US20240298693A1

US20240298693A1 - Tobacco medium and aerosol-generating article comprising the same

Info

Publication number: US20240298693A1
Application number: US18/276,976
Authority: US
Inventors: Hyeon Tae KIM; Jun Won SHIN
Original assignee: KT&G Corp
Current assignee: KT&G Corp
Priority date: 2021-05-20
Filing date: 2022-05-10
Publication date: 2024-09-12
Also published as: JP2024504401A; WO2022245034A1; EP4340643A1; CN116600662A; KR102676406B1; KR20220157143A; EP4340643A4

Abstract

The present invention relates to a tobacco media and an aerosol-generating article including the same, and more particularly to a tobacco media for use in a non-combustible aerosol-generating article. The present invention is directed to a tobacco medium including a pulverized tobacco material and a pH adjuster, such that the tobacco medium includes at least 70 wt % of the pulverized tobacco material on a dry weight basis, the pulverized tobacco material includes at least 4 wt % of nicotine on a dry weight basis, the tobacco medium includes at least 2.8 wt % of nicotine on a dry weight basis, and a PH of the tobacco medium is in the range of 6 and 9.

Description

TECHNICAL FIELD

This description relates to a tobacco medium including a tobacco material, and to an aerosol-generating article including the tobacco medium.

BACKGROUND ART

In a conventional traditional cigarette that is ignited and combusted, tobacco leaves are heated with a temperature of about 800° C. to 850° C. On the other hand, non-combustible cigarettes (e.g., heat-not-burn cigarettes) may generate an aerosol at relatively low temperatures. For example, non-combustible cigarettes may be heated by a device at a temperature of about 280° C. to 350° C. to generate an aerosol.
Non-combustible cigarettes can be classified into heating type cigarettes and non-heating type cigarettes, and in both types of cigarettes, it is important to facilitate nicotine transfer at lower temperatures. Specifically, in non-heating type cigarettes, it should be possible to smoothly transfer nicotine without raising a temperature, Even in heating type cigarettes, nicotine transfer at relatively lower temperatures should be facilitated to minimize device size and battery consumption.
Accordingly, there are a number of conventional techniques for alkalizing and providing tobacco raw materials in order to facilitate nicotine transfer at low heating temperatures or under non-heating conditions. Since nicotine in the tobacco material exists in a salt state and is difficult to vaporize at low temperatures, nicotine may be alkalized so that it can be smoothly provided to users in the form of free-base nicotine.

DOCUMENT OF RELATED ART

(Patent Document 1) KR10-1851091 B

DISCLOSURE

Technical Problem

When the tobacco raw material is alkalized, off-flavor may increase and the storability of the nicotine in the tobacco raw material decreases due to the volatilization of the free-base nicotine that is a result of alkalinization.
An object of an embodiment of the present invention is to provide a tobacco medium capable of increasing an amount of nicotine transfer even at a low temperature and a low pH.
The problem to be solved in an embodiment is not limited thereto, and it will be understood that the object or effect that can be grasped from the means to solve the problem or embodiment described below is also included.

Technical Solution

A tobacco medium according to an embodiment of the present invention includes a pulverized tobacco material and a pH adjuster, wherein the tobacco medium includes at least 70 wt % of the pulverized tobacco material on a dry weight basis, the pulverized tobacco material includes at least 4 wt % of nicotine on a dry weight basis, the tobacco medium includes at least 2.8 wt % of nicotine on a dry weight basis, and a PH of the tobacco medium is in the range of 6 to 9.
In an aerosol-generating article including a tobacco medium according to an embodiment of the present invention, the tobacco medium includes a pulverized tobacco material and a pH adjuster, wherein the tobacco medium includes at least 70 wt % of the pulverized tobacco material on a dry weight basis, the pulverized tobacco material includes at least 4 wt % of nicotine on a dry weight basis, the tobacco medium includes at least 2.8 wt % of nicotine on a dry weight basis, and a pH of the tobacco medium is between 6 and 9.

Advantageous Effects

According to an embodiment of the present invention, it is possible to provide a tobacco medium that can smoothly transfer nicotine, reduce off-flavor caused by alkalinization, and reduce a nicotine loss rate during storage, even at a relatively low temperature and a low pH without additional nicotine salt supplementation.

DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an aerosol-generating article according to an embodiment of the present invention.

FIG. 2 schematically shows an embodiment in which a tobacco medium is a granular medium of a core-shell structure according to an embodiment of the present invention.

BEST MODE

A tobacco medium according to an embodiment of the present invention includes a pulverized tobacco material and a pH adjuster, wherein the tobacco medium includes at least 70 wt % of the pulverized tobacco material on a dry weight basis, the pulverized tobacco material includes at least 4 wt % of nicotine on a dry weight basis, the tobacco medium includes at least 2.8 wt % of nicotine on a dry weight basis, and a PH of the tobacco medium is in the rage of 6 to 9.
The tobacco medium may be included in a non-combustible aerosol-generating article.
The heating temperature of the article may be 30° C. to 180° C.
The tobacco medium may be manufactured in a form of reconstituted tobacco leaves or granules.
The form of granule may be a structure including a core and a shell surrounding the core.
The tobacco medium may further include a coating layer on an outside of the reconstituted tobacco leaves or granules.
The coating layer may include pores.
A tobacco medium according to an embodiment of the present invention includes a pulverized tobacco material and a pH adjuster, wherein the tobacco medium includes at least 70 wt % of the pulverized tobacco material on a dry weight basis, the pulverized tobacco material includes at least 4 wt % of nicotine on a dry weight basis, the tobacco medium includes at least 2.8 wt % of nicotine on a dry weight basis, and a pH of the tobacco medium is in the range of 6 to 9.
In an aerosol-generating article including a tobacco medium according to an embodiment of the present invention, the tobacco medium includes a pulverized tobacco material and a pH adjuster, wherein the tobacco medium includes at least 70 wt % of the pulverized tobacco material on a dry weight basis, the pulverized tobacco material includes at least 4 wt % of nicotine on a dry weight basis, the tobacco medium includes at least 2.8 wt % of nicotine on a dry weight basis, and a pH of the tobacco medium is in the range of 6 to 9.
The aerosol-generating article may generate an aerosol without combustion when heated at a heating temperature.
The heating temperature of the article may be in the range of 30° C. to 180° C.

MODE FOR INVENTION

Hereinafter, the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily practice it with reference to the accompanying technology. However, it will be apparent to those skilled in the art that the present invention may be embodied in various different forms and is not limited to the embodiments described below.
The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, and it should be understood that this does not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.
Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those skilled in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application.
In addition, it is apparent that the accompanying drawings in the present application are for embodying the present invention and are not intended to limit or restrict the scope of the present invention. What can be easily inferred by an expert in the art from the drawings and the following detailed description is construed as belonging to the scope of the rights.
In one embodiment, the present invention relates to a tobacco medium included in an aerosol-generating article, and specifically to a tobacco medium included in a non-combustible aerosol-generating article.
In the present disclosure, a “non-combustible aerosol-generating article” may refer to a non-combustible cigarette (or non-combustible cigarette article) that generates an aerosol without combustion. By way of example, the non-combustible aerosol-generating article may be a heating type aerosol-generating article or a non-heating type aerosol-generating article.
As an example, the heating type aerosol-generating article may be an article that generates an aerosol by using hot air heated by electrical energy, and a user may smoke by inhaling the aerosol released from the article. In general, an aerosol-generating article may include a medium portion and a filter portion, and the medium portion may include a tobacco medium.
As an example, the non-combustible aerosol-generating article of the present invention may provide sufficient nicotine without off-flavor even at a low temperature (e.g., 30° C. to 180° C.).
FIG. 1 is a diagram for explaining an aerosol-generating article according to an embodiment of the present invention.
Referring to FIG. 1 , an aerosol-generating article 100 may include a tobacco rod 110 and a filter rod 120.
As one embodiment, the filter rod 120 may be composed of a single segment or a plurality of segments. For example, the filter rod 120 may include a first segment for cooling the aerosol and a second segment for filtering a predetermined component included in the aerosol. If necessary, the filter rod 120 may additionally include more segments that perform other functions.
In one embodiment, the tobacco rod 110 and the filter rod 120 may be wrapped by one or more wrappers 130. At least one hole through which external air flows or internal gas flows may be formed in the wrapper 130. As another example, when two or more wrappers 130 are used, the tobacco rod 110 may be packaged by a first wrapper and the filter rod 120 may be packaged by a second wrapper. Then, the tobacco rod 110 and the filter rod 120 wrapped by individual wrappers are coupled, and the entire cigarette can be repackaged by a third wrapper. As another example, if the filter rod 120 is composed of a plurality of segments as described above, the segments may be wrapped by respective wrappers, and then the entire cigarette may be repackaged by another wrapper.
In the present disclosure, a “tobacco medium” may refer to an aerosol-generating material that releases volatile compounds upon heating. The tobacco medium may include tobacco materials having nicotine, such as pH adjusters, leaf tobacco, and may additionally include excipients such as binders or other additives.
In one embodiment, the tobacco medium of the present invention may include a pulverized tobacco material and a pH adjuster.
In one embodiment, the tobacco medium may be prepared in the form of granules, reconstituted tobacco leaves or the like including tobacco materials and excipients.
In the present disclosure, the “tobacco material” may refer to a material forming an aerosol-generating substrate, and may be tobacco leaf pieces, tobacco stems, tobacco dust generated during tobacco processing, and/or a strip of main leaf blade of tobacco leaves. Tobacco leaf may be at least one selected from flue-cured, burley, oriental, cigar leaf, and toast, but is not limited thereto.
In the present disclosure, the “pH adjuster” may serve to alkalize nicotine in a salt state present in a tobacco material to convert it to free-base nicotine. Since nicotine in salt state is difficult to vaporize or aerosolize at a low temperature, nicotine can be alkalized through the pH adjuster to be converted into a form of free-base nicotine and transferred to a user.
In one embodiment, the tobacco medium may include a pulverized tobacco material and a pH adjuster. The tobacco medium may include at least 70 wt % of a pulverized tobacco material on a dry weight basis, and the pulverized tobacco material may include at least 4 wt % of nicotine on a dry weight basis. That is, the tobacco medium includes at least 2.8 wt % of nicotine on a dry weight basis. The pH of the tobacco medium may be in the range of 6 to 9.
In one embodiment, the tobacco medium alkalinizes the tobacco material through the pH adjuster, thereby converting nicotine present in a salt state into free-base nicotine. As a result, vapor pressure may be increased, and thus nicotine transfer is facilitated even under relatively low temperature conditions.
In one embodiment, an amount of nicotine transfer may be increased at a relatively low temperature by using the tobacco medium described above. The tobacco medium may be filled in a non-combustible aerosol-generating article, and the non-combustible aerosol-generating article may be heated by a device at a heating temperature of 30° C. to 180° C.
Accordingly, the tobacco medium according to an embodiment may transfer a sufficient amount of nicotine while minimizing nicotine loss and off-flavor during storage at a heating temperature much lower than that of a general heating type aerosol-generating device.
Specifically, the tobacco material according to an embodiment may include a relatively high nicotine content, and thus a sufficient amount of free-base nicotine can be provided even at a relatively low temperature. In this regard, the tobacco material of the present invention can be useful in a non-heating type aerosol-generating article or a heating type aerosol-generating article having a low heating temperature, and it is possible to achieve miniaturization of a device and minimize battery consumption.
In addition, the tobacco material according to an embodiment may include a relatively high nicotine content, and thus a sufficient amount of free-base nicotine can be provided even at a relatively low pH. Therefore, by applying a relatively low pH, it is possible to reduce the off-flavor generated during conversion to free-base nicotine and reduce a nicotine loss rate during storage. For example, a sufficient amount of free-base nicotine may be provided using a relatively small amount of the pH adjuster.
In one embodiment, the tobacco medium of the present invention may include, on a dry weight basis, at least 70 wt %, preferably at least 75 wt %, more preferably at least 80 wt % of pulverized tobacco material, and an excipient having a pH adjuster. If the tobacco material included in the tobacco medium is below the above-mentioned range, the excipients content becomes overly high, which results in a problem that a sufficient amount of nicotine cannot be provided to a user.
As one embodiment, the pulverized tobacco material included in the tobacco medium of the present invention may include at least 4 wt % of nicotine on a dry weight basis. In one embodiment, the pulverized tobacco material included in the tobacco medium of the present invention may include a relatively high content of nicotine. For example, the nicotine content may be at least 4.5 wt % on a dry weight basis, at least 5 wt % on a dry weight basis, or at least 5.5 wt % on a dry weight basis.
As one embodiment, the tobacco medium of the present invention may include at least 2.8 wt % of nicotine on a dry weight basis. For example, the tobacco medium of the present invention may include at least 3.15 wt %, or at least 3.5 wt %, or at least 3.85 wt % of nicotine on a dry weight basis.
The present invention can provide a high amount of nicotine transfer with a relatively small amount of the pH adjuster by using the tobacco material including a relatively high content of nicotine as described above. In addition, a low pH may be maintained with a relatively small amount of the pH adjuster, and the free-base nicotine content is high even at a relatively low pH. Accordingly, nicotine transfer is facilitated, off-flavor is reduced, and the amount of free-base nicotine lost during storage can be reduced.
As an example, the tobacco material of the present invention may be obtained by pulverizing leaf tobacco of a species having a relatively high nicotine content, or by pulverizing leaf tobacco in which several species are mixed.
As one embodiment, the tobacco medium including the pH adjuster may have a pH of 6 to 9, preferably 6 to 8, and more preferably 6 to 7.
The tobacco medium of the present invention can be characterized in that it can smoothly transfer nicotine even in the above-described pH range that is neutral or weakly basic by including the tobacco material having a relatively high nicotine content.
Examples of the pH adjuster include, but are not limited to, one or more basic inorganic salts selected from the group consisting of alkali metal carbonate, alkaline earth metal carbonate, alkali metal hydrogen carbonate, alkaline earth metal hydrogen carbonate, alkali metal hydroxide, alkaline earth metal hydroxide, alkali metal phosphate, alkaline earth metal phosphate, alkali metal phosphate monohydrogen salt, and alkaline earth metal phosphate monohydrogen salt.
In one embodiment, a non-combustible aerosol-generating article may be filled with the tobacco medium of the present invention. The non-combustible aerosol-generating article may include a non-heating type aerosol-generating article that applies no heat and a heating type aerosol-generating article that applies a relatively low heating temperature. As an example, the heating type aerosol-generating article of the present invention may be an article that applies a lower heating temperature than a typical heating type aerosol-generating article.
According to an embodiment, the aerosol-generating article of the present invention may have a heating temperature of 30° C. to 180° C. of a device. For example, the heating temperature of the tobacco medium during heating may be heated to 100° C. to 180° C. or 150° C. to 180° C. The heating temperature may be at least 30° C.
The tobacco medium of the present invention as described above includes the pulverized tobacco material and the pH adjuster. The tobacco medium may include at least 70 wt % of the pulverized tobacco material on a dry weight basis, and the pulverized tobacco material may include at least 4 wt % of nicotine on a dry weight basis. That is, the tobacco medium may include at least 2.8 wt % of nicotine on a dry weight basis. Also, the pH of the tobacco medium may be 6 to 9. Accordingly, by including the tobacco material with the high nicotine content, it is possible to smoothly transfer nicotine even at a relatively low temperature. Accordingly, the tobacco medium of the present invention can be used in a heating type aerosol-generating article and a non-heating type aerosol-generating article as described above.
As one embodiment, the tobacco medium of the present invention described above is not limited to a particular shape. For example, the tobacco medium may be prepared in the form of reconstituted tobacco leaves or granules.
As an example, the form of reconstituted tobacco leaves may refer to fragments obtained by finely chopping reconstituted tobacco sheets, or it may refer to a plurality of tobacco strands which are cut from reconstituted tobacco sheets.
For example, the reconstituted tobacco sheets are formed by using a slurry which is formed by pulverizing tobacco raw materials such as tobacco leaf pieces, tobacco stems, and/or tobacco fines generated during tobacco processing and mixing them with an aerosol generating material, a flavoring solution, a binder, water, etc. Then, the dried reconstituted tobacco sheets are cut or shredded to form tobacco strands. Meanwhile, natural pulp or cellulose may be added and one or more binders may be mixed in when making the slurry.
As an example, the granular form may be configured as a single layer, or may be configured as a multilayer structure including a core and a shell surrounding the core. Specifically, the granular form having the core-shell structure may be composed of a “core” formed by spheroidizing the pulverized tobacco material, etc. and a “shell” surrounding the core. The shell may have one or more layers.
FIG. 2 schematically shows an embodiment in which a tobacco medium is configured as a granular medium of a core-shell structure according to an embodiment of the present invention.
A granular tobacco medium 200 according to an embodiment of the present invention may have a twofold structure configured of one core 210 and one shell 220 as shown in (a) of FIG. 2 , a threefold structure configured of the core 210 and two-layered shells 220 and 230 as shown in (b) of FIG. 2 , or a triple structure configured of the core 210 and three-layered shells 220, 230, and 240 as shown in (c) of FIG. 2 .
As one embodiment, the core-shell structure of the present invention may be manufactured by a method generally used in the art. For example, the core may be manufactured by spheroidizing the cut tobacco raw material, and preferably may be formed by an atomizing process such as spray chilling.
The core can then be layered with powder to form the shell surrounding the core. Preferably, the core-shell structure may be formed by dispersing the core particles in the shell material that is in a molten state.
As one embodiment, the tobacco medium of the present invention may additionally include a coating layer on an outside. As an example, as described above, the tobacco medium of the present invention may be prepared in the form of reconstituted tobacco leaves or granules, and may include a coating layer surrounding the media in the form of reconstituted tobacco leaves or granules. When the coating layer is additionally included, due to the increase in the hardness of the tobacco medium, manufacturing workability may be improved. The material that can constitute the coating layer may be used without limitation. Examples of such a material may include, as a binder material, one or more selected from the group consisting of alginate; cellulose such as methylcellulose, ethylcellulose, ethylhydroxyethylcellulose and carboxymethylcellulose; dextran; gum; gum derivative such as hydroxyethyl guar gum, hydroxypropyl guar gum, hydroxyethyl locust bean gum and hydroxypropyl locust bean gum; pectin such as fruit pectin, citrus pectin and tobacco pectin; starch such as modified or derivatized starch; pullulan; and konjac powder.
In one embodiment, it is preferable that the coating layer has pores in order to increase an amount of nicotine transfer from the tobacco material included in the tobacco medium of the present invention.
In one embodiment, a heat-not-burn cigarette (i.e., an aerosol-generating article that is heated rather than combusted) may be filled with the medium of the present invention. The medium may be preferably included in a cigarette that is generally indirectly heated with electrical energy.
By way of example, a cigarette including the tobacco medium of the present invention may be inserted into an aerosol-generating article including a heater. When the cigarette is heated by the heater, an aerosol is generated from the tobacco medium, which a user can inhale.
In one embodiment, the tobacco medium of the present invention may include an excipient having the pulverized tobacco material and the excipient. The excipient may include a pH adjuster, a binder, an aerosol former and other additive, except for the tobacco material, but is not limited thereto.
As an example, the binder is a material capable of increasing hardness by allowing the pulverized tobacco material to be well bound, and as described above, any material known in the art may be used without limitation. For example, the binder may include one or more selected from the group consisting of alginate; cellulose such as methylcellulose, ethylcellulose, ethylhydroxyethylcellulose and carboxymethylcellulose; dextran; gum; gum derivative such as hydroxyethyl guar gum, hydroxypropyl guar gum, hydroxyethyl locust bean gum and hydroxypropyl locust bean gum; pectin such as fruit pectin, citrus pectin and tobacco pectin; starch such as modified or derivatized starch; pullulan; and konjac powder.
As an example, the aerosol former is a material that is volatilized when heated above a specific volatilization temperature to transfer nicotine and the like as an aerosol. For example, the aerosol former may include one or more selected from the group consisting of monohydric alcohol such as menthol; polyhydric alcohol such as triethylene glycol, tetraethylene glycol, 1,3-butanediol, erythritol, propylene glycol and glycerol; ester of polyhydric alcohol such as glycerol mono-, di- or triacetate; aliphatic ester of mono-, di- or polycarboxylic acid such as diethyl suberate, dimethyldodecanedioate, dimethyl tetradecanedioate, ethyl laurate, lauryl acetate and triethyl citrate; benzyl benzoate; benzyl phenyl acetate; ethyl vanylate; lauric acid; myristic acid; propylene carbonate; and tributyrin, but is not limited thereto.
In one embodiment, the excipient included in the tobacco medium of the present invention may additionally include one or more selected from the group consisting of a wetting agent, a plasticizer, a flavoring agent, a tobacco and non-tobacco fiber, an aqueous and non-aqueous solvent, and a combination thereof as other additive, but is not limited thereto.
As an example, the wetting agent is a material that helps to maintain a desired level of moisture in the tobacco medium, and may include, but is not limited to, glycerin or propylene glycol.
As an example, the plasticizer is an agent that increases a moldability by making the material flexible, and may include, for example, one or more selected from the group consisting of triacetin, dibutyl phthalate, dibutyl sebacate, diethyl phthalate, dimethyl phthalate, acetyltributyl citrate, acetyltriethyl citrate, diacetylated monoglyceride, dibutyl sebacate, mineral oil, benzyl benzoate, chlorbutanol, glycerin monostearate, lanolin alcohol, and cellulose acetate phthalate compatible plasticizer, but is not limited thereto.
As an example, a flavor may also be referred to as a flavoring agent, and may be an agent that imparts taste and/or aroma to an aerosol generated from a tobacco material. The agent may include licorice, sucrose, fructose syrup, isosweet, cocoa, lavender, cinnamon, cardamom, celery, fenugreek, cascarilla, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, mint oil, caraway, cognac, jasmine, chamomile, menthol, cinnamon, ylang-ylang, sage, spearmint, ginger, coriander or coffee, and the like, but is not limited thereto.
As an example, a tobacco cellulose fiber may be included as a tobacco fiber, and a non-tobacco cellulose fiber may be included as a non-tobacco fiber. The inclusion of cellulosic fiber can advantageously increase the tensile strength of the tobacco medium. By way of example, a suitable non-tobacco cellulosic fiber is known in the art and may include one or more selected from the group consisting of a hardwood fiber, a softwood fiber, a jute fiber, and a flax fiber, but is not limited thereto.
An embodiment of the present invention may provide an aerosol-generating article including the tobacco medium described above. Specifically, the aerosol-generating article of the present invention may be a non-combustible aerosol-generating article. It may generally include a filter portion and a medium portion, and the medium portion may include the tobacco medium of the present invention.
As an example, the aerosol-generating article may be manufactured in a generally cylindrical shape, and may preferably have a diameter in the range of 5 mm to 8 mm to have the same shape and size as a conventional combustible cigarette, but is not limited thereto. In addition, as an example, the filter portion included in the aerosol-generating article may be of a type commonly used in the art to which the present invention pertains.
Hereinafter, examples are given for a detailed description of the present invention. The present invention is not limited to the following examples, and in the following examples, “%” means wt % unless otherwise specified.

EXAMPLE

1. Comparison of Properties According to pH of the Tobacco Media Including the Same Tobacco Material

(1) Tobacco Media Preparation and pH Measurement

A tobacco medium was prepared using the pulverized tobacco material having the same nicotine content. Tobacco leaves, tobacco stems, and the like were pulverized, and after making a slurry by including potassium carbonate as a basic pH adjuster, glycerol as an aerosol former, hydroxyethyl guar gum as a binder, water to help form granules, and ethanol as a solvent as shown in the composition in Table 1 below, granules were formed. The pulverized tobacco material included in the granules (a) and (b) has a nicotine content of about 2.9 wt %.

TABLE 1

Component (g)	Granule (g)	Granule (b)

Pulverized tobacco material	100	100
Potassium carbonate	3.5	8.0
Binder	1	1
Solvent	64	64

The pH of the granules (a) and (b) at room temperature (about 25° C.) was measured with a pH meter. Granule (a) showed a pH of 7.54, and granule (b) showed a pH of 8.87.
For each granule, the free-base nicotine content was calculated using the Henderson-Hasselbalch equation of Equation 1 below. The free-base nicotine content among the total nicotine content of the granule (a) was 24.87 wt %, and the free-base nicotine content among the total nicotine content of the granule (b) was 87.62 wt %.
$\begin{matrix} pH = pKa + \log \frac{B}{[{BH}^{+}]} & [Equation 1] \end{matrix}$ $B + H^{+} \vec{\leftarrow} {BH}^{+}$ $% free base nicotine = \frac{\frac{B}{[{BH}^{+}]}}{\frac{B}{[{BH}^{+}]} + 1} \times 100$

- (*Henderson-Hasselbalch equation and by using a pKa value of 8.02)

(2) Measurement of an Amount of Nicotine Transfer and Sensory Evaluation

A stick (i.e., cigarette) containing the tobacco medium prepared in experiment 1.(1) above was prepared. The amount of nicotine transfer (mg/10 puff) during 10 puffs was measured by heating the stick at a temperature of about 70° C., and the off-flavor, pungency, and overall preference during smoking were scored on a 7-point scale and an average value is shown in Table 2 below.
Off-flavor during smoking refers to a taste or aroma that does not harmonize with the original taste or aroma of cigarettes and lowers the value of a product. The weaker off-flavor a user felt during smoking, the lower the score.
Pungency refers to the degree of stinging, tingling, or pricking sensation in a throat, nose, or mouth 1 second after inhalation. The lower the pungency, the lower the score.
The overall tobacco taste was evaluated such that the score becomes higher (i.e., closer to 7 points) as the desirability of the cigarette was higher based on the overall flavor of cigarettes felt after inhalation.
That is, the lower sensory evaluation score for off-flavor and pungency indicates the better evaluation result. By contrast, the higher sensory evaluation score for the overall tobacco taste indicates the better evaluation results.

TABLE 2

	Amount of	Off-flavor		Overall
	nicotine transfer	during		tobacco
Category	(mg/10 puff)	smoking	Pungency	taste

Granule (a)	0.79	3.1	3.6	4.7
Granule (b)	1.46	3.8	4.8	4.2

As a result, even if the nicotine content of the pulverized tobacco material was the same, the stick containing the tobacco medium with a high pH delivered a larger amount of nicotine even at a low temperature due to the high free-base nicotine content. In addition, even if the same pulverized tobacco material was used, it was found that the stick containing the tobacco medium with a high pH (granule (b)) had strong off-flavor and pungency during smoking, and a low score was given for the overall tobacco taste.

(3) Nicotine Storage Evaluation

Nicotine storage property was evaluated for the tobacco medium prepared in experiment 1.(1) above. It was observed for about 8 weeks under two storage conditions: the medium was opened (OPEN); and the medium was sealed in a plastic bag at room temperature. The results are shown in Table 3 below.

TABLE 3

	Storage	Nicotine reduction rate
Category	condition	after 8 weeks (wt %)

Granule (a)	OPEN	28.9
	Plastic bag	17.8
Granule (b)	OPEN	88.1
	Plastic bag	47.0

As a result, the tobacco medium with a high pH (granule (b)) showed a high nicotine reduction rate after 8 weeks.

2. Comparison of Properties of a Tobacco Media Including Different Tobacco Materials

(1) Tobacco Media Preparation and pH Measurement

Tobacco media in the form of granules including the tobacco material with a high nicotine content was prepared (Examples 1 and 2). By pulverizing leaf tobacco having a nicotine content of about 6.4 wt %, the slurry was formed as in experiment 1.(1) above, by including potassium carbonate as a basic pH adjuster, glycerol as an aerosol former, hydroxyethyl guar gum as a binder, water to help form granules, ethanol as a solvent, as in the composition of Table 4 below, and then granules were formed.
In Comparative Example 1, a slurry was prepared using the pulverized tobacco material having a nicotine content of about 2.9 wt %, in the manner as described above, and then granules were formed.

TABLE 4

			Comparative
Components (g)	Example 1	Example 2	Example 1

Pulverized tobacco material	100	100	100
Potassium carbonate	3.5	5.0	3.5
Binder	1	1	1
Solvent	64	64	64

For each tobacco medium of Examples 1 and 2 and Comparative Example 1, when a pH was measured with a pH meter at room temperature (about 25° C.), Example 1 showed a pH of 6.6, Example 2 showed a pH of 7.3, and Comparative Example 1 showed a pH of 7.3. Example 1 and Comparative Example 1 had the same pH adjuster content, but Comparative Example 1 exhibited a higher pH, indicating a pH of 7.3, which was the same as that of Example 2.
Based on this, for each tobacco medium, the free-base nicotine content was calculated using the Henderson-Hasselbalch equation of Equation 1 above. As a result of the calculation, the free-base nicotine content among the total nicotine content of Example 1 was 6.6 wt %, and the free-base nicotine content among the total nicotine content of Example 2 and Comparative Example 1 was 16 wt %.

(2) Measurement of an Amount of Nicotine Transfer

Sticks containing the tobacco medium of Examples 1 and 2 and Comparative Example in experiment 2.(1) above were prepared. Each stick was filled with 400 mg of tobacco medium and heated to a temperature of about 70° C., and the amount of nicotine transfer (mg/10 puff) was measured during 10 puffs. The amount of free-base nicotine was calculated and shown in Table 5 below.

TABLE 5

			Comparative
Category	Example 1	Example 2	Example 1

An amount of nicotine	0.44	0.76	0.32
transfer (mg/10 puff)
Calculated value of	1.00	4.06	1.86
free-base nicotine
(mg/400 mg)

As a result, Example 1 with a low pH showed a higher amount of nicotine transfer. In addition, Comparative Example 1 and Example 2 had the same PH, but an amount of nicotine transfer of Example 2 was higher than that of Comparative Example 1.
Compared to Comparative Example 1 including a conventional tobacco material having a nicotine content of 0.1 wt % to 3.5 wt %, it can be seen that when the tobacco raw material having a high nicotine content of at least 4 wt % was used as in the example, more nicotine could be transferred at a lower pH, so there were advantages in terms of off-flavor and storability.
Although the above has been described with reference to the preferred embodiment of the present invention, it can be understood that those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention as described in the claims below.

Claims

What is claimed is:

1. A tobacco medium comprising:

a pulverized tobacco material; and

a pH adjuster,

wherein the tobacco medium includes at least 70 wt % of the pulverized tobacco material on a dry weight basis,

the pulverized tobacco material includes at least 4 wt % of nicotine on a dry weight basis,

the tobacco medium includes at least 2.8 wt % of nicotine on a dry weight basis, and

a PH of the tobacco medium is in a range of 6 to 9.

2. The tobacco medium according to claim 1, wherein the tobacco medium is included in a non-combustible aerosol-generating article.

3. The tobacco medium according to claim 2, wherein the aerosol-generating article has a heating temperature of 30° C. to 180° C.

4. The tobacco medium according to claim 1, wherein the tobacco medium is manufactured in a form of reconstituted tobacco leaves or granules.

5. The tobacco medium according to claim 4, wherein the form of granules is a structure including a core and a shell surrounding the core.

6. The tobacco medium according to claim 4, wherein the tobacco medium further includes a coating layer on an outside of the reconstituted tobacco leaves or granules.

7. The tobacco medium according to claim 4, wherein the coating layer has pores to increase an amount of nicotine transfer from the tobacco material.

8. An aerosol-generating article comprising a tobacco medium,

wherein the tobacco medium comprises a pulverized tobacco material and a pH adjuster,

the tobacco medium includes at least 70 wt % of the pulverized tobacco material on a dry weight basis;

a pH of the tobacco medium is in a range of 6 to 9.

9. The aerosol-generating article according to claim 8, wherein the aerosol-generating article generates an aerosol without combustion when heated at a heating temperature.

10. The aerosol-generating article according to claim 9, wherein the heating temperature is in a range of 30° C. to 180° C.