Dried tobacco leaves and smoking articles

Abstract

A dried tobacco leaf obtained by drying such that it exhibits a green color. The dried tobacco leaf preferably has an a value of -2 or less, as measured according to the Lab method defined in CIE 1976.

Description

Technical Field

[0001] This invention relates to a dried tobacco leaf and to a smoking article. Background Technology

[0002] In noncombustible tobacco products, tobacco sticks are typically heated at approximately 150°C–350°C to volatilize and generate flavor components, which are then delivered along with an aerosol. In other words, tobacco raw materials capable of effectively producing flavor and aroma within a temperature range of 150°C–350°C are desirable in noncombustible tobacco products.

[0003] Raw materials conventionally used in combustible tobacco products are often used as tobacco raw materials in non-combustible smoking products. Existing tobacco raw materials are classified into several types based on variety, such as flue-cured (Virginia), Burley, and aromatic tobacco. Flue-cured tobacco is a tobacco raw material with a rich aroma and is widely used in combustible tobacco products known as flue-cured blends. Burley tobacco has a strong flavor and is used in combustible tobacco products known as American blends. Aromatic tobacco has characteristic flavors and can balance the overall flavor and aroma of blends.

[0004] The quality of raw materials is greatly influenced by variety and cultivation methods, and also largely depends on post-harvest processing methods, such as curing. Throughout the long history of tobacco cultivation, curing methods suitable for each variety have been extensively studied, and appropriate drying methods for each corresponding variety have now been established. Flue-cured tobacco undergoes a process called curing after harvest. This involves drying the raw material for 5-7 days in a controlled environment, typically with temperatures gradually increased to 30°C-70°C (NPTL 1 and 2). Burley tobacco undergoes a process called air-drying after harvest. This involves drying the raw material at approximately ambient temperature for 30-40 days without exposure to direct sunlight (NPTL 3). Aromatic tobacco is first air-dried for one day after harvest, then dried by exposure to sunlight (called sun-drying / air-drying), and may also undergo fermentation depending on the variety (NPTL 4).

[0005] Therefore, the methods and conditions for drying tobacco leaves vary greatly depending on the variety. Although the appearance quality also varies depending on the variety, one contributing factor is the difference in processing. For example, dried flue-cured tobacco exhibits a yellowish-brown color. Dried burley tobacco exhibits a dark brown color. Aromatic tobacco varies further depending on the variety grown, but exhibits a slightly greenish-brown color.

[0006] In the United States, from the 1930s to the 1950s, scientific explanations were developed for the quality changes during conditioning. These findings were compiled by Frankenburg et al. in a review (NPTL 5). Changes in the early stages of conditioning were thought to occur primarily due to changes induced by plant respiration, and after cell death, changes in chemical composition occurred due to residual enzyme activity. Typical component changes included protein hydrolysis, accompanied by an increase in soluble nitrogen components such as certain amino acids and ammonia (NPTL 6). Starch was hydrolyzed and converted into low-molecular-weight sugars, including monosaccharides (NPTL 2). These reactions occurred because the counterbalancing processes that normally occur in growing tobacco leaves were lost. In other words, the metabolism of these components differed fundamentally from that during growth. Simultaneously with hydrolysis, various components also changed through oxidation. As conditioning progressed, the dynamic balance of the redox system inherent in living plants was lost, and many internal components of the tobacco leaf became significantly oxidized. Carbohydrates and organic acids were oxidized under the influence of enzyme groups involved in the respiratory system within the living organism (NPTL 7 and 8). Phenolic and polyphenolic compounds, as well as terpenoids, also undergo oxidative decomposition (NPTL 9 to 11). As mentioned above, several methods exist for processing tobacco, depending on the variety and purpose. Among these, air-drying actively induces oxidation of the chemical components. Simultaneously, roasting is designed to minimize the effects of oxidation. Citation List

[0007] Non-patent literature

[0008] [NPTL 1] Peedin, GF: Production practices: Flue-cured tobacco, pp. 104-142. In Tobacco: Production Chemistry and Technology, edited by Davis, DL, Nielsen, MT; Blackwell Science: Oxford, UK (1999).

[0009] [NPTL 2] Abubakar, Y., Young, JH, Johnson, WH and Weeks, WW: Changes in moisture and chemical composition of flue-cured tobacco during curing. Tob. Sci., 44, 51-58 (2000)

[0010] [NPTL 3] Palmer, GK and Pearce, RC: Production practices: Lightair-cured tobacco, pp. 143-153. In Tobacco: Production Chemistry and Technology, edited by Davis, DL, Nielsen, MT; Blackwell Science: Oxford, UK (1999).

[0011] [NPTL 4] Gilchrist, SN: Production practices: Oriental tobacco, pp. 154-163. In Tobacco: Production Chemistry and Technology, edited by Davis, DL, Nielsen, MT; Blackwell Science: Oxford, UK (1999).

[0012] [NPTL 5] Frankenburg, WG: Chemical Changes in the Harvested Tobacco Leaf. I. Chemical and Enzymatic Conversations during the Curing Process. Advances in Enzymolozy, Vol. VI, 6, 309-387 (1946)

[0013] [NPTL 6] Young, JR and Jeffrey, RN: Changes in certain water-soluble nitrogenous constituents of burley tobacco during storage. Plant Plysiol, 18, 433-438 (1943).

[0014] [NPTL 7] Pucher, GW and Vickery, HB: The metabolism of the organic acids of tobacco leaves; effect of culture of excised leaves in solutions of organic acid salts. J. Biol. Chem., 178, 557-575 (1949)

[0015] [NPTL 8] Vickert, HB and Abrahams, MD: The metabolism of the organic acids of tobacco leaves; effect of culture of excised leaves in solutions of d-isocitrate and acetate. J. Biol. Chem., 180, 37-45 (1949)

[0016] [NPTL 9] Sheen, SJ and Calvert, J.: Studies on polyphenol content, activities and isozymes of polyphenol oxidase and peroxidase during air-curing in three tobacco types. Plant Physiol. 44, 199-204 (1969)

[0017] [NPTL 10] Weston, TJ: Biochemical characteristics of tobacco leaves during flue-curing. Phytochemistry, 7, 921-930 (1968).

[0018] [NPTL 11] Wahlberg, I., Kerstin, K., Austin, DJ, Junker, D., Roeraade, J., Enzell, CR, and Johnson, WH: Effects of flue-curing and aging on the volatile, neutral, and acidic constituents of Virginia tobacco. Phytochemistry, 16, 1217-1231 (1977) Summary of the Invention

[0019] The problem to be solved by the present invention

[0020] Based on years of research and experience, the technology for adjusting the process of drying tobacco leaves to obtain dried leaves of desired quality—that is, conditioning technology—has been passed down to this day. However, the "quality" mentioned herein is a prerequisite for use in combustible tobacco products and is not necessarily considered optimal for non-combustible tobacco products. Conversely, even raw materials considered unsuitable for combustible tobacco products may provide unexpected effects for non-combustible tobacco products. In view of these circumstances, the problem to be solved by the present invention is to provide dried tobacco leaves suitable for non-combustible tobacco products.

[0021] Solution to the problem

[0022] Conventionally, tobacco leaves are dried to a brown color before use. However, the inventors of this invention have discovered that when this drying process is carried out, the components suitable for non-combustible smoking products are reduced, but when a specific drying process is performed, these components are not lost. In other words, the above problem is solved by the following invention.

[0023] Aspect 1

[0024] A type of dried tobacco leaf, obtained by drying it to reveal its green color.

[0025] Aspect 2

[0026] As disclosed in aspect 1, the dried tobacco leaves have an a content of -2 or less. Values, such as L as defined in CIE 1976 a b The method was used for measurement.

[0027] Aspect 3

[0028] As disclosed in aspect 1 or 2, the dried tobacco leaves include the step of placing the harvested fresh leaves in an environment of 45°C or lower until the moisture content of the leaf portion becomes 25 wt% or less.

[0029] Aspect 4

[0030] The dried tobacco leaves disclosed in any one of aspects 1 to 3, wherein the drying includes placing the harvested fresh leaves in an environment of 30°C-40°C and 60%-70% relative humidity for 6-12 hours, followed by placing the leaves in an environment of 45°C or lower until the moisture content of the leaf portion becomes 25 wt% or less.

[0031] Aspect 5

[0032] The dried tobacco leaves disclosed in any of aspects 1 to 4 are produced by removing only the leaf portion during the drying stage, wherein the moisture content of the leaf portion has been reduced to 12 wt% or less.

[0033] Aspect 6

[0034] The dried tobacco leaves disclosed in any of aspects 1 to 5 are common tobacco (Nicotiana tabacum).

[0035] Aspect 7

[0036] The dried tobacco leaves disclosed in any of aspects 1 to 6 are Burley tobacco.

[0037] Aspect 8

[0038] A tobacco composition comprising dried tobacco leaves as disclosed in any one of aspects 1 to 7, wherein the composition contains 5-90 wt% of the dried tobacco leaves.

[0039] Aspect 9

[0040] The composition disclosed in aspect 8 further comprises 3-30 wt% of an aerosol source.

[0041] Aspect 10

[0042] The composition disclosed in aspect 9, wherein the aerosol source is selected from the group consisting of glycerol, propylene glycol, 1,3-propanediol and combinations thereof.

[0043] Aspect 11

[0044] The composition disclosed in any one of aspects 8 to 10 further comprises 5-85 wt% reconstituted cut tobacco or 5-85 wt% cut tobacco.

[0045] Aspect 12

[0046] The compositions disclosed in any of aspects 8 to 11 further comprise a non-tobacco flavoring agent.

[0047] Aspect 13

[0048] The composition disclosed in aspect 12, wherein the non-tobacco flavoring agent is selected from the group consisting of flavoring agents, coolants, and combinations thereof.

[0049] Aspect 14

[0050] The composition disclosed in aspect 13, wherein the flavoring agent is menthol.

[0051] Aspect 15

[0052] A heated non-burning smoking article comprising dried tobacco leaves as disclosed in any one of aspects 1 to 9, or a composition as disclosed in any one of aspects 8 to 14.

[0053] Advantages of the present invention

[0054] This invention enables the provision of dried tobacco leaves suitable for non-combustible smoking products. Attached Figure Description

[0055] [ Figure 1 An example of a heated but non-burning smoking product is shown.

[0056] [ Figure 2 An embodiment of a heated, non-burning smoking system is shown.

[0057] [ Figure 3 [Image] is a diagram showing a method for producing dried tobacco leaves.

[0058] [ Figure 4 The image above is a diagram showing the comparison example and the steps in the example. Detailed Implementation

[0059] In this disclosure, the range “XY” includes X and Y as endpoints. Furthermore, in this disclosure, unless otherwise stated, “weight” means dry weight.

[0060] 1. Dried tobacco leaves

[0061] According to this embodiment, the dried tobacco leaves are obtained by drying harvested tobacco leaves (fresh leaves) to make them appear green. Making the harvested tobacco leaves appear green by drying them avoids the reduction of components suitable for non-combustible smoking products. The dried tobacco leaves can be actual leaves obtained through drying, or leaf segments separated from leaves obtained through drying.

[0062] The hue of the dried tobacco leaves is not limited, as long as they are visually recognizable as green. However, on the other hand, the dried tobacco leaves preferably have an a content of -2 or less. Values, such as L as defined in CIE 1976 a b The method was used for measurement. The value is more preferably -4 or smaller. For a There is no lower limit to the value, but it is preferably -8 or greater. The values ​​correspond to positions between magenta and green, with larger values ​​closer to magenta and smaller values ​​closer to green.

[0063] L value, a value and b The value can be measured on the surface of the tobacco leaf using a spectrophotometer (e.g., KONICA MINOLTA / CM3500d, Konica Minolta Holdings, Inc., etc.). Specifically, the surface of the tobacco leaf is illuminated with standard light (the standard light source D65, CIE and ISO reference light used for colorimetry), and the reflected light is measured (reflected color measurement / exclusion of specular component (SCE) method) to determine a. Values, etc. The color definition conforms to the standards of the International Commission on Illumination (CIE) and JIS.

[0064] In one embodiment, the component suitable for non-combustible smoking articles (hereinafter also referred to as "Component H") is a component having a retention index (RI) of 1800-3100 in gas chromatography. Component H expresses the inherent aroma of tobacco. Component H is a group of components including chlorophyll, leaf surface resins, higher fatty acids, and partially decomposed products of higher hydrocarbons. Specifically, Component H includes neophytadiene (RI = 1842), phytol (RI = 2114), α-cerebrominated trienediol (α-CBT, RI = 2242), and linoleic acid (RI = 2145), etc. Meanwhile, the component having an RI of 1365 or greater and less than 1800 (hereinafter also referred to as "Component L") is a group of components including cerebrominated trienediene decomposition products and carotenoid decomposition products. Component L includes 3-oxo-α-ionone (RI = 1648), solanone (RI = 1368), norsanodione (RI = 1489) and megastigmatrienone (RI = 1581), etc.

[0065] RI can be determined by well-known methods using a mixture of standard n-alkanes, but is preferably determined by the following method.

[0066] 1) Dilute a standard n-alkane mixture (e.g., C7-C40 manufactured by Merck) with hexane and use hexane (C6) to tetradecane (C40) as an index.

[0067] 2) Determine the linear retention index based on the following equation and regard it as RI.

[0068] RI = 100×{[(tr(unknown)-tr(n)] / [tr(N)-tr(n)]+n}

[0069] n = the number of carbon atoms in the n-alkane eluted immediately before the unknown component.

[0070] N = The number of carbon atoms in the n-alkane eluted immediately after the unknown component.

[0071] tr = Retention time

[0072] The dried tobacco leaves are preferably common tobacco, and more preferably Burley tobacco. Burley tobacco has a low sugar content, and therefore the production of grain-like aromas can be reduced. Heated tobacco products produce characteristic grain-like aromas during use. It is preferable to suppress this aroma. One reason for the production of grain-like aromas is the decomposition of sugar components. Due to heating, sugars produce thermally decomposing components, typically furans. That is, when the dried tobacco leaves have a high sugar content, grain-like aromas may increase. Catabolism occurs during the drying process of fresh leaves, thereby increasing sugars, and as a result, grain-like aromas may be produced. However, when using Burley tobacco, grain-like aromas can be suppressed.

[0073] 2. A method for producing dried tobacco leaves

[0074] According to this embodiment, the dried tobacco leaves are obtained by drying harvested fresh leaves under conditions that allow the dried leaves to exhibit a green color. However, when fresh leaves are dried at high temperatures from the beginning, brown dried tobacco leaves tend to be obtained. The reasons for this are not limited, but when fresh leaves are suddenly exposed to high temperatures, the cells in the fresh leaves are damaged, and enzymes that oxidize component H in the fresh leaves are released outside the cells. It is presumed that component H is oxidized due to the reaction between the enzymes and component H. Therefore, drying is preferably carried out in stages.

[0075] In one mode, drying preferably includes the step of placing fresh leaves in an environment of 45°C or lower until the moisture content of the leaf portion becomes 25 wt% or less (low-temperature drying step). When drying is carried out at low temperatures in this manner, drying simultaneously inhibits cell damage in the fresh leaves, so component H is less likely to oxidize and browning is less likely to occur. The upper limit of the target moisture content of the leaf portion (hereinafter also referred to as "target moisture content") is preferably 20 wt% or less. There is no limitation on the lower limit of the target moisture content, but it is preferably 15 wt% or more. There is no limitation on the lower limit of the temperature, but from the perspective of efficiency, etc., the temperature is preferably 35°C or more. There is no limitation on humidity, but it is preferably 30%-40% relative humidity (30%-40% RH).

[0076] The dried tobacco leaves obtained in the low-temperature drying step preferably undergo a drying process at 65°C-75°C and 15%-25% RH to reduce the moisture content of the leaf portion to 12 wt% or less (high-temperature drying step). Figure 3This mode is illustrated in (1). The leaf and vein portions are exposed to high temperatures through a high-temperature drying step, but since moisture has been removed from the leaf portions, the oxidation reaction of component H produced by enzymes is inhibited, and browning is also suppressed. The upper limit of the target moisture content in this step can also be set to 10 wt% or less. Meanwhile, excessive drying may cause the decomposition of component H, therefore the lower limit of the moisture content in the leaf portions is preferably 8 wt% or more. The temperature is preferably 67°C-70°C. Furthermore, the humidity is preferably 17%-23% RH.

[0077] After this step, the leaf portion and vein portion can be separated, and the leaf portion can be used as dried tobacco. When the leaf portion is used as dried tobacco at this stage, when its moisture content is 12 wt% or less, discoloration of the leaf portion can be suppressed. The reason is as follows: In the typical process of drying tobacco, the leaf portion is dried first, while the vein portion still contains a large amount of moisture at this stage. If heating and drying continue until the vein portion is dry, the leaf portion will discolor. However, by preferentially drying the leaf portion and separating it, discoloration can be suppressed. Furthermore, preferentially drying and separating the leaf portion prevents tobacco deterioration and degradation due to residual moisture in the leaf portion during steps after tobacco removal, i.e., during packaging, storage, and distribution.

[0078] Preferably, the dried tobacco leaves obtained in the high-temperature drying step are subjected to humidity conditioning. There are no restrictions on the humidity conditioning conditions, but 20°C-25°C and 50%-70% RH are preferred. Humidity conditioning prevents the tobacco leaves from cracking during removal and packaging operations. From this perspective, the temperature is preferably 21°C-23°C, and the humidity is preferably 55%-65% RH. Figure 3 (2) shows a preferred mode that includes a humidity control step.

[0079] Prior to the low-temperature drying step, a humidity conditioning step (pretreatment step) can be provided on the fresh leaves at a temperature of 30°C-40°C and a RH of 60%-70%. Pretreatment allows for better suppression of component changes caused by the aforementioned cell damage. From this perspective, the temperature is preferably 32°C-38°C, and the humidity is preferably 62%-67% RH. Figure 3 (3) shows a preferred mode that includes a humidity control step.

[0080] 3. Tobacco Composition

[0081] Dried tobacco leaves can be used as tobacco compositions. The composition preferably contains 5-90 wt%, and more preferably 30-70 wt%, of dried tobacco leaves (hereinafter also referred to as "component (A)").

[0082] (1) Tobacco materials other than dried tobacco leaves (hereinafter also referred to as "Component (B)")

[0083] The tobacco composition may contain tobacco material (component (B)) other than dried tobacco leaves. Component (B) is not limited, as long as it is material derived from plants of the genus *Nicotiana*. Specific examples of component (B) that may be listed include cut tobacco, tobacco powder, tobacco sheets, and shredded tobacco commonly used in the art. These tobacco materials may be used alone or in combination. Component (B) is preferably cut tobacco or cut material obtained from tobacco sheets, from the perspective of better miscibility with component (A).

[0084] For example, common tobacco and yellow tobacco (Nicotiana rustica), belonging to the genus Nicotiana, can be appropriately used as tobacco leaves in component (B). Varieties that can be used include, but are not limited to, well-known varieties such as burley and flue-cured tobacco. One or more of these tobacco varieties can be blended for use. Suitable blends of the aforementioned varieties can be used as mixtures to achieve the desired flavor.

[0085] The amount of component (B) in the composition is preferably 5-85 wt%, and more preferably 25-65 wt%.

[0086] (2) Aerosol source (hereinafter also referred to as "component (C)")

[0087] The tobacco composition may contain an aerosol source (component (C)). Component (C) is a material that is heated and vaporized and cooled to produce an aerosol, or atomized to produce an aerosol. When the composition contains an aerosol source, a sufficient amount of smoke can be achieved. Known aerosol sources can be used, examples of which include: polyols such as glycerol, vegetable glycerol, propylene glycol (PG), and 1,3-propanediol; and triethyl citrate (TEC) and triacetin. The aerosol source is preferably selected from the group consisting of glycerol, propylene glycol, 1,3-propanediol, and combinations thereof. The amount of the aerosol source in the composition is preferably 3-30 wt%, and more preferably 10-15 wt%. An amount of aerosol source exceeding the upper limit may cause staining of tobacco segments, etc., and an amount below the lower limit risks reducing the perceived smoke delivery.

[0088] (3) Non-tobacco flavorings (component (D))

[0089] The tobacco composition may further contain non-tobacco flavoring agents (also referred to as "component (D)"). Non-tobacco flavoring agents are flavoring agents that are not derived from tobacco. Examples that can be listed include flavoring agents, cooling agents, and combinations thereof. Well-known flavoring agents and cooling agents can be used.

[0090] The following can be used alone or in combination as flavoring agents:

[0091] p-Methoxyacetophenone, acetophenone, acetylpyrazine, 2-acetylthiazole, alfalfa extract, pentanol, amyl butyrate, trans-anisole, star anise oil, apple juice, Peruvian gum oil, beeswax absolute, benzaldehyde, benzoin extract, benzyl alcohol, benzyl benzoate, benzyl phenylacetate, benzyl propionate, 2,3-butanedione, 2-butanol, butyl butyrate, butyric acid, caramel, cardamom oil, carob absolute, β-carotene, carrot juice, L-carvone, β-caryophyllene, cinnamon bark Oils, cypress oil, celery seed oil, chamomile oil, cinnamaldehyde, cinnamic acid, cinnamyl alcohol, cinnamyl cinnamate, citronellol, DL-citronellol, sage extract, cocoa, coffee, chamomile oil, coriander oil, cuminaldehyde, artemisia oil, δ-decanoic acid, γ-decanoic acid, decanoic acid, dill oil, 3,4-dimethyl-1,2-cyclopentanedione, 4,5-dimethyl-3-hydroxy-2,5-dihydrofuran-2-one, 3,7-dimethyl-6-octenic acid, 2,3-dimethyl... Pyrazine, 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, ethyl 2-methylbutyrate, ethyl acetate, ethyl butyrate, ethyl hexanoate, ethyl isovalerate, ethyl lactate, ethyl laurate, ethyl acetopropionate, ethyl maltol, ethyl octanoate, ethyl oleate, ethyl palmitate, ethyl phenylacetate, ethyl propionate, ethyl stearate, ethyl valerate, ethyl vanillin, ethyl vanillin glucoside, 2-ethyl-3,(5 or 6)-dimethylpyrazine, 5-ethyl-3-hydroxy 4-Methyl-2(5H)-furanone, 2-ethyl-3-methylpyrazine, eucalyptol, fenugreek oil, broom oil, gentian root extract, geraniol, geraniol acetate, grape juice, guaiacol, guava extract, γ-heptanol, γ-caprolactone, hexanoic acid, cis-3-hexen-1-ol, hexyl acetate, hexanol, hexyl phenylacetate, honey, 4-hydroxy-3-pentenoic acid lactone, 4-hydroxy-4-(3-hydroxy-1-butenyl)-3,5,5-Trimethyl-2-cyclohexen-1-one, 4-(p-hydroxyphenyl)-2-butanone, sodium 4-hydroxyundecanoate, immortelle absolute oil, β-ionone, isoamyl acetate, isoamyl butyrate, isoamyl phenylacetate, isobutyrate, isobutyl phenylacetate, jasmine absolute oil, kola nut extract, rockrose oil, terpene-free lemon oil, licorice extract, linalool, linalyl acetate, Angelica sinensis root oil, maltol, maple syrup, menthol, menthone, L-menthol acetate, p-methoxybenzaldehyde, methyl-2-pyrrole 4'-Methylacetophenone, methyl anthranilate, methyl phenylacetate, methyl salicylate, 4'-methylacetophenone, methylcyclopentenolone, 3-methylvaleric acid, mimosa absolute oil, molasses, myristic acid, nerol, nerolidol, γ-nonalactone, myristole oil, δ-octylactone, octanal, caprylic acid, neroli oil, orange oil, orris root oil, palmitic acid, ω-pentadecanolactone, peppermint oil, Paraguayan orange leaf oil, phenethyl alcohol, phenylacetic acid, phenylacetic acid, piperaldehyde, plum extract, propenyl ethyl guaiacol, propionate, 3-propyl Indole, plum juice, pyruvic acid, raisin extract, rose oil, rum, sage oil, sandalwood oil, spearmint oil, styrax essential oil, marigold oil, tea distillate, α-terpinene ester, terpinene acetate ester, 5,6,7,8-tetrahydroquinoxaline, 1,5,5,9-tetramethyl-13-oxehera (8.3.0.0(4.9))tridecane, 2,3,5,6-tetramethylpyrazine, thyme oil, tomato extract, 2-tetranone, triethyl citrate, 4-(2,6,6-trimethyl... 1-Cyclohexenyl)-2-buten-4-one, 2,6,6-trimethyl-2-cyclohexen-1,4-dione, 4-(2,6,6-trimethyl-1,3-cyclohexadienyl)-2-buten-4-one, 2,3,5-trimethylpyrazine, γ-undecyl lactone, γ-valerol lactone, vanilla extract, vanillin, veratral, violet leaf essential oil, N-ethyl-p-menthane-3-carbamate (WS-3), and ethyl-2-(p-menthane-3-carbamate)acetate (WS-5).

[0092] Menthol is preferred. Ordinary tobacco materials contain a relatively large amount of a component (component L) with an RI of 1600 or less. In ordinary tobacco materials, there is interference between the flavoring agent and component L, and the characteristics of the flavoring agent may not be fully expressed. However, the tobacco composition of this embodiment can fully express the characteristics of the flavoring agent. Menthol has an RI of 1600 or less, therefore the tobacco composition containing menthol allows for a proper enjoyment of the menthol flavor.

[0093] Tobacco compositions can be produced by well-known methods. For example, tobacco filling materials can be produced by mixing these components. Alternatively, the composition can be prepared by mixing these components, spreading the composition on a substrate to form a sheet, and using the sheet as the composition without further processing.

[0094] 4. Heated but not burned smoking products

[0095] The tobacco composition is suitable for heated tobacco products that do not burn. Figure 1 An embodiment of a heated non-burning smoking article is shown. As shown in the accompanying drawings, the heated non-burning smoking article 20 includes: a tobacco segment 20A, a cylindrical cooling portion 20B with circumferential perforations, and a filter portion 20C. The heated non-burning smoking article 20 may include other components besides these. There is no limitation on the axial length of the heated non-burning smoking article 20, but the axial length is preferably 40-90 mm, more preferably 50-75 mm, and even more preferably 50-60 mm. Furthermore, the circumferential length of the heated non-burning smoking article 20 is preferably 16-25 mm, more preferably 20-24 mm, and even more preferably 21-23 mm. In an exemplary model that can be exemplified, the length of the tobacco segment 20A is 20 mm, the length of the cooling portion 20B is 20 mm, and the length of the filter portion 20C is 7 mm. The lengths of the components can be appropriately modified according to manufacturability and desired quality, etc. Figure 1 The pattern of setting the first segment 25 is shown, but this segment is not required, and only the second segment 26 can be set on the downstream side of the cooling section 20B.

[0096] 1) Tobacco Section 20A

[0097] The tobacco filling material 21 in tobacco segment 20A comprises the aforementioned component (A) or a tobacco composition containing the aforementioned component. There are no particular limitations on the method for packaging the tobacco filling material 21 inside the wrapper 22; however, for example, the tobacco filling material 21 may be encapsulated in the wrapper 22, or the tobacco filling material 21 may be packaged inside a cylindrical wrapper 22. When the tobacco filling material has a longitudinal shape (e.g., a rectangular shape), the tobacco filling material may be packaged such that the longitudinal direction of each rectangular shape is randomly oriented inside the wrapper 22, or it may be packaged such that the longitudinal direction is aligned with or perpendicular to the axial direction of the tobacco segment 20A. The tobacco segment 20A is heated to thereby vaporize the tobacco components, the aerosol source, and the water contained in the tobacco filling material 21, and is then ready for inhalation of these components.

[0098] 2) Cooling section 20B

[0099] The cooling section 20B is preferably formed of a cylindrical member. The cylindrical member can be, for example, a paper tube 23 obtained by processing cardboard into a cylindrical shape. Alternatively, the cooling section 20B can also be formed of a thin sheet of material that is wrinkled and then pleated, gathered, or folded to form a channel. Examples of such materials that can be used include sheet materials selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polylactic acid, cellulose acetate, and aluminum foil. The total surface area of ​​the cooling section 20B is appropriately set considering cooling efficiency and can be, for example, 300-1000 mm². 2 / mm. The cooling section 20B is preferably provided with perforations 24. The perforations 24 allow outside air to be introduced into the cooling section 20B during inhalation. Therefore, the aerosol vaporized components generated by heating the tobacco section 20A are liquefied because the aerosol vaporized components come into contact with outside air, causing their temperature to drop and forming an aerosol. There is no particular limitation on the diameter (spanning length) of the perforations 24, and the diameter can be, for example, 0.5-1.5 mm. There is no particular limitation on the number of perforations 24, and one, two, or more perforations can be present. For example, multiple perforations 24 can be provided on the circumference of the cooling section 20B.

[0100] The cooling section 20B can be formed in the shape of a rod with an axial length of, for example, 7-28 mm. The axial length of the cooling section 20B can be, for example, 18 mm. The cooling section 20B can have a substantially circular axial cross-sectional shape with a diameter of 5-10 mm. The diameter of the cooling section can be, for example, approximately 7 mm.

[0101] 3) Filter section 20°C

[0102] There are no particular restrictions on the configuration of the filter section 20C, but it can be formed by a single or multiple filler layers. The outer side of the filler layer can be wrapped with one or more sheets of wrapping paper. For example, the airflow resistance of the filter section 20C can be appropriately modified by the amount and material of the filter filler material. For instance, when the filter filler material is cellulose acetate fiber, increasing the amount of cellulose acetate fiber filling the filter section 20C may lead to an increase in airflow resistance. When the filter filler material is cellulose acetate fiber, the packing density of the cellulose acetate fiber can be 0.13-0.18 g / cm³. 3 Air resistance is a value measured using an air resistance meter (trade name: SODIMAX, manufactured by SODIM).

[0103] There is no particular limitation on the circumferential length of the filter section 20C, but this circumferential length is preferably 16-25 mm, more preferably 20-24 mm, and even more preferably 21-23 mm. The axial length of the filter section 20C ( Figure 1 The horizontal length of the filter section 20C can be selected to be 4-10 mm, and this length is chosen to achieve an airflow resistance of 15-60 mmH2O per segment. The axial length of the filter section 20C is preferably 5-9 mm, and more preferably 6-8 mm. There are no particular limitations on the cross-sectional shape of the filter section 20C, but the cross-sectional shape can be, for example, circular, elliptical, or polygonal. In addition, easily broken capsules, flavor beads, or flavorings containing flavoring agents can be directly added to the filter section 20C.

[0104] The filter section 20C may include a central hole portion as a first segment 25. The central hole portion may include a first filling layer 25a having one or more hollow portions, and an inner rod wrapping (inner wrapping paper) 25b covering the filling layer. The central hole portion functions to reinforce the suction nozzle portion. The shape of the central hole portion can be maintained by thermoforming without the need for the inner rod wrapping 25b. The filter section 20C may include a second segment 26. The second segment 26 includes a second filling layer 26a and an inner rod wrapping (inner wrapping paper) 26b covering the second filling layer 26a. The second filling layer 26a may, for example, be formed as a rod with an inner diameter of φ5.0 mm-φ1.0 mm, filled with high-density cellulose acetate fibers, wherein a plasticizer containing triacetin is added in an amount of 6-20 wt% relative to the weight of cellulose acetate, and the plasticizer is modulated. The second filling layer has high bulk density fibers, so air and aerosol flow only through the hollow portions during suction, and hardly through the filling layer. The second filling layer inside the central hole is a fiber filling layer, so users will hardly feel any discomfort when touching the outside during use.

[0105] The first filling layer 25a and the second filling layer 26a are connected by an outer rod wrapping (outer wrapping paper) 27. For example, the outer rod wrapping 27 can be a cylindrical paper. Furthermore, the tobacco segment 20A, the cooling section 20B, and the connecting first filling layer 25a and second filling layer 26a are connected by a mouthpiece liner 28. These connections can be formed, for example, by coating the inner surface of the mouthpiece liner 28 with glue (such as vinyl acetate-based glue) and wrapping the three components. These components can also be connected using multiple liners via multiple individual connectors.

[0106] The combination of heated non-burning smoking products with heating devices for generating aerosols, especially heated non-burning smoking systems. Figure 2 An example of the system is shown. The heated non-burning smoking system in the accompanying drawings includes a heated non-burning smoking article 20 and a heating device 10 for externally heating the tobacco segment 20A.

[0107] The heating device 10 includes a body 11, a heater 12, a metal tube 13, a battery unit 14, and a control unit 15. The body 11 has a cylindrical recess 16, wherein the heater 12 and the metal tube 13 are positioned facing the smoking section 20A inserted into the recess 16. The heater 12 may be a resistive heater, wherein the battery unit 14 supplies power according to commands from the control unit 15 controlling the temperature, causing the heater 12 to heat. Heat emitted from the heater 12 is transferred to the tobacco section 20A through the highly thermally conductive metal tube 13. The accompanying drawings illustrate a mode in which the heating device 10 heats the tobacco section 20A from the outside, but the tobacco section can also be heated from the inside. There are no particular limitations on the heating temperature generated by the heating device 10, and this heating temperature is preferably 400°C or lower, more preferably 150-400°C, and even more preferably 200-350°C. The heating temperature refers to the temperature of the heater in the heating device 10. In addition, a sensor can be installed inside the tobacco segment 20A to heat the tobacco segment 20A by means of IH method.

[0108] Preferred embodiments are disclosed below.

[0109] Aspect 1

[0110] A type of dried tobacco leaf, obtained by drying it to reveal its green color.

[0111] Aspect 2

[0112] As disclosed in aspect 1, the dried tobacco leaves have an a content of -2 or less. Values, such as L as defined in CIE 1976 a b The method was used for measurement.

[0113] Aspect 3

[0114] As disclosed in aspect 1 or 2, the dried tobacco leaves include the step of placing the harvested fresh leaves in an environment of 45°C or lower until the moisture content of the leaf portion becomes 25 wt% or less.

[0115] Aspect 4

[0116] As disclosed in any one of aspects 1 to 3, the dried tobacco leaves, wherein the drying includes placing the harvested fresh leaves in an environment of 30°C-40°C and 60%-70% relative humidity for 6-12 hours, followed by

[0117] Place these leaves in an environment of 45°C or lower until the moisture content of the leaf portion becomes 25 wt% or less.

[0118] Aspect 5

[0119] The dried tobacco leaves disclosed in any of aspects 1 to 4 are produced by removing only the leaf portion during the drying stage, wherein the moisture content of the leaf portion has been reduced to 12 wt% or less.

[0120] Aspect 6

[0121] The dried tobacco leaves disclosed in any of aspects 1 to 5 are ordinary tobacco.

[0122] Aspect 7

[0123] The dried tobacco leaves disclosed in any of aspects 1 to 6 are Burley tobacco.

[0124] Aspect 8

[0125] A tobacco composition comprising dried tobacco leaves as disclosed in any one of aspects 1 to 7, wherein the composition contains 5-90 wt% of the dried tobacco leaves.

[0126] Aspect 9

[0127] The composition disclosed in aspect 8 further comprises 3-30 wt% of an aerosol source.

[0128] Aspect 10

[0129] The composition disclosed in aspect 9, wherein the aerosol source is selected from the group consisting of glycerol, propylene glycol, 1,3-propanediol and combinations thereof.

[0130] Aspect 11

[0131] The composition disclosed in any one of aspects 8 to 10 further comprises 5-85 wt% reconstituted cut tobacco or 5-85 wt% cut tobacco.

[0132] Aspect 12

[0133] The compositions disclosed in any of aspects 8 to 11 further comprise a non-tobacco flavoring agent.

[0134] Aspect 13

[0135] The composition disclosed in aspect 12, wherein the non-tobacco flavoring agent is selected from the group consisting of flavoring agents, coolants, and combinations thereof.

[0136] Aspect 14

[0137] The composition disclosed in aspect 13, wherein the flavoring agent is menthol.

[0138] Aspect 15

[0139] A heated non-burning smoking article comprising dried tobacco leaves as disclosed in any one of aspects 1 to 9, or a composition as disclosed in any one of aspects 8 to 14. Example

[0140] [Comparison Example 1]

[0141] Harvested Burley tobacco leaves were hung in arched sheds lined with dark curtains and dried naturally for 40 days. The dried leaves were then humidified in a dark room at 35°C and 60% relative humidity. Afterward, the leaf sections and veins were separated, and the leaf coloration was measured. Visual observation revealed that the leaf sections were brown rather than green.

[0142] [Example 1]

[0143] Harvested Burley tobacco leaves were dried at 68°C and 20% relative humidity for 72 hours. After drying, the leaves were conditioned at 22°C and 60% relative humidity for 48 hours. The leaf portions were then separated from the veins, and the leaf coloration was assessed. Visual observation showed the leaves were green. Furthermore, L was standardized according to CIE 1976. a b The method measures the coloration of the leaf portion. The specific measurements are as follows.

[0144] 1) In order to obtain the average coloration of the entire leaf portion after drying and humidity conditioning, leaf portions of tobacco leaves corresponding to 10 or more leaves are ground and pulverized to obtain powder samples with a size of 2 mm or smaller.

[0145] 2) A 5 g pulverized powder sample was measured using a spectrophotometer (instrument name: CM3500d, Konica Minolta). The measurement was performed by filling a transparent glass dish with the powder sample to a layer thickness of 1 cm or greater, illuminating it with standard light (D65 light source) from the bottom of the container, and measuring the reflected light by the exclusion of specular component (SCE) method. The measurements were repeated three times using the spectrophotometer, and the average values ​​are given in Table 1.

[0146] The same method is used to evaluate the coloring in the following examples and comparison examples.

[0147] [Example 2]

[0148] Harvested Burley tobacco leaves were dried at 45°C and 32% relative humidity until the leaf moisture content dropped below 25%. The leaves were then dried at 68°C and 20% relative humidity until the vein moisture content dropped below 12 wt%. After drying, the leaves were conditioned at 22°C and 60% relative humidity for 48 hours. The leaf and vein portions were then separated, and the leaf coloration was measured. Visual observation showed the leaves to be green.

[0149] [Example 3]

[0150] Harvested Burley tobacco leaves were conditioned at 35°C and 64% relative humidity for 12 hours, followed by conditioned at 45°C and 32% relative humidity until the leaf moisture content dropped below 25 wt%. The leaves were then dried at 68°C and 20% relative humidity until the vein moisture content dropped below 12 wt%. After drying, the leaves were conditioned at 22°C and 60% relative humidity for 48 hours. The leaf and vein portions were then separated, and the leaf coloration was measured. Visual observation showed the leaves were green.

[0151] [Example 4]

[0152] Harvested Burley tobacco leaves were humidified at 35°C and 64% relative humidity for 12 hours, then dried at 45°C and 32% relative humidity until the moisture content of the leaves dropped below 12 wt%. The dried leaves were separated from the still-moisturized midrib, and the leaf color was then measured. Visual observation showed that the leaves were green. Figure 4 The drying steps for each example are shown in the diagram.

[0153] [Table 1]

[0154]

[0155] [Example A] Sensory evaluation of heated non-burning smoking products

[0156] The dried tobacco leaves obtained in Comparative Example 1 and Examples 1-4 were each cut into 0.8 mm wide slices. Standard flue-cured tobacco slices were prepared, and the slices obtained in each example were blended with flue-cured tobacco slices at a weight ratio of 50:50. Figure 1The heated non-burning smoking article shown has a tobacco segment 20A with a length of 20 mm, a cooling section 20B with a length of 20 mm, and a filter section 20C with a length of 7 mm. Each tobacco segment 20A is filled with 0.3 g of blended cut tobacco.

[0157] The smoking product was heated using a heating device, and the smoking was assessed by a panel of 10 trained experts. The mildness of the smoking was assessed using a five-point scale. The results are shown in the table below.

[0158] 1. Not particularly mild

[0159] 2 Not mild

[0160] 3 Standards

[0161] 4. Mild

[0162] 5. Very mild

[0163] [Table 2]

[0164]

[0165] Compared to Comparative Example 1, the dried tobacco leaves used in Examples 1-4 have lower a Furthermore, compared to the dried tobacco leaves used in Comparative Example 1, the smoking products of Examples 1-4 are superior in terms of flavor mildness. Among them, the smoking products of Examples 2-4 exhibit particularly good flavor mildness.

[0166] Green-colored dried tobacco leaves can be obtained by drying harvested tobacco leaves under specific conditions to avoid the browning that inevitably occurs in conventional curing methods. These green-colored dried tobacco leaves, when applied to non-combustible smoking products, clearly impart a milder aroma.

[0167] [Example 5]

[0168] The harvested flue-cured tobacco leaves were dried at 68°C and 20% relative humidity for 72 hours. After drying, the leaves were conditioned at 22°C / 60% RH for 48 hours, and then the leaf and vein portions were separated.

[0169] [Example B] Comparison of sugar content

[0170] The glucose and fructose content of the leaf portions of dried tobacco leaves obtained in Examples 1, 2, 3, and 5 were measured. Specifically, the glucose and fructose content were measured according to the following method.

[0171] The tobacco leaves were ground to a size of 1.0 mm or smaller. 1.0 g ± 0.001 g of the ground tobacco leaves were weighed into a glass vial, 40 mL of 50 v / v% acetonitrile solution was added, and the mixture was shaken at 200 rpm for 30 minutes. After shaking, further extraction was performed at room temperature for 30 minutes using Bransonic (Bransonic Cleaner, Branson Ultrasonic Co., Danbury, Connecticut, USA) at room temperature. The extract was filtered through a PVDF membrane filter with a pore size of 0.2 µm (Whatmann), and the resulting filtrate was subjected to instrumental analysis. High-performance liquid chromatography (Agilent 1200 HPLC system) was used as the analytical instrument. The instrumental analysis conditions are as follows.

[0172] 1) Detector

[0173] A refractive index detector (G1362A refractive index detector (Agilent Technologies, California, USA)) was used. The temperature was set to 35°C, and measurements were performed using an absolute calibration curve method (calibration curve range: 0.1–10 g / L).

[0174] 2) Column

[0175] Carbohydrate column used (250 × 4.6 mm ID, 4 µm, Waters Co., Milford, Massachusetts, USA).

[0176] 3) Elution conditions

[0177] Eluent: Acetonitrile (75 v / v%)

[0178] Flow rate: 1.0 mL / min

[0179] Injection volume: 20 µL

[0180] [Table 3]

[0181]

[0182] The flue-cured tobacco in Example 5 was dried using the same method as in Example 1 to obtain dried tobacco leaves. These dried tobacco leaves have a higher glucose content than those in Example 1. When the sugar content is high, the production of sugar-related heating aromas becomes dominant, resulting in a grain-like aroma. These results indicate that Burley tobacco is a suitable variety. Meanwhile, the dried tobacco leaves obtained in Examples 2 and 3 have a lower sugar content than those obtained in Example 1. These results indicate that the drying methods in Examples 2 and 3 are more suitable than the drying method in Example 1.

Claims

1. A dried tobacco leaf obtained by drying to reveal its green color.

2. The dried tobacco leaf as described in claim 1, having an a content of -2 or less. Values, such as L as defined in CIE 1976 a b The method was used for measurement.

3. The dried tobacco leaves as described in claim 1 or 2, wherein, The drying process involves placing the harvested fresh leaves at 45°C or lower until the moisture content of the leaf portion becomes 25 wt% or less.

4. The dried tobacco leaves according to any one of claims 1 to 3, wherein, The drying process involves placing the harvested fresh leaves at 30°C-40°C and 60%-70% relative humidity for 6-12 hours, followed by placing the leaves at 45°C or lower until the moisture content of the leaf portion becomes 25 wt% or less.

5. The dried tobacco leaf as claimed in any one of claims 1 to 4, wherein the dried tobacco leaf is produced by removing only the leaf portion during the drying stage, wherein the moisture content of the leaf portion has been reduced to 12 wt% or less.

6. The dried tobacco leaf as claimed in any one of claims 1 to 5, wherein the dried tobacco leaf is ordinary tobacco.

7. The dried tobacco leaf as claimed in any one of claims 1 to 6, wherein the dried tobacco leaf is Burley tobacco.

8. A tobacco composition comprising dried tobacco leaves as described in any one of claims 1 to 7, wherein the composition contains 5-90 wt% of the dried tobacco leaves.

9. The composition of claim 8, further comprising 3-30 wt% of an aerosol source.

10. The composition of claim 9, wherein, The aerosol source is selected from the group consisting of glycerol, propylene glycol, 1,3-propanediol and combinations thereof.

11. The composition according to any one of claims 8 to 10, further comprising 5-85 wt% reconstituted cut tobacco or 5-85 wt% cut tobacco.

12. The composition of any one of claims 8 to 11, further comprising a non-tobacco flavoring agent.

13. The composition of claim 12, wherein, The non-tobacco flavoring agent is selected from the group consisting of flavoring agents, cooling agents, and combinations thereof.

14. The composition of claim 13, wherein, The flavoring agent is menthol.

15. A heated non-burning smoking article comprising dried tobacco leaves as claimed in any one of claims 1 to 9, or a composition as claimed in any one of claims 8 to 14.

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