Aerosol-generating article configured for enhanced flavor delivery

Abstract

An aerosol-generating article (10) for generating an aerosol upon heating, the aerosol-generating article comprising: an aerosol-generating element (12) comprising a strip (121) of aerosol-generating substrate defined by a wrapper (122); a downstream section (14) disposed immediately downstream of the aerosol-generating element and extending from a downstream end of the aerosol-generating element to a downstream end of the aerosol-generating article; and an upstream section (16) disposed immediately upstream of the aerosol-generating element and extending from an upstream end of the aerosol-generating element (12) to an upstream end of the aerosol-generating article. A flavor material (50) is disposed in at least one of the downstream section (14), the upstream section (16), and a wrapper (122) defining a strip (121) of aerosol-generating substrate. The flavor material (50) comprises: a polysaccharide matrix structure comprising gellan gum and an emulsifier; and a flavor formulation dispersed within the polysaccharide matrix structure, wherein the flavor formulation is at least partially trapped within the polysaccharide matrix structure and is releasable from the polysaccharide matrix structure upon heating of the flavor material.

Description

Technical Field

[0001] The present disclosure relates to a flavor material for use in an aerosol-generating article. Furthermore, the present disclosure relates to an aerosol-generating article comprising such a flavor material. Background Art

[0002] Aerosol-generating articles in which an aerosol-generating substrate (e.g., a tobacco-containing substrate or a non-tobacco nicotine-containing substrate) is heated rather than burned are known in the art. Typically, in such heated smoking articles, an aerosol is generated by transferring heat from a heat source to a physically separated aerosol-generating substrate or material, which may be positioned in contact with, inside, 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. When the released compounds cool, the compounds condense to form an aerosol.

[0003] Several aerosol generating devices for consuming aerosol generating articles are disclosed in the art. Such devices include, for example, electrically heated aerosol generating devices, wherein an aerosol is generated by transferring heat from one or more electrical heater elements of the aerosol generating device to an aerosol generating substrate of the aerosol generating article. For example, electrically heated aerosol generating devices comprising internal heater blades adapted to be inserted into the aerosol generating substrate have been proposed. As an alternative, an inductively heatable aerosol generating article comprising an aerosol generating substrate and a susceptor arranged within the aerosol generating substrate has been proposed by WO 2015 / 176898.

[0004] In the past it has been proposed to include a flavour source in addition to the aerosol-generating substrate in aerosol-generating articles. Indeed, this practice is relatively common in conventional filter cigarettes and many solutions have been described in the art for providing flavours at a location in the mouthpiece filter or dispersed within the tobacco cut filler.

[0005] However, given the way in which the aerosol is generated in an aerosol-generating article and how the aerosol is delivered to the consumer, ensuring consistent flavor delivery during use may be difficult, and as a result, the consumer may perceive the flavor intensity to fluctuate or decrease over time. In addition, even before the aerosol-generating article is used, some flavor species may be lost during certain production steps or during transportation and storage of the aerosol-generating article.

[0006] It has been previously proposed to reduce the loss of volatile flavors from conventional filter cigarettes during storage by flavor encapsulation, for example in the form of capsules or microcapsules containing a flavor formulation. The encapsulated flavors can be released by opening the packaging structure before or during smoking the filter cigarette, for example by manually crushing the structure. However, the encapsulated flavors are typically released from the packaging structure in a single burst, and therefore such solutions may not provide sustained, intense flavor delivery during use of the article.

[0007] There is therefore a need to provide aerosol-generating articles containing flavour materials that are associated with an enhanced flavour perception by consumers, particularly towards the end of the use life 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 flavour material.

[0009] The aerosol-generating article may comprise an aerosol-generating element comprising a strip of aerosol-generating substrate defined by a wrapper.The flavour material may be provided in the wrapper defining the strip of aerosol-generating substrate.

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

[0011] Flavour material may be provided in the downstream section.

[0012] For example, the downstream section may comprise a hollow tubular element disposed 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 flavour material may be disposed in the hollow tubular element.

[0013] As an alternative, the downstream section may include a hollow tubular element disposed downstream of the aerosol generating element, and the flavor material may be disposed between the downstream end of the aerosol generating element and the upstream end of the hollow tubular element. For example, the flavor material may be sandwiched between the aerosol generating element and the hollow tubular element.

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

[0015] Flavour material may be provided in the upstream section.

[0016] For example, the upstream section may comprise an upstream element disposed immediately upstream of the aerosol-generating element.The downstream end of the upstream element may abut the upstream end of the aerosol-generating element.The flavour material may be disposed in the upstream element.

[0017] As an alternative, the upstream section may include an upstream element disposed upstream of the aerosol generating element, and the flavor material may be disposed between the upstream end of the aerosol generating element and the downstream end of the upstream element. For example, the flavor material may be sandwiched between the aerosol generating element and the upstream element.

[0018] The flavor material may include a polysaccharide matrix structure including gellan gum and an emulsifier; and a flavor preparation dispersed within the polysaccharide matrix structure. The flavor preparation may be at least partially captured within the polysaccharide matrix structure and may be released from the polysaccharide matrix structure when the flavor material is heated.

[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 comprises an aerosol-generating element comprising a strip of an aerosol-generating substrate defined by a wrapper. In addition, the aerosol-generating article comprises a downstream section disposed immediately downstream of the aerosol-generating element and extending from a downstream end of the aerosol-generating element to a downstream end of the aerosol-generating article; and

[0020] An upstream section is disposed 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. The aerosol generating article includes a flavor material disposed in at least one of the downstream section, the upstream section, and a wrapper defining a strip of an aerosol generating substrate. The flavor material comprises: a polysaccharide matrix structure comprising gellan gum and an emulsifier; and a flavor formulation dispersed within the polysaccharide matrix structure, wherein the flavor formulation is at least partially trapped within the polysaccharide matrix structure and can be released from the polysaccharide matrix structure upon heating of the flavor material.

[0021] As used herein with reference to the present invention, the term "aerosol-generating article" is used to describe an article comprising an aerosol-generating substrate, which is heated to generate an inhalable aerosol for delivery to a user.

[0022] As used herein with reference to the present invention, the term "aerosol-generating substrate" is used to describe a substrate comprising an aerosol-generating material which is capable of releasing volatile compounds that can generate an aerosol upon heating.

[0023] As used herein with reference to 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 may be visible or invisible. Aerosols may include vapors of substances that are normally liquid or solid at room temperature, as well as solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

[0024] As used herein with reference to the present invention, the term "aerosol-generating device" is used to describe a device that interacts with an 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, in use, the aerosol leaves the aerosol-generating article for delivery to a user. 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. In use, the user directly or indirectly draws on the proximal end of the aerosol-generating article in order 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 to 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 invention may be described as being upstream or downstream of each other based on their relative position between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article.

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

[0029] As used herein with reference to the present invention, the term "length" is used to describe the largest dimension of an aerosol-generating article or a component of an aerosol-generating article in the longitudinal direction.

[0030] As used herein with reference to the present invention, the term "transverse" is used to describe a direction perpendicular to the longitudinal direction. Unless otherwise stated, references to a "cross-section" of an aerosol-generating article or component of an aerosol-generating article refer to a cross-section.

[0031] As used herein with reference to the present invention, the term "width" refers to the largest dimension of an aerosol-generating article or a component of an aerosol-generating article in the transverse direction. In the case where 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. In the case where a component of an aerosol-generating article has a substantially circular cross-section, the width of a component of an aerosol-generating article corresponds to the diameter of the component of an aerosol-generating article.

[0032] As used herein with reference to the present invention, the term "hollow tubular element" is used to refer to a generally cylindrical element having a lumen along its longitudinal axis. The tubular portion may have a generally circular, oval or elliptical cross-section. The lumen may have a generally circular, oval or elliptical cross-section. In particular, the term "hollow tubular element" is used to refer to an element defining at least one gas flow conduit that establishes uninterrupted fluid communication between an upstream end of the hollow tubular element and a downstream end of the tubular element.

[0033] In general, it has been recognized that the use of flavor materials in aerosol-generating articles (where the aerosol-generating substrate is intended to be heated to generate an aerosol) presents different challenges and imposes different limitations than what has been encountered in the past with conventional cigarettes (where the substrate is burned to generate smoke). The inventors have discovered that providing flavor materials at selected locations on the exterior of a rod of an aerosol-generating substrate allows flavor species to be released and delivered to a consumer during use in a controlled manner, such that the flavor species can merge with aerosol species generated when the aerosol-generating substrate is heated. Because the flavor materials are exposed to a heating profile that is different from the heating profile experienced by the aerosol-generating substrate during use, for example, because the flavor materials are further away from or closer to the heat source than the aerosol-generating substrate, it may be possible to control the intensity and duration of flavor release without interfering with the mechanism of aerosol species release.

[0034] For example, the inventors have found that aerosol-generating articles according to the invention may exhibit generally more efficient puff-by-puff flavour release, as the level of flavour species released with each successive puff may remain substantially constant or even gradually increase during the use cycle of the article.

[0035] In addition, because the flavor formulation is at least partially trapped within the matrix structure before being released upon heating, aerosol-generating articles according to the present invention have been found to experience significantly reduced loss of flavor species during storage, transportation, etc., even under stress conditions. This makes the use of flavor and other ingredients of the flavor formulation particularly efficient.

[0036] Furthermore, as will be discussed in more detail below, the inventors have discovered that by adjusting the relative proportions of the various ingredients in the formulation or by changing the composition of the matrix (e.g., by selecting a combination of certain polysaccharides to form the matrix), or by doing both, certain properties of the flavor material can be advantageously fine-tuned to specific needs associated with use in an aerosol-generating article. For example, the flavor release profile can be adjusted so that the flavor is released in a more continuous "wave" during use. As a result, the consumer can perceive the flavor note more intensely or for a longer period of time during use. Thus, aerosol-generating articles according to the present invention can provide a wider width of flavor profile that is not available with existing aerosol-generating articles.

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

[0038] In aerosol-generating articles according to the 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 elodea. The repeating unit of the polymer is a tetrasaccharide consisting of two D-glucose residues and one L-rhamnose residue and one D-glucuronic acid residue. Gellan gum has been approved by authorities in many jurisdictions, including Japan, the United States, Canada, China, South Korea and the European Union, for food, non-food, cosmetic and pharmaceutical uses.

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

[0041] In the flavor material according to the present invention, gellan gum is preferably low acyl gellan gum. This is partially deacylated or fully deacylated gellan gum. Its most common form is a fully deacylated form without detectable acyl groups, also known as deacylated gellan gum.

[0042] It is preferred to use low acyl gellan gum to form the polysaccharide matrix of the flavor material according to the present invention because low acyl gellan gum is able to form gels at very low concentrations. In addition, the texture of gellan gum-based gels varies with the acyl content, with low acyl gellan gum generally forming firmer, less elastic and more brittle gels than high acyl gellan gum.

[0043] In embodiments where the polysaccharide matrix structure comprises gellan gum and an emulsifier, a flavor material can be advantageously provided in which a significant portion of the flavor formulation is effectively captured within the polysaccharide matrix structure. This is beneficial because it will improve the stability of the flavor material. In addition, as will be discussed in more detail below, it will affect the release pattern of flavors when the flavor material is heated, and thus can help adjust the flavor release profile during use.

[0044] In addition, from a manufacturing perspective, a stable polysaccharide matrix structure comprising gellan gum and an emulsifier can be formed by supplying heat to the starting reagents without the need to use a crosslinking agent. In fact, by kneading and emulsifying the flavor preparation and gellan gum in a heated water bath, the polysaccharide-encapsulated flavor can be in an emulsified state, which is then substantially maintained after drying and cooling. Advantageously, this allows a large amount of flavor to be provided in a fixed state within the polysaccharide matrix, and thus a flavor material with a high flavor content can be provided.

[0045] Preferably, the emulsifier is lecithin. It is advantageous to use lecithin as an emulsifier because it is generally available and generally considered to be non-toxic. Like gellan gum, lecithin is commonly used as an additive in the food industry and has been approved for such use by the U.S. Food and Drug Administration and EU authorities. Therefore, the pairing of gellan gum and lecithin is particularly suitable for inclusion in flavor materials for human use.

[0046] Preferably, where the polysaccharide matrix comprises gellan gum and an emulsifier, the gellan gum comprises 5 to 99.9 wt % of the flavouring material on a dry weight basis.

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

[0048] Gellan gum preferably accounts for up to 80% by weight of the flavor material on a dry weight basis, more preferably up to 60% by weight of the flavor material on a dry weight basis, even more preferably up to 40% by weight of the flavor material on a dry weight basis, and particularly preferably up to 30% by weight of the flavor material on a dry weight basis.

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

[0050] In other embodiments, gellan gum accounts for 10% to 80% by weight of the flavor material on a dry weight basis, preferably 10% to 60% by weight of the flavor material on a dry weight basis, more preferably 10% to 40% by weight of the flavor material on a dry weight basis, and even more preferably 10% to 30% by weight of the flavor material on a dry weight basis.

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

[0052] In a preferred embodiment, the emulsifier is lecithin and accounts for 0.01% to 2% by weight of the flavor material on a dry weight basis. Preferably, lecithin accounts for 0.02% to 2% by weight of the flavor material on a dry weight basis. More preferably, lecithin accounts for 0.05% to 2% by weight of the flavor material on a dry weight basis. Even more preferably, lecithin accounts for 0.1% to 2% by weight of the flavor 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 one other polysaccharide selected from guar gum, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose, and hydroxypropyl methylcellulose.

[0055] It has been found that the flavor material according to the present invention, wherein the polysaccharide matrix structure comprises a combination of gellan gum and one or more polysaccharides listed above, provides different flavor release profiles when heated. For example, in an embodiment wherein the polysaccharide matrix structure comprises another combination of gellan gum and the polysaccharides listed above, a flavor release profile characterized by two different peaks at two different temperatures has been observed. Without wishing to be bound by theory, it is speculated that this is due to different interaction strengths between the flavor and each polysaccharide in the matrix structure, and may also be related to thermal decomposition of each polysaccharide at slightly different temperatures.

[0056] Since different polysaccharide combinations in the matrix structure will 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 the flavor release during use of an aerosol-generating article containing the flavor material. In addition, different flavor materials, each containing a polysaccharide matrix structure comprising a different polysaccharide combination, can be used in combination in a single aerosol-generating article to further adjust and control the flavor delivery during the entire use cycle of the aerosol-generating article. For example, combining different flavor materials according to the present invention in a single aerosol-generating article (where the different flavor materials are adapted to release a majority of the flavor at different temperatures or at different times during the use cycle) can help keep the overall flavor delivery generally consistent throughout.

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

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

[0059] In some embodiments, the at least one additional polysaccharide comprises 1.0 wt % to 35 wt % or less of the flavor delivery material on a dry weight basis, preferably 2.0 wt % to 35 wt % or less of the flavor delivery material on a dry weight basis, and more preferably 5.0 wt % to 35 wt % or less of the flavor delivery material on a dry weight basis.

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

[0061] In a further embodiment, the at least one additional polysaccharide comprises 1.0 wt % to 15 wt % or less of the flavor delivery material on a dry weight basis, preferably 2.0 wt % to 15 wt % or less of the flavor delivery material on a dry weight basis, more preferably 5.0 wt % to 15 wt % or less of the flavor delivery material on a dry weight basis.

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

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

[0064] The flavor material may comprise up to 90% by weight flavor on a dry weight basis. Preferably, the flavor material may comprise up to 85% by weight flavor on a dry weight basis. More preferably, the flavor material may comprise up to 80% by weight flavor on a dry weight basis. Even more preferably, the flavor material may comprise up to 75% by weight flavor on a dry weight basis.

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

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

[0067] Flavours suitable for inclusion in the flavour formulation of the flavour material according to the present invention include, but are not limited to, menthol, limonene and eugenol.

[0068] Menthol is a monoterpenoid that can be produced synthetically or obtained from the oil of peppermint or other mints. It imparts a minty, cooling flavor note.

[0069] Limonene is a cyclic monoterpene commonly found in the oils of citrus peels. It is also a component of the aromatic resins of many coniferous and hardwood trees. It imparts citrus-like flavor notes.

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

[0071] The present inventors have found that menthol and limonene can be entrapped and immobilized within a polysaccharide matrix quite easily and, therefore, flavour materials comprising flavour formulations containing menthol, limonene or a mixture thereof show very good stability.

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

[0073] The flavor material may comprise at least 0.01 wt% menthol by dry weight. Preferably, the flavor material comprises at least 1 wt% menthol by dry weight. More preferably, the flavor material comprises at least 5 wt% menthol by dry weight. Even more preferably, the flavor material comprises at least 10 wt% menthol by dry weight.

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

[0075] The flavor material may comprise up to 90% by weight of menthol on a dry weight basis. Preferably, the flavor material may comprise up to 85% by weight of menthol on a dry weight basis. More preferably, the flavor material may comprise up to 80% by weight of menthol on a dry weight basis. Even more preferably, the flavor material may comprise up to 75% by weight of menthol on a dry weight basis.

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

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

[0078] The flavour formulation typically comprises a solvent into which the flavour will at least partially dissolve. Suitable solvents for inclusion in the flavour formulation of flavour 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 flavour in a given solvent can affect the degree to which the flavour remains stable within the flavour material during storage of an aerosol-generating article containing the flavour material. In more detail, the inventors have found that a higher affinity between the flavour and the solvent favourably affects stability.

[0080] The Hansen solubility parameters provide a model for estimating the mutual affinity in any given flavor / solvent pairing.

[0081] The solubility parameter δ, measured in MPa, is an indicator of the dispersion forces (δ d ), intermolecular forces between molecules (δ p ) and hydrogen bonds between molecules (δ h ) is a function of the energy parameters related to , as expressed by the following formula:

[0082] δ 2=(δ d ) 2 +(δ p ) 2 +(δ h ) 2

[0083] Parameter δ d , δ p and δ h It 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 calculated based on the formula:

[0084] (R a ) 2 =4(δ d2 -δ d1 ) 2 +(δ p2 –δ p1 ) 2 +(δ h2 –δ h1 ) 2

[0085] Generally, it is understood that the lower the R a Values ​​indicate higher affinity for a given flavor / solvent pairing.

[0086] With regard to the formulation of flavors for inclusion in the flavor material according to the invention, the inventors have studied the pairing of flavors with glycerol as solvent. In doing so, they have identified a number of flavor / glycerol pairs that exhibit particularly good stability of the flavors within the flavor material during storage.

[0087] Preferably, the flavor / glycerol pair for inclusion in the flavor formulation of the flavor material according to the present invention has a flavor / glycerol pair R of less than or equal to 22 MPa. a The inventors have found that this situation is considered to indicate a particularly high affinity between the flavor and glycerol, and therefore has such an R a The flavor / glycerol pairings of the present invention consistently result in flavor materials having particularly good flavor stability during storage. On this basis, the present inventors have found that preferred flavor / glycerol pairs for inclusion in flavor formulations of flavor materials according to the present invention include: d-limonene / glycerol, l-menthone / glycerol, (E)-citral / glycerol, decanal / glycerol, linalool / glycerol. In some embodiments, the flavor material further comprises a compound having the formula C n H 2n+2 O n of polyols.

[0088] 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 referred to as diols, triols, and tetraols, respectively.

[0089] Preferred polyols for inclusion in the flavoring material according to the present invention include glycerol, sorbitol, xylitol, mannitol and erythritol.

[0090] Incorporating a polyol into the flavour material has a beneficial effect on its flexibility. This may make the flavour material easier to handle and have a predetermined form, thereby facilitating its incorporation into an aerosol-generating article.

[0091] Preferably, in the embodiment where the flavor material comprises a polyol as described above, the polyol comprises 0.01 wt % to 20 wt % of the flavor material on a dry weight basis. More preferably, the polyol comprises 0.01 wt % to 15 wt % of the flavor material on a dry weight basis. Even more preferably, the polyol comprises 0.01 wt % to 10 wt % of the flavor material on a dry weight basis.

[0092] In some embodiments, the flavor material comprises fibers, preferably cellulosic fibers.

[0093] The present inventors have found that the inclusion of fibres can increase the structural strength of the flavour material, which is particularly beneficial in those embodiments where the polysaccharide matrix of the flavour entrapping formulation is not supported by a carrier sheet material.

[0094] In flavor material embodiments comprising cellulosic fibers, the cellulosic fibers may comprise at least 0.01% by weight of the flavor material on a dry weight basis.

[0095] The incorporation of fibres, particularly cellulose fibres, may advantageously improve the tensile strength of the flavour material, particularly when it is provided in sheet form. This will facilitate the manufacturing process of both the flavour material itself and the aerosol-generating article comprising the flavour material.

[0096] Preferably, the cellulose fibers account for at least 0.05% by weight of the flavor material on a dry weight basis. More preferably, the cellulose fibers account for at least 0.5% by weight of the flavor material on a dry weight basis. Even more preferably, the cellulose fibers account for at least 1.0% by weight of the flavor material on a dry weight basis. In a particularly preferred embodiment, the cellulose fibers account for at least 2.0% by weight of the flavor material on a dry weight basis.

[0097] The cellulose fibers may comprise 10% or less by weight of the flavor material on a dry weight basis. Preferably, the cellulose fibers comprise 8.0% or less by weight of the flavor material on a dry weight basis. More preferably, the cellulose fibers comprise 7.0% or less by weight of the flavor material on a dry weight basis. Even more preferably, the cellulose fibers comprise 5.0% or less by weight of the flavor material on a dry weight basis.

[0098] In some embodiments, the fiber accounts for 0.01% to 10% by weight of the flavor material on a dry weight basis. Preferably, the fiber accounts for 0.01% to 8.0% by weight of the flavor material on a dry weight basis. More preferably, the fiber accounts for 0.01% to 7.0% by weight of the flavor material on a dry weight basis. Even more preferably, the fiber accounts for 0.01% to 5% by weight of the flavor material on a dry weight basis.

[0099] In other embodiments, the fiber accounts for 1.0% to 10% by weight of the flavor material on a dry weight basis. Preferably, the fiber accounts for 1.0% to 8.0% by weight of the flavor material on a dry weight basis. More preferably, the fiber accounts for 1.0% to 7.0% by weight of the flavor material on a dry weight basis. Even more preferably, the fiber accounts for 1.0% to 5% by weight of the flavor material on a dry weight basis.

[0100] In a further embodiment, the fiber accounts for 2.0% to 10% by weight of the flavor material on a dry weight basis. Preferably, the fiber accounts for 2.0% to 8.0% by weight of the flavor material on a dry weight basis. More preferably, the fiber accounts for 2.0% to 7.0% by weight of the flavor material on a dry weight basis. Even more preferably, the fiber accounts for 2.0% to 5% by weight of the flavor material on a dry weight basis.

[0101] In some embodiments, flavor materials according to the present invention may include calcium salts or magnesium salts, or both, such as calcium chloride or calcium lactate.

[0102] In embodiments where the flavor material comprises calcium salt or magnesium salt or both, the one or more salts comprise 0.01 wt% to 10 wt% on a dry weight basis. Preferably, the one or more salts comprise 0.01 wt% to 5 wt% on a dry weight basis.

[0103] The flavor material according to the present invention may typically contain water. This is because the flavor material will typically be manufactured by combining the various compounds described above in a water bath. After drying, the water content will decrease, but may generally not be zero.

[0104] Therefore, the flavour material according to the present invention may comprise 0.01 to 10 wt% water, preferably 0.01 to 8 wt% water, more preferably 0.01 to 6 wt% water, even more preferably 0.01 to 4 wt% water.

[0105] In some embodiments, the flavor material comprises 0.5 wt % to 10 wt % water, preferably 0.01 wt % to 8 wt % water, more preferably 0.5 wt % to 6 wt % water, even more preferably 0.5 wt % to 4 wt % water.

[0106] In other embodiments, the flavor material comprises 1.0 wt% to 10 wt% water, preferably 1.0 wt% to 8 wt% water, more preferably 1.0 wt% to 6 wt% water, even more preferably 1.0 wt% to 4 wt% water.

[0107] In a further embodiment, the flavor material comprises 1.5 wt% to 10 wt% water, preferably 1.5 wt% to 8 wt% water, more preferably 1.5 wt% to 6 wt% water, even more preferably 1.5 wt% to 4 wt% water.

[0108] In certain embodiments, the flavor material further comprises a carrier material. The polysaccharide matrix structure and the flavor formulation entrapped therein are supported by the carrier material.

[0109] In certain embodiments, the carrier material is a carrier sheet material. As used herein, the term "sheet material" refers to a layered material whose width and length are much greater than its thickness. For example, the carrier material can be a sheet of homogenized tobacco material or a sheet of paper material.

[0110] It has been found that the inclusion of a carrier sheet material in the flavour material for use in an aerosol-generating article according to the invention enhances the structural strength of the flavour material as the carrier sheet material supports the polysaccharide matrix that captures the flavour formulation and holds it in place. By selecting and adjusting certain properties of the carrier sheet material (e.g. its thickness), flavour materials can be obtained that are particularly resistant to wear and tear and have particularly good mechanical properties.

[0111] It has been found that flavour materials comprising a carrier material are easier to handle and can be stored more conveniently, for example in the form of a tube, compared to flavour materials having a comparable composition and matrix structure but lacking the support of a carrier sheet material. This advantageously facilitates its incorporation into aerosol-generating articles, particularly within the framework of a high-speed automated manufacturing process.

[0112] The flavor material comprising a carrier material also has the following advantages: the polysaccharide matrix structure and the flavor formulation entrapped therein can be deposited onto a carrier material, in particular, a carrier sheet material, to form a flavor material that is actually 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). This makes it easy to incorporate the flavor material at a predetermined location within the aerosol-generating article, as will be described in more detail below.

[0113] For example, the polysaccharide matrix structure of the flavor capture formulation can be formed in situ on the carrier sheet material. If the in situ forming step is carried out after the manufacturing process from which the carrier sheet material is obtained, the in situ forming step can even be carried out at a later date or at a different location.

[0114] As mentioned previously, in some preferred embodiments the carrier sheet material may be in the form of a sheet of homogenised tobacco material.

[0115] As used in this specification, term " homogenized tobacco material " contains any tobacco material formed by the agglomeration of tobacco material particles.Sheet material or the web material of homogenized tobacco material are formed by making particulate tobacco agglomerate, and this particulate tobacco is by one or both grinding or otherwise powdering and obtains in tobacco blade and tobacco leaf stem.In addition, homogenized tobacco material can comprise one or more in tobacco dust, tobacco granules and other particulate tobacco byproducts formed during a spot of processing, operation and transportation of tobacco.The sheet material of homogenized tobacco material can be produced by casting, extruding, papermaking process or other any suitable techniques known in the art.

[0116] Sheets or webs of homogenized tobacco material for use in the present invention may have a tobacco content of at least about 40% by weight on a dry basis, more preferably at least about 60% by weight on a dry basis, more preferably at least about 70% by weight on a dry basis, and most preferably at least about 90% by weight on a dry basis.

[0117] The sheet or web of the homogenized tobacco material used as the carrier sheet material can include one or more intrinsic binders (i.e. tobacco endogenous binders), one or more non-intrinsic binders (i.e. tobacco exogenous binders) or their combination, to help agglomeration particle tobacco.Alternately or additionally, the sheet of the homogenized tobacco material used as the carrier sheet material can include other additives, including but not limited to tobacco and non-tobacco fibers, aerosol forming agents, humectants, plasticizers, flavors, fillers, aqueous and non-aqueous solvents and their combination.

[0118] Suitable non-inherent binders for inclusion in sheets or webs of homogenized tobacco material for use as carrier sheet material are known in the art and include, but are not limited to: gums such as guar gum, xanthan gum, gum arabic and locust bean gum; cellulosic binders such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose and ethyl cellulose; polysaccharides such as starch; organic acids such as alginic acid; conjugate base salts of organic acids such as sodium alginate, agar and pectin; and combinations thereof.

[0119] Suitable non-tobacco fibers for inclusion in a sheet or web of homogenized tobacco material used 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 used as a carrier sheet material, the non-tobacco fibers may be treated by suitable methods known in the art, including, but not limited to, mechanical pulping; refining; chemical pulping; bleaching; kraft pulping; and combinations thereof.

[0120] Preferably, the sheet or web of homogenised tobacco material comprises an aerosol former. As used herein, the term "aerosol former" describes any suitable known compound or mixture of compounds which, in use, promotes the formation of an aerosol and which is substantially resistant to thermal degradation at the operating temperature of the aerosol generating article.

[0121] Suitable aerosol formers are known in the art and include, but are not limited to, polyols such as propylene glycol, triethylene glycol, 1,3-butylene glycol, glycerol; esters of polyols such as glycerol monoacetate, glycerol diacetate or glycerol triacetate; and fatty acid esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

[0122] Preferred aerosol formers are polyols or mixtures thereof such as propylene glycol, triethylene glycol, 1,3-butylene glycol and most preferably glycerol.

[0123] The sheet or web of homogenised tobacco material may comprise a single aerosol-forming agent. Alternatively, the sheet or web of homogenised tobacco material may comprise a combination of two or more aerosol-forming agents.

[0124] The sheet or web of homogenized tobacco material has an aerosol forming agent content of greater than 10% by dry weight. Preferably, the sheet or web of homogenized tobacco material has an aerosol forming agent content of greater than 12% by dry weight. More preferably, the sheet or web of homogenized tobacco material has an aerosol forming agent content of greater than 14% by dry weight. Even preferably, the sheet or web of homogenized tobacco material has an aerosol forming agent content of greater than 16% by dry weight.

[0125] The sheet of homogenised tobacco material may have an aerosol former content of from about 10% to about 30% by dry weight.Preferably, the sheet or web of homogenised tobacco material has an aerosol former content of less than 25% by dry weight.

[0126] In a preferred embodiment, the sheet of homogenised tobacco material has an aerosol former content of about 20% by dry weight.

[0127] The sheet or web of homogenized tobacco used as the carrier sheet material in the flavor material of the present invention can be manufactured by methods known in the art (e.g., methods disclosed in International Patent Application WO-A-2012 / 164009A2). In a preferred embodiment, the sheet of homogenized tobacco material used as the carrier sheet material is formed by a slurry comprising granular tobacco, guar gum, cellulose fibers and glycerol through a casting process.

[0128] In other embodiments, the carrier sheet material can be in the form of a sheet of non-tobacco aerosol generating material. For example, the carrier sheet material can be a sheet of a sorbent non-tobacco material loaded with nicotine (for example, in the form of nicotine salts) and an aerosol forming agent. The example of such a strip is described in International Application WO-A-2015 / 082652. In addition or as an alternative, the carrier sheet material can be a sheet of homogenized non-tobacco plant material such as an aromatic non-tobacco plant material.

[0129] In certain embodiments, the carrier sheet material may be in the form of a paper wrapper material. This has the benefit that the flavor material may be used as a replacement or supplement for conventional paper wrapper materials in the manufacture of aerosol-generating articles. Thus, the flavor material may be incorporated into the aerosol-generating article without significantly changing existing manufacturing processes and without requiring major modifications to existing manufacturing equipment.

[0130] In particular, in some embodiments, the flavor material comprising the paper wrapper material as the carrier material may define a strip of the aerosol-generating substrate. Thus, the flavor material is immediately outside the strip of the aerosol-generating substrate and is held at a predetermined controlled position at the periphery of the aerosol-generating element, rather than being dispersed within the aerosol-generating substrate.

[0131] In some embodiments, the flavor material comprises greater than 0.1 wt % carbon particles, wherein the carbon particles have a volume average particle size greater than 10 microns.

[0132] It has been found that the inclusion of carbon-based materials (such as graphite, expanded graphite, graphene, etc.) in the flavor material of the aerosol-generating article according to the present invention enhances flavor release, particularly at lower temperatures, relative to flavor materials of comparable composition and structure but lacking the carbon-based material. Without wishing to be bound by theory, it is speculated that this is related to the enhancement of the thermal conductivity of the flavor material, which may allow the flavor formulation to be released more rapidly from the polysaccharide matrix structure because a certain threshold temperature may be reached more quickly.

[0133] The improvement in flavor release is believed to be related to a more uniform temperature distribution throughout the flavor material during use. With a greater proportion of the flavor material reaching a sufficiently high temperature to release the flavor species from the matrix structure, the flavor formulation can be used more efficiently.

[0134] The improved flavor release provided by flavor materials comprising carbon particles as set forth above may also allow a heater configured to supply heat to an aerosol-generating article incorporating the flavor delivery material to operate at a lower temperature and therefore require less power.

[0135] 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 flavor delivery material that is more uniform in thermal conductivity. This may mean that, during use, temperature gradients in flavor materials of the aerosol-generating article that are exposed to different parts of the same heating curve are minimized.

[0136] Preferably, the carbon particles are composed of one or more of the following: graphite particles, expanded graphite particles and graphene particles. In a preferred embodiment, the carbon particles are composed of one or both of expanded graphite particles and graphene particles.

[0137] Advantageously, particles (such as those listed above, particularly graphite and expanded graphite) may have high thermal conductivity and low density, and therefore, they may be able to greatly improve the thermal conductivity of the flavor material without significantly increasing the density of the flavor material. This may be advantageous because an increase in density may increase the weight and, therefore, the shipping cost for a given volume of the flavor material itself. Likewise, when the flavor material is incorporated into an aerosol-generating article, an increase in density may have a proportional impact on shipping costs.

[0138] Additionally, particles such as those listed above have the benefit of being inductively heatable, and therefore heat can be supplied directly within the flavour material according to the invention when the flavour material is exposed to the electromagnetic field generated by the induction coil.

[0139] Preferably, the carbon particles have a volume average particle size of 30 microns to 150 microns.

[0140] As used herein, the term "volume average particle size" may refer to an average value calculated using the following equation, where d[4,3] is the volume average particle size, and d is the particle size.

[0141]

[0142] In other words, the volume average particle size may refer to an average value calculated by dividing the sum of the fourth powers of the particle sizes by the sum of the third powers of the particle sizes.

[0143] Surprisingly, the inventors have found that these relatively small particle size ranges are particularly effective in increasing the thermal conductivity of the flavor material, particularly when the flavor material is in the form of or comprises a sheet. Additionally, these relatively small particle sizes can advantageously result in a more uniform thermal conductivity distribution, and result in a sheet having a more uniform thickness, than if a larger particle size were used.

[0144] In embodiments where the flavour material comprises a carrier sheet material supporting a polysaccharide structure that captures the flavour formulation, carbon particles may be contained within the carrier sheet material. This may be advantageous because carbon particles within this size range may be easily mixed with similarly sized particles used to make the carrier sheet material, such as in the case of a sheet of homogenised tobacco material or other plant material.

[0145] The carbon particles may have a particle size distribution having a D10 particle size, a D50 particle size, and a D90 particle size. In this particle size distribution, 10% of the particles have a particle size less than or equal to the D10 particle size, and 90% of the particles have a particle size less than or equal to the D90 particle size. The D50 particle size is the median particle size, so 50% of the particles have a particle size less than or equal to the D50 particle size.

[0146] The D90 particle size can be less than or equal to 50, 40, 30, 25, 20, 15, 10, 8, 5, or 3 times the D10 particle size. The D90 particle size can be greater than or equal to 2, 3, 5, or 8 times the D10 particle size.

[0147] The D90 particle size can be 3 to 50 times, 3 to 40 times, 3 to 30 times, 3 to 25 times, 3 to 20 times, 3 to 15 times, 3 to 10 times, 3 to 8 times, 3 to 5 times, 5 to 50 times, 5 to 40 times, 5 to 30 times, 5 to 25 times, 5 to 20 times, 5 to 15 times, 5 to 10 times, 5 to 8 times, 8 to 50 times, 8 to 40 times, 8 to 30 times, 8 to 25 times, 8 to 20 times, 8 to 15 times, 8 to 10 times, 10 to 50 times, 10 to 40 times, 10 to 30 times, 10 to 25 times, 10 to 20 times, 10 to 15 times, 15 to 50 times, 15 to 40 times, 15 to 30 times, 15 to 25 times, 15 to 20 times,

[0148] Preferred particle size distributions may have a D90 particle size between 3 and 25 times, or 3 and 15 times, the D10 particle size. Particularly preferred particle size distributions may have a D90 particle size between 5 and 20 times, or 5 and 10 times, the D10 particle size.

[0149] In certain preferred embodiments, in the flavor material according to the present invention, the carbon particles have a particle size distribution having a D90 particle size and a D10 particle size, and the D90 particle size is not greater than 25 times or 15 times the D10 particle size.

[0150] A compromise must be made in terms of particle size distribution. A tighter particle size distribution may advantageously provide a more uniform thermal conductivity throughout the flavor material. This is because the particle size variation in different locations in the flavor material will be smaller. This may advantageously allow for a more efficient use of the flavor formulation throughout the flavor material. However, a tighter particle size distribution may disadvantageously be more difficult to achieve and more expensive. The inventors have discovered that the above-described particle size distribution may provide an optimal compromise between these two factors.

[0151] The desired D10 and D90 particle sizes can be obtained by sieving. Sieving can therefore be used to obtain a narrow particle size distribution when required.

[0152] The carbon particles can have a D10 particle size greater than or equal to 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 microns. Each of the carbon particles can have a particle size greater than or equal to 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 microns.

[0153] The carbon particles may have a D10 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 microns. Each of the carbon particles may have a 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 microns.

[0154] The carbon particles may have a D90 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 microns. Each of the carbon particles may have a 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 microns.

[0155] The carbon particles can have a D90 particle size greater than or equal to 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 microns. Each of the carbon particles can have a particle size greater than or equal to 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 microns.

[0156] The carbon particles can have one or both of a D50 particle size and a volume average particle size greater than or equal to 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 microns.

[0157] The carbon particles may have one or both of a D50 particle size and 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 microns.

[0158] One or both of the D50 particle size and the volume average particle size of the carbon particles may be between 1 and 1000 microns, preferably between 10 and 200 microns, more preferably between 30 and 150 microns, or even more preferably between 50 and 75 microns. Alternatively or in addition, each of the carbon particles may have a particle size between 1 and 1000 microns, preferably between 10 and 200 microns, more preferably between 30 and 150 microns, or even more preferably between 50 and 75 microns.

[0159] Surprisingly, the inventors have found that these relatively small particle size ranges are particularly effective in increasing the thermal conductivity of flavour materials used in aerosol-generating articles according to the invention, particularly in view of use conditions where the flavour materials are exposed to relatively low temperatures during use.

[0160] The carbon particles can have a volume average particle size greater than or equal to 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 microns.

[0161] It may be particularly preferred that the carbon particles have a volume average particle size greater than 10 microns.

[0162] The carbon particles can 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 microns.

[0163] The carbon particles may have a volume average particle size of between 1 and 1000 microns, 10 and 200 microns, 30 and 150 microns or 50 and 75 microns. These volume average particle size ranges may be particularly preferred where the flavour material comprises or is in the form of a sheet.

[0164] The carbon particles can have a volume average particle size that is at least 2, 3, 5, 8, 10, 15, or 20 times the number average particle size.

[0165] It may be particularly preferred if the thermally conductive particles are or contain graphite particles.

[0166] The graphite particles may have a particle size distribution with a D10 particle size between 5 and 20, such as 10 and 14 microns, such as about 12 microns. The graphite particles may have a particle size distribution with a D50 particle size between 25 and 45 microns, such as about 35 microns. The graphite particles may have a particle size distribution with a D90 particle size between 45 and 75 microns, such as about 55 microns. Advantageously, such particles are commercially available, and the inventors have found that such particles provide a significant increase in the thermal conductivity of the flavor material.

[0167] It may be particularly preferred if the thermally conductive particles are or contain expanded graphite particles.

[0168] Expanded graphite particles can have a particle size distribution with a D10 particle size of 5 and 20 microns, for example, between 9 and 12 microns, for example, about 10.5 microns. Expanded graphite particles can have a particle size distribution with a D50 particle size of 15 and 25 microns, for example, about 20 microns. Expanded graphite particles can have a particle size distribution with a D90 particle size of 46 and 66 microns, for example, about 56 microns. Advantageously, such particles are commercially available, and the inventor has found that such particles provide a significant increase in the thermal conductivity of flavor materials. Expanded graphite particles can also advantageously reduce the overall density of flavor materials.

[0169] Each of the carbon particles may have three mutually perpendicular dimensions. The largest of the three dimensions may be no more than 10, 8, 5, 3, or 2 times larger than the smallest of the three dimensions. The largest of the three dimensions may be no more than 10, 8, 5, 3, or 2 times larger than the second largest of the three dimensions. Each of the three dimensions may be substantially equal. Each of the carbon particles may be substantially spherical.

[0170] The carbon particles may include at least 10, 20, 50, 100, 200, 500, or 1000 particles.

[0171] In the flavor material according to the present invention, the carbon particles account for 0.01 wt % to 10 wt % of the flavor material on a dry weight basis.

[0172] In some embodiments, the flavor material comprises greater than 0.1% by weight of an additive selected from the group consisting of a polycarboxylic acid, a salt containing a bicarbonate functional group, and mixtures thereof.

[0173] It has been found that the inclusion of additives selected from the above group in the flavour material used in aerosol-generating articles according to the present invention has an effect on the flavour release profile, in particular by promoting and enhancing flavour release at lower temperatures compared to a flavour material having substantially the same composition and structure but without such additives.

[0174] Without wishing to be bound by theory, this effect is understood to be related to the release of gaseous compounds upon thermal decomposition of the additive. These gaseous compounds are believed to disrupt the polysaccharide matrix structure, presumably by opening some of the inner pockets within which the flavour formulation is secured.

[0175] Thus, the improved flavor release provided by a flavor material comprising one or more additives as set out above may also allow a heater configured to supply heat to an aerosol-generating article incorporating the flavor material to operate at a lower temperature and thus require less power during use.

[0176] It may be advantageous to further control the flavor release profile by adjusting the amount of additive or by selecting a particular additive, or both. Indeed, it has been found that including a larger amount of additive in the flavor material generally results in a more pronounced shift in the flavor release profile toward lower temperatures. Additionally, the use of different additives that thermally decompose at different temperatures, either alone or in combination, may advantageously provide a means for even more finely tuning the flavor release profile of an aerosol-generating article containing a flavor material.

[0177] Preferably, the additive thermally decomposes at a temperature below 220 degrees Celsius at a pressure of 1 bar. More preferably, the additive thermally decomposes at a temperature below 200 degrees Celsius at a pressure of 1 bar. Even more preferably, the additive thermally decomposes at a temperature below 180 degrees Celsius at a pressure of 1 bar.

[0178] The additive may be thermally decomposed at a temperature of at least 100 degrees Celsius, preferably at least 120 degrees Celsius, more preferably at least 140 degrees Celsius, at a pressure of 1 bar.

[0179] In some embodiments, the additive is thermally decomposed 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.

[0180] In other embodiments, the additive is thermally decomposed at a temperature of 100 to 200 degrees Celsius, preferably 120 to 200 degrees Celsius, more preferably 140 to 200 degrees Celsius, at a pressure of 1 bar.

[0181] In a further embodiment, the additive is thermally decomposed at a temperature of 100 to 180 degrees Celsius, preferably 120 to 180 degrees Celsius, more preferably 140 to 180 degrees Celsius, at a pressure of 1 bar.

[0182] The use of one or more selected additives that thermally decompose at a temperature within the above range at a pressure of 1 bar has been identified as being particularly beneficial because, upon heating of the flavor material according to the invention, these additives will begin to thermally decompose at a temperature significantly lower than the temperature at which the one or more polysaccharides forming the matrix thermally decompose. As a result, the gaseous products generated upon thermal decomposition of the one or more additives interact with the matrix structure and may disrupt its integrity, such as by gradually opening one or more pockets of the matrix structure within which the flavor formulation is trapped, and they may do this before the integrity of the matrix structure can be affected by the application of heat alone.

[0183] Polycarboxylic acids suitable for use as additives in the flavor material according to the present invention include, but are not limited to, tartronic acid, malonic acid, and citric acid.

[0184] Salts containing a bicarbonate functional group suitable for use as an additive in the flavor material according to the present invention include, but are not limited to, sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, calcium bicarbonate, ammonium bicarbonate.

[0185] Preferably, the additive accounts for less than or equal to 25% by weight of the flavor material on a dry weight basis. More preferably, the additive accounts for less than or equal to 20% by weight of the flavor material on a dry weight basis. Even more preferably, the additive accounts for less than or equal to 15% by weight of the flavor material on a dry weight basis. In a particularly preferred embodiment, the additive accounts for less than or equal to 10% by weight of the flavor material on a dry weight basis.

[0186] Preferably, the additive comprises at least 0.25% by weight of the flavor material on a dry weight basis. More preferably, the additive comprises at least 0.5% by weight of the flavor material on a dry weight basis. Even more preferably, the additive comprises at least 1.0% by weight of the flavor material on a dry weight basis.

[0187] Flavour materials for use in aerosol-generating articles according to the present invention may be prepared by different routes.

[0188] A method of making such a flavor material may include a first step of preparing an aqueous composition comprising a flavor preparation, a polysaccharide and an emulsifier; a second step of casting the aqueous composition on a substantially flat support surface; a third step of allowing the aqueous composition to gel on the support surface; and a fourth step of drying the gelled aqueous composition. The dried flavor material may then be removed from the support surface. The support surface may be a metal plate.

[0189] Another method of making such a flavor delivery 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 on a carrier sheet material located 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 and the carrier sheet material. The dried flavor material in which the carrier sheet material supports the polysaccharide matrix entrapping the flavor formulation may then be removed from the support surface.

[0190] Yet another method of making such a flavor delivery 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 on a carrier sheet material (e.g., homogenized tobacco material) located 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 and the carrier sheet material. The dried flavor material in which the carrier sheet material supports the polysaccharide matrix that captures the flavor formulation may then be removed from the support surface.

[0191] As will be apparent from the foregoing description of flavor materials for incorporation in aerosol-generating articles according to the present invention, the present invention provides a range of new aerosol-generating articles that are capable of delivering flavor to consumers in a more consistent and controlled manner. In addition, because the flavor formulation is at least partially captured within the matrix until released when heat is supplied to the aerosol-generating article during use, the loss of flavor species during storage and transportation of the aerosol-generating article can be greatly reduced. Coupled with the enhancement of flavor release that can be obtained, especially at lower temperatures, this results in a particularly efficient use of flavors for certain embodiments.

[0192] As briefly described above, an aerosol-generating article according to the present invention comprises, in order, an upstream section; an aerosol-generating element; and a downstream section. The aerosol-generating element comprises a strip of aerosol-generating substrate defined by a wrapper. A flavor material of the type described in detail above is disposed in at least one of: the wrapper defining the strip of aerosol-generating substrate, the upstream section, and the downstream section.

[0193] In other words, the flavour material is provided at a location within the aerosol-generating article other than within the strip of aerosol-generating substrate.

[0194] The downstream section is disposed immediately downstream of the aerosol generating element and extends from the downstream end of the aerosol generating element to the downstream end of the aerosol generating article.The upstream section is disposed 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.

[0195] In some embodiments, the downstream section comprises a hollow tubular element disposed immediately downstream of the aerosol-generating element. The upstream end of the hollow tubular element abuts the downstream end of the aerosol-generating element, and the flavor material is disposed in the hollow tubular element.

[0196] In other embodiments, the downstream section comprises a hollow tubular element disposed downstream of the aerosol generating element, and the flavor material is disposed between the downstream end of the aerosol generating element and the upstream end of the hollow tubular element. For example, the flavor material is sandwiched between the aerosol generating element and the hollow tubular element.

[0197] In some embodiments, the upstream section comprises an upstream element disposed immediately upstream of the aerosol-generating element. A downstream end of the upstream element abuts an upstream end of the aerosol-generating element, and the flavor material is disposed in the upstream element.

[0198] In other embodiments, the upstream section includes an upstream element disposed upstream of the aerosol-generating element, and the flavor material is disposed between the upstream end of the aerosol-generating element and the downstream end of the upstream element.

[0199] For example, the flavour material is sandwiched between the aerosol generating element and the upstream element.

[0200] The downstream section may also 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 further include an aerosol-cooling element disposed between the hollow tubular element and the mouthpiece element. The hollow tubular element and the one or more additional components disposed downstream of the hollow tubular element form the downstream section of the aerosol-generating article.

[0201] The upstream element may have a length of at least about 2 millimeters, at least about 3 millimeters, or at least about 4 millimeters.

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

[0203] The upstream element may have a length between about 2 mm and about 10 mm, between about 2 mm and about 8 mm, or between about 2 mm and about 6 mm.

[0204] The upstream element may have a length between about 3 mm and about 10 mm, between about 3 mm and about 8 mm, or between about 3 mm and about 6 mm.

[0205] The upstream element may have a length between about 4 mm and about 10 mm, between about 4 mm and about 8 mm, or between about 4 mm and about 6 mm.

[0206] For example, the upstream element may have a length of approximately 5 mm.

[0207] The length of the upstream element may be selected based on a desired balance between the ability of the upstream element to prevent or limit movement of aerosol-generating material upstream from the aerosol-generating element and the RTD (resistance to draw) of the upstream element.

[0208] The length of the upstream element may be selected based on the desired overall length of the aerosol-generating article.

[0209] 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.

[0210] The ratio of the length of the upstream element to the overall length of the aerosol-generating article may be less than or equal to about 0.25, less than or equal to about 0.2, or less than or equal to about 0.15.

[0211] Preferably, the upstream element has a substantially circular cross-section.

[0212] The upstream element may have an outer diameter of at least about 5 mm, about 6 mm, or about 7 mm.

[0213] The upstream element may have an outer diameter of less than or equal to 12 mm, less than or equal to about 10 mm, or less than or equal to about 8 mm.

[0214] The upstream element may have an outer diameter between about 5 mm and about 12 mm, between about 5 mm and about 10 mm, or between about 5 mm and about 8 mm.

[0215] The upstream element may have an outer diameter between about 6 mm and about 12 mm, between about 6 mm and about 10 mm, or between about 6 mm and about 8 mm.

[0216] The upstream element may have an outer diameter between about 7 mm and about 12 mm, between about 7 mm and about 10 mm, or between about 7 mm and about 8 mm.

[0217] For example, the upstream element may have an outer diameter of approximately 7.1 mm.

[0218] Preferably, the outer diameter of the upstream element is substantially the same as the outer diameter of the aerosol-generating element.

[0219] Preferably, the outer diameter of the upstream element is substantially the same as the outer diameter of the aerosol-generating article.

[0220] As described above, the upstream element is upstream of the aerosol-generating element and may abut the aerosol-generating element.This may advantageously improve the ability of the upstream element to prevent or restrict the aerosol-generating substrate from moving upstream from the aerosol-generating element.

[0221] The upstream element may be at the upstream end of the aerosol-generating article. The aerosol-generating article may comprise a further element upstream of the upstream element. For example, the further element upstream of the upstream element may act as a cap or cover to help avoid damage to the upstream element.

[0222] Preferably, the majority of the aerosol generated by the aerosol-generating article is generated by the aerosol-generating substrate.All of the aerosol generated by the aerosol-generating article may be generated by the aerosol-generating substrate.

[0223] As mentioned above, the aerosol-generating element comprises an aerosol-generating substrate in the form of a rod.As used herein with reference to the present invention, the term "rod" is used to denote a generally cylindrical element having a generally circular, oval or elliptical cross-section.

[0224] The aerosol-generating element may have a length of at least about 8 mm, at least about 9 mm, or at least about 10 mm.

[0225] The aerosol-generating element may have a length of less than or equal to about 16 mm, less than or equal to about 15 mm, or less than or equal to about 14 mm.

[0226] The aerosol-generating element may have a length of between about 8 mm and about 16 mm, between about 8 mm and about 15 mm, or between about 8 mm and about 14 mm.

[0227] The aerosol-generating element may have a length of between about 9 mm and about 16 mm, between about 9 mm and about 15 mm, or between about 9 mm and about 14 mm.

[0228] The aerosol-generating element may have a length of between about 10 mm and about 16 mm, between about 10 mm and about 15 mm, or between about 10 mm and about 14 mm.

[0229] For example, the aerosol generating element may have a length of approximately 12 millimetres.

[0230] The ratio between the length of the aerosol-generating element and 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.

[0231] The ratio between the length of the aerosol-generating element and the overall length of the aerosol-generating article may be less than or equal to about 0.40, less than or equal to about 0.35, or less than or equal to about 0.3.

[0232] The ratio between the length of the aerosol-generating element and the overall length of the aerosol-generating article may be between about 0.10 and about 0.40, between about 0.10 and about 0.35, or between about 0.10 and about 0.30.

[0233] The ratio between the length of the aerosol-generating element and the overall length of the aerosol-generating article may be between about 0.15 and about 0.40, between about 0.15 and about 0.35, or between about 0.15 and about 0.30.

[0234] The ratio between the length of the aerosol-generating element and the overall length of the aerosol-generating article may be between about 0.20 and about 0.40, between about 0.20 and about 0.35, or between about 0.20 and about 0.30.

[0235] Preferably, the aerosol-generating element has a substantially circular cross-section.

[0236] The aerosol generating element may have an outer diameter of at least about 5 mm, about 6 mm or about 7 mm.

[0237] The aerosol-generating element may have an outer diameter of less than or equal to 12 mm, less than or equal to about 10 mm, or less than or equal to about 8 mm.

[0238] The aerosol generating element may have an outer diameter of between about 5 mm and about 12 mm, between about 5 mm and about 10 mm, or between about 5 mm and about 8 mm.

[0239] The aerosol generating element may have an outer diameter of between about 6 mm and about 12 mm, between about 6 mm and about 10 mm, or between about 6 mm and about 8 mm.

[0240] The aerosol generating element may have an outer diameter of between about 7 mm and about 12 mm, between about 7 mm and about 10 mm, or between about 7 mm and about 8 mm.

[0241] For example, the aerosol generating element may have an outer diameter of approximately 7.1 mm.

[0242] The aerosol-generating substrate may have a density of at least about 150 mg / cm3, at least about 175 mg / cm3, at least about 200 mg / cm3, or at least about 250 mg / cm3.

[0243] The aerosol-generating substrate may have a density of less than or equal to about 500 mg / cm3, less than or equal to about 450 mg / cm3, less than or equal to about 400 mg / cm3, or less than or equal to about 350 mg / cm3.

[0244] The aerosol-generating substrate may have a density between about 150 mg / cm3 and about 500 mg / cm3, between about 150 mg / cm3 and about 450 mg / cm3, between about 150 mg / cm3 and about 400 mg / cm3, or between about 150 mg / cm3 and about 350 mg / cm3.

[0245] The aerosol-generating substrate may have a density between about 175 mg / cm3 and about 500 mg / cm3, between about 175 mg / cm3 and about 450 mg / cm3, between about 175 mg / cm3 and about 400 mg / cm3, or between about 175 mg / cm3 and about 350 mg / cm3.

[0246] The aerosol-generating substrate may have a density between about 200 mg / cm3 and about 500 mg / cm3, between about 200 mg / cm3 and about 450 mg / cm3, between about 200 mg / cm3 and about 400 mg / cm3, or between about 200 mg / cm3 and about 350 mg / cm3.

[0247] The aerosol-generating substrate may have a density between about 250 mg / cm3 and about 500 mg / cm3, between about 250 mg / cm3 and about 450 mg / cm3, between about 250 mg / cm3 and about 400 mg / cm3, or between about 250 mg / cm3 and about 350 mg / cm3.

[0248] For example, the aerosol-generating substrate may have a density of approximately 300 mg / cm3.

[0249] The RTD of the strip of aerosol-generating substrate may be at least about 4 mm H2O, at least about 5 mm H2O, or at least about 6 mm H2O.

[0250] The RTD of the strip of aerosol-generating substrate may be less than or equal to about 10 mm H2O, less than or equal to about 9 mm H2O, or less than or equal to about 8 mm H2O.

[0251] The RTD of the strip of aerosol-generating substrate may be between about 4 mm H2O and about 10 mm H2O, between about 4 mm H2O and about 9 mm H2O, or between about 4 mm H2O and about 8 mm H2O.

[0252] The RTD of the strip of aerosol-generating substrate may be between about 5 mm H2O and about 10 mm H2O, between about 5 mm H2O and about 9 mm H2O, or between about 5 mm H2O and about 8 mm H2O.

[0253] The RTD of the strip of aerosol-generating substrate may be between about 6 mm H2O and about 10 mm H2O, between about 6 mm H2O and about 9 mm H2O, or between about 6 mm H2O and about 8 mm H2O.

[0254] The aerosol-generating substrate may be a solid aerosol-generating substrate.

[0255] Preferably, the aerosol-generating substrate comprises an aerosol former.

[0256] The aerosol former may be any suitable known compound or mixture of compounds that facilitates the formation of a dense and stable aerosol in use. The aerosol former may facilitate the aerosol being substantially resistant to thermal degradation at temperatures typically applied during use of the aerosol-generating article. Suitable aerosol formers are, for example: polyols such as triethylene glycol, 1,3-butylene glycol, propylene glycol and glycerol; esters of polyols such as glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.

[0257] Preferably, the aerosol former comprises one or more of glycerol and propylene glycol. The aerosol former may consist of glycerol or propylene glycol or a combination of glycerol and propylene glycol.

[0258] The aerosol-generating substrate may comprise at least about 5 wt%, at least about 10 wt%, or at least about 12 wt% aerosol former based on the dry weight of the aerosol-generating substrate.

[0259] The aerosol-generating substrate may comprise less than or equal to about 30 wt %, less than or equal to about 25 wt %, or less than or equal to about 20 wt % of aerosol-forming agent based on the dry weight of the aerosol-generating substrate.

[0260] The aerosol-generating substrate may comprise between about 5 wt % and about 30 wt %, between about 5 wt % and about 25 wt %, or between about 5 wt % and about 20 wt % of the aerosol-forming agent, based on the dry weight of the aerosol-generating substrate.

[0261] The aerosol-generating substrate may comprise between about 10 wt % and about 30 wt %, between about 10 wt % and about 25 wt %, or between about 10 wt % and about 20 wt % of the aerosol-forming agent, based on the dry weight of the aerosol-generating substrate.

[0262] The aerosol-generating substrate may comprise between about 12 wt % and about 30 wt %, between about 12 wt % and about 25 wt %, or between about 12 wt % and about 20 wt % of the aerosol-forming agent, based on the dry weight of the aerosol-generating substrate.

[0263] The aerosol-generating substrate may comprise a plurality of shreds of tobacco material.The aerosol-generating substrate may comprise a plurality of shreds of homogenised tobacco material.

[0264] As used herein with reference to the present invention, the term "chip" refers to an element having a length that is substantially greater than its width and thickness.

[0265] As used herein with reference to the present invention, the term "homogenised tobacco material" is used to describe a material formed by agglomerating particulate tobacco material.

[0266] Shreds of homogenised tobacco material may be formed from sheets of homogenised tobacco material, for example by cutting or shredding. Shreds of homogenised tobacco material may be formed by other methods, for example by extrusion.

[0267] The shreds 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.

[0268] The shreds of tobacco material may have a width of less than or equal to about 2 millimeters, less than or equal to about 1.2 millimeters, or less than about 0.9 millimeters.

[0269] The shreds of tobacco material may have a width of between about 0.3 mm and about 2 mm, between about 0.3 mm and about 1.2 mm, or between about 0.3 mm and about 0.9 mm.

[0270] The shreds of tobacco material may have a width of between about 0.5 mm and about 2 mm, between about 0.5 mm and about 1.2 mm, or between about 0.5 mm and about 0.9 mm.

[0271] The shreds of tobacco material may have a width of between about 0.6 mm and about 2 mm, between about 0.6 mm and about 1.2 mm, or between about 0.6 mm and about 0.9 mm.

[0272] The shreds of tobacco material may have a length of at least about 10 millimetres.

[0273] The shreds of tobacco material may have a length of less than or equal to about 40 millimetres.

[0274] The shreds of tobacco material may have a length of between about 10 millimeters and about 40 millimeters.

[0275] At least about 20% by weight on a dry weight basis of the plurality of tobacco material fragments may extend along the entire length of the aerosol-generating substrate.At least about 20% by weight on a dry weight basis of the plurality of tobacco material fragments may have a length substantially the same as the length of the aerosol-generating substrate.

[0276] Less than or equal to about 60% by weight on a dry weight basis of the plurality of tobacco material fragments may extend along the entire length of the aerosol-generating substrate.Less than or equal to about 60% by weight on a dry weight basis of the plurality of tobacco material fragments may have substantially the same length as the length of the aerosol-generating substrate.

[0277] Between about 20% and 60% by weight on a dry weight basis of the plurality of tobacco material fragments may extend along the entire length of the aerosol-generating substrate. Between about 20% and 60% by weight on a dry weight basis of the plurality of tobacco material fragments may have a length substantially the same as the length of the aerosol-generating substrate.

[0278] The size of the aerosol generating material (such as a plurality of tobacco material fragments) of the aerosol generating substrate can have an impact on the heat distribution within the aerosol generating substrate. In addition, the size of the aerosol generating material can have an impact on the suction resistance of the product. In addition, the size of the aerosol generating material can affect the ability of the upstream element to prevent or limit the aerosol generating material from moving into the longitudinally extending channel of the upstream element. The size of the aerosol generating material can also affect the ability of the upstream element to prevent or limit the aerosol generating material from moving upstream along the longitudinally extending channel and leaving the upstream element.

[0279] 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 homogenised tobacco material.

[0280] At least about 60 weight percent of the plurality of pellets or granules may have a maximum dimension greater than about 1 mm, at least about 70 weight percent of the plurality of pellets or granules may have a maximum dimension greater than about 1 mm, or at least about 80 weight percent of the plurality of pellets or granules may have a maximum dimension greater than about 1 mm.

[0281] Where the homogenized plant material is in the form of a plurality of pellets or granules, at least about 70% by weight of the plurality of pellets or granules may have a maximum dimension greater than about 0.5 mm, at least about 80% by weight of the plurality of pellets or granules may have a maximum dimension greater than about 0.5 mm, or at least about 90% by weight of the plurality of pellets or granules may have a maximum dimension greater than about 0.5 mm.

[0282] For example, at least about 80% by weight of the plurality of pellets or granules may have a maximum dimension greater than about 1 mm and at least about 90% by weight of the plurality of pellets or granules may have a maximum dimension greater than about 0.5 mm.

[0283] The aerosol-generating substrate may comprise one or more sheets of tobacco material.

[0284] The aerosol-generating substrate may comprise one or more sheets of homogenised tobacco material.

[0285] The one or more sheets of tobacco material may each individually have a thickness of at least about 100 microns, at least about 150 microns, or at least about 300 microns.

[0286] As used herein with reference to the present invention, individual thickness refers to the thickness of an individual tobacco material sheet, while combined thickness refers to the total thickness of all tobacco material sheets that make up the aerosol-generating substrate. For example, if the aerosol-generating substrate is formed by two individual tobacco material sheets, the combined thickness is the sum of the thicknesses of the two individual tobacco material sheets, or the measured thickness of the two tobacco material sheets if the two tobacco material sheets are stacked in the aerosol-generating substrate.

[0287] The one or more sheets of tobacco material may each individually have a thickness of less than or equal to about 600 microns, less than or equal to about 300 microns, or less than or equal to about 250 microns.

[0288] The one or more sheets of tobacco material may each individually have a thickness of between about 100 microns and about 600 microns, between about 100 microns and about 300 microns, or between about 100 microns and about 250 microns.

[0289] The one or more sheets of tobacco material may each individually have a thickness of between about 150 microns and about 600 microns, between about 150 microns and about 300 microns, or between about 150 microns and about 250 microns.

[0290] The one or more sheets of tobacco material may each individually have a thickness of between about 250 microns and about 600 microns, between about 250 microns and about 300 microns, or between about 250 microns and about 250 microns.

[0291] The one or more sheets of tobacco material may each individually have substantially the same length as the length of the aerosol-generating substrate.

[0292] The one or more sheets of tobacco material may be one or more of curled, folded, gathered and pleated.

[0293] The curling, folding, gathering or pleating of the one or more tobacco material sheets can cause the splitting of the one or more tobacco material sheets to form tobacco material fragments. For example, the one or more tobacco material sheets can be curled to a certain extent so that the integrity of the one or more tobacco material sheets is destroyed at a plurality of parallel ridges or corrugations, causing the material to separate, and causing the fragments forming tobacco material.

[0294] An aerosol-generating article may comprise a susceptor disposed within an aerosol-generating substrate.

[0295] As used herein with reference to the present invention, the term "susceptor" refers to a material that can convert electromagnetic energy into heat. When placed within a fluctuating electromagnetic field, eddy currents induced in the susceptor cause heating of the susceptor.

[0296] The susceptor is arranged in thermal contact with the aerosol-generating substrate. Thus, when the susceptor becomes hot, the aerosol-generating substrate is heated by the susceptor to generate an aerosol. The susceptor may be arranged in direct physical contact with the aerosol-generating substrate.

[0297] The upstream element may advantageously prevent or limit upstream migration of the susceptor during storage, transport and use of the aerosol-generating article.

[0298] The susceptor may be an elongate susceptor.

[0299] As used herein with reference to the present invention, the term "elongated" is used to describe a component of an aerosol-generating article having a length that is greater than its width and thickness.

[0300] The elongated susceptor may be arranged substantially longitudinally within the aerosol-generating substrate. That is, the longitudinal axis of the elongated susceptor may be substantially parallel to the longitudinal axis of the aerosol-generating element. For example, the longitudinal axis of the elongated susceptor may be within plus or minus 10 degrees of being parallel to the longitudinal axis of the aerosol-generating element. The elongated susceptor may be located at a radially central position within the strip of the aerosol-generating substrate and extend along the longitudinal axis of the aerosol-generating element.

[0301] The susceptor may extend from a downstream end of the aerosol-generating element towards an upstream end of the aerosol-generating element.

[0302] The susceptor may extend from an upstream end of the aerosol-generating element towards a downstream end of the aerosol-generating element.

[0303] The susceptor may extend from the upstream end of the aerosol-generating substrate towards the downstream end of the aerosol-generating element. That is, the susceptor may extend along the entire length of the aerosol-generating element.

[0304] The length of the susceptor may be substantially the same as the length of the aerosol generating element.

[0305] The susceptor may extend partially along the length of the aerosol generating element.

[0306] The susceptor may be spaced apart from the downstream end of the aerosol-generating substrate.

[0307] The susceptor may be spaced apart from the upstream end of the aerosol generating element.

[0308] The susceptor may be spaced from both the downstream end and the upstream end of the aerosol generating element.

[0309] The length of the susceptor may be less than the length of the aerosol generating element.

[0310] The susceptor may be entirely enclosed within the aerosol-generating substrate. That is, the aerosol-generating substrate may completely surround the susceptor.

[0311] The susceptors may be in the form of needles, strips, ribbons or leaves.

[0312] The susceptor may have a length of at least about 5 mm, at least about 6 mm, or at least about 8 mm.

[0313] The susceptor may have a length of less than or equal to about 15 mm, less than or equal to about 12 mm, or less than or equal to about 10 mm.

[0314] The susceptor may have a length between about 5 mm and about 15 mm, between about 5 mm and about 12 mm, or between about 5 mm and about 10 mm.

[0315] The susceptor may have a length between about 6 mm and about 15 mm, between about 6 mm and about 12 mm, or between about 6 mm and about 10 mm.

[0316] The susceptor may have a length between about 8 mm and about 15 mm, between about 8 mm and about 12 mm, or between about 8 mm and about 10 mm.

[0317] The susceptor may have a width of at least about 1 mm.

[0318] The susceptor may have a width of less than or equal to about 5 millimeters.

[0319] The susceptor may have a width between about 1 mm and about 5 mm.

[0320] The susceptor may have a thickness of at least about 0.01 mm or at least about 0.5 mm.

[0321] The susceptor may have a thickness of less than or equal to about 2 millimeters, less than or equal to about 500 microns, or less than or equal to about 100 microns.

[0322] The susceptor may have a thickness between about 10 microns and about 2 millimeters, between about 10 microns and about 500 microns, or between about 10 microns and about 100 microns.

[0323] The susceptor may have a thickness between about 0.5 mm and about 2 mm.

[0324] The susceptor may have a generally circular cross-section.

[0325] The susceptor may have a cross-section that is substantially constant along the length of the susceptor.

[0326] If the susceptor has the form of a strip or blade, the strip or blade may have a rectangular shape having a width between about 2 mm and about 8 mm or between about 3 mm and about 5 mm. For example, the susceptor in the form of a strip or blade may have a width of about 4 mm.

[0327] If the susceptor has the form of a strip or blade, the strip or blade may have a rectangular shape and a thickness between about 0.03 mm and about 0.15 mm or between about 0.05 mm and about 0.09 mm. For example, the susceptor in the form of a strip or blade may have a thickness of about 0.07 mm or about 0.06 mm.

[0328] 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.

[0329] The susceptor may comprise or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, or ferromagnetic steel or stainless steel. Suitable susceptors may be or include aluminum. The susceptor may be formed of 400 series stainless steel, such as grade 410 or grade 420 or grade 430 stainless steel. Different materials will dissipate different amounts of energy when positioned within an electromagnetic field having similar frequency and field strength values.

[0330] Thus, the parameters of the susceptor, such as material type, length, width and thickness, can be altered within a known electromagnetic field to provide the required power dissipation. The susceptor can be heated to temperatures in excess of 250 degrees Celsius.

[0331] Suitable susceptors may include a non-metallic core having a metal layer disposed on the non-metallic core, such as metal traces formed on the surface of a ceramic core. The susceptor may have an outer protective layer, such as a ceramic protective layer or a glass protective layer encapsulating the susceptor. The susceptor may include a protective coating formed of glass, ceramic, or an inert metal formed on the core of the susceptor material.

[0332] The susceptor may be a multi-material susceptor and may include a first susceptor material and a second susceptor material.

[0333] In the context of the present invention, hollow tubular element provides unrestricted flow channel. This means that hollow tubular element provides negligible suction resistance (RTD) level. As used herein with reference to the present invention, the RTD of term "negligible RTD level" for describing is less than 1mm H2O / 10 millimeters of length of hollow tubular matrix element, less than 0.4mm H2O / 10 millimeters of length of hollow tubular matrix element or less than 0.1mm H2O / 10 millimeters of length of hollow tubular matrix element. Therefore, flow channel should not contain any parts that will hinder air from flowing in the longitudinal direction. Preferably, flow channel is empty substantially.

[0334] 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.

[0335] The hollow tubular element can have an overall length of less than or equal to about 30 millimeters, less than or equal to about 25 millimeters, or less than or equal to about 23 millimeters.

[0336] The hollow tubular element may have an overall length of between about 10 mm and about 30 mm, between about 10 mm and about 25 mm, or between about 10 mm and about 23 mm.

[0337] The hollow tubular element may have an overall length of between about 12 mm and about 30 mm, between about 12 mm and about 25 mm, or between about 12 mm and about 23 mm.

[0338] The hollow tubular element may have an overall length of between about 12 mm and about 30 mm, between about 12 mm and about 25 mm, or between about 12 mm and about 23 mm.

[0339] The overall length of the hollow tubular element may be selected based on the desired overall length of the aerosol-generating article.

[0340] 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; and polymeric materials such as low-density polyethylene (LDPE). Other suitable materials include polyhydroxyalkanoate (PHA) fibers.

[0341] In some embodiments, a ventilation zone may be provided at a position downstream of the aerosol generating element. By providing a ventilation zone at a position along the hollow tubular element itself or at a position along an intermediate element provided between the hollow tubular element and the mouthpiece, satisfactory cooling of the aerosol flow generated when the aerosol generating substrate is heated and drawn through the hollow tubular element can be achieved. 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 drop caused by allowing cooler external air to enter the aerosol generating article downstream of the aerosol generating element via the ventilation zone may have a favorable effect on the nucleation and growth of aerosol particles.

[0342] The ventilation zone may comprise a plurality of perforations through the tubular wall of the hollow tubular element. The ventilation zone may comprise at least one row of circumferential perforations. The ventilation zone may comprise two rows of circumferential perforations. For example, the perforations may be formed on a production line during manufacture of the aerosol-generating article. Each row of circumferential perforations may comprise 8 to 30 perforations.

[0343] As described 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.

[0344] The mouthpiece element may be a mouthpiece filter element. The mouthpiece element may include at least one filter segment for filtering aerosol generated when the aerosol generating substrate is heated. For example, the mouthpiece element may include one or more segments of fibrous filter material. Suitable fibrous filter 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.

[0345] The mouthend element may consist of a single filter segment.The mouthend element may comprise two or more filter segments axially aligned with each other in abutting end-to-end relationship.

[0346] Parameters or characteristics described herein with respect to the mouthpiece element as a whole may equally apply to the filter segment of the mouthpiece element.

[0347] The mouthpiece element may have a low particle filtration efficiency.

[0348] The mouthend element may have an RTD of less than or equal to about 25 mm H2O, less than or equal to about 20 mm H2O, or less than or equal to about 15 mm H2O.

[0349] The mouthpiece element may have an RTD of at least about 10 mm H20.

[0350] The mouthend element may have an RTD between about 10 mm H2O and about 25 mm H2O, or between about 10 mm H2O and about 20 mm H2O, or between about 10 mm H2O and about 15 mm H2O.

[0351] Preferably, the mouthend element has a substantially circular cross-section.

[0352] Preferably, the mouthend element has an outer diameter that is substantially the same as the outer diameter of the aerosol-generating article.

[0353] The mouthend element may have a length of at least about 3 mm or at least about 5 mm.

[0354] The length of the mouthend element may be less than or equal to about 11 mm or less than or equal to about 9 mm.

[0355] The length of the mouthend element may be between about 3 mm and about 11 mm or between about 3 mm and about 9 mm.

[0356] The length of the mouthend element may be between about 5 mm and about 11 mm or between about 5 mm and about 9 mm.

[0357] For example, the mouthend element may be approximately 7 mm in length.

[0358] The length of the mouthend element may be selected based on the desired overall length of the aerosol-generating article.

[0359] The mouthend element may be defined by a stick wrap.

[0360] The mouthend element may be non-ventilated such that air does not enter the aerosol-generating article along the mouthend element.

[0361] The mouthend element may be connected to one or more adjacent components of the aerosol-generating article by means of a tipping wrapper.

[0362] The aerosol-generating article may comprise a mouth-end cavity at the downstream end of the aerosol-generating article. Where present, the mouth-end cavity may be downstream of the mouthpiece element.

[0363] The mouth end cavity may be defined by a hollow tubular element disposed at the downstream end of the mouthpiece. Alternatively, the mouth end cavity may be defined by an outer wrapper of the mouthpiece element, wherein the outer wrapper extends from the mouthpiece element in the downstream direction.

[0364] The aerosol-generating article may have an overall length of at least about 35 mm, at least about 38 mm, at least about 40 mm, or at least about 42 mm.

[0365] The aerosol-generating article may have an overall length of less than or equal to about 100 mm, less than or equal to about 70 mm, less than or equal to about 60 mm, or less than or equal to about 50 mm.

[0366] The aerosol-generating article may have an overall length of between about 35 mm and about 100 mm, between about 35 mm and about 70 mm, between about 35 mm and about 60 mm, or between about 35 mm and about 50 mm.

[0367] The aerosol-generating article may have an overall length of between about 38 mm and about 100 mm, between about 38 mm and about 70 mm, between about 38 mm and about 60 mm, or between about 38 mm and about 50 mm.

[0368] The aerosol-generating article may have an overall length of between about 40 mm and about 100 mm, between about 40 mm and about 70 mm, between about 40 mm and about 60 mm, or between about 40 mm and about 50 mm.

[0369] The aerosol-generating article may have an overall length of between about 42 mm and about 100 mm, between about 42 mm and about 70 mm, between about 42 mm and about 60 mm, or between about 42 mm and about 50 mm.

[0370] For example, the aerosol-generating article may have an overall length of approximately 45 mm.

[0371] Preferably, the aerosol-generating article has a substantially circular cross-section.

[0372] The aerosol-generating article may have an outer diameter of at least about 5 mm, at least about 6 mm, or at least about 7 mm.

[0373] The aerosol-generating article may have an outer diameter of less than or equal to about 12 mm, less than or equal to about 10 mm, or less than or equal to about 8 mm.

[0374] The aerosol-generating article may have an outer diameter of between about 5 mm and about 12 mm, between about 5 mm and about 10 mm, or between about 5 mm and about 8 mm.

[0375] The aerosol-generating article may have an outer diameter of between about 6 mm and about 12 mm, between about 6 mm and about 10 mm, or between about 6 mm and about 8 mm.

[0376] The aerosol-generating article may have an outer diameter of between about 7 mm and about 12 mm, between about 7 mm and about 10 mm, or between about 7 mm and about 8 mm.

[0377] For example, the aerosol-generating article may have an outer diameter of approximately 7.1 mm.

[0378] In an aerosol-generating article according to the invention, a flavor material having the structure and formulation described above is disposed at a location in at least one of the upstream section, the downstream section, or the wrapper of the aerosol-generating substrate defining the aerosol-generating element. Incorporation of flavor materials into an aerosol-generating article according to the invention may be performed according to one of several routes.

[0379] For example, the fragments of the flavor material may be incorporated into a tow of cellulose acetate fibers from which the upstream element or hollow tubular element may be formed. As an alternative, the fragments of the flavor material may be incorporated into a stick wrapper for a strip of aerosol-generating substrate defining an aerosol-generating element.

[0380] As a further alternative, a flavour 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 define a strip of an aerosol-generating substrate.

[0381] As a further alternative, fragments of flavour material may be sandwiched between the upstream element and the aerosol-generating element or between the hollow tubular element and the aerosol-generating element.

[0382] It has been found that the flavor material as described above is combined at one or more positions in the aerosol generating article discussed here to have an impact on the flavor release curve and flavor transfer rate during the use of the aerosol generating article. Without wishing to be bound by theory, this is because compared with the solution at the position in the strip of the aerosol generating substrate known in the art where the flavor material has been arranged, in the aerosol generating article according to the present invention, the flavor material is usually exposed to less intense heating than the aerosol generating substrate. This is related to the average distance between the flavor material and the heat source being 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 the aerosol generating device configured to heat the aerosol generating substrate will be discussed in more detail below.

[0383] Furthermore, aerosol-generating articles in which an aerosol-generating substrate is heated to generate an aerosol - as opposed to being combusted to generate smoke - are typically heated to relatively low temperatures.

[0384] The inventors have found that aerosol-generating articles according to the present invention can provide a satisfactory rate of flavour delivery during use because the flavour material can be adapted to release flavour in a controlled manner within a predetermined temperature range. This can be achieved a) by selecting and adjusting the polysaccharide matrix composition, or b) by including (as described above) carbon particles in the flavour material, or c) by including (as described above) an additive in the flavour material that is capable of generating gaseous compounds when it is thermally decomposed, or d) by any combination of a), b) and c).

[0385] Thus, despite being exposed to less intense heating, the flavor material included in an aerosol-generating article according to the present invention is able to release flavor in a more consistent manner throughout the use cycle of the aerosol-generating article. For example, through some embodiments, the inventors have observed that the flavor release associated with successive puffs during use of the aerosol-generating article can remain substantially constant until the last puff, or even increase slightly toward the end of the use cycle. This is quite surprising and contrary to what is typically found when flavor materials are incorporated into an aerosol-generating matrix, namely that the flavor release increases and reaches a maximum during the first few puffs, and then gradually decreases as the consumer approaches the end of the use cycle.

[0386] In embodiments where the flavor material is disposed at a location in the upstream section or in the downstream section, the distance between the flavor material and the aerosol generating element may be at least 5% of the outer diameter of the aerosol generating element. The distance between the flavor material and the aerosol generating element is measured as the linear distance between the geometric center of the flavor material and the nearest end surface of the aerosol generating element. For example, if the flavor material is disposed in the upstream section, such as in the upstream element, the distance between the flavor material and the aerosol generating element is measured as the linear distance between the geometric center of the flavor material and the upstream end of the strip of aerosol generating substrate.

[0387] Preferably, the distance between the flavour material and the aerosol-generating element may be at least 10% of the outer diameter of the aerosol-generating element. More preferably, the distance between the flavour material and the aerosol-generating element may be at least 15% of the outer diameter of the aerosol-generating element.

[0388] In embodiments where the flavor material is disposed at a location in the upstream section or in the downstream section, the distance between the flavor material and the aerosol-generating element is preferably less than or equal to 50% of the outer diameter of the aerosol-generating element. More preferably, the distance between the flavor material and the aerosol-generating element is preferably less than or equal to 40% of the outer diameter of the aerosol-generating element. Even more preferably, the distance between the flavor material and the aerosol-generating element is preferably less than or equal to 30% of the outer diameter of the aerosol-generating element.

[0389] In some embodiments where the flavor material is disposed at a position in the segment or in a downstream segment (such as in an upstream element or in a hollow tubular element), the distance between the flavor material and the aerosol generating element is 5% to 50% of the outer diameter of the aerosol generating element, preferably 5% to 40% of the outer diameter of the aerosol generating element, and more preferably 5% to 30% of the outer diameter of the aerosol generating element.

[0390] In other embodiments where the flavor material is disposed at a position in the upstream section or in the downstream section (such as in an upstream element or in a hollow tubular element), the distance between the flavor material and the aerosol generating element is 10% to 50% of the outer diameter of the aerosol generating element, preferably 10% to 40% of the outer diameter of the aerosol generating element, and more preferably 10% to 30% of the outer diameter of the aerosol generating element.

[0391] In further embodiments where the flavor material is disposed at a position in the upstream section or in the downstream section (such as in an upstream element or in a hollow tubular element), the distance between the flavor material and the aerosol generating element is 15% to 50% of the outer diameter of the aerosol generating element, preferably 15% to 40% of the outer diameter of the aerosol generating element, and more preferably 15% to 30% of the outer diameter of the aerosol generating element.

[0392] The present disclosure also relates to an aerosol generating system. The aerosol generating system may include an aerosol generating article as described above. The aerosol generating system may also include an aerosol generating device configured to heat an aerosol generating substrate of the aerosol generating article. The aerosol generating device may include a housing defining a cavity configured to receive the aerosol generating article.

[0393] According to a second aspect of the present invention, an aerosol generating system is provided, comprising: an aerosol generating article according to the first aspect of the present invention; and an aerosol generating device configured to heat an aerosol generating substrate of the aerosol generating article, wherein the aerosol generating device comprises a shell defining a cavity configured to receive the aerosol generating article.

[0394] The aerosol generating device may be a handheld aerosol generating device.

[0395] The aerosol generating device may be an electrically operated aerosol generating device.

[0396] The aerosol generating device may comprise a power supply and control electronics.

[0397] The aerosol generating device may comprise a battery and control electronics.

[0398] The aerosol-generating device may be configured to heat the aerosol-generating substrate from the inside. That is, the aerosol-generating device may be configured to supply heat to the aerosol-generating substrate from a location inside the aerosol-generating article.

[0399] 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.

[0400] In other embodiments, the aerosol generating article includes a susceptor element disposed at a position within the aerosol generating element, and the aerosol generating device includes an inductor coil positioned on or within the housing, the power supply of the aerosol generating device being connected to the inductor coil and being 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, and the current 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) between 1 and 5 kiloamperes per meter (kA m), preferably between 2 and 3 kA / m, for example about 2.5 kA / m.

[0401] The aerosol-generating device may be configured to heat the aerosol-generating substrate from the inside. That is, the aerosol-generating device may be configured to supply heat to the aerosol-generating substrate from a location external to the aerosol-generating article.

[0402] For example, in some embodiments, the aerosol generating device comprises a heater element positioned around the periphery of the cavity and configured to heat the aerosol-generating substrate of the aerosol-generating article from outside of an aerosol-generating element of the aerosol-generating article.

[0403] The present invention is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples may be combined with any one or more features of another example, embodiment or aspect described herein.

[0404] Example Ex1: An aerosol-generating article for generating an aerosol when heated, the aerosol-generating article comprising: an aerosol-generating element, the aerosol-generating element comprising a strip of an aerosol-generating substrate defined by a packaging; a downstream section, the downstream section being arranged 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, the upstream section being arranged 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; wherein the aerosol-generating article comprises a flavor material arranged in at least one of the packaging, the downstream section and the upstream section defining the strip of the aerosol-generating substrate; wherein the flavor material comprises: a polysaccharide matrix structure comprising gellan gum and an emulsifier; and a flavor preparation dispersed within the polysaccharide matrix structure, wherein the flavor preparation is at least partially captured within the polysaccharide matrix structure and can be released from the polysaccharide matrix structure when the flavor material is heated.

[0405] Example Ex2: An aerosol-generating article according to example Ex1, wherein the downstream section comprises a hollow tubular element disposed immediately downstream of the aerosol-generating element, the upstream end of the hollow tubular element being adjacent to the downstream end of the aerosol-generating element; wherein the flavor material is disposed in the hollow tubular element.

[0406] Example Ex3: An aerosol-generating article according to example Ex1, wherein the upstream section comprises an upstream element disposed immediately upstream of the aerosol-generating element, a downstream end of the upstream element being adjacent to an upstream end of the aerosol-generating element; wherein the flavor material is disposed in the upstream element.

[0407] Example Ex4: An aerosol-generating article according to any one of Examples Ex1 to Ex3, wherein the polysaccharide matrix structure comprises gellan gum as the sole polysaccharide or a combination of gellan gum and at least one other polysaccharide selected from guar gum, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose and hydroxypropyl methylcellulose.

[0408] Example Ex5: An aerosol-generating article according to any one of Examples Ex1 to Ex4, wherein the gellan gum accounts for 5% to 99.9% by weight of the flavor material on a dry weight basis.

[0409] Example Ex6: An aerosol-generating article according to any one of Examples Ex1 to Ex5, further comprising a n H 2n+ 2O n of polyols.

[0410] Example Ex7: An aerosol-generating article according to example Ex6, wherein the polyol is selected from glycerol, sorbitol, xylitol, mannitol and erythritol.

[0411] Example Ex8: An aerosol-generating article according to example Ex6 or example Ex7, wherein the polyol accounts for 0.01 wt% to 20 wt% of the flavor material on a dry weight basis.

[0412] Example Ex9: An aerosol-generating article according to any of the preceding examples, further comprising fibers.

[0413] Example Ex10: An aerosol-generating article according to example Ex9, wherein the fibers account for 0.01 wt% to 10 wt% of the flavor material on a dry weight basis.

[0414] Example Ex11: An aerosol-generating article according to any one of the preceding examples, comprising 0.01 wt% to 80 wt% menthol.

[0415] Example Ex 12: An aerosol-generating article according to any one of the preceding examples, wherein the flavor material further comprises a carrier material, wherein the polysaccharide matrix structure and the flavor formulation are supported by the carrier material.

[0416] Example Ex 13: An aerosol-generating article according to example Ex 12, wherein the carrier material is a sheet of homogenised tobacco material.

[0417] Example Ex14: An aerosol-generating article according to example Ex12, wherein the carrier material is a sheet of stick paper wrapper material.

[0418] Example Ex15: An aerosol-generating article according to any of the preceding examples, comprising a ventilation zone at a location along the hollow tubular element, the ventilation zone being configured to enable air to enter the axial lumen of the hollow tubular element.

[0419] Example Ex16: An aerosol-generating article according to any of the preceding examples, wherein the upstream element comprises a rod extending to and defining a distal end of the aerosol-generating article, the flavor material being disposed at a position within the rod.

[0420] Example Ex 17: An aerosol-generating article according to any one of the preceding examples, wherein the aerosol-generating substrate comprises tobacco material.

[0421] Example Ex 18: An aerosol-generating article according to example Ex 17, wherein the tobacco material comprises a sheet of homogenised tobacco material.

[0422] Example Ex19: An aerosol-generating article according to example Ex17, wherein the tobacco material comprises one or more of tobacco cut filler, cut reconstituted tobacco and cut homogenized tobacco material.

[0423] Example Ex20: An aerosol generating system, comprising: an aerosol generating article according to any one of Examples Ex1 to Ex19; and an aerosol generating device configured to heat the aerosol generating substrate of the aerosol generating article, wherein the aerosol generating device comprises a shell defining a cavity configured to receive the aerosol generating article.

[0424] Example Ex21: An aerosol-generating system according to example Ex20, 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.

[0425] Example Ex22: An aerosol generating system according to Example Ex20, wherein the aerosol generating article includes a sensor element arranged at a position within the aerosol generating element; and wherein the aerosol generating device includes an inductor coil positioned on or within the shell, and a power source connected to the inductor coil and configured to provide a high-frequency oscillating current to the inductor coil.

[0426] Example Ex23: An aerosol generating system according to Example Ex20, wherein the aerosol generating device includes a heater element, which is positioned around the periphery of the cavity and is configured to heat the aerosol generating substrate of the aerosol generating article from the outside of the aerosol generating element of the aerosol generating article. BRIEF DESCRIPTION OF THE DRAWINGS

[0427] Several examples will now be further described with reference to the accompanying drawings, in which:

[0428] Figure 1 shows a schematic side cross-sectional view of an aerosol-generating article according to the present invention comprising a flavour material in an upstream element;

[0429] Figure 2 shows a schematic side cross-sectional view of another aerosol-generating article according to the present invention comprising a flavour material in a wrapper defining an aerosol-generating substrate of an aerosol-generating element;

[0430] Figure 3 Shown in Figure 1 and Figure 2 scanning electron microscope images of flavor materials used in aerosol-generating articles; and

[0431] Figure 4 A scanning electron microscope image of another flavour material suitable for use in aerosol-generating articles according to the invention is shown. DETAILED DESCRIPTION

[0432] Figure 1 An aerosol-generating article 10 according to the present invention is shown in FIG. Figure 1 The aerosol-generating article 10 shown in 2 comprises an aerosol-generating element 12 and a downstream section 14 at a position downstream of the aerosol-generating element 12. Furthermore, the aerosol-generating article 10 comprises an upstream section 16 at a position upstream of the aerosol-generating element 12.

[0433] The aerosol-generating element 12 comprises a strip 121 of an aerosol-generating substrate and a wrapper 122 defining the strip 121 .

[0434] The ventilation zone 60 is disposed at a location downstream of the aerosol generating element 12 .

[0435] In more detail, Figure 1 In the embodiment of the invention, the downstream section 14 comprises a mouthpiece element 18 and a hollow section 20. The hollow section 20 comprises 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 generating element 12. Figure 1 As shown in the figure, the upstream end of the aerosol-cooling element 22 is adjacent to the downstream end of the aerosol generating element 12. The mouthpiece element 18 is positioned immediately downstream of the aerosol-cooling element 22. Figure 1 As shown in the Figures, the upstream end of the mouthpiece element 18 abuts the downstream end of the aerosol-cooling element 22. The mouthpiece element 18 comprises a rod 24 of low density filter material.

[0436] The aerosol-generating substrate 121 is in the form of a gathered sheet of homogenised tobacco material. However, other types of tobacco-containing substrates, such as tobacco cut filler, may replace the gathered sheet of homogenised tobacco material.

[0437] The upstream section 16 comprises a cylindrical rod 26 of compressed and plasticized cellulose acetate defined by a wrapper 28. The rod 26 of the upstream section 16 has a length of about 5 mm.

[0438] Furthermore, the aerosol-generating article comprises a flavour material 50. In more detail, a plurality of fragments of flavour material in the form of sheets are dispersed within the cylindrical rod 26. The flavour material 50 is of the type described in detail above.

[0439] Figure 2 Another aerosol-generating article 100 according to the present invention is shown in FIG. Figure 2 The aerosol generating article 100 shown in Figure 1 The aerosol generator 10 shown in FIG. 1 is substantially the same in structure and geometry, and only its differences will be described below. Figure 1 The differences in aerosol generation 10 are shown in FIG.

[0440] In the aerosol-generating article 100, the aerosol-generating substrate 121 is in the form of shreds of homogenised tobacco material. However, other types of tobacco-containing substrates, such as tobacco cut filler or a gathered sheet of homogenised tobacco material, may replace the shreds of homogenised tobacco material.

[0441] Furthermore, in the aerosol-generating article 100 , the flavour material 50 is disposed in a wrapper 122 that defines an aerosol-generating substrate 121 .

[0442] Preparation A - Flavor material comprising a menthol formulation entrapped in a gellan gum polysaccharide matrix

[0443] 100g water is heated to about 60 degrees Celsius and 3.0g gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80 to 85 degrees Celsius, and kept at this temperature for 5 minutes. Subsequently, the mixture is cooled to a temperature in the range of 70 to 75 degrees Celsius and 0.1g lecithin, 1.1g graphite and 8.0g menthol are added to the mixture. This flavor-containing mixture is homogenized for 3 minutes. Subsequently, the resulting aqueous composition is cast on a metal tray, gelled and dried in a static oven at 65 degrees Celsius. The flavor material in sheet form is obtained.

[0444] Preparation B - Flavor Material Comprising a Menthol Formulation Encapsulated in a Gellan Gum-Guar Polysaccharide Matrix

[0445] 100g water is heated to about 60 degrees Celsius and 1.0g gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80 to 85 degrees Celsius, and kept at this temperature for 5 minutes. Subsequently, the mixture is cooled to a temperature in the range of 70 to 75 degrees Celsius and 0.1g lecithin, 1.1g graphite and 8.0g menthol are added to the mixture. This flavor-containing mixture is homogenized for 3 minutes. Subsequently, 2.0g guar gum is added to the mixture, and then it is homogenized again for another 3 minutes. Subsequently, the resulting aqueous composition is cast on a metal tray, and it is allowed to gel and dry in a static oven of 75 degrees Celsius. The flavor material in sheet form is obtained.

[0446] Preparation C - A thin film comprising a gellan gum polysaccharide matrix entrapped in a carrier sheet material (paper wrapper) Flavor materials for hol preparations

[0447] 100g water is heated to about 60 degrees Celsius and 3.0g gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80 to 85 degrees Celsius, and kept at this temperature for 5 minutes. Subsequently, the mixture is cooled to a temperature in the range of 70 to 75 degrees Celsius and 0.1g lecithin and 8.0g menthol are added to the mixture. This flavor-containing mixture is homogenized for 3 minutes. Subsequently, the resulting aqueous composition is cast on a paper wrapper containing graphite particles on a metal tray, and it is gelled and dried in a static oven at 65 degrees Celsius. Obtain a flavor material comprising a layer of a gellan gum matrix that captures a menthol preparation, which is fixed on a graphite-containing paper wrapper.

[0448] Preparation D - A gellan gum polysaccharide matrix comprising a gellan gum polysaccharide matrix entrapped on a carrier sheet material (homogenized tobacco material) Flavor materials in menthol preparations

[0449] 100g water is heated to about 60 degrees Celsius and in this water-bath, 3.0g gellan gum is added. The gained mixture is homogenized and heated to the temperature in the scope of 80 to 85 degrees Celsius, and kept 5 minutes at this temperature. Subsequently the mixture is cooled to the temperature in the scope of 70 to 75 degrees Celsius and in the mixture, 0.1g lecithin and 8.0g menthol are added. This flavor-containing mixture was homogenized 3 minutes. Subsequently, the gained aqueous composition is cast on the sheet material of the homogenized tobacco material that comprises graphite particles on the metal tray, and its gelation is dried in the static oven of 65 degrees Celsius. Obtain a kind of flavor material, it comprises the layer of the gellan gum matrix that captures the menthol preparation, and this layer is fixed on the homogenized tobacco material that contains graphite.

[0450] Preparation E - Comprising gellan gum-guar gum polyols captured on a carrier sheet material (homogenized tobacco material) supported on a carrier sheet material (homogenized tobacco material) Flavor materials for menthol formulations in a sugar matrix

[0451] 100g water is heated to about 60 degrees Celsius and 1.0g gellan gum is added to this water-bath. The resulting mixture is homogenized and heated to the temperature in the range of 80 to 85 degrees Celsius, and kept at this temperature for 5 minutes. Subsequently, the mixture is cooled to the temperature in the range of 70 to 75 degrees Celsius and 0.1g lecithin and 8.0g menthol are added to the mixture. This flavor-containing mixture was homogenized for 3 minutes. Subsequently, 2.0g guar gum was added to the mixture, and then it was homogenized again for another 3 minutes. Subsequently, the gained aqueous composition is cast on the sheet material of the homogenized tobacco material that comprises graphite particles and is positioned on the metal tray, and its gelation is dried in the static oven of 65 degrees Celsius. Obtain a kind of flavor material, it comprises the layer of the gellan gum / guar gum matrix that captures the menthol preparation, and this layer is fixed on the homogenized tobacco material containing graphite.

[0452] Preparation F - comprising a gellan gum-alginate matrix entrapped on a carrier sheet material (homogenized tobacco material) Flavor materials for menthol preparations in foods

[0453] 100g water is heated to about 60 degrees Celsius and in this water-bath, 2.0g gellan gum and 0.5g alginate are added. The resulting mixture is homogenized and heated to the temperature in the range of 90 to 95 degrees Celsius, and kept at this temperature for 5 minutes. Subsequently, the mixture is cooled to the temperature in the range of 70 to 75 degrees Celsius and in the mixture, 0.1g lecithin and 8.0g menthol are added. This flavor-containing mixture is homogenized for 3 minutes. Subsequently, 2.0g guar gum is added in the mixture, and then it is homogenized again for another 3 minutes. Subsequently, the gained aqueous composition is cast on the sheet material of the homogenized tobacco material that comprises graphite particles and is positioned on the metal tray, and its gelation is dried in the static oven of 65 degrees Celsius. Obtain a kind of flavor material, it comprises the layer of the gellan gum / alginate matrix that captures the menthol preparation, and this layer is fixed on the homogenized tobacco material containing graphite.

[0454] Preparation G - Aerosol-generating article comprising a flavor material produced according to Preparation A

[0455] Preparation with Figure 1 An aerosol-generating article having the overall structure and geometry shown in .

[0456] An amount (constituting a total menthol content of 5 mg) of a flavor material produced according to Preparation A was disposed at a location immediately upstream of the aerosol generating element. An amount (constituting a total menthol content of 10 mg) of a flavor material produced according to Preparation A was disposed at a location along the hollow tubular element immediately downstream of the aerosol generating element.

[0457] Preparation H - Aerosol-generating article comprising a flavor material produced according to Preparation A

[0458] Preparation with Figure 1 An aerosol-generating article having the overall structure and geometry shown in .

[0459] An amount (constituting a total menthol content of 5 mg) of a flavor material produced according to Preparation A was disposed at a location immediately upstream of the aerosol generating element. An amount (constituting a total menthol content of 5 mg) of a flavor material produced according to Preparation A was disposed at a location along the hollow tubular element immediately downstream of the aerosol generating element. Additionally, an amount (constituting a total menthol content of 5 mg) of a flavor material produced according to Preparation A was disposed at a location within the aerosol generating substrate.

[0460] Preparation I - Aerosol-generating article comprising a flavor material produced according to Preparation A

[0461] Preparation with Figure 1 An aerosol-generating article having the overall structure and geometry shown in .

[0462] An amount of a flavor material produced according to Preparation A (constituting a total menthol content of 15 mg) was disposed at a location along the hollow tubular member immediately downstream of the aerosol generating element.

[0463] Comparative Preparation A - comprising gellan gum polysaccharide entrapped on a carrier sheet material (homogenized tobacco material) Flavor materials for menthol formulations in a matrix

[0464] 100g water is heated to about 60 degrees Celsius and in this water-bath, 3.0g gellan gum is added. The gained mixture is homogenized and heated to the temperature in the scope of 80 to 85 degrees Celsius, and kept 5 minutes at this temperature. Subsequently the mixture is cooled to the temperature in the scope of 70 to 75 degrees Celsius and in the mixture, 0.1g lecithin and 8.0g menthol are added. This flavor-containing mixture was homogenized 3 minutes. Subsequently, the gained aqueous composition is cast on the sheet material of the homogenized tobacco material without graphite particles and positioned on the metal tray, and its gelation is dried in the static oven of 65 degrees Celsius. Obtain a kind of flavor material, it comprises the layer of the gellan gum matrix that captures the menthol preparation, and this layer is fixed on the homogenized tobacco material without graphite.

[0465] Comparative Preparation B - comprising gellan gum / guar entrapped on a carrier sheet material (homogenized tobacco material) Flavor materials for menthol formulations in a gum polysaccharide matrix

[0466] 100g water is heated to about 60 degrees Celsius and 1.0g gellan gum is added to this water bath. The resulting mixture is homogenized and heated to the temperature in the range of 80 to 85 degrees Celsius, and kept at this temperature for 5 minutes. Subsequently, the mixture is cooled to the temperature in the range of 70 to 75 degrees Celsius and 0.1g lecithin and 8.0g menthol are added to the mixture. This flavor-containing mixture was homogenized for 3 minutes. Subsequently, 2.0g guar gum was added to the mixture, and then it was homogenized again for another 3 minutes. Subsequently, the gained aqueous composition is cast onto the sheet material of the homogenized tobacco material without carbon particles and on the metal tray, and its gelation is dried in the static oven of 65 degrees Celsius. Obtain a kind of flavor material, which comprises the layer of the gellan gum / guar gum matrix that captures the menthol preparation, and this layer is fixed on the homogenized tobacco material without graphite.

[0467] Morphological characterization

[0468] Figure 2 A scanning electron microscope (SEM) image of a flavor material 50 produced according to Preparation E embedded in wax is shown. As can be seen from the image, the internal structure of the flavor material includes a matrix 52 having a plurality of small pockets 54 suitable for capturing the flavor composition, the pockets 54 being dispersed in the matrix 52. The pockets are relatively evenly distributed in the material and are relatively uniform in size. The flavor material 50 also includes a carrier sheet material 56 in the form of a sheet of homogenized tobacco material containing graphite particles, which supports the matrix 52. The SEM technique cannot distinguish the graphite particles from the rest of the carrier sheet material.

[0469] Figure 3An SEM image of a flavor material 150 produced according to Preparation A embedded in wax is shown. From this image, it can be seen that the internal structure of the flavor material includes a matrix 52 having a plurality of pockets 54 suitable for capturing the flavor composition, with the pockets 54 dispersed in the matrix 52. The domains are relatively uniformly distributed in the material and are relatively uniform in size. Figure 2 Compared to the flavor material 50 of FIG. 1 , the flavor material 150 does not include a carrier sheet material supporting the matrix, and the carbon particles are embedded in the matrix structure. The SEM technique cannot distinguish the graphite particles from the rest of the matrix structure.

[0470] Thermogravimetric analysis

[0471] The flavor release profile of the flavor material produced according to the above preparation can be analyzed in a thermogravimetric analysis (TGA). The TGA test is performed using a thermogravimetric machine coupled / connected to a mass spectrometer or similar equipment. In the analysis, the flavor material is heated from 25 degrees Celsius to 400 degrees Celsius in an inert nitrogen atmosphere, wherein the temperature is increased at a rate of 15 degrees Celsius per minute with an air flow of 60 ml per minute. As the temperature is increased, the release of menthol is evaluated by detecting menthol molecules by means of specific ions representing menthol.

[0472] Data collected from TGA testing of flavor materials according to the present invention can be compared with data collected from equivalent TGA testing of a separate flavor formulation (e.g., pure menthol). One such comparison can provide some information about the release mechanism and kinetics, which can help fine-tune the flavor release profile when the flavor material is incorporated into an aerosol-generating article.

[0473] When heated in the described thermogravimetric analysis, pure menthol is released unimodally between 50°C and 166°C, with a maximum at around 138°C.

[0474] In contrast, when heated in the described thermogravimetric analysis, the flavor material produced according to Preparation E was found to provide a multimodal release of menthol. A first portion (about 57%) of the menthol was released between 62 degrees Celsius and 239 degrees Celsius, with a local maximum at about 194 degrees Celsius. A second portion (about 24%) of the menthol was released between 240 degrees Celsius and 305 degrees Celsius, with a local maximum at about 252 degrees Celsius. A third portion (about 19%) of the menthol was released between 305 degrees Celsius and 387 degrees Celsius, with a local maximum at about 344 degrees Celsius.

[0475] The release maximum of the first portion of menthol is at just below 200 degrees Celsius, which may indicate that some of the menthol preparation is dissolved or relatively weakly fixed in the flavor material. On the other hand, the release maximum of the second portion of menthol is around 250 degrees Celsius - a temperature associated with thermal degradation of gellan gum - which may support the hypothesis that a significant portion of the menthol preparation is trapped in the matrix structure and has a somewhat stronger interaction with the gellan gum in the matrix structure. The release of the third portion of menthol at even higher temperatures may indicate that the menthol preparation interacts with the guar gum in the matrix structure in a different manner.

[0476] The same TGA test was performed on a flavor material prepared according to Preparation D. It was found that the flavor material provided a bimodal release of menthol. A first small portion (about 9%) of menthol was released between about 68 degrees Celsius and about 148 degrees Celsius, with a local maximum at about 125 degrees Celsius. A second much larger significant portion (about 91%) of menthol was released between 230 degrees Celsius and 245 degrees Celsius, with a local maximum at about 242 degrees Celsius.

[0477] The release of the first portion of menthol at around 130 degrees Celsius may indicate that a small portion of the menthol preparation contained in the flavor material is not immobilized. On the other hand, the release of a larger portion of the menthol preparation contained in the flavor material at higher temperatures seems to indicate a stronger interaction with the gellan gum, which results in effective immobilization.

[0478] Comparison between the menthol release profiles of flavor materials prepared according to Preparations E and D suggests that adjusting the composition of the polysaccharide matrix - for example, using gellan gum alone or in combination with another polysaccharide - can help fine-tune flavor delivery when the flavor material is incorporated into an aerosol-generating article. In particular, it may be possible to control at what temperature the flavor release begins and around what temperature the flavor release reaches a maximum. In addition, flavor materials with different flavor release profiles (with local maxima at different temperatures) (such as flavor materials prepared according to Preparations E and D) can be combined in a single aerosol-generating article to provide consumers with an even wider range of flavor delivery options.

[0479] The same TGA test was performed on a flavor material prepared according to Comparative Preparation B, which differed from the flavor material prepared according to Preparation E only in that the sheet of carrier homogenized tobacco material did not include graphite particles. Similar to the flavor material prepared according to Preparation E, the flavor material produced according to Comparative Preparation B was found to provide a multimodal release of menthol when heated in the described thermogravimetric analysis. The first portion (about 41%) of menthol was released in the lower temperature range, and then the second portion (about 34%) and the third portion (about 25%) of menthol were released in the higher temperature intervals.

[0480] Comparison between the menthol release profiles of Preparation E and Comparative Preparation B shows that the inclusion of carbon particles in the flavor material tends to enhance the thermal release of menthol at lower temperatures. In particular, a shift of about 5 degrees Celsius toward lower temperatures was observed, with a local maximum associated with the first portion of menthol release observed at about 199 degrees Celsius for the flavor material produced according to Comparative Preparation B.

[0481] Additional testing conducted under isothermal conditions has confirmed that, especially at lower temperatures, the flavor material produced according to Preparation E releases significantly more menthol than the flavor delivery produced according to Comparative Preparation B. At 150 degrees Celsius, the flavor material produced according to Preparation E releases about 1.73 times the menthol of the flavor delivery produced according to Comparative Preparation B. At 180 degrees Celsius, the flavor material produced according to Preparation E releases about 1.5 times the menthol of the flavor delivery produced according to Comparative Preparation B. This appears to confirm that the presence of the carbon particles makes the supply of heat more efficient, presumably because they enhance heat transfer by conduction and promote a more uniform temperature distribution throughout the flavor material. As a result, a greater portion of the menthol reaches conditions for release from the flavor material more quickly.

[0482] The same TGA test described above was performed on a flavor material prepared according to Comparative Preparation A, which differed from the flavor material prepared according to Preparation D only in that graphite particles were not included in the flavor delivery material. Similar to the flavor material prepared according to Preparation D, the flavor material produced according to Comparative Preparation A was found to provide a bimodal release of menthol when heated in the described thermogravimetric analysis.

[0483] The menthol release profile of Preparation D was compared to the menthol release profile of Comparative Preparation A by plotting the cumulative amount of menthol released by each flavor material side by side. The results of this comparison indicate that the inclusion of carbon particles in the flavor material tends to enhance the thermal release of menthol. In particular, a shift of about 5 degrees Celsius or more toward lower temperatures was observed for the flavor material produced according to Preparation D. For example, 40% of the menthol contained in the flavor material produced according to Preparation D had been released when the flavor material reached 240 degrees Celsius, while the flavor material produced according to Comparative Preparation A only reached the same 40% release threshold at 245 degrees Celsius. Similarly, 60% of the menthol contained in the flavor material produced according to Preparation D had been released when the flavor material reached 243 degrees Celsius, while the flavor material produced according to Comparative Preparation A only reached the same 40% release threshold at about 249 degrees Celsius.

[0484] Thermal stability

[0485] The thermal stability of the flavor material according to the present invention under stress conditions can be evaluated by aging the flavor material at a constant temperature and monitoring its weight loss over time. To this end, samples of the flavor material cut into pieces of regular and uniform size are weighed and distributed in a series of Schott glass open bottles. The samples are aged for a period of two weeks in a laboratory oven set at 50 degrees Celsius. For the flavor material produced according to Preparation E, a weight loss of about 24% was measured at the end of the test. It is presumed that such a weight loss value includes not only some migration of flavor species, but also the loss of moisture and glycerol, and is therefore considered satisfactory.

[0486] Evaluation of flavor delivery in aerosol-generating products

[0487] Flavour delivery of aerosol-generating articles incorporating flavour materials according to the invention may be assessed by heating the aerosol-generating article in a commercially available compatible heating device and measuring the menthol delivered at the mouth end of the article per puff.

[0488] In more detail, proton transfer mass spectrometry (PTR-MS) may be used to analyze the products released per puff from an aerosol-generating article heated by a heating device.

[0489] The puff-by-puff menthol delivery of aerosol-generating articles produced according to Preparations G, H, and I was measured. The three aerosol-generating articles tested had substantially the same overall structure and geometry, and contained the same total amount of flavor material. However, the flavor material was arranged and distributed at different locations within the aerosol-generating article, and therefore, the experiment allowed the inventors to evaluate whether and how menthol release and delivery differed with the positioning of the flavor material. For aerosol-generating articles made according to Preparations G, H, and I, delivery rates of 7%, 10%, and 6% were observed, respectively.

[0490] Aerosol-generating articles made according to Preparations G and I that did not contain any flavor material at a location within the aerosol-generating substrate exhibited similar menthol delivery rates. This experimental finding demonstrates that placement of flavor materials of the type described above at a location upstream or downstream of the aerosol-generating element is associated with satisfactory flavor delivery rates during use.

[0491] The slightly higher delivery rate measured for the aerosol-generating article prepared according to Preparation H shows that arranging the flavour material at a location within the aerosol-generating substrate - in accordance with solutions known from the prior art - does contribute to the overall flavour delivery rate.

[0492] However, the fact that the aerosol-generating article prepared according to Preparation H was not superior to the aerosol-generating articles prepared according to Preparations G and I appears to indicate that incorporation of the flavor materials described herein at locations other than within the aerosol-generating matrix, particularly those flavor materials that exhibit enhanced flavor delivery at lower temperatures, may be used to adjust and customize flavor release characteristics in a manner that is not possible with aerosol-generating articles known in the art.

[0493] For the purpose of this specification and the appended claims, unless otherwise stated, all numbers indicating amounts, quantities, percentages, etc. should be understood to be modified by the term "about" in all cases. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may or may not be specifically listed herein. Therefore, in this context, the number A is understood to be A±5%A. In this context, the number A can be regarded as including a numerical value within the general standard error for the measurement of the attribute modified by the number A. In certain cases used in the appended claims, the number A may deviate from the percentages listed above, provided that the amount of A deviation does not substantially affect the basic features and novel features of the invention claimed for protection. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may or may not be specifically listed herein.

Claims

1. An aerosol-generating article for generating an aerosol upon heating, the aerosol-generating article comprising: an aerosol-generating element comprising a strip of an aerosol-generating substrate defined by a wrapper; a downstream section disposed immediately downstream of the aerosol-generating element and extending from a downstream end of the aerosol-generating element to a downstream end of the aerosol-generating article; as well as an upstream section disposed immediately upstream of the aerosol-generating element and extending from an upstream end of the aerosol-generating element to an upstream end of the aerosol-generating article; wherein the aerosol-generating article comprises a flavor material disposed in at least one of the downstream section, the upstream section, and the wrapper defining the strip of the aerosol-generating substrate; wherein the flavor material comprises: a polysaccharide matrix structure comprising gellan gum and an emulsifier; and a flavor formulation dispersed within the polysaccharide matrix structure, wherein the flavor formulation is at least partially entrapped within the polysaccharide matrix structure and is releasable from the polysaccharide matrix structure upon heating of the flavor material.

2. An aerosol-generating article according to claim 1, wherein the downstream section comprises a hollow tubular element disposed immediately downstream of the aerosol-generating element, the upstream end of the hollow tubular element being adjacent to the downstream end of the aerosol-generating element; wherein the flavor material is disposed in the hollow tubular element.

3. An aerosol-generating article according to claim 1, wherein the upstream section comprises an upstream element disposed immediately upstream of the aerosol-generating element, a downstream end of the upstream element being adjacent to an upstream end of the aerosol-generating element; wherein the flavor material is disposed in the upstream element.

4. An aerosol-generating article according to any one of claims 1 to 3, wherein the polysaccharide matrix structure comprises gellan gum as the sole polysaccharide or a combination of gellan gum and at least one other polysaccharide selected from guar gum, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose and hydroxypropyl methylcellulose; wherein the gellan gum preferably constitutes 5% to 99.9% by weight of the flavor material on a dry weight basis.

5. An aerosol-generating article according to any one of claims 1 to 4, further comprising a n H 2n+2 O n The polyol is preferably selected from glycerol, sorbitol, xylitol, mannitol and erythritol, or wherein the polyol preferably accounts for 0.01 wt % to 20 wt % of the flavor material on a dry weight basis, or both.

6. An aerosol-generating article according to any preceding claim, further comprising fibres, wherein the fibres preferably comprise from 0.01 wt% to 10 wt% of the flavouring material on a dry weight basis.

7. An aerosol-generating article according to any one of the preceding claims, wherein the flavour material further comprises a carrier material, wherein the polysaccharide matrix structure and the flavour formulation are supported by the carrier material, wherein the carrier material is preferably a sheet of homogenised tobacco material or a sheet of stick paper wrapper material.

8. An aerosol-generating article according to any one of the preceding claims, comprising a ventilation zone at a position along the hollow tubular element, the ventilation zone being configured to enable air to enter the axial lumen of the hollow tubular element.

9. An aerosol-generating article according to any one of the preceding claims, wherein the upstream element comprises a rod extending to and defining the distal end of the aerosol-generating article, the flavour material being provided at a position within the rod.

10. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating substrate comprises tobacco material.

11. An aerosol-generating article according to claim 10, wherein the tobacco material comprises a sheet of homogenised tobacco material or one or more of tobacco cut filler, cut reconstituted tobacco and cut homogenised tobacco material.

12. An aerosol generating 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, wherein the aerosol-generating device comprises a housing defining a cavity configured to receive the aerosol-generating article.

13. An aerosol-generating system according to 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. An aerosol generating system according to claim 12, wherein the aerosol generating article includes a sensor element arranged at a position within the aerosol generating element; and wherein the aerosol generating device includes an inductor coil positioned on or within the shell, and a power source connected to the inductor coil and configured to provide a high-frequency oscillating current to the inductor coil.

15. An aerosol generating system according to claim 12, wherein the aerosol generating device includes a heater element, which is positioned around the periphery of the cavity and is configured to heat the aerosol generating substrate of the aerosol generating article from the outside of the aerosol generating element of the aerosol generating article.

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