Aerosol-generating article configured for enhanced flavor delivery

Abstract

The aerosol-generating article (10) for generating an aerosol upon heating comprises an aerosol-generating element (12) including a rod (121) of aerosol-generating substrate surrounded by a wrapper (122), a downstream section (14) provided immediately downstream of the aerosol-generating element and extending from the downstream end of the aerosol-generating element to the downstream end of the aerosol-generating article, and an upstream section (16) provided immediately upstream of the aerosol-generating element and extending from the upstream end of the aerosol-generating element (12) to the upstream end of the aerosol-generating article. A flavorant (50) is provided in at least one of the downstream section (14), the upstream section (16), and the wrapper (122) surrounding the rod (121) of aerosol-generating substrate. The flavoring material (50) includes a polysaccharide matrix structure including gellan gum and an emulsifier, and a flavoring agent formulation dispersed within the polysaccharide matrix structure, the flavoring agent formulation being at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavoring material.

Description

[Technical Field]

[0001] The present disclosure relates to flavoring materials for use in aerosol-generating articles. Additionally, the present disclosure relates to aerosol-generating articles that include one such flavoring material. [Background technology]

[0002] For example, aerosol-generating articles in which an aerosol-generating substrate, such as a tobacco-containing substrate or a non-tobacco nicotine-containing substrate, is heated rather than combusted, are known in the art. Typically, in such heated smoking articles, the 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 aerosol-generating substrate by heat transfer from the heat source and are entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

[0003] Several aerosol generating devices for consuming aerosol-generating articles have been disclosed in the art. Such devices include, for example, electrically heated aerosol generating devices in which an aerosol is generated by heat transfer from one or more electric heater elements of the aerosol generating device to an aerosol-generating substrate of the aerosol-generating article. For example, an electrically heated aerosol generating device has been proposed that includes an internal heater blade adapted to be inserted into the aerosol-generating substrate. Alternatively, WO 2015 / 176898 proposes an inductively heated aerosol-generating article that includes an aerosol-generating substrate and a susceptor disposed within the aerosol-generating substrate.

[0004] It has been proposed in the past to include a flavor source in addition to the aerosol-generating substrate in an aerosol-generating article. Indeed, this practice is relatively common in conventional filter cigarettes, and many solutions have been described in the art for providing flavorants at locations within the mouthpiece filter or within the tobacco cut filler.

[0005] However, given how aerosols are generated and delivered to consumers within aerosol-generating articles, it can be difficult to ensure consistent flavor delivery during use, and consumers may perceive fluctuations or a decrease in flavor intensity over time. Furthermore, even before the aerosol-generating article is used, some flavor species may be lost during certain manufacturing processes or during transportation and storage of the aerosol-generating article.

[0006] It has previously been proposed to reduce the loss of volatile flavors from smoking conventional filter cigarettes during storage by encapsulating the flavors, for example, in the form of capsules or microcapsules containing a flavor formulation. The encapsulated flavor species can be released before or during smoking of the filter cigarette by breaking open the encapsulation structure, for example, by crushing the structure by hand. However, because the encapsulated flavors are typically released from the encapsulation structure with a single burst, one of these solutions may not provide a consistently strong flavor delivery during use of the article.

[0007] Therefore, a need is felt to provide an aerosol-generating article that contains flavor materials associated with enhancing the consumer's flavor perception, particularly toward the end of the use cycle of the aerosol-generating article. Summary of the Invention

[0008] The present disclosure relates to an aerosol-generating article for generating an aerosol upon heating. The aerosol-generating article may include a flavoring material.

[0009] The aerosol-generating article may comprise an aerosol-generating element comprising a rod of aerosol-generating substrate surrounded by a wrapper. A flavourant may be provided within the wrapper surrounding the rod of aerosol-generating substrate.

[0010] The aerosol-generating article may be provided immediately downstream of the aerosol-generating element and may comprise a downstream section extending from the downstream end of the aerosol-generating element to the downstream end of the aerosol-generating article.

[0011] Flavourants may be provided in the downstream section.

[0012] For example, the downstream section may include a hollow tubular element provided immediately downstream of the aerosol-generating element. The upstream end of the hollow tubular element may abut the downstream end of the aerosol-generating element. The flavorant may be provided within the hollow tubular element.

[0013] Alternatively, the downstream section may include a hollow tubular element provided downstream of the aerosol-generation element, and the flavorant may be provided between the downstream end of the aerosol-generation element and the upstream end of the hollow tubular element, for example, the flavorant may be sandwiched between the aerosol-generation element and the hollow tubular element.

[0014] The aerosol-generating article may be provided immediately upstream of the aerosol-generating element and may comprise an upstream section extending from the upstream end of the aerosol-generating element to the upstream end of the aerosol-generating article.

[0015] Flavourants may be provided in the upstream section.

[0016] For example, the upstream section may include an upstream element provided immediately upstream of the aerosol-generation element. The downstream end of the upstream element may abut the upstream end of the aerosol-generation element. A flavorant may be provided in the upstream element.

[0017] Alternatively, the upstream section may include an upstream element provided upstream of the aerosol-generation element, and the flavorant may be provided between the upstream end of the aerosol-generation element and the downstream end of the upstream element, for example, the flavorant may be sandwiched between the aerosol-generation element and the upstream element.

[0018] The flavoring material may include a polysaccharide matrix structure including gellan gum and an emulsifier, and a flavoring agent formulation dispersed within the polysaccharide matrix structure. The flavoring agent formulation may be at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavoring material.

[0019] According to a first aspect of the present invention, there is provided an aerosol-generating article for generating an aerosol upon heating, the aerosol-generating article comprising an aerosol-generating element including a rod of aerosol-generating substrate surrounded by a wrapper, the aerosol-generating article further comprising: a downstream section provided immediately downstream of the aerosol-generating element and extending from the downstream end of the aerosol-generating element to the downstream end of the aerosol-generating article;

[0020] and an upstream section provided immediately upstream of the aerosol-generating element and extending from the upstream end of the aerosol-generating element to the upstream end of the aerosol-generating article. The aerosol-generating article includes a flavorant provided in at least one of the downstream section, the upstream section, and a wrapper surrounding the rod of aerosol-generating substrate. The flavorant includes a polysaccharide matrix structure including gellan gum and an emulsifier, and a flavorant formulation dispersed within the polysaccharide matrix structure, the flavorant formulation being at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavorant.

[0021] As used herein in connection with the present invention, the term "aerosol-generating article" is used to describe an article that includes an aerosol-generating substrate that is heated to generate and deliver an inhalable aerosol to a user.

[0022] As used herein in connection with the present invention, the term "aerosol-generating substrate" is used to describe a substrate that includes an aerosol-forming material that is capable of releasing, upon heating, a volatile compound that is capable of generating an aerosol.

[0023] As used herein in connection with the present invention, the term "aerosol" is used to describe a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets in a gas. Aerosols can be visible or invisible. Aerosols may contain not only vapors of substances that are normally liquids or solids at room temperature, but also solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

[0024] As used herein with respect to the present invention, the term "aerosol-generating device" is used to describe a device that interacts with the aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0025] The aerosol-generating article according to the present invention has a proximal end through which the aerosol exits the aerosol-generating article for delivery to a user during use. The proximal end of the aerosol-generating article may also be referred to as the downstream end or mouth end of the aerosol-generating article. During use, a user draws directly or indirectly on the proximal end of the aerosol-generating article to inhale the aerosol generated by the aerosol-generating article.

[0026] The aerosol-generating article according to the present invention has a distal end. The distal end is opposite the proximal end. The distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosol-generating article.

[0027] Components of an aerosol-generating article according to the present invention may be described as being upstream or downstream of one another based on their relative location between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article.

[0028] As used herein with respect to the present invention, the term "longitudinal direction" is used to describe the direction between the upstream and downstream ends of the aerosol-generating article. During use, air is drawn longitudinally through the aerosol-generating article.

[0029] As used herein with respect to the present invention, the term "length" is used to describe the greatest dimension along the longitudinal axis of an aerosol-generating article or a component of an aerosol-generating article.

[0030] As used herein in connection with the present invention, the term "transverse" is used to describe a direction perpendicular to the longitudinal axis. Unless otherwise specified, a "cross section" of an aerosol-generating article or a component of an aerosol-generating article refers to a cross section.

[0031] As used herein with respect to the present invention, the term "width" refers to the largest lateral dimension of an aerosol-generating article or a component of an aerosol-generating article. If the aerosol-generating article has a substantially circular cross-section, the width of the aerosol-generating article corresponds to the diameter of the aerosol-generating article. If the component of the aerosol-generating article has a substantially circular cross-section, the width of the component of the aerosol-generating article corresponds to the diameter of the component of the aerosol-generating article.

[0032] As used herein with respect to the present invention, the term "hollow tubular element" is used to mean a generally cylindrical element having a lumen along its longitudinal axis. The tubular portion may have a substantially circular, oval, or elliptical cross section. The tubular space may be generally circular, oval, or elliptical in cross section. Specifically, the term "hollow tubular element" is used to mean an element that defines at least one airflow conduit that establishes uninterrupted fluid communication between the upstream end of the tubular element and the downstream end of the hollow tubular element.

[0033] It is generally recognized that the use of flavoring materials in aerosol-generating articles, which means that the aerosol-generating substrate is heated to generate an aerosol, presents different challenges and brings about different constraints compared to the situation previously encountered with traditional cigarettes, where the substrate is burned to generate smoke. The inventors have discovered that by providing a flavoring material at a selected location outside the rod of the aerosol-generating substrate, it is possible to release and deliver the flavoring material to the consumer in a controlled manner during use, so that the flavoring material can be combined with the aerosol species generated as the aerosol-generating substrate heats. Because the flavoring material is exposed to a heating profile that is different from the heating profile the aerosol-generating substrate experiences during use, for example, due to the flavoring material being closer or farther from the heat source than the aerosol-generating substrate, it may be possible to control the intensity and duration of flavor release without disrupting the mechanism by which the aerosol species are released.

[0034] By way of example, the inventors have found that aerosol-generating articles according to the present invention may exhibit generally more efficient per-puff flavor release in that the level of flavor species released with each successive puff may remain substantially constant or may increase progressively during the use cycle of the article.

[0035] Additionally, because the flavor formulation is at least partially entrapped within the matrix structure until released upon heating, aerosol-generating articles according to the present invention have been found to significantly reduce loss of flavor species, even under stress conditions, during storage, transport, etc. This allows for particularly efficient use of the flavor and other components of the flavor formulation.

[0036] Furthermore, as discussed in more detail below, the inventors have found that by adjusting the relative proportions of the various components in the formulation, or by altering the composition of the matrix (e.g., by selecting a particular combination of polysaccharides to form the matrix), or both, it is possible to advantageously fine-tune some of the properties of a flavoring material to the specific needs associated with its use in an aerosol-generating article. For example, the flavor release profile can be tailored so that the flavor is released in more continuous "waves" during use. As a result, the consumer may perceive the flavor notes as being more intense and longer-lasting during use. Therefore, an aerosol-generating article according to the present invention may offer a wider range of flavor profiles than was previously possible with existing aerosol-generating articles.

[0037] The inventors have also found that it may be possible to enhance the release of flavor species from approximately selected relatively low-temperature flavor materials by incorporating into the flavor material certain compounds, such as carbon particles or additives that undergo thermal decomposition to produce gaseous compounds as products of that thermal decomposition. This is beneficial because such heat-enhanced flavor materials can be provided at locations within the aerosol-generating article that are heated at a lower intensity than the aerosol-generating substrate, without this difference in heat supply being detrimental to the intensity and quality of flavor delivery experienced by the consumer.

[0038] In the aerosol-generating article according to the present invention, the polysaccharide matrix structure preferably comprises gellan gum and an emulsifier.

[0039] The term "gellan gum" is used to identify a water-soluble anionic polysaccharide produced by the bacterium Sphingomonas elodia. The repeating unit of the polymer is a tetrasaccharide, consisting of two residues of D-glucose and one residue each of L-rhamnose and D-glucuronic acid. Gellan gum has been approved for food, non-food, cosmetic, and pharmaceutical uses by authorities in many jurisdictions, including Japan, the United States, Canada, China, South Korea, and the EU.

[0040] Two forms of gellan gum are known, namely high acyl gellan gum and low acyl gellan gum, which differ by the degree / percentage of substitution with O-acyl groups.

[0041] In the flavoring material according to the present invention, the gellan gum is preferably low-acyl gellan gum, which is either partially deacylated or completely deacylated gellan gum, the most common form of which is the completely deacylated form with no detectable acyl groups, also called deacetylated gellan gum.

[0042] The use of low acyl gellan gum to form the polysaccharide matrix of flavor materials according to the present invention is preferred due to its ability to form gels at very low concentrations. In addition, the texture of gellan gum-based gels varies with acyl content, with low acyl gellan gum typically forming firmer, less elastic, and more brittle gels compared to high acyl gellan gum.

[0043] In embodiments in which the polysaccharide matrix structure comprises gellan gum and an emulsifier, a flavorant can be advantageously provided in which a substantial proportion of the flavorant formulation is effectively entrapped within the polysaccharide matrix structure. This is beneficial in terms of improving the stability of the flavorant. Furthermore, as discussed in more detail below, this can have an impact on how flavor species are released upon heating of the flavorant, and thus can be useful for tailoring the flavorant release profile during use.

[0044] Additionally, from a manufacturing perspective, a stable polysaccharide matrix structure comprising gellan gum and an emulsifier can be formed by providing heat to the initiator reagent without the need for a cross-linking agent. Indeed, by kneading and emulsifying the flavor formulation and gellan gum in a heated aqueous bath, the polysaccharide-coated flavor can be brought into an emulsified state, which is then substantially preserved after drying and cooling. Advantageously, this allows for a significant amount of flavor to be immobilized within the polysaccharide matrix, and thus flavor materials with high flavor content may be provided.

[0045] Preferably, the emulsifier is lecithin.The use of lecithin as emulsifier is advantageous in that it is generally available and generally recognized as non-toxic.Similar to gellan gum, lecithin is commonly used as an additive in the food industry, and is approved for such use by both the US Food and Drug Administration and EU authorities.Thus, the combination of gellan gum and lecithin is particularly suitable for being contained in flavor materials intended for human use.

[0046] Preferably, when the polysaccharide matrix comprises gellan gum and an emulsifier, the gellan gum comprises from 5 percent to 99.9 percent by weight of the flavor material on a dry weight basis.

[0047] More preferably, gellan gum comprises at least 7 weight percent of the flavor material on a dry weight basis, and even more preferably, comprises at least 10 weight percent of the flavor material on a dry weight basis.

[0048] Preferably, gellan gum comprises up to 80 weight percent of the flavoring material on a dry weight basis, more preferably up to 60 weight percent of the flavoring material on a dry weight basis, even more preferably up to 40 weight percent of the flavoring material on a dry weight basis, and especially preferably up to 30 weight percent of the flavoring material on a dry weight basis.

[0049] In some embodiments, gellan gum comprises from 5 weight percent to 80 weight percent of the flavor material on a dry weight basis, preferably from 5 weight percent to 60 weight percent of the flavor material on a dry weight basis, more preferably from 5 weight percent to 40 weight percent of the flavor material on a dry weight basis, and even more preferably from 5 weight percent to 30 weight percent of the flavor material on a dry weight basis.

[0050] In other embodiments, gellan gum comprises from 10 weight percent to 80 weight percent of the flavor materials on a dry weight basis, preferably from 10 weight percent to 60 weight percent of the flavor materials on a dry weight basis, more preferably from 10 weight percent to 40 weight percent of the flavor materials on a dry weight basis, and even more preferably from 10 weight percent to 30 weight percent of the flavor materials on a dry weight basis.

[0051] The emulsifier may comprise 0.01 to 2 percent by weight of the flavor material on a dry weight basis. Preferably, the emulsifier comprises 0.02 to 2 percent by weight of the flavor material on a dry weight basis. More preferably, the emulsifier comprises 0.05 to 2 percent by weight of the flavor material on a dry weight basis. Even more preferably, the emulsifier comprises 0.1 to 2 percent by weight of the flavor material on a dry weight basis.

[0052] In a preferred embodiment, the emulsifier is lecithin and comprises 0.01 to 2 weight percent of the flavoring material on a dry weight basis. Preferably, the lecithin comprises 0.02 to 2 weight percent of the flavoring material on a dry weight basis. More preferably, the lecithin comprises 0.05 to 2 weight percent of the flavoring material on a dry weight basis. Even more preferably, the lecithin comprises 0.1 to 2 weight percent of the flavoring material on a dry weight basis.

[0053] In certain embodiments, the polysaccharide matrix structure comprises gellan gum as the only polysaccharide.

[0054] In other embodiments, the polysaccharide matrix structure comprises gellan gum in combination with at least an additional polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose, and hydroxypropylmethylcellulose.

[0055] It has been found that flavoring materials according to the present invention, in which the polysaccharide matrix structure comprises gellan gum in combination with one or more of the polysaccharides listed above, provide different flavor release profiles upon heating. For example, in embodiments in which the polysaccharide matrix structure comprises gellan gum in combination with another of the polysaccharides listed above, a flavor release profile characterized by two distinct peaks at two different temperatures has been observed. Without wishing to be bound by theory, this is hypothesized to be due to different strengths of interaction between the flavor and each polysaccharide within the matrix structure, and may need to be done with each polysaccharide undergoing thermal degradation at slightly different temperatures.

[0056] Because different combinations of polysaccharides within the matrix structure generally result in slightly different flavor release profiles when the flavor material is heated, embodiments in which gellan gum is combined with one or more of the other polysaccharides listed above can be advantageously used to fine-tune flavor release during use of an aerosol-generating article containing the flavor material. In addition, different flavor materials, each containing a polysaccharide matrix structure with a different combination of polysaccharides, may be used in combination with a single aerosol-generating article to further adjust and control flavor delivery throughout the use cycle of the aerosol-generating article. For example, incorporating different flavor materials according to the present invention into a single aerosol-generating article, where the different flavor materials are adapted to release the majority of their flavor at different temperatures or at different times during the use cycle, can help maintain a substantially consistent overall flavor delivery throughout.

[0057] In flavor material embodiments in which the matrix structure comprises gellan gum in combination with at least one of the additional polysaccharides listed above, the at least one additional polysaccharide may comprise at least 0.01 weight percent of the flavor delivery material on a dry weight basis. Preferably, the at least one additional polysaccharide comprises at least 0.1 weight percent of the flavor delivery material on a dry weight basis. More preferably, the at least one additional polysaccharide comprises at least 1.0 weight percent of the flavor delivery material on a dry weight basis. Even more preferably, the at least one additional polysaccharide comprises at least 2.0 weight percent of the flavor delivery material on a dry weight basis. In particularly preferred embodiments, the at least one additional polysaccharide comprises at least 5 weight percent of the flavor delivery material on a dry weight basis.

[0058] In flavor material embodiments in which the matrix structure comprises gellan gum in combination with at least one of the additional polysaccharides listed above, the at least one additional polysaccharide may comprise 80 weight percent or less of the flavor delivery material on a dry weight basis. Preferably, the at least one additional polysaccharide comprises 35 weight percent or less of the flavor delivery material on a dry weight basis. More preferably, the at least one additional polysaccharide comprises 25 weight percent or less of the flavor delivery material on a dry weight basis. Even more preferably, the at least one additional polysaccharide comprises 15 weight percent or less of the flavor delivery material on a dry weight basis.

[0059] In some embodiments, the at least one additional polysaccharide comprises from 1.0 weight percent to no more than 35 weight percent of the flavor delivery material on a dry weight basis, preferably from 2.0 weight percent to no more than 35 weight percent of the flavor delivery material on a dry weight basis, and more preferably from 5.0 weight percent to no more than 35 weight percent of the flavor delivery material on a dry weight basis.

[0060] In other embodiments, the at least one additional polysaccharide comprises from 1.0 weight percent to 25 weight percent or less of the flavor delivery material on a dry weight basis, preferably from 2.0 weight percent to 25 weight percent or less of the flavor delivery material on a dry weight basis, and more preferably from 5.0 weight percent to 25 weight percent or less of the flavor delivery material on a dry weight basis.

[0061] In a further embodiment, the at least one additional polysaccharide comprises from 1.0 weight percent to no more than 15 weight percent of the flavor delivery material on a dry weight basis, preferably from 2.0 weight percent to no more than 15 weight percent of the flavor delivery material on a dry weight basis, and more preferably from 5.0 weight percent to no more than 15 weight percent of the flavor delivery material on a dry weight basis.

[0062] The flavoring material may comprise at least 0.01 weight percent flavoring agent on a dry weight basis. Preferably, the flavoring material comprises at least 1 weight percent flavoring agent on a dry weight basis. More preferably, the flavoring material comprises at least 5 weight percent flavoring agent on a dry weight basis. Even more preferably, the flavoring material comprises at least 10 weight percent flavoring agent on a dry weight basis.

[0063] In certain embodiments, the flavoring material comprises at least 20 weight percent flavor on a dry weight basis, preferably at least 25 weight percent flavor on a dry weight basis, and more preferably at least 30 weight percent flavor on a dry weight basis.

[0064] The flavoring material may be up to 90 weight percent flavoring on a dry weight basis. Preferably, the flavoring material may be up to 85 weight percent flavoring on a dry weight basis. More preferably, the flavoring material may be up to 80 weight percent flavoring on a dry weight basis. Even more preferably, the flavoring material may be up to 75 weight percent flavoring on a dry weight basis.

[0065] In certain preferred embodiments, the flavoring material comprises from 20 weight percent to 80 weight percent flavoring on a dry weight basis, preferably from 25 weight percent to 80 weight percent flavoring on a dry weight basis, and more preferably from 30 weight percent to 80 weight percent flavoring on a dry weight basis.

[0066] In other preferred embodiments, the flavoring material comprises from 20 weight percent to 75 weight percent flavoring on a dry weight basis, preferably from 25 weight percent to 75 weight percent flavoring on a dry weight basis, and more preferably from 30 weight percent to 75 weight percent flavoring on a dry weight basis.

[0067] Suitable flavorants for inclusion in flavor formulations of flavoring materials according to the present invention include, but are not limited to, menthol, limonene, and eugenol.

[0068] Menthol is a monoterpenoid that may be produced synthetically or obtained from peppermint or other mint oils, and it imparts a minty, cooling flavor note.

[0069] Limonene is a cyclic monoterpene typically found in the peel oils of citrus fruits. It is also a component of the aromatic resins of many coniferous and broadleaf trees. It imparts citrus-flavored notes.

[0070] Eugenol is an allyl-chain substituted guaiacol commonly found in the essential oils of clove, nutmeg, cinnamon, basil, and bay leaf, where it imparts spicy, clove-like flavor notes.

[0071] The inventors have found that menthol and limonene can be relatively easily entrapped and immobilized within a polysaccharide matrix, and that flavoring materials containing flavor formulations containing menthol, limonene, or mixtures thereof therefore exhibit very good stability.

[0072] In a preferred embodiment, the flavor formulation comprises menthol.

[0073] The flavoring material may comprise at least 0.01 weight percent menthol on a dry weight basis. Preferably, the flavoring material comprises at least 1 weight percent menthol on a dry weight basis. More preferably, the flavoring material comprises at least 5 weight percent menthol on a dry weight basis. Even more preferably, the flavoring material comprises at least 10 weight percent menthol on a dry weight basis.

[0074] In certain embodiments, the flavoring material comprises at least 20 weight percent menthol on a dry weight basis, preferably at least 25 weight percent menthol on a dry weight basis, and more preferably at least 30 weight percent menthol on a dry weight basis.

[0075] The flavorant may be up to 90 percent menthol by weight on a dry weight basis. Preferably, the flavorant may be up to 85 percent menthol by weight on a dry weight basis. More preferably, the flavorant may be up to 80 percent menthol by weight on a dry weight basis. Even more preferably, the flavorant may be up to 75 percent menthol by weight on a dry weight basis.

[0076] In certain preferred embodiments, the flavoring material comprises from 20 weight percent to 80 weight percent menthol on a dry weight basis, preferably from 25 weight percent to 80 weight percent menthol on a dry weight basis, and more preferably from 30 weight percent to 80 weight percent menthol on a dry weight basis.

[0077] In other preferred embodiments, the flavoring material comprises from 20 weight percent to 75 weight percent menthol on a dry weight basis, preferably from 25 weight percent to 75 weight percent menthol on a dry weight basis, and more preferably from 30 weight percent to 75 weight percent menthol on a dry weight basis.

[0078] Flavor formulations typically include a solvent that the flavor is at least partially dissolved in. Suitable solvents for inclusion in flavor formulations of flavoring materials according to the present invention include, but are not limited to, water and glycerol.

[0079] The inventors have found that the solubility of a flavorant in a given solvent can affect how stable the flavorant is retained within the flavorant during storage of an aerosol-generating article containing the flavorant. More specifically, the inventors have found that greater affinity between the flavorant and the solvent favorably affects stability.

[0080] The Hansen Solubility Parameters provide a model for estimating the mutual compatibility of any given flavor / solvent combination.

[0081] The solubility parameter δ measured in MPa is calculated according to the following formula: δ 2 =(δ d ) 2 +(δ p ) 2 +(δ h ) 2 The intermolecular dispersion force (δ d ), intermolecular forces between molecules (δ p ), and intermolecular hydrogen bonds (δ h ) is a function of the parameter .

[0082] parameter, δ d , δ p , and δ h can be considered as the coordinates of a point in three-dimensional space (Hansen space). The distance R between two molecules in Hansen space a provides an indication of the affinity between two molecules and is represented by the following formula: (R a ) 2 =4(δ d2 -δ d1 ) 2 +(δ p2 -δ p1 ) 2 +(δh2 -δ h1 ) 2 It is calculated based on:

[0083] In general, R a It is understood that a lower value of indicates a higher affinity for a given flavor / solvent combination.

[0084] With reference to flavor formulations for inclusion in flavoring materials according to the present invention, the inventors have investigated combining flavorings with glycerol as a solvent and, in doing so, have identified several flavoring / glycerol combinations that exhibit particularly good stability of the flavoring within the flavoring material during storage.

[0085] Flavor / glycerol combinations for inclusion in flavor formulations of flavoring materials according to the present invention may be selected from the group consisting of R a The inventors believe that this condition indicates a particularly high affinity between the flavor and glycerol, and therefore that such an R a have consistently led to flavorants with particularly good flavor stability during storage. Based on this, the inventors have found that preferred flavorant / glycerol combinations for inclusion in flavor formulations of flavorants according to the present invention include d-limonene / glycerol, l-menthone / glycerol, (E)-citral / glycerol, decanal / glycerol, and linalool / glycerol. In some embodiments, the flavorant is a compound of formula C n H 2n+2 O n The polyol further comprises:

[0086] The term "polyol" is used herein to describe an organic compound containing two or more hydroxyl groups. Polyols containing two, three, and four hydroxyl groups may also be called diols, triols, and tetrols, respectively.

[0087] Preferred polyols for inclusion in flavoring materials according to the present invention include glycerol, sorbitol, xylitol, mannitol, and erythritol.

[0088] The incorporation of a polyol into a flavorant has a beneficial effect on its flexibility, which makes it easier to handle and gives it a defined shape, which may facilitate its incorporation into an aerosol-generating article.

[0089] Preferably, in embodiments in which the flavorant comprises a polyol as described above, the polyol comprises from 0.01 weight percent to 20 weight percent of the flavorant on a dry weight basis. More preferably, the polyol comprises from 0.01 weight percent to 15 weight percent of the flavorant on a dry weight basis. Even more preferably, the polyol comprises from 0.01 weight percent to 10 weight percent of the flavorant on a dry weight basis.

[0090] In some embodiments, the flavoring material comprises fiber, preferably cellulose fiber.

[0091] The inventors have found that the inclusion of fiber can increase the structural strength of the flavoring material, which is particularly beneficial in embodiments where the polysaccharide matrix that entraps the flavoring agent formulation is not supported by a carrier sheet material.

[0092] In embodiments where the flavoring material includes cellulosic fibers, the cellulosic fibers may comprise at least 0.01 weight percent of the flavoring material on a dry weight basis.

[0093] The incorporation of fibers, especially cellulose fibers, may advantageously improve the tensile strength of the flavoring material, especially when provided in sheet form, which facilitates the manufacturing process of both the flavoring material itself and the aerosol-generating article containing the flavoring material.

[0094] Preferably, the cellulose fibers comprise at least 0.05 weight percent of the flavoring material on a dry weight basis. More preferably, the cellulose fibers comprise at least 0.5 weight percent of the flavoring material on a dry weight basis. Even more preferably, the cellulose fibers comprise at least 1.0 weight percent of the flavoring material on a dry weight basis. In a particularly preferred embodiment, the cellulose fibers comprise at least 2.0 weight percent of the flavoring material on a dry weight basis.

[0095] The cellulose fibers may comprise 10 weight percent or less of the flavoring material on a dry weight basis. Preferably, the cellulose fibers comprise 8.0 weight percent or less of the flavoring material on a dry weight basis. More preferably, the cellulose fibers comprise 7.0 weight percent or less of the flavoring material on a dry weight basis. Even more preferably, the cellulose fibers comprise 5.0 weight percent or less of the flavoring material on a dry weight basis.

[0096] In some embodiments, the fiber comprises from 0.01 weight percent to 10 weight percent of the flavoring material on a dry weight basis. Preferably, the fiber comprises from 0.01 weight percent to 8.0 weight percent of the flavoring material on a dry weight basis. More preferably, the fiber comprises from 0.01 weight percent to 7.0 weight percent of the flavoring material on a dry weight basis. Even more preferably, the fiber comprises from 0.01 weight percent to 5 weight percent of the flavoring material on a dry weight basis.

[0097] In other embodiments, the fiber comprises between 1.0 weight percent and 10 weight percent of the flavoring material on a dry weight basis. Preferably, the fiber comprises between 1.0 weight percent and 8.0 weight percent of the flavoring material on a dry weight basis. More preferably, the fiber comprises between 1.0 weight percent and 7.0 weight percent of the flavoring material on a dry weight basis. Even more preferably, the fiber comprises between 1.0 weight percent and 5 weight percent of the flavoring material on a dry weight basis.

[0098] In further embodiments, the fiber comprises 2.0 to 10 weight percent of the flavoring material on a dry weight basis. Preferably, the fiber comprises 2.0 to 8.0 weight percent of the flavoring material on a dry weight basis. More preferably, the fiber comprises 2.0 to 7.0 weight percent of the flavoring material on a dry weight basis. Even more preferably, the fiber comprises 2.0 to 5 weight percent of the flavoring material on a dry weight basis.

[0099] In some embodiments, flavoring materials according to the present invention may include calcium salts or magnesium salts, such as calcium chloride or calcium lactate, or both.

[0100] In embodiments where the flavoring material includes a calcium salt or a magnesium salt, or both, the salt or salts comprise from 0.01 to 10 weight percent on a dry weight basis. Preferably, the salt or salts comprise from 0.01 to 5 weight percent on a dry weight basis.

[0101] Flavoring materials according to the present invention may generally contain water, since flavoring materials are generally produced by combining the various compounds described above in an aqueous bath. After drying, the water content is reduced, but generally may not be zero.

[0102] Thus, the flavoring material according to the present invention may comprise from 0.01 weight percent to 10 weight percent water, preferably from 0.01 weight percent to 8 weight percent water, more preferably from 0.01 weight percent to 6 weight percent water, and even more preferably from 0.01 weight percent to 4 weight percent water.

[0103] In some embodiments, the flavoring material comprises between 0.5 weight percent and 10 weight percent water, preferably between 0.01 weight percent and 8 weight percent water, more preferably between 0.5 weight percent and 6 weight percent water, and even more preferably between 0.5 weight percent and 4 weight percent water.

[0104] In other embodiments, the flavoring material comprises between 1.0 weight percent and 10 weight percent water, preferably between 1.0 weight percent and 8 weight percent water, more preferably between 1.0 weight percent and 6 weight percent water, and even more preferably between 1.0 weight percent and 4 weight percent water.

[0105] In a further embodiment, the flavoring material comprises between 1.5 weight percent and 10 weight percent water, preferably between 1.5 weight percent and 8 weight percent water, more preferably between 1.5 weight percent and 6 weight percent water, and even more preferably between 1.5 weight percent and 4 weight percent water.

[0106] In certain embodiments, the flavoring material further comprises a carrier material, which supports the polysaccharide matrix structure and the flavoring agent formulation entrapped therein.

[0107] In some embodiments, the carrier material is a carrier sheet material. As used herein, the term "sheet material" refers to a layered material having a width and length that are substantially greater than its thickness. For example, the carrier material may be a sheet of homogenized tobacco material or a sheet of paper material.

[0108] It has been found that the inclusion of a carrier sheet material in a flavoring material for use in an aerosol-generating article according to the invention enhances the structural strength of the flavoring material, with the carrier sheet material supporting and holding in place the polysaccharide matrix that entraps the flavoring agent formulation. By selecting and adjusting certain properties of the carrier sheet material (e.g., its thickness), a flavoring material can be obtained that is particularly resistant to wear and tear and has particularly good mechanical properties.

[0109] It has been found that, compared to flavorants of comparable composition and matrix structure but lacking the support of a carrier sheet material, flavorants comprising a carrier material are easier to handle and can be more conveniently stored, for example in the form of a bobbin, which advantageously facilitates their incorporation into aerosol-generating articles, particularly within the framework of high-speed automated manufacturing processes.

[0110] Flavourants comprising a carrier material also have the advantage that the polysaccharide matrix structure and flavourant formulation entrapped therein can be deposited on the carrier material, particularly a carrier sheet material, to form a flavourant that is in sheet form and can therefore be cut into pieces having a predetermined average size (e.g., a predetermined cut width or a predetermined cut length, or both), which facilitates the incorporation of the flavourant into a predetermined location within an aerosol-generating article, as described in more detail below.

[0111] For example, the polysaccharide matrix structure enclosing the flavor formulation may be formed in situ on a carrier sheet material. If this in situ forming step follows the manufacturing process from which the carrier sheet material is obtained, the in situ forming step may be carried out at a later date or at a different location.

[0112] As noted above, in some preferred embodiments, the carrier sheet material may be in the form of a sheet of homogenized tobacco material.

[0113] As used herein, the term "homogenized tobacco material" encompasses any tobacco material formed by agglomeration of particles of tobacco material. A sheet or web of homogenized tobacco material is formed by agglomerating particulate tobacco obtained by grinding or otherwise pulverizing one or both of tobacco lamina and tobacco stem. In addition, the homogenized tobacco material may contain one or more small amounts of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. A sheet of homogenized tobacco material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0114] The sheets or webs of homogenized tobacco material used in the present invention may have a tobacco content of at least about 40 weight percent on a dry weight basis, more preferably at least about 60 weight percent on a dry weight basis, even more preferably at least about 70 weight percent on a dry weight basis, and most preferably at least about 90 weight percent on a dry weight basis.

[0115] The sheet or web of homogenized tobacco material may include one or more intrinsic binders (i.e., tobacco intrinsic binders), one or more extrinsic binders (i.e., tobacco extrinsic binders), or combinations thereof, to assist in agglomerating the particulate tobacco. Alternatively, or additionally, the sheet of homogenized tobacco material for use as a carrier sheet material may include other additives, including, but not limited to, tobacco and non-tobacco fibers, aerosol formers, humectants, plasticizers, flavorants, fillers, aqueous and non-aqueous solvents, and combinations thereof.

[0116] Extrinsic binders suitable for inclusion in sheets or webs of homogenized tobacco material for use as carrier sheet materials are well 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), conjugate base salts of organic acids (such as sodium alginate), agar, pectin, and combinations thereof.

[0117] Non-tobacco fibers suitable for inclusion in sheets or webs of homogenized tobacco material for use as a carrier sheet material are known in the art and include, but are not limited to, cellulose fibers, softwood fibers, hardwood fibers, jute fibers, and combinations thereof. Prior to inclusion in a sheet of homogenized tobacco material for use as a carrier sheet material, the non-tobacco fibers may be processed by any suitable process known in the art, including, but not limited to, mechanical pulping, refining, chemical pulping, bleaching, sulfate pulping, and combinations thereof.

[0118] Preferably, the sheet or web of homogenized tobacco material includes an aerosol former. As used herein, the term "aerosol former" describes any suitable known compound or mixture of compounds that facilitates the formation of an aerosol during use and that is substantially resistant to thermal decomposition at the operating temperatures of the aerosol-generating article.

[0119] Suitable aerosol formers are known in the art and include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, triacetate, etc.), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.).

[0120] Preferred aerosol formers are polyhydric alcohols such as propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerin, or mixtures thereof.

[0121] The sheet or web of homogenized tobacco material may include a single aerosol former. Alternatively, the sheet or web of homogenized tobacco material may include a combination of two or more aerosol formers.

[0122] The homogenized sheet or web of tobacco material has an aerosol former content of greater than 10 percent on a dry weight basis. Preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than 12 percent on a dry weight basis. More preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than 14 percent on a dry weight basis. Even more preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than 16 percent on a dry weight basis.

[0123] The sheet of homogenized tobacco material may have an aerosol former content of from about 10 percent to about 30 percent on a dry weight basis. Preferably, the sheet or web of homogenized tobacco material has an aerosol former content of less than 25 percent on a dry weight basis.

[0124] In one preferred embodiment, the sheet of homogenized tobacco material has an aerosol former content of approximately 20 percent on a dry weight basis.

[0125] Sheets or webs of homogenized tobacco for use as carrier sheet materials in the flavoring materials of the present invention may be made by methods known in the art (e.g., the methods disclosed in International Patent Application WO-A-2012 / 164009 A2). In a preferred embodiment, sheets of homogenized tobacco material for use as carrier sheet materials are formed from a slurry comprising particulate tobacco, guar gum, cellulose fibers, and glycerin by a casting process.

[0126] In other embodiments, the carrier sheet material may be in the form of a sheet of non-tobacco aerosol-generating material. For example, the carrier sheet material may be a sheet of absorbent non-tobacco material loaded with nicotine (e.g., in the form of a nicotine salt) and an aerosol former. Examples of such rods are described in International Application No. WO-A-2015 / 082652. Additionally or alternatively, the carrier sheet material may be a sheet of homogenized non-tobacco plant material, such as an aromatic non-tobacco plant material.

[0127] In certain embodiments, the carrier sheet material may be in the form of a paper wrapper material. This has the advantage that the flavoring material may be used as a replacement for, or in addition to, conventional paper wrapper materials in the manufacture of aerosol-generating articles. Thus, the flavoring material may be incorporated into the aerosol-generating article without significantly changing existing manufacturing processes and without requiring significant modification of existing manufacturing equipment.

[0128] In particular, in some embodiments, the flavourant, which includes a paper wrapper material as a carrier material, may surround the rod of the aerosol-generating substrate, such that the flavourant is just outside the rod of the aerosol-generating substrate and is held in a predetermined, controlled position around the periphery of the aerosol-generating element, instead of being dispersed within the aerosol-generating substrate.

[0129] In some embodiments, the flavoring material further comprises greater than 0.1 weight percent carbon particles, the carbon particles having a volume average particle size greater than 10 micrometers.

[0130] It has been found that the inclusion of a carbon-based material, such as graphite, expanded graphite, or graphene, in the flavoring material of an aerosol-generating article according to the present invention enhances flavor release, particularly at low temperatures, relative to a flavoring material of comparable composition and structure but lacking the carbon-based material. Without wishing to be bound by theory, this is hypothesized to be related to the enhanced thermal conductivity of the flavoring material, which may allow it to reach a certain threshold temperature more quickly, thereby allowing the flavoring agent formulation to be released more quickly from the polysaccharide matrix structure.

[0131] The improved flavor release is believed to be related to a more uniform temperature distribution throughout the flavorant during use, allowing for greater use efficiency of the flavor formulation when a greater proportion of the flavorant reaches a temperature high enough to release the flavor species from the matrix structure.

[0132] The improved release of flavor species provided by flavor materials containing the above-mentioned carbon particles may also supply heat to aerosol-generating articles incorporating the flavor delivery material, enabling heaters configured to operate cooler and therefore require less power.

[0133] By adjusting the amount and size of the carbon particles, it may be possible to control and fine-tune the flavor release enhancement. For example, a relatively narrow particle size distribution may provide a more homogeneous flavor delivery material with respect to thermal conductivity. This may mean that, during use, temperature gradients within the flavor material provided to different parts of the aerosol-generating article that are subjected to the same heating profile are minimized.

[0134] The carbon particles preferably comprise one or more of graphite particles, expanded graphite particles, and graphene particles. In a preferred embodiment, the carbon particles comprise one or both of expanded graphite particles and graphene particles.

[0135] Advantageously, particles such as those listed above, particularly graphite and expanded graphite, may have high thermal conductivity and low density, and therefore may be able to substantially improve the thermal conductivity of flavoring materials without significantly increasing the density of the flavoring materials. This may be advantageous in that increasing density may increase the weight of the flavoring material itself for a given volume, and therefore may also increase transportation costs. Similarly, increasing density may have a proportional impact on transportation costs when the flavoring material is incorporated into an aerosol-generating article.

[0136] Additionally, particles such as those listed above have the advantage that they may be inductively heated, so that heat may be supplied directly into the flavor material according to the present invention when the flavor material is exposed to an electromagnetic field generated by an induction coil.

[0137] Preferably, the carbon particles have a volume average particle size of 30 micrometers to 150 micrometers.

[0138] As used herein, the term "volume average particle size" may refer to the average calculated using the following formula, where d[4,3] is the volume average particle size and d is the particle size:

number

[0139] In other words, the volume average particle size may refer to the average calculated by dividing the sum of the fourth power of the particle size by the sum of the third power of the particle size.

[0140] Surprisingly, the inventors have found that these relatively small particle size ranges are particularly effective in increasing the thermal conductivity of the flavoring material when the flavoring material is in the form of or comprises a sheet. In addition, these relatively small particle sizes may advantageously result in a more uniform thermal conductivity and may also result in a sheet having a more uniform thickness than when larger particle sizes are used.

[0141] In embodiments where the flavorant comprises a carrier sheet material supporting a polysaccharide structure that entraps the flavorant formulation, the carbon particles may be included within the carrier sheet material, which may be advantageous in that carbon particles in this size range may be readily mixed with particles of similar size used in the manufacture of the carrier sheet material, such as in the case of sheets of homogenized tobacco or other plant material.

[0142] The carbon particles may have a particle size distribution having a D10 particle size, a D50 particle size, and a D90 particle size. In such a particle size distribution, 10% of the particles have a particle size equal to or less than the D10 particle size and 90% of the particles have a particle size equal to or less than the D90 particle size. The D50 particle size is the median particle size, such that 50% of the particles have a particle size equal to or less than the D50 particle size.

[0143] The D90 particle size may be 50, 40, 30, 25, 20, 15, 10, 8, 5, or 3 times or less the D10 particle size. The D90 particle size may be 2, 3, 5, or 8 times or more the D10 particle size.

[0144] The D90 particle size may be 3 to 50, 3 to 40, 3 to 30, 3 to 25, 3 to 20, 3 to 15, 3 to 10, 3 to 8, 3 to 5, 5 to 50, 5 to 40, 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 10, 5 to 8, 8 to 50, 8 to 40, 8 to 30, 8 to 25, 8 to 20, 8 to 15, 8 to 10, 10 to 50, 10 to 40, 10 to 30, 10 to 25, 10 to 20, 10 to 15, 15 to 50, 15 to 40, 15 to 30, 15 to 25, or 15 to 20 times the D10 particle size.

[0145] A preferred particle size distribution may have a D90 particle size that is 3 to 25, or 3 to 15 times the D10 particle size. A particularly preferred particle size distribution may have a D90 particle size that is 5 to 20, or 5 to 10 times the D10 particle size.

[0146] In certain preferred embodiments, in the flavourant according to the present invention, the carbon particles have a particle size distribution of a D90 particle size and a D10 particle size, the D90 particle size being no more than 25 or 15 times the D10 particle size.

[0147] A compromise must be made regarding particle size distribution. A tighter particle size distribution may advantageously provide a more uniform thermal conductivity throughout the flavoring material. This is because there is less variation in particle size at different locations within the flavoring material. This may advantageously allow for more efficient use of the flavoring agent formulation throughout the flavoring material. However, a tighter particle size distribution may disadvantageously be more difficult and expensive to achieve. The inventors have found that the particle size distribution described above may provide an optimal compromise between these two factors.

[0148] The desired D10 and D90 particle sizes may be obtained by sieving. Thus, if desired, sieving may be used to obtain a narrow particle size distribution.

[0149] The carbon particles may have a D10 particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more. Each of the carbon particles may have a particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more.

[0150] The carbon particles may have a D10 particle size of 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers or less. Each of the carbon particles may have a particle size of 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers or less.

[0151] The carbon particles may have a D90 particle size of 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers or less. Each of the carbon particles may have a particle size of 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers or less.

[0152] The carbon particles may have a D90 particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more. Each of the carbon particles may have a particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more.

[0153] The carbon particles may have a D50 particle size and / or a volume average particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or greater.

[0154] The carbon particles may have a D50 particle size and / or a volume average particle size of less than or equal to 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers.

[0155] The carbon particles may have one or both of a D50 particle size and a volume average particle size of 1 to 1000, preferably 10 to 200, more preferably 30 to 150, or even more preferably 50 to 75 micrometers. Alternatively, or additionally, each of the carbon particles may have a particle size of 1 to 1000, preferably 10 to 200, more preferably 30 to 150, or even more preferably 50 to 75 micrometers.

[0156] Surprisingly, the inventors have found that these relatively small particle size ranges are particularly effective in increasing the thermal conductivity of flavor materials for use in aerosol-generating articles according to the present invention, particularly in view of use conditions in which the flavor materials are exposed to relatively low temperatures during use.

[0157] The carbon particles may have a volume average particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more.

[0158] It may be particularly preferred that the carbon particles have a volume average particle size of greater than 10 micrometers.

[0159] The carbon particles may have a volume average particle size of less than or equal to 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers.

[0160] The carbon particles may have a volume average particle size of 1 to 1000, 10 to 200, 30 to 150, or 50 to 75 micrometers. These average particle size ranges may be particularly preferred when the flavoring material comprises or is in the form of a sheet.

[0161] The carbon particles may have a volume average particle size that is at least 2, 3, 5, 8, 10, 15, or 20 times the number average particle size.

[0162] It may be particularly preferred that the thermally conductive particles are or include graphite particles.

[0163] The graphite particles may have a particle size distribution with a D10 particle size of 5 to 20, such as 10 to 14 micrometers, e.g., approximately 12 micrometers. The graphite particles may have a particle size distribution with a D50 particle size of 25 to 45 micrometers, e.g., approximately 35 micrometers. The graphite particles may have a particle size distribution with a D90 particle size of 45 to 75 micrometers, e.g., approximately 55 micrometers. Advantageously, such particles are commercially available and have been found by the inventors to provide a significant increase in the thermal conductivity of the flavoring material.

[0164] It may be particularly preferred that the thermally conductive particles are or include expanded graphite particles.

[0165] The expanded graphite particles may have a particle size distribution with a D10 particle size of 5 to 20, e.g., 9 to 12 micrometers, e.g., approximately 10.5 micrometers. The expanded graphite particles may have a particle size distribution with a D50 particle size of 15 to 25 micrometers, e.g., approximately 20 micrometers. The expanded graphite particles may have a particle size distribution with a D90 particle size of 46 to 66 micrometers, e.g., approximately 56 micrometers. Advantageously, such particles are commercially available and have been found by the inventors to provide a significant increase in the thermal conductivity of the flavoring material. The expanded graphite particles may also advantageously reduce the overall density of the flavoring material.

[0166] Each of the carbon particles may have three mutually perpendicular dimensions. The largest of these three dimensions may be no more than 10, 8, 5, 3, or 2 times larger than the smallest of these three dimensions. The largest of these three dimensions may be no more than 10, 8, 5, 3, or 2 times larger than the second largest of these three dimensions. Each of these three dimensions may be substantially equal. Each of the carbon particles may be substantially spherical.

[0167] The carbon particles may include at least 10, 20, 50, 100, 200, 500, or 1000 particles.

[0168] In the flavor material according to the present invention, the carbon particles comprise between 0.01 weight percent and 10 weight percent of the flavor material on a dry weight basis.

[0169] In some embodiments, the flavoring material comprises greater than 0.1 weight percent of an additive selected from the group consisting of polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof.

[0170] It has been found that the inclusion of an additive selected from the group described above in a flavoring material for use in an aerosol-generating article according to the present invention affects the flavor release profile, particularly by facilitating and enhancing flavor release at lower temperatures compared to a flavoring material having substantially the same composition and structure but not containing such an additive.

[0171] Without wishing to be bound by theory, this effect is understood to be related to gaseous compounds released upon thermal decomposition of the additive, which disrupt the polysaccharide matrix structure, presumably by rupturing open some of the internal pockets within which the flavor formulation is immobilized.

[0172] Therefore, the improved release of flavor species provided by flavor materials containing one or more of the above-mentioned additives may also provide heat to aerosol-generating articles incorporating the flavor materials, enabling heaters to be configured to operate at lower temperatures and therefore require less power during use.

[0173] By adjusting the content of additives, or by selecting specific additives, or both, it may be advantageous to further control the flavor release profile.In fact, it has been found that including a larger amount of additives in the flavor material generally causes a more significant shift in the flavor release profile toward lower temperatures.Furthermore, the use of different additives, alone or in combination, that undergo thermal decomposition at different temperatures may advantageously provide a tool for even more fine-tuning the flavor release profile of aerosol-generating articles containing flavor materials.

[0174] Preferably, the additive is pyrolyzed at a temperature of less than 220 degrees Celsius and a pressure of 1 bar. More preferably, the additive is pyrolyzed at a temperature of less than 200 degrees Celsius and a pressure of 1 bar. Even more preferably, the additive is pyrolyzed at a temperature of less than 180 degrees Celsius and a pressure of 1 bar.

[0175] The additive may be pyrolyzed at a temperature of at least 100 degrees Celsius, preferably at least 120 degrees Celsius, more preferably at least 140 degrees Celsius, and at a pressure of 1 bar.

[0176] In some preferred embodiments, the additive is pyrolyzed at a temperature of 100 degrees Celsius to 220 degrees Celsius, preferably 120 degrees Celsius to 220 degrees Celsius, more preferably 140 degrees Celsius to 220 degrees Celsius, at a pressure of 1 bar.

[0177] In some preferred embodiments, the additive is pyrolyzed at a temperature of 100 degrees Celsius to 200 degrees Celsius, preferably 120 degrees Celsius to 200 degrees Celsius, more preferably 140 degrees Celsius to 200 degrees Celsius, at a pressure of 1 bar.

[0178] In a further embodiment, the additive is pyrolyzed at a temperature of 100 degrees Celsius to 180 degrees Celsius, preferably 120 degrees Celsius to 180 degrees Celsius, more preferably 140 degrees Celsius to 180 degrees Celsius, at a pressure of 1 bar.

[0179] The use of one or more selected additives that thermally decompose at a temperature within the aforementioned range and a pressure of 1 bar has been identified as particularly advantageous because, upon heating of the flavoring material according to the present invention, these additives begin to thermally decompose at temperatures significantly lower than the temperatures at which the matrix-forming polysaccharide or polysaccharides thermally decompose. As a result, the gaseous products produced upon thermal decomposition of the additive may interact with the matrix structure and disrupt its integrity, such as by progressively rupturing open pockets in the matrix structure in which the flavoring agent formulation is trapped, before the integrity of the matrix structure can be affected by the supply of heat alone.

[0180] Polycarboxylic acids suitable for use as additives in flavoring materials according to the present invention include, but are not limited to, tartronic acid, malonic acid, and citric acid.

[0181] Salts containing bicarbonate functionality suitable for use as additives in flavoring materials according to the present invention include, but are not limited to, sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, calcium bicarbonate, ammonium bicarbonate.

[0182] Preferably, the additives comprise 25 weight percent or less of the flavoring material on a dry weight basis. More preferably, the additives comprise 20 weight percent or less of the flavoring material on a dry weight basis. Even more preferably, the additives comprise 15 weight percent or less of the flavoring material on a dry weight basis. In particularly preferred embodiments, the additives comprise 10 weight percent or less of the flavoring material on a dry weight basis.

[0183] Preferably, the additive comprises at least 0.25 weight percent of the flavoring material on a dry weight basis, more preferably at least 0.5 weight percent of the flavoring material on a dry weight basis, and even more preferably at least 1.0 weight percent of the flavoring material on a dry weight basis.

[0184] Flavour materials for use in aerosol-generating articles according to the present invention can be prepared by different routes.

[0185] One such method for producing a flavoring material may include a first step of preparing an aqueous composition containing a flavoring agent formulation, a polysaccharide, and an emulsifier, a second step of casting the aqueous composition onto a substantially flat support surface, a third step of causing the aqueous composition to gel on the support surface, and a fourth step of drying the gelled aqueous composition. The dried flavoring material may then be removed from the support surface. The support surface may be a metal plate.

[0186] Another method of producing one such flavor delivery device according to the present invention may include a first step of preparing an aqueous composition comprising a flavor formulation, a polysaccharide, and an emulsifier, a second step of casting the aqueous composition onto a carrier sheet material placed on a substantially flat support surface, a third step of gelling the aqueous composition on the carrier sheet material, and a fourth step of drying the gelled aqueous composition, where the carrier sheet material supports a polysaccharide matrix that entraps the flavor formulation, which may then be removed from the support surface.

[0187] A further method for producing such a flavor delivery device according to the present invention may include a first step of preparing an aqueous composition comprising a flavor formulation, a polysaccharide, and an emulsifier, a second step of spraying the aqueous composition onto a carrier sheet material (e.g., homogenized tobacco material) placed on a substantially flat support surface, a third step of gelling the aqueous composition onto the carrier sheet material, and a fourth step of drying the gelled aqueous composition and carrier sheet material. The dried flavor formulation, with the carrier sheet material supporting a polysaccharide matrix that entraps the flavor formulation, may then be removed from the support surface.

[0188] As is apparent from the foregoing description of flavoring materials for incorporation into aerosol-generating articles according to the present invention, the present invention provides a new range of aerosol-generating articles capable of delivering flavor to consumers in a more consistent and controlled manner. Furthermore, because the flavoring agent formulation is at least partially trapped within the matrix until released when heat is supplied to the aerosol-generating article during use, loss of flavor species during storage and transport of the aerosol-generating article can be significantly reduced. For certain embodiments, this allows for particularly efficient use of flavoring agents, especially in combination with the enhanced flavor release that can be obtained at low temperatures.

[0189] As briefly described above, an aerosol-generating article according to the present invention comprises, in a sequential arrangement, an upstream section, an aerosol-generating element, and a downstream section. The aerosol-generating element comprises a rod of aerosol-generating substrate surrounded by a wrapper. A flavorant of the type described in the preceding paragraphs is provided in at least one of the wrapper surrounding the rod of aerosol-generating substrate, the upstream section, and the downstream section.

[0190] In other words, the flavourant is provided at a location within the aerosol-generating article other than within the rod of the aerosol-generating substrate.

[0191] The downstream section is provided immediately downstream of the aerosol-generating element and extends from the downstream end of the aerosol-generating article to the downstream end of the aerosol-generating article, and the upstream section is provided immediately upstream of the aerosol-generating element and extends from the upstream end of the aerosol-generating element to the upstream end of the aerosol-generating article.

[0192] In some embodiments, the downstream section comprises a hollow tubular element provided immediately downstream of the aerosol-generation element, the upstream end of the hollow tubular element abutting the downstream end of the aerosol-generation element, and the flavorant provided within the hollow tubular element.

[0193] In other embodiments, the downstream section comprises a hollow tubular element provided downstream of the aerosol-generation element, and the flavorant is provided between the downstream end of the aerosol-generation element and the upstream end of the hollow tubular element, e.g., the flavorant is sandwiched between the aerosol-generation element and the hollow tubular element.

[0194] In some embodiments, the upstream section comprises an upstream element provided immediately upstream of the aerosol-generation element, the downstream end of the upstream element abutting the upstream end of the aerosol-generation element, and the flavorant provided within the upstream element.

[0195] In other embodiments, the upstream section includes an upstream element provided upstream of the aerosol-generation element, and the flavorant is provided between the upstream end of the aerosol-generation element and the downstream end of the upstream element.

[0196] For example, the flavorant may be sandwiched between the aerosol-generating element and the upstream element.

[0197] The downstream section may further include one or more components downstream of the hollow tubular element. For example, the aerosol-generating article may include a mouthpiece element that extends all the way to and defines the proximal end of the aerosol-generating article. The aerosol-generating article may additionally include an aerosol cooling element provided between the hollow tubular element and the mouthpiece element. The hollow tubular cooling element and one or more additional components provided downstream of the hollow tubular element form the downstream section of the aerosol-generating article.

[0198] The upstream element may have a length of at least about 2 millimeters, at least about 3 millimeters, or at least about 4 millimeters.

[0199] The upstream element may have a length of about 10 millimeters or less, about 8 millimeters or less, or about 6 millimeters or less.

[0200] The upstream element may have a length of about 2 millimeters to about 10 millimeters, about 2 millimeters to about 8 millimeters, or about 2 millimeters to about 6 millimeters.

[0201] The upstream element may have a length of about 3 millimeters to about 10 millimeters, about 3 millimeters to about 8 millimeters, or about 3 millimeters to about 6 millimeters.

[0202] The upstream element may have a length of about 4 millimeters to about 10 millimeters, about 4 millimeters to about 8 millimeters, or about 4 millimeters to about 6 millimeters.

[0203] For example, the upstream element may have a length of about 5 millimeters.

[0204] The length of the upstream element may be selected based on the desired balance between the ability of the upstream element to prevent or limit upstream migration of the aerosol-generating material from the aerosol-generating element and the RTD (resistance to withdrawal) of the upstream element.

[0205] The length of the upstream element may be selected based on the desired overall length of the aerosol-generating article.

[0206] The ratio of the length of the upstream element to the overall length of the aerosol-generating article may be at least about 0.03, at least about 0.05, or at least about 0.07.

[0207] The ratio of the length of the upstream element to the overall length of the aerosol-generating article may be about 0.25 or less, about 0.2 or less, or about 0.15 or less.

[0208] The upstream element preferably has a substantially circular cross section.

[0209] The upstream element may have an outer diameter of at least about 5 millimeters, about 6 millimeters, or about 7 millimeters.

[0210] The upstream element may have an outer diameter of 12 millimeters or less, about 10 millimeters or less, or about 8 millimeters or less.

[0211] The upstream element may have an outer diameter of about 5 millimeters to about 12 millimeters, about 5 millimeters to about 10 millimeters, or about 5 millimeters to about 8 millimeters.

[0212] The upstream element may have an outer diameter of about 6 millimeters to about 12 millimeters, about 6 millimeters to about 10 millimeters, or about 6 millimeters to about 8 millimeters.

[0213] The upstream element may have an outer diameter of about 7 millimeters to about 12 millimeters, about 7 millimeters to about 10 millimeters, or about 7 millimeters to about 8 millimeters.

[0214] For example, the upstream element may have an outer diameter of about 7.1 millimeters.

[0215] Preferably, the outer diameter of the upstream element is substantially the same as the outer diameter of the aerosol-generation element.

[0216] Preferably, the outer diameter of the upstream element is substantially the same as the outer diameter of the aerosol-generating article.

[0217] As mentioned above, the upstream element may be upstream of the aerosol-generation element and abut against it, which may advantageously improve the ability of the upstream element to prevent or restrict upstream movement of the aerosol-generating substrate from the aerosol-generation element.

[0218] The upstream element may be at the upstream end of the aerosol-generating article. The aerosol-generating article may include an additional element upstream of the upstream element. For example, the additional element upstream of the upstream element may act as a cap or cover to help prevent damage to the upstream element.

[0219] Preferably, the majority of the aerosol generated by the aerosol-generating article is generated by the aerosol-generating substrate. The entire aerosol generated by the aerosol-generating article may be generated by the aerosol-generating substrate.

[0220] As noted above, the aerosol-generating element comprises an aerosol-generating substrate in the form of a rod. As used herein with respect to the present invention, the term "rod" is used to mean a generally cylindrical element having a substantially circular, oval or elliptical cross-section.

[0221] The aerosol-generating element may have a length of at least about 8 millimeters, at least about 9 millimeters, or at least about 10 millimeters.

[0222] The aerosol-generating element may have a length of about 16 millimeters or less, about 15 millimeters or less, or about 14 millimeters or less.

[0223] The aerosol-generating element may have a length of about 8 millimeters to about 16 millimeters, about 8 millimeters to about 15 millimeters, or about 8 millimeters to about 14 millimeters.

[0224] The aerosol-generating element may have a length of about 9 millimeters to about 16 millimeters, about 9 millimeters to about 15 millimeters, or about 9 millimeters to about 14 millimeters.

[0225] The aerosol-generating element may have a length of about 10 millimeters to about 16 millimeters, about 10 millimeters to about 15 millimeters, or about 10 millimeters to about 14 millimeters.

[0226] For example, the aerosol-generating element may have a length of about 12 millimeters.

[0227] The ratio of the length of the aerosol-generating element to the overall length of the aerosol-generating article may be at least about 0.10, at least about 0.15, or at least about 0.20.

[0228] The ratio of the length of the aerosol-generating element to the overall length of the aerosol-generating article may be about 0.40 or less, about 0.35 or less, or about 0.3 or less.

[0229] The ratio of the length of the aerosol-generating element to the overall length of the aerosol-generating article may be from about 0.10 to about 0.40, from about 0.10 to about 0.35, or from about 0.10 to about 0.30.

[0230] The ratio of the length of the aerosol-generating element to the overall length of the aerosol-generating article may be from about 0.15 to about 0.40, from about 0.15 to about 0.35, or from about 0.15 to about 0.30.

[0231] The ratio of the length of the aerosol-generating element to the overall length of the aerosol-generating article may be from about 0.20 to about 0.40, from about 0.20 to about 0.35, or from about 0.20 to about 0.30.

[0232] Preferably, the aerosol-generating element has a substantially circular cross-section.

[0233] The aerosol-generating element may have an outer diameter of at least about 5 millimeters, at least about 6 millimeters, or at least about 7 millimeters.

[0234] The aerosol-generating element may have an outer diameter of 12 millimeters or less, about 10 millimeters or less, or about 8 millimeters or less.

[0235] The aerosol-generating element may have an outer diameter of about 5 millimeters to about 12 millimeters, about 5 millimeters to about 10 millimeters, or about 5 millimeters to about 8 millimeters.

[0236] The aerosol-generating element may have an outer diameter of about 6 millimeters to about 12 millimeters, about 6 millimeters to about 10 millimeters, or about 6 millimeters to about 8 millimeters.

[0237] The aerosol-generating element may have an outer diameter of about 7 millimeters to about 12 millimeters, about 7 millimeters to about 10 millimeters, or about 7 millimeters to about 8 millimeters.

[0238] For example, the aerosol-generating element may have an outer diameter of about 7.1 millimeters.

[0239] The aerosol-generating substrate may have a density of at least about 150 milligrams per cubic centimeter, at least about 175 milligrams per cubic centimeter, at least about 200 milligrams per cubic centimeter, or at least about 250 milligrams per cubic centimeter.

[0240] The aerosol-generating substrate may have a density of about 500 milligrams per cubic centimeter or less, about 450 milligrams per cubic centimeter or less, about 400 milligrams per cubic centimeter or less, or about 350 milligrams per cubic centimeter or less.

[0241] The aerosol-generating substrate may have a density of from about 150 milligrams / cubic centimeter to about 500 milligrams / cubic centimeter, from about 150 milligrams / cubic centimeter to about 450 milligrams / cubic centimeter, from about 150 milligrams / cubic centimeter to about 400 milligrams / cubic centimeter, or from about 150 milligrams / cubic centimeter to about 350 milligrams / cubic centimeter.

[0242] The aerosol-generating substrate may have a density of from about 175 milligrams / cubic centimeter to about 500 milligrams / cubic centimeter, from about 175 milligrams / cubic centimeter to about 450 milligrams / cubic centimeter, from about 175 milligrams / cubic centimeter to about 400 milligrams / cubic centimeter, or from about 175 milligrams / cubic centimeter to about 350 milligrams / cubic centimeter.

[0243] The aerosol-generating substrate may have a density of from about 200 milligrams / cubic centimeter to about 500 milligrams / cubic centimeter, from about 200 milligrams / cubic centimeter to about 450 milligrams / cubic centimeter, from about 200 milligrams / cubic centimeter to about 400 milligrams / cubic centimeter, or from about 200 milligrams / cubic centimeter to about 350 milligrams / cubic centimeter.

[0244] The aerosol-generating substrate may have a density of from about 250 milligrams / cubic centimeter to about 500 milligrams / cubic centimeter, from about 250 milligrams / cubic centimeter to about 450 milligrams / cubic centimeter, from about 250 milligrams / cubic centimeter to about 400 milligrams / cubic centimeter, or from about 250 milligrams / cubic centimeter to about 350 milligrams / cubic centimeter.

[0245] For example, the aerosol-generating substrate may have a density of about 300 milligrams per cubic centimeter.

[0246] The RTD of the rod of the aerosol-generating substrate may be at least about 4 millimeters H2O, at least about 5 millimeters H2O, or at least about 6 millimeters H2O.

[0247] The RTD of the rod of the aerosol-generating substrate may be about 10 millimeters H2O or less, about 9 millimeters H2O or less, or about 8 millimeters H2O or less.

[0248] The RTD of the rod of the aerosol-generating substrate may be from about 4 millimeters H2O to about 10 millimeters H2O, from about 4 millimeters H2O to about 9 millimeters H2O, or from about 4 millimeters H2O to about 8 millimeters H2O.

[0249] The RTD of the rod of the aerosol-generating substrate may be from about 5 millimeters H2O to about 10 millimeters H2O, from about 5 millimeters H2O to about 9 millimeters H2O, or from about 5 millimeters H2O to about 8 millimeters H2O.

[0250] The RTD of the rod of the aerosol-generating substrate may be from about 6 millimeters H2O to about 10 millimeters H2O, from about 6 millimeters H2O to about 9 millimeters H2O, or from about 6 millimeters H2O to about 8 millimeters H2O.

[0251] The aerosol-generating substrate may be a solid aerosol-generating substrate.

[0252] The aerosol-generating substrate preferably comprises an aerosol-forming material.

[0253] The aerosol former can be any suitable known compound or mixture of compounds that promotes the formation of a dense, stable aerosol during use. The aerosol former can promote the aerosol to be substantially resistant to thermal decomposition at temperatures typically encountered during use of the aerosol-generating article. Suitable aerosol formers include, for example, polyhydric alcohols (e.g., triethylene glycol, 1,3-butanediol, propylene glycol, glycerin, etc.), esters of polyhydric alcohols (e.g., glycerol mono-, di-, or triacetate, etc.), aliphatic esters of mono-, di-, or polycarboxylic acids (e.g., dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.), and combinations thereof.

[0254] The aerosol former preferably comprises one or more of glycerin and propylene glycol. The aerosol former may consist of glycerin, or propylene glycol, or a combination of glycerin and propylene glycol.

[0255] The aerosol-generating substrate may comprise at least about 5 weight percent, at least about 10 weight percent, or at least about 12 weight percent aerosol former, based on the dry weight of the aerosol-generating substrate.

[0256] The aerosol-generating substrate may comprise about 30 weight percent or less, about 25 weight percent or less, or about 20 weight percent or less of aerosol formers, based on the dry weight of the aerosol-generating substrate.

[0257] The aerosol-generating substrate may comprise from about 5 weight percent to about 30 weight percent, from about 5 weight percent to about 25 weight percent, or from about 5 weight percent to about 20 weight percent of aerosol-forming material, based on the dry weight of the aerosol-generating substrate.

[0258] The aerosol-generating substrate may comprise from about 10 weight percent to about 30 weight percent, from about 10 weight percent to about 25 weight percent, or from about 10 weight percent to about 20 weight percent aerosol-forming material, based on the dry weight of the aerosol-generating substrate.

[0259] The aerosol-generating substrate may comprise from about 12 weight percent to about 30 weight percent, from about 12 weight percent to about 25 weight percent, or from about 12 weight percent to about 20 weight percent aerosol former, based on the dry weight of the aerosol-generating substrate.

[0260] The aerosol-generating substrate may comprise a plurality of strips of tobacco material.The aerosol-generating substrate may comprise a plurality of strips of homogenized tobacco material.

[0261] As used herein with respect to the present invention, the term "strip" means an element having a length that is substantially greater than its width and thickness.

[0262] As used herein with respect to the present invention, the term "homogenized tobacco material" is used to describe a material formed by agglomerating particulate tobacco material.

[0263] The strips of homogenized tobacco material may be formed from a sheet of homogenized tobacco material, for example, by cutting or chopping. The strips of homogenized tobacco material may also be formed by other methods, for example, by extrusion.

[0264] The strips of tobacco material may have a width of at least about 0.3 millimeters, at least about 0.5 millimeters, or at least about 0.6 millimeters.

[0265] The strips of tobacco material may have a width of about 2 millimeters or less, about 1.2 millimeters or less, or less than about 0.9 millimeters.

[0266] The strips of tobacco material may have a width of about 0.3 millimeters to about 2 millimeters, about 0.3 millimeters to about 1.2 millimeters, or about 0.3 millimeters to about 0.9 millimeters.

[0267] The strips of tobacco material may have a width of about 0.5 millimeters to about 2 millimeters, about 0.5 millimeters to about 1.2 millimeters, or about 0.5 millimeters to about 0.9 millimeters.

[0268] The strips of tobacco material may have a width of about 0.6 millimeters to about 2 millimeters, about 0.6 millimeters to about 1.2 millimeters, or about 0.6 millimeters to about 0.9 millimeters.

[0269] The strips of tobacco material may have a length of at least about 10 millimeters.

[0270] The strips of tobacco material may have a length of about 40 millimeters or less.

[0271] The strips of tobacco material may have a length of from about 10 millimeters to about 40 millimeters.

[0272] On a dry weight basis, at least about 20 weight percent of the plurality of strips of tobacco material may extend along the entire length of the aerosol-generating substrate.On a dry weight basis, at least about 20 weight percent of the plurality of strips of tobacco material may have a length substantially the same as the length of the aerosol-generating substrate.

[0273] On a dry weight basis, about 60 percent by weight or less of the plurality of strips of tobacco material may extend along the entire length of the aerosol-generating substrate.On a dry weight basis, about 60 percent by weight or less of the plurality of strips of tobacco material may have a length substantially the same as the length of the aerosol-generating substrate.

[0274] Between about 20 percent and 60 percent by weight of the plurality of strips of tobacco material, on a dry weight basis, may extend along the entire length of the aerosol-generating substrate. Between about 20 percent and 60 percent by weight of the plurality of strips of tobacco material, on a dry weight basis, may have a length that is substantially the same as the length of the aerosol-generating substrate.

[0275] The size of the aerosol-generating material of an aerosol-generating substrate, such as multiple strips of tobacco material, can play a role in the distribution of heat within the aerosol-generating substrate. The size of the aerosol-generating material can also play a role in the resistance to withdrawal of the article. Additionally, the size of the aerosol-generating material can affect the ability of the upstream element to prevent or restrict migration of the aerosol-generating material into the longitudinally extending channels of the upstream element. The size of the aerosol-generating material can also affect the ability of the upstream element to prevent or restrict upstream migration of the aerosol-generating material along the longitudinally extending channels and out of the upstream element.

[0276] The aerosol-generating substrate may comprise a plurality of pellets or granules of tobacco material.The aerosol-generating substrate may comprise a plurality of pellets or granules of homogenized tobacco material.

[0277] At least about 60 percent by weight of the plurality of pellets or granules may have a largest dimension greater than about 1 millimeter, at least about 70 percent by weight of the plurality of pellets or granules may have a largest dimension greater than about 1 millimeter, or at least about 80 percent by weight of the plurality of pellets or granules may have a largest dimension greater than about 1 millimeter.

[0278] If the homogenized plant material is in the form of a plurality of pellets or granules, at least about 70 percent by weight of the plurality of pellets or granules may have a maximum dimension greater than about 0.5 millimeters, at least about 80 percent by weight of the plurality of pellets or granules may have a maximum dimension greater than about 0.5 millimeters, or at least about 90 percent by weight of the plurality of pellets or granules may have a maximum dimension greater than about 0.5 millimeters.

[0279] For example, at least about 80 weight percent of the plurality of pellets or granules may have a maximum dimension greater than about 1 millimeter, and at least about 90 weight percent of the plurality of pellets or granules may have a maximum dimension greater than about 0.5 millimeters.

[0280] The aerosol-generating substrate may comprise one or more sheets of tobacco material.

[0281] The aerosol-generating substrate may comprise one or more sheets of homogenized tobacco material.

[0282] Each individual ply or sheet of tobacco material can have a thickness of at least about 100 micrometers, at least about 150 micrometers, or at least about 300 micrometers.

[0283] As used herein with respect to the present invention, individual thickness refers to the thickness of an individual sheet of tobacco material, and combined thickness refers to the total thickness of all sheets of tobacco material that make up the aerosol-generating substrate. For example, if the aerosol-generating substrate is formed from two individual sheets of tobacco material, the combined thickness is the sum of the thicknesses of the two individual sheets of tobacco material, or the measured thickness of the two sheets of tobacco material when the two sheets of tobacco material are laminated to the aerosol-generating substrate.

[0284] The one or more sheets of tobacco material may each individually have a thickness of not more than about 600 micrometers, not more than about 300 micrometers, or not more than about 250 micrometers.

[0285] The one or more sheets of tobacco material can each individually have a thickness of from about 100 micrometers to about 600 micrometers, from about 100 micrometers to about 300 micrometers, or from about 100 micrometers to about 250 micrometers.

[0286] The one or more sheets of tobacco material can each individually have a thickness of from about 150 micrometers to about 600 micrometers, from about 150 micrometers to about 300 micrometers, or from about 150 micrometers to about 250 micrometers.

[0287] The one or more sheets of tobacco material can each individually have a thickness of from about 250 micrometers to about 600 micrometers, from about 250 micrometers to about 300 micrometers, or from about 250 micrometers to about 250 micrometers.

[0288] The one or more sheets of tobacco material may each individually have a length that is substantially the same as the length of the aerosol-generating substrate.

[0289] The one or more sheets of tobacco material may be subjected to one or more of the following processes: crimping, folding, gathering, and pleating.

[0290] Crimping, folding, gathering, or pleating one or more sheets of tobacco material may cause the one or more sheets of tobacco material to split to form strips of tobacco material. For example, one or more sheets of tobacco material may be crimped to an extent that the integrity of the one or more sheets of tobacco material is broken at a plurality of parallel ridges or corrugations, causing the material to separate and forming strips of tobacco material.

[0291] The aerosol-generating article may comprise a susceptor disposed within an aerosol-generating substrate.

[0292] As used herein with respect to this specification, the term "susceptor" refers to a material capable of converting electromagnetic energy into heat. When located within a varying electromagnetic field, induced eddy currents in the susceptor cause heating of the susceptor.

[0293] The susceptor is positioned in thermal contact with the aerosol-generating substrate, such that when the susceptor is heated, the aerosol-generating substrate is heated by the susceptor and an aerosol is generated. The susceptor may be disposed in direct physical contact with the aerosol-generating substrate.

[0294] The upstream element may advantageously prevent or limit upstream movement of the susceptor during storage, transport, and use of the aerosol-generating article.

[0295] The susceptor may be an elongated susceptor.

[0296] As used herein with respect to the present invention, the term "elongated" is used to describe a component of an aerosol-generating article that has a length that is greater than its width and thickness.

[0297] The elongated susceptor may be disposed substantially longitudinally within the aerosol-generating substrate. That is, the longitudinal axis of the elongated susceptor may be approximately parallel to the longitudinal axis of the aerosol-generating element. For example, the longitudinal axis of the elongated susceptor may be parallel to the longitudinal axis of the aerosol-generating element within ±10 degrees. The elongated susceptor is located at a radially central position within the rod of the aerosol-generating substrate and extends along the longitudinal axis of the aerosol-generating element.

[0298] The susceptor may extend from the downstream end of the aerosol-generating element towards the upstream end of the aerosol-generating element.

[0299] The susceptor may extend from the upstream end of the aerosol-generating element towards the downstream end of the aerosol-generating element.

[0300] The susceptor may extend from the upstream end of the aerosol-generating substrate to the downstream end of the aerosol-generating element, i.e., the susceptor may extend along the entire length of the aerosol-generating element.

[0301] The length of the susceptor may be substantially the same as the length of the aerosol-generating element.

[0302] The susceptor may extend partway along the length of the aerosol-generating element.

[0303] The susceptor may be spaced from the downstream end of the aerosol-generating substrate.

[0304] The susceptor may be spaced from the upstream end of the aerosol-generating element.

[0305] The susceptor may be spaced from both the downstream end and the upstream end of the aerosol-generating element.

[0306] The length of the susceptor may be less than the length of the aerosol-generating element.

[0307] The susceptor may be completely enclosed within the aerosol-generating substrate, i.e., the aerosol-generating substrate may completely surround the susceptor.

[0308] The susceptor may be in the form of a pin, rod, strip, or blade.

[0309] The susceptor may have a length of at least about 5 millimeters, at least about 6 millimeters, or at least about 8 millimeters.

[0310] The susceptor may have a length of about 15 millimeters or less, about 12 millimeters or less, or about 10 millimeters or less.

[0311] The susceptor may have a length of about 5 millimeters to about 15 millimeters, about 5 millimeters to about 12 millimeters, or about 5 millimeters to about 10 millimeters.

[0312] The susceptor may have a length of about 6 millimeters to about 15 millimeters, about 6 millimeters to about 12 millimeters, or about 6 millimeters to about 10 millimeters.

[0313] The susceptor may have a length of about 8 millimeters to about 15 millimeters, about 8 millimeters to about 12 millimeters, or about 8 millimeters to about 10 millimeters.

[0314] The susceptor may have a width of at least about 1 millimeter.

[0315] The susceptor may have a width of about 5 millimeters or less.

[0316] The susceptor may have a width of about 1 millimeter to about 5 millimeters.

[0317] The susceptor may have a thickness of at least about 0.01 millimeters to at least about 0.5 millimeters.

[0318] The susceptor may have a thickness of about 2 millimeters or less, about 500 micrometers or less, or about 100 micrometers or less.

[0319] The susceptor may have a thickness of about 10 micrometers to about 2 millimeters, about 10 micrometers to about 500 micrometers, or about 10 micrometers to about 100 micrometers.

[0320] The susceptor may have a thickness of about 0.5 millimeters to about 2 millimeters.

[0321] The susceptor may have a substantially circular cross section.

[0322] The susceptor may have a substantially constant cross section along the length of the susceptor.

[0323] When the susceptor has the shape of a strip or blade, the strip or blade may have a rectangular shape with a width of about 2 millimeters to about 8 millimeters, or about 3 millimeters to about 5 millimeters. As an example, a susceptor in the form of a strip of blade may have a width of about 4 millimeters.

[0324] When the susceptor is in the form of a strip or blade, the strip or blade may have a rectangular shape and a thickness of about 0.03 millimeters to about 0.15 millimeters, or about 0.05 millimeters to about 0.09 millimeters. As an example, a susceptor in the form of a strip of blade may have a thickness of about 0.07 millimeters or 0.06 millimeters.

[0325] The susceptor may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-generating substrate. For example, the susceptor may comprise metal or carbon.

[0326] The susceptor may include or consist of a ferromagnetic material (e.g., ferromagnetic alloy, ferritic iron, or ferromagnetic steel or stainless steel). A suitable susceptor may be or include aluminum. The susceptor may be formed from 400 series stainless steel, such as grade 410, or grade 420, or grade 430 stainless steel. Different materials dissipate different amounts of energy when placed in electromagnetic fields having similar values ​​of frequency and field strength.

[0327] Thus, the parameters of the susceptor, such as the type of material, length, width, and thickness, may all be modified to provide the desired power dissipation within a known electromagnetic field. The susceptor may be heated to temperatures in excess of 250°C.

[0328] A suitable susceptor may include a non-metallic core having a metal layer disposed thereon (e.g., a metal track formed on the surface of a ceramic core). The susceptor may have a protective outer layer, such as a protective ceramic or glass layer, encapsulating the susceptor. The susceptor may also include a protective coating formed of glass, ceramic, or an inert metal formed over a core of susceptor material.

[0329] The susceptor may be a multi-material susceptor and may include a first susceptor material and a second susceptor material.

[0330] In the context of the present invention, a hollow tubular element provides an unrestricted flow channel. This means that the hollow tubular element provides a negligible level of resistance to withdrawal (RTD). As used herein with respect to the present invention, the term "negligible RTD" is used to describe an RTD of less than 1 mmH2O per 10 millimeters of the length of the hollow tubular substrate element, less than 0.4 mmH2O per 10 millimeters of the length of the hollow tubular substrate element, or less than 0.1 mmH2O per 10 millimeters of the length of the hollow tubular substrate element. Therefore, the flow channel should not include any components that would obstruct the longitudinal flow of air. Preferably, the flow channel is substantially empty.

[0331] The hollow tubular element may have an overall length of at least about 10 millimeters, at least about 12 millimeters, or at least about 15 millimeters.

[0332] The hollow tubular element may have an overall length of about 30 millimeters or less, 25 millimeters or less, or about 23 millimeters or less.

[0333] The hollow tubular element may have an overall length of about 10 millimeters to about 30 millimeters, about 10 millimeters to about 25 millimeters, or about 10 millimeters to about 23 millimeters.

[0334] The hollow tubular element may have an overall length of about 12 millimeters to about 30 millimeters, about 12 millimeters to about 25 millimeters, or about 12 millimeters to about 23 millimeters.

[0335] The hollow tubular element may have an overall length of about 12 millimeters to about 30 millimeters, about 12 millimeters to about 25 millimeters, or about 12 millimeters to about 23 millimeters.

[0336] The overall length of the hollow tubular element may be selected based on the desired overall length of the aerosol-generating article.

[0337] The hollow tubular element may be formed from any suitable material or combination of materials. For example, the hollow tubular element may be formed from one or more materials selected from the group consisting of cellulose acetate, paper-based materials such as paper or cardboard, crimped paper, and polymeric materials such as low-density polyethylene (LDPE). Other suitable materials include polyhydroxyalkanoate (PHA) fibers.

[0338] In some embodiments, a ventilation zone may be provided downstream of the aerosol-generating element. Satisfactory cooling of the aerosol stream generated upon heating of the aerosol-generating substrate and drawn through the hollow tubular element may be achieved by providing a ventilation zone along the hollow tubular element itself or along an intermediate element provided between the hollow tubular element and the mouthpiece. One such intermediate element may also be described as an aerosol-cooling element. One such intermediate element may also be provided in the form of a hollow tubular element. Without wishing to be bound by theory, the temperature reduction caused by admitting cooler ambient air through the ventilation zone into the aerosol-generating article downstream of the aerosol-generating element may have a beneficial effect on aerosol particle nucleation and growth.

[0339] The ventilation zone may include a plurality of perforations through the tubular wall of the hollow tubular element. The ventilation zone may comprise at least one circumferential row of perforations. The ventilation zone may include two circumferential rows of perforations. For example, the perforations may be formed online during manufacture of the aerosol-generating article. Each circumferential row of perforations may include 8 to 30 perforations.

[0340] As mentioned above, the aerosol-generating article may comprise a mouthpiece element located downstream of the aerosol-generating substrate and at the downstream or mouth or proximal end of the aerosol-generating article.

[0341] The mouthpiece element may be a mouthpiece filter element. The mouthpiece element may include at least one filter segment for filtering aerosol generated upon heating of the aerosol-generating substrate. For example, the mouthpiece element may include one or more segments of fibrous filtering material. Suitable fibrous filtering materials are known in the art. For example, the at least one mouthpiece filter segment may include a cellulose acetate filter segment formed from cellulose acetate tow.

[0342] The mouthpiece element may consist of a single filter segment. The mouthpiece element may include two or more filter segments abutting and axially aligned in end-to-end relationship with one another.

[0343] Parameters or characteristics described herein with respect to the mouthpiece element as a whole may be equally applied to the filter segment of the mouthpiece element.

[0344] The mouthpiece element may have a low particulate filtration efficiency.

[0345] The mouthpiece element may have an RTD of about 25 millimeters H2O or less, about 20 millimeters H2O or less, or about 15 millimeters H2O or less.

[0346] The mouthpiece element may have an RTD of at least about 10 millimeters H2O.

[0347] The mouthpiece element may have an RTD of about 10 millimeters HO to about 25 millimeters HO, about 10 millimeters HO to about 20 millimeters HO, or about 10 millimeters HO to about 15 millimeters HO.

[0348] The mouthpiece element preferably has a substantially circular cross section.

[0349] Preferably, the mouthpiece element has an outer diameter that is substantially the same as the outer diameter of the aerosol-generating article.

[0350] The mouthpiece element may have a length of at least about 3 millimeters, or at least about 5 millimeters.

[0351] The length of the mouthpiece element may be about 11 millimeters or less, or about 9 millimeters or less.

[0352] The length of the mouthpiece element may be from about 3 millimeters to about 11 millimeters, or from about 3 millimeters to about 9 millimeters.

[0353] The length of the mouthpiece element may be from about 5 millimeters to about 11 millimeters, or from about 5 millimeters to about 9 millimeters.

[0354] For example, the mouthpiece element may have a length of about 7 millimeters.

[0355] The length of the mouthpiece element may be selected based on the desired overall length of the aerosol-generating article.

[0356] The mouthpiece element may be surrounded by a plug wrap.

[0357] The mouthpiece element may be non-vented so that air does not enter the aerosol-generating article along the mouthpiece element.

[0358] The mouthpiece element may be connected to one or more of the adjacent components of the aerosol-generating article by a tipping wrapper.

[0359] The aerosol-generating article may include an oral end cavity at the downstream end of the aerosol-generating article. If present, the oral end cavity may be downstream of the mouthpiece element.

[0360] The oral end cavity may be defined by a hollow tubular element provided at the downstream end of the mouthpiece. Alternatively, the oral end cavity may be defined by an outer wrapper of the mouthpiece element, where the outer wrapper extends in a downstream direction from the mouthpiece element.

[0361] The aerosol-generating article may have a total length of at least about 35 millimeters, at least about 38 millimeters, at least about 40 millimeters, or at least about 42 millimeters.

[0362] The aerosol-generating article may have an overall length of about 100 millimeters or less, about 70 millimeters or less, about 60 millimeters or less, or 50 millimeters or less.

[0363] The aerosol-generating article may have a total length of about 35 millimeters to about 100 millimeters, about 35 millimeters to about 70 millimeters, about 35 millimeters to about 60 millimeters, or about 35 millimeters to about 50 millimeters.

[0364] The aerosol-generating article may have a total length of about 38 millimeters to about 100 millimeters, about 38 millimeters to about 70 millimeters, about 38 millimeters to about 60 millimeters, or about 38 millimeters to about 50 millimeters.

[0365] The aerosol-generating article may have a total length of about 40 millimeters to about 100 millimeters, about 40 millimeters to about 70 millimeters, about 40 millimeters to about 60 millimeters, or about 40 millimeters to about 50 millimeters.

[0366] The aerosol-generating article may have a total length of about 42 millimeters to about 100 millimeters, about 42 millimeters to about 70 millimeters, about 42 millimeters to about 60 millimeters, or about 42 millimeters to about 50 millimeters.

[0367] For example, the aerosol-generating article may have a total length of about 45 millimeters.

[0368] Preferably, the aerosol-generating article has a substantially circular cross-section.

[0369] The aerosol-generating article may have an outer diameter of at least about 5 millimeters, at least about 6 millimeters, or at least about 7 millimeters.

[0370] The aerosol-generating article may have an outer diameter of about 12 millimeters or less, about 10 millimeters or less, or about 8 millimeters or less.

[0371] The aerosol-generating article may have an outer diameter of from about 5 millimeters to about 12 millimeters, or from about 5 millimeters to about 10 millimeters, or from about 5 millimeters to about 8 millimeters.

[0372] The aerosol-generating article may have an outer diameter of from about 6 millimeters to about 12 millimeters, or from about 6 millimeters to about 10 millimeters, or from about 6 millimeters to about 8 millimeters.

[0373] The aerosol-generating article may have an outer diameter of from about 7 millimeters to about 12 millimeters, or from about 7 millimeters to about 10 millimeters, or from about 7 millimeters to about 8 millimeters.

[0374] For example, the aerosol-generating article may have an outer diameter of about 7.1 millimeters.

[0375] In aerosol-generating articles according to the present invention, a flavorant having the structure and formulation described above is provided in at least one of the upstream section, the downstream section, or a wrapper surrounding the aerosol-generating substrate of the aerosol-generating element. Incorporating a flavorant into aerosol-generating articles according to the present invention can be carried out according to one of several routes.

[0376] For example, the flavorant pieces may be combined with a tow of cellulose acetate fibers from which the upstream element or hollow tubular element can be formed. Alternatively, the flavorant pieces may be incorporated into the plug wrap used to surround the rod of aerosol-generating substrate of the aerosol-generating element.

[0377] As a further alternative, a flavouring material comprising a carrier sheet material in the form of a paper wrapper may be used alone or in combination with another paper wrapper to surround the rod of aerosol-generating substrate.

[0378] As a further alternative, the pieces of flavourant may be sandwiched between the upstream element and the aerosol-generation element, or between the hollow tubular element and the aerosol-generation element.

[0379] It has been found that incorporating the flavoring materials described above into one or more of the locations within the aerosol-generating articles discussed herein affects the flavor release profile and flavor transfer rate during use of the aerosol-generating article. Without wishing to be bound by theory, this is because, in an aerosol-generating article according to the present invention, the flavoring material is generally exposed to less intense heating than the aerosol-generating substrate, as opposed to solutions known in the art in which the flavoring material is provided at a location within the rod of the aerosol-generating substrate. This is related to the fact that the average distance between the flavoring material and a heat source is generally greater than the distance between the aerosol-generating substrate and the same heat source. The mutual arrangement and interaction of the aerosol-generating article according to the present invention and an aerosol-generating device configured to heat the aerosol-generating substrate will be discussed in more detail below.

[0380] Furthermore, aerosol-generating articles in which the aerosol-generating substrate is heated to generate the aerosol are typically heated to a relatively low temperature rather than being combusted to generate smoke.

[0381] The inventors have found that aerosol-generating articles according to the present invention can provide satisfactory flavor transfer rates during use because the flavorant can be adapted to release flavor in a controlled manner within a predetermined temperature range. This can be achieved by a) selecting and adjusting the polysaccharide matrix composition, or b) including carbon particles in the flavorant (consistent with the foregoing), or c) including an additive in the flavorant (consistent with the foregoing) that has the ability to generate gaseous compounds upon thermal decomposition, or d) any combination of a), b), and c).

[0382] Thus, despite being subjected to less intense heating, the flavoring material contained in the aerosol-generating article according to the present invention has the ability to release flavor in a more consistent manner throughout the entire use cycle of the aerosol-generating article. For example, in some embodiments, the inventors have observed that the flavor release associated with successive puffs during use of the aerosol-generating article may remain substantially constant until the last puff, or may increase slightly toward the end of the use cycle. This is quite surprising, as it contrasts with what is typically observed when flavoring materials are incorporated into the aerosol-generating substrate, i.e., flavor release increases during the first few puffs and only gradually decreases as the consumer approaches the end of the use cycle.

[0383] In embodiments in which the flavoring material is provided in a position within the upstream section or the downstream section, the distance between the flavoring material and the aerosol-generating element may be at least 5 percent of the outer diameter of the aerosol-generating element. The distance between the flavoring material and the aerosol-generating element is measured as the linear distance between the geometric center of the flavoring material and the nearest end face of the aerosol-generating element. For example, if the flavoring material is provided in the upstream section, such as the upstream element, the distance between the flavoring material and the aerosol-generating element is measured as the linear distance between the geometric center of the flavoring material and the upstream end of the rod of the aerosol-generating substrate.

[0384] Preferably, the distance between the flavorant and the aerosol-generating element may be at least 10 percent of the outer diameter of the aerosol-generating element. More preferably, the distance between the flavorant and the aerosol-generating element may be at least 15 percent of the outer diameter of the aerosol-generating element.

[0385] In embodiments in which the flavorant is provided at a location within the upstream section or the downstream section, the distance between the flavorant and the aerosol-generating element is preferably 50 percent or less of the outer diameter of the aerosol-generating element, more preferably 40 percent or less of the outer diameter of the aerosol-generating element, and even more preferably 30 percent or less of the outer diameter of the aerosol-generating element.

[0386] In some embodiments where the flavorant is provided at a location within the section or downstream section (e.g., within an upstream element or within a hollow tubular element), the distance between the flavorant and the aerosol-generating element is between 5 percent and 50 percent of the outer diameter of the aerosol-generating element, preferably between 5 percent and 40 percent of the outer diameter of the aerosol-generating element, and more preferably between 5 percent and 30 percent of the outer diameter of the aerosol-generating element.

[0387] In other embodiments where the flavorant is provided at a location within the upstream section or downstream section (e.g., within the upstream element or within the hollow tubular element), the distance between the flavorant and the aerosol-generating element is between 10 percent and 50 percent of the outer diameter of the aerosol-generating element, preferably between 10 percent and 40 percent of the outer diameter of the aerosol-generating element, and more preferably between 10 percent and 30 percent of the outer diameter of the aerosol-generating element.

[0388] In further embodiments in which the flavorant is provided at a location within the upstream section or downstream section (e.g., within the upstream element or within a hollow tubular element), the distance between the flavorant and the aerosol-generating element is between 15 percent and 50 percent of the outer diameter of the aerosol-generating element, preferably between 15 percent and 40 percent of the outer diameter of the aerosol-generating element, and more preferably between 15 percent and 30 percent of the outer diameter of the aerosol-generating element.

[0389] The present disclosure also relates to an aerosol-generating system. The aerosol-generating system may comprise an aerosol-generating article as described above. The aerosol-generating system may further comprise an aerosol-generating device configured to heat an aerosol-generating substrate of the aerosol-generating article. The aerosol-generating device may comprise a housing defining a cavity configured to receive the aerosol-generating article.

[0390] According to a second aspect of the present invention, there is provided an aerosol generation system comprising an aerosol-generating article according to the first aspect of the present invention and an aerosol generating apparatus configured to heat an aerosol-generating substrate of the aerosol-generating article, the aerosol generating apparatus comprising a housing defining a cavity configured to receive the aerosol-generating article.

[0391] The aerosol generating device may be a handheld aerosol generating device.

[0392] The aerosol generating device may be an electrically operated aerosol generating device.

[0393] The aerosol generating device may include a power source and control electronics.

[0394] The aerosol generating device may include a battery and control electronics.

[0395] The aerosol-generating device may be configured to heat the aerosol-generating substrate internally, i.e. the aerosol-generating device may be configured to supply heat to the aerosol-generating substrate from a location internal to the aerosol-generating article.

[0396] For example, in some embodiments, the aerosol generating device comprises a heater element configured to be inserted into the aerosol generating element when the aerosol-generating article is received within the cavity of the aerosol generating device.

[0397] In another embodiment, the aerosol-generating article includes a susceptor element provided in a position within the aerosol-generating element, and the aerosol-generating device includes an inductor coil positioned on or within the housing. The aerosol-generating device's power supply is connected to the inductor coil and configured to provide a high-frequency oscillating current to the inductor coil. This generates an alternating magnetic field that induces a voltage in the susceptor element. The induced voltage causes a current to flow in the susceptor element, which causes Joule heating of the susceptor element, which in turn heats the aerosol-generating substrate. The aerosol-generating device may be capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, e.g., about 2.5 kA / m.

[0398] The aerosol-generating device may be configured to heat the aerosol-generating substrate internally, i.e. the aerosol-generating device may be configured to supply heat to the aerosol-generating substrate from a location external to the aerosol-generating article.

[0399] For example, in some embodiments, the aerosol-generating device comprises heater elements positioned around the periphery of the cavity and configured to heat the aerosol-generating substrate of the aerosol-generating article from outside the aerosol-generating element of the aerosol-generating article. [Example]

[0400] The present invention is defined in the claims. However, 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 any other example, embodiment, or aspect described herein.

[0401] Example 1: 1. An aerosol-generating article for generating an aerosol upon heating, the aerosol-generating article comprising: an aerosol-generating element including a rod of aerosol-generating substrate surrounded by a wrapper; a downstream section provided immediately downstream of the aerosol-generating element and extending from the downstream end of the aerosol-generating element to the downstream end of the aerosol-generating article; and an upstream section provided immediately upstream of the aerosol-generating element and extending from the upstream end of the aerosol-generating element to the upstream end of the aerosol-generating article; the aerosol-generating article comprising a flavorant provided in at least one of the downstream section, the upstream section, and the wrapper surrounding the rod of aerosol-generating substrate; the flavorant comprising a polysaccharide matrix structure including gellan gum and an emulsifier, and a flavorant formulation dispersed within the polysaccharide matrix structure; the flavorant formulation being at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavorant. Example 2: An aerosol-generating article as described in Example 1, wherein the downstream section includes a hollow tubular element provided immediately downstream of the aerosol-generating element, the upstream end of the hollow tubular element abutting the downstream end of the aerosol-generating element, and the flavor material is provided within the hollow tubular element. Example 3: 2. The aerosol-generating article of claim 1, wherein the upstream section includes an upstream element provided immediately upstream of the aerosol-generating element, the downstream end of the upstream element abutting the upstream end of the aerosol-generating element, and the flavor material is provided within the upstream element. Example 4: 4. An aerosol-generating article according to any one of Examples 1 to 3, wherein the polysaccharide matrix structure comprises gellan gum as the only polysaccharide or gellan gum in combination with at least one additional polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose, and hydroxypropyl methylcellulose. Example 5: 5. An aerosol-generating article according to any one of Examples 1 to 4, wherein the gellan gum comprises between 5 weight percent and 99.9 weight percent of the flavor material on a dry weight basis. Example 6: formula C n H 2n+2 O n 6. The aerosol-generating article of any one of Examples 1 to 5, further comprising a polyol having the formula: Example 7: The aerosol-generating article of Example 6, wherein the polyol is selected from the group consisting of glycerol, sorbitol, xylitol, mannitol, and erythritol. Example 8: The aerosol-generating article of Example 6 or Example 7, wherein the polyol comprises 0.01 weight percent to 20 weight percent of the flavor material on a dry weight basis. Example 9: An aerosol-generating article according to any one of Examples 1 to 8, further comprising fibers. Example 10: 10. The aerosol-generating article of Example 9, wherein the fibers comprise 0.01 weight percent to 10 weight percent of the flavor material on a dry weight basis. Example 11: 11. An aerosol-generating article according to any one of Examples 1 to 10, comprising 0.01 weight percent to 80 weight percent menthol. Example 12: 12. An aerosol-generating article according to any one of Examples 1 to 11, wherein the flavourant further comprises a carrier material, the polysaccharide matrix structure and flavourant formulation being supported by the carrier material. Example 13: 13. The aerosol-generating article of Example 12, wherein the carrier material is a sheet of homogenized tobacco material. Example 14: 13. The aerosol-generating article of Example 12, wherein the carrier material is a sheet of plug paper wrapper material. Example 15: An aerosol-generating article described in any one of Examples 1 to 14, wherein the article has a ventilation zone located along the hollow tubular element, the ventilation zone configured to allow air to enter the axial lumen of the hollow tubular element. Example 16: An aerosol-generating article described in any one of Examples 1 to 15, wherein the upstream element comprises a plug extending to and defining the distal end of the aerosol-generating article, and the flavoring material is provided at a location within the plug. Example 17: 17. An aerosol-generating article according to any one of Examples 1 to 16, wherein the aerosol-generating substrate comprises tobacco material. Example 18: 18. The aerosol-generating article of Example 17, wherein the tobacco material comprises a sheet of homogenized tobacco material. Example 19: 18. The aerosol-generating article of Example 17, wherein the tobacco material comprises one or more of tobacco cut filler, reconstituted shred tobacco, and homogenized shred tobacco material. Example 20: An aerosol generating system comprising an aerosol-generating article according to any one of Examples 1 to 19 and an aerosol-generating device configured to heat an aerosol-generating substrate of the aerosol-generating article, the aerosol-generating device comprising a housing defining a cavity configured to receive the aerosol-generating article. Example 21: An aerosol generating system as described in Example 20, wherein the aerosol generating device comprises a heater element configured to be inserted into the aerosol generating element when the aerosol-generating article is received in the cavity of the aerosol generating device. Example 22: An aerosol generating system as described in Example 20, wherein the aerosol generating article comprises a susceptor element provided in a position within the aerosol generating element, and the aerosol generating device comprises an inductor coil positioned on or within the housing, and a power source connected to the inductor coil and configured to provide a high-frequency oscillating current to the inductor coil. Example 23: An aerosol generating system as described in Example 20, wherein the aerosol generating device comprises heater elements positioned around the periphery of the cavity and configured to heat the aerosol generating substrate of the aerosol generating article from outside the aerosol generating element of the aerosol generating article.

[0402] The embodiments will now be further described with reference to the figures. [Brief explanation of the drawings]

[0403] [Figure 1] FIG. 1 shows a schematic cross-sectional side view of an aerosol-generating article according to the present invention, which includes a flavorant within an upstream element. [Figure 2] FIG. 2 shows a schematic cross-sectional side view of another aerosol-generating article according to the present invention, which includes a flavoring material within a wrapper that surrounds the aerosol-generating substrate of an aerosol-generating element. [Figure 3] FIG. 3 shows a scanning electron microscope image of the flavoring material used in the aerosol-generating article of FIGS. [Figure 4] FIG. 4 shows a scanning electron microscope image of another flavor material suitable for use in an aerosol-generating article according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0404] Figure 1 shows an aerosol-generating article 10 according to the present invention. The aerosol-generating article 10 shown in Figure 1 comprises an aerosol-generating element 12 and a downstream section 14 located downstream of the aerosol-generating element 12. Furthermore, the aerosol-generating article 10 comprises an upstream section 16 located upstream of the aerosol-generating element 12.

[0405] The aerosol-generating element 12 comprises a rod 121 of aerosol-generating substrate and a wrapper 122 surrounding the rod 121 .

[0406] A ventilation zone 60 is provided at a location downstream of the aerosol-generating element 12 .

[0407] More specifically, in the embodiment of Figure 1, the downstream section 14 comprises a mouthpiece element 18 and a hollow section 20. The hollow section 20 includes an aerosol cooling element 22 comprising a hollow tubular element and a ventilation zone 60 comprising a plurality of openings formed through the wall of the hollow tubular element. The aerosol cooling element 22 is positioned immediately downstream of the aerosol generation element 12. As shown in the drawing of Figure 1, the upstream end of the aerosol cooling element 22 abuts the downstream end of the aerosol generation element 12. The mouthpiece element 18 is positioned immediately downstream of the aerosol cooling element 22. As shown in the drawing of Figure 1, the upstream end of the mouthpiece element 18 abuts the downstream end of the aerosol cooling element 22. The mouthpiece element 18 comprises a plug 24 of low-density filtration material.

[0408] The aerosol-generating substrate 121 is in the form of a collection of sheets of homogenized tobacco material, although other types of tobacco-containing substrates, such as tobacco cut filler, can replace the collection of sheets of homogenized tobacco material.

[0409] The upstream section 16 comprises a cylindrical plug 26 of compressed plasticized cellulose acetate surrounded by a wrapper 28. The plug 26 in the upstream section 16 is approximately 5 millimeters in length.

[0410] The aerosol-generating article further includes a flavorant 50. More particularly, a plurality of pieces of flavorant in sheet form are dispersed within the cylindrical plug 26. The flavorant 50 is of the type described in detail above.

[0411] Another aerosol-generating article 100 according to the present invention is shown in Figure 2. The aerosol-generating article 100 shown in Figure 2 has substantially the same structure and geometry as the aerosol-generating article 10 shown in Figure 1 and will be described below insofar as it differs from the aerosol-generating article 10 shown in Figure 1.

[0412] In the aerosol-generating article 100, the aerosol-generating substrate 121 is in the form of strips of homogenized tobacco material. However, other types of tobacco-containing substrates, such as tobacco cut filler or an assemblage of sheets of homogenized tobacco material, can replace the strips of homogenized tobacco material.

[0413] Furthermore, in the aerosol-generating article 100 , the flavorant 50 is provided within a wrapper 122 that surrounds the aerosol-generating substrate 121 .

[0414] Preparation A - Flavoring material containing a menthol formulation entrapped within a gellan gum polysaccharide matrix 100g of water is heated to approximately 60°C and 3.0g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70-75°C, and 0.1g of lecithin, 1.1g of graphite, and 8.0g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. The resulting aqueous composition is then cast onto a metal tray, allowed to stand, and dried in a static oven at 65°C. A sheet of flavor material is obtained.

[0415] Preparation B - Flavoring material containing menthol formulation entrapped within a gellan gum-guar polysaccharide matrix 100g of water is heated to approximately 60°C and 1.0g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70-75°C, and 0.1g of lecithin, 1.1g of graphite, and 8.0g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. 2.0g of guar is then added to the mixture, which is then homogenized again for another 3 minutes. The resulting aqueous composition is then cast onto a metal tray, left to gel, and dried in a static oven at 75°C. A sheet of flavor material is obtained.

[0416] Preparation C - A flavoring material containing a menthol formulation entrapped within a gellan gum polysaccharide matrix supported on a carrier sheet material (paper wrapper) 100 g of water is heated to approximately 60°C, and 3.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70-75°C, and 0.1 g of lecithin and 8.0 g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. The resulting aqueous composition is then cast onto a paper wrapper containing graphite particles placed on a metal tray, allowed to gel, and dried in a static oven at 65°C. A flavor material is obtained containing a layer of gellan gum matrix encapsulating the immobilized menthol formulation on the graphite-containing paper wrapper.

[0417] Preparation D - A flavoring material containing a menthol formulation entrapped within a gellan gum polysaccharide matrix supported on a carrier sheet material (homogenized tobacco material). 100 g of water is heated to approximately 60°C, and 3.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70-75°C, and 0.1 g of lecithin and 8.0 g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. The resulting aqueous composition is then cast onto a sheet of homogenized tobacco material containing graphite particles placed on a metal tray, allowed to gel, and dried at 65°C in a static oven. This results in a flavor material containing a layer of gellan gum matrix encapsulating the immobilized menthol formulation on the graphite-containing homogenized tobacco material.

[0418] Prepared E-flavoring material containing a menthol formulation entrapped within a gellan gum-guar polysaccharide matrix supported on a carrier sheet material (homogenized tobacco material) 100g of water is heated to approximately 60°C, and 1.0g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70-75°C, and 0.1g of lecithin and 8.0g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. 2.0g of guar is then added to the mixture, which is then homogenized again for another 3 minutes. The resulting aqueous composition is then cast onto a sheet of homogenized tobacco material containing graphite particles placed on a metal tray, allowed to gel, and dried at 65°C in a static oven. This results in a flavor material containing a layer of gellan gum / guar matrix encapsulating the immobilized menthol formulation on the graphite-containing homogenized tobacco material.

[0419] Preparation F - A flavor material containing a menthol formulation entrapped within a gellan gum-alginate matrix supported on a carrier sheet material (homogenized tobacco material). 100g of water is heated to approximately 60°C, and 2.0g of gellan gum and 0.5g of alginate are added to the water bath. The resulting mixture is homogenized and heated to a temperature between 90-95°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature between 70-75°C, and 0.1g of lecithin and 8.0g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. 2.0g of guar is then added to the mixture, which is then homogenized again for another 3 minutes. The resulting aqueous composition is then cast onto a sheet of homogenized tobacco material containing graphite particles placed on a metal tray, allowed to gel, and dried at 65°C in a static oven. This results in a flavor material containing a layer of gellan gum / alginate matrix encapsulating the immobilized menthol formulation on the graphite-containing homogenized tobacco material.

[0420] Preparation G - Aerosol-generating articles containing flavoring materials produced according to Preparation A An aerosol-generating article was prepared having the general structure and geometry shown in FIG.

[0421] An amount of flavor material produced according to Preparation A, accounting for an overall content of 5 mg menthol, was provided at a location immediately upstream of the aerosol-generating element. An amount of flavor material produced according to Preparation A, accounting for an overall content of 10 mg menthol, was provided at a location along the hollow tubular element immediately downstream of the aerosol-generating element.

[0422] Preparation H - Aerosol-generating articles containing flavoring materials produced according to Preparation A An aerosol-generating article was prepared having the general structure and geometry shown in FIG.

[0423] An amount of flavor material produced according to Preparation A, accounting for an overall content of 5 mg menthol, was provided at a location immediately upstream of the aerosol-generating element. An amount of flavor material produced according to Preparation A, accounting for an overall content of 5 mg menthol, was provided at a location along the hollow tubular element immediately downstream of the aerosol-generating element. In addition, an amount of flavor material produced according to Preparation A, accounting for an overall content of 5 mg menthol, was provided at a location within the aerosol-generating substrate.

[0424] Preparation I - Aerosol-generating article containing a flavoring material produced according to Preparation A An aerosol-generating article was prepared having the general structure and geometry shown in FIG.

[0425] An amount of flavor material produced according to Preparation A, accounting for an overall content of 15 mg of menthol, was provided at a location along the hollow tubular element immediately downstream of the aerosol-generating element.

[0426] Comparative Preparation A - A flavoring material comprising a menthol formulation entrapped within a gellan gum polysaccharide matrix supported on a carrier sheet material (homogenized tobacco material) 100 g of water is heated to approximately 60°C, and 3.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70-75°C, and 0.1 g of lecithin and 8.0 g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. The resulting aqueous composition is then cast onto a sheet of homogenized tobacco material without graphite particles, placed on a metal tray, allowed to gel, and dried at 65°C in a static oven. A flavor material is obtained, comprising a layer of gellan gum matrix encapsulating the immobilized menthol formulation on the graphite-free homogenized tobacco material.

[0427] Comparative Preparation B - A flavor material comprising a menthol formulation entrapped within a gellan gum / guar polysaccharide matrix supported on a carrier sheet material (homogenized tobacco material) 100 g of water is heated to approximately 60°C, and 1.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70-75°C, and 0.1 g of lecithin and 8.0 g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. 2.0 g of guar is then added to the mixture, which is then homogenized again for another 3 minutes. The resulting aqueous composition is then cast onto a sheet of homogenized tobacco material placed on a metal tray without carbon particles, allowed to gel, and dried at 65°C in a static oven. This results in a flavor material containing a layer of gellan gum / guar matrix encapsulating the immobilized menthol formulation on the graphite-free homogenized tobacco material.

[0428] Morphological characterization 2 shows a scanning electron microscope (SEM) image of flavorant 50 produced according to Preparation E embedded in wax. The image shows that the internal structure of the flavorant comprises a matrix 52 having a plurality of small pockets 54 adapted to entrap flavor compositions, the pockets 54 being dispersed throughout the matrix 52. The pockets are relatively evenly dispersed throughout the material and relatively consistent in size. Flavorant 50 further comprises a carrier sheet material 56 in the form of a sheet of homogenized tobacco material containing graphite particles, which supports matrix 52. SEM techniques do not allow for the graphite particles to be distinguished from the remainder of the carrier sheet material.

[0429] FIG. 3 shows an SEM image of flavor material 150 produced according to Preparation A embedded in wax. The image shows that the internal structure of the flavor material comprises a matrix 52 with a plurality of small pockets 54 adapted to entrap flavor compositions, the pockets 54 being dispersed throughout the matrix 52. The regions are relatively evenly dispersed throughout the material and relatively consistent in size. In contrast to flavor material 50 of FIG. 2, flavor material 150 does not include a carrier sheet material supporting the matrix, and the carbon particles are embedded within the matrix structure. SEM techniques do not allow for the graphite particles to be distinguished from the remainder of the matrix structure.

[0430] thermogravimetric analysis The flavor release profile of the flavor material produced according to the above preparation can be analyzed by thermogravimetric analysis (TGA). TGA testing is performed using a thermogravimetric machine or similar equipment coupled to a mass spectrometer. In the analysis, the flavor material is heated from 25°C to 400°C in an inert nitrogen atmosphere, increasing the temperature at a rate of 15°C per minute and with an airflow of 60 ml per minute. As the temperature increases, the release of menthol is evaluated by detecting the menthol molecule with a specific ion that represents menthol.

[0431] Data collected from performing TGA tests on flavorants according to the present invention can be compared with data collected from performing an equivalent TGA test on the flavorant formulation alone (e.g., pure menthol). One such comparison can provide some information regarding the release mechanism and dynamics, which can be useful in fine-tuning the flavorant release profile when the flavorant is incorporated into an aerosol-generating article.

[0432] When heated in the described thermogravimetric analysis, pure menthol was released unimodally between 50°C and 166°C, with a maximum at approximately 138°C.

[0433] In contrast, the flavor material produced according to Formulation E was found to provide a multi-modal release of menthol when heated in the described thermogravimetric analysis. A first proportion of menthol (about 57 percent) was released between 62°C and 239°C, with a maximum at about 194°C. A second proportion of menthol (about 24 percent) was released between 240°C and 305°C, with a maximum at about 252°C. A third proportion of menthol (about 19 percent) was released between 305°C and 387°C, with a maximum at about 344°C.

[0434] The release of a first percentage of menthol at a maximum temperature slightly below 200°C may suggest that a portion of the menthol formulation is solubilized or relatively weakly immobilized within the flavoring material. On the other hand, the release of a second percentage of menthol at a maximum temperature of about 250°C (a temperature associated with gellan gum thermal decomposition) may support the assumption that a large portion of the menthol formulation is trapped within the matrix structure and has some stronger interaction with the gellan gum within the matrix structure. The release of a third percentage of menthol at yet a higher temperature may suggest that the menthol formulation interacts differently with the guar within the matrix structure.

[0435] The same TGA test was performed on a flavor material prepared according to Formulation D. This flavor material was found to provide a bimodal release of menthol. A first, small percentage (about 9 percent) of menthol was released between about 68 degrees Celsius and about 148 degrees Celsius, with a maximum at approximately 125 degrees Celsius. A second, much larger percentage (about 91 percent) of menthol was released between 230 degrees Celsius and 245 degrees Celsius, with a maximum at approximately 242 degrees Celsius.

[0436] The release of the first proportion of menthol at approximately 130 degrees Celsius may indicate that a small portion of the menthol preparation contained in the flavoring material is not immobilized, whereas a larger portion of the menthol preparation contained in the flavoring material released at higher temperatures may indicate a stronger interaction with gellan gum, which results in effective immobilization.

[0437] A comparison between the menthol release profiles of flavoring materials prepared according to Preparation E and Preparation D demonstrates that tailoring the composition of the polysaccharide matrix, for example, using gellan gum alone or in combination with another polysaccharide, can be useful for fine-tuning flavor delivery when the flavoring material is incorporated into an aerosol-generating article. In particular, it may be possible to control the temperature at which flavor release begins and the temperature at which flavor release is maximized. In addition, flavoring materials with different flavor release profiles, such as those prepared according to Preparation E and Preparation D, can be combined in a single aerosol-generating article to provide consumers with an even wider range of flavor delivery options.

[0438] The same TGA test was performed on a flavorant prepared according to Comparative Preparation B, which differed from the flavorant prepared according to Preparation E only in that the carrier sheet of homogenized tobacco material did not contain graphite particles. Similar to the flavorant prepared according to Preparation E, the flavorant produced according to Comparative Preparation B was found to provide a multi-modal release of menthol when heated in the described thermogravimetric analysis, releasing a first proportion of menthol (about 41 percent) in a lower temperature range, followed by a second proportion (about 34 percent) and a third proportion (about 25 percent) of menthol in a higher temperature interval.

[0439] A comparison of the menthol release profiles between Preparation E and Comparative Preparation B suggests that the inclusion of carbon particles in the flavorant tends to enhance the thermal release of menthol at lower temperatures. Specifically, a shift of approximately 5 degrees Celsius toward lower temperatures is observed, with the maximum associated with the release of the first percentage of menthol being observed at approximately 199 degrees Celsius for the flavorant produced according to Comparative Preparation B.

[0440] Additional testing performed under isothermal conditions demonstrated that, particularly at lower temperatures, flavor materials produced according to Formulation E release significantly more menthol than flavor deliveries produced according to Comparative Formulation B. At 150°C, flavor materials produced according to Formulation E released approximately 1.73 times more menthol than flavor deliveries produced according to Comparative Formulation B. At 180°C, flavor materials produced according to Formulation E released approximately 1.5 times more menthol than flavor deliveries produced according to Comparative Formulation B. This appears to confirm that the presence of carbon particles provides a more effective heat delivery, likely by enhancing heat transfer by conduction and promoting a more uniform temperature distribution throughout the flavor material. As a result, a larger portion of the menthol becomes released more rapidly from the flavor material.

[0441] The same TGA testing described above was performed on a flavorant prepared according to Comparative Preparation A, which differs from a flavorant prepared according to Preparation D only in that graphite particles are not included in the preferred delivery material. Similar to the flavorant prepared according to Preparation D, the flavorant produced according to Comparative Preparation A was found to provide a bimodal release of menthol when heated in the described thermogravimetric analysis.

[0442] The menthol release profile of Preparation D was compared to that of Comparative Preparation A by plotting the cumulative amount of menthol released by each flavorant side by side. The results of this comparison suggest that the inclusion of carbon particles in the flavorant tends to enhance the thermal release of menthol. Specifically, a shift of approximately 5 degrees Celsius or more toward lower temperatures was observed for the flavorant produced according to Preparation D. For example, 40 percent of the menthol contained in the flavorant produced according to Preparation D was released when the flavorant reached 240 degrees Celsius, while the flavorant produced according to Comparative Preparation A only reached the same 40 percent release threshold at approximately 245 degrees Celsius. Similarly, 60 percent of the menthol contained in the flavorant produced according to Preparation D was released when the flavorant reached 243 degrees Celsius, while the flavorant produced according to Comparative Preparation A only reached the same 40 percent release threshold at approximately 249 degrees Celsius.

[0443] thermal stability The thermal stability of the flavoring material according to the present invention under stress conditions can be evaluated by aging the flavoring material at a constant temperature and monitoring its weight loss over time. For this purpose, samples of the flavoring material cut into pieces of regular and uniform size are weighed and distributed into a series of open Schott glass bottles. The samples are aged for a period of two weeks in a laboratory oven set at 50 degrees Celsius. For the flavoring material produced according to Preparation E, a weight loss of approximately 24 percent was measured at the end of the test. It is assumed that this weight loss value accounts for the migration of some flavor species as well as the loss of moisture and glycerol, and is therefore considered satisfactory.

[0444] Evaluating flavor delivery in aerosol-generating articles The flavor delivery of an aerosol-generating article incorporating a flavoring material according to the present invention can be evaluated by heating the aerosol-generating article in a compatible commercially available heating device and measuring the menthol delivered at the mouth end of the article with each puff.

[0445] More specifically, the products emitted in each puff from an aerosol-generating article heated by a heating device may be analyzed using proton transfer mass spectrometry (PTR-MS).

[0446] The menthol delivery per puff was measured for aerosol-generating articles produced according to Preparations G, H, and I. The three aerosol-generating articles tested had substantially the same overall structure and geometry and contained the same overall amount of flavorant. However, because the flavorant was disposed and distributed at different locations within the aerosol-generating article, the experiment allowed the inventors to evaluate whether and how menthol release and delivery varied depending on the positioning of the flavorant. Transfer rates of 7 percent, 10 percent, and 6 percent were observed for the aerosol-generating articles prepared according to Preparations G, H, and I, respectively.

[0447] Aerosol-generating articles prepared according to Formulations G and I, which did not include any flavorant located within the aerosol-generating substrate, exhibited similar menthol transfer rates. This experimental finding confirmed that providing flavorants of the types described above at locations upstream or downstream of the aerosol-generating element is associated with satisfactory flavorant transfer rates during use.

[0448] The slightly higher transport rate measured for the aerosol-generating article prepared according to Preparation H suggests that providing flavor materials at locations within the aerosol-generating substrate contributes to the overall flavor transport rate, consistent with solutions known from the prior art.

[0449] However, the fact that the aerosol-generating article prepared according to Preparation H is not superior to the aerosol-generating articles prepared according to Preparations G and I may be taken to suggest that the incorporation of flavoring materials described herein, particularly flavoring materials that exhibit enhanced flavor delivery at lower temperatures at locations other than within the aerosol-generating substrate, may be used to adjust and tailor flavor release characteristics in ways not possible with aerosol-generating articles known in the art.

[0450] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like should be understood in all instances to be modified by the term "about." Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. Thus, in this context, the number A is understood as A ± 5%. Within this context, the number A may be considered to include a numerical value that is within the typical standard error for the measurement of the property that the number A modifies. In some cases, as used in the appended claims, the number A may deviate by the percentages recited above, provided that the amount by which A deviates does not materially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. 1. An aerosol-generating article for generating an aerosol upon heating, the aerosol-generating article comprising: an aerosol-generating element comprising a rod of aerosol-generating substrate surrounded by a wrapper; a downstream section provided immediately downstream of the aerosol-generating element and extending from the downstream end of the aerosol-generating element to the downstream end of the aerosol-generating article; an upstream section provided immediately upstream of the aerosol-generating element and extending from the upstream end of the aerosol-generating element to the upstream end of the aerosol-generating article; the aerosol-generating article includes a flavoring material provided in at least one of the downstream section, the upstream section, and the wrapper surrounding the rod of aerosol-generating substrate; The aerosol-generating article, wherein the flavoring material comprises a polysaccharide matrix structure comprising gellan gum and an emulsifier, and a flavoring agent formulation dispersed within the polysaccharide matrix structure, the flavoring agent formulation being at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavoring material.

2. 2. The aerosol-generating article of claim 1, wherein the downstream section comprises a hollow tubular element provided immediately downstream of the aerosol-generating element, the upstream end of the hollow tubular element abutting the downstream end of the aerosol-generating element, and the flavor material is provided within the hollow tubular element.

3. 2. The aerosol-generating article of claim 1, wherein the upstream section includes an upstream element provided immediately upstream of the aerosol-generating element, the downstream end of the upstream element abutting the upstream end of the aerosol-generating element, and the flavor material provided within the upstream element.

4. 4. An aerosol-generating article according to any one of claims 1 to 3, wherein the polysaccharide matrix structure comprises gellan gum as the only polysaccharide or gellan gum in combination with at least a further polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose, and hydroxypropyl methylcellulose, and the gellan gum preferably accounts for from 5 to 99.9 percent by weight of the flavor material on a dry weight basis.

5. Formula C n H 2n+2 O n wherein the polyol is preferably selected from the group consisting of glycerol, sorbitol, xylitol, mannitol, and erythritol, and / or the polyol preferably accounts for 0.01 to 20 percent by weight of the flavor material on a dry weight basis.

6. 6. An aerosol-generating article according to any one of claims 1 to 5, further comprising fibres, said fibres preferably comprising from 0.01 to 10 percent by weight of said flavouring material on a dry weight basis.

7. 7. An aerosol-generating article according to any one of claims 1 to 6, wherein the flavourant further comprises a carrier material, the polysaccharide matrix structure and the flavourant formulation being supported by the carrier material, the carrier material being preferably a sheet of homogenised tobacco material or a sheet of plug paper wrapper material.

8. 8. An aerosol-generating article according to any one of claims 1 to 7, wherein the article comprises a ventilation zone at a position along the hollow tubular element, the ventilation zone being configured to allow air to enter the axial lumen of the hollow tubular element.

9. 9. An aerosol-generating article according to any one of claims 1 to 8, wherein the upstream element comprises a plug extending to and defining the distal end of the aerosol-generating article, and the flavouring material is provided at a location within the plug.

10. 10. The aerosol-generating article according to any one of claims 1 to 9, wherein the aerosol-generating substrate comprises tobacco material.

11. 11. The aerosol-generating article of claim 10, wherein the tobacco material comprises a sheet of homogenized tobacco material, or one or more of tobacco cut filler, reconstituted shred tobacco, and homogenized shred tobacco material.

12. 12. An aerosol generation system comprising an aerosol-generating article according to any one of claims 1 to 11 and an aerosol-generating device configured to heat the aerosol-generating substrate of the aerosol-generating article, the aerosol-generating device comprising a housing defining a cavity configured to receive the aerosol-generating article.

13. 13. The aerosol generating system of claim 12, wherein the aerosol generating device comprises a heater element configured to be inserted into the aerosol generating element when the aerosol-generating article is received in the cavity of the aerosol generating device.

14. 13. The aerosol generating system of claim 12, wherein the aerosol generating article comprises a susceptor element provided in a position within the aerosol generating element, and the aerosol generating device comprises an inductor coil positioned on or within the housing, and a power source connected to the inductor coil and configured to provide a high-frequency oscillating current to the inductor coil.

15. 13. The aerosol generating system of claim 12, wherein the aerosol generating device comprises heater elements positioned around the periphery of the cavity and configured to heat the aerosol-generating substrate of the aerosol-generating article from outside the aerosol-generating element of the aerosol-generating article.

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