Flavor materials with controlled heat release for use in aerosol-generating articles

Abstract

A flavor material (50) for use in an aerosol-generating article, the flavor material comprising: a polysaccharide matrix structure; and a flavor formulation dispersed within the polysaccharide matrix structure, wherein the aerosol-generating 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. The flavor material comprises more than 0.1% by weight of an additive selected from the group consisting of polycarboxylic acids, bicarbonate functional group-containing salts, and mixtures thereof. An aerosol-generating article (10) comprising one such flavor material (50) is also provided.

Description

[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.

[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] 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 somewhere in the mouthpiece filter or in the tobacco cut filler rod.

[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]

[0006] Accordingly, there is a need to provide flavour materials, and aerosol-generating articles containing flavour materials, that are associated with enhanced flavour perception by consumers, particularly towards the end of the life cycle of the aerosol-generating article.

[0008] The present disclosure relates to a flavor material for use in an aerosol generating article, wherein a flavor formulation can be released from the flavor material upon heating the flavor material. The flavor material can include a matrix structure and a flavor formulation dispersed within the matrix structure. The flavor formulation is at least partially captured within the matrix structure and can be released from the matrix structure upon heating the flavor material. The matrix structure can be a polysaccharide matrix structure. The flavor material can include greater than 0.1% by weight of an additive selected from a polycarboxylic acid, a salt containing a bicarbonate functional group, and mixtures thereof.

[0009] According to a first aspect of the present invention, there is provided a flavor material for use in an aerosol generating article; the flavor material comprising: a polysaccharide matrix structure; and a flavor preparation dispersed within the polysaccharide matrix structure. 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. The flavor material comprises greater than 0.1% by weight of an additive selected from a polycarboxylic acid, a salt containing a bicarbonate functional group, and mixtures thereof.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] It has been found that the inclusion of additives selected from the above group in the flavour material according to the 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.

[0023] 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.

[0024] Thus, according to the present invention, the improved flavour release provided by the flavour material may also allow a heater configured to supply heat to an aerosol-generating article incorporating the flavour material to operate at a lower temperature and therefore require less power during use.

[0025] By adjusting the content of the additive or by selecting a particular additive or both, it may be advantageous to further control the flavor release profile. In fact, it has been found that including a greater amount of additive in the flavor material generally results in a more significant shift of the flavor release profile towards lower temperatures.

[0026] 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 flavour release profile of a flavour material of an aerosol-generating article containing the flavour material.

[0027] 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 by adjusting the relative proportions of the various ingredients in the formulation or by changing the composition of the substrate (e.g., by selecting a combination of certain polysaccharides to form the substrate), or by doing both, certain properties of the flavor material can be advantageously finely tailored 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 may perceive the flavor note more intensely or for a longer period of time during use. Thus, the flavor material according to the present invention can provide a wider width of the flavor profile that is not obtainable with known flavor materials.

[0028] When flavour materials according to the present invention are incorporated into an aerosol-generating article, such as a heat-not-burn article configured to generate an aerosol upon heating a tobacco-containing aerosol-generating substrate, it has been found that the puff-by-puff flavour release is generally more effective.

[0029] Because the flavor preparation is at least partially trapped within the matrix prior to release upon heating, the flavor material according to the present invention has been found to exhibit increased stability. For example, even under stress conditions, a significant reduction in the loss of flavor species during storage, transportation, etc. has been observed. Coupled with the enhanced flavor release at lower temperatures, this makes the use of flavors and other ingredients of the flavor preparation particularly efficient.

[0030] As briefly described above, the flavor material according to the present invention contains more 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 a mixture thereof.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] For example, these additives may begin to thermally decompose at least 5 degrees Celsius lower than the thermal decomposition temperature of the one or more polysaccharides forming the matrix structure. Preferably, these additives may begin to thermally decompose at least 10 degrees Celsius lower than the thermal decomposition temperature of the one or more polysaccharides forming the matrix structure. More preferably, these additives may begin to thermally decompose at least 15 degrees Celsius lower than the thermal decomposition temperature of the one or more polysaccharides forming the matrix structure. Even more preferably, these additives may begin to thermally decompose at least 20 degrees Celsius lower than the thermal decomposition temperature of the one or more polysaccharides forming the matrix structure.

[0038] Polycarboxylic acids suitable for use as additives in the flavor material according to the present invention include, but are not limited to, tartronic acid and malonic acid.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] In some embodiments, the additives comprise 0.25% to 25% by weight of the flavor material on a dry weight basis, preferably 0.25% to 20% by weight of the flavor material on a dry weight basis, more preferably 0.25% to 15% by weight of the flavor material on a dry weight basis, and even more preferably 0.25% to 10% by weight of the flavor material on a dry weight basis.

[0043] In other embodiments, the additives comprise 0.5 to 25% by weight of the flavor material on a dry weight basis, preferably 0.5 to 20% by weight of the flavor material on a dry weight basis, more preferably 0.5 to 15% by weight of the flavor material on a dry weight basis, and even more preferably 0.5 to 10% by weight of the flavor material on a dry weight basis.

[0044] In a further embodiment, the additive accounts for 1.0 wt % to 25 wt % of the flavor material on a dry weight basis, preferably 1.0 wt % to 20 wt % of the flavor material on a dry weight basis, more preferably 1.0 wt % to 15 wt % of the flavor material on a dry weight basis, and even more preferably 1.0 wt % to 10 wt % of the flavor material on a dry weight basis.

[0045] 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.

[0046] This is advantageous because the structural strength of the flavor material is improved by the carrier material providing a support function. From a manufacturing perspective, this may be particularly beneficial because access to the flavor material enhanced by the carrier material will generally be easier.

[0047] 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. The purposes of the homogenized tobacco material for the manufacture of flavor material according to the present invention will be described in more detail below.

[0048] Embodiments in which the carrier material is a carrier sheet material also have the advantage that the polysaccharide matrix structure and the flavor formulation entrapped therein can be deposited onto the carrier sheet material to form a flavor material that is actually in sheet form as a whole 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 combine the flavor material with an aerosol-generating substrate in certain aerosol-generating articles, as will be described in more detail below.

[0049] In other embodiments, the carrier material may include a plurality of fragments cut from a sheet material, the fragments having a predetermined average size (e.g., a predetermined cut width or a predetermined cut length or both). As an alternative, the carrier material may include a plurality of fragments cut from naturally occurring plant material, preferably plant leaf material (e.g., tobacco leaves). In some embodiments, the carrier material may be tobacco cut filler.

[0050] In all embodiments of the flavor material comprising a carrier material, the polysaccharide matrix structure of the flavor-trapping formulation may be formed in situ on the carrier material. The in situ forming step may even be performed at a later date or at a different location if the in situ forming step is performed after the manufacturing process from which the carrier material is obtained.

[0051] The use of a carrier sheet material to support the polysaccharide matrix structure and entrapped flavor formulation may have the additional benefit that, by selecting and adjusting certain properties of the carrier sheet material (e.g., its thickness), a flavor material that is more easily formed into a barrel may be obtained, and thus the flavor material may be more easily handled and handled when incorporated into an aerosol-generating article. The increased structural strength provided by the carrier sheet material may be particularly beneficial in view of high-speed automated manufacturing processes.

[0052] As mentioned previously, in some preferred embodiments the carrier sheet material may be in the form of a sheet of homogenised tobacco material.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] Preferred aerosol formers are polyols or mixtures thereof such as propylene glycol, triethylene glycol, 1,3-butylene glycol and most preferably glycerol.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] In a preferred embodiment, the sheet of homogenised tobacco material has an aerosol former content of about 20% by dry weight.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] Preferably, the polysaccharide matrix structure comprises gellan gum and an emulsifier. 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] In certain embodiments, the polysaccharide matrix structure comprises gellan gum as the only polysaccharide.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] Flavours suitable for inclusion in the flavour formulation of the flavour material according to the present invention include, but are not limited to:

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] In a preferred embodiment, the flavor preparation comprises menthol.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] The Hansen solubility parameters provide a model for estimating the mutual affinity in any given flavor / solvent pairing.

[0111] 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:

[0112] δ 2 =(δ d ) 2 +(δ p ) 2 +(δ h ) 2

[0113] 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 aProvides an indication of the affinity between two molecules and is calculated based on the formula:

[0114] (R a ) 2 =4(δ d2 -δ d1 ) 2 +(δ p2 –δ p1 ) 2 +(δ h2 –δ h1 ) 2

[0115] Generally, it is understood that the lower the R a Values ​​indicate higher affinity for a given flavor / solvent pairing.

[0116] 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.

[0117] 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 consistently result in flavor materials with particularly good flavor stability during storage. On this basis, the 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 certain embodiments, the flavor material further comprises greater than 0.1% by weight of carbon particles having a volume average particle size greater than 10 microns.

[0118] It has been found that the inclusion of carbon-based materials (such as graphite, expanded graphite, graphene, etc.) in the flavor material 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.

[0119] Thus, the carbon particles and additives may work synergistically to enhance the release of flavor species at lower temperatures compared to flavor materials without both carbon particles and additives and compared to embodiments of flavor materials according to the present invention that do not include carbon particles.

[0120] 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.

[0121] The improved flavor species release provided by embodiments of flavor materials according to the present invention comprising carbon particles as described 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.

[0122] By adjusting the amount and size of the carbon particles within the ranges described in more detail below, the flavor release enhancement can be controlled and fine-tuned. For example, a relatively narrow particle size distribution can provide a flavor delivery material that is more uniform in thermal conductivity. This can mean that, during use, temperature gradients in the flavor delivery material of the aerosol-generating article that are exposed to different parts of the same heating curve are minimized.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] Preferably, the carbon particles have a volume average particle size of 30 microns to 150 microns.

[0127] 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.

[0128]

[0129] 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.

[0130] 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.

[0131] In embodiments where the carbon particles are contained within a carrier sheet material supporting a polysaccharide structure that captures the flavor formulation, particles in this size range can also be more easily mixed with particles of similar size used to make the carrier sheet material, such as in the case of sheets of homogenized tobacco material or other plant material.

[0132] 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.

[0133] 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.

[0134] 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,

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] Surprisingly, the inventors have found that these relatively small particle size ranges are particularly effective in increasing the thermal conductivity of flavor materials according to the present invention, particularly in those embodiments in which the flavor material comprises a carrier sheet material supporting a polysaccharide matrix that captures the flavor formulation. In addition, these relatively small particle sizes can advantageously result in a carrier sheet material that is more uniform in thermal conductivity and in a carrier sheet material having a more uniform thickness than if larger particle sizes were used. Particles within this size range can also be more easily mixed with similarly sized particles used in some manufacturing processes for forming carrier sheet materials.

[0147] 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.

[0148] It may be particularly preferred that the carbon particles have a volume average particle size greater than 10 microns.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] It may be particularly preferred if the thermally conductive particles are or contain graphite particles.

[0153] 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.

[0154] It may be particularly preferred if the thermally conductive particles are or contain expanded graphite particles.

[0155] 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.

[0156] 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.

[0157] The carbon particles may include at least 10, 20, 50, 100, 200, 500, or 1000 particles.

[0158] 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.

[0159] In some embodiments, the flavor material further comprises a compound having formula C n H 2n+2 O n of polyols.

[0160] 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.

[0161] Preferred polyols for inclusion in the flavoring material according to the present invention include glycerol, sorbitol, xylitol, mannitol and erythritol.

[0162] 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.

[0163] 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.

[0164] In some embodiments, the flavor material comprises fibers, preferably cellulose fibers. The incorporation of fibers, especially cellulose fibers, can advantageously improve the tensile strength of the flavor material, particularly when it is provided in sheet form. This will facilitate the manufacturing process of both the flavor material itself and the aerosol-generating article comprising the flavor material. This benefit can be particularly felt in those embodiments in which the polysaccharide matrix entrapping the flavor formulation is not supported by a carrier material.

[0165] In the flavor material embodiment comprising cellulose fibers, the cellulose fibers may account for at least 0.01% by weight of the flavor material on a dry weight basis. 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.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] Provide Ca 2+ Ion or Mg 2+ ions or both can be beneficial [any benefit?]

[0172] 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.

[0173] In embodiments where the flavor material comprises citrate, the citrate comprises 0.01 wt% to 5 wt% on a dry weight basis. Preferably, the citrate comprises 0.01 wt% to 1 wt% on a dry weight basis.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] The flavouring material according to the invention can be prepared by different routes.

[0180] A method for producing a flavor material according to the present invention may include a first step of preparing an aqueous composition comprising a flavor preparation, a polysaccharide, an emulsifier and an additive selected from a polycarboxylic acid, a salt containing a bicarbonate functional group and a mixture thereof; a second step of casting the aqueous composition on a substantially flat support surface; a third step of gelling the aqueous composition 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.

[0181] Another method of manufacturing flavor delivery according to the present invention may include a first step of preparing an aqueous composition comprising a flavor formulation, a polysaccharide, an emulsifier and an additive selected from the group consisting of a polycarboxylic acid, a salt containing a bicarbonate functional group and mixtures thereof; a second step of casting the aqueous composition on a carrier sheet material located on a substantially flat support surface; a third step of allowing the aqueous composition to gel on the carrier sheet material; and a fourth step of drying the gelled aqueous composition and the carrier sheet material. The dried flavor material wherein the carrier sheet material supports the polysaccharide matrix entrapping the flavor formulation may then be removed from the support surface.

[0182] Yet another method of manufacturing flavor delivery according to the present invention may include a first step of preparing an aqueous composition comprising a flavor formulation, a polysaccharide, an emulsifier, and an additive selected from a polycarboxylic acid, a salt containing a bicarbonate functional group, and mixtures thereof; 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 allowing the aqueous composition to gel 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.

[0183] The present disclosure relates to an aerosol generating article comprising a flavor material, wherein a flavor formulation can be released from the flavor material upon heating the flavor material. The flavor material can include a matrix structure and a flavor formulation dispersed within the matrix structure. The flavor formulation is at least partially captured within the matrix structure and can be released from the matrix structure upon heating the flavor material. The matrix structure can be a polysaccharide matrix structure. The flavor material can include greater than 0.1% by weight of an additive selected from a polycarboxylic acid, a salt containing a bicarbonate functional group, and mixtures thereof.

[0184] According to another aspect of the present invention, an aerosol generating article comprising a flavor material is provided, wherein a flavor is releasable from the flavor material upon heating the flavor delivery material. The flavor material comprises a polysaccharide matrix structure; and a flavor formulation dispersed within the polysaccharide matrix structure. The flavor formulation is captured within the polysaccharide matrix structure and is releasable from the polysaccharide matrix structure upon heating the flavor material. 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.

[0185] As will be apparent from the foregoing description of flavor materials according to the present invention, by incorporating such a flavor material in an aerosol-generating article, a range of new aerosol-generating articles can be advantageously provided that are capable of delivering flavor to a consumer in a more easily 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 enhanced flavor release at lower temperatures, this makes the use of flavors and other ingredients of the flavor formulation particularly efficient.

[0186] Aerosol-generating articles according to the present invention have been found to provide a more efficient release of flavour species during use compared to corresponding aerosol-generating articles containing corresponding flavour materials as described above without additives.

[0187] In particular, in certain embodiments, it has been observed that the release of flavor species remains consistently high and varies less dramatically from one puff to the next.

[0188] In certain embodiments, in aerosol-generating articles according to the present invention, the flavour material further comprises a carrier sheet material, wherein the polysaccharide matrix structure and the flavour formulation are supported by the carrier sheet material.

[0189] The carrier sheet material provides support for the polysaccharide matrix structure that entraps the flavour formulation and therefore, by adjusting the composition and geometry of the carrier sheet material, the manufacture of the aerosol-generating article may be facilitated.

[0190] In certain embodiments, the aerosol-generating article comprises a strip of aerosol-generating substrate; a downstream segment disposed downstream of the strip of aerosol-generating substrate and extending to a mouth end of the aerosol-generating article; and optionally, an upstream segment disposed downstream of the strip of aerosol-generating substrate and extending to a distal end of the aerosol-generating article. The flavor material is disposed in at least one of the strip of aerosol-generating substrate, the downstream segment, and the optional upstream segment.

[0191] Where the flavour material comprises a carrier sheet material as described above, the carrier sheet material may be a sheet of homogenised tobacco material. In these embodiments, the aerosol-generating article may comprise a rod of aerosol-generating substrate; a downstream section disposed downstream of the rod of aerosol-generating substrate and extending to the mouth end of the aerosol-generating article; optionally, an upstream section disposed downstream of the rod of aerosol-generating substrate and extending to the distal end of the aerosol-generating article; and the flavour material may be disposed in the rod of aerosol-generating substrate.

[0192] Incorporation of flavour materials according to the present invention into aerosol-generating articles may be carried out according to one of several routes.

[0193] For example, fragments of flavour material may be mixed with solid particles of aerosol-generating material, such as cut tobacco, to form a rod of an aerosol-generating substrate for an aerosol-generating article.

[0194] Alternatively or additionally, the fragments of flavor material may be disposed at other locations within the aerosol-generating article, such as along a downstream section of the aerosol-generating article. The downstream section of the aerosol-generating article may comprise a plurality of components, and thus, the flavor material may be incorporated into any of such components.

[0195] As a further alternative, the flavour material comprising the carrier sheet material in the form of a paper wrapper may be used alone or in combination with another paper wrapper as a stick wrapper for a strip of an aerosol-generating article.

[0196] This list of possible arrangements is not intended to be exhaustive, and it will be apparent that different placements of the flavour material in the aerosol-generating article may be possible, provided that the flavour material is supplied with sufficient heat during use of the aerosol-generating article to release the flavour formulation from the polysaccharide matrix.

[0197] The aerosol-generating article containing a flavor material according to the present invention can be used in combination with an aerosol-generating device, such as a handheld electric heater configured to supply heat to the aerosol-generating article in a controlled manner. In this way, by heating the aerosol-generating substrate and the flavor material, a flavor-enriched aerosol can be delivered to the consumer.

[0198] Therefore, the aerosol generating article according to the present invention is particularly applicable in an aerosol generating system, which comprises an aerosol generating device, the aerosol generating device having a heating chamber, the aerosol generating article being received in the heating chamber so that heat can be supplied to the aerosol generating substrate. This can be achieved by providing one or more heating elements arranged around the periphery of the heating chamber, the one or more heating elements being resistively heated or inductively heated. Alternatively, this can also be achieved by a resistively heated blade-shaped component of the aerosol generating device, which blade-shaped component is inserted into the aerosol generating substrate when the aerosol generating article is inserted into the heating chamber.

[0199] According to yet another alternative, a susceptor element may be provided within the aerosol-generating substrate, and the aerosol-generating device may have an inductor for generating an alternating or fluctuating electromagnetic field. When the aerosol-generating article is engaged with the aerosol-generating device, the fluctuating electromagnetic field generated by the inductor induces a current in the susceptor element, thereby causing the susceptor element to heat up. An electrically operated 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.

[0200] 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.

[0201] Example Ex1: A flavor material for use in an aerosol-generating article, the flavor material comprising: a polysaccharide matrix structure; a flavor preparation dispersed in the polysaccharide matrix structure, wherein the flavor preparation is at least partially captured in the polysaccharide matrix structure and can be released from the polysaccharide matrix structure when the flavor material is heated; and greater than 0.1% by weight of an additive selected from a polycarboxylic acid, a salt containing a bicarbonate functional group, and a mixture thereof.

[0202] Example Ex2: A flavour material according to example Ex1, wherein the additive is thermally decomposed at a temperature below 220 degrees Celsius at 1 bar.

[0203] Example Ex3: The flavor material according to example Ex1 or Ex2, wherein the additive begins to thermally decompose at a temperature at least 5 degrees Celsius lower than the thermal decomposition temperature of the polysaccharide forming the matrix structure.

[0204] Example Ex4: The flavor material according to any one of Examples Ex1 to Ex3, wherein the additive comprises one or more of tartronic acid, malonic acid, citric acid, sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, calcium bicarbonate, and ammonium bicarbonate.

[0205] Example Ex5: The flavor material according to any one of the preceding examples, wherein the additive accounts for less than or equal to 25% by weight of the flavor material on a dry weight basis.

[0206] Example Ex6: The flavor material according to any one of the preceding examples, wherein the additive accounts for less than or equal to 10% by weight of the flavor material on a dry weight basis.

[0207] Example Ex7: The flavor material according to any one of the preceding examples, wherein the additive accounts for at least 1% by weight of the flavor material on a dry weight basis.

[0208] Example Ex8: The flavor material according to any one of Examples Ex1 to Ex7, further comprising a carrier material, wherein the polysaccharide matrix structure, the flavor preparation and the additive are supported by the carrier material.

[0209] Example Ex9: The flavor material according to any one of Examples Ex1 to Ex8, 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.

[0210] Example Ex10: The flavor material according to Example Ex9, wherein the gellan gum accounts for 5 wt% to 99.9 wt% of the flavor material on a dry weight basis.

[0211] Example Ex11: The flavor material according to any one of Examples Ex1 to Ex10, wherein the flavor material further comprises a compound having formula C n H 2n+2 O n of polyols.

[0212] Example Ex12: The flavor material according to example Ex11, wherein the polyol is selected from glycerol, sorbitol, xylitol, mannitol and erythritol.

[0213] Example Ex13: The flavor material according to example Ex11 or Ex2, wherein the polyol accounts for 0.01 wt% to 20 wt% of the flavor material on a dry weight basis.

[0214] Example Ex14: The flavor material according to any one of the preceding examples, further comprising greater than 0.1% by weight of carbon particles, the carbon particles having a volume average particle size greater than 10 microns.

[0215] Example Ex15: The flavor material according to example Ex14, wherein the carbon particles consist of one or more of the following: graphite particles, expanded graphite particles, and graphene particles.

[0216] Example Ex16: The flavor material according to example Ex14 or Ex15, wherein the carbon particles have a volume average particle size of 30 microns to 150 microns.

[0217] Example Ex17: The flavor material according to any one of Examples Ex14 to Ex16, wherein the carbon particles have a particle size distribution having a D90 particle size and a D10 particle size, wherein the D90 particle size is not greater than 25 times or 15 times the D10 particle size.

[0218] Example Ex18: The flavor material according to any one of Examples Ex14 to Ex17, wherein the carbon particles account for 0.01 wt% to 10 wt% of the flavor material on a dry weight basis.

[0219] Example Ex19: The flavor material according to any one of the preceding examples, further comprising fiber.

[0220] Example Ex20: The flavor material according to Example 20, wherein the fiber accounts for 0.01 wt% to 10 wt% of the flavor material on a dry weight basis.

[0221] Example Ex21: The flavor material according to any one of the preceding examples, comprising 0.01 wt% to 80 wt% of menthol.

[0222] Example Ex22: The flavor material according to any one of examples Ex8 to Ex21, wherein the carrier sheet material is a sheet of homogenized tobacco material.

[0223] Example Ex23: An aerosol-generating article comprising a flavor material according to any one of Examples Ex1 to Ex22.

[0224] Example Ex24: An aerosol generating article according to Example Ex23, the aerosol generating article comprising: a strip of an aerosol generating substrate; a downstream section arranged downstream of the strip of the aerosol generating substrate and extending to the mouth end of the aerosol generating article; optionally, an upstream section arranged downstream of the strip of the aerosol generating substrate and extending to the distal end of the aerosol generating article; wherein the flavor material is arranged in at least one of the strip of the aerosol generating substrate, the downstream section and the optional upstream section.

[0225] Example Ex25: An aerosol generating article according to Example Ex23, when according to any one of Examples Ex8 to Ex22, wherein the carrier material is a sheet of homogenized tobacco material or a tobacco cut filler; wherein the aerosol generating article comprises: a strip of an aerosol generating substrate; a downstream section arranged downstream of the strip of the aerosol generating substrate and extending to the mouth end of the aerosol generating article; optionally, an upstream section arranged downstream of the strip of the aerosol generating substrate and extending to the distal end of the aerosol generating article; wherein the flavor material is arranged in the strip of the aerosol generating substrate.

[0226] Several examples will now be further described with reference to the accompanying drawings, in which:

[0227] Figure 1 shows a schematic side cross-sectional view of an aerosol-generating article comprising a flavour material in a rod of an aerosol-generating substrate according to the present invention; and

[0228] Figure 2 Shown in Figure 1 Scanning electron microscope image of a flavor material used in an aerosol-generating article.

[0229] 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 comprises a strip 12 of aerosol-generating substrate and a downstream section 14 at a position downstream of the strip 12 of aerosol-generating substrate. Furthermore, the aerosol-generating article 10 comprises an upstream section 16 at a position upstream of the strip 12 of aerosol-generating substrate.

[0230] The ventilation zone 60 is provided at a location downstream of the strip 12 of aerosol-generating substrate.

[0231] In more detail, Figure 1In 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 strip 12 of aerosol-generating substrate. Figure 1 As shown in the figure, the upstream end of the aerosol-cooling element 22 is adjacent to the downstream end of the strip of aerosol-generating substrate 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.

[0232] The rod 12 comprises an aerosol-generating substrate 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.

[0233] 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.

[0234] Furthermore, the aerosol-generating article comprises a flavour material 50. In more detail, a plurality of fragments of flavour material in sheet form are dispersed within the rod 12. The flavour material 50 is of the type described in detail above.

[0235] Examples of suitable formulations for the flavor material 50 and methods for forming the flavor material 50 are set forth below.

[0236] Preparation A - Flavor delivery of a formulation comprising menthol entrapped in a gellan gum polysaccharide matrix + 5 wt% additives Material

[0237] 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, 1.2g tartronic acid 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 rich in additives is obtained in the form of a sheet.

[0238] Preparation B - Flavor delivery of a formulation comprising menthol entrapped in a gellan gum polysaccharide matrix + 10 wt% additives Material

[0239] 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, 2.4g tartronic acid 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 rich in additives is obtained in the form of a sheet.

[0240] Preparation C - Containing a polysaccharide matrix of gellan gum entrapped on a carrier sheet material (homogenized tobacco material) Flavor delivery material of menthol formulation + 5 wt% additives

[0241] 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, 1.2g tartaric acid and 8.0g menthol are added. This mixture containing flavor is homogenized 3 minutes. Subsequently, the gained aqueous composition is cast on the sheet material of the homogenized tobacco material on the metal tray, and its gelation is dried in the static oven of 65 degrees Celsius. Obtain a kind of flavor material that is rich in additives, it comprises the layer of the gellan gum matrix that captures the menthol preparation, and this layer is fixed on the sheet material of the homogenized tobacco material.

[0242] Comparative Preparation - Flavor Delivery of Formulations Comprising Menthol Encapsulated in a Gellan Gum Polysaccharide Matrix Without Additives Material

[0243] 100g of water is heated to about 60 degrees Celsius and 3.0g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80 to 85 degrees Celsius and kept at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70 to 75 degrees Celsius and 0.1g of lecithin and 8.0g of 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 without additives is obtained in the form of a sheet.

[0244] Preparation D - Aerosol-generating article comprising a flavor delivery material produced according to Preparation A

[0245] An amount (consisting of 5 mg of total menthol content) of the flavor delivery material produced according to Preparation A was added to a strip of a commercial aerosol-generating article (produced by Philip Morris Products SA). )middle.

[0246] Morphological characterization

[0247] Figure 2 An SEM image of a flavor delivery 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 delivery material includes a matrix 52 having a plurality of pockets 54 suitable for capturing the flavor composition, the pockets 54 being dispersed in the matrix 52. The domains are relatively uniformly distributed in the material and are relatively uniform in size. The SEM technique cannot distinguish the additive from the rest of the matrix structure, and the additive is understood to be dispersed therein in a generally uniform manner.

[0248] Thermogravimetric analysis

[0249] 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 connected to a mass spectrometer or similar TGA 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 rate 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.

[0250] 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.

[0251] To provide a comparative reference, pure menthol in liquid form was also heated in the above thermogravimetric analysis. A single peak release of pure menthol was observed between 50 degrees Celsius and 166 degrees Celsius, with a maximum at around 138 degrees Celsius.

[0252] The menthol release profiles of the flavor materials produced according to Preparations A and B were compared to the menthol release profile of the flavor material produced according to the Comparative Preparation by plotting the cumulative amount of menthol released by each flavor material side by side.

[0253] The results of this comparison show that including additives in the flavor material tends to enhance the thermal release of menthol at lower temperatures. The comparatively prepared flavor material only starts to significantly release menthol above 230 degrees Celsius, and when the temperature approaches 300 degrees Celsius, almost all of the menthol content has been released.

[0254] In contrast, the Preparation A flavor material containing 5 wt% tartronic acid appears to release a first portion of its menthol content between 90 degrees Celsius and 150 degrees Celsius and a second portion of its menthol content between 160 degrees Celsius and 250 degrees Celsius.

[0255] The Preparation B flavor material containing 10 wt% tartronic acid also appears to begin releasing menthol at around 90 degrees Celsius, but then releases the remainder of its menthol content at a significantly higher rate, with most of the menthol having been released by the time the temperature reaches about 180 degrees.

[0256] Interestingly, from a qualitative point of view, the cumulative menthol release profile of the preparation B flavor material was found to be similar to that of pure menthol, but was offset by about 20 to 30 degrees Celsius toward higher temperatures. In contrast, the cumulative menthol release profile of the preparation A flavor material showed that at lower temperatures, its behavior was generally consistent with the preparation B flavor material, while at higher temperatures, its behavior deviated from the preparation B flavor material because it provided a delayed and more gradual release of the remainder of the menthol. Without wishing to be bound by theory, this may indicate that a larger amount of the additive (malonic acid) in the flavor material can destroy the matrix structure, so that the matrix structure no longer fixes menthol at a temperature of 140 degrees or higher. On the other hand, a smaller amount of the additive (malonic acid) causes some destruction of the matrix structure, whereby menthol release begins at a lower temperature, but some residual integrity of the matrix structure is retained, and therefore, some menthol remains fixed until a higher temperature is reached.

[0257] Comparison between the menthol release profiles of flavor materials prepared according to Preparations A and B and the comparative preparations shows that adjusting the amount of additive in the flavor material can help fine-tune the 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 having different flavor release profiles when exposed to the same heating profile (such as flavor materials prepared according to Preparations A and B) can be combined in a single aerosol-generating article to provide consumers with an even wider range of flavor delivery options.

[0258] 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. A flavor material for use in an aerosol-generating article, the flavor material comprising: Polysaccharide matrix structure; 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; as well as Greater than 0.1% by weight of an additive selected from the group consisting of polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof.

2. The flavor material according to claim 1, wherein the additive thermally decomposes at a temperature below 220 degrees Celsius at 1 bar.

3. The flavor material according to claim 1 or 2, wherein the additive begins to thermally decompose at a temperature at least 5 degrees Celsius lower than the thermal decomposition temperature of the polysaccharide forming the matrix structure.

4. The flavor material according to any one of claims 1 to 3, wherein the additive comprises one or more of tartronic acid, malonic acid, citric acid, sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, calcium bicarbonate, and ammonium bicarbonate.

5. The flavor material according to any one of the preceding claims, wherein the additive comprises less than or equal to 25% by weight of the flavor material on a dry weight basis, preferably wherein the additive comprises less than or equal to 10% by weight of the flavor material on a dry weight basis or wherein the additive comprises at least 1% by weight of the flavor material on a dry weight basis or both.

6. The flavor material according to any one of claims 1 to 5, further comprising a carrier material, wherein the polysaccharide matrix structure, the flavor formulation and the additives are supported by the carrier material, preferably a sheet of homogenized tobacco material.

7. The flavor material according to any one of claims 1 to 6, 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 accounts for 5% to 99.9% by weight of the flavor material on a dry weight basis.

8. The flavor material according to any one of claims 1 to 7, further comprising a compound having the formula C n H 2n+2 O n The polyol is preferably selected from glycerol, sorbitol, xylitol, mannitol and erythritol, or wherein the polyol accounts for 0.01 wt % to 20 wt % of the flavor material on a dry weight basis, or both.

9. A flavour material according to any one of the preceding claims, further comprising greater than 0.1 wt% carbon particles having a volume average particle size greater than 10 microns, preferably a volume average particle size of 30 to 150 microns.

10. The flavor material according to claim 9, wherein the carbon particles consist of one or more of the following: Graphite particles, expanded graphite particles and graphene particles, the carbon particles preferably account for 0.01 wt% to 10 wt% of the flavor material on a dry weight basis.

11. The flavor material according to claim 9 or 10, wherein the carbon particles have a particle size distribution having a D90 particle size and a D10 particle size, wherein the D90 particle size is not greater than 25 times or 15 times the D10 particle size.

12. A flavour material according to any preceding claim, further comprising fibres, wherein the fibres preferably constitute 0.01 wt% to 10 wt% of the flavour material on a dry weight basis.

13. An aerosol-generating article comprising a flavour material according to any one of claims 1 to 12.

14. An aerosol-generating article according to claim 13, comprising: strips of aerosol-generating substrate; a downstream section disposed downstream of the strip of aerosol-generating substrate and extending to the mouth end of the aerosol-generating article; Optionally, an upstream section disposed downstream of the strip of aerosol-generating substrate and extending to a distal end of the aerosol-generating article; Wherein the flavour material is provided in at least one of the stripe, the downstream section and, optionally, the upstream section of the aerosol-generating substrate.

15. An aerosol-generating article according to claim 13 when dependent on any one of claims 6 to 12, wherein the carrier material is a sheet of homogenised tobacco material or tobacco cut filler; wherein the aerosol-generating article comprises: strips of aerosol-generating substrate; a downstream section disposed downstream of the strip of aerosol-generating substrate and extending to the mouth end of the aerosol-generating article; Optionally, an upstream section disposed downstream of the strip of aerosol-generating substrate and extending to a distal end of the aerosol-generating article; Wherein the flavour material is disposed in a strip of the aerosol-generating substrate.

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