EP4651738A1

EP4651738A1 - Tobacco treatment

Info

Publication number: EP4651738A1
Application number: EP24700786.7A
Authority: EP
Inventors: Tamas MARSI; Rodrigo DORFEY; Pamela LIMA; Constanza GALLO; Jason SYMONDS; Agustin PIAGGIO; Batir ABDURAHMANOV
Original assignee: Nicoventures Trading Ltd
Current assignee: Nicoventures Trading Ltd
Priority date: 2023-01-16
Filing date: 2024-01-16
Publication date: 2025-11-26
Also published as: WO2024153622A1; JP2026503258A; GB202300605D0; TW202432006A; KR20250136825A; CN120751936A

Abstract

The invention provides a process for producing dry ice expanded tobacco and treated dry ice expanded tobacco obtainable by this process. The invention also provides a non-combustible aerosol provision system or an aerosol-free delivery system comprising the treated dry ice expanded tobacco. The invention also provides an aerosol-generating material and consumable for use in a non-combustible aerosol provision system comprising the treated dry ice expanded tobacco.

Description

Tobacco Treatment

Field

The present invention relates to a process and in particular a process for the treatment of dry ice expanded tobacco (DIET).

Background

After harvesting, tobacco material can be cured to prepare the leaf for consumption. The tobacco material may be further treated, for example by aging or fermentation, to enhance the organoleptic properties of the tobacco. However, these processes can be lengthy and the quality of the resulting tobacco material can be variable. Treatments to enhance or add flavours and aromas to the tobacco material at a later stage of tobacco processing often involve the addition of one or more additive(s) to the tobacco and can require additional processing steps and equipment, which can be costly and timeconsuming.

Summary

According to a first aspect of the invention, a process is provided for treating dry ice expanded tobacco (DIET) which has been enclosed within a moisture-retaining material, the process comprising exposing the tobacco to an ambient processing temperature of above 45°C, wherein the tobacco has a packing density of 60 to 160 kg/m³ at the start of the process and has a moisture content of between about 10% and 23% before and during treatment. The process may be used to produce a tobacco with desirable organoleptic properties.

The DIET may optionally be suitable for use in a non-combustible aerosol delivery system or in an aerosol-free delivery system. Thus, according to a second aspect of the invention, a process is provided for producing DIET for use in a non-combustible aerosol delivery system or an aerosol-free delivery system, the process comprising exposing DIET which has been enclosed within a moisture-retaining material to an ambient processing temperature of above 45°C, wherein the tobacco has a packing density of 60 to 160 kg/m³ at the start of the process and has a moisture content of between about 10% and 23% before and during treatment. The process may be used to produce a tobacco with desirable organoleptic properties. Features of aspects and embodiments described herein are applicable to both the first and second aspects of the invention.

The processes of the first or second aspect may comprise enclosing or securing the tobacco within the moisture-retaining material before exposing the tobacco to the specified conditions.

According to a third aspect, treated dry ice expanded tobacco is provided which is obtainable by the process of the first or second aspects.

A fourth aspect provides treated dry ice expanded tobacco produced according to (or obtained by) the process of the first or second aspects.

A fifth aspect provides an aerosol-generating material for use in a non-combustible aerosol provision system, the aerosol-generating material comprising the treated dry ice expanded tobacco material of the third or the fourth aspects.

A sixth aspect provides a consumable for use in a non-combustible aerosol provision system, the consumable comprising the treated dry ice expanded tobacco of the third or the fourth aspects or the aerosol-generating material of the fifth aspect.

A further aspect provides a non-combustible aerosol provision system comprising the treated dry ice expanded tobacco material of the third or fourth aspects, the aerosol-generating material of the fifth aspect, or the consumable of the sixth aspect. The processes described herein may also further comprise incorporating treated dry ice expanded tobacco material into a non-combustible aerosol provision system, or an aerosol-generating material or consumable therefor.

The processes described herein may further comprise incorporating the treated dry ice expanded tobacco material into a blend. The blend may be suitable for use in a non- combustible aerosol provision system, or an aerosol-generating material or consumable therefor. Suitable amounts of the treated dry ice expanded tobacco material in the blend are set out below. A further aspect provides use of the treated dry ice expanded tobacco material of the third or fourth aspects for the manufacture of: an aerosol-generating material for use in a non-combustible aerosol provision system or a consumable for use in a non-combustible aerosol provision system; or for the manufacture of an aerosol-free delivery system.

A further aspect provides an aerosol-free delivery system comprising the treated dry ice expanded tobacco material of the third or fourth aspects. The processes described herein may also further comprise incorporating the dry ice expanded tobacco material into an aerosol-free delivery system.

A further aspect provides a tobacco extract manufactured from the DIET of the third or fourth aspect. A further aspect provides a nicotine delivery system comprising such an extract.

Brief Description of the Figures

For the purposes of illustration only, embodiments of the invention are described below with reference to the accompanying drawings, in which:

Figure 1 is a process flow diagram for the manufacture of dry ice expanded tobacco;

Figure 2 shows a cross section through a tobacco leaf before (top) and after (bottom) dry ice expansion. The scale bar (centre, bottom) of each image corresponds to a distance of 100 microns.

Figure 3 is a process flow diagram for the manufacture of expanded stem tobacco.

Figure 4 is a photograph in which treated DIET is being passed through a set of doffers.

Detailed Description

Expanded tobacco material is tobacco material that has been subjected to an expansion process. Expansion involves increasing the volume of the cell structure of the tobacco material which may result in an increase in the area and spacing between any fibres present in the tobacco material. After being subjected to the expansion process, the tobacco material has a higher fill value, but lower density, than the tobacco material prior to the expansion process. Expanded tobacco may be blended with other types of tobacco, for example to provide consumables for non-combustible aerosol provision systems, or aerosol-free delivery systems, having a lower overall weight than convention consumables or aerosol-free delivery systems. Reducing the overall weight can provide numerous advantages, such as reduced transportation costs. Furthermore, reducing the weight may also have a positive impact on the environment because less energy may be required for transportation. In addition, consumers may prefer to carry and use a lighter-weight consumable or delivery system. Types of expanded tobacco include dry ice expanded tobacco and expanded stem. Expanded stem is formed by steam expansion of stem tobacco.

However, expanded tobacco materials may compromise the organoleptic properties of tobacco blends containing them, which may limit the amount of the expanded tobacco material that can be included in the blends whilst maintaining an acceptable taste profile.

The present invention relates to a process for the treatment of dry ice expanded tobacco (DIET). The treatment favourably changes the organoleptic properties of the DIET. The inventors have, however, found that these desirable changes in organoleptic properties are not observed when the same treatment is performed on other types of expanded tobacco. In particular, no significant change in taste profile between treated and untreated expanded stem (i.e. expanded stem tobacco before and after a treatment process as described herein) was determined by expert smokers. In contrast, a change in taste profile was found between treated and untreated DIET (i.e. DIET before and after a treatment process as described herein). That is, the inventors have surprisingly found that the process of the invention is particularly suitable for improving the organoleptic properties of DIET, whereas it is not suitable for improving the organoleptic properties of expanded stem.

The favourable change in the organoleptic properties of the DIET tobacco provided by the process herein means that the treated tobacco can be added to tobacco blends (for example for use in a non-combustible aerosol provision system or aerosol-free delivery system) in higher quantities than untreated DIET tobacco without compromising the organoleptic properties of the tobacco blends.

The inventors have also found that the high fill value of the dry ice expanded tobacco is maintained during the process of the invention. The fill value of the dry ice expanded tobacco may even increase during the process.

As used herein, the term ‘treated tobacco’ refers to tobacco that has undergone the treatment process described herein, and the term ‘untreated tobacco’ refers to tobacco that has not undergone the treatment process. The tobacco used in the process of the invention is dry ice expanded tobacco (DIET).

Tobacco undergoes a number of steps prior to consumption by the consumer. On the field the following steps are usually carried out by the farmer: seeding; transplanting; growing; harvesting; and curing.

Tobacco is generally cured after harvesting to reduce the moisture content of the tobacco, usually from around 80% to around 20% or lower. Tobacco can be cured in a number of different ways, including air-, fire-, flue- and sun-curing. During the curing period, the tobacco undergoes certain chemical changes and turns from a green colour to yellow, orange or brown. The temperature, relative humidity and packing density are carefully controlled to try to prevent houseburn and rot, which are common problems encountered during curing.

At a Green Leaf Threshing (GLT) plant the tobacco is sold by the farmer and then usually undergoes the following steps: re-grading; green-leaf blending; conditioning; stem removal by de-stemming or threshing (or not in the case of whole leaf); drying; and packing.

Usually after curing, the stem may be removed from the lamina. This may be done by threshing, in which the midribs and partially the lamina ribs are separated from the lamina by machine threshing. An alternative way to remove the stem from lamina is manually, with the so-called ‘hand stripping’ process. Alternatively, tobacco may be ‘butted’, which means that the thick part of the stem is cut, while the rest of the tobacco leaf remains integral. In addition to curing, the tobacco may be further processed to enhance its taste and aroma. Aging and fermentation are known techniques for enhancing the taste and aroma of tobacco. These processes can be applied to tobacco materials such as threshed lamina, hand-stripped lamina, butted lamina and/or whole leaf tobacco.

Aging usually takes place after the tobacco has been cured, threshed (or butted or hand-stripped) and packed. Tobaccos that undergo aging include Oriental, flue-cured and air-cured tobaccos. During aging the tobacco might be stored generally at temperatures of around 20°C to around 40°C and relative humidities present at the respective country of origin/aging or under controlled warehouse conditions for around 1 to 3 years.

It is important that the moisture content of the tobacco is kept at a relatively low level during aging, for example up to around 10-13%, as mould will form in tobacco with higher moisture content.

Fermentation is a process that is applied to particular tobaccos, including dark aircured tobacco, cured Oriental tobacco and cigar tobacco, to give the tobacco a more uniform colour and to change the aroma and taste. Fermentation is generally not applied to flue-cured and light air-cured tobacco. Fermentation is also generally not applied to DIET tobacco.

The fermentation parameters, such as the moisture content of the tobacco and the ambient conditions, vary depending on the type of tobacco that is undergoing fermentation. Generally, the fermentation moisture is either similar to the moisture content of the tobacco when it has been received from the farmer (around 16-20%), or the tobacco is conditioned to a slightly higher moisture content. Care has to be taken to avoid the production of different rots, which occur when the tobacco is fermented at a moisture content that is too high. The duration of the fermentation period can vary, ranging from several weeks to several years.

Generally, fermentation involves the treatment of tobacco in large volumes and is applied to whole leaf, with subsequent removal of the stem after process. The tobacco can be arranged into large piles, which is then turned at intervals to move the tobacco at the periphery into the centre of the pile. Alternatively, the tobacco is placed into chambers with a volume of several square meters. Treatment of such large volumes of tobacco can be cumbersome and/or time-consuming.

Significantly, fermentation relies on the activity of microorganisms to effect changes in the tobacco material and the fermentation conditions, including temperature and moisture content of the tobacco, are selected to enhance the microbiological activity during fermentation. For example, during fermentation treatment temperatures must typically be controlled within the range of 38-40 °C. In most, if not all, cases the fermentation of tobacco relies upon microorganisms already present in the tobacco material. However, suitable microorganisms could potentially be added to the tobacco material at the start of the fermentation process.

After the above treatments, generally the tobacco is transported to other locations to be further processed, for example before it is incorporated into a tobacco-containing product.

Tobacco may additionally or alternatively be treated with additives to improve or enhance the flavour and aroma of the tobacco. However, this requires additional processing steps and apparatus, making the tobacco preparation process more lengthy and often more costly. In addition, it can be desirable to have a tobacco material that has a taste and aroma that is enjoyed by consumers but has not had any additives applied to it to achieve this. This would be the case for consumers who would like a natural tobacco product that also has a pleasant flavour and/or taste, for example. Additives are generally applied in the location at which the smoking article is being produced, although the point at which additives are applied can vary.

In some embodiments, the process of treating tobacco material as described herein produces a dry ice expanded tobacco material with desirable organoleptic properties within a period of time that may be shorter than the more traditional techniques such as fermentation and aging and without the addition of flavour or aromatising additives. In some embodiments, the process of the present invention involves no fermentation or essentially no fermentation. This may be demonstrated by the presence of little or no microbial content of the tobacco material at the end of the process. Thus, in one embodiment the microbial content of the tobacco material at the end of the process is lower than the microbial content of the tobacco material at the start of the process.

In some embodiments, the process of treating dry ice expanded tobacco material as described herein produces a tobacco with an enhanced flavour profile or enhanced organoleptic properties (compared to the flavour profile of dry ice expanded tobacco which has not been treated or which has been treated using only conventional curing processes). This means that there is a reduction in off-notes or irritants, whilst retaining the taste characteristics of the tobacco as would be seen following conventional curing. As used herein, the terms “enhance” or “enhancement” are used in the context of the flavour or organoleptic properties to mean that there is an improvement or refinement in the taste or in the quality of the taste, as identified by expert smokers. This may, but does not necessarily, include a strengthening of the taste.

In some embodiments, the process of treating dry ice expanded tobacco material as described herein produces a tobacco material wherein at least one undesirable taste or flavour characteristic has been reduced. For example, dryness and irritant off-notes may be reduced.

In some embodiments, the process described herein may be used to enhance the organoleptic properties of a dry ice expanded tobacco starting material which has poor organoleptic (e.g. taste) properties. It has been found that at least one effect that the processing has on the dry ice expanded tobacco material is the removal or reduction of organoleptic factors that have a negative impact on the overall organoleptic properties of the tobacco material. In some embodiments, the process may also result in the increase of positive organoleptic properties.

In some embodiments, the process of treating dry ice expanded tobacco may be adjusted to produce a treated material with particular selected organoleptic characteristics. This may, for example, involve the adjustment of one or more of the parameters of the process.

In some embodiments, the process of treating dry ice expanded tobacco material as described herein transforms the flavour profile of the tobacco (compared to the flavour profile of tobacco which has not been treated or which has been treated using only conventional curing processes). This means that there is a significant change in the organoleptic properties of the tobacco following the processing, so that the taste characteristics of the tobacco are changed compared to those of untreated DIET tobacco. As used herein, the terms “transform” or “transformation” are used in the context of the flavour or organoleptic properties to mean that there is change from one overall taste or sensory character to another, as identified by expert smokers. This may include an improvement and/or refinement in the taste or in the quality of the taste.

In some embodiments, including those where the organoleptic properties of the tobacco starting material are transformed, the processing has the effect of not only reducing or removing organoleptic factors that have a negative effect, but also introducing or increasing organoleptic factors that have a positive effect. For example, in some embodiments, the process described herein leads to an increase in the products of the Maillard Reaction, many of which are known to contribute to desirable organoleptic properties.

Reference made herein to the organoleptic properties of the tobacco material may be 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.

The tobacco material used in the disclosure is dry ice expanded tobacco. As used herein, the term ‘tobacco material’ includes any part and any related by-product, 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.

Any type, style and/or variety of dry ice expanded tobacco may be treated. Examples of tobacco which may be used include but are not limited to Virginia, Burley, Oriental, Comum, 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. In some embodiments, the tobacco material comprises lamina tobacco material. The tobacco may comprise from about 70% to 100% by weight lamina material. For example, the tobacco may comprise from about 80% to 100% by weight lamina material, such as from about 90 to about 99% by weight lamina material.

The tobacco material may comprise up to 50%, up to 60%, up to 70%, up to 80%, up to 90%, or up to 100% by weight lamina tobacco material. In some embodiments, the tobacco material comprises up to 100% by weight lamina tobacco material. In other words, the tobacco material may comprise substantially entirely or entirely lamina tobacco material.

In particular embodiments, the tobacco material comprises, consists essentially of, or consists of, lamina tobacco, such as a lamina tobacco comprising lamina Virginia tobacco. In some cases, the lamina tobacco may be selected from Virginia or a blend of Virginia and Burley tobacco. The weight ratio of the Virginia to Burley may be from 1:10 to 10:1 , such as from 1:5 to 5:1 , 1 :2 to 2:1, 1:1.5 to 1.5:1 or 1.2:1 to 1:1.2.

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

When the tobacco material comprises lamina tobacco material, the lamina may be in whole leaf form or cut form. Typically, the tobacco material (such as lamina tobacco) is in cut form. Using cut tobacco reduces the time needed to impregnate/permeate the tobacco with liquid carbon dioxide during the dry ice expansion.

In some embodiments, the DIET material comprises stem tobacco material. The tobacco may comprise up to about 20% by weight of stem material, such as up to about 15% by weight of stem. For example, the tobacco material may comprise 1-20% by weight of stem material and 80-99% by weight of lamina tobacco, such as 5-15% by weight of stem material and 85-95% by weight of lamina material.

Pre-prepared DIET may be treated according to the process of the invention. For example, DIET is commercially available. Alternatively, the process may comprise dry ice expansion of a tobacco material to provide the DIET, and then treating the DIET as described herein.

Methods of forming DIET are known in the art. For example, dry ice expansion involves permeating (or impregnating) the tobacco with liquid carbon dioxide under pressure, for example by submerging and soaking the tobacco in liquid carbon dioxide. Excess liquid and/or gaseous carbon dioxide can be recovered for reuse, for example by draining the liquid. The process may comprise converting the liquid carbon dioxide within the tobacco into solid carbon dioxide (dry ice), for example by reducing the pressure. The carbon dioxide within the tobacco solidifies into dry ice when the system is unpressurised. This phase change may occur at the triple point pressure for CO2 (60.4 psig and minus 69.83 degrees F.). The solid carbon dioxide is then subjected to conditions under which the solid carbon dioxide vaporizes (or under which the solid carbon dioxide undergoes sublimation to form gaseous carbon dioxide), thereby causing the tobacco material to expand. For example, the tobacco material comprising the solid carbon dioxide can be rapidly heated as set out below. After warming, the dry ice sublimates to form gaseous carbon dioxide, which forces the tobacco to expand.

A suitable method of dry ice expansion may comprise impregnating the cell structure of tobacco with liquid carbon dioxide. Typically, the tobacco that is impregnated is cut tobacco. Suitable conditions for this impregnation step may comprise contacting the tobacco material in an impregnator vessel with liquid carbon dioxide at a temperature of -40 to -10 °C, such as -25 to -15 °C, for a period of around 1-10 minutes, such as 2-8 or 3-7 minutes, under pressure. . The pressure may be for example 435 psig (3000 kPa). Suitable cut widths are disclosed below in the description of Figure 1.

Immediately prior to impregnation, the tobacco material may have a moisture content of 10-40% such as 15-35%, or 20-30%. After the impregnation step, the process typically then comprises reducing the pressure within the impregnator vessel sufficiently to cause solidification of the liquid carbon dioxide within the cell structure. For example, the pressure may be reduced to atmospheric pressure (1 atm). The process may then involve rapidly heating the tobacco to sublime the solid carbon dioxide in the tobacco cells, thereby causing the tobacco to expand. This rapid heating may be carried out by introducing the tobacco material comprising solid carbon dioxide into a gas stream having a temperature of from 250 to 400 °C, such as 300-360 °C, or about 330 °C. The process may then comprise hydrating the dry ice expanded tobacco to the desired initial moisture content for further treatment by the process of the invention.

Figure 1 depicts a suitable exemplary process for preparing dry ice expanded tobacco. Bales of tobacco material are sliced and then the bales are conditioned using water and steam. The tobacco material can be any of the tobacco materials described herein. Lamina tobacco, in particular lamina Virginia tobacco, is particularly preferred. One reason for this is that it exhibits desirable organoleptic properties and, compared with other tobacco varieties, relatively low levels of compounds considered to be undesirable. Another benefit of using Virginia tobacco is that it tends to readily expand during the expansion process. In some embodiments, stem tobacco may be used in addition to lamina. After conditioning, the conditioned tobacco material is blended with other conditioned tobacco materials or mixed before being fed into a cutter. Preferably, the cutter cuts the tobacco material at 25 to 28 cuts per inch (CPI). A cut width of 25 CPI is particularly preferred, although other cut widths could be used. Cutting the tobacco material increases its surface area and thus reduces the time it takes to become impregnated with liquid during the impregnation step. These cut widths may also increase the fill value of the final material.

After wetting the cut material and blending the wet cut material, the material has a moisture content of around 26%. This material is then fed into an impregnator vessel, which is subsequently charged with carbon dioxide at a temperature of -20 °C for around 6 minutes under pressure. These conditions ensure that the carbon dioxide stays in a liquid form and has enough time to penetrate and be absorbed into the tobacco material. Following on from this, the impregnated tobacco material is fed into a sublimator, the pressure is reduced to allow the liquid carbon dioxide to solidify, the impregnated tobacco material is then heated in a gas stream at a temperature of 330 °C. This results in rapid volatilisation of the moisture and carbon dioxide in the tobacco material, which causes it to expand.

Other gas temperatures may be used. For example, the gas temperature may be between about 250 °C and about 400 °C or more. The maximum temperature is preferably below the combustion temperature of the tobacco material. High temperatures may improve the rate of expansion and thus the efficiency of the process. The fill value of the tobacco material may also be controlled by changing the temperature. Increasing the temperature may lead to more moisture being driven off from the material and thus a higher fill value of the final material. Conversely, using lower temperatures may decrease the fill value of the final material.

The high gas temperatures can be achieved by any suitable means (e.g. by heating air using a hot plate or burner). The tobacco material at the end of the sublimation is relatively dry and has a moisture content of around 6%. The moisture content is increased to around 12% to 14% (the target is often 13.6%) by hydrating it in a reordering cylinder to produce the final expanded tobacco material. The expanded material may have a fill value of at least about 6 cm³/g.

When referring to “moisture” it is important to understand that there are widely varying and conflicting definitions and terminology in use. It is common for “moisture” or “moisture content” to be used to refer to water content of a material but in relation to the certain industries, such as the tobacco industry, it is necessary 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 dry 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 110°C ± 1°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).

Figure 2 shows a cross section through a tobacco leaf before (top) and after (bottom) dry ice expansion. The scale bar (centre, bottom) of each image corresponds to a distance of 100 microns. The expansion of the tobacco material during the dry ice expansion process can be seen from a comparison of these images. A different known type of expanded tobacco to DIET is expanded stem (which may also be referred to as expanded stem or steam treated stem (STS)). The process of forming expanded stem typically involves treating the stem with steam, which causes expansion of the material and an increase in its fill value.

Figure 3 illustrates one such process for expanding tobacco stem. Tobacco is loaded into a feeder. The tobacco stem can be derived from any of the varieties of tobacco described herein. After the addition of water, the moisture content of the stem is around 34%. The mixture is then blended with stem from other batches and/or mixed thoroughly, at which point the stem has a moisture content of between around 30% and around 40%, such as around 36%. The material is then cut to ensure the portions of stem are of consistent dimensions. This cutting may help to further increase the fill value of the material. Water is then applied to the cut stem to increase its moisture content to between about 35% and about 45%. The relatively high moisture levels attained in this step help to increase the expansion of the stem during the subsequent expansion steps. Following this, the material is subjected to steam treatment at temperatures in excess of 100 °C (e.g. using steam or superheated steam). This results in expansion of the stem and an increase in its fill value. The steam can be applied at a rate of at least 200 kg/hr such as greater than 300 kg/hr or greater than 350 kg/hr, e.g. around 375 kg/hr to around 500 kg/hr. Higher applications rates may also be used. The rate of throughput can be increased by using higher steam application rates. After dust removal using a dust extractor, the expanded stem can be stored.

As set out in the Summary, the moisture content of the DIET before and during treatment is between about 10% and about 23%. As used herein, the term ‘moisture content’ refers to the percentage of oven volatiles present in the DIET material.

In some embodiments, the moisture content of the DIET before and during treatment is between about 10% and 15.5%, optionally between about 10.5% and 15% or between about 11% and 14%. The moisture content of the DIET may be about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 21%, about 22% or about 23%. In some embodiments, for example when the moisture content of the DIET is between about 10% and 20%, optionally between about 10% and 18%, it is not necessary to redry the tobacco following the treatment process.

The DIET material is enclosed within, e.g. secured within, a moisture-retaining material, to limit moisture losses and to retain a desired level of moisture during the process.

The process may further comprise enclosing or securing the DIET material within the moisture-retaining material before treating the tobacco according to the process of the invention.

The DIET may be completely sealed within the moisture-retaining material. Alternatively, the DIET material may not be completely sealed within the moistureretaining material. In some embodiments, a moisture-retaining material is wrapped around the DIET material. In other embodiments, the moisture-retaining material is wrapped around a storage container which contains the DIET material. In some embodiments, the DIET material is placed within a moisture-retaining container. Thus, the process of the invention may be carried out on DIET material, wherein the moisture-retaining material has been wrapped around the DIET material or wherein the moisture-retaining material has been wrapped around a storage container which contains the DIET material. In addition or alternatively, the process of the invention may be carried out on DIET material which has been placed in a moisture-retaining container.

The moisture-retaining material may be any material that is sufficiently impermeable to moisture to retain the desired amount of moisture during the treatment process. The amount of moisture that is retained in the DIET material may be at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5% or 100% of the moisture which was present in the DIET material prior to treatment. In some embodiments, between 99% and 100% of the moisture content of the DIET material is retained during the process.

It is desirable for the moisture-retaining material to be resistant to degradation during the tobacco treatment process. For example, it is desirable for the moisture-retaining material to withstand the temperatures of the treatment process, without breaking down to become moisture-permeable or to release compounds that may be taken up by the tobacco material. The temperature reached by the DIET material during the process may therefore be taken into consideration when selecting the moisture-retaining material.

The moisture-retaining material may comprise a flexible material. This flexible material may be wrapped around the DIET material and/or formed into a pouch into which the DIET is placed. In some embodiments, the moisture-retaining material comprises plastic material. In some embodiments, the moisture-retaining material comprises flexible polymeric material, optionally a polymeric or plastic film. In some embodiments, the moisture-retaining material comprises polyethylene. In some embodiments, the moisture-retaining material comprises polyesters, nylon and/or polypropylene. In some embodiments, the moisture-retaining material is Polyliner®. Polyliner® is available through a number of suppliers, including Plastrela Flexible Packaging, located in Brazil.

Alternatively or in addition, the moisture-retaining material may comprise a rigid material, such as metal for example, which is formed into a vessel or container. In these embodiments, a separate storage container as discussed below may not be required.

In embodiments where the DIET material reaches a temperature of about 100°C or above, the moisture-retaining material may be pressure-resistant.

In some embodiments, the process may comprise allowing the tobacco material to rest when enclosed within the moisture-retaining material for a rest period, before it is exposed to the ambient processing temperature. The rest period may be at least 15 days, such as at least 30 days. For example the rest period may be from 15-75 days such as 20-60 days or 30-45 days.

At the start of the process, the DIET material has a packing density of 60 to 160 kg/m³ In some embodiments, the DIET material has a packing density at the start of the treatment of 70-140 kg/m³, 90-135 kg/m³, 100-130 kg/m³ or 105-125 kg/m³. The process/treatment starts when the DIET is exposed to the ambient processing temperature as defined herein. That is, the DIET has a packing density of 60 to 160 kg/m³, such as 70-140 kg/m³, 90-135 kg/m³, 100-130 kg/m³ or 105-125 kg/m³, when the DIET is exposed to the ambient processing temperature.

Packing density herein is calculated by dividing the weight of the DIET by the volume occupied by the DIET. The packing densities herein are to be calculated based on the total weight of the tobacco material, including any water/moisture in the tobacco material.

When the volume of the storage container, the volume enclosed by the moistureretaining material and the volume occupied by the DIET are substantially the same or exactly the same (for example when the storage container is filled substantially completely or completely with DIET material and tightly enclosed, wrapped or secured within in moisture-retaining material), the packing density may be calculated by dividing the weight of tobacco placed in the storage container by the volume of the storage container.

The volume of the storage container and/or the volume enclosed by the moistureretaining material (which may be substantially the same) may be selected to achieve the desired packing density for the desired amount of tobacco to be treated, and at the same time allows the treatment of the tobacco to take place at a suitable rate.

When the DIET does not occupy the entire volume of the moisture-retaining material, the volume occupied by the DIET may be calculated by subtracting the volume of any empty space (e.g. any void space above the tobacco material after it has been placed within the moisture-retaining material and optionally the storage container) from the total volume enclosed by the moisture-retaining material.

The packing density of the DIET material during and/or following treatment may be similar or substantially similar to the packing density of the DIET material at the start of the process. In some cases, the volume occupied by the DIET material decreases during the treatment and so the packing density of the DIET material is increased during and/or following the treatment.

The DIET material may be placed in a storage container after it has been enclosed or secured within a moisture-retaining material. Alternatively, the DIET material may be placed in a storage container and then enclosed or secured within a moisture-retaining material, such as by wrapping a moisture-retaining material around the storage container. Placing the DIET in a container enables the tobacco to be handled easily.

Alternatively or in addition, the container may be oriented on its side. This arrangement may be particularly beneficial when the DIET material comprises tobacco lamina that is in a horizontal position when placed in the storage container, as placing the storage container on its side achieves a more even packing density.

In some embodiments, the container has a volume of between about 0.2 m³ and about 1.0 m³, optionally between about 0.4 m³ and about 0.8 m³. In some embodiments, the container has a volume of about 0.7 m³.

In some embodiments, the volume occupied by DIET at the start of the process is between about 0.2 m³ and about 1.0 m³, optionally between about 0.4 m³ and about 0.8 m³. In some embodiments, the volume occupied by the DIET at the start of the process is about 0.7 m³.

In some embodiments, the storage container is a case for tobacco known as a C-48 box. The C-48 box is generally made of cardboard and has dimensions of about 115 x 70 x 75 cm.

The DIET may be placed in a tobacco processing area. As used herein, the term ‘tobacco processing area’ is the area, which can be a room or chamber, in which the treatment process is carried out. The ambient process conditions, i.e. the conditions of the tobacco processing area, may be controlled during the process. This may be achieved by placing the DIET material enclosed or secured within the moistureretaining material into a controlled environment, such as a chamber. The DIET material may be placed on one or more rack(s) within a chamber, to allow optimal ventilation to maintain constant ambient process conditions around the tobacco. The rack(s) may have one or more shelve(s) comprising bars with gaps between the bars and/or other apertures, to assist in the maintenance of constant ambient process conditions around the tobacco. The ambient processing humidity may be maintained at a level to avoid significant moisture loss from the DIET material. As used herein, the term ‘ambient processing humidity’ refers to the humidity of the tobacco processing area. As used herein, the term ‘ambient relative processing humidity’ refers to the relative humidity of the tobacco processing area.

In some embodiments, the ambient relative processing humidity is about 65%. The ambient relative processing humidity may be at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65% or at least 70%.

The ambient processing temperature is at least about 45°C. In some embodiments, the ambient processing temperature is at least about 50°C. In some embodiments, the ambient processing temperature may be maintained at above 55°C, optionally at about 60°C. As used herein, the term ‘ambient processing temperature’ refers to the temperature of the tobacco processing area.

In some embodiments, the ambient processing temperature is at least 46°C, at least 47°C, at least 48°C, at least 49°C, at least 50°C, at least 51°C, at least 52°C, at least

53°C, at least 54°C, at least 55°C, at least 56°C, at least 57°C, at least 58°C, at least

59°C, at least 60°C, at least 61°C, at least 62°C, at least 63°C, at least 64°C, at least

65°C, at least 66°C, at least 67°C, at least 68°C, at least 69°C or at least 70°C. In some embodiments, the ambient processing temperature is up to 60°C, up to 70°C, up to 75°C, up to 80°C, up to 85°C, up to 90°C, up to 95°C, up to 100°C, up to 105°C, up to 110°C, up to 115°C or up to 120°C.

In embodiments in which the ambient processing temperature is about 45°C, the ambient processing humidity may be about 30-70 g water/m³. In embodiments in which the ambient processing temperature is about 55°C, the ambient processing humidity may be about 40-80 g water/m³. In embodiments in which the ambient processing temperature is about 60°C, the ambient processing humidity may be about 50-110 g water/m³. In embodiments in which the ambient processing temperature is about 70°C, the ambient processing humidity may be about 50-160 g water/m³. In embodiments in which the ambient processing temperature is about 80°C, the ambient processing humidity may be about 50-230 g water/m³. In embodiments in which the ambient processing temperature is about 90°C, the ambient processing humidity may be about 50-340 g water/m³. In embodiments in which the ambient processing temperature is about 100°C or higher, the ambient processing humidity may be about 50-500 g water/m³.

In some embodiments, the ambient processing temperature is 60°C and the ambient relative processing humidity is 60%.

During the process the temperature of the DIET material reaches the ambient processing temperature. The DIET material may reach the ambient processing temperature within a short period of time. For example, the DIET material may reach the ambient processing temperature within 4 to 10 days, optionally within 5 to 9 days, within 7 to 9 days and/or within 4 to 7 days.

To achieve this, the amount of DIET treated may be optimised for the heat to be transferred to the centre of the tobacco material sufficiently rapidly. The rate at which the temperature of the DIET material rises and reaches the ambient processing temperature will be dependent upon a number of factors, including the ambient processing temperature, the density of the DIET and the overall amount of DIET being treated.

In some embodiments, the DIET material reaches a temperature of above 55°C and/or at least 60°C within about 9 days. In some embodiments, the DIET material reaches a temperature of above 55°C and/or at least 60°C within about 7 days. In some embodiments, the DIET material reaches a temperature of above 55°C and/or at least 60°C within about 5 days. In such embodiments, the ambient processing temperature may be 60°C.

In some embodiments, the temperature to which the DIET material is raised is at least about 55°C or at least about 60°C. Additionally or alternatively, the temperature to which the DIET material should be raised may be up to about 80°C, up to about 85°C, up to about 90°C, up to about 95°C, or up to about 100°C.

In some embodiments, the beneficial effects of the processing according to the invention may be achieved within shorter processing periods by employing a higher ambient processing temperature. The temperature of the DIET material may rise during the treatment process, to reach a second temperature that is higher than ambient processing temperature. This may be achieved with the assistance of exothermic reactions taking place during the treatment process.

In some embodiments, the DIET material reaches a second temperature which is above the ambient processing temperature. In some embodiments, the second temperature is at least 1°C above the ambient processing temperature, at least 2°C, at least 3°C, at least 4°C, at least 5°C, at least 7°C, at least 10°C, at least 12°C, at least 15°C, at least 17°C or at least 20°C above the ambient processing temperature. In some embodiments, the DIET material reaches a second temperature which is above the ambient processing temperature within about 7 to 13 days, and/or the second is reached within about 13 days or within about 11 days. In some embodiments, the DIET material reaches a second temperature of at least 5°C above the ambient processing temperature within about 11 to 13 days.

The temperature of the DIET material may reach up to 60°C, up to 65°C, up to 70°C, up to 75°C, up to 80°C, up to 85°C, up to 90°C, up to 95°C, up to 100°C, up to 105°C, up to 110°C, up to 115°C, up to 120°C, up to 125°C, up to 130°C, up to 135°C, up to 140°C, up to 145°C or up to 150°C during the treatment process.

Alternatively or in addition, the temperature of the DIET material may reach at least 60°C, at least 65°C, at least 70°C, at least 75°C, at least 80°C, at least 85°C, at least 90°C, at least 95°C, at least 100°C, at least 105°C, at least 110°C, at least 115°C, at least 120°C, at least 125°C, at least 130°C, at least 135°C, at least 140°C, at least 145°C or at least 150°C during the treatment process. In practice, the upper temperature may be limited by the thermal tolerance of the moisture-retaining material.

In some embodiments, the temperature of the DIET material may reach between about 55°C and about 90°C, between about 55°C and about 80°C, or between 60°C and about 70°C.

The DIET may be enclosed or secured within the moisture-retaining material and exposed to the ambient processing temperature for a sufficiently long period of time for the DIET to develop the desirable organoleptic properties, and for a sufficiently short period of time to not cause unwanted delay in the tobacco supply chain.

The DIET material is enclosed or secured within the moisture-retaining material for a period of time and at an ambient processing temperature and ambient processing humidity suitable to give rise to an increase in the temperature of the tobacco to or above a threshold temperature, wherein the moisture content of the tobacco is between about 10% and 23%. In some embodiments, the threshold temperature is 55°C, 60°C or 65°C.

In some embodiments, the DIET material is exposed to the ambient processing temperature of above 45°C (or any of the ambient processing temperatures disclosed herein) for about 5 to 65 days, such as 10 to 50 days, 20 to 45, 30 to 40 days or 35 to 40 days.

In other words, the duration of the treatment (excluding any period where the DIET material is enclosed or secured within the moisture-retaining material before being exposed to the ambient processing temperature) may be about 5 to 65 days, such as such as 10 to 50 days, 20 to 45 days, 30 to 40 days or 35 to 40 days. For example, in cases where the DIET is lamina Virginia tobacco, the treatment duration may be 35 to 45 days. For example, in cases where the DIET tobacco is a blend of lamina Virginia tobacco and lamina Burley tobacco, the treatment duration may be 30-40 days.

In other embodiments, the DIET material is exposed to the ambient processing temperature of above 45°C (or any of the ambient processing temperatures disclosed herein) for about 30 to 65 days, such as about 40 to 50 days, or about 43 to 48 days. In other words, the duration of the treatment (excluding any period where the DIET material is enclosed or secured within the moisture-retaining material before being exposed to the ambient processing temperature) may be about 30 to 65 days, such as about 40 to 50 days, or about 43 to 48 days. Increasing the duration of the treatment may increase the quantity of products of the Maillard reaction and may thereby provide a more intense flavour profile of the treated DIET. Embodiments in which the DIET material reaches a higher temperature may require a shorter process period than embodiments in which the DIET material reaches a lower temperature.

In other embodiments, the process involves treating the DIET material until the temperature of the DIET material reaches a target temperature, and then allowing the tobacco material to cool. This cooling may be effected by removing the DIET material from the processing area which is being held at an elevated temperature. In some embodiments, the target temperature is 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C. In some embodiments, the target temperature is within the range of 62 to 67°C. The target temperature may differ for different types of tobacco.

After the treatment process described herein, for example after exposing the tobacco to the ambient processing temperature for any of the treatment durations described above, the DIET may be allowed to rest for a stabilisation period. The DIET typically remains enclosed within, or secured within, the moisture-retaining material during this stabilisation period.

The stabilisation period may be initiated by removing the DIET material from the processing area which is being held at an elevated temperature. For example, the DIET material may be transported to a different processing area at a lower temperature, which may be about 30 °C or below (such as from about 18 °C to about 30 °C, or from about 20 °C to about 25 °C, e.g. around 22 °C).

During the stabilisation period the temperature of the DIET gradually reduces, typically to a temperature of about 30 °C or below (such as from about 18 °C to about 30 °C, or from about 20 °C to about 25 °C, e.g. around 22 °C). After the treatment process, the moisture content on the periphery (or on the outside or on the surface) of the body (such as a bale) of the dry ice expanded tobacco is typically higher than the moisture content in the centre (or core) of the body of the dry ice expanded tobacco. During the stabilisation period, moisture from the peripheral dry ice expanded tobacco may be absorbed back by the dry ice expanded tobacco in the centre/core.

In other words, after the treatment process the moisture is typically not homogeneously distributed throughout the batch of treated dry ice expanded tobacco, with the dry ice expanded tobacco on the periphery of the batch having a higher moisture content than the dry ice expanded tobacco at the centre (or core) of the batch. During the stabilisation period, the moisture may become homogeneously distributed throughout the batch of treated tobacco material. This may help to prevent microbial growth on the treated dry ice expanded tobacco at the periphery of the batch and thereby reduce waste and improve the shelf life of the treated dry ice expanded tobacco.

The moisture content of the DIET after the stabilisation period may be between about 10% and about 18%, optionally between about 10% and about 15.5%, optionally between about 10.5% and about 15%, such as between about 11% and about 14%.

The duration of the stabilisation period may be at least 15 days, such as at least 30 days. For example, the stabilisation period may be from 15-75 days, such as 20-60 days or 30-45 days. Typically, the stabilisation period is around 40 days.

When the treatment process is conducted in a storage container as discussed above, such as a cardboard box, the stabilisation period may also enable the storage container to regain rigidity which is reduced during the treatment process. This may facilitate subsequent handling and transportation of the treated dry ice expanded tobacco material.

The inventors have discovered that the treatment process described herein may lead to the formation of hard clumps (which may also be referred to as blocks or pads) of DIET tobacco. Tobacco clumps may also form during the stabilisation period in which the temperature of the treated DIET gradually reduces. Such clumps may need to be removed before the treated DIET can be used in products such as non-combustible aerosol provision systems, aerosol-generating materials or consumables for noncombustible aerosol provision systems, and aerosol-free delivery systems. Moreover, the inventors have identified that such tobacco clumps do not form when treating other forms of tobacco to DIET, such as when treating lamina tobacco which has not previously been dry ice expanded. Without wishing to be bound by theory, the inventors believe that the tobacco clumps form due the compressible, or fluffy, nature of the dry ice expanded tobacco. During the treatment process in which the temperature of the dry ice expanded tobacco is increased, the dry ice expanded tobacco material at the top of the moisture retaining material may compress the dry ice expanded tobacco material beneath it, leading to the formation of compacted tobacco layers, or tobacco clumps, in the lower portion of the body, or batch, of dry ice expanded tobacco being treated.

In particular embodiments, after the treatment process described herein, for example after exposing the tobacco to the ambient processing temperature for the treatment durations described above, the process further comprises one or more steps of breaking up any clumps of tobacco material formed during treatment of the DIET. For example, the process may further comprise applying one or more shear forces to clumps of tobacco material and/or shredding the tobacco clumps.

The process may also be done manually, e.g. by using hands or a hand-operated tool (e.g. hammer, mallet, pole, etc.) to break up the clumps of tobacco material formed during treatment of the DIET. Alternatively, the process may be carried out using machinery, for example as part of a production line.

In particular embodiments, the process may further comprise passing the treated DIET through one or more rollers to break up any tobacco clumps in the treated DIET. In particular embodiments, each of the one or more rollers comprises a plurality of teeth, spikes and/or protruding rods on the surface thereof. In particular embodiments, the one of more rollers may be one or more doffers. The treated dry ice expanded tobacco is typically spread out over a a conveying means, such as a conveyor belt, configured to transport the treated DIET towards the rollers. The conveying means and one or more rollers may be arranged such that in use the treated dry ice expanded tobacco drops through, or falls through, the one or more rollers, thereby breaking up the one or more tobacco clumps. For example, a plurality of conveying means may be staggered such that there are one or more drops between them and one or more rollers may be arranged in the one or more drops.

In some embodiments, the process may comprise multiple sequential rolling steps. In particular embodiments the one or more rolling steps are continued until the wt% of tobacco clumps reaches a target value or until the wt% of tobacco material having a particle size of 2.5 cm or less reaches a target value. The target value may be in any the ranges set out below, such as in the range of less than or equal to 15 wt% of tobacco clumps or the the range of 85 wt% or more of the DIET having a particle size of 2.5 cm or less.

In some embodiments, the process may further comprise a first rolling step using one or more first rollers comprising a plurality of first teeth, first spikes and/or first protruding rods on the surface thereof and a second rolling step using one or more second rollers comprising a plurality of second teeth, second spikes and/or second protruding rods on the surface thereof, wherein the spacing between the plurality of first teeth, first spikes and/or first protruding rods is greater than the spacing between the plurality of second teeth, second spikes and/or second protruding rods. Any tobacco clumps are broken up into smaller clumps having a first particle size in the first rolling step. The smaller tobacco clumps provided by the first rolling step are then broken up into yet smaller clumps having a smaller second particle size in the second rolling step. In particular embodiments, the first rolling step occurs once and the second rolling step occurs two or more times. Performing the second rolling step multiple times may further reduce the wt% of tobacco clumps in the treated DIET. In particular embodiments, the second rolling step occurs twice, that is the treated DIET is passed through the one or more second rollers twice.

As used herein, the wt % of tobacco clumps refers to the mass percentage of the treated DIET material which does not pass through a mesh having a 2.5 cm x 2.5 cm hole size, relative to the total mass of the treated DIET material. In some embodiments, the one or more steps of breaking up any clumps of tobacco material provides DIET comprising less than or equal to 15 wt% (i.e. 0-15 wt%) of tobacco clumps, optionally less than or equal to 10 wt% of tobacco clumps, such as less than or equal to 5 wt% of tobacco clumps, less than or equal to 2 wt % of tobacco clumps, or less than or equal to 1 wt% of tobacco clumps.

In other words, the one or more steps of breaking up any clumps of tobacco material may provide DIET in which 85 wt% or more (i.e. 85-100 wt%) of the DIET has a particle size of 2.5 cm or less, optionally wherein 90 wt% or more, such as 95 wt% or more, 98 wt% or more, or 99 wt% or more of the DIET has a particle size of 2.5 cm or less. In this context, the wt % of the treated DIET material having a particle size of 2.5 cm or less denotes the mass percentage of the treated DIET material which passes through a mesh having a 2.5 cm x 2.5 cm hole size, relative to the total mass of the treated DIET material.

When the one or more steps of breaking up any clumps of tobacco material are performed (for example when the treated tobacco spread out and is passed through one or more rollers), the treated DIET may be more rapidly cooled and the stabilisation period described above can surprisingly be avoided without adversely affecting the fill value, moisture content, moisture distribution and taste profile of the treated DIET. For example, the temperature of the DIET may decrease to a temperature of about 30 °C or below (such as from about 18 °C to about 30 °C, or from about 20 °C to about 25 °C, e.g. around 22 °C) over a period of from 0.05 to 3 hours, optionally from 0.1 to 2 hours, such as from 0.15 to 1 hours or from 0.2 to 0.7 hours. Avoiding the stabilisation period may significantly reduce the overall processing time of the DIET tobacco material.

A further aspect of the invention is directed to a process comprising breaking up any tobacco clumps in a treated DIET material which has been produced by a process as described in the Summary. The embodiments described above apply mutatis mutandis to this aspect of the invention.

Filling value (also referred to herein as fill value) is a measure of the volume occupied by a given mass of tobacco when a given pressure is applied at a given moisture content. That is, the fill value is a measure of the ability of a material to occupy a specific volume at a given moisture content. In this invention, filling value may be determined by Test Method A as disclosed in the Examples section below.

As set out above, the high fill value of the dry ice expanded tobacco is maintained during the process. The fill value of the dry ice expanded tobacco may even increase during the process. In some embodiments, the fill value of the treated DIET at 13.5% moisture content is at least 6 cm³/g, such as at least 6.5 cm³/g or at least 7 cm³/g. In some embodiments, the fill value of the treated DIET at 13.5% moisture content is 6 to 10 cm³/g, such as 6.5 to 9 cm³/g or 7 to 8 cm³/g.

In some embodiments, the fill value of the untreated DIET at 13.5% moisture content is at least 6 cm³/g, such as at least 6.5 cm³/g or at least 7 cm³/g. In some embodiments, the fill value of the untreated DIET at 13.5% moisture content is 6 to 10 cm³/g, such as 6.5 to 9 cm³/g or 7 to 8 cm³/g.

It has been found that at least one change to the organoleptic properties of the tobacco material is a result of a reduction in the negative properties, for example as a result of a reduction in tobacco material components that have an unpleasant taste or have an irritant effect. In some embodiments, the organoleptic properties are changed by an increase in the positive properties, for example as a result of the increase in or introduction of components that make a positive contribution to the organoleptic properties, such as components having pleasant flavours.

In some embodiments the tobacco material is treated so that it has desirable organoleptic properties that are produced in a reliable way and at relatively high volumes. In some embodiments, the process is a batch process.

After the DIET has been incubated for the desired length of time, the treated tobacco may be cooled down while remaining in the moisture-retaining material.

The process parameters are sufficiently gentle for the treated DIET material to maintain some or all of its physical properties. For example, the DIET material remains sufficiently intact following treatment to allow handling and/or processing for incorporation into a tobacco-containing product, such as a consumable for noncombustible aerosol provision systems, or an aerosol-free delivery system. This enables the treated DIET material to undergo handling in accordance with standard processes.

The treated DIET material may have a different colour from untreated DIET material. In some embodiments, the DIET material is darker than untreated tobacco material. Importantly, the treated DIET material has organoleptic properties that are acceptable and/or desirable for the consumer. Thus, tobacco material with desirable organoleptic properties can be produced by the treatment of DIET under a specific set of conditions, and without requiring the addition of one or more further chemical(s), which may be hazardous and/or expensive. Moreover, the treated DIET does not need to undergo an additional treatment step to remove the further chemical(s), which would add extra cost and time to the tobacco treatment process. The organoleptic properties of the treated DIET material may be developed when the tobacco material is enclosed or secured within the moisture-retaining material, during which period the components in the tobacco material undergo chemical changes and modifications, to give desirable organoleptic characteristics to the final product. The treated tobacco material may, in some embodiments, have a sweet spicy and/or dark note. The treated tobacco material may not, in some embodiments, have a dry and/or bitter note.

In some embodiments the chemical composition of the treated DIET material differs significantly from untreated DIET material. For example, as shown in the data set out in the Example, in some embodiments the majority of the sugars in the treated DIET material are converted and the concentration of nicotine and total amino acids is reduced.

Without being bound by theory, it is thought that the change in the levels of at least some of these compounds is due at least in part to the Maillard reaction taking place during the process. A caramelisation reaction may also be taking place during the process, which may lead to reduced levels of reducing and non-reducing sugars.

In addition, in some embodiments a significant decrease in the content of various amino acids may be seen.

The process may therefore lead to an increase in at least one of the products of the Maillard reaction in the treated DIET material. Products of the Maillard reaction include:

2.6-deoxyfructosazine; 2,5-deoxyfructosazine; 5-acetyl-2,3-dihydro-1H-pyrrolizine; 2,3- dihydro-5-methyl-1 H-pyrrolizine-7-carboxaldehyde; 1 ,2,3,4,5,6-hexahydro-5-(1- hydroxyethylidene)-7H-cyclopenta[b]pyridin-7-one; 1-(1-pyrrolidinyl)-2-butanone; 1- (2,3-dihydro-1 H-pyrrolizi n-5-yl)- 1 ,4-pentanedione; 2,3,4,5,6,7-hexahydro- cyclopent[b]azepin-8(1 H)-one; 5-(2-furanyl)-1 ,2,3,4,5,6-hexahydro-7H- cyclopenta[b]pyridin-7-one; 4-(2-furanylmethylene)-3,4-dihydro-2H-pyrrole; and

1.2.3.4.5.6-hexahydro-7H-cyclopenta[b]pyridin-7-one. An increase in the concentration of carotenoids may also be indicative that the Maillard reaction has taken place. The treated DIET material may, in some embodiments, contain a reduced level of nicotine compared with untreated tobacco material, as shown in the Example. Nicotine is known to have a bitter taste and therefore having reduced levels of this compound can have a positive effect on the taste and flavour of the treated tobacco material.

The production of DIET material with desirable organoleptic properties advantageously removes the requirement to add further substances to the tobacco to provide or enhance its organoleptic properties. Such substances include flavourants and/or aromatising ingredients.

As used herein, the terms “flavour” and “flavourant” refer to materials which, where local regulations permit, may be used to create a desired taste or aroma in a product for adult consumers. They may include extracts (e.g., licorice, hydrangea, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb, Wintergreen, cherry, berry, peach, apple, Drambuie, bourbon, scotch, whiskey, spearmint, peppermint, lavender, cardamon, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, or a mint oil from any species of the genus Mentha), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, oil, liquid, or powder.

The treated DIET material may be incorporated into a non-combustible aerosol provision system. For example, the treated DIET material may be incorporated into an aerosol-generating material for use in a non-combustible aerosol provision system or into a consumable for use a non-combustible aerosol provision system.

The treated DIET material may be incorporated into an aerosol-free delivery system.

As used herein, the term “delivery system” is intended to encompass systems that deliver at least one substance to a user, and includes: non-combustible aerosol provision systems that release compounds from an aerosolgenerating material without combusting the aerosol-generating material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosol-generating materials; and aerosol-free delivery systems that deliver the at least one substance to a user orally, nasally, transdermally or in another way without forming an aerosol, including but not limited to, lozenges, gums, patches, articles comprising inhalable powders, and oral products such as oral tobacco which includes snus or moist snuff, wherein the at least one substance may or may not comprise nicotine.

According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user.

In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system.

In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosol-generating material is not a requirement.

In some embodiments, the non-combustible aerosol provision system is an aerosolgenerating material heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating system.

In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosolgenerating material and a solid aerosol-generating material. The solid aerosolgenerating material may comprise, for example, tobacco or a non-tobacco product. Typically, the non-combustible aerosol provision system may comprise a noncombustible aerosol provision device and a consumable for use with the noncombustible aerosol provision device.

In some embodiments, the disclosure relates to consumables comprising aerosolgenerating material and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure.

In some embodiments, the non-combustible aerosol provision system, such as a non- combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energised so as to distribute power in the form of heat to an aerosol-generating material or to a heat transfer material in proximity to the exothermic power source.

In some embodiments, the non-combustible aerosol provision system may comprise an area for receiving the consumable, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, a filter and/or an aerosol-modifying agent.

In some embodiments, the consumable for use with the non-combustible aerosol provision device may comprise aerosol-generating material, an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and/or an aerosol-modifying agent.

An aerosol-generating material is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol-generating material may, for example, be in the form of a solid, liquid or semi-solid (such as a gel).

In addition to the DIET, the aerosol-generating material may comprise one or more active substances and/or flavours, one or more aerosol-former materials, and optionally one or more other functional materials. In some embodiments, the DIET provided by the processes described herein may be mixed with a further aerosol-generating material. That is, the DIET may be incorporated into an aerosol-generating composition (or a blend) comprising (i) the DIET or an aerosol-generating material comprising the DIET, and (ii) optionally one or more further aerosol-generating materials. The aerosol-generating material (i) comprising the DIET and/or the further aerosol-generating material (ii) may comprise one or more active substances and/or flavours, one or more aerosol-former materials, and optionally one or more other functional materials.

The aerosol-generating material may comprise a binder, such as a gelling agent, and an aerosol former. Optionally, a filler may also be present. Optionally, a solvent, such as water, is also present and one or more other components of the aerosol-generating material may or may not be soluble in the solvent.

The aerosol-generating material may comprise or be in the form of an aerosolgenerating film. The aerosol-generating film may comprise a binder, such as a gelling agent, and an aerosol former. Optionally, a filler may also be present.

The aerosol-generating film may have a thickness of about 0.015 mm to about 1 mm. For example, the thickness may be in the range of about 0.05 mm, 0.1 mm or 0.15 mm to about 0.5 mm or 0.3 mm.

The aerosol-generating film may be continuous. For example, the film may comprise or be a continuous sheet of material. The sheet may be in the form of a wrapper, it may be gathered to form a gathered sheet or it may be shredded to form a shredded sheet. The shredded sheet may comprise one or more strands or strips of aerosol-generating material.

The aerosol-generating film may be discontinuous. For example, the aerosolgenerating film may comprise one or more discrete portions or regions of aerosolgenerating material, such as dots, stripes or lines, which may be supported on a support. In such embodiments, the support may be planar or non-planar.

The aerosol-generating film may be formed by combining DIET with a binder, such as a gelling agent, a solvent, such as water, an aerosol-former and one or more other components, to form a slurry and then heating the slurry to volatilise at least some of the solvent to form the aerosol-generating film.

The slurry may be heated to remove at least about 60 wt%, 70 wt%, 80 wt%, 85 wt% or 90 wt% of the solvent.

The aerosol-generating material may comprise or be an “amorphous solid”. In some embodiments, the aerosol-generating material comprises an aerosol-generating film that is an amorphous solid. The amorphous solid may be a “monolithic solid”. The amorphous solid may be substantially non-fibrous. In some embodiments, the amorphous solid may be a dried gel. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. In some embodiments, the amorphous solid may, for example, comprise from about 50wt%, 60wt% or 70wt% of amorphous solid, to about 90wt%, 95wt% or 100wt% of amorphous solid.

The aerosol-former material may comprise one or more constituents capable of forming an aerosol. In some embodiments, the aerosol-former material may comprise one or more of glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1 ,3-butylene glycol, erythritol, meso-Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

Aerosol-generating materials for use in non-combustible aerosol provision systems may typically comprise higher amounts of aerosol-former materials than smokable materials for use in combustible aerosol provision systems. For example, an aerosolgenerating material comprising the DIET may comprise aerosol former in a total amount of from 10 to 60 wt% calculated on a dry weight basis (DWB), such as from 10 to 50 wt% (DWB), 12 to 30 wt% (DWB), or 15 to 35 wt% (DWB). In these embodiments, dry weight basis (DWB) refers to the whole of the material, other than any water, and may include components which by themselves are liquid at room temperature and pressure, such as glycerol.

In some embodiments, an aerosol-generating composition (or a blend) comprises (i) the DIET, or an aerosol-generating material comprising the DIET, and (ii) optionally one or more further aerosol-generating materials, and the total amount of aerosol-former present in the aerosol generating composition (or blend) may be from 4 to 30 wt% (DWB), such as from 5 to 25 wt% (DWB), from 5 to 20 wt% (DWB) or from 10 to 20 wt% (DWB) of the composition (or blend) In these embodiments, dry weight basis (DWB) refers to the whole of the composition (or blend), other than any water, and may include components which by themselves are liquid at room temperature and pressure, such as glycerol.

The aerosol-generating material may be present on or in a support, to form a substrate. The support may, for example, be or comprise paper, card, paperboard, cardboard, reconstituted material, a plastics material, a ceramic material, a composite material, glass, a metal, or a metal alloy. In some embodiments, the support comprises a susceptor. In some embodiments, the susceptor is embedded within the material. In some alternative embodiments, the susceptor is on one or either side of the aerosolgenerating material.

A susceptor is a material that is heatable by penetration with a varying magnetic field, such as an alternating magnetic field. The susceptor may be an electrically-conductive material, so that penetration thereof with a varying magnetic field causes induction heating of the heating material. The heating material may be magnetic material, so that penetration thereof with a varying magnetic field causes magnetic hysteresis heating of the heating material. The susceptor may be both electrically-conductive and magnetic, so that the susceptor is heatable by both heating mechanisms. The device that is configured to generate the varying magnetic field is referred to as a magnetic field generator, herein.

In some embodiments, the delivery system is an aerosol-free delivery system that delivers at least one substance to a user orally, nasally, transdermally or in another way without forming an aerosol, including but not limited to, lozenges, gums, patches, articles comprising inhalable powders, and oral products such as oral tobacco which includes snus or moist snuff, wherein the at least one substance may or may not comprise nicotine.

In some embodiments, tobacco extracts may be created from DIET material which has undergone the processing described herein. In some embodiments, the extract may be a liquid, for example it may be an aqueous extract. In other embodiments, the extract may be produced by supercritical fluid extraction.

Thus, one aspect provides a process for manufacturing a tobacco extract from DIET tobacco material which has been treated by the process described herein.

In some embodiments, the extracts may be used in non-combustible aerosol provision systems or aerosol-free delivery systems. For example, the tobacco extracts may be heated to create an inhalable vapour in an electronic cigarette or similar device.

Alternatively, the extracts may be added to tobacco or another material for heating, such as in a heat-not-burn product.

As set out above, the favourable change in the organoleptic properties of the DIET tobacco provided by the process herein means that the treated tobacco can be added to tobacco blends (for example for use in a non-combustible aerosol provision system or aerosol-free delivery system), or to aerosol generating materials or consumables for use in non-combustible aerosol provision systems in higher quantities than untreated DIET tobacco without compromising the organoleptic properties of the tobacco blends, aerosol generating materials or consumables. Thus, the processes described herein may further comprise incorporating the treated tobacco into a blend.

In some embodiments, a tobacco blend may comprise the treated tobacco in an amount of from 1 to 40 wt%, such as from 5 to 35 wt%, from 5 to 30 wt%, from 10 to 27, from 12.5 to 25 wt%, or from 15 to 25 wt%, relative to the total weight of the blend.

The blend may further comprise one or more other tobacco varieties, optionally including one or more Virginia tobaccos, one or more Burley tobaccos, one of more Oriental tobaccos and combinations thereof. The treated dry ice expanded tobacco may contribute dark taste characteristics such that the blend can provided sufficient dark taste notes with lower inclusions of Burley tobacco varieties.

In particular embodiments, in addition to the treated dry ice expanded tobacco, the blend may further comprise one or more Burley tobacco varieties in a total amount of 30 wt% or less, such as 25 wt% or less, 20 wt% or less, or 15 wt% or less, relative to the total weight of the blend. For example, the blend may further comprise one or more Burley tobacco varieties in a total amount of from 1 to 30 wt%, from 1 to 25 wt%, such as from 2 to 20 wt%, from 3 to 15 wt% or from 5 to 10 wt%. In addition to the treated dry ice expanded tobacco, the blend may further comprise one or more Virginia tobacco varieties in a total amount of up to 55 wt%, such as from 1 to 55 wt%, from 1 to 50 wt%, from 10 to 40 wt%, or from 15 to 35 wt%, relative to the total weight of the blend. In addition to the treated dry ice expanded tobacco, the blend may further comprise one or more Oriental tobacco varieties in a total amount of up to 35 wt%, such as from 1 to 35 wt%, from 1 to 30 wt%, from 2 to 25 wt% or from 5 to 20 wt%, relative to the total weight of the blend. These amounts do not include any Virginia, Burley or Oriental tobacco within the treated dry ice expanded tobacco itself.

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 invention(s) may be practiced and provide for superior tobacco treatment processes. 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.

Examples

Test Method A

In the below examples, the fill value of the tobacco was measured according to the following process.

A 15 g sample of the tobacco material was deposited into a 60 mm diameter cylinder of a densimeter and then the tobacco material was compressed with a 2.90 ± 0.03 kg piston for 30 seconds. The height of the piston in the densimeter as well as the moisture content of the samples were measured. The fill values of the samples were calculated according to the following formulae.

The volume occupied by the tobacco material when compressed was determined using

Formula 1 : z ₉ h

Volume (cm ) = n x x — v⁷ 10

Formula 1 r = radius of cylinder (cm) h = measured height (mm)

The fill value was then determined using the measured volume and mass of tobacco material according to Formula 2:

Formula 2

The fill value was corrected to account for its moisture content using Formula 3: ₀

100 - M

Formula 3

FVo = Fill value at moisture content M_o%

FV = Fill value determined at moisture content M% (cm³/10 g)

M_o = 13.5% (target moisture content)

M = Actual moisture content of tobacco material (%)

0.8 = constant Moisture content (oven volatiles) is measured as the reduction in mass when a sample is dried in a forced draft oven at a temperature regulated to 110°C ± 1°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.

EXAMPLE 1

Production of DIET tobacco

Lamina Virginia and Burley tobacco were conditioned, mixed, cut and dried.

The tobacco material was then formed into dry ice expanded tobacco. The cut Virginia and cut Burley tobacco were wetted. For Sample R below, the Virginia and Burley tobacco were then blended. The wet and optionally blended tobacco material had a moisture content of around 26%. The tobacco material was then fed into an impregnator vessel, which was subsequently charged with carbon dioxide at a temperature of -20 °C for around 6 minutes under pressure. The impregnated tobacco material was fed into a sublimator and the pressure was then reduced to allow the liquid carbon dioxide to solidify. The impregnated tobacco material was then heated in a gas stream at a temperature of 330 °C which led to rapid volatilisation of the moisture and carbon dioxide in the tobacco material.

Sample A below is dry ice expanded of lamina Virginia tobacco. Sample R below is a 1:1 w/w blend of dry ice expanded lamina Virginia and Burley tobacco.

Production of expanded stem tobacco

Tobacco stems obtained by green-leaf threshing were wet to a moisture content of 25- 35% and then cut to a cut width of 25-28 CPI. The cut stem was then expanded by steam treatment involving heating to a temperature of 180-250 °C for a period of 15 seconds to 3 minutes, leading to vaporisation of water within the tobacco cells and expansion of the tobacco. After the steam treatment the stem tobacco had a moisture content of 13-14%.

Treatment of Tobacco

80 kg of the DIET tobacco was packed in a single walled cardboard box having external dimensions of 0.835 m x 1.120 m x 0.765 m, wrapped with polyethylene liner (Polyliner®), and was set to rest for a minimum period of 30 days before being exposed to the ambient processing conditions of 60°C and 60% relative humidity and a process time of 35, 37 or 39 days (for Sample A) or 35 days (for Sample R). The packing density of the tobacco before treatment was about 123 kg/m³.

70 kg of the expanded stem was packed in a C-48 box, wrapped with polyethylene liner (Polyliner®), and was set to rest for a minimum period of 30 days before being exposed to the ambient processing conditions of 60°C and 60% relative humidity and a process time of 14, 21 or 28 days.

Taste evaluation

Cigarettes comprising the untreated DIET, untreated expanded stem, treated DIET, or treated expanded stem were produced. A blind smoking trial was then conducted by expert smokers. No significant difference in taste was observed for the treated expanded stem as compared to the untreated expanded stem. However, an increase in spicy taste notes was observed for the treated DIET (for both Sample A and Sample R) as compared to the untreated DIET. An increase in tannin taste notes was also observed for the treated Sample R DIET compared to the untreated control.

Thus, the taste properties of DIET tobacco were unexpectedly improved by the treatment, unlike other forms of expanded tobacco (expanded stem).

Analysis of fill value

Fill values of the DIET tobaccos were measured before and after treatment. The values were corrected to adjust for moisture content and the values quoted are for a reference moisture content of 13.5%.

Table 1: Fill value of treated and untreated DIET tobacco

Sample A Sample R

Analysis of Nicotine

The nicotine content of the treated tobacco was analysed by a colorimetric method (continuous flow analysis using an AutoAnalyzer 3 machine). The results of the analysis are provided in Table 2.

Table 2: Nicotine content of treated and untreated tobacco

Sample A

Sample R

It can be seen from Table 2 that the tobacco material contains a reduced amount of nicotine after treatment compared with before treatment.

Analysis of Sugars

The total sugar content of the treated tobacco was analysed by a colorimetric determination of all reducing substances plus sucrose. The colorimetric method was continuous flow analysis using an AutoAnalyzer 3 machine. The results of the analysis are provided in Table 3.

Table 3: Sugar content of treated and untreated tobacco

Sample A

Sample R

The results in Table 3 show that the tobacco contains a reduced amount of sugars after treatment compared with before treatment.

Analysis of moisture

To support the theory that sugars in the tobacco material are being reduced, the moisture content was analysed before and after processing. As the tobacco material was wrapped in moisture-retaining material there was no water being introduced into the tobacco material from the environment. Thus, it is believed that the increase in water/moisture observed post processing is generated by the reduction of the sugars in the tobacco material.

Table 4: Analysis of moisture (measured as Oven Volatiles (OV))

Sample A Sample R

Analysis of Amino Acids Analysis of the treated tobacco using ultrahigh pressure liquid chromatography (LIPLC) with a Q-TOF (quadruple-time of flight) analyzer indicated a significant decrease in the content of amino acids, as indicated by the data shown in Table 5 below.

Table 5: Analysis of amino acid content Sample A

Sample R Analysis of carotenoids

Analysis of the treated tobacco indicated a significant increase in the content of carotenoids, as indicated by the data shown in Table 6 below.

Table 6: Analysis of carotenoids Sample A

Sample R

EXAMPLE 2

Lamina Virginia tobacco was treated by the method set out in Example 1 for Sample A for a duration of 39 days. After the treatment, the temperature of the DIET tobacco was 64 °C. The temperature of the tobacco was then gradually reduced to 22 °C during a stabilisation period of 40 days. Large clumps of tobacco were observed within the treated DIET material. The properties of the tobacco after the stabilisation period are shown in the table below (Test 1).

After the stabilisation period, the DIET tobacco had a moisture content (OV) of 14% and a fill value of 6.8 cc/g. The proportion of the tobacco which did not pass through a mesh having a hole size of 2.5 cm x 2.5 cm was 40 wt%.

In Test 2 below, immediately after the treatment, the tobacco material was conveyed through a first set of doffers in the form of rollers comprising a plurality of rods protruding from the surface thereof, and then through a second set of doffers in the form of rollers comprising a plurality of rods protruding from the surface thereof. The spacing between the protruding rods on the first set of doffers was greater than the spacing between the protruding rods on the second set of doffers. In Test 3 below, the tobacco material was conveyed for a second time through the second set of doffers. In Test 4 below, the tobacco material was conveyed for a third time through the second set of doffers. The cooling time for Tests 2-4 was 30 minutes or less. Figure 4 shows treated DIET being passed through a set of doffers. having a hole size of 2.5 cm x 2.5 cm

Cigarettes comprising the untreated DIET, untreated expanded stem, treated DIET, or treated expanded stem were produced. A blind smoking trial was then conducted by expert smokers. A panel of expert smokers determined that there was no significant difference between the sensorial profile of the cigarette comprising the tobacco produced in Test 2, Test 3 and Test 4 vs the control sample (a cigarette comprising the tobacco produced in Test 1).

EXAMPLE 3

The following tobacco blends were created by mixing an aerosol generating material (Component H), varieties of Virginia tobacco, varieties of Burley tobacco, and varieties of Oriental tobacco and either conventional dry ice expanded tobacco (which had not been subjected to the treatment process described herein) or dry ice expanded tobacco treated according to the procedure described in Example 2. Component H is a gel comprising 35 wt% glycerol, 9 wt% carboxymethyl cellulose, 47 wt% powdered cellulose and 9 wt% wood pulp calculated on a dry weight basis which was formed by casting and drying a slurry comprising the above components and water and drying the slurry.

The blends were incorporated into an article and heated within a commercially available GLO HYPER X2, Tobacco Heating Device. The heating profile involved a 4- minute heating session at 240 °C and 20 seconds to first puff,.

The sensory characteristics of the aerosol produced were evaluated by a sequential monadic test method by 8 panellists in triplicate. Blend 2 provided improved sensory characteristics of lower irritation and lower mouth drying even though Blend 2 contained a higher proportion of dry ice expanded tobacco than Blend 1. At least parity on dark taste notes was also observed for Blend 2 despite the lower inclusion of Burley varieties.

Levels of toxicants were also evaluated (measured as a % reduction relative to the toxicant amounts produced by a standardised TobReg 9 cigarette).

The abbreviation NR means not recorded.

The inclusion of the treated dry ice expanded tobacco in Blend 2 led to a greater reduction in the level of NNN than the control sample.

Claims

1. A process for producing dry ice expanded tobacco for use in a non-combustible aerosol delivery system or an aerosol-free delivery system, the process comprising exposing dry ice expanded tobacco which has been enclosed within a moistureretaining material to an ambient processing temperature of above 45°C, wherein the tobacco material has a packing density of 60 to 160 kg/m³ at the start of the process and has a moisture content of between about 10% and 23% before and during treatment.

2. A process according to claim 1 , wherein the tobacco material has a packing density of 90 to 135 kg/m³ at the start of the process.

3. A process according to claim 2, wherein the tobacco material has a packing density of 100 to 130 kg/m³ at the start of the process.

4. A process according to any one of the preceding claims, wherein the dry ice expanded tobacco comprises lamina tobacco.

5. A process according to claim 4, wherein the lamina tobacco comprises Virginia tobacco, such as wherein the lamina tobacco is Virginia tobacco or a blend of Virginia and Burley tobacco.

6. A process according to claim 4 or claim 5 wherein the dry ice expanded tobacco consists of, or consists essentially of, the lamina tobacco.

7. A process according to any one of the preceding claims wherein the treated tobacco material has a fill value at 13.5% moisture of at least 6 cm³/g.

8. A process according to any one of the preceding claims, the process comprising dry ice expansion of a tobacco material to provide the dry ice expanded tobacco before exposing the dry ice expanded tobacco to the ambient processing temperature.

9. A process according to any one of the preceding claims, wherein the tobacco material has a moisture content of between about 10% and 15.5% before and during treatment.

10. A process according to any one of the preceding claims, wherein the tobacco material is exposed to the ambient processing temperature for 5 to 65 days.

11. A process according to any one of the preceding claims, wherein the microbial content of the treated tobacco material is lower than the microbial content of the untreated tobacco material.

12. A process according to any one of the preceding claims, wherein the temperature of the tobacco material reaches the ambient processing temperature within about 4 to 10 days.

13. A process according to any one of the preceding claims, wherein the temperature of the tobacco material reaches a second temperature that is higher than the ambient processing temperature, such as wherein the second temperature is at least 2°C above the ambient processing temperature.

14. A process according to claim 13, wherein the second temperature is reached within about 7 to 13 days.

15. A process according to any one of the preceding claims, wherein the process results in a reduction in the content at least one of the compounds selected from the group consisting of: nicotine, reducing sugars, non-reducing sugars and amino acids in the treated tobacco material.

16. A process according to any one of the preceding claims, wherein the process involves essentially no fermentation.

17. A process according to any one of the preceding claims, wherein the ambient processing humidity is between about 50-500 g water/m³ for ambient processing temperatures around or above 100°C, about 50-340 g water/m³ for ambient processing temperatures around 90°C, about 50-230 g water/m³ for ambient processing temperatures around 80°C, about 50-160 g water/m³ for ambient processing temperatures around 70°C, about 50-110 g water/m³ for ambient processing temperatures around 60°C or about 40-80 g water/m³ for ambient processing temperatures around 55°C.

18. A process according to any one of the preceding claims, wherein the moistureretaining material is wrapped around the tobacco material, such as wherein the moisture-retaining material comprises flexible polymeric material, such as wherein the flexible polymeric material comprises polyethylene.

19. A process according to any one of the preceding claims, wherein the tobacco material is placed in a chamber to control the ambient processing temperature and/or ambient relative processing humidity.

20 A process according to any one of the preceding claims further comprising breaking up any clumps of tobacco material formed during treatment of the dry ice expanded tobacco.

21 The process according to claim 20, comprising passing the treated DIET through one or more rollers comprising a plurality of teeth, spikes and/or protruding rods on the surface thereof.

22 The process according to any one of the preceding claims, wherein during the process the dry ice expanded tobacco reaches a temperature (“TX”) that is equal to or higher than the ambient processing temperature and wherein the dry ice expanded tobacco is subsequently cooled from temperature (“TX”) to a temperature of 30 °C or below, such as from about 18 °C to about 30 °C, from about 20 °C to about 25 °C, or about 22 °C, over a period of from 0.05 to 3 hours, such as from 0.1 to 2 hours, such as from 0.15 to 1 hours or from 0.2 to 0.7 hours.

23. T reated dry ice expanded tobacco obtainable by the process of any one of the preceding claims.

24. An aerosol-generating material for use in a non-combustible aerosol provision system, the aerosol-generating material comprising the treated dry ice expanded tobacco material of claim 23.

25. A consumable for use in a non-combustible aerosol provision system, the consumable comprising the treated dry ice expanded tobacco of claim 23 or the aerosol-generating material of claim 24.

26. A non-combustible aerosol provision system comprising the treated dry ice expanded tobacco material of claim 23, the aerosol-generating material of claim 24, or the consumable of claim 25.

27. Use of the treated dry ice expanded tobacco material of claim 23 for the manufacture of: an aerosol-generating material for use in a non-combustible aerosol provision system or a consumable for use in a non-combustible aerosol provision system; or for the manufacture of an aerosol-free delivery system.

28. An aerosol-free delivery system comprising the treated dry ice expanded tobacco material of claim 23.