that can selectively separate the feed liquid by using the pressure difference. Compared with solvent separation or other traditional filtration, membrane separation is a separation action at the molecular level, and the whole process is a physical process without phase change and the addition of other additives.

[0036] In the process of membrane filtration, the inorganic ceramic membrane is first selected for filtration and clarification to ensure the clarity of the sample without blocking the nanofiltration process to be carried out in the next step. The inorganic ceramic membrane is resistant to organic solvents, acids and alkalis, and high temperatures, and is easy to clean, has a long service life, and has a low overall cost.

[0037] The pore size of the inorganic ceramic membrane is in the range of 1.0-0.01um, preferably 0.1-0.01um, and most preferably 0.05um, so as to further remove smaller macromolecular compounds such as colloids, and the transmittance is 80%.

[0038] Furthermore, the inorganic ceramic membrane filtration takes between 20 minutes and 2 hours, preferably 30 minutes.

[0039] The inorganic ceramic membrane with a lower pore size has a higher cost and a longer operating time. Compared with this extract, the same amount of distillate solution takes 2 hours to filter with a 0.01um membrane, while it only takes 30 minutes with a 0.05um membrane. Due to the problem of filtration accuracy, the permeate of a larger pore size membrane will take more time in the nanofiltration process, which will also affect the efficiency.

[0040] The molecular weight cutoff of the solvent-resistant nanofiltration membrane is 200D-900D, preferably 300D-700D, and more preferably 500D.

[0041] The reason for choosing solvent-resistant nanofiltration membrane is that ethanol solvent and superheated steam-retort are mostly organic compounds, which have a certain corrosive and dissolving effect on ordinary nanofiltration membranes and will damage non-solvent membranes. They are not suitable for separating and enriching substances containing a large amount of organic compounds.

[0042] The smaller the molecular weight cutoff of the solvent-resistant nanofiltration membrane, the greater the working pressure required by the membrane, the higher the power, the greater the cost, and the greater the probability that the membrane will be damaged by high pressure penetration; at the same time, for the tobacco raw material, the interception amount of 500D can penetrate small molecular impurities such as acetic acid, and can also intercept most of the other flavor molecules, without the need to select membrane equipment with higher costs and smaller molecular retention amounts.

[0043] The working temperature of the extract in the solvent-resistant nanofiltration membrane is controlled within 45°C, and the preferred temperature is 40°C-45°C. On the one hand, too high a temperature (greater than 50°C) will cause membrane damage, and at the same time volatilize and take away smaller aroma molecules in the extract, resulting in loss of extract aroma, affecting the final application of the extract. However, too low a temperature is also unnecessary, as too low a temperature will consume more refrigerant and energy, increase process costs, and have little effect on the aroma substances in the extract.

[0044] The end point of the solvent-resistant nanofiltration membrane filtration is that the total amount of the enrichment side accounts for 15-25% of the input amount, and the more preferred choice is 20%. Too high a proportion will cause the final retentate to be too dilute, affecting its application in heated cigarettes. In addition, too much retentate also indicates that compounds such as acetic acid have not completely passed through, and the final product has poor color. If the retentate is over-enriched, on the one hand, air will enter the solvent-resistant nanofiltration membrane device, causing the solvent-resistant nanofiltration membrane device to be damaged. On the other hand, too high an enrichment concentration will cause some compounds to precipitate, affecting the final use.

[0045] Furthermore, the solvent-resistant nanofiltration membrane filtration process takes between 1 hour and 2 hours. Preferably, the solvent-resistant nanofiltration membrane filtration process takes 1 hour and 20 minutes.

[0046] If the distillate is extracted by solvent, an extractant suitable for extracting aroma substances will inevitably be used, such as organic solvents such as ethyl acetate and n-hexane. However, these extractants are not suitable for adding to the aerosol generating product. Therefore, an additional step of removing the organic solvent is required, such as rotary evaporation. On the one hand, this will increase the steps and reduce the production efficiency of large-scale production. On the other hand, rotary evaporation will also lead to the loss of some aroma substances. In addition, rotary evaporation cannot completely remove the solvent, and the residual solvent will affect the aroma quality.

[0047] Although the solution containing tobacco flavor components finally obtained contains ethanol, it can be directly added to the aerosol generating product as a flavor component additive. After elution and recovery, no other treatment is required and it can be directly used, which is convenient and efficient. Ethanol not only plays a role in recovery, but also can volatilize quickly when the ethanol solution containing flavor components is directly added to the aerosol generating product, and the flavor substances dissolved therein can exist in the aerosol generating product, which will not affect the use of the aerosol generating product.

[0048] The "aerosol generating article" comprises a tobacco element and a mouthpiece element. The tobacco element comprises an aerosol-forming substrate. The mouthpiece element is the last part of the aerosol generating article in the downstream direction. The consumer contacts the mouthpiece element so as to transfer the aerosol generated by the aerosol generating article through the mouthpiece element to the consumer.

[0049] Further, the "aerosol generating article" may also include an aerosol cooling element, which may include one or more longitudinally extending channels. For example, the aerosol cooling element includes a gathered sheet or a curled gathered sheet, which may include a gathered sheet of a material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), cellulose acetate (CA) and aluminum foil. The aerosol cooling element may be located downstream of the tobacco element.

[0050] Further, the "aerosol generating article" may also include a support element. The support element is arranged immediately downstream of the tobacco element, and the support element is configured to prevent the aerosol-forming substrate from moving downstream during the insertion of the heating element of the aerosol generating device into the aerosol-forming substrate of the aerosol generating article. The support element may be formed by any suitable material or combination of materials. For example, the support element is formed by one or more materials selected from the group including: cellulose acetate; paperboard; corrugated paper, such as corrugated heat-resistant paper or corrugated sulfate paper; and polymer materials, such as low-density polyethylene (LDPE). In a preferred embodiment, the support element is formed by cellulose acetate.

[0051] The term "aerosol generating device" is used to describe a device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol. Preferably, the aerosol generating device is a smoking device that interacts with an aerosol-forming substrate of said aerosol-generating article to generate an aerosol that is directly inhalable into the lungs of a user through the user's mouth.

[0052] The term "aerosol-forming substrate" refers to a substrate that is capable of generating volatile compounds upon heating, which volatile compounds can form an aerosol.

[0053] The flavor component additive may be disposed in any part of the aerosol-generating article, including any one or more of the tobacco element, the support element, the aerosol-cooling element or the mouthpiece element.

[0054] Beneficial effects: Compared with the prior art, the advantages of the present invention are:

[0055] 1) The inventor surprisingly found that the content of the main flavor components obtained by the method of the present invention is significantly improved compared with the prior art when implementing the technical solution of the present invention, and the flavor components are also richer. The reason is that on the one hand, because there is no nitrogen, the rapid expansion of the superheated steam after heating leads to the existence of a micro-positive pressure environment in the device, and the external oxygen does not enter the device, so that a slight aerobic environment is formed in the retort. The trace oxygen in the retort participates in the interaction of the compounds under the high temperature environment, and cracks and synthesizes more original aromatic substances of tobacco. In addition, without the introduction of nitrogen, the low concentration of oxygen in the kettle cannot cause the raw materials to burn, which has no effect on the safety of the whole method, and also avoids the possibility of suffocation caused by misoperation of the staff; on the other hand, the membrane filtration also allows the solution containing tobacco flavor components to retain some water-soluble flavor components, such as acid substances. Therefore, the above two aspects jointly contribute to better aroma performance.

[0056] 2) The ceramic membrane and solvent-resistant nanofiltration membrane are selected as the refining process of the extract, avoiding the use of low flash point and high volatility organic solvents such as ethyl acetate and n-hexane. The residual organic solvent in the final extract is reduced, the harm to the environment during the solvent recovery and disposal process is avoided, and the personal safety of the staff is also avoided.

[0057] 3) In the application of the solvent-resistant nanofiltration membrane, small molecular impurities such as acetic acid are removed, and part of solvents such as water and ethanol are also removed, which plays a role in enrichment and concentration. The intercepted extract can be directly used as a flavor component, without the need for the water and solvent removal steps of a rotary evaporator, and the process is more efficient.

[0058] 4) The tobacco flavor components prepared by the present invention can produce a characteristic aroma close to the burning of traditional cigarettes when heated or atomized. Adding them to new tobacco products such as heated cigarettes or electronic cigarettes can increase their characteristic aromas such as roasted aroma and burnt sweet aroma, making their taste closer to traditional cigarettes. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 A flow chart of the method for extracting tobacco aroma components according to the present invention is shown.

[0060] Figure 2 A comparison diagram of the method for extracting tobacco flavor components according to Example 1 of the present invention and Comparative Example 1 is shown.

[0061] Figure 3 A schematic diagram of a device involved in the method for extracting tobacco flavor components of the present invention is shown. DETAILED DESCRIPTION

[0062] The detailed features and advantages of the present invention are described in detail in the specific implementation modes below, and the contents are sufficient to enable any person skilled in the art to understand the technical contents of the present invention and implement them accordingly. Moreover, according to the description, claims and drawings disclosed in this specification, those skilled in the art can easily understand the relevant objects and advantages of the present invention.

[0063] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0064] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0065] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0066] like Figure 3As shown, the experimental equipment used in the distillation-drying and collecting process of the present invention includes an electrical control cabinet 1, a water vapor generator 2, a superheated steam device 3 and a dry distillation device 4, a water cooling system 5 and a product collecting device 6. The water vapor generator 2 is connected to the superheated steam device 3, the superheated steam device 3 is connected to the dry distillation device 4, the dry distillation device 4 is connected to the water cooling system 5, and the water cooling system 5 is connected to the product collecting device 6 (the water vapor generator 1, the superheated steam device 3 and the dry distillation device 4 are all connected to the electrical control cabinet 1, and the control cabinet can control the temperature of these three devices and the amount of steam). During the experiment, the main switch of the above equipment is turned on through the electrical control cabinet 1. After the temperature of the dry distillation device 4 reaches 55-65°C, tobacco leaf fragments are added into the dry distillation device 4, and then the valve of the dry distillation device 4 is closed, and then The water vapor generated by the water vapor generating device 2 will be passed to the superheated steam device 3. At this time, the water vapor is heated in the superheated steam device 3. After being heated to 150°C, the valve of the dry distillation device 4 is opened. At this time, the heated water vapor will pass into the dry distillation device 4, and then the dry distillation device 4 is heated from the preheating temperature to the reaction temperature, and the heat is kept. The precursor substances of the tobacco leaves will undergo pyrolysis and chemical reactions under this condition, and the generated aroma substances will be taken away by the water vapor, and then condensed and cooled through the water cooling system 5, and then all the distillates in the distillation-dry distillation process will be collected at one time at the collection device 6. The flavor component composition of the present invention can be directly added as an additive to tobacco raw materials or reconstituted tobacco leaves to form cigarettes and cigarette sticks, and is particularly suitable for use in heat-not-burn smoke-generating bodies. The flavor substances extracted by the present invention are not burned, and the flavor components can also be well released only in the heated state.

[0067] The present invention will be further described below in conjunction with specific embodiments.

[0068] Example 1

[0069] Reference Figure 1 , put in 1000g tobacco leaves, preheat the dry distillation device, after the temperature reaches 60°C, introduce the superheated water vapor into the dry distillation device, and the flow rate of the superheated water vapor is 350g / h, and heat the dry distillation device to a reaction temperature of 350°C to simultaneously dry distill and distill the tobacco raw material, and the rate of heating from the preheating temperature to the reaction temperature of 350°C is 3°C / min; when the reaction temperature reaches 350°C, keep the temperature for 20 minutes, condense and cool through a secondary condensation system, and collect distillates at 150-200°C, 200-250°C, 250-300°C and 300-350°C respectively. Take out a small portion of the distillates in each of the above temperature sections for gas chromatography analysis.

[0070] The product was qualitatively analyzed by gas chromatography-mass spectrometry (TRACE DSQ gas chromatography-mass spectrometry, FINNIGAN, USA), and the method was as follows: chromatographic conditions: DB-5 elastic quartz capillary column (30m×250μm×0.25μm); carrier gas He, flow rate 1mL / min; injection port temperature 250℃; FID detector temperature 280℃; initial temperature 40℃, maintained for 5min, heated to 100℃ at 2℃ / min, maintained for 2min, and heated to 250℃ at 8℃ / min. Injection volume 0.5μL; split ratio 20; chromatographic column flow rate 30.3mL / min. Mass spectrometry conditions: EI ion source 250℃, quadrupole temperature 150℃, electron energy 70eV, scanning mass range 33-450u, electron multiplier voltage 1347V.

[0071] The distillates from each temperature range were mixed and 2 volumes of 95% ethanol were added to prepare a distillate ethanol solution. The beaker containing the materials was sealed with plastic wrap and placed in a -5°C refrigerator for overnight (about 12 hours). The soluble matter was removed by filtering with laboratory medium-speed filter paper.

[0072] After the membrane equipment was cleaned with 1% sodium hydroxide, it was rinsed with water until the pH was neutral and then used. The filtered distillate solution was poured into an inorganic ceramic membrane device with a pore size of 0.05um, and the device was turned on for membrane separation. It took 30 minutes, and the mass of the material on the permeate side was 514g, that is, the operation was stopped after about 80% was passed, and the permeate was collected. The permeate was placed in a solvent-resistant nanofiltration membrane with a molecular weight cutoff of 500D, which took 1 hour and 20 minutes, and the mass of the permeate was 405g. 100g of the retained liquid was collected, and the alcohol content was about 60% tested with an alcohol meter, which was the final tobacco flavor component.

[0073] Comparative Example 1 (Example 1 disclosed in CN114504119A)

[0074] The dry distillation device is set to 80°C, and nitrogen is introduced into the device at a nitrogen flow rate of 80 mL / min. 400 g of tobacco raw material (flue-cured tobacco leaf fragments, 10 mesh) is added to the dry distillation device. Water vapor is passed from the water vapor generating device to the superheated steam device at a rate of 5600 mL / min, and then to the dry distillation device after secondary heating. Distillates at the temperature sections of 150-200°C and 200-250°C are collected. A small portion of the distillate from each of the above temperature sections is taken out for gas chromatography analysis.

[0075] The distillates from different fractions are extracted three times with an extractant having a volume ratio of ethyl acetate to normal hexane of 1:1, the first volume ratio being 1:1, and the second and third volume ratios being dry distillation product to extractant 4:1, to obtain an extract mixture, anhydrous sodium sulfate is added to the extract mixture, and the mixture is stirred for 2 hours for dehydration, and the dehydrated extract mixture is subjected to rotary evaporation to recover the solvent, to obtain tobacco flavor components that can be used for flavoring novel tobacco products, the yield is calculated, and the product is qualitatively analyzed using the gas chromatography-mass spectrometry instrument.

[0076] Reference Figure 2 , the process comparison of Example 1 and Comparative Example 1:

[0077] From the comparison of the two processes for extracting tobacco flavor components, the process of the present invention does not use nitrogen, so there is no need to use a nitrogen tank as a whole, which reduces the risk of suffocation caused by nitrogen leakage. In addition, there is no need to mix superheated steam and nitrogen, and the overall process is more simple and efficient. At the same time, membrane separation technology is finally used to separate and enrich flavor substances, and low-flavor and high-volatility organic solvents such as ethyl acetate and n-hexane are not used. Environmental pollution will not be caused by solvent recovery and waste processes, and harm to human health will be reduced. The process will be more environmentally friendly and safe. On the basis of the increasing attention paid to environmental protection and employee occupational health, improving and optimizing the old process is an inevitable requirement of the modern process technology development process.

[0078] Comparison of main aroma components between Example 1 and Comparative Example 1:

[0079] Table 1: Comparison of main aroma components of Example 1 and Comparative Example 1 at a temperature range of 200°C-250°C by GC-MS

[0080]

[0081]

[0082] From the analysis results of the main aroma components of GC-MS in the same temperature range of 200°C-250°C, the main aroma components of the tobacco aroma component extract of Example 1 are compared with the main aroma components of the tobacco aroma component extract of Comparative Example 1. Except for the furfural content being about 6% less (within the analytical error range), the other components are higher or similar than the tobacco aroma component extract of Comparative Example 1, wherein methylcyclopentenolone is 36% higher than Comparative Example 1. Methylcyclopentenolone has good sensory properties and obvious caramel flavor. It is widely used in coffee and tobacco for flavor enhancement and fixation. 3-Methylvaleric acid is a characteristic aroma component of tobacco leaves, which can soften smoke and reduce stimulation in tobacco, and (E)-9-tetradecene-1-ol acetate as a higher fatty acid ester can also improve smoke and has a positive effect on the taste of tobacco. An important reason why Example 1 of the present invention has richer aroma substances than Comparative Example 1 is that in the dry distillation process of Example 1, no nitrogen is introduced, but only superheated water vapor is introduced, so that the trace oxygen existing in the dry distillation kettle participates in the interaction of the compounds under the high temperature environment, and cracks and synthesizes more aroma substances.

[0083] In addition, the membrane filtration also allows the final solution containing tobacco flavor components to retain some water-soluble flavor components, such as acid substances, such as acetic acid, etc. Therefore, the above two aspects together contribute to better aroma performance of the present invention.

[0084] Comparison of sensory evaluation of tobacco flavor extracts of Example 1 and Comparative Example 1

[0085] A panel of 10 people conducted a sensory evaluation of the aroma and scored six indicators: fragrance, smoke, strength, pungency, aftertaste, and uniformity.

[0086] Table 2 Heated cigarette smoking results

[0087]

[0088]

[0089] The above extracts were added to blank heated cigarettes at one thousandth for sample preparation. Ten sensory evaluators of heated cigarettes independently scored the five indicators of aroma, smoke, strength, irritation and aftertaste. The average values ​​of the evaluation scores of the 10 smokers on different indicators were calculated and statistically analyzed to produce a smoking evaluation result table.

[0090] The final results show that the addition of the two process extracts has a certain improvement on the quality of the blank cigarettes. Among them, the extract of Example 1 is better than the extract of Comparative Example 1 in terms of aroma, smoke, and strength. Only the irritation is lower than that of solvent extraction. The possible reason is that the membrane filtration in Example 1 is generally effective in removing water-soluble alkaloids such as nicotine.

[0091] In general, the total process sensory score of Example 1 is higher than that of Comparative Example 1.

[0092] Table 3: Overall evaluation of the aroma of the extracts of Example 1 and Comparative Example 1

[0093]

[0094] In terms of aroma evaluation, the extract of Comparative Example 1 showed rich aroma, roasted sweet aroma, good clumping ability, and good aroma quantity, while the extract of Example 1 showed rich aroma in the evaluation of cigarettes, accompanied by pleasant burnt sweet aroma and woody aroma, without burnt bitter smell, good clumping ability, sufficient aroma quantity, and better overall performance evaluation.

Claims

1. A method for extracting tobacco flavor components, characterized in that: include: a) distillation-drying: including adding tobacco into a dry distillation device, preheating the dry distillation device, passing superheated steam into the dry distillation device, and heating the dry distillation device to a kettle temperature of 100-450° C., so as to simultaneously distill and dry distill the tobacco; b) Collection: including collecting the distillate distilled during the entire distillation-drying process; c) Elution recovery: including adding ethanol to the distillate, placing it in a refrigeration device for alcohol precipitation, then coarse filtration, and finally membrane filtration to obtain a solution containing tobacco flavor components.

2. The method according to claim 1, characterized in that The preheating temperature of the dry distillation device is 55-65°C.

3. The method according to claim 1, characterized in that The gas flow rate of the superheated water vapor entering the dry distillation device is 200-450 g·h -1 .

4. The method according to claim 1, characterized in that The heating rate of the dry distillation device is 0.5-4.5℃·min -1 .

5. The method according to claim 1, characterized in that The ethanol concentration is at least 90%.

6. The method according to claim 1, characterized in that The temperature of the refrigeration equipment is controlled at -10°C-0°C.

7. The method according to claim 1, characterized in that The membrane filtration includes inorganic ceramic membrane filtration and solvent-resistant nanofiltration membrane filtration.

8. The method according to claim 1, characterized in that The coarse filtration includes filtering using filter paper.

9. The method according to claim 7, characterized in that The pore size range of the inorganic ceramic membrane is 1.0-0.01 um.

10. The method according to claim 7, characterized in that The molecular weight cut-off of the solvent-resistant nanofiltration membrane is 200D-900D.

11. A flavor additive, characterized in that: The flavor additive comprises flavor components directly obtained by the method for extracting tobacco flavor components according to any one of claims 1 to 10.

12. An aerosol generating product, characterized in that Contains the flavor additive as claimed in claim 11.

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