METHOD FOR ENRICHING BURNT-SWEET AROMA NOTE IN YUNNAN FLUE-CURED TOBACCO AND AEROSOL-FORMING MATERIAL

Abstract

A method for enriching a burnt-sweet aroma note in Yunnan flue-cured tobacco includes: S1: diluting a Yunnan flue-cured tobacco extract with a diluent to obtain an obtained diluted solution; S2: subjecting the obtained diluted solution to an elution treatment using a C18 column under a pressure of 5-20 bar, the elution treatment including: first performing a primary elution with a first eluent, then performing a secondary elution with a second eluent, and collecting a secondary elution solution as a collected secondary elution solution, the first eluent including water or an aqueous ethanol solution with a mass concentration of less than 10%, and the second eluent including an aqueous ethanol solution with a mass concentration of 38-42%; and S3: concentrating the collected secondary elution solution to obtain a sample with the burnt-sweet aroma note.

Claims

1. A method for enriching a burnt-sweet aroma note in Yunnan flue-cured tobacco, comprising: S1: diluting a Yunnan flue-cured tobacco extract with a diluent to obtain an obtained diluted solution; S2: subjecting the obtained diluted solution to an elution treatment using a C18 column under a pressure of 5-20 bar, the elution treatment comprising: first performing a primary elution with a first eluent, then performing a secondary elution with a second eluent, and collecting a secondary elution solution as a collected secondary elution solution, wherein the first eluent comprises water or an aqueous ethanol solution with a mass concentration of less than 10%, and wherein the second eluent comprises an aqueous ethanol solution with a mass concentration of 38-42%; and S3: concentrating the collected secondary elution solution to obtain a sample with the burnt-sweet aroma note.

2. The method of claim 1, wherein in S2, a flow rate of the elution treatment is 20 mL/min-80 mL/min.

3. The method of claim 1, wherein in S2, an amount of the first eluent is 3 BV-5 BV, and/or wherein an amount of the second eluent is 3 BV-5 BV.

4. The method of claim 1, wherein in S1, a mass ratio of the Yunnan flue-cured tobacco extract to a solvent is 1:1-1:5.

5. The method of claim 2, wherein in S1, a mass ratio of the Yunnan flue-cured tobacco extract to a solvent is 1:1-1:5.

6. The method of claim 3, wherein in S1, a mass ratio of the Yunnan flue-cured tobacco extract to a solvent is 1:1-1:5.

7. The method of claim 1, wherein in S1, the diluent comprises at least one of water, ethanol, propylene glycol, and glycerol.

8. The method of claim 1, wherein in S3, concentration under reduced pressure is adopted, and/or wherein the concentration is performed until a density of a concentrated solution is 1.1920-1.208 g/cm.sup.3.

9. The method of claim 8, wherein in S3, a temperature for the concentration under reduced pressure is 45-65 C., and a pressure for the concentration under reduced pressure is 60-120 mbar.

10. A sample of a burnt-sweet aroma note of Yunnan flue-cured tobacco enriched by the method of claim 1, the sample comprising: 20-30 g/ml of furfural; 20-30 g/mL of 3-methyl-1,2-cyclopentenedione; 20-25 g/mL of maltol; and 35-40 g/mL of 2-cyclopentene-1,4-dione.

11. A sample of a burnt-sweet aroma note of Yunnan flue-cured tobacco enriched by the method of claim 2, the sample comprising: 20-30 g/ml of furfural; 20-30 g/mL of 3-methyl-1,2-cyclopentenedione; 20-25 g/mL of maltol; and 35-40 g/mL of 2-cyclopentene-1,4-dione.

12. A sample of a burnt-sweet aroma note of Yunnan flue-cured tobacco enriched by the method of claim 3, the sample comprising: 20-30 g/ml of furfural; 20-30 g/mL of 3-methyl-1,2-cyclopentenedione; 20-25 g/mL of maltol; and 35-40 g/mL of 2-cyclopentene-1,4-dione.

13. A sample of a burnt-sweet aroma note of Yunnan flue-cured tobacco enriched by the method of claim 4, the sample comprising: 20-30 g/ml of furfural; 20-30 g/mL of 3-methyl-1,2-cyclopentenedione; 20-25 g/mL of maltol; and 35-40 g/mL of 2-cyclopentene-1,4-dione.

14. A sample of a burnt-sweet aroma note of Yunnan flue-cured tobacco enriched by the method of claim 5, the sample comprising: 20-30 g/ml of furfural; 20-30 g/mL of 3-methyl-1,2-cyclopentenedione; 20-25 g/mL of maltol; and 35-40 g/mL of 2-cyclopentene-1,4-dione.

15. A sample of a burnt-sweet aroma note of Yunnan flue-cured tobacco enriched by the method of claim 6, the sample comprising: 20-30 g/ml of furfural; 20-30 g/mL of 3-methyl-1,2-cyclopentenedione; 20-25 g/mL of maltol; and 35-40 g/mL of 2-cyclopentene-1,4-dione.

16. A sample of a burnt-sweet aroma note of Yunnan flue-cured tobacco enriched by the method of claim 7, the sample comprising: 20-30 g/ml of furfural; 20-30 g/mL of 3-methyl-1,2-cyclopentenedione; 20-25 g/mL of maltol; and 35-40 g/mL of 2-cyclopentene-1,4-dione.

17. An aerosol-forming material, comprising: the sample of claim 10.

18. The aerosol-forming material of claim 17, wherein the aerosol-forming material comprises atomization liquid comprising 0.5-2 wt % of the sample of the burnt-sweet aroma note of Yunnan flue-cured tobacco and 98-99.5 wt % of a solvent.

19. The aerosol-forming material of claim 18, wherein the solvent comprises a mixed solvent of propylene glycol and glycerol.

20. The aerosol-forming material of claim 19, wherein a mass ratio of the propylene glycol to the glycerol is 6:4-1:1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Subject matter of the present disclosure will be described in even greater detail below based on the exemplary FIGURES. All features described and/or illustrated herein can be used alone or combined in different combinations. The features and advantages of various embodiments will become apparent by reading the following detailed description with reference to the attached drawings, which illustrate the following:

[0008] FIG. 1 shows detection results of burnt-sweet aroma components in an ethanol extract of Yun 87 of the present invention, sample 1-2 obtained in Example 1, and sample 2-2 obtained in Comparative Example 1.

DETAILED DESCRIPTION

[0009] In an embodiment, the technical problem to be solved by the present invention is to overcome the defects in the prior art, such as the absence of a method for enriching a burnt-sweet aroma note from Yunnan flue-cured tobacco, or the methods for enriching from other tobacco leaves exhibiting a relatively high content of impurities, the burnt-sweet aroma of the aerosol-forming material not being prominent, or the overall tobacco aroma having poor harmony. Thus, in an embodiment, the present invention provides a method for enriching a burnt-sweet aroma note in Yunnan flue-cured tobacco and an aerosol-forming material.

[0010] In a first aspect, the present invention provides a method for enriching a burnt-sweet aroma note in Yunnan flue-cured tobacco, including steps of: [0011] S1: diluting a Yunnan flue-cured tobacco extract with a diluent to obtain a diluted solution; [0012] S2: subjecting the obtained diluted solution to an elution treatment using a C18 column under a pressure of 5-20 bar, where the elution treatment includes: first performing a primary elution with a first eluent, then performing a secondary elution with a second eluent, and collecting a secondary elution solution, [0013] where the first eluent is water or an aqueous ethanol solution with a mass concentration of less than 10%, and the second eluent is an aqueous ethanol solution with a mass concentration of 38-42%; and [0014] S3: concentrating the collected secondary elution solution to obtain a sample with the burnt-sweet aroma note.

[0015] In some optional embodiments, in step S2, the flow rate of the elution treatment is 20 mL/min-80 mL/min.

[0016] In some optional embodiments, in step S2, the amount of the first eluent is 3 BV-5 BV; and/or the amount of the second eluent is 3 BV-5 BV.

[0017] In some optional embodiments, in step S1, the mass ratio of the Yunnan flue-cured tobacco extract to a solvent is 1:1-1:5.

[0018] In some optional embodiments, in step S1, the diluent includes at least one of water, ethanol, propylene glycol, and glycerol.

[0019] In some optional embodiments, in step S3, concentration under reduced pressure is adopted; and/or the concentration is performed until the density of a concentrated solution is 1.1920-1.208 g/cm.sup.3.

[0020] In some optional embodiments, in step S3, the temperature for the concentration under reduced pressure is 45-65 C., and the pressure for the concentration under reduced pressure is 60-120 mbar.

[0021] In a second aspect, the present invention provides a sample of a burnt-sweet aroma note of Yunnan flue-cured tobacco enriched by the above method, including 20-30 g/ml of furfural, 20-30 g/mL of 3-methyl-1,2-cyclopentenedione, 20-25 g/mL of maltol, and 35-40 g/mL of 2-cyclopentene-1,4-dione.

[0022] In a third aspect, the present invention provides an aerosol-forming material, including the above sample of a burnt-sweet aroma note of Yunnan flue-cured tobacco.

[0023] In some optional embodiments, the aerosol-forming material includes 0.5-2 wt % of the sample of the burnt-sweet aroma note of Yunnan flue-cured tobacco and 98-99.5 wt % of a solvent;

[0024] optionally, the solvent is a mixed solvent of propylene glycol and glycerol; and further optionally, the mass ratio of the propylene glycol to the glycerol is 6:4-1:1.

[0025] In the present invention, the Yunnan flue-cured tobacco extract is an ethanol extract of Yun 87, which can be obtained through commercially available channels.

[0026] In the present invention, the C18 column is Daiso RPS C18, 50 m, which can be obtained through commercially available channels.

[0027] The technical solution of the present invention has the following advantages:

[0028] the method for enriching a burnt-sweet aroma note in Yunnan flue-cured tobacco provided in the present invention includes steps of: S1: diluting a Yunnan flue-cured tobacco extract with a diluent to obtain a diluted solution; S2: subjecting the obtained diluted solution to an elution treatment using a C18 column under a pressure of 5-20 bar, where the elution treatment includes: first performing a primary elution with a first eluent, then performing a secondary elution with a second eluent, and collecting a secondary elution solution, where the first eluent is water or an aqueous ethanol solution with a mass concentration of less than 10%, and the second eluent is an aqueous ethanol solution with a mass concentration of 38-42%; and S3: concentrating the collected secondary elution solution to obtain a sample with the burnt-sweet aroma note. In the present invention, by selecting the C18 column for elution with a specific eluent under a certain pressure, the primary elution step can remove impurities (including impurities such as polysaccharides and proteins) as much as possible, and the secondary elution can elute components of a burnt-sweet aroma note as comprehensively as possible to achieve the enrichment of target components. If the ethanol concentration in the second eluent is too low, the components of the caramel aroma note cannot be completely eluted, resulting in partial loss. If the ethanol concentration in the second eluent is too high, other impurities will be brought in. This method is simple to operate, can realize the efficient enrichment of the components of the burnt-sweet aroma note in the Yunnan flue-cured tobacco extract, and can remove the impurity components therein. When the enriched sample is used in the aerosol-forming material, the burnt-sweet aroma of the aerosol-forming material is prominent and the overall tobacco aroma is harmonious.

[0029] The following examples are provided to better understand the present invention. They are not limited to the most preferred embodiments, and do not constitute a limitation to the content and the scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the present invention with the features of other prior art shall fall within the scope of protection of the present invention.

[0030] For those examples in which specific experimental steps or conditions are not specified, the operations or conditions of the conventional experimental steps described in the documents in the art can be carried out. For those reagents or instruments for which the manufacturers are not specified, they are all conventional reagent products that can be obtained through commercially available channels.

Example 1

[0031] This example provided a method for enriching a burnt-sweet aroma note in a Yunnan flue-cured tobacco extract, and the specific steps and operating parameters were as follows: [0032] (1) sample dilution: the Yunnan flue-cured tobacco extract (ethanol extract of Yun 87) was diluted with propylene glycol as the diluent according to a mass ratio of 1:3 to obtain a diluted solution; [0033] (2) medium-pressure preparation: the diluted solution obtained in step (1) was subjected to gradient elution using a medium-pressure preparative C18 column (Daiso RPS C18, 50 m, 2.0 kg of packing material, column size 460100 mm). Water, a 40 wt % aqueous ethanol solution, an 80 wt % aqueous ethanol solution, and a 95 wt % aqueous ethanol solution were separately used as the elution solutions. Under a pressure of 10 bar, gradient elution was performed at a flow rate of 50 mL/min, and the amount of each eluent was 5 BV. The solutions eluted in each gradient were collected; [0034] (3) filtration: the solutions eluted in each gradient in step (2) were filtered through a 400-mesh nylon net, and the elution filtrates of each gradient were obtained; [0035] (4) concentration: the elution filtrates of each gradient in step (3) were concentrated under reduced pressure by using a rotary evaporator (65 C., 60 mbar) until there was no liquid dripping. The density of the concentrated solution was controlled to be 1.1920-1.208 g/cm.sup.3, and 4 components were respectively obtained, which were labeled as sample 1-1, sample 1-2, sample 1-3, and sample 1-4; and [0036] (5) each component in step (4) was formulated into an aerosol-forming material according to the above aerosol-forming material formula (the concentrated sample component accounted for 2 wt %, the solvent accounted for 98 wt %, and the solvent was a mixed solvent of propylene glycol and glycerol with a mass ratio of 6:4). According to the Aroma Style Evaluation Form for Tobacco-flavored E-cigarettes in the enterprise standard Sensory Evaluation Standard for Tobacco-flavored E-cigarettes (see Table 1), sensory evaluation was carried out on each component by 7 professional sensory evaluators and summarized. During the sensory evaluation, if the relevant aroma note was perceived, it was ticked in the corresponding box in the evaluation form of Table 1. The aroma note ticked by 4 or more evaluators was defined as the primary aroma note, and the aroma note ticked by 3 or fewer evaluators was defined as the secondary aroma note, and the sensory evaluation results were obtained (see Table 2).

TABLE-US-00001 TABLE 1 Category Indicator Tobacco aroma Sample 1-1 Sample 1-2 Sample 1-3 Sample 1-4 Characteristic Hay aroma aroma of Bean aroma category A Roasted aroma Cocoa aroma Sweet aroma Burnt aroma Woody aroma Smoky aroma Characteristic Fruity aroma aroma of Spicy aroma category B Herbaceous aroma Green aroma Floral aroma Wine aroma Milk aroma Comprehensive description: Sensory evaluator Date: Note: a burnt-sweet aroma is a burnt aroma mingled with a sweet aroma.

TABLE-US-00002 TABLE 2 Component number Sensory evaluation Sample 1-1 Roasted aroma and smoky aroma Sample 1-2 The primary aroma notes are a burnt-sweet aroma and a roasted aroma Sample 1-3 The primary aroma notes are a hay aroma, a floral aroma and a fruity aroma Sample 1-4 Hay aroma and green aroma [0037] (6) the aroma component analysis was performed on the component with an obvious burnt-sweet aroma note (sample 1-2). The specific analysis method was as follows: [0038] preparation of the sample to be tested: 500 L of the component with an obvious burnt-sweet aroma note (sample 1-2) obtained in step (4) and 500 L of the ethanol extract of Yun 87 were separately pipetted into centrifuge tubes. Then, 500 L of a dichloromethane solution containing internal standards (the internal standards were 10.0 mg/mL of 2-methyl-3-heptanone and 2-octanol respectively) was added. Oscillation (3000 rpm) was performed for 10 min for sufficient extraction, followed by centrifugation (10000 rpm) for 5 min. An appropriate amount of the extraction solution was taken, passed through a 0.24-m organic-phase filter membrane, and transferred to a chromatography vial for GC-MS/MS analysis. [0039] determination of aroma components: the determination of aroma components was performed on a GC-MS/MS (model: Agilent 5977B GC/MSD 8890GC System). The specific parameters were as follows: the chromatographic column was a DB-5 MS ultra-inert column (60 m, 0.25 mm, 0.25 m); split injection 10:1; injection volume 1 L; column oven temperature: kept at 40 C. for 2 minutes, then increased to 150 C. at a rate of 3 C./min and kept for 2 min, then increased to 300 C. at a rate of 5 C./min and kept for 1 min, and finally increased to 320 C. at a rate of 10 C./min and kept for 1 min; MSD temperature 280 C.; solution delay 5.8 min; scanning range: 35-550; threshold: 150; scanning speed N=2; and mass spectrometry adopted full-scan mode. The data were compared with those in the NIST20 library through retrieval. Each component was investigated and determined one by one. The representative substances of the burnt-sweet aroma note were analyzed both qualitatively and quantitatively to demonstrate the enrichment effect. Moreover, through data retrieval and manual verification, combined with literature review on the aroma note characteristics of aroma components, 4 common components (furfural, 3-methyl-1,2-cyclopentenedione, maltol, 2-cyclopentene-1,4-dione) were used as the representation of the burnt-sweet aroma note (see Table 3). The comparison of aroma components is shown in FIG. 1.

TABLE-US-00003 TABLE 3 Component Comparative content in the Example 1 Example 1 ethanol extract Component Component Retention Aroma of Yun 87 content in content in Component time note (g/mL) sample 1-2 sample 2-2 name (Rt/min) characterization (g/mL) (g/mL) (g/mL) Furfural 52.26 Toast-like 7.84 25.06 0.67 aroma, woody aroma 2-cyclopentene- 54.27 Burnt-sweet 10.19 36.32 0.46 1,4-dione aroma 3-methyl-1,2- 54.56 Caramel-like 6.18 22.12 0.17 cyclopentenedione aroma Maltol 58.01 With a special 12.89 23.14 1.07 flavor of burnt butterscotch

Example 2

[0040] This example provided a method for enriching a burnt-sweet aroma note in a Yunnan flue-cured tobacco extract, and the specific steps and operating parameters were as follows: [0041] (1) sample dilution: the Yunnan flue-cured tobacco extract (ethanol extract of Yun 87) was diluted with ethanol as the diluent according to a mass ratio of 1:1 to obtain a diluted solution; [0042] (2) medium-pressure preparation: the diluted solution obtained in step (1) was subjected to gradient elution using a medium-pressure preparative C18 column (Daiso RPS C18, 50 m, 2.0 kg of packing material, column size 460100 mm). A 5% aqueous ethanol solution and a 38 wt % aqueous ethanol solution were separately used as the elution solutions. Under a pressure of 5 bar, gradient elution was performed at a flow rate of 20 mL/min, and the amount of each eluent was 4 BV. The solutions eluted in each gradient were collected; [0043] (3) filtration: the solutions eluted in each gradient in step (2) were filtered through a 400-mesh nylon net, and the elution filtrates of each gradient were obtained; [0044] (4) concentration: the elution filtrates of each gradient in step (3) were concentrated under reduced pressure by using a rotary evaporator (65 C., 60 mbar) until there was no liquid dripping. The density of the concentrated solution was controlled to be 1.1920-1.208 g/cm.sup.3, and the corresponding concentrated components eluted with the aqueous ethanol solutions were respectively obtained.

Example 3

[0045] This example provided a method for enriching a burnt-sweet aroma note in a Yunnan flue-cured tobacco extract, and the specific steps and operating parameters were as follows: [0046] (1) sample dilution: the Yunnan flue-cured tobacco extract (ethanol extract of Yun 87) was diluted with water as the diluent according to a mass ratio of 1:5 to obtain a diluted solution; [0047] (2) medium-pressure preparation: the diluted solution obtained in step (1) was subjected to gradient elution using a medium-pressure preparative C18 column (Daiso RPS C18, 50 m, 2.0 kg of packing material, column size 460100 mm). A 9 wt % aqueous ethanol solution and a 40 wt % aqueous ethanol solution were separately used as the elution solutions. Under a pressure of 20 bar, gradient elution was performed at a flow rate of 80 ml/min, and the amount of each eluent was 3 BV. The solutions eluted in each gradient were collected; [0048] (3) filtration: the solutions eluted in each gradient in step (2) were filtered through a 400-mesh nylon net, and the elution filtrates of each gradient were obtained; [0049] (4) concentration: the elution filtrates of each gradient in step (3) were concentrated under reduced pressure by using a rotary evaporator (45 C., 120 mbar) until there was no liquid dripping. The density of the concentrated solution was controlled to be 1.1920-1.208 g/cm.sup.3, and the corresponding concentrated components eluted with the aqueous ethanol solutions were respectively obtained.

Comparative Example 1

[0050] This comparative example provided a method for enriching a burnt-sweet aroma note in a Yunnan flue-cured tobacco extract, and the specific steps and operating parameters were as follows: [0051] (1) sample dilution: the Yunnan flue-cured tobacco extract (ethanol extract of Yun 87) was diluted with propylene glycol as the diluent according to a mass ratio of 1:3 to obtain a diluted solution; [0052] (2) medium-pressure preparation: the diluted solution obtained in step (1) was subjected to gradient elution using a medium-pressure preparative C8 column (Daiso RPS C8, 50 m, 2.0 kg of packing material, column size 460100 mm). Water, a 40% aqueous ethanol solution, an 80% aqueous ethanol solution, and a 95% aqueous ethanol solution were separately used as the elution solutions. Under a pressure of 10 bar, gradient elution was performed at a flow rate of 50 ml/min, and the amount of each eluent was 5 BV. The solutions eluted in each gradient were collected; [0053] (3) filtration: the solutions eluted in each gradient of the aqueous ethanol solution in step (2) were filtered through a 400-mesh nylon net, and the elution filtrates of each gradient were obtained; [0054] (4) concentration: the elution filtrates of each gradient in step (3) were concentrated under reduced pressure by using a rotary evaporator (65 C., 60 mbar) until there was no liquid dripping. The density of the concentrated solution was controlled to be 1.1920-1.208 g/cm.sup.3, and 4 components were respectively obtained, which were labeled as sample 2-1, sample 2-2, sample 2-3, and sample 2-4; and [0055] (5) each component in step (4) was formulated into an aerosol-forming material according to the above aerosol-forming material (the concentrated sample component accounted for 2 wt %, the solvent accounted for 98 wt %, and the solvent was a mixed solvent of propylene glycol and glycerol with a mass ratio of 6:4). According to the Aroma Style Evaluation Form for Tobacco-flavored E-cigarettes in the enterprise standard Sensory Evaluation Standard for Tobacco-flavored E-cigarettes (see Table 1), sensory evaluation was carried out on each component by 7 professional sensory evaluators and summarized. During the sensory evaluation, if the relevant aroma note was perceived, it was ticked in the corresponding box in the evaluation form of Table 1. The aroma note ticked by 4 or more evaluators was defined as the primary aroma note, and the aroma note ticked by 3 or fewer evaluators was defined as the secondary aroma note, and the sensory evaluation results were obtained (see Table 4). In addition, the components with obvious burnt-sweet aroma notes were subjected to an analysis of their aroma components (the specific analysis method was the same as that in Example 1). Moreover, through data retrieval and manual verification, combined with literature review on the aroma note characteristics of aroma components, 4 common components (furfural, 3-methyl-1,2-cyclopentenedione, maltol, 2-cyclopentene-1,4-dione) were used as the representation of the burnt-sweet aroma note. The comparison of aroma components is shown in FIG. 1.

TABLE-US-00004 TABLE 4 Component number Sensory evaluation Sample 2-1 Roasted aroma and smoky aroma Sample 2-2 The primary aroma note is a smoky aroma, with a burnt-sweet aroma. Sample 2-3 The primary aroma note is a hay aroma, with a burnt-sweet aroma at the base. Sample 2-4 Hay aroma, green aroma, floral aroma, and fruity aroma

[0056] From the comparison of the experimental results of the ethanol extract of Yun 87, the examples, and the comparative examples, the enrichment method provided in the present invention could enrich the small-amount substances of the burnt-sweet aroma note in the ethanol extract of Yun 87 and remove impurities. When applied to the aerosol-forming material, it made the burnt-sweet aroma note prominent and the tobacco aroma harmonious and natural. However, the samples provided by the comparative examples contained more impurities and could not effectively enrich the target components.

Comparative Example 2

[0057] This comparative example provided a method for enriching a burnt-sweet aroma note in a Yunnan flue-cured tobacco extract. Compared with Example 1, the only difference was that no pressure was applied in the elution process, and the elution was performed at normal pressure.

[0058] This led to a very slow separation efficiency, so that the key target components diffused in different eluents and could not be effectively enriched.

Comparative Example 3

[0059] This comparative example provided a method for enriching a burnt-sweet aroma note in a Yunnan flue-cured tobacco extract. Compared with Example 1, the only difference was that a macroporous resin column (D101, 0.3 mm) was used instead of the C18 column.

[0060] The particle size of the macroporous resin was between 0.3-1.25 mm, and the material was a polymer. The separation degree was low, and the target effective components could not be concentrated and enriched. Each sample contained components of the burnt aroma note.

Comparative Example 4

[0061] This comparative example provided a method for enriching a burnt-sweet aroma note in a Yunnan flue-cured tobacco extract. Compared with Example 1, the only difference was that a 40 wt % aqueous methanol solution was used instead of the 40 wt % aqueous ethanol solution in step (2).

[0062] Since the polarity of methanol is greater than that of ethanol, if 40% methanol is used to replace ethanol, some impurities with relatively high polarity will be introduced during the enrichment of the effective components. Moreover, methanol is a toxic solvent and is not suitable as a solvent for electronic atomization devices as it is harmful to the body.

[0063] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.

[0064] The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article a or the in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of or should be interpreted as being inclusive, such that the recitation of A or B is not exclusive of A and B, unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of at least one of A, B and C should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of A, B and/or C or at least one of A, B or C should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.