KR20250071270A - Supported flavouring substances for aerosol generating articles or nicotine containing products - Google Patents

Abstract

A flavoring material (50) for use in an aerosol-generating article is provided, wherein the flavoring material is releasable from the flavoring material when the flavoring material is heated. The flavoring material (50) comprises: a polysaccharide matrix structure comprising gellan gum and an emulsifier; a flavoring formulation dispersed within the polysaccharide matrix structure, wherein the flavoring formulation is at least partially entrapped within the polysaccharide matrix structure and is releasable from the polysaccharide matrix structure when the flavoring material is heated; and a carrier sheet material, wherein the polysaccharide matrix structure and the flavoring formulation are supported by the carrier sheet material. Also provided is an aerosol-generating article (10) comprising one such flavoring material (50).

Description

Supported flavouring substances for aerosol generating articles or nicotine containing products

The present disclosure relates to a flavoring material for use in an aerosol-generating article. The present disclosure also relates to an aerosol-generating article comprising one such flavoring material.

Aerosol-generating articles are known in the art in which an aerosol-generating substrate, such as a tobacco-containing substrate or a non-tobacco nicotine-containing substrate, is heated without combustion. Typically, in such heated smoking articles, the aerosol is generated by heat transfer from a heat source to a physically separate aerosol-generating substrate or material, which may be 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 entrained into air drawn through the aerosol-generating article. As the released compounds cool, the compounds condense to form an aerosol.

Several aerosol-generating devices for consuming an aerosol-generating article have been disclosed in the art. Such devices include, for example, electrically heated aerosol-generating devices in which the 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 which comprises an internal heater blade adapted to be inserted within an aerosol-generating substrate. Alternatively, an inductively heatable aerosol-generating article comprising an aerosol-generating substrate and a susceptor arranged within the aerosol-generating substrate has been proposed by WO 2015/176898.

In addition to the aerosol-generating substrate, it has been proposed to include a flavouring source in the aerosol-generating article. Indeed, this practice is relatively common in conventional filter cigarettes, and a number of solutions have been described in the art for providing the flavouring agent at a location within the tobacco filler rod or within the mouthpiece filter.

However, given how the aerosol is generated and delivered to the consumer from the aerosol-generating article, it may be difficult to ensure consistent flavor delivery during use, so that the consumer may perceive fluctuations or decreases in flavor intensity over time. Additionally, even before the aerosol-generating article is used, some flavor species may be lost during certain production steps or during transportation and storage of the aerosol-generating article.

For example, it has been previously proposed to reduce the loss of volatile flavourants during smoking of conventional filter cigarettes by encapsulating flavourants, for example in capsule or microcapsule form containing the flavour formulation, during storage. The encapsulated flavourants may be released prior to or during smoking of the filter cigarette by breaking open the encapsulating structure, for example by manually crushing the structure. However, the encapsulated flavourants are typically released from the encapsulating structure in a single rupture, and thus one such solution may not provide consistently strong flavour delivery during use of the article.

Therefore, it is believed that there is a need to provide aerosol-generating articles containing flavouring substances as well as flavouring agents, which are associated with enhanced flavour perception for consumers, particularly towards the end of the use cycle of the aerosol-generating article.

The present disclosure relates to a flavoring material for use in an aerosol-generating article, wherein a flavoring formulation is capable of being released from the flavoring material upon heating the flavoring material. The flavoring material can include a matrix structure and a flavoring formulation dispersed within the matrix structure. The flavoring formulation is at least partially entrapped within the matrix structure and can be released from the matrix structure upon heating of the flavoring material. The matrix structure can be a polysaccharide matrix structure. The flavoring material can include a carrier sheet material, wherein the polysaccharide matrix structure and the flavoring formulation are supported by the carrier sheet material.

According to one aspect of the present invention, a flavoring material for use in an aerosol-generating article is provided; the flavoring material comprises a polysaccharide matrix structure; and a flavoring formulation dispersed within the polysaccharide matrix structure. The flavoring formulation is at least partially entrapped within the polysaccharide matrix structure and is capable of being released from the polysaccharide matrix structure upon heating of the flavoring material. The flavoring material comprises a carrier sheet material, wherein the polysaccharide matrix structure and the flavoring formulation are supported by the carrier sheet material.

As used herein, the term "sheet material" refers to a thin layer of material whose width and length are substantially greater than their thickness. For example, the carrier sheet material may be a sheet of homogenized tobacco material or a sheet of paper material. Examples of homogenized tobacco material suitable for producing a flavouring substance according to the present invention will be described in more detail below.

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

As used herein with reference to the present invention, the term "aerosol-generating substrate" is used to describe a substrate comprising an aerosol-forming material capable of releasing a volatile compound upon heating, which is capable of generating an aerosol.

As used herein and in reference to the present invention, the term "aerosol" is used to describe a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets in a gas. An aerosol may be visible or invisible. An aerosol may include a vapor of a substance that is normally a liquid or solid at room temperature, as well as solid particles, or liquid droplets, or a combination of solid particles and liquid droplets.

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

An aerosol-generating article according to the present invention has a proximal end through which an 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 the mouth end of the aerosol-generating article. During use, a user inhales, directly or indirectly, on the proximal end of the aerosol-generating article to inhale the aerosol generated by the aerosol-generating article.

An 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 an upstream end of the aerosol-generating article.

The 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 positions between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article.

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

As used herein in connection with the present invention, the term “length” is used to describe the maximum dimension of an aerosol-generating article or a component of an aerosol-generating article in the longitudinal direction.

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

As used herein in connection with the present invention, the term "width" refers to the maximum dimension of an aerosol-generating article or a component of an aerosol-generating article in a transverse direction. When 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. When a 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.

As used herein in connection with the present invention, the term "hollow tubular element" is used to refer to a generally cylindrical element having a lumen along its longitudinal axis. The tubular portion may have a substantially circular, oval, or elliptical cross-section. The lumen may have a substantially circular, oval, or elliptical cross-section. In particular, the term "hollow tubular element" is used to describe an element that defines at least one airflow conduit that establishes unobstructed fluid communication between an upstream end of the hollow tubular element and a downstream end of the tubular element.

It has been found that the inclusion of a carrier sheet material in the flavouring substance according to the present invention improves the structural strength of the flavouring substance by the carrier sheet material supporting and holding in place the polysaccharide matrix that captures the flavouring formulation. By selecting and adjusting certain properties of the carrier sheet material (e.g. thickness), it is possible to obtain a flavouring substance which is particularly resistant to wear and has particularly good mechanical properties.

Compared to flavouring substances having a similar composition and matrix structure but lacking the support of a carrier sheet material, it has therefore been found that the flavouring substance according to the invention is easier to handle and can be more conveniently stored, for example in the form of bobbins. This advantageously facilitates their integration into aerosol-generating articles, especially within the framework of high-speed automated manufacturing processes.

The flavouring material according to the present invention also has the advantage that the polysaccharide matrix structure and the flavouring formulation entrapped therein are deposited on the carrier sheet material to form a flavouring material that is substantially in the form of a sheet and that can be cut into pieces having a predetermined average size (e.g., a predetermined cut width or a predetermined cut length or both). This facilitates combining the flavouring material according to the present invention with an aerosol-generating substrate in certain aerosol-generating articles, as will be described in more detail below.

In some embodiments, the carrier sheet material may alternatively comprise a plurality of pieces cut from the 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 naturally occurring plant material, preferably plant leaf material (e.g., tobacco sheath).

In the flavoring material according to the present invention, the polysaccharide matrix structure entrapping the flavoring agent formulation can be formed in situ on the carrier sheet material. If this in situ forming step follows a manufacturing process by which the carrier sheet material can be obtained, the in situ forming step can even be performed later or at a different location.

In general, it has been recognized that the use of flavouring materials in aerosol-generating articles, where the aerosol-generating substrate is intended to be heated to generate an aerosol, presents different challenges and poses different constraints than those encountered in the past in conventional cigarettes, where the substrate is combusted to generate smoke. The inventors have found that it may be advantageously possible to fine-tune the specific properties of a flavouring material to the specific needs associated with its use in an aerosol-generating article by adjusting the relative proportions of the various components in the formulation, by altering the composition of the matrix - for example, by selecting a particular combination of polysaccharides to form the matrix - or both. For example, the flavour release profile may be adjusted so that the flavour is released in more continuous "waves" during use. As a result, the consumer may perceive a more intense or sustained flavour sensation for a longer period during use. Thus, the flavouring material according to the present invention may provide a wider range of flavour profiles that are not accessible to known flavouring materials.

When the flavouring material according to the present invention is incorporated into an aerosol-generating article, such as a heated-non-combustion article configured to generate an aerosol upon heating a tobacco-containing aerosol-generating substrate, the flavour release per puff has been found to be generally more efficient.

Since the flavouring agent formulation is at least partially entrapped within the matrix until it is released upon heating, the flavouring agent according to the invention has been found to exhibit increased stability. For example, it has been observed that even under stress conditions, during storage, transportation etc., a significantly reduced loss of flavouring species occurs. Combined with the improved flavour release, this allows for a particularly efficient use of the flavouring agent and other components of the flavouring agent formulation.

Preferably, the polysaccharide matrix structure comprises gellan gum and an emulsifier. The term "gellan gum" is used to identify a water-soluble anionic polysaccharide produced by the bacterium Sphingomonas elodea . The repeating unit of the polymer is a tetrasaccharide consisting of two 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, Korea and the European Union.

Two forms of gellan gum are known, namely high acyl gellan gum and low acyl gellan gum, which differ in the degree/% of substitution by O-acyl groups.

In the flavoring substance according to the present invention, the gellan gum is preferably a low acyl gellan gum. This is a partially deacylated or fully deacylated gellan gum. The most common form is a fully deacylated form without detectable acyl groups, which is also called deacetylated gellan gum.

The use of low acyl gellan gum to form the polysaccharide matrix of the flavoring substance 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 generally forming firmer, less elastic, and more brittle gels than high acyl gellan gum.

In embodiments where the polysaccharide matrix structure comprises gellan gum and an emulsifier, a significant portion of the flavor formulation can advantageously be provided with a flavor agent that is effectively entrapped within the polysaccharide matrix structure. This is advantageous in that it improves the stability of the flavor agent. Furthermore, as discussed in more detail below, it can help to tailor the flavor agent release profile during use, as it affects how flavor species are released when the flavor agent is heated.

Furthermore, from a manufacturing standpoint, a stable polysaccharide matrix structure comprising gellan gum and an emulsifier can be formed by supplying heat to the starting reagents without requiring the use of a cross-linking agent. In fact, by kneading and emulsifying the flavor formulation and gellan gum in a heated water bath, the polysaccharide-coated flavoring agent can be brought into an emulsified state, which is then substantially preserved after drying and cooling. Advantageously, this allows a considerable amount of flavoring agent to be provided in a fixed state within the polysaccharide matrix, so that a flavoring substance having a high flavoring agent content can be provided.

Preferably, the emulsifier is lecithin. The use of lecithin as an emulsifier is advantageous in that it is widely 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 this purpose by both the US Food and Drug Administration and the EU authorities. Thus, the pairing of gellan gum and lecithin is specifically designed for inclusion in flavoring substances for human use.

Preferably, when the polysaccharide matrix comprises gellan gum and an emulsifier, gellan gum constitutes from 5 wt % to 99.9 wt % of the flavoring material on a dry weight basis.

More preferably, gellan gum constitutes at least 7 wt. % of the flavoring material on a dry weight basis, and even more preferably at least 10 wt. % of the flavoring material on a dry weight basis.

Gellan gum preferably constitutes at most 80 wt.-% of the flavouring material on a dry weight basis, more preferably at most 60 wt.-% of the flavouring material on a dry weight basis, even more preferably at most 40 wt.-% of the flavouring material on a dry weight basis, and particularly preferably at most 30 wt.-% of the flavouring material on a dry weight basis.

In some embodiments, the gellan gum constitutes from 5 wt % to 80 wt % of the flavor material on a dry weight basis, preferably from 5 wt % to 60 wt % of the flavor material on a dry weight basis, more preferably from 5 wt % to 40 wt % of the flavor material on a dry weight basis, and even more preferably from 5 wt % to 30 wt % of the flavor material on a dry weight basis.

In another embodiment, the gellan gum constitutes from 10 wt % to 80 wt % of the flavor material on a dry weight basis, preferably from 10 wt % to 60 wt % of the flavor material on a dry weight basis, more preferably from 10 wt % to 40 wt % of the flavor material on a dry weight basis, and even more preferably from 10 wt % to 30 wt % of the flavor material on a dry weight basis.

The emulsifier can comprise from 0.01% to 2% by weight of the flavoring material on a dry weight basis. Preferably, the emulsifier comprises from 0.02% to 2% by weight of the flavoring material on a dry weight basis. More preferably, the emulsifier comprises from 0.05% to 2% by weight of the flavoring material on a dry weight basis. Even more preferably, the emulsifier comprises from 0.1% to 2% by weight of the flavoring material on a dry weight basis.

In a preferred embodiment, the emulsifier is lecithin and constitutes from 0.01% to 2% by weight of the flavoring material on a dry weight basis. Preferably, the lecithin constitutes from 0.02% to 2% by weight of the flavoring material on a dry weight basis. More preferably, the lecithin constitutes from 0.05% to 2% by weight of the flavoring material on a dry weight basis. Even more preferably, the lecithin constitutes from 0.1% to 2% by weight of the flavoring material on a dry weight basis.

In certain embodiments, the polysaccharide matrix structure comprises gellan gum as the sole polysaccharide.

In another embodiment, 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 carboxymethyl cellulose, and hydroxypropyl methyl cellulose.

Flavouring materials according to the present invention, wherein the polysaccharide matrix structure comprises gellan gum in combination with one or more of the polysaccharides listed above, have been found to provide different flavouring agent release profiles upon heating. For example, in embodiments wherein the polysaccharide matrix structure comprises gellan gum in combination with another of the polysaccharides listed above, flavouring agent release profiles were observed which were characterized by two distinct peaks at two different temperatures. Without wishing to be bound by theory, it is postulated that this is due to different strengths of interaction between the flavouring agent and each of the polysaccharides within the matrix structure, and may also be related to each of the polysaccharides undergoing thermal degradation at slightly different temperatures.

Since different combinations of polysaccharides within the matrix structure will generally result in slightly different flavorant release profiles when the flavorant is heated, embodiments in which gellan gum is combined with one or more of the other polysaccharides listed above may advantageously be used to fine-tune flavorant release during use of an aerosol-generating article containing the flavorant. Additionally, different flavorant materials containing a polysaccharide matrix structure, each comprising a different combination of polysaccharides, may be used in combination in a single aerosol-generating article to further tune and control flavorant delivery over the entire use cycle of the aerosol-generating article. For example, incorporating different flavorant materials according to the present invention into a single aerosol-generating article, wherein the different flavorant materials are configured to release a majority of the flavorant at different temperatures or at different times during the use cycle, may help to keep the overall flavor delivery substantially constant throughout.

In embodiments of the flavoring material comprising gellan gum in combination with at least one of the additional polysaccharides listed above, the at least one additional polysaccharide can constitute at least 0.01 wt % of the flavor delivery material on a dry weight basis. Preferably, the at least one additional polysaccharide constitutes at least 0.1 wt % of the flavor delivery material on a dry weight basis. More preferably, the at least one additional polysaccharide constitutes at least 1.0 wt % of the flavor delivery material on a dry weight basis. Even more preferably, the at least one additional polysaccharide constitutes at least 2.0 wt % of the flavor delivery material on a dry weight basis. In a particularly preferred embodiment, the at least one additional polysaccharide constitutes at least 5 wt % of the flavor delivery material on a dry weight basis.

In embodiments of the flavor material comprising gellan gum in combination with at least one of the additional polysaccharides listed above, the at least one additional polysaccharide can constitute no more than 80 wt% of the flavor delivery material on a dry weight basis. Preferably, the at least one additional polysaccharide constitutes no more than 35 wt% of the flavor delivery material on a dry weight basis. More preferably, the at least one additional polysaccharide constitutes no more than 25 wt% of the flavor delivery material on a dry weight basis. Even more preferably, the at least one additional polysaccharide constitutes no more than 15 wt% of the flavor delivery material on a dry weight basis.

In some embodiments, the at least one additional polysaccharide constitutes from 1.0 wt % to 35 wt % of the flavor delivery material on a dry weight basis, preferably from 2.0 wt % to 35 wt % of the flavor delivery material on a dry weight basis, more preferably from 5.0 wt % to 35 wt % of the flavor delivery material on a dry weight basis.

In another embodiment, the at least one additional polysaccharide constitutes from 1.0 wt % to 25 wt % of the flavor delivery material on a dry weight basis, preferably from 2.0 wt % to 25 wt % of the flavor delivery material on a dry weight basis, more preferably from 5.0 wt % to 25 wt % of the flavor delivery material on a dry weight basis.

In a further embodiment, the at least one additional polysaccharide constitutes from 1.0 wt % to 15 wt % of the flavour delivery material on a dry weight basis, preferably from 2.0 wt % to 15 wt % of the flavour delivery material on a dry weight basis, more preferably from 5.0 wt % to 15 wt % of the flavour delivery material on a dry weight basis.

The flavoring material can comprise at least 0.01 wt % of a flavoring agent on a dry weight basis. Preferably, the flavoring material comprises at least 1 wt % of a flavoring agent on a dry weight basis. More preferably, the flavoring material comprises at least 5 wt % of a flavoring agent on a dry weight basis. Even more preferably, the flavoring material comprises at least 10 wt % of a flavoring agent on a dry weight basis.

In certain embodiments, the flavoring material comprises at least 20% by weight of a flavoring agent on a dry weight basis, preferably at least 25% by weight of a flavoring agent on a dry weight basis, more preferably at least 30% by weight of a flavoring agent on a dry weight basis.

The flavoring material can have up to 90 wt % of a flavoring agent on a dry weight basis. Preferably, the flavoring material can have up to 85 wt % of a flavoring agent on a dry weight basis. More preferably, the flavoring material can have up to 80 wt % of a flavoring agent on a dry weight basis. Even more preferably, the flavoring material can have up to 75 wt % of a flavoring agent on a dry weight basis.

In certain preferred embodiments, the flavoring material comprises from 20 wt % to 80 wt % of the flavoring agent on a dry weight basis, preferably from 25 wt % to 80 wt % of the flavoring agent on a dry weight basis, more preferably from 30 wt % to 80 wt % of the flavoring agent on a dry weight basis.

In another preferred embodiment, the flavoring material comprises from 20 wt % to 75 wt % of the flavoring agent on a dry weight basis, preferably from 25 wt % to 75 wt % of the flavoring agent on a dry weight basis, more preferably from 30 wt % to 75 wt % of the flavoring agent on a dry weight basis.

Suitable flavoring agents for inclusion in the flavor formulations of the flavoring substances according to the present invention include, but are not limited to, menthol, limonene, and eugenol.

Menthol is a monoterpenoid that can be made synthetically or obtained from the oils of peppermint or other mints. It has a minty aroma and a cooling taste.

Limonene is a cyclic monoterpene, commonly found in the oils of citrus fruit peels. It is also a component of the aromatic resins of many coniferous and deciduous trees. It has a citrusy aroma.

Eugenol is an allyl chain-substituted guaiacol, commonly found in the essential oils of clove, nutmeg, cinnamon, basil, and bay leaf. It has a spicy, clove-like flavor.

The present inventors have found that menthol and limonene can be fairly easily captured and fixed within a polysaccharide matrix, and therefore, a flavouring substance containing a flavouring formulation containing menthol, limonene or a mixture thereof exhibits very good stability.

In a preferred embodiment, the flavoring formulation comprises menthol.

The flavoring material can comprise at least 0.01 wt % menthol on a dry weight basis. Preferably, the flavoring material comprises at least 1 wt % menthol on a dry weight basis. More preferably, the flavoring material comprises at least 5 wt % menthol on a dry weight basis. Even more preferably, the flavoring material comprises at least 10 wt % menthol on a dry weight basis.

In certain embodiments, the flavoring substance comprises at least 20% by weight menthol on a dry weight basis, preferably at least 25% by weight menthol on a dry weight basis, more preferably at least 30% by weight menthol on a dry weight basis.

The flavoring material can have up to 90 wt % menthol on a dry weight basis. Preferably, the flavoring material can have up to 85 wt % menthol on a dry weight basis. More preferably, the flavoring material can have up to 80 wt % menthol on a dry weight basis. Even more preferably, the flavoring material can have up to 75 wt % menthol on a dry weight basis.

In certain preferred embodiments, the flavoring substance comprises from 20% to 80% by weight menthol on a dry weight basis, preferably from 25% to 80% by weight menthol on a dry weight basis, more preferably from 30% to 80% by weight menthol on a dry weight basis.

In another preferred embodiment, the flavoring material comprises from 20 wt % to 75 wt % menthol on a dry weight basis, preferably from 25 wt % to 75 wt % menthol on a dry weight basis, more preferably from 30 wt % to 75 wt % menthol on a dry weight basis.

In some embodiments, the flavor formulation comprises particulate plant material. The particulate plant material can be obtained by crushing, grinding, or crushing plant material, such as plant leaves, plant stems, flowers, seeds, and the like.

The use of particulate plant material has been found to advantageously provide a stable method for incorporating flavour compounds into flavouring substances according to the present invention, which allows for optimised delivery of the flavour into the aerosol during use.

In some preferred embodiments, the particulate plant material is selected from one or more of clove particles, star anise particles, rosemary particles, peppermint particles, sage particles, chamomile particles, and lavender particles. Preferably, the particulate plant material is selected from clove particles, star anise particles, and rosemary particles. More preferably, the particulate plant material consists of clove particles.

As is known, cloves are the effectively dried flower buds and stems of the clove tree ( Syzygium aromaticum ), a tree of the Myrtaceae family, and are commonly used as a spice. Accordingly, each clove comprises a calyx, and a corolla of unopened petals forming a globular portion attached to the calyx. The term "clove particles" as used herein encompasses particles derived from clove tree ( Syzygium aromaticum ) buds and stems, and may include whole cloves, milled or ground cloves, or cloves that have been physically processed to reduce particle size.

Providing clove particles in a flavoring agent for use in aerosol generating articles is desirable in certain markets because it provides a unique sensory user experience that is popular with some users.

Clove has a distinctive and aromatic odor, which is due to the presence of one or more flavoring compounds, which are volatile compounds in the plant material and volatilize when heated. The main component of clove essential oil is eugenol (4-allyl-2-methoxyphenol, chemical formula: C10H12O2, Chemical Abstracts Service Registry Number 97-53-0). Eugenol is the compound primarily responsible for the clove aroma, and typically makes up about 70% to about 90% of clove essential oil. However, clove flavor also includes, but is not limited to, other compounds such as acetyl eugenol, beta-caryophyllene and vanillin, crategolic acid, tannins such as bicornin, gallotannic acid, methyl salicylate, the flavonoids eugenin, kaempferol, rhamnetin and eugenitin, triterpenoids such as olenolic acid, and sesquiterpenes. The presence of clove flavor can be determined by measuring the eugenol content in an aerosol produced when the plant material is heated. However, the presence of clove flavor can also be determined by measuring the content of other compounds found in clove essential oil, including but not limited to those listed above.

Preferably, the flavoring material comprises at least 0.001 wt % of particulate plant material. More preferably, the flavoring material comprises at least 0.01 wt % of particulate plant material. Even more preferably, the flavoring material comprises at least 0.1 wt % of particulate plant material.

In a particularly preferred embodiment, the flavouring substance comprises at least 1 wt. % of particulate plant material, preferably at least 2 wt. % of particulate plant material, more preferably at least 5 wt. % of particulate plant material, even more preferably at least 10 wt. % of particulate plant material.

Preferably, the flavoring substance comprises no more than 80 wt% particulate plant material. More preferably, the flavoring substance comprises no more than 70 wt% particulate plant material. Even more preferably, the flavoring substance comprises no more than 60 wt% particulate plant material.

In some embodiments, the flavoring agent comprises from 1 wt % to 80 wt % particulate plant material, preferably from 2 wt % to 80 wt % particulate plant material, more preferably from 5 wt % to 80 wt % particulate plant material, and even more preferably from 10 wt % to 80 wt % particulate plant material.

In another embodiment, the flavoring agent comprises 1 wt % to 70 wt % of particulate plant material, preferably 2 wt % to 70 wt % of particulate plant material, more preferably 5 wt % to 70 wt % of particulate plant material, and even more preferably 10 wt % to 70 wt % of particulate plant material.

In a further embodiment, the flavoring substance comprises 1 wt % to 60 wt % of particulate plant material, preferably 2 wt % to 60 wt % of particulate plant material, more preferably 5 wt % to 60 wt % of particulate plant material, and even more preferably 10 wt % to 60 wt % of particulate plant material.

In some embodiments, the flavoring agent further comprises a polyol having the formula C _n H _2n+2 O _n .

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 be referred to as diols, triols, and tetrols, respectively.

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

Incorporating a polyol into the flavoring agent has a beneficial effect on its flexibility. This can make the flavoring agent easier to handle and provide it with a desired shape, which can facilitate its incorporation into an aerosol-generating article.

Preferably, in embodiments where the flavoring material comprises a polyol as described above, the polyol constitutes from 0.01 wt % to 20 wt % of the flavoring material on a dry weight basis. More preferably, the polyol constitutes from 0.01 wt % to 15 wt % of the flavoring material on a dry weight basis. Even more preferably, the polyol constitutes from 0.01 wt % to 10 wt % of the flavoring material on a dry weight basis.

In some embodiments, the flavoring material comprises fibers, preferably cellulose fibers. The incorporation of fibers, particularly cellulose fibers, can 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 comprising the flavoring material. The advantage is particularly felt in embodiments where the polysaccharide matrix entrapping the flavoring formulation is not supported by a carrier material.

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

In embodiments of the flavoring material comprising cellulose fibers, the cellulose fibers can constitute at least 0.01 wt % of the flavoring material on a dry weight basis. Preferably, the cellulose fibers constitute at least 0.05 wt % of the flavoring material on a dry weight basis. More preferably, the cellulose fibers constitute at least 0.5 wt % of the flavoring material on a dry weight basis. Even more preferably, the cellulose fibers constitute at least 1.0 wt % of the flavoring material on a dry weight basis. In a particularly preferred embodiment, the cellulose fibers constitute at least 2.0 wt % of the flavoring material on a dry weight basis.

The cellulose fibers can constitute no more than 10 wt % of the flavor material on a dry weight basis. Preferably, the cellulose fibers constitute no more than 8.0 wt % of the flavor material on a dry weight basis. More preferably, the cellulose fibers constitute no more than 7.0 wt % of the flavor material on a dry weight basis. Even more preferably, the cellulose fibers constitute no more than 5.0 wt % of the flavor material on a dry weight basis.

In some embodiments, the fibers constitute from 0.01% to 10% by weight of the flavor material on a dry weight basis. Preferably, the fibers constitute from 0.01% to 8.0% by weight of the flavor material on a dry weight basis. More preferably, the fibers constitute from 0.01% to 7.0% by weight of the flavor material on a dry weight basis. Even more preferably, the fibers constitute from 0.01% to 5% by weight of the flavor material on a dry weight basis.

In another embodiment, the fibers constitute from 1.0 wt % to 10 wt % of the flavor material on a dry weight basis. Preferably, the fibers constitute from 1.0 wt % to 8.0 wt % of the flavor material on a dry weight basis. More preferably, the fibers constitute from 1.0 wt % to 7.0 wt % of the flavor material on a dry weight basis. Even more preferably, the fibers constitute from 1.0 wt % to 5 wt % of the flavor material on a dry weight basis.

In a further embodiment, the fibers constitute from 2.0 wt % to 10 wt % of the flavor material on a dry weight basis. Preferably, the fibers constitute from 2.0 wt % to 8.0 wt % of the flavor material on a dry weight basis. More preferably, the fibers constitute from 2.0 wt % to 7.0 wt % of the flavor material on a dry weight basis. Even more preferably, the fibers constitute from 2.0 wt % to 5 wt % of the flavor material on a dry weight basis.

In some embodiments, the flavoring material according to the present invention may comprise a calcium salt or a magnesium salt or both, such as calcium chloride or calcium lactate.

In embodiments where the flavoring agent comprises a calcium salt or a magnesium salt or both, the salt or salts constitute from 0.01 wt % to 10 wt % on a dry weight basis. Preferably, the salt or salts constitute from 0.01 wt % to 5 wt % on a dry weight basis.

The flavoring substance according to the present invention may generally contain water. This is because the flavoring substance will generally be prepared by combining the various compounds described above in an aqueous bath. After drying, the water content will be reduced, but may generally not be zero.

Therefore, the flavoring substance according to the present invention may contain 0.01 wt% to 10 wt% water, preferably 0.01 wt% to 8 wt% water, more preferably 0.01 wt% to 6 wt% water, and even more preferably 0.01 wt% to 4 wt% water.

In some embodiments, the flavoring agent comprises from 0.5 wt % to 10 wt % water, preferably from 0.01 wt % to 8 wt % water, more preferably from 0.5 wt % to 6 wt % water, and even more preferably from 0.5 wt % to 4 wt % water.

In another embodiment, the flavoring substance comprises from 1.0 wt % to 10 wt % water, preferably from 1.0 wt % to 8 wt % water, more preferably from 1.0 wt % to 6 wt % water, and even more preferably from 1.0 wt % to 4 wt % water.

In a further embodiment, the flavoring substance comprises from 1.5 wt % to 10 wt % water, preferably from 1.5 wt % to 8 wt % water, more preferably from 1.5 wt % to 6 wt % water, even more preferably from 1.5 wt % to 4 wt % water.

As mentioned above, in some preferred embodiments, the carrier sheet material may be in the form of a sheet of homogenized tobacco material.

As used herein, the term "homogenized tobacco material" includes any tobacco material formed by agglomerating particles of tobacco material. Sheets or webs of homogenized tobacco material are formed by agglomerating particulate tobacco obtained by grinding or otherwise pulverizing one or both of the tobacco leaf lamina and the tobacco leaf stem. The homogenized tobacco material may also include trace amounts of one or more of tobacco dust, tobacco fines, and other particulate tobacco byproducts formed during the processing, handling, and shipping of the tobacco. Sheets of homogenized tobacco material may be manufactured by casting, extrusion, papermaking, or any other suitable process known in the art.

The sheet or web of homogenized tobacco material for use in the present invention can have a tobacco content of at least about 40 wt % on a dry weight basis, more preferably at least about 60 wt % on a dry weight basis, more preferably at least about 70 wt % on a dry weight basis, and most preferably at least about 90 wt % on a dry weight basis.

The sheet or web of homogenized tobacco material for use as a carrier sheet material may comprise one or more intrinsic binders, which are tobacco-intrinsic binders, one or more extrinsic binders, which are tobacco-extrinsic binders, or a combination thereof, to help agglomerate the particulate tobacco. Alternatively, or additionally, the sheet or web of homogenized tobacco material for use as a carrier sheet material may comprise other additives, including but not limited to, tobacco and non-tobacco fibers, aerosol formers, humectants, plasticizers, flavoring agents, fillers, aqueous and non-aqueous solvents, and combinations thereof.

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

Suitable non-tobacco fibers for incorporation into a sheet or web of homogenized tobacco material for use as a carrier sheet material are known in the art and include, but are not limited to, cellulosic fibers; softwood fibers; hardwood fibers; jute fibers; and combinations thereof. Prior to incorporation into a sheet of homogenized tobacco material for use as a carrier sheet material, the non-tobacco fibers can be treated by any suitable process known in the art including, but not limited to, mechanical pulping; refining; chemical pulping; bleaching; sulfate pulping; and combinations thereof.

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

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 and glycerin; esters of polyhydric alcohols such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

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

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

The sheet or web of homogenized tobacco material has an aerosol former content of greater than 10% on a dry weight basis. Preferably, the sheet or web of homogenized tobacco material has an aerosol former content of greater than 12% on a dry weight basis. Preferably, the sheet or web of homogenized tobacco material has an aerosol former content of greater than 14% on a dry weight basis. Preferably, the sheet or web of homogenized tobacco material has an aerosol former content of greater than 16% on a dry weight basis.

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

In a preferred embodiment, the sheet of homogenized tobacco material has an aerosol former content of about 20% on a dry weight basis.

Sheets or webs of homogenized tobacco for use as carrier sheet material in the flavouring material of the present invention can be made by methods known in the art, for example by the methods disclosed in international patent application WO-A-2012/164009 A2. In a preferred embodiment, the sheets of homogenized tobacco material for use as carrier sheet material are formed by a casting process from a slurry comprising particulate tobacco, guar gum, cellulose fibers and glycerin.

In another embodiment, the carrier sheet material can be in the form of a sheet of non-tobacco aerosol-generating material. For example, the carrier sheet material can be a sheet of a sorbent non-tobacco material loaded with nicotine (e.g., in the form of a nicotine salt) and an aerosol-forming agent. Examples of such loads are described in international application WO-A-2015/082652. Additionally or alternatively, the carrier sheet material can be a sheet of homogenized non-tobacco plant material, such as an aromatic non-tobacco plant material.

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 can be used as an alternative to, or in addition to, conventional paper wrapper materials in the manufacture of aerosol-generating articles. Thus, the flavoring material can be incorporated into an aerosol-generating article without significantly altering the existing manufacturing process and without requiring significant modifications to existing manufacturing equipment.

In certain embodiments, the carrier sheet material comprises carbon particles. Preferably, the carrier sheet material comprises greater than 0.1 wt. % carbon particles, wherein the carbon particles have a volume average particle size greater than 10 μm.

It has been found that incorporating carbon-based materials, such as graphite, expanded graphite, graphene, and the like, into the carrier sheet material of the flavoring agent according to the present invention enhances flavor release, particularly at lower temperatures, relative to flavoring agents having a similar composition and structure but lacking the carbon-rich carrier sheet material. Without being bound by theory, it is hypothesized that this is related to an enhancement in the thermal conductivity of the carrier sheet material, which allows for faster release of the flavoring agent formulation from the polysaccharide matrix structure because it can reach a certain critical temperature more quickly.

The improvement in flavor release is believed to be associated with a more uniform temperature distribution throughout the flavoring agent during use. As a greater proportion of the flavoring agent reaches a temperature high enough to release flavor species from the matrix structure, the use efficiency of the flavoring agent formulation may be increased.

The improved release of flavour species provided by embodiments of the flavour material according to the present invention comprising carbon particles as described above also allows a heater configured to supply heat to an aerosol-generating article comprising the flavour delivery material to operate at a lower temperature and thus require less power.

By adjusting the amount and size of the carbon particles, it may be possible to control and fine-tune the flavor release enhancement. For example, a relatively narrow particle size distribution may provide a more homogeneous carrier sheet material in terms of 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 exposed to the same heating profile are minimized.

Preferably, the carbon particles 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.

Advantageously, particles such as those listed above, particularly graphite and expanded graphite, can have high thermal conductivity and low density, and thus can substantially improve the thermal conductivity of the carrier sheet material without significantly increasing the density of the flavouring material. This can be advantageous because an increase in density can increase the weight for a given volume of the flavouring material itself, and thus the transport costs. Likewise, an increase in density can potentially have a proportional effect on the transport costs when the flavouring material is incorporated into an aerosol-generating article.

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

Preferably, the carbon particles have a volume average particle size of 30 μm to 150 μm.

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

That is, the volume average particle size may refer to an average calculated by dividing the sum of particle sizes for the fourth power by the sum of particle sizes for the third power.

Surprisingly, the inventors have found that this relatively small particle size range is particularly effective in increasing the thermal conductivity of the carrier material, particularly when the carrier material is in the form of a sheet. Furthermore, this relatively small particle size may advantageously result in a more homogeneous distribution of thermal conductivity, and in a sheet having a more uniform thickness than would be the case if a larger particle size were used. Furthermore, it may also be easier to mix particles of this size range with particles of similar size used to prepare the carrier sheet material, such as in the case of sheets of homogenized tobacco material or other plant material.

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

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

The D90 particle size is 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 It can be 30, 15 to 25, 15 to 20 times.

A desirable particle size distribution can have a D90 particle size of from 3 to 25, or from 3 to 15 times the D10 particle size. A particularly desirable particle size distribution can have a D90 particle size of from 5 to 20, or from 5 to 10 times the D10 particle size.

In certain preferred embodiments, in the flavouring material according to the present invention, the carbon particles have a particle size distribution having a D90 particle size and a D10 particle size, wherein the D90 particle size is 25 times or 15 times or less than the D10 particle size.

A compromise must be made with respect to particle size distribution. A tighter particle size distribution can advantageously provide more uniform thermal conductivity throughout the flavor material. This is because there is less variation in particle size at different locations within the flavor material. This advantageously allows for more efficient use of the flavor formulation throughout the flavor material. However, a tighter particle size distribution can disadvantageously be more difficult and costly to achieve. The inventors have found that the particle size distribution described above can provide an optimal compromise between these two factors.

The desired D10 and D90 particle sizes can be obtained by sieving. Thus, a narrow particle size distribution can be obtained by sieving if desired.

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

The D10 particle size of the carbon particles can be less than or equal to 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3 or 2 μm. Each of the carbon particles can have a particle size less than or equal to 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3 or 2 μm.

The D90 particle size of the carbon particles can be less than or equal to 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3 or 2 μm. Each of the carbon particles can have a particle size less than or equal to 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3 or 2 μm.

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

One or both of the D50 particle size and the volume average particle size of the carbon particles can be greater than or equal to 1, 2, 3, 5, 10, 20, 30, 35, 50, 75, 100, 150, 200, 250, 500, or 900 μm.

One or both of the D50 particle size and the volume average particle size of the carbon particles can be less than or equal to 1000, 900, 500, 200, 100, 150, 100, 75, 50, 35, 30, 20, 10, 5, 3 or 2 μm.

One or both of the D50 particle size and the volume average particle size of the carbon particles can be from 1 to 1000, preferably from 10 to 200, more preferably from 30 to 150, or even more preferably from 50 to 75 μm. Alternatively, or additionally, each of the carbon particles can have a particle size of from 1 to 1000, preferably from 10 to 200, more preferably from 30 to 150, or even more preferably from 50 to 75 μm.

Surprisingly, the inventors have found that this relatively small particle size range is particularly effective in increasing the thermal conductivity of the flavouring material according to the present invention, particularly in those embodiments where the flavouring material comprises a carrier sheet material supporting a polysaccharide matrix entrapping the flavouring formulation. Furthermore, this relatively small particle size may advantageously result in a more homogeneous carrier sheet material in terms of thermal conductivity, and a carrier sheet material having a more uniform thickness than would be the case if larger particle sizes were used. Furthermore, it may be easier to mix particles of this size range with particles of similar size used in some manufacturing processes for forming the carrier sheet material.

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

It may be particularly desirable for the volume average particle size of the carbon particles to be greater than 10 μm.

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

The carbon particles can have a volume average particle size of from 1 to 1000, from 10 to 200, from 30 to 150, or from 50 to 75 μm. These volume average particle size ranges can be particularly desirable when the flavoring material comprises or is in the form of a sheet.

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

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

The graphite particles can have a particle size distribution having a D10 particle size of from 5 to 20, for example from 10 to 14 μm, for example about 12 μm. The graphite particles can have a particle size distribution having a D50 particle size of from 25 to 45 μm, for example about 35 μm. The graphite particles can have a particle size distribution having a D90 particle size of from 45 to 75 μm, for example about 55 μm. Advantageously, such particles are commercially available and have been found by the inventors to provide a significant increase in the thermal conductivity of the flavour material.

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

The expanded graphite particles can have a particle size distribution having a D10 particle size of from 5 to 20, for example from 9 to 12 μm, for example about 10.5 μm. The expanded graphite particles can have a particle size distribution having a D50 particle size of from 15 to 25 μm, for example about 20 μm. The expanded graphite particles can have a particle size distribution having a D90 particle size of from 46 to 66 μm, for example about 56 μm. Advantageously, such particles are commercially available and have been found by the inventors to provide a significant increase in the thermal conductivity of the flavour material. The expanded graphite particles can also advantageously reduce the overall density of the flavour material.

Each of the carbon particles can have three mutually perpendicular dimensions. The largest of these three dimensions can be no greater than 10, 8, 5, 3, or 2 times the smallest of these three dimensions. The largest of these three dimensions is no greater than 10, 8, 5, 3, or 2 times the second largest of these three dimensions. Each of these three dimensions can be substantially the same. Each of the carbon particles can be substantially spherical.

The carbon particles can comprise at least 10, 20, 50, 100, 200, 500, or 1000 particles.

In the flavoring material according to the present invention, the carbon particles constitute 0.01 wt% to 10 wt% of the flavoring material on a dry weight basis.

In the flavoring material according to the present invention, the polysaccharide matrix structure and the flavoring agent formulation form a layer on the carrier sheet material. The layer can have a thickness of at least 5 μm.

In the flavoring material according to the present invention, the polysaccharide matrix structure and the flavoring agent formulation form a layer on the carrier sheet material, the layer preferably has a thickness of at least 10 μm, more preferably the layer has a thickness of at least 15 μm, and even more preferably the layer has a thickness of at least 20 μm.

In the flavoring material according to the present invention, the polysaccharide matrix structure and the flavoring agent formulation form a layer on the carrier sheet material, the layer preferably has a thickness of 150 μm or less, more preferably the layer has a thickness of 125 μm or less, and even more preferably the layer has a thickness of 100 μm or less.

In some embodiments, the polysaccharide matrix structure and the flavoring agent formulation form a layer on the carrier sheet material, the layer preferably having a thickness of from 10 μm to 150 μm, more preferably having a thickness of from 10 μm to 125 μm, and even more preferably having a thickness of from 10 μm to 100 μm.

In another embodiment, the polysaccharide matrix structure and the flavoring agent formulation form a layer on the carrier sheet material, the layer preferably having a thickness of from 15 μm to 150 μm, more preferably having a thickness of from 15 μm to 125 μm, and even more preferably having a thickness of from 15 μm to 100 μm.

In a further embodiment, the polysaccharide matrix structure and the flavoring agent formulation form a layer on the carrier sheet material, the layer preferably having a thickness of from 20 μm to 150 μm, more preferably having a thickness of from 20 μm to 125 μm, and even more preferably having a thickness of from 20 μm to 100 μm.

The flavoring material according to the present invention can be prepared by different routes. The present disclosure also relates to a method for preparing a flavoring material according to the present invention, which may comprise a first step of heating water to a temperature of at least 50° C. The method may comprise a second step of dispersing gellan gum in the heated water to form an aqueous gellan gum dispersion. The method may comprise a third step of heating the gellan gum aqueous dispersion to a temperature of at least 80° C. to dissolve the gellan gum and form an aqueous gellan gum solution. The method may comprise a fourth step of cooling the aqueous gellan gum solution to a temperature of from 65° C. to 75° C. The method may comprise a fifth step of adding a flavoring formulation and an emulsifier to the cooled aqueous gellan gum solution to form a precursor composition. The method may comprise a sixth step of applying the precursor composition onto a carrier sheet material. The method may comprise a seventh step of drying the carrier sheet material having the applied precursor composition to obtain a flavor delivery material.

According to another aspect of the present invention, a method for preparing a flavoring material according to the present invention is provided, the method comprising: a first step of heating water to a temperature of at least 50° C.; a second step of dispersing gellan gum in the heated water to form an aqueous gellan gum dispersion; a third step of heating the aqueous gellan gum dispersion to a temperature of at least 80° C. to dissolve the gellan gum and form an aqueous gellan gum solution; a fourth step of cooling the aqueous gellan gum solution to a temperature of from 65° C. to 75° C.; a fifth step of adding a flavoring formulation and an emulsifier to the cooled aqueous gellan gum solution to form a precursor composition; a sixth step of applying the precursor composition onto a carrier sheet material; and a seventh step of drying the carrier sheet material having the applied precursor composition to obtain a flavor delivery material.

In some embodiments, the method further comprises a step of adding a polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethyl cellulose, and hydroxypropyl methyl cellulose to the cooled aqueous gellan gum solution. This additional step may be performed prior to the sixth step of applying the precursor composition onto the carrier sheet material.

Preferably, in the method according to the present invention, the emulsifier is lecithin.

In some embodiments, the sixth step of applying the precursor composition onto the carrier sheet material comprises casting or spraying the precursor composition onto the carrier sheet material.

Preferably, the sixth step of applying the precursor composition onto the carrier sheet material comprises a step of forming a layer of the precursor composition on the carrier sheet material having a thickness of at least 10 μm.

The present disclosure also relates to an aerosol-generating article comprising a flavoring agent, wherein a flavoring formulation is capable of being released from the flavoring agent upon heating the flavoring agent. The flavoring agent can comprise a matrix structure and a flavoring agent formulation dispersed within the matrix structure. The flavoring agent formulation is capable of being at least partially entrapped within the matrix structure and released from the matrix structure upon heating of the flavoring agent. The matrix structure can be a polysaccharide matrix structure. The flavoring agent can comprise a carrier sheet material, wherein the polysaccharide matrix structure and the flavoring agent formulation are supported by the carrier sheet material.

According to a further aspect of the present invention, an aerosol-generating article is provided comprising a flavoring agent, wherein the flavoring agent is releasable from the flavoring agent upon heating the flavor delivery agent. The flavoring agent comprises a polysaccharide matrix structure; and a flavoring formulation dispersed within the polysaccharide matrix structure. The flavoring agent formulation is entrapped within the polysaccharide matrix structure and is releasable from the polysaccharide matrix structure upon heating of the flavoring agent. The flavoring agent further comprises a carrier sheet material, wherein the polysaccharide matrix structure and the flavoring agent formulation are supported by the carrier sheet material.

As will be apparent from the foregoing description of the flavouring agents according to the present invention, by incorporating one such flavouring agent into an aerosol-generating article, it is advantageously possible to provide a new range of aerosol-generating articles capable of delivering flavour to the consumer in a more consistent and controlled manner. Furthermore, since the flavouring agent formulation is at least partially entrapped within the matrix until it is released when heat is supplied to the aerosol-generating article during use, loss of flavouring species during storage and transport of the aerosol-generating article can be significantly reduced.

Because the carrier sheet material provides enhanced structural support for the polysaccharide matrix structure that entraps the flavor formulation, the manufacture of the aerosol-generating article can be facilitated by tailoring the composition and geometry of the carrier sheet material of the aerosol-generating article. In some embodiments, as discussed in more detail below, the carrier sheet material is also a source of an aerosolizable species, and thus by closely combining it with the flavor source at selected locations within the aerosol-generating article, a number of interesting results can be provided.

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

As described above, the carrier sheet material may in particular be a sheet of homogenized tobacco material. In embodiments where the flavouring material comprises one such carrier sheet material, the aerosol-generating article may comprise: a rod of an aerosol-generating substrate; a downstream section provided downstream of the rod of the aerosol-generating substrate and extending to a mouth end of the aerosol-generating article; optionally an upstream section provided downstream of the rod of the aerosol-generating substrate and extending to a distal end of the aerosol-generating article; and the flavouring material may be provided to the rod of the aerosol-generating substrate.

Incorporating a flavouring agent according to the present invention into an aerosol-generating article can be accomplished by one of several routes.

For example, pieces of a flavoring substance can be mixed with solid particles of an aerosol-generating material, such as cut tobacco, to form a rod of the aerosol-generating substrate of an aerosol-generating article.

Alternatively, or additionally, a piece of flavouring material may be provided at another location within the aerosol-generating article, such as along a downstream section of the aerosol-generating article. The downstream section of the aerosol-generating article may comprise multiple components, and thus the flavouring material may be incorporated into any one of these components.

As another alternative, the flavouring material comprising a carrier sheet material in the form of a paper wrapper may be used alone or in combination with other paper wrappers as a plug wrap for a load of an aerosol-generating article.

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

An aerosol-generating article containing a flavoring substance 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. This heats the aerosol-generating substrate and the flavoring substance, thereby delivering a flavor-rich aerosol to the consumer.

As such, the aerosol-generating article according to the present invention finds particular application in an aerosol-generating system comprising an aerosol-generating device having a heating chamber in which the aerosol-generating article is accommodated such 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, wherein one or more of the heating elements are resistively or inductively heated. Alternatively, this may also be achieved by a resistively heated blade-shaped component of the aerosol-generating device which is inserted into the aerosol-generating substrate when the aerosol-generating article is inserted into the heating chamber.

According to another alternative, the susceptor element can be provided within the aerosol-generating substrate, and the aerosol-generating device can have an inductor for generating an alternating or fluctuating electromagnetic field. When the aerosol-generating article is engaged with the aerosol-generating device, the fluctuating electromagnetic field generated by the inductor induces a current in the susceptor element, thereby heating the susceptor element. The electrically operated aerosol-generating device can generate a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloampere per metre (kA/m), preferably 2 to 3 kA/m, for example about 2.5 kA/m.

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

Example Ex1: A flavouring material for use in an aerosol-generating article, wherein the flavouring material is releasable from the flavouring material when the flavouring material is heated; the flavouring material comprises: a polysaccharide matrix structure comprising gellan gum and an emulsifier; a flavouring formulation dispersed within the polysaccharide matrix structure, the flavouring formulation being at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavouring material; and a carrier sheet material, wherein the polysaccharide matrix structure and the flavouring formulation are supported by the carrier sheet material.

Example Ex2: A flavoring substance according to Example Ex1, wherein the polysaccharide matrix structure comprises gellan gum as the sole polysaccharide, or gellan gum in combination with at least an additional polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethyl cellulose, and hydroxypropyl methyl cellulose.

Example Ex3: A flavoring substance according to Example Ex1 or Ex2, wherein the gellan gum constitutes 5 wt% to 99.9 wt% of the flavoring substance on a dry weight basis.

Example Ex4: A flavoring substance according to any one of Examples Ex1 to Ex3, further comprising a polyol having the formula C _n H _2n+2 O _n .

Example Ex5: In Example Ex4, the polyol is a flavoring substance selected from the group consisting of glycerol, sorbitol, xylitol, mannitol, and erythritol.

Example Ex6: A flavoring substance according to Example Ex4 or Ex5, wherein the polyol accounts for 0.01 wt% to 20 wt% of the flavoring substance on a dry weight basis.

Example Ex7: A flavoring substance according to any of the preceding examples, further comprising fibers.

Example Ex8: A flavoring substance according to Example Ex7, wherein the fiber constitutes 0.01 wt% to 10 wt% of the flavoring substance on a dry weight basis.

Example Ex9: A flavoring substance according to any one of the preceding examples, comprising from 0.01 wt% to 80 wt% menthol.

Example Ex10: A flavouring substance according to any one of the preceding examples, wherein the carrier sheet material is a sheet of homogenised tobacco material.

Example Ex11: A flavoring substance according to any one of the preceding examples, wherein the carrier sheet material is a sheet of plug paper wrapper material.

Example Ex12: A flavoring material according to any one of the preceding examples, wherein the polysaccharide matrix structure and the flavoring agent formulation form a layer on the carrier sheet material, the layer having a thickness of at least 10 μm.

Example Ex13: A flavoring material according to Example Ex12, wherein the layer has a thickness of less than 150 μm.

Example Ex14: A flavouring material according to any of the preceding examples, wherein the carrier sheet material comprises greater than 0.1 wt. % carbon particles, wherein the carbon particles have a volume average particle size greater than 10 μm.

Example Ex15: A flavoring substance according to Example Ex14, wherein the carbon particles have a volume average particle size of greater than 10 μm.

Example Ex16: A flavoring substance according to Example Ex14 or Example Ex15, wherein the carbon particles have a volume average particle size of 30 μm to 150 μm.

Example Ex17: A flavoring substance according to any one of Examples Ex14 to Ex16, wherein the carbon particles are formed of at least one of graphite particles, expanded graphite particles, and graphene particles.

Example Ex18: A flavoring material according to any one of Examples Ex14 to Ex17, wherein the carbon particles constitute 0.01 wt% to 10 wt% of the flavoring material on a dry weight basis.

Example Ex19: A flavoring substance according to any one of Examples Ex14 to Ex18, wherein the carbon particles have a particle size distribution having a volume D90 particle size and a number D10 particle size, wherein the volume D90 particle size is no more than 25 or 15 times the D10 particle size.

Example Ex20: A method for preparing a flavoring material for use in an aerosol-generating article, the method comprising the steps of: heating water to a temperature of at least 50° C.; dispersing gellan gum in the heated water to form an aqueous gellan gum dispersion; heating the aqueous gellan gum dispersion to a temperature of at least 80° C. to dissolve the gellan gum and form an aqueous gellan gum solution; cooling the aqueous gellan gum solution to a temperature of from 65° C. to 75° C.; adding a flavoring formulation and an emulsifier to the cooled aqueous gellan gum solution to form a precursor composition; applying the precursor composition onto a carrier sheet material; and drying the carrier sheet material having the applied precursor composition to obtain a flavoring material.

Example Ex21: A method according to Example Ex20, further comprising adding a polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethyl cellulose, and hydroxypropyl methyl cellulose to the cooled gellan gum aqueous solution.

Example Ex22: A method according to Example Ex20 or Ex21, wherein the emulsifier is lecithin.

Example Ex23: A method according to any one of Examples Ex20 to Ex22, wherein the step of applying the precursor composition onto the carrier sheet material comprises the step of casting or spraying the precursor composition onto the carrier sheet material.

Example Ex24: A method according to any one of Examples Ex20 to Ex23, wherein the step of applying the precursor composition onto the carrier sheet material comprises the step of forming a layer of the precursor composition on the carrier sheet material having a thickness of at least 10 μm.

Example Ex25: An aerosol-generating article comprising a flavoring agent, wherein the flavoring agent is capable of being released from the flavoring agent when the flavor delivery material is heated; wherein the flavoring agent is according to any one of Examples Ex 1 to Ex 19.

Example Ex26: An aerosol-generating article comprising a flavoring agent, wherein the flavoring agent is releasable from the flavoring agent upon heating the flavor delivery material; the flavoring agent comprises: a polysaccharide matrix structure comprising gellan gum and an emulsifier; a flavoring formulation dispersed within the polysaccharide matrix structure, the flavoring formulation being at least partially entrapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavoring agent; and a carrier sheet material, wherein the polysaccharide matrix structure and the flavoring formulation are supported by the carrier sheet material.

Example Ex27: An aerosol-generating article according to Example Ex25, wherein the article comprises: a rod of an aerosol-generating substrate; a downstream section provided downstream of the rod of the aerosol-generating substrate and extending to a mouth end of the aerosol-generating article; optionally an upstream section provided downstream of the rod of the aerosol-generating substrate and extending to a distal end of the aerosol-generating article; wherein the flavourant is provided in at least one of the rod of the aerosol-generating substrate; the downstream section; and the optional upstream section.

Embodiment Ex28: An aerosol-generating article according to Embodiment Ex26 or Ex27, wherein the carrier sheet material is a sheet of homogenized tobacco material; the aerosol-generating article comprises: a rod of an aerosol-generating substrate; a downstream section provided downstream of the rod of the aerosol-generating substrate and extending to a mouth end of the aerosol-generating article; optionally an upstream section provided downstream of the rod of the aerosol-generating substrate and extending to a distal end of the aerosol-generating article; wherein the flavourant is provided within the rod of the aerosol-generating substrate.

Now, the embodiment will be further described with reference to the drawings:
FIG. 1 is a schematic cross-sectional side view of an aerosol-generating article according to the present invention comprising a flavoring substance within a rod of an aerosol-generating substrate; and
Figure 2 shows a scanning electron microscope image of the flavoring material used in the aerosol-generating article of Figure 1.

An aerosol-generating article (10) according to the present invention is illustrated in FIG. 1. The aerosol-generating article (10) illustrated in FIG. 1 includes a rod (12) of an aerosol-generating substrate and a downstream section (14) located downstream of the rod (12) of the aerosol-generating substrate. In addition, the aerosol-generating article (10) includes an upstream section (16) located upstream of the rod (12) of the aerosol-generating substrate.

A ventilation zone (60) is provided at a downstream location of the load (12) of the aerosol generating material.

More specifically, in the embodiment of FIG. 1, the downstream section (14) includes a mouthpiece element (18) and a hollow section (20). The hollow section (20) includes an aerosol-cooling element (22) including a hollow tubular element and a venting section (60), the venting section including a plurality of openings formed through a wall of the hollow tubular element. The aerosol-cooling element (22) is positioned immediately downstream of the rod (12) of the aerosol-generating substrate. As illustrated in the drawing of FIG. 1, an upstream end of the aerosol-cooling element (22) abuts a downstream end of the rod (12) of the aerosol-generating substrate. The mouthpiece element (18) is positioned immediately downstream of the aerosol-cooling element (22). As illustrated in the drawing of FIG. 1, an upstream end of the mouthpiece element (18) abuts a downstream end of the aerosol-cooling element (22). The mouthpiece element (18) comprises a plug (24) of low-density filter material.

The rod (12) comprises an aerosol generating substrate in the form of a pleated sheet of homogenized tobacco material. However, other types of tobacco containing substrates, such as tobacco charcoal, may be substituted for the pleated sheet of homogenized tobacco material.

The upstream section (16) comprises a cylindrical plug (26) of compressed and plasticized cellulose acetate surrounded by a wrapper (28). The plug (26) of the upstream section (16) has a length of about 5 mm.

Additionally, the aerosol-generating article comprises a flavoring substance (50). More specifically, a plurality of pieces of the flavoring substance in sheet form are dispersed within the rod (12). The flavoring substance (50) is of the type described in detail above.

Examples of formulations suitable for flavoring substances (50) and processes for forming flavoring substances (50) are presented below.

Preparation A - Flavouring agent comprising a menthol formulation entrapped in a gellan gum polysaccharide matrix supported on a carrier sheet material (paper wrapper)

100 g of water is heated to about 60° C. and 3.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80° C. to 85° C. and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70° C. to 75° C. and 0.1 g of lecithin and 8.0 g of menthol are added to the mixture. The flavored mixture is homogenized for 3 minutes. Subsequently, the resulting aqueous composition is cast onto a sheet of paper wrapper material placed on a metal tray, left to gel and dried in a steel oven at 75° C. A layer comprising a gellan gum matrix which captures the menthol formulation fixed on the paper wrapper is obtained.

Manufacturing B1 - Flavouring agent comprising a menthol formulation entrapped in a gellan gum-guar polysaccharide matrix supported on a carrier sheet material (homogenised tobacco material)

100 g of water is heated to about 60° C. and 1.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80° C. to 85° C. and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70° C. to 75° C. and 0.1 g of lecithin and 8.0 g of menthol are added to the mixture. The flavoured mixture is homogenized for 3 minutes. Then 2.0 g of guar is added to the mixture and homogenized again for another 3 minutes. Subsequently, the resulting aqueous composition is cast onto a sheet of homogenized tobacco material, placed on a metal tray, left to gel and dried in a steel oven at 75° C. A layer comprising a gellan gum/guar matrix entrapping the menthol formulation fixed on the homogenized tobacco material is obtained.

Manufacturing B2 - Flavouring material comprising a menthol formulation entrapped in a gellan gum-guar polysaccharide matrix supported on a carrier sheet material (homogenised tobacco material)

100 g of water is heated to about 60° C. and 1.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80° C. to 85° C. and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70° C. to 75° C. and 0.1 g of lecithin and 8.0 g of menthol are added to the mixture. The flavoured mixture is homogenized for 3 minutes. Then 2.0 g of guar is added to the mixture and homogenized again for another 3 minutes. Subsequently, the resulting aqueous composition is cast onto a sheet of paper wrapper material, placed on a metal tray, left to gel and dried in a steel oven at 75° C. A layer comprising a gellan gum/guar matrix entrapping the menthol formulation fixed on the paper wrapper material is obtained.

Preparation C - Flavouring agent comprising a menthol formulation entrapped in a gellan gum-alginate polysaccharide matrix supported on a carrier sheet material (homogenised tobacco material)

100 g of water is heated to about 60° C. and 2.0 g of gellan gum and 0.5 g of alginate are added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 90° C. to 95° C. and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70° C. to 75° C. and 0.1 g of lecithin and 8.0 g of menthol are added to the mixture. The flavoured mixture is homogenized for 3 minutes. Subsequently, the resulting aqueous composition is cast onto a sheet of homogenized tobacco material, placed on a metal tray, left to gel and dried in a steel oven at 75° C. A layer comprising a gellan gum/alginate matrix entrapping a menthol formulation fixed on the homogenized tobacco material is obtained.

Manufacture D1 - Aerosol-generating article containing a flavouring substance produced according to Manufacture A

An amount of flavouring substance produced according to Preparation A, constituting a total content of 5 mg of menthol, was added to a load of a commercially available aerosol-generating article (HEET® by Philip Morris Products S.A.).

Manufacture D2 - Aerosol-generating article containing a flavouring substance produced according to Manufacture A

An amount of flavouring substance produced according to Preparation A, constituting a total content of 35 mg of menthol, was added to a load of a commercially available aerosol-generating article (HEET® by Philip Morris Products S.A.).

Manufacture D3 - Aerosol-generating article containing a flavouring substance produced according to Manufacture A

An amount of flavouring substance produced according to Preparation A, constituting a total content of 37 mg of menthol, was added to a load of a commercially available aerosol-generating article (HEET® by Philip Morris Products S.A.).

Morphological characterization

FIG. 2 illustrates a scanning electron microscope (SEM) image of a flavoring material (50) produced according to manufacture B1 embedded in wax. It can be seen from the image that the internal structure of the flavoring material comprises a matrix (52) having a plurality of small pockets (54) configured to capture the flavor composition, and that the pockets (54) are dispersed throughout the matrix (52). The pockets are relatively evenly distributed throughout the material and are relatively uniform in size. The flavoring material (50) further comprises a carrier sheet material (56) in the form of a sheet of homogenized tobacco material, the carrier sheet material (56) supporting the matrix (52).

Thermogravimetric analysis

The flavor release profile of the flavoring substance manufactured according to the above manufacturing examples can be analyzed by thermogravimetric analysis (TGA). The TGA test is performed using a thermogravimetric instrument coupled to a mass spectrometer or similar TGA equipment. In the analysis, the flavoring substance is heated from 25° C. to 400° C. in an inert nitrogen atmosphere, the temperature is increased at a rate of 15° C. per minute, and an air flow of 60 ml per minute is generated. As the temperature increases, the release of menthol is evaluated by detecting menthol molecules via specific ions representing menthol.

The data collected from performing TGA testing on a flavoring agent according to the present invention can be compared to data collected from performing an equivalent TGA test on the flavoring agent alone (e.g., pure menthol). One such comparison can provide some information regarding the release mechanism and kinetics, which can aid in fine-tuning the flavoring agent release profile when incorporated into an aerosol-generating article.

In the described thermogravimetric analysis, when heated, pure menthol was released in a single mode between 50°C and 166°C, with a maximum at about 138°C.

In contrast, when heated in the described thermogravimetric analysis, the flavouring substance produced according to Preparation B2 was found to provide a multimodal release of menthol. A first, smaller fraction of menthol was released between about 57°C and about 137°C with a local maximum of about 116°C. A second, much more consistent fraction of menthol was released between about 229°C and 264°C with a local maximum of about 243°C. A third, smaller fraction of menthol was released between about 265°C and 302°C with a local maximum of about 279°C.

The release of the first fraction of menthol, which peaks just above 115°C, may indicate that some of the menthol formulation is dissolved or relatively weakly fixed within the flavoring agent. On the other hand, the release of the second, much larger fraction of menthol, which peaks above 240°C, a temperature that may be associated with the thermal decomposition of gellan gum, may support the hypothesis that a significant portion of the menthol formulation is entrapped within the matrix structure and has some stronger interactions with the gellan gum within the matrix structure. The release of the remainder of the menthol at the much higher temperatures may indicate that the menthol formulation interacts with the guar within the matrix structure in a different manner and is much more stably retained.

The same TGA test was performed on a flavoring material prepared according to Preparation A. This flavoring material was also found to provide multimodal release of menthol. A first, smaller fraction of menthol was released between about 57°C and about 239°C with a local maximum of about 200°C. A second, more significant fraction of menthol was released between 240°C and 306°C with a local maximum of about 249°C. An additional fraction of menthol was released between about 307°C and about 384°C with a local maximum of about 351°C.

The release of the first fraction of menthol around 200°C may suggest that a smaller portion of the menthol formulation contained in the flavouring substance is less strongly fixed, whereas a larger portion of the menthol formulation contained in the flavouring substance released at higher temperatures seems to suggest a stronger interaction with gellan gum, resulting in effective fixation.

A comparison of the menthol release profiles of the flavouring substances prepared according to Formulations B2 and E demonstrates that adjusting the composition of the polysaccharide matrix, for example by using gellan gum alone or in combination with other polysaccharides, can help to fine-tune flavour delivery when the flavouring substances are incorporated into an aerosol-generating article. In particular, it may be possible to control the temperature at which flavour release is initiated and the temperature at which flavour release is maximized. Furthermore, flavouring substances having different flavour release profiles with local maxima at different temperatures, such as those prepared according to Formulations B2 and E, can be combined in a single aerosol-generating article to provide the consumer with a much wider range of flavour delivery options.

Thermal stability

The thermal stability of the flavouring substance according to the invention under stress conditions can be assessed by maturing the flavouring substance at a constant temperature and monitoring its weight loss over time. For this purpose, samples of the flavouring substance cut into pieces of regular and uniform size are weighed and distributed into a series of Schott glass open bottles. The samples are matured in a laboratory oven set at 50° C. for a period of two weeks. For the flavouring substance produced according to preparation A, a weight loss of about 35% was measured at the end of the test. This weight loss value is considered satisfactory, since it is assumed to account for some migration of the flavouring species as well as for moisture and glycerol losses.

Evaluation of flavor delivery by puff

The flavour delivery of an aerosol-generating article comprising a flavouring agent according to the present invention can be assessed by heating the aerosol-generating article in a commercially available and compatible heating device and measuring the menthol delivered to the mouth end of the article with each puff.

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

The puff-by-puff menthol delivery of aerosol-generating articles produced according to formulations D1, D2 and D3 was measured. Their behavior was compared to that of a commercially available aerosol-generating article (HEET® from Philip Morris Products S.A.) loaded with 5 mg of pure menthol.

It was observed that commercially available aerosol-generating articles loaded with pure menthol reached their maximum menthol delivery at the third puff time point, after which the menthol level gradually decreased. In contrast, in aerosol-generating articles produced according to formulations D1, D2 and D3, menthol delivery was found to increase up to the third puff and was subsequently maintained substantially around the same level throughout the use cycle of the article and up to the twelfth puff.

Manufacturing E1 - Flavouring substance comprising clove particles entrapped in a gellan gum polysaccharide matrix supported on a carrier sheet material (homogenised tobacco material)

160 g of water is heated to about 60° C. and 6.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80° C. to 85° C. and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70° C. to 75° C. and 0.2 g of lecithin and 8.0 g of clove powder are added to the mixture. The clove-containing mixture is homogenized for 3 minutes. Subsequently, the resulting aqueous composition is cast onto a sheet of homogenized tobacco material placed on a metal tray, left to gel and dried in a steel oven at 75° C. A layer comprising a gellan gum matrix which captures the clove-containing formulation fixed on the homogenized tobacco material is obtained.

Manufacturing E2 - Flavouring substance comprising clove particles entrapped in a gellan gum polysaccharide matrix supported on a carrier sheet material (homogenised tobacco material)

160 g of water is heated to about 60° C. and 6.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80° C. to 85° C. and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70° C. to 75° C. and 0.2 g of lecithin and 8.0 g of clove powder are added to the mixture. The clove-containing mixture is homogenized for 3 minutes. Subsequently, the resulting aqueous composition is cast onto a sheet of homogenized tobacco material placed on a metal tray, left to gel and dried in a steel oven at 75° C. A layer comprising a gellan gum matrix which captures the clove-containing formulation fixed on the homogenized tobacco material is obtained.

Manufacturing E3 - Flavouring material comprising menthol and clove particles entrapped in a gellan gum polysaccharide matrix supported on a carrier sheet material (homogenised tobacco material)

160 g of water is heated to about 60° C. and 6.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80° C. to 85° C. and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70° C. to 75° C. and 0.2 g of lecithin, 4.0 g of menthol and 4.0 g of clove powder are added to the mixture. The flavour-containing mixture is homogenized for 3 minutes. Subsequently, the resulting aqueous composition is cast onto a sheet of homogenized tobacco material placed on a metal tray, left to gel and dried in a steel oven at 75° C. A layer comprising a gellan gum matrix entrapping the clove-containing formulation fixed on the homogenized tobacco material is obtained.

Manufacturing E4 - Flavouring substance comprising clove particles entrapped in a gellan gum-guar polysaccharide matrix supported on a carrier sheet material (homogenised tobacco material)

160 g of water is heated to about 60° C. and 3.0 g of gellan gum is added to the water bath. The resulting mixture is homogenized and heated to a temperature in the range of 80° C. to 85° C. and maintained at this temperature for 5 minutes. The mixture is then cooled to a temperature in the range of 70° C. to 75° C. and 0.2 g of lecithin and 8.0 g of clove powder are added to the mixture. The clove-containing mixture is homogenized for 3 minutes. Then 2.0 g of guar is added to the mixture and homogenized again for another 3 minutes. Subsequently, the resulting aqueous composition is cast onto a paper wrapper material and placed on a metal tray, left to gel and dried in a steel oven at 75° C. A layer comprising a gellan gum/guar matrix entrapping the menthol formulation fixed on the paper wrapper material is obtained.

Thermogravimetric analysis

The flavour release profile of the flavouring substance prepared according to Formulations E1 to E4 can be analyzed by thermogravimetric analysis (TGA). The TGA test is performed using a thermogravimetric instrument coupled to a mass spectrometer or similar TGA equipment. In the analysis, the flavouring substance is heated from 25° C. to 400° C. in an inert nitrogen atmosphere, the temperature is increased at a rate of 15° C. per minute and an air flow of 60 ml per minute is generated. As the temperature increases, the release of eugenol is evaluated by detecting eugenol molecules via specific ions representing eugenol.

The data collected from performing TGA tests on the flavoring agent according to the present invention can be compared with data collected from performing equivalent TGA tests on pure eugenol and clove material alone. One such comparison can provide some information about the release mechanism and dynamics, which can help to fine-tune the flavoring agent release profile when incorporated into an aerosol-generating article.

In the described thermogravimetric analysis, when heated, pure eugenol was released in a single mode between 90°C and 199°C, with a maximum at about 191°C, whereas when clove powder was heated under the same conditions, eugenol was released in a single mode between 88°C and 216°C, with a maximum at about 151°C.

In contrast, when heated in the described thermogravimetric analysis, the flavouring substance produced according to Preparation B2 was found to provide a multimodal release of eugenol. A first, smaller fraction of eugenol was released between about 215°C and about 228°C, with a local maximum at about 222°C. A second, much more consistent fraction of eugenol was released between about 229°C and 300°C, with a local maximum at about 248°C.

The release of the first fraction of eugenol, which has a maximum at about 215°C, may indicate that some of the clove powder is relatively weakly fixed within the flavour substance, and thus eugenol is released only at slightly higher temperatures than pure eugenol and clove powder alone. On the other hand, the release of the second, much larger fraction of eugenol, which has a maximum above 240°C, a temperature which may be associated with the thermal decomposition of gellan gum, may support the hypothesis that a significant portion of the clove powder is actually entrapped within the matrix structure and has some stronger interactions with gellan gum within the matrix structure.

For the purposes of this description and the appended claims, unless otherwise indicated, all numbers expressing quantities, quantities, percentages, and so forth, will be understood to be modified in all instances by the term "about." Additionally, all ranges are inclusive of the disclosed maximum and minimum points, and include therein any intermediate ranges which may or may not be specifically enumerated herein. Thus, in this context, the number A is to be understood as A ± 5% of A. Within this context, the number A may be considered to include a numerical value that is within the normal standard error for the measurement of the characteristic that the number A modifies. In some instances 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(s) of the claimed invention. Additionally, all ranges are inclusive of the disclosed maximum and minimum points, and include therein any intermediate ranges which may or may not be specifically enumerated herein.

Claims (15)

A flavoring material for use in an aerosol-generating article, wherein when the flavoring material is heated, the flavoring agent is releasable from the flavoring material; and the flavoring material comprises:
Polysaccharide matrix structure comprising gellan gum and emulsifier;
A flavor formulation dispersed within said polysaccharide matrix structure, said flavor formulation being at least partially entrapped within said polysaccharide matrix structure and capable of being released from said polysaccharide matrix structure upon heating of said flavoring substance; and
A flavouring material comprising a carrier sheet material, wherein the polysaccharide matrix structure and the flavouring agent formulation are supported by the carrier sheet material. A flavoring substance in claim 1, wherein the polysaccharide matrix structure comprises gellan gum as the sole polysaccharide, or gellan gum in combination with at least an additional polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethyl cellulose, and hydroxypropyl methyl cellulose. A flavoring substance according to claim 1 or 2, wherein the gellan gum constitutes 5 wt% to 99.9 wt% of the flavoring substance on a dry weight basis. A flavoring substance according to any one of claims 1 to 3, further comprising a polyol having the formula C _n H _2n+2 O _n , wherein the polyol is selected from the group consisting of glycerol, sorbitol, xylitol, mannitol, and erythritol, or wherein the polyol constitutes 0.01 wt % to 20 wt % of the flavoring substance on a dry weight basis. A flavoring substance according to any one of claims 1 to 4, further comprising fibers, wherein the fibers constitute 0.01 wt% to 10 wt% of the flavoring substance on a dry weight basis. A flavouring substance according to any one of claims 1 to 5, wherein the carrier sheet material is a sheet of homogenised tobacco material or a sheet of plug paper wrapper material. A flavouring substance according to any one of claims 1 to 6, wherein the carrier sheet material comprises more than 0.1 wt% carbon particles, wherein the carbon particles have a volume average particle size of more than 10 μm. A flavouring substance according to any one of claims 1 to 7, wherein the polysaccharide matrix structure and the flavouring agent formulation form a layer on the carrier sheet material, the layer having a thickness of at least 10 μm, preferably less than 150 μm. A method for producing a flavoring substance for use in an aerosol generating article, said method comprising:
A step of heating water to a temperature of at least 50℃;
A step of dispersing gellan gum in the heated water to form an aqueous gellan gum dispersion;
A step of heating the gellan gum aqueous dispersion to a temperature of at least 80°C to dissolve the gellan gum and form a gellan gum aqueous solution;
A step of cooling the above gellan gum aqueous solution to a temperature of 65°C to 75°C;
A step of forming a precursor composition by adding a flavoring formulation and an emulsifier to the above-mentioned cooled gellan gum aqueous solution;
A step of applying the above precursor composition onto a carrier sheet material;
A method comprising the step of drying a carrier sheet material having the above-described applied precursor composition to obtain a flavoring substance. A method according to claim 9, further comprising the step of adding a polysaccharide selected from the group consisting of guar, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethyl cellulose, and hydroxypropyl methyl cellulose to the cooled gellan gum aqueous solution. A method according to claim 9 or 10, wherein the step of applying the precursor composition onto the carrier sheet material comprises the step of casting or spraying the precursor composition onto the carrier sheet material. A method according to any one of claims 9 to 11, wherein the step of applying the precursor composition onto the carrier sheet material comprises the step of forming a layer of the precursor composition on the carrier sheet material having a thickness of at least 10 μm. An aerosol-generating article comprising a flavoring agent, wherein the flavoring agent is capable of being released from the flavoring agent when the flavor delivery agent is heated; and the flavoring agent comprises:
Polysaccharide matrix structure comprising gellan gum and emulsifier;
A flavor formulation dispersed within said polysaccharide matrix structure, said flavor formulation being at least partially entrapped within said polysaccharide matrix structure and being releasable from said polysaccharide matrix structure upon heating of said flavoring substance; and
An aerosol-generating article comprising a carrier sheet material, wherein the polysaccharide matrix structure and the flavoring formulation are supported by the carrier sheet material. An aerosol-generating article in accordance with claim 13, comprising: a rod of an aerosol-generating substrate; a downstream section provided downstream of the rod of the aerosol-generating substrate and extending to a mouth end of the aerosol-generating article; and optionally an upstream section provided downstream of the rod of the aerosol-generating substrate and extending to a distal end of the aerosol-generating article; wherein the flavourant is provided in at least one of the rod of the aerosol-generating substrate; the downstream section; and the optional upstream section. An aerosol-generating article according to claim 13 or 14, wherein the carrier sheet material is a sheet of homogenized tobacco material; the aerosol-generating article comprises: a rod of an aerosol-generating substrate; a downstream section provided downstream of the rod of the aerosol-generating substrate and extending to a mouth end of the aerosol-generating article; optionally an upstream section provided downstream of the rod of the aerosol-generating substrate and extending to a distal end of the aerosol-generating article; and the flavouring material is provided within the rod of the aerosol-generating substrate.