WO2023111548A1

WO2023111548A1 - Methods and apparatus for treating plant-derived material

Info

Publication number: WO2023111548A1
Application number: PCT/GB2022/053213
Authority: WO
Inventors: Matthias Link; Dietmar Franke; Frank Plueckhahn
Original assignee: British American Tobacco (Investments) Limited
Priority date: 2021-12-15
Filing date: 2022-12-14
Publication date: 2023-06-22
Also published as: GB202118183D0

Abstract

The present invention provides a method of treating plant-derived material comprising intermittently contacting a plant-derived material with a heated surface to locally heat the material upon said contact and collecting the volatile components released from plant-derived material. Also provided is an apparatus for treating plant-derived material. The invention also provides volatile components collected as part of the treatment of the plant-derived material, as well as uses of and products comprising the same.

Description

Methods and apparatus for treating plant-derived material

Field

The present invention provides a method of treating plant-derived material. Also provided is an apparatus for treating plant-derived material. The invention also provides volatile components collected as part of the treatment of the plant-derived material, as well as uses of and products comprising the same.

Background Various processes and apparatus are known for heat treating plant-derived material. The heating results in the release of volatile components of the plant-derived material and these components are often desirable as they contribute to the aroma and taste of the material. In the course of many known treatment methods, these components are lost. There is also the risk of volatile components being altered in a detrimental way by the heat treatment.

Summary

According to a first aspect of the invention, a method is provided comprising: intermittently contacting plant-derived material with a heated surface to locally heat the material upon said contact; and collecting the volatile components released from the plant-derived material.

In some embodiments, the volatile components are collected in a gas flow. In some embodiments, the volatile components are trapped and/or extracted.

In some embodiments, the plant-derived material is selected from the group consisting of: tobacco, wood, tea, coffee, cocoa, herbs and spices.

In some embodiments, the plant-derived material is freshly harvested, dried, cured or roasted.

In some embodiments, the plant-derived material is agitated so that it is intermittently in contact with the heated surface. In some embodiments, the heated surface has a temperature of from at least about ioo°C to about 3OO°C prior to contact with the plant-derived material. In some embodiments, the heated surface has a temperature of from at least about 12O°C to about 25O°C prior to contact with the plant-derived material, or from at least about 15O°C to about 3OO°C prior to contact with the plant-derived material. In some embodiments, contacting the plant-derived material with the heated surface heats the plant-derived material to a peak temperature of from about 12O°C to about 23O°C.

In some embodiments, the plant-derived material has a moisture content of at least about 5% OV prior to contact with the heated surface.

In some embodiments, the plant-derived material has a moisture content of from about 5 to about 25% OV prior to contact with the heated surface, or a moisture content of from about 12 to about 16% OV prior to contact with the heated surface.

In some embodiments, the plant-derived material is intermittently contacted with the heated surface for a period of from at least about 1 minute to about 180 minutes.

In some embodiments, the method is a continuous process. In alternative embodiments, the method is a batch process.

In some embodiments, the plant-derived material is tobacco material. In some embodiments, the tobacco material comprises one or more selected from the group consisting of: cut stem, cut lamina, leaf lamina, small lamina, stem fibres, short stem and long stem.

In some embodiments, the method further comprises applying at least one of the collected volatile components to a substrate. In some embodiments, the substrate comprises the plant-derived material treated by intermittent contact with the heated surface.

According to a second aspect of the invention, an apparatus is provided comprising a heated surface provided to intermittently contact plant-derived material and a means for collecting the volatile components released. In some embodiments, the apparatus further comprises a means for agitating the plant- derived material. In some embodiments, the means for agitating the plant-derived material comprises at least one of the group consisting of: a screw mechanism; a dual screw mechanism; air flow; and a rotating drum.

In some embodiments, the heated surface has a temperature of from at least about ioo°C to about 3OO°C prior to contact with the plant-derived material.

In some embodiments, the heated surface has a temperature of from at least about 12O°C to about 25O°C prior to contact with the plant-derived material, or from at least about 15O°C to about 3OO°C prior to contact with the plant-derived material.

In some embodiments, the heated surface is heated by a heating medium, the heating medium being water, oil, steam, electricity, or combinations thereof.

According to a third aspect of the invention, an extract is provided, comprising volatile components collected by the method according to the first aspect of the invention.

According to a fourth aspect of the invention, a composition is provided, comprising a substrate and at least one of the collected volatile components.

In some embodiments, the substrate comprises a treated plant-derived material obtained or obtainable by a method according to the first aspect of the invention. According to a fifth aspect of the invention, a tobacco industry product is provided, comprising an extract according to the third aspect, or a composition according to the fourth aspect of the invention.

According to a sixth aspect of the invention, use of a collected volatile component obtained or obtainable by a method according to the first aspect of the invention is provided, for the manufacture of a tobacco industry product.

Brief Description of the Figures

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figures la and ib each show a process flow chart of an exemplary method. Figure 2 is an illustration of an apparatus for treating plant-derived material.

Figure 3 is a schematic illustration of the progress of the plant-derived material through the apparatus. Detailed Description

Many plant-derived materials may be heat treated for a variety of reasons. In some cases, the material needs to be dried before its use or before further processing steps.

The determination of moisture content in plant-derived materials can be important, as it can influence their processing properties and the properties of the treated product. It is common for the terms “moisture” and “moisture content” to be used to refer to water content of a material, but this is difficult to determine in natural products such as plant-derived materials. It is therefore desirable to differentiate between “moisture” as water content and “moisture” as oven volatiles. Water content is defined as the percentage of water contained in the total mass of a solid substance. Volatiles are defined as the percentage of volatile components contained in the total mass of a solid substance. This includes water and all other volatile compounds. Oven diy mass is the mass that remains after the volatile substances have been driven off by heating. It is expressed as a percentage of the total mass. Oven volatiles (OV) are the mass of volatile substances that were driven off.

Moisture content (oven volatiles) may be measured as the reduction in mass when a sample is dried in a forced draft oven at a temperature regulated to no°C ± i°C for three hours ± 0.5 minutes. After drying, the sample is cooled in a desiccator to room temperature for approximately 30 minutes, to allow the sample to cool.

Unless stated otherwise, references to moisture content herein are references to oven volatiles (OV). Different types of drying apparatus are known and these are usually selected based upon the desired moisture content of the resultant dried plant-derived material, and upon the nature of the plant-derived material to be dried.

A Cased- Leaf Dryer (CLD) is one type of apparatus that dries plant-derived material, such as leaf tobacco (not cut tobacco), to very low final moisture content (to as low as about 4%). The leaf tobacco that is dried using such an apparatus would usually have a starting moisture content of about 28% to about 36%. The drying process involves laying the tobacco on a band with holes. The tobacco is dried by hot air that is passed through the holes in the band. The band is not directly heated but it may be indirectly heated by the passage of hot air through the dryer. The tobacco remains in contact with the band during the drying and temperature of the heated air used to dry the tobacco leaf is generally between 8o°C and 17O°C, while the vast majority is between ioo°C and 14O°C. Even where the dryers are running at 17O°C, the temperature of the tobacco does not exceed ioo°C as the tobacco catches fires at ‘hot spots’ because the hot air is still rich in oxygen.

Other known types of apparatus for drying tobacco and other plant-derived materials are a Flash Tower Dryer and Fluidised Bed Dryer. The drying process involves the creation of turbulence in a stream of plant material by the passage of air/ steam mixture through the dryer. The beds of these dryers are not heated, instead the air/ steam mixture is heated. Fluidised Bed Dryers are used to dry cut tobacco stem which tends to have a starting moisture content in the region of 28% to 50% OV. Flash Tower Dryers, including HTD (High Temperature Dryers), HXD (High Expansion Flash Dryers) and Air Dryers, do not have a bed but also rely on heated air/ steam mixture and they are mainly used to dry cut tobacco lamina which may have a starting moisture content in the region of 20% to 36% OV, and sometimes (exceptionally) to dry cut tobacco stem with a starting moisture content in the region of 28% to 50% OV. The residence time for the plant-derived material in a Flash Tower Dryer is very short and often just a few seconds. In contrast, plant derived material maybe dried in a Fluidised Bed Dryer for several minutes. The final moisture content of the processed material produced by such apparatus is above about 10% OV. The material in both of these dryer types reach temperatures of from about 5O°C to ioo°C.

A further known type of apparatus for drying tobacco and other plant-derived material is a Drum Dryer. This type of dryer utilises a heated metal drum, and the drying process may be regarded as a mixture of air drying together with drying via a heated surface. The rotation of the drum causes the material to tumble and creates some level of turbulence of the material and air. Whilst the metal surface is heated, this is only to a temperature of about 60 to 13O°C. The final moisture content of tobacco processed using this type of apparatus is higher than 10%. Typically, the moisture content of the starting material will depend on the type of material being dried. Cut tobacco lamina will have a starting moisture content of between 20% and 26%, cut tobacco stem a starting moisture content of 28% to 50%. Following a treatment period within the drum dryer of 3 to 4 minutes (for cut stem) or 4 to 7 minutes for (cut lamina), the treated tobacco has a moisture content of 12 to 15%. All of these drying apparatus vent gases that are generated during the heating process. This gas will include the water and volatiles that are released as a consequence of the heating.

In contrast to these known drying processes and apparatus, key aspects of the method of treating plant-derived material and of the apparatus of the invention include a combination of: intermittently contacting the plant-derived material with a heated surface or surfaces so that the material is locally heated; and collecting the volatile components that are released from the plant-derived material by said localised heating. It has been found that the exposure of plant-derived material to a hot surface not only dries the material to very low levels of water content, but also reduces the moisture content (based in oven volatiles), meaning that the plant-derived material releases volatile components. These volatile components will include important aroma and flavour components for some plant-derived material and their loss will have a detrimental effect on the treated material. Alternatively or additionally, the volatiles maybe valuable in their own right. For these reasons, the volatile components are collected in the methods disclosed herein.

The collected volatile components may be reincorporated into the treated plant-derived material, if desired. In some embodiments, the collected volatile components may undergo further processing before being added back to the treated material. For example, the collected volatile components may be separated and only selected components added back. Alternatively or in addition, the volatile components may be concentrated before being added back. In addition, in some embodiments, other components (not released from the plant-derived material) maybe added to the collected volatile components before they are added back to the treated plant-derived material. In other embodiments, the volatile components collected form a new product separate from the treated plant-derived material. The product maybe in gaseous form, liquid form or solid form, depending upon the components present and the proposed use thereof.

The volatile components may be trapped using established technologies such as, for example, freezing or cold trapping, or using a base material for subsequent liquid extraction. In some embodiments, the gases formed as a result of the heat treatment of the plant-derived material are drawn out of the treatment chamber, for example by a vacuum pumping system. The gas stream is then cooled in order to condense the vapours. In some embodiments, the gases maybe sublimated, transforming the gas molecules directly into the solid (crystalline) phase and bypassing the liquid phase. The cold trap may be cooled by any available means, such as mechanical refrigeration, dry ice or liquid nitrogen.

The processing of some plant-derived materials according to the methods of some embodiments of the present invention leads to chemical changes in the material and these chemical changes will not only be seen in the treated plant-derived material but also in the volatile components that are released.

The trapped volatile components may, in some embodiments, be used to generate flavour mixtures which are perceived to deliver flavour impressions of the plant-derived material from which they are derived. The trapped volatile components may be used to generate an extract in one or more suitable forms, including in liquid form and solid form. In some embodiments, the trapped volatile components are condensed into liquid form. In some embodiments, this liquid may then be converted into a solid form, such as a powder. In other embodiments, the volatile components are deposited directly into solid form.

The extract may include the volatile components in concentrated form (that is, in a form more concentrated than they were present in the plant material from which they are derived). In some embodiments, the extract generated from the trapped volatile components is added or applied to a carrier or substrate. In some embodiments, the carrier or substrate may be selected to enhance or control the release of the flavour components. In some embodiments, the carrier or substrate may be selected from one or more of: a fibrous material (such as filter material, for example cellulose acetate tow), a sheet material, an adsorbent material (such as adsorbent carbon, activated carbon, silica gel, alumina, polymeric resin, zeolite, sepiolite and mixtures thereof), and a plant material (such as tobacco material).

In some embodiments, the extract is applied to the treated plant-derived material from which the trapped volatile components are derived. Thus, the method comprising intermittently contacting plant-derived material with a heated surface and collecting the volatile components released from the plant-derived material may further comprise generating a flavour mixture from the volatile components and applying this to the treated plant-derived material (for example, once it has cooled). The extracts generated from the trapped volatile components may be used in a variety of ways and in a variety of products. For example, it may be desirable for these extracts to be used in tobacco industry products. Such products include, for example, tobacco heating products and e-cigarettes, and the extract may be used in order to alter or enhance the flavour of the aerosols produced by such devices. Where the plant-derived material is tobacco, the extract produced from the volatile components released by the plant-derived material may include tobacco flavours and aromas. When such extracts are used in a tobacco heating product or in e-cigarettes, they can provide sensations that resemble or are reminiscent of a conventional cigarette. Additionally or alternatively, the treated plant-derived material produced by the methods disclosed herein may be used in tobacco industry products. In some embodiments, the treated plant-derived material may be the material produced as a result of the intermittent contact with a heated surface which leads to the release of the volatile components. In other embodiments, the treated plant-derived material may include one or more additives. In some embodiments, the treated plant-derived material may be combined with one or more flavour mixtures, optionally the extract generated from the treatment of the plant-derived material itself.

As used herein, the term “plant-derived material” includes any part and any related by- product of a plant. It will include, for example, one or more of the following: leaves, stems, roots, seeds and parts thereof. The plant-derived material may be any botanical and, in some embodiments, is a plant with a desirable flavour or aroma. Suitable plant materials include botanicals such as wood, tea, coffee, cocoa, herbs and spices, as well as any kind, style or variety of tobacco.

In some embodiments, the plant-derived material is wood. Almost any wood may be used. The volatile components collected following the heat treatment of this material can have a “fire-cured” type of flavour. The addition of the flavour mixture produced from these volatile components to tobacco, for example tobacco for use in combustible smoking articles such as cigarettes, or for tobacco heating devices, can produce a “fire- cured” taste without the need for fire-cured tobacco. This is advantageous as firecuring tobacco can lead to an undesirable increase in the levels of polycyclic aromatic hydrocarbons (PAHs) in the tobacco and/or in the aerosols produced by heating or combusting the tobacco.

As used herein, the term “tobacco material” includes any part and any related byproduct, such as for example the leaves or stems, of any member of the genus Nicotiana. The tobacco material for use in the present invention is preferably from the species Nicotiana tabacum.

In some embodiments, the tobacco starting material - that is the tobacco material before treatment using the method disclosed herein - is one or more selected from the group consisting of: cut stem, cut lamina, leaf lamina, small lamina, stem fibres, short stem and long stem.

Any type, style and/ or variety of tobacco may be treated. Examples of tobacco which may be used include, but are not limited to, Virginia, Burley, Oriental, Co mum, Amarelinho and Maryland tobaccos, and blends of any of these types. The skilled person will be aware that the treatment of different types, styles and/ or varieties will result in tobacco with different organoleptic properties.

The tobacco or other plant-derived material may be pre-treated according to known practices. The tobacco material to be treated may comprise and/or consist of post-curing tobacco. As used herein, the term ‘post-curing tobacco’ refers to tobacco that has been cured but has not undergone any further treatment process to alter the taste and/ or aroma of the tobacco material. The post-curing tobacco may have been blended with other styles, varieties and/or types. Post-curing tobacco does not comprise or consist of cut rag tobacco.

Alternatively or in addition, the tobacco material to be treated may comprise and/ or consist of tobacco that has been processed to a stage that takes place at a Green Leaf Threshing (GLT) plant. This may comprise tobacco that has been re-graded, green-leaf blended, conditioned, de-stemmed or threshed (or not in the case of whole leaf), dried and/ or packed.

In some embodiments, the tobacco material comprises lamina tobacco material. For example, the tobacco may comprise between about 70% and 100% lamina material. In some embodiments, the tobacco material comprises up to about 50%, up to about 60%, up to about 70%, up to about 80%, up to about 90%, or up to about 95% lamina tobacco material. In some embodiments, the tobacco material comprises up to 100% lamina tobacco material. In other words, the tobacco material may comprise substantially entirely or entirely lamina tobacco material.

Alternatively or in addition, the tobacco material may comprise at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or at least about 95% lamina tobacco material.

When the tobacco material comprises lamina tobacco material, the lamina may be in whole leaf form. In some embodiments, the tobacco material comprises cured whole leaf tobacco. In some embodiments, the tobacco material substantially comprises cured whole leaf tobacco. In some embodiments, the tobacco material consists essentially of cured whole leaf tobacco. In some embodiments, the tobacco material does not comprise cut rag tobacco. In some embodiments, the tobacco is cut lamina and/or expanded tobacco (such as dry ice expanded tobacco, DIET).

In some embodiments, the tobacco material comprises stem tobacco material. The tobacco may comprise between about 90% and 100% stem material. The tobacco material may comprise up to about 50%, up to about 60%, up to about 70%, up to about 80%, up to about 90%, or up to about 95% stem tobacco material. In some embodiments, the tobacco material comprises up to 100% stem tobacco material. In other words, the tobacco material may comprise substantially entirely or entirely stem tobacco material.

Alternatively or in addition, the tobacco material may comprise at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or at least about 95% stem tobacco material.

In some embodiments, the tobacco material comprises a blend of lamina and stem.

In some embodiments, the tobacco material comprises expanded tobacco, such as dry ice expanded tobacco (DIET).

The intermittent contact of the plant-derived material with the heated surface results in a repetitive short term exposure to intense heat. In some embodiments, this intermittent contact maybe achieved by agitating the plant-derived material. The temperature of the heated surface, and thus the temperature to which the plant-derived material is exposed, is significantly higher than about ioo°C, and, in some embodiments, is at least about 15O°C. Therefore, the intermittent contact is important in order to ensure that the plant-derived material is not burnt as a result of prolonged continuous exposure to surfaces at such high temperatures. In some embodiments, the intermittent contact of the plant-derived material with the heated surface results in the plant-derived material being seared or scorched. This is as a result of the exposure to a sudden and intense heat. This has a drying effect but also results in a treatment of the plant-derived material that is different to the gentle drying processes known in the prior art.

In some embodiments, the oxygen levels surrounding the plant-derived material during treatment may be reduced. This may have the effect of reducing the risk of ‘hot spots’ forming as a result of the exposure to the heated surface, and to reduce the risk of the plant-derived material burning. Such reduction in the oxygen level can therefore allow the plant-derived material to be treated at higher temperatures than in the prior art processes and apparatus. In some embodiments, the oxygen level is reduced by the application of steam.

Without wishing to be bound by any particular theory or theories, it is hypothesised that the process can be split into two phases. During the first phase, the plant-derived material is being dried as a result of the exposure to the heat which drives off volatile components, including water, in a kind of steam distillation of the plant-derived material. During the second phase, an effect which is referred to herein as “searing” occurs. It is during this second phase that the main chemical changes in the plant- derived material appear to occur. These chemical changes may result in further volatiles being released by the material.

It is hypothesised that the brief contact of the plant-derived material, and especially of tobacco material, with the heated surface, and the local searing of the tobacco, may lead to an increase in the products of the Maillard and caramelisation reactions, many of which are known to contribute to desirable organoleptic properties. This is discussed in more detail in the Example below. The Maillard reaction is a chemical reaction between amino acids and sugars, and these are present in the starting material, but are seen in reduced quantities in the treated material. It is a non-enzymatic reaction which typically occurs at temperatures of from about 140 to 165°C. In addition to the pleasing effects of the Maillard reaction products on the organoleptic properties, the reaction is also responsible for the browning of materials. It has been observed that the material treated in accordance with embodiments of the present invention has a darker brown colour than the starting material.

In some embodiments, the process of treating plant-derived material as described herein produces a treated material with an enhanced flavour profile or enhanced aroma properties (compared to the flavour profile of plant-derived material which has not been treated or which has been treated using only conventional processes). As used herein, the terms “enhance” or “enhancement” are used in the context of the flavour or aroma properties to mean that there is an improvement or refinement in the taste or aroma, or in the quality of the taste or aroma. This may, but does not necessarily, include a strengthening of the taste or aroma. In embodiments where the collected volatile components are added to the treated material, the taste and aroma characteristics may be strengthened. Where the collected volatile components are concentrated or include additional components, the taste or aroma characteristics of the treated material may be strengthened.

In the case of tobacco material and some other plant-derived materials, the treatment may improve the organoleptic properties of the treated material. Reference made herein to the organoleptic properties of the tobacco material maybe reference to the organoleptic properties of the tobacco material itself, for example when used orally by a consumer. Additionally, or alternatively, the reference is to the organoleptic properties of smoke produced by combusting the tobacco material, or of vapour produced by heating the tobacco material. In some embodiments, the treated tobacco material affords a tobacco product including said tobacco material with desirable organoleptic properties when said product is used or consumed.

In some embodiments, the temperature of the heated surface is in the range of from about too °C to about 3OO°C. In some embodiments the temperature is at least about 1O5°C, no°C, 115°C, 12O°C, 125°C, 13O°C, 135°C, 14O°C, 145°C, 15O°C, 155°C, i6o°C, 165°C, 17O°C, 175°C, I8O°C, I85°C, 19O°C, 195°C or at least about 200°C. In some embodiments the temperature of the heated surface is up to about 295°C, 29O°C, 285°C, 28O°C, 275°C, 27O°C, 265^OC, 26O°C, 255°C, 25O°C, 245°C, 24O°C, 235°C, 23O°C, 225°C, 220°C, 215°C, 2io°C, 2O5°C or up to about 200°C. In some embodiments, the heated surface has a temperature of from at least about 12O°C to about 25O°C, or from at least about 15O°C to about 3OO°C.

When discussing the temperature of the heated surface, reference is made herein to the temperature prior to contact with the plant-derived material. This is because the contact with the plant-derived material and the drying process can lead to cooling of the heated surface. Therefore, the exact temperature of the heated surface during the drying process will depend on how much “drying work” is done. For example, in the initial stages where water is being evaporated from the plant-derived material, a greater amount of energy will be utilised, thus leading to greater cooling of the heated surface.

It is therefore the temperature of the heated surface prior to contact with the plant- derived material that can be readily and accurately determined.

In some embodiments, the temperature of the heated surface is controlled to minimise significant changes during the treatment process. For example, a feedback mechanism maybe used to ensure that the temperature is maintained within an acceptable range, heating the surface when the temperature drops as a result of the treatment of plant- derived material.

In some embodiments, it is appropriate to adjust the temperature of the heated surface according to the type of plant-derived material being treated. One reason why this is appropriate is that the different plant-derived materials have different starting moisture contents and so treatment will involve removing different amounts of moisture and volatiles. Also, the different plant-derived materials have different physical characteristics. For example, leaf is a more fragile structure whilst wood is more dense and robust.

In some embodiments, the heated surface is metal, such as stainless steel, or any other appropriate steel and metal types with sufficient heat transfer characteristics. In other embodiments, the heated surface is made from any material with sufficient heat transfer characteristics that can be heated to the temperatures used in the methods described herein. For example, ceramic surfaces maybe used.

The heated surface may, for example, be heated indirectly by a heating medium, such as a heating medium selected from the group consisting of oils, water or steam. In some embodiments, thermal oils are the preferred heating medium. Alternatively or in addition, the heated surface may be heated directly. In some embodiments, the heated surface is heated by electricity.

In some embodiments, the heated surface has a temperature prior to contact with the plant-derived material in the range of from about 17O°C to about 19O°C for treating more fragile materials, such as leaf. In some embodiments, the heated surface has a temperature prior to contact with the plant-derived material of above 200°C for treating more robust materials, such as wood, and optionally in the range of from about 220°C to about 25O°C.

When the plant-derived material is intermittently and repeatedly contacted with the heated surface, this will heat the plant-derived material. Given the high temperatures of the heated surface, the temperature of the plant-derived is raised significantly. In some embodiments, as a result of the treatment method, the temperature of the plant- derived material is raised to a peak temperature in the range of from about 120 °C to about 23O°C. In some embodiments the peak temperature of the plant-derived material is at least about 125°C, 13O°C, 135°C, 14O°C, 145°C, 15O°C, 155°C, i6o°C, 165°C, 17O°C, 175°C, I8O°C, I85°C, 19O°C, 195°C, 200°C, 2O5°C, 2io°C, 215°C or at least about 220°C. In some embodiments the peak temperature of the plant-derived material is up to about 225°C, 220°C, 215°C, 2io°C, 195°C, 19O°C, 185°C, i8o°C, 175°C, 17O°C, 165°C, I6O°C, 155°C, 15O°C, 145°C, 14O°C, 135°C, 13O°C or up to about 125°C.

The temperature of the plant-derived material may be measured with suitable measurement devices, such as infrared measurement or electrical resistance thermometers. In some embodiments, the plant-derived material is heated under an inert atmosphere.

In some embodiments, an inert gas, such as nitrogen, saturated steam, carbon dioxide or mixtures thereof, is added in the apparatus to control the oxygen level and thereby steer desired chemical reaction during processing.

In other embodiments, the plant-derived material is heated under an oxidative atmosphere.

In some embodiments, the heat treatment of the plant-derived material has a drying effect and the moisture content of said plant-derived material is reduced. For example, the treated plant-derived material may have a moisture content of from 0% to about 10% oven volatiles (OV). In other words, the treated plant-derived material has a moisture content of no greater than about 10% OV. In some embodiments, the moisture content of the treated plant-derived material is no greater than 9.5%, 9%, 8.5%, 8%, 7.5%, 7%, 6.5%, 6%, 5.5%, 5%, 4.5%, 4%, 3-5%, 3%, 2.5%, 2%, 1.5%, 1% or no greater than about 0.5% OV. In some embodiments, the treated plant-derived material has a moisture content of no greater than about 2% OV.

In some embodiments, the starting material (before heat treatment) has a moisture content of at least about 5% OV. In some embodiments, the moisture content of the plant-derived starting material is at least about 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, or at least about 24% OV. In some embodiments, the moisture content of the plant-derived starting material is no greater than about 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%? 12%, 11%, 10%, 9%, 8%, 7%, or no greater than about 6% OV. In some embodiments, the plant-derived starting material has a moisture content of from at least about 5% to about 25% OV, or from at least about 5% to about 20% OV. In some embodiments, the plant-derived starting material has a moisture content of from at least about 12% to about 16% OV. Thus, in some embodiments, the starting material to be used in the process of the present invention has a moisture content that means that the plant-derived material is already dried. In some embodiments, the primary purpose of the treatment of this plant-derived is not to further reduce the moisture content of the plant-derived starting material, but to achieve the physical and chemical changes to the plant-derived material as a result of the searing caused by the brief contact with the high temperature of the heated surface. In some embodiments, this effect is achieved without burning or substantially without burning the plant-derived material as a result of the contact with the heated surface. In some embodiments, the moisture content of the plant-derived material may be adjusted during the treatment process by adding moisture. Moisture may be introduced to the plant-derived material during treatment in the form of water or steam. This may be sprayed onto the plant-derived material whilst it is being intermittently contacted with a heated surface.

In some embodiments, this introduction of moisture increases the moisture content of the plant-derived material by 2% to 5% OV. In some embodiments, the moisture is introduced at different positions throughout the process. As this moisturising of the plant-derived material is occurring during the treatment, the moisture content will be reduced again as the moisturized plant-derived material contacts the heated surface. The method may include multiple additions of moisture, so that the moisture content of the plant-derived material fluctuates up and down repeatedly during the treatment.

In some embodiments, the treatment involves repeatedly and intermittently contacting plant-derived material with one or more heated surfaces over a treatment period of from at least about 1 minute to about 15 minutes. In some embodiments, the period for which the plant-derived material is intermittently contacted with the heated surface is at least about 1 minute, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or at least about 14 minutes. In some embodiments, the period for which the plant-derived material is intermittently contacted with the heated surface is up to about 14 minutes, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3 or up to about 2 minutes. In some embodiments, the plant-derived material is contacted with the heated surface for a total period of from at least about 2 minutes to about 10 minutes, or from at least about 2.5 minutes to about 5 minutes.

The intermittent contact may involve the plant-derived material being in direct and continuous contact with a heated surface for a period of up to about 5 seconds. In some embodiments, the average length of the period(s) of direct and continuous contact is from about 0.1 seconds to about 3 seconds.

Reference herein to intermittent contact of the plant-derived material with the heated surface means that any part of the plant-derived material is only temporarily in direct contact with the heated surface. In some embodiments, this means that the plant- derived material is moved relative to the heated surface, to prevent the plant-derived material coming to rest in a particular position in contact with the heated surface for too long, and/or ensuring that the same part of the plant-derived material does not remain in direct contact with the heated surface for too long. Extended contact of the same part of the plant-derived material with the heated surface will lead to burning which will have a detrimental effect on the physical and chemical properties of the plant-derived material and may result in undesirable volatile components being created and collected.

In some embodiments, the methods include agitating the plant-derived material as it is treated. In some embodiments, an apparatus is provided which includes a means for agitating the plant-derived material.

In some embodiments, it is preferred that the plant-derived material is agitated by tumbling the plant-derived material. This may, for example, be achieved by picking up the plant-derived material being treated, lifting it and then allowing it to fall, creating a tumbling movement of the plant-derived material.

In some embodiments, the movement of the plant-derived material may be created by a mechanism such as one comprising one or more screws. In such an arrangement, the screw includes a helical surface encircling a shaft which is rotated, wherein the helical surface is configured to pick up plant-derived material. As the shaft rotates, the helical surface scoops up at least a portion of the plant-derived material being treated. This plant-derived material is then carried and lifted by the rotating helical surface until the rotation of the screw allows it to fall (under gravity) away from the screw. In some embodiments, the screw or screws may be positioned to move plant-derived material through a treatment chamber, as well as to agitate the plant-derived material. Such an arrangement allows plant-derived material to be treated in a continuous manner. In some embodiments, the helical surface and/ or the shaft of the screw may be heated to provide the heated surface used to treat the plant-derived material. Where two screws are used to move the plant-derived material, these screws maybe positioned in parallel and are positioned to contact and move all of the plant-derived material to be treated. In some embodiments, the screw may include additional paddles to assist the picking up and carrying of the plant-derived material. These paddles may also be heated surfaces used to treat the plant-derived material.

In other embodiments, the plant-derived material may be agitated in a rotating drum. The inside of the drum may be the chamber within which the plant-derived material is treated. The plant-derived material lies inside the drum and may be picked up from the bottom of the drum and lifted as the drum rotates. The picking up of the plant-derived material may be facilitated by the drum having an inner surface which is capable of maintaining contact with the plant-derived material, for example by virtue of having a rough surface or protrusions, such as paddles, which scoop up the plant-derived material. As the drum rotates, the plant-derived material in contact with the drum’s inner surface is lifted until the rotation of the drum allows it to fall (under gravity) away from the drum wall and back to the bottom of the drum. This can create a tumbling and mixing of the plant-derived material. The irregularities on the inner surface of the drum may help to control how long the plant-derived material remains in contact with the drum wall. The irregularities may also be used to ensure that the plant-derived material does not remain in contact with the drum wall as it falls (sliding back down the wall), thereby enhancing the tumbling movement of the plant-derived material. The speed of rotation will also affect the tumbling motion, as will the orientation of the axis of rotation. In some embodiments, the inner surface of the drum may be the heated surface used to treat the plant-derived material. The drum may rotate about a horizontal or substantially horizontal axis. In other embodiments, rotation about an inclined axis may allow the plant-derived material to maintain contact with the drum inner surface for longer and will also move the plant-derived material in a longitudinal direction. Longitudinal movement of the plant-derived material as a result of the rotation of the drum may additionally or alternatively be achieved by having appropriately positioned and/or angled protrusions on the inner surface of the drum.

In other embodiments, the plant-derived material may be agitated by air flow. For example, plant-derived material is picked up and moved by air flow.

In some embodiments, the plant-derived material is not agitated by the flow of air through the device. In some embodiments, the apparatus for treating plant-derived material does not include means for pumping of air through the apparatus to agitate the plant-derived material.

In some embodiments, the method is a continuous method. For example, plant- derived starting material is continuously fed into the apparatus, is treated and then leaves the apparatus as treated plant-derived material. In alternative embodiments, the method is a batch process, in which a batch of plant-derived starting material is fed into the apparatus, processed to produce a batch of treated plant-derived material which is removed before a new batch is processed.

In some embodiments, after treatment, the treated plant-derived material may be conditioned. For example, in some embodiments, moisture may be added to the treated plant-derived material. In some embodiments, this is achieved by exposing the treated plant-derived material to water and/or steam. In some embodiments, the moisture content is increased to above about 10% OV, or from about 10 to about 20% OV.

In some embodiments, after treatment, the treated plant-derived material may be cooled. In some embodiments, this may involve the use of a cooling belt, where ambient air or cooled air is passing through a layer of processed plant-derived material.

In other embodiments, the plant-derived material may be cooled by any one or more of the following steps: resting, passing through a cooling cylinder, air lifting, and cooling via fluidised bed, etc.

The flow charts shown in Figures la and lb summarise exemplary processes for treating plant-derived material. The plant-derived starting material may optionally have undergone pre-treatment. Where the material is tobacco material the pre-treatment maybe, for example, the conventional primary manufacturing (PMD) processes, which include, for example, one or more of: conditioning of raw stem, subsequent rolling, cutting and expansion/drying and mixing. In some embodiments, the pre-treatment of lamina may include slicing, conditioning, casing (optional), cutting, drying, cooling and mixing.

The moisture content of the plant-derived starting material may be in the region of 14.5% OV, for example. The starting material is fed into the treatment apparatus where it is treated by intermittent contact with a heated surface. During the treatment, the plant-derived material is agitated to create the intermittent contact with the heated surface. The treatment results in a reduction in the moisture content to as low as 0% OV. Once the treatment of the plant-derived material by intermittent contact with the heated surface has been completed, the treated plant-derived material may optionally undergo conditioning. In the illustrated process, this involves adding water or steam to the treated plant-derived material to increase its moisture content to in the region of 14-5% OV, for example.

The process parameters are sufficiently gentle for the treated plant-derived material to maintain some or all of its physical properties. For example, the plant-derived material remains sufficiently intact following treatment to allow handling and/or processing. Where the material is tobacco material, this may mean that the treated tobacco is suitable for incorporation into a tobacco-containing product, such as a smoking article. This enables the treated plant-derived material to undergo handling in accordance with standard processes, in the same manner as conventional plant-derived material which has not undergone the processing as described herein.

A specific illustrative example of an apparatus suitable for carrying out embodiments of the methods described herein is shown in Figures 2 and 3. In this embodiment, the apparatus 1 includes two screws 2 in a dual screw arrangement. It is believed that this arrangement means that any part of the plant-derived material may only be in contact with the heated surface for a period in the order of seconds at any one time as a result of the agitation or turbulence generated by the screws in the apparatus.

The plant-derived material 8 is treated in the apparatus 1 including conveying screws 2 which include a helical surface 3 and shaft 4, wherein the screws 2 move the plant- derived material through the treatment chamber 7 of the apparatus 1. The screws 2 are rotated and the shafts 4 of the screws 2 are rotated by a drive mechanism 11, including a motor.

The plant-derived starting material enters the treatment chamber 7 via the inlet 5, whereupon the rotating screws pick up the plant-derived material, tumbling it and moving it through the treatment chamber towards the outlet 6.

More specifically, a mass of plant-derived material 8 enters the treatment chamber 7 through the inlet 5. As the screw 2 rotates, the plant-derived material is picked up, with some of the plant-derived material coming into direct contact with the helical surface 3 and possibly also the shaft 4 of the screw 2. The plant-derived material is dragged along, lifted and dropped by the screw 2, so that it is both conveyed through the treatment chamber 7 and tumbled. Plant-derived material which has been lifted as a result of the rotating screw(s) subsequently falls into the mass of plant-derived material 8 being conveyed through the chamber 7, and the mass is constantly being mixed and moved, resulting in different parts of the mass coming into contact with the screws 2 at different times.

In the illustrated embodiment, the surfaces of the screws 2 are heated and they contact the plant-derived material intermittently, in accordance with the methods for treating the material.

The screws 2 have metal surfaces which are heated by a heating medium which is fed into the apparatus 1 via heating medium pipes 10. In the illustrated embodiment, the heating medium is thermal oil which is heated to a desired temperature.

Only part of the plant-derived material being treated will be in direct contact with a heated surface at any one time. As the plant-derived material is conveyed, it will be tumbled and mixed, providing agitation or turbulence of the plant-derived material and the required intermittent contact with the heated surface(s). The individual contact time is believed to be no more than a few seconds at a time. The dynamics of the plant- derived material flow ensures a homogenous treatment of the entire mass, induced by the shape of the screws. In the illustrated apparatus, the treatment chamber may be divided into different temperature zones 9. These represent different sections of the screws and these may be separately heated. Therefore, the apparatus can be configured to have surfaces that are heated to varying temperatures. In some embodiments, it maybe desirable to control the drying and the searing phases of the treatment by exposing the plant-derived material to heated surfaces having different temperatures at different points in the treatment process.

An extract comprising volatile components collected by a method as disclosed herein may be incorporated into a tobacco industry product. In some embodiments, the extract maybe applied to a substrate for incorporation into the product. A composition may be provided, comprising a substrate and at least one volatile component collected by a method as disclosed herein. Such a composition may also be used in a tobacco industry product. In some embodiments, the substrate may comprise a treated plant- derived material, such as a plant-derived material treated according to a method as disclosed herein.

A tobacco industry product refers to any item made in, or sold by the tobacco industry, typically including a) cigarettes, cigarillos, cigars, tobacco for pipes or for roll-your-own cigarettes, (whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes); b) non-smoking products incorporating tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes such as snuff, snus, hard tobacco, and heat-not-burn (HnB) products; and c) other nicotine-delivery systems such as inhalers, aerosol generation devices including e-cigarettes, lozenges and gum. This list is not intended to be exclusive, but merely illustrates a range of products which are made and sold in the tobacco industry.

The extracts, compositions and treated plant-derived material disclosed herein maybe incorporated into a smoking article. As used herein, the term ‘smoking article’ includes smokeable products such as cigarettes, cigars and cigarillos whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes and also heat-not-burn products. In some embodiments, the extracts, compositions and/ or treated plant-derived material may be incorporated into smoking articles in combination with the tobacco included in such products. Alternatively, the extracts, compositions and/or treated plant-derived material may replace the tobacco included in such products. In some embodiments, an extract is applied to tobacco or other materials used to generate an aerosol in a smoking article. The extracts, compositions and treated plant-derived material, such as treated tobacco material, maybe included in roll-your-own tobacco and/or pipe tobacco.

The extracts, compositions and treated plant-derived material, such as treated tobacco material, may be incorporated into a smokeless tobacco product. ‘Smokeless tobacco product’ is used herein to denote any tobacco product which is not intended for combustion. This includes any smokeless tobacco product designed to be placed in the oral cavity of a user for a limited period of time, during which there is contact between the user’s saliva and the product. In some embodiments, the extracts, compositions and/ or treated plant-derived material may be incorporated into smoking articles in combination with the tobacco included in such products. Alternatively, the extracts, compositions and/or treated plant-derived material may replace the tobacco included in such products. The extracts, compositions and treated plant-derived material may be blended with one or more tobacco materials before being incorporated into a smoking article or smokeless tobacco product or used for roll-your-own or pipe tobacco.

Where both an extract generated from the trapped volatile components and the treated plant-derived material are incorporated into the same tobacco industry product, they maybe introduced separately or in combination. If introduced separately, the extract and the treated plant-derived material may be incorporated into different parts of the product. In some embodiments, the extract (containing volatile components released from the plant-derived material) may be included in components for tobacco industry products such as filters, smoking article mouthpieces, consumable components for use with THP devices, and e-liquids or e-liquid reservoirs, etc. An extract in the form of a liquid may, for instance, be encapsulated to produce flavours to be released on demand. In some embodiments, the extract is encapsulated in spherical capsules or other forms of capsule, and the capsules may be incorporated within any tobacco industry product, such as cigarette filters or mouthpieces for THP products.

Example Methods according to the invention were carried out on tobacco material, namely Cut Expanded Stem (CES) having a (starting) moisture content of 14.5% OV. A mass of tobacco particles is used as the infeed material and is treated by the methods using an apparatus as shown in Figures 2 and 3.

The process can be described as exposing the particles of tobacco (stem) to hot metal surfaces for seconds, before the individual particles ‘fall’ back into the overall mass of tobacco material being treated.

The residence time of the mass of tobacco particles within the apparatus (and therefore the treatment period) is between 1 and 5 minutes. The heated metal surfaces are heated by a jacket which is heated as well as the screws, bringing the heated surfaces to the desired temperature, via synthetic oil.

Three different temperature scenarios were tested, namely: 23O°C, 24O°C and 25O°C.

This means that the heating medium (oil) temperature used to heat the heated surfaces was set to these temperatures. This leads to different temperatures in different parts of the apparatus.

The figures and parameters provided in Table 1 below reflect the individual temperatures throughout the treatment process when the heating medium (oil) temperature is set to 25O°C.

Table 1

In the experiments, the tobacco was treated by processes involving residence times (or treatment periods) of around 2 to 3 minutes and a rate of throughput of tobacco material of around 50 kg/h of cut stem having a moisture content of approximately 14-5% OV.

The process can be split into two different phases. Throughout the first phase, the stem particles are losing their moisture. At a heating medium (oil) temperature of 25O°C the stems have a moisture content of 0% OV after approximately 1 minute. The second phase occurs for the remainder of the treatment and the effect has been termed “searing”. Throughout this second phase the main changes are happening.

Table 2 compares the chemical make up of untreated tobacco with that which is treated in an apparatus which is heated to different heating medium temperatures.

Table 2

As may be seen from Table 2, the nicotine content of the treated tobacco is reduced by more than 50% at a heating medium temperature of 25O°C, total sugars and ammonia by more than 80%. The increase in chloride content reflects a loss of overall organic matter and the significant increase in fill value indicates the changes in the cell structure of the treated tobacco.

The data shows that the tobacco material undergoes significant changes throughout processing.

It has been shown that these changes translate into changes in the organoleptic properties of the processed material, which are discernible in the smoke produced when the treated tobacco is combusted, for example in a cigarette. The organoleptic properties of this smoke are described in very positive terms by expert smokers, indicating that the tobacco treatment leads to the production of the treated material with beneficial and desirable properties. This is both in terms of the reduction in some undesirable tobacco constituents, and improved organoleptic properties. In addition, these changes indicate some of the volatile components that will be collected in accordance with the processes disclosed herein.

One of these components will be nicotine. Nicotine is volatilised during the heat treatment and will be collected.

Further components will include the volatile flavour and aroma compounds that are found in tobacco material. These volatile components will be volatilised during the heat treatment. Further components may include volatile products of the Maillard and caramelisation reactions which have been observed.

In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration various embodiments in which the claimed inventions may be practiced and provide for superior methods, apparatus and treated tobacco materials and extracts therefrom. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and teach the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future.

Claims

- 28 - Claims

1. A method comprising: intermittently contacting plant-derived material with a heated surface to locally heat the material upon said contact; and collecting the volatile components released from the plant-derived material.

2. A method as claimed in claim 1, wherein the volatile components are collected in a gas flow.

3. A method as claimed in either claim 1 or claim 2, wherein the volatile components are trapped and/or extracted.

4. A method as claimed in any one of the preceding claims, wherein the plant- derived material is selected from the group consisting of: tobacco, wood, tea, coffee, cocoa, herbs and spices.

5. A method as claimed in any one of the preceding claim, wherein the plant- derived material is freshly harvested, dried, cured or roasted.

6. A method as claimed in any one of the preceding claims, wherein the plant- derived material is agitated so that it is intermittently in contact with the heated surface.

7. A method as claimed in any one of the preceding claims, wherein the heated surface has a temperature of from at least about ioo°C to about 3OO°C prior to contact with the plant-derived material.

8. A method as claimed in claim 7, wherein the heated surface has a temperature of from at least about 12O°C to about 25O°C prior to contact with the plant-derived material, or from at least about 15O°C to about 3OO°C prior to contact with the plant- derived material.

9. A method as claimed in any one of the preceding claims, wherein contacting the plant-derived material with the heated surface heats the plant-derived material to a peak temperature of from about 12O°C to about 23O°C.

10. A method as claimed in any one of the preceding claims, wherein the plant- derived material has a moisture content of at least about 5% OV prior to contact with the heated surface .

11. A method as claimed in claim 10, wherein the plant-derived material has a moisture content of from about 5 to about 25% OV prior to contact with the heated surface, or a moisture content of from about 12 to about 16% OV prior to contact with the heated surface.

12. A method as claimed in any one of the preceding claims, wherein plant-derived material is intermittently contacted with the heated surface for a period of from at least about 1 minute to about 180 minutes.

13. A method as claimed in any one of the preceding claims, wherein the method is a continuous process.

14. A method as claimed in any one of claims 1 to 12, wherein the method is a batch process.

15. A method as claimed in any one of the preceding claims, wherein the plant- derived material is tobacco material.

16. A method as claimed in claim 15, wherein the tobacco material comprises one or more selected from the group consisting of: cut stem, cut lamina, leaf lamina, small lamina, stem fibres, short stem and long stem.

17. A method as claimed in any one of the preceding claims, wherein the method further comprises applying at least one of the collected volatile components to a substrate.

18. A method as claimed in claim 17, wherein the substrate comprises the plant- derived material treated by intermittent contact with the heated surface.

19. An apparatus comprising a heated surface provided to intermittently contact plant-derived material and a means for collecting the volatile components released.

20. An apparatus as claimed in claim 19, further comprising a means for agitating the plant-derived material.

21. An apparatus as claimed in claim 20, wherein the means for agitating the plant- derived material comprises at least one of the group consisting of: a screw mechanism; a dual screw mechanism; air flow; and a rotating drum.

22. An apparatus as claimed in any one of claims 19 to 21, wherein the heated surface has a temperature of from at least about ioo°C to about 3OO°C prior to contact with the plant-derived material.

23. An apparatus as claimed in claim 22, wherein the heated surface has a temperature of from at least about 12O°C to about 25O°C prior to contact with the plant-derived material, or from at least about 15O°C to about 3OO°C prior to contact with the plant-derived material.

24. An apparatus as claimed in any one of claims 19 to 23, wherein the heated surface is heated by a heating medium, the heating medium being water, oil, steam, electricity, or combinations thereof.

25. An extract comprising volatile components collected by the method as claimed in any one of claims 1 to 18.

26. A composition comprising a substrate and at least one of the collected volatile components.

27. A composition as claimed in claim 26, wherein the substrate comprises a treated plant-derived material obtained or obtainable by a method as claimed in any one of claims 1 to 18.

28. A tobacco industry product comprising an extract as claimed in claim 25, or a composition as claimed in claim 26 or claim 27.

29. A tobacco industry product as claimed in claim 28, wherein the extract is provided in a consumable component of a smoking article.

30. A tobacco industry product as claimed in claim 28 or 29, wherein the extract is provided in an aerosol generating component of a tobacco heating device.

31. A tobacco industry product as claimed in claim 28, wherein the extract is provided as a liquid for use in an aerosol generation device.

32. Use of a collected volatile component obtained or obtainable by a method as claimed in any one of claims 1 to 18 for the manufacture of a tobacco industry product.