Method for producing tobacco material, and tobacco material

Abstract

This method for producing a tobacco material comprises: heating a tobacco raw material having a water content in a range from 5 to 30 mass% using a heating device having an inlet, an outlet, and a heating chamber, at a temperature of 290-400°C, while the tobacco raw material, in a state of being packed in the heating chamber, is conveyed inside the heating chamber; conveying the tobacco raw material from the heating device to a cooling device which is continuous with the heating device and is provided with a cooling chamber; and cooling the tobacco raw material while the tobacco raw material, in a state of being packed in the cooling chamber, is conveyed inside the cooling chamber.

Description

Tobacco material manufacturing method and tobacco material

[0001] The present invention relates to a method for producing a tobacco material and a tobacco material.

[0002] After being harvested, tobacco leaves undergo various processing steps, including drying at farms, a long-term aging process lasting from one to several years at raw material factories, and blending and chopping at manufacturing factories, before being used to manufacture flavor inhalers such as cigarettes. Through these various processing steps, tobacco leaves become rich-flavored tobacco material. Such tobacco material is called "leaf tobacco" to distinguish it from tobacco plant leaves.

[0003] It is known that during the drying and aging process of tobacco leaves, alkaloids contained in tobacco leaves are nitrosated to produce tobacco-specific nitrosamines (TSNAs). TSNAs refer to four compounds: 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), and N'-nitrosoanabasine (NAB).

[0004] Attempts have been made to reduce the amount of TSNA contained in tobacco leaves. For example, Patent Document 1 discloses heating a tobacco material to a temperature higher than 110°C in the presence of water or steam in order to reduce the amount of substrate-bound NNK in the tobacco material. Patent Document 1 discloses that heating the tobacco material releases at least a portion of the substrate-bound NNK from the insoluble tobacco matrix of the tobacco material.

[0005] International Publication No. 2014 / 140346

[0006] The present inventors focused on the problem that when tobacco leaves are heated to reduce the amount of TSNA contained in the leaf tobacco, the flavor components contained in the leaf tobacco volatilize and the amount of the flavor components also decreases. An object of the present invention is to solve this problem, that is, to provide a tobacco material that retains the flavor components while reducing the amount of TSNA.

[0007] According to a first aspect, there is provided a method for producing a tobacco material, the method comprising: using a heating device having an inlet, an outlet, and a heating chamber, heating tobacco material having a moisture content in the range of 5 to 30% by mass at a temperature of 290 to 400°C while the tobacco material is filled in the heating chamber and transported through the heating chamber; transporting the tobacco material from the heating device to a cooling device that is continuous with the heating device and has a cooling chamber, and cooling the tobacco material while the tobacco material is filled in the cooling chamber and transported through the cooling chamber.

[0008] According to a second aspect, there is provided a tobacco material obtainable by the method according to the first aspect.

[0009] According to a third aspect, there is provided a tobacco material having an NNN content of 3.0 [μg / g D.W.] or less, an NAT content of 2.0 [μg / g D.W.] or less, and a mass ratio of acetic acid to citric acid of 0.3 or more.

[0010] According to a fourth aspect, there is provided a non-combustion heating type flavor inhaler including the tobacco material according to the second or third aspect.

[0011] According to the present invention, it is possible to provide a tobacco material that retains flavor components while reducing the amount of TSNAs.

[0012] FIG. 1 is a cross-sectional view showing an example of a tobacco material production apparatus. FIG. 2A is a schematic front view showing an example of an aerosol generation apparatus. FIG. 2B is a schematic top view of the aerosol generation apparatus shown in FIG. 2A. FIG. 2C is a schematic bottom view of the aerosol generation apparatus shown in FIG. 2A. FIG. 3 is a schematic side cross-sectional view showing an example of a flavor-generating article. FIG. 4 is a cross-sectional view of the aerosol generation apparatus shown in FIG. 2B along line III-III. FIG. 5 is a graph showing the NNN content. FIG. 6 is a graph showing the NAT content. FIG. 7 is a graph showing the mass ratio of acetic acid to citric acid. FIG. 8 is a graph showing the nicotine content. FIG. 9 is a graph showing the NNN content. FIG. 10 is a graph showing the NAT content. FIG. 11 is a graph showing the mass ratio of acetic acid to citric acid. FIG. 12 is a graph showing the nicotine content. FIG. 13 is a graph showing the ammonia content.

[0013] The present invention will be described in detail below. However, the following description is for the purpose of explaining the present invention and is not intended to limit the present invention. The embodiments described below are more specific embodiments of any of the above aspects. The following items can be incorporated into each of the above aspects alone or in combination.

[0014] 1. Tobacco material manufacturing method A tobacco material manufacturing method includes: using a heating device having an inlet, an outlet, and a heating chamber, heating tobacco material having a moisture content in the range of 5 to 30% by mass at a temperature of 290 to 400°C while the tobacco material is packed into the heating chamber and transported through the heating chamber; transporting the tobacco material from the heating device to a cooling device that is continuous with the heating device and has a cooling chamber, and cooling the tobacco material while the tobacco material is packed into the cooling chamber and transported through the cooling chamber.

[0015] In the above method, the tobacco raw material is first heated while being packed into the heating chamber of a heating device. Therefore, even if moisture or flavor components volatilize from the tobacco raw material during heating, the volatilized moisture and flavor components can be maintained in the vicinity of the tobacco raw material. The tobacco raw material is then transported to a cooling device connected to the heating device, where it is cooled while being packed into the cooling chamber of the cooling device. Therefore, in the above method, the tobacco raw material is transported to the cooling device, and gases present in the vicinity of the tobacco raw material are also transported to the cooling device. This allows the tobacco raw material to be cooled in the cooling chamber of the cooling device while the moisture and flavor components volatilized from the tobacco raw material are present in the vicinity of the tobacco raw material. Cooling the tobacco raw material in this state allows the moisture and flavor components volatilized from the tobacco raw material to be returned to the tobacco raw material. As a result, the above method makes it possible to obtain a tobacco material that retains flavor components (e.g., organic acids, nicotine, etc.) while reducing the amount of TSNAs.

[0016] The above method can be carried out, for example, using a tobacco material production apparatus shown in Figure 1. Below, the "tobacco material production apparatus" will be described first, followed by a description of the heating step (S1) and the cooling step (S2).

[0017] <Tobacco material manufacturing apparatus> Fig. 1 is a cross-sectional view showing an example of a tobacco material manufacturing apparatus. As shown in Fig. 1, the tobacco material manufacturing apparatus 10 includes a heating device 20 and a cooling device 30.

[0018] The heating device 20 has a structure similar to that of a single-screw extruder, that is, the heating device 20 includes a cylinder 22, a screw 23, a motor 24, a band heater 25, and a cover body 26.

[0019] The cylinder 22 is a cylindrical metal member whose first end is closed by a disk portion and whose other end, a second end, is tapered. In FIG. 1 , the cylinder 22 is tapered at the second end, but the cylinder 22 may be a cylindrical member whose second end is not tapered and whose diameter is substantially constant along its entire length. A through-hole is provided in the center of the disk portion closing the first end of the cylinder 22. The cylinder 22 also has a through-hole near the first end, which serves as an inlet 22A for introducing tobacco raw material into the heating chamber 22C, which is the internal space of the cylinder, and which connects the heating chamber 22C with the external space of the tobacco material production apparatus 10. The outlet 22B is an opening provided at the second end of the cylinder 22.

[0020] Here, a hopper 21 is provided at the inlet 22A. The hopper 21 may be omitted.

[0021] The screw 23 has a screw shaft whose length is parallel to the length of the cylinder 22, and screw blades fixed to the screw shaft. One end of the screw shaft, to which the screw blades are not attached, is inserted into a through-hole in the disc portion and protrudes outside the cylinder 22. This end is connected to the rotating shaft of the motor 24. The remaining part of the screw 23 is located inside the cylinder 22. The screw 23 rotates when the motor 24 is driven, and transports the tobacco material within the heating chamber 22C toward the outlet 22B. The combination of the screw 23 and the motor 24 is an example of a "mechanism for transporting tobacco material within the heating chamber."

[0022] The band heater 25 is wrapped around a portion of the cylinder 22 from the vicinity of the insertion port 22A to the vicinity of the second end. The band heater 25 heats the tobacco raw material via the cylinder 22. The band heater 25 includes a resistance heating element 25A and an insulator 25B. The band heater 25 is controlled to a set temperature by a temperature regulator (not shown). The heating device 20 may include another heater instead of the band heater 25.

[0023] The cover body 26 covers the band heater 25 and the portion of the cylinder 22 around which the band heater 25 is wound. The cover body 26 can be omitted.

[0024] The cooling device 30 is continuous with the heating device 20. The cooling device 30 includes a cooling pipe 31, a cooling jacket 32, a pump, piping, and a heat exchanger, none of which are shown.

[0025] The cooling pipe 31 is a cylindrical member made of metal. The cooling pipe 31 has one opening serving as an inlet 31A and the other opening serving as an outlet 31B, and an internal space serving as a cooling chamber 31C. The cooling pipe 31 is fixed to the heating device 20 so that the inlet 31A is connected to the outlet 22B, i.e., so that the heating chamber 22C and the cooling chamber 31C are continuous. With this configuration, the tobacco production apparatus 10 allows the tobacco raw material, after being heated in the heating device 20, to enter the cooling chamber 31C from the inlet 31A without coming into contact with outside air, be transported within the cooling chamber 31C, be cooled in the process, and be discharged from the outlet 31B.

[0026] The cooling jacket 32 ​​is a metal member having a flow path 32A formed therein for circulating a cooling liquid such as water. In this example, the cooling jacket 32 ​​is provided so as to surround the tapered second end of the cylinder 22. The cooling jacket 32 ​​may also be provided so as to surround the cooling pipe 31.

[0027] The flow path 32A of the cooling jacket 32 ​​forms a circulation path together with the piping. A pump and a heat exchanger are installed in this circulation path. The cooling device 30 cools the cooling liquid using the heat exchanger and drives the pump to circulate the cooling liquid through the above-mentioned circulation path, supplying the cooled cooling liquid to the flow path 32A of the cooling jacket 32. The cooling jacket 32 ​​enables heat exchange between the tobacco material and the cooling liquid via the second end of the cylinder 22 and the cooling pipe 31.

[0028] Next, we will explain the operation of the tobacco material production apparatus 10. The tobacco material production apparatus 10 performs a heating step (S1) and a cooling step (S2). The heating step (S1) and the cooling step (S2) are steps performed in a heating device 20 and a cooling device 30, respectively.

[0029] In the heating step (S1), the tobacco material production apparatus 10 drives the motor 24 to rotate the screw 23, and operates the hopper 21 to feed the tobacco material into the heating chamber 22C. Here, the tobacco material is continuously fed so that the portion of the heating chamber 22C downstream of the feed opening 22A is filled with the tobacco material. By rotating, the screw 23 transports the tobacco material within the heating chamber 22C toward the outlet 22B, and applies pressure and shear force to the tobacco material.

[0030] In the heating step (S1), the tobacco material production apparatus 10 further operates the band heater 25. The band heater 25 heats the tobacco raw material in the heating chamber 22C via the cylinder 22.

[0031] The tobacco material moved downstream by the rotation of the screw 23 is discharged through the outlet 22B to the outside of the cylinder 22. The tobacco material discharged to the outside of the cylinder 22 enters the cooling chamber 31C through the inlet 31A without coming into contact with the outside air.

[0032] In the cooling step (S2), the tobacco material production apparatus 10 operates the cooling device 30. Tobacco raw material is continuously supplied from the heating chamber 22C to the cooling chamber 31C. Therefore, within the cooling chamber 31C, the tobacco raw material continuously moves from the inlet 31A toward the discharge outlet 31B. During this movement, the tobacco raw material is cooled by the heat exchange described above. After being sufficiently cooled, the tobacco raw material is discharged to the outside of the tobacco material production apparatus 10 through the discharge outlet 31B.

[0033] <Heating step (S1)> In the heating step (S1), tobacco raw material having a moisture content in the range of 5 to 30% by mass is heated at a temperature of 290 to 400°C using the heating device 20 described above while being filled into a heating chamber and transported within the heating chamber.

[0034] (Tobacco raw material) "Tobacco raw material" can be tobacco shreds that are ready to be blended into tobacco products, such as combustion-type or heat-type flavor inhalers. "Tobacco shreds ready to be blended into tobacco products" refers to tobacco shreds that have undergone various processing steps, such as a drying process on a farm, a long-term aging process of one to several years at a raw material factory, and subsequent blending and cutting at a manufacturing factory, and are ready to be blended into tobacco products.

[0035] Tobacco shreds are cut tobacco leaves. Tobacco shreds may be shredded leaves, shredded backbones, shredded reconstituted tobacco (i.e., tobacco material obtained by processing leaf waste, shredded waste, backbone waste, fine powder, etc. generated during factory operations into a reusable form), or a mixture thereof. Tobacco shreds may be pulverized, and the resulting pulverized material may be used for the heating step (S1). The pulverized tobacco shreds have an average particle size of, for example, 100 to 500 μm. In this specification, the average particle size refers to the number-average particle size measured using a laser scattering diffraction particle size analyzer.

[0036] The shredded tobacco may be of any variety, such as flue-cured, burley, oriental, etc. The shredded tobacco may be of a single variety or a mixture of different varieties.

[0037] The tobacco raw material has a moisture content of 5 to 30% by mass. The tobacco raw material preferably has a moisture content of 5 to 15% by mass. Tobacco shreds ready to be blended into tobacco products such as combustion-type or heat-type flavor inhalers have a low moisture content, for example, a moisture content of about 10%. Therefore, tobacco shreds ready to be blended into tobacco products such as combustion-type or heat-type flavor inhalers may be used as the tobacco raw material without adding water. Alternatively, water may be added to tobacco shreds ready to be blended into tobacco products such as combustion-type or heat-type flavor inhalers to achieve the above moisture content, and the resulting tobacco raw material may be used. When a tobacco raw material is prepared by adding water to tobacco shreds in this way, the moisture content of the tobacco raw material refers to the sum of the amount of moisture contained in the tobacco shreds before the addition of water and the amount of water added.

[0038] Using a tobacco raw material with a low moisture content can reduce the proportion of heating energy used for evaporating water. This allows the heating energy to be used efficiently for reducing TSNAs. Furthermore, using a tobacco raw material with a low moisture content can reduce the risk of flavor components volatilizing along with the volatilized water. Furthermore, heating a tobacco raw material with a specified moisture content while it is filled in a heating chamber can prevent the tobacco raw material from burning.

[0039] The "moisture content WC1 of the tobacco material before the heating step (S1)" can be obtained by the procedure described below. The tobacco material before the heating step (S1) is dried under open conditions at 100°C for 1 hour. The mass of the sample after drying is measured, and the difference between the mass of the sample after drying and the mass of the sample before drying is calculated, and the obtained difference is used as the "moisture content." The "moisture content WC1" is calculated from the "moisture content" value using the following formula: Moisture content WC1 [%] = (moisture content / mass of sample before drying) × 100.

[0040] The moisture content WC1 of the tobacco raw material before the heating step (S1) is preferably measured immediately before heating in the heating step (S1). "Immediately before heating" refers to, for example, within two hours before the start of the heating step (S1), and preferably within one hour before the start of the heating step (S1).

[0041] Furthermore, the tobacco raw material preferably has a pH of 4.5 to 6.5. In this specification, the pH of the tobacco raw material refers to a value measured by the following measurement method.

[0042] 2.0 g of tobacco raw material was weighed into a vial, 20 mL of distilled water was added, and the mixture was subjected to extraction by shaking at 200 rpm for 10 minutes. The resulting extract was allowed to stand for 5 minutes, and then the pH of the extract was measured using a pH meter (LAQUA F-72, manufactured by Horiba, Ltd.). The measured pH was taken as the pH of the tobacco raw material.

[0043] (Heating Conditions) As described above, in the heating step (S1), the tobacco raw material is heated at a temperature of 290 to 400°C using the heating device 20 while being filled in the heating chamber 22C and transported within the heating chamber 22C.

[0044] The tobacco raw material is heated while being filled in the heating chamber 22C. As described above, for example, ground tobacco shreds can be used as the tobacco raw material. The tobacco raw material is preferably filled in the heating chamber 22C so as to occupy almost the entire volume of the heating chamber 22C. Specifically, the tobacco raw material is heated in a state where it occupies a volume of 1 cm of the heating chamber 22C. ３ The tobacco raw material is preferably filled into the heating chamber 22C in an amount of 0.15 g or more (generally, 0.15 to 0.60 g) per cm 3 of the volume of the heating chamber 22C. ３ More preferably, the tobacco raw material is filled into the heating chamber 22C in an amount of 0.20 to 0.60 g per cm 3 of the volume of the heating chamber 22C. ３ It is more preferable that the amount of the powder filled in the heating chamber 22C be 0.25 to 0.45 g per 1000 ml of the powder.

[0045] When the tobacco raw material is heated while being filled in the heating chamber 22C, even if moisture or flavor components volatilize from the tobacco raw material, the volatilized moisture and flavor components can be kept present in the vicinity of the tobacco raw material. This allows the tobacco raw material to be cooled in the subsequent cooling step (S2) in a similar state (i.e., a state in which the volatilized moisture and flavor components are present in the vicinity of the tobacco raw material). As a result, the moisture and flavor components volatilized from the tobacco raw material can be returned to the tobacco raw material. In other words, it is possible to prevent the moisture and flavor components contained in the tobacco raw material from being lost due to volatilization.

[0046] For example, by continuously feeding tobacco raw material into hopper 21 and adjusting the transport speed of the tobacco raw material within heating chamber 22C, it is possible to create a state in which the tobacco raw material is filled within heating chamber 22C.

[0047] Heating is performed at a temperature of 290 to 400°C, preferably 290 to 380°C, and more preferably 290 to 350°C. The heating temperature refers to the set temperature of the heating device 20. If the heating temperature is lower than 290°C, the TSNA reduction effect cannot be sufficiently obtained. From the viewpoint of safety, the heating temperature is preferably 400°C or less.

[0048] The heating device 20 may be configured so that the heating temperature of the band heater 25 can be set for each block, as in a typical single-screw extruder. However, it is not necessary to change the heating temperature for each block; all blocks may use the same heating temperature within the range of 290 to 400°C. Alternatively, the heating temperature may be changed for each block, in which case the highest heating temperature is generally set within the range of 290 to 400°C. In one example, the heating temperature for all blocks may be set within the range of 290 to 400°C, and the heating temperature may increase from upstream to downstream of the heating chamber 22C. Setting the heating temperature of the band heater 25 in this manner is effective in reliably maintaining the temperature of the tobacco raw material itself (i.e., the product temperature) at the set temperature.

[0049] Heating is performed while transporting the tobacco material within the heating chamber 22C at a speed of, for example, 5 to 50 cm / min, preferably 7 to 35 cm / min, and more preferably 10 to 25 cm / min. The length of the heating chamber 22C in the transport direction is, for example, 30 to 300 cm, preferably 35 to 200 cm, and more preferably 35 to 150 cm. The length of the heating chamber 22C in the transport direction refers to the length from the first end to the second end of the cylinder 22, i.e., the length from the inner wall of the heating chamber 22C on the motor 24 side to the outlet 22B. Heating is performed for, for example, 0.6 to 60 minutes, preferably 1 to 30 minutes, and more preferably 2 to 15 minutes.

[0050] The heating is preferably carried out under atmospheric pressure conditions, i.e., the heating does not need to be carried out under high pressure conditions.

[0051] Furthermore, heating is preferably performed without adding water to the tobacco material. That is, it is preferable that no water is added to the tobacco material throughout the heating step (S1). As described above, the tobacco material is heated while filled in the heating chamber 22C. Therefore, even if the moisture contained in the tobacco material evaporates, the evaporated moisture can be kept near the tobacco material. As a result, in the subsequent cooling step (S2), the moisture evaporated from the tobacco material can be returned to the tobacco material. Therefore, even if water is not added to the tobacco material during the heating step (S1), the tobacco material obtained after the cooling step (S2) can maintain the moisture content WC1 of the tobacco material before the heating step (S1).

[0052] Specifically, the moisture content WC1 of the tobacco material before the heating step (S1) (i.e., the initial moisture content WC1 of the tobacco material) is 5 to 30% by mass, as described above. Typically, the moisture content WC2 of the tobacco material obtained after the cooling step (S2) is equal to or greater than the moisture content WC1 of the tobacco material before the heating step (S1). The moisture content WC2 of the tobacco material obtained after the cooling step (S2) is, for example, 5 to 35% by mass. Note that the moisture content WC2 of the tobacco material may be higher than the moisture content WC1 of the tobacco material, which is thought to be due to the occurrence of a dehydration reaction during heating. Furthermore, heat-treating the tobacco material under conditions that allow this dehydration reaction to occur (specifically, heating intensity conditions that allow the dehydration reaction to increase the moisture content WC1 of the tobacco material) is thought to be an important factor that affects the "mass ratio of acetic acid to citric acid" of the tobacco material ultimately obtained. The "mass ratio of acetic acid to citric acid" is an indicator that represents the effect of suppressing irritation when a tobacco material is incorporated into a flavor inhaler and a user inhales tobacco flavor (hereinafter also referred to as the irritation suppression effect).

[0053] Adding no water to the tobacco raw material during the heating step (S1) offers the following advantages. Specifically, adding no water to the tobacco raw material during the heating step (S1) can keep the moisture content of the tobacco raw material low, thereby reducing the proportion of heating energy used to evaporate water. This allows the heating energy to be used efficiently to reduce TSNA. Furthermore, adding no water to the tobacco raw material during the heating step (S1) can reduce the risk of flavor components volatilizing along with the volatilizing water.

[0054] For these reasons, it is desirable to use a tobacco material having a moisture content WC1 of 5 to 30% by mass as the tobacco material and to heat the tobacco material without adding water. This allows a tobacco material with a low moisture content WC2 to be obtained after the cooling step (S2). If the moisture content WC2 of the tobacco material is low, there is no need to perform heat drying to reduce the moisture content before incorporating the tobacco material into the flavor inhaler. Such heat drying is undesirable because it volatilizes the flavor components retained in the tobacco material. If the moisture content WC2 of the tobacco material is within the range of 5 to 35% by mass, the tobacco material can be incorporated into the flavor inhaler without performing heat drying to reduce the moisture content.

[0055] <Cooling step (S2)> In the cooling step (S2), the tobacco raw material after the heating step (S1) is transported from the heating device 20 to the cooling device 30 connected to the heating device 20, and the tobacco raw material is cooled while being transported within the cooling chamber 31C while being filled therein.

[0056] As shown in Figure 1, the cooling pipe 31 of the cooling device 30 is fixed to the heating device 20 so that the heating chamber 22C and the cooling chamber 31C are continuous. Therefore, the tobacco material after the heating step (S1) is transported from the heating device 20 to the cooling device 30 without being exposed to outside air. At this time, gas present in the vicinity of the tobacco material is also transported to the cooling device 30 together with the tobacco material without leaking outside these devices. In this way, the cooling step (S2) is carried out immediately after the heating step (S1).

[0057] After being transported to the cooling device 30, the tobacco raw material is cooled while being filled in the cooling chamber 31C. When the tobacco raw material is cooled while being filled in the cooling chamber 31C, the evaporated moisture and flavor components are present in the vicinity of the tobacco raw material, and therefore the evaporated moisture and flavor components can be returned to the tobacco raw material. In other words, the moisture and flavor components contained in the tobacco raw material can be prevented from being lost due to volatilization.

[0058] For example, by using the action of the screw 23 to continuously push the tobacco material from the heating chamber 22C into the cooling chamber 31C, it is possible to create a state in which the tobacco material is filled in the cooling chamber 31C.

[0059] The tobacco material is preferably filled into the cooling chamber 31C so as to occupy almost the entire volume of the cooling chamber 31C. Specifically, the tobacco material is filled to a volume of 1 cm 3 of the cooling chamber 31C. ３ The tobacco raw material is preferably filled into the cooling chamber 31C in an amount of 0.15 g or more (generally, 0.15 to 0.60 g) per cm 3 of the volume of the cooling chamber 31C. ３ More preferably, the tobacco raw material is filled into the cooling chamber 31C in an amount of 0.20 to 0.60 g per 1 cm of the volume of the cooling chamber 31C. ３ It is more preferable that the amount of the powder filled in the cooling chamber 31C be 0.25 to 0.45 g per 1000 ml of the cooling chamber 31C.

[0060] Cooling is preferably carried out so that the tobacco material obtained after the cooling step (S2), i.e., the tobacco material discharged from the discharge port 31B of the cooling device 30, is cooled to a temperature of 70 to 140° C. In the cooling step (S2), the tobacco raw material is cooled while being transported within the cooling chamber 31C, and when it is finally cooled to a temperature within the above range, much of the evaporated moisture and flavor components can be returned to the tobacco raw material.

[0061] Cooling is performed while transporting the tobacco raw material within the cooling chamber 31C at a speed of, for example, 5 to 50 cm / min, preferably 7 to 35 cm / min, and more preferably 10 to 25 cm / min. The length of the cooling chamber 31C in the transport direction is, for example, 10 to 300 cm, preferably 10 to 200 cm, and more preferably 10 to 150 cm. The length of the cooling chamber 31C in the transport direction refers to the length from the entrance 31A of the cooling chamber 31C to the discharge outlet 31B. Cooling is performed for a period of, for example, 0.6 to 60 minutes.

[0062] The cooling is preferably carried out under atmospheric pressure conditions, i.e., the cooling does not need to be carried out under reduced pressure conditions.

[0063] The moisture content WC2 of the tobacco material obtained after the cooling step (S2) is, for example, 5 to 35% by mass, preferably 5 to 20% by mass. Generally, the moisture content WC2 of the tobacco material obtained after the cooling step (S2) is equal to or greater than the moisture content WC1 of the tobacco material that is the starting material.

[0064] The "moisture content WC2 of the tobacco material obtained after the cooling step (S2)" can be obtained using the same procedure as the "moisture content WC1 of the tobacco raw material before the heating step (S1)." That is, the tobacco material after the cooling step (S2) is dried at 100°C for 1 hour under open conditions. The mass of the sample after drying is measured, and the difference between the mass of the sample after drying and the mass of the sample before drying is calculated, and this difference is used as the "moisture content." The "moisture content WC2" is calculated from the "moisture content" value using the following formula: Moisture content WC2 [%] = (moisture content / mass of sample before drying) × 100.

[0065] The moisture content WC2 of the tobacco material obtained after the cooling step (S2) is preferably measured immediately after the cooling step (S2). "Immediately after cooling" refers to, for example, within two hours after the end of the cooling step (S2), and preferably within one hour after the end of the cooling step (S2).

[0066] <Effects> When a tobacco material is produced according to the above-described "method for producing a tobacco material," it is possible to obtain a tobacco material that retains flavor components (for example, organic acids, nicotine, etc.) while reducing the amount of TSNAs.

[0067] Specifically, the obtained tobacco material can have a reduced NNN content and a reduced NAT content, in particular, compared to the starting tobacco material. Because NNN and NAT account for a large proportion of TSNA, reducing the NNN and NAT contents of the tobacco material is important in reducing the total amount of TSNA.

[0068] Furthermore, the resulting tobacco material can have a higher mass ratio of acetic acid to citric acid compared to the starting tobacco material, while maintaining the same level of nicotine content as the starting tobacco material. As described above, the "mass ratio of acetic acid to citric acid" is an indicator of the effect of suppressing irritation when a user inhales tobacco flavors after incorporating the tobacco material into a flavor inhaler (i.e., the irritation suppression effect). Therefore, the greater the "mass ratio of acetic acid to citric acid" of the tobacco material, the less irritation there is to the user's nasal cavity, oral cavity, or throat, providing the user with an easier inhalation experience and a more pleasant flavor.

[0069] On the other hand, if the cooling step (S2) is not performed in the above-mentioned "tobacco material manufacturing method," and only the heating step (S1) is performed, flavor components such as organic acids and nicotine will volatilize from the tobacco raw material along with water. Therefore, in this case, although the amount of TSNAs can be reduced, a tobacco material that retains the flavor components cannot be obtained.

[0070] 2. Tobacco Material According to another aspect, there is provided a tobacco material obtained by the above-described "method for producing a tobacco material." Compared to the tobacco raw material that is the starting material for the "method for producing a tobacco material," this tobacco material is characterized by having a lower TSNA content and retaining flavor components.

[0071] According to one embodiment, a tobacco material is provided having an NNN content of 3.0 [μg / g D.W.] or less, an NAT content of 2.0 [μg / g D.W.] or less, and a mass ratio of acetic acid to citric acid of 0.3 or more, where [μg / g D.W.] represents the mass [μg] per 1 g of the dry weight of the tobacco material.

[0072] In the tobacco material, the NNN content is, for example, 0.001 to 3.0 μg / g D.W., preferably 0.001 to 2.8 μg / g D.W., and more preferably 0.001 to 2.0 μg / g D.W. The NAT content in the tobacco material is, for example, 0.001 to 2.0 μg / g D.W., preferably 0.001 to 1.8 μg / g D.W., and more preferably 0.001 to 1.0 μg / g D.W. In the tobacco material, the mass ratio of acetic acid to citric acid is preferably 0.5 or more, and more preferably 1.0 or more. When the amount of citric acid is extremely small, the mass ratio of acetic acid to citric acid becomes infinitely large. Therefore, the upper limit of the mass ratio of acetic acid to citric acid is not particularly limited, but is, for example, 200.

[0073] Since NNN and NAT account for a large proportion of TSNA, a low NNN content and low NAT content in a tobacco material means a low total amount of TSNA. As described above, the mass ratio of acetic acid to citric acid is an index that represents the effect of suppressing irritation (irritation suppression effect) when a tobacco material is incorporated into a flavor inhaler and a user inhales tobacco flavor. In this specification, the mass ratio of acetic acid to citric acid is also referred to as "acetic acid / citric acid."

[0074] The tobacco material can be further characterized by maintaining a nicotine content compared to the tobacco material that is the starting material for the "tobacco material manufacturing method." That is, the nicotine content of the tobacco material is, for example, 2.0 [% D.B.] or more. Here, the unit [% D.B.] represents a proportion (i.e., a percentage) when the dry weight of the tobacco material is taken as 100.

[0075] In the tobacco material, the nicotine content is preferably 2.0 to 5.0 [% DB], and more preferably 2.0 to 4.0 [% DB].

[0076] Furthermore, the tobacco material can be further characterized by a reduced ammonia content compared to the tobacco material that is the starting material for the "tobacco material manufacturing method." That is, the ammonia content of the tobacco material is, for example, 2000 μg / g D.W. or less. Here, the unit μg / g D.W. represents the mass μg per 1 g of the dry weight of the tobacco material.

[0077] In the tobacco material, the ammonia content is preferably 1 to 2000 [% D.W.].

[0078] The following describes how to measure the "NNN content," "NAT content," "citric acid content," "acetic acid content," "nicotine content," and "ammonia content" of a tobacco material.

[0079] The "NNN content" and "NAT content" of a tobacco material can be measured using the procedure described below. 200 μL of a mixed internal standard solution and 20 mL of a 0.1 M ammonium acetate aqueous solution are added, in that order, to 0.5 g of a sample (tobacco material), and the mixture is subjected to shaking and extraction to prepare a sample solution. The sample solution is diluted 10-fold with a 0.1 M ammonium acetate aqueous solution, filled into a vial, and quantitatively analyzed using LC-MS / MS (liquid chromatography tandem mass spectrometry). Quantitative analysis of NNN and NAT is performed according to the method specified in ISO 21766:2021.

[0080] The "citric acid content" and "acetic acid content" of a tobacco material can be measured using the procedure described below. 10 mL of distilled water is added to 1 g of a sample (tobacco material), and the mixture is shaken at room temperature for 30 minutes to perform shaking extraction to prepare a sample solution. The sample solution is then filtered and quantitatively analyzed using capillary electrophoresis (CE). Quantitative analysis of citric acid and acetic acid is performed using the following analytical conditions: Instrument: Agilent 7100 CE system Capillary: 75 μm × 72 cm fused silica capillary (Agilent G1600-62311) Buffer: Agilent Organic Acid Buffer (pH 5.6, P / N 8500-6785) Voltage: -25.0 kV Sample injection: Pressure injection, 50 mbar for 2 seconds Detection wavelength: 350 nm (bandwidth 20 nm) Reference wavelength: 200 nm (bandwidth 10 nm) Temperature: 20°C

[0081] The "nicotine content" of tobacco material can be measured using the procedure described below. To 0.5 g of sample (tobacco material), 10 mL of distilled water, 20 mL of hexane conversion solvent (n-heptadecane standard solution (hexane solution)), and 5 mL of alkaline extraction solvent (8 mol / L sodium hydroxide solution) are added in that order, and the sample solution is prepared by shaking and extraction. The supernatant liquid (hexane layer) of the sample solution is placed in a vial, and quantitative analysis of nicotine is performed using GC (gas chromatography). Quantitative analysis of nicotine is performed using the following analytical conditions: Apparatus: Agilent 8890 GC System Column: CAM (30 m x 250 μm x 0.25 μm) (Agilent) Detector: Flame ionization detector (FID) Oven temperature program: 170°C (10 minutes) Injection volume: 1 μL (split ratio 50:1)

[0082] The "ammonia content" of a tobacco material can be measured by the following procedure. A sample (tobacco material) is extracted using a sulfuric acid solution to prepare a sample solution. The sample solution is separated in an analytical column using an ion chromatograph analyzer (non-suppressor type), and then detected and measured with an electrical conductivity detector to determine the ammonia (NH ３) is quantified. Quantitative analysis of ammonia is carried out according to the method specified in ISO 21045:2018.

[0083] 3. Flavor Inhaler The above-described "tobacco material" can be incorporated into any flavor inhaler containing a tobacco flavor source. That is, according to another aspect, a flavor inhaler containing the above-described "tobacco material" is provided. Flavor inhalers include combustion-type flavor inhalers, non-combustion-heating-type flavor inhalers, and non-heating-type flavor inhalers. According to one embodiment, a non-combustion-heating-type flavor inhaler containing the above-described "tobacco material" is provided.

[0084] A non-combustion heating type flavor inhaler is a flavor inhaler that provides a user with tobacco flavor by heating a tobacco flavor source without burning it. Hereinafter, a non-combustion heating type flavor inhaler will also be simply referred to as a "heating type flavor inhaler." The heating type flavor inhaler of the present invention has the same configuration as a normal heating type flavor inhaler, except that the tobacco flavor source is replaced with the above-mentioned "tobacco material."

[0085] According to a preferred embodiment, there is provided a non-combustion heating type flavor inhaler including: a flavor generating article including a flavor source containing the above-mentioned "tobacco material" and a wrapper wrapped around the flavor source; and a heater that heats the flavor source contained in the flavor generating article. The flavor generating article is also called a tobacco stick. The flavor generating article may further include a filter downstream of the flavor source (i.e., on the mouthpiece side).

[0086] An example of a heated flavor inhaler will be described below with reference to Figures 2A, 2B, 2C, 3, and 4. In this example, the heated flavor inhaler is composed of an aerosol generating device 100 and a tobacco stick 200. Figure 2A is a schematic front view of an example of the aerosol generating device. Figure 2B is a schematic top view of the aerosol generating device shown in Figure 2A. Figure 2C is a schematic bottom view of the aerosol generating device shown in Figure 2A. Figure 3 is a schematic side cross-sectional view of an example of a tobacco stick. Figure 4 is a cross-sectional view taken along line III-III of the aerosol generating device shown in Figure 2B.

[0087] For ease of explanation, the drawings may include an X-Y-Z Cartesian coordinate system. In this coordinate system, the Z axis faces vertically upward, the X-Y plane is positioned so as to cut the aerosol generation device 100 horizontally, and the Y axis is positioned so as to extend from the front to the back of the aerosol generation device 100. The Z axis can also be referred to as the insertion direction of the tobacco stick contained in the chamber 150 of the atomization unit 130 described below, or the axial direction of the chamber 150. The X axis is a direction perpendicular to the Y axis and the Z axis, and the X axis and the Y axis can also be referred to as the radial direction perpendicular to the axial direction of the chamber 150, or the radial direction of the chamber 150.

[0088] The aerosol generating device 100 is configured to generate an aerosol containing tobacco flavor components by heating a tobacco stick 200 containing the above-mentioned "tobacco material."

[0089] As shown in FIGS. 2A to 2C , the aerosol generating device 100 includes an outer housing 101 (corresponding to an example of a housing), a slide cover 102, and a switch unit 103. The outer housing 101 constitutes the outermost housing of the aerosol generating device 100 and is sized to fit in a user's hand. When using the flavor inhaler, a user can hold the aerosol generating device 100 in their hand and inhale the aerosol. The outer housing 101 may be formed by assembling multiple components. The outer housing 101 may be made of resin, for example, and in particular, may be formed of polycarbonate (PC), ABS (Acrylonitrile-Butadiene-Styrene) resin, PEEK (Polyetheretherketone), a polymer alloy containing multiple types of polymers, or a metal such as aluminum.

[0090] The outer housing 101 has an opening (not shown) for receiving a tobacco stick, and the sliding cover 102 is slidably attached to the outer housing 101 to close this opening. Specifically, the sliding cover 102 is configured to be movable along the outer surface of the outer housing 101 between a closed position (position shown in FIGS. 2A and 2B ) in which the opening of the outer housing 101 is closed, and an open position (position shown in FIG. 4 ) in which the opening is open. For example, a user can manually operate the sliding cover 102 to move the sliding cover 102 between the closed position and the open position. This allows or restricts access of tobacco sticks to the inside of the aerosol generation device 100.

[0091] The switch unit 103 is used to switch the operation of the aerosol generation device 100 on and off. For example, a user can operate the switch unit 103 while a tobacco stick is inserted into the aerosol generation device 100, thereby supplying power from a power source (see reference numeral 121 in FIG. 4 ) to a heater (see reference numeral 140 in FIG. 4 ), thereby heating the tobacco stick without burning it. The switch unit 103 may be a switch provided outside the outer housing 101, or may be a switch located inside the outer housing 101. When the switch is located inside the outer housing 101, the switch is indirectly pressed by pressing the switch unit 103 on the surface of the outer housing 101. In this example, an example in which the switch of the switch unit 103 is located inside the outer housing 101 will be described.

[0092] The aerosol generating device 100 may further include a terminal (not shown). The terminal may be an interface for connecting the aerosol generating device 100 to, for example, an external power source. If the power source of the aerosol generating device 100 is a rechargeable battery, connecting the external power source to the terminal allows the external power source to pass current through the power source and charge the power source. In addition, connecting a data transmission cable to the terminal may allow data related to the operation of the aerosol generating device 100 to be transmitted to an external device.

[0093] Next, the tobacco stick used in the aerosol generating device 100 will be described. Fig. 3 is a schematic side cross-sectional view of an example of a tobacco stick 200. In this example, a flavor inhaler is configured by the aerosol generating device 100 and the tobacco stick 200. As shown in Fig. 3, the tobacco stick 200 has a smokable article 201, a tubular member 204, a hollow filter portion 206, and a filter portion 205.

[0094] The smokable article 201 is wrapped in a first cigarette paper 202. The tubular member 204, hollow filter portion 206, and filter portion 205 are wrapped in a second cigarette paper 203 that is different from the first cigarette paper 202. The second cigarette paper 203 also wraps a portion of the first cigarette paper 202 that wraps the smokable article 201. This connects the tubular member 204, hollow filter portion 206, and filter portion 205 to the smokable article 201. However, the second cigarette paper 203 may be omitted, and the tubular member 204, hollow filter portion 206, and filter portion 205 may be connected to the smokable article 201 using the first cigarette paper 202. A lip release agent 207 is applied to the outer surface of the second cigarette paper 203 near the end on the filter portion 205 side, to make it easier for the user to release their lips from the second cigarette paper 203. The portion of the tobacco stick 200 to which the lip release agent 207 is applied functions as the mouthpiece of the tobacco stick 200 .

[0095] Smokable article 201 contains the above-described "tobacco material" as a tobacco flavor source. As described above, when used in a heated flavor inhaler, the above-described "tobacco material" can reduce negative sensations during inhalation (i.e., irritation, and burning and itchy sensations in the mouth) without reducing the smoking experience.

[0096] The first cigarette paper 202 wrapping the smokable article 201 may be a breathable sheet member. The tubular member 204 may be a paper tube or a hollow filter. In this example, the tobacco stick 200 includes the smokable article 201, the tubular member 204, the hollow filter portion 206, and the filter portion 205, but the configuration of the tobacco stick 200 is not limited to this. For example, the hollow filter portion 206 may be omitted, and the tubular member 204 and the filter portion 205 may be disposed adjacent to each other.

[0097] Next, the internal structure of the aerosol generating device 100 will be described. FIG. 4 is a cross-sectional view of the aerosol generating device 100 taken along line III-III in FIG. 2B. As shown in FIG. 4, an inner housing 110 (corresponding to an example of a housing) is provided inside the outer housing 101 of the aerosol generating device 100. The inner housing 110 is made of, for example, a resin, particularly polycarbonate (PC), ABS (Acrylonitrile-Butadiene-Styrene) resin, PEEK (Polyetheretherketone), a polymer alloy containing multiple types of polymers, or a metal such as aluminum. From the viewpoints of heat resistance and strength, the inner housing 110 is preferably made of PEEK. A power supply unit 120 and an atomization unit 130 are provided in the internal space of the inner housing 110.

[0098] The power supply unit 120 has a power supply 121. The power supply 121 may be, for example, a rechargeable battery or a non-rechargeable battery. The power supply 121 is electrically connected to the atomizing unit 130. This allows the power supply 121 to supply power to the atomizing unit 130 so as to appropriately heat the tobacco stick 200.

[0099] 4, the atomization unit 130 has a metal chamber 150 (corresponding to an example of a cylindrical portion) extending in the insertion direction (Z-axis direction) of the tobacco stick 200, a heater 140 covering a part of the chamber 150, a heat insulating portion 132, and a substantially cylindrical insertion guide member 134 (corresponding to an example of a guide portion) that abuts against the opening of the chamber 150. The chamber 150 is configured to surround the periphery of the tobacco stick 200. The heater 140 is configured to include a heating portion that contacts the outer peripheral surface of the chamber 150 and heats the tobacco stick 200 inserted into the chamber 150.

[0100] 4, a bottom member 136 (corresponding to an example of an abutment portion) is provided at the bottom of the chamber 150. The bottom member 136 abuts against the tobacco stick 200 inserted into the chamber 150 in the insertion direction of the tobacco stick 200, and can function as a stopper that positions the tobacco stick 200. Here, the chamber 150 and the bottom member 136 form a storage portion that stores at least a portion of the tobacco stick 200. The bottom member 136 can be formed from, for example, a resin material. The bottom member 136 has an uneven surface that abuts against the tobacco stick 200, and can define a first air flow path that can supply air to the air intake port of the tobacco stick 200 (i.e., that communicates with the tobacco stick 200 stored in the storage portion). The bottom member 136 is made of, for example, resin, particularly polycarbonate (PC), ABS (Acrylonitrile-Butadiene-Styrene) resin, PEEK (Polyetheretherketone), a polymer alloy containing multiple types of polymers, or a metal such as aluminum. Note that the bottom member 136 is preferably made of a material with low thermal conductivity to prevent heat from being transferred to the heat insulating portion 132, etc.

[0101] The heat insulating section 132 is generally cylindrical overall and is disposed to cover the chamber 150. The heat insulating section 132 may include, for example, an aerogel sheet. The insertion guide member 134 is disposed between the sliding cover 102 in the closed position and the chamber 150. The insertion guide member 134 is made of, for example, resin, and in particular, may be formed from polycarbonate (PC), ABS (Acrylonitrile-Butadiene-Styrene) resin, PEEK (Polyetheretherketone), or a polymer alloy containing multiple types of polymers. The insertion guide member 134 may also be formed from metal, glass, ceramic, or the like. From the standpoint of heat resistance, the insertion guide member 134 is preferably made of PEEK. When the slide cover 102 is in the open position, the insertion guide member 134 communicates with the outside of the aerosol generating device 100, and guides the insertion of the tobacco stick 200 into the chamber 150 by inserting the tobacco stick 200 into the insertion guide member 134. By providing the insertion guide member 134, the tobacco stick 200 can be easily inserted into the chamber 150.

[0102] The aerosol generating device 100 further has a first holding part 137 and a second holding part 138 that hold both ends of the chamber 150 and the heat insulating part 132. The first holding part 137 is arranged to hold the ends of the chamber 150 and the heat insulating part 132 on the negative Z-axis side. The second holding part 138 is arranged to hold the ends of the chamber 150 and the heat insulating part 132 on the slide cover 102 side (positive Z-axis side).

[0103] 4. Preferred Embodiments Preferred embodiments are summarized below.

[0104] [A1] A method for producing a tobacco material, comprising: using a heating device having an inlet, an outlet, and a heating chamber, heating tobacco material having a moisture content within the range of 5 to 30% by mass at a temperature of 290 to 400°C while the tobacco material is filled in the heating chamber and transported through the heating chamber; transporting the tobacco material from the heating device to a cooling device continuous with the heating device and equipped with a cooling chamber, and cooling the tobacco material while being transported through the cooling chamber in a filled state. [A2] The method according to [A1], wherein the heating device further comprises a transport mechanism that transports the tobacco material within the heating chamber. [A3] The method according to [A2], wherein the transport mechanism includes a motor and a screw that rotates when driven by the motor. [A4] The method according to any one of [A1] to [A3], wherein the heating device further comprises a heater that heats the tobacco material. [A5] The method according to any one of [A1] to [A4], wherein the cooling device further comprises a cooling mechanism that cools the tobacco raw material.

[0105] [A6] The method according to [A5], wherein the cooling mechanism includes a cooling jacket having a flow path for circulating cooling water. [A7] The method according to any one of [A1] to [A6], wherein the cooling device further includes an inlet and an outlet, and the cooling device is fixed to the heating device so that the inlet is connected to the outlet of the heating device. [A8] The method according to any one of [A1] to [A7], wherein the heating is performed at a temperature of 290 to 380°C, preferably 290 to 350°C. [A9] The method according to any one of [A1] to [A8], wherein the heating is performed while conveying the tobacco material through the heating chamber at a speed of 5 to 50 cm / min. [A10] The method according to any one of [A1] to [A9], wherein the heating is performed while conveying the tobacco material through the heating chamber at a speed of 7 to 35 cm / min, preferably 10 to 25 cm / min.

[0106] [A11] The method according to any one of [A1] to [A10], wherein the heating chamber has a length in the conveying direction of 30 to 300 cm. [A12] The method according to any one of [A1] to [A11], wherein the heating chamber has a length in the conveying direction of 35 to 200 cm, preferably 35 to 150 cm. [A13] The method according to any one of [A1] to [A12], wherein the heating is carried out for a period of 0.6 to 60 minutes. [A14] The method according to any one of [A1] to [A13], wherein the heating is carried out for a period of 1 to 30 minutes, preferably 2 to 15 minutes. [A15] The method according to any one of [A1] to [A14], wherein the heating is carried out under atmospheric pressure.

[0107] [A16] The method of any one of [A1] to [A15], wherein the heating is carried out without adding water to the tobacco material throughout the entire heating period. [A17] The method of any one of [A1] to [A16], wherein the cooling is carried out while conveying the tobacco material through the cooling chamber at a speed of 5 to 50 cm / min. [A18] The method of any one of [A1] to [A17], wherein the cooling is carried out while conveying the tobacco material through the cooling chamber at a speed of 7 to 35 cm / min, preferably 10 to 25 cm / min. [A19] The method of any one of [A1] to [A18], wherein the cooling chamber has a length in the conveyance direction of 10 to 300 cm. [A20] The method of any one of [A1] to [A19], wherein the cooling chamber has a length in the conveyance direction of 10 to 200 cm, preferably 10 to 150 cm.

[0108] [A21] The method according to any one of [A1] to [A20], wherein the cooling is carried out so that the tobacco material obtained after the cooling is cooled to a temperature of 70 to 140°C. [A22] The method according to any one of [A1] to [A21], wherein the cooling is carried out for a period of 0.6 to 60 minutes. [A23] The method according to any one of [A1] to [A22], wherein the cooling is carried out under atmospheric pressure conditions. [A24] The tobacco material is cooled to a temperature of 1 cm3 of the heating chamber. ３[A25] The method according to any one of [A1] to [A23], wherein the tobacco material is filled into the heating chamber in an amount of 0.15 g or more, preferably 0.20 g or more, per 1 cm 3 of the volume of the heating chamber. ３ The method according to any one of [A1] to [A24], wherein the heating chamber is filled with the granules in an amount of 0.15 to 0.60 g, preferably 0.20 to 0.60 g, more preferably 0.25 to 0.45 g per 1000 sieves.

[0109] [A26] The tobacco raw material has a volume of 1 cm 3 of the cooling chamber. ３ [A27] The method according to any one of [A1] to [A25], wherein the tobacco material is filled into the cooling chamber in an amount of 0.15 g or more, preferably 0.20 g or more, per 1 cm of the volume of the cooling chamber. ３ [A28] The method of any one of [A1] to [A27], wherein the tobacco material before heating has a moisture content of 5 to 15% by mass. [A29] The method of any one of [A1] to [A28], wherein the tobacco material obtained after cooling has a moisture content of 5 to 35% by mass. [A30] The method of any one of [A1] to [A29], wherein the tobacco material obtained after cooling has a moisture content of 5 to 20% by mass.

[0110] [B1] A tobacco material obtained by the method described in any one of [A1] to [A30]. [B2] A tobacco material having an NNN content of 3.0 [μg / g D.W.] or less, an NAT content of 2.0 [μg / g D.W.] or less, and a mass ratio of acetic acid to citric acid of 0.3 or more. [B3] A tobacco material obtained by the method described in any one of [A1] to [A30], having an NNN content of 3.0 [μg / g D.W.] or less, an NAT content of 2.0 [μg / g D.W.] or less, and a mass ratio of acetic acid to citric acid of 0.3 or more. [B4] The NNN content is 0.001 to 3.0 [μg / g D.W.], preferably 0.001 to 2.8 [μg / g D.W.]. [B5] The tobacco material according to any one of [B2] to [B4], wherein the NAT content is 0.001 to 2.0 [μg / g D.W.], preferably 0.001 to 1.8 [μg / g D.W.], more preferably 0.001 to 1.0 [μg / g D.W.].

[0111] [B6] The tobacco material according to any one of [B2] to [B5], wherein the mass ratio of acetic acid to citric acid is 0.5 or more, preferably 1.0 or more. [B7] The tobacco material according to any one of [B2] to [B6], wherein the mass ratio of acetic acid to citric acid is 0.3 to 200, preferably 0.5 to 200, more preferably 1.0 to 200. [B8] The tobacco material according to any one of [B2] to [B7], wherein the nicotine content of the tobacco material is 2.0 [% D.B.] or more. [B9] The tobacco material according to [B8], wherein the nicotine content is 2.0 to 5.0 [% D.B.], preferably 2.0 to 4.0 [% D.B.]. [B10] The tobacco material has an ammonia content of 2000 [μg / g D.W.] or more. [B11] The tobacco material according to any one of [B2] to [B9], wherein the ammonia content is 1 to 2000 [μg / g D.W.]. [B11] The tobacco material according to [B10], wherein the ammonia content is 1 to 2000 [μg / g D.W.].

[0112] [C1] A non-combustion heating type flavor inhaler comprising the tobacco material according to any one of [B1] to [B11]. [C2] A non-combustion heating type flavor inhaler comprising: a flavor source comprising the tobacco material according to any one of [B1] to [B11] and a wrapper wrapped around the flavor source; and a heater that heats the flavor source contained in the flavor generating product.

[0113] Example 1 In Example 1, the relationship between the heating temperature and the effect of reducing TSNA, and the relationship between the heating temperature and the effect of retaining flavor components were investigated.

[0114] 1-1. Preparation of Tobacco Materials Tobacco materials 1A to 1G were prepared using the tobacco material production apparatus 10 shown in Figure 1, with the heating temperatures changed as follows: Tobacco material 1A: 190°C Tobacco material 1B: 220°C Tobacco material 1C: 250°C Tobacco material 1D: 290°C Tobacco material 1E: 305°C Tobacco material 1F: 320°C Tobacco material 1G: 350°C.

[0115] 300 g of ground tobacco shreds was used as the tobacco raw material, which was the starting material. Specifically, Burley tobacco shreds were ground in a grinder to an average particle size of 250 μm, and 300 g of the resulting ground tobacco shreds were used per test. The moisture content WC1 of the tobacco raw material was 10% by mass. The tobacco raw material was heated at the above temperature while being transported through the heating chamber 22C in a state filled therein. The tobacco raw material was then transported to the cooling chamber 31C connected to the heating chamber 22C, and cooled while being transported through the cooling chamber 31C in a state filled therein.

[0116] The heating and cooling conditions were as follows: No moisture was added to the tobacco raw material during heating.

[0117] <Heating conditions> Heating temperature (set temperature of heating device): 190°C, 220°C, 250°C, 290°C, 305°C, 320°C, or 350°C Length of heating chamber in conveying direction: 38 cm Diameter of screw shaft: 0.8 cm Outer diameter of screw blade: 2.0 cm Screw rotation speed: 10 rpm Conveying speed within heating chamber: 20 cm / min Heating time: approximately 2 minutes Pressure within heating chamber: atmospheric pressure Filling rate of tobacco raw material within heating chamber: 0.3 g / cm ３ <Cooling conditions> Length of cooling chamber in conveying direction: 12 cm Conveying speed in cooling chamber: 20 cm / min Cooling time: 0.6 min Pressure in cooling chamber: atmospheric pressure Filling rate of tobacco raw material in cooling chamber: 0.3 g / cm ３ Temperature of the tobacco material obtained after cooling: 75°C.

[0118] 1-2. Evaluation Method The moisture content, NNN content, NAT content, citric acid content, acetic acid content, and nicotine content of the prepared tobacco materials were measured as described in the detailed description. The mass ratio of acetic acid to citric acid was calculated from the measurement results of the citric acid content and acetic acid content.

[0119] 1-3. Results The moisture contents WC2 of tobacco materials 1A to 1G were all within the range of 10 to 14% by mass, and were equal to or greater than the moisture contents WC1 of the tobacco raw material, which was the starting material. The reason the moisture contents did not decrease is thought to be because the water that volatilized from the tobacco raw material during the heating process remained near the tobacco raw material and returned to the tobacco raw material during the subsequent cooling process. The slight increase in moisture content is thought to be due to a dehydration reaction.

[0120] The results for NNN content are shown in Figure 5. The results for NAT content are shown in Figure 6. The results for the mass ratio of acetic acid to citric acid are shown in Figure 7. The results for nicotine content are shown in Figure 8. In Figures 5 to 8, "Untreated" indicates the results for the tobacco material that was the starting material.

[0121] At heating temperatures of 190°C, 220°C, and 250°C, the NNN content increased by about two times compared to the starting material (tobacco raw material), whereas at heating temperatures of 290°C or higher, the NNN content could be reduced compared to the starting material (tobacco raw material) (Figure 5). Furthermore, at heating temperatures of 290°C or higher, the effect of reducing the NNN content was greater the higher the heating temperature (Figure 5).

[0122] Similarly, when the heating temperatures were 190°C, 220°C, and 250°C, the NAT content increased by about two-fold compared to the starting material (tobacco raw material), whereas when the heating temperature was 290°C or higher, the NAT content could be reduced compared to the starting material (tobacco raw material) (Figure 6). Furthermore, when the heating temperature was 290°C or higher, the effect of reducing the NAT content was greater the higher the heating temperature (Figure 6).

[0123] The mass ratio of acetic acid to citric acid was approximately the same as that of the starting material (tobacco material) at heating temperatures of 190°C, 220°C, and 250°C, whereas it increased compared to the starting material (tobacco material) at heating temperatures of 290°C or higher (Figure 7). As described above, the mass ratio of acetic acid to citric acid is an indicator of the effect of suppressing irritation when a tobacco material is incorporated into a flavor inhaler and a user inhales tobacco flavor (irritation suppression effect). Therefore, when the heating temperature is 290°C or higher, the resulting tobacco material can exhibit an irritation suppression effect. Furthermore, when the heating temperature is 290°C or higher, the higher the heating temperature, the higher the mass ratio of acetic acid to citric acid and the higher the irritation suppression effect (Figure 7).

[0124] Regarding the nicotine content, regardless of the heating temperature used, the tobacco material was able to retain approximately the same amount of nicotine as the starting material (tobacco material) (Figure 8).

[0125] These results demonstrate that when tobacco materials are produced according to the method of the present invention, tobacco materials can be produced that retain flavor components while reducing the amount of TSNAs.

[0126] Example 2 In Example 2, the influence of the cooling process on the TSNA reduction effect and the flavor component retention effect was investigated.

[0127] 2-1. Preparation of Tobacco Materials Tobacco materials were prepared according to the same procedure as described in Example 1. Specifically, tobacco materials 2A to 2G, 3A to 3G, 4A to 4G, and 5A to 5G were prepared using the tobacco material production apparatus 10 shown in Figure 1, with the heating temperature, heating time, and whether or not a cooling step was performed being changed as follows.Tobacco material 2A: heated at 190°C for 120 seconds, followed by cooling. Tobacco material 2B: heated at 220°C for 120 seconds, followed by cooling. Tobacco material 2C: heated at 250°C for 120 seconds, followed by cooling. Tobacco material 2D: heated at 290°C for 120 seconds, followed by cooling. Tobacco material 2E: heated at 305°C for 120 seconds, followed by cooling. Tobacco material 2F: heated at 320°C for 120 seconds, followed by cooling. Tobacco material 2G: heated at 350°C for 120 seconds, followed by cooling. Tobacco material 3A: heated at 190°C for 120 seconds, without subsequent cooling. Tobacco material 3B: heated at 220°C for 120 seconds, without subsequent cooling. Tobacco material 3C: heated at 250°C for 120 seconds, without subsequent cooling. Tobacco material 3D: heated at 290°C for 120 seconds, without subsequent cooling. Tobacco material 3E: heated at 305°C for 120 seconds, without subsequent cooling. Tobacco material 3F: heated at 320°C for 120 seconds, without subsequent cooling. Tobacco material 3G: heated at 350°C for 120 seconds, without subsequent cooling. Tobacco material 4A: heated at 190°C for 240 seconds, with subsequent cooling. Tobacco material 4B: heated at 220°C for 240 seconds, with subsequent cooling. Tobacco material 4C: heated at 250°C for 240 seconds, with subsequent cooling. Tobacco material 4D: heated at 290°C for 240 seconds, with subsequent cooling. Tobacco material 4E: heated at 305°C for 240 seconds, with subsequent cooling. Tobacco material 4F: heated at 320°C for 240 seconds, with subsequent cooling. Tobacco material 4G: heated at 350°C for 240 seconds, with subsequent cooling. Tobacco material 5A: heated at 190°C for 240 seconds, without subsequent cooling. Tobacco material 5B: heated at 220°C for 240 seconds without subsequent cooling. Tobacco material 5C: heated at 250°C for 240 seconds without subsequent cooling. Tobacco material 5D: heated at 290°C for 240 seconds without subsequent cooling. Tobacco material 5E: heated at 305°C for 240 seconds without subsequent cooling. Tobacco material 5F: heated at 320°C for 240 seconds without subsequent cooling. Tobacco material 5G: heated at 350°C for 240 seconds without subsequent cooling.

[0128] "With cooling" refers to a case where the tobacco material was heated using the heating device shown in Fig. 1, and then cooled under specified cooling conditions using the cooling device shown in Fig. 1. "Without cooling" refers to a case where the tobacco material was heated using the heating device shown in Fig. 1, and then the tobacco material was discharged from the heating device and left to cool at room temperature (approximately 20°C).

[0129] 2-2. Evaluation Method The moisture content, NNN content, NAT content, citric acid content, acetic acid content, nicotine content, and ammonia content of the prepared tobacco materials were measured as described in the detailed description. The mass ratio of acetic acid to citric acid was calculated from the measurement results of the citric acid content and acetic acid content.

[0130] 2-3. Results The moisture contents WC2 of tobacco materials 2A to 2G were all within the range of 10 to 14% by mass, which was equal to or greater than the moisture contents WC1 of the starting material (tobacco raw material). The moisture contents WC2 of tobacco materials 3A to 3D were low at 2 to 4% by mass because no cooling step was performed. The moisture contents WC2 of tobacco materials 4A to 4G were all within the range of 10 to 16% by mass, which was equal to or greater than the moisture contents WC1 of the starting material (tobacco raw material). The moisture contents WC2 of tobacco materials 5A to 5E were low at 2 to 5% by mass because no cooling step was performed.

[0131] For tobacco materials 3E to 3G and tobacco materials 5F to 5G, the temperature of the tobacco raw material discharged from the heating device was high, so the tobacco raw material was actively cooled for safety reasons. For this reason, data including moisture content was not collected for tobacco materials 3E to 3G and tobacco materials 5F to 5G.

[0132] The results for NNN content are shown in Figure 9. The results for NAT content are shown in Figure 10. The results for the mass ratio of acetic acid to citric acid are shown in Figure 11. The results for nicotine content are shown in Figure 12. The results for ammonia content are shown in Figure 13. In Figures 9 to 13, data for "with cooling" are shown with solid lines, and data for "without cooling" are shown with dotted lines.

[0133] The NNN content was reduced compared to the starting material (tobacco raw material) at heating temperatures of 290°C or higher, both when a cooling step was performed and when no cooling step was performed (Figure 9). The NNN content of the starting material (tobacco raw material) was 3.03 [μg / g D.W.]. Furthermore, when the heating temperature was 290°C or higher, the effect of reducing the NNN content was greater the higher the heating temperature (Figure 9).

[0134] Similarly, the NAT content was reduced compared to the starting material (tobacco raw material) at heating temperatures of 290°C or higher, both when a cooling step was performed and when no cooling step was performed (Figure 10). The NAT content of the starting material (tobacco raw material) was 1.96 [μg / g D.W.]. Furthermore, when the heating temperature was 290°C or higher, the effect of reducing the NAT content was greater the higher the heating temperature (Figure 10).

[0135] When the cooling process was performed, the mass ratio of acetic acid to citric acid increased at heating temperatures of 290°C or higher compared to the starting material (tobacco raw material) ( FIG. 11 ). Note that for the starting material (tobacco raw material), the mass ratio of acetic acid to citric acid was 0.21. Furthermore, when the heating temperature was 290°C or higher, the higher the heating temperature, the greater the value of the mass ratio of acetic acid to citric acid ( FIG. 11 ).

[0136] Regarding the nicotine content, when the cooling process was not performed, the nicotine content decreased as the heating temperature increased. In contrast, when the cooling process was performed, the nicotine content in the tobacco material was approximately the same as that in the starting material (tobacco raw material), even when the heating temperature increased (Figure 12). The nicotine content of the starting material (tobacco raw material) was 3.48 [% D.B.].

[0137] Regarding the ammonia content, even after the cooling process, the ammonia could not be retained in the tobacco material, and the ammonia content decreased as the heating temperature increased ( FIG. 13 ). The ammonia content of the starting material (tobacco material) was 2501 μg / g D.W.

[0138] These results demonstrate that when a tobacco material is produced by carrying out a heating step followed by a cooling step according to the method of the present invention, it is possible to produce a tobacco material that retains flavor components while reducing the amount of TSNA.

[0139] 10... tobacco material manufacturing apparatus, 20... heating device, 30... cooling device, 21... hopper, 22... cylinder, 22A... inlet, 22B... outlet, 22C... heating chamber, 23... screw, 24... motor, 25... band heater, 25A... resistance heating element, 25B... insulator, 26... cover body, 31... cooling pipe, 31A... inlet, 31B... outlet, 31C... cooling chamber, 32... cooling jacket, 32A... flow path, 100... aerosol generating device, 101... outer housing, 102... slide Door cover, 103...switch portion, 110...inner housing, 120...power supply portion, 121...power supply, 130...atomization portion, 132...heat insulation portion, 134...insertion guide member, 136...bottom member, 137...first holding portion, 138...second holding portion, 140...heater, 150...chamber, 200...tobacco stick, 201...smokable article, 202...first cigarette paper, 203...second cigarette paper, 204...cylindrical member, 205...filter portion, 206...hollow filter portion, 207...lip release agent.

Claims

1. A method for manufacturing a tobacco material, comprising: heating tobacco raw material having a moisture content in the range of 5 to 30% by mass at a temperature of 290 to 400°C while conveying the tobacco raw material filled in a heating chamber using a heating device having an inlet, an outlet, and a heating chamber; and conveying the tobacco raw material from the heating device to a cooling device that is continuous with the heating device and has a cooling chamber, and cooling the tobacco raw material while conveying the tobacco raw material filled in the cooling chamber through the cooling chamber.

2. The method according to claim 1, wherein the heating device further comprises a mechanism for conveying the tobacco raw material in the heating chamber.

3. The method according to claim 1 or 2, wherein the heating is performed while conveying the tobacco raw material through the heating chamber at a speed of 5 to 50 cm / min.

4. The method according to any one of claims 1 to 3, wherein the heating chamber has a length in the conveying direction of 30 to 300 cm.

5. The method according to any one of claims 1 to 4, wherein the heating is performed over a period of 0.6 to 60 minutes.

6. The method according to any one of claims 1 to 5, wherein the heating is performed under atmospheric pressure conditions.

7. The method according to any one of claims 1 to 6, wherein the cooling is performed while conveying the tobacco raw material through the cooling chamber at a speed of 5 to 50 cm / min.

8. The method according to any one of claims 1 to 7, wherein the cooling chamber has a length in the conveying direction of 10 to 300 cm.

9. The method according to any one of claims 1 to 8, wherein the cooling is performed such that the tobacco material obtained after cooling is cooled to a temperature of 70 to 140°C.

10. The method according to any one of claims 1 to 9, wherein the cooling is performed over a period of 0.6 to 60 minutes.

11. The method according to any one of claims 1 to 10, wherein the cooling is performed under atmospheric pressure conditions.

12. The tobacco material is filled into the heating chamber in an amount of 0.20 g or more per 1 cm ３ of the volume of the heating chamber. The method according to any one of claims 1 to 11.

13. The tobacco raw material is filled into the cooling chamber in an amount of 0.20 g or more per 1 cm ３ of the volume of the cooling chamber. The method according to any one of claims 1 to 12.

14. The method according to any one of claims 1 to 13, wherein the moisture content of the tobacco raw material before heating is 5 to 15% by mass.

15. The method according to any one of claims 1 to 14, wherein the moisture content of the tobacco material obtained after cooling is 5 to 35% by mass.

16. A tobacco material obtained by the method according to any one of claims 1 to 15.

17. A tobacco material having an NNN content of 3.0 [μg / g D.W.] or less, an NAT content of 2.0 [μg / g D.W.] or less, and a mass ratio of acetic acid to citric acid of 0.3 or more.

18. The tobacco material according to claim 17, wherein the nicotine content is 2.0 [% D.B.] or more.

19. The tobacco material according to claim 17 or 18, wherein the ammonia content is 2000 [μg / g D.W.] or less.

20. A non-combustion heating type flavor attractor containing the tobacco material according to any one of claims 16 to 19.

Images