RU2831437C1 - New aerosol generating substrate - Google Patents

Abstract

FIELD: liquid atomisation or spraying devices.

SUBSTANCE: invention relates to an aerosol-generating article. Aerosol-generating article comprises an aerosol-generating substrate, wherein the aerosol-generating substrate is formed from a homogenised plant material containing from 1 wt.% to 65 wt.% of plant particles other than tobacco, in terms of dry weight; from 15 wt.% to 55 wt.% of the aerosol forming substance in terms of dry weight; from 5 wt.% to 10 wt.% of cellulose ether in terms of dry weight; and from 5 wt.% to 50 wt.% of additional cellulose in terms of dry weight. Additional cellulose is in the form of isolated cellulose and is not obtained from plant particles that are not tobacco, wherein the ratio of additional cellulose to cellulose ether in the homogenised plant material is at least 2. Non-tobacco particles are selected from rosemary particles, star anise particles, ginger particles, cloves particles, eucalyptus particles or combinations thereof.

EFFECT: invention enables to obtain an aerosol-generating article with an improved taste and taste fullness in the oral cavity, as well as with reduced sensation of irritation, bitterness or astringent taste compared to sensations provided by a conventional combustible cigarette.

18 cl, 11 dwg, 6 tbl, 3 ex

Description

The present invention relates to aerosol-generating substrates containing homogenized plant material formed from plant particles other than tobacco, and to aerosol-generating articles containing such an aerosol-generating substrate.

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

Some aerosol-generating articles contain a flavor additive that is delivered to the consumer during use of the article to provide the consumer with other sensations, such as to enhance the mouthfeel of the aerosol. The flavor additive may be used to deliver a taste sensation (taste), an olfactory sensation (smell), or both a taste and olfactory sensation to the user inhaling the aerosol. It is known to provide heated aerosol-generating articles that contain flavor additives.

It is also known to provide flavor additives in conventional combustible cigarettes, which are smoked by lighting the end of the cigarette opposite the mouthpiece, causing the tobacco rod to burn to generate inhaled smoke. One or more flavor additives are typically mixed with the tobacco in the tobacco rod to impart additional flavor to the inhaled smoke when the tobacco is burned. Such flavor additives may be provided, for example, in the form of an essential oil.

The aerosol from a conventional cigarette, which contains many components that interact with receptors located in the mouth, provides a sensation of "mouth fullness", i.e. a relatively strong sensation in the mouth. "Mouth feel" as used herein refers to the physical sensations in the mouth caused by a food, drink or aerosol, and is distinct from taste. It is a fundamental sensory attribute that, along with taste and smell, determines the overall flavor of a food or aerosol. However, the aerosol from a conventional cigarette can also cause undesirable sensations of irritation, bitterness or astringency.

There are difficulties in reproducing the consumer experience provided by conventional combustible cigarettes in aerosol-generating products in which the aerosol-generating substrate is heated rather than combusted. This is partly due to the lower temperatures achieved when heating such aerosol-generating products, which results in a different profile of the volatile compounds released.

It would be desirable to provide a new aerosol generating substrate for a heated aerosol generating article that provides an aerosol with an improved mouthfeel and mouthfeel. It would be particularly desirable if such an aerosol generating substrate could provide an aerosol with a sensation comparable to that provided by a conventional combustible cigarette. It would be particularly desirable if such an aerosol generating substrate could provide an aerosol with a reduced sensation of irritation, bitterness, or astringency compared to that provided by a conventional combustible cigarette.

It would also be desirable to provide such an aerosol generating substrate that can be easily incorporated into an aerosol generating article and that can be manufactured using existing high-speed methods and devices.

The present invention relates to an aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate is formed from homogenized plant material. The homogenized plant material may comprise from 1 percent by weight to 65 percent by weight of non-tobacco plant particles, or from 1 percent by weight to 65 percent by weight of tobacco particles, based on dry weight. The homogenized plant material may comprise from 15 percent by weight to 55 percent by weight of an aerosol-forming substance, based on dry weight. The homogenized plant material may comprise from 2 percent by weight to 10 percent by weight of a cellulose ether, based on dry weight. The homogenized plant material may comprise from 5 percent by weight to 50 percent by weight of additional cellulose, based on dry weight. The additional cellulose may be derived from plant particles other than tobacco. The ratio of additional cellulose to cellulose ether may be at least 2.

According to the present invention, there is provided an aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate is formed from homogenized plant material comprising: from 1 percent by weight to 65 percent by weight of non-tobacco plant particles, based on dry weight; from 15 percent by weight to 55 percent by weight of an aerosol-forming agent, based on dry weight; from 2 percent by weight to 10 percent by weight of a cellulose ether, based on dry weight; and from 5 percent by weight to 50 percent by weight of additional cellulose, based on dry weight. According to the present invention, the additional cellulose is not derived from non-tobacco plant particles, and the ratio of additional cellulose to cellulose ether in the homogenized plant material is at least 2.

According to the present invention, there is further provided an aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate is formed from homogenized plant material comprising: from 1 percent by weight to 65 percent by weight of tobacco particles on a dry weight basis; from 15 percent by weight to 55 percent by weight of an aerosol-forming agent on a dry weight basis; from 2 percent by weight to 10 percent by weight of a cellulose ether on a dry weight basis; and from 5 percent by weight to 50 percent by weight of additional cellulose on a dry weight basis. According to the present invention, the additional cellulose is not derived from tobacco particles and the ratio of additional cellulose to cellulose ether in the homogenized plant material is at least 2.

As used herein, the term "aerosol-generating article" refers to an article for producing an aerosol, wherein the article comprises an aerosol-generating substrate that is suitable and designed to be heated or burned to release volatile compounds that can form an aerosol. A conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end. The localized heat provided by the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates inhalable smoke. In contrast, in "heated aerosol-generating articles," the aerosol is generated by heating the aerosol-generating substrate rather than by burning the aerosol-generating substrate. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which the aerosol is generated as a result of heat transfer from a combustible heat-generating element or heat source to a physically separated aerosol-generating substrate.

Also known are aerosol generating articles that are adapted for use in an aerosol generating system that supplies an aerosol forming substance to the aerosol generating articles. In such a system, the aerosol generating substrate in the aerosol generating articles contains substantially less aerosol forming substance relative to the aerosol generating substrate that contains and provides substantially all of the aerosol forming substance used in aerosol formation during operation.

As used herein, the term "aerosol-generating substrate" refers to a substrate that is capable of releasing volatile compounds upon heating that can form an aerosol. The aerosol generated from aerosol-generating substrates may be visible or invisible to the human eye and may contain vapors (e.g., finely dispersed particles of substances that are in a gaseous state and are typically liquid or solid at room temperature), as well as gases and liquid droplets of condensed vapors.

As used herein, the term "homogenized plant material" encompasses any plant material formed by agglomerating plant particles. For example, sheets or webs of homogenized plant material for aerosol-generating substrates according to the present invention may be formed by agglomerating plant material particles obtained by grinding, milling, or grinding non-tobacco plant material and, optionally, one or more of tobacco leaf lamellas and tobacco leaf veins. The homogenized plant material may be obtained by casting, extrusion, papermaking, or any other suitable methods known in the art.

In the context of this document, the term "plant particles" includes particles obtained from any suitable plant material and capable of generating one or more volatile aromatic compounds when heated. This term should be understood as excluding particles of neutral plant material, such as cellulose, which do not contribute to the perceived effect of the aerosol-generating substrate. Depending on the plant from which the plant particles are obtained, the plant particles may be made from crushed or powdered leaf blades, fruits, petioles, stems, roots, seeds, buds or bark or any other suitable part of the plant.

According to one aspect of the present invention, the plant particles comprise plant particles that are not tobacco. The plant particles that are not tobacco may be used in combination with tobacco particles, or the homogenized plant material may be substantially free of tobacco. According to another aspect of the present invention, the plant particles are tobacco particles. As used herein, the term "plant particles" refers to plant particles that are not tobacco, tobacco particles, or a combination thereof, as provided in the homogenized plant material.

In the context of this document, the term "additional cellulose" encompasses any cellulose material introduced into the homogenized plant material that is not derived from non-tobacco plant particles or tobacco particles provided in the homogenized plant material. The additional cellulose is introduced into the homogenized plant material in addition to the non-tobacco plant material or tobacco material as a source of cellulose that is separate and distinct from any cellulose substantially provided in any plant particles present. In particular, the additional cellulose is in the form of isolated cellulose. This means that the cellulose is derived from the plant material but is not extracted and separated from other components of the plant material such as lignin and hemicellulose. Consequently, the provision of additional cellulose is separate from any plant material present and is at least partially purified.

Preferably, the additional cellulose is in the form of an inert cellulose material that has a neutral effect on the sensory organs. Therefore, the additional cellulose does not substantially affect the organoleptic characteristics of the aerosol generated from the aerosol-generating substrate. For example, the additional cellulose is preferably a material that is substantially tasteless and odorless.

Preferably, less than about 2 percent by weight of each characteristic compound present in the homogenized plant material, as defined below, is derived from additional cellulose, more preferably less than about 1 percent by weight to most preferably about 0 percent by weight on a dry weight basis.

Preferably, less than about 2 percent by weight of any nicotine present in the homogenized plant material, as defined below, comes from additional cellulose, more preferably less than about 1 percent by weight to most preferably about 0 percent by weight on a dry weight basis.

Accordingly, the additional cellulose preferably provides minor amounts and preferably substantially zero amounts of any characteristic compounds from the non-tobacco material or tobacco material.

The additional cellulose may consist of a single type of cellulose material or may be a combination of different types of cellulose material that provide different properties, as described in more detail below.

The present invention provides an aerosol generating article that comprises a new aerosol generating substrate formed from homogenized plant material formed with at least one of non-tobacco plant particles and tobacco particles in combination with a cellulose ether and additional cellulose material. It was found that the combination of cellulose ether and additional cellulose material at a certain level and with a certain ratio advantageously provides a homogenized plant material having improved tensile strength and uniformity.

For certain non-tobacco plants, it has previously been found that it is technically difficult to produce homogenized plant material having acceptable tensile strength when the proportion of non-tobacco plant particles is above a certain level. Consequently, with such plants, it is difficult to provide usable homogenized plant material having a sufficiently high level of non-tobacco plant particles to achieve the desired level of flavoring in the generated aerosol. It has been found that above a threshold level of non-tobacco plant particles, the homogenized plant material has low tensile strength and has a non-uniform texture. If the tensile strength of the homogenized plant material is too low, it is brittle and cannot be effectively processed to form an aerosol-generating substrate, particularly on an industrial scale.

The inventors of the present invention have found that by using a specific combination of cellulose ether and additional cellulose in the homogenized plant material as defined above, a more effective binding action of non-tobacco plant particles can be achieved and the resulting homogenized plant material has a significantly higher tensile strength. Consequently, the resulting homogenized plant material can be readily processed to form an aerosol generating substrate using existing high-speed apparatus and techniques. Consequently, for certain non-tobacco plant materials, it is possible to create acceptable homogenized plant materials having a higher level of non-tobacco plant particles than was previously possible.

In addition, it has been found that the use of this combination of cellulose ether and additional cellulose in the aerosol-generating substrate of the aerosol-generating articles of the present invention provides for improved delivery of aerosol from the aerosol-generating substrate. In particular, it is possible to achieve a significant improvement in the delivery of aerosol from aerosol-generating substrates that are heated to a relatively low temperature during use to generate the aerosol. For example, as described in more detail below, it has been found that the present invention is particularly effective for aerosol-generating substrates adapted to be heated to a temperature below 275 degrees Celsius during use.

As defined above, the homogenized plant material forming the aerosol generating substrate of the aerosol generating articles of the present invention comprises from about 2 percent by weight to about 10 percent by weight of a cellulose ether, based on dry weight. It has been found that the cellulose ether provides highly effective binding properties when used together with plant particles in the homogenized plant material.

The homogenized plant material contains at least about 2 percent by weight of cellulose ether, preferably at least about 3 percent by weight of cellulose ether, more preferably at least about 4 percent by weight of cellulose ether, and more preferably about 5 percent by weight of cellulose ether on a dry weight basis.

The homogenized plant material contains no more than about 10 percent by weight cellulose ether, preferably no more than about 9 percent by weight cellulose ether, more preferably no more than about 8 percent by weight cellulose ether, more preferably no more than about 7 percent by weight cellulose ether on a dry weight basis.

For example, the homogenized plant material may contain from about 3 percent by weight to about 9 percent by weight cellulose ether, or from about 4 percent by weight to about 8 percent by weight cellulose ether, or from about 4 percent by weight to about 7 percent by weight cellulose ether, or about 5 percent by weight cellulose ether on a dry weight basis.

Suitable cellulose ethers for use in the present invention include, but are not limited to, methylcellulose, hydroxypropylmethylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, ethylhydroxyethylcellulose, and carboxymethylcellulose (CMC). In particularly preferred embodiments, the cellulose ether is carboxymethylcellulose.

It is believed that additional cellulose included in the homogenized plant material forming the aerosol generating substrate of the aerosol generating articles of the present invention provides additional structure and reinforcement for binding and supporting plant particles and aerosol forming agent within the homogenized material.

Additional cellulose may contain cellulose powder.

The term "cellulose powder" is used herein to denote purified cellulose material in powder form, which is obtained from the processing and purification of plant fibers containing cellulose. Cellulose powder is therefore a cellulose material that has been at least partially purified.

Preferably, the cellulose powder has at least about 90 percent purity, more preferably at least about 95 percent purity, more preferably at least about 97 percent purity, and more preferably at least about 99 percent purity.

Preferably, the cellulose powder contains at least about 90 percent by weight cellulose, more preferably at least about 95 percent by weight cellulose, and most preferably at least about 97 percent by weight cellulose, more preferably at least about 99 percent by weight cellulose, based on dry weight. The amount of cellulose can be determined using techniques known in the art.

Preferably, the cellulose powder is formed from particles with an average particle size that is less than about 250 microns, more preferably less than about 100 microns.

Cellulose powder may be in the form of a powdered cellulose product formed by mechanically breaking down and cleaning cellulose fibres without chemical modification. Cellulose powder is classified as food additive E460(ii) according to Regulation (EC) No 1333/2008.

Alternatively, the cellulose powder may be in the form of chemically modified cellulose such as microcrystalline cellulose, which is classified as food additive number E460(i) under (EC) 1333/2008. Microcrystalline cellulose is pure, partially depolymerised cellulose in crystalline form, which is synthesised by treating alpha-cellulose with mineral acids.

A suitable cellulose powder for use in the present invention is available as microcrystalline cellulose type SK-105 or SK-101, or cellulose powder type M-60 from Gumix International, Inc. of New Jersey.

Preferably, the amount of cellulose powder corresponds to at least about 5 percent by weight of the homogenized plant material on a dry weight basis, more preferably at least about 6 percent by weight of the homogenized plant material, more preferably at least about 7 percent by weight of the homogenized plant material, and more preferably at least about 8 percent by weight of the homogenized plant material on a dry weight basis.

The amount of cellulose powder may vary above this minimum level depending on the amount by weight of other components in the homogenized plant material and, in particular, depending on the amount by weight of plant particles. In certain embodiments, the cellulose powder may replace a certain proportion of plant particles in the homogenized plant material without significantly affecting the characteristics of the generated aerosol.

Preferably, the amount of cellulose powder corresponds to no more than about 45 percent by weight of the homogenized plant material, more preferably no more than about 40 percent by weight of the homogenized plant material on a dry weight basis.

In certain embodiments, such as embodiments having a relatively high level of plant particles in the homogenized plant material, the amount of cellulose powder may be relatively low. In such embodiments, the amount of cellulose powder may be from about 5 percent by weight to about 15 percent by weight of the homogenized plant material, or from about 6 percent by weight to about 12 percent by weight of the homogenized plant material, or from about 7 percent by weight to about 11 percent by weight of the homogenized plant material, or from about 8 percent by weight to about 10 percent by weight of the homogenized plant material on a dry weight basis.

In other embodiments, such as embodiments having a relatively low level of plant particles in the homogenized plant material, the amount of cellulose powder may be relatively high. In such embodiments, the amount of cellulose powder may be from about 15 percent by weight to about 45 percent by weight of the homogenized plant material, or from about 20 percent by weight to about 40 percent by weight of the homogenized plant material, or from about 25 percent by weight to about 35 percent by weight of the homogenized plant material on a dry weight basis.

Preferably, the weight ratio of cellulose powder to cellulose ether in the homogenized plant material is at least about 1.5, i.e., the amount of cellulose powder is at least 1.5 times the amount of cellulose ether. More preferably, the weight ratio of cellulose powder to cellulose ether in the homogenized plant material is at least about 1.6, more preferably at least about 1.8.

As an alternative or in addition to the cellulose powder, the additional cellulose may comprise reinforcing cellulose fibers. The term "reinforcing cellulose fibers" is used herein to denote fibers obtained directly from plant-based materials, each fiber having a length that is significantly greater than its width. The reinforcing cellulose fibers preferably have a fiber length of at least 400 microns. Suitable reinforcing cellulose fibers for use in the present invention include, for example, wood pulp fibers. A suitable source of reinforcing cellulose fibers for use in the present invention is available as "ECF Bleached Hardwood Kraft Pulp" from Storaenso, Sweden.

The reinforcing cellulose fibers can advantageously perform the function of mechanical reinforcement in the homogenized plant material forming the aerosol-generating substrate of the aerosol-generating articles according to the present invention. The reinforcing cellulose fibers can improve the binding of plant particles in the homogenized plant material and provide an improvement in tensile strength in combination with the cellulose ether.

Preferably, the amount of reinforcing cellulose fibers corresponds to at least about 3 percent by weight of the homogenized plant material on a dry weight basis, more preferably at least about 4 percent by weight of the homogenized plant material, more preferably at least about 5 percent by weight of the homogenized plant material, and more preferably at least about 6 percent by weight of the homogenized plant material on a dry weight basis.

Preferably, the amount of reinforcing cellulose fibers corresponds to no more than about 12 percent by weight of the homogenized plant material, more preferably at least about 11 percent by weight of the homogenized plant material, more preferably at least about 10 percent by weight of the homogenized plant material, more preferably at least about 8 percent by weight of the homogenized plant material on a dry weight basis.

For example, the homogenized plant material may contain from about 3 percent by weight to about 12 percent by weight reinforcing cellulosic fibers, or from about 4 percent by weight to about 11 percent by weight reinforcing cellulosic fibers, or from about 5 percent by weight to about 10 percent by weight reinforcing cellulosic fibers, or from about 6 percent by weight to about 8 percent by weight reinforcing cellulosic fibers on a dry weight basis.

Preferably, the weight ratio of the reinforcing cellulose fibres to the cellulose ether in the homogenised plant material is at least about 0.5, i.e., the amount of reinforcing cellulose fibres is at least half the amount of cellulose ether. More preferably, the weight ratio of the reinforcing cellulose fibres to the cellulose ether in the homogenised plant material is at least about 0.75, more preferably at least about 1.

In preferred embodiments, the additional cellulose comprises cellulose powder and reinforcing cellulose fibers. In such embodiments, the weight ratio of cellulose powder to reinforcing cellulose fibers is preferably at least about 1.5, more preferably at least about 1.75, more preferably at least about 2.

Preferably, the amount of additional cellulose provided in the homogenized plant material is adjusted such that the total amount of additional cellulose and plant particles corresponds to no more than 75 percent by weight of the homogenized plant material. Preferably, at least about 25 percent by weight of the homogenized plant material is thus provided by other components, including cellulose ether and aerosol forming agent.

The homogenized plant material forming the aerosol generating substrate of the aerosol generating articles of the present invention further comprises from about 5 percent by weight to about 55 percent by weight of an aerosol former. After evaporation, the aerosol former may carry other vaporized compounds released from the aerosol generating substrate upon heating, such as nicotine and flavor additives, into the aerosol. Aerosol formers suitable for inclusion in the homogenized plant material are known in the art and include, but are not limited to: polyhydric alcohols such as triethylene glycol, propylene glycol, 1,3-butanediol, and glycerol; 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. The homogenized plant material may contain a single aerosol forming agent or a combination of two or more aerosol forming agents.

In preferred embodiments of the present invention, the aerosol forming agent is glycerol.

Preferably, the homogenized plant material contains at least about 10 percent by weight of the aerosol forming agent, more preferably at least about 15 percent by weight of the aerosol forming agent on a dry weight basis.

Preferably, the homogenized plant material contains no more than about 50 percent by weight of the aerosol forming agent, more preferably no more than about 45 percent by weight of the aerosol forming agent on a dry weight basis.

The amount of aerosol forming substance can be adapted depending on the composition of the homogenized plant material, such as the type or amount of plant particles, in order to obtain an aerosol having the desired levels of flavor compounds from plant particles. The amount of aerosol forming substance can also be adapted depending on the intended manner of heating the aerosol-generating substrate during use and, in particular, depending on the temperature to which the aerosol-generating substrate will be heated during heating of the aerosol-generating article in the corresponding aerosol-generating device.

In certain embodiments of the present invention, the aerosol-generating substrate is adapted to be heated to a temperature above 300 degrees Celsius, such as about 350 degrees Celsius. This temperature range is typically achieved when the aerosol-generating substrate is heated by an internal heating element, such as in the commercially available IQOS device (Philip Morris Products SA, Switzerland). In such embodiments, the homogenized plant material preferably comprises from about 5 percent by weight to about 40 percent by weight of an aerosol forming agent, more preferably from about 10 percent by weight to about 35 percent by weight of an aerosol forming agent, more preferably from about 15 percent by weight to about 30 percent by weight of an aerosol forming agent, more preferably from about 15 percent by weight to about 30 percent by weight of an aerosol forming agent, based on dry weight.

In a preferred embodiment of the present invention, the homogenized plant material contains from 50 percent by weight to 65 percent by weight of non-tobacco particles, on a dry weight basis; and from 15 percent by weight to 25 percent by weight of aerosol forming agent, on a dry weight basis.

In another preferred embodiment of the present invention, the homogenized plant material contains from 50 percent by weight to 65 percent by weight of tobacco particles, based on dry weight; and from 15 percent by weight to 25 percent by weight of an aerosol forming agent, based on dry weight.

In other embodiments of the present invention, the aerosol generating substrate is adapted to be heated to a temperature below 300 degrees Celsius or below 275 degrees Celsius. In such embodiments, it has generally been found to be advantageous to provide a relatively high level of aerosol former in order to provide the desired levels of flavor compounds from plant particles in the aerosol generated by heating. In such embodiments, the homogenized plant material preferably comprises from about 30 percent by weight to about 55 percent by weight of aerosol former, more preferably from about 30 percent by weight to about 50 percent by weight of aerosol former, more preferably from about 30 percent by weight to about 45 percent by weight of aerosol former on a dry weight basis.

In a preferred embodiment of the present invention, the homogenized plant material contains from 10 percent by weight to 55 percent by weight of non-tobacco particles, on a dry weight basis; and from 30 percent by weight to 45 percent by weight of aerosol forming agent, on a dry weight basis.

In another preferred embodiment of the present invention, the homogenized plant material contains from 10 percent by weight to 55 percent by weight of tobacco particles, based on dry weight; and from 30 percent by weight to 45 percent by weight of aerosol forming agent, based on dry weight.

In such embodiments where the aerosol generating substrate is intended to be heated to a relatively low temperature, it has been found that the inclusion of a cellulose ether in the homogenized plant material advantageously improves aerosol formation and, in particular, the delivery of the aerosol forming agent compared to other binding materials.

As defined above, the homogenized plant material comprises from about 1 percent by weight to about 65 percent by weight of plant particles, wherein the plant particles provide flavor compounds to the aerosol generated from the aerosol generating substrate. The plant particles may be non-tobacco plant particles, tobacco particles, or a combination of non-tobacco plant particles and tobacco particles. The amount of plant particles provided in the homogenized plant material can be adjusted depending on the desired level of flavor compounds in the resulting aerosol. This may depend to some extent on the choice of plant from which the plant particles are obtained or on the level of any other flavor-providing components of the homogenized plant material.

Preferably, the homogenized plant material contains at least about 5 percent by weight of plant particles, more preferably at least about 10 percent by weight of plant particles, more preferably at least about 15 percent by weight of plant particles, and more preferably at least about 20 percent by weight of plant particles.

Preferably, the homogenized plant material contains no more than about 60 percent by weight of plant particles, more preferably no more than about 55 percent by weight of plant particles, more preferably no more than about 50 percent by weight of plant particles, more preferably no more than about 45 percent by weight of plant particles.

As defined above, according to the first aspect of the present invention, the homogenized plant material comprises particles of plants that are not tobacco. The particles of plants that are not tobacco may be obtained from one or more plants that are not tobacco, depending on the desired aroma of the resulting aerosol. Preferably, the particles of plants that are not tobacco comprise rosemary particles, ginger particles, star anise particles, clove particles, eucalyptus particles, or combinations thereof.

In certain embodiments, substantially all of the plant particles forming the homogenized plant material are non-tobacco plant particles. In alternative embodiments, the homogenized plant material comprises non-tobacco plant particles in combination with at least one of tobacco particles or hemp particles, as described below. Preferably, the total amount by weight of non-tobacco particles, tobacco particles, and hemp particles does not exceed 65 percent by weight on a dry weight basis.

In the following description of the present invention, the term "particulate plant material" is used to refer to the aggregate of plant material particles that are used to form the homogenized plant material.

If the homogenized plant material comprises a combination of non-tobacco plant particles and tobacco particles, the homogenized plant material preferably comprises at least about 1 percent by weight of tobacco particles, more preferably at least about 5 percent by weight of tobacco particles, more preferably at least about 10 percent by weight of tobacco particles, more preferably at least about 20 percent by weight of tobacco particles, more preferably at least about 30 percent by weight of tobacco particles, more preferably at least about 40 percent by weight of tobacco particles on a dry weight basis. Preferably, the homogenized plant material comprises up to about 64 percent by weight of tobacco particles, more preferably up to about 60 percent by weight of tobacco particles, more preferably up to about 55 percent by weight of tobacco particles, more preferably up to about 50 percent by weight of tobacco particles on a dry weight basis.

The weight ratio of non-tobacco plant particles to tobacco particles in the particulate plant material forming the homogenized plant material may vary depending on the desired flavor characteristics and composition of the aerosol. For example, the weight ratio of non-tobacco plant particles to tobacco particles may be from about 1:60 to 60:1, or from about 1:10 to about 10:1, or from about 1:5 to 5:1.

According to a second aspect of the present invention, the homogenized plant material comprises tobacco particles. In certain embodiments, substantially all of the plant particles forming the homogenized plant material are tobacco particles. Alternatively, the tobacco particles may be combined with one or more other types of plant particles, as described above.

For all embodiments of the present invention, the term "tobacco particles" describes particles of any plant belonging to the genus Nicotiana . The term "tobacco particles" includes ground or powdered tobacco leaf lamellae, ground or powdered tobacco leaf stems, tobacco dust, tobacco fines, and other particulate tobacco by-products generated during the processing, handling, and shipping of tobacco. In a preferred embodiment, the tobacco particles are substantially all derived from tobacco leaf lamellae. In contrast, separated nicotine and nicotine salts are compounds derived from tobacco, but are not considered tobacco particles for the purposes of the present invention and are not included in the percentage of particulate plant material.

The tobacco particles may be derived from one or more varieties of tobacco plants. Any type of tobacco may be used in the blend. Examples of types of tobacco that may be used include, but are not limited to, sun-cured tobacco, flue-cured tobacco, Burley tobacco, Maryland tobacco, Oriental tobacco, Virginia tobacco, and other specialty tobaccos.

Flue-curing is a method of drying tobacco that is especially widely used with Virginia tobaccos. During the flue-curing process, heated air is circulated through tightly packed tobacco. During the first stage, the tobacco leaves turn yellow and wither. During the second stage, the leaf blades are completely dry. During the third stage, the leaf stems are completely dry.

Burley tobacco plays an important role in many tobacco blends. Burley tobacco has a distinctive flavor and aroma, and also has the ability to absorb large amounts of sauce.

Oriental tobacco has small leaves and pronounced aromatic qualities. However, oriental tobacco has a milder flavor than, for example, Burley tobacco. Therefore, in general, oriental tobacco is used in relatively small proportions in tobacco blends.

Kasturi, Maduro and Yatim are subtypes of sun-cured tobacco that may be used. Preferably, Kasturi tobacco and flue-cured tobacco may be used in a mixture to produce tobacco particles. Accordingly, the tobacco particles in the particulate plant material may comprise a mixture of Kasturi tobacco and flue-cured tobacco.

The tobacco particles may have a nicotine content of at least about 2.5 percent by weight on a dry weight basis. More preferably, the tobacco particles may have a nicotine content of at least about 3 percent, even more preferably at least about 3.2 percent, still more preferably at least about 3.5 percent, most preferably at least about 4 percent by weight on a dry weight basis. When the aerosol-generating substrate comprises tobacco particles in combination with non-tobacco particles, tobacco species having a higher nicotine content are preferred to maintain similar nicotine levels compared to conventional aerosol-generating substrates without non-tobacco particles, since the overall amount of nicotine would otherwise be reduced due to the substitution of non-tobacco particles for the tobacco particles.

Nicotine may optionally be included in the aerosol generating substrate, although it is considered a non-tobacco material for the purposes of the present invention. Nicotine may comprise one or more nicotine salts selected from the list consisting of nicotine lactate, nicotine citrate, nicotine pyruvate, nicotine bitartrate, nicotine benzoate, nicotine pectate, nicotine alginate and nicotine salicylate. Nicotine may be included in addition to low-nicotine tobacco, or nicotine may be included in an aerosol generating substrate that has a reduced or zero tobacco content.

Preferably, the homogenized plant material comprises one or more organic acids for binding nicotine in the homogenized plant material by forming one or more nicotine salts. The one or more organic acids are preferably one or more carboxylic acids. The carboxylic acid may comprise a ketone group. Preferably, the carboxylic acid may comprise a ketone group that has less than about 10 carbon atoms or less. Preferred carboxylic acids for use in the present invention include, but are not limited to, lactic acid and levulinic acid. Preferably, the homogenized plant material comprises from about 0.5 percent by weight to about 2 percent by weight of the acid, most preferably lactic acid.

Preferably, the aerosol generating substrate comprises at least 0.1 milligrams of nicotine per gram of substrate on a dry weight basis. More preferably, the aerosol generating substrate comprises at least about 0.5 mg of nicotine per gram of substrate, more preferably at least about 1 mg of nicotine per gram of substrate, more preferably at least about 1.5 mg of nicotine per gram of substrate, more preferably at least about 2 mg of nicotine per gram of substrate, more preferably at least about 3 mg of nicotine per gram of substrate, more preferably at least about 4 mg of nicotine per gram of substrate, more preferably at least about 5 mg of nicotine per gram of substrate on a dry weight basis.

Preferably, the aerosol generating substrate comprises up to about 50 mg nicotine per gram of substrate on a dry weight basis. More preferably, the aerosol generating substrate comprises up to about 45 mg nicotine per gram of substrate, more preferably up to about 40 mg nicotine per gram of substrate, more preferably up to about 35 mg nicotine per gram of substrate, more preferably up to about 30 mg nicotine per gram of substrate, more preferably up to about 25 mg nicotine per gram of substrate, more preferably up to about 20 mg nicotine per gram of substrate on a dry weight basis.

For example, the aerosol-generating substrate may comprise from about 0.1 mg to about 50 mg nicotine per gram of substrate, or from about 0.5 mg to about 45 mg nicotine per gram of substrate, or from about 1 mg to about 40 mg nicotine per gram of substrate, or from about 2 mg to about 35 mg nicotine per gram of substrate, or from about 5 mg to about 30 mg nicotine per gram of substrate, or from about 10 mg to about 25 mg nicotine per gram of substrate, or from about 15 mg to about 20 mg nicotine per gram of substrate, on a dry weight basis. In certain preferred embodiments of the present invention, the aerosol-generating substrate comprises from about 1 mg to about 20 mg nicotine per gram of substrate, on a dry weight basis.

Specific nicotine content ranges for an aerosol-generating substrate include all forms of nicotine that may be present in the aerosol-generating substrate, including nicotine inherently present in the tobacco material, as well as nicotine that is optionally separately added to the aerosol-generating substrate, such as in the form of a nicotine salt.

Alternatively or in addition to including tobacco particles in the homogenized plant material of the aerosol generating substrate of the present invention, the homogenized plant material may contain at least about 1 percent by weight of hemp particles on a dry weight basis. The term "hemp particles" refers to particles of the hemp plant, such as the species Cannabis sativa, Cannabis indica and Cannabis ruderalis .

Preferably, the homogenized plant material contains at least about 1 percent by weight of hemp particles, more preferably at least about 5 percent by weight of hemp particles, more preferably at least about 10 percent by weight of hemp particles, more preferably at least about 20 percent by weight of hemp particles, more preferably at least about 30 percent by weight of hemp particles, more preferably at least about 40 percent by weight of hemp particles on a dry weight basis.

Preferably, the homogenized plant material contains up to about 64 percent by weight hemp particles, more preferably up to about 60 percent by weight hemp particles, more preferably up to about 55 percent by weight hemp particles, more preferably up to about 50 percent by weight hemp particles on a dry weight basis.

One or more cannabinoid compounds may optionally be included in the aerosol generating substrate, although it is considered a non-hemp material for the purposes of the present invention. In the context of this document regarding the present invention, the term "cannabinoid compound" describes any of a class of naturally occurring compounds that are contained in parts of the hemp plant, namely the species Cannabis sativa , Cannabis indica and Cannabis ruderalis . Cannabinoid compounds are particularly concentrated in the female flower heads and are commonly sold as hemp oil. Cannabinoid compounds naturally occurring in the hemp plant include tetrahydrocannabinol (THC) and cannabidiol (CBD). In the context of the present invention, the term "cannabinoid compounds" is used to describe both naturally occurring cannabinoid compounds and synthetically produced cannabinoid compounds.

For example, the aerosol generating substrate may comprise a cannabinoid compound selected from the group consisting of: tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin (CBE), cannabicitran (CBT), and combinations thereof.

In particularly preferred embodiments of the present invention, the homogenized plant material comprises rosemary particles. The inventors have found that by incorporating rosemary particles into an aerosol-generating substrate, it is advantageous to produce an aerosol that allows for novel sensory experiences. Such an aerosol provides unique flavors and aromas and can provide an increased level of mouthfeel.

In addition, the inventors of the present invention have found that an aerosol with an improved rosemary aroma and flavor can be advantageously obtained compared to an aerosol obtained by adding rosemary additives, such as rosemary oil. Rosemary oil is obtained by distillation from the leaves of the rosemary plant and has a flavor composition that differs from rosemary particles, presumably due to the distillation process, during which certain flavor additives can be selectively removed or retained. Moreover, in some aerosol-generating substrates proposed herein, rosemary particles can be included at a sufficient level to impart a desired rosemary flavor, while maintaining a sufficient amount of tobacco material to provide a desired level of nicotine to the consumer.

In addition, it was unexpectedly discovered that the inclusion of rosemary particles in an aerosol-generating substrate provides a significant reduction in certain undesirable aerosol compounds compared to an aerosol produced from an aerosol-generating substrate containing 100 percent tobacco particles without rosemary particles.

In such embodiments, the homogenized plant material may contain from about 10 percent by weight to about 65 percent by weight rosemary particles. The homogenized plant material may optionally contain a combination of rosemary particles and tobacco particles.

For example, in one preferred embodiment, the homogenized plant material comprises from about 50 percent by weight to about 65 percent by weight rosemary particles on a dry weight basis. In such embodiments, the homogenized plant material preferably comprises from about 15 percent by weight to about 25 percent by weight aerosol former on a dry weight basis.

For homogenized plant materials in which the plant particles comprise rosemary particles, it has previously been found that it is difficult to form a sheet of homogenized plant material having a plant particle content that is greater than about 30 percent by weight using known sheet forming processes. It has been found that at this relatively high level of rosemary particles, the resulting homogenized plant material is particularly brittle and porous, with low tensile strength, so that the homogenized plant material is not suitable for use in forming an aerosol generating substrate. The inventors of the present invention have surprisingly found that by incorporating a combination of a cellulose ether and additional cellulose, as defined above, into the homogenized plant material, it is possible to create a significantly improved homogenized plant material comprising up to 65 percent by weight of rosemary particles. In particular, it is possible to produce a homogenized plant material containing 50 percent by weight to 60 percent by weight rosemary particles, which has a uniform texture and significantly improved tensile strength.

In another preferred embodiment, the homogenized plant material contains from about 10 percent by weight to about 55 percent by weight of rosemary particles on a dry weight basis and from about 35 percent by weight to about 45 percent by weight of aerosol forming agent on a dry weight basis. This embodiment, in which the content of aerosol forming agent is relatively high, is particularly suitable for use in a heating device that heats an aerosol-generating substrate to a temperature of less than 275 degrees, as described above. The relatively high content of aerosol forming agent ensures optimal delivery of flavor compounds from the rosemary particles to the aerosol generated from the aerosol-generating substrate upon heating.

The presence of rosemary in homogenized plant material (such as molded leaf) can be accurately determined by DNA barcoding. Methods for performing DNA barcoding based on the nuclear ITS2 gene, the rbcL and matK system, and the plastid intergenic spacer trnH-psbA are well known in the art and can be used (Chen S, Yao H, Han J, Liu C, Song J, et al. (2010) Validation of the ITS2 Region as a Novel DNA Barcode for Identifying Medicinal Plant Species. PLoSONE 5(1): e8613; Hollingsworth PM, Graham SW, Little DP (2011) Choosing and Using a Plant DNA Barcode. PLoS ONE 6(5): e19254).

The inventors of the present invention have carried out a complex analysis and characterization of aerosols generated from the aerosol-generating substrates of the present invention, which contain rosemary particles and a mixture of rosemary and tobacco particles, and compared these aerosols with aerosols obtained from existing aerosol-generating substrates formed from tobacco material without rosemary particles. Based on this, the inventors of the present invention were able to identify a group of "characteristic compounds", which are compounds present in the aerosols and obtained from rosemary particles. Thus, the detection of these characteristic compounds in the aerosol within a certain range of weight fraction can be used to identify aerosols that are obtained from an aerosol-generating substrate containing rosemary particles. These characteristic compounds are not present to a significant extent in the aerosol generated from tobacco material. In addition, the proportion of the characteristic compounds in the aerosol and the ratio of the characteristic compounds to each other clearly indicate the use of rosemary plant material, rather than rosemary oil. Similarly, the presence of these characteristic compounds in specific proportions in the aerosol-generating substrate indicates the incorporation of rosemary particles into the substrate.

In particular, the determined levels of the characteristic compounds in the substrate and the aerosol are specific to the rosemary particles present in the homogenised rosemary-based material. The level of each characteristic compound depends on the manner in which the rosemary particles are processed during the production of the homogenised plant material. The level also depends on the composition of the homogenised plant material and, in particular, will be affected by the level of other components in the homogenised plant material. The level of the characteristic compounds in the homogenised plant material will differ from the level of the same compound in the original rosemary material. It will also differ from the level of the characteristic compounds in materials containing rosemary particles but which do not correspond to the present invention as defined herein.

In a similar manner, characteristic compounds can be identified for other plant materials, whereby the presence of characteristic compounds at some level within specifically defined ranges is characteristic of the inclusion of the plant material in the homogenized plant material.

To characterize aerosols, the present inventors used complementary non-targeted differential screening (NTDS) using liquid chromatography coupled to high-resolution mass spectrometry with accurate mass determination (LC-HRAM-MS) in parallel with two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS).

Non-targeted screening (NTS) is a key technique for characterizing the chemical composition of complex matrices by matching unknown compound detections with spectral databases (putative screening analysis [SSA]) or, if preliminary data are inconsistent, by elucidating the structure of unknowns using, for example, first-order fragmentation (MS/MS) information matched to in silico predicted fragments from compound databases (non-targeted analysis [NTA]). It provides simultaneous measurement and the ability to semi-quantify large numbers of small molecules in samples using an unbiased approach.

If the focus is on comparing two or more aerosol samples as described above to assess any significant differences in chemical composition between uncontrolled samples, or if preliminary group-related data are available between sample groups, non-targeted differential screening (NTDS) can be performed. A complementary differential screening approach using liquid chromatography coupled to high-resolution mass spectrometry with accurate mass (LC-HRAM-MS) in parallel with two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS) was applied to provide comprehensive analytical coverage to identify the most significant differences in aerosol composition between aerosols generated from articles containing 100% by weight rosemary as the particulate plant material and aerosols generated from articles containing 100% by weight tobacco as the particulate plant material.

The aerosol was generated and collected using the apparatus and methodology detailed below.

LC-HRAM-MS analysis was performed using a Thermo QExactive ^TM high-resolution mass spectrometer in both full scan and data-dependent modes. A total of three different methods were used to cover a wide range of substances with different ionization properties and compound classes. Samples were analyzed by RP chromatography with heated electrospray ionization (HESI) in both positive and negative modes and atmospheric pressure chemical ionization (APCI) in positive mode. The methods are described in the following papers: Arndt, D. et al , "Indepth characterization of chemical differences between heat-not-burn tobacco products and cigarettes using LC-HRAM-MS-based non-targeted differential screening"(DOI:10.13140/RG.2.2.11752.16643); Wachsmuth, C. et al , “Comprehensive chemical characterisation of complex matrices through integration of multiple analytical modes and databases for LC-HRAM-MS-based non-targeted screening” (DOI: 10.13140/RG.2.2.12701.61927); and “Buchholz, C. et al , “Increasing confidence for compound identification by fragmentation database and in silico fragmentation comparison with LC-HRAM-MS-based non-targeted screening of complex matrices” (DOI: 10.13140/RG.2.2.17944.49927), all retrieved from the 66th ASMS Conference on Mass Spectrometry and Related Topics, San Diego, USA (2018). The methods are further described in the following papers: Arndt, D. et al , “A complex matrix characterization approach, applied to cigarette smoke, that integrates multiple analytical methods and compound identification strategies for non-targeted liquid chromatography with high-resolution mass spectrometry” (DOI: 10.1002/rcm.8571).ar

GCxGC-TOFMS analysis was performed using an Agilent GC model 6890A or 7890A equipped with an automatic liquid nebulizer (model 7683B) and a temperature modulator coupled to a LECO Pegasus 4D™ mass spectrometer using three different methods for non-polar, polar, and highly volatile compounds in the aerosol. The methods are described in the following papers: Almstetter et al , “Non-targeted screening using GC×GC-TOFMS for in-depth chemical characterization of aerosol from a heat-not-burn tobacco product” (DOI: 10.13140/RG.2.2.36010.31688/1); and Almstetter et al , “Non-targeted differential screening of complex matrices using GC×GC-TOFMS for comprehensive characterization of the chemical composition and determination of significant differences” (DOI: 10.13140/RG.2.2.32692.55680), obtained from the 66th and 64th ASMS Conferences on Mass Spectrometry and Related Topics, San Diego, USA, respectively.

The results of the analytical methods provided information on the main compounds responsible for the differences in aerosols generated by such articles. The purpose of the untargeted differential screening using both the LC-HRAM-MS and GCxGC-TOFMS analytical platforms was to identify compounds that were present in high amounts in aerosols of a sample of the aerosol-generating substrate according to the present invention containing 100 percent rosemary particles relative to a comparative sample of the aerosol-generating substrate containing 100 percent tobacco particles. The NTDS methodology is described in the documents listed above.

Based on this information, the present inventors were able to identify specific compounds in the aerosol that can be considered "characteristic _compounds " derived from rosemary particles in the substrate. Characteristic compounds unique to rosemary include, but are not limited to: betulinic acid ((3β)-3-hydroxy-lup-20(29)-ene- ₂₈ -oic acid, chemical formula: _C30H48O3 , Chemical Abstracts number 472-15-1); rosmaridiphenol (4,5-dihydroxy-12,12-dimethyl-6-(propan-2-yl)tricyclo[9.4.0.0 ³ , ⁸ ]pentadeca-3,5,7-trien-2-one), chemical formula: C ₂₀ H ₂₈ O ₃ , Chemical Abstracts number 1729-95-2; and 12-O-methylcarnosol, chemical formula: C ₂₁ H ₂₈ O ₄ , Chemical Abstracts number 85514-27-8.

For the purposes of the present invention, targeted screening may be performed on a sample of an aerosol-generating substrate to identify the presence and amount of each of the characteristic compounds in the substrate. Such a targeted screening method is described below. As described, the characteristic compounds may be detected and measured both in the aerosol-generating substrate and in the aerosol obtained from the aerosol-generating substrate.

As defined above, certain preferred embodiments of the aerosol generating article according to the present invention comprise an aerosol generating substrate formed from homogenized plant material comprising rosemary particles. As a result of the inclusion of rosemary particles, the aerosol generating substrate comprises certain proportions of "characteristic compounds" of rosemary, as described above. In particular, the aerosol generating substrate preferably comprises at least 50 micrograms of betulinic acid per gram of substrate, at least 20 micrograms of rosmaridiphenol per gram of substrate, and at least 0.3 micrograms of 12-O-methylcarnosol per gram of substrate, based on dry weight.

By defining the aerosol generating substrate relative to desired levels of signature compounds, consistency between products can be ensured despite potential differences in signature compound levels in the starting materials. This advantageously allows for more effective quality control of the product.

Preferably, the aerosol generating substrate comprises at least about 100 micrograms of betulinic acid per gram of substrate, more preferably at least about 250 micrograms of betulinic acid per gram of substrate, more preferably at least about 500 micrograms of betulinic acid per gram of substrate on a dry weight basis. Alternatively or additionally, the aerosol generating substrate preferably comprises no more than about 4000 micrograms of betulinic acid per gram of substrate, more preferably no more than about 3500 micrograms of betulinic acid per gram of substrate, more preferably no more than about 3000 micrograms of betulinic acid per gram of substrate, and more preferably no more than about 2500 micrograms of betulinic acid per gram of substrate on a dry weight basis.

For example, the aerosol generating substrate may contain from about 50 micrograms to about 4000 micrograms of betulinic acid per gram of substrate, or from about 100 micrograms to about 3500 micrograms of betulinic acid per gram of substrate, or from about 250 micrograms to about 3000 micrograms of betulinic acid per gram of substrate, or from about 500 micrograms to about 2500 micrograms of betulinic acid per gram of substrate on a dry weight basis.

Preferably, the aerosol generating substrate comprises at least about 50 micrograms of rosmaridiphenol per gram of substrate, more preferably at least about 100 micrograms of rosmaridiphenol per gram of substrate, more preferably at least about 200 micrograms of rosmaridiphenol per gram of substrate on a dry weight basis. Alternatively or additionally, the aerosol generating substrate preferably comprises no more than about 2000 micrograms of rosmaridiphenol per gram of substrate, more preferably no more than about 1750 micrograms of rosmaridiphenol per gram of substrate, more preferably no more than about 1500 micrograms of rosmaridiphenol per gram of substrate, and more preferably no more than about 1000 micrograms of rosmaridiphenol per gram of substrate on a dry weight basis.

For example, the aerosol generating substrate may contain from about 20 micrograms to about 2000 micrograms of rosmarin diphenol per gram of substrate, or from about 50 micrograms to about 1750 micrograms of rosmarin diphenol per gram of substrate, or from about 100 micrograms to about 1500 micrograms of rosmarin diphenol per gram of substrate, or from about 200 micrograms to about 1000 micrograms of rosmarin diphenol per gram of substrate on a dry weight basis.

Preferably, the aerosol generating substrate comprises at least about 1 microgram of 12-O-methylcarnosol per gram of substrate, more preferably at least about 2 micrograms of 12-O-methylcarnosol per gram of substrate, more preferably at least about 4 micrograms of 12-O-methylcarnosol per gram of substrate on a dry weight basis. Alternatively or additionally, the aerosol generating substrate preferably comprises no more than about 40 micrograms of 12-O-methylcarnosol per gram of substrate, more preferably no more than about 30 micrograms of 12-O-methylcarnosol per gram of substrate, more preferably no more than about 25 micrograms of 12-O-methylcarnosol per gram of substrate, and more preferably no more than about 20 micrograms of 12-O-methylcarnosol per gram of substrate on a dry weight basis.

For example, the aerosol generating substrate may contain from about 0.3 micrograms to about 40 micrograms of 12-O-methylcarnosol per gram of substrate, or from about 1 microgram to about 30 micrograms of 12-O-methylcarnosol per gram of substrate, or from about 2 micrograms to about 25 micrograms of 12-O-methylcarnosol per gram of substrate, or from about 4 micrograms to about 20 micrograms of 12-O-methylcarnosol per gram of substrate on a dry weight basis.

Preferably, the ratio of the characteristic compounds in the aerosol-generating substrate is such that the amount of betulinic acid per gram of substrate is at least 2 times greater than the amount of rosmaridiphenol per gram of substrate, more preferably at least 2.5 times greater than the amount of rosmaridiphenol per gram of substrate, even more preferably at least 3 times greater than the amount of rosmaridiphenol per gram of substrate.

This ratio of betulinic acid to rosmaridiphenol is characteristic of the incorporation of rosemary particles into the aerosol-generating substrate.

Preferably, the aerosol generating substrate comprises greater than 0.5 percent by weight of 1,8-cineole on a dry weight basis. More preferably, the aerosol generating substrate comprises greater than about 1 percent by weight of 1,8-cineole on a dry weight basis.

As defined above, the present invention also provides an aerosol generating article that comprises an aerosol generating substrate formed from homogenized plant material containing rosemary particles, wherein upon heating the aerosol generating substrate, an aerosol is generated that contains "characteristic compounds" of rosemary.

For the purposes of the present invention, the aerosol-generating substrate is heated according to "test method A". In test method A, an aerosol-generating article that contains the aerosol-generating substrate is heated in a holder of a tobacco heating system 2.2 (THS2.2 holder) according to a machine smoking regimen approved by Health Canada. For the purposes of performing test method A, the aerosol-generating substrate is provided in an aerosol-generating article that is compatible with the THS2.2 holder.

The holder of the tobacco heating system 2.2 (THS2.2 holder) corresponds to the commercially available IQOS device (Philip Morris Products SA, Switzerland) as described in Smith et al., 2016, Regul. Toxicol. Pharmacol. 81 (S2) S82-S92. Aerosol generating products for use in combination with the IQOS device are also commercially available.

The Health Canada smoking regimen is a clearly defined and accepted smoking protocol as defined in Health Canada 2000 - Tobacco Products Information Regulations SOR/2000-273, Schedule 2; published by the Department of Justice, Canada. The test method is described in ISO/TR 19478-1:2014. In the Health Canada smoking test, aerosol is collected from a sample of an aerosol-generating substrate over 12 puffs with a puff volume of 55 millimetres, a puff duration of 2 seconds and an inter-puff interval of 30 seconds, with all ventilation blocked if ventilation is present.

Thus, in the context of the present invention, the expression "under heating of the aerosol-generating substrate according to Test Method A" means heating of the aerosol-generating substrate in a THS2.2 holder according to the machine smoking regime approved by Health Canada, as defined in Health Canada 2000 - Tobacco Products Information Regulations SOR/2000-273, Schedule 2, published by the Department of Justice Canada, the test method being described in ISO/TR 19478-1:2014.

For analytical purposes, the aerosol generated by heating the aerosol generating substrate is captured using a suitable device depending on the analytical method to be used. In a suitable method for generating samples for LC-HRAM-MS analysis, the dispersed phase is captured using a standard 44 mm Cambridge glass fibre filter pad (according to ISO 3308) and a filter holder (according to ISO 4387 and ISO 3308). The remaining gas phase is collected downstream of the filter pad using two successive microimpingers (20 ml), each containing methanol and an internal standard solution (ISTD) (10 ml), maintained at -60 degrees Celsius using a mixture of dry ice and isopropanol. The trapped dispersed phase and gas phase are then recombined and extracted using methanol from the microimpingers by shaking the sample, vigorously mixing for 5 minutes and centrifuging (4500 g, 5 minutes, 10 degrees Celsius). The resulting extract is diluted with methanol and mixed in an Eppendorf thermal mixer (5 degrees Celsius, 2000 rpm). Test samples from the extract are analyzed by LC-HRAM-MS in a combination of full scan mode and fragmentation mode depending on the data to identify characteristic compounds. For the purposes of the present invention, LC-HRAM-MS analysis is suitable for the identification and quantification of betulinic acid, rosmaridiphenol and 12-O-methylcarnosol.

Samples for GCxGC-TOFMS analysis can be generated in a similar manner, but for GCxGC-TOFMS analysis, different solvents are suitable for the extraction and analysis of polar compounds, non-polar compounds, and volatile compounds isolated from the whole aerosol.

For non-polar and polar compounds, the total aerosol is collected using a standard 44 mm Cambridge glass fibre filter pad (ISO 3308) and filter holder (ISO 4387 and ISO 3308) and two microimpingers are connected in series and sealed. Each microimpinger (20 ml) contains 10 ml of dichloromethane/methanol (80:20 v/v) containing the internal standard (ISTD) and retention index marker (RIM) compounds. The microimpingers are maintained at -80 °C using a mixture of dry ice and isopropanol. For the analysis of non-polar compounds, the dispersed phase of the total aerosol is extracted from the glass fibre filter pad using the contents of the microimpingers. Water is added to an aliquot (10 ml) of the resulting extract and the sample is shaken and centrifuged as described above. The dichloromethane layer is separated, dried with sodium sulfate and analyzed by GCxGC-TOFMS in full scan mode. For the analysis of polar compounds, the water layer remaining from the preparation of the non-polar sample described above is used. ISTD and RIM compounds are added to the water layer, which is then analyzed directly by GCxGC-TOFMS in full scan mode.

For volatile compounds, the entire aerosol is collected using two 20 mL sealed microimpingers in series, each filled with 10 mL of N,N-dimethylformamide (DMF) containing ISTD and RIM compounds. The microimpingers are maintained at -50 to -60 °C using a mixture of dry ice and isopropanol. After collection, the contents of the two microimpingers are combined and analyzed by GCxGC-TOFMS in full scan mode.

For the purposes of the present invention, GCxGC-TOFMS analysis is suitable for the identification and quantification of 12-O-methylcarnosol.

The aerosol generated by heating the aerosol generating substrate according to the present invention according to Test Method A is preferably characterized by the amounts and ratios of the characteristic compounds, betulinic acid, rosmaridiphenol and 12-O-methylcarnosol, as defined above.

Preferably, in an aerosol-generating article comprising an aerosol-generating substrate as described above, upon heating the aerosol-generating substrate according to Test Method A, an aerosol is generated comprising at least 30 micrograms of betulinic acid per gram of substrate on a dry weight basis; at least 1 microgram of rosmaridiphenol per gram of substrate on a dry weight basis; and at least 1 microgram of 12-O-methylcarnosol per gram of substrate on a dry weight basis.

The ranges define the amount of each characteristic compound in the generated aerosol per gram of aerosol-generating substrate (also referred to herein as "substrate"). This is equal to the total amount of the characteristic compound measured in the aerosol collected during Test Method A divided by the dry weight of the aerosol-generating substrate before heating.

When the aerosol generating substrate is heated according to Test Method A, an aerosol is preferably generated, preferably containing at least about 30 micrograms of betulinic acid per gram of substrate on a dry weight basis.

More preferably, the aerosol generated from the aerosol-generating substrate according to the present invention comprises at least about 100 micrograms of betulinic acid per gram of substrate on a dry weight basis. Even more preferably, the aerosol generated from the aerosol-generating substrate according to the present invention comprises at least about 250 micrograms of betulinic acid per gram of substrate on a dry weight basis. Alternatively or additionally, the aerosol generated from the aerosol-generating substrate preferably comprises up to about 3000 micrograms of betulinic acid per gram of substrate on a dry weight basis. More preferably, the aerosol generated from the aerosol-generating substrate comprises up to about 2500 micrograms of betulinic acid per gram of substrate on a dry weight basis. Even more preferably, the aerosol generated from the aerosol generating substrate contains up to about 2000 micrograms of betulinic acid per gram of substrate on a dry weight basis.

When the aerosol generating substrate is heated according to Test Method A, an aerosol is generated that preferably contains at least about 1 microgram of rosmarin diphenol per gram of substrate on a dry weight basis.

Preferably, the aerosol generated from the aerosol-generating substrate according to the present invention further comprises at least about 10 micrograms of rosmaridiphenol per gram of substrate on a dry weight basis. More preferably, the aerosol generated from the aerosol-generating substrate according to the present invention comprises at least about 25 micrograms of rosmaridiphenol per gram of substrate on a dry weight basis. Alternatively or additionally, the aerosol generated from the aerosol-generating substrate preferably comprises up to about 150 micrograms of rosmaridiphenol per gram of substrate on a dry weight basis. More preferably, the aerosol generated from the aerosol-generating substrate comprises up to about 120 micrograms of rosmaridiphenol per gram of substrate on a dry weight basis. Even more preferably, the aerosol generated from the aerosol generating substrate contains up to about 100 micrograms of rosmarin diphenol per gram of substrate on a dry weight basis.

When the aerosol generating substrate is heated according to Test Method A, an aerosol is generated that preferably contains at least about 1 microgram of 12-O-methylcarnosol per gram of substrate on a dry weight basis.

Preferably, the aerosol generated from the aerosol-generating substrate of the present invention comprises at least about 10 micrograms of 12-O-methylcarnosol per gram of substrate on a dry weight basis. Even more preferably, the aerosol generated from the aerosol-generating substrate of the present invention comprises at least about 25 micrograms of 12-O-methylcarnosol per gram of substrate on a dry weight basis. Alternatively or additionally, the aerosol generated from the aerosol-generating substrate preferably comprises up to about 150 micrograms of 12-O-methylcarnosol per gram of substrate on a dry weight basis. More preferably, the aerosol generated from the aerosol-generating substrate comprises up to about 120 micrograms of 12-O-methylcarnosol per gram of substrate on a dry weight basis. Even more preferably, the aerosol generated from the aerosol generating substrate contains up to about 100 micrograms of 12-O-methylcarnosol per gram of substrate on a dry weight basis.

In some embodiments, an aerosol generated from an aerosol-generating substrate according to the present invention comprises at least 30 micrograms of betulinic acid per gram of substrate on a dry weight basis; at least 1 microgram of rosmaridiphenol per gram of substrate on a dry weight basis; and at least 1 microgram of 12-O-methylcarnosol per gram of substrate on a dry weight basis.

Preferably, the aerosol obtained from the aerosol-generating substrate according to the present invention during Test Method A further comprises at least about 0.1 micrograms of nicotine per gram of substrate, more preferably at least about 1 microgram of nicotine per gram of substrate, more preferably at least about 2 micrograms of nicotine per gram of substrate. Preferably, the aerosol comprises up to about 10 micrograms of nicotine per gram of substrate, more preferably up to about 7.5 micrograms of nicotine per gram of substrate, more preferably up to about 4 micrograms of nicotine per gram of substrate. For example, the aerosol may comprise from about 0.1 micrograms to about 10 micrograms of nicotine per gram of substrate, or from about 1 microgram to about 7.5 micrograms of nicotine per gram of substrate, or from about 2 micrograms to about 4 micrograms of nicotine per gram of substrate. In some embodiments of the present invention, the aerosol may comprise zero micrograms of nicotine.

Various methods known in the art may be used to measure the amount of nicotine in an aerosol.

Alternatively or additionally, the aerosol obtained from the aerosol-generating substrate according to the present invention during Test Method A may optionally further comprise at least about 20 milligrams of cannabinoid compound per gram of substrate, more preferably at least about 50 milligrams of cannabinoid compound per gram of substrate, more preferably at least about 100 milligrams of cannabinoid compound per gram of substrate. Preferably, the aerosol comprises up to about 250 milligrams of cannabinoid compound per gram of substrate, more preferably up to about 200 milligrams of cannabinoid compound per gram of substrate, more preferably up to about 150 milligrams of cannabinoid compound per gram of substrate. For example, the aerosol may contain from about 20 milligrams to about 250 milligrams of cannabinoid compound per gram of substrate, or from about 50 milligrams to about 200 milligrams of cannabinoid compound per gram of substrate, or from about 100 milligrams to about 150 milligrams of cannabinoid compound per gram of substrate. In some embodiments of the present invention, the aerosol may contain zero micrograms of cannabinoid compound.

Preferably, the cannabinoid compound is selected from CBD and THC. More preferably, the cannabinoid compound is CBD.

Various methods known in the art may be used to measure the amount of cannabinoid compound in an aerosol.

Carbon monoxide may also be present in the aerosol generated from the aerosol generating substrate according to the present invention during Test Method A and may be measured and used to further characterize the aerosol. Nitrogen oxides, such as nitric oxide and nitrogen dioxide, may also be present in the aerosol and may be measured and used to further characterize the aerosol.

According to the present invention, the aerosol generated from the aerosol generating substrate during test method A preferably has an amount of betulinic acid per gram of substrate that is preferably at least 5 times greater than the amount of rosmarin diphenol per gram of substrate.

More preferably, the amount of betulinic acid in the aerosol generated from the aerosol-generating substrate during test method A is at least 10 times the amount of rosmaridiphenol per gram of substrate, so that the ratio of betulinic acid to rosmaridiphenol is at least 10 to 1. Even more preferably, the amount of betulinic acid in the aerosol generated from the aerosol-generating substrate during test method A is at least 20 times the amount of rosmaridiphenol per gram of substrate, so that the ratio of betulinic acid to rosmaridiphenol is at least 20 to 1.

In preferred embodiments, the amount of betulinic acid in the aerosol generated from the aerosol generating substrate during Test Method A is such that the ratio of betulinic acid to rosmaridiphenol is from 5 to 1 to 20 to 1.

Certain ratios of betulinic acid to rosmaridifenol characterize the aerosol obtained from rosemary particles. In contrast, in the aerosol obtained from rosemary oil, the ratio of betulinic acid to rosmaridifenol will be significantly different.

The presence of rosemary in the aerosol-generating substrate and the proportion of rosemary provided in the aerosol-generating substrate can be determined by measuring the amount of characteristic compounds in the substrate and comparing it with the corresponding amount of characteristic compounds in pure rosemary-based material. The presence and amount of characteristic compounds can be determined using any suitable methods known to a person skilled in the art.

In a suitable method, a 250 milligram sample of the aerosol-generating substrate is mixed with 5 milliliters of methanol and extracted by shaking, vigorous mixing for 5 minutes and centrifugation (4500 g, 5 minutes, 10 degrees Celsius). Aliquots (300 microliters) of the extract are transferred to a silanized chromatography vial and diluted with methanol (600 microliters) and internal standard solution (ISTD) (100 microliters). The vials are capped and the contents are mixed for 5 minutes using an Eppendorf thermal mixer (5 degrees Celsius; 2000 rpm). Test samples from the resulting extract are analyzed by LC-HRAM-MS in a combination of full scan and fragmentation modes on a data-dependent basis to identify representative compounds.

In alternative embodiments, the non-tobacco plant particles comprise clove particles. Cloves are known to be essentially the dried flower buds and stems of Syzygium aromaticum , a tree in the Myrtaceae family, and are widely used as a spice. Accordingly, each clove comprises a calyx consisting of sepals and a corolla of unopened petals that form a globular portion attached to the calyx. As used herein, the term "clove particles" encompasses particles obtained from the buds and stems of Syzygium aromaticum , and may include whole cloves, crushed or crumbled cloves, or cloves that have been otherwise physically processed to reduce particle size.

As a result of the inclusion of clove particles, the aerosol-generating substrate contains certain proportions of "characteristic compounds" of clove. Characteristic compounds unique to clove include, but are not limited to: eugenol acetate (Chemical Abstracts No. 93-28-7), and beta-caryophyllene (Chemical Abstracts No. 87-44-5), and eugenol. In particular, the aerosol-generating substrate contains at least about 125 micrograms of eugenol per gram of substrate, at least about 125 micrograms of eugenol acetate per gram of substrate, and at least about 1 microgram of beta-caryophyllene per gram of substrate, on a dry weight basis.

Preferably, the ratio of the characteristic compounds in the aerosol generating substrate is such that the amount of eugenol per gram of substrate is no more than 3 times the amount of eugenol acetate per gram of substrate, more preferably no more than twice the amount of eugenol acetate per gram of substrate, based on dry weight. Alternatively or additionally, the amount of eugenol per gram of substrate is at least 50 times the amount of beta-caryophyllene per gram of substrate, based on dry weight. These ratios of eugenol to eugenol acetate and beta-caryophyllene are characteristic for inclusion of clove particles. In contrast, in clove oil, the ratio of eugenol to eugenol acetate would be significantly higher and the ratio of eugenol to beta-caryophyllene would be significantly lower.

In alternative embodiments, the non-tobacco plant particles comprise star anise particles. As used herein, the term "star anise particles" encompasses particles obtained from the dried fruit of plants of the genus Illicium, preferably particles obtained from Illicium verum Hooker fil. (Illiciaceae) .

As a result of the inclusion of star anise particles, the aerosol-generating substrate comprises certain proportions of "characteristic compounds" of star anise. Characteristic substances unique to star anise include, but are not limited to, (E)-anethole, epoxyanethole, and benzyl isoeugenol ester. In particular, the aerosol-generating substrate comprises at least about 70 micrograms of (E)-anethole per gram of substrate, at least about 50 micrograms of epoxyanethole per gram of substrate, and at least about 130 micrograms of benzyl isoeugenol ester per gram of substrate, on a dry weight basis.

Preferably, the ratio of the characteristic compounds in the aerosol-generating substrate is such that the amount of (E)-anethole per gram of substrate exceeds the amount of epoxy-anethole per gram of substrate by no more than 5 times, more preferably exceeds the amount of epoxy-anethole per gram of substrate by no more than 3 times, based on dry weight. This ratio of (E)-anethole to epoxy-anethole is significantly lower than the corresponding ratio in star anise oil and is characteristic of the inclusion of star anise particles in the aerosol-generating substrate. In contrast, star anise oil typically contains no more than trace amounts of epoxy-anethole and a relatively high proportion of (E)-anethole.

In alternative embodiments, the non-tobacco plant particles comprise ginger particles. As used herein, the term "ginger particles" encompasses particles obtained from the dried root of plants of the genus Ginger, preferably particles obtained from Zingiberaceae.

As a result of the incorporation of ginger particles, the aerosol generating substrate contains certain proportions of "characteristic compounds" of ginger. Characteristic compounds unique to ginger include, but are not limited to: [10]-shogaol-(1-(4-hydroxy-3-methoxyphenyl)tetradec-4-en-3-one), [8]-shogaol-(1-(4-hydroxy-3-methoxyphenyl)dodec-4-en-3-one), [6]-shogaol-(1-(4-hydroxy-3-methoxyphenyl)dec-4-en-3-one), [6]-gingerol-((S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone), and [10]-gingerol-((S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-tetradecanone). In particular, the aerosol generating substrate comprises at least about 10 micrograms of [6]-gingerol per gram of substrate, at least about 90 micrograms of [10]-gingerol per gram of substrate, at least about 70 micrograms of [10]-shogaol per gram of substrate, at least about 30 micrograms of [8]-shogaol per gram of substrate, and at least about 80 micrograms of [6]-shogaol per gram of substrate, based on dry weight.

Preferably, the ratio of the characteristic compounds in the aerosol-generating substrate is such that the amount of [6]-shogaol per gram of substrate is at least 5 times the amount of [6]-gingerol per gram of substrate, more preferably at least 7.5 times the amount of [6]-gingerol per gram of substrate, based on dry weight. In contrast, ginger oil typically has a level of [6]-gingerol that is equal to or greater than the level of [6]-shogaol.

In alternative embodiments, the non-tobacco plant particles comprise eucalyptus particles. As used herein, the term "eucalyptus particles" encompasses particles obtained from plants of the genus Eucalyptus, preferably particles obtained from one or more of E. globulus, E. radiata, E. citriodora and E. smithii, most preferably particles obtained from E. globulus, such as ground or powdered eucalyptus leaf blades and ground or powdered eucalyptus leaf stems. The eucalyptus leaf particles are made exclusively from the leaf of the eucalyptus plant. The eucalyptus stem particles are made exclusively from the leaf stem of the eucalyptus plant. The eucalyptus particles in the aerosol generating substrate according to the present invention may comprise either eucalyptus leaf particles or eucalyptus stem particles, or both eucalyptus leaf particles and eucalyptus stem particles.

As a result of the inclusion of eucalyptus particles, the aerosol-generating substrate contains certain proportions of "characteristic compounds" of eucalyptus. Characteristic compounds unique to eucalyptus include, but are not limited to: eucalyptin, 8-desmethyleucalyptin, and eucalyptol. In particular, the aerosol-generating substrate contains at least 0.04 mg eucalyptol per gram of substrate, at least 0.2 mg eucalyptin per gram of substrate, and at least 0.2 mg 8-desmethyleucalyptin per gram of substrate, on a dry weight basis.

Preferably, the ratio of the characteristic compounds in the aerosol generating substrate is such that the amount of eucalyptin per gram of substrate is at least 3 times the amount of eucalyptol per gram of substrate, more preferably at least 4 times the amount of eucalyptol per gram of substrate, based on dry weight. Alternatively or additionally, the amount of 8-desmethyleucalyptin per gram of substrate is at least 3 times the amount of eucalyptol per gram of substrate, based on dry weight. The presence of eucalyptin and 8-desmethyleucalyptin in significantly higher levels than eucalyptol is characteristic of the inclusion of eucalyptus particles. In contrast, eucalyptus oil contains levels of eucalyptol that are significantly higher than the levels of eucalyptin and 8-desmethyleucalyptin.

In embodiments in which the homogenized plant material comprises tobacco particles, the aerosol-generating substrate comprises certain proportions of "characteristic compounds" of tobacco. Characteristic compounds generated from tobacco include, but are not limited to, cotinine and damascenone. In particular, the aerosol-generating substrate preferably comprises at least about 60 micrograms of cotinine per gram of substrate and at least about 10 micrograms of damascenone per gram of substrate.

The composition of the homogenized plant material can advantageously be adjusted by mixing the desired quantities and types of particles of different plants. This allows the formation of an aerosol-generating substrate from a single homogenized plant material, if desired, without the need to combine or mix different mixtures, as is the case, for example, in the production of conventional cut filler. Consequently, the production of the aerosol-generating substrate can potentially be simplified.

The particulate plant material used in the aerosol generating substrates of the present invention can be adapted to provide a desired particle size distribution. Particle size distributions are referred to herein as D values, wherein the D value refers to the percentage by number of particles that have a diameter less than or equal to the stated D value. For example, in a D95 particle size distribution, 95 percent by number of particles have a diameter less than or equal to the stated D95 value, and 5 percent by number of particles have a diameter greater than the stated D95 value. Similarly, in a D5 particle size distribution, 5 percent by number of particles have a diameter less than or equal to the D5 value, and 95 percent by number of particles have a diameter greater than the stated D5 value. In combination, the D5 and D95 values thus provide an indication of the particle size distribution of the particulate plant material.

The particulate plant material may have a range from a D95 value that is greater than or equal to 50 microns to a D95 value that is less than or equal to 400 microns. This means that the particulate plant material may have a distribution represented by any D95 value in the specified range, i.e., the D95 may be equal to 50 microns or the D95 may be equal to 55 microns , etc. , up to the point that the D95 may be equal to 400 microns. By providing a D95 value in this range, the inclusion of relatively large plant particles in the homogenized plant material is avoided. This is desirable since the generation of an aerosol from such large plant particles is likely to be relatively inefficient. In addition, the inclusion of large plant particles in the homogenized plant material may adversely affect the consistency of the material.

Preferably, the particulate plant material may have a D95 value of greater than or equal to about 50 microns to a D95 value of less than or equal to about 350 microns, more preferably a D95 value of greater than or equal to about 100 microns to a D95 value of less than or equal to about 300 microns. Both the non-tobacco particulate material and the tobacco particulate material may have D95 values of greater than or equal to about 50 microns to a D95 value of less than or equal to about 400 microns, preferably D95 values of greater than or equal to 100 microns to a D95 value of less than or equal to about 350 microns, more preferably D95 values of greater than or equal to about 200 microns to a D95 value of less than or equal to about 300 microns.

Preferably, the particulate plant material may have a D5 value of greater than or equal to about 10 microns to a D5 value of less than or equal to about 50 microns, more preferably a D5 value of greater than or equal to about 20 microns to a D5 value of less than or equal to about 40 microns. By providing a D5 value in this range, the inclusion of very fine dust particles in the homogenized plant material is avoided, which may be desirable from a manufacturing standpoint.

Preferably, the maximum particle size of the plant material in particulate form is about 250 microns, more preferably about 200 microns.

In some embodiments, the particulate plant material may be specially ground to form particles having a desired particle size distribution. Therefore, the use of specially ground plant material advantageously improves the uniformity of the particulate plant material and the consistency of the homogenized plant material.

The diameter of 100 percent of the particulate plant material may be less than or equal to about 500 microns, more preferably less than or equal to about 450 microns. The diameter of 100 percent of the particulate non-tobacco material and 100 percent of the particulate tobacco material may be less than or equal to about 500 microns, more preferably less than or equal to about 450 microns. The range of sizes of the non-tobacco particles allows them to be combined with tobacco particles in existing sheet forming processes.

In addition to the above-described components, the homogenized plant material may optionally further comprise one or more lipids that promote the diffusion of volatile components (e.g., aerosol forming agents, (E)-anethole, and nicotine), wherein the lipid is included in the homogenized plant material during manufacture as described herein. Lipids suitable for inclusion in the homogenized plant material include, but are not limited to: medium chain triglycerides, cocoa butter, palm oil, palm kernel oil, mango butter, shea butter, soybean oil, cottonseed oil, coconut oil, hydrogenated coconut oil, candelilla wax, carnauba wax, shellac, sunflower wax, rice bran wax, and Revel A; and combinations thereof.

Alternatively or additionally, the homogenized plant material may further comprise a pH modifier.

The homogenized plant material is preferably in the form of a solid or a gel. However, in some embodiments, the homogenized material may be in the form of a solid that is not a gel. Preferably, the homogenized material is not provided in the form of a film.

The homogenized plant material may be provided in any suitable form. For example, the homogenized plant material may be in the form of one or more sheets. As used herein with reference to the present invention, the term "sheet" describes a layered element having a width and a length that are substantially greater than its thickness.

Alternatively or additionally, the homogenized plant material may be in the form of a plurality of beads or granules.

Alternatively or additionally, the homogenized plant material may be in a form that can fill a cartridge or a consumable for a hookah, or that can be used in a hookah device. The present invention provides a cartridge or a hookah device that contains homogenized plant material.

Alternatively or additionally, the homogenized plant material may be in the form of a plurality of strands, strips or pieces. As used herein, the term "strand" describes an elongated element of material whose length substantially exceeds its width and thickness. The term "strand" should be considered to include strips, pieces and any other homogenized plant material having a similar shape. The strands of homogenized plant material may be formed from a sheet of homogenized plant material, such as by cutting or dividing into pieces, or by other methods, such as by an extrusion method.

In some embodiments, the filaments may be formed in situ in the aerosol-generating substrate as a result of separating or splitting a sheet of homogenized plant material during the formation of the aerosol-generating substrate, for example, as a result of pleating. The filaments of homogenized plant material in the aerosol-generating substrate may be separated from each other. Alternatively, each filament of homogenized plant material in the aerosol-generating substrate may be at least partially connected to an adjacent filament or filaments along the length of the filaments. For example, adjacent filaments may be connected via one or more fibers. This may occur, for example, if the filaments were formed as a result of separating a sheet of homogenized plant material during the production of the aerosol-generating substrate, as described above.

Preferably, the aerosol generating substrate is provided in the form of one or more sheets of homogenized plant material. In various embodiments of the present invention, the one or more sheets of homogenized plant material may be obtained by a casting process. Each of the one or more sheets, as described herein, may individually have a thickness of from about 100 micrometers to 600 micrometers, preferably from 150 micrometers to 300 micrometers, and most preferably from 200 micrometers to 250 micrometers. The individual thickness refers to the thickness of an individual sheet, while the cumulative thickness refers to the total thickness of all sheets that make up the aerosol generating substrate. For example, if the aerosol generating substrate is formed from two individual sheets, then the cumulative thickness is the sum of the thicknesses of the two individual sheets or the measured thickness of the two sheets when the two sheets are stacked on top of each other in the aerosol generating substrate.

Each of the one or more sheets as described herein may individually have a grammage of from about 100 g/ ^m2 to about 300 g/ ^m2 .

Each of the one or more sheets as described herein may individually have a density of from about 0.3 g/cm³ up to approximately 1.3 g/cm³, and preferably from about 0.7 g/cm³up to approximately 1.0 g/cm³.

The term "tensile strength" is used throughout this specification to indicate the measure of force required to stretch a sheet of homogenized plant material before it breaks. More specifically, tensile strength is the maximum tensile force per unit width that a sheet material will withstand before breaking, and is measured in the machine direction or cross direction of the sheet material. It is expressed in units of newtons per metre of material (N/m). Tests for measuring the tensile strength of sheet material are well known. A suitable test is published in the 2014 publication of ISO 1924-2, "Paper and board - Determination of tensile strength - Part 2: Constant-rate method".

The materials and equipment required to perform the test in accordance with ISO 1924-2 are: universal tensile/compression testing machine, Instron 5566, or equivalent; 100 Newton tensile load cell, Instron, or equivalent; two pneumatically operated grips; a steel measuring block, 180 ± 0.25 millimetres long (approximately 10 millimetres wide, approximately 3 millimetres thick); a strip cutter with two cutting edges, 15 ± 0.05 x approximately 250 millimetres, Adamel Lhomargy, or equivalent; a scalpel; computer-based data acquisition software, Merlin, or equivalent; and compressed air.

The sample is prepared by first conditioning a sheet of homogenized plant material for at least 24 hours at a temperature of 22 ± 2 degrees Celsius and a relative humidity of 60 ± 5% prior to testing. The sample is then cut in the machine direction or cross direction to a size of approximately 250 x 15 ± 0.1 millimeters using a strip cutter with two cutting edges. The edges of the test samples must be trimmed neatly, so no more than three test samples are cut at a time.

The tensile/compression testing apparatus is set by installing a 100 Newton tensile load cell, turning on the universal tensile/compression testing machine and the computer, and selecting the measurement method specified in the software, with a test speed set to 8 millimeters per minute. The tensile load cell is then calibrated and the pneumatic grips are installed. The test distance between the pneumatic grips is adjusted to 180 ± 0.5 millimeters by means of a steel measuring block, with the distance and force set to zero.

The test specimen is then placed squarely and centrally between the jaws, avoiding contact of the fingers with the area to be tested. The upper jaw is closed, with the paper strip hanging in the open lower jaw. The force is set to zero. The paper strip is then pulled downwards slightly and the lower jaw is closed; the initial force should be between 0.05 and 0.20 Newton. As the upper jaw moves upwards, a gradually increasing force is applied until the test specimen breaks. The same procedure is repeated with the remaining test specimens. The result is valid if the test specimen breaks when the jaws are separated by more than 10 millimetres. If this is not the case, the result is discarded and an additional measurement is taken.

Each of the one or more sheets of homogenized plant material as described herein may individually have a tensile strength at a peak value in the transverse direction of from 50 N/m to 400 N/m, or preferably from 150 N/m to 350 N/m. Given that the thickness of the sheet affects the tensile strength, and if the thickness varies in a batch of sheets, it may be desirable to normalize the value relative to a specific sheet thickness.

If the test sample of available homogenised plant material is smaller than the sample described in the ISO 1924-2 test as described above, the test scale can be easily reduced to accommodate the available test sample size.

Each of the one or more sheets as described herein may individually have a peak tensile strength in the machine direction of 100 N/m to 800 N/m, or preferably 280 N/m to 620 N/m, normalized to a sheet thickness of 215 μm. Machine direction refers to the direction in which the sheet material is wound onto or unwound from a reel and fed into the machine, with the transverse direction being perpendicular to the machine direction. Such tensile strength values make the sheets and methods described herein particularly suitable for subsequent operations involving mechanical loads.

Providing a sheet having the thickness, grammage and tensile strength levels as defined above advantageously optimizes the sheet processability for forming an aerosol generating substrate and ensures the prevention of damage such as sheet rupture during high-speed sheet processing.

In embodiments of the present invention, in which the aerosol-generating substrate comprises one or more sheets of homogenized plant material, the sheets are preferably in the form of one or more collected sheets. The term "collected" as used herein is used to describe a sheet of homogenized plant material that is rolled, folded, or otherwise compressed or narrowed in a direction substantially transverse to the cylindrical axis of the rod or shaft. The term "longitudinal" as used herein refers to a direction corresponding to the main longitudinal axis of the aerosol-generating article that extends between the upstream and downstream ends of the aerosol-generating article. During use, air is drawn through the aerosol-generating article in the longitudinal direction. The term "transverse" refers to a direction that is perpendicular to the longitudinal axis. As used herein, the term "length" refers to the dimension of a component in the longitudinal direction, and the term "width" refers to the dimension of a component in the transverse direction. For example, in the case of a rod or bar having a circular cross-section, the maximum width corresponds to the diameter of the circle.

The term "rod" as used herein denotes a generally cylindrical element with a substantially polygonal, circular, oval or elliptical cross-section. The term "rod" as used herein refers to a generally cylindrical element with a substantially polygonal cross-section, and preferably with a circular, oval or elliptical cross-section. The rod may have a length that is greater than or equal to the length of the rod. Typically, the rod has a length that is greater than the length of the rod. The rod may comprise one or more rods, preferably aligned in the longitudinal direction.

As used herein, the terms "upstream" and "downstream" describe the relative positions of elements or portions of elements of an aerosol-generating article relative to the direction in which the aerosol is transported during use through the aerosol-generating article. The downstream end of the air flow path is the end through which the aerosol is delivered to the user of the article.

One or more sheets of homogenized plant material may be assembled transversely relative to its longitudinal axis and surrounded by a wrapper to form a continuous rod or rod. The continuous rod may be divided into a plurality of individual rods or rods. The wrapper may be a paper wrapper or a non-paper wrapper, as described in more detail below.

Alternatively, one or more sheets of homogenized plant material can be cut into threads, as mentioned above. In such embodiments, the aerosol-generating substrate comprises a plurality of threads of homogenized plant material. The threads can be used to form a rod. Typically, the width of such threads is at least about 0.2 mm or at least about 0.5 mm. Preferably, the width of such threads is no more than about 5 mm, or about 4 mm, or about 3 mm, or about 1.5 mm. For example, the width of the threads can be from about 0.25 mm to about 5 mm, or from about 0.25 mm to about 3 mm, or from about 0.5 mm to about 1.5 mm.

The length of the threads is preferably more than about 5 mm, such as from about 5 mm to about 15 mm, from about 8 mm to about 12 mm, or about 12 mm. Preferably, the threads have substantially the same length relative to each other. The length of the threads can be determined by a manufacturing process in which the rod is cut into shorter rods, and the length of the threads corresponds to the length of the rod. The threads can be brittle, which can lead to breakage, especially during handling. In such cases, the length of some threads can be shorter than the length of the rod.

The plurality of threads preferably extend substantially in the longitudinal direction along the length of the aerosol-generating substrate aligned with the longitudinal axis. Preferably, the plurality of threads are thus aligned substantially parallel to each other. The plurality of longitudinal threads of the homogenized plant material are preferably substantially uncrimped.

Each strand of homogenized plant material preferably has a mass to surface area ratio of at least about 0.02 milligrams per square millimeter, more preferably at least about 0.05 milligrams per square millimeter. Preferably, each strand of homogenized plant material has a mass to surface area ratio of no more than about 0.2 milligrams per square millimeter, more preferably no more than about 0.15 milligrams per square millimeter. The mass to surface area ratio is calculated by dividing the mass of the strand of homogenized plant material in milligrams by the geometric surface area of the strand of homogenized plant material in square millimeters.

One or more sheets of homogenized plant material may be textured by corrugating, embossing or perforating. The one or more sheets may be textured before being collected or before being cut into threads. Preferably, the one or more sheets of homogenized plant material are corrugated before being collected, whereby the homogenized plant material may be in the form of a corrugated sheet, more preferably in the form of a collected corrugated sheet. As used herein, the term "corrugated sheet" means a sheet having a plurality of substantially parallel folds or flutes, generally aligned with the longitudinal axis of the article.

In one embodiment, the aerosol generating substrate may be in the form of a single rod of aerosol generating substrate. Preferably, the rod of aerosol generating substrate may comprise a plurality of strands of homogenized plant material. Most preferably, the rod of aerosol generating substrate may comprise one or more sheets of homogenized plant material. Preferably, the one or more sheets of homogenized plant material may be corrugated such that they have a plurality of folds or corrugations substantially parallel to the cylindrical axis of the rod. This treatment advantageously facilitates the collection of the corrugated sheet of homogenized plant material to form a rod. Preferably, one or more sheets of homogenized plant material may be collected. It should be understood that the corrugated sheets of homogenized plant material may alternatively or additionally have a plurality of substantially parallel folds or corrugations located at an acute or obtuse angle to the cylindrical axis of the rod. The sheet may be corrugated to such an extent that the integrity of the sheet is broken at multiple parallel folds or corrugations, causing material to separate and resulting in the formation of pieces, threads or strips of homogenized plant material.

In another embodiment, the aerosol generating substrate comprises a first rod containing a first homogenized plant material and a second rod containing a second homogenized plant material, wherein the first homogenized plant material and the second homogenized plant material are different from each other. Two or more rods can be combined so that they are adjacent end to end and extend to form a rod. Two rods can be arranged in the longitudinal direction with a gap between them, as a result of which a cavity is created in the rod. The rods can be arranged in any suitable manner in the rod.

The homogenized plant material used in the aerosol generating substrates of the present invention may be produced by a variety of methods, including papermaking, molding, dough reduction, extrusion, or any other suitable process.

In certain preferred embodiments of the present invention, the homogenized plant material is in the form of a molded sheet. The term "molded sheet" is used herein to refer to a sheet product made by a casting process that consists of casting a pulp containing plant particles (e.g., non-tobacco particles or a mixture of tobacco particles and non-tobacco particles) and a binder onto a support surface such as a conveyor belt, drying the pulp, and removing the dried sheet from the support surface. An example of a casting or sheet molding process is described, for example, in US-A-5,724,998, with respect to the manufacture of tobacco in the form of molded leaves. In the sheet molding process, particulate plant materials are mixed with a liquid component, typically water, to form a pulp. Other added components in the pulp may include fibers, a binder, and an aerosol former. The particulate plant materials may agglomerate in the presence of a binder. The pulp is poured onto a supporting surface and dried to form a sheet of homogenized plant material.

In certain preferred embodiments, the homogenized plant material used in the articles of the present invention is produced by a casting process. The homogenized plant material produced by the casting process typically comprises agglomerated particulate plant material.

During the sheet forming process, since essentially all of the soluble fraction is retained in the plant material, most of the flavour-giving substances are retained. Additionally, energy-intensive papermaking steps are eliminated.

The present invention further provides methods for producing an aerosol generating substrate comprising homogenized plant material as defined above. In a first step of the method, a mixture is formed comprising particulate plant material, water, an aerosol forming agent, a cellulose ether and additional cellulose. A sheet is formed from the mixture, and then the sheet is dried. Preferably, the mixture is an aqueous mixture. As used herein, the term "dry weight" refers to the weight of a particular non-aqueous component relative to the sum of the weights of all non-aqueous components in the mixture, expressed as a percentage. The composition of aqueous mixtures can be considered as a "dry weight percent". This refers to the weight of the non-aqueous components relative to the weight of the entire aqueous mixture, expressed as a percentage.

Preferably, the cellulose ether is dispersed in an aerosol former and the dispersion of the cellulose ether and the aerosol former is added to a mixture of non-tobacco plant particles in water.

The mixture may be a pulp. As used herein, the term "pulp" means a homogenized aqueous mixture with a relatively low dry weight. The pulp used in the method herein may preferably have a dry weight of from about 5 percent to 60 percent.

Alternatively, the mixture may be a dough-like mass. As used herein, the term "dough-like mass" denotes an aqueous mixture with a relatively high dry weight. The dough-like mass used in the method herein may preferably have a dry weight of at least 60 percent, more preferably at least 70 percent.

Suspensions having a dry weight greater than 30 percent and pasty masses may be preferred in certain embodiments of the method.

The step of mixing the particulate plant material, water and other components can be carried out using any suitable means. For low viscosity mixtures, i.e. some suspensions, it is preferable that the mixing be carried out using a high intensity mixer or a high shear mixer. This mixing breaks up and evenly distributes the various phases of the mixture. For higher viscosity mixtures, i.e. some pasty masses, a kneading process can be used to evenly distribute the various phases of the mixture.

The methods according to the present invention may further comprise a step of vibrating the mixture to distribute the various components. Vibrating the mixture, i.e., for example, vibrating a container or intermediate bin in which the homogenized mixture is located, may promote homogenization of the mixture, in particular when the mixture is a low-viscosity mixture, i.e., some suspensions. Less mixing time may be required to homogenize the mixture to the target value optimal for casting, if vibration is also applied together with mixing.

If the mixture is a pulp, the web of homogenized plant material is preferably formed by a casting process comprising casting the pulp onto a support surface, such as a conveyor belt. The method for producing homogenized plant material includes the step of drying said formed web to form a sheet. The formed web can be dried at room temperature or at an ambient temperature of at least about 60 degrees Celsius, more preferably at least about 80 degrees Celsius for a suitable period of time. Preferably, the formed web is dried at an ambient temperature of no more than 200 degrees Celsius, more preferably no more than about 160 degrees Celsius. For example, the formed web can be dried at a temperature of from about 60 degrees Celsius to about 200 degrees Celsius or from about 80 degrees Celsius to about 160 degrees Celsius. Preferably, the moisture content of the sheet after drying is from about 5 percent to about 15 percent based on the total weight of the sheet. After drying, the sheet can be removed from the supporting surface. The formed sheet has such a tensile strength that it can be moved by mechanical means and wound on or unwound from a reel without breaking or deforming.

If the mixture is a dough-like mass, the dough-like mass can be extruded in the form of a sheet, threads or strips before the step of drying the extruded mixture. Preferably, the dough-like mass can be extruded in the form of a sheet. The extruded mixture can be dried at room temperature or at a temperature of at least about 60 degrees Celsius, more preferably at least about 80 degrees Celsius for a suitable period of time. Preferably, the formed web is dried at an ambient temperature of no more than 200 degrees Celsius, more preferably no more than about 160 degrees Celsius. For example, the formed web can be dried at a temperature of from about 60 degrees Celsius to about 200 degrees Celsius or from about 80 degrees Celsius to about 160 degrees Celsius. Preferably, the moisture content of the extruded mixture after drying is from about 5 percent to about 15 percent, based on the total weight of the sheet. A sheet formed from a dough-like mass requires less drying time and/or lower drying temperatures due to the significantly lower water content relative to a web formed from pulp.

After drying the sheet, the method may optionally include the step of applying a nicotine salt, preferably together with an aerosol forming agent, to the sheet, as described in the disclosure of document WO-A-2015/082652.

After drying the sheet, the methods according to the present invention may optionally include the step of cutting the sheet into threads, pieces or strips to form an aerosol-generating substrate, as described above. The threads, pieces or strips may be brought together to form a rod of aerosol-generating substrate by a suitable means. In the formed rod of aerosol-generating substrate, the threads, pieces or strips may be substantially aligned, for example, in the longitudinal direction of the rod. Alternatively, the threads, pieces or strips may be randomly oriented in the rod.

In certain preferred embodiments, the method further comprises a step of corrugating the sheet. This may facilitate the gathering of the sheet to form a rod, as described below. The "corrugating" step produces a sheet having a plurality of folds or corrugations.

In certain preferred embodiments, the method further comprises the step of gathering the sheet to form a rod. The term "gathered" means a sheet that is rolled, folded, or otherwise compressed or narrowed in a direction substantially transverse to the longitudinal axis of the aerosol-generating substrate. The step of "gathering" the sheet can be accomplished by any suitable means that provides the necessary transverse compression of the sheet.

The methods of the present invention may optionally further include the step of winding the sheet onto a reel after the drying step.

Other known processes which can be used to produce homogenised plant materials are pasty reconstitution processes of the type described, for example, in US-A-3,894,544; and extrusion processes of the type described, for example, in GB-A-983,928. In general, the densities of homogenised plant materials produced by extrusion processes and pasty reconstitution processes are higher than the densities of homogenised plant materials produced by casting processes.

Preferably, the aerosol generating substrate of the aerosol generating articles according to the present invention comprises at least about 200 mg of homogenized plant material, more preferably at least about 250 mg of homogenized plant material, and more preferably at least about 300 mg of homogenized plant material.

The aerosol generating articles according to the present invention comprise a rod containing a substrate in one or more rods. The rod of the aerosol generating substrate may have a length of about 5 mm to about 120 mm. For example, the rod may preferably have a length of about 10 to about 45 mm, more preferably about 10 mm to 15 mm, most preferably about 12 mm.

In alternative embodiments, the rod preferably has a length of about 30 mm to about 45 mm or about 33 mm to about 41 mm. If the rod is formed from a single rod of aerosol-generating substrate, the rod has the same length as the rod.

The aerosol-generating substrate rod may have an outer diameter of about 5 mm to about 10 mm, depending on its intended purpose. For example, in some embodiments, the rod may have an outer diameter of about 5.5 mm to about 8 mm or about 6.5 mm to about 8 mm. The outer diameter of the aerosol-generating substrate rod corresponds to the diameter of the rod containing any wrappers.

The aerosol-generating substrate rod of the aerosol-generating articles of the present invention is preferably surrounded by one or more wrappers along at least a portion of its length. The one or more wrappers may comprise a paper wrapper or a non-paper wrapper, or both. Paper wrappers suitable for use in particular embodiments of the present invention are known in the art and include, but are not limited to, cigarette papers and filter wicks. Non-paper wrappers suitable for use in particular embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco materials.

In particular embodiments of the present invention, the aerosol-generating substrate is surrounded along at least a portion of its length by a heat-conducting sheet material, such as a metal foil, such as aluminum foil or metallized paper. The metal foil or metallized paper serves the purpose of quickly conducting heat through the aerosol-generating substrate. In addition, the metal foil or metallized paper can serve to prevent the aerosol-generating substrate from igniting if the consumer attempts to set it on fire. In addition, during use, the metal foil or metallized paper can prevent unpleasant odors generated by heating the outer wrapper from entering the aerosol generated from the aerosol-generating substrate. For example, this can be a problem for aerosol-generating articles having an aerosol-generating substrate that is heated from the outside during use to generate the aerosol. Alternatively or additionally, a metallized wrapper may be used to facilitate detection or identification of the aerosol-generating article when it is inserted into the aerosol-generating device during use. The metal foil or metallized paper may contain metal particles, such as iron particles.

One or more wrappers surrounding the aerosol generating substrate preferably have a total thickness of from about 0.1 mm to about 0.9 mm.

The inner diameter of the aerosol-generating substrate rod is preferably from about 3 mm to about 9.5 mm, more preferably from about 4 mm to about 7.5 mm, more preferably from about 5 mm to about 7.5 mm. "Inner diameter" corresponds to the diameter of the aerosol-generating substrate rod, excluding the thickness of the wrappers, but measured with the wrappers in place.

Aerosol generating articles according to the present invention also include, but are not limited to, a cartridge or consumable for a hookah.

The aerosol generating articles according to the present invention may optionally comprise a support element comprising at least one hollow tube located immediately downstream of the aerosol generating substrate. One of the functions of the tube is to position the aerosol generating substrate towards the distal end of the aerosol generating article so that it can come into contact with the heating element. The tube is designed to prevent the aerosol generating substrate from moving along the aerosol generating article towards other downstream elements when the heating element is inserted into the aerosol generating substrate. The tube also acts as a separating element to separate the downstream elements from the aerosol generating substrate. The tube may be made of any material such as cellulose acetate, polymer, cardboard or paper.

Alternatively or additionally, the aerosol-generating articles according to the present invention may optionally comprise an aerosol-cooling element downstream of the aerosol-generating substrate and immediately downstream of the hollow tube forming the support element. In use, the aerosol formed by the volatile compounds released from the aerosol-generating substrate passes through the aerosol-cooling element and is cooled by it before inhalation by the user. The lower temperature allows the vapors to condense to form an aerosol. The spacer or aerosol-cooling element may be a hollow tube, such as a hollow cellulose acetate tube or a cardboard tube, which may be similar to the support element, located immediately downstream of the aerosol-generating substrate. The aerosol-cooling element may be a hollow tube that has an equal outer diameter, but a smaller or larger inner diameter than the hollow tube of the support element.

In one embodiment, the paper-wrapped aerosol cooling element comprises one or more longitudinal channels made of any suitable material, such as metal foil, paper laminated with foil, a polymer sheet, preferably made of a synthetic polymer, and substantially non-porous paper or cardboard. In some embodiments, the paper-wrapped aerosol cooling element may comprise one or more sheets made of a material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), paper laminated with a polymer sheet, and aluminum foil. Alternatively, the aerosol cooling element may be made of woven or non-woven filaments of a material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA) and cellulose acetate (CA). In a preferred embodiment, the aerosol cooling element is a corrugated and assembled sheet of polylactic acid wrapped in filter paper. In another preferred embodiment, the aerosol cooling element comprises a longitudinal channel and is made of woven filaments of a synthetic polymer, such as polylactic acid filaments, which are wrapped in paper.

One or more additional hollow tubes may be provided downstream of the aerosol cooling element.

The aerosol generating articles of the present invention may further comprise a filter or mouthpiece downstream of the aerosol generating substrate and, if present, a support element and an aerosol cooling element. The filter may comprise one or more filter materials for removing particulate components, gaseous components, or a combination thereof. Suitable filter materials are known in the art and include, but are not limited to: fibrous filter materials, such as, for example, cellulose acetate tow and paper; adsorbents, such as, for example, activated alumina, zeolites, molecular sieves, and silica gel; biodegradable polymers, including, for example, polylactic acid (PLA), Mater-Bi®, hydrophobic viscose fibers, and bioplastics; and combinations thereof. The filter may be located at the downstream end of the aerosol generating article. The filter may be a cellulose acetate filter rod. The filter in one embodiment has a length of approximately 7 mm, but may have a length of from approximately 5 mm to approximately 10 mm.

Aerosol generating articles according to the present invention may comprise a mouth end cavity at a downstream end of the article. The mouth end cavity may be formed by one or more wrappers extending downstream of a filter or mouthpiece. Alternatively, the mouth end cavity may be formed by a separate tubular element provided at a downstream end of the aerosol generating article.

The aerosol generating articles according to the present invention preferably further comprise a ventilation zone provided at a location along the aerosol generating article. For example, the aerosol generating article may be provided at a location along a hollow tube provided downstream of the aerosol generating substrate.

Aerosol generating articles according to the present invention may optionally further comprise an upstream element at the upstream end of the aerosol generating substrate. The upstream element may be a porous rod element, such as a rod of fibrous filter material, such as cellulose acetate.

In preferred embodiments of the present invention, the aerosol-generating article comprises an aerosol-generating substrate, at least one hollow tube downstream of the aerosol-generating substrate, and a filter downstream of the at least one hollow tube. Optionally, the aerosol-generating article further comprises a cavity at the mouthpiece end at the downstream end of the filter. Optionally, the aerosol-generating article further comprises an upstream element at the upstream end of the aerosol-generating substrate. Preferably, the ventilation zone is provided at a location along the at least one hollow tube.

In a particularly preferred embodiment with such an arrangement, the aerosol generating article comprises an aerosol generating substrate, an upstream element at the upstream end of the aerosol generating substrate, a support element downstream of the aerosol generating substrate, an aerosol cooling element downstream of the support element, and a filter downstream of the aerosol cooling element. Preferably, both the support element and the aerosol cooling element have the form of a hollow tube. Preferably, the aerosol generating substrate comprises an elongated element in the form of a current collector, passing longitudinally through it.

In one particularly preferred example, the aerosol generating substrate has a length of approximately 33 mm and an outer diameter of approximately 5.5 mm to 6.7 mm, wherein the aerosol generating substrate contains approximately 340 mg of homogenized plant material in the form of a plurality of filaments, wherein the homogenized plant material contains approximately 14 percent by weight of glycerol based on dry weight. In this embodiment, the aerosol generating article has a total length of approximately 74 mm and comprises a tow filter made of cellulose acetate fiber having a length of approximately 10 mm, as well as a cavity at the mouth end formed by a hollow tube having a length of approximately 6-7 mm. The aerosol generating article comprises a hollow tube downstream of the aerosol generating substrate, wherein the hollow tube has a length of approximately 25 mm and is provided in the ventilation zone.

The aerosol generating articles according to the present invention may have a total length of at least about 30 mm or at least about 40 mm. The total length of the aerosol generating article may be less than 90 mm or less than about 80 mm.

In one embodiment, the aerosol-generating article has a total length of about 40 mm to about 50 mm, preferably about 45 mm. In another embodiment, the aerosol-generating article has a total length of about 70 mm to about 90 mm, preferably about 80 mm to about 85 mm. In another embodiment, the aerosol-generating article has a total length of about 72 mm to about 76 mm, preferably about 74 mm.

The aerosol-generating article may have an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm. In one embodiment, the aerosol-generating article has an outer diameter of about 7.3 mm.

The aerosol-generating articles of the present invention may further comprise one or more aerosol-modifying elements. The aerosol-modifying element may comprise an aerosol-modifying means. As used herein, the term aerosol-modifying means is used to describe any means that, when used, modifies one or more features or properties of an aerosol passing through a filter. Suitable aerosol-modifying means include, but are not limited to, means that, when used, impart a flavor or aroma to an aerosol passing through a filter, or means that, when used, remove flavors from an aerosol passing through a filter.

The aerosol modifying agent may be one or more of moisture or a liquid flavor additive. Water or moisture may modify the sensations experienced by the user, for example by moistening the generated aerosol, which may have a cooling effect on the aerosol and may reduce the perception of astringency experienced by the user. The aerosol modifying element may be in the form of a flavor delivering element for delivering one or more liquid flavor additives. Alternatively, the liquid flavor additive may be added directly to the homogenized rosemary-based material, for example by adding the flavor to the pulp or raw material during the production of the homogenized rosemary-based material or by spraying the liquid flavor additive onto the surface of the homogenized rosemary-based material.

One or more liquid flavor additives may comprise any flavor-giving compound or plant extract suitable for placement in liquid form with the possibility of release in the flavor-delivering element to improve the taste of the aerosol obtained during use of the aerosol-generating article. Flavor additives, liquid or solid, may also be located directly in the material that forms the filter, such as cellulose acetate tow. Suitable flavoring agents or aroma imparting agents include, but are not limited to, menthol, mint such as peppermint and spearmint, chocolate, licorice, citrus and other fruit flavoring agents, gamma-octalactone, vanillin, ethyl vanillin, breath freshening flavoring agents, spice flavoring agents such as cinnamon, methyl salicylate, linalool, eugenol, bergamot oil, geranium oil, lemon oil, hemp oil, and tobacco flavoring agent. Other suitable flavoring agents may include flavoring compounds selected from the group consisting of an acid, an alcohol, an ester, an aldehyde, a ketone, a pyrazine, combinations or mixtures thereof, and the like.

In particular embodiments of the present invention, the aerosol modifying agent may be an essential oil obtained from one or more plants.

An aerosol modifying agent may be an adsorbent material, such as activated carbon, that removes certain components of the aerosol passing through the filter and thus alters the taste and aroma of the aerosol.

One or more aerosol modifying elements may be located downstream of the aerosol generating substrate or inside the aerosol generating substrate. The aerosol generating substrate may comprise homogenized plant material and an aerosol modifying element. In various embodiments, the aerosol modifying element may be located adjacent to the homogenized plant material or embedded in the homogenized plant material. Typically, the aerosol modifying elements may be located downstream of the aerosol generating substrate, most often inside an aerosol cooling element, inside a filter of the aerosol generating article, such as inside a filter rod or inside a cavity, preferably inside a cavity between filter rods. The one or more aerosol modifying elements may be in the form of one or more of a thread, a capsule, a microcapsule, a bead, or a polymer matrix material, or a combination thereof.

If the aerosol modifying element is in the form of a thread, as described in document WO-A-2011/060961, the thread may be formed from paper, such as filter paper, and the thread may be filled with at least one aerosol modifying agent and located within the main part of the filter. Other materials that may be used to form the thread include acetyl cellulose and cotton.

If the aerosol modifying element is in the form of a capsule, as described in WO-A-2007/010407, WO-A-2013/068100 and WO-A-2014/154887, the capsule may be a destructible capsule located inside the filter, wherein the inner core of the capsule contains an aerosol modifying agent that can be released by destructing the outer shell of the capsule when the filter is subjected to an external force. The capsule may be located inside a filter rod, or inside a cavity, preferably inside a cavity between filter rods.

If the aerosol modifying element is in the form of a polymer matrix material, the polymer matrix material releases the flavour additive when the aerosol generating article is heated, for example when the polymer matrix is heated above the melting point of the polymer matrix material, as described in WO-A-2013/034488. Typically, such a polymer matrix material may be located within a bead within the aerosol generating substrate. Alternatively or additionally, the flavour additive may be contained within domains of the polymer matrix material and may be released from the polymer matrix material when the polymer matrix material is compressed. Preferably, the flavour additive is released when the polymer matrix material is compressed with a force of approximately 15 Newton. Such taste modifying elements may provide a delayed release of the liquid flavour additive in a force range of at least 5 Newton, such as 5 N to 20 N, as described in document WO2013/068304. Typically, such a polymer matrix material may be located inside a ball inside the filter.

The aerosol generating article may comprise a combustible heat source and an aerosol generating substrate located downstream of the combustible heat source, the aerosol generating substrate being as described above in relation to the first aspect of the present invention.

For example, the substrates described herein may be used in the types of heated aerosol-generating articles described in WO-A-2009/022232, which comprise a combustible carbon-based heat source, an aerosol-generating substrate located downstream of the combustible heat source, and a heat-conducting element surrounding and in contact with a rear portion of the combustible carbon-based heat source and an adjacent front portion of the aerosol-generating substrate. However, it should be understood that the substrates described herein may also be used in heated aerosol-generating articles comprising combustible heat sources of other designs.

The present invention provides an aerosol generating system that comprises an aerosol generating device that comprises a heating element and an aerosol generating article for use with the aerosol generating device, wherein the aerosol generating article comprises an aerosol generating substrate as described above.

In a preferred embodiment, the aerosol generating substrates described herein can be used in heated aerosol generating articles for use in electrical aerosol generating systems, in which the aerosol generating substrate of the heated aerosol generating article is heated by an electrical heat source.

For example, the aerosol generating substrates described herein may be used in heated aerosol generating articles of the type described in EP-A-0 822 760.

The heating element of such aerosol generating devices may be of any suitable shape for conducting heat. Heating of the aerosol generating substrate may be achieved from the inside, from the outside, or both. The heating element may preferably be a heating plate or pin adapted to be inserted into the substrate, whereby the substrate is heated from the inside. Alternatively, the heating element may partially or completely surround the substrate and heat the substrate circumferentially from the outside.

The aerosol generating system may be an electrical aerosol generating system comprising an induction heating device. Induction heating devices typically comprise an induction source configured to be connected to a current collector, which may be provided externally relative to the aerosol generating substrate or internally in the aerosol generating substrate. The induction source generates an alternating electromagnetic field, which induces magnetization or eddy currents in the current collector. The current collector may be heated as a result of hysteresis losses or induced eddy currents, which heat the current collector by means of ohmic or resistive heating.

Electric aerosol generating systems that comprise an induction heating device may also comprise an aerosol generating article that comprises an aerosol generating substrate and a current collector that is in thermal proximity to the aerosol generating substrate. Typically, the current collector is in direct contact with the aerosol generating substrate and heat is transferred from the current collector to the aerosol generating substrate primarily by conduction. Examples of electric aerosol generating systems that comprise induction heating devices and aerosol generating articles that comprise current collectors are described in WO-A1-95/27411 and WO-A1-2015/177255.

The current collector may be a plurality of current-receiving particles that may be deposited on the aerosol-generating substrate or enclosed in it. When the aerosol-generating substrate is in the form of one or more sheets, the plurality of current-receiving particles may be deposited on one or more sheets or enclosed within them. The current-receiving particles are immobilized by the substrate, for example in the form of a sheet, and remain in the initial position. Preferably, the current-receiving particles may be uniformly distributed in the homogenized plant material of the aerosol-generating substrate. Due to the fact that the current collector has the form of particles, heat is produced according to the distribution of particles in the sheet of the homogenized plant material of the substrate. Alternatively, the current collector in the form of one or more sheets, strips, pieces or rods may also be located near the homogenized plant material or used as enclosed in the homogenized plant material. In one embodiment, the aerosol-generating substrate comprises one or more current-collecting strips. For example, the rod of the aerosol-generating substrate may comprise an elongated current-collecting element extending longitudinally through it. In another embodiment, the current-collecting element is in the aerosol-generating device.

The current collector may have a heat loss of more than 0.05 J/kg, preferably a heat loss of more than 0.1 J/kg. Heat loss is the ability of the current collector to transfer heat to the surrounding material. Since the current collector particles are preferably uniformly distributed in the aerosol-generating substrate, uniform heat losses from the current collector particles can be achieved, which ensures a uniform heat distribution in the aerosol-generating substrate and leads to a uniform temperature distribution in the aerosol-generating article. It has been found that a specific minimum heat loss of 0.05 J/kg in the current collector particles allows the aerosol-generating substrate to be heated to a substantially uniform temperature, which ensures the generation of the aerosol. Preferably, the average temperatures achieved inside the aerosol-generating substrate in such embodiments are from about 200 degrees Celsius to about 240 degrees Celsius.

The risk of overheating of the aerosol-generating substrate can be reduced by using current collector materials having a Curie temperature, which ensures the heating process due to hysteresis losses only up to a certain maximum temperature. The current collector can have a Curie temperature of about 200 degrees Celsius to about 450 degrees Celsius, preferably about 240 degrees Celsius to about 400 degrees Celsius, for example about 280 degrees Celsius. When the current collector material reaches its Curie temperature, the magnetic properties change. At the Curie temperature, the current collector material changes from the ferromagnetic phase to the paramagnetic phase. At this point, the heating based on energy losses due to the orientation of the ferromagnetic domains stops. Further heating is then mainly based on the formation of an eddy current, so that the heating process is automatically reduced when the Curie temperature of the current collector material is reached. Preferably, the receiver material and its Curie temperature are matched to the composition of the aerosol generating substrate to achieve optimal temperatures and temperature distributions in the aerosol generating substrate for optimal aerosol generation.

In some preferred embodiments of the aerosol generating article according to the present invention, the current collector is made of ferrite. Ferrite is a ferromagnetic material with high magnetic permeability and is particularly suitable as a current collector material. The main component of ferrite is iron. Other metallic components, such as zinc, nickel, manganese, or non-metallic components, such as silicon, can be present in various amounts. Ferrite is a relatively inexpensive, commercially available material. Ferrite is available in the form of particles in the particle size ranges used in the particulate plant material forming the homogenized plant material according to the present invention. Preferably, the particles are fully sintered ferrite powder, such as, for example, FP160, FP215, FP350, supplied by PPT, Indiana, U.S.A.

In certain embodiments of the present invention, an aerosol generating system comprises an aerosol generating article that comprises an aerosol generating substrate as defined above, a source of a substance for forming an aerosol, and means for vaporizing the substance for forming an aerosol, preferably a heating element as described above. The source of the substance for forming an aerosol may be a reservoir, which may be refillable or replaceable and is located on the aerosol generating device. Although the reservoir is physically separated from the aerosol generating article, the generated vapor is directed through the aerosol generating article. The vapor comes into contact with the aerosol generating substrate, which releases volatile compounds, such as nicotine and flavor additives in the particulate plant material, to form an aerosol. Optionally, in order to avoid evaporation of compounds in the aerosol-generating substrate, the aerosol-generating system may further comprise a heating element for heating the aerosol-generating substrate, preferably in a manner consistent with the aerosol-forming substance. However, in certain embodiments, the heating element used to heat the aerosol-generating article is separate from the heater that heats the aerosol-forming substance.

As defined above, the present invention further provides an aerosol obtained by heating an aerosol generating substrate, wherein the aerosol comprises specific amounts and ratios of characteristic compounds obtained from rosemary particles as defined above.

Specific embodiments will be described below, by way of example only, with reference to the accompanying graphic materials, in which:

Fig. 1 shows a first embodiment of a substrate of an aerosol generating article as described herein;

Fig. 2 shows an aerosol generating system that comprises an aerosol generating article and an aerosol generating device that comprises an electric heating element;

Fig. 3 shows an aerosol generating system that comprises an aerosol generating article and an aerosol generating device that comprises a combustible heating element;

Fig. 4a and 4b illustrate a second embodiment of a substrate for an aerosol generating article as described herein;

Fig. 5 shows a third embodiment of a substrate for an aerosol generating article as described herein;

Fig. 6 shows a cross-sectional view of filter 1050, additionally containing an aerosol modifying element, wherein

Fig. 6a shows an aerosol modifying element in the form of a spherical capsule or ball inside a filter rod.

Fig. 6b shows an aerosol modifying element in the form of a thread inside a filter rod.

Fig. 6c shows an aerosol modifying element in the form of a spherical capsule inside a cavity in the filter;

Fig. 7 shows a cross-sectional view of a rod of a substrate 1020 generating an aerosol, which additionally contains an elongated element in the form of a current collector; and

Fig. 8 shows an experimental setup for collecting aerosol samples to be analyzed for the purpose of measuring characteristic compounds.

Fig. 1 shows a heated aerosol-generating article 1000 that includes a substrate as described herein. The article 1000 includes four elements; an aerosol-generating substrate 1020, a hollow cellulose acetate tube 1030, a separator element 1040, and a mouthpiece filter 1050. These four elements are arranged in series, aligned along one axis, and joined by a cigarette paper 1060 to form the aerosol-generating article 1000. The article 1000 has a mouth end 1012 that the user inserts into his or her mouth during use, and a distal end 1013 located at the opposite end of the article from the mouth end 1012. An embodiment of the aerosol-generating article shown in Fig. 1, particularly suitable for use with an electric aerosol generating device comprising a heater for heating an aerosol generating substrate.

When assembled, the length of the 1000 product is approximately 45 millimeters, the outer diameter is approximately 7.2 millimeters, and the inner diameter is approximately 6.9 millimeters.

The aerosol generating substrate 1020 comprises a rod formed from a sheet of homogenized plant material containing rosemary particles either alone or in combination with tobacco particles.

Several examples of homogenized plant material suitable for forming the aerosol generating substrate 1020 are shown in Table 1 below (see samples B-D). The leaf is collected, pleated and wrapped in filter paper (not shown) to form a plug. The leaf contains additives, including glycerol, as an aerosol generating agent.

The aerosol-generating article 1000 shown in Fig. 1 is configured to be engaged with an aerosol-generating device for consumption. Such an aerosol-generating device comprises means for heating an aerosol-generating substrate 1020 to a temperature sufficient for forming an aerosol. Typically, the aerosol-generating device may comprise a heating element that surrounds the aerosol-generating article 1000 near the aerosol-generating substrate 1020, or a heating element that is inserted into the aerosol-generating substrate 1020.

After engagement with the aerosol generating device, the user draws on the mouth end 1012 of the smoking article 1000, and the aerosol generating substrate 1020 is heated to a temperature of approximately 375 degrees Celsius. At this temperature, volatile compounds are released from the aerosol generating substrate 1020. These compounds condense to form an aerosol. The aerosol is drawn through the filter 1050 and into the user's mouth.

Fig. 2 shows a part of an electrical aerosol generating system 2000, which uses a heating plate 2100 for heating an aerosol generating substrate 1020 of an aerosol generating article 1000. The heating plate is installed inside a chamber accommodating an aerosol generating article of an electrical aerosol generating device 2010. The aerosol generating device forms a plurality of air holes 2050 for providing air passage to the aerosol generating article 1000. The air flow is indicated by arrows in Fig. 2. The aerosol generating device contains a power supply unit and an electronic circuit, which are not shown in Fig. 2. The aerosol generating article 1000 shown in Fig. 2 is similar to that shown in Fig. 1.

In an alternative configuration shown in Fig. 3, the aerosol generating system is shown with a combustible heating element. Although it is assumed that the article 1000 shown in Fig. 1 is used in conjunction with an aerosol generating device, the article 1001 shown in Fig. 3 comprises a combustible heat source 1080 that can be ignited and can transfer heat to the aerosol generating substrate 1020 to form an inhalable aerosol. The combustible heat source 80 is a carbon element that is placed near the aerosol generating substrate at the distal end 13 of the rod 11. Elements that are substantially the same as the elements shown in Fig. 1 are designated by the same numbers.

In Fig. 4a and 4b a second embodiment of the heated article 4000a, 4000b generating an aerosol is shown. The aerosol generating substrate 4020a, 4020b comprises a first downstream rod 4021 formed from particulate plant material comprising mainly rosemary particles and a second upstream rod 4022 formed from particulate plant material comprising mainly tobacco particles. Homogenized plant material suitable for use in the first downstream rod is shown in Table 1 below as one of Samples B-D. Homogenized tobacco material suitable for use in the second upstream rod is shown in Table 1 below as Sample A. Sample A contains only tobacco particles and is included for comparative purposes only.

In each of the rods, the homogenized plant material is presented in the form of sheets, which are corrugated and wrapped in filter paper (not shown). Both sheets contain additives, including glycerol, as an aerosol forming substance. In the embodiment shown in Fig. 4a, the rods are combined end to end to form a rod and have an equal length of approximately 6 mm each. In a more preferred embodiment (not shown), the second rod is preferably longer than the first rod, for example preferably 2 mm longer, more preferably 3 mm longer, whereby the second rod has a length of 7 or 7.5 mm, and the first rod has a length of 5 or 4.5 mm, to ensure the desired ratio of tobacco particles to rosemary particles in the substrate. In Fig. 4b, the support element 1030 for the cellulose acetate tube is not shown.

The article 4000a, 4000b, similar to the article 1000 shown in Fig. 1, is particularly suitable for use with the electrical system 2000 generating an aerosol, which contains the heater shown in Fig. 2. Elements that are substantially the same as the elements shown in Fig. 1 are designated by the same numbers. A person skilled in the art can assume that a combustible heat source (not shown) can instead be used with the second embodiment instead of the electrical heating element in a configuration similar to the configuration containing the combustible heat source 1080 in the article 1001 shown in Fig. 3.

Fig. 5 shows a third embodiment of a heated article 5000 that generates an aerosol. The aerosol-generating substrate 5020 comprises a rod formed from a first sheet of homogenized plant material formed from particulate plant material containing a portion of rosemary particles and a second sheet of homogenized plant material containing mainly molded leaf tobacco.

Homogenized plant material suitable for use as the first sheet is shown in Table 1 below as one of Samples B-E. Homogenized tobacco material suitable for use as the second sheet is shown in Table 1 below as Sample A. Sample A contains only tobacco particles and is included for comparative purposes only.

The second sheet overlaps the first sheet, and the combined sheets are corrugated, collected and at least partially wrapped with filter paper (not shown) to form a rod, which is part of the rod. Both sheets contain additives, including glycerol, as an aerosol forming agent. Article 5000, similar to article 1000 shown in Fig. 1, is particularly suitable for use with an electrical system 2000 that generates an aerosol, which contains a heater shown in Fig. 2. Elements that are substantially the same as those shown in Fig. 1 are designated by the same numbers. A person skilled in the art can assume that a combustible heat source (not shown) can instead be used with the third embodiment instead of an electrical heating element in a configuration similar to a configuration containing a combustible heat source 1080 in article 1001 shown in Fig. 3.

Fig. 6 shows a sectional view of the filter 1050, which further comprises an aerosol modifying element. In Fig. 6a, the filter 1050 further comprises an aerosol modifying element in the form of a spherical capsule or ball 605.

In the embodiment shown in Fig. 6a, a capsule or ball 605 is inserted into a filter segment 601 and surrounded on all sides by a filter material 603. In this embodiment, the capsule comprises an outer shell and an inner central part, and the inner central part contains a liquid flavor additive. The liquid flavor additive is intended to impart flavor to the aerosol during use of an aerosol-generating article provided with a filter. The capsule 605 releases at least a portion of the liquid flavor additive when the filter is subjected to an external force, for example, by squeezing by the consumer. In the embodiment shown, the capsule is generally spherical, with a substantially continuous outer shell containing the liquid flavor additive.

In the embodiment shown in Fig. 6b, the filter segment 601 comprises a rod of filter material 603 and a central thread 607 for carrying a flavoring substance, which extends axially through the rod of filter material 603 parallel to the longitudinal axis of the filter 1050. The central thread 607 for carrying a flavoring substance has substantially the same length as the rod of filter material 603, as a result of which the ends of the central thread 607 for carrying a flavoring substance are visible at the ends of the filter segment 601. In Fig. 6b, the filter material 603 is an acetate cellulose tow. The central thread 607 for carrying a flavoring substance is formed from a twisted filter filament and is filled with an aerosol modifying agent.

In the embodiment shown in Fig. 6c, the filter segment 601 comprises more than one rod of filter material 603, 603'. Preferably, the rods of filter material 603, 603' are formed from cellulose acetate, whereby they can filter the aerosol provided by the aerosol-generating article. The wrapper 609 is wrapped around the rods 603, 603' of the filter and connects them. Inside the cavity 611, a capsule 605 is located, comprising an outer shell and an inner central part, and the inner central part contains a liquid flavor additive. Otherwise, the capsule is similar to the embodiment shown in Fig. 6a.

Fig. 7 shows a cross-sectional view of an aerosol generating substrate 1020 that further comprises an elongated strip 705 in the form of a susceptor. The aerosol generating substrate 1020 comprises a rod 703 formed from a sheet of homogenized plant material containing tobacco particles and rosemary particles. The elongated strip 705 in the form of a susceptor is contained within the rod 703 and extends in a longitudinal direction between an upstream end and a downstream end of the rod 703. In use, the elongated strip 705 in the form of a susceptor heats the homogenized plant material by means of induction heating, as described above.

Example 1

Various samples of homogenized plant material for use in the aerosol generating substrate according to the present invention, as described above with reference to the figures, were prepared from aqueous pulps having the compositions shown in Table 1. Samples B-E contain rosemary particles according to a preferred embodiment of the present invention. In samples B-D, rosemary particles are combined with tobacco particles. Sample A contains only tobacco particles. Sample E contains only rosemary particles.

Particulate plant material in all samples A-E accounted for 65 percent of the dry weight of the homogenized plant material, with glycerol, CMC, cellulose powder, and reinforcing cellulose fibers accounting for the remaining 35 percent of the dry weight of the homogenized plant material.

In the table below % DWB stands for "on a dry weight basis", in this case the percentage by weight calculated relative to the dry weight of the homogenized plant material. Rosemary powder was formed from Rosmarinus Officinalis leaves from Spain, which were ground to a final D95=133 microns by triple impact milling. The rosemary powder was sieved to remove particles larger than 200 microns. More specifically, sample E was prepared from an aqueous pulp containing:

rosemary: 17.78 kg/100 kg pulp

glycerol: 4.50 kg/100 kg pulp

CMC: 1.25 kg/100 kg pulp

cellulose powder: 2.50 kg/100 kg pulp

cellulose fibers: 1.00 kg/100 kg pulp

water: 72.97 kg/100 kg pulp.

Table 1. Dry matter content in pulps

Sample Rosemary (% DWB) Tobacco
(% DWB) Glycerol
(% DWB) CMC
(% DWB) Cellulose powder (%DWB) Cellulose fibers
(% DWB) A 0 65 17 5 9 4 B 1 64 17 5 9 4 C 6.5 58.5 17 5 9 4 D 13 52 17 5 9 4 E 65 0 17 5 9 4

The pulps were formed using a forming bar (0.6 mm) on a glass plate, dried in an oven at 140 degrees Celsius, and then dried in a second oven at 135 degrees Celsius.

For each of the AE samples of homogenized plant material, a rod was prepared from a single continuous sheet of homogenized plant material, each sheet having a width of between 100 mm and 125 mm. The individual sheets had a thickness of approximately 220 microns and a grammage of approximately 135 g/ ^m2 _. The cutting width of each sheet was adapted based on the thickness of each sheet to produce rods of comparable volume. The sheets were corrugated to a height of between 165 microns and 170 microns and rolled into rods having a length of approximately 12 mm and a diameter of approximately 7 mm, wrapped in paper.

For each of the rods, an aerosol generating article was manufactured having an overall length of approximately 45 mm and having the structure shown in Fig. 3, which comprises from the downstream end: a cellulose acetate filter (approximately 7 mm long) at the mouth end, an aerosol divider comprising a pleated sheet of polylactic acid polymer (approximately 18 mm long), a hollow acetate tube (approximately 8 mm long) and a rod of aerosol generating substrate.

For sample E of the homogenized plant material in which rosemary particles comprised 100 percent of the plant particles, characteristic rosemary compounds were extracted from a rod of homogenized plant material using methanol as detailed above. The extract was analyzed as described above to confirm the presence of characteristic compounds and to measure the amounts of characteristic compounds. The results of this analysis are shown in Table 2 below, in which the amounts reported correspond to the amount per aerosol-generating article, wherein the aerosol-generating substrate of the aerosol-generating article contained 178 mg of sample E of the homogenized plant material.

For comparative purposes, the amounts of characteristic compounds present in the particulate plant material (rosemary particles) used to make sample E are also shown. In the particulate material, the amounts shown correspond to the amount of characteristic compound in a sample of particulate plant material having a weight corresponding to the total weight of particulate plant material in an aerosol-generating article containing 178 mg of sample E.

Table 2. Quantities of rosemary-specific compounds in particulate plant material and aerosol-generating substrate

Characteristic connection Amount in plant material in particulate form
(micrograms per product) Quantity in aerosol generating substrate
(micrograms per product) Betulinic acid 717 608 Rosemarydiphenol 243 290 12-O-methylcarnosol 5.6 3.9

For each of the samples B-D containing a proportion of rosemary particles, the amount of characteristic compounds can be estimated from the values in Table 2, assuming that the amount is present in proportion to the weight of the rosemary particles.

The primary aerosol streams of aerosol-generating articles containing aerosol-generating substrates formed from samples A-E of homogenized plant material were generated in accordance with test method A as defined above. For each sample, the aerosol that was produced was captured and analyzed.

As described in detail above, in accordance with Test Method A, aerosol-generating products were tested using the commercially available Tobacco Heating System 2.2 Holder of the IQOS® Combustion-Free Heating Device (THS2.2 Holder) from Philip Morris Products SA. The aerosol-generating products were heated according to the Health Canada approved machine smoking mode for 30 puffs with a puff volume of 55 ml, a puff duration of 2 seconds and an inter-puff interval of 30 seconds (as described in ISO/TR 19478-1:2014).

The aerosol generated during the smoking test was collected on a Cambridge filter pad and extracted using a liquid solvent. Fig. 10 shows an apparatus suitable for generating and collecting aerosol from aerosol generating articles.

The aerosol generating device 111 shown in Fig. 10 is a commercially available tobacco heating device (IQOS). The contents of the mainstream aerosol generated during the smoking test approved by Health Canada, as described in detail above, were collected in the aerosol collection chamber 113 on the aerosol collection line 120. The glass fiber filter pad 140 is a 44 mm Cambridge fiberglass filter pad (CFP) in accordance with ISO 4387 and ISO 3308.

For LC-HRAM-MS analysis :

The extraction solution 170, 170a, which in this case is methanol and an internal standard solution (ISTD), is present in a volume of 10 ml in each microimpinger 160, 160a. Each of the cold baths 161, 161a contains a mixture of dry ice and isopropyl ether to maintain each of the microimpingers 160, 160a at a temperature of approximately -60 °C. The vapor-gas phase is captured in the extraction solution 170, 170a when the aerosol passes as bubbles through the microimpingers 160, 160a. The combined solutions from the two microimpingers are separated as an impinger-captured vapor-gas phase solution 180 at step 181.

The CFP and the impinger trapped headspace solution 180 are combined in a clean Pyrex® tube in step 190. In step 200, all particulate material is extracted from the CFP using the impinger trapped headspace solution 180 (which contains methanol as a solvent) by means of thorough shaking (disintegrating the CFP), vigorous mixing for 5 minutes and finally centrifugation (4500 g, 5 minutes, 10°C). Aliquots (300 µl) of the recovered whole aerosol extract 220 were transferred to a silanized chromatography vial and diluted with methanol (700 µl) since the extraction solution 170, 170a already contained the internal standard solution (ISTD). The vials were capped and their contents were mixed for 5 minutes using an Eppendorf Thermomixer (5°C; 2000 rpm).

Aliquots (1.5 µl) of diluted extracts were injected and analyzed by LC-HRAM-MS in both full scan and fragmentation modes depending on the data for compound identification.

For GCxGC-TOFMS analysis:

As described above, when obtaining samples for GCxGC-TOFMS experiments, different solvents are suitable for the extraction and analysis of polar compounds, non-polar compounds, and volatile compounds isolated from the total aerosol. The experimental setup is identical to that described for collecting samples for LC-HRAM-MS, except as noted below.

Non-polar and polar components

Extraction solution 171,171a is present in a volume of 10 ml and is a mixture of 80:20 v/v dichloromethane and methanol, also containing compounds representing a retention index marker (RIM) and a stable isotopically labeled internal standard (ISTD). Each of the cold baths 162, 162a contains a mixture of dry ice and isopropanol to maintain each of the microimpingers 160, 160a at a temperature of approximately -78 °C. The vapor-gas phase is captured in the extraction solution 171, 171a when the aerosol passes as bubbles through the microimpingers 160, 160a. The combined solutions from the two microimpingers are separated as an impinger-captured vapor-gas phase solution 210 at step 182.

Non-polar components

The CFP and the impinger trapped headspace solution 210 are combined in a clean Pyrex® tube at step 190. At step 200, all particulate material is extracted from the CFP using the impinger trapped headspace solution 210 (which contains dichloromethane and methanol as a solvent) by vigorous shaking (to disintegrate the CFP), vigorous mixing for 5 minutes, and finally centrifugation (4500 g, 5 minutes, 10°C) to separate the polar and non-polar components of the whole aerosol extract 230.

At step 250, a 10-mL aliquot 240 of the whole aerosol extract 230 was collected. At step 260, a 10-mL aliquot of water was added and the entire sample was vortexed and centrifuged. The non-polar fraction 270 was separated, dried over sodium sulfate and analyzed by GCxGC-TOFMS in full scan mode.

Complete components

ISTD and RIM compounds were added to the polar fraction 280, which was then directly analyzed by GCxGC-TOFMS in full scan mode.

Each smoking replicate (n=3) contains the accumulated captured and recovered non-polar fraction 270 and polar fraction 280 for each sample.

Volatile components

All the aerosol was captured using two microimpingers 160, 160a arranged in series. The extraction solution 172, 172a, which in each case is N, N-dimethylformamide (DMF) containing compounds representing a retention index marker (RIM) and a stable isotopically labeled internal standard (ISTD), is present in a volume of 10 ml in each microimpinger 160, 160a. Each of the cold baths 161, 161a contains a mixture of dry ice and isopropyl ether to maintain each of the microimpingers 160, 160a at a temperature of approximately -60 °C. The vapor-gas phase is captured in the extraction solution 170, 170a when the aerosol passes as bubbles through the microimpingers 160, 160a. The combined solutions from the two microimpingers are separated as the volatiles containing phase 211 in step 183. The volatiles containing phase 211 is analyzed separately from the other phases and injected directly into the GCxGC-TOFMS method using cold on-column injection without further preparation.

Table 3 below shows the levels of characteristic compounds from rosemary particles in the aerosol generated from an aerosol-generating article that contains sample E of homogenized plant material containing only rosemary particles. For comparison purposes, Table 3 also shows the levels of characteristic compounds in the aerosol generated from an aerosol-generating article that contains sample A of homogenized plant material containing only tobacco particles (and therefore not produced in accordance with the present invention).

Table 3. Content of characteristic compounds in aerosol

Compound Sample A
(micrograms per product) Sample E (micrograms per gram) Sample E (micrograms per 55 ml puff) Sample E
(micrograms per product) Betulinic acid 0 2275 33.75 405 Rosemarydiphenol 0 109 1.62 19.4 12-O-methylcarnosol 0 118.5 0.68 21.1

For example, relatively high levels of characteristic compounds would be measured in the aerosol generated from sample E. The ratio of betulinic acid to rosmaridiphenol would typically be greater than 20:1. Measured levels of characteristic compounds within the above ranges would indicate the presence of rosemary particles in the sample and in the homogenized leaf composition as defined above. In contrast, for tobacco-only sample A, which contained essentially no rosemary particles, characteristic compound levels would be equal to or close to zero.

For each of the samples B-D containing a proportion of rosemary particles, the amount of characteristic compounds in the aerosol can be estimated from the values in Table 3, assuming that the amount is present in proportion to the weight of rosemary particles in the aerosol-generating substrate from which the aerosol is generated.

It was also found that the aerosol produced from Sample E, containing 65 percent by weight rosemary powder, resulted in reduced levels of several undesirable aerosol constituents compared to the aerosol level in Sample A, produced using 100 percent by weight tobacco based on the dry weight of the particulate plant material.

Example 2

Sheets of homogenized plant material according to the present invention were formed using the compositions shown in Table 4 below as Formulation 1 and Formulation 2. For comparison purposes, a third sheet of homogenized plant material using an alternative binder (and therefore not made in accordance with the present invention) was formed using the composition shown in Table 4 below as Formulation 3. All sheets had a relatively high level of rosemary particles and were formed using the sheet forming method as set out above in Example 1.

Table 4. Dry matter content in pulps

Sample Rosemary powder
(% DWB) Glycerol
(% DWB) Guar
(% DWB) CMC
(% DWB) Cellulose powder
(% DWB) Cellulose fibers
(% DWB) 1 57 25 0 5 10 3 2 54 35 0 5 0 6 3 75 18 3 0 0 4

It was found that the molded sheet formed from samples 1 and 2 according to the present invention has a uniform texture with a relatively uniform thickness and high tensile strength. The molded sheet can be easily removed from the molding plate and formed into a rod of aerosol-generating substrate. In contrast, it was found that the molded sheet formed from sample 3 using a known binder instead of the combination of CMC and cellulose is porous and brittle and has virtually no tensile strength. It was found that the molded sheet cannot be easily separated from the molding plate and it breaks into fragments in such a way that it is impossible to form a rod of aerosol-generating substrate from it. This example demonstrates that the use of a combination of CMC and additional cellulose instead of guar gum as a binder provides a significantly improved sheet of homogenized plant material with significantly improved tensile strength and uniformity.

The molded sheet formed from Sample 2 has a relatively high level of aerosol generating substance (35 percent by weight) and is particularly suitable for use in forming an aerosol generating substrate of an aerosol generating article that is intended to be heated to a temperature below 275 degrees Celsius.

It was found that when heated to a temperature of approximately 265 degrees Celsius, the aerosol generating substrate formed from the molded sheet formed from Sample 2 provided significantly improved aerosol delivery compared to the molded sheet from Sample 3. In particular, the aerosol delivery improved to a greater extent than expected based on the level of aerosol forming agent alone. This demonstrates the improvement in aerosol delivery provided by the incorporation of CMC as a binder in place of guar gum.

Example 3

The following homogenized plant materials according to the present invention were prepared using the sheet forming method as described above for Example 1, each containing a different type of non-tobacco plant material. For each plant material, the composition shown in Table 5 below was used:

Table 5. Composition of homogenized plant materials

Component Quantity (% DWB) Powder of plant origin 54 CMC 5 Cellulose fibers 6 Glycerol 35

The properties of the resulting homogenized plant materials are shown below in Table 6.

Table 6. Properties of homogenized plant materials

Powder of plant origin Grammage (g/m) ² ) Thickness (microns) Observations during production Star anise 209 409 Good quality sheet. Large thickness. Ginger 207 221 Good quality sheet Carnation 209 215 Good quality sheet Eucalyptus 197 218 Good quality sheet Rosemary 135 223 Good quality sheet

In each case, the resulting homogenized plant material was found to have acceptable thickness and tensile strength to be incorporated into an aerosol generating product.

Claims (43)

1. An aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate is formed from homogenized plant material comprising: from 1 percent by weight to 65 percent by weight of plant particles other than tobacco, calculated on a dry weight basis; from 15 percent by weight to 55 percent by weight of aerosol forming substance on a dry weight basis; from 5 percent by weight to 10 percent by weight of cellulose ether, calculated on a dry weight basis; and from 5 percent by weight to 50 percent by weight of additional cellulose on a dry weight basis, wherein the additional cellulose is in the form of isolated cellulose and is not derived from plant particles other than tobacco, and wherein the ratio of additional cellulose to cellulose ether in the homogenized plant material is at least 2; wherein the non-tobacco particles are selected from rosemary particles, star anise particles, ginger particles, clove particles, eucalyptus particles, or combinations thereof. 2. An aerosol generating article according to claim 1, wherein the homogenized plant material further comprises at least 1 percent by weight of tobacco particles. 3. An aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate is formed from homogenized plant material comprising: from 1 percent by weight to 65 percent by weight of tobacco particles on a dry weight basis; from 15 percent by weight to 55 percent by weight of aerosol forming substance on a dry weight basis; from 5 percent by weight to 10 percent by weight of cellulose ether, calculated on a dry weight basis; and from 5 percent by weight to 50 percent by weight of additional cellulose on a dry weight basis, wherein the additional cellulose is in the form of isolated cellulose and is not obtained from tobacco particles, and the ratio of additional cellulose to cellulose ether in the homogenized plant material is at least 2. 4. An aerosol generating article according to any one of claims 1 to 3, wherein the additional cellulose comprises cellulose powder, wherein the amount of cellulose powder corresponds to at least 5 percent by weight of the homogenized plant material, calculated on a dry weight basis. 5. The aerosol generating article of claim 4, wherein the ratio of cellulose powder to cellulose ether in the homogenized plant material is at least 1.5. 6. An aerosol generating article according to claim 4 or 5, wherein the cellulose powder comprises at least 95 percent by weight cellulose, more preferably at least 97 percent. 7. An aerosol generating article according to any one of the preceding claims, wherein the additional cellulose comprises reinforcing cellulose fibres, wherein the amount of reinforcing cellulose fibres corresponds to at least 3 percent by weight of the homogenized plant material, calculated on a dry weight basis. 8. An aerosol generating article according to claim 7, wherein the ratio of reinforcing cellulose fibres to cellulose ether in the homogenised plant material is at least 1. 9. An aerosol generating article according to any one of the preceding claims, wherein the additional cellulose comprises cellulose powder and reinforcing cellulose fibres, wherein the ratio of cellulose powder to reinforcing cellulose fibres is at least 1.5. 10. An aerosol generating article according to any one of the preceding claims, wherein the cellulose ether comprises carboxymethyl cellulose (CMC). 11. An aerosol-generating article according to any of the preceding paragraphs, wherein the total amount of plant particles other than tobacco or tobacco particles and additional cellulose does not exceed 75 percent by weight of the homogenized plant material on a dry weight basis. 12. An aerosol generating article according to any one of the preceding claims, wherein the homogenized plant material comprises rosemary particles. 13. An aerosol generating article according to claim 1, wherein the homogenized plant material comprises: from 50 percent by weight to 65 percent by weight of non-tobacco particles, calculated on a dry weight basis; and from 15 percent by weight to 25 percent by weight of aerosol forming agent, calculated on a dry weight basis. 14. An aerosol generating article according to claim 2, wherein the homogenized plant material comprises: from 50 percent by weight to 65 percent by weight of tobacco particles on a dry weight basis; and from 15 percent by weight to 25 percent by weight of aerosol forming agent, calculated on a dry weight basis. 15. An aerosol generating article according to claim 1, wherein the homogenized plant material comprises: from 10 percent by weight to 55 percent by weight of non-tobacco particles, calculated on a dry weight basis; and from 30 percent by weight to 45 percent by weight of aerosol forming agent, calculated on a dry weight basis. 16. An aerosol generating article according to claim 2, wherein the homogenized plant material comprises: from 10 percent by weight to 55 percent by weight of tobacco particles on a dry weight basis; and from 30 percent by weight to 45 percent by weight of aerosol forming agent, calculated on a dry weight basis. 17. An aerosol-generating article according to claim 12, wherein the aerosol-generating substrate comprises: at least 50 micrograms of betulinic acid per gram of substrate on a dry weight basis; at least 20 micrograms of rosmarindiphenol per gram of substrate on a dry weight basis and at least 0.3 micrograms 12-O-methylcarnosol per gram of substrate on a dry weight basis. 18. An aerosol-generating article according to claim 17, wherein heating the aerosol-generating substrate according to test method A described in ISO/TR 19478-1:2014 generates an aerosol comprising: at least 30 micrograms of betulinic acid per gram of substrate on a dry weight basis; at least 1 microgram of rosmarindiphenol per gram of substrate on a dry weight basis; and at least 1 microgram 12-O-methylcarnosol per gram of substrate on a dry weight basis.

Images