Method for preparing extract, extract, atomizable liquid, and atomization device

Abstract

A method for preparing an extract, comprising the following steps: sequentially heating a tobacco raw material in a flowing gas to at least two gradient temperatures for microwave pyrolysis; collecting the gaseous pyrolysis product in at least one gas absorption bottle by means of the flowing gas; and combining a collected liquid in the at least one gas absorption bottle, and obtaining an extract, wherein the at least two gradient temperatures are each independently 100-900°C, and the heating time for heating to each gradient temperature is each independently 10-60 min. The extract prepared by the above preparation method can improve the aroma richness and tobacco-like sensation of atomizable liquids, thereby improving the vaping experience of users. Also provided are an extract, an atomizable liquid, and an atomization device.

Description

Preparation method of extract, extract, atomizing liquid and atomizing device

[0001] Cross-references to related applications

[0002] This disclosure is based on and claims priority to Chinese Patent Application No. 202411186923.0, filed on August 27, 2024, entitled “Method for preparing an extract, extract, atomizing liquid and atomizing device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of tobacco technology, and particularly to a method for preparing an extract, the extract, an atomizing liquid, and an atomizing device. Background Technology

[0004] Due to differences in temperature and smoking mechanisms, novel tobacco products produce significantly fewer harmful components than traditional cigarettes. In the context of international tobacco control, novel tobacco products represent a future direction for the tobacco industry. However, the significant differences in flavor between novel tobacco products and traditional cigarettes have become a bottleneck hindering their rapid development. Therefore, there is an urgent need to find substances that can compensate for the lack of aroma components in novel tobacco products to improve their smoking quality.

[0005] Currently, research mainly focuses on using different extraction and separation techniques, such as solvent extraction, supercritical extraction, and molecular distillation, to obtain aroma substances suitable for new tobacco products from tobacco. However, the extracts obtained by these methods are not satisfactory in terms of aroma and taste.

[0006] Therefore, a new extraction method needs to be developed to improve the quality of the extract in terms of aroma, taste, and other aspects. Summary of the Invention

[0007] In view of this, the main objective of this disclosure is to provide a method for preparing an extract, the extract, an atomizing liquid, and an atomizing device. The extract obtained by the preparation method of this disclosure can enhance the aroma intensity and smoke-like sensation, provide a taste that is closer to traditional tobacco products, improve the smoking quality of tobacco products, and enhance the safety of the extract.

[0008] Therefore, the first aspect of this disclosure provides a method for preparing an extract, the method comprising the following steps: microwave pyrolysis of tobacco raw material by sequentially heating it to at least two gradient temperatures in a flowing gas, collecting the gaseous pyrolysis products in at least one gas absorption bottle using the flowing gas, and combining the collected liquids in at least one gas absorption bottle to obtain an extract, wherein the at least two gradient temperatures are each independently between 100°C and 900°C, and the heating time to each gradient temperature is each independently between 10 min and 60 min.

[0009] In some embodiments, the tobacco raw material is selected from one or more of tobacco leaves, tobacco extracts, and tobacco stems.

[0010] In some implementations, at least two temperature gradients include a first temperature gradient of 100°C to 450°C and a second temperature gradient of greater than 450°C and less than or equal to 900°C.

[0011] In some implementations, at least two temperature gradients include a first temperature gradient of 100°C-300°C, a second temperature gradient of greater than 300°C and less than or equal to 450°C, and a third temperature gradient of greater than 450°C and less than or equal to 900°C.

[0012] In some embodiments, at least two temperature gradients include a first temperature gradient of 100°C-250°C, a second temperature gradient of greater than 250°C and less than or equal to 450°C, a third temperature gradient of greater than 450°C and less than or equal to 700°C, and a fourth temperature gradient of greater than 700°C and less than or equal to 900°C.

[0013] In some embodiments, at least two gradient temperatures include a first gradient temperature of 100°C-250°C, a second gradient temperature of greater than 250°C and less than or equal to 400°C, a third gradient temperature of greater than 400°C and less than or equal to 600°C, a fourth gradient temperature of greater than 600°C and less than or equal to 750°C, and a fifth gradient temperature of greater than 750°C and less than or equal to 900°C.

[0014] In some implementations, the gas includes one or more of air, oxygen, or an inert gas.

[0015] In some embodiments, the gas flow rate is 100 mL / min to 200 mL / min.

[0016] In some embodiments, at least one gas absorption bottle includes a gas absorbent, which includes one or more of pure water, ethanol, propylene glycol, and glycerol; preferably, the gas absorbent includes propylene glycol.

[0017] In some embodiments, the temperature of at least one gas absorption bottle is below 0°C, preferably -5°C to -20°C.

[0018] The second aspect of this disclosure also provides an extract prepared according to the preparation method of the first aspect of this disclosure.

[0019] In some embodiments, the extract comprises 4-oxoisophorone, furfural, furfuryl alcohol, and baker's ketone, wherein the mass concentration ratio of 4-oxoisophorone:furfural:furfuryl alcohol:baker's ketone is 1:0.2-40:0.6-200:0.01-2.

[0020] In some embodiments, the extract includes one or more of methylcyclopentenolone, α-damascone, 2-methyl-2-pentenal, mesmin, 2-methylpyrazine, isovaleric acid, guaiacol, and ambroxol.

[0021] In some embodiments, the extract includes one or more of 2-acetylpyridine, 3-methylpyridine, 4-methylpyridine, 3-vinylpyridine, and 2,3,5-trimethylpyrazine.

[0022] A third aspect of this disclosure also provides an atomizing liquid comprising an extract prepared according to the preparation method of the first aspect of this disclosure or an extract prepared according to the second aspect of this disclosure, wherein the content of the extract is 0.01%-5% based on the total weight of the atomizing liquid.

[0023] The fourth aspect of this disclosure also provides an atomizing device, including the atomizing liquid of the third aspect of this disclosure.

[0024] The method for preparing the extract disclosed herein simulates the reaction of tobacco raw materials at different temperature ranges by carrying out at least two stages of microwave pyrolysis reaction within different temperature ranges. This allows the tobacco raw materials to fully release characteristic aroma components within different temperature ranges, resulting in an extract rich in aroma components. Applying the prepared extract to atomizing liquid can enhance the aroma intensity and tobacco-like sensation of the liquid, making it closer to the aroma and taste of traditional tobacco products, providing users with a superior smoking experience. Furthermore, the preparation method disclosed herein does not require the introduction of multiple organic solvents for extraction, reducing safety risks and making the production method green and safe. Detailed Implementation

[0025] The technical solutions of this disclosure will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of the embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0026] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the event of any conflict, this specification shall prevail.

[0027] It should be noted that, in the embodiments of this disclosure, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a method or apparatus that includes a list of elements includes not only the elements expressly described, but also other elements not expressly listed, or elements inherent to implementing the method or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other related elements in the method or apparatus that includes that element.

[0028] It should be noted that the terms "first," "second," and "third" used in the embodiments of this disclosure are merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first," "second," and "third" can be interchanged in a specific order or sequence where permitted. It should be understood that the objects distinguished by "first," "second," and "third" can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in an order other than those illustrated or described herein.

[0029] Electronic cigarettes and other types of non-combustible tobacco products have low evaporation temperatures, so they can only simulate the aroma of cigarettes with flavorings. However, most non-combustible tobacco products on the market have a relatively low degree of smoke simulation. The tobacco flavor products are mainly based on charred and roasted aromas, combined with a small amount of tobacco puree, which cannot perfectly simulate the characteristic aroma of traditional cigarette combustion, especially the characteristic top aroma of tobacco is seriously lacking.

[0030] Currently, techniques such as solvent extraction, supercritical fluid extraction, and molecular distillation are commonly used to extract aroma compounds from tobacco raw materials. However, the tobacco extracts prepared by these methods often lack complete aroma and characteristic tobacco flavor. Related technologies improve the simulation of tobacco smoke by adding tobacco extracts prepared by pyrolysis, but this typically involves heating and pyrolyzing the tobacco raw materials through dry distillation. This method is inefficient, time-consuming, and unevenly heated, easily leading to product instability. Another reported technique involves extracting tobacco leaves with organic solvents followed by microwave pyrolysis. This method is not only inefficient but also introduces organic solvents such as ethanol, dichloromethane, ethyl acetate, and acetone, posing certain safety risks. Furthermore, because this method involves extracting the tobacco leaves before pyrolysis, some aroma compounds are lost.

[0031] In view of the above, the first aspect of this disclosure provides a method for preparing an extract, comprising the following steps:

[0032] Tobacco raw materials are microwave pyrolyzed by sequentially heating to at least two gradient temperatures in a flowing gas. The gaseous pyrolysis products are collected in at least one gas absorption bottle using the flowing gas. The collected liquids in at least one gas absorption bottle are combined to obtain an extract. The at least two gradient temperatures are 100℃-900℃, and the heating time to each gradient temperature is 10min-60min.

[0033] Traditional cigarette combustion is a complex reaction process involving multiple temperature ranges. This disclosure simulates the reaction of traditional cigarettes at different temperature ranges by subjecting tobacco raw materials to microwave pyrolysis in at least two stages at at least two temperature gradients. The pyrolysis products are carried out by flowing gas and collected in a gas absorption bottle to obtain an extract. This process enhances the variety of aroma components in the extract. When the obtained extract is applied to novel tobacco products, it can improve the aroma intensity and tobacco-like sensation, thereby enhancing the smoking characteristics and pleasure of the novel tobacco products, giving them a flavor profile closer to traditional cigarettes, and improving the user's smoking experience.

[0034] In this disclosure, at least two temperature gradients are defined as 100℃-900℃. During combustion, traditional cigarettes primarily undergo volatilization and distillation in the 100℃-200℃ range, distillation, thermal decomposition, and thermal synthesis reactions in the 200℃-450℃ range, and combustion, intense oxidation, and thermal decomposition reactions in the 450℃-900℃ range. Different temperature ranges provide different aroma experiences. By maintaining the temperature gradients within these ranges, the reactions of traditional cigarettes during combustion at different temperature intervals can be simulated, thereby releasing richer aroma components. This results in an extract with enhanced aroma intensity and a more smoky feel, allowing it to be applied to novel tobacco products with aroma and smoking characteristics closer to traditional cigarettes, thus improving the user's smoking experience. For example, the at least two gradient temperatures can be values ​​between 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, 900°C, or any two of these values. In this disclosure, the at least two gradient temperatures can be the same or different.

[0035] In this disclosure, at least one gas absorption bottle is used. By using at least one gas absorption bottle, the pyrolysis products carried by the gas can be fully absorbed, reducing the loss of aroma components and thus increasing the aroma intensity. Exemplarily, the number of gas absorption bottles can be one, two, three, four, or five. In some preferred embodiments, the number of gas absorption bottles is three. In this disclosure, the pyrolysis products collected from all gas absorption bottles are combined as an extract.

[0036] In some embodiments, the tobacco raw material includes one or more of tobacco leaves, tobacco extracts, and tobacco stems. In this disclosure, tobacco extract refers to a natural extract obtained from tobacco leaves, including but not limited to tobacco leaf extract, tobacco aqueous extract, and tobacco alcohol extract.

[0037] In some implementations, at least two temperature gradients include a first temperature gradient of 100°C to 450°C and a second temperature gradient of greater than 450°C and less than or equal to 900°C.

[0038] In some implementations, at least two temperature gradients include a first temperature gradient of 100°C-300°C, a second temperature gradient of greater than 300°C and less than or equal to 450°C, and a third temperature gradient of greater than 450°C and less than or equal to 900°C.

[0039] In some embodiments, at least two temperature gradients include a first temperature gradient of 100°C-250°C, a second temperature gradient of greater than 250°C and less than or equal to 450°C, a third temperature gradient of greater than 450°C and less than or equal to 700°C, and a fourth temperature gradient of greater than 700°C and less than or equal to 900°C.

[0040] In some embodiments, at least two gradient temperatures include a first gradient temperature of 100°C-250°C, a second gradient temperature of greater than 250°C and less than or equal to 400°C, a third gradient temperature of greater than 400°C and less than or equal to 600°C, a fourth gradient temperature of greater than 600°C and less than or equal to 750°C, and a fifth gradient temperature of greater than 750°C and less than or equal to 900°C.

[0041] In this disclosure, the heating time to each gradient temperature is 10-60 minutes. By keeping the heating time within this range, the tobacco raw material can be fully pyrolyzed within different microwave pyrolysis temperature ranges, releasing more aroma components, enhancing the aroma intensity and tobacco-like sensation of the extract, thereby improving the user's smoking experience. For example, the heating time can be 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, or a value within a range of any two of these values. In this disclosure, the heating time to each gradient temperature can be the same or different.

[0042] In some embodiments, the preparation method further includes holding the temperature for 5-30 minutes after heating to each gradient temperature. This holding time further promotes the full release of tobacco substances from the tobacco raw material within the corresponding temperature range, enhancing the aroma intensity of the extract and thus improving the user's smoking experience. Exemplarily, the holding time can be 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, or a range consisting of any two of these values. In this disclosure, the holding time for each stage can be the same or different.

[0043] In some embodiments, the gas includes one or more of air, oxygen, or an inert gas. Using such a gas facilitates the extraction of gaseous pyrolysis products and allows for adjustment of the oxygen content to obtain pyrolysis products with different aroma profiles. For example, when the pyrolysis reaction does not require oxygen, using an inert gas, such as nitrogen, can both extract the gaseous pyrolysis products and increase the aroma component content within them. When the pyrolysis reaction requires oxygen, air or oxygen can be used to adjust the oxygen content of the pyrolysis reaction system. Higher oxygen content in the system results in more substances contributing to a sweet taste in the pyrolysis products, thereby enhancing the sweetness of the extract.

[0044] In some embodiments, the gas flow rate is 100 mL / min to 200 mL / min. Maintaining the gas flow rate within this range facilitates the removal of pyrolysis products from the microwave pyrolysis of tobacco raw materials from the reaction system, and allows the gas absorption bottle to fully absorb the pyrolysis products, reducing the loss of aroma substances and enhancing the aroma intensity and tobacco-like sensation of the extract. Exemplarily, the gas flow rate can be 100 mL / min, 120 mL / min, 140 mL / min, 160 mL / min, 180 mL / min, 200 mL / min, or a value within a range of any two of these values.

[0045] In this disclosure, the gas flow rate can be controlled using methods known in the art, without any particular limitation. Exemplarily, the gas flow rate is controlled by a mass flow controller.

[0046] In some embodiments, at least one gas absorption bottle includes a gas absorbent. The gas absorbent effectively absorbs the pyrolysis products carried by the gas, reducing the loss of aroma components. In some embodiments, the gas absorbent includes one or more of pure water, ethanol, propylene glycol, and glycerol; preferably, the gas absorbent includes propylene glycol. Using propylene glycol as a gas absorbent is beneficial for the absorption of pyrolysis products, and propylene glycol can be used in the electronic atomizing liquid without needing to be removed. Furthermore, this disclosure uses a solvent that can be directly used in the atomizing liquid as the gas absorbent, avoiding the use of other organic solvents, such as ethanol and ethyl acetate, for extraction operations, thus reducing the safety risks during the preparation process and the prepared extract.

[0047] In some embodiments, the amount of gas absorbent in each gas absorption bottle is 10 ml to 30 ml. This allows for the sufficient absorption of pyrolysis products carried out by the gas, while reducing the amount of gas absorbent used and saving costs.

[0048] In some embodiments, the temperature of the gas absorption bottle is below 0°C. By keeping the gas absorption bottle at a low temperature, the pyrolysis products carried out by the gas can be rapidly condensed, thereby improving the collection efficiency of the pyrolysis products. Exemplarily, the temperature of the gas absorption bottle can be 0°C, -5°C, -10°C, -15°C, -20°C, -25°C, -30°C, or a value between any two of these values. In some optional embodiments, the temperature of the gas absorption bottle is -5°C to -20°C, preferably -20°C.

[0049] In some embodiments, the preparation method further includes filtering the collected pyrolysis products after collection. Filtration removes any possible solid impurities present in the pyrolysis products, thereby improving the purity of the extract.

[0050] The second aspect of this disclosure also provides an extract prepared according to the preparation method of the first aspect of this disclosure. The extract prepared by the method of this disclosure has abundant aroma components; when applied to an atomizing liquid, it can enhance the aroma intensity and smoke-like sensation of the atomizing liquid, thereby improving the user's smoking experience.

[0051] In some embodiments, the extract includes 4-oxoisophorone, furfural, furfuryl alcohol, and baker's ketone, wherein the concentration ratio of 4-oxoisophorone:furfural:furfuryl alcohol:baker's ketone is 1:0.2-40:0.6-200:0.01-2. These substances are mainly aroma compounds produced by the cleavage of sugars, proteins, and alkaloids in tobacco raw materials, which are beneficial for enriching and enhancing the aroma of tobacco. For example, 4-oxoisophorone provides a tea aroma, furfural provides a roasted sweet aroma, furfuryl alcohol provides a sweet taste, and baker's ketone provides a rum and bread aroma.

[0052] In some embodiments, the extract further includes one or more of methylcyclopentenolone, α-damascone, 2-methyl-2-pentenal, mesmin, 2-methylpyrazine, isovaleric acid, guaiacol, and ambroxol. These substances are derived from the pyrolysis of tobacco or tobacco precursors and are beneficial for enhancing the aroma intensity and enriching the taste of tobacco. For example, methylcyclopentenolone has a nutty and maple and walnut aroma; α-damascone has a rose-like aroma; 2-methyl-2-pentenal is a strawberry acid precursor with a strawberry aroma; mesmin has a characteristic nicotine aroma; 2-methylpyrazine provides nutty, musty, roasted, and earthy aromas; isovaleric acid has a sweet fruity aroma, such as blueberry; guaiacol has a smoky aroma; and ambroxol has a dry ambergris aroma, as well as a pine and cypress-like woody aroma, and a green and tea-like fragrance.

[0053] In other embodiments, the extract includes one or more of 2-acetylpyridine, 3-methylpyridine, 4-methylpyridine, 3-vinylpyridine, and 2,3,5-trimethylpyrazine. These substances are derived from the pyrolysis of tobacco or tobacco precursors and are beneficial for enhancing the aroma intensity and flavor of tobacco.

[0054] A third aspect of this disclosure also provides an atomizing liquid, comprising an extract prepared according to the preparation method of the first aspect of this disclosure or an extract of the second aspect of this disclosure, wherein the content of the extract is 0.01%-5% based on the total weight of the atomizing liquid. By adding the extract of this disclosure to the atomizing liquid, the aroma intensity, flavor, strength, and tobacco-like sensation of the atomizing liquid can be enhanced, making the inhalation experience closer to that of traditional cigarettes and improving the user's inhalation experience. Exemplarily, the content of the extract, based on the total weight of the atomizing liquid, can be 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 0.8%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, or a value within a range of any two of these values. In some embodiments, the content of the extract, based on the total weight of the atomizing liquid, is 0.01-2%.

[0055] In some embodiments, the atomizing fluid further includes an atomizing agent, which includes one or more of propylene glycol and glycerol.

[0056] In some embodiments, the content of the atomizing agent is 95%-99.99% based on the total weight of the atomizing liquid.

[0057] The fourth aspect of this disclosure also provides an atomizing device, including the atomizing liquid of the third aspect of this disclosure.

[0058] The present disclosure will now be described in further detail with reference to specific embodiments. These descriptions are merely illustrative and not intended to limit the scope of the disclosure.

[0059] Example

[0060] The tobacco leaves and tobacco extracts used in the following examples were purchased from Yunnan Henggang Technology Co., Ltd., and the propylene glycol was purchased from SKC, South Korea.

[0061] The thermocouples used in the following examples are type K thermocouples;

[0062] The mass flow controller is an AS200 mass flow controller;

[0063] The instrument used for microwave pyrolysis was a vertical microwave pyrolysis reactor CY-CR1000C-M, which included a 2M-246-03TAG water-cooled microwave magnetron.

[0064] The instrument used for hot reflux extraction was an SF-2L small-scale reflux apparatus.

[0065] Example 1

[0066] Weigh 50g of tobacco leaves and place them in a pyrolysis tube. Insert a thermocouple and introduce air at a flow rate of 200mL / min using a mass flow controller. Once prepared, start the microwave pyrolysis reaction. Microwave pyrolysis is performed using gradient heating. The first gradient temperature is set to 300℃, with a heating time of 20min to reach it and a holding time of 10min. The second gradient temperature is set to 450℃, with a heating time of 10min and a holding time of 10min. The third gradient temperature is set to 900℃, with a heating time of 40min and a holding time of 5min. During the holding process, the microwave automatically starts heating when the temperature drops 2℃ below the preset temperature and automatically shuts off when the temperature rises 2℃ above the preset temperature. Driven by the airflow, the gaseous substances produced by pyrolysis enter the first condensation gas absorption bottle at 0°C. The remaining gaseous substances are carried by the incoming gas into the second and third condensation gas absorption bottles at -20°C. Each gas absorption bottle contains 10 ml of propylene glycol to collect the pyrolysis gases. The liquids in the first, second and third gas absorption bottles are combined and filtered with filter paper to obtain the extract.

[0067] Comparative Example 1

[0068] Weigh 50g of tobacco leaves and add them to a round-bottom flask. Add 80v / v% ethanol aqueous solution at a material-to-liquid mass ratio of 1:10. Perform hot reflux extraction using an SF-2L small-scale reflux apparatus. The tobacco leaves are placed in the round-bottom flask, and the flask is heated by an electric heating mantle. The evaporated ethanol and water are passed into a condenser and refluxed. The extraction temperature is 95℃ and the extraction time is 120min. After extraction, filter and collect the filtrate. Concentrate the extract using a rotary evaporator.

[0069] Comparative Example 2

[0070] Weigh 50g of tobacco leaves and place them in a pyrolysis tube. Insert a thermocouple and introduce air at a flow rate of 200mL / min using a mass flow controller. After preparation, turn on the microwave to initiate the pyrolysis reaction. Set the microwave pyrolysis temperature to 450℃, the heating time to 450℃ to 30min, and the holding time to 10min. Driven by the airflow, the gaseous substances produced by pyrolysis enter the first condenser gas absorption bottle at 0℃. The remaining gaseous substances are carried by the introduced gas into the second and third condenser gas absorption bottles at -20℃. Each gas absorption bottle contains 10ml of propylene glycol to collect the pyrolysis gases. Combine the liquids from the first, second, and third gas absorption bottles, filter using filter paper, and obtain the extract.

[0071] Sensory evaluation

[0072] The extract was added at a 2% addition rate to a mixed solvent of propylene glycol (PG): glycerol (VG) = 6:4 (solvent content 98%) to obtain the atomizing liquid. The atomizing liquid was then loaded into a disposable electronic atomizer. Seven judges conducted sensory evaluations, assessing aroma, vapor production, balance, penetration, strength, irritation, and aftertaste. The sensory evaluation primarily used aroma, vapor production, balance, penetration, strength, irritation, and aftertaste as criteria, combined with the sensory characteristics of electronic cigarettes. The scoring criteria for the sensory evaluation are shown in Table 1.

[0073] Table 1: Scoring Criteria for Sensory Evaluation

[0074] Aroma component detection

[0075] The obtained extract was analyzed by gas chromatography-mass spectrometry (GC-MS).

[0076] Gas chromatography (GC) test conditions:

[0077] Chromatographic column: DB-5MS (60m*0.25mm*0.25μm);

[0078] Injection volume: 2 μL;

[0079] Flow split ratio: 10:1;

[0080] Inlet temperature: 200℃;

[0081] Carrier gas: High-purity He gas;

[0082] Flow rate: 1.5 mL / min;

[0083] Temperature program: Hold at 40℃ for 2 min, increase to 150℃ at a rate of 3℃ / min and hold for 2 min, increase to 300℃ at a rate of 5℃ / min and hold for 1 min, and finally increase to 320℃ at a rate of 10℃ / min and hold for 1 min.

[0084] Mass spectrometry (MS) testing conditions:

[0085] Ion source temperature: 300℃;

[0086] Transmission line temperature: 280℃;

[0087] Scan range: m / z 33-350.

[0088] Volatile compounds in the samples were retrieved by computer and qualitatively identified using the NIST 2.0 mass spectrometry database and the Aroma Office database. Semi-quantitative analysis was performed using the internal standard method, and the content of each aroma component was calculated based on the ratio of its peak area to the internal standard peak area. Results were accurate to 0.01 μg / g.

[0089] The extracts from Example 1 and Comparative Examples 1-2 were subjected to sensory evaluation and aroma component detection according to the methods described above. The results are shown in Tables 2 and 3-4, respectively.

[0090] Table 2: Sensory evaluation results of the extracts from Example 1 and Comparative Examples 1-2

[0091] Table 3: Number of aroma components in the extracts of Example 1 and Comparative Examples 1-2

[0092] Table 4: Content of key aroma components in the extracts of Example 1 and Comparative Examples 1-2

[0093] The results above show that the extract prepared in Example 1 of this disclosure has a richer aroma profile, stronger smokiness, power, and aftertaste compared to the extract prepared in Comparative Example 1, further replicating the cigarette smoking experience. The aroma component detection results show that the number and total content of aroma components in the extract prepared by the method of this disclosure are significantly higher than those in the extract prepared by the hot reflux method in Comparative Example 1. Furthermore, the extract of this disclosure contains significantly more key aroma components that enhance the sensory experience than that of Comparative Example 1. Compared to the extract obtained by microwave pyrolysis at a single temperature in Comparative Example 2, the extract obtained by microwave pyrolysis at at least two gradient temperatures in this disclosure has a better sensory evaluation, with increased number of aroma components and higher content of key aroma components.

[0094] Example 2

[0095] Weigh 50g of tobacco extract and place it in a pyrolysis tube. Insert a thermocouple and introduce nitrogen gas at a flow rate of 200mL / min using a mass flow controller. After preparation, start the microwave pyrolysis reaction. A gradient heating method is used for pyrolysis. The first stage is set at a microwave pyrolysis temperature of 250℃, with a heating time of 20min and a holding time of 10min. The second stage is set at a microwave pyrolysis temperature of 400℃, with a heating time of 20min and a holding time of 10min. The third stage is set at a microwave pyrolysis temperature of 850℃, with a heating time of 40min and a holding time of 10min. Driven by the airflow, the gaseous substances produced by pyrolysis enter the first condenser gas absorption bottle. The remaining gaseous substances are carried by the incoming gas into the second and third condenser gas absorption bottles, which are in an environment of -20°C. Each gas absorption bottle contains 10 ml of propylene glycol to collect the gases produced by pyrolysis. The liquids in the first, second and third gas absorption bottles are combined and filtered with filter paper to obtain the tobacco pyrolysis extract.

[0096] Comparative Example 3

[0097] Weigh 50g of tobacco extract and add 500g of anhydrous ethanol for alcohol precipitation to obtain refined tobacco extract. The parameters for the alcohol precipitation process are as follows: prepare the mixture according to the ratio of raw material to anhydrous ethanol = 1:10 (W:W), and settle at -18℃ for 12h.

[0098] The extracts of Example 2 and Comparative Example 3 were subjected to sensory evaluation and aroma component testing according to the above method. The results are shown in Tables 5 and 6-7, respectively.

[0099] Table 5: Sensory evaluation results of the extracts from Example 2 and Comparative Example 3

[0100] Table 6: Number of aroma components in the extracts of Example 2 and Comparative Example 3

[0101] Table 7: Content of key aroma components in the extracts of Example 2 and Comparative Example 4

[0102] The results above show that, compared to Comparative Example 3, the extract obtained by microwave pyrolysis using three temperature gradients in Example 2 of this disclosure has a fuller tobacco aroma, and a stronger smoky flavor and strength. The aroma component analysis results indicate that the number of aroma components and the content of key aroma components in the extract of Example 2 are significantly higher than those in the extract of Comparative Example 3.

[0103] The above description is only a preferred embodiment of this disclosure and does not limit the patent scope of this disclosure. All equivalent structural transformations made using the contents of this specification under the inventive concept of this disclosure, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this disclosure.

Claims

1. A method for preparing an extract, wherein, The method includes the following steps: Tobacco raw materials are microwave pyrolyzed by sequentially heating to at least two gradient temperatures in a flowing gas. The gaseous pyrolysis products are collected in at least one gas absorption bottle using the flowing gas. The collected liquids in the at least one gas absorption bottle are combined to obtain the extract. The at least two gradient temperatures are each independently between 100°C and 900°C, and the heating time to each gradient temperature is each independently between 10 min and 60 min.

2. The preparation method according to claim 1, wherein, The tobacco raw materials are selected from one or more of tobacco leaves, tobacco extracts, and tobacco stems.

3. The preparation method according to claim 1 or 2, wherein, The at least two temperature gradients satisfy one of the following conditions: The at least two temperature gradients include a first temperature gradient of 100°C-450°C and a second temperature gradient of greater than 450°C and less than or equal to 900°C. The at least two gradient temperatures include a first gradient temperature of 100℃-300℃, a second gradient temperature of greater than 300℃ and less than or equal to 450℃, and a third gradient temperature of greater than 450℃ and less than or equal to 900℃. The at least two temperature gradients include a first gradient temperature of 100℃-250℃, a second gradient temperature greater than 250℃ and less than or equal to 450℃, a third gradient temperature greater than 450℃ and less than or equal to 700℃, and a fourth gradient temperature greater than 700℃ and less than or equal to 900℃; or The at least two temperature gradients include a first temperature gradient of 100℃-250℃, a second temperature gradient of greater than 250℃ and less than or equal to 400℃, a third temperature gradient of greater than 400℃ and less than or equal to 600℃, a fourth temperature gradient of greater than 600℃ and less than or equal to 750℃, and a fifth temperature gradient of greater than 750℃ and less than or equal to 900℃.

4. The preparation method according to claim 1 or 2, wherein, The gas includes one or more of air, oxygen, or an inert gas; Preferably, the gas flow rate is 100 mL / min to 200 mL / min.

5. The preparation method according to claim 1 or 2, wherein, The at least one gas absorption bottle includes a gas absorbent, which includes one or more of pure water, ethanol, propylene glycol, and glycerol; preferably, the gas absorbent includes propylene glycol. Preferably, the temperature of the at least one gas absorption bottle is below 0°C, and more preferably -5°C to -20°C.

6. The extract prepared by any one of claims 1-5.

7. The extract according to claim 6, wherein, The extract comprises 4-oxoisophorone, furfural, furfuryl alcohol, and baker's ketone, wherein the mass concentration ratio of 4-oxoisophorone:furfural:furfuryl alcohol:baker's ketone is 1:0.2-40:0.6-200:0.01-2.

8. The extract according to claim 6 or 7, wherein, The extract also includes at least one of the following groups of substances: One or more of the following: methylcyclopentenolone, α-damascone, 2-methyl-2-pentenal, mesmin, 2-methylpyrazine, isovaleric acid, guaiacol, and ambroxol; or One or more of 2-acetylpyridine, 3-methylpyridine, 4-methylpyridine, 3-vinylpyridine, and 2,3,5-trimethylpyrazine.

9. An atomizing fluid, wherein, The extract includes the extract prepared by the preparation method according to any one of claims 1-5 or the extract according to any one of claims 6-8, wherein the content of the extract is 0.01%-5% based on the total weight of the atomizing liquid.

10. An atomizing device, wherein, Includes the atomizing liquid as described in claim 9.

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