Tobacco extract for tobacco-flavor electronic cigarette as well as extraction method and application of tobacco extract

Abstract

The invention relates to a method for extracting a tobacco extract for a tobacco-flavor electronic cigarette, which comprises the following steps of: respectively adding a tobacco raw material and an extracting agent propylene glycol into continuous countercurrent extraction equipment according to the weight ratio of the tobacco raw material to the extracting agent propylene glycol of (0.8-3.0): 1, washing the obtained solid by using an ethanol water solution, and collecting a washing solution, thereby obtaining the tobacco extract for the tobacco-flavor electronic cigarette. And carrying out reduced pressure distillation on the washing liquid to remove ethanol to obtain reduced pressure distillation residues, and combining the reduced pressure distillation residues with the extracting solution to obtain the tobacco extract. The invention also relates to an application of the tobacco extract in a tobacco-flavored electronic cigarette. The extract obtained through the continuous countercurrent extraction process contains nicotine, organic acid and reducing sugar components from tobacco raw materials, the components can well present typical cigarette smell and aroma in the heating atomization process, and the tobacco-flavor electronic cigarette with the real cigarette smell and aroma style is achieved. The extract provided by the invention can be directly used in an electronic cigarette atomization product, and subsequent complicated processes such as separation and purification are not required to be introduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of tobacco plant extract production. More specifically, the present invention relates to a tobacco extract for tobacco flavored electronic cigarettes, an extraction method of the tobacco extract, and a use of the tobacco extract. Background Art

[0002] As the global ban on the sale of flavored e-cigarettes is enforced and implemented in a wider area, some e-cigarette companies and tobacco companies in many countries are actively investing in the development of tobacco-flavored e-cigarettes (one of the new tobacco products). The technical difficulty in the development of tobacco-flavored e-cigarettes is that e-cigarette products are difficult to present the typical taste and aroma of tobacco. The fundamental reason is that on the one hand, it is difficult for existing tobacco extracts to enter the e-cigarette aerosol formula, because the main components of e-cigarette aerosols are propylene glycol and glycerin. Substances that cannot be dissolved in the atomizer will cause e-cigarette oil stratification after entering the formula. On the other hand, the e-cigarette oil formula has a low tolerance for high-boiling point macromolecules. High-boiling point macromolecules (such as boiling points greater than 300°C) cannot migrate well to the aerosol during the heating and atomization process and remain in the atomization core. Long-term heating will cause carbon deposition and burning, which seriously affects the quality of smoking. Based on the above logic, tobacco water extract (also known as water extract), which contains a large amount of high-boiling point macromolecular substances, alcohol extracts of different concentrations (also known as alcohol extracts), extracts of various organic solvents (such as petroleum ether, n-hexane, dichloromethane, ethyl acetate, etc.) (also known as tobacco oil) and its refined products (also known as tobacco pure oil or essential oil), as well as tobacco supercritical extracts and subcritical extracts and their refined products, etc., which contain lipophilic substances, are not suitable for entering the e-cigarette oil formula. Even if added, the amount added is limited and cannot present the typical tobacco flavor and aroma.

[0003] Propylene glycol is generally not used as an extraction solvent in the production of extracts because the boiling point of propylene glycol is close to 185°C. After extracting the target substance with propylene glycol, the extract is difficult to desolventize and concentrate. Not only is the heating temperature for desolventizing high, but high-temperature desolventizing will also cause the extracted substances to be heated, oxidized or decomposed. In particular, the aroma of flavor substances will be changed or destroyed if they are overheated.

[0004] In view of the technical defects of the prior art, the inventors completed the present invention through a large number of experimental studies and analytical summaries. Summary of the invention

[0005] [Technical issues to be solved]

[0006] The object of the present invention is to provide a tobacco extract for tobacco-flavored electronic cigarettes.

[0007] Another object of the present invention is to provide a method for extracting the tobacco extract.

[0008] Another object of the present invention is to provide use of the tobacco extract.

[0009] [Technical solution]

[0010] The present invention is achieved through the following technical solutions.

[0011] The invention relates to a method for extracting a tobacco extract for a tobacco-flavored electronic cigarette.

[0012] The extraction steps of this extraction method are as follows:

[0013] (1) adding tobacco raw material and extractant propylene glycol into a continuous countercurrent extraction device from a solid raw material inlet and a liquid raw material inlet respectively according to a weight ratio of tobacco raw material to extractant propylene glycol of 0.8 to 3.0:1, extracting for 30 to 150 minutes at room temperature to 80° C. with stirring, obtaining an extract from a liquid phase discharge end and obtaining a solid from a solid phase discharge end;

[0014] (2) washing the solid obtained in step (1) with an ethanol aqueous solution and collecting the washing liquid;

[0015] (3) removing ethanol from the washing liquid obtained in step (2) by vacuum distillation to obtain a vacuum distillation residue;

[0016] (4) The reduced pressure distillation residue obtained in step (3) is combined with the extract obtained in step (1) to obtain the tobacco extract.

[0017] According to a preferred embodiment of the present invention, the tobacco raw material is one or more tobacco raw materials selected from flue-cured tobacco, burley tobacco, sun-cured yellow tobacco, sun-cured red tobacco or other aromatic tobacco.

[0018] According to another preferred embodiment of the present invention, the water content of the tobacco raw material is 10-18% by weight.

[0019] According to another preferred embodiment of the present invention, the tobacco raw material is a tobacco powder having a particle size of 40 to 250 meshes obtained by processing tobacco using a grinder, a mechanical pulverizer or a jet mill pulverizer.

[0020] According to another preferred embodiment of the present invention, the weight ratio of the tobacco raw material to the extractant propylene glycol is 1.5-2.5:1.

[0021] According to another preferred embodiment of the present invention, in step (1), the tobacco raw material and the extractant propylene glycol are extracted in an extraction device at a temperature of 38 to 68° C. and a screw rotation speed of 1 to 20 rpm for 40 to 90 min.

[0022] According to another preferred embodiment of the present invention, the solid matter in step (2) is washed 2 to 4 times with an ethanol aqueous solution having a mass concentration of 95% or more, and the mass of the ethanol aqueous solution used for each washing is 2 to 3 times the weight of the solid matter.

[0023] According to another preferred embodiment of the present invention, the collected washing liquid is subjected to reduced pressure distillation to remove ethanol and water at a pressure of -0.085 to -0.1 MPa and a temperature of 40 to 60° C. using a distillation device.

[0024] According to another preferred embodiment of the present invention, the washing liquid remaining after the reduced pressure distillation contains less than 1% ethanol and less than 3% water by weight.

[0025] In the present invention, the ratio of the mass percentage of nicotine to soluble reducing sugar in the obtained tobacco extract to the total mass percentage of nicotine to soluble reducing sugar in the tobacco raw material is 60-150:100.

[0026] The invention also relates to a tobacco extract obtained by the extraction method.

[0027] According to a preferred embodiment of the present invention, it contains 0.5-5.0% nicotine, 0.2-10.0% reducing sugar, 0.5-3.0% organic acid and 0.2-5.0% nitrogen-containing compound by weight.

[0028] According to another preferred embodiment of the present invention, the reducing sugar is glucose, fructose, maltose, sucrose or oligosaccharide; the organic acid is malic acid, oxalic acid, citric acid, glycolic acid, succinic acid, malonic acid, fumaric acid or pyruvic acid; and the nitrogen-containing compound is tobacco amino acid, tobacco protein, ammonia, amide or amine.

[0029] The present invention also relates to use of the tobacco extract in tobacco-flavored electronic cigarettes.

[0030] According to a preferred embodiment of the present invention, the tobacco extract is added to the tobacco flavored electronic cigarette in an amount of 10-70% by weight.

[0031] According to another preferred embodiment of the present invention, the tobacco-flavored electronic cigarette is a Chinese flue-cured tobacco flavored electronic cigarette, an American mixed electronic cigarette, an English flue-cured tobacco flavored electronic cigarette, a cigar flavored electronic cigarette, or a pipe tobacco flavored electronic cigarette.

[0032] The present invention will be described in more detail below.

[0033] The invention relates to a method for extracting a tobacco extract for a tobacco-flavored electronic cigarette.

[0034] The extraction steps of this extraction method are as follows:

[0035] (1) adding tobacco raw material and extractant propylene glycol into a continuous countercurrent extraction device from a solid raw material inlet and a liquid raw material inlet respectively according to a weight ratio of tobacco raw material to extractant propylene glycol of 0.8 to 3.0:1, extracting for 30 to 150 minutes at room temperature to 80° C. with stirring, obtaining an extract from a liquid phase discharge end and obtaining a solid from a solid phase discharge end;

[0036] (2) washing the solid obtained in step (1) with an ethanol aqueous solution and collecting the washing liquid;

[0037] (3) removing ethanol from the washing liquid obtained in step (2) by vacuum distillation to obtain a vacuum distillation residue;

[0038] (4) The reduced pressure distillation residue obtained in step (3) is combined with the extract obtained in step (1) to obtain the tobacco extract.

[0039] In the present invention, the continuous countercurrent extraction equipment is usually composed of a feeding hopper, a spiral extraction cylinder, a slag discharge screw conveyor, etc. After being coarsely crushed, the solid raw material is fed from the feeding hopper, the extraction cylinder rotates, and the spiral belt fixed on the inner wall of the extraction cylinder slowly pushes the material from the solid raw material inlet to the downstream end. At the same time, the extractant enters the extraction cylinder from the liquid raw material inlet at the other end of the equipment, and flows from the rear end of the cylinder through the moving material to the front end. The solid and liquid phases are fully in contact in this reverse motion, thereby extracting the effective components in the solid raw material. The material is forced to be pushed to the slag discharge port by the slag discharge screw conveyor and discharged. The slag discharge screw squeezes the material at the same time, squeezes out the residual extract from the material to reduce the residual extract in the slag.

[0040] The continuous countercurrent extraction equipment is a mature equipment that can be purchased from the market, such as the continuous countercurrent extraction equipment produced and sold by Shanghai Youchang Pharmaceutical Equipment Co., Ltd.

[0041] The tobacco raw materials used in the present invention are one or more tobacco raw materials selected from flue-cured tobacco, burley tobacco, sun-cured yellow tobacco, sun-cured red tobacco or other aromatic tobacco, which are common tobacco leaf products on the market. Usually, the water content of the tobacco raw materials is 10-18% by weight.

[0042] The water content of the tobacco raw material used in the present invention is detected according to the standard analysis methods of the oven method, the electric measurement method, the radio frequency method and the infrared moisture meter method. If the water content of the tobacco raw material is lower than 10%, the tobacco raw material will become more brittle and easy to break; if the water content of the tobacco raw material is higher than 18%, it will be unfavorable for the separation of stems and leaves, resulting in leaves in stems and stems in leaves, and the control index cannot be reached; therefore, the water content of the tobacco raw material is suitable to be 10-18%, preferably 12-16%;

[0043] Before adding the above tobacco raw materials to the extraction equipment, a grinder, a mechanical pulverizer or a jet mill pulverizer is used to process the above tobacco raw materials into tobacco powder with a particle size of 40 to 250 meshes.

[0044] The particle size of the tobacco raw material used in the present invention is detected according to the standard detection method related to the standard sieve. If the particle size of the tobacco raw material is less than 40 meshes, the contact area between the material and the extractant is small and cannot be fully extracted; if the particle size of the tobacco raw material is higher than 250 meshes, the risk of low-pressure explosion increases; therefore, the particle size of the tobacco raw material is appropriately 40 to 250 meshes, preferably 80 to 200 meshes.

[0045] The grinder, mechanical pulverizer or air flow pulverizer pulverizing equipment used in the present invention are all pulverizing equipment commonly used in the field of tobacco processing technology, such as the DX-55 / 201 grinder sold by Guangzhou Daxiang Electronic Machinery Equipment Co., Ltd. under the trade name of stainless steel grinder pulverizer, the DXF-06D mechanical pulverizer sold by Guangzhou Xiangming Machinery Equipment Co., Ltd. under the trade name of small pulverizer, and the CWL-QLF-50 air flow pulverizer pulverizing equipment sold by Hunan Chuangwei Mechanical and Electrical Equipment Manufacturing Co., Ltd. under the trade name of air flow pulverizer; when pulverizing tobacco raw materials, these pulverizing equipment are operated in accordance with the operating procedures of these pulverizing equipment.

[0046] In the present invention, the material is extracted for 30-150 minutes at room temperature to 80°C and under stirring in a continuous countercurrent extraction device. When the extraction temperature and the extraction time are within the range, if the weight ratio of the tobacco raw material to the extractant propylene glycol is greater than 3:1, the extractant and the material cannot be fully contacted; if the weight ratio of the tobacco raw material to the extractant propylene glycol is less than 0.8:1, the extraction concentration ratio is low; therefore, the weight ratio of the tobacco raw material to the extractant propylene glycol is 0.8 to 3:1, which is reasonable, preferably 1.5 to 2.5:1.

[0047] When the weight ratio of tobacco raw material to extractant propylene glycol and the extraction time are within the described range, if the extraction temperature is low, the extraction rate is low and the extraction time is long; if the extraction temperature is higher than 80°C, the extraction process cost is high and there are hidden dangers in process safety; therefore, the extraction temperature is suitable to be room temperature to 80°C, preferably 38 to 68°C.

[0048] When the weight ratio of tobacco raw material to extractant propylene glycol and the extraction temperature are within the described range, if the extraction time is shorter than 30 minutes, it is not conducive to the full immersion of propylene glycol in the tobacco material, and too short an extraction time leads to low extraction efficiency; if the extraction time is longer than 150 minutes, it has an adverse effect on process cost and production capacity; therefore, an extraction time of 30 to 150 minutes is appropriate, preferably 40 to 90 minutes.

[0049] Optionally, an extraction tank can be used as the extraction equipment, and the commonly used one is 1-5m 3 Stainless steel tank; with stirring device inside the tank, or overall rotating mechanism of the tank; top feeding, bottom discharging; with or without steam heating / electric heating of tank interlayer; equipped with temperature detection and alarm device inside the tank; with or without extraction liquid circulation device. This equipment is a general equipment in China, generally designed and customized according to production line and process requirements, and commissioned to mechanical equipment manufacturers for production.

[0050] Since the extraction tank usually does not have a filtering function, after the above extraction step, a filtering device is used to filter to obtain the solid matter and the filtrate propylene glycol extract, such as a bag filter, an intermittent pressure filter, a plate and frame filter press or a spiral ribbon centrifuge, which are all products currently sold on the market.

[0051] According to the present invention, the solid obtained by filtration is washed with an ethanol aqueous solution. Specifically, the ratio of the solid in grams to the ethanol aqueous solution in milliliters is 1:2-4, and the solid is washed 2-4 times with an ethanol aqueous solution having a concentration of 95% or more by volume. If the ratio of the solid to the ethanol aqueous solution is greater than 1:2, the washing is insufficient; if the ratio of the solid to the ethanol aqueous solution is less than 1:4, the solvent recovery process component is high; therefore, the ratio of the solid to the ethanol aqueous solution is 1:2-4, preferably 1:2.4-3.5; it is also undesirable to use the ethanol aqueous solution to wash the solid for more than the above range, because the process component is high.

[0052] The collected washing liquid is subjected to reduced pressure distillation to remove ethanol and water under the conditions of -0.085 to -0.1 MPa and 40 to 60° C. using a distillation device. When the temperature of the reduced pressure distillation is within the range, if the pressure of the reduced pressure distillation is lower than -0.085 MPa, the reduced pressure evaporation efficiency is low, the material needs to be heated to a higher temperature, and the energy consumption is high; therefore, it is reasonable for the pressure of the reduced pressure distillation to be -0.085 to -0.1 MPa, preferably -0.088 to -0.096 MPa;

[0053] The washing liquid was tested for ethanol and water content after distillation under reduced pressure, wherein the ethanol content was less than 3% by weight according to the gas chromatography standard method.

[0054] The distillation equipment used in the present invention is a single-effect evaporator unit, a double-effect evaporator unit, a triple-effect evaporator unit or a quadruple-effect evaporator unit, all of which are products currently sold on the market, such as the WXZ single-effect evaporator unit sold by Changshu Chunlai Machinery Co., Ltd. as a single-effect external circulation evaporator, the SJN-II-500 double-effect evaporator unit sold by Wenzhou Yuanzhong Machinery Co., Ltd. as a double-effect vacuum concentrator, and the DJZ500-8000 triple-effect evaporator unit sold by Changshu Chunlai Machinery Co., Ltd. as a triple-effect energy-saving external circulation vacuum concentrator.

[0055] The ethanol obtained by collecting the washing liquid and distilling it under reduced pressure can be recycled and reused, and the remaining material from the distillation under reduced pressure is combined with the above-mentioned propylene glycol extract to obtain the tobacco extract.

[0056] According to the present invention, the ratio of the mass percentage of nicotine to soluble reducing sugar in the obtained tobacco extract to the total mass percentage of nicotine to soluble reducing sugar in the tobacco raw material is 60 to 150: 100. In particular, when a continuous countercurrent extraction device is used, since the feed amount of the tobacco raw material is usually greater than the feed amount of the extractant, the concentration of the effective component finally enriched in the extract is higher, and its mass percentage is even higher than the mass percentage of the effective component contained in the tobacco raw material itself.

[0057] In the present invention, the main purpose of using the filtrate propylene glycol extract to extract different batches of tobacco raw materials (which are different from the tobacco raw materials used in the extraction method of the present invention) in the same way is to increase the content of effective substances in the extract and achieve the technical requirement of stably presenting the taste and aroma of tobacco.

[0058] Here, if the nicotine and soluble reducing sugar content obtained by extraction is less than 20% of the corresponding content of the tobacco raw material, the extraction efficiency is low, the utilization rate of the raw materials is low, and the smoke of the obtained extract is insufficient. Therefore, it is appropriate that the soluble reducing sugar content is 20-80% of the corresponding content of the extracted tobacco raw material.

[0059] As another optional embodiment, the extraction device used is an extraction device having 3 to 8 extraction units connected in series, wherein the extraction unit is formed by sequentially connecting an extraction tank, an evaporator, a slag filter and a slag desolventizing device. When using this extraction device, the tobacco raw material enters the extraction device from the solid material end of the extraction device in an intermittent manner, and the propylene glycol extractant enters the extraction device from the liquid material end of the extraction device in an intermittent manner. This type of equipment is also a mature equipment that can be purchased on the market.

[0060] The invention also relates to a tobacco extract obtained by the extraction method.

[0061] According to the GC-MSMS analysis of "French Electronic Cigarette Standard 3: XP D90-300-3-2016", the potassium permanganate titration method of GB 5009.7-2016, the ultraviolet spectrophotometry of T / CCCMHPIE1.2-2016 and the standard analysis method of SH / T 0224-1992 Kjeldahl nitrogen determination method, the tobacco extract of the present invention contains 0.5-5.0% nicotine, 0.2-10.0% reducing sugar, 0.5-3.0% organic acid and 0.2-5.0% nitrogen-containing compound by weight, wherein the reducing sugar is glucose, fructose, maltose, sucrose or oligosaccharide; the organic acid is malic acid, oxalic acid, citric acid, glycolic acid, succinic acid, malonic acid, fumaric acid or pyruvic acid; the nitrogen-containing compound is tobacco amino acid, tobacco protein, free amino acid, glutamine or asparagine.

[0062] The present invention also relates to use of the tobacco extract in tobacco-flavored electronic cigarettes.

[0063] According to the present invention, the amount of the tobacco extract added to the tobacco-flavored electronic cigarette is 10 to 70% by weight. If the amount of the tobacco extract added to the tobacco-flavored electronic cigarette is less than 10%, the concentration of the tobacco flavor and aroma is low and the tobacco flavor is too light; if the amount of the tobacco extract added to the tobacco-flavored electronic cigarette is higher than 70%, it is difficult to further add other components to the electronic cigarette aerosol formula, and it is easy to burn; therefore, the amount of the tobacco extract added to the tobacco-flavored electronic cigarette is appropriate to be 10 to 70%, preferably 20 to 50%, and more preferably 30 to 45%.

[0064] In the present invention, the tobacco-flavored electronic cigarette refers to a tobacco-flavored electronic cigarette with a tobacco flavor and aroma style close to the Chinese flue-cured tobacco flavor, American mixed cigarette flavor, English flue-cured tobacco flavor, cigar flavor or pipe tobacco flavor.

[0065] In accordance with GB 5606.4-2005 Cigarettes Part 4: Sensory Technical Requirements, a smoking evaluation panel consisting of 7 smoking evaluation personnel was organized to conduct a comparative smoking evaluation on the electronic cigarettes containing the tobacco extract of the present invention and the currently sold electronic cigarettes containing tobacco extract as control samples. The smoking evaluation results are shown in the specific implementation method section.

[0066] [Beneficial Effects]

[0067] The present invention mainly provides atomized material with typical tobacco flavor and aroma for tobacco-flavored electronic cigarettes, and focuses on providing nicotine, organic acid and reducing sugar components from tobacco raw materials. These components can well present typical tobacco flavor and aroma during the heating and atomization process.

[0068] Another beneficial effect of the present invention is that through the preferred extraction process, the tobacco chemical components as mentioned above are obtained in one step, and the obtained extract can be directly used in the electronic cigarette aerosol, without the need to introduce subsequent complex processes such as separation and purification, and directly presents the tobacco flavor and aroma.

[0069] In addition, by applying the determined extraction process of the present invention, the ratio of effective components such as nicotine, organic acid and reducing sugar that present the tobacco taste and aroma is closer to the actual ratio of tobacco raw materials, and the beneficial effect is that the tobacco taste reduction is relatively high, the smoking taste is highly similar to that of traditional cigarettes, and the aroma quality even exceeds that of traditional tobacco. For example, the green smell and irritation are significantly improved, thanks to the fact that the substances with a boiling point below 120-150°C are fully removed in the process determined by the present invention. DETAILED DESCRIPTION

[0070] The present invention will be better understood through the following examples.

[0071] In the present invention, unless otherwise specified, "%" used to explain concentration, content or ratio refers to mass percentage, and ":" refers to mass ratio.

[0072] Example 1

[0073] The quality of the products obtained by repeatedly extracting tobacco raw materials for different times using filtrate propylene glycol extract as the extractant was investigated using conventional extraction equipment and extraction methods.

[0074] Yunnan tobacco raw materials (batch C2L, 2022, moisture content of 13%) were processed into tobacco powder with a particle size of 80 mesh by a mechanical pulverizer. The tobacco powder and propylene glycol were added to an extraction tank at a weight ratio of 1:8, extracted at 60°C with stirring for 4 hours, and filtered to obtain a section of residue and a section of filtrate.

[0075] The obtained first-stage filtrate is re-entered into the rear end of the equipment as the extract, and an equal amount of Yunnan tobacco raw materials from the same batch are taken and entered from the front end of the equipment (if the weight ratio of tobacco powder to extract is greater than 1:8, new propylene glycol is added until the weight ratio is 1:8), and extraction is carried out under the same parameter adjustment to obtain second-stage slag and second-stage filtrate.

[0076] The process was repeated to obtain a total of eight sections of slag and eight sections of filtrate, and samples of the filtrate from each section were taken for subsequent experiments.

[0077] For the first-stage residue and the first-stage filtrate, the residue was washed three times with 3 times the weight of a 95% ethanol aqueous solution, and the collected washing liquid was distilled under reduced pressure (pressure -0.085 to -0.1 MPa, temperature 40 to 60°C) to remove ethanol. The ethanol portion can be recovered and reused, and the residue from the reduced pressure distillation is combined with the obtained first-stage filtrate to obtain tobacco extract sample 1.

[0078] For the second-stage residue and the second-stage filtrate, the two stages of residue were combined and the same parameters were used (3 times the weight of 95% ethanol aqueous solution was used for washing 3 times, and the collected washing liquid was distilled under reduced pressure to remove ethanol, and the ethanol portion could be recovered and reused) to obtain the reduced pressure distillation residue, which was then combined with the obtained second-stage filtrate to obtain tobacco extract sample 2.

[0079] Based on the same experimental steps, tobacco extract samples 3 to 8 were obtained respectively.

[0080] The obtained extract samples were determined according to the French Electronic Cigarette Standard 3: XP D90-300-3-2016 GC-MSMS analysis, GB5009.7-2016 potassium permanganate titration method, T / CCCMHPIE1.2-2016 ultraviolet spectrophotometry and SH / T 0224-1992 Kjeldahl nitrogen determination method standard analysis methods. The results are shown in Table 1:

[0081] Table 1 Detection of extract components obtained by different repeated extraction times

[0082]

[0083] The test results show that as the filtrate is used repeatedly, the contents of nicotine, reducing sugar, total sugar and nitrogen-containing compounds in the obtained extract are significantly increased.

[0084] Therefore, in order to obtain a tobacco extract having a tobacco flavor and aroma style close to the flavor of Chinese flue-cured tobacco, the filtrate propylene glycol extract is preferably reused 4 times or more.

[0085] The tobacco extract was added to a tobacco-flavored electronic cigarette (i.e., the atomizer of a steam-type electronic cigarette) at an amount of 30% by total weight. According to GB 5606.4-2005 Cigarettes Part 4: Sensory Technical Requirements, a smoking evaluation panel consisting of 7 smoking evaluation personnel was organized to compare and evaluate the obtained tobacco-flavored electronic cigarette with the currently sold electronic cigarette containing tobacco extract as a control sample. The scoring results are shown in Table 2:

[0086] Table 2 Scoring results of extracts obtained by different repeated extraction times

[0087]

[0088] From the test results, it can be seen that as the number of times the filtrate is repeatedly used increases, the smoking score is significantly improved, especially the quality, quantity, and similarity of the aroma to traditional tobacco. When the filtrate propylene glycol extract is preferably reused 4 times or more, the smoking score reaches more than 80 points, which can well restore the real cigarette smoke.

[0089] Therefore, four extractions were used as the basis for subsequent experiments.

[0090] Example 2

[0091] Since conventional extraction equipment (extraction tank) and extraction methods are not conducive to industrial continuous operation, and the large amount of propylene glycol used leads to high costs, the quality of the extract is examined by improving the extraction equipment and extraction method.

[0092] The same batch of Yunnan tobacco raw materials in Example 1 was crushed to 80 meshes to obtain tobacco powder, and a discontinuous countercurrent extraction device consisting of four extraction tanks was used for extraction. The tobacco powder in each extraction tank was extracted four times, and its operation mode was taken as an example of the tobacco powder in tank No. 1. When the powder was extracted for the first time, the extracting liquid used was the three-stage filtrate from tank No. 4, and four-stage filtrate was separated after the extraction was completed; when it was in the second extraction, the extracting liquid used was the two-stage filtrate from tank No. 3, and three-stage filtrate was separated after the extraction was completed; when it was in the third extraction, the extracting liquid used was the three-stage filtrate from tank No. 2, and two-stage filtrate was separated after the extraction was completed; when it was in the fourth extraction, the extracting liquid used was a new propylene glycol extract, and one-stage filtrate was separated after the extraction was completed.

[0093] This countercurrent extraction method increases the concentration gradient of the solid-liquid phase during the extraction process, so that the solution never reaches a saturated state, which is beneficial to the acquisition of effective substances in the raw materials.

[0094] In each extraction, the weight ratio of tobacco powder to extract is 1:8. When the first, second or third stage filtrate is insufficient, new propylene glycol is added as the extract for the subsequent extraction step until the solid-liquid ratio is 1:8. In each extraction, the extraction is performed at 60°C and stirred for 4 hours. After four extractions, the residue and the four-stage filtrate are filtered to obtain the residue, which is washed three times with 3 times the weight of 95% ethanol aqueous solution. The collected washing liquid is distilled under reduced pressure (pressure -0.085 to -0.1MPa, temperature 40 to 60°C) to remove ethanol. The ethanol part can be recycled and reused, and the residue from the reduced pressure distillation is combined with the obtained four-stage filtrate to obtain a tobacco extract using Yunnan tobacco leaves as raw materials.

[0095] Different tobacco raw materials are extracted by the same steps to obtain a propylene glycol extract containing nicotine and soluble reducing sugar.

[0096] The obtained extract was determined according to the French Electronic Cigarette Standard 3: XP D90-300-3-2016 GC-MSMS analysis, GB5009.7-2016 potassium permanganate titration method, T / CCCMHPIE1.2-2016 ultraviolet spectrophotometry and SH / T 0224-1992 Kjeldahl nitrogen determination method standard analysis method. The results are shown in Table 3:

[0097] Table 3: Statistical data of component detection of propylene glycol discontinuous countercurrent extract (extraction) of different tobacco raw materials:

[0098] Table 3 Component detection results of discontinuous countercurrent extracts of different tobacco raw materials

[0099]

[0100] Compared with Example 1, it can be seen that the extract obtained by four-stage discontinuous countercurrent extraction has significantly higher reducing sugar, total sugar, total nitrogen and nicotine contents in the extract obtained in this example than in the extract samples 4 to 8 in Example 1. It can be seen that continuous countercurrent extraction can increase the concentration of active ingredients in the extract.

[0101] The tobacco extract was added to a tobacco flavored electronic cigarette (i.e., the atomizer of a steam-type electronic cigarette) in an amount of 30% by total weight, and scored using the same smoking evaluation method as in Example 1. The results are shown in Table 4.

[0102] Table 4 Discontinuous countercurrent extract smoking results of different tobacco raw materials

[0103]

[0104] Example 3

[0105] In order to further simplify the extraction method and increase the concentration of effective ingredients in the extract, conventional continuous countercurrent extraction equipment was used for extraction, and the same batch of Yunnan tobacco raw materials as in Example 1 were crushed to 80 meshes to obtain tobacco powder as raw material.

[0106] The continuous countercurrent extraction equipment is composed of a material bin, a feeding system, a continuous countercurrent extraction line, an extract filtration system, an extract storage tank, a slag extrusion solid-liquid separation device, a slag washing tank, an evaporation concentrator, a cooler and a slag drying and desolventizing system extraction unit connected in sequence. The tobacco raw material enters the solid raw material end at the front end of the extraction equipment in a continuous manner, and the propylene glycol extractant enters the liquid raw material end at the rear end of the extraction equipment in a continuous manner. The solid and liquid raw materials are pushed in reverse respectively, and finally the slag is obtained from the slag outlet and the filtrate is obtained from the liquid phase outlet.

[0107] The residue is washed three times with 3 times the weight of 95% ethanol aqueous solution, and the collected washing liquid is distilled under reduced pressure (pressure -0.085 to -0.1 MPa, temperature 40 to 60°C) to remove ethanol. The ethanol portion can be recovered and reused, and the residue from the reduced pressure distillation is combined with the obtained filtrate to obtain an extract.

[0108] In the continuous countercurrent extraction equipment, the weight ratio of tobacco raw material to extractant propylene glycol was 2:1, the equipment temperature was set to 50°C, and the extraction was carried out for 90 minutes.

[0109] The obtained extract was determined according to the French Electronic Cigarette Standard 3: XP D90-300-3-2016 GC-MSMS analysis, GB5009.7-2016 potassium permanganate titration method, T / CCCMHPIE1.2-2016 ultraviolet spectrophotometry and SH / T 0224-1992 Kjeldahl nitrogen determination method standard analysis method, and the results are shown in Table 5:

[0110] Table 5 Detection results of components of continuous countercurrent extract of Yunnan tobacco leaves

[0111]

[0112] The tobacco extract was added to a tobacco flavor electronic cigarette (i.e., atomizer of a steam type electronic cigarette) in an amount of 30% by total weight, and the sample obtained in Example 2 was used as a control.

[0113] Table 6 Evaluation results of continuous countercurrent extraction of Yunnan tobacco leaves

[0114]

[0115] In summary, the extract of the present invention contains nicotine, organic acid and reducing sugar components from tobacco raw materials. These components can well present typical tobacco flavor and aroma during the heating and atomization process, thus realizing a tobacco-flavored electronic cigarette with a real cigarette flavor and aroma style. The present invention can obtain the above-mentioned tobacco chemical components in one step through the continuous countercurrent extraction process, and the obtained extract can be directly used in the electronic cigarette aerosol, without the need to introduce subsequent complex processes such as separation and purification, and directly presents the tobacco flavor and aroma.

[0116] In addition, by applying the determined extraction process of the present invention, the ratio of effective components such as nicotine, organic acids and reducing sugars that present the tobacco taste and aroma is relatively close to the actual ratio of the tobacco raw materials. Thanks to the sufficient removal of substances with a boiling point below 120-150°C, the tobacco flavor reduction of the extract of the present invention is relatively high, the smoking taste is highly similar to that of traditional cigarettes, and the aroma quality even exceeds that of traditional tobacco, such as the green smell and irritation are significantly improved.

Claims

1. A method for extracting tobacco extract for tobacco flavored electronic cigarettes, characterized in that The extraction steps of this extraction method are as follows: (1) adding tobacco raw material and extractant propylene glycol into a continuous countercurrent extraction device from a solid raw material inlet and a liquid raw material inlet respectively according to a weight ratio of tobacco raw material to extractant propylene glycol of 0.8 to 3.0:1, extracting for 30 to 150 minutes at room temperature to 80° C. with stirring, obtaining an extract from a liquid phase discharge end and obtaining a solid from a solid phase discharge end; (2) washing the solid obtained in step (1) with an ethanol aqueous solution and collecting the washing liquid; (3) removing ethanol from the washing liquid obtained in step (2) by vacuum distillation to obtain a vacuum distillation residue; (4) The reduced pressure distillation residue obtained in step (3) is combined with the extract obtained in step (1) to obtain the tobacco extract.

2. The extraction method according to claim 1, characterized in that The tobacco raw material in step (1) is one or more tobacco raw materials selected from flue-cured tobacco, burley tobacco, sun-cured yellow tobacco, sun-cured red tobacco or other spice tobacco.

3. The extraction method according to claim 1 or 2, characterized in that The water content of the tobacco raw material in step (1) is 10-18% by weight.

4. The extraction method according to claim 1 or 2, characterized in that The tobacco raw material in step (1) is a tobacco powder with a particle size of 40 to 250 mesh obtained by processing tobacco using a grinder, a mechanical pulverizer or a jet pulverizer.

5. The extraction method according to claim 1, characterized in that In step (1), the weight ratio of tobacco raw material to extractant propylene glycol is 1.5-2.5:

1.

6. The extraction method according to claim 1, characterized in that In step (1), the tobacco raw material and the extractant propylene glycol are extracted in an extraction device at a temperature of 38 to 68° C. and a screw rotation speed of 1 to 20 rpm for 40 to 90 minutes.

7. The extraction method according to claim 1, characterized in that In step (2), the solid matter is washed 2 to 4 times with an ethanol aqueous solution having a mass concentration of 95% or more, and the mass of the ethanol aqueous solution used for each washing is 2 to 3 times the weight of the solid matter.

8. The extraction method according to claim 1, characterized in that The washing liquid in step (3) is subjected to reduced pressure distillation to remove ethanol and water at a pressure of -0.085 to -0.1 MPa and a temperature of 40 to 60° C. using a distillation device.

9. The extraction method according to claim 1, characterized in that The vacuum distillation residue obtained in step (3) contains less than 1% by weight of ethanol and less than 3% by weight of water.

10. The extraction method according to claim 1, characterized in that The ratio of the mass percentage of nicotine and soluble reducing sugar in the obtained tobacco extract to the total mass percentage of nicotine and soluble reducing sugar in the tobacco raw material is 60-150:

100.

11. The tobacco extract obtained by the extraction method according to any one of claims 1 to 10.

12. The tobacco extract according to claim 11, characterized in that It contains 0.5-5.0% nicotine, 0.2-10.0% reducing sugar, 0.5-3.0% organic acid and 0.2-5.0% nitrogen-containing compound by weight.

13. The tobacco extract according to claim 12, characterized in that The reducing sugar is glucose, fructose, maltose, sucrose or oligosaccharide; the organic acid is malic acid, oxalic acid, citric acid, glycolic acid, succinic acid, malonic acid, fumaric acid or pyruvic acid; and the nitrogen-containing compound is tobacco amino acid, tobacco protein, ammonia, amide or amine.

14. Use of the tobacco extract according to claim 11 in tobacco-flavored electronic cigarettes.

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