Flavour material with controlled heat release for use in aerosol-generating articles - Patent Application 20070122999

Abstract

A flavoring material (50) for use in an aerosol-generating article, the flavoring material comprising a polysaccharide matrix structure and a flavorant formulation dispersed within the polysaccharide matrix structure, the aerosol-generating formulation being at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavoring material. The flavoring material comprises greater than 0.1 weight percent of an additive selected from the group consisting of polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof. Also provided is an aerosol-generating article (10) comprising one such flavoring material (50).

Description

[Technical Field]

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

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

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

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

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

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

[0007] Therefore, a need is felt to provide flavor materials, as well as aerosol-generating articles containing flavor materials, that are associated with enhanced flavor perception for consumers, particularly towards the end of the use cycle of the aerosol-generating article. Summary of the Invention

[0008] The present disclosure relates to a flavoring material for use in an aerosol-generating article, wherein the flavoring agent formulation is releasable from the flavoring agent upon heating. The flavoring material may include a matrix structure and a flavoring agent formulation dispersed within the matrix structure. The flavoring agent formulation is at least partially entrapped within the matrix structure and releasable from the matrix structure upon heating of the flavoring agent. The matrix structure may be a polysaccharide matrix structure. The flavoring material may include greater than 0.1 weight percent of an additive selected from the group consisting of polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof.

[0009] According to a first aspect of the present invention, there is provided a flavoring material for use in an aerosol-generating article, the flavoring material comprising a polysaccharide matrix structure and a flavorant formulation dispersed within the polysaccharide matrix structure. The flavorant formulation is at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavoring material. The flavoring material comprises greater than 0.1 weight percent of an additive selected from the group consisting of polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof.

[0010] As used herein in connection with the present invention, the term "aerosol-generating article" is used to describe an article that includes an aerosol-generating substrate that is heated to generate and deliver an inhalable aerosol to a user.

[0011] As used herein in connection with the present invention, the term "aerosol-generating substrate" is used to describe a substrate that includes an aerosol-forming material that is capable of releasing, upon heating, a volatile compound that is capable of generating an aerosol.

[0012] As used herein in connection with the present invention, the term "aerosol" is used to describe a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets in a gas. Aerosols can be visible or invisible. Aerosols may contain not only vapors of substances that are normally liquids or solids at room temperature, but also solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

[0013] As used herein in connection with the present invention, the term "aerosol-generating device" is used to describe a device that interacts with the aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0014] The aerosol-generating article according to the present invention has a proximal end through which the aerosol exits the aerosol-generating article for delivery to a user during use. The proximal end of the aerosol-generating article may also be referred to as the downstream end or mouth end of the aerosol-generating article. During use, a user draws directly or indirectly on the proximal end of the aerosol-generating article to inhale the aerosol generated by the aerosol-generating article.

[0015] The aerosol-generating article according to the present invention has a distal end. The distal end is opposite the proximal end. The distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosol-generating article.

[0016] Components of an aerosol-generating article according to the present invention may be described as being upstream or downstream of one another based on their relative location between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article.

[0017] As used herein in relation to this specification, the term "longitudinal direction" is used to describe the direction between the upstream and downstream ends of the aerosol-generating article. During use, air is drawn longitudinally through the aerosol-generating article.

[0018] As used herein in connection with the present invention, the term "length" is used to describe the greatest dimension along the longitudinal axis of an aerosol-generating article or a component of an aerosol-generating article.

[0019] As used herein in connection with the present invention, the term "transverse" is used to describe a direction perpendicular to the longitudinal axis. Unless otherwise specified, a "cross section" of an aerosol-generating article or a component of an aerosol-generating article refers to a cross section.

[0020] As used herein in connection with the present invention, the term "width" refers to the largest transverse dimension of an aerosol-generating article or a component of an aerosol-generating article. If the aerosol-generating article has a substantially circular cross-section, the width of the aerosol-generating article corresponds to the diameter of the aerosol-generating article. If the component of the aerosol-generating article has a substantially circular cross-section, the width of the component of the aerosol-generating article corresponds to the diameter of the component of the aerosol-generating article.

[0021] As used herein in connection with the present invention, the term "hollow tubular element" is used to describe a generally cylindrical element having a tubular space along its longitudinal axis. The tubular portion may be generally circular, oval, or elliptical in cross section. The tubular space may be generally circular, oval, or elliptical in cross section. Specifically, the term "hollow tubular element" is used to describe an element that defines at least one airflow conduit that establishes uninterrupted fluid communication between an upstream end of the hollow tubular element and a downstream end of the hollow tubular element.

[0022] It has been found that the inclusion of an additive selected from the above-mentioned group in a flavor material according to the invention affects the flavor release profile, in particular by facilitating and intensifying the release of flavor at lower temperatures compared to a flavor material having substantially the same composition and structure but not containing such additives.

[0023] Without wishing to be bound by theory, this effect is understood to be related to gaseous compounds released upon thermal decomposition of the additives, which are believed to disrupt the polysaccharide matrix structure, possibly by destroying some of the internal pockets in which the flavor formulation is immobilized.

[0024] Thus, the improved release of flavor species provided by the flavor materials according to the present invention may also supply heat to aerosol-generating articles incorporating the flavor materials, enabling heaters configured to operate at lower temperatures and therefore require less power during use.

[0025] By adjusting the additive content, or by selecting a particular additive, or both, it may be possible to advantageously further control the flavor release profile. Indeed, it has been found that including a higher amount of additive in the flavoring material generally causes a more significant shift in the flavor release profile toward lower temperatures.

[0026] Furthermore, the use of different additives, alone or in combination, that undergo thermal decomposition at different temperatures may advantageously provide a tool for even more fine-tuning the flavor release profile of a flavor material or an aerosol-generating article containing a flavor material.

[0027] It is generally recognized that the use of flavoring materials in aerosol-generating articles, which means that the aerosol-generating substrate is heated to generate the aerosol, presents different challenges and brings different constraints compared to the conditions previously encountered with traditional cigarettes, where the substrate is burned to generate smoke. The inventors have found that by adjusting the relative ratios of the various components in the formulation or by changing the composition of the matrix, for example, by selecting a specific combination of polysaccharides to form the matrix, or by doing both, it may be advantageously possible to fine-tune the specific characteristics of the flavoring material to the specific needs associated with its use in aerosol-generating articles. For example, the flavor release profile may be tailored to have flavors released in more continuous "waves" during use. As a result, consumers may perceive flavor notes that are stronger or longer lasting during use. Thus, flavoring materials according to the present invention may offer a broader flavor profile not accessible with known flavoring materials.

[0028] It has been found that when flavor materials according to the present invention are incorporated into an aerosol-generating article, such as a heat-and-burn article configured to generate an aerosol upon heating of a tobacco-containing aerosol-generating substrate, flavor release per puff is generally more efficient.

[0029] Because the flavor formulation is at least partially entrapped within the matrix until released upon heating, flavor materials according to the present invention have been found to exhibit increased stability. For example, it has been observed that loss of flavor species during storage, transport, etc. is significantly reduced, even under stress conditions. Combined with enhanced flavor release at lower temperatures, this allows for particularly efficient use of flavors and other components of the flavor formulation.

[0030] As briefly mentioned above, flavoring materials according to the present invention contain greater than 0.1 weight percent of an additive selected from polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof.

[0031] Preferably, the additive is pyrolyzed at a temperature of less than 220 degrees Celsius and a pressure of 1 bar. More preferably, the additive is pyrolyzed at a temperature of less than 200 degrees Celsius and a pressure of 1 bar. Even more preferably, the additive is pyrolyzed at a temperature of less than 180 degrees Celsius and a pressure of 1 bar.

[0032] The additive may be pyrolyzed at a temperature of at least 100 degrees Celsius, preferably at least 120 degrees Celsius, more preferably at least 140 degrees Celsius, and at a pressure of 1 bar.

[0033] In some embodiments, the additive is pyrolyzed at a temperature between 100 degrees Celsius and 220 degrees Celsius, preferably between 120 degrees Celsius and 220 degrees Celsius, more preferably between 140 degrees Celsius and 220 degrees Celsius, at a pressure of 1 bar.

[0034] In another embodiment, the additive is pyrolyzed at a temperature between 100 degrees Celsius and 200 degrees Celsius, preferably between 120 degrees Celsius and 200 degrees Celsius, more preferably between 140 degrees Celsius and 200 degrees Celsius, at a pressure of 1 bar.

[0035] In a further embodiment, the additive is pyrolyzed at a temperature of 100 degrees Celsius to 180 degrees Celsius, preferably 120 degrees Celsius to 180 degrees Celsius, more preferably 140 degrees Celsius to 180 degrees Celsius, at a pressure of 1 bar.

[0036] The use of one or more selected additives that thermally decompose at a temperature within the aforementioned range and a pressure of 1 bar has been identified as particularly advantageous because, upon heating of the flavoring material according to the present invention, these additives begin to thermally decompose at temperatures significantly lower than the temperatures at which the matrix-forming polysaccharides thermally decompose. As a result, the gaseous products produced upon thermal decomposition of the additives may interact with the matrix structure and destroy its integrity, such as by progressively destroying pockets in the matrix structure in which the flavoring agent formulation is trapped, before the integrity of the matrix structure can be affected by the supply of heat alone.

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

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

[0039] Salts containing bicarbonate functionality suitable for use as additives in flavoring materials according to the present invention include, but are not limited to, sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, calcium bicarbonate, and ammonium bicarbonate.

[0040] Preferably, the additives comprise 25 weight percent or less of the flavoring material on a dry weight basis. More preferably, the additives comprise 20 weight percent or less of the flavoring material on a dry weight basis. Even more preferably, the additives comprise 15 weight percent or less of the flavoring material on a dry weight basis. In particularly preferred embodiments, the additives comprise 10 weight percent or less of the flavoring material on a dry weight basis.

[0041] Preferably, the additive comprises at least 0.25 weight percent of the flavoring material on a dry weight basis. More preferably, the additive comprises at least 0.5 weight percent of the flavoring material on a dry weight basis. Even more preferably, the additive comprises at least 1.0 weight percent of the flavoring material on a dry weight basis.

[0042] In some embodiments, the additive comprises from 0.25 weight percent to 25 weight percent of the flavoring material on a dry weight basis, preferably from 0.25 weight percent to 20 weight percent of the flavoring material on a dry weight basis, more preferably from 0.25 weight percent to 15 weight percent of the flavoring material on a dry weight basis, and even more preferably from 0.25 weight percent to 10 weight percent of the flavoring material on a dry weight basis.

[0043] In other embodiments, the additive comprises from 0.5 weight percent to 25 weight percent of the flavoring material on a dry weight basis, preferably from 0.5 weight percent to 20 weight percent of the flavoring material on a dry weight basis, more preferably from 0.5 weight percent to 15 weight percent of the flavoring material on a dry weight basis, and even more preferably from 0.5 weight percent to 10 weight percent of the flavoring material on a dry weight basis.

[0044] In a further embodiment, the additive comprises from 1.0 weight percent to 25 weight percent of the flavoring material on a dry weight basis, preferably from 1.0 weight percent to 20 weight percent of the flavoring material on a dry weight basis, more preferably from 1.0 weight percent to 15 weight percent of the flavoring material on a dry weight basis, and even more preferably from 1.0 weight percent to 10 weight percent of the flavoring material on a dry weight basis.

[0045] In certain embodiments, the flavoring material further comprises a carrier material, wherein the polysaccharide matrix structure and the flavoring agent formulation entrapped therein are carried by the carrier material.

[0046] This is advantageous in that the structural strength of the flavouring material is improved by the carrier material performing a carrying function, which can be particularly beneficial from a manufacturing standpoint, as handling of flavouring material reinforced by a carrier material can generally be easier.

[0047] In some embodiments, the carrier material is a carrier sheet material. As used herein, the term "sheet material" refers to a thin layer of material having a width and length that are substantially greater than its thickness. For example, the carrier material may be a sheet of homogenized tobacco material or a sheet of paper material. The use of homogenized tobacco material to produce flavoring materials according to the present invention is 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 flavorant formulation entrapped therein can be deposited on the carrier sheet material to form a flavorant that is actually in whole sheet form and can therefore be cut into pieces having a predetermined average size (e.g., a predetermined cut width or a predetermined cut length, or both), which facilitates combining the flavorant with an aerosol-generating substrate within a particular aerosol-generating article, as described in more detail below.

[0049] In other embodiments, the carrier material may comprise a plurality of pieces cut from a sheet material, the pieces having a predetermined average size (e.g., a predetermined cut width or a predetermined cut length, or both). Alternatively, the carrier material may comprise a plurality of pieces cut from a natural plant material, preferably a plant leaf material (e.g., tobacco lamina). In some embodiments, the carrier material may be tobacco cut filler.

[0050] In all embodiments of the flavoring material that include a carrier material, the polysaccharide matrix structure that entraps the flavoring agent formulation may be formed in situ on the carrier material. If this in situ formation step follows the manufacturing process from which the carrier material may be obtained, the in situ formation step may be performed at a later date or at a different location.

[0051] The use of a carrier sheet material carrying a polysaccharide matrix structure and an entrapped flavorant formulation can have the additional advantage that, by selecting and adjusting certain properties of the carrier sheet material (e.g., its thickness), it is possible to obtain a flavorant that is easier to form into a bobbin and therefore easier to handle and process when the flavorant is incorporated into an aerosol-generating article. In view of high-speed automated manufacturing processes, the increased structural strength provided by the carrier sheet material can be particularly beneficial.

[0052] As noted above, in some preferred embodiments, the carrier sheet material may be in the form of a sheet of homogenized tobacco material.

[0053] As used herein, the term "homogenized tobacco material" encompasses any tobacco material formed by agglomeration of particles of tobacco material. A sheet or web of homogenized tobacco material is formed by agglomerating particulate tobacco obtained by grinding or otherwise pulverizing one or both of tobacco lamina and tobacco stem. In addition, the homogenized tobacco material may contain one or more small amounts of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. A sheet of homogenized tobacco material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0054] The sheets or webs of homogenized tobacco material used in the present invention may have a tobacco content of at least about 40 weight percent on a dry weight basis, more preferably at least about 60 weight percent on a dry weight basis, even more preferably at least about 70 weight percent on a dry weight basis, and most preferably at least about 90 weight percent on a dry weight basis.

[0055] A sheet or web of homogenized tobacco material for use as a carrier sheet material may include one or more intrinsic binders (i.e., tobacco intrinsic binders), one or more extrinsic binders (i.e., tobacco extrinsic binders), or combinations thereof to aid in agglomerating the particulate tobacco. Alternatively, or additionally, a sheet of homogenized tobacco material for use as a carrier sheet material may include other additives, including, but not limited to, tobacco and non-tobacco fibers, aerosol formers, humectants, plasticizers, flavorants, fillers, aqueous and non-aqueous solvents, and combinations thereof.

[0056] Suitable extrinsic binders for inclusion in sheets or webs of homogenized tobacco material for use as carrier sheet materials are well known in the art and include, but are not limited to, gums such as guar gum, xanthan gum, gum arabic, and locust bean gum; cellulosic binders such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and ethyl cellulose; polysaccharides such as starch; organic acids such as alginic acid, conjugate base salts of organic acids such as sodium alginate, agar, and pectin; and combinations thereof.

[0057] Non-tobacco fibers suitable for inclusion in sheets or webs of homogenized tobacco material for use as a carrier sheet material are known in the art and include, but are not limited to, cellulose fibers, softwood fibers, hardwood fibers, jute fibers, and combinations thereof. Prior to inclusion in a sheet of homogenized tobacco material for use as a carrier sheet material, the non-tobacco fibers may be processed by any suitable process known in the art, including, but not limited to, mechanical pulping, refining, chemical pulping, bleaching, sulfate pulping, and combinations thereof.

[0058] Preferably, the sheet or web of homogenized tobacco material includes an aerosol former. As used herein, the term "aerosol former" describes any suitable known compound or mixture of compounds that facilitates the formation of an aerosol during use and that is substantially resistant to thermal decomposition at the operating temperatures of the aerosol-generating article.

[0059] Suitable aerosol formers are known in the art and include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, triacetate, etc.), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.).

[0060] Preferred aerosol formers are polyhydric alcohols such as propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerin, or mixtures thereof.

[0061] The sheet or web of homogenized tobacco material may include a single aerosol former. Alternatively, the sheet or web of homogenized tobacco material may include a combination of two or more aerosol formers.

[0062] The homogenized sheet or web of tobacco material has an aerosol former content of greater than 10 percent on a dry weight basis. Preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than 12 percent on a dry weight basis. More preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than 14 percent on a dry weight basis. Even more preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than 16 percent on a dry weight basis.

[0063] The sheet of homogenized tobacco material may have an aerosol former content of from about 10 percent to about 30 percent on a dry weight basis. Preferably, the sheet or web of homogenized tobacco material has an aerosol former content of less than 25 percent on a dry weight basis.

[0064] In one preferred embodiment, the sheet of homogenized tobacco material has an aerosol former content of approximately 20 percent on a dry weight basis.

[0065] Sheets or webs of homogenized tobacco for use as carrier sheet materials in the flavoring materials of the present invention may be made by methods known in the art (e.g., the method disclosed in International Patent Application No. WO-A-2012 / 164009(A2)). In a preferred embodiment, sheets of homogenized tobacco material for use as carrier sheet materials are formed from a slurry comprising particulate tobacco, guar gum, cellulose fibers, and glycerin by a casting process.

[0066] In other embodiments, the carrier sheet material may be in the form of a sheet of non-tobacco aerosol-generating material. For example, the carrier sheet material may be a sheet of absorbent non-tobacco material loaded with nicotine (e.g., in the form of a nicotine salt) and an aerosol former. Examples of such rods are described in International Application No. WO-A-2015 / 082652. Additionally or alternatively, the carrier sheet material may be a sheet of homogenized non-tobacco plant material, such as a flavored 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 advantage that the flavoring material may be used in place of, or in addition to, conventional paper wrapper materials in the manufacture of aerosol-generating articles. Thus, the flavoring material may be incorporated into the aerosol-generating article without significantly changing existing manufacturing processes and without requiring significant modification of existing manufacturing equipment.

[0068] The polysaccharide matrix structure preferably contains gellan gum and an emulsifier. The term "gellan gum" is used to identify a water-soluble anionic polysaccharide produced by the bacterium Sphingomonas elodia. The repeating unit of the polymer is a tetrasaccharide, consisting of two residues of D-glucose and one residue each of L-rhamnose and D-glucuronic acid. Gellan gum has been approved for food, non-food, cosmetic, and pharmaceutical uses by authorities in many jurisdictions, including Japan, the United States, Canada, China, South Korea, and the EU.

[0069] Two forms of gellan gum are known, namely high acyl gellan gum and low acyl gellan gum, which differ by the degree / percentage of substitution with O-acyl groups.

[0070] In the flavoring material according to the present invention, the gellan gum is preferably low-acyl gellan gum, which is either partially deacylated or fully deacylated, the most common form being the fully deacylated form with no detectable acyl groups, also known as deacetylated gellan gum.

[0071] The use of low acyl gellan gum to form the polysaccharide matrix of the flavor material according to the present invention is preferred because low acyl gellan gum can form gels at very low concentrations. Furthermore, the texture of gellan gum-based gels varies depending on the acyl content, with low acyl gellan gum typically forming firmer, less elastic, and more brittle gels compared to high acyl gellan gum.

[0072] In embodiments in which the polysaccharide matrix structure comprises gellan gum and an emulsifier, flavorings can be advantageously provided in which a substantial portion of the flavoring agent formulation is effectively entrapped within the polysaccharide matrix structure, which is beneficial in terms of improving flavoring agent stability. Furthermore, as discussed in more detail below, this can affect how flavor species are released upon heating of the flavoring agent, thereby helping to tailor the flavoring agent release profile during use.

[0073] Furthermore, from a manufacturing perspective, a stable polysaccharide matrix structure comprising gellan gum and an emulsifier can be formed by providing heat to an initiator reagent without the need for a cross-linking agent. Indeed, by kneading and emulsifying a flavor formulation and gellan gum in a heated aqueous bath, the polysaccharide-coated flavor can be brought into an emulsified state, which is then substantially preserved after drying and cooling. Advantageously, this allows a significant amount of flavor to be provided immobilized within the polysaccharide matrix, thereby providing a flavor material with a high flavor content.

[0074] Preferably, the emulsifier is lecithin.The use of lecithin as emulsifier has the advantage that it is commonly available and generally recognized as non-toxic.Like gellan gum, lecithin is commonly used as an additive in the food industry, and is approved for such use by both the US Food and Drug Administration and EU authorities.Thus, the combination of gellan gum and lecithin is particularly suitable for being included in flavor materials intended for human use.

[0075] When the polysaccharide matrix comprises gellan gum and an emulsifier, the gellan gum preferably comprises 5 to 99.9 percent by weight of the flavor material on a dry weight basis.

[0076] More preferably, gellan gum comprises at least 7 weight percent of the flavor materials on a dry weight basis, and even more preferably at least 10 weight percent of the flavor materials on a dry weight basis.

[0077] Preferably, the gellan gum comprises up to 80 weight percent of the flavoring material on a dry weight basis, more preferably up to 60 weight percent of the flavoring material on a dry weight basis, even more preferably up to 40 weight percent of the flavoring material on a dry weight basis, and especially preferably up to 30 weight percent of the flavoring material on a dry weight basis.

[0078] In some embodiments, gellan gum comprises from 5 weight percent to 80 weight percent of the flavor materials on a dry weight basis, preferably from 5 weight percent to 60 weight percent of the flavor materials on a dry weight basis, more preferably from 5 weight percent to 40 weight percent of the flavor materials on a dry weight basis, and even more preferably from 5 weight percent to 30 weight percent of the flavor materials on a dry weight basis.

[0079] In other embodiments, gellan gum comprises from 10 weight percent to 80 weight percent of the flavor materials on a dry weight basis, preferably from 10 weight percent to 60 weight percent of the flavor materials on a dry weight basis, more preferably from 10 weight percent to 40 weight percent of the flavor materials on a dry weight basis, and even more preferably from 10 weight percent to 30 weight percent of the flavor materials on a dry weight basis.

[0080] The emulsifier may comprise from 0.01 weight percent to 2 weight percent of the flavor material on a dry weight basis. Preferably, the emulsifier comprises from 0.02 weight percent to 2 weight percent of the flavor material on a dry weight basis. More preferably, the emulsifier comprises from 0.05 weight percent to 2 weight percent of the flavor material on a dry weight basis. Even more preferably, the emulsifier comprises from 0.1 weight percent to 2 weight percent of the flavor material on a dry weight basis.

[0081] In a preferred embodiment, the emulsifier is lecithin and comprises 0.01 to 2 weight percent of the flavoring material on a dry weight basis. Preferably, the lecithin comprises 0.02 to 2 weight percent of the flavoring material on a dry weight basis. More preferably, the lecithin comprises 0.05 to 2 weight percent of the flavoring material on a dry weight basis. Even more preferably, the lecithin comprises 0.1 to 2 weight percent of the flavoring material on a dry weight basis.

[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 an additional polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose, and hydroxypropylmethylcellulose.

[0084] It has been found that flavoring materials according to the present invention, in which the polysaccharide matrix structure comprises gellan gum in combination with one or more of the polysaccharides listed above, provide different flavor release profiles upon heating. For example, in embodiments in which the polysaccharide matrix structure comprises gellan gum in combination with another of the polysaccharides listed above, a flavor release profile characterized by two distinct peaks at two different temperatures has been observed. Without wishing to be bound by theory, this is hypothesized to be due to different strengths of interaction between the flavor and each polysaccharide within the matrix structure, and may need to be done with each polysaccharide undergoing thermal degradation at slightly different temperatures.

[0085] Because different combinations of polysaccharides within a matrix structure generally lead to slightly different flavor release profiles when the flavor material is heated, embodiments in which gellan gum is combined with one or more of the other polysaccharides listed above can be advantageously used to fine-tune flavor release during use of an aerosol-generating article containing the flavor material. Furthermore, different flavor materials, each containing a polysaccharide matrix structure with a different combination of polysaccharides, may be used in combination with a single aerosol-generating article to further adjust and control flavor delivery throughout the use cycle of the aerosol-generating article. For example, incorporating different flavor materials according to the present invention into a single aerosol-generating article, where the different flavor materials are adapted to release the majority of their flavor at different temperatures or at different times during the use cycle, may help maintain a substantially consistent overall flavor delivery throughout.

[0086] In flavor material embodiments in which the matrix structure comprises gellan gum in combination with at least one of the aforementioned additional polysaccharides, the at least one additional polysaccharide may comprise at least 0.01 weight percent of the flavor delivery material on a dry weight basis. Preferably, the at least one additional polysaccharide comprises at least 0.1 weight percent of the flavor delivery material on a dry weight basis. More preferably, the at least one additional polysaccharide comprises at least 1.0 weight percent of the flavor delivery material on a dry weight basis. Even more preferably, the at least one additional polysaccharide comprises at least 2.0 weight percent of the flavor delivery material on a dry weight basis. In particularly preferred embodiments, the at least one additional polysaccharide comprises at least 5 weight percent of the flavor delivery material on a dry weight basis.

[0087] In flavor material embodiments in which the matrix structure comprises gellan gum in combination with at least one of the aforementioned additional polysaccharides, the at least one additional polysaccharide may comprise 80 weight percent or less of the flavor delivery material on a dry weight basis. Preferably, the at least one additional polysaccharide comprises 35 weight percent or less of the flavor delivery material on a dry weight basis. More preferably, the at least one additional polysaccharide comprises 25 weight percent or less of the flavor delivery material on a dry weight basis. Even more preferably, the at least one additional polysaccharide comprises 15 weight percent or less of the flavor delivery material on a dry weight basis.

[0088] In some embodiments, the at least one additional polysaccharide comprises from 1.0 weight percent to no more than 35 weight percent of the flavor delivery material on a dry weight basis, preferably from 2.0 weight percent to no more than 35 weight percent of the flavor delivery material on a dry weight basis, and more preferably from 5.0 weight percent to no more than 35 weight percent of the flavor delivery material on a dry weight basis.

[0089] In other embodiments, the at least one additional polysaccharide comprises from 1.0 weight percent to 25 weight percent or less of the flavor delivery material on a dry weight basis, preferably from 2.0 weight percent to 25 weight percent or less of the flavor delivery material on a dry weight basis, and more preferably from 5.0 weight percent to 25 weight percent or less of the flavor delivery material on a dry weight basis.

[0090] In a further embodiment, the at least one additional polysaccharide comprises from 1.0 weight percent to no more than 15 weight percent of the flavor delivery material on a dry weight basis, preferably from 2.0 weight percent to no more than 15 weight percent of the flavor delivery material on a dry weight basis, and more preferably from 5.0 weight percent to no more than 15 weight percent of the flavor delivery material on a dry weight basis.

[0091] The flavoring material may comprise at least 0.01 weight percent flavoring agent on a dry weight basis. Preferably, the flavoring material comprises at least 1 weight percent flavoring agent on a dry weight basis. More preferably, the flavoring material comprises at least 5 weight percent flavoring agent on a dry weight basis. Even more preferably, the flavoring material comprises at least 10 weight percent flavoring agent on a dry weight basis.

[0092] In certain embodiments, the flavoring material comprises at least 20 weight percent flavor on a dry weight basis, preferably at least 25 weight percent flavor on a dry weight basis, and more preferably at least 30 weight percent flavor on a dry weight basis.

[0093] The flavoring material may be up to 90 weight percent flavoring on a dry weight basis. Preferably, the flavoring material may be up to 85 weight percent flavoring on a dry weight basis. More preferably, the flavoring material may be up to 80 weight percent flavoring on a dry weight basis. Even more preferably, the flavoring material may be up to 75 weight percent flavoring on a dry weight basis.

[0094] In certain preferred embodiments, the flavoring material comprises from 20 weight percent to 80 weight percent flavoring on a dry weight basis, preferably from 25 weight percent to 80 weight percent flavoring on a dry weight basis, and more preferably from 30 weight percent to 80 weight percent flavoring on a dry weight basis.

[0095] In other preferred embodiments, the flavoring material comprises from 20 weight percent to 75 weight percent flavoring on a dry weight basis, preferably from 25 weight percent to 75 weight percent flavoring on a dry weight basis, and more preferably from 30 weight percent to 75 weight percent flavoring on a dry weight basis.

[0096] Flavoring agents suitable for inclusion in flavoring formulations of flavoring materials according to the present invention include, but are not limited to:

[0097] Suitable flavorants for inclusion in flavor formulations of flavoring materials according to the present invention include, but are not limited to, menthol, limonene, and eugenol.

[0098] Menthol is a monoterpenoid that may be produced synthetically or obtained from peppermint or other mint oils, which imparts the cooling flavor note of mint.

[0099] Limonene is a cyclic monoterpene typically found in the oils of citrus fruit peels. It is also a component of the aromatic resins of numerous cone and broadleaf trees, which impart citrus flavor notes.

[0100] Eugenol is an allyl-substituted guaiacol commonly found in the essential oils of clove, nutmeg, cinnamon, basil, and bay leaf. It imparts spicy, clove-like flavor notes.

[0101] The inventors have found that menthol and limonene can be fairly easily entrapped and immobilized within the polysaccharide matrix, and therefore flavoring materials containing flavor formulations containing menthol, limonene or mixtures thereof exhibit very good stability.

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

[0103] The flavoring material may comprise at least 0.01 weight percent menthol on a dry weight basis. Preferably, the flavoring material comprises at least 1 weight percent menthol on a dry weight basis. More preferably, the flavoring material comprises at least 5 weight percent menthol on a dry weight basis. Even more preferably, the flavoring material comprises at least 10 weight percent menthol on a dry weight basis.

[0104] In certain embodiments, the flavoring material comprises at least 20 weight percent menthol on a dry weight basis, preferably at least 25 weight percent menthol on a dry weight basis, and more preferably at least 30 weight percent menthol on a dry weight basis.

[0105] The flavoring material may be up to 90 percent menthol by weight on a dry weight basis. Preferably, the flavoring material may be up to 85 percent menthol by weight on a dry weight basis. More preferably, the flavoring material may be up to 80 percent menthol by weight on a dry weight basis. Even more preferably, the flavoring material may be up to 75 percent menthol by weight on a dry weight basis.

[0106] In certain preferred embodiments, the flavoring material comprises from 20 weight percent to 80 weight percent menthol on a dry weight basis, preferably from 25 weight percent to 80 weight percent menthol on a dry weight basis, and more preferably from 30 weight percent to 80 weight percent menthol on a dry weight basis.

[0107] In other preferred embodiments, the flavoring material comprises from 20 weight percent to 75 weight percent menthol on a dry weight basis, preferably from 25 weight percent to 75 weight percent menthol on a dry weight basis, and more preferably from 30 weight percent to 75 weight percent menthol on a dry weight basis.

[0108] Flavor formulations typically include a solvent that the flavor is at least partially dissolved in. Suitable solvents for inclusion in flavor formulations of flavoring materials according to the present invention include, but are not limited to, water and glycerol.

[0109] The inventors have found that the solubility of a flavorant in a given solvent can affect how stable the flavorant is retained within the flavorant during storage of an aerosol-generating article containing the flavorant. More specifically, the inventors have found that greater affinity between the flavorant and the solvent favorably affects stability.

[0110] The Hansen Solubility Parameters provide a model for estimating the mutual affinity of any given flavor / solvent pairing.

[0111] The solubility parameter δ, measured in MPa, is a function of the intermolecular dispersion forces (δ) as expressed by the following equation: d ), intermolecular forces between molecules (δ p ), and intermolecular hydrogen bonds (δ h ) is a function of the parameter σ. δ 2 =(δ d ) 2 +(δ p ) 2 +(δ h ) 2

[0112] parameter, δ d , δ p , and δ h can be considered as the coordinates of a point in three-dimensional space (Hansen space). The distance R between two molecules in Hansen space aprovides an indication of the affinity between two molecules and is calculated based on the following formula: (R a ) 2 =4(δ d2 -δ d1 ) 2 +(δ p2 -δ p1 ) 2 +(δ h2 -δ h1 ) 2

[0113] In general, R a It is understood that a lower value of indicates a higher affinity for a given flavor / solvent combination.

[0114] With reference to flavor formulations for inclusion in flavoring materials according to the present invention, the inventors have considered combining flavorings with glycerol as a solvent and, in doing so, have identified several flavoring / glycerol combinations that exhibit particularly good stability of the flavoring within the flavoring material during storage.

[0115] Flavor / glycerol combinations for inclusion in flavor formulations of flavoring materials according to the present invention may be selected from the group consisting of R a The inventors believe that this condition indicates a particularly high affinity between the flavor and glycerol, and therefore that such an R a have consistently resulted in flavor materials with particularly good flavor stability during storage. Based on this, the inventors have found that preferred flavor / glycerol combinations 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, and linalool / glycerol. In certain embodiments, the flavor material further comprises greater than 0.1 weight percent carbon particles, the carbon particles having a volume average particle size greater than 10 micrometers.

[0116] It has been found that the inclusion of carbon-based materials, such as graphite, expanded graphite, graphene, etc., in the flavoring material according to the present invention enhances flavor release, particularly at low temperatures, relative to flavoring materials of comparable composition and structure but lacking the carbon-based material. Without wishing to be bound by theory, this is hypothesized to be related to an increased thermal conductivity of the flavoring material, which may cause the flavoring agent formulation to be released more quickly from the polysaccharide matrix structure, as a certain threshold temperature may be reached more quickly.

[0117] Thus, the carbon particles and additives may act synergistically to promote the release of flavor species at lower temperatures compared to flavor materials without either, compared to embodiments of flavor materials according to the present invention that do not include carbon particles.

[0118] Improved flavor release is believed to be associated with a more uniform temperature distribution throughout the flavorant during use, allowing for greater use efficiency of the flavor formulation when a proportion of the flavorant reaches a temperature high enough to release the flavor species from the matrix structure.

[0119] The improved release of flavor species provided by embodiments of the flavor material according to the present invention comprising carbon particles as described above may also allow heaters configured to supply heat to aerosol-generating articles incorporating the flavor delivery material to operate at lower temperatures and therefore require less power.

[0120] By adjusting the amount and size of the carbon particles within ranges described in more detail below, it may be possible to control and fine-tune the enhanced flavor release. For example, a relatively narrow particle size distribution may provide a more homogeneous flavor delivery material with respect to thermal conductivity. This may mean that, during use, temperature gradients in the flavor delivery material provided to different parts of the aerosol-generating article that are subjected to the same heating profile are minimized.

[0121] The carbon particles preferably comprise one or more of graphite particles, expanded graphite particles, and graphene particles. In a preferred embodiment, the carbon particles comprise one or both of expanded graphite particles and graphene particles.

[0122] Advantageously, particles such as those listed above, particularly graphite and expanded graphite, may have high thermal conductivity and low density, and may therefore be able to substantially improve the thermal conductivity of the flavoring material without significantly increasing the flavoring material's density. This may be advantageous because increasing density increases the weight of the flavoring material per given volume, and therefore may increase transportation costs. Similarly, increasing density may have a proportional impact on transportation costs when the flavoring material is incorporated into an aerosol-generating article.

[0123] Furthermore, particles such as those listed above have the advantage that they can be inductively heated, and therefore can provide heat directly into the flavor material according to the present invention when the flavor material is exposed to an electromagnetic field generated by an induction coil.

[0124] The carbon particles preferably have a volume average particle size of 30 micrometers to 150 micrometers.

[0125] As used herein, the term "volume average particle size" may refer to the average calculated using the following formula, where d[4,3] is the volume average particle size and d is the particle size:

number

[0126] In other words, the volume average particle size may refer to the average calculated by dividing the sum of the fourth power of the particle size by the sum of the third power of the particle size.

[0127] Surprisingly, the inventors have found that these relatively small particle size ranges are particularly effective in increasing the thermal conductivity of the flavoring material when the flavoring material is in the form of or comprises a sheet. In addition, these relatively small particle sizes may advantageously result in a more uniform distribution of thermal conductivity and may also result in a sheet having a more uniform thickness than when larger particle sizes are used.

[0128] In embodiments in which the carbon particles are contained within a carrier sheet material carrying a polysaccharide structure that entraps the flavorant formulation, it may also be easier to mix particles in this size range with particles of similar size used to manufacture the carrier sheet material, such as in the case of sheets of homogenized tobacco or other plant material.

[0129] The carbon particles may have a particle size distribution having a D10 particle size, a D50 particle size, and a D90 particle size. In such a particle size distribution, 10% of the particles have a particle size equal to or less than the D10 particle size and 90% of the particles have a particle size equal to or less than the D90 particle size. The D50 particle size is the median particle size, such that 50% of the particles have a particle size equal to or less than the D50 particle size.

[0130] The D90 particle size may be 50, 40, 30, 25, 20, 15, 10, 8, 5, or 3 times or less the D10 particle size. The D90 particle size may be 2, 3, 5, or 8 times or more the D10 particle size.

[0131] The D90 particle size may be 3 to 50, 3 to 40, 3 to 30, 3 to 25, 3 to 20, 3 to 15, 3 to 10, 3 to 8, 3 to 5, 5 to 50, 5 to 40, 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 10, 5 to 8, 8 to 50, 8 to 40, 8 to 30, 8 to 25, 8 to 20, 8 to 15, 8 to 10, 10 to 50, 10 to 40, 10 to 30, 10 to 25, 10 to 20, 10 to 15, 15 to 50, 15 to 40, 15 to 30, 15 to 25, or 15 to 20 times the D10 particle size.

[0132] A preferred particle size distribution may have a D90 particle size that is 3 to 25, or 3 to 15 times the D10 particle size. A particularly preferred particle size distribution may have a D90 particle size that is 5 to 20, or 5 to 10 times the D10 particle size.

[0133] In certain preferred embodiments, in the flavourant according to the present invention, the carbon particles have a particle size distribution having a D90 particle size and a D10 particle size, the D90 particle size being no more than 25 or 15 times the D10 particle size.

[0134] A compromise must be made regarding particle size distribution. A tighter particle size distribution may advantageously provide a more uniform thermal conductivity throughout the flavoring material. This is because there is less variation in particle size at different locations within the flavoring material. This may advantageously allow for more efficient use of the flavoring agent formulation throughout the flavoring material. However, a tighter particle size distribution may disadvantageously be more difficult and expensive to achieve. The inventors have found that the particle size distribution described above may provide an optimal compromise between these two factors.

[0135] The desired D10 and D90 particle sizes may be obtained by sieving. Thus, if desired, sieving may be used to obtain a narrow particle size distribution.

[0136] The carbon particles may have a D10 particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more. Each of the carbon particles may have a particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more.

[0137] The carbon particles may have a D10 particle size of 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers or less. Each of the carbon particles may have a particle size of 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers or less.

[0138] The carbon particles may have a D90 particle size of 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers or less. Each of the carbon particles may have a particle size of 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers or less.

[0139] The carbon particles may have a D90 particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more. Each of the carbon particles may have a particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more.

[0140] The carbon particles may have a D50 particle size and / or a volume average particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or greater.

[0141] The carbon particles may have a D50 particle size and / or a volume average particle size of less than or equal to 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers.

[0142] The carbon particles may have one or both of a D50 particle size and a volume average particle size of 1 to 1000, preferably 10 to 200, more preferably 30 to 150, or even more preferably 50 to 75 micrometers. Alternatively, or additionally, each of the carbon particles may have a particle size of 1 to 1000, preferably 10 to 200, more preferably 30 to 150, or even more preferably 50 to 75 micrometers.

[0143] Surprisingly, the inventors have found that these relatively small particle size ranges are particularly effective in increasing the thermal conductivity of flavoring materials according to the present invention, particularly in embodiments in which the flavoring material comprises a carrier sheet material carrying a polysaccharide matrix that entraps the flavoring agent formulation. In addition, these relatively small particle sizes may advantageously result in a carrier sheet material that is more homogeneous in terms of thermal conductivity and may also result in a carrier sheet material having a more uniform thickness than when larger particle sizes are used. It may also be easier to blend particles in this size range with similarly sized particles used in some manufacturing processes to form carrier sheet materials.

[0144] The carbon particles may have a volume average particle size of 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 micrometers or more.

[0145] It may be particularly preferred that the carbon particles have a volume average particle size of greater than 10 micrometers.

[0146] The carbon particles may have a volume average particle size of less than or equal to 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3, or 2 micrometers.

[0147] The carbon particles may have a volume average particle size of 1 to 1000, 10 to 200, 30 to 150, or 50 to 75 micrometers. These volume average particle size ranges may be particularly preferred when the flavoring material comprises or is in the form of a sheet.

[0148] The carbon particles may have a volume average particle size that is at least 2, 3, 5, 8, 10, 15, or 20 times the number average particle size.

[0149] It may be particularly preferred that the thermally conductive particles are or include graphite particles.

[0150] The graphite particles may have a particle size distribution with a D10 particle size of 5 to 20, such as 10 to 14 micrometers, e.g., approximately 12 micrometers. The graphite particles may have a particle size distribution with a D50 particle size of 25 to 45 micrometers, e.g., approximately 35 micrometers. The graphite particles may have a particle size distribution with a D90 particle size of 45 to 75 micrometers, e.g., approximately 55 micrometers. Advantageously, such particles are commercially available and have been found by the inventors to provide a significant increase in the thermal conductivity of the flavoring material.

[0151] It may be particularly preferred that the thermally conductive particles are or include expanded graphite particles.

[0152] The expanded graphite particles may have a particle size distribution with a D10 particle size of 5 to 20, e.g., 9 to 12 micrometers, e.g., approximately 10.5 micrometers. The expanded graphite particles may have a particle size distribution with a D50 particle size of 15 to 25 micrometers, e.g., approximately 20 micrometers. The expanded graphite particles may have a particle size distribution with a D90 particle size of 46 to 66 micrometers, e.g., approximately 56 micrometers. Advantageously, such particles are commercially available and have been found by the inventors to provide a significant increase in the thermal conductivity of the flavoring material. The expanded graphite particles may also advantageously reduce the overall density of the flavoring material.

[0153] Each of the carbon particles may have three mutually perpendicular dimensions. The largest of these three dimensions may be no more than 10, 8, 5, 3, or 2 times larger than the smallest of these three dimensions. The largest of these three dimensions may be no more than 10, 8, 5, 3, or 2 times larger than the second largest of these three dimensions. Each of these three dimensions may be substantially equal. Each of the carbon particles may be substantially spherical.

[0154] The carbon particles may include at least 10, 20, 50, 100, 200, 500, or 1000 particles.

[0155] In the flavor material according to the present invention, the carbon particles comprise between 0.01 weight percent and 10 weight percent of the flavor material on a dry weight basis.

[0156] In some embodiments, the flavorant has the formula C n H 2n+2 O n The polyol further comprises:

[0157] The term "polyol" is used herein to describe an organic compound containing two or more hydroxyl groups. Polyols containing two, three, and four hydroxyl groups may also be called diols, triols, and tetrols, respectively.

[0158] Preferred polyols for inclusion in flavoring materials according to the present invention include glycerol, sorbitol, xylitol, mannitol, and erythritol.

[0159] The incorporation of a polyol into a flavorant has a beneficial effect on its flexibility, which may make it easier to handle and give it a defined form, facilitating its incorporation into an aerosol-generating article.

[0160] In embodiments in which the flavorant comprises a polyol as described above, the polyol preferably comprises from 0.01 weight percent to 20 weight percent of the flavorant on a dry weight basis. More preferably, the polyol comprises from 0.01 weight percent to 15 weight percent of the flavorant on a dry weight basis. Even more preferably, the polyol comprises from 0.01 weight percent to 10 weight percent of the flavorant on a dry weight basis.

[0161] In some embodiments, the flavoring material comprises fibers, preferably cellulose fibers. The incorporation of fibers, particularly cellulose fibers, may advantageously improve the tensile strength of the flavoring material, especially when provided in sheet form. This facilitates the manufacturing process of both the flavoring material itself and the aerosol-generating article containing the flavoring material. This advantage is particularly felt in embodiments in which the polysaccharide matrix that entraps the flavoring agent formulation is not supported by a carrier material.

[0162] In embodiments of the flavoring material that include cellulose fiber, the cellulose fiber may comprise at least 0.01 weight percent of the flavoring material on a dry weight basis. Preferably, the cellulose fiber comprises at least 0.05 weight percent of the flavoring material on a dry weight basis. More preferably, the cellulose fiber comprises at least 0.5 weight percent of the flavoring material on a dry weight basis. Even more preferably, the cellulose fiber comprises at least 1.0 weight percent of the flavoring material on a dry weight basis. In particularly preferred embodiments, the cellulose fiber comprises at least 2.0 weight percent of the flavoring material on a dry weight basis.

[0163] The cellulose fibers may comprise 10 weight percent or less of the flavoring material on a dry weight basis. Preferably, the cellulose fibers comprise 8.0 weight percent or less of the flavoring material on a dry weight basis. More preferably, the cellulose fibers comprise 7.0 weight percent or less of the flavoring material on a dry weight basis. Even more preferably, the cellulose fibers comprise 5.0 weight percent or less of the flavoring material on a dry weight basis.

[0164] In some embodiments, the fiber comprises from 0.01 weight percent to 10 weight percent of the flavoring material on a dry weight basis. Preferably, the fiber comprises from 0.01 weight percent to 8.0 weight percent of the flavoring material on a dry weight basis. More preferably, the fiber comprises from 0.01 weight percent to 7.0 weight percent of the flavoring material on a dry weight basis. Even more preferably, the fiber comprises from 0.01 weight percent to 5 weight percent of the flavoring material on a dry weight basis.

[0165] In other embodiments, the fiber comprises 1.0 to 10 weight percent of the flavoring material on a dry weight basis. Preferably, the fiber comprises 1.0 to 8.0 weight percent of the flavoring material on a dry weight basis. More preferably, the fiber comprises 1.0 to 7.0 weight percent of the flavoring material on a dry weight basis. Even more preferably, the fiber comprises 1.0 to 5 weight percent of the flavoring material on a dry weight basis.

[0166] In further embodiments, the fiber comprises 2.0 to 10 weight percent of the flavoring material on a dry weight basis. Preferably, the fiber comprises 2.0 to 8.0 weight percent of the flavoring material on a dry weight basis. More preferably, the fiber comprises 2.0 to 7.0 weight percent of the flavoring material on a dry weight basis. Even more preferably, the fiber comprises 2.0 to 5 weight percent of the flavoring material on a dry weight basis.

[0167] In some embodiments, flavoring materials according to the present invention may include calcium salts, such as calcium chloride or calcium lactate, or magnesium salts, or both.

[0168] Ca 2+ ions or Mg 2+ ions, or both, is advantageously provided [benefit?]

[0169] In embodiments where the flavoring material includes a calcium salt or a magnesium salt, or both, the salt comprises from 0.01 to 10 weight percent on a dry weight basis. Preferably, the salt comprises from 0.01 to 5 weight percent on a dry weight basis.

[0170] In embodiments where the flavoring material includes citrate, the citrate comprises from 0.01 to 5 weight percent on a dry weight basis. Preferably, the citrate comprises from 0.01 to 1 weight percent on a dry weight basis.

[0171] Flavoring materials according to the present invention may generally contain water, since flavoring materials are generally produced by combining the various compounds described above in an aqueous bath. After drying, the water content is reduced, but generally may not be zero.

[0172] Thus, the flavoring material according to the present invention may comprise from 0.01 weight percent to 10 weight percent water, preferably from 0.01 weight percent to 8 weight percent water, more preferably from 0.01 weight percent to 6 weight percent water, and even more preferably from 0.01 weight percent to 4 weight percent water.

[0173] In some embodiments, the flavoring material comprises between 0.5 weight percent and 10 weight percent water, preferably between 0.01 weight percent and 8 weight percent water, more preferably between 0.5 weight percent and 6 weight percent water, and even more preferably between 0.5 weight percent and 4 weight percent water.

[0174] In other embodiments, the flavoring material comprises between 1.0 weight percent and 10 weight percent water, preferably between 1.0 weight percent and 8 weight percent water, more preferably between 1.0 weight percent and 6 weight percent water, and even more preferably between 1.0 weight percent and 4 weight percent water.

[0175] In a further embodiment, the flavoring material comprises between 1.5 weight percent and 10 weight percent water, preferably between 1.5 weight percent and 8 weight percent water, more preferably between 1.5 weight percent and 6 weight percent water, and even more preferably between 1.5 weight percent and 4 weight percent water.

[0176] The flavouring material according to the invention can be prepared by different routes.

[0177] A method for producing a flavoring material according to the present invention may include a first step of preparing an aqueous composition containing a flavoring agent 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 casting the aqueous composition onto 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 flavoring material may then be removed from the support surface. The support surface may be a metal plate.

[0178] Another method of producing a flavor delivery according to the present invention may include a first step of preparing an aqueous composition containing a flavor formulation, a polysaccharide, an emulsifier, and an additive selected from a polycarboxylic acid, a salt containing bicarbonate functionality, and mixtures thereof, a second step of casting the aqueous composition onto a carrier sheet material placed on a substantially flat support surface, a third step of gelling the aqueous composition onto the carrier sheet material, and a fourth step of drying the gelled aqueous composition and the carrier sheet material. The dried flavor formulation, with the carrier sheet material carrying the polysaccharide matrix entrapping the flavor formulation, may then be removed from the support surface.

[0179] A further method for producing a flavor delivery according to the present invention may include a first step of preparing an aqueous composition containing a flavor formulation, a polysaccharide, an emulsifier, and an additive selected from a polycarboxylic acid, a salt containing bicarbonate functional groups, and mixtures thereof, a second step of spraying the aqueous composition onto a carrier sheet material (e.g., homogenized tobacco material) placed on a substantially flat support surface, a third step of gelling the aqueous composition onto the carrier sheet material, and a fourth step of drying the gelled aqueous composition and the carrier sheet material. The dried flavor formulation, in which the carrier sheet material carries a polysaccharide matrix entrapping the flavor formulation, may then be removed from the support surface.

[0180] The present disclosure relates to an aerosol-generating article including a flavoring material, wherein a flavoring agent formulation is releasable from the flavoring material upon heating. The flavoring material may include a matrix structure and a flavoring agent formulation dispersed within the matrix structure. The flavoring agent formulation is at least partially entrapped within the matrix structure and releasable from the matrix structure upon heating of the flavoring material. The matrix structure may be a polysaccharide matrix structure. The flavoring material may include greater than 0.1 weight percent of an additive selected from the group consisting of polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof.

[0181] According to another aspect of the present invention, there is provided an aerosol-generating article including a flavoring material, wherein the flavoring is releasable from the flavoring material upon heating of a flavor-delivery material. The flavoring material includes a polysaccharide matrix structure and a flavoring formulation dispersed within the polysaccharide matrix structure. The flavoring formulation is entrapped within the polysaccharide matrix structure and is releasable from the polysaccharide matrix structure upon heating of the flavoring material. The flavoring material includes greater than 0.1 weight percent of an additive selected from the group consisting of polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof.

[0182] As is clear from the foregoing description of flavoring materials according to the present invention, by incorporating such flavoring materials into aerosol-generating articles, it is possible to advantageously provide a new range of aerosol-generating articles in which flavor can be more easily and controlledly delivered to the consumer. Furthermore, because the flavoring agent formulation is at least partially trapped within the matrix until released when heat is supplied to the aerosol-generating article during use, loss of flavor species during storage and transport of the aerosol-generating article can be significantly reduced. Combined with enhanced flavor release at lower temperatures, this allows for particularly efficient use of the flavoring agent and other components of the flavoring agent formulation.

[0183] It has been found that aerosol-generating articles according to the present invention provide a more efficient release of flavour species during use compared to corresponding aerosol-generating articles containing equivalent flavour materials that do not contain additives in line with the foregoing description.

[0184] In particular, in certain embodiments, the release of flavor species has been observed to remain consistently high and not vary significantly from one puff to the next.

[0185] In certain embodiments, in an aerosol-generating article according to the present invention, the flavorant further comprises a carrier sheet material, and the polysaccharide matrix structure and flavorant formulation are carried by the carrier sheet material.

[0186] The carrier sheet material provides a support for the polysaccharide matrix structure that entraps the flavorant formulation, and therefore, by tailoring the composition and shape of the carrier sheet material, it may be possible to facilitate the manufacture of the aerosol-generating article.

[0187] In certain embodiments, the aerosol-generating article comprises a rod of aerosol-generating substrate, a downstream section provided downstream of the rod of aerosol-generating substrate and extending to the mouth end of the aerosol-generating article, and optionally an upstream section provided downstream of the rod of aerosol-generating substrate and extending to the distal end of the aerosol-generating article, and a flavourant is provided on at least one of the rod of aerosol-generating substrate, the downstream section and any upstream section.

[0188] Where the flavourant comprises a carrier sheet material as described above, the carrier sheet material may be a sheet of homogenized tobacco material. In these embodiments, the aerosol-generating article may comprise a rod of aerosol-generating substrate, a downstream section provided downstream of the rod of aerosol-generating substrate and extending to the mouth end of the aerosol-generating article, and optionally an upstream section provided downstream of the rod of aerosol-generating substrate and extending to the distal end of the aerosol-generating article, and the flavourant may be provided within the rod of aerosol-generating substrate.

[0189] Incorporation of flavoring materials into aerosol-generating articles according to the present invention can be accomplished according to one of several routes.

[0190] For example, pieces of flavouring material may be mixed with solid particles of aerosol-generating material, such as tobacco, to form a rod of aerosol-generating substrate in an aerosol-generating article.

[0191] Alternatively, or additionally, the pieces of flavorant may be provided at other locations within the aerosol-generating article, such as along a downstream section of the aerosol-generating article, which may include multiple components, such that the flavorant may be incorporated into any one of those components.

[0192] As a further alternative, the flavoring material comprising a carrier sheet material in the form of a paper wrapper may be used alone or in combination with another paper wrapper as a plug wrap for the rod of aerosol-generating article.

[0193] This list of possible arrangements is not intended to be exhaustive, and it will be apparent that different arrangements of the flavoring material within the aerosol-generating article may be possible, provided that sufficient heat is supplied to the flavoring material during use of the aerosol-generating article to release the flavoring agent formulation from the polysaccharide matrix.

[0194] Aerosol-generating articles containing flavorants according to the present invention may be used in combination with an aerosol-generating device, such as a handheld electric heater, configured to supply heat in a controlled manner to the aerosol-generating article, which can heat the aerosol-generating substrate and flavorant, thereby delivering a flavor-rich aerosol to the consumer.

[0195] Thus, the aerosol-generating article according to the present invention finds particular application in aerosol generation systems comprising an aerosol-generating device having a heating chamber in which the aerosol-generating article is received so that heat can be supplied to the aerosol-generating substrate. This may 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 or inductively heated. Alternatively, this may also be achieved by a resistively heated blade-shaped component of the aerosol-generating device that is inserted into the aerosol-generating substrate when the aerosol-generating article is inserted into the heating chamber.

[0196] According to yet another alternative, the susceptor element may be provided within the aerosol-generating substrate, and the aerosol-generating device may include an inductor for generating an alternating or fluctuating electromagnetic field. When an aerosol-generating article engages the aerosol-generating device, the fluctuating electromagnetic field generated by the inductor induces current in the susceptor element, heating it. The electrically operated aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes per meter (kA m), preferably 2 to 3 kA / m, e.g., about 2.5 kA / m. [Example]

[0197] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of any other example, embodiment, or aspect described herein.

[0198] Example 1: 1. A flavoring material for use in an aerosol-generating article, comprising: a polysaccharide matrix structure; a flavoring agent formulation dispersed within the polysaccharide matrix structure, the flavoring agent formulation being at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavoring material; and greater than 0.1 weight percent of an additive selected from the group consisting of polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof. Example 2: 10. The flavoring material of example 1, wherein the additive thermally decomposes at a temperature below 220 degrees Celsius and 1 bar. Example 3: 3. The flavoring material of example 1 or 2, wherein the additive begins to thermally decompose at a temperature at least 5 degrees Celsius below the temperature of thermal decomposition of the polysaccharide that forms the matrix structure. Example 4: 4. The flavoring material according to any one of Examples 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. Example 5: 5. The flavoring material of any one of Examples 1-4, wherein the additive comprises 25 weight percent or less of the flavoring material on a dry weight basis. Example 6: 6. The flavoring material of any one of Examples 1 to 5, wherein the additive comprises 10 weight percent or less of the flavoring material on a dry weight basis. Example 7: 7. The flavoring material of any one of Examples 1 to 6, wherein the additive comprises at least 1 weight percent of the flavoring material on a dry weight basis. Example 8: 8. The flavoring material according to any one of Examples 1 to 7, further comprising a carrier material, wherein the polysaccharide matrix structure, the flavoring agent formulation, and the additive are carried by the carrier material. Example 9: 9. The flavoring material of any one of Examples 1 to 8, wherein the polysaccharide matrix structure comprises gellan gum as the only polysaccharide or comprises gellan gum in combination with at least one further polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose, and hydroxypropyl methylcellulose. Example 10: The flavor material of Example 9, wherein the gellan gum comprises between 5 weight percent and 99.9 weight percent of the flavor material on a dry weight basis. Example 11: formula C n H 2n+2 11. The flavoring material according to any one of Examples 1 to 10, further comprising a polyol having On. Example 12: The flavoring material of Example 11, wherein the polyol is selected from the group consisting of glycerol, sorbitol, xylitol, mannitol, and erythritol. Example 13: The flavoring material of Examples 11 or 2, wherein the polyol comprises from 0.01 weight percent to 20 weight percent of the flavoring material on a dry weight basis. Example 14: 14. The flavoring material of any one of Examples 1-13, further comprising greater than 0.1 weight percent carbon particles, the carbon particles having a volume average particle size greater than 10 micrometers. Example 15: 15. The flavoring material of Example 14, wherein the carbon particles comprise one or more of graphite particles, expanded graphite particles, and graphene particles. Example 16: 16. The flavoring material of Example 14 or 15, wherein the carbon particles have a volume average particle size of 30 micrometers to 150 micrometers. Example 17: 17. The flavoring material according to any one of Examples 14 to 16, wherein the carbon particles have a particle size distribution having a D90 particle size and a D10 particle size, and the D90 particle size is 25 times or 15 times or less the D10 particle size. Example 18: 18. The flavoring material of any one of Examples 14 to 17, wherein the carbon particles comprise 0.01 weight percent to 10 weight percent of the flavoring material on a dry weight basis. Example 19: 19. The flavoring material according to any one of Examples 1 to 18, further comprising fiber. Example 20: The flavoring material of Example 20, wherein the fiber comprises from 0.01 weight percent to 10 weight percent of the flavoring material on a dry weight basis. Example 21: 21. The flavoring material of any one of Examples 1 to 20, comprising 0.01 weight percent to 80 weight percent menthol. Example 22: 22. The flavoring material of any one of Examples 8 to 21, wherein the carrier sheet material is a sheet of homogenized tobacco material. Example 23: An aerosol-generating article comprising the flavoring material described in any one of Examples 1 to 22. Example 24: An aerosol-generating article as described in Example 23, comprising a rod of aerosol-generating substrate, a downstream section provided downstream of the rod of aerosol-generating substrate and extending to the mouth end of the aerosol-generating article, and optionally an upstream section provided downstream of the rod of aerosol-generating substrate and extending to the distal end of the aerosol-generating article, wherein a flavor material is provided in at least one of the rod of the aerosol-generating substrate, the downstream section, and any upstream section. Example 25: An aerosol-generating article as described in Example 23 when dependent on any one of Examples 8 to 22, wherein the carrier material is a sheet of homogenized tobacco material or tobacco cut filler, the aerosol-generating article comprises a rod of aerosol-generating substrate, a downstream section provided downstream of the rod of aerosol-generating substrate and extending to the mouth end of the aerosol-generating article, and optionally an upstream section provided downstream of the rod of aerosol-generating substrate and extending to the distal end of the aerosol-generating article, and the flavor material is provided within the rod of aerosol-generating substrate.

[0199] The embodiments will now be further described with reference to the figures. [Brief explanation of the drawings]

[0200] [Figure 1] FIG. 1 shows a schematic cross-sectional side view of an aerosol-generating article according to the present invention, which comprises a flavorant on a rod within an aerosol-generating substrate. [Figure 2] FIG. 2 shows a scanning electron microscope image of the flavoring material used in the aerosol generator of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0201] Figure 1 shows an aerosol-generating article 10 according to the present invention. The aerosol-generating article 10 shown in Figure 1 comprises a rod of aerosol-generating substrate 12 and a downstream section 14 located downstream of the rod of aerosol-generating substrate 12. The aerosol-generating article 10 further comprises an upstream section 16 located upstream of the rod of aerosol-generating substrate 12.

[0202] A ventilation zone 60 is provided at a location downstream of the rod 12 of the aerosol-generating substrate.

[0203] More specifically, in the embodiment of Figure 1, the downstream section 14 comprises a mouthpiece element 18 and a hollow section 20. The hollow section 20 includes an aerosol-cooling element 22 comprising a hollow tubular element and a ventilation zone 60 comprising a plurality of openings formed through the wall of the hollow tubular element. The aerosol-cooling element 22 is located immediately downstream of the rod of aerosol-generating substrate 12. As shown in the drawing of Figure 1, the upstream end of the aerosol-cooling element 22 abuts the downstream end of the rod of aerosol-generating substrate 12. The mouthpiece element 18 is positioned immediately downstream of the aerosol-cooling element 22. As shown in the drawing of Figure 1, the upstream end of the mouthpiece element 18 abuts the downstream end of the aerosol-cooling element 22. The mouthpiece element 18 comprises a plug 24 of low-density filtration material.

[0204] The rod 12 includes an aerosol-generating substrate in the form of a collection of sheets of homogenized tobacco material, although other types of tobacco-containing substrates, such as tobacco cut filler, can replace the collection of sheets of homogenized tobacco material.

[0205] The upstream section 16 comprises a cylindrical plug 26 of compressed plasticized cellulose acetate surrounded by a wrapper 28. The plug 26 in the upstream section 16 is approximately 5 millimeters in length.

[0206] The aerosol-generating article further includes a flavorant 50. More particularly, a plurality of pieces of flavorant in sheet form are dispersed within the rod 12. The flavorant 50 is of the type described in detail above.

[0207] Examples of suitable formulations of flavorant 50, and processes for forming flavorant 50, are set forth below.

[0208] Preparation A - Flavor delivery material containing a menthol formulation entrapped in a gellan gum polysaccharide matrix + 5 weight percent additives 100g of water is heated to approximately 60°C and 3.0g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature between 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature between 70-75°C and 0.1g of lecithin, 1.2g of tartronic acid, and 8.0g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. The resulting aqueous composition is then cast onto a metal tray, gelled, and dried in a static oven at 65°C. This results in a sheet of additive-concentrated flavor material.

[0209] Preparation B - Flavor delivery material containing a menthol formulation entrapped in a gellan gum polysaccharide matrix + 10 weight percent additives 100g of water is heated to approximately 60°C and 3.0g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature between 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature between 70-75°C and 0.1g of lecithin, 2.4g of tartronic acid, and 8.0g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. The resulting aqueous composition is then cast onto a metal tray, gelled, and dried in a static oven at 65°C. This results in a sheet of additive-concentrated flavor material.

[0210] Preparation C - Flavor delivery material containing a menthol formulation entrapped in a gellan gum polysaccharide matrix + 5 weight percent additive on a carrier sheet material (homogenized tobacco material) 100g of water is heated to approximately 60°C and 3.0g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature between 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature between 70-75°C and 0.1g of lecithin, 1.2g of tartronic acid, and 8.0g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. The resulting aqueous composition is then cast onto a sheet of homogenized tobacco material placed on a metal tray, gelled, and dried in a static oven at 65°C. This results in an additive-enriched flavor material containing a layer of gellan gum matrix entrapping the menthol formulation immobilized on the sheet of homogenized tobacco material.

[0211] Comparative Preparation—Flavor Delivery Material Comprising a Menthol Formulation Entrapped in an Additive-Free Gellan Gum Polysaccharide Matrix 100g of water is heated to approximately 60°C and 3.0g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature between 80-85°C and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature between 70-75°C and 0.1g of lecithin and 8.0g of menthol are added to the mixture. The flavor-containing mixture is homogenized for 3 minutes. The resulting aqueous composition is then cast onto a metal tray, gelled, and dried in a static oven at 65°C. A sheet of additive-free flavor material is obtained.

[0212] Preparation D - Aerosol-generating article containing a flavor-delivering material prepared according to Preparation A An amount of flavor delivery material produced according to Preparation A was adjusted to an overall menthol content of 5 mg and added to a rod of a commercially available aerosol-generating article (HEET® by Philip Morris Products SA).

[0213] Morphological characterization 2 shows an SEM image of a flavor delivery material 150 made according to Formulation A embedded in wax. From the image, it can be seen that the internal structure of the flavor delivery material comprises a matrix 52 having a plurality of small pockets 54 adapted to trap flavor compositions, the pockets 54 being dispersed throughout the matrix 52. The domains are relatively uniformly distributed throughout the material and relatively consistent in size. The SEM technique cannot distinguish the additive from the rest of the matrix structure, and it is understood to be substantially uniformly dispersed.

[0214] thermogravimetric analysis The flavor release profile of flavor materials prepared according to the above formula can be analyzed by thermogravimetric analysis (TGA). TGA testing is performed using a thermogravimetric machine coupled to a mass spectrometer or similar TGA instrument. In the analysis, flavor materials are heated to 25°C to 400°C in an inert nitrogen atmosphere, with the temperature increasing at a rate of 15°C per minute and an airflow of 60 ml per minute. As the temperature increases, the release of menthol is assessed by detecting the menthol molecule via specific ions representing menthol.

[0215] Data collected from performing TGA tests on flavorants according to the present invention can be compared to data collected from performing equivalent TGA tests on the flavorant formulation alone (e.g., pure menthol). One such comparison can provide some information regarding the release mechanism and dynamics, which can be useful for fine-tuning the flavorant release profile when the flavorant is incorporated into an aerosol-generating article.

[0216] To provide a comparative reference, pure menthol in liquid form was also heated in the thermogravimetric analysis described above. Unimodal release of pure menthol was observed between 50°C and 166°C, with a maximum at approximately 138°C.

[0217] The menthol release profiles of the flavor materials produced according to Formulations A and B were compared to the menthol release profile of the flavor material produced according to the comparative formulation by plotting the cumulative amount of menthol released by each flavor material side by side.

[0218] The results of this comparison suggest that the inclusion of additives in flavorings tends to enhance the thermal release of menthol at lower temperatures: the flavorings of the comparative preparations only began to release significant menthol above 230°C, with nearly all of the menthol content being released as the temperature approached 300°C.

[0219] In contrast, the flavor material of Formulation A, which contained 5 weight percent tartronic acid, appeared to release a first fraction of its menthol content between 90 degrees Celsius and about 150 degrees Celsius, and a second fraction of its menthol content between 160 degrees Celsius and 250 degrees Celsius.

[0220] The flavor material of Formulation B, containing 10 weight percent tartronic acid, also appeared to begin releasing menthol at about 90 degrees Celsius, but continued to release the remainder of its menthol content at a significantly higher rate, with most of the menthol being released by the time the temperature reached about 180 degrees Celsius.

[0221] Interestingly, from a qualitative perspective, the cumulative menthol release profile of the flavor material from Preparation B was found to be similar to that of pure menthol, but shifted to higher temperatures by 20–30°C. In contrast, the cumulative menthol release profile of the flavor material from Preparation A suggested behavior substantially consistent with that of the flavor material from Preparation B at lower temperatures, while exhibiting a different behavior at higher temperatures due to a slower, more gradual release of the remaining menthol. Without wishing to be bound by theory, this may indicate that the higher the additive (tartronic acid) in the flavor material, the greater the disruption of the matrix structure, such that the matrix structure can no longer immobilize menthol at temperatures above 140°C. On the other hand, a smaller amount of additive (tartronic acid) causes some disruption of the matrix structure, such that menthol release begins at lower temperatures, but the remaining integrity of the matrix structure is maintained, and some of the menthol remains immobilized until higher temperatures are reached.

[0222] This comparison between the menthol release profiles of flavoring materials prepared according to Preparations A and B, along with the comparative preparation, indicates that adjusting the amount of additive in the flavoring material can help fine-tune flavor delivery when the flavoring material is incorporated into an aerosol-generating article. In particular, it may be possible to control the temperature at which flavor release begins and the temperature at which flavor release is maximized. Furthermore, flavoring materials that have different flavor release profiles when exposed to the same heating profile, such as those prepared according to Preparations A and B, can be combined in a single aerosol-generating article to provide consumers with even wider flavor delivery options.

[0223] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like should be understood in all instances to be modified by the term "about." Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. Thus, in this context, the number A is understood as A ± 5%. Within this context, the number A may be considered to include a numerical value that is within the typical standard error for the measurement of the property that the number A modifies. In some cases, as used in the appended claims, the number A may deviate by the percentages recited above, provided that the amount by which A deviates does not materially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. 1. A flavoring material for use in an aerosol-generating article, comprising: a polysaccharide matrix structure; a flavorant formulation dispersed within the polysaccharide matrix structure, wherein the flavorant formulation is at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavorant; and greater than 0.1 weight percent of an additive selected from the group consisting of polycarboxylic acids, salts containing bicarbonate functional groups, and mixtures thereof.

2. 10. The flavoring material of claim 1, wherein the additive pyrolyzes at a temperature below 220 degrees Celsius and 1 bar.

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

4. 4. The flavoring material according to claim 1, 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. 5. The flavoring material according to any one of claims 1 to 4, wherein the additive accounts for no more than 25 weight percent of the flavoring material on a dry weight basis, preferably no more than 10 weight percent of the flavoring material on a dry weight basis, or the additive accounts for at least 1 weight percent of the flavoring material on a dry weight basis, or both.

6. 6. The flavoring material according to claim 1, further comprising a carrier material, wherein the polysaccharide matrix structure, the flavoring agent formulation, and the additive are carried by the carrier material, and the carrier material is preferably a sheet of homogenized tobacco material.

7. 7. The flavoring material of any one of claims 1 to 6, wherein the polysaccharide matrix structure comprises gellan gum as the only polysaccharide or comprises gellan gum in combination with at least one further polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose, and hydroxypropyl methylcellulose, and wherein the gellan gum accounts for 5 to 99.9 percent by weight of the flavoring material on a dry weight basis.

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

9. 9. The flavoring material according to any one of claims 1 to 8, further comprising more than 0.1 percent by weight of carbon particles, said carbon particles having a volume average particle size of more than 10 micrometers, preferably between 30 micrometers and 150 micrometers.

10. The flavor material according to claim 9, wherein the carbon particles are one or more of graphite particles, expanded graphite particles, and graphene particles, and the carbon particles preferably account for 0.01 weight percent to 10 weight percent of the flavor material on a dry weight basis.

11. 11. The flavoring material of claim 9 or 10, wherein the carbon particles have a particle size distribution having a D90 particle size and a D10 particle size, the D90 particle size being no more than 25 or 15 times the D10 particle size.

12. 12. A flavouring material according to any one of claims 1 to 11, further comprising fibre, said fibre preferably comprising from 0.01 to 10 percent by weight of said flavouring material on a dry weight basis.

13. An aerosol-generating article comprising the flavoring material of any one of claims 1 to 12.

14. 14. An aerosol-generating article according to claim 13, comprising: a rod of aerosol-generating substrate; a downstream section provided downstream of the rod of aerosol-generating substrate and extending to the mouth end of the aerosol-generating article; and optionally an upstream section provided downstream of the rod of aerosol-generating substrate and extending to the distal end of the aerosol-generating article, wherein the flavoring material is provided in at least one of the rod of aerosol-generating substrate, the downstream section, and any upstream section.

15. 14. The 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 homogenized tobacco material or tobacco cut filler, the aerosol-generating article comprises a rod of aerosol-generating substrate, a downstream section provided downstream of the rod of aerosol-generating substrate and extending to the mouth end of the aerosol-generating article, and optionally an upstream section provided downstream of the rod of aerosol-generating substrate and extending to the distal end of the aerosol-generating article, and the flavorant is provided within the rod of aerosol-generating substrate.

Images