Novel aerosol-generating substrates containing oreganum species

Abstract

The aerosol-generating article (1000) (4000a, 4000b) (5000) comprises an aerosol-generating substrate (1020) formed from a homogenized oregano material comprising oregano particles, an aerosol former, and a binder. The aerosol-generating substrate further comprises at least 50 micrograms of ursolic acid per gram of substrate, on a dry weight basis, at least 5 micrograms of isothymol per gram of substrate, on a dry weight basis, and at least 1.5 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

Description

[Technical field]

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

[0002] Aerosol-generating articles are known in the art in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than combusted. Typically, in such articles, an aerosol is generated by transferring heat from a heat source to a physically separated 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 are entrained in the air drawn through the article. Upon cooling, the released compounds condense to form an aerosol.

[0003] Some aerosol-generating articles include flavorings that are delivered to the consumer during use of the article to provide the consumer with a different sensory experience, 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 to generate 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] Aerosols from conventional cigarettes contain 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] There are difficulties in replicating the consumer experience provided by traditional combustible cigarettes with aerosol-generating articles in which the aerosol-generating substrate is heated rather than combusted, due in part to the cooler temperatures reached during heating of such aerosol-generating articles, which release a different profile of volatile compounds.

[0007] It is desirable to provide novel aerosol-generating substrates for heated aerosol-generating articles that provide aerosols with improved flavor and body. Such aerosol-generating substrates are particularly desirable if they can provide aerosols with a sensory experience comparable to that provided by conventional combustible cigarettes. Also, such aerosol-generating substrates are particularly desirable if they can provide aerosols with reduced levels of undesirable aerosol compounds compared to existing aerosol-generating substrates, such as those that contain 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 a homogenized plant material, referred to herein as "homogenized oregano material," that includes oregano particles. The homogenized oregano material may further include an aerosol former. The homogenized oregano material may further include a binder. The aerosol-generating substrate may further include at least about 50 micrograms of ursolic acid per gram of substrate, on a dry weight basis. The aerosol-generating substrate may further include at least about 5 micrograms of isothymol per gram of substrate, on a dry weight basis. The aerosol-generating substrate may further include at least about 1.5 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

[0010] According to the present invention, there is provided an aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate being formed of a homogenized oregano material comprising oregano particles. According to the present invention, the homogenized oregano material comprises oregano particles, an aerosol former, and a binder. The aerosol-generating substrate further comprises at least about 50 micrograms of ursolic acid per gram of substrate, on a dry weight basis, at least about 5 micrograms of isothymol per gram of substrate, on a dry weight basis, and at least about 1.5 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

[0011] Upon heating of an aerosol-generating substrate of an aerosol-generating article according to the present invention by Test Method A described below, an aerosol is preferably generated comprising at least about 1.5 micrograms of ursolic acid per gram of substrate, on a dry weight basis, at least about 0.5 micrograms of isothymol per gram of substrate, on a dry weight basis, and at least about 0.5 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

[0012] Preferably, upon heating of the aerosol-generating substrate according to Test Method A, the aerosol generated from the aerosol-generating substrate may comprise ursolic acid in an amount of at least 0.04 micrograms per aerosol puff. Upon heating of the aerosol-generating substrate according to Test Method A, the aerosol generated from the aerosol-generating substrate may comprise isothymol in an amount of at least 0.01 micrograms per aerosol puff. Upon heating of the aerosol-generating substrate according to Test Method A, the aerosol generated from the aerosol-generating substrate may comprise thymohydroquinone in an amount of at least 0.01 micrograms per aerosol puff. The aerosol puff has a volume of 55 milliliters when generated by the smoking machine.

[0013] According to the present invention, there is provided an aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate being formed from a homogenized oregano material comprising oregano particles, the aerosol-generating substrate comprising at least about 50 micrograms of ursolic acid per gram of substrate, on a dry weight basis, at least about 5 micrograms of isothymol per gram of substrate, on a dry weight basis, and at least about 1.5 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

[0014] The present disclosure also relates to an aerosol-generating substrate formed of homogenized plant material including oregano particles, referred to herein as "homogenized oregano material." The homogenized oregano material may further include an aerosol former. The homogenized plant material may further include a binder. The aerosol-generating substrate may include at least about 50 micrograms of ursolic acid per gram of substrate on a dry weight basis. The aerosol-generating substrate may include at least about 5 micrograms of isothymol per gram of substrate on a dry weight basis. The aerosol-generating substrate may include at least about 1.5 micrograms of thymohydroquinone per gram of substrate on a dry weight basis.

[0015] According to the present invention, there is provided an aerosol-generating substrate formed of homogenized oregano material, the homogenized oregano material comprising oregano particles, an aerosol former, and a binder, the aerosol-generating substrate further comprising at least 50 micrograms of ursolic acid per gram of substrate, on a dry weight basis, at least 5 micrograms of isothymol per gram of substrate, on a dry weight basis, and at least 1.5 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

[0016] The present disclosure additionally relates to an aerosol generated upon heating of the aerosol-generating substrate. The aerosol may comprise ursolic acid in an amount of at least 0.04 micrograms per aerosol puff. The aerosol may comprise isothymol in an amount of at least about 0.01 micrograms per aerosol puff. The aerosol may comprise thymohydroquinone in an amount of at least about 0.01 micrograms per aerosol puff. The aerosol puff has a volume of 55 milliliters when generated by a smoking machine.

[0017] There is further provided in accordance with the present invention an aerosol produced upon heating of an aerosol-generating substrate, the aerosol comprising ursolic acid in an amount of at least about 0.04 micrograms per aerosol puff, isothymol in an amount of at least about 0.01 micrograms per aerosol puff, and thymohydroquinone in an amount of at least about 0.01 micrograms per aerosol puff, 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 comprising oregano particles, water, an aerosol former, a binder, and optionally tobacco particles, casting or extruding the slurry into the form of a sheet or strand, and drying the sheet or strand, preferably at a temperature of from 80 degrees Celsius to 160 degrees Celsius. If a sheet of the aerosol-generating substrate is formed, the sheet may optionally be cut into strands or the sheet may be assembled to form a rod. The sheet may optionally be crimped prior to the assembly step.

[0019] The following references to aerosol-generating substrates and aerosols of the 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 generating an aerosol, where the article comprises an aerosol-generating substrate suitable and intended to be heated or burned to release volatile compounds capable of forming an aerosol. A conventional cigarette is ignited when a user applies a flame to one end of the cigarette and draws air through the other end. The 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 the aerosol-generating substrate. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which the aerosol is generated by the transfer of heat from a combustible fuel element or heat source to a physically separated aerosol-generating substrate.

[0021] Aerosol-generating articles are also known that are adapted for use in aerosol-generating systems that supply aerosol formers to the aerosol-generating article, in which the aerosol-generating substrate within the aerosol-generating article contains substantially less aerosol former 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 vapors (e.g., gaseous 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] The term "homogenized plant material" as used herein includes 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 oregano plant material and, optionally, plant material obtained by grinding, crushing, or comminuting tobacco material, such as tobacco blades or tobacco stems. The 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 oregano material" refers to homogenized plant material that includes oregano particles, optionally in combination with tobacco particles. The term "homogenized tobacco material" refers to homogenized plant material that includes tobacco particles but does not include oregano particles, and is therefore not in accordance with the present invention.

[0025] As used herein, the term "oregano particles" includes particles derived from the leaves of Oreganum vulgare. Oreganum vulgare L. is a flowering plant of the Lamiaceae family native to western and southwestern Eurasia and the Mediterranean coastal region. Oregano is a culinary herb, and its leaves are commonly used to impart a unique flavor to dishes.

[0026] In contrast, oregano essential oil is a distillate extracted from the leaves of the oregano plant. The main flavor compounds contained in oregano essential oil include isothymol (carvacrol) and thymol.

[0027] The present invention provides an aerosol-generating article incorporating an aerosol-generating substrate formed of homogenized plant material including oregano particles, referred to herein as homogenized oregano material. The present invention also provides an aerosol derived from such an aerosol-generating substrate. The inventors of the present invention have found that by incorporating oregano particles into an aerosol-generating substrate, it is advantageously possible to generate an aerosol that provides a novel sensory experience. Such an aerosol may provide a unique flavor and provide an enhanced level of body.

[0028] Additionally, the inventors have found that it is possible to produce an aerosol having an advantageously improved oregano aroma and flavor, as compared to aerosols produced by the addition of an oregano additive such as oregano oil. Oregano oil (CAS Registry Number 8007-11-2) is obtained by steam distillation from the seeds of the oregano plant and has a different flavorant composition than oregano granules, which is believed to result from the distillation process, which may selectively remove or retain certain flavorants. Isothymol (carvacrol) is the main component of oregano oil, making up to 75 percent of oregano oil.

[0029] Furthermore, in certain aerosol-generating substrates provided herein, oregano particles are incorporated at a level sufficient to provide a desirable oregano flavor, while maintaining sufficient tobacco material to provide a desirable level of nicotine to the consumer.

[0030] Moreover, it has been surprisingly found that the inclusion of oregano 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 oregano particles. In particular, as described below, it has been surprisingly found that the inclusion of oregano particles in an aerosol-generating substrate provides a significant reduction in certain phenolic compounds compared to aerosols generated from an aerosol-generating substrate containing 100 percent tobacco particles without oregano particles. Moreover, it has been found that this reduction is greater than would be proportionally expected as a result of the reduction in tobacco particles.

[0031] The presence of oregano 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 lineages, 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. PLoSONE 5(1):e8613;Hollingsworth PM, Graham SW, Little DP (2011) Choosing and Using a Plant DNA Barcode. PLoS ONE 6(5):e19254).

[0032] The inventors have carried out a complex analysis and characterization of the aerosols generated from the aerosol-generating substrate of the present invention incorporating oregano particles and mixtures of oregano particles and tobacco particles, and a comparison of such aerosols with those generated from existing aerosol-generating substrates formed from tobacco material without oregano particles. Based on this, the inventors have been able to identify a group of "signature compounds" present in the aerosols, which are compounds originating from oregano particles. Thus, detection of the characteristic compounds in aerosols in a specific range of weight percentages can be used to identify aerosols originating from aerosol-generating substrates containing oregano particles. These characteristic compounds are notably absent in aerosols generated from tobacco material. Moreover, the percentages of the characteristic compounds in the aerosols and the ratios of the characteristic compounds to each other clearly indicate the use of oregano plant material, and not oregano oil. Similarly, the presence of these characteristic compounds in a specific percentage in the aerosol-generating substrate indicates the inclusion of oregano particles in the substrate.

[0033] In particular, the defined levels of the characteristic compounds in the substrate and aerosol are specific to the oregano particles present in the homogenized oregano material. The level of each characteristic compound depends on the way in which the oregano particles were processed during the production of the homogenized oregano material. The level also depends on the composition of the homogenized oregano material, and may be influenced in particular by the levels of other components in the homogenized oregano material. The level of the characteristic compounds in the homogenized oregano material may differ from the level of the same compounds in the starting oregano material. It may also differ from the level of the characteristic compounds in a material that contains oregano particles but is not according to the invention as defined herein.

[0034] To perform aerosol characterization, the inventors 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).

[0035] Non-targeted screening (NTS) is an important method to characterize 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 matches, for example, using primary fragmentation (MS / MS) derived information matching 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.

[0036] As mentioned above, non-targeted differential screening (NTDS) can be performed when focusing on the comparison of two or more aerosol samples to assess in an uncontrolled way significant differences in chemical composition between samples or when prior knowledge related groups are 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 an aerosol derived from an article containing 100% by weight oregano as particulate plant material and an aerosol derived from an article containing 100% by weight tobacco as particulate plant material.

[0037] The aerosol was generated and collected using the apparatus and methods described in detail below.

[0038] LC-HRAM-MS analysis was performed using a Thermo QExactive™ high-resolution mass spectrometer in both full scan and data-dependent modes. Thus, 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).

[0039] 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-burn 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).

[0040] Results from the analytical method provided information on the main compounds responsible for the differences in the aerosols generated by these articles. The untargeted differential screening using both analytical platforms LC-HRAM-MS and GCxGC-TOFMS was focused on compounds that were present in higher amounts in the aerosols of samples of aerosol-generating substrates according to the invention containing 100 percent oregano particles versus a comparison sample of aerosol-generating substrates containing 100 percent tobacco particles. The NTDS method is described in the literature listed above.

[0041] Based on this information, the inventors were able to identify certain compounds within the aerosol that could be considered "signature compounds" derived from the oregano particles in the substrate. Signature compounds derived from oregano include, but are not limited to, ursolic acid (3β-hydroxyurs-12-en-28-oic acid), chemical formula: 30 H 48 O3, CAS Registry Number 77-52-1; Isothymol, also known as carvacrol or cymophenol, (2-methyl-5-(propan-2-yl)phenol), chemical formula: C 10 H 14 O, CAS Registry Number 499-75-2); and thymohydroquinone, (2-methyl-5-propan-2-ylbenzene-1,4-diol), chemical formula: C 10 H 14 O2, CAS Registry Number 2217-60-9).

[0042] For purposes of the present invention, targeted screening may be performed on a sample of the 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.

[0043] As defined above, the aerosol-generating article of the present invention comprises an aerosol-generating substrate formed from homogenized plant material containing oregano particles. As a result of the inclusion of oregano particles, the aerosol-generating substrate comprises a specific proportion of oregano's "characteristic compounds" as described above. In particular, the aerosol-generating substrate preferably comprises, on a dry weight basis, at least 50 micrograms of ursolic acid per gram substrate, at least 5 micrograms of isothymol per gram substrate, and at least 1.5 micrograms of thymohydroquinone per gram substrate.

[0044] 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 levels of the characteristic compound in the raw materials, which advantageously allows for more effective control of product quality.

[0045] The aerosol-generating substrate preferably contains at least about 200 micrograms of ursolic acid per gram of substrate, and more preferably at least about 500 micrograms of ursolic acid per gram of substrate, on a dry weight basis. Alternatively or additionally, the aerosol-generating substrate preferably contains no more than about 6500 micrograms of ursolic acid per gram of substrate, more preferably no more than about 4000 micrograms of ursolic acid per gram of substrate, and even more preferably no more than about 2500 micrograms of ursolic acid per gram of substrate, on a dry weight basis.

[0046] For example, the aerosol-generating substrate may contain, on a dry weight basis, from about 50 micrograms to about 6500 micrograms of ursolic acid per gram of substrate, or from about 200 micrograms to about 4000 micrograms of ursolic acid per gram of substrate, or from about 500 micrograms to about 2500 micrograms of ursolic acid per gram of substrate.

[0047] In certain particularly preferred embodiments, the aerosol-generating substrate may preferably contain from about 1000 micrograms to about 2000 micrograms of ursolic acid per gram of aerosol-generating substrate, and more preferably from about 1200 micrograms to about 1800 micrograms of ursolic acid per gram of aerosol-generating substrate. For example, the level of ursolic acid may be within these ranges for preferred embodiments of the invention in which the aerosol-generating substrate contains from 15 percent to 20 percent by weight of oregano particles on a dry weight basis.

[0048] The aerosol-generating substrate preferably contains at least about 50 micrograms of isothymol per gram of substrate, and more preferably at least about 100 micrograms of isothymol per gram of substrate, on a dry weight basis. Alternatively or additionally, the aerosol-generating substrate preferably contains no more than about 600 micrograms of isothymol per gram of substrate, more preferably no more than about 400 micrograms of isothymol per gram of substrate, and even more preferably no more than about 250 micrograms of isothymol per gram of substrate, on a dry weight basis.

[0049] For example, the aerosol-generating substrate may contain, on a dry weight basis, from about 5 micrograms to about 600 micrograms of isothymol per gram of substrate, or from about 50 micrograms to about 400 micrograms of isothymol per gram of substrate, or from about 100 micrograms to about 250 micrograms of isothymol per gram of substrate.

[0050] In certain particularly preferred embodiments, the aerosol-generating substrate may comprise from about 100 micrograms to about 200 micrograms of isothymol per gram of aerosol-generating substrate, more preferably from about 120 micrograms to about 160 micrograms of isothymol per gram of aerosol-generating substrate. For example, the level of isothymol may be within these ranges for preferred embodiments of the invention in which the aerosol-generating substrate comprises 15 percent to 20 percent by weight of oregano particles, on a dry weight basis.

[0051] The aerosol-generating substrate preferably contains at least about 10 micrograms of thymohydroquinone per gram of substrate, more preferably at least about 25 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis. Alternatively or additionally, the aerosol-generating substrate preferably contains no more than about 200 micrograms of thymohydroquinone per gram of substrate, more preferably no more than about 150 micrograms of thymohydroquinone per gram of substrate, and even more preferably no more than about 100 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

[0052] For example, the aerosol-generating substrate may contain, on a dry weight basis, from about 1.5 micrograms to about 200 micrograms of thymobidroquinone per gram of substrate, or from about 10 micrograms to about 150 micrograms of thymobidroquinone per gram of substrate, or from about 25 micrograms to about 100 micrograms of thymobidroquinone per gram of substrate.

[0053] In certain particularly preferred embodiments, the aerosol-generating substrate may contain from about 20 micrograms to about 60 micrograms of thymobidroquinone per gram of aerosol-generating substrate, more preferably from about 30 micrograms to about 50 micrograms of thymobidroquinone per gram of aerosol-generating substrate. For example, the level of thymobidroquinone may be within these ranges for preferred embodiments of the invention in which the aerosol-generating substrate contains from 15 percent to 20 percent by weight of oregano particles, on a dry weight basis.

[0054] The ratio of characteristic compounds in the aerosol-generating substrate is preferably at least 8 times the amount of ursolic acid per gram of substrate compared to the amount of isothymol per gram of substrate, and more preferably at least 10 times the amount of isothymol per gram of substrate.

[0055] The ratio of the characteristic compounds in the aerosol-generating substrate is preferably such that the amount of ursolic acid per gram of substrate is at least 25 times the amount of thymohydroquinone per gram of substrate, and more preferably is at least 30 times the amount of thymohydroquinone per gram of substrate.

[0056] Thus, these ratios of ursolic acid to isothymol and thymohydroquinone are characteristic of the inclusion of oregano particles in an aerosol-generating substrate.

[0057] As defined above, the present invention also provides an aerosol-generating article comprising an aerosol-generating substrate formed from homogenized plant material comprising oregano particles, wherein upon heating of the aerosol-generating substrate an aerosol comprising the "characteristic compounds" of oregano is generated.

[0058] 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 regime. For purposes of carrying out Test Method A, the aerosol-generating substrate is provided in an aerosol-generating article that is compatible with a THS2.2 holder.

[0059] The Tobacco Heating System 2.2 Holder (THS2.2 Holder) was developed based on the method described in Smith et al., 2016, Regul. Toxicol. Pharmacol. 81(S2)S82-S92 of the commercially available iQOS device (Philip Morris Products SA, Switzerland). Aerosol-generating articles for use with the IQOS device are also commercially available.

[0060] The Health Canada smoking regimen is a well-defined and accepted smoking protocol as defined in the Health Canada 2000-Tobacco Products Information Regulations SOR / 2000-273, Schedule 2 published by the Canadian Department 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 using a puff volume of 55 millimeters, a puff duration of 2 seconds, and a 30 second interval between puffs, with all ventilation shut off, if any.

[0061] Therefore, in the context of the present invention, the expression "involving heating of an aerosol-generating substrate in accordance with Test Method A" means involving heating of an aerosol-generating substrate in a THS2.2 holder under a Health Canada mechanical smoking regimen, as defined in Health Canada 2000-Tobacco Products Information Regulations SOR / 2000-273, Schedule 2 published by the Canadian Department of Justice, which test method is described in ISO / TR 19478-1:2014.

[0062] For analytical purposes, the aerosol generated from the heating of the aerosol generating substrate is trapped using an appropriate device depending on the analytical method 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 successive microimpingers (20 mL) each containing methanol and an internal standard (ISTD) solution (10 mL), maintained at -60 degrees Celsius 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 for 5 minutes and centrifuging (4500 g, 5 minutes, 10 degrees Celsius). The resulting extract is diluted with methanol and mixed in an Eppendorf ThermoMixer (5 degrees Celsius, 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 the present invention, LC-HRAM-MS analysis is suitable for the identification and quantification of ursolic acid.

[0063] Samples for analysis by GCxGC-TOFMS can be generated in a similar manner, however, for GCxGC-TOFMS analysis, different solvents are appropriate for extraction and analysis of polar, non-polar, and volatile compounds separated from the bulk aerosol.

[0064] For non-polar and polar compounds, the whole aerosol is 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 micro-impingers connected in series and sealed. Each micro-impinger (20 mL) contains 10 mL of dichloromethane / methanol (80:20 v / v) containing internal standard (ISTD) and retention index marker (RIM) compounds. The micro-impingers are maintained at -80 degrees Celsius using a mixture of dry ice and isopropanol. For the analysis of non-polar compounds, the particulate phase of the whole aerosol is extracted from the glass fiber filter pad using the contents of the micro-impinger. Water is added to an aliquot (10 mL) of the resulting extract and the sample is shaken and centrifuged as described above. The dichloromethane layer is 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.

[0065] For volatile compounds, the entire aerosol is collected using two serially connected and sealed microimpingers (20 mL), filled with 10 mL of N,N-dimethylformamide containing ISTD and RIM compounds, respectively. The microimpingers are maintained at -50 to -60 degrees Celsius 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.

[0066] For the purposes of the present invention, GCxGC-TOFMS analysis is suitable for the identification and quantification of isothymol and thymohydroquinone.

[0067] 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, isothymol and thymohydroquinone, as defined above.

[0068] In an aerosol-generating article comprising the aerosol-generating substrate described above, it is preferred that upon heating of the aerosol-generating substrate by Test Method A, an aerosol is generated which comprises at least 1.5 micrograms of ursolic acid per gram of substrate, on a dry weight basis, at least 0.5 micrograms of isothymol per gram of substrate, on a dry weight basis, and at least 0.5 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

[0069] The ranges define the amount of each of the characteristic compounds in the generated aerosol per gram of aerosol-generating substrate (also referred to herein as "substrate"), which is equal to the total amount of the characteristic compound measured in the aerosol collected during Test Method A divided by the dry weight of the aerosol-generating substrate before heating.

[0070] Preferably, heating of the aerosol-generating substrate in accordance with Test Method A generates an aerosol comprising at least about 10 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 comprises at least about 25 micrograms of ursolic acid per gram of substrate, on a dry weight basis.

[0071] Alternatively or additionally, the aerosol generated from the aerosol-generating substrate preferably contains at most about 200 micrograms of ursolic acid per gram of substrate on a dry weight basis. More preferably, the aerosol generated from the aerosol-generating substrate contains at most about 150 micrograms of ursolic acid 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 ursolic acid per gram of substrate on a dry weight basis.

[0072] Preferably, heating of the aerosol-generating substrate in accordance with Test Method A generates an aerosol containing at least about 5 micrograms of isothymol 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 10 micrograms of isothymol per gram of substrate, on a dry weight basis.

[0073] Alternatively or additionally, the aerosol generated from the aerosol-generating substrate preferably contains at most about 50 micrograms of isothymol per gram of substrate on a dry weight basis. More preferably, the aerosol generated from the aerosol-generating substrate contains at most about 35 micrograms of isothymol per gram of substrate on a dry weight basis. Even more preferably, the aerosol generated from the aerosol-generating substrate contains at most about 25 micrograms of isothymol per gram of substrate on a dry weight basis.

[0074] Preferably, heating of the aerosol-generating substrate in accordance with Test Method A generates an aerosol containing at least about 5 micrograms of thymohydroquinone 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 10 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

[0075] Alternatively or additionally, the aerosol generated from the aerosol-generating substrate preferably contains at most about 50 micrograms of thymohydroquinone per gram of substrate on a dry weight basis.More preferably, the aerosol generated from the aerosol-generating substrate contains at most about 35 micrograms of thymohydroquinone per gram of substrate on a dry weight basis.Even more preferably, the aerosol generated from the aerosol-generating substrate contains at most about 25 micrograms of thymohydroquinone per gram of substrate on a dry weight basis.

[0076] Preferably, the aerosol generated from the aerosol-generating substrate according to the invention during Test Method A further comprises 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, more preferably at least about 2 micrograms of nicotine per gram of substrate, on a dry weight basis. Preferably, the aerosol comprises 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, more preferably at most about 4 micrograms of nicotine per gram of substrate, on a dry weight basis. For example, the aerosol may comprise from about 0.1 micrograms to about 10 micrograms of nicotine per gram of substrate, or from about 1 micrograms 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, on a dry weight basis. In some embodiments of the present invention, the aerosol may contain zero micrograms of nicotine.

[0077] To measure the amount of nicotine in the aerosol, various methods known in the art can be applied.

[0078] 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, more preferably at least about 100 milligrams of cannabinoid compound per gram of substrate, on a dry weight basis. 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 more preferably up to about 150 milligrams of cannabinoid compound per gram of substrate, on a dry weight basis. For example, the aerosol may contain, on a dry weight basis, 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 invention, the aerosol may contain zero micrograms of cannabinoid compound.

[0079] Preferably, the cannabinoid compound is selected from CBD and THC, more preferably the cannabinoid compound is CBD.

[0080] Various methods known in the art can be applied to measure the amount of cannabinoid compounds in the aerosol.

[0081] Carbon monoxide may also be present in the aerosol generated from an aerosol-generating substrate according to the 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.

[0082] 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 twice the amount of isothymol per gram of substrate. Thus, the ratio of ursolic acid to isothymol is at least 2:1. More preferably, the amount of ursolic acid in the aerosol generated from the aerosol-generating substrate during Test Method A is at least three times the amount of isothymol per gram of substrate, thus, the ratio of ursolic acid to isothymol is at least 3:1.

[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 twice the amount of thymobidroquinone per gram of substrate. Thus, the ratio of ursolic acid to thymobidroquinone is at least 2:1. More preferably, the amount of ursolic acid in the aerosol generated from the aerosol-generating substrate during Test Method A is at least three times the amount of thymobidroquinone per gram of substrate, thus, the ratio of ursolic acid to thymobidroquinone is at least 3:1.

[0084] A defined ratio of ursolic acid to isothymol and thymohydroquinone characterizes the aerosol derived from oregano particles. In contrast, in aerosols generated from oregano oil, the ratio of ursolic acid to isothymol and thymohydroquinone will be significantly different.

[0085] The aerosol generated from an aerosol-generating substrate according to the 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 contain less than 5 milligrams of aerosol former per gram of substrate, which may be appropriate, for example, when 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] To measure the amount of aerosol formers in an aerosol, various methods known in the art can be applied.

[0088] As discussed above, the presence of characteristic compounds in the aerosol in defined amounts and ratios indicates the inclusion of oregano particles in the homogenized plant material forming the aerosol-generating substrate.

[0089] The aerosol-generating substrate according to the present invention preferably comprises a homogenized oregano material comprising at least about 0.5 weight percent oregano particles on a dry weight basis. Preferably, the homogenized oregano material comprises at least about 0.75 weight percent oregano particles, more preferably at least about 1.5 weight percent oregano particles, more preferably at least about 2.5 weight percent oregano particles, more preferably at least about 3 weight percent oregano particles, more preferably at least about 4 weight percent oregano particles, more preferably at least about 5 weight percent oregano particles, more preferably at least about 6 weight percent oregano particles, more preferably at least about 7 weight percent oregano particles, more preferably at least about 8 weight percent oregano particles, more preferably at least 9 weight percent oregano particles, more preferably at least 10 weight percent oregano particles on a dry weight basis.

[0090] In certain embodiments of the invention, the plant particles forming the homogenized oregano material may comprise at least 99.5 percent by weight oregano particles, or at least 95 percent by weight oregano particles, or at least 90 percent by weight oregano particles, based on the dry weight of the plant particles. Thus, in such embodiments, the aerosol-generating substrate comprises oregano particles and is substantially free of other plant particles. For example, the plant particles forming the homogenized oregano material may comprise about 100 percent by weight oregano particles.

[0091] In an alternative embodiment of the present invention, the homogenized oregano material may include oregano particles in combination with at least one of tobacco particles or cannabis particles, as described below.

[0092] In the following description of the invention, the term "particulate plant material" is 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 oregano particles, or may be a mixture of oregano particles with tobacco particles, cannabis particles, or both tobacco particles and cannabis particles.

[0093] The homogenized oregano material may contain up to about 100 weight percent oregano particles on a dry weight basis, preferably up to about 90 weight percent oregano particles, more preferably up to about 80 weight percent oregano particles, more preferably up to about 70 weight percent oregano particles, more preferably up to about 60 weight percent oregano particles, and more preferably up to about 50 weight percent oregano particles on a dry weight basis.

[0094] For example, the homogenized oregano material may contain, on a dry weight basis, from about 0.5 weight percent to about 100 weight percent oregano particles, or from about 2.5 weight percent to about 90 weight percent oregano particles, or from about 10 weight percent to about 80 weight percent oregano particles, or from about 15 weight percent to about 70 weight percent oregano particles, or from about 20 weight percent to about 60 weight percent oregano particles, or from about 30 weight percent to about 50 weight percent oregano particles.

[0095] In certain particularly preferred embodiments of the present invention, the homogenized oregano material comprises from about 15 weight percent to about 20 weight percent oregano particles on a dry weight basis.

[0096] As discussed above, the inventors have identified a number of "signature compounds," which are compounds that are characteristic of the oregano plant and thus indicative of the presence of oregano plant particles within the aerosol-generating substrate.

[0097] The amount of the characteristic compounds present in the pure oregano particles is expected to be different from the amount present in the aerosol-generating substrate. The substrate fabrication process, including hydration in a slurry or suspension and drying at high temperatures, as well as the presence of other components such as aerosol formers, will differentially modify the amount of each of the characteristic compounds. The integrity of the oregano particles and the stability of the compounds under temperature and manipulation during manufacture can affect the final amount of the compounds present in the substrate. Thus, it is contemplated that the ratio of the characteristic compounds to each other will be different after the oregano particles are incorporated into substrates in various physical forms, such as sheets, strands, and granules.

[0098] The presence of oregano in the aerosol-generating substrate and the proportion of oregano provided in the aerosol-generating substrate can be determined by measuring the amount of the characteristic compound in the substrate and comparing this to the corresponding amount of the characteristic compound in the pure oregano material. The presence and amount of the characteristic compound can be performed using any suitable technique that would be known to one of skill in the art.

[0099] In a suitable technique, a sample of 250 milligrams of aerosol-generating substrate is mixed with 5 milliliters of methanol and extracted by shaking, stirring for 5 minutes and centrifugation (4500 g, 5 minutes, 10 degrees Celsius). An aliquot of the extract (300 microliters) is transferred to a silanized chromatography vial and diluted with methanol (600 microliters) and an internal standard (ISTD) solution (100 microliters). The vial is closed and mixed for 5 minutes using an Eppendorf ThermoMixer (5 degrees Celsius, 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.

[0100] In some embodiments, the homogenized oregano material further comprises up to about 75 weight percent tobacco particles on a dry weight basis.

[0101] For example, the homogenized oregano 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, more preferably about 20 weight percent to about 65 weight percent tobacco particles, more preferably about 25 weight percent to about 60 weight percent tobacco particles, and more preferably about 30 weight percent to about 70 weight percent tobacco particles.

[0102] In some preferred embodiments, the homogenized oregano material comprises, on a dry weight basis, from about 5 weight percent to about 20 weight percent oregano particles, and from about 55 weight percent to about 70 weight percent tobacco particles.

[0103] The weight ratio of oregano particles to tobacco particles in the particulate plant material forming the homogenized oregano material can vary depending on the desired flavor characteristics and composition of the aerosol.Preferably, the homogenized oregano material comprises a weight ratio of oregano particles to tobacco particles of 1:4 or less, meaning that the oregano particles make up 20% or less of the total particulate plant material.More preferably, the homogenized oregano material comprises a weight ratio of oregano particles to tobacco particles of 1:5 or less, and more preferably 1:6 or less.

[0104] For example, in a first preferred embodiment, the weight ratio of oregano particles to tobacco particles is 1:4. A ratio of 1:4 corresponds to a particulate plant material consisting of about 20 weight percent oregano particles and about 80 weight percent tobacco particles. For a homogenized oregano material formed with about 75 weight percent particulate plant material, this corresponds to about 15 weight percent oregano particles and about 60 weight percent tobacco particles in the homogenized oregano material on a dry weight basis.

[0105] In another embodiment, the homogenized oregano material comprises a weight ratio of oregano particles to tobacco particles of 1:9. In yet another embodiment, the homogenized oregano material comprises a weight ratio of oregano particles to tobacco particles of 1:30.

[0106] In the context of the present invention, the term "tobacco particles" refers to particles of any plant member 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 a preferred embodiment, the tobacco particles are substantially entirely derived from tobacco lamina. In contrast, isolated nicotine and nicotine salts, although compounds derived from tobacco, are not considered tobacco particles for purposes of the present invention and are not included in the percentage of particulate plant material.

[0107] 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 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.

[0108] 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 turn yellow and wither. During the second stage, the leaf lamina dries completely. During the third stage, the leaf stem dries completely.

[0109] 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.

[0110] Orient is a type of tobacco that has small leaves and high aromatic qualities. However, Orient tobacco has a milder flavor than, for example, Burley. Thus, Orient tobacco is generally used in relatively small proportions in tobacco blends.

[0111] Kasturi, Madura, and Jatim are subtypes of sun-cured tobacco that may be used. Preferably, Kasturi and flue-cured tobaccos are used in a blend to produce tobacco particles. Thus, the tobacco particles in the particulate plant material may comprise a blend of Kasturi and flue-cured tobaccos.

[0112] The tobacco particles may have a nicotine content of at least about 2.5 weight percent based on dry weight. More preferably, the tobacco particles may have a nicotine content of at least about 3 weight percent based on dry weight, 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 oregano particles, the tobacco with higher nicotine content preferably maintains a similar level of nicotine to a typical aerosol-generating substrate without oregano particles, since the total amount of nicotine would otherwise be reduced due to the replacement of tobacco particles with oregano particles.

[0113] Alternatively, the tobacco particles may have a nicotine content of less than about 2.5 percent by weight based on dry weight. For example, the tobacco particles may have a nicotine content of less than about 2 percent by weight, less than about 1.5 percent by weight, or less than about 1 percent by weight. In some embodiments, the tobacco particles may have a nicotine level of substantially zero.

[0114] As a result of the inclusion of tobacco particles, the aerosol-generating substrates of such embodiments, and the aerosols generated therefrom, contain a particular proportion of "signature compounds" of tobacco. Characteristic compounds generated from tobacco include, but are not limited to, anatabine, cotinine, and damascenone.

[0115] 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 content tobacco, or nicotine may be incorporated into an aerosol-generating substrate having reduced or zero tobacco content.

[0116] In a particular embodiment of the invention, the aerosol-generating substrate comprises a homogenized oregano material formed from particulate plant material consisting solely of oregano particles, having nicotine, such as a nicotine salt, incorporated into the aerosol-generating substrate.

[0117] 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, the aerosol-generating substrate comprises at least about 0.5 mg of nicotine per gram of substrate on a dry weight basis, 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.

[0118] Preferably, the aerosol-generating substrate comprises, on a dry weight basis, a maximum of about 50 mg of nicotine per gram of substrate. More preferably, the aerosol-generating substrate comprises, on a dry weight basis, 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.

[0119] 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.

[0120] 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.

[0121] In some embodiments, the aerosol-generating substrate contains substantially zero nicotine.

[0122] As an alternative or in addition to including tobacco particles in the homogenized oregano material of the aerosol-generating substrate according to the invention, the homogenized oregano material may include up to 75 weight percent cannabis particles on a dry weight basis. The term "cannabis particles" refers to particles of the cannabis plant, such as Cannabis sativa, Cannabis indica, and Cannabis ruderalis.

[0123] 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.

[0124] One or more cannabinoid compounds may optionally be incorporated into the aerosol-generating substrate, which is considered a non-cannabis material for purposes of the present invention. As used herein with respect to the present invention, the term "cannabinoid compounds" describes any one of a class of naturally occurring compounds found in parts of the cannabis plant, namely Cannabis sativa, Cannabis indica, and Cannabis ruderalis. Cannabinoid compounds are particularly concentrated in the female flower heads, which 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 compounds" is used to describe both naturally occurring and synthetically produced cannabinoid compounds.

[0125] 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.

[0126] The homogenized oregano material may further comprise a proportion of other plant flavour particles in addition to the oregano particles or a combination of oregano particles and at least one of tobacco particles and cannabis particles ("particulate plant material").

[0127] For purposes of the present invention, the term "other botanical flavour particles" refers to particles of non-oregano, non-tobacco and non-cannabis plant material capable of generating one or more flavourings upon heating. This term is considered 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 ground or powdered leaf laminae, fruits, petioles, stems, roots, seeds, buds or skins from other plants. Suitable botanical flavour 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, tea particles, bamboo particles, industrial hemp particles and combinations thereof.

[0128] The composition of the homogenized oregano material may advantageously be adjusted by blending desired amounts and types of different plant particles. This allows an aerosol-generating substrate to be formed from a single homogenized oregano material, if desired, without the need for combining or mixing different blends, as is the case, for example, in the manufacture of conventional cut fillers. Thus, manufacture of the aerosol-generating substrate may potentially be simplified.

[0129] 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 the number 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 number of particles have a diameter equal to or less than a given D95 value, and 5 percent of the number of particles have a diameter greater than a given D95 value. Similarly, in a D5 particle size distribution, 5 percent of the number of particles have a diameter equal to or less than a given D5 value, and 95 percent of the number of particles have a diameter greater than a given D5 value. Thus, in combination, the D5 and D95 ​​values ​​provide an indication of the particle size distribution of particulate plant material.

[0130] The particulate plant material may have a D95 value of 50 microns or more to a D95 value of 400 microns or less. This means that the particulate plant material may be of a distribution represented by any D95 value within a given range, i.e., the D95 may be 50 microns, or the D95 may be 55 microns, etc., up to a D95 of 400 microns. By providing a D95 value within this range, the inclusion of relatively large plant particles within the homogenized oregano 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 oregano material may adversely affect the consistency of the material.

[0131] The particulate plant material may preferably have a D95 value of about 50 microns or more and about 350 microns or less, more preferably a D95 value of about 75 microns or more and about 300 microns or less. Both the particulate oregano material and the particulate tobacco material may have a D95 value of about 50 microns or more and about 400 microns or less, preferably a D95 value of about 75 microns or more and about 350 microns or less, more preferably a D95 value of about 100 microns or more and about 300 microns or less.

[0132] Preferably, the particulate plant material may have a D5 value of about 10 microns or more to about 50 microns or less, and more preferably, a D5 value of about 20 microns or more to about 40 microns or less. Providing a D5 value within this range avoids the inclusion of very small dust particles in the homogenized oregano material, which may be desirable from a manufacturing standpoint.

[0133] In some embodiments, the particulate plant material containing oregano particles may be purposely milled to form particles having a desired particle size distribution. The use of purposely milled plant material advantageously improves the homogeneity of the particulate plant material and the consistency of the homogenized oregano material.

[0134] The diameter of 100 percent of the particulate plant material may be about 300 microns or less, more preferably about 275 microns or less. The diameter of 100 percent of the particulate oregano material and 100 percent of the particulate tobacco material may be about 300 microns or less, more preferably about 275 microns or less. The particle size range of the oregano particles allows them to be combined with tobacco particles in existing cast leaf processes.

[0135] The homogenized oregano 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, more preferably at least about 65 weight percent particulate plant material, comprising oregano particles as described above. The homogenized oregano material preferably comprises, on a dry weight basis, no more than about 95 weight percent particulate plant material, more preferably no more than about 90 weight percent particulate plant material, and even more preferably no more than about 85 weight percent particulate plant material. For example, the homogenized oregano 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 oregano material comprises, on a dry weight basis, about 75 weight percent particulate plant material.

[0136] Thus, the particulate plant material is typically combined with one or more other ingredients to form a homogenized oregano material.

[0137] As defined above, the homogenized oregano material further includes an aerosol former. Upon volatilization, the aerosol former can carry other vaporized compounds that are released from the aerosol-generating substrate upon heating, such as nicotine and flavorants in the aerosol. The aerosolization of a particular compound from an aerosol-generating substrate is not determined solely by its boiling point. The amount of a compound that is aerosolized can be influenced by the physical form of the substrate, as well as by other components that are also present in the substrate. The stability of the compound under the temperature and time frame of aerosolization also impacts the amount of the compound present in the aerosol.

[0138] Suitable aerosol formers for inclusion within the homogenized oregano 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 dimethyl tetradecanedioate). The homogenized oregano material may contain a single aerosol former or a combination of two or more aerosol formers.

[0139] The homogenized oregano material preferably has an aerosol former content of from about 5% to about 30% by weight on a dry weight basis, such as from about 10% to about 25% by weight on a dry weight basis, or from about 15% to about 20% by weight on a dry weight basis.

[0140] For example, where 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 content may preferably be from about 5 weight percent to about 30 weight percent on a dry weight basis.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.

[0141] In other embodiments, the homogenized oregano 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 stream of aerosol former contacts the aerosol-generating substrate so as to entrain flavors from the aerosol-generating substrate in the aerosol.

[0142] The aerosol former may act as a wetting agent in the aerosol-generating substrate.

[0143] Alternatively, or additionally, the homogenized oregano material may further comprise an acid. The acid may comprise a carboxylic acid. The carboxylic acid may comprise a ketone group. Preferably, the carboxylic acid may comprise a ketone group having less than about 10 carbon atoms, such as levulinic acid or lactic acid, or less than about 6 carbon atoms or less than about 4 carbonate atoms. The inclusion of an acid may be particularly advantageous when the aerosol-generating substrate is in the form of a gel, as described below.

[0144] As defined above, the homogenized oregano material further comprises a binder for modifying the mechanical properties of the particulate plant material, wherein the binder is included in the homogenized oregano material during manufacture as described herein. Suitable exogenous binders known to those skilled in the art are known in the art and include, but are not limited to, 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, polysaccharides such as starch, organic acids such as alginic acid, sodium alginate, conjugate base salts of organic acids such as agar and pectin, and combinations thereof. Preferably, the binder comprises guar gum.

[0145] The binder is preferably present in an amount of about 1% to about 10% by weight, based on the dry weight of the homogenized oregano material, and preferably in an amount of about 2% to about 5% by weight, based on the dry weight of the homogenized oregano material.

[0146] In addition, the homogenized oregano material may optionally further comprise one or more lipids to enhance the diffusion rate of the volatile components (e.g., aerosol formers, (E)-anethole, and nicotine), which lipids are included in the homogenized oregano material during manufacture as described herein. Suitable lipids for inclusion in the homogenized plant 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 Revel A, and combinations thereof.

[0147] Alternatively, or additionally, the homogenized oregano material may further comprise a pH adjuster.

[0148] Alternatively or additionally, the homogenized oregano material may further include reinforcing fibers to alter the mechanical properties of the homogenized oregano material, where the reinforcing fibers are included in the homogenized oregano material during the manufacture described herein. Suitable exogenous fibers for inclusion in the homogenized oregano material are known in the art and include fibers formed from non-tobacco and non-oregano materials, including, but not limited to, cellulose fibers, soft wood fibers, hard wood fibers, jute fibers, and combinations thereof. Exogenous fibers derived from tobacco and / or oregano may also be added. Any fibers added to the homogenized oregano material are not considered to form part of the "particulate plant material" defined above. Prior to inclusion in the homogenized oregano material, the fibers may be treated by any 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.

[0149] Suitable fibers are typically greater than 400 micrometers and have a length of 4 mm or less, preferably in the range of 0.7 mm to 4 mm. The fibers are preferably 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 oregano material may depend on the type of material, particularly the method used to produce the homogenized oregano 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 where the homogenized oregano material is oregano paper formed in a papermaking process.

[0150] In a preferred embodiment of the present invention, the homogenized oregano material comprises oregano 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. In such an embodiment, the homogenized oregano material preferably further comprises about 2 weight percent to about 15 weight percent of fiber. Particularly preferred, the binder is guar gum.

[0151] The homogenized plant material of the aerosol-generating substrate according to the invention may comprise a single type of homogenized plant material, or two or more types of homogenized plant material having mutually different compositions or morphologies. For example, in one embodiment, the aerosol-generating substrate comprises oregano 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 oregano particles within mutually different sheets.

[0152] The homogenized oregano 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 membrane.

[0153] The homogenized plant material may be provided in any suitable form. For example, the homogenized oregano material may be in the form of one or more sheets. As used herein with respect to the present invention, the term "sheet" describes a layered element having a width and length substantially greater than its thickness.

[0154] Alternatively, or additionally, the homogenized oregano material may be in the form of a plurality of pellets or granules.

[0155] Alternatively, or additionally, the homogenized oregano material may be in a form that can be filled into a cartridge or shisha consumable, or used in a shisha device. The present invention includes a cartridge or shisha device that includes the homogenized oregano material.

[0156] Alternatively, or additionally, the homogenized oregano 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 width and length substantially greater than its width and thickness. The term "strand" should be considered to encompass strips, pieces, and any other homogenized oregano material having a similar form. Strands of homogenized oregano material may be formed from a sheet of homogenized oregano material, for example, by cutting or shredding, or by other methods, such as extrusion methods.

[0157] In some embodiments, the strands may be formed in situ within the aerosol-generating substrate as a result of splitting or breaking of a sheet of homogenized oregano material during formation of the aerosol-generating substrate, for example as a result of crimping. The strands of homogenized oregano material within the aerosol-generating substrate may be separated from one another. Alternatively, each strand of homogenized oregano material within the aerosol-generating substrate may be at least partially connected to one or more adjacent strands along the length of the strand. 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 oregano material during manufacture of the aerosol-generating substrate, as described above.

[0158] The aerosol-generating substrate is preferably in the form of one or more sheets of homogenized oregano material. In various embodiments of the present invention, the one or more sheets of homogenized oregano material may be produced by a casting process. In various embodiments of the present invention, the one or more sheets of homogenized oregano material may be produced by a papermaking process. The one or more sheets described herein may each individually have a thickness of from 100 micrometers to 600 micrometers, preferably from 150 micrometers to 350 micrometers, and most preferably from 200 micrometers to 250 micrometers. Individual thickness refers to the thickness of an individual sheet, and combined thickness refers to the total thickness of all sheets that make up 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, and the two sheets are stacked within the aerosol-generating substrate.

[0159] One or more of the sheets described herein may each individually have a weight of about 100 g / m 2 ~about 300g / m 2 The sheet may have a basis weight of 100 g.

[0160] One or more of the sheets described herein may each individually have a density of about 0.3 g / cm3 ~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 granular material is 0.01 to 0.05.

[0161] The term "tensile strength" is used throughout this specification to indicate a measurement of the force required to stretch a sheet of homogenized oregano material to breakage. More specifically, tensile strength is the maximum pulling force per unit width that the sheet material will withstand before breaking, measured in the machine direction or 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."

[0162] The materials and equipment required to perform the test in accordance with ISO 1924-2 are a general purpose tensile / compression testing machine (Instron 5566, or equivalent), a 100 Newton tensile load cell (Instron, or equivalent), two pneumatically operated grips, a steel gauge block 180±0.25 mm long (width: approximately 10 mm, thickness: approximately 3 mm), 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.

[0163] Samples are prepared by first conditioning a sheet of homogenized oregano material at 22±2 degrees Celsius and 60±5% relative humidity for at least 24 hours prior to testing. 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 ends of the test pieces should be neatly cut so that no more than three test specimens are cut at the same time.

[0164] The tension / compression testing apparatus is set up by installing a 100 Newton tension load cell, powering on the universal tension / compression testing machine and computer, selecting a predefined measurement method in the software, and setting the test speed to 8 millimeters / minute. The tension load cell is then calibrated and pneumatically actuated grips are attached. The test distance between the pneumatically actuated grips is adjusted to 180 ± 0.5 millimeters by a steel gauge block, and the distance and force are set to zero.

[0165] The test specimen is then placed straight and centered between the grips, avoiding finger contact with the area to be tested. The upper grip is 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 grip is closed, the initial force should be 0.05-0.20 Newtons. While the upper grip is moving upwards, 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 are moved apart a distance of more than 10 millimeters. If not, the result is rejected and additional measurements are performed.

[0166] If the available test specimen of homogenized oregano 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.

[0167] One or more sheets of homogenized oregano material described herein may each individually have a tensile strength at 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.

[0168] One or more of the sheets described herein may each individually have a tensile strength of 100N / m to 800N / m, or preferably 280N / m to 620N / 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.

[0169] 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, of the sheet is avoided during high speed processing of the sheet.

[0170] In embodiments of the invention in which the aerosol-generating substrate comprises one or more sheets of homogenized oregano material, the sheets are preferably in the form of an assembly of one or more sheets. As used herein, the term "assembly" means that the sheet of homogenized oregano material is spiraled, 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 requisite transverse compression of the sheets.

[0171] As used herein, the term "longitudinal" refers to a direction corresponding to the main longitudinal axis of the aerosol-generating article extending between the upstream and downstream ends of the aerosol-generating article. In 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, for a plug or rod having a circular cross section, the maximum width corresponds to the diameter of the circle.

[0172] 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 having 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 comprise one or more plugs, preferably aligned longitudinally.

[0173] 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 at which the aerosol is delivered to a user of the article.

[0174] One or more sheets of homogenized oregano material may be collected 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.

[0175] Alternatively, one or more sheets of homogenized oregano material may be cut into strands as mentioned above. In such an embodiment, the aerosol-generating substrate comprises a plurality of strands of homogenized oregano material. The strands may be used to form plugs. Typically, such strands have a width of at least about 0.2 mm, or at least about 0.5 mm. Preferably, such strands have a width of 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 may 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.

[0176] 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, the length of the strands corresponding to the length of the plugs. The strands are fragile and may break, especially during transitions. In such cases, the length of some of the strands may be shorter than the length of the plugs.

[0177] The plurality of strands preferably extend substantially longitudinally along the length of the aerosol-generating substrate, aligned with the longitudinal axis, and are thus preferably aligned substantially parallel to one another. The plurality of longitudinal strands of aerosol-generating material are preferably substantially non-coiled.

[0178] The homogenized oregano material strands 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 homogenized oregano material strands preferably each have a mass to surface area ratio of about 0.2 milligrams per square millimeter or less, more preferably about 0.15 milligrams per square millimeter or less. The mass to surface area ratio is calculated by dividing the mass of the homogenized oregano material strands in milligrams by the geometric surface area of ​​the homogenized oregano material strands in square millimeters.

[0179] The one or more sheets of homogenized oregano material may be textured by crimping, embossing, or perforation. The one or more sheets may be textured before being assembled or before being cut into strands. The one or more sheets of homogenized oregano material are preferably crimped prior to assembly so that the homogenized oregano material may be in the form of a crimped sheet, more preferably in the form of 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.

[0180] In one embodiment, the aerosol-generating substrate may be in the form of a single plug of aerosol-generating substrate. The plug of aerosol-generating substrate may preferably comprise a plurality of strands of homogenized oregano material. Most preferably, the plug of aerosol-generating substrate may comprise one or more sheets of homogenized oregano material. The one or more sheets of homogenized oregano material may preferably be crimped to have a plurality of ridges or corrugations substantially parallel to the cylindrical axis of the plug. This process advantageously facilitates assembling the crimped sheet of homogenized oregano material to form a plug. Preferably, the one or more sheets of homogenized oregano material may be assembled. Of course, the crimped sheet of homogenized oregano material may alternatively or additionally have a plurality of substantially parallel ridges or corrugations that form an acute or obtuse angle with respect to the cylindrical axis of the plug. The sheet may be crimped to the extent that the integrity of the sheet is interrupted in a plurality of parallel ridges or corrugations, causing separation of the material and resulting in the formation of pieces, strands or strips of the homogenized oregano material.

[0181] In another embodiment of the aerosol-generating substrate, the homogenized plant material comprises a first plug comprising a first homogenized plant material and a second plug comprising a second homogenized plant material, where the first homogenized plant material and the second homogenized plant material comprise different levels of oregano particles and tobacco particles. For example, the first homogenized plant material may comprise about 50 weight percent to about 75 weight percent oregano particles on a dry weight basis, and the second homogenized plant material comprises about 50 weight percent to about 75 weight percent tobacco particles on a dry weight basis. Overall, according to the present invention, it is preferred that the homogenized plant material in the aerosol-generating substrate comprises at least 2.5 weight percent oregano particles and up to 70 weight percent tobacco particles on a dry weight basis.

[0182] In such an arrangement, the first homogenized plant material preferably comprises a first particulate plant material having a higher percentage of oregano particles than the second homogenized plant material, which may be a homogenized tobacco material substantially free of oregano particles.

[0183] 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.

[0184] Optionally, the aerosol-generating substrate may comprise one or more plugs. Preferably, the substrate may comprise 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.

[0185] 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.

[0186] For example, in a preferred arrangement, a downstream plug containing a major proportion of oregano particles may abut an upstream plug containing a major proportion of tobacco particles to form a rod. Alternative configurations are also envisioned in which the upstream and downstream positions of each plug are altered relative to one another. Alternative configurations are also envisioned in which a third homogenized plant material contains different proportions of oregano particles and tobacco particles to form a third plug. If more than one plug is 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 wrapped in a thermally conductive sheet material, as described below.

[0187] 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 total length of the plugs may be about 10 mm to about 40 mm, preferably about 10 to about 15 mm, more preferably about 12 mm. The first plug and the second plug may have the same length or different lengths. When 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 oregano particles in the substrate. Generally, the substrate may preferably comprise 0 to 75 weight percent tobacco particles and 0.5 to 75 weight percent oregano particles on a dry weight basis. The second plug is preferably at least 40 to 50 percent longer than the first plug.

[0188] 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. Of course, all other physical properties described with respect to the embodiment in which a single homogenized plant material is present are equally applicable to the embodiment in which a first homogenized plant material and a second homogenized plant material are present. Furthermore, of course, the description of additives (e.g., binders, lipids, fibers, aerosol formers, humectants, plasticizers, flavors, fillers, aqueous and non-aqueous solvents, and combinations thereof) with respect to the embodiment in which a single homogenized plant material is present are equally applicable to the embodiment in which a first homogenized plant material and a second homogenized plant material are present.

[0189] 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.

[0190] The first sheet may be a textured sheet and the second sheet may be a non-textured sheet.

[0191] Both the first and second sheets may be textured sheets.

[0192] 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 perforated, alternatively the first sheet may be perforated and the second sheet crimped.

[0193] Both the first and second sheets may be morphologically differently crimped sheets from one another, for example, the second sheet may be crimped with a different number of crimps per sheet unit width compared to the first sheet.

[0194] The sheets may be assembled to form a plug. The sheets that are assembled to form a plug may have different physical dimensions. The width and thickness of the sheets may vary.

[0195] It may be desirable to assemble two sheets, each having a different thickness, or each having a different width, which may vary the physical properties of the plug, which may facilitate the formation of a blended plug of aerosol-generating substrate from sheets of different chemical composition.

[0196] 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.

[0197] The first sheet may have a first width and the second sheet may have a second width different from the first width.

[0198] The first sheet and the second sheet may be disposed in an overlapping relationship prior to being assembled together or at the time they are 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.

[0199] If it is desired that both the first and second sheets are 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 are assembled to form a plug of aerosol-generating substrate. Optionally, the sheets may be crimped together prior to assembly to facilitate assembly.

[0200] 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 crinkle the first sheet differently relative to the second sheet.

[0201] It will be understood that all other physical properties described with respect to the embodiment in which a single homogenized plant material is present are equally applicable to the embodiment 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 the embodiment in which a single homogenized plant material is present are equally applicable to the embodiment in which a first homogenized plant material and a second homogenized plant material are present.

[0202] 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.

[0203] The homogenized oregano material is preferably in the form of "cast leaf". The term "cast leaf" is used herein to refer to a sheet product made by a casting process based on casting a slurry containing plant particles (e.g. oregano particles, or tobacco particles and oregano particles in a mixture) and a binder (e.g. guar gum) onto a support surface (such as 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 US Pat. No. A-5,724,998 for the production of 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 binders. The slurry is cast onto a support surface and dried to form a sheet of homogenized oregano material.

[0204] In certain preferred embodiments, the homogenized oregano material used in the articles according to the invention is manufactured by casting. Homogenized oregano material made by a casting process typically comprises agglomerated particulate plant material.

[0205] In the cast leaf process, substantially all of the soluble fraction is retained within the plant material, advantageously preserving most of the flavor. Additionally, the energy-intensive papermaking process is avoided.

[0206] In one preferred embodiment of the present invention, a mixture is formed that includes particulate plant material, water, a binder, and an aerosol former to form a homogenized oregano material. A sheet is formed from the mixture, and the sheet is then dried. The mixture is preferably an aqueous mixture. As used herein, "dry mass" refers to the weight of the particulate non-water component relative to the sum of the weights of all non-water components in the mixture, expressed as a percentage. The composition of an aqueous mixture may be referred to by "dry mass percentage," which refers to the weight of the non-water component relative to the weight of the entire aqueous mixture, expressed as a percentage.

[0207] The mixture may be a slurry. As used herein, a "slurry" is a homogenized aqueous mixture having a relatively low dry mass. As used in the methods herein, a slurry may preferably have a dry mass of 5 percent to 60 percent.

[0208] Alternatively, the mixture may be a dough. As used herein, a "dough" is an aqueous mixture having a relatively high dry mass. As used in the methods herein, a dough may preferably have a dry mass of at least 60 percent, more preferably at least 70 percent.

[0209] Slurries and doughs containing greater than 30 percent dry mass may be preferred in certain embodiments of the process of the present invention.

[0210] The step of mixing the particulate plant material, water, and other optional components may 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 high shear mixer. Such mixing breaks down and uniformly disperses the various phases of the mixture. For higher viscosity mixtures, i.e. some lumps, a kneading process may be used to uniformly distribute the various phases of the mixture.

[0211] The method according to the invention may further comprise a step of vibrating the mixture to disperse the various components. Vibrating the mixture, i.e. for example vibrating the tank or silo in which the homogenized mixture is present, may help homogenize the mixture, especially if it is a low viscosity mixture, i.e. some slurry. If not only mixing but also vibration is performed, shorter mixing times may be required to homogenize the mixture to the optimal target value for casting.

[0212] When the mixture is a slurry, the web of homogenized oregano material is preferably formed by a casting process that includes casting the slurry onto a support surface, such as a belt conveyor. The method of making homogenized oregano material includes drying the cast web to form a sheet. The cast web may be dried at room temperature or at an ambient temperature of at least about 60 degrees Celsius, more preferably at least about 80 degrees Celsius, for a suitable length of time. The cast web is preferably dried at an ambient temperature of not more than 200 degrees Celsius, more preferably not more than about 160 degrees Celsius. For example, the cast web may be dried at a temperature of about 60 degrees Celsius to about 200 degrees Celsius, or about 80 degrees Celsius to about 160 degrees Celsius. The moisture content of the sheet after drying is preferably about 5 percent to about 15 percent 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 on or unwound from a bobbin without breaking or deforming.

[0213] If the mixture is a dough mass, the dough mass may be extruded in the form of a sheet, strand, or strip prior to the step of drying the extruded mixture. Preferably, the dough mass may be extruded in the form of a sheet. The extruded mixture may be dried at room temperature or at a temperature of at least about 60 degrees Celsius, more preferably at least about 80 degrees Celsius, for a suitable length of time. The extruded mixture is preferably dried at an ambient temperature of not more than 200 degrees Celsius, more preferably not more than about 160 degrees Celsius. For example, the extruded mixture may be dried at a temperature of about 60 degrees Celsius to about 200 degrees Celsius, or about 80 degrees Celsius to about 160 degrees Celsius. 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 a web formed from a slurry, a sheet formed from the dough mass requires a shorter drying time and / or a lower drying temperature.

[0214] 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.

[0215] After the sheet has dried, the method according to the invention may optionally include cutting the sheet into strands, pieces or strips for formation of an aerosol-generating substrate, as described above. The strands, pieces or strips may be brought together using suitable means to form a rod of the aerosol-generating substrate. In the formed rod of the 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.

[0216] The method according to the invention may optionally further comprise, after the drying step, a step of winding the sheet onto a bobbin.

[0217] 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 the 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 invention, the plant material will include tobacco particles, optionally combined with oregano particles.

[0218] More specifically, the method of producing plant paper includes a first step of mixing plant material with water to form a dilute suspension that primarily contains discrete cellulose fibers. The suspension has a lower viscosity and a higher water content than the slurries produced in the casting process. This first step may involve soaking, optionally in the presence of an alkali such as sodium hydroxide, and optionally the application of heat.

[0219] The method further includes a second step of separating the suspension into an insoluble portion comprising the insoluble residue of the fibrous plant material and a liquid or aqueous portion comprising the soluble plant compounds. Water remaining in the insoluble residue of the fibrous plant material may be drained through a screen acting as a sieve so that a web of randomly woven fibers may be laid down. Water may be further removed from this web by pressing with rollers, optionally assisted by suction or vacuum.

[0220] 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 is formed.

[0221] 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 matter or concentrated plant matter from another process can be added to the sheet. The extract or concentrated extract may be from another variety of the same species of plant, or from another species of plant.

[0222] This process has been used with tobacco to make reconstituted tobacco products, also known as tobacco paper, as described in US Patent No. A-3,860,012. The same process may be used with one or more plants to produce paper-like sheet materials, such as sheets of oregano paper.

[0223] 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 oregano material is in the form of oregano paper.

[0224] The homogenized tobacco material or homogenized oregano material produced by such processes is called tobacco paper or oregano paper. Homogenized plant material produced by papermaking processes is distinguishable 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. Mixed tobacco oregano paper refers to homogenized plant material produced by such processes using a mixture of tobacco and oregano materials.

[0225] In embodiments where the aerosol-generating substrate comprises a combination of oregano particles and tobacco particles, the aerosol-generating substrate may comprise one or more sheets of oregano paper and one or more sheets of tobacco paper. The sheets of oregano 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 oregano 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 oregano in the aerosol-generating substrate may be adjusted by varying the number of tobacco and oregano sheets, respectively, or the amount of oregano and tobacco strands, strips or pieces, respectively, within the rod.

[0226] For example, the number or amount of tobacco and oregano sheets or strands may be adjusted to provide a cumin to tobacco ratio of about 1:4, or about 1:9, or about 1:30.

[0227] Other known processes which may be applied to the production of homogenized plant material are, for example, the dough reconstitution process of the type described in US-A-3,894,544, and the extrusion process of the type described in GB-A-983,928. Generally, the density of homogenized plant material produced by the extrusion and dough reconstitution processes is greater than the density of homogenized plant material produced by the casting process.

[0228] In an alternative embodiment of the present invention, the homogenized oregano material is in the form of a gel composition formed of oregano particles, an aerosol former, and a binder.

[0229] When the homogenized oregano material is in the form of a gel composition containing oregano particles, the binder preferably comprises a cellulose ether, such as carboxymethyl cellulose. The binder may be present in an amount of about 1 weight percent to about 5 weight percent, based on the total weight of the gel. For example, the gel composition may comprise 1.5 weight percent to 3.5 weight percent sodium carboxymethyl cellulose.

[0230] The gel composition preferably comprises at least about 60 weight percent of an aerosol former, such as glycerin, based on the total weight of the gel. For example, the gel composition may comprise 65 to 85 weight percent glycerin.

[0231] Optionally, the gel composition may further include an acid, such as lactic acid. The acid may be present in an amount of up to about 6 weight percent, based on the total weight of the gel composition. Optionally, the gel composition may include up to about 5 weight percent nicotine, based on the total weight of the gel composition. Optionally, the gel composition includes about 10 weight percent to about 30 weight percent water, based on the total weight of the gel composition.

[0232] In embodiments where the homogenized oregano material is in the form of a gel composition, the aerosol-generating substrate preferably comprises a porous medium loaded with the gel composition. The term "porous" is used herein to refer to a material that provides a plurality of pores or openings that allow the passage of air through the material.

[0233] The porous medium may be any suitable porous material capable of holding or retaining the gel composition. Ideally, the porous medium may allow the gel composition to move within it. In certain embodiments, the porous medium comprises natural materials, synthetic, or semi-synthetic, or a combination thereof. In certain embodiments, the porous medium comprises a sheet material, a foam, or a fiber, such as loose fiber, or a combination thereof. In certain embodiments, the porous medium comprises a woven, non-woven, or extruded material, or a combination thereof. It is preferred that the porous medium comprises cotton, paper, viscose, PLA, or cellulose acetate, or a combination thereof. It is preferred that the porous medium comprises a sheet material, such as cotton or cellulose acetate. In a particularly preferred embodiment, the porous medium comprises a sheet made of cotton fibers.

[0234] The porous media used in the present invention may be crimped or chopped. In a preferred embodiment, the porous media is crimped. In an alternative embodiment, the porous media comprises chopped porous media. The crimping or chopping process can be before or after loading with the gel composition.

[0235] Preferably, when the homogenized oregano material is in the form of a gel composition loaded onto a porous medium, the aerosol-generating substrate comprises an elongated susceptor element extending longitudinally through or adjacent to the porous medium.

[0236] Preferably, the aerosol-generating substrate of an aerosol-generating article according to the present invention comprises at least about 200 mg of homogenized oregano material, more preferably at least about 250 mg of homogenized oregano material, more preferably at least about 275 mg of homogenized oregano material.

[0237] An aerosol-generating article according to the 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 preferably has a length of from about 10 to about 45 mm, more preferably from about 10 mm to about 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.

[0238] 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 the aerosol-generating substrate corresponds to the diameter of the rod including any wrapper.

[0239] The rod of aerosol-generating substrate of the aerosol-generating article according to the invention is preferably surrounded along at least a portion of its length by one or more wrappers. The one or more wrappers may comprise a paper wrapper or a non-paper wrapper, or both. Suitable paper wrappers for use in certain embodiments of the 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 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 oregano material formed from particulate plant material, the particulate plant material containing oregano 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.

[0240] In certain embodiments of the present invention, the aerosol-generating substrate is surrounded along at least a portion of its length by a heat-conducting sheet material, such as, for example, a metal foil, such as aluminum foil, or metalized paper. The metal foil or metalized paper serves the purpose of rapidly conducting heat throughout the aerosol-generating substrate. In addition, the metal foil or metalized paper may function to prevent ignition of the aerosol-generating substrate if a consumer attempts to ignite it. Furthermore, during use, the metal foil or metalized paper may prevent odors generated with heating of the outer wrapper 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 heated externally during use to generate an aerosol. Alternatively, or additionally, a 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 include metal particles, such as iron particles.

[0241] The one or more wrappers surrounding the aerosol-generating substrate preferably have a total thickness of from about 0.1 mm to about 0.9 mm.

[0242] 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. Aerosol-generating articles according to the present invention also include, but are not limited to, cartridges or shisha consumables.

[0243] The aerosol-generating article according to the invention may optionally include a support element comprising at least one hollow tube immediately downstream of the aerosol-generating substrate. One function of the tube is to position the aerosol-generating substrate towards the distal end of the aerosol-generating article so that it can come into contact with the heating element. The tube acts to prevent the aerosol-generating substrate from being forced along the aerosol-generating article towards 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.

[0244] Alternatively or additionally, the aerosol-generating article according to the invention optionally comprises an aerosol cooling element downstream of the aerosol-generating substrate and immediately downstream of the hollow tube forming the support element. In use, the aerosol formed by the volatile compounds released 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 aerosol cooling element may be a hollow tube, such as a hollow cellulose acetate tube or a cardboard tube, which may be similar to the support element immediately downstream of the aerosol-generating substrate. The aerosol cooling element may be a hollow tube with the same outer diameter but with an inner diameter smaller or larger than the hollow tube forming the support element. In one embodiment, the aerosol cooling element rolled in paper comprises 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 polymeric sheet, and aluminum foil. Alternatively, the aerosol cooling element may be made of woven or non-woven 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 an assembly of crimped sheets of polylactic acid wrapped in 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.

[0245] One or more additional hollow tubes may be provided downstream of the aerosol cooling element.

[0246] The aerosol-generating article according to the present invention may further comprise a filter or mouthpiece downstream of the aerosol-generating substrate and, if present, the support element and the aerosol cooling element. The filter may comprise one or more filtration materials for removing particulate components, gaseous components, or a combination thereof. Suitable filtration materials are known in the art and include, but are not limited to, fibrous filtration 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 about 7 mm long, but may have a length of about 5 mm to about 10 mm.

[0247] An aerosol-generating article according to the invention may include an oral end cavity at the downstream end of the article. The oral end cavity may be defined by one or more wrappers extending downstream from the filter or mouthpiece. Alternatively, the oral end cavity may be defined by a separate tubular element provided at the downstream end of the aerosol-generating article.

[0248] Preferably, the aerosol-generating article according to the invention 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.

[0249] Aerosol-generating articles according to the present invention may optionally further comprise an upstream element at the upstream end of the aerosol-generating substrate. The upstream element may be a porous plug element, such as a plug of fibrous filtration material, such as cellulose acetate.

[0250] In a preferred embodiment of the 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.

[0251] In a particularly preferred embodiment having this arrangement, the aerosol-generating article comprises an aerosol-generating substrate, an upstream element at the upstream end of the aerosol-generating substrate, a support element downstream of the aerosol-generating substrate, an aerosol cooling element downstream of the support element, and a filter downstream of the aerosol cooling element. Both the support element and the aerosol cooling element are preferably in the form of a hollow tube. The aerosol-generating substrate preferably comprises an elongated susceptor element extending longitudinally through the substrate.

[0252] In one particularly preferred embodiment, the aerosol-generating substrate has a length of about 33 mm and an outer diameter of about 5.5 mm to 6.7 mm, the aerosol-generating substrate comprises about 340 mg of homogenized oregano material in the form of a plurality of strands, the homogenized oregano material comprising 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 is provided.

[0253] Aerosol-generating articles according to the invention may have an overall length of at least about 30mm, or at least about 40mm. The overall length of the aerosol-generating article may be less than 90mm, or less than about 80mm.

[0254] 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.

[0255] The aerosol-generating article may have an outer diameter of from about 5 mm to about 8 mm, preferably from about 6 mm to about 8 mm, In one embodiment, the aerosol-generating article has an outer diameter of about 7.3 mm.

[0256] The aerosol-generating article according to the present invention may further comprise one or more aerosol modification elements. The aerosol modification elements 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 taste or aroma to the aerosol that passes through the filter in use, or agents that remove flavors from the aerosol that passes through the filter in use.

[0257] 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 wetting 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, the liquid flavorings may be added directly to the homogenized oregano material, for example, by adding flavoring to the slurry or ingredients during the manufacture of the homogenized oregano material, or by spraying the liquid flavorings onto the surface of the homogenized oregano material.

[0258] The one or more liquid flavorings may include any flavoring 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. The liquid or solid flavorings may also be disposed directly on the material forming the filter, such as cellulose acetate tow. Suitable flavors or flavorings include, but are not limited to, menthol, mint (such as peppermint and oak pitta), chocolate, licorice, citrus and other fruit flavors, gamma octalactone, vanillin, ethyl vanillin, breath freshener flavors, spice flavors (such as cinnamon), methyl salicylate, linalool, eugenol, bergamot oil, geranium oil, lemon oil, cannabis oil, and tobacco flavors. Other suitable flavors may include flavoring compounds selected from the group consisting of acids, alcohols, esters, aldehydes, ketones, pyrazines, combinations thereof, or blends thereof, and the like.

[0259] In certain embodiments of the present invention, the aerosol modifier may be an essential oil derived from one or more plants. For example, a homogenized oregano material may include oregano oil, such as oregano essential oil, to further enhance the oregano flavor delivered to the consumer upon heating.

[0260] In certain embodiments of the present invention, the aerosol-generating substrate may comprise homogenized plant material comprising a combination of particulate oregano material, such as tea particles, and oregano oil.

[0261] The aerosol modifier may be an adsorbent material, such as activated carbon, that removes certain components of the aerosol passing through the filter and thereby modifies the taste and aroma of the aerosol.

[0262] 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 oregano material and an aerosol modifying element. In various embodiments, the aerosol modifying element may be located adjacent to the homogenized oregano material or embedded in the homogenized oregano material. Typically, the aerosol modifying element may be located downstream of the aerosol-generating substrate, most typically within an aerosol cooling element, within a filter of the aerosol-generating article, e.g., within a filter plug, or within a cavity, preferably within a cavity 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 polymeric matrix materials, or combinations thereof.

[0263] 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.

[0264] 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 may 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 cavity, preferably within a cavity between filter plugs.

[0265] When the aerosol modifying element is in the form of a polymeric matrix material, the polymeric matrix material releases the flavouring 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 flavouring may be trapped within a domain of the polymeric matrix material and releasable from the polymeric matrix material upon compression of the polymeric matrix material. Preferably, the flavouring is released upon compression of the polymeric matrix material at a force of about 15 Newtons. Such a flavour modifying element may provide a sustained release of the liquid flavouring over a force range of at least 5 Newtons, such as 5N to 20N, as described in WO2013 / 068304. Typically, such a polymeric matrix material may be located within beads within the filter.

[0266] 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.

[0267] For example, a substrate as described herein may be used in a heated aerosol-generating article of the type disclosed in WO-A-2009 / 022232, comprising 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 a substrate as described herein may also be used in heated aerosol-generating articles comprising combustible heat sources having other configurations.

[0268] 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 an aerosol generating substrate as described above.

[0269] In a preferred embodiment, the aerosol-generating substrate as described herein may be used in a heated aerosol-generating article for use in an electrically operated aerosol generating system in which the aerosol-generating substrate of the heated aerosol-generating article is heated by an electrical heat source.

[0270] For example, an aerosol-generating substrate as described herein may be used in heated aerosol-generating articles of the type disclosed in EP-A-0 822 760.

[0271] The heating element of such an aerosol-generating device may be in any suitable form for conducting heat. Heating of the aerosol-generating substrate may be accomplished internally, externally, or both. The heating element may preferably be a heater blade or pin adapted to be inserted into the substrate such that the substrate is heated from the inside. Alternatively, the heating element may partially or completely surround the substrate and heat it circumferentially from the outside.

[0272] 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 external to the aerosol-generating substrate or internal 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 up as a result of hysteresis losses or induced eddy currents, which heat the susceptor through ohmic or resistive heating.

[0273] The electrically operated aerosol generating system comprising an induction heating device also comprises 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 comprising an induction heating device and an aerosol-generating article having a susceptor are described in WO-A1-95 / 27411 and WO-A1-2015 / 177255.

[0274] The susceptor may be a plurality of susceptor particles that may be deposited on or embedded within the aerosol-generating substrate. If 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. The susceptor particles may, for example, be fixed by the substrate in sheet form and remain in their initial position. The susceptor particles may preferably be uniformly distributed within the homogenized oregano 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 oregano material sheet of the substrate. Alternatively, susceptors in the form of one or more sheets, strips, pieces, or rods may also be used to be placed next to the homogenized oregano material or embedded within the homogenized oregano material. In one embodiment, the aerosol-forming substrate comprises one or more susceptor strips. For example, a rod of the aerosol-generating substrate may comprise an elongated susceptor element extending longitudinally through its substrate. In another embodiment, the susceptor is present in an aerosol generating device.

[0275] The susceptor may have a heat loss of more than 0.05 Joules / kilogram, preferably more than 0.1 Joules / kilogram. Heat loss is the capacity of the susceptor to transfer heat to the surrounding material. Since the susceptor particles are preferably uniformly distributed within the aerosol-generating substrate, uniform heat loss from the susceptor particles is achieved, thus resulting in a uniform heat distribution within the aerosol-generating substrate, which may result 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 an embodiment, the average temperature reached within the aerosol-generating substrate is preferably about 200 degrees Celsius to about 240 degrees Celsius.

[0276] The reduction of the risk of overheating of the aerosol-generating substrate may be supported by the use of a susceptor material with a Curie temperature, which allows the heating process due to hysteresis losses to reach only up to a certain maximum temperature. The susceptor may have a Curie temperature of about 200 degrees Celsius to about 450 degrees Celsius, preferably about 240 degrees Celsius to about 400 degrees Celsius, for example about 280 degrees Celsius. When the susceptor material reaches its Curie temperature, it changes magnetic properties. At the Curie temperature, the susceptor material changes from a ferromagnetic phase to a paramagnetic phase. At this point, heating based on energy losses due to the orientation of the ferromagnetic regions stops. Thereafter, further heating is mainly based on the formation of eddy currents, such that the heating process is automatically reduced when 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 in order to achieve optimal temperature and temperature distribution within the aerosol-generating substrate for optimal aerosol generation.

[0277] In some preferred embodiments of the aerosol-generating article according to the 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 main component of ferrite is iron. Other metallic components (e.g. zinc, nickel, manganese) or non-metallic components (e.g. silicon) may be present in various 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 invention. The particles are preferably fully sintered ferrite powders, such as, for example, FP160, FP215, FP350 by PPT (Indiana, USA).

[0278] In a particular embodiment of the present invention, the aerosol generating system comprises an aerosol-generating article comprising 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 can be a reservoir present on the aerosol generating device, which can be refillable or replaceable. 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.

[0279] The present invention further provides an aerosol produced upon heating of an aerosol-generating substrate as defined above, the aerosol comprising specific amounts and ratios of characteristic compounds derived from oregano particles as defined above.

[0280] According to the present invention, the aerosol comprises ursolic acid in an amount of at least 0.04 micrograms per aerosol puff, isothymol in an amount of at least 0.01 micrograms per aerosol puff, and thymohydroquinone in an amount of at least 0.01 micrograms per aerosol puff, the aerosol puff having a volume of 55 milliliters when generated by a smoking machine. For the purposes of the present invention, a "puff" is defined as the volume of aerosol released 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. Thus, any reference herein to an aerosol "puff" is understood to refer to a 55 milliliter puff unless otherwise stated.

[0281] 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.

[0282] Preferably, the aerosol according to the present invention comprises at least about 0.1 micrograms of ursolic acid per aerosol puff, more preferably at least about 0.5 micrograms of ursolic acid per aerosol puff. Alternatively or additionally, the aerosol generated from the aerosol-generating substrate comprises at most about 5 micrograms of ursolic acid per aerosol puff, preferably at most about 4 micrograms of ursolic acid per aerosol puff, more preferably at most about 3 micrograms of ursolic acid per aerosol puff. For example, the aerosol generated from the aerosol-generating substrate may comprise from about 0.04 micrograms to about 5 micrograms of ursolic acid per aerosol puff, or from about 0.1 micrograms of ursolic acid per aerosol puff to about 4 micrograms of ursolic acid per aerosol puff, or from about 0.5 micrograms to about 3 micrograms of ursolic acid per aerosol puff.

[0283] The aerosol according to the present invention preferably comprises at least about 0.05 micrograms of isothymol per aerosol puff, more preferably at least about 0.2 micrograms of isothymol per aerosol puff. Alternatively or additionally, the aerosol generated from the aerosol-generating substrate preferably comprises at most about 1.25 micrograms of isothymol per aerosol puff, more preferably at most about 1 microgram of isothymol per aerosol puff, and even more preferably at most about 0.75 micrograms of isothymol per aerosol puff. For example, the aerosol generated from the aerosol-generating substrate may comprise from about 0.01 micrograms to about 1.25 micrograms of isothymol per aerosol puff, or from about 0.05 micrograms to about 1 microgram of isothymol per aerosol puff, or from about 0.2 micrograms to about 0.75 micrograms of isothymol per aerosol puff.

[0284] The aerosol according to the invention preferably contains at least about 0.05 micrograms of thymobidroquinone per aerosol puff, more preferably at least about 0.1 micrograms of thymobidroquinone per aerosol puff.Alternatively or additionally, the aerosol generated from the aerosol-generating substrate preferably contains at most about 1.25 micrograms of thymobidroquinone per aerosol puff, more preferably at most about 1 microgram of thymobidroquinone per aerosol puff, and even more preferably at most about 0.75 micrograms of thymobidroquinone per aerosol puff. For example, the aerosol generated from the aerosol-generating substrate may contain from about 0.01 micrograms to about 1.25 micrograms of thymobidroquinone per aerosol puff, or from about 0.05 micrograms to about 1 microgram of thymobidroquinone per aerosol puff, or from about 0.2 micrograms to about 0.75 micrograms of thymobidroquinone per aerosol puff.

[0285] According to the present invention, the aerosol composition is such that the amount of ursolic acid per aerosol puff is preferably at least twice the amount of isothymol per aerosol puff.Therefore, the ratio of ursolic acid to isothymol in the aerosol is preferably at least about 2:1.Preferably, the aerosol composition is such that the amount of ursolic acid per aerosol puff is at least three times the amount of isothymol per aerosol puff.

[0286] According to the present invention, the aerosol composition is such that the amount of ursolic acid per aerosol puff is preferably at least twice the amount of thymohydroquinone per aerosol puff.Therefore, the ratio of ursolic acid to thymohydroquinone in the aerosol is preferably at least about 2:1.Preferably, the aerosol composition is such that the amount of ursolic acid per aerosol puff is at least three times the amount of thymohydroquinone per aerosol puff.

[0287] A defined ratio of ursolic acid to isothymol and thymohydroquinone characterizes the aerosol derived from oregano particles. In contrast, in aerosols generated from oregano essential oil, the ratio of ursolic acid to isothymol and thymohydroquinone will be significantly different.

[0288] The aerosol according to the invention preferably further comprises 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. The aerosol preferably 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 from about 0.1 milligrams to about 0.6 milligrams of aerosol former per aerosol puff, or from about 0.2 milligrams to about 0.5 milligrams of aerosol former per aerosol puff, or from about 0.3 milligrams to about 0.4 milligrams of aerosol former per aerosol puff. These values ​​are based on a smoke volume of 55 milliliters, as defined above.

[0289] Suitable aerosol formers for use in the present invention are described above.

[0290] The aerosol generated from the aerosol-generating substrate according to the 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 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 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.

[0291] Alternatively or additionally, the aerosol 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 more preferably at least about 2 milligrams of cannabinoid compound per aerosol puff. The aerosol preferably comprises at most about 5 milligrams of cannabinoid compound per aerosol puff, more preferably at most about 4 milligrams of cannabinoid compound per aerosol puff, and more preferably at most about 3 milligrams of cannabinoid compound per aerosol puff. For example, the aerosol may comprise about 0.5 milligrams to about 5 milligrams of cannabinoid compound per aerosol puff, or about 1 milligrams to about 4 milligrams of cannabinoid compound per aerosol puff, or about 2 milligrams to about 3 milligrams of cannabinoid compound per aerosol puff. In some embodiments of the invention, the aerosol may contain zero micrograms of cannabinoid compounds. These values ​​are based on a puff volume of 55 milliliters, as defined above.

[0292] Preferably, the cannabinoid compound is selected from CBD and THC, more preferably the cannabinoid compound is CBD.

[0293] 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.

[0294] Aerosols according to the present invention containing characteristic compounds from oregano particles may 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 comprises particles having a MMAD ranging from about 0.1 to about 3 microns to optimize delivery of nicotine from the aerosol.

[0295] The median aerodynamic diameter (MMAD) of an aerosol refers to the particle dynamic diameter at which half of the particulate mass of the aerosol is occupied by particles with an aerodynamic diameter larger than the MMAD and half is occupied 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, measured in g / cm. 3 is defined as the diameter of a spherical particle having a density of

[0296] 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.

[0297] As defined above, the present invention further provides an aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate comprising homogenized oregano 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 0.04 micrograms per aerosol puff, isothymol in an amount of at least 0.01 micrograms per aerosol puff, and thymohydroquinone in an amount of at least 0.01 micrograms per aerosol puff, and the aerosol puff has a volume of 55 milliliters when generated by a smoking machine.

[0298] For purposes of the present invention, a "puff" is defined as the volume of aerosol released 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. Thus, any reference herein to an aerosol "puff" is understood to refer to a 55 milliliter puff unless otherwise stated. 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 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.

[0299] Preferably, the amount of ursolic acid per aerosol puff is at least twice the amount of isothymol per aerosol puff, and more preferably, the amount of isothymol per aerosol puff is at least three times the amount of isothymol per aerosol puff.

[0300] Preferably, the amount of ursolic acid per aerosol puff is at least twice the amount of thymobidroquinone per aerosol puff, and more preferably, is at least three times the amount of thymobidroquinone per aerosol puff.

[0301] The present invention also provides an aerosol-generating substrate formed from homogenized plant material comprising oregano particles, an aerosol former and a binder, as defined above, the aerosol-generating substrate comprising at least 50 micrograms of ursolic acid per gram of substrate, on a dry weight basis, at least 5 micrograms of isothymol per gram of substrate, on a dry weight basis, and at least 1.5 micrograms of thymohydroquinone per gram of substrate, on a dry weight basis.

[0302] Below is provided 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. EXAMPLES

[0303] Example 1. 1. An aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate comprising a homogenized oregano material, the homogenized oregano material comprising oregano particles, an aerosol former, and a binder, the aerosol-generating substrate comprising: At least 50 micrograms of ursolic acid per gram of substrate on a dry weight basis; At least 5 micrograms of isothymol per gram of substrate on a dry weight basis; and at least 1.5 micrograms of thymohydroquinone per gram of substrate on a dry weight basis. Example 2. The aerosol-generating article of Example 1, wherein the amount of ursolic acid per gram of substrate is at least 8 times the amount of isothymol per gram of substrate. Example 3. An aerosol-generating article as described in Example 1 or 2, wherein the amount of ursolic acid per gram of substrate is at least 25 times the amount of thymohydroquinone per gram of substrate. Example 4. 4. An aerosol-generating article as described in Example 1, 2 or 3, wherein the aerosol-generating substrate comprises, on a dry weight basis, from 50 micrograms to 6000 micrograms of ursolic acid per gram of substrate. Example 5. 5. An aerosol-generating article as described in any one of Examples 1 to 4, wherein the aerosol-generating substrate comprises, on a dry weight basis, 5 to 600 micrograms of isothymol per gram of substrate. Example 6. 6. An aerosol-generating article according to any one of Examples 1 to 5, wherein the aerosol-generating substrate comprises, on a dry weight basis, from 1.5 micrograms to 200 micrograms of thymohydroquinone per gram of substrate. Example 7. When the aerosol-generating substrate was heated by test method A, At least 1.5 micrograms of ursolic acid per gram of substrate on a dry weight basis; At least 0.5 micrograms of isothymol per gram of substrate on a dry weight basis; and at least 0.5 micrograms of thymohydroquinone per gram of substrate on a dry weight basis. Example 8. The aerosol-generating article of Example 7, wherein heating of the aerosol-generating substrate by Test Method A generates an aerosol comprising up to 200 micrograms of ursolic acid per gram of substrate on a dry weight basis. Example 9. 9. The aerosol-generating article of any one of Examples 7 to 8, wherein heating of the aerosol-generating substrate in accordance with Test Method A generates an aerosol comprising at most 50 micrograms of isothymol per gram of substrate on a dry weight basis. Example 10. 10. The aerosol-generating article of Example 7, 8 or 9, wherein heating of the aerosol-generating substrate in accordance with Test Method A generates an aerosol comprising up to 50 micrograms of thymohydroquinone per gram of substrate on a dry weight basis. Example 11. An aerosol-generating article as described in any one of Examples 7 to 10, wherein upon heating of the aerosol-generating substrate by Test Method A, an aerosol containing 0 micrograms of nicotine per gram of substrate is generated. Example 12. Under the Health Canada mechanical smoking regimen, heating of the aerosol-generating substrate in the THS2.2 holder resulted in: At least 1.5 micrograms of ursolic acid per gram of substrate on a dry weight basis; At least 0.5 micrograms of isothymol per gram of substrate on a dry weight basis; and at least 0.5 micrograms of thymohydroquinone per gram of substrate on a dry weight basis. Example 13. An aerosol-generating article according to any one of Examples 1 to 12, wherein the homogenized oregano material comprises at least 0.5 weight percent oregano particles on a dry weight basis. Example 14. An aerosol-generating article according to any one of Examples 1 to 13, wherein the homogenized oregano material comprises up to 50 weight percent oregano particles on a dry weight basis. Example 15. An aerosol-generating article as described in any one of Examples 1 to 14, wherein the homogenized oregano material further comprises up to about 75 weight percent tobacco particles on a dry weight basis. Example 16. An aerosol-generating article according to any one of Examples 1 to 15, wherein the homogenized oregano material further comprises tobacco particles, and the weight ratio of oregano particles to tobacco particles is 1:4 or less. Example 17. 17. The aerosol-generating article of Example 15 or 16, wherein the homogenized oregano material comprises, on a dry weight basis, between 5 weight percent and 20 weight percent oregano particles and between 55 weight percent and 70 weight percent tobacco particles. Example 18. An aerosol-generating article according to any one of Examples 1-17, wherein the homogenized oregano material contains substantially zero nicotine. Example 19. An aerosol-generating article as described in any one of Examples 1 to 17, wherein the aerosol-generating substrate further comprises at least 0.1 mg of nicotine per gram of substrate on a dry weight basis. Example 20. 20. The aerosol-generating article of example 19, wherein the aerosol-generating substrate comprises, on a dry weight basis, from 1 milligram to 20 milligrams of nicotine per gram of substrate. Example 21. 21. An aerosol-generating article according to any one of Examples 1 to 20, wherein the oregano particles have a D95 value of about 50 microns or more and about 400 microns or less. Example 22. An aerosol-generating article according to any one of Examples 1 to 21, wherein the oregano particles have a D5 value of about 10 microns or more and about 50 microns or less. Example 23. An aerosol-generating article according to any one of Examples 1 to 22, wherein the oregano particles are intentionally ground. Example 24. An aerosol-generating article according to any one of Examples 1 to 23, wherein 100 percent of the oregano particles have a diameter of 300 microns or less. Example 25. 25. The aerosol-generating article of any one of Examples 1-24, wherein the homogenized oregano material comprises up to 75 percent by weight of particulate plant material, the particulate plant material comprising oregano particles. Example 26. The aerosol-generating article of any one of Examples 1-25, wherein the homogenized oregano material has an aerosol former content of 5 weight percent to 30 weight percent on a dry weight basis. Example 27. An aerosol-generating article according to any one of Examples 1 to 26, 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, pectin, and combinations thereof. Example 28. 28. The aerosol-generating article of any one of Examples 1-27, wherein the binder comprises guar gum. Example 29. An aerosol-generating article according to any one of Examples 1 to 28, wherein the homogenized oregano material comprises, on a dry weight basis, 1 weight percent to 10 weight percent of the binder. Example 30. 30. The aerosol-generating article of any one of Examples 1-29, wherein the homogenized oregano material further comprises fibers. Example 31. 31. The aerosol-generating article of example 30, wherein the fibers have a length of greater than 400 micrometers. Example 32. 32. The aerosol-generating article of embodiment 30 or 31, 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 33. The aerosol-generating article of example 30 or example 31, 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 34. An aerosol-generating article as described in any one of Examples 1 to 33, wherein the homogenized oregano material comprises oregano 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 35. 35. The aerosol-generating article of example 34, wherein the homogenized oregano material further comprises about 2 weight percent to about 15 weight percent fiber. Example 36. 36. The aerosol-generating article of example 34 or 35, wherein the binder is guar gum. Example 37. An aerosol-generating article according to any one of Examples 1 to 36, wherein the homogenized oregano material is in the form of one or more sheets. Example 38. 38. The aerosol-generating article of example 37, wherein each of the one or more sheets has a thickness of 100 micrometers to 600 micrometers. Example 39. One or more sheets, each of 100 g / m 2 ~300g / m 2 The aerosol-generating article of example 38, having a mass of about 1.0 g. Example 40. Each of one or more sheets is 0.3 g / m 3 ~1.3g / m 3 40. The aerosol-generating article of example 38 or 39, having a density of Example 41. 41. The aerosol-generating article of embodiment 38, 39 or 40, wherein each of the one or more sheets has a peak cross-direction tensile strength of from 50 N / m to 400 N / m. Example 42. 41. The aerosol-generating article of any one of Examples 38 to 40, 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 43. 43. The aerosol-generating article of any one of Examples 38 to 42, wherein the one or more sheets are in the form of an assembly of one or more sheets. Example 44. An aerosol-generating article as described in any one of Examples 1-36, wherein the homogenized oregano material is in the form of a plurality of strands. Example 45. An aerosol-generating article as described in Example 44, wherein the strands have a width of at least 0.2 mm. Example 46. 46. ​​The aerosol-generating article of any one of Examples 44 to 45, wherein the plurality of strands are aligned with the longitudinal axis and extend substantially longitudinally along the length of the aerosol-generating substrate. Example 47. 47. The aerosol-generating article of example 44, 45 or 46, wherein each of the plurality of strands has a mass-to-surface area ratio of at least 0.02 milligrams per square millimeter. Example 48. An aerosol-generating article as described in any one of Examples 1 to 47, wherein the homogenized oregano material in the aerosol-generating substrate is in the form of a cast leaf. Example 49. An aerosol-generating article as described in any one of Examples 1 to 47, wherein the homogenized oregano material in the aerosol-generating substrate is in the form of oregano paper. Example 50. When the aerosol-generating substrate is heated by the test method A, the aerosol generated from the aerosol-generating substrate is Ursolic acid in an amount of at least 0.04 micrograms per aerosol puff; isothymol in an amount of at least 0.01 micrograms per aerosol puff; and thymohydroquinone in an amount of at least 0.01 micrograms per aerosol puff; An aerosol-generating article as described in any one of Examples 1 to 49, wherein the aerosol puff has a volume of 55 milliliters when generated by the smoking machine, the amount of ursolic acid per aerosol puff is at least twice the amount of isothymol per aerosol puff, and the amount of ursolic acid per aerosol puff is at least twice the amount of thymohydroquinone per aerosol puff. Example 51. 1. An aerosol-generating article comprising an aerosol-generating substrate, the aerosol-generating substrate comprising a homogenized oregano material comprising oregano 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 52. 52. The aerosol-generating article of Example 51, wherein the homogenized oregano material further comprises an essential oil, preferably oregano essential oil. Example 53. 53. The aerosol-generating article of Example 51 or 52, wherein the homogenized oregano material further comprises tobacco particles. Example 54. An aerosol-generating article as described in any one of Examples 51-53, wherein the homogenized oregano material comprises at least 0.5 weight percent oregano particles on a dry weight basis. Example 55. 1. An aerosol-generating substrate comprising a homogenized oregano material comprising oregano particles, an aerosol former and a binder, the aerosol-generating substrate comprising: At least 50 micrograms of ursolic acid per gram of substrate on a dry weight basis; At least 5 micrograms of isothymol per gram of substrate on a dry weight basis; and at least 1.5 micrograms of thymohydroquinone per gram of substrate on a dry weight basis. Example 56. 1. An aerosol generation system comprising: An aerosol generating device having a heating element; An aerosol generating system comprising an aerosol-generating article according to any one of Examples 1 to 54. Example 57. 57. The aerosol generating system of Example 56, wherein the heating element is a heater blade adapted to be inserted into the aerosol-generating substrate. Example 57. 56. An aerosol produced upon heating the aerosol-generating substrate of Example 55, comprising: Ursolic acid in an amount of at least 0.04 micrograms per aerosol puff; isothymol in an amount of at least 0.01 micrograms per aerosol puff; and thymohydroquinone in an amount of at least 0.01 micrograms per aerosol puff; An aerosol puff having a volume of 55 milliliters when produced by a smoking machine, an amount of ursolic acid per aerosol puff being at least twice the amount of isothymol per aerosol puff, and an amount of ursolic acid per aerosol puff being at least twice the amount of thymohydroquinone per aerosol puff. Example 58. 1. A method of making an aerosol-generating substrate, comprising the steps of: forming a slurry comprising oregano 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 degrees Celsius to 160 degrees Celsius. Example 59. The method of example 58, wherein the slurry is cast onto a support surface and allowed to dry to form a sheet of cast leaves. Example 60. 1. A method of making an aerosol-generating substrate, comprising the steps of: forming a dilute suspension comprising oregano 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 oregano paper.

[0304] Specific embodiments will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0305] [Figure 1] FIG. 1 illustrates a first embodiment of a substrate of an aerosol-generating article as described herein. [Diagram 2] FIG. 2 illustrates an aerosol generating system comprising an aerosol generating article and an aerosol generating device comprising an electric heating element. [Diagram 3] FIG. 3 illustrates an aerosol generating system comprising an aerosol generating device that includes 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. [Diagram 5] FIG. 5 illustrates a third embodiment of a substrate for an aerosol-generating article described herein. [Figure 6]

[0033] Figures 6a, 6b, and 6c are each 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 comprising 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 PREFERRED EMBODIMENTS

[0306] FIG. 1 illustrates a heated aerosol-generating article 1000 that includes a substrate as described herein. The article 1000 includes 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 arranged in sequential and coaxial alignment and assembled by cigarette paper 1060 to form the aerosol-generating article 1000. The article 1000 has an oral end 1012 that a user inserts into his or her mouth during use, and a distal end 1013 at the opposite end of the article relative to the oral end 1012. The embodiment of the aerosol-generating article illustrated in FIG. 1 is particularly suitable for use with an electrically operated aerosol generating device that includes a heater for heating the aerosol-generating substrate.

[0307] When assembled, article 1000 is approximately 45 millimeters in length and has an outer diameter of approximately 7.2 millimeters and an inner diameter of approximately 6.9 millimeters.

[0308] The aerosol-generating substrate 1020 includes a plug formed from a sheet of homogenized oregano material containing oregano particles, alone or in combination with tobacco particles.

[0309] Some examples of suitable homogenized oregano materials for forming the aerosol-generating substrate 1020 are shown in Table 1 below (see Samples B-D). The sheets are assembled, crimped, and rolled into filter paper (not shown) to form a plug. The sheets contain additives including glycerol as an aerosol former.

[0310] 1 is designed to engage an aerosol-generating device for consumption. Such an aerosol-generating device includes a means for heating an aerosol-generating substrate 1020 to a sufficient temperature to form an aerosol. Typically, the aerosol-generating device may include a heating element that surrounds the aerosol-generating article 1000 adjacent to the aerosol-generating substrate 1020 or a heating element that is inserted into the aerosol-generating substrate 1020.

[0311] Upon engagement with the aerosol-generating device, a user draws on the mouth end 1012 of the smoking article 1000 and the aerosol-generating substrate 1020 is heated 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 passes through a filter 1050 and is drawn into the user's mouth.

[0312] Figure 2 illustrates a portion of an electrically powered aerosol generating system 2000 that utilizes a heating blade 2100 to heat an aerosol-generating substrate 1020 of an aerosol-generating article 1000. The heating blade is mounted within an aerosol article receiving chamber of an electrically powered aerosol generating device 2010. The aerosol generating device defines a number of air holes 2050 to allow air to flow to the aerosol-generating article 1000. The airflow is indicated by arrows in Figure 2. The aerosol generating device includes a power source and electronics, which are not shown in Figure 2. The aerosol-generating article 1000 of Figure 2 is as described with respect to Figure 1.

[0313] In an alternative configuration shown in Figure 3, an aerosol generating system is shown with a combustible heating element. While article 1000 of Figure 1 is intended to be consumed in conjunction with an aerosol generating device, article 1001 of Figure 3 includes a combustible heat source 1080 that may be ignited and transfer heat to an aerosol-generating substrate 1020 to form an inhalable aerosol. Combustible heat source 80 is 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.

[0314] 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 a particulate plant material comprising oregano particles and a second upstream plug 4022 formed from a particulate plant material comprising primarily tobacco particles. A suitable homogenized oregano material for use in the first downstream plug is set forth in Table 1 below as one of Samples A-D. A suitable homogenized tobacco material for use in the second upstream plug is set forth in Table 1 below as Sample E. Sample E contains only tobacco particles and is included for comparison purposes only.

[0315] In each plug, the homogenized plant material is in the form of a sheet, which is crimped and rolled into a 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 assembled in an end-to-end abutting relationship to form a rod, each about 6 mm long. In a more preferred embodiment (not shown), the second plug is preferably longer than the first plug, for example, 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 oregano particles in the substrate. In FIG. 4b, the cellulose acetate tube support element 1030 is omitted.

[0316] Articles 4000a, 4000b similar to article 1000 of Figure 1 are particularly suitable for use in the electrically operated aerosol generating system 2000 with heater shown in Figure 2. Elements essentially the same as those in Figure 1 are numbered the same. It may be envisioned by one 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 article 1001 of Figure 3.

[0317] 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 oregano material formed of particulate plant material including a proportion of oregano particles, and a second sheet of homogenized tobacco material including primarily cast leaf tobacco.

[0318] A suitable homogenized oregano material for use as the first sheet is set forth below in Table 1 as one of Samples A-D. A suitable homogenized tobacco material for use as the second sheet is set forth below in Table 1 as Sample E. Sample E contains only tobacco particles and is included for comparison purposes only.

[0319] 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 part of the rod. Both sheets include an additive including glycerol as an aerosol former. Article 5000, similar to article 1000 of FIG. 1, is particularly suitable for use in an electrically operated aerosol generating system 2000 with a heater as shown in FIG. 2. Elements that are essentially the same as those in FIG. 1 are numbered the same. It may be envisioned by one 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.

[0320] 6a, 6b and 6c are cross-sectional views of a filter 1050 further including an aerosol modification element. In FIG. 6a, filter 1050 further comprises an aerosol modification element in the form of a spherical capsule or bead 605.

[0321] 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, the inner core containing a liquid flavourant. The liquid flavourant is for flavouring the aerosol during use of the aerosol-generating article provided with the filter. The capsule 605 releases at least a portion of the liquid flavourant 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 flavourant.

[0322] 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.

[0323] In the embodiment of Figure 6c, the 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 the cavity 611 is a capsule 605 comprising an outer shell and an inner core, the inner core containing a liquid flavourant. Alternatively, the capsule may be similar to the embodiment of Figure 6a.

[0324] 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 oregano material including tobacco particles and oregano 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. In use, the elongated susceptor strips 705 heat the homogenized oregano material by induction heating, as described above.

[0325] Working Example As described above with reference to the figures, different samples of homogenized plant material for use in an aerosol-generating substrate according to the invention may be prepared from an aqueous slurry having the composition shown in Table 1. Sample A contains only oregano particles and no tobacco particles according to the invention. Samples B-D contain oregano particles and tobacco particles according to the invention. Sample E contains only tobacco particles and is included for comparison purposes only.

[0326] The particulate plant material in all samples A through E constitutes approximately 75 percent of the dry weight of the homogenized plant material, with glycerol, guar gum, and cellulose fiber making up the remaining approximately 25 percent of the dry weight of the homogenized plant material. The samples are prepared from aqueous slurries containing 78-79 kg of water per 100 kg of slurry.

[0327] 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. Oregano powder may be formed from dried oregano leaves, which may be ground to a final D95=175 microns by triple impact milling. [Table 1]

[0328] 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.

[0329] For each of homogenized plant material samples A-E, plugs can be generated from a single continuous sheet of homogenized plant material, each having a width of 100 mm to 125 mm. The individual sheets have a thickness of about 235 micrometers and a weight of about 180 g / m 2 The cut width of each sheet is about 132 mm. The sheets may be crimped to a height of 165 micrometers to 170 micrometers and rolled into plugs having a length of about 12 mm and a diameter of about 7 mm and surrounded by a paper wrapper. The weight of the homogenized plant material in each plug is about 285 mg, and the total weight of each plug is about 293.6 mg.

[0330] For each plug, an aerosol-generating article having an overall length of about 45 mm may be formed having a structure as shown in FIG. 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.

[0331] For homogenized plant material sample B, in which oregano particles comprised 20 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 amount 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, the aerosol-generating substrate of the aerosol-generating article comprising 285 mg of homogenized plant material sample B.

[0332] For comparative purposes, the amount of the characteristic compound present in the particulate plant material (oregano particles) used to form Sample B 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 285 mg of Sample B.

[0333] For each of samples A, C and D containing a proportion of oregano 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 oregano particles. [Table 2]

[0334] Main stream 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 aerosol generated may be contained and analyzed.

[0335] As detailed above, according to Test Method A, the 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 the Health Canada mechanical smoking regimen for 30 puffs using a puff volume of 55 ml, a puff duration of 2 seconds, and a puff interval of 30 seconds (as described in ISO / TR19478-1:2014).

[0336] Aerosols generated during smoking tests are collected on Cambridge filter pads and extracted with a liquid solvent. Figure 10 shows a suitable apparatus for generating and collecting aerosols from an aerosol-generating article.

[0337] 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 is ISO 4387 and ISO 3308 compliant.

[0338] For LC-HRAM-MS analysis : The extraction solvent 170, 170a, in this case methanol and internal standard (ISTD) solution, is present in each microimpinger 160, 160a at a volume of 10 mL. The cold baths 161, 161a each contain dry ice-isopropyl ether to maintain the microimpingers 160, 160a, respectively, at approximately -60°C. The gas-vapor phase is trapped within the extraction solvent 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.

[0339] 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 break up 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) since the extraction solvent 170, 170a already contains the internal standard (ISTD) solution. The vial was closed and mixed for 5 minutes using an Eppendorf ThermoMixer (5° C., 2000 rpm).

[0340] For compound identification, aliquots (1.5 μL) of the diluted extracts were injected and analyzed by LC-HRAM-MS in both full scan and data-dependent fragmentation modes.

[0341] 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, non-polar, 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.

[0342] Non-polar and polar The extraction solvent 171, 171a is present in a volume of 10 mL and is a mixture of 80:20 v / v dichloromethane and methanol, also containing a retention index marker (RIM) compound and a stable isotope labeled internal standard (ISTD). The cold baths 162, 162a each contain a dry ice-isopropanol mixture to maintain the microimpingers 160, 160a, respectively, at approximately -78°C. The gas-vapor phase is trapped within the extraction solvent 171, 171a as the aerosol is bubbled through the microimpingers 160, 160a. The combined solutions from the two microimpingers are separated in step 182 as impinger trapped gas-vapor phase solution 210.

[0343] 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.

[0344] A 10 mL aliquot 240 of the entire aerosol extract 230 was removed in step 250. A 10 mL aliquot of water was added and the entire sample was shaken and centrifuged in step 260. The non-polar fraction 270 was separated, dried over sodium sulfate, and analyzed by GCxGC-TOFMS in full scan mode.

[0345] polarity ISTD and RIM compounds were added to the polar fraction 280, which was directly analyzed by GCxGC-TOFMS in full scan mode.

[0346] Each smoking replicate (n=3) contains 270 accumulations of the entrapped reconstituted non-polar fraction and 280 accumulations of the non-polar fraction for each sample.

[0347] 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) retention indicator marker (RIM) compounds and stable isotope labeled internal standards (ISTDs), are present in each microimpinger 160, 160a at a volume of 10 mL. Cold baths 161, 161a each contain dry ice-isopropanol ether to maintain the microimpingers 160, 160a at approximately −60° C., respectively. The gas-vapor phase is trapped within the extraction solvent 170, 170a as the aerosol is bubbled through the microimpingers 160, 160a. The combined solution from the two microimpingers is separated as a volatile-containing phase 211 in step 183. 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.

[0348] Table 3 below shows the levels of characteristic compounds from oregano particles in aerosols generated from an aerosol-generating article incorporating homogenized plant material sample B containing only oregano particles. For comparative purposes, Table 3 also shows the levels of characteristic compounds in aerosols generated from an aerosol-generating article incorporating homogenized plant material sample E containing only tobacco particles (and thus not according to the invention). [Table 3]

[0349] Relatively high levels of characteristic compounds were measured in the aerosol generated from Sample B. The ratio of ursolic acid to isothymol was greater than 1, and the ratio of isothymol to thymohydroquinone was greater than 8. Thus, the levels of characteristic compounds indicated the presence of oregano particles in the sample. In contrast, the levels of characteristic compounds were found to be zero or near zero for Sample E, which was tobacco-only and substantially free of oregano particles.

[0350] For each of Samples A, C and D containing oregano particles, the amount of the 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 oregano particles in the aerosol-generating substrate from which the aerosol was generated.

[0351] Table 4 below compares the levels of certain aerosol components in the aerosol generated from an aerosol-generating article incorporating Sample B (20:80 ratio of oregano to tobacco) to the aerosol generated from the tobacco-only Sample E. The reduction shown is the percentage reduction effected by replacing 20 percent of the tobacco particles in the homogenized material of Sample E with oregano particles.

[0352] As shown in Table 4, the aerosol generated from Sample B, which contained 20 weight percent oregano particles based on the dry weight of the particulate plant material, resulted in reduced levels of phenol, o-cresol, and m-cresol when compared to the levels of the same compounds in the aerosol generated from Sample E, which contained 100 weight percent tobacco based on the dry weight of the particulate plant material.

[0353] 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 20 percent of the tobacco particles with oregano particles. Thus, the combination of oregano particles with tobacco particles results in an unexpectedly high reduction in the levels of these compounds. Thus, the inclusion of oregano particles can reduce the levels of certain undesirable compounds in the aerosol while providing an aerosol with improved sensory properties. [Table 4]

Claims

1. An aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate comprises a homogenized oregano material, and the homogenized oregano material comprises, on a dry weight basis, at least 2.5 wt% of oregano particles, an aerosol former, and a binder, and the aerosol-generating substrate comprises, on a dry weight basis, at least 200 micrograms of ursolic acid per gram of the substrate, and comprises, on a dry weight basis, at least 5 micrograms of isothymol per gram of the substrate, and comprises, on a dry weight basis, at least 1.5 micrograms of thymohydroquinone per gram of the substrate, and the aerosol-generating article.

2. The amount of ursolic acid per gram of the substrate is at least 8 times the amount of isothymol per gram of the substrate, and the amount of ursolic acid per gram of the substrate is at least 25 times the amount of thymohydroquinone per gram of the substrate. The aerosol-generating article according to claim 1.

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

4. The homogenized oregano material comprises, on a dry weight basis, 5 wt% to 30 wt% of an aerosol former and 1 wt% to 10 wt% of a binder. The aerosol-generating article according to claim 1.

5. The binder comprises guar gum. The aerosol-generating article according to claim 1.

6. The homogenized oregano material further comprises tobacco particles, and the weight ratio of oregano particles to tobacco particles is 1:4 or less. The aerosol-generating article according to claim 1.

7. The homogenized oregano material in the aerosol-generating substrate is in the form of cast leaf. The aerosol-generating article according to claim 1.

8. The homogenized oregano material in the aerosol-generating substrate is in the form of oregano paper. The aerosol-generating article according to claim 1.

9. With the heating of the aerosol-generating substrate by Test Method A, comprises, on a dry weight basis, at least 1.5 micrograms of ursolic acid per gram of the substrate, and comprises, on a dry weight basis, at least 0.5 micrograms of isothymol per gram of the substrate, At least 0.5 micrograms of timosupquinone per gram of the substrate on a dry weight basis, and An aerosol generating article according to claim 1, which generates an aerosol containing

10. With the heating of the aerosol generating substrate by Test Method A, the aerosol generated from the aerosol generating substrate is At least 0.04 micrograms of the amount of ursolic acid per puff of the aerosol, At least 0.01 micrograms of the amount of isothymol per puff of the aerosol, At least 0.01 micrograms of the amount of timosupquinone per puff of the aerosol, Including When the puff of the aerosol is generated by a smoking machine, it has a volume of 55 milliliters, and the amount of ursolic acid per puff of the aerosol is at least twice the amount of isothymol per puff of the aerosol, and the amount of ursolic acid per puff of the aerosol is at least twice the amount of timosupquinone per puff of the aerosol. The aerosol generating article according to claim 1.

11. An aerosol generating substrate comprising a homogenized oregano material containing at least 2.5 weight percent of oregano particles, an aerosol former, and a binder on a dry weight basis, wherein the aerosol generating substrate At least 200 micrograms of ursolic acid per gram of the substrate on a dry weight basis, At least 5 micrograms of isothymol per gram of the substrate on a dry weight basis, At least 1.5 micrograms of timosupquinone per gram of the substrate on a dry weight basis, Including, an aerosol generating substrate.

12. An aerosol generating system, An aerosol generating device provided with a heating element, An aerosol generating article according to any one of claims 1 to 10, Comprising, an aerosol generating system.

13. An aerosol generated when heating the aerosol generating substrate according to claim 11, wherein the aerosol At least 0.04 micrograms of the amount of ursolic acid per puff of the aerosol, At least 0.01 micrograms of the amount of isothymol per puff of the aerosol, At least 0.01 micrograms of the amount of timosupquinone per puff of the aerosol, Including An aerosol having a volume of 55 milliliters when generated by a smoking machine, wherein the amount of ursolic acid per aerosol puff is at least twice the amount of isothymol per aerosol puff, and the amount of ursolic acid per aerosol puff is at least twice the amount of timosupquinone per aerosol puff.

14. A method for producing an aerosol generating substrate according to claim 11, comprising: forming a slurry comprising oregano particles, water, an aerosol former, a binder, and optionally tobacco particles; casting or extruding the slurry in the form of a sheet or strand; drying the sheet or strand at 80 to 160 degrees Celsius; A method comprising.

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