Method for treating tobacco raw material

Abstract

This application proposes a method for treating a tobacco raw material. The method includes: performing first-stage treatment and / or second-stage treatment on a tobacco raw material, where the first-stage treatment includes: (1-1) performing at least one leaf moisturizing and redrying on the tobacco raw material; and (1-2) placing the tobacco raw material subjected to leaf moisturizing and redrying in a controlled environment for equilibration; and the second-stage treatment includes: (2-1) adding a mixed material liquid to a tobacco raw material not subjected to the first-stage treatment or the tobacco raw material subjected to the first-stage treatment, the mixed material liquid including a base, amino acids, and water; (2-2) storing the tobacco raw material added with the mixed material liquid; (2-3) baking the tobacco raw material treated in step (2-2); and (2-4) placing the baked tobacco raw material in a controlled environment for equilibration.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese Patent Application No. 202311428404.6, filed on October 30, 2023, which is incorporated by reference in its entirety.TECHNICAL FIELD

[0002] This application relates to the technical field of tobacco, and specifically, to a method for treating a tobacco raw material.BACKGROUND

[0003] Heat-not-burn cigarettes refers to a smoking method in which a tobacco substance is heated by an electronic device rather than being combusted. When used with an electronic heating device, such cigarettes allow consumers to perceive the flavor of tobacco. In addition, because a tobacco core of the heat-not-burn cigarette is heated at low temperature, the release of tar and undesirable substances in the mainstream smoke can be significantly reduced. This smoking method has become increasingly popular both in China and other countries, and the heat-not-burn cigarettes have become a major development direction in the tobacco industry.

[0004] However, because the heat-not-burn cigarettes have the characteristic of "heating cut tobacco or tobacco extracts rather than combusting cut tobacco", their sensory quality during smoking differs significantly from that of conventional cigarettes. For example, during smoking, heat-not-burn cigarettes may exhibit low expression of aromatic style characteristics, increased off-flavor irritation, reduced comfort, and the like. Therefore, the current method for treating a tobacco raw material still requires further improvement.SUMMARY

[0005] This application is based on discovery and recognition of the inventors with respect to the following facts and problems: In the related art, tobacco raw materials for heat-not-burn cigarettes are pre-treated, to reduce acidic notes of an aerosol, decrease off-flavor irritation, and improve comfort to some extent. However, there have been no reports on pre-treatment methods specifically for enhancing the expression of aromatic style characteristics of tobacco raw materials for heat-not-burn cigarettes. This application proposes a method for treating a tobacco raw material, to enhance the expression of aromatic style characteristics of tobacco for heat-not-burn cigarettes. In the method, relative release amounts of acidic, neutral, and basic flavor components in a raw material are modified, to balance an aerosol composition under heating conditions. The method has significant practical implications for enhancing the aroma fidelity of tobacco for heat-not-burn cigarettes and improving the sensory quality of the heat-not-burn cigarettes during smoking.

[0006] In view of this, to at least relieve or solve at least one of the foregoing problems to some extent, in an aspect of this application, this application proposes a method for treating a tobacco raw material. In some embodiments of this application, the method for treating a tobacco raw material includes: performing first-stage treatment and / or second-stage treatment on a tobacco raw material. The first-stage treatment includes the following steps: (1-1) performing at least one leaf moisturizing and redrying on the tobacco raw material, the leaf moisturizing and redrying including: performing steam conditioning on the tobacco raw material; and drying the tobacco raw material subjected to steam conditioning; and (1-2) placing the tobacco raw material subjected to leaf moisturizing and redrying in a controlled environment for equilibration. The second-stage treatment includes the following step: (2-1) adding a mixed material liquid to a tobacco raw material not subjected to the first-stage treatment or the tobacco raw material subjected to the first-stage treatment, the mixed material liquid including a base, amino acids, and water, the base including one or more of sugar materials, cocoa powder, cocoa extract, licorice powder, licorice extract, citric acid, acetic acid, and Burley tobacco pyrolysate; (2-2) storing the tobacco raw material added with the mixed material liquid; (2-3) baking the tobacco raw material treated in step (2-2); and (2-4) placing the baked tobacco raw material in a controlled environment for equilibration. During heating, the treated tobacco raw material exhibits significant expression of aromatic style characteristics, reduced off-flavor, irritation, and throat hit, and significantly improved comfort.

[0007] In some embodiments of this application, the method for treating a tobacco raw material includes: performing the first-stage treatment and the second-stage treatment on the tobacco raw material. Therefore, the expression of aromatic style characteristics of the tobacco is further enhanced.

[0008] In some embodiments of this application, the first-stage treatment includes a step of performing leaf moisturizing and redrying on the tobacco raw material twice.

[0009] In some embodiments of this application, in step (2-1), the mixed material liquid is added to the tobacco raw material not subjected to the first-stage treatment, and in the mixed material liquid, the mass of the base accounts for 3% to 10% of the initial mass of the tobacco raw material, the mass of the amino acids accounts for 1% to 3% of the initial mass of the tobacco raw material, and the mass of water accounts for 30% to 40% of the initial mass of the tobacco raw material; or the mixed material liquid is added to the tobacco raw material subjected to the first-stage treatment, and in the mixed material liquid, the mass of the base accounts for 3% to 10% of the mass of the tobacco raw material subjected to the first-stage treatment, the mass of the amino acids accounts for 1% to 3% of the mass of the tobacco raw material subjected to the first-stage treatment, and the mass of water accounts for 30% to 40% of the mass of the tobacco raw material subjected to the first-stage treatment. During high-temperature baking, sugars in the base undergo Maillard reaction with the amino acids, thereby enhancing the expression of aromatic style characteristics of tobacco. Another substance in the base may improve smoking taste and reduce irritation during smoking.

[0010] In some embodiments of this application, in step (1-1), the moisture content of the tobacco raw material subjected to steam conditioning is 20% to 24%. This can reduce ammonia-nitrogen off-flavor to some extent and evaporate part of free nicotine, thereby decreasing the irritation and alkaline notes during tobacco smoking.

[0011] In some embodiments of this application, in the method for treating a tobacco raw material, at least one of the following conditions is satisfied: in step (1-1), the tobacco raw material subjected to steam conditioning is dried at 50°C to 90°C; and in step (1-1), the moisture content of the dried tobacco raw material is 10% to 12%. Drying the tobacco raw material at the foregoing temperature can quickly remove part of the moisture and volatile alkaline off-flavor components and some free alkali from the raw material. This is beneficial for reducing the ammonia-nitrogen off-flavor, throat hit, and irritation of the tobacco, balancing the aroma components in the tobacco, and enhancing the expression of aromatic style characteristics of tobacco. Drying the tobacco to the moisture content within the foregoing range can effectively remove volatile alkaline off-flavor and free alkali from the tobacco raw material. The dried tobacco raw material has an appropriate moisture content, which is favorable for subsequent treatment.

[0012] In some embodiments of this application, in the method for treating a tobacco raw material, at least one of the following conditions is satisfied: in step (1-2), the equilibration time is 24 h to 48 h, and / or the equilibration temperature is 22°C to 25°C, and / or the relative humidity during equilibration is 60% to 65%; and in step (2-4), the equilibration time is 24 h to 48 h, and / or the equilibration temperature is 22°C to 25°C, and / or the relative humidity during equilibration is 60% to 65%. Performing equilibration under the foregoing conditions is beneficial for improving the stability of the tobacco raw material.

[0013] In some embodiments of this application, in the method for treating a tobacco raw material, at least one of the following conditions is satisfied: the tobacco raw material includes a Burley tobacco raw material; the amino acids include one or more of aspartic acid, glutamic acid, lysine, and histidine; the sugar materials include one or more of glucose, fructose, sucrose, white granulated sugar, and invert sugar; and the tobacco raw material includes at least one of leaf tobacco and cut tobacco. Adding the foregoing amino acids can enhance the expression of aromatic style characteristics of the tobacco to some extent. Both the leaf tobacco and the cut tobacco can be treated by using the method proposed in this application, to enhance the expression of aromatic style characteristics of the tobacco.

[0014] In some embodiments of this application, in the method for treating a tobacco raw material, at least one of the following conditions is satisfied: in step (2-2), the tobacco raw material added with the mixed material liquid is stored in an environment at 40°C to 60°C for 4 h to 8 h; and in step (2-2), the moisture content of the treated tobacco raw material is 30% to 40%. In this way, the tobacco raw material can fully absorb the mixed material liquid, which is beneficial to further improving the expression of aromatic style characteristics of the tobacco.

[0015] In some embodiments of this application, in the method for treating a tobacco raw material, at least one of the following conditions is satisfied: in step (2-3), the baking temperature is 90°C to 150°C; and in step (2-3), the moisture content of the baked tobacco raw material is 8% to 10%. Within the foregoing temperature range, the sugars undergo Maillard reaction with the amino acids, thereby enhancing the expression of aromatic style characteristics of the tobacco. The appropriate moisture content of the baked tobacco raw material is favorable for subsequent equilibration.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The foregoing and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments with reference to the drawings. FIG. 1 is a flowchart of a method for treating a tobacco raw material according to an embodiment of this application. FIG. 2 is a flowchart of a method for treating a tobacco raw material according to another embodiment of this application. FIG. 3 is a flowchart of a method for treating a tobacco raw material according to still another embodiment of this application. DETAILED DESCRIPTION

[0017] The embodiments of this application are described below in detail. The following embodiments are exemplary, are merely used for explaining this application, and are not intended to limit this application.

[0018] In an aspect of this application, this application proposes a method for treating a tobacco raw material. In some embodiments of this application, referring to FIG. 1 to FIG. 3, the method for treating a tobacco raw material may include performing first-stage treatment and / or second-stage treatment on a tobacco raw material.

[0019] In some embodiments of this application, referring to FIG. 1 and FIG. 3, first-stage treatment may include the following steps:(1-1) Perform at least one leaf moisturizing and redrying on the tobacco raw material.

[0020] In some embodiments of this application, leaf moisturizing and redrying may be performed on the tobacco raw material once, twice, three times, or more times.

[0021] In some embodiments of this application, the leaf moisturizing and redrying may include the following steps:(1-1-1) Perform steam conditioning on the tobacco raw material.

[0022] In some embodiments of this application, steam conditioning is performed on the tobacco raw material, to increase the moisture content of the tobacco raw material to 20% to 24%. The increased moisture content and improved flexibility of the tobacco raw material subjected to steam conditioning is favorable for subsequent operations. During steam conditioning, some volatile off-flavor components, free nicotine, and the like may be evaporated, which is beneficial for reducing irritation and ammonia-nitrogen off-flavor during smoking and enhancing the expression of aromatic style characteristics of tobacco.(1-1-2) Bake the tobacco raw material subjected to steam conditioning.

[0023] In some embodiments of this application, the tobacco raw material may be dried to the moisture content of 10% to 12%. Drying can evaporate volatile off-flavor components, free nicotine, and the like from the tobacco, which is beneficial for further reducing irritation and off-flavor during smoking and further enhancing the expression of aromatic style characteristics of the tobacco.

[0024] In some embodiments of this application, the tobacco raw material may include a Burley tobacco raw material. In some specific embodiments of this application, the tobacco raw material may be a Burley tobacco raw material. During heating, alkaline aroma components in an aerosol of the Burley tobacco are significantly higher than other aroma components. Through steam conditioning and redrying, volatile alkaline off-flavor (mainly ammonia-nitrogen notes) and some free nicotine in the tobacco raw material may be removed, thereby reducing the ammonia-nitrogen off-flavor, throat hit, and irritation of the Burley tobacco, balancing the aroma components in the Burley tobacco, making aromatic style characteristics of the Burley tobacco more easily perceptible.

[0025] In some embodiments of this application, in step (1-1), the tobacco raw material subjected to steam conditioning is dried at 50°C to 90°C. For example, the drying temperature may be 50°C, 60°C, 70°C, 80°C, or 90°C. Drying the raw material at the foregoing temperature can remove some volatile alkaline off-flavor and free nicotine in the tobacco raw material, thereby effectively reducing the ammonia-nitrogen off-flavor, throat hit, and irritation during smoking, and making aromatic style characteristics of the tobacco more easily perceptible. Specifically, the Burley tobacco raw material subjected to steam conditioning is dried at 50°C to 90°C, to make the aromatic style characteristics of the Burley tobacco more easily perceptible, thereby facilitating improving the expression of aromatic style characteristics of the Burley tobacco.

[0026] In this application, in step (1-1), the tobacco raw material subjected to steam conditioning may be dried at 70°C to 90°C. For example, the drying temperature may be 70°C, 73°C, 75°C, 78°C, 80°C, 82°C, 85°C, 87°C, or 90°C. Drying the tobacco raw material at the foregoing temperature is beneficial to shortening the drying time, removing some alkaline off-flavor and free nicotine, and enhancing the expression of aromatic style characteristics of the tobacco.

[0027] In some embodiments of this application, the first-stage treatment may include a step of performing leaf moisturizing and redrying on the tobacco raw material twice. Performing leaf moisturizing and redrying twice can remove more volatile alkaline off-flavor and free alkali, thereby further reducing the ammonia-nitrogen off-flavor, throat hit, and irritation of the tobacco, and making the aromatic style characteristics of the tobacco more easily perceptible.

[0028] In some embodiments of this application, the tobacco raw material may include at least one of leaf tobacco and cut tobacco. The leaf tobacco refers to a tobacco raw material obtained by removing stems from tobacco leaves and redrying the tobacco leaves. The method proposed in this application may be applied to treatment of the leaf tobacco and / or the cut tobacco, to enhance the expression of aromatic style characteristics of the tobacco. In some embodiments of this application, the tobacco raw material may be leaf tobacco or cut tobacco. In some other embodiments of this application, the tobacco raw material may be a combination of leaf tobacco and cut tobacco.(1-2) Perform equilibration on the tobacco raw material subjected to leaf moisturizing and redrying.

[0029] In this step, the tobacco raw material subjected to leaf moisturizing and redrying is placed in a controlled environment for 24 h to 48 h (such as 24 h, 30 h, 36 h, 40 h, or 48 h). In the controlled environment, the temperature may be 22°C to 25°C, and the relative humidity may be 60% to 65%. For example, the temperature may be 22°C, 23°C, 24°C, or 25°C, and the relative humidity may be 60%, 61%, 62%, 63%, 64%, or 65%. Placing the tobacco raw material at the foregoing temperature and the relative humidity for 24 h to 48 h can maintain uniform and appropriate moisture content in the tobacco, thereby achieving stable quality of the tobacco.

[0030] In some embodiments of this application, referring to FIG. 2 and FIG. 3, the second-stage treatment may include the following steps:(2-1) Add a mixed material liquid to the tobacco raw material.

[0031] In this step, the mixed material liquid is added to a tobacco raw material not subjected to the first-stage treatment or the tobacco raw material subjected to the first-stage treatment.

[0032] In some embodiments of this application, the mixed material liquid may include a base, amino acids, and water. The base may include one or more of sugar materials, cocoa powder, cocoa extract, licorice powder, licorice extract, citric acid, acetic acid, and Burley tobacco pyrolysate. The sugar materials may include one or more of glucose, fructose, sucrose, white granulated sugar, and invert sugar. Adding the foregoing mixed material liquid can improve the expression of aromatic style characteristics of the tobacco.

[0033] In some specific embodiments of this application, adding the foregoing mixed material liquid to the Burley tobacco raw material can enhance the expression of aromatic style characteristics of the Burley tobacco. For example, sugars undergo Maillard reaction with the amino acids during subsequent high-temperature heating, to enhance the expression of aromatic style characteristics of the Burley tobacco. Cocoa powder or cocoa extract can enhance the nutty aroma of the Burley tobacco. Licorice or licorice extract can improve the taste of the Burley tobacco and reduce irritation. Citric acid, acetic acid, and the like can neutralize alkaline notes of the Burley tobacco during heating, thereby reducing an excessively strong alkaline aroma in the heated Burley tobacco, and making the aromatic style characteristics of the Burley tobacco more easily perceptible.

[0034] In some embodiments of this application, the amino acids in the mixed material liquid may include one or more of aspartic acid, glutamic acid, lysine, histidine, and the like. In some specific embodiments of this application, the amino acids in the mixed material liquid may be aspartic acid, glutamic acid, lysine, or histidine. In some other specific embodiments, the amino acids in the mixed material liquid may be a combination of two or more of aspartic acid, glutamic acid, lysine, and histidine. All of the foregoing amino acids can enhance the expression of aromatic style characteristics of the tobacco and improve the sensory quality of the tobacco during smoking.

[0035] In some embodiments of this application, referring to FIG. 2, in step (2-1), the mixed material liquid is added to the tobacco raw material not subjected to the first-stage treatment, and in the mixed material liquid, the mass of the base may account for 3% to 10% of the initial mass of the tobacco raw material, the mass of the amino acids may account for 1% to 3% of the initial mass of the tobacco raw material, and the mass of water may account for 30% to 40% of the initial mass of the tobacco raw material. For example, in the mixed material liquid, the mass of the base may account for 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% of the initial mass of the tobacco raw material, the mass of the amino acids may account for 1%, 1.5%, 2%, 2.5%, or 3% of the initial mass of the tobacco raw material, and the mass of water may account for 30%, 32%, 35%, 37%, or 40% of the initial mass of the tobacco raw material.

[0036] In some other embodiments of this application, referring to FIG. 3, in step (2-1), the mixed material liquid is added to the tobacco raw material subjected to the first-stage treatment, and in the mixed material liquid, the mass of the base may account for 3% to 10% (such as 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%) of the mass of the tobacco raw material subjected to the first-stage treatment, the mass of the amino acids may account for 1% to 3% (such as 1%, 1.5%, 2%, 2.5%, or 3%) of the mass of the tobacco raw material subjected to the first-stage treatment, and the mass of water may account for 30% to 40% (such as 30%, 32%, 35%, 37%, or 40%) of the mass of the tobacco raw material subjected to the first-stage treatment. In this way, the mixed material liquid contains appropriate masses of the base, the amino acids, and water. After being added to the tobacco raw material, the mixed material liquid can be fully absorbed. During subsequent baking, some components in the base may undergo Maillard reaction with the amino acids, thereby enhancing the expression of aromatic style characteristics of the tobacco.(2-2) Store the tobacco raw material added with the mixed material liquid.

[0037] In some embodiments of this application, after the mixed material liquid is added, the Burley tobacco raw material may be stored in an environment at 40°C to 60°C for 4 h to 8 h. For example, the Burley tobacco raw material may be stored in an environment at 40°C, 45°C, 50°C, 55°C, or 60°C for 4 h, 5 h, 6 h, 7 h, or 8 h. This promotes the absorption of the mixed material liquid by the tobacco, thereby improving the utilization of the mixed material liquid.

[0038] In some embodiments of this application, in step (2-2), the tobacco raw material added with the mixed material liquid is stored in an environment at 50°C to 60°C for 6 h to 8 h. For example, the tobacco raw material may be stored in an environment at 50°C, 52°C, 55°C, 57°C, or 60°C for 6 h, 6.5 h, 7 h, 7.5 h, or 8 h. In this way, the tobacco can more fully absorb the mixed material liquid, thereby further improving the utilization of the mixed material liquid, and further facilitating enhancing the expression of aromatic style characteristics of the tobacco.

[0039] In some embodiments of this application, in step (2-2), the moisture content of the treated tobacco raw material may be 30% to 40%. For example, the moisture content may be 30%, 32%, 35%, 37%, or 40%. During baking, the tobacco raw material loses part of moisture. Before baking, the moisture content of the tobacco raw material is controlled to fall within the foregoing range, which may promote Maillard reaction during baking. In addition, after baking, the tobacco raw material still has a particular content of moisture.(2-3) Perform baking.

[0040] The tobacco raw material treated in step (2-2) is baked. The baking temperature may be 90°C to 150°C. For example, the baking temperature may be 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C. In some embodiments of this application, the moisture content of the baked tobacco raw material may be 8% to 10%. Through high-temperature baking, the sugars undergo Maillard reaction with the amino acids, to increase characteristic aroma substances of the tobacco, thereby enhancing the expression of aromatic style characteristics of the tobacco, and improving the fidelity of conventional tobacco aroma of the tobacco during heating. After being added with the mixed material liquid and stored, the Burley tobacco raw material is baked at 90°C to 150°C, and the sugars undergo Maillard reaction with the amino acids, thereby increasing characteristic aroma substances of the Burley tobacco and further enhancing the expression of aromatic style characteristics of the Burley tobacco.

[0041] In some embodiments of this application, in step (2-3), the baking temperature may be 110°C to 130°C. For example, the baking temperature may be 110°C, 115°C, 120°C, 125°C, or 130°C. The foregoing temperature range is more favorable for Maillard reaction between the sugars and the amino acids, and further increases the content of the characteristic aroma substances of the tobacco, thereby enhancing the expression of aromatic style characteristics of the tobacco.(2-4) Perform equilibration on the baked tobacco raw material.

[0042] The baked tobacco raw material is placed in a controlled environment for 24 h to 48 h (such as 24 h, 30 h, 36 h, 40 h, or 48 h). In the controlled environment, the temperature may be 22°C to 25°C, and the relative humidity may be 60% to 65%. For example, the temperature may be 22°C, 23°C, 24°C, or 25°C, and the relative humidity may be 60%, 61%, 62%, 63%, 64%, or 65%. Placing the tobacco raw material at the foregoing temperature and the relative humidity for 24 h to 48 h can maintain uniform and appropriate moisture content in the tobacco, thereby achieving stable quality of the tobacco.

[0043] In some specific embodiments of this application, referring to FIG. 1, only the first-stage treatment may be performed on the tobacco raw material, to enhance the expression of aromatic style characteristics of the tobacco during smoking.

[0044] In some other specific embodiments of this application, referring to FIG. 2, only the second-stage treatment may be performed on the tobacco raw material.

[0045] In still some other specific embodiments of this application, referring to FIG. 3, the first-stage treatment and the second-stage treatment may be performed on the tobacco raw material, to further highlight the aromatic style characteristics of the tobacco during smoking.

[0046] This application is described below by using specific examples. A person skilled in the art can understand that the following specific examples are merely for the purpose of description, and are not intended to limit the scope of this application in any way. In addition, in the following examples, unless otherwise specified, the used materials and equipment are all commercially available. If specific treatment conditions and treatment methods are not explicitly described in the following examples, treatment may be performed by using conditions and methods well-known in the art.Example 1

[0047] Only the first-stage treatment was performed on a Burley tobacco raw material. Specifically, leaf moisturizing and redrying was performed on the Burley tobacco raw material once, including the following steps sequentially: (1) steam conditioning was performed on the Burley tobacco raw material, where the moisture content of the Burley tobacco raw material subjected to steam conditioning was 22% to 24%; (2) the raw material subjected to steam conditioning was dried, where the drying temperature was 90°C, and the moisture content of the dried Burley tobacco raw material was 10% to 12%; and (3) the dried raw material was placed in a controlled environment for 24 h (equilibration conditions: the temperature was 22°C, and the relative humidity was 60%) to obtain a pre-treated tobacco raw material. Example 2

[0048] Only the first-stage treatment was performed on a Burley tobacco raw material. Specifically, leaf moisturizing and redrying was performed on the Burley tobacco raw material twice, including the following steps sequentially: (1) steam conditioning was performed on the Burley tobacco raw material, where the moisture content of the Burley tobacco raw material subjected to steam conditioning was 22% to 24%; (2) the raw material subjected to steam conditioning was dried, where the drying temperature was 90°C, and the moisture content of the dried Burley tobacco raw material was 10% to 12%; (3) steam conditioning was performed on the Burley tobacco raw material dried in step (2), where the moisture content of the Burley tobacco raw material subjected to steam conditioning was 20% to 22%; (4) the raw material subjected to steam conditioning in step (3) was dried, where the drying temperature was 70°C, and the moisture content of the dried Burley tobacco raw material was 10% to 12%; and (5) the raw material dried in step (4) was placed in a controlled environment for 24 h (equilibration conditions: the temperature was 22°C, and the relative humidity was 60%) to obtain a pre-treated tobacco raw material. Example 3

[0049] Only the second-stage treatment was performed on a Burley tobacco raw material, including the following steps sequentially: (1) a mixed material liquid was prepared, where the mixed material liquid included a base, amino acids, and water, and in the mixed material liquid, the mass of the base (including fructose-containing syrup, cocoa extract, citric acid, licorice extract, and the like) accounted for 3% of the initial mass of the Burley tobacco raw material, the mass of the amino acids (lysine) accounted for 1.5% of the initial mass of the Burley tobacco raw material, and the mass of water accounted for 40% of the initial mass of the Burley tobacco raw material; (2) the prepared mixed material liquid was uniformly sprayed into the Burley tobacco raw material, and the Burley tobacco raw material was stored in an environment at 55°C for 6 h; (3) high-temperature baking was performed on the Burley tobacco raw material stored in step (2), where baking conditions included that the Burley tobacco raw material was baked at 130°C for 2 min, baked at 120°C for 2 min, and baked at 110°C for 2 min, and the moisture content of the baked raw material was 8% to 10%; and (4) the baked raw material was placed in a controlled environment for 48 h (equilibration conditions: the temperature was 22°C, and the relative humidity was 60%) to obtain a pre-treated tobacco raw material. Example 4

[0050] The first-stage treatment (including performing leaf moisturizing and redrying twice) and the second-stage treatment were performed on a Burley tobacco raw material, including the following steps sequentially: (1) steam conditioning was performed on the Burley tobacco raw material, where the moisture content of the Burley tobacco raw material subjected to steam conditioning was 22% to 24%; (2) the raw material subjected to steam conditioning was dried, where the drying temperature was 90°C, and the moisture content of the dried Burley tobacco raw material was 10% to 12%; (3) steam conditioning was performed on the Burley tobacco raw material dried in step (2), where the moisture content of the Burley tobacco raw material subjected to steam conditioning was 20% to 22%; (4) the raw material subjected to steam conditioning in step (3) was dried, where the drying temperature was 70°C, and the moisture content of the dried Burley tobacco raw material was 10% to 12%; (5) the raw material dried in step (4) was placed in a controlled environment for 24 h (equilibration conditions: the temperature was 22°C, and the relative humidity was 60%); (6) a mixed material liquid was prepared according to the mass of the Burley tobacco raw material equilibrated in step (5), where the mixed material liquid included a base, amino acids, and water, and in the mixed material liquid, the mass of the base (including fructose-containing syrup, cocoa extract, citric acid, licorice extract, and the like) accounted for 3% of the mass of the Burley tobacco raw material equilibrated in step (5), the mass of the amino acids (lysine) accounted for 1.5% of the mass of the Burley tobacco raw material equilibrated in step (5), and the mass of water accounted for 40% of the mass of the Burley tobacco raw material equilibrated in step (5); (7) the prepared mixed material liquid was uniformly sprayed into the Burley tobacco raw material, and the Burley tobacco raw material was stored in an environment at 55°C for 6 h; (8) high-temperature baking was performed on the Burley tobacco raw material stored in step (7), where the baking conditions included that the Burley tobacco raw material was baked at 130°C for 2 min, baked at 120°C for 2 min, and baked at 110°C for 2 min, and the moisture content of the baked Burley tobacco raw material was 8% to 10%; and (9) the baked raw material was placed in a controlled environment for 48 h (equilibration conditions: the temperature was 22°C, and the relative humidity was 60%) to obtain a pre-treated tobacco raw material. Example 5

[0051] A difference from Example 4 was that, in Example 5, the fructose-containing syrup in the base in Example 4 was replaced with invert sugar, and 1.5% lysine in Example 4 was replaced with 1% aspartic acid + 0.5% glutamic acid, and the remaining steps and parameters were the same as those in Example 4.Evaluation of application effects:

[0052] After the pre-treated tobacco raw materials prepared by using the methods of Example 1 to Example 5 and an untreated Burley tobacco raw material (control sample) were mixed with an aerosol-generating agent (such as propylene glycol or glycerol) in the same proportion, the sensory quality was evaluated using a heat-not-burn device. Evaluation results are shown in Table 1 below: Table 1 Evaluation results of sensory quality of the pre-treated tobacco raw materials of the examples and the untreated Burley tobacco raw materialSample Aerosol characteristics Aroma characteristics Taste characteristics ControlLow aerosol density, strong throat hit, poor cohesiveness, and harsh aerosolPoor aroma quality, flat aroma volume, heavy off- flavor, and low expression of aromatic style characteristics of Burley tobacco High irritation, heavy alkaline flavor and poor aftertaste, and poor comfortExample 1Slightly high aerosol density, slightly strong throat hit, acceptable cohesiveness, and slightly smooth aerosolSlightly good aroma quality, and acceptable aroma volume, slightly light off-flavor, and acceptable and slightly enhanced expression of aromatic style characteristics of Burley tobacco Minimal irritation, slightly poor aftertaste, and slightly poor comfortExample 2Relatively high aerosol density, moderate to slightly strong throat hit, relatively good cohesiveness, and relatively smooth aerosolRelatively good aroma quality, relatively sufficient aroma volume, relatively light off-flavor, and slightly high and enhanced expression of aromatic style characteristics of Burley tobacco Slight irritation, acceptable aftertaste, and acceptable comfortExample 3Relatively high aerosol density, moderate to slightly strong throat hit, relatively good cohesiveness, and relatively smooth aerosolRelatively good aroma quality, sufficient aroma volume, relatively light off-flavor, and relatively high and relatively obviously enhanced expression of aromatic style characteristics of Burley tobacco Slight irritation, relatively clean aftertaste, and relatively good comfortExample 4Relatively high aerosol density, moderate throat hit, good cohesiveness, and smooth aerosolGood aroma quality, sufficient aroma volume, light off-flavor, and relatively high and obviously enhanced expression of aromatic style characteristics of Burley tobacco Irritation free, clean aftertaste, and good comfortExample 5High aerosol density, moderate throat hit, good cohesiveness, and smooth aerosolGood aroma quality, sufficient aroma volume, light off-flavor, and high and obviously enhanced expression of aromatic style characteristics of Burley tobacco Low irritation, clean aftertaste, and good comfort

[0053] In Table 1, the results are compared according to the sensory evaluation: High aerosol density > relatively high aerosol density > slightly high aerosol density > low aerosol density; moderate throat hit > moderate to slightly strong throat hit > slightly strong throat hit > strong throat hit; good cohesiveness > relatively good cohesiveness > acceptable cohesiveness > poor cohesiveness; smooth aerosol > relatively smooth aerosol > slightly smooth aerosol > harsh aerosol; good aroma quality > relatively good aroma quality > slightly good aroma quality > poor aroma quality; sufficient aroma volume > relatively sufficient aroma volume > acceptable aroma volume > flat aroma volume; light off-flavor > relatively light off-flavor > slightly light off-flavor > heavy off-flavor; high and obviously enhanced expression of aromatic style characteristics of Burley tobacco > relatively high and obviously enhanced expression of aromatic style characteristics of Burley tobacco > relatively high and relatively obviously enhanced expression of aromatic style characteristics of Burley tobacco > slightly high and enhanced expression of aromatic style characteristics of Burley tobacco > acceptable and slightly enhanced expression of aromatic style characteristics of Burley tobacco > low expression of aromatic style characteristics of Burley tobacco; irritation free > low irritation > slight irritation > minimal irritation > high irritation; clean aftertaste > relatively clean aftertaste > acceptable aftertaste > slightly poor aftertaste > heavy alkaline flavor and poor aftertaste; and good comfort > relatively good comfort > acceptable comfort > slightly poor comfort > poor comfort.

[0054] It can be learned from Table 1 that, compared with the untreated Burley tobacco raw material, the treated Burley tobacco raw materials of Example 1 to Example 5 all have some improvement in the sensory quality during smoking. Compared with Example 1 and Example 2 in which only the first-stage treatment is performed and Example 3 in which only the second-stage treatment is performed, Example 4 and Example 5 in which both the first-stage treatment and the second-stage treatment are performed on the Burley tobacco raw materials achieve more significant sensory quality enhancement. The slight differences in the aroma characteristics and the taste characteristics between Example 4 and Example 5 are mainly attributed to the different types of amino acids used. Lysine in Example 4 enhances the expression of aromatic style characteristics of the Burley tobacco, imparting a sweet taste with no irritation. In contrast, the combination of aspartic acid and glutamic acid in Example 5 has a stronger effect on enhancing the expression of aromatic style characteristics of the Burley tobacco but introduces a salty taste and some irritation.

[0055] After leaf moisturizing and redrying or material adding and high-temperature baking is performed on the Burley tobacco raw material, the sensory evaluation shows that off-flavor, irritation, and throat hit of the Burley tobacco raw material in a heat-not-burn state are reduced, comfort is significantly improved, aerosol clarity is enhanced, and the expression of aromatic style characteristics of the Burley tobacco is enhanced. After leaf moisturizing and redrying or material adding and high-temperature baking is performed on the Burley tobacco raw material, the sensory evaluation shows that the Burley tobacco raw material in the heat-not-burn state exhibit good comfort, high aroma concentration, moderate throat hit, pronounced cocoa and nutty aroma, and significant expression of aromatic style characteristics of the Burley tobacco.

[0056] In conclusion, the method for treating a tobacco raw material proposed in this application has the following beneficial effects: through leaf moisturizing and redrying (namely, steam conditioning and drying), volatile alkaline off-flavor (mainly ammonia-nitrogen notes) and some free nicotine can be removed from the tobacco raw material, thereby reducing the ammonia-nitrogen off-flavor, throat hit, and irritation of the tobacco. In addition, the composition of aroma components in the tobacco is balanced, making aromatic style characteristics of the tobacco more easily perceptible. The tobacco raw material is added with the base and the amino acids and stored, and baked at high temperature to promote Maillard reaction, thereby increasing the content of characteristic aroma substances in the tobacco, enhancing the expression of aromatic style characteristics of the tobacco, and improving the fidelity of conventional tobacco aroma of the tobacco during heating. The process requires relatively simple process stages and mature process equipment, making it applicable to scaled production and application. The process has practical significance for production and development of heat-not-burn cigarette products.

[0057] In the description of this specification, references to terms such as "an embodiment", "another embodiment", "yet another embodiment", "some embodiments", and "some other embodiments" mean that a specific feature, structure, material, or characteristic described with reference to the embodiment is included in at least one embodiment of this application. In this specification, the exemplary description of the foregoing terms do not necessarily refer to the same embodiment or example. Furthermore, the specific feature, structure, material, or characteristic described may be combined in any suitable manner in any one or more embodiments or examples. In addition, a person skilled in the art may combine and assemble different embodiments or examples described in this specification, as well as features of different embodiments or examples, provided that they are not contradictory to each other.

[0058] Although the embodiments of this application are illustrated and described above, it may be understood that, the foregoing embodiments are exemplary and are not to be construed as limitations on this application, and a person of ordinary skill in the art may make changes, modifications, replacements, and variations to the foregoing embodiments within the scope of this application.

Claims

1. A method for treating a tobacco raw material, comprising: performing first-stage treatment and / or second-stage treatment on a tobacco raw material, wherein the first-stage treatment comprises the following steps: (1-1) performing at least one leaf moisturizing and redrying on the tobacco raw material, the leaf moisturizing and redrying comprising: performing steam conditioning on the tobacco raw material; and drying the tobacco raw material subjected to steam conditioning; and (1-2) placing the tobacco raw material subjected to leaf moisturizing and redrying in a controlled environment for equilibration; and the second-stage treatment comprises the following steps: (2-1) adding a mixed material liquid to a tobacco raw material not subjected to the first-stage treatment or the tobacco raw material subjected to the first-stage treatment, the mixed material liquid comprising a base, amino acids, and water, and the base comprising one or more of sugar materials, cocoa powder, cocoa extract, licorice powder, licorice extract, citric acid, acetic acid, and Burley tobacco pyrolysate; (2-2) storing the tobacco raw material added with the mixed material liquid; (2-3) baking the tobacco raw material treated in step (2-2); and (2-4) placing the baked tobacco raw material in a controlled environment for equilibration.

2. The method of claim 1, comprising: performing the first-stage treatment and the second-stage treatment on the tobacco raw material.

3. The method of claim 1 or 2, wherein the first-stage treatment comprises a step of performing leaf moisturizing and redrying on the tobacco raw material twice.

4. The method of claim 1, wherein in step (2-1), the mixed material liquid is added to the tobacco raw material not subjected to the first-stage treatment, and in the mixed material liquid, the mass of the base accounts for 3% to 10% of the initial mass of the tobacco raw material, the mass of the amino acids accounts for 1% to 3% of the initial mass of the tobacco raw material, and the mass of water accounts for 30% to 40% of the initial mass of the tobacco raw material; or the mixed material liquid is added to the tobacco raw material subjected to the first-stage treatment, and in the mixed material liquid, the mass of the base accounts for 3% to 10% of the mass of the tobacco raw material subjected to the first-stage treatment, the mass of the amino acids accounts for 1% to 3% of the mass of the tobacco raw material subjected to the first-stage treatment, and the mass of water accounts for 30% to 40% of the mass of the tobacco raw material subjected to the first-stage treatment.

5. The method of any one of claims 1 to 4, wherein, in step (1-1), the moisture content of the tobacco raw material subjected to steam conditioning is 20% to 24%.

6. The method of any one of claims 1 to 5, wherein at least one of the following conditions is satisfied: in step (1-1), the tobacco raw material subjected to steam conditioning is dried at 50°C to 90°C; and in step (1-1), the moisture content of the dried tobacco raw material is 10% to 12%.

7. The method of any one of claims 1 to 6, wherein at least one of the following conditions is satisfied: in step (1-2), the equilibration time is 24 h to 48 h, and / or the equilibration temperature is 22°C to 25°C, and / or the relative humidity during equilibration is 60% to 65%; and in step (2-4), the equilibration time is 24 h to 48 h, and / or the equilibration temperature is 22°C to 25°C, and / or the relative humidity during equilibration is 60% to 65%.

8. The method of any one of claims 1 to 7, wherein at least one of the following conditions is satisfied: the tobacco raw material comprises a Burley tobacco raw material; the amino acids comprise one or more of aspartic acid, glutamic acid, lysine, and histidine; the sugar materials comprise one or more of glucose, fructose, sucrose, white granulated sugar, and invert sugar; and the tobacco raw material comprises at least one of leaf tobacco and cut tobacco.

9. The method of any one of claims 1 to 8, wherein at least one of the following conditions is satisfied: in step (2-2), the tobacco raw material added with the mixed material liquid is stored in an environment at 40°C to 60°C for 4 h to 8 h; and in step (2-2), the moisture content of the treated tobacco raw material is 30% to 40%.

10. The method of any one of claims 1 to 9, wherein at least one of the following conditions is satisfied: in step (2-3), the baking temperature is 90°C to 150°C; and in step (2-3), the moisture content of the baked tobacco raw material is 8% to 10%.

Images