Novel aerosol-generating substrates containing thyme species

Abstract

The heated aerosol-generating article (1000) (4000a, 4000b) (5000) includes an aerosol-generating substrate (1020), which is formed from a homogenized thyme material including thyme particles, an aerosol former, and a binder. The aerosol-generating substrate further includes at least 400 micrograms of ursolic acid per gram of substrate, on a dry weight basis, and at least 150 micrograms of thymol per gram of substrate, on a dry weight basis. The amount of ursolic acid per gram of substrate is at least about twice the amount of thymol per gram of substrate.

Description

[Technical Field]

[0001] The present invention relates to aerosol-generating substrates comprising homogenized plant material formed from thyme particles, and to aerosol-generating articles incorporating such aerosol-generating substrates. The present invention further relates to aerosols derived from aerosol-generating substrates comprising thyme particles. [Background technology]

[0002] Heated aerosol-generating articles, in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than combusted (also known as non-combustion heated articles), are known in the art. Typically, in such articles, the aerosol is generated by transferring heat from a heat source to a physically separate aerosol-generating substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the substrate by heat transfer from the heat source and become entrained in the air drawn through the article. As the released compounds cool, they condense to form an aerosol.

[0003] Some aerosol-generating articles comprise flavorings that are delivered to the consumer during use of the article to provide a different sensory experience to the consumer, for example, to enhance the flavor of the aerosol. Flavorings can be used to deliver a taste (flavor), an odor (smell), or both taste and odor to the user inhaling the aerosol. It is known to provide heated aerosol-generating articles that include flavorings.

[0004] It is also known to provide flavorants to conventional combustible cigarettes, which are smoked by lighting the end of the cigarette opposite the mouthpiece so that the tobacco rod burns, generating inhalable smoke. Typically, one or more flavorants are mixed with the tobacco in the tobacco rod to provide additional flavor to the mainstream smoke as the tobacco is burned. Such flavorants may be provided, for example, as essential oils.

[0005] Aerosol from conventional cigarettes contains many components that interact with receptors located in the mouth, providing a sensation of "body," or a relatively strong mouthfeel. "Mouthfeel," as used herein, refers to the physical sensation in the mouth caused by a food, beverage, or aerosol, and is distinct from taste. Mouthfeel, along with taste and odor, is a fundamental sensory attribute that determines the overall flavor of a food or aerosol.

[0006] Reproducing the consumer experience provided by traditional combustible cigarettes with aerosol-generating articles in which the aerosol-generating substrate is heated rather than combusted is difficult, in part because of the lower temperatures reached during heating of such aerosol-generating articles, which result in the release of a different profile of volatile compounds.

[0007] It would be desirable to provide novel aerosol-generating substrates for heated aerosol-generating articles that provide aerosols with improved flavor and body. Such aerosol-generating substrates would be particularly desirable if they could provide aerosols with a sensory experience comparable to that provided by conventional combustible cigarettes. Furthermore, such aerosol-generating substrates would be particularly desirable if they could provide aerosols with reduced levels of undesirable aerosol compounds compared to existing aerosol-generating substrates, such as those containing only tobacco.

[0008] It would be further desirable to provide such an aerosol-generating substrate that can be easily incorporated into an aerosol-generating article and that can be manufactured using existing rapid methods and equipment. Summary of the Invention

[0009] The present disclosure relates to an aerosol-generating article including an aerosol-generating substrate, the aerosol-generating substrate being formed from homogenized plant material containing thyme particles, referred to herein as "homogenized thyme material." The homogenized thyme material may further include an aerosol former. The homogenized thyme material may further include a binder. The aerosol-generating substrate may further include, on a dry weight basis, at least about 400 micrograms of ursolic acid per gram of substrate. The aerosol-generating substrate may further include, on a dry weight basis, at least about 150 micrograms of thymol per gram of substrate. The amount of ursolic acid per gram of substrate may be at least about twice the amount of thymol per gram of substrate.

[0010] The present invention provides an aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate being formed from a homogenized thyme material containing thyme particles. The homogenized thyme material comprises thyme particles, an aerosol former, and a binder. The aerosol-generating substrate further comprises, on a dry weight basis, at least about 400 micrograms of ursolic acid per gram of substrate and at least about 150 micrograms of thymol per gram of substrate. The amount of ursolic acid per gram of substrate is at least about twice the amount of thymol per gram of substrate.

[0011] Preferably, upon heating an aerosol-generating substrate of an aerosol-generating article according to the present invention in accordance with Test Method A described below, an aerosol is generated comprising at least about 10 micrograms of ursolic acid per gram of substrate, on a dry weight basis, and at least 5 micrograms of thymol per gram of substrate, on a dry weight basis, wherein the amount of ursolic acid in the aerosol per gram of substrate is at least as great as the amount of thymol in the aerosol per gram of substrate.

[0012] Preferably, upon heating the aerosol-generating substrate according to Test Method A, the aerosol generated from the aerosol-generating substrate may contain ursolic acid in an amount of at least 0.25 micrograms per aerosol puff. Upon heating the aerosol-generating substrate according to Test Method A, the aerosol generated from the aerosol-generating substrate may contain thymol in an amount of at least 0.1 micrograms per aerosol puff. The amount of ursolic acid per aerosol puff is preferably at least the same as the amount of thymol per aerosol puff. The aerosol puff has a volume of 55 milliliters when generated by the smoking machine.

[0013] The present invention provides an aerosol-generating article comprising an aerosol-generating substrate formed from a homogenized thyme material containing thyme particles. The aerosol-generating substrate contains, on a dry weight basis, at least about 400 micrograms of ursolic acid per gram of substrate and at least about 150 micrograms of thymol per gram of substrate. The amount of ursolic acid per gram of substrate is at least about twice the amount of thymol per gram of substrate.

[0014] The present disclosure also relates to an aerosol-generating substrate formed of homogenized plant material containing thyme particles, referred to herein as "homogenized thyme material." The homogenized thyme material may further comprise an aerosol former. The homogenized thyme material may further comprise a binder. The aerosol-generating substrate may comprise, on a dry weight basis, at least about 400 micrograms of ursolic acid per gram of substrate. The aerosol-generating substrate may comprise, on a dry weight basis, at least about 150 micrograms of thymol per gram of substrate. The amount of ursolic acid per gram of substrate may be at least about twice the amount of thymol per gram of substrate.

[0015] According to the present invention, there is provided an aerosol-generating substrate formed from a homogenized thyme material, the homogenized thyme material comprising thyme particles, an aerosol former, and a binder, the aerosol-generating substrate further comprising at least 400 micrograms of ursolic acid per gram of substrate on a dry weight basis, and at least 150 micrograms of thymol per gram of substrate on a dry weight basis, the amount of ursolic acid per gram of substrate being at least twice the amount of thymol per gram of substrate.

[0016] The present disclosure also relates to an aerosol generated upon heating an aerosol-generating substrate. The aerosol may contain ursolic acid in an amount of at least 0.25 micrograms per aerosol puff. The aerosol may contain thymol in an amount of at least about 0.1 micrograms per aerosol puff. The amount of ursolic acid in the aerosol per gram of substrate may be at least the same as the amount of thymol in the aerosol per gram of substrate. The aerosol puff has a volume of 55 milliliters when generated by a smoking machine.

[0017] The present invention further provides an aerosol produced upon heating of an aerosol-generating substrate, the aerosol comprising ursolic acid in an amount of at least about 0.25 micrograms per aerosol puff and thymol in an amount of at least about 0.1 micrograms per aerosol puff, the amount of ursolic acid in the aerosol per gram of substrate being at least the same as the amount of thymol in the aerosol per gram of substrate, and the aerosol puff having a volume of 55 milliliters when generated by a smoking machine.

[0018] The present invention further provides a method of making an aerosol-generating substrate, comprising forming a slurry containing thyme particles, water, an aerosol former, a binder, and optionally tobacco particles, casting or extruding the slurry in the form of a sheet or strand, and drying the sheet or strand, preferably at a temperature of from 80° C. to 160° C. If a sheet of the aerosol-generating substrate is formed, the sheet may optionally be cut into strands or assembled to form a rod. The sheet may optionally be crimped prior to the assembly step.

[0019] The following references to the aerosol-generating substrates and aerosols of the present invention are considered to be applicable to all aspects of the invention unless otherwise indicated.

[0020] As used herein, the term "aerosol-generating article" refers to an article for producing an aerosol, where the article comprises an aerosol-generating substrate that is suitable and intended to be heated or burned to release volatile compounds capable of forming an aerosol. A conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end. Localized heat provided by the flame and the oxygen in the air drawn through the cigarette ignites the end of the cigarette, and the resulting combustion produces inhalable smoke. In contrast, in a "heated aerosol-generating article," the aerosol is generated by heating the aerosol-generating substrate rather than by burning it. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which the aerosol is generated by transferring heat from a combustible fuel element or heat source to a physically separated aerosol-generating substrate.

[0021] Also known are aerosol-generating articles adapted for use in aerosol-generating systems that supply aerosol formers to the aerosol-generating article, where the aerosol-generating substrate in the aerosol-generating article contains substantially less aerosol formers relative to the aerosol-generating substrate that carries and provides substantially all of the aerosol formers used to form the aerosol during operation.

[0022] As used herein, the term "aerosol-generating substrate" refers to a substrate capable of generating, upon heating, volatile compounds capable of forming an aerosol. The aerosol generated from an aerosol-generating substrate may or may not be visible to the human eye and may include vapor (e.g., gaseous fine particles of a substance that is normally a liquid or solid at room temperature) as well as gas and liquid droplets of condensed vapor.

[0023] As used herein, the term "homogenized plant material" encompasses any plant material formed by agglomeration of plant particles. For example, a sheet or web of homogenized plant material for an aerosol-generating substrate of the present invention may be formed by agglomerating particles of plant material obtained by grinding, milling, or comminuting thyme plant material and, optionally, tobacco material such as tobacco blades or tobacco stems. Homogenized plant material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0024] As used herein, the term "homogenized thyme material" refers to homogenized plant material containing thyme particles, optionally in combination with tobacco particles. The term "homogenized tobacco material" refers to homogenized plant material containing tobacco particles but not thyme particles, and is therefore not in accordance with the present invention.

[0025] As used herein, the term "thyme particles" encompasses particles derived from the leaves and flowers of the thyme plant (Thymus vulgaris). Thyme is an evergreen herbaceous plant of the Thymus species that is widely cultivated in the Mediterranean region. Thyme leaves are commonly used as culinary herbs for food flavoring. In contrast, thyme oil is a distillate extracted from the thyme plant, and ursolic acid and thymol are compounds derived from thyme.

[0026] The present invention provides aerosol-generating articles incorporating aerosol-generating substrates formed from homogenized plant material containing thyme particles, referred to herein as homogenized thyme material. The present invention also provides aerosols derived from such aerosol-generating substrates. The inventors have found that by incorporating thyme particles into the aerosol-generating substrate, it is advantageously possible to produce aerosols that provide a novel sensory experience. Such aerosols may provide a unique flavor and an enhanced level of body.

[0027] Furthermore, the inventors have found that it is possible to produce an aerosol with an advantageously improved thyme aroma and flavor compared to aerosols produced by the addition of thyme additives such as thyme oil. Thyme oil (Chemical Abstracts Service Registration No. 8007-46-3) is obtained by steam distillation from thyme plants, primarily their leaves. It has a different flavor composition than thyme particles, likely due to the distillation process, which may selectively remove or retain certain flavorants. Thymol is one of the main components of thyme oil. Thyme oil contains very low levels, or essentially none, of ursolic acid.

[0028] Furthermore, in certain aerosol-generating substrates provided herein, thyme particles are incorporated at a level sufficient to provide a desirable thyme flavor, while maintaining sufficient tobacco material to provide a desirable level of nicotine to the consumer.

[0029] Furthermore, it has been surprisingly found that the inclusion of thyme particles in an aerosol-generating substrate provides a significant reduction in certain undesirable aerosol compounds compared to aerosols generated from an aerosol-generating substrate containing 100 percent tobacco particles without thyme particles. In particular, as described below, it has been surprisingly found that the inclusion of thyme particles in an aerosol-generating substrate provides a significant reduction in certain polycyclic aromatic hydrocarbons (PAHs) and phenolic compounds compared to aerosols generated from an aerosol-generating substrate containing 100 percent tobacco particles without thyme particles. Furthermore, this reduction has been found to be greater than would be proportionally expected as a result of the reduction in tobacco particles.

[0030] The presence of thyme in homogenized plant material (such as cast leaves) can be reliably identified by DNA barcoding. Methods for performing DNA barcoding based on the nuclear genes ITS2, rbcL, and matK, and the plastid intergenic spacer trnH-psbA are known in the art and can be used (Chen S, Yao H, Han J, Liu C, Song J, et al. (2010) Validation of the ITS2 Region as a Novel DNA Barcode for Identifying Medicinal Plant Species. PLoS ONE 5(1):e8613; Hollingsworth PM, Graham SW, Little DP (2011) Choosing and Using a Plant DNA Barcode. PLoS ONE 6(5):e19254).

[0031] The inventors conducted a complex analysis and characterization of aerosols generated from aerosol-generating substrates of the present invention incorporating thyme particles and mixtures of thyme and tobacco particles, and compared these aerosols with aerosols generated from existing aerosol-generating substrates formed from tobacco material without thyme particles. Based on this, the inventors were able to identify a group of "signature compounds" present in the aerosol that are derived from thyme particles. Thus, detection of the characteristic compounds within a specific range of weight percentages in the aerosol can be used to identify aerosols derived from aerosol-generating substrates containing thyme particles. These characteristic compounds are particularly absent or present in only trace amounts in aerosols generated from tobacco material. Furthermore, the proportions of the characteristic compounds in the aerosol and their ratios to each other clearly indicate the use of thyme plant material, rather than thyme oil. Similarly, the presence of these characteristic compounds in specific proportions in the aerosol-generating substrate indicates the presence of thyme particles within the substrate.

[0032] In particular, the defined levels and ratios of characteristic compounds in the substrate and aerosol are specific to the thyme particles present in the homogenized thyme material. The levels of each characteristic compound depend on the way the thyme particles were processed during the production of the homogenized thyme material. The levels also depend on the composition of the homogenized thyme material and may be affected, in particular, by the levels of other components in the homogenized thyme material. The levels of characteristic compounds in the homogenized thyme material may differ from the levels of the same compounds in the starting thyme material. This may also differ from the levels of characteristic compounds in a material containing thyme particles but not according to the invention as defined herein.

[0033] To perform aerosol characterization, we used a complementary non-targeted differential screening (NTDS) using liquid chromatography coupled to a high-resolution accurate mass spectrometer (LC-HRAM-MS) in parallel with two-dimensional gas chromatography coupled to a time-of-flight mass spectrometer (GCxGC-TOFMS).

[0034] Non-targeted screening (NTS) is an important method for characterizing the chemical composition of complex matrices, either by matching the features of unknown detected compounds to spectral databases (suspect screening [SSA]) or by elucidating unknown structures in the absence of prior knowledge by using primary fragmentation (MS / MS)-derived information that matches in silico predicted fragments from compound databases (non-targeted analysis [NTA]). NTS allows for simultaneous measurements and the ability to semi-quantitate a large number of small molecules from a sample using an unbiased approach.

[0035] As mentioned above, non-targeted differential screening (NTDS) can be performed when focusing on the comparison of two or more aerosol samples to assess significant differences in chemical composition between samples in an uncontrolled manner, or when prior knowledge of the relevant groups is available between sample groups. Complementary differential screening using liquid chromatography coupled to a high-resolution accurate mass spectrometer (LC-HRAM-MS) in parallel with two-dimensional gas chromatography coupled to a time-of-flight mass spectrometer (GCxGC-TOFMS) is applied to ensure comprehensive analytical coverage to identify the most relevant differences in aerosol composition between aerosols derived from articles containing 100% thyme by weight as particulate plant material and those containing 100% tobacco by weight as particulate plant material.

[0036] The aerosol was generated and collected using the equipment and methods described in detail below.

[0037] LC-HRAM-MS analysis was performed using a Thermo QExactive™ high-resolution mass spectrometer in both full scan and data-dependent modes. Three different methods were applied to cover a wide range of materials with different ionization properties and compound classes. Samples were analyzed using heated electrospray ionization (HESI) in positive and negative modes, and RP chromatography with atmospheric pressure chemical ionization (APCI) in positive mode. The methods are: Arndt, D. et al, “In depth characterization of chemical differences between heat-not-burn tobacco products and cigarettes using LC-HRAM-MS-based non-targeted differential screening” (DOI:10.13140 / RG.2.2.11752.16643), Wachsmuth, C. et al, “Comprehensive chemical characterization of complex matrices through integration of multiple analytical modes and databases for LC-HRAM-MS-based non-targeted screening” (DOI:10.13140 / RG.2.2.12701.61927) and “Buchholz, C. et al, “Increasing confidence for compound identification by fragmentation database and in silico fragmentation comparison with LC-HRAM-MS-based non-targeted screening of complex matrices” (DOI: 10.13140 / RG.2.2.17944.49927) (all from the 66th ASMS Conference on Mass Spectrometry and Allied Topics, San Diego, USA (2018)).The method is further described in: Arndt, D. et al., "A complex matrix characterization approach, applied to cigarette smoke, that integrates multiple analytical methods and compound identification strategies for non-targeted liquid chromatography with high-resolution mass spectrometry" (DOI: 10.1002 / rcm.8571).

[0038] GCxGC-TOFMS analysis was performed in three different ways for non-polar, polar, or highly volatile compounds in the aerosol using an Agilent GC Model 6890A or 7890A instrument equipped with an automatic liquid injector (Model 7683B) and a thermal modulator coupled to a LECO Pegasus 4D™ mass spectrometer. The methods are described in: Almstetter et al., “Non-targeted screening using GC×GC-TOFMS for in-depth chemical characterization of aerosol from a heat-not-burned tobacco product” (DOI: 10.13140 / RG.2.2.36010.31688 / 1) and Almstetter et al., “Non-targeted differential screening of complex matrices using GC×GC-TOFMS for comprehensive characterization of the chemical composition and determination of significant differences” (DOI: 10.13140 / RG.2.2.32692.55680) (66th and 64th ASMS Conferences on Mass Spectrometry and Allied Topics, San Diego, USA, respectively).

[0039] Results from the analytical methods provided information on the major compounds responsible for the differences in the aerosols generated by these articles. The focus of the untargeted differential screening, using both analytical platforms LC-HRAM-MS and GCxGC-TOFMS, was on compounds that were present in greater amounts in the aerosols of samples of aerosol-generating substrates according to the invention containing 100 percent thyme particles versus control samples of aerosol-generating substrates containing 100 percent tobacco particles. The NTDS method is described in the literature listed above.

[0040] Based on this information, the inventors were able to identify specific compounds within the aerosol that could be considered "signature compounds" derived from thyme particles in the substrate. Signature compounds derived from thyme include, but are not limited to: ursolic acid (3-beta-3-hydroxy-urs-12-en-28-oic acid, chemical formula: C) 30 H 48 O3, Chemical Abstracts Service Registry No. 77-52-1; thymol (5-methyl-2-(propan-2-yl)phenol), chemical formula: C 10 H 14 O, Chemical Abstracts Service Registry No. 89-83-8; isothymol or carvacrol (5-isopropyl-2-methylphenol, chemical formula: C 10 H 14 O, Chemical Abstracts Service Registry No. 499-75-2), betulinic acid ((3β)-3-hydroxy-lup-20(29)-en-28-oic acid, chemical formula: C 30 H 48 O3, Chemical Abstracts Service Registry No. 472-15-1), and thymobidroquinone (2-methyl-5-propan-2-ylbenzene-1,4-diol, chemical formula: C 10 H 14 O2, Chemical Abstracts Service registration number 2217-60-9).

[0041] For purposes of the present invention, targeted screening may be performed on a sample of an aerosol-generating substrate to identify the presence and amount of each of the characteristic compounds in the substrate. Such targeted screening methods are described below. As described, the characteristic compounds may be detected and measured both in the aerosol-generating substrate and in the aerosol derived from the aerosol-generating substrate.

[0042] As defined above, the aerosol-generating article of the present invention comprises an aerosol-generating substrate formed from homogenized plant material containing thyme particles. As a result of the inclusion of thyme particles, the aerosol-generating substrate comprises a specific proportion of thyme "characteristic compounds," as described above. In particular, the aerosol-generating substrate preferably contains, on a dry weight basis, at least 400 micrograms of ursolic acid per gram of substrate and at least 150 micrograms of thymol per gram of substrate.

[0043] By defining the aerosol-generating substrate for a desired level of the characteristic compound, it is possible to ensure consistency between products despite potential differences in the level of the characteristic compound in the raw materials, which advantageously allows for more effective control of product quality.

[0044] The aerosol-generating substrate preferably contains, on a dry weight basis, at least about 1000 micrograms of ursolic acid per gram of substrate, and more preferably at least about 2000 micrograms of ursolic acid per gram of substrate. Alternatively, or additionally, the aerosol-generating substrate preferably contains, on a dry weight basis, no more than about 7000 micrograms of ursolic acid per gram of substrate, more preferably no more than about 6000 micrograms of ursolic acid per gram of substrate, and even more preferably no more than about 5000 micrograms of ursolic acid per gram of substrate.

[0045] For example, the aerosol-generating substrate may contain, on a dry weight basis, from about 400 micrograms to about 7000 micrograms of ursolic acid per gram of substrate, or from about 1000 micrograms to about 6000 micrograms of ursolic acid per gram of substrate, or from about 2000 micrograms to about 5000 micrograms of ursolic acid per gram of substrate.

[0046] In certain preferred embodiments, the aerosol-generating substrate may contain from about 400 micrograms to about 3500 micrograms of ursolic acid per gram of aerosol-generating substrate, and more preferably from about 1000 micrograms to about 3000 micrograms of ursolic acid per gram of aerosol-generating substrate. For example, the level of ursolic acid may be within these ranges for a first preferred embodiment of the invention, as described below, in which the aerosol-generating substrate contains 2.5 to 25 percent by weight of thyme particles on a dry weight basis.

[0047] The aerosol-generating substrate preferably contains at least about 500 micrograms of thymol per gram of substrate, and more preferably at least about 1000 micrograms of thymol per gram of substrate, on a dry weight basis. Alternatively, or additionally, the aerosol-generating substrate preferably contains no more than about 3000 micrograms of thymol per gram of substrate, more preferably no more than about 2750 micrograms of thymol per gram of substrate, and even more preferably no more than about 2500 micrograms of thymol per gram of substrate, on a dry weight basis.

[0048] For example, the aerosol-generating substrate may contain, on a dry weight basis, from about 150 micrograms to about 3000 micrograms of thymol per gram of substrate, or from about 500 micrograms to about 2750 micrograms of thymol per gram of substrate, or from about 1000 micrograms to about 2500 micrograms of thymol per gram of substrate.

[0049] In certain particularly preferred embodiments, the aerosol-generating substrate may contain from about 150 micrograms to about 1500 micrograms of thymol per gram of aerosol-generating substrate, and more preferably from about 500 micrograms to about 1300 micrograms of thymol per gram of aerosol-generating substrate. For example, thymol levels may be within these ranges for a first preferred embodiment of the invention, as described below, in which the aerosol-generating substrate contains from 2.5 percent to 25 percent thyme particles by weight on a dry weight basis.

[0050] As defined above, the ratio of characteristic compounds in the aerosol-generating substrate is such that the amount of ursolic acid per gram of substrate is at least about 2 times the amount of thymol per gram of substrate, more preferably at least about 2.25 times the amount of thymol per gram of substrate, and more preferably at least about 2.5 times the amount of thymol per gram of substrate. Thus, the ratio of ursolic acid to thymol in the aerosol-generating substrate is significantly greater than the ratio of ursolic acid to thymol in thyme oil, due to the much higher ratio of ursolic acid present in thyme particles compared to thyme oil.

[0051] Thus, the ratio of ursolic acid to thymol is characteristic of the inclusion of thyme particles in the aerosol-generating substrate.

[0052] Preferably, the aerosol-generating substrate may further comprise, on a dry weight basis, from about 1 mg to about 20 mg of betulinic acid per gram of substrate, or from about 2 mg to about 18 mg of betulinic acid per gram of substrate, or from about 5 mg to about 15 mg of betulinic acid per gram of substrate.

[0053] Preferably, the aerosol-generating substrate may further comprise, on a dry weight basis, from about 50 micrograms to about 1000 micrograms of isothymol per gram of substrate, or from about 250 micrograms to about 1000 micrograms of isothymol per gram of substrate, or from about 1000 micrograms to about 2500 micrograms of isothymol per gram of substrate.

[0054] Preferably, the aerosol-generating substrate may further comprise, on a dry weight basis, from about 25 micrograms to about 400 micrograms of thymohydroquinone per gram of substrate, or from about 50 micrograms to about 350 micrograms of thymohydroquinone per gram of substrate, or from about 100 micrograms to about 250 micrograms of thymohydroquinone per gram of substrate.

[0055] As defined above, the present invention also provides an aerosol-generating article comprising an aerosol-generating substrate formed from homogenized plant material containing thyme particles, wherein upon heating of the aerosol-generating substrate, an aerosol containing thyme "characteristic compounds" is generated.

[0056] For purposes of the present invention, the aerosol-generating substrate is heated in accordance with "Test Method A." In Test Method A, an aerosol-generating article incorporating the aerosol-generating substrate is heated in a Tobacco Heating System 2.2 holder (THS2.2 holder) under Health Canada's mechanical smoking regimen. For purposes of conducting Test Method A, the aerosol-generating substrate is provided in an aerosol-generating article that is compatible with a THS2.2 holder.

[0057] The Tobacco Heating System 2.2 Holder (THS2.2 Holder) corresponds to the commercially available iQOS device (Philip Morris Products SA, Switzerland) described in Smith et al., 2016, Regul. Toxicol. Pharmacol. 81(S2)S82-S92. Aerosol-generating articles for use with the IQOS device are also commercially available.

[0058] The Health Canada smoking regimen is a clearly defined and accepted smoking protocol in Health Canada's Tobacco Product Information Regulations 2000, SOR / 2000-273, Schedule 2 (published by the Canadian Ministry of Justice). The test method is described in ISO / TR 19478-1:2014. In the Health Canada smoking test, aerosol is collected from a sample aerosol-generating substrate over 12 puffs with a puff volume of 55 millimeters, a puff duration of 2 seconds, and a 30-second interval between puffs, with all ventilation, if present, shut off.

[0059] Thus, in the context of the present invention, the phrase "involving heating of an aerosol-generating substrate in accordance with Test Method A" means heating of the aerosol-generating substrate in a THS2.2 holder under the Health Canada Tobacco Product Information Regulations 2000 SOR / 2000-273, Schedule 2 (published by the Canadian Department of Justice), Health Canada's mechanical smoking regimen, which test method is described in ISO / TR 19478-1:2014.

[0060] For analytical purposes, the aerosol generated from heating the aerosol-generating substrate is trapped using appropriate equipment, depending on the analytical method being used. In a preferred method for generating samples for analysis by LC-HRAM-MS, the particle phase is trapped using a conditioned 44 mm Cambridge glass fiber filter pad (compliant with ISO 3308) and a filter holder (compliant with ISO 4387 and ISO 3308). The remaining gas phase is collected downstream from the filter pad using two consecutive microimpingers (20 mL), each containing methanol and an internal standard (ISTD) solution (10 mL), maintained at -60 °C using a mixture of dry ice and isopropanol. The trapped particle and gas phases are then recombined, and the sample is extracted from the microimpingers with methanol by shaking, stirring, and centrifuging (4500 g, 5 min, 10 °C). The resulting extract is diluted with methanol and mixed in an Eppendorf ThermoMixer (5 °C, 2000 rpm). Test samples from the extracts are analyzed by LC-HRAM-MS in a combination of full scan and data-dependent fragmentation modes to identify characteristic compounds. For the purposes of this invention, LC-HRAM-MS analysis is suitable for the identification and quantification of ursolic acid, thymol, and betulinic acid.

[0061] Samples for analysis by GCxGC-TOFMS can be generated in a similar manner, but for GCxGC-TOFMS analysis, different solvents are appropriate for extraction and analysis of polar, non-polar, and volatile compounds separated from the bulk aerosol.

[0062] For nonpolar and polar compounds, the whole aerosol was collected using a calibrated 44 mm Cambridge glass fiber filter pad (compliant with ISO 3308) and filter holder (compliant with ISO 4387 and ISO 3308), followed by two microimpingers connected in series and sealed. Each microimpinger (20 mL) contained 10 mL of dichloromethane / methanol (80:20 v / v) containing internal standard (ISTD) and retention index marker (RIM) compounds. The microimpingers were maintained at -80°C using a mixture of dry ice and isopropanol. For analysis of nonpolar compounds, the whole aerosol particle phase was extracted from the glass fiber filter pad using the contents of the microimpinger. Water was added to an aliquot (10 mL) of the resulting extract, and the sample was shaken and centrifuged as described above. The dichloromethane layer was separated, dried over sodium sulfate, and analyzed by GCxGC-TOFMS in full scan mode. For the analysis of polar compounds, use the remaining aqueous layer from the non-polar sample preparation described above. ISTD and RIM compounds are added to the aqueous layer, which is then directly analyzed by GCxGC-TOFMS in full scan mode.

[0063] For volatile compounds, the entire aerosol is collected using two serially connected and sealed microimpingers (20 mL), each filled with 10 mL of N,N-dimethylformamide containing the ISTD and RIM compounds. The microimpingers are maintained at -50 to -60 °C using a mixture of dry ice and isopropanol. After collection, the contents of the two microimpingers are combined and analyzed by GCxGC-TOFMS in full scan mode.

[0064] For the purposes of the present invention, GCxGC-TOFMS analysis is suitable for the identification and quantification of thymol, isothymol and thymohydroquinone.

[0065] The aerosol generated upon heating of an aerosol-generating substrate of the present invention according to Test Method A is preferably characterized by the amounts and ratios of the characteristic compounds, ursolic acid, and thymol, as defined above.

[0066] In an aerosol-generating article comprising the aerosol-generating substrate described above, heating the aerosol-generating substrate according to Test Method A preferably generates an aerosol containing at least about 10 micrograms of ursolic acid per gram of substrate, on a dry weight basis, and at least about 5 micrograms of thymol per gram of substrate, on a dry weight basis. The amount of ursolic acid in the aerosol per gram of substrate is preferably at least the same as the amount of thymol in the aerosol per gram of substrate. In other words, the amount of ursolic acid is equal to or greater than the amount of thymol in the aerosol per gram of substrate.

[0067] The ranges define the amount of each characteristic compound in the generated aerosol per gram of aerosol-generating substrate (also referred to herein as "substrate"), which is equal to the total amount of characteristic compounds measured in the aerosol collected during Test Method A divided by the dry weight of the aerosol-generating substrate before heating.

[0068] Preferably, heating the aerosol-generating substrate according to Test Method A generates an aerosol containing at least about 25 micrograms of ursolic acid per gram of substrate on a dry weight basis. More preferably, the aerosol generated from an aerosol-generating substrate according to the present invention contains at least about 50 micrograms of ursolic acid per gram of substrate on a dry weight basis.

[0069] Alternatively or additionally, the aerosol generated by the aerosol-generating substrate preferably contains, on a dry weight basis, at most about 250 micrograms of ursolic acid per gram of substrate. More preferably, the aerosol generated by the aerosol-generating substrate contains, on a dry weight basis, at most about 200 micrograms of ursolic acid per gram of substrate. Even more preferably, the aerosol generated by the aerosol-generating substrate contains, on a dry weight basis, at most about 150 micrograms of ursolic acid per gram of substrate.

[0070] In certain embodiments of the invention, the aerosol generated from the aerosol-generating substrate may contain up to 150 micrograms of ursolic acid per gram of substrate, more preferably up to 100 micrograms of ursolic acid per gram of substrate, on a dry weight basis. For example, the level of ursolic acid may be within these ranges for a first preferred embodiment of the invention, as described below, in which the aerosol-generating substrate contains 2.5 to 25 percent by weight thyme particles, on a dry weight basis.

[0071] Preferably, heating the aerosol-generating substrate according to Test Method A generates an aerosol containing at least about 20 micrograms of thymol per gram of substrate on a dry weight basis. More preferably, the aerosol generated from an aerosol-generating substrate according to the present invention contains at least about 50 micrograms of thymol per gram of substrate on a dry weight basis.

[0072] Alternatively, or additionally, the aerosol generated from the aerosol-generating substrate preferably contains at most about 150 micrograms of thymol per gram of substrate on a dry weight basis. More preferably, the aerosol generated from the aerosol-generating substrate contains at most about 125 micrograms of thymol per gram of substrate on a dry weight basis. Even more preferably, the aerosol generated from the aerosol-generating substrate contains at most about 100 micrograms of thymol per gram of substrate on a dry weight basis.

[0073] In certain embodiments of the invention, the aerosol generated from the aerosol-generating substrate may contain up to 100 micrograms of thymol per gram of substrate, more preferably up to 75 micrograms of thymol per gram of substrate, on a dry weight basis. For example, thymol levels may be within these ranges for a first preferred embodiment of the invention, as described below, in which the aerosol-generating substrate contains 2.5 to 25 percent by weight thyme particles, on a dry weight basis.

[0074] Preferably, during Test A, the aerosol generated from an aerosol-generating substrate according to the present invention further comprises, on a dry weight basis, from about 0.5 micrograms to about 15 micrograms of isothymol per gram of substrate, more preferably from about 2 micrograms to about 12 micrograms of isothymol per gram of substrate, and even more preferably from about 5 micrograms to about 10 micrograms of isothymol per gram of substrate.

[0075] Preferably, during Test A, the aerosol generated from the aerosol-generating substrate according to the present invention further comprises, on a dry weight basis, from about 40 micrograms to about 750 micrograms of betulinic acid per gram of substrate, more preferably from about 100 micrograms to about 600 micrograms of betulinic acid per gram of substrate, and even more preferably from about 250 micrograms to about 500 micrograms of betulinic acid per gram of substrate.

[0076] Preferably, during Test A, the aerosol generated from an aerosol-generating substrate according to the present invention further comprises, on a dry weight basis, from about 0.5 micrograms to about 15 micrograms of thymobidroquinone per gram of substrate, more preferably from about 2 micrograms to about 12 micrograms of thymobidroquinone per gram of substrate, and even more preferably from about 5 micrograms to about 10 micrograms of thymobidroquinone per gram of substrate.

[0077] The aerosol generated from the aerosol-generating substrate of the present invention during Test Method A preferably contains at least about 0.1 micrograms of nicotine per gram of substrate, more preferably at least about 1 microgram of nicotine per gram of substrate, and even more preferably at least about 2 micrograms of nicotine per gram of substrate. The aerosol preferably contains at most about 10 micrograms of nicotine per gram of substrate, more preferably at most about 7.5 micrograms of nicotine per gram of substrate, and even more preferably at most about 4 micrograms of nicotine per gram of substrate. For example, the aerosol may contain from about 0.1 micrograms to about 10 micrograms of nicotine per gram of substrate, or from about 1 microgram to about 7.5 micrograms of nicotine per gram of substrate, or from about 2 micrograms to about 4 micrograms of nicotine per gram of substrate. In some embodiments of the present invention, the aerosol may contain zero micrograms of nicotine.

[0078] Various methods known in the art can be applied to measure the amount of nicotine in the aerosol.

[0079] Alternatively, or in addition, the aerosol generated from an aerosol-generating substrate according to the present invention during Test Method A may optionally further comprise at least about 20 milligrams of cannabinoid compound per gram of substrate, more preferably at least about 50 milligrams of cannabinoid compound per gram of substrate, and more preferably at least about 100 milligrams of cannabinoid compound per gram of substrate. Preferably, the aerosol comprises up to about 250 milligrams of cannabinoid compound per gram of substrate, more preferably up to about 200 milligrams of cannabinoid compound per gram of substrate, and even more preferably up to about 150 milligrams of cannabinoid compound per gram of substrate. For example, the aerosol may comprise from about 20 milligrams to about 250 milligrams of cannabinoid compound per gram of substrate, or from about 50 milligrams to about 200 milligrams of cannabinoid compound per gram of substrate, or from about 100 milligrams to about 150 milligrams of cannabinoid compound per gram of substrate. In some embodiments of the present invention, the aerosol may contain zero micrograms of cannabinoid compounds.

[0080] Preferably the cannabinoid compound is selected from CBD and THC, more preferably the cannabinoid compound is CBD.

[0081] Various methods known in the art can be applied to measure the amount of cannabinoid compounds in the aerosol.

[0082] Carbon monoxide may also be present in the aerosol generated from an aerosol-generating substrate according to the present invention during Test Method A, and can be measured and used to further characterize the aerosol. Oxides of nitrogen, such as nitric oxide and nitrogen dioxide, may also be present in the aerosol, and can be measured and used to further characterize the aerosol.

[0083] According to the present invention, the aerosol generated from the aerosol-generating substrate during Test Method A preferably has an amount of ursolic acid per gram of substrate that is at least the same as the amount of thymol per gram of substrate. Thus, the ratio of ursolic acid to thymol is at least 1:1. More preferably, the amount of ursolic acid in the aerosol generated from the aerosol-generating substrate during Test Method A is at least 1.5 times the amount of thymol per gram of substrate, thus, the ratio of ursolic acid to thymol is at least 1.5:1.

[0084] A defined ratio of ursolic acid to thymol characterizes aerosols derived from thyme particles. In contrast, the ratio of ursolic acid to thymol in aerosols generated from thyme oil will be significantly different due to the much higher ratio of ursolic acid present in thyme particles compared to thyme oil, which contains little or no ursolic acid.

[0085] The aerosol generated from an aerosol-generating substrate of the present invention during Test Method A may further comprise at least about 5 milligrams of aerosol former per gram of aerosol-generating substrate, or at least about 10 milligrams of aerosol per gram of substrate, or at least about 15 milligrams of aerosol former per gram of substrate. Alternatively or additionally, the aerosol may comprise up to about 30 milligrams of aerosol former per gram of substrate, or up to about 25 milligrams of aerosol former per gram of substrate, or up to about 20 milligrams of aerosol former per gram of substrate. For example, the aerosol may comprise from about 5 milligrams to about 30 milligrams of aerosol former per gram of substrate, or from about 10 milligrams to about 25 milligrams of aerosol former per gram of substrate, or from about 15 milligrams to about 20 milligrams of aerosol former per gram of substrate. In alternative embodiments, the aerosol may comprise less than 5 milligrams of aerosol former per gram of substrate. This may be appropriate, for example, where the aerosol former is provided separately within the aerosol-generating article or device.

[0086] Suitable aerosol formers for use in the present invention are described below.

[0087] Various methods known in the art can be applied to measure the amount of aerosol formers in an aerosol.

[0088] As mentioned above, the presence and defined ratios of characteristic compounds in the aerosol indicate the inclusion of thyme particles in the homogenized plant material forming the aerosol-generating substrate.

[0089] Preferably, the aerosol-generating substrate of an aerosol-generating article according to the present invention comprises a homogenized thyme material comprising, on a dry weight basis, at least about 2.5 weight percent thyme particles. Preferably, the homogenized thyme material comprises, on a dry weight basis, at least about 3 weight percent thyme particles, more preferably at least about 4 weight percent thyme particles, more preferably at least about 5 weight percent thyme particles, more preferably at least about 6 weight percent thyme particles, more preferably at least about 7 weight percent thyme particles, more preferably at least about 8 weight percent thyme particles, more preferably at least about 9 weight percent thyme particles, more preferably at least about 10 weight percent thyme particles.

[0090] The homogenized thyme material may contain, on a dry weight basis, up to about 100 weight percent thyme particles. Preferably, the homogenized plant material contains, on a dry weight basis, up to about 90 weight percent thyme particles, more preferably up to about 80 weight percent thyme particles, more preferably up to about 70 weight percent thyme particles, more preferably up to about 60 weight percent thyme particles, and even more preferably up to about 50 weight percent thyme particles.

[0091] For example, the homogenized thyme material can contain, on a dry weight basis, from about 2.5 weight percent to about 100 weight percent thyme particles, or from about 5 weight percent to about 90 weight percent thyme particles, or from about 10 weight percent to about 80 weight percent thyme particles, or from about 15 weight percent to about 70 weight percent thyme particles, or from about 20 weight percent to about 60 weight percent thyme particles, or from about 30 weight percent to about 50 weight percent thyme particles.

[0092] In certain particularly preferred embodiments of the present invention, the homogenized thyme material comprises, on a dry weight basis, from about 15 weight percent to about 25 weight percent thyme particles.

[0093] While providing a usable material for an aerosol-generating article, the weight of thyme particles that can be incorporated into the homogenized thyme material may depend, to some extent, on the composition of the homogenized thyme material. For example, the maximum amount of thyme particles that can be incorporated into the homogenized thyme material may depend on the nature of the binder, as described below.

[0094] According to a first preferred embodiment of the present invention, the homogenized thyme material contains, on a dry weight basis, at most about 25 weight percent thyme particles, preferably at most about 24 weight percent thyme particles, more preferably at most about 23 weight percent thyme particles, more preferably at most about 22 weight percent thyme particles, more preferably at most about 21 weight percent thyme particles, and even more preferably at most about 20 weight percent thyme particles. For example, the homogenized thyme material of the aerosol-generating article according to the first preferred embodiment of the present invention contains, on a dry weight basis, from about 2.5 weight percent to about 25 weight percent thyme particles, or from about 4 weight percent to about 24 weight percent thyme particles, or from about 5 weight percent to about 23 weight percent thyme particles, or from about 6 weight percent to about 22 weight percent thyme particles, or from about 8 weight percent to about 21 weight percent thyme particles, or from about 10 weight percent to about 20 weight percent thyme particles.

[0095] According to a second preferred embodiment of the present invention, the homogenized thyme material comprises at most about 65 weight percent thyme particles, more preferably at most about 60 weight percent thyme particles, more preferably at most about 55 weight percent thyme seed particles, more preferably at most about 50 weight percent thyme particles, and even more preferably at most about 45 weight percent thyme particles. For example, the homogenized thyme material of the aerosol-generating article according to the first preferred embodiment of the present invention comprises, on a dry weight basis, from about 2.5 weight percent to about 65 weight percent thyme particles, or from about 10 weight percent to about 60 weight percent thyme particles, or from about 15 weight percent to about 55 weight percent thyme particles, or from about 20 weight percent to about 50 weight percent thyme particles, or from about 30 weight percent to about 45 weight percent thyme particles, or from about 35 weight percent to about 45 weight percent thyme particles.

[0096] In certain embodiments of the present invention, the plant particles forming the homogenized thyme material may comprise at least 98 percent thyme particles, or at least 95 percent thyme particles, or at least 90 percent thyme particles by weight, based on the dry weight of the plant particles. Thus, in such embodiments, the aerosol-generating substrate comprises thyme particles and is substantially free of other plant particles. For example, the plant particles forming the homogenized thyme material may comprise about 100 percent thyme particles by weight.

[0097] In an alternative embodiment of the present invention, the homogenized thyme material may include thyme particles in combination with at least one of tobacco particles or cannabis particles, as described below.

[0098] In the following description of the invention, the terms "particulate plant material" and "plant particles" are used collectively to refer to the particles of plant material used to form the homogenized plant material. The particulate plant material may consist essentially of thyme particles, or may be a mixture of thyme particles with tobacco particles, cannabis particles, or both tobacco particles and cannabis particles.

[0099] As mentioned above, the inventors have identified a number of "signature compounds" that are characteristic of the thyme plant and, therefore, are indicative of the presence of thyme plant particles within the aerosol-generating substrate.

[0100] The amount of characteristic compounds present in pure thyme particles is expected to differ from the amount present in the aerosol-generating substrate. The substrate fabrication process, including hydration in a slurry or suspension and drying at elevated temperatures, and the presence of other components, such as aerosol formers, will differentially modify the amount of each characteristic compound. The integrity of the thyme particles and the stability of the compounds under temperature and operating conditions during fabrication can affect the final amount of compound present in the substrate. Therefore, it is contemplated that the ratio of characteristic compounds to each other will differ after the thyme particles are incorporated into substrates in various physical forms, such as sheets, strands, and granules.

[0101] The presence of thyme in the aerosol-generating substrate and the proportion of thyme provided in the aerosol-generating substrate can be determined by measuring the amount of characteristic compounds in the substrate and comparing this to the corresponding amount of characteristic compounds in pure thyme material. The presence and amount of characteristic compounds can be determined using any suitable technique that would be known to one skilled in the art.

[0102] In a suitable technique, a 250-milligram sample of aerosol-generating substrate is mixed with 5 milliliters of methanol and extracted by shaking, stirring for 5 minutes, and centrifugation (4500 g, 10°C, 5 minutes). An aliquot of the extract (300 microliters) is transferred to a silanized chromatography vial and diluted with methanol (600 microliters) and internal standard (ISTD) solution (100 microliters). The vial is closed and mixed for 5 minutes using an Eppendorf ThermoMixer (5°C, 2000 rpm). Samples from the resulting extract are analyzed by LC-HRAM-MS in a combination of full scan and data-dependent fragmentation modes for identification of characteristic compounds.

[0103] In some embodiments, the homogenized thyme material further comprises up to about 75 weight percent tobacco particles on a dry weight basis.

[0104] For example, the homogenized thyme material preferably contains, on a dry weight basis, about 10 weight percent to about 75 weight percent tobacco particles, more preferably about 15 weight percent to about 70 weight percent tobacco particles, even more preferably about 20 weight percent to about 65 weight percent tobacco particles, even more preferably about 25 weight percent to about 60 weight percent tobacco particles, and even more preferably about 30 weight percent to about 70 weight percent tobacco particles.

[0105] In some preferred embodiments, the homogenized thyme material comprises, on a dry weight basis, from about 5 percent to about 25 percent by weight thyme particles and from about 50 percent to about 70 percent by weight tobacco particles.

[0106] In the aerosol-generating article according to the first preferred embodiment of the present invention, the homogenized thyme material, as defined above, preferably comprises, on a dry weight basis, about 50 weight percent to about 75 weight percent tobacco particles, more preferably about 55 weight percent to about 70 weight percent tobacco particles, and more preferably about 60 weight percent to about 65 weight percent tobacco particles. For example, the homogenized thyme material according to the first embodiment may comprise, on a dry weight basis, about 5 weight percent to about 25 weight percent thyme particles and about 50 weight percent to about 70 weight percent tobacco particles.

[0107] In the aerosol-generating article according to the second preferred embodiment of the present invention, the homogenized thyme material, as defined above, preferably comprises, on a dry weight basis, about 5 weight percent to about 65 weight percent tobacco particles, more preferably about 10 weight percent to about 60 weight percent tobacco particles, and more preferably about 20 weight percent to about 55 weight percent tobacco particles. For example, the homogenized thyme material according to the second embodiment may comprise, on a dry weight basis, about 2.5 weight percent to about 65 weight percent thyme particles and about 1 weight percent to about 65 weight percent tobacco particles.

[0108] The weight ratio of thyme particles to tobacco particles in the particulate plant material forming the homogenized thyme material can vary depending on the desired flavor characteristics and composition of the aerosol. Preferably, the homogenized thyme material contains a weight ratio of thyme particles to tobacco particles of about 1:3 or less, meaning that the thyme particles account for 33.3% or less of the total particulate plant material. More preferably, the homogenized thyme material contains a weight ratio of thyme particles to tobacco particles of 1:4 or less, and more preferably, 1:5 or less.

[0109] For example, in a first preferred embodiment, the weight ratio of thyme particles to tobacco particles is about 1:2.33. A ratio of 1:2.33 corresponds to a particulate plant material consisting of about 30% by weight thyme particles and about 70% by weight tobacco particles. For a homogenized thyme material formed with about 75% by weight particulate plant material, this corresponds to about 22.5% by weight thyme particles and about 52.5% by weight tobacco particles in the homogenized thyme material, on a dry weight basis.

[0110] In another embodiment, the homogenized thyme material comprises a weight ratio of thyme particles to tobacco particles of 1:9. In yet another embodiment, the homogenized thyme material comprises a weight ratio of thyme particles to tobacco particles of 1:30.

[0111] For purposes of the present invention, the term "tobacco particles" describes particles of any plant material of the Nicotiana species. The term "tobacco particles" encompasses ground or powdered tobacco lamina, ground or powdered tobacco stems, tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. In preferred embodiments, the tobacco particles are derived substantially entirely from tobacco lamina. In contrast, isolated nicotine and nicotine salts, although tobacco-derived compounds, are not considered tobacco particles for purposes of the present invention and are not included in the proportion of particulate plant material.

[0112] The tobacco particles may be prepared from one or more tobacco plant varieties. Any type of tobacco may be used in the blend. Examples of types of tobacco materials that may be used include, but are not limited to, sun-cured tobacco, flue-cured tobacco, burley tobacco, Maryland tobacco, Orient tobacco, Virginia tobacco, and other specialty tobaccos.

[0113] Flame-curing is a tobacco curing method used specifically with Virginia tobacco. During the flue-curing process, heated air is circulated through tightly packed tobacco. During the first stage, the tobacco leaves yellow and wither. During the second stage, the leaf lamina dries completely. During the third stage, the leaf stem dries completely.

[0114] Burley tobacco plays an important role in many tobacco blends. It has a unique flavor and aroma and the ability to absorb large amounts of casing.

[0115] Orient is a type of tobacco with small leaves and high aromatic qualities. However, Orient tobacco has a milder flavor than, for example, Burley. Therefore, Orient tobacco is generally used in relatively small proportions in tobacco blends.

[0116] Kasturi, Madura, and Jatim are subtypes of sun-cured tobacco that can be used. Preferably, Kasturi and flue-cured tobaccos are blended to produce tobacco particles. Thus, the tobacco particles in the particulate plant material can comprise a blend of Kasturi and flue-cured tobaccos.

[0117] The tobacco particles may have a nicotine content of at least about 2.5 weight percent on a dry weight basis. More preferably, the tobacco particles may have a nicotine content of at least about 3 weight percent on a dry weight basis, even more preferably at least about 3.2 weight percent, even more preferably at least about 3.5 weight percent, and most preferably at least about 4 weight percent. When the aerosol-generating substrate comprises tobacco particles in combination with thyme particles, the tobacco with the higher nicotine content preferably maintains a similar level of nicotine to a typical aerosol-generating substrate without thyme particles, since the total amount of nicotine would otherwise be reduced due to the substitution of thyme particles for tobacco particles.

[0118] As a result of the inclusion of tobacco particles, the aerosol-generating substrates and the aerosols generated therefrom of these embodiments contain a particular proportion of "signature compounds" of tobacco. Characteristic compounds generated from tobacco include, but are not limited to, anatabine, cotinine, and damascenone.

[0119] Nicotine may optionally be incorporated into the aerosol-generating substrate, which for purposes of the present invention is considered a non-tobacco material. The nicotine may comprise one or more nicotine salts selected from the list consisting of nicotine lactate, nicotine citrate, nicotine pyruvate, nicotine bitartrate, nicotine benzoate, nicotine pectinate, nicotine alginate, and nicotine salicylate. The nicotine may be incorporated in addition to low-nicotine tobacco, or the nicotine may be incorporated into an aerosol-generating substrate having reduced or no tobacco content.

[0120] In certain embodiments of the invention, the aerosol-generating substrate comprises a homogenized thyme material formed from particulate plant material consisting solely of thyme particles, having nicotine, such as a nicotine salt, incorporated into the aerosol-generating substrate.

[0121] Preferably, the aerosol-generating substrate comprises at least about 0.1 mg of nicotine per gram of substrate on a dry weight basis, more preferably at least about 0.5 mg of nicotine per gram of substrate, more preferably at least about 1 mg of nicotine per gram of substrate, more preferably at least about 1.5 mg of nicotine per gram of substrate, more preferably at least about 2 mg of nicotine per gram of substrate, more preferably at least about 3 mg of nicotine per gram of substrate, more preferably at least about 4 mg of nicotine per gram of substrate, more preferably at least about 5 mg of nicotine per gram of substrate on a dry weight basis.

[0122] Preferably, the aerosol-generating substrate contains, on a dry weight basis, a maximum of about 50 mg of nicotine per gram of substrate, more preferably, a maximum of about 45 mg of nicotine per gram of substrate, more preferably, a maximum of about 40 mg of nicotine per gram of substrate, more preferably, a maximum of about 35 mg of nicotine per gram of substrate, more preferably, a maximum of about 30 mg of nicotine per gram of substrate, more preferably, a maximum of about 25 mg of nicotine per gram of substrate, more preferably, a maximum of about 20 mg of nicotine per gram of substrate.

[0123] For example, the aerosol-generating substrate may contain, on a dry weight basis, from about 0.1 mg to about 50 mg of nicotine per gram of substrate, or from about 0.5 mg to about 45 mg of nicotine per gram of substrate, or from about 1 mg to about 40 mg of nicotine per gram of substrate, or from about 2 mg to about 35 mg of nicotine per gram of substrate, or from about 5 mg to about 30 mg of nicotine per gram of substrate, or from about 10 mg to about 25 mg of nicotine per gram of substrate, or from about 15 mg to about 20 mg of nicotine per gram of substrate. In certain preferred embodiments of the invention, the aerosol-generating substrate contains, on a dry weight basis, from about 1 mg to about 20 mg of nicotine per gram of substrate.

[0124] The defined range of nicotine content for the aerosol-generating substrate includes all forms of nicotine that may be present in the aerosol-generating substrate, including nicotine inherently present in the tobacco material, as well as nicotine optionally added separately to the aerosol-generating substrate, for example in the form of a nicotine salt.

[0125] As an alternative to, or in addition to, including tobacco particles in the homogenized thyme material of an aerosol-generating substrate according to the present invention, the homogenized thyme material may include up to 75 weight percent cannabis particles on a dry weight basis. The term "cannabis particles" refers to particles of cannabis plants, such as Cannabis sativa, Cannabis indica, and Cannabis ruderalis.

[0126] For example, the particulate plant material may comprise, on a dry weight basis, from about 40 weight percent to about 75 weight percent cannabis particles, more preferably from about 45 weight percent to about 60 weight percent tobacco particles, and more preferably from about 50 weight percent to about 65 weight percent tobacco particles.

[0127] One or more cannabinoid compounds may optionally be incorporated into the aerosol-generating substrate, but this is considered a non-cannabis material for purposes of the present invention. As used herein with respect to the present invention, the term "cannabinoid compound" describes any one of a class of naturally occurring compounds found in parts of the cannabis plant, i.e., Cannabis sativa, Cannabis indica, and Cannabis ruderalis. Cannabinoid compounds are particularly concentrated in the female flower heads and are commonly sold as cannabis oil. Naturally occurring cannabinoid compounds in the cannabis plant include tetrahydrocannabinol (THC) and cannabidiol (CBD). In the context of the present invention, the term "cannabinoid compound" is used to describe both naturally occurring and synthetically produced cannabinoid compounds.

[0128] For example, the aerosol-generating substrate may comprise a cannabinoid compound selected from the group consisting of tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin (CBE), cannabicitran (CBT), and combinations thereof.

[0129] The homogenized thyme material may further comprise a proportion of other plant-flavored particles in addition to thyme particles or a combination of thyme particles and at least one of tobacco particles and cannabis particles ("particulate plant material").

[0130] For purposes of the present invention, the term "other botanical flavor particles" refers to particles of non-thyme, non-tobacco, and non-cannabis plant material capable of releasing one or more flavoring agents upon heating. This term is intended to exclude particles of inert plant material, such as cellulose, that do not contribute to the sensory output of the aerosol-generating substrate. The particles may be derived from crushed or powdered leaf laminae, fruits, petioles, stems, roots, seeds, buds, or peels from other plants. Suitable botanical flavor particles for inclusion in aerosol-generating substrates according to the present invention are known to those skilled in the art and include, but are not limited to, clove particles and tea particles.

[0131] The composition of the homogenized thyme material can advantageously be adjusted by blending desired amounts and types of different plant particles. This allows aerosol-generating substrates to be formed from a single homogenized thyme material, if desired, without the need to combine or mix different blends, as is the case, for example, in the production of conventional cut fillers. Thus, the manufacture of aerosol-generating substrates can potentially be simplified.

[0132] The particulate plant material used in the aerosol-generating substrate of the present invention can be adapted to provide a desired particle size distribution. The particle size distribution herein is described as a D value, whereby the D value refers to the percentage of particles having a diameter equal to or less than a given D value. For example, in a D95 particle size distribution, 95 percent of the particles have a diameter equal to or less than a given D95 value, and 5 percent of the particles have a diameter greater than the given D95 value. Similarly, in a D5 particle size distribution, 5 percent of the particles have a diameter equal to or less than the D5 value, and 95 percent of the particles have a diameter greater than the given D5 value. Thus, in combination, the D5 and D95 ​​values ​​provide an indication of the particle size distribution of the particulate plant material.

[0133] The particulate plant material can have a D95 value of 50 microns or more to 250 microns or less. This means that the particulate plant material can have a distribution represented by any D95 value within a given range. That is, the D95 can be 50 microns, or the D95 can be 60 microns, or the D95 can be up to 250 microns. By providing a D95 value within this range, the inclusion of relatively large plant particles in the homogenized thyme material is avoided. This is desirable because aerosol generation from such large plant particles is likely to be relatively inefficient. Furthermore, the inclusion of large plant particles in the homogenized thyme material can adversely affect the consistency of the material.

[0134] The particulate plant material preferably has a D95 value of from about 50 microns or more to about 250 microns or less, more preferably from about 75 microns or more to about 200 microns or less. Both the particulate thyme material and the particulate tobacco material preferably have a D95 value of from about 50 microns or more to about 250 microns or less, more preferably from about 75 microns or more to about 200 microns or less.

[0135] Preferably, the particulate plant material may have a D5 value of about 1 micron or more to about 8 microns or less, and more preferably about 2 microns or more to about 6 microns or less. Providing a D5 value within this range avoids the inclusion of very small dust particles in the homogenized thyme material, which may be desirable from a manufacturing standpoint.

[0136] In some embodiments, the particulate plant material may be intentionally ground to form particles having a desired particle size distribution. The use of intentionally ground plant material advantageously improves the homogeneity of the particulate plant material and the consistency of the homogenized thyme material.

[0137] The diameter of 100 percent of the particulate plant material may be about 400 microns or less, more preferably about 300 microns or less. The diameter of 100 percent of the particulate thyme material and 100 percent of the particulate tobacco material may be about 400 microns or less, more preferably about 300 microns or less. The particle size range of the thyme particles allows them to be combined with tobacco particles in existing cast leaf processes.

[0138] The homogenized thyme material preferably comprises, on a dry weight basis, at least about 55 weight percent particulate plant material, more preferably at least about 60 weight percent particulate plant material, and more preferably at least about 65 weight percent particulate plant material, including thyme particles as described above. The homogenized thyme material preferably comprises, on a dry weight basis, not more than about 95 weight percent particulate plant material, more preferably not more than about 90 weight percent particulate plant material, and even more preferably not more than about 85 weight percent particulate plant material. For example, the homogenized thyme material may comprise, on a dry weight basis, from about 55 weight percent to about 95 weight percent particulate plant material, or from about 60 weight percent to about 90 weight percent particulate plant material, or from about 65 weight percent to about 85 weight percent particulate plant material. In one particularly preferred embodiment, the homogenized thyme material comprises, on a dry weight basis, about 75 weight percent particulate plant material.

[0139] Preferably, in the homogenized thyme material of the first preferred embodiment, the total weight of particulate plant material, as described above, is about 75 weight percent or less on a dry weight basis.

[0140] Preferably, in the homogenized thyme material of the second preferred embodiment, the total weight of particulate plant material, as described above, is about 75 weight percent or less on a dry weight basis, or about 65 weight percent or less on a dry weight basis.

[0141] Thus, the particulate plant material is combined with one or more other ingredients to form a homogenized thyme material.

[0142] As defined above, the homogenized thyme material further includes an aerosol former. Upon volatilization, the aerosol former can carry other vaporized compounds, such as nicotine and flavorings in the aerosol, that are released from the aerosol-generating substrate upon heating. The aerosolization of a particular compound from an aerosol-generating substrate is not determined solely by its boiling point. The amount of a compound aerosolized can be affected by the physical form of the substrate as well as other components present in the substrate. The stability of the compound under the temperature and time frame of aerosolization also affects the amount of compound present in the aerosol.

[0143] Aerosol formers suitable for inclusion in the homogenized thyme material are known in the art and include, but are not limited to, polyhydric alcohols (such as triethylene glycol, propylene glycol, 1,3-butanediol, and glycerol), esters of polyhydric alcohols (such as glycerol mono-, di-, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate and tetradecanedioate). The homogenized thyme material can contain a single aerosol former or a combination of two or more aerosol formers.

[0144] When the substrate is intended for use in an aerosol-generating article for an electrically operated aerosol-generating system having a heating element, the aerosol former is preferably glycerol.

[0145] The amount of aerosol former may be adapted depending on the composition of the homogenized thyme material, such as the type or amount of plant particles, to achieve an aerosol having a desired level of flavor compounds from the plant particles. The amount of aerosol former may also be adapted depending on the intended method for heating the aerosol-generating substrate during use, in particular the temperature to which the aerosol-generating substrate will be heated during heating of the aerosol-generating article in the associated aerosol-generating device.

[0146] The homogenized thyme material preferably has an aerosol former content of from about 5 weight percent to about 55 weight percent on a dry weight basis, such as from about 10 weight percent to about 45 weight percent on a dry weight basis, or from about 15 weight percent to about 40 weight percent on a dry weight basis.

[0147] The aerosol former content may be from about 5 weight percent to about 30 weight percent on a dry weight basis. For example, in a homogenized thyme material according to the first preferred embodiment of the present invention, the aerosol former content, as defined above, is preferably from about 5 weight percent to about 30 weight percent on a dry weight basis, more preferably from about 10 weight percent to about 25 weight percent, and more preferably from about 15 weight percent to about 20 weight percent.

[0148] Alternatively, the aerosol former content may be from about 15 weight percent to about 55 weight percent on a dry weight basis. For example, in a homogenized thyme material according to the second preferred embodiment of the present invention, the aerosol former content, as defined above, is preferably from about 15 weight percent to about 55 weight percent on a dry weight basis, more preferably from about 25 weight percent to about 50 weight percent, and more preferably from about 35 weight percent to about 45 weight percent.

[0149] In other embodiments, the homogenized thyme material may have an aerosol former content of about 1 percent to about 5 percent by weight on a dry weight basis. For example, if the substrate is intended for use in an aerosol-generating article in which the aerosol former is held in a reservoir separate from the substrate, the substrate may have an aerosol former content of greater than 1 percent and less than about 5 percent. In such embodiments, the aerosol former volatilizes upon heating, and the aerosol former stream contacts the aerosol-generating substrate so as to incorporate flavors from the aerosol-generating substrate into the aerosol.

[0150] The aerosol former may act as a wetting agent in the aerosol-generating substrate.

[0151] As defined above, the homogenized thyme material further comprises a binder for modifying the mechanical properties of the particulate plant material, wherein the binder is included in the homogenized thyme material during production as described herein. Suitable exogenous binders are well known to those skilled in the art and include, but are not limited to, gums such as guar gum, xanthan gum, gum arabic, and locust bean gum; cellulose-based binders such as cellulose ethers such as hydroxypropyl cellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose, methyl cellulose, and ethyl cellulose; polysaccharides such as starch; organic acids such as alginic acid; conjugate base salts of organic acids such as sodium alginate, agar, and pectin; and combinations thereof. Preferably, the binder comprises guar gum.

[0152] Preferably, the binder is present in an amount of from about 1 weight percent to about 10 weight percent, preferably from about 2 weight percent to about 9 weight percent, and more preferably from about 3 weight percent to about 8 weight percent on a dry weight basis.

[0153] In certain embodiments, the homogenized thyme material comprises, on a dry weight basis, about 1 weight percent to about 10 weight percent of a binder, most preferably guar gum. For example, in an aerosol-generating article according to a first preferred embodiment of the present invention, the homogenized thyme material, as defined above, preferably comprises, on a dry weight basis, about 1 weight percent to about 10 weight percent of a binder, most preferably guar gum. For example, the homogenized thyme material of the first preferred embodiment may comprise about 2.5 weight percent to about 25 weight percent of thyme particles, about 5 weight percent to about 30 weight percent of an aerosol former, and about 1 weight percent to about 10 weight percent of a binder.

[0154] In certain embodiments, the homogenized thyme material preferably comprises, on a dry weight basis, about 2 to about 10 weight percent of a binder, most preferably a cellulose ether. For example, in the aerosol-generating article according to the second preferred embodiment, as defined above, the homogenized thyme material preferably comprises, on a dry weight basis, about 2 to about 10 weight percent of a binder, most preferably a cellulose ether. A particularly preferred binder is carboxymethylcellulose (CMC). For example, the homogenized thyme material of the second preferred embodiment may comprise about 2.5 to about 65 weight percent thyme particles, about 15 to about 55 weight percent aerosol former, and about 2 to about 10 weight percent cellulose ether.

[0155] Additionally, the homogenized thyme material of any embodiment may optionally further comprise additional cellulose. For example, the homogenized thyme material may comprise from about 5 weight percent to about 50 weight percent additional cellulose.

[0156] As used herein, the term "additional cellulose" encompasses any cellulosic material incorporated into the homogenized thyme material that is not derived from the thyme particles or tobacco particles provided therein. Thus, the additional cellulose is incorporated into the homogenized thyme material in addition to the thyme plant material or tobacco material as a separate and distinct cellulose source relative to any cellulose inherently provided within the thyme particles or tobacco particles. The additional cellulose is typically derived from a plant different from the thyme particles or tobacco particles. Preferably, the additional cellulose is in the form of an inert cellulose material that is sensorily inert and therefore does not substantially affect the sensory properties of the aerosol generated from the aerosol-generating substrate. For example, the additional cellulose is preferably a tasteless and odorless material.

[0157] The additional cellulose may consist of one type of cellulose material, or may be a combination of different types of cellulose materials that provide different properties, as described in more detail below.

[0158] It is believed that the additional cellulose incorporated into the homogenized thyme material that forms the aerosol-generating substrate of the aerosol-generating article according to the present invention provides additional structure and reinforcement to bind and support the plant particles and aerosol formers within the homogenized material.

[0159] The incorporation of additional cellulose has been found to be particularly beneficial in homogenized thyme materials in which the binder comprises a cellulose ether, as described above. The combination of cellulose ether and additional cellulosic material at specific, defined levels and within defined ratios has been found to advantageously provide homogenized thyme materials with improved tensile strength and homogeneity.

[0160] Producing a homogenized thyme material with acceptable tensile strength using certain types of binder materials can be technically difficult when the proportion of thyme particles exceeds a certain level. With some binder materials, it has been found that above a threshold level of thyme particles, the homogenized thyme material has low tensile strength and a non-uniform texture. If the tensile strength of the homogenized thyme material is too low, it is brittle and cannot be effectively processed to form an aerosol-generating substrate, especially on an industrial scale.

[0161] The inventors of the present application have discovered that by using a specific combination of cellulose ether and additional cellulose in the homogenized thyme material, as defined above, a more effective binding effect of the thyme particles can be achieved, and the resulting homogenized thyme material has significantly higher tensile strength. Therefore, the resulting homogenized thyme material can be easily processed to form an aerosol-generating substrate using existing high-speed equipment and techniques.

[0162] Preferably, the ratio of additional cellulosic material to cellulose ether in the homogenized thyme material is at least 2.

[0163] Preferably, the additional cellulose comprises cellulose powder. The term "cellulose powder" is used herein to refer to a purified cellulose-based material in powder form derived from cellulose fibers. The cellulose powder is preferably formed of particles with an average particle size of less than 100 microns. The cellulose powder may be in the form of microcrystalline cellulose. Suitable cellulose powders for use in the present invention are available as microcrystalline cellulose types SK-105 or SK-101, or cellulose powder type M-60, from Gumix International, Inc. (New Jersey).

[0164] Preferably, the amount of cellulose powder corresponds to at least about 5 weight percent homogenized thyme material, more preferably at least about 6 weight percent homogenized thyme material, more preferably at least about 7 weight percent homogenized thyme material, and even more preferably at least about 8 weight percent homogenized thyme material, on a dry weight basis.

[0165] The amount of cellulose powder may be adjusted above this minimum level depending on the weight of other components in the homogenized thyme material, particularly the weight of plant particles. In certain embodiments, the cellulose powder can replace a proportion of the plant particles in the homogenized thyme material without significantly affecting the properties of the generated aerosol.

[0166] Preferably, the amount of cellulose powder corresponds to about 45 weight percent or less of the homogenized thyme material, on a dry weight basis, and more preferably to about 40 weight percent or less of the homogenized thyme material.

[0167] In certain embodiments, such as those having a relatively high level of particulate plant material in the homogenized thyme material, the amount of cellulose powder may be relatively low. In such embodiments, the amount of cellulose powder may be, on a dry weight basis, from about 5 weight percent to about 15 weight percent of the homogenized thyme material, or from about 6 weight percent to about 12 weight percent of the homogenized thyme material, or from about 7 weight percent to about 11 weight percent of the homogenized thyme material, or from about 8 weight percent to about 10 weight percent of the homogenized thyme material.

[0168] In other embodiments, such as those having a relatively low level of particulate plant material in the homogenized thyme material, the amount of cellulose powder may be relatively higher. In such embodiments, the amount of cellulose powder may be from about 15 weight percent to about 45 weight percent of the homogenized thyme material, or from about 20 weight percent to about 40 weight percent of the homogenized thyme material, or from about 25 weight percent to about 35 weight percent of the homogenized thyme material, on a dry weight basis.

[0169] Preferably, when the homogenized thyme material comprises cellulose ether and cellulose powder, the weight ratio of cellulose powder to cellulose ether in the homogenized plant material is at least about 1.5, i.e., the amount of cellulose powder is at least 1.5 times the amount of cellulose ether. More preferably, the weight ratio of cellulose powder to cellulose ether in the homogenized thyme material is at least about 1.6, and even more preferably at least about 1.8.

[0170] Instead of or in addition to cellulose powder, the additional cellulose may include cellulose fibers. The term "cellulose fibers" as used herein refers to fibers obtained directly from plant-derived materials, each fiber having a length significantly greater than its width. Preferably, the cellulose fibers have a fiber length of at least 400 microns. Suitable cellulose fibers for use in the present invention include, for example, wood pulp fibers. A suitable source of cellulose fibers for use in the present invention is available as ECF bleached hardwood kraft pulp from Storaenso (Sweden).

[0171] Cellulose fibres may advantageously act as mechanical reinforcement in the homogenised thyme material that forms the aerosol-generating substrate of the aerosol-generating article according to the invention, improving the bonding of plant particles in the homogenised thyme material and providing improved tensile strength, particularly when combined with a cellulose ether binder.

[0172] Preferably, the amount of cellulose reinforcing fiber corresponds to at least about 3 weight percent homogenized thyme material, more preferably at least about 4 weight percent homogenized thyme material, more preferably at least about 5 weight percent homogenized thyme material, and even more preferably at least about 6 weight percent homogenized thyme material, on a dry weight basis.

[0173] Preferably, the amount of cellulose reinforcing fiber corresponds to about 12 weight percent or less of homogenized thyme material, more preferably at least about 11 weight percent of homogenized thyme material, more preferably at least about 10 weight percent of homogenized thyme material, and even more preferably at least about 8 weight percent of homogenized thyme material, on a dry weight basis.

[0174] For example, the homogenized thyme material may contain, on a dry weight basis, from about 3 weight percent to about 12 weight percent cellulose fiber, or from about 4 weight percent to about 11 weight percent cellulose fiber, or from about 5 weight percent to about 10 weight percent cellulose fiber, or from about 6 weight percent to about 8 weight percent cellulose fiber.

[0175] Preferably, when the homogenized thyme material contains cellulose ether and cellulose fiber, the weight ratio of cellulose fiber to cellulose ether in the homogenized thyme material is at least about 0.5, i.e., the amount of cellulose powder is at least half the amount of cellulose ether. More preferably, the weight ratio of cellulose fiber to cellulose ether in the homogenized thyme material is at least about 0.75, and even more preferably at least about 1.

[0176] In preferred embodiments, the additional cellulose comprises cellulose powder and cellulose fiber, and in such embodiments, the weight ratio of cellulose powder to cellulose fiber is preferably at least about 1.5, more preferably at least about 1.75, and even more preferably at least about 2.

[0177] Preferably, the amount of additional cellulose provided in the homogenized thyme material corresponds to a total of no more than 75 weight percent of the homogenized thyme material in terms of the total amount of additional cellulose and plant particles. Accordingly, it is preferred that at least about 25 weight percent of the homogenized thyme material be provided by the cellulose ether and other components, including the aerosol former.

[0178] In the aerosol-generating article according to the second preferred embodiment of the present invention, the homogenized thyme material preferably comprises, on a dry weight basis, from about 2 weight percent to about 10 weight percent cellulose ether and from about 5 weight percent to about 50 weight percent additional cellulose. Preferably, the ratio of additional cellulose to cellulose ether is at least 2.

[0179] For example, a homogenized thyme material according to a second preferred embodiment of the present invention may comprise, on a dry weight basis, 2.5 to 75 weight percent thyme particles, 15 to 55 weight percent aerosol former, on a dry weight basis, 2 to 10 weight percent cellulose ether, and 3 to 50 weight percent additional cellulose. Preferably, such a homogenized thyme material further comprises at least about 1 weight percent tobacco particles, on a dry weight basis.

[0180] In addition to the above-mentioned components, the homogenized thyme material may optionally further comprise one or more lipids to enhance the diffusion rate of the volatile components (e.g., the aerosol former and nicotine), which lipids are included in the homogenized plant material during the preparation described herein. Suitable lipids for inclusion in the homogenized thyme material include, but are not limited to, medium chain triglycerides, cocoa butter, palm oil, palm kernel oil, mango oil, shea butter, soybean oil, cottonseed oil, coconut oil, hydrogenated coconut oil, candelilla wax, carnauba wax, shellac, sunflower wax, sunflower oil, rice bran, and Revell A, and combinations thereof.

[0181] Alternatively, or additionally, the homogenized thyme material may further comprise a pH adjuster.

[0182] Alternatively, or additionally, the homogenized thyme material may further comprise fibers to alter the mechanical properties of the homogenized thyme material, where the fibers are included in the homogenized thyme material during the manufacturing process described herein. Suitable exogenous fibers for inclusion in the homogenized thyme material are known in the art and include fibers formed from non-tobacco and non-thyme materials, including, but not limited to, cellulose fibers, softwood fibers, hardwood fibers, jute fibers, and combinations thereof. Exogenous fibers derived from tobacco and / or thyme may also be added. Any fibers added to the homogenized thyme material are not considered to form part of the "particulate plant material" defined above. Prior to inclusion in the homogenized thyme material, the fibers may be processed by a suitable process known in the art, including, but not limited to, mechanical pulping, refining, chemical pulping, bleaching, sulfate pulping, and combinations thereof. Typically, the fibers have a length greater than their width.

[0183] Suitable fibers are typically greater than 400 micrometers and have lengths of 4 mm or less, preferably in the range of 0.7 mm to 4 mm. Preferably, the fibers are present in an amount of at least about 2 weight percent, based on the dry weight of the substrate. The amount of fiber in the homogenized thyme material may depend on the type of material, particularly the method used to produce the homogenized thyme material. In some embodiments, the fibers may be present in an amount of about 2 weight percent to about 15 weight percent, most preferably about 4 weight percent, based on the dry weight of the substrate. For example, this level of fiber may be present where the homogenized plant material is in the form of cast leaves. In other embodiments, the fibers may be present in an amount of at least about 30 weight percent, or at least about 40 weight percent. For example, this higher level of fiber is likely to be provided when the homogenized thyme material is thyme paper formed in a papermaking process.

[0184] In a preferred embodiment of the present invention, the homogenized thyme material comprises, on a dry weight basis, about 5 to about 30 weight percent of an aerosol former, and about 1 to about 10 weight percent of a binder. In such an embodiment, the homogenized thyme material preferably further comprises about 2 to about 15 weight percent of fiber. A particularly preferred binder is guar gum.

[0185] The homogenized plant material in the aerosol-generating substrate according to the present invention may comprise a single type of homogenized plant material, or two or more types of homogenized plant material having different compositions or morphologies. For example, in one embodiment, the aerosol-generating substrate comprises thyme particles and tobacco or cannabis particles contained within the same sheet of homogenized plant material. However, in other embodiments, the aerosol-generating substrate may comprise tobacco or cannabis particles and thyme particles within different sheets.

[0186] The homogenized thyme material is preferably in the form of a solid or gel. However, in some embodiments, the homogenized material may be in the form of a solid that is not a gel. The homogenized material is preferably not in the form of a film.

[0187] The homogenized thyme material can be provided in any suitable form. For example, the homogenized thyme material can be in the form of one or more sheets. As used herein with respect to the present invention, the term "sheet" describes a laminar element having a width and length that is substantially greater than its thickness.

[0188] Alternatively, or additionally, the homogenized thyme material may be in the form of a plurality of pellets or granules.

[0189] Alternatively, or additionally, the homogenized thyme material may be in a form that can fill a cartridge or shisha consumable, or be used in a shisha device. The present invention includes a cartridge or shisha device that includes the homogenized thyme material.

[0190] Alternatively, or additionally, the homogenized thyme material may be in the form of multiple strands, strips, or pieces. As used herein, the term "strand" describes an elongated element of material having a length substantially greater than its width and thickness. The term "strand" is intended to encompass strips, pieces, and any other homogenized thyme material having a similar form. Strands of homogenized thyme material may be formed from a sheet of homogenized thyme material, for example, by cutting or chopping, or by other methods, such as extrusion.

[0191] In some embodiments, the strands may be formed in situ within the aerosol-generating substrate as a result of splitting or cracking of a sheet of homogenized thyme material during the formation of the aerosol-generating substrate, e.g., as a result of crimping. The strands of homogenized thyme material within the aerosol-generating substrate may be separated from one another. Alternatively, each strand of homogenized thyme material within the aerosol-generating substrate may be at least partially connected to adjacent strands along its length. For example, adjacent strands may be connected by one or more fibers. This may occur, for example, when strands are formed due to splitting of a sheet of homogenized thyme material during the manufacture of the aerosol-generating substrate, as described above.

[0192] The aerosol-generating substrate is preferably in the form of one or more sheets of homogenized thyme material. In various embodiments of the present invention, the one or more sheets of homogenized thyme material may be produced by a casting process. In various embodiments of the present invention, the one or more sheets of homogenized thyme material may be produced by a papermaking process. The one or more sheets described herein may each individually have a thickness of 100 micrometers to 600 micrometers, preferably 150 micrometers to 300 micrometers, and most preferably 200 micrometers to 250 micrometers. Individual thickness refers to the thickness of an individual sheet, while combined thickness refers to the total thickness of all sheets comprising the aerosol-generating substrate. For example, if the aerosol-generating substrate is formed from two individual sheets, the combined thickness is the thickness of the two individual sheets, or the sum of the measured thicknesses of the two sheets, stacked within the aerosol-generating substrate.

[0193] One or more of the sheets described herein may each individually have a weight of about 100 g / m 2 ~about 300g / m 2 , or approximately 100 g / m 2 ~about 200g / m 2 The sheet may have a basis weight of

[0194] One or more of the sheets described herein may each individually have a density of about 0.3 g / cm 3 ~Approx. 1.3g / cm 3 and may have a density of about 0.7 g / cm 3 ~Approx. 1.0g / cm 3 It is preferred that the density of the cellulose acylate is 0.05 to 0.15.

[0195] The term "tensile strength" is used throughout this specification to refer to the measurement of the force required to stretch a sheet of homogenized time material to failure. More specifically, tensile strength is the maximum pulling force per unit width that the sheet material will withstand before failure, measured in either the machine direction or the cross direction of the sheet material. It is expressed in units of Newtons per meter of material (N / m). Tests for measuring the tensile strength of sheet materials are well known. A suitable test is described in the 2014 edition of International Standard ISO 1924-2, entitled "Paper and paperboard - Test methods for tensile properties - Part 2: Constant rate of extension method."

[0196] The materials and equipment required to perform the test in accordance with ISO 1924-2 are a general-purpose tension / compression testing machine (Instron 5566 or equivalent), a 100 Newton tensile load cell (Instron or equivalent), two pneumatically operated grips, a 180 ± 0.25 mm long steel gauge block (approximately 10 mm wide and 3 mm thick), a double-blade strip cutter (size 15 ± 0.05 x approximately 250 mm, Adamel Lhomargy or equivalent), a scalpel, computer-operated acquisition software (Merlin or equivalent), and compressed air.

[0197] Samples are prepared by first conditioning a sheet of homogenized thyme material at 22±2 degrees Celsius and 60±5% relative humidity for at least 24 hours prior to testing. The samples are then cut into approximately 250 x 15±0.1 millimeters in either the machine or cross direction with a double-blade strip cutter. The edges of the test specimens should be neatly cut so that no more than three test specimens are cut at the same time.

[0198] The tension / compression testing device is set up by installing a 100 Newton tension load cell, powering on the general-purpose tension / compression testing machine and computer, selecting a predefined measurement method in the software, and setting the test speed to 8 mm / min. The tension load cell is then calibrated and pneumatic grips are attached. The test distance between the pneumatic grips is adjusted to 180 ± 0.5 mm using a steel gauge block, and the distance and force are set to zero.

[0199] The test specimen is then placed straight and centered between the grips, avoiding finger contact with the area being tested. The upper grips are closed and the paper strip is suspended in the open lower grip. The force is set to zero. The paper strip is gently pulled down and then the lower grips are closed, with an initial force of 0.05-0.20 Newtons. As the upper grips move upward, a gradually increasing force is applied until the test specimen breaks. The same procedure is repeated with the remaining test specimens. The result is valid when the test specimen breaks when the grips move apart a distance of more than 10 millimeters. If not, the result is rejected and additional measurements are performed.

[0200] If the available test specimen of homogenized thyme material is smaller than the sample described in the test according to ISO 1924-2, as described above, the test can be easily scaled down to accommodate the available size of the test specimen.

[0201] One or more sheets of the homogenized time material described herein may each individually have a tensile strength at the peak in the tolerance direction of 50 N / m to 400 N / m, or preferably 150 N / m to 350 N / m. Given that sheet thickness affects tensile strength and that batches of sheets may exhibit thickness variations, it may be desirable to normalize values ​​to a particular sheet thickness.

[0202] One or more sheets described herein may each individually have a tensile strength of 100 N / m to 800 N / m, or preferably 280 N / m to 620 N / m, at the peak in the machine direction, normalized to a sheet thickness of 215 μm. The machine direction refers to the direction in which the sheet material is wound onto or unwound from the bobbin and fed into the machine, and the tolerance direction is perpendicular to the machine direction. These values ​​of tensile strength make the sheets and methods described herein particularly suitable for subsequent operations involving mechanical stress.

[0203] Providing a sheet having the above-defined levels of thickness, basis weight, and tensile strength advantageously optimizes the machinability of the sheet to form aerosol-generating substrates and ensures that damage, such as tearing, to the sheet is avoided during high speed processing of the sheet.

[0204] In embodiments of the invention in which the aerosol-generating substrate comprises one or more sheets of homogenized thyme material, the sheets are preferably in the form of an assembly of one or more sheets. As used herein, the term "assembling" means that the sheets of homogenized thyme material are convoluted, folded, or otherwise compressed or contracted in a direction substantially transverse to the cylindrical axis of the plug or rod. The step of "assembling" the sheets may be carried out by any suitable means that provides the necessary transverse compression of the sheets.

[0205] As used herein, the term "longitudinal" refers to a direction corresponding to the major longitudinal axis of the aerosol-generating article, extending between the upstream and downstream ends of the aerosol-generating article. During use, air is drawn through the aerosol-generating article in the longitudinal direction. The term "transverse" refers to a direction perpendicular to the longitudinal axis. As used herein, the term "length" refers to the dimension of a component in the longitudinal direction, and the term "width" refers to the dimension of a component in the transverse direction. For example, in the case of a plug or rod having a circular cross-section, the maximum width corresponds to the diameter of the circle.

[0206] As used herein, the term "plug" refers to a generally cylindrical element having a substantially polygonal, circular, oval, or elliptical cross-section. As used herein, the term "rod" refers to a generally cylindrical element of a substantially polygonal cross-section, and preferably a circular, oval, or elliptical cross-section. A rod may have a length equal to or greater than the length of a plug. Typically, a rod has a length greater than the length of a plug. A rod may include one or more plugs, which are preferably aligned longitudinally.

[0207] As used herein, the terms "upstream" and "downstream" describe the relative location of an element (or portion of an element) of an aerosol-generating article with respect to the direction in which aerosol is transported through the aerosol-generating article during use. The downstream end of the airflow path is the end from which the aerosol is delivered to a user of the article.

[0208] One or more sheets of homogenized thyme material may be gathered transversely to their longitudinal axis and surrounded by a wrapper to form a continuous rod or plug. The continuous rod may be separated into a plurality of individual rods or plugs. The wrapper may be a paper wrapper or a non-paper wrapper, as described in more detail below.

[0209] Alternatively, one or more sheets of homogenized thyme material may be cut into strands, as mentioned above. In such embodiments, the aerosol-generating substrate comprises a plurality of strands of homogenized thyme material. The strands can be used to form plugs. Typically, the width of such strands is at least about 0.2 mm, or at least about 0.5 mm. Typically, the width of such strands is preferably about 5 mm, or about 4 mm, or about 3 mm, or about 1.5 mm or less. For example, the width of the strands can be about 0.25 mm to about 5 mm, or about 0.25 mm to about 3 mm, or about 0.5 mm to about 1.5 mm.

[0210] The length of the strands is preferably greater than about 5 mm, for example, about 5 mm to about 20 mm, or about 8 mm to about 15 mm, or about 12 mm. The strands preferably have substantially the same length as each other. The length of the strands may be determined by the manufacturing process, whereby the rod is cut into shorter plugs, and the length of the strands corresponds to the length of the plugs. The strands are fragile and may break, especially during transition. In such cases, the length of some of the strands may be shorter than the length of the plugs.

[0211] The strands preferably extend substantially longitudinally along the length of the aerosol-generating substrate, aligned with the longitudinal axis, and are therefore preferably aligned substantially parallel to one another.

[0212] The strands of homogenized thyme material preferably each have a mass-to-surface area ratio of at least about 0.02 milligrams per square millimeter, more preferably at least about 0.05 milligrams per square millimeter. The strands of homogenized thyme material preferably each have a mass-to-surface area ratio of no more than about 0.2 milligrams per square millimeter, more preferably no more than about 0.15 milligrams per square millimeter. The mass-to-surface area ratio is calculated by dividing the mass of the strands of homogenized thyme material in milligrams by the geometric surface area of ​​the strands of homogenized thyme material in square millimeters.

[0213] One or more sheets of homogenized thyme material may be textured by crimping, embossing, or perforation. One or more sheets may be textured before being gathered or before being cut into strands. Preferably, one or more sheets of homogenized thyme material are crimped prior to gathering so that the homogenized thyme material can be in the form of a crimped sheet, more preferably a collection of crimped sheets. As used herein, the term "crimped sheet" refers to a sheet having a plurality of substantially parallel ridges or corrugations that are generally aligned along the longitudinal axis of the article.

[0214] In one embodiment, the aerosol-generating substrate may be in the form of a single plug of aerosol-generating substrate. Preferably, the plug of aerosol-generating substrate may comprise multiple strands of homogenized thyme material. Most preferably, the plug of aerosol-generating substrate may comprise one or more sheets of homogenized thyme material. Preferably, the one or more sheets of homogenized thyme material may be crimped to have multiple ridges or corrugations substantially parallel to the cylindrical axis of the plug. This advantageously facilitates assembling the crimped sheets of homogenized thyme material to form a plug. Preferably, the one or more sheets of homogenized thyme material may be assembled. Of course, the crimped sheets of homogenized thyme material may alternatively or additionally have multiple substantially parallel ridges or corrugations that form acute or obtuse angles with respect to the cylindrical axis of the plug. The sheets may be crimped to an extent that the integrity of the sheet is interrupted at the multiple parallel ridges or corrugations, causing separation of the material and resulting in the formation of pieces, strands, or strips of homogenized thyme material.

[0215] In another embodiment of the aerosol-generating substrate, the homogenized plant material comprises a first plug containing a first homogenized plant material and a second plug containing a second homogenized plant material, wherein the first homogenized plant material and the second homogenized plant material contain different levels of thyme particles and tobacco particles. For example, the first homogenized plant material may contain, on a dry weight basis, about 50 weight percent to about 75 weight percent thyme particles, and the second homogenized plant material contains, on a dry weight basis, about 50 weight percent to about 75 weight percent tobacco particles. Overall, according to the present invention, the homogenized plant material within the aerosol-generating substrate preferably contains, on a dry weight basis, at least 2.5 weight percent thyme particles and up to 70 weight percent tobacco particles.

[0216] In such an arrangement, the first homogenized plant material preferably comprises a first particulate plant material having a higher proportion of thyme particles than the second homogenized plant material, which may be a homogenized tobacco material substantially free of thyme particles.

[0217] Preferably, the first homogenized plant material may be in the form of one or more sheets and the second homogenized plant material may be in the form of one or more sheets.

[0218] Optionally, the aerosol-generating substrate may include one or more plugs. Preferably, the substrate may include a first plug and a second plug, and the first homogenized plant material may be located within the first plug and the second homogenized plant material may be located within the second plug.

[0219] Two or more plugs may extend end-to-end in abutting relationship to form a rod. Two plugs may be longitudinally positioned with a gap between them, thereby creating a cavity within the rod. The plugs may be in any suitable arrangement within the rod.

[0220] For example, in a preferred arrangement, a downstream plug containing a predominant proportion of thyme particles may abut an upstream plug containing a predominant proportion of tobacco particles to form a rod. Alternative configurations are also contemplated in which the upstream and downstream positions of each plug are altered relative to one another. Alternative configurations are also contemplated in which a third homogenized plant material contains different proportions of thyme particles and tobacco particles to form a third plug. When two or more plugs are provided, the homogenized plant material may be provided in the same form in each plug or in different forms in each plug, i.e., aggregated or chopped. One or more plugs may optionally be individually or together packaged in a thermally conductive sheet material, as described below.

[0221] The first plug may comprise one or more sheets of the first homogenized plant material, and the second plug may comprise one or more sheets of the second homogenized plant material. The combined length of the plugs may be about 10 mm to about 40 mm, preferably about 10 mm to about 15 mm, and more preferably about 12 mm. The first plug and the second plug may have the same length or different lengths. If the first plug and the second plug have the same length, the length of each plug may preferably be about 6 mm to about 20 mm. The second plug may preferably be longer than the first plug to provide a desired ratio of tobacco particles to thyme particles in the substrate. Generally, the substrate may preferably comprise, on a dry weight basis, 0 to 75 weight percent tobacco particles and 2.5 to 75 weight percent thyme particles. The second plug is preferably at least 40 to 50 percent longer than the first plug.

[0222] When the first homogenized plant material and the second homogenized plant material are in the form of one or more sheets, the one or more sheets of the first homogenized plant material and the second homogenized plant material can preferably be a conglomerate of sheets. The one or more sheets of the first homogenized plant material and the second homogenized plant material can preferably be a crimped sheet. It should be understood that all other physical properties described with respect to embodiments in which a single homogenized plant material is present are equally applicable to embodiments in which a first homogenized plant material and a second homogenized plant material are present. Furthermore, it should be understood that descriptions of additives (e.g., binders, lipids, fibers, aerosol formers, humectants, plasticizers, flavors, fillers, aqueous and non-aqueous solvents, and combinations thereof) with respect to embodiments in which a single homogenized plant material is present are equally applicable to embodiments in which a first homogenized plant material and a second homogenized plant material are present.

[0223] In yet another embodiment of the aerosol-generating substrate, the first homogenized plant material is in the form of a first sheet and the second homogenized plant material is in the form of a second sheet, the second sheet at least partially overlying the first sheet.

[0224] The first sheet may be a textured sheet and the second sheet may be a non-textured sheet.

[0225] Both the first and second sheets may be textured sheets.

[0226] The first sheet may be a textured sheet that is textured differently than the second sheet. For example, the first sheet may be crimped and the second sheet may be perforated. Alternatively, the first sheet may be perforated and the second sheet may be crimped.

[0227] Both the first and second sheets may be morphologically differently crimped sheets, for example, the second sheet may be crimped with a different number of crimps per sheet unit width compared to the first sheet.

[0228] The sheets may be assembled to form a plug. The sheets that assemble to form a plug may have different physical dimensions. The width and thickness of the sheets may vary.

[0229] It may be desirable to assemble two sheets, each having a different thickness, or each having a different width. This can vary the physical properties of the plug. This can facilitate the formation of a blended plug of aerosol-generating substrate from sheets of different chemical compositions.

[0230] The first sheet may have a first thickness and the second sheet may have a second thickness that is a multiple of the first thickness, for example, the second sheet may have a thickness that is two or three times the first thickness.

[0231] The first sheet may have a first width and the second sheet may have a second width different from the first width.

[0232] The first sheet and the second sheet may be disposed in an overlapping relationship before or at the time of being assembled together. The sheets may have the same width and thickness. The sheets may have different thicknesses. The sheets may have different widths. The sheets may be textured differently.

[0233] If it is desired that both the first and second sheets be textured, the sheets may be textured simultaneously before being assembled. For example, the sheets may be placed in overlapping relationship and passed through a texturing means such as a pair of crimping rollers. Suitable apparatus and processes for simultaneous crimping are described with reference to Figure 2 of WO-A-2013 / 178766. In a preferred embodiment, a second sheet of the second homogenized plant material is placed on top of the first sheet of the first homogenized plant material, and the combined sheets assemble to form a plug of aerosol-generating substrate. Optionally, the sheets may be crimped together prior to assembly to facilitate assembly.

[0234] Alternatively, each sheet may be textured separately and then assembled together into a plug. For example, if the two sheets have different thicknesses, it may be desirable to crimp the first sheet differently relative to the second sheet.

[0235] It will be understood that all other physical properties described with respect to embodiments in which a single homogenized plant material is present are equally applicable to embodiments in which a first homogenized plant material and a second homogenized plant material are present. Additionally, it will be understood that the descriptions of additives (e.g., binders, lipids, fibers, aerosol formers, humectants, plasticizers, flavors, fillers, aqueous and non-aqueous solvents, and combinations thereof) with respect to embodiments in which a single homogenized plant material is present are equally applicable to embodiments in which a first homogenized plant material and a second homogenized plant material are present.

[0236] The homogenized plant material used in the aerosol-generating substrate according to the present invention may be produced by a variety of methods, including papermaking, casting, dough reconstitution, extrusion or any other suitable process.

[0237] The homogenized thyme material is preferably in the form of "cast leaf." The term "cast leaf" refers to a sheet product made by a casting process based on casting a slurry containing plant particles (e.g., thyme particles, or a mixture of tobacco and thyme particles) and a binder (e.g., guar gum) onto a support surface (e.g., a belt conveyor), drying the slurry, and removing the dried sheet from the support surface. An example of a casting or cast leaf process is described, for example, in U.S. Pat. No. 5,724,998 for making cast leaf tobacco. In the cast leaf process, particulate plant material is mixed with a liquid component, typically water, to form a slurry. Other added components in the slurry may include fibers, binders, and aerosol formers. The particulate plant material may be agglomerated in the presence of a binder. The slurry is cast onto a support surface and dried to form a sheet of homogenized thyme material.

[0238] In certain preferred embodiments, the homogenized thyme material used in articles according to the present invention is made by casting. Homogenized thyme material made by a casting process typically comprises agglomerated particulate plant material.

[0239] The cast leaf process advantageously preserves most of the flavor by retaining virtually all of the soluble fraction within the plant material, and also avoids the energy-intensive papermaking process.

[0240] In one preferred embodiment of the present invention, a mixture containing particulate plant material, water, a binder, and an aerosol former is formed to form a homogenized thyme material. A sheet is formed from the mixture, and the sheet is then dried. Preferably, the mixture is an aqueous mixture. As used herein, "dry weight" refers to the weight of the particulate non-water components relative to the total weight of all non-water components in the mixture, expressed as a percentage. The composition of an aqueous mixture may be referred to by "dry weight percent," which refers to the weight of the non-water components relative to the weight of the entire aqueous mixture, expressed as a percentage.

[0241] The mixture may be a slurry. As used herein, a "slurry" is a homogenized aqueous mixture having a relatively low dry weight. Preferably, the slurry used in the methods herein may have a dry weight of 5 to 60 percent.

[0242] Alternatively, the mixture may be a dough. As used herein, a "dough" is an aqueous mixture having a relatively high dry weight. Preferably, the dough used in the methods herein may have a dry weight of at least 60 percent, more preferably at least 70 percent.

[0243] Slurries containing greater than 30 percent dry weight and dough are preferred in certain embodiments of the process of the present invention.

[0244] The step of mixing the particulate plant material, water, and other optional ingredients can be carried out by any suitable means. For low-viscosity mixtures, i.e., some slurries, mixing is preferably carried out using a high-energy mixer or a high-shear mixer. Such mixing breaks down and uniformly distributes the various phases of the mixture. For high-viscosity mixtures, i.e., some lumps, a kneading process can be used to uniformly distribute the various phases of the mixture.

[0245] The method according to the present invention may further comprise a step of vibrating the mixture to distribute the various components. Vibrating the mixture, i.e., for example, vibrating the tank or silo in which the homogenized mixture is located, may help homogenize the mixture, especially if the mixture is a low-viscosity mixture, i.e., some slurries. When vibration is performed in addition to mixing, shorter mixing times may be required to homogenize the mixture to the optimum target value for casting.

[0246] When the mixture is a slurry, the web of homogenized thyme material is preferably formed by a casting process that includes casting the slurry onto a support surface, such as a belt conveyor. The method for producing homogenized thyme material includes drying the cast web to form a sheet. The cast web may be dried for a suitable length of time at room temperature or at an ambient temperature of at least about 60°C, more preferably at least about 80°C. The cast web is preferably dried at an ambient temperature not exceeding 200°C, more preferably not exceeding about 160°C. For example, the cast web may be dried at a temperature of about 60°C to about 200°C, or about 80°C to about 160°C. The moisture content of the dried sheet is preferably about 5% to about 15%, based on the total weight of the sheet. The sheet may then be removed from the support surface after drying. The cast sheet has tensile strength such that it can be mechanically manipulated and wound onto or unwound from a bobbin without breakage or deformation.

[0247] If the mixture is a dough mass, the dough mass may be extruded into sheets, strands, or strips prior to drying the extruded mixture. Preferably, the dough mass can be extruded into a sheet. The extruded mixture may be dried at room temperature or at a temperature of at least about 60°C, more preferably at least about 80°C, for a suitable length of time. The extruded mixture is preferably dried at ambient temperatures not exceeding 200°C, more preferably not exceeding about 160°C. For example, the extruded mixture may be dried at temperatures of about 60°C to about 200°C, or about 80°C to about 160°C. The moisture content of the extruded mixture after drying is preferably about 5 percent to about 15 percent, based on the total weight of the sheet. As a result of the significantly lower moisture content relative to webs formed from slurries, sheets formed from dough mass require less drying time and / or lower drying temperatures.

[0248] After drying the sheet, the method may optionally include coating a nicotine salt onto the sheet, preferably together with an aerosol former, as described in the disclosure of WO-A-2015 / 082652.

[0249] After drying the sheet, the method according to the present invention may optionally include cutting the sheet into strands, pieces, or strips to form the aerosol-generating substrate described above. The strands, pieces, or strips may be joined together using suitable means to form a rod of aerosol-generating substrate. In the formed rod of aerosol-generating substrate, the strands, pieces, or strips may be substantially aligned, for example, along the longitudinal axis of the rod. Alternatively, the strands, pieces, or strips may be randomly oriented within the rod.

[0250] The method according to the present invention may optionally further comprise winding the sheet onto a bobbin after the drying step. The present invention further provides an alternative papermaking method for producing a sheet of homogenized plant material in the form of plant "paper." Plant paper refers to a reconstituted plant sheet formed by a process of extracting plant material with a solvent to produce an extract of soluble plant compounds and an insoluble residue of fibrous plant material, and recombining the extract with the insoluble residue. The extract may optionally be concentrated or further processed before being recombined with the insoluble residue. The insoluble residue may optionally be purified and combined with additional plant fiber before being recombined with the extract. In the method according to the present invention, the plant material comprises thyme particles, optionally combined with tobacco particles.

[0251] More specifically, the method for producing plant paper involves a first step of mixing plant material with water to form a dilute suspension, which primarily contains discrete cellulose fibers. The suspension has a lower viscosity and a higher water content than the slurries produced in casting processes. This first step may involve soaking, optionally in the presence of an alkali such as sodium hydroxide, and optionally the application of heat.

[0252] The method further includes a second step of separating the suspension into an insoluble portion containing the insoluble residue of the fibrous plant material and a liquid or aqueous portion containing the soluble plant compounds. Water remaining in the insoluble residue of the fibrous plant material can be drained through a screen acting as a sieve to allow a web of randomly woven fibers to be laid down. Water can be further removed from this web by pressing with rollers, optionally with the assistance of suction or vacuum.

[0253] After the aqueous portion and water are removed, the insoluble residue is formed into a sheet, preferably a generally flat, uniform sheet of plant fiber.

[0254] Preferably, the method further comprises concentrating the extract of soluble plant compounds removed from the sheet and adding the concentrated extract to the sheet of insoluble residue of fibrous plant material to form a sheet of homogenized plant material. Alternatively or additionally, soluble plant material or concentrated plant material from another process may be added to the sheet. The extract or concentrated extract may be from a different variety of the same species of plant, or from a different species of plant.

[0255] This process has been used with tobacco to make reconstituted tobacco products, also known as tobacco paper, as described in U.S. Pat. No. 3,860,012. The same process may be used with one or more plants to produce paper-like sheet materials, such as sheets of thyme paper.

[0256] In certain preferred embodiments, the homogenized plant material used in the articles according to the invention is produced by the paper-making process defined above, in such embodiments, the homogenized thyme material is in the form of thyme paper.

[0257] Homogenized tobacco material or homogenized thyme material produced by such processes is called tobacco paper or thyme paper. Homogenized plant material produced by papermaking processes can be distinguished by the presence of multiple fibers throughout the material, visible to the eye or under an optical microscope, especially when the paper is moistened with water. In contrast, homogenized plant material produced by casting processes contains fewer fibers than paper and tends to separate into a slurry when moistened. Blended tobacco thyme paper refers to homogenized plant material produced by such processes using a mixture of tobacco and thyme materials.

[0258] In embodiments in which the aerosol-generating substrate comprises a combination of thyme particles and tobacco particles, the aerosol-generating substrate may comprise one or more sheets of thyme paper and one or more sheets of tobacco paper. The sheets of thyme paper and tobacco paper may be interleaved or stacked with one another before being assembled to form a rod. Optionally, the sheets may be crimped. Alternatively, the sheets of thyme paper and tobacco paper may be cut into strands, strips, or pieces and then combined to form a rod. The relative amounts of tobacco and thyme in the aerosol-generating substrate can be adjusted by varying the number of tobacco and thyme sheets, respectively, or the amount of thyme and tobacco strands, strips, or pieces, respectively, within the rod.

[0259] For example, the number or amount of tobacco and thyme sheets or strands may be adjusted to provide a thyme to tobacco ratio of about 1:4, or about 1:9, or about 1:30.

[0260] Other known processes which may be applied to the production of homogenized plant material are, for example, dough reconstitution processes of the type described in U.S. Pat. No. 3,894,544, and extrusion processes of the type described in GB-A-983,928. Generally, the density of homogenized plant material produced by extrusion and dough reconstitution processes is greater than the density of homogenized plant material produced by casting processes.

[0261] Preferably, the aerosol-generating substrate of an aerosol-generating article according to the present invention comprises at least about 200 mg of homogenized plant material, more preferably at least about 220 mg of homogenized plant material, more preferably at least about 250 mg of homogenized plant material.

[0262] The aerosol-generating article according to the present invention comprises a rod comprising an aerosol-generating substrate in one or more plugs. The rod of aerosol-generating substrate may have a length of from about 5 mm to about 120 mm. For example, the rod may preferably have a length of from about 10 mm to about 45 mm, more preferably from about 10 mm to 15 mm, and most preferably about 12 mm. In alternative embodiments, the rod preferably has a length of from about 30 mm to about 45 mm, or from about 33 mm to about 41 mm. When the rod is formed from a single plug of aerosol-generating substrate, the plug has the same length as the rod.

[0263] The rods of aerosol-generating substrates may have an outer diameter of about 5 mm to about 10 mm depending on their intended use. For example, in some embodiments, the rods may have an outer diameter of about 5.5 mm to about 8 mm, or about 6.5 mm to about 8 mm. The "outer diameter" of the rod of aerosol-generating substrate corresponds to the diameter of the rod including any wrapper.

[0264] The rod of aerosol-generating substrate in an aerosol-generating article according to the present invention is preferably surrounded by one or more wrappers along at least a portion of its length. The one or more wrappers may comprise a paper wrapper, a non-paper wrapper, or both. Suitable paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, cigarette paper and filter plug wrap. Suitable non-paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material. Homogenized tobacco wrappers are particularly suitable for use in embodiments in which the aerosol-generating substrate comprises one or more sheets of homogenized thyme material formed from particulate plant material, the particulate plant material containing thyme particles in combination with a low weight percentage of tobacco particles, such as between 20 weight percent and 0 weight percent tobacco particles, on a dry weight basis.

[0265] In certain embodiments of the present invention, the aerosol-generating substrate is surrounded along at least a portion of its length by a thermally conductive sheet material, such as a metal foil, e.g., aluminum foil or metalized paper. The metal foil or metalized paper serves the purpose of rapidly conducting heat throughout the aerosol-generating substrate. Additionally, the metal foil or metalized paper may serve to prevent the aerosol-generating substrate from igniting if a consumer attempts to light it. Furthermore, during use, the metal foil or metalized paper may prevent odors generated as the outer wrapper heats from entering the aerosol generated from the aerosol-generating substrate. For example, this may be problematic for aerosol-generating articles having an aerosol-generating substrate that is externally heated during use to generate the aerosol. Alternatively, or additionally, the metalized wrapper may be used to facilitate detection or recognition of the aerosol-generating article when inserted into an aerosol-generating device during use. The metal foil or metalized paper may contain metal particles, such as iron particles.

[0266] The one or more wrappers surrounding the aerosol-generating substrate preferably have an overall thickness of from about 0.1 mm to about 0.9 mm.

[0267] The inner diameter of the rod of the aerosol-generating substrate is preferably from about 3 mm to about 9.5 mm, more preferably from about 4 mm to about 7.5 mm, more preferably from about 5 mm to about 7.5 mm. "Inner diameter" corresponds to the diameter of the rod of the aerosol-generating substrate, not including the thickness of the wrapper, but measured with the wrapper still in place.

[0268] Aerosol-generating articles according to the present invention also include, but are not limited to, cartridges or shisha consumables.

[0269] The aerosol-generating article according to the present invention may optionally include at least one hollow tube immediately downstream of the aerosol-generating substrate. One function of the tube is to position the aerosol-generating substrate toward the distal end of the aerosol-generating article so that it can contact the heating element. The tube acts to prevent the aerosol-generating substrate from being forced along the aerosol-generating article toward other downstream elements when the heating element is inserted into the aerosol-generating substrate. The tube also acts as a spacer element to separate the downstream elements from the aerosol-generating substrate. The tube may be made of any material, such as cellulose acetate, polymer, cardboard, or paper.

[0270] The aerosol-generating article according to the present invention optionally includes one or more spacers or aerosol cooling elements downstream of the aerosol-generating substrate and immediately downstream of the hollow tube. During use, the aerosol formed by volatile compounds emitted from the aerosol-generating substrate passes through and is cooled by the aerosol cooling element before being inhaled by the user. The low temperature allows the vapor to condense into an aerosol. The spacer or aerosol cooling element may be a hollow tube, such as a hollow cellulose acetate tube or cardboard tube, similar to that immediately downstream of the aerosol-generating substrate. The spacer may be a hollow tube with an outer diameter equal to that of the hollow cellulose acetate tube, but with a smaller or larger inner diameter. In one embodiment, the paper-wrapped aerosol cooling element includes one or more longitudinal channels made of any suitable material, such as metal foil, foil-laminated paper, polymeric sheets, preferably made of synthetic polymers, and substantially non-porous paper or cardboard. In some embodiments, the paper-wrapped aerosol cooling element may include one or more sheets made of a material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), paper laminated with a polymer sheet, and aluminum foil. Alternatively, the aerosol cooling element may be made of woven fibers or nonwoven filaments of a material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), and cellulose acetate (CA). In a preferred embodiment, the aerosol cooling element is a crimped and aggregated polylactic acid sheet wrapped within filter paper. In another preferred embodiment, the aerosol cooling element includes longitudinal channels and is made of woven filaments of a synthetic polymer, such as polylactic acid filaments, wrapped in paper.

[0271] The aerosol-generating article according to the present invention may further comprise a filter or mouthpiece downstream of the aerosol-generating substrate and the hollow acetate tube, spacer, or aerosol cooling element. The filter may comprise one or more filtering materials for removing particulate components, gaseous components, or a combination thereof. Suitable filtering materials are known in the art and include, but are not limited to, fibrous filtering materials such as cellulose acetate tow and paper; adsorbents such as activated alumina, zeolites, molecular sieves, and silica gel; biodegradable polymers including polylactic acid (PLA), Matabi®, hydrophobic viscose fibers, and bioplastics; and combinations thereof. The filter may be located at the downstream end of the aerosol-generating article. The filter may be a cellulose acetate filter plug. In one embodiment, the filter is approximately 7 mm long, but may also have a length of approximately 5 mm to approximately 10 mm.

[0272] The aerosol-generating article according to the present invention may further comprise a mouth-end cavity at the downstream end of the article. The mouth-end cavity may be defined by one or more wrappers extending downstream from the filter or mouthpiece. Alternatively, the mouth-end cavity may be defined by a separate tubular element provided at the downstream end of the aerosol-generating article.

[0273] The aerosol-generating article according to the present invention preferably further comprises a ventilation zone provided at a location along the aerosol-generating article, for example, the aerosol-generating article may be provided at a location along a hollow tube provided downstream of the aerosol-generating substrate.

[0274] In a preferred embodiment of the present invention, the aerosol-generating article comprises an aerosol-generating substrate, at least one hollow tube downstream of the aerosol-generating substrate, and a filter downstream of the at least one hollow tube. Optionally, the aerosol-generating article further comprises an oral end cavity at the downstream end of the filter. Preferably, a ventilation zone is provided at a location along the at least one hollow tube.

[0275] In one particularly preferred embodiment having this configuration, the aerosol-generating substrate has a length of about 33 mm and an outer diameter of about 5.5 mm to 6.7 mm, and the aerosol-generating substrate contains about 340 mg of homogenized thyme material in the form of a plurality of strands, the homogenized thyme material containing about 14 weight percent glycerol on a dry weight basis. In this embodiment, the aerosol-generating article has an overall length of about 74 mm and includes a cellulose acetate tow filter having a length of about 10 mm and an oral end cavity defined by a hollow tube having a length of about 6 to 7 mm. The aerosol-generating article includes a hollow tube downstream of the aerosol-generating substrate, the hollow tube having a length of about 25 mm, and a ventilation zone provided therein.

[0276] Aerosol-generating articles according to the present invention may have an overall length of at least about 30 mm, or at least about 40 mm. The overall length of the aerosol-generating article may be less than 90 mm, or less than about 80 mm.

[0277] In one embodiment, the aerosol-generating article has an overall length of about 40 mm to about 50 mm, preferably about 45 mm. In another embodiment, the aerosol-generating article has an overall length of about 70 mm to about 90 mm, preferably about 80 mm to about 85 mm. In another embodiment, the aerosol-generating article has an overall length of about 72 mm to about 76 mm, preferably about 74 mm.

[0278] The aerosol-generating article may have an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm. In one embodiment, the aerosol-generating article has an outer diameter of about 7.3 mm.

[0279] The aerosol-generating article according to the present invention may further comprise one or more aerosol modification elements. The aerosol modification element may provide an aerosol modifier. As used herein, the term aerosol modifier is used to describe any substance that, in use, modifies one or more characteristics or properties of the aerosol that passes through the filter. Suitable aerosol modifiers include, but are not limited to, agents that impart a flavor or aroma to the aerosol that passes through the filter in use, or agents that remove flavor from the aerosol that passes through the filter in use.

[0280] The aerosol modifier may be one or more of water or liquid flavorings. The water or moisture may modify the sensory experience of the user, for example, by moistening the generated aerosol, which may provide a cooling effect to the aerosol and reduce the perception of harshness experienced by the user. The aerosol modifier may be in the form of a flavor delivery element for delivering one or more liquid flavorings. Alternatively, liquid flavorings can be added directly to the homogenized plant material, for example, by adding flavor to the slurry or ingredients during the production of the homogenized plant material, or by spraying the liquid flavorings onto the surface of the homogenized plant material.

[0281] The one or more liquid flavoring agents may include any flavor compound or plant extract suitable for releasably disposing in liquid form within the flavor delivery element to enhance the flavor of the aerosol generated during use of the aerosol-generating article. Liquid or solid flavoring agents may also be disposed directly on the material forming the filter, such as cellulose acetate tow. Suitable flavors or flavoring agents include, but are not limited to, menthol, mint (such as peppermint and Dutch spice), chocolate, licorice, citrus and other fruit flavors, gamma octalactone, vanillin, ethyl vanillin, breath freshening flavors, spice flavors (such as cinnamon), methyl salicylate, linalool, eugenol, bergamot oil, geranium oil, lemon oil, cannabis oil, and tobacco flavor. Other suitable flavors may include flavor compounds selected from the group consisting of acids, alcohols, esters, aldehydes, ketones, pyrazines, combinations or blends thereof, and the like.

[0282] The aerosol modifier may be an adsorbent material, such as activated carbon, that removes certain components of the aerosol passing through the filter, thereby altering the taste and aroma of the aerosol.

[0283] The one or more aerosol modifying elements may be located downstream of or within the aerosol-generating substrate. The aerosol-generating substrate may include a homogenized thyme material and an aerosol modifying element. In various embodiments, the aerosol modifying element may be disposed adjacent to the homogenized thyme material or embedded in the homogenized thyme material. Typically, the aerosol modifying element may be located downstream of the aerosol-generating substrate, most typically within an aerosol cooling element, a filter of the aerosol-generating article, e.g., within a filter plug, or within a recess between filter plugs. The one or more aerosol modifying elements may be in the form of one or more of threads, capsules, microcapsules, beads, or a polymeric matrix material, or a combination thereof.

[0284] Where the aerosol modifying element is in the form of a thread, the thread may be formed from paper, such as a filter plug wrap, and the thread may be loaded with at least one aerosol modifier and located within the body of the filter, as described in WO-A-2011 / 060961. Other materials that can be used to form the thread include cellulose acetate and cotton.

[0285] Where the aerosol modifying element is in the form of a capsule, the capsule may be a frangible capsule located within a filter, the inner core of the capsule containing the aerosol modifier that can be released upon rupture of the outer shell of the capsule when the filter is subjected to an external force, as described in WO-A-2007 / 010407, WO-A-2013 / 068100 and WO-A-2014 / 154887. The capsule may be located within a filter plug or within a recess between filter plugs.

[0286] When the aerosol modifying element is in the form of a polymeric matrix material, the polymeric matrix material releases the flavorant when the aerosol-generating article is heated, such as when the polymeric matrix is ​​heated above the melting point of the polymeric matrix material, as described in WO-A-2013 / 034488. Typically, such a polymeric matrix material may be located within beads within the aerosol-generating substrate. Alternatively, or additionally, the flavorant may be confined within a domain of the polymeric matrix material and releasable from the polymeric matrix material upon compression of the polymeric matrix material. Preferably, the flavorant is released upon compression of the polymeric matrix material at a force of about 15 Newtons. Such a flavor modifying element may provide sustained release of the liquid flavorant over a force range of at least 5 Newtons, such as 5N to 20N, as described in WO 2013 / 068304. Typically, such a polymeric matrix material may be located within beads within a filter.

[0287] The aerosol-generating article may comprise a combustible heat source and an aerosol-generating substrate downstream of the combustible heat source, the aerosol-generating substrate being as described above in relation to the first aspect of the invention.

[0288] For example, the substrates described herein may be used in heated aerosol-generating articles of the type disclosed in WO-A-2009 / 022232, which comprise a combustible carbon-based heat source, an aerosol-generating substrate downstream of the combustible heat source, and a thermally conductive element surrounding and in contact with a rear portion of the combustible carbon-based heat source and an adjacent front portion of the aerosol-generating substrate, although it will be appreciated that the substrates described herein may also be used in heated aerosol-generating articles with combustible heat sources having other configurations.

[0289] The present invention provides an aerosol-generating system comprising an aerosol-generating device including a heating element and an aerosol-generating article for use in the aerosol-generating device, the aerosol-generating article comprising the aerosol-generating substrate described above.

[0290] In a preferred embodiment, the aerosol-generating substrates described herein may be used in heated aerosol-generating articles for use in electrically operated aerosol-generating systems in which the aerosol-generating substrate of the heated aerosol-generating article is heated by an electrical heat source.

[0291] For example, the aerosol-generating substrates described herein may be used in heated aerosol-generating articles of the type disclosed in EP-A-0 822 760.

[0292] The heating element of such an aerosol-generating device may be in any suitable form that conducts heat. Heating of the aerosol-generating substrate may be achieved internally, externally, or both. Preferably, the heating element may be a heater blade or pin adapted to be inserted into the substrate so that the substrate is heated from the inside. Alternatively, the heating element may partially or completely surround the substrate and heat the substrate circumferentially from the outside.

[0293] The aerosol-generating system may be an electrically operated aerosol-generating system equipped with an induction heating device. The induction heating device typically includes an induction source configured to be coupled to the susceptor, which may be provided externally or internally to the aerosol-generating substrate. The induction source generates an alternating electromagnetic field, which induces magnetization or eddy currents in the susceptor. The susceptor may heat as a result of hysteresis losses or induced eddy currents, which heat the susceptor through ohmic or resistive heating.

[0294] The electrically operated aerosol-generating system including an induction heating device also includes an aerosol-generating article having an aerosol-generating substrate and a susceptor in thermal proximity to the aerosol-generating substrate. Typically, the susceptor is in direct contact with the aerosol-generating substrate, and heat is transferred from the susceptor to the aerosol-generating substrate primarily by conduction. Examples of electrically operated aerosol-generating systems including an induction heating device and an aerosol-generating article having a susceptor are described in WO-A1-95 / 27411 and WO-A1-2015 / 177255.

[0295] The susceptor may be a plurality of susceptor particles that can be deposited on or embedded within the aerosol-generating substrate. When the aerosol-generating substrate is in the form of one or more sheets, the plurality of susceptor particles may be deposited on or embedded within the one or more sheets. For example, the susceptor particles may be fixed by the substrate in sheet form and remain in their initial position. Preferably, the susceptor particles can be uniformly distributed throughout the homogenized thyme material of the aerosol-generating substrate. Due to the particulate nature of the susceptor, heat is generated according to the distribution of the particles within the homogenized thyme material sheet of the substrate. Alternatively, susceptors in the form of one or more sheets, strips, pieces, or rods may be placed next to the homogenized thyme material or embedded in the homogenized thyme material. In one embodiment, the aerosol-forming substrate includes one or more susceptor strips. In another embodiment, the susceptor is present within the aerosol-generating device.

[0296] The susceptor may have a heat loss greater than 0.05 Joules / kilogram, preferably greater than 0.1 Joules / kilogram. Heat loss is the capacity of the susceptor to transfer heat to surrounding materials. Because the susceptor particles are preferably uniformly distributed within the aerosol-generating substrate, uniform heat loss from the susceptor particles is achieved, thereby generating a uniform heat distribution within the aerosol-generating substrate and resulting in a uniform temperature distribution within the aerosol-generating article. It has been found that a specific minimum heat loss of 0.05 Joules / kilogram in the susceptor particles allows the aerosol-generating substrate to be heated to a substantially uniform temperature to provide aerosol generation. In such embodiments, the average temperature reached within the aerosol-generating substrate is preferably between about 200°C and about 240°C.

[0297] Reducing the risk of overheating the aerosol-generating substrate can be achieved by using a susceptor material with a Curie temperature, which allows the heating process due to hysteresis losses to reach only a certain maximum temperature. The susceptor may have a Curie temperature between about 200°C and about 450°C, preferably between about 240°C and about 400°C, for example, about 280°C. When the susceptor material reaches its Curie temperature, it changes magnetic properties. At the Curie temperature, the susceptor material changes from a ferromagnetic to a paramagnetic phase. At this point, heating due to energy losses caused by the orientation of the ferromagnetic domains ceases. Thereafter, further heating is primarily based on the formation of eddy currents, so that the heating process is automatically reduced once the Curie temperature of the susceptor material is reached. The susceptor material and its Curie temperature are preferably matched to the composition of the aerosol-generating substrate to achieve optimal temperature and temperature distribution within the aerosol-generating substrate for optimal aerosol generation.

[0298] In some preferred embodiments of the aerosol-generating article according to the present invention, the susceptor is made of ferrite. Ferrite is a ferromagnetic material with high magnetic permeability and is particularly suitable as a susceptor material. The primary component of ferrite is iron. Other metallic components (e.g., zinc, nickel, manganese) or non-metallic components (e.g., silicon) may be present in varying amounts. Ferrite is a relatively inexpensive, commercially available material. Ferrite is available in particulate form within the size range of the particles used in the particulate plant material forming the homogenized plant material according to the present invention. The particles are preferably fully sintered ferrite powders, such as FP160, FP215, or FP350 from PPT (Indiana, USA).

[0299] In certain embodiments of the present invention, an aerosol-generating system comprises an aerosol-generating article including an aerosol-generating substrate as defined above, a source of aerosol former, and a means for vaporizing the aerosol former, preferably a heating element as described above. The source of aerosol former may be a refillable or replaceable reservoir present on the aerosol-generating device. The reservoir is physically separate from the aerosol-generating article, and the generated vapor is directed through the aerosol-generating article. The vapor contacts the aerosol-generating substrate, which releases volatile compounds, such as nicotine and flavorants, in the particulate plant material to form an aerosol. Optionally, to assist in the vaporization of the compounds in the aerosol-generating substrate, the aerosol-generating system may further comprise a heating element, preferably coordinated with the aerosol former, for heating the aerosol-generating substrate. However, in certain embodiments, the heating element used to heat the aerosol-generating article is separate from the heater that heats the aerosol former.

[0300] The present invention further provides an aerosol produced upon heating of an aerosol-generating substrate, as defined above, wherein the aerosol comprises specific amounts and ratios of characteristic compounds derived from thyme particles as defined above.

[0301] According to the present invention, the aerosol comprises ursolic acid in an amount of at least 0.25 micrograms per aerosol puff and thymol in an amount of at least 0.1 micrograms per aerosol puff, the aerosol puff having a volume of 55 milliliters when generated by a smoking machine. For purposes of the present invention, a "puff" is defined as the volume of aerosol emitted from an aerosol-generating substrate upon heating and collected for analysis, and the aerosol puff has a puff volume of 55 milliliters generated by a smoking machine. Accordingly, any reference herein to an aerosol "puff" is understood to refer to a 55 milliliter puff unless otherwise specified.

[0302] The ranges shown define the total amount of each component measured in a 55 milliliter puff of aerosol. The aerosol may be generated from an aerosol-generating substrate using any suitable means and may be trapped and analyzed as described above to identify and measure the amounts of characteristic compounds within the aerosol. For example, a "puff" may correspond to a 55 milliliter puff measured in a smoking machine, such as that used in the Health Canada test method described herein.

[0303] Preferably, the aerosols according to the present invention contain at least about 0.5 micrograms of ursolic acid per aerosol puff, more preferably at least about 1 microgram per aerosol puff. Alternatively, or additionally, the aerosol generated from the aerosol-generating substrate contains at most about 5 micrograms of ursolic acid per aerosol puff, preferably at most about 4.5 micrograms of ursolic acid per aerosol puff, and more preferably at most about 4 micrograms of ursolic acid per aerosol puff. For example, the aerosol generated from the aerosol-generating substrate may contain from about 0.25 micrograms to about 5 micrograms of ursolic acid per aerosol puff, or from about 0.5 micrograms to about 4.5 micrograms of ursolic acid per aerosol puff, or from about 1 microgram to about 4 micrograms of ursolic acid per aerosol puff.

[0304] Aerosols according to the present invention preferably contain at least about 0.5 micrograms of thymol per aerosol puff, and more preferably at least about 1 microgram of thymol per aerosol puff. Alternatively, or additionally, the aerosol generated from the aerosol-generating substrate preferably contains at most about 3 micrograms of thymol per aerosol puff, more preferably at most about 2.5 micrograms of thymol per aerosol puff, and even more preferably at most about 2 micrograms of thymol per aerosol puff. For example, the aerosol generated from the aerosol-generating substrate may contain from about 0.1 micrograms to about 3 micrograms of thymol per aerosol puff, or from about 0.5 micrograms to about 2.5 micrograms of thymol per aerosol puff, or from about 1 microgram to about 2 micrograms of thymol per aerosol puff.

[0305] According to the present invention, the aerosol composition is such that the amount of ursolic acid per aerosol puff is preferably at least equal to the amount of thymol per aerosol puff.Therefore, the ratio of ursolic acid to thymol in aerosol is preferably at least about 1:1.Preferably, the amount of ursolic acid per aerosol puff is at least about 1.5 times the amount of thymol per aerosol puff.

[0306] A defined ratio of ursolic acid to thymol characterizes aerosols derived from thyme particles. In contrast, the ratio of ursolic acid to thymol in aerosols generated from thyme essential oil will vary significantly.

[0307] Preferably, the aerosol according to the present invention further comprises from about 0.02 micrograms to about 0.25 micrograms of isothymol per aerosol puff, or from about 0.05 micrograms to about 0.2 micrograms of isothymol per aerosol puff, or from about 0.1 micrograms to about 0.15 micrograms of isothymol per aerosol puff.

[0308] Aerosols according to the present invention preferably further comprise at least about 0.1 milligrams of aerosol former per aerosol puff, more preferably at least about 0.2 milligrams of aerosol per aerosol puff, and even more preferably at least about 0.3 milligrams of aerosol former per aerosol puff. Preferably, the aerosol comprises at most 0.6 milligrams of aerosol former per aerosol puff, more preferably at most 0.5 milligrams of aerosol former per aerosol puff, and even more preferably at most 0.4 milligrams of aerosol former per aerosol puff. For example, the aerosol may comprise between about 0.1 milligrams and about 0.6 milligrams of aerosol former per aerosol puff, or between about 0.2 milligrams and about 0.5 milligrams of aerosol former per aerosol puff, or between about 0.3 milligrams and about 0.4 milligrams of aerosol former per aerosol puff. These values ​​are based on a smoke volume of 55 milliliters, as defined above.

[0309] Suitable aerosol formers for use in the present invention are described above.

[0310] The aerosol generated from the aerosol-generating substrate of the present invention preferably further comprises at least about 2 micrograms of nicotine per aerosol puff, more preferably at least about 20 micrograms of nicotine per aerosol puff, and even more preferably at least about 40 micrograms of nicotine per aerosol puff. The aerosol preferably comprises at most about 200 micrograms of nicotine per aerosol puff, more preferably at most about 150 micrograms of nicotine per aerosol puff, and even more preferably at most about 75 micrograms of nicotine per aerosol puff. For example, the aerosol may comprise from about 2 micrograms to about 200 micrograms of nicotine per aerosol puff, or from about 20 micrograms to about 150 micrograms of nicotine per aerosol puff, or from about 40 micrograms to about 75 micrograms of nicotine per aerosol puff. These values ​​are based on a puff volume of 55 milliliters, as defined above. In some embodiments of the present invention, the aerosol may contain zero micrograms of nicotine.

[0311] Alternatively or additionally, the aerosols according to the present invention may optionally further comprise at least about 0.5 milligrams of cannabinoid compound per aerosol puff, more preferably at least about 1 milligram of cannabinoid compound per aerosol puff, and even more preferably at least about 2 milligrams of cannabinoid compound per aerosol puff. Preferably, the aerosol comprises up to about 5 milligrams of cannabinoid compound per aerosol puff, more preferably up to about 4 milligrams of cannabinoid compound per aerosol puff, and even more preferably up to about 3 milligrams of cannabinoid compound per aerosol puff. For example, the aerosol may comprise from about 0.5 milligrams to about 5 milligrams of cannabinoid compound per aerosol puff, or from about 1 milligram to about 4 milligrams of cannabinoid compound per aerosol puff, or from about 2 milligrams to about 3 milligrams of cannabinoid compound per aerosol puff. In some embodiments of the present invention, the aerosol may contain zero micrograms of cannabinoid compounds. These values ​​are based on a puff volume of 55 milliliters, as defined above.

[0312] Preferably the cannabinoid compound is selected from CBD and THC, more preferably the cannabinoid compound is CBD.

[0313] Carbon monoxide may also be present in aerosols according to the invention and may be measured and used to further characterize the aerosol. Oxides of nitrogen, such as nitric oxide and nitrogen dioxide, may also be present in aerosols and may be measured and used to further characterize the aerosol.

[0314] Aerosols according to the present invention containing characteristic compounds from thyme particles can be formed from particles having a mass median aerodynamic diameter (MMAD) ranging from about 0.01 to 200 microns, or from about 1 to 100 microns. When the aerosol contains nicotine as described above, the aerosol preferably contains particles having a MMAD ranging from about 0.1 to about 3 microns to optimize delivery of nicotine from the aerosol.

[0315] The mass median aerodynamic diameter (MMAD) of an aerosol refers to the particle dynamic diameter at which half of the aerosol's particulate mass is occupied by particles with an aerodynamic diameter larger than the MMAD and half by particles with an aerodynamic diameter smaller than the MMAD. The aerodynamic diameter is the mass of a particle that has the same settling velocity as the particle being characterized, 1 g / cm. 3 is defined as the diameter of a spherical particle having a density of

[0316] The mass median aerodynamic diameter of the aerosol according to the present invention can be determined according to Schaller et al., "Evaluation of the Tobacco Heating System 2.2., Section 2.8, Part 2: Chemical composition, genotoxicity, cytotoxicity and physical properties of the aerosol," Regul. Toxicol. and Pharmacol., 81 (2016) S27-S47.

[0317] As defined above, the present invention further provides an aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate comprises homogenized plant material, and upon heating of the aerosol-generating substrate in accordance with Test Method A, an aerosol generated from the aerosol-generating substrate comprises ursolic acid in an amount of at least 0.25 micrograms per aerosol puff and thymol in an amount of at least 0.1 micrograms per aerosol puff, wherein the amount of ursolic acid per aerosol puff is at least the same as the amount of thymol per aerosol puff, and the aerosol puff has a volume of 55 milliliters when generated by a smoking machine.

[0318] For purposes of the present invention, a "puff" is defined as the volume of aerosol emitted from an aerosol-generating substrate upon heating and collected for analysis, with an aerosol puff having a puff volume of 55 milliliters generated by a smoking machine. Accordingly, any reference herein to an aerosol "puff" is understood to refer to a 55 milliliter puff unless otherwise specified. The ranges provided define the total amount of each component measured in a 55 milliliter puff of aerosol. The aerosol may be generated from an aerosol-generating substrate using any suitable means and may be trapped and analyzed as described above to identify and measure the amount of characteristic compounds within the aerosol. For example, a "puff" may correspond to a 55 milliliter puff measured in a smoking machine, such as that used in the Health Canada test method described herein.

[0319] The present invention also provides an aerosol-generating substrate formed from homogenized plant material comprising thyme particles, an aerosol former, and a binder, as defined above, wherein the aerosol-generating substrate comprises at least 400 micrograms of ursolic acid per gram of substrate on a dry weight basis, and at least 150 micrograms of thymol per gram of substrate on a dry weight basis, wherein the amount of ursolic acid per gram of substrate is at least about twice the amount of thymol per gram of substrate.

[0320] The following provides a non-exhaustive list of non-limiting examples, any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0321] Example 1 1. An aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate comprising homogenized dill seed material, the homogenized dill seed material comprising dill seed particles, an aerosol former, and a binder, the aerosol-generating substrate comprising: At least 100 micrograms of carvone per gram of substrate on a dry weight basis; and at least 2 micrograms of limonene per gram of substrate on a dry weight basis. Example 2 10. The aerosol-generating article of claim 1, wherein the amount of carvone per gram of substrate is 50 times or less than the amount of limonene per gram of substrate. Example 3 3. The aerosol-generating article of Example 1 or Example 2, wherein the aerosol-generating substrate comprises, on a dry weight basis, 100 micrograms to 4500 micrograms of carvone per gram of substrate. Example 4 4. An aerosol-generating article according to any one of Examples 1 to 3, wherein the aerosol-generating substrate comprises, on a dry weight basis, from 2 micrograms to 200 micrograms of limonene per gram of substrate. Example 5 When the aerosol-generating substrate was heated using Test Method A, At least 20 micrograms of carvone per gram of substrate on a dry weight basis; an aerosol is generated that contains at least 2 micrograms of limonene per gram of substrate on a dry weight basis; An aerosol-generating article according to any one of Examples 1 to 4, wherein the amount of carvone in the aerosol per gram of substrate is 10 times or less the amount of limonene in the aerosol per gram of substrate. Example 6 An aerosol-generating article as described in Example 5, wherein heating the aerosol-generating substrate in accordance with Test Method A generates an aerosol containing up to 1,500 micrograms of carvone per gram of substrate on a dry weight basis. Example 7 An aerosol-generating article as described in Example 5 or Example 6, wherein upon heating of the aerosol-generating substrate in accordance with Test Method A, an aerosol is generated comprising at most 300 micrograms of limonene per gram of substrate on a dry weight basis. Example 8 An aerosol-generating article according to any one of Examples 5 to 7, wherein heating of the aerosol-generating substrate by Test Method A generates an aerosol containing 0 micrograms of nicotine per gram of substrate. Example 9 Under Health Canada's mechanical smoking regimen, heating of the aerosol-generating substrate in the THS2.2 holder At least 20 micrograms of carvone per gram of substrate on a dry weight basis; an aerosol is generated that contains at least 2 micrograms of limonene per gram of substrate on a dry weight basis; An aerosol-generating article according to any one of Examples 1 to 4, wherein the amount of carvone in the aerosol per gram of substrate is 10 times or less the amount of limonene in the aerosol per gram of substrate. Example 10 An aerosol-generating article described in any one of Examples 1 to 9, wherein the homogenized dill seed material contains at least 2.5 weight percent dill seed particles on a dry weight basis. Example 11 An aerosol-generating article described in any one of Examples 1 to 10, wherein the homogenized dill seed material contains up to 25 weight percent dill seed particles on a dry weight basis. Example 12 An aerosol-generating article described in any one of Examples 1 to 11, wherein the homogenized dill seed material contains up to 65 weight percent dill seed particles on a dry weight basis. Example 13 An aerosol-generating article described in any one of Examples 1 to 12, wherein the homogenized dill seed material further contains up to about 75 weight percent tobacco particles on a dry weight basis. Example 14 An aerosol-generating article described in any one of Examples 1 to 13, wherein the homogenized dill seed material further contains tobacco particles and the weight ratio of dill seed particles to tobacco particles is 1:4 or less. Example 15 An aerosol-generating article described in Example 13 or Example 14, wherein the homogenized dill seed material comprises, on a dry weight basis, 5 weight percent to 20 weight percent dill seed particles and 55 weight percent to 70 weight percent tobacco particles. Example 16 An aerosol-generating article described in any one of Examples 1 to 15, wherein the homogenized dill seed material contains substantially zero nicotine. Example 17 An aerosol-generating article as described in Examples 1-15, wherein the aerosol-generating substrate further comprises at least 0.1 milligrams of nicotine per gram of substrate on a dry weight basis. Example 18 18. The aerosol-generating article of example 17, wherein the aerosol-generating substrate contains, on a dry weight basis, from 1 milligram to 20 milligrams of nicotine per gram of substrate. Example 19 An aerosol-generating article described in any one of Examples 1 to 18, wherein the dill seed particles have a D95 value of about 200 microns or more and about 900 microns or less. Example 20 An aerosol-generating article described in any one of Examples 1 to 19, wherein the dill seed particles have a D5 value of about 10 microns or more and about 50 microns or less. Example 21 An aerosol-generating article described in any one of Examples 1 to 20, in which the dill seed particles are intentionally crushed. Example 22 An aerosol-generating article described in any one of Examples 1 to 21, in which 100 percent of the dill seed particles have a diameter of 300 microns or less. Example 23 An aerosol-generating article described in any one of Examples 1 to 22, wherein the homogenized dill seed material comprises up to 75 weight percent particulate plant material, and the particulate plant material comprises dill seed particles. Example 24 An aerosol-generating article described in any one of Examples 1 to 23, wherein the homogenized dill seed material has an aerosol former content of 5 weight percent to about 30 weight percent on a dry weight basis. Example 25 An aerosol-generating article according to any one of Examples 1 to 24, wherein the binder is selected from gums such as guar gum, xanthan gum, gum arabic and locust bean gum, cellulosic binders such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose and ethyl cellulose, organic acids such as starch, alginic acid, conjugate base salts of organic acids such as sodium alginate, polysaccharides such as agar and pectin, and combinations thereof. Example 26 An aerosol-generating article described in any one of Examples 1 to 25, wherein the homogenized dill seed material contains 1 weight percent to 10 weight percent binder on a dry weight basis. Example 27 The aerosol-generating article of any one of Examples 1 to 26, wherein the binder comprises guar gum. Example 28 An aerosol-generating article described in any one of Examples 1 to 26, wherein the binder comprises a cellulose ether and the homogenized dill seed material comprises about 2 weight percent to about 10 weight percent of the cellulose ether. Example 29 An aerosol-generating article as described in Example EX28, wherein the homogenized dill material further comprises additional cellulose not derived from dill seed particles, the additional cellulose comprising at least one of cellulose powder and cellulose fiber. Example 30 29. The aerosol-generating article of Example 29, wherein the ratio of additional cellulose material to cellulose ether in the homogenized dill seed material is at least 2. Example 31 An aerosol-generating article as described in Example 29 or Example 30, wherein the homogenized dill material comprises, on a dry weight basis, 2.5 weight percent to 75 weight percent dill seed particles, on a dry weight basis, 15 weight percent to 55 weight percent aerosol former, on a dry weight basis, 2 weight percent to 10 weight percent cellulose ether, and 3 weight percent to 50 weight percent additional cellulose. Example 32 An aerosol-generating article described in any one of Examples 1 to 31, wherein the homogenized dill seed material further contains fibers. Example 33 33. The aerosol-generating article of Example 32, wherein the fibers have a length of greater than 400 micrometers. Example 34 The aerosol-generating article of example 32 or example 33, wherein the fibers are present in an amount of about 2 weight percent to about 15 weight percent, based on the dry weight of the aerosol-generating substrate. Example 35 The aerosol-generating article of Example 32 or Example 33, wherein the fibers are present in an amount of at least 30 weight percent, based on the dry weight of the aerosol-generating substrate. Example 36 An aerosol-generating article described in any one of Examples 1 to 35, wherein the homogenized dill seed material comprises dill seed particles, about 5 weight percent to about 30 weight percent of an aerosol former, and about 1 weight percent to about 10 weight percent of a binder, on a dry weight basis. Example 37 An aerosol-generating article as described in Example 36, wherein the homogenized dill seed material further contains about 2 weight percent to about 15 weight percent fiber. Example 38 The aerosol-generating article of Example 36 or Example 37, wherein the binder is guar gum. Example 39 An aerosol-generating article described in any one of Examples 1 to 38, wherein the homogenized dill seed material is in the form of one or more sheets. Example 40 39. The aerosol-generating article of claim 39, wherein each of the one or more sheets has a thickness of 100 micrometers to 600 micrometers. Example 41 One or more sheets, each of 100 g / m 2 ~300g / m 2 39. The aerosol-generating article of Example 39, having a mass of 1000 grammes. Example 42 One or more sheets each having a density of 0.3 g / cm 3 ~1.3 g / cm 3 The aerosol-generating article according to Examples 39 to 41, having a density of Example 43 An aerosol-generating article according to any one of Examples 39 to 42, wherein each of the one or more sheets has a peak tensile strength in the cross direction of from 50 N / m to 400 N / m. Example 44 44. The aerosol-generating article of any one of Examples 39 to 43, wherein each of the one or more sheets has a peak machine direction tensile strength of from 100 N / m to 800 N / m. Example 45 The aerosol-generating article of any one of Examples 39 to 44, wherein the one or more sheets are in the form of an assembly of one or more sheets. Example 46 An aerosol-generating article described in any one of Examples 1 to 38, wherein the homogenized dill seed material is in the form of multiple strands. Example 47 An aerosol-generating article as described in Example 46, wherein the strands have a width of at least 0.2 mm. Example 48 An aerosol-generating article as described in example 46 or example 47, wherein the plurality of strands are aligned with the longitudinal axis and extend substantially longitudinally along the length of the aerosol-generating substrate. Example 49 The aerosol-generating article of Example 46, Example 47, or Example 48, wherein each of the plurality of strands has a mass-to-surface area ratio of at least 0.02 milligrams per square millimeter. Example 50 An aerosol-generating article according to any one of Examples 1 to 49, wherein the homogenized dill seed material in the aerosol-generating substrate is in the form of cast leaves. Example 51 An aerosol-generating article according to any one of Examples 1 to 49, wherein the homogenized dill seed material in the aerosol-generating substrate is in the form of dill seed paper. Example 52 When the aerosol-generating substrate is heated by test method A, the aerosol generated from the aerosol-generating substrate is carvone in an amount of at least 0.5 micrograms per aerosol puff; and limonene in an amount of at least 0.05 micrograms per aerosol puff; An aerosol-generating article as described in any one of Examples 1 to 51, wherein the aerosol puff has a volume of 55 milliliters when generated by a smoking machine, and the amount of carvone per aerosol puff is 10 times or less the amount of limonene per aerosol puff. Example 53 An aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate comprising homogenized dill seed material comprising dill seed particles, about 5 weight percent to about 30 weight percent of an aerosol former, and about 1 weight percent to about 10 weight percent of a binder, on a dry weight basis. Example 54 An aerosol-generating article as described in Example 53, wherein the homogenized dill seed material further comprises an essential oil, preferably dill seed essential oil. Example 55 An aerosol-generating article described in Example 53 or Example 54, wherein the homogenized dill seed material further contains tobacco particles. Example 56 An aerosol-generating article described in any one of Examples 53 to 55, wherein the homogenized dill seed material contains at least 2.5 weight percent dill seed particles on a dry weight basis. Example 57 1. An aerosol-generating substrate comprising a homogenized dill seed material comprising dill seed particles, an aerosol former, and a binder, the aerosol-generating substrate comprising: At least 100 micrograms of carvone per gram of substrate on a dry weight basis; An aerosol-generating substrate comprising, on a dry weight basis, at least 2 micrograms of limonene per gram of substrate, and wherein the amount of carvone per gram of substrate is not more than 50 times the amount of limonene per gram of substrate. Example 58 1. An aerosol generating system comprising: an aerosol generating device having a heating element; An aerosol-generating system comprising the aerosol-generating article according to any one of Examples 1 to 56. Example 59 59. The aerosol-generating system of Example 58, wherein the heating element is a heater blade adapted to be inserted into the aerosol-generating substrate. Example 60 The aerosol is carvone in an amount of at least 0.5 micrograms per aerosol puff; and limonene in an amount of at least 0.05 micrograms per aerosol puff; An aerosol produced upon heating of the aerosol-generating substrate described in Example 57, wherein the aerosol puff has a volume of 55 milliliters when generated by a smoking machine and the amount of carvone per gram of substrate is 10 times or less the amount of carvone per gram of substrate. Example 61 1. A method of making an aerosol-generating substrate, comprising: forming a slurry comprising dill seed particles, water, an aerosol former, a binder, and optionally tobacco particles; casting or extruding the slurry in the form of a sheet or strand; and drying the sheet or strand at 80 to 160 degrees Celsius. Example 62 The method of example 60, wherein the slurry is cast onto a support surface and allowed to dry to form a sheet of cast leaves. Example 63 1. A method of making an aerosol-generating substrate, comprising: forming a dilute suspension comprising dill seed particles, water, and optionally tobacco particles; separating the suspension into an insoluble portion and a liquid extract; forming the insoluble portion into a sheet; concentrating the liquid extract and applying the concentrated liquid extract to a sheet to form a dill seed paper.

[0322] Specific embodiments will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief explanation of the drawings]

[0323] [Figure 1] FIG. 1 illustrates a first embodiment of the substrate of the aerosol-generating article described herein. [Figure 2] FIG. 2 illustrates an aerosol generating system comprising an aerosol generating device including an aerosol-generating article and an electric heating element. [Figure 3]FIG. 3 illustrates an aerosol generating system comprising an aerosol generating device including an aerosol-generating article and a combustible heating element. [Figure 4] 4a and 4b illustrate a second embodiment of the substrate of the aerosol-generating article described herein. [Figure 5] FIG. 5 illustrates a third embodiment of the substrate of the aerosol-generating article described herein. [Figure 6] Figures 6a, 6b, and 6c are cross-sectional views of a filter 1050 further including an aerosol modification element. Figure 6a illustrates an aerosol modification element in the form of a spherical capsule or bead within a filter plug. Figure 6b illustrates an aerosol modification element in the form of a thread within a filter plug. Figure 6c illustrates an aerosol modification element in the form of a spherical capsule within a cavity within the filter. [Figure 7] FIG. 7 is a cross-sectional view of a plug of an aerosol-generating substrate 1020 further including an elongated susceptor element. [Figure 8] FIG. 8 illustrates the experimental setup for collecting aerosol samples that are analyzed to measure characteristic compounds. DETAILED DESCRIPTION OF THE INVENTION

[0324] FIG. 1 illustrates a heated aerosol-generating article 1000 including a substrate as described herein. The article 1000 comprises four elements: an aerosol-generating substrate 1020, a hollow cellulose acetate tube 1030, a spacer element 1040, and a mouthpiece filter 1050. These four elements are sequentially arranged in a coaxial configuration and assembled with cigarette paper 1060 to form the aerosol-generating article 1000. The article 1000 has a mouth end 1012, which a user inserts into the mouth during use, and a distal end 1013 at the opposite end of the article from the mouth end 1012. The embodiment of the aerosol-generating article illustrated in FIG. 1 is particularly suitable for use in an electrically operated aerosol-generating device that includes a heater for heating the aerosol-generating substrate.

[0325] When assembled, article 1000 is approximately 45 millimeters long, has an outer diameter of approximately 7.2 millimeters, and an inner diameter of approximately 6.9 millimeters.

[0326] The aerosol-generating substrate 1020 comprises a plug formed from a sheet of homogenized thyme material containing thyme particles, either alone or in combination with tobacco particles.

[0327] Some examples of suitable homogenized time materials for forming the aerosol-generating substrate 1020 are shown in Table 1 below (see Samples A-D). The sheets are gathered, crimped, and wrapped with filter paper (not shown) to form a plug. The sheets contain additives, including glycerin as an aerosol former.

[0328] The aerosol-generating article 1000 illustrated in Figure 1 is designed to be engaged with an aerosol-generating device for consumption. Such an aerosol-generating device includes means for heating the aerosol-generating substrate 1020 to a sufficient temperature to form an aerosol. Generally, the aerosol-generating device may include a heating element surrounding the aerosol-generating article 1000 adjacent to the aerosol-generating substrate 1020, or a heating element inserted into the aerosol-generating substrate 1020.

[0329] Upon engaging the aerosol-generating device, a user draws on the mouth end 1012 of the smoking article 1000, causing the aerosol-generating substrate 1020 to heat to a temperature of approximately 375 degrees Celsius. At this temperature, volatile compounds are released from the aerosol-generating substrate 1020. These compounds condense to form an aerosol. The aerosol is drawn through the filter 1050 and into the user's mouth.

[0330] Figure 2 illustrates a portion of an electrically operated aerosol-generating system 2000 utilizing a heating blade 2100 to heat the aerosol-generating substrate 1020 of an aerosol-generating article 1000. The heating blade is mounted within the aerosol-article-receiving chamber of an electrically operated aerosol-generating device 2010. The aerosol-generating device defines a plurality of air holes 2050 for allowing air to flow through the aerosol-generating article 1000. The air flow is indicated by arrows in Figure 2. The aerosol-generating device includes a power source and electronic components, which are not shown in Figure 2. The aerosol-generating article 1000 of Figure 2 is as described with respect to Figure 1.

[0331] In an alternative configuration shown in Figure 3, an aerosol-generating system is shown with a combustible heating element. While item 1000 of Figure 1 is intended to be consumed in conjunction with an aerosol-generating device, item 1001 of Figure 3 includes a combustible heat source 1080 that can be ignited to transfer heat to an aerosol-generating substrate 1020 to form an inhalable aerosol. Combustible heat source 80 can be a charcoal element assembled adjacent to the aerosol-generating substrate at the distal end 13 of rod 11. Elements that are essentially the same as those in Figure 1 are numbered the same.

[0332] 4a and 4b illustrate a second embodiment of a heated aerosol-generating article 4000a, 4000b. The aerosol-generating substrate 4020a, 4020b comprises a first downstream plug 4021 formed from particulate plant material including thyme particles and a second upstream plug 4022 formed from particulate plant material primarily including tobacco particles. A suitable homogenized thyme material for use in the first downstream plug is shown in Table 1 below as one of Samples A-D. A suitable homogenized tobacco material for use in the second upstream plug is shown in Table 1 below as Sample E. Sample E contains only tobacco particles and is included for comparison purposes only.

[0333] In each plug, the homogenized plant material is in the form of a sheet, which is crimped and rolled onto filter paper (not shown). Both sheets contain an additive, including glycerol as an aerosol former. In the embodiment shown in FIG. 4a, the plugs are joined end-to-end in an abutting relationship to form a rod, each approximately 6 mm long. In a more preferred embodiment (not shown), the second plug is preferably longer than the first plug, e.g., preferably 2 mm longer, and more preferably 3 mm longer, such that the second plug is 7 or 7.5 mm long and the first plug is 5 or 4.5 mm long to provide the desired ratio of tobacco particles to thyme particles in the substrate. In FIG. 4b, the cellulose acetate tube support element 1030 is omitted.

[0334] 1 are particularly suitable for use in the electrically operated aerosol generating system 2000 with a heater shown in FIG. 2. Elements that are essentially the same as those in FIG. 1 are numbered the same. It will be appreciated by those skilled in the art that a combustible heat source (not shown) may alternatively be used in the second embodiment in place of an electric heating element in a configuration similar to that including combustible heat source 1080 of item 1001 in FIG. 3.

[0335] Figure 5 illustrates a third embodiment of a heated aerosol-generating article 5000. The aerosol-generating substrate 5020 comprises a rod formed from a first sheet of homogenized thyme material formed from particulate plant material including a proportion of thyme particles, and a second sheet of homogenized tobacco material including primarily cast leaf tobacco.

[0336] A suitable homogenized thyme material for use as the first sheet is shown below in Table 1 as one of Samples A-D. A suitable homogenized tobacco material for use as the second sheet is shown below in Table 1 as Sample E. Sample E contains only tobacco particles and is included for comparison purposes only.

[0337] A second sheet is placed on top of the first sheet, and the combined sheets are crimped, assembled, and at least partially wrapped with filter paper (not shown) to form a plug that is a portion of a rod. Both sheets contain an additive, including glycerol, as an aerosol former. Article 5000, similar to article 1000 of FIG. 1, is particularly suitable for use in electrically operated aerosol generating system 2000 with a heater, as shown in FIG. 2. Elements essentially identical to those in FIG. 1 are numbered the same. It will be apparent to those skilled in the art that a combustible heat source (not shown) may alternatively be used in the third embodiment in place of an electric heating element, in a configuration similar to that including combustible heat source 1080 of article 1001 of FIG. 3.

[0338] 6a, 6b, and 6c are cross-sectional views of a filter 1050 further including an aerosol-modifying element. In FIG. 6a, filter 1050 further comprises an aerosol-modifying element in the form of a spherical capsule or bead 605.

[0339] In the embodiment of Figure 6a, capsules or beads 605 are embedded within filter segment 601 and are surrounded on all sides by filter material 603. In this embodiment, the capsule comprises an outer shell and an inner core containing a liquid flavorant. The liquid flavorant is for flavoring the aerosol during use of the aerosol-generating article provided with the filter. The capsule 605 releases at least a portion of the liquid flavorant when the filter is subjected to an external force, for example, by squeezing by the consumer. In the illustrated embodiment, the capsule is generally spherical and has a substantially continuous outer shell containing the liquid flavorant.

[0340] In the embodiment of Figure 6b, the filter segment 601 comprises a plug of filter material 603 and a central flavor-bearing thread 607 extending axially through the plug of filter material 603 parallel to the longitudinal axis of the filter 1050. The central flavor-bearing thread 607 is substantially the same length as the plug of filter material 603 such that the ends of the central flavor-bearing thread 607 are visible at the ends of the filter segment 601. In Figure 6b, the filter material 603 is cellulose acetate tow. The central flavor-bearing thread 607 is formed from twisted filter plug wrap and is loaded with an aerosol modifier.

[0341] In the embodiment of Figure 6c, filter segment 601 comprises two or more plugs 603, 603' of filter material. The plugs of filter material 603, 603' are formed from cellulose acetate so as to be capable of filtering the aerosol provided by the aerosol-generating article. A wrapper 609 is wrapped around and connects the filter plugs 603, 603'. Within cavity 611 is capsule 605, which includes an outer shell and an inner core, the inner core containing a liquid flavorant. Alternatively, the capsule may be similar to the embodiment of Figure 6a.

[0342] 7 is a cross-sectional view of an aerosol-generating substrate 1020 further including elongated susceptor strips 705. The aerosol-generating substrate 1020 comprises a plug 703 formed from a sheet of homogenized thyme material containing tobacco particles and thyme particles. The elongated susceptor strips 705 are embedded within the plug 703 and extend longitudinally between the upstream and downstream ends of the plug 703. During use, the elongated susceptor strips 705 heat the homogenized thyme material by induction heating, as described above. [Example]

[0343] As described above with reference to the figures, different samples of homogenized plant material for use in aerosol-generating substrates according to the invention can be prepared from aqueous slurries having the compositions shown in Table 1. Sample A contains only thyme particles according to the invention and no tobacco particles. Samples B-D contain thyme particles according to the invention and tobacco particles. Sample E contains only tobacco particles and is included for comparative purposes only.

[0344] Sample A is formed with a CMC binder in combination with cellulose fibers in accordance with a second preferred embodiment of the present invention. Sample A was prepared from an aqueous slurry containing 72.97 kg of water per 100 kg of slurry, with the remainder accounted for by the ingredients in the relative amounts shown in Table 1.

[0345] Samples B-D are formed in accordance with a first preferred embodiment of the present invention with an amount of thyme particles of 25 weight percent or less and a guar gum binder. Samples B-D are prepared from an aqueous slurry containing 78-79 kg of water per 100 kg of slurry.

[0346] In the tables below, %DWB refers to "dry weight basis," in this case the weight percent calculated relative to the dry weight of the homogenized plant material. Thyme powder may be formed from dried thyme, which may be milled by triple impact milling to a final D95=77.3 microns.

[0347] The slurry may be cast onto a glass plate using a casting bar (0.6 mm) and dried in an oven for 7 minutes at 140 degrees Celsius, followed by a second oven for 30 seconds at 120 degrees Celsius. [Table 1]

[0348] For each of homogenized plant material samples A-E, plugs can be produced from a single continuous sheet of homogenized plant material, each having a width of 100 mm to 130 mm. The individual sheets preferably have a thickness of about 220 microns and a weight of about 189 g / m 2 The homogenized plant material has a basis weight of approximately 272 mg. Each sheet has a cut width of approximately 120 mm. The sheets can be crimped to a height of 165 microns to 170 microns, rolled into plugs having a length of approximately 12 mm and a diameter of approximately 7 mm, and surrounded by a paper wrapper. The homogenized plant material in each plug weighs approximately 272 mg, and the total weight of each plug is approximately 281 mg.

[0349] For each plug, an aerosol-generating article having a total length of about 45 mm can be formed having a structure as shown in Figure 3, comprising, from the downstream end, an oral end cellulose acetate filter (about 7 mm long), an aerosol spacer (about 18 mm long) comprising a crimped sheet of polylactic acid polymer, a hollow acetate tube (about 8 mm long), and the plug of aerosol-generating substrate.

[0350] For homogenized plant material Sample A, in which thyme particles comprised 100 percent of the particulate plant material, characteristic compounds were extracted from plugs of homogenized plant material using methanol as detailed above. The extracts were analyzed as described above to confirm the presence of the characteristic compounds and to measure the amounts of the characteristic compounds. The results of this analysis are shown in Table 2 below, where the amounts shown correspond to the amount per aerosol-generating article, and the aerosol-generating substrate of the aerosol-generating article contained 272 mg of homogenized plant material Sample A.

[0351] For comparative purposes, the amount of the characteristic compound present in the particulate plant material (thyme particles) used to form Sample E is also shown. For the particulate material, the amount shown corresponds to the amount of the characteristic compound in a sample of particulate plant material having a weight corresponding to the total weight of particulate plant material in the aerosol-generating article containing 272 mg of Sample A. [Table 2]

[0352] For each of the other samples containing a certain proportion of thyme particles, the amount of the characteristic compound can be estimated based on the values ​​in Table 2 by assuming that the amount is present in proportion to the weight of the thyme particles.

[0353] Mainstream aerosols from aerosol-generating articles incorporating aerosol-generating substrates formed from homogenized plant material samples A-E may be generated in accordance with Test Method A, as defined above. For each sample, the generated aerosol may be trapped and analyzed.

[0354] As detailed above, according to Test Method A, an aerosol-generating article can be tested using a commercially available Philip Morris Products SA IQOS® heat-not-burn device Tobacco Heating System 2.2 Holder (THS2.2 Holder). The aerosol-generating article is heated under Health Canada's mechanical smoking regimen for 30 puffs with a puff volume of 55 ml, a puff duration of 2 seconds, and 30 seconds between puffs (as described in ISO / TR19478-1:2014).

[0355] The aerosol generated during the smoking test is collected on a Cambridge filter pad and extracted with a liquid solvent. Figure 10 shows a suitable apparatus for generating and collecting aerosol from an aerosol-generating article.

[0356] The aerosol generating device 111 shown in Figure 10 is a commercially available tobacco heating device (IQOS). The mainstream aerosol content generated during the Health Canada smoking test detailed above is collected in an aerosol collection chamber 113 on an aerosol collection line 120. The glass fiber filter pad 140 is a 44 mm Cambridge glass fiber filter pad (CFP) that complies with ISO 4387 and ISO 3308.

[0357] For LC-HRAM-MS analysis : Extraction solvents 170, 170a, in this case methanol and internal standard (ISTD) solution, are present in each microimpinger 160, 160a at a volume of 10 mL. Cold baths 161, 161a each contain dry ice-isopropyl ether to maintain the microimpingers 160, 160a, respectively, at approximately −60° C. A gas-vapor phase is trapped within the extraction solvents 170, 170a as the aerosol is bubbled through the microimpingers 160, 160a. The combined solutions from the two microimpingers are separated in step 181 as impinger-trapped gas-vapor phase solution 180.

[0358] The CFP and impinger-trapped gas-vapor phase solution 180 are combined in a clean Pyrex® tube in step 190. In step 200, all particulate matter is extracted from the CFP using the impinger-trapped gas-vapor phase solution 180 (containing methanol as a solvent) by thorough shaking (to disintegrate the CFP), stirring for 5 minutes, and finally centrifugation (4500 g, 5 minutes, 10°C). An aliquot (300 μL) of the total reconstituted aerosol extract 220 was transferred to a silanized chromatography vial and diluted with methanol (700 μL) because the extraction solvent 170, 170a already contained the internal standard (ISTD) solution. The vial was closed and mixed for 5 minutes using an Eppendorf ThermoMixer (5°C, 2000 rpm).

[0359] For compound identification, aliquots (1.5 μL) of the diluted extract were injected and analyzed by LC-HRAM-MS in both full scan and data-dependent fragmentation modes.

[0360] About GCxGC-TOFMS analysis: As mentioned above, when preparing samples for GCxGC-TOFMS experiments, different solvents are appropriate for the extraction and analysis of polar, nonpolar, and volatile compounds separated from whole aerosols. The experimental setup is identical to that described for LC-HRAM-MS sample collection, with the exceptions noted below.

[0361] Non-polar and polar Extraction solvent 171, 171a is present in a volume of 10 mL and is an 80:20 v / v mixture of dichloromethane and methanol, also containing a retention index marker (RIM) compound and a stable isotope-labeled internal standard (ISTD). Cold baths 162, 162a each contain a dry ice-isopropanol mixture to maintain microimpingers 160, 160a, respectively, at approximately −78°C. A gas-vapor phase is trapped within extraction solvent 171, 171a as the aerosol is bubbled through microimpingers 160, 160a. The combined solutions from the two microimpingers are separated in step 182 as impinger-trapped gas-vapor phase solution 210.

[0362] non-polar The CFP and impinger-trapped gas-vapor phase solution 210 are combined in a clean Pyrex® tube in step 190. In step 200, all particulate matter is extracted from the CFP using impinger-trapped gas-vapor phase solution 210 (containing dichloromethane and methanol as solvents) by thorough shaking (to break down the CFP), stirring for 5 minutes, and finally centrifugation (4500 g, 5 minutes, 10° C.) to separate polar and non-polar components of the total aerosol extract 230.

[0363] In step 250, a 10 mL aliquot 240 of the entire aerosol extract 230 was removed. In step 260, a 10 mL aliquot of water was added and the entire sample was shaken and centrifuged. The non-polar fraction 270 was isolated, dried over sodium sulfate, and analyzed by GCxGC-TOFMS in full scan mode.

[0364] polarity ISTD and RIM compounds were added to the polar fraction 280, which was directly analyzed by GCxGC-TOFMS in full scan mode.

[0365] Each smoking replicate (n=3) contains an accumulation of 270% of the entrapped reconstituted non-polar fraction and 280% of the non-polar fraction for each sample.

[0366] Volatile components The entire aerosol was trapped using two microimpingers 160, 160a in series. Extraction solvents 172, 172a, in this case N,N-dimethylformamide (DMF), a retention indicator marker (RIM) compound, and a stable isotope-labeled internal standard (ISTD), were present in each microimpinger 160, 160a at a volume of 10 mL. Cold baths 161, 161a each contained dry ice-isopropanol ether to maintain the microimpingers 160, 160a at approximately -60°C, respectively. The gas-vapor phase was trapped within the extraction solvents 170, 170a as the aerosol was bubbled through the microimpingers 160, 160a. The combined solution from the two microimpingers was separated in step 183 as a volatile-containing phase 211. The volatile-containing phase 211 is analyzed separately from the other phases and injected directly into the GCxGC-TOFMS using cool on-column without further preparation.

[0367] Table 3 below shows the levels of characteristic compounds from thyme particles in aerosols generated from an aerosol-generating article incorporating homogenized plant material sample A, which contains 75 weight percent thyme particles. For comparison purposes, Table 3 also shows the levels of characteristic compounds in aerosols generated from an aerosol-generating article incorporating homogenized plant material sample E, which contains only tobacco particles (and is therefore not in accordance with the present invention). [Table 3]

[0368] Relatively high levels of characteristic compounds were measured in the aerosol generated from Sample A. The ratio of ursolic acid to thymol was greater than 1.5. Thus, the levels of characteristic compounds indicated the presence of thyme particles in the sample. In contrast, the tobacco-only Sample E, which was substantially free of thyme particles, was found to have zero or near-zero levels of characteristic compounds.

[0369] For each of Samples B through D, which contain a proportion of thyme particles, the amount of characteristic compound in the aerosol can be estimated based on the values ​​in Table 3 by assuming that the amount is present in proportion to the weight of thyme particles in the aerosol-generating substrate from which the aerosol was generated.

[0370] Table 4 below compares the levels of specific aerosol components in aerosols generated from aerosol-generating articles incorporating Sample B (30:70 thyme to tobacco ratio) with aerosols generated from tobacco-only Sample E. The reduction shown is the percentage reduction brought about by replacing 30 percent of the tobacco particles in the homogenized material of Sample E with thyme particles. [Table 4]

[0371] As shown in Table 4, the aerosol generated from Sample B, which contained 30 weight percent thyme particles based on the dry weight of the particulate plant material, resulted in reduced levels of several undesirable aerosol compounds when compared to the aerosol generated from Sample E. For example, significant reductions were observed in the levels of several polycyclic aromatic hydrocarbons (PAHs), including benzo[a]pyrene, benz[a]anthracene, and dibenz[a,h]anthracenepyrene. Significant reductions were also observed in the levels of several phenolic compounds, including phenol, o-cresol, m-cresol, p-cresol, and m_p-cresol, as well as isoprene and 1,3-butadiene.

[0372] In most cases, the reduction in the levels of these undesirable aerosol compounds is significantly greater than the percentage reduction expected as a result of replacing 30 percent of the tobacco particles with thyme particles. Thus, the combination of thyme particles and tobacco particles results in an unexpectedly high reduction in the levels of these compounds. Thus, the inclusion of thyme particles can reduce the levels of certain undesirable compounds in the aerosol while providing an aerosol with improved sensory properties.

Claims

1. 1. A heated aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate comprising a homogenized thyme material, the homogenized thyme material comprising, on a dry weight basis, at least 2.5 percent by weight of thyme particles, an aerosol former, and a binder, the aerosol-generating substrate comprising: at least 400 micrograms of ursolic acid per gram of said substrate on a dry weight basis; at least 150 micrograms of thymol per gram of said substrate on a dry weight basis; the amount of said ursolic acid per gram of said substrate is at least about twice the amount of said thymol per gram of said substrate; The heated aerosol-generating article further comprises at least one hollow tube immediately downstream of the aerosol-generating substrate.

2. 2. The heated aerosol-generating article according to claim 1, wherein the aerosol-generating substrate further comprises, on a dry weight basis, from 1 milligram to 20 milligrams of nicotine per gram of the substrate.

3. 3. The heated aerosol-generating article of claim 1, wherein the homogenized thyme material comprises, on a dry weight basis, 5 to 55 percent by weight of an aerosol former and 1 to 10 percent by weight of a binder.

4. The heated aerosol-generating article according to any one of claims 1 to 3, wherein the binder comprises guar gum.

5. The heated aerosol-generating article according to any one of claims 1 to 3, wherein the binder comprises a cellulose ether.

6. 6. The heated aerosol-generating article of claim 5, wherein the aerosol-generating substrate further comprises additional cellulose not derived from the thyme particles, the additional cellulose comprising at least one of cellulose powder and cellulose fiber.

7. A heated aerosol-generating article according to any one of claims 1 to 6, wherein the homogenized thyme material further contains tobacco particles, and the weight ratio of the thyme particles to the tobacco particles is 1:3 or less.

8. 8. The heated aerosol-generating article according to claim 1, wherein the homogenized thyme material in the aerosol-generating substrate is in the form of cast leaves.

9. 8. The heated aerosol-generating article according to claim 1, wherein the homogenized thyme material in the aerosol-generating substrate is in the form of thyme paper.

10. When the aerosol-generating substrate is heated by Test Method A, at least 10 micrograms of ursolic acid per gram of said substrate on a dry weight basis; an aerosol is generated that contains at least 5 micrograms of thymol per gram of said substrate on a dry weight basis; 10. The heated aerosol-generating article according to claim 1, wherein the amount of ursolic acid in the aerosol per gram of substrate is at least the same as the amount of thymol in the aerosol per gram of substrate.

11. When the aerosol-generating substrate is heated by test method A, the aerosol generated from the aerosol-generating substrate is ursolic acid in an amount of at least 0.25 micrograms per aerosol puff; thymol in an amount of at least 0.1 micrograms per aerosol puff; 11. The heated aerosol-generating article of claim 1, wherein the aerosol puff has a volume of 55 milliliters when produced by a smoking machine, and the amount of ursolic acid per aerosol puff is at least the same as the amount of thymol per aerosol puff.

12. 1. An aerosol generating system comprising: an aerosol generating device having a heating element; An aerosol generating system comprising the heated aerosol-generating article according to any one of claims 1 to 11.

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