Method for preparing flavor based on low-grade tobacco leaves and application thereof

Abstract

The present application relates to a method for preparing flavor based on low-grade tobacco leaves and application thereof, which comprises the following steps: threshing, increasing temperature and humidity, puffing, drying, crushing, and reacting tobacco powder with sugar under high temperature or microwave condition to prepare tobacco flavor compounds; preparing flavor base and gel base, and finally obtaining flavor. The present application uses waste low-grade tobacco leaves as raw material, and turns waste into treasure. The prepared flavor can significantly improve the tobacco aroma and smoke amount of cigarettes when applied to cigarettes, and the product still retains good sensory style after being stored for more than 1 year.

Description

A method for preparing flavorings based on low-grade tobacco leaves and its application Technical Field

[0001] This invention belongs to the field of tobacco extraction technology, specifically relating to a method and application for preparing flavorings based on low-grade tobacco leaves. Background Technology

[0002] my country is a major tobacco-growing and producing country, with a tobacco leaf output of 4.5 million to 5 million tons. Low-grade tobacco leaves refer to all grades below the Zhonghuang Grade 5, Shanghuang Grade 4, and Qinghuang Grade 2 as defined in GB2635-86. In terms of appearance, these leaves are brownish-yellow or yellowish-brown with a bluish tinge, uneven in thickness, loosely structured, have weak luster, often have noticeable blemishes, large damaged areas, and insufficient oil content. In terms of smoking quality, they lack aroma, have a rough flavor, a pronounced bitter and astringent taste, an unpleasant aftertaste, and leave a significant amount of residue on the tongue and mouth. A large amount of low-grade tobacco leaves, accounting for 25% of total tobacco production, is generated during harvesting and processing. Except for a small amount used to produce tobacco paste and pesticides, most of these leaves are discarded, which not only wastes resources but also pollutes the soil environment.

[0003] Low-grade tobacco leaves, as a unique biomass raw material, are rich in tobacco aroma components and chemical components such as sugars, proteins, and cellulose. Fully utilizing these resources is of great significance for the high-value utilization of low-grade tobacco leaves. Currently, the utilization of effective components in low-grade tobacco leaves mainly focuses on extracting proteins, cellulose, chlorogenic acid, rutin, and other polyphenols, as well as specific components such as nicotine and solanesol. However, influenced by factors such as region, soil, climate, variety, and cultivation methods, tobacco leaf quality and use value are classified into several types, and low-grade tobacco leaves also have different style characteristics and grades, such as light aroma, strong aroma, and medium aroma. For different types of low-grade tobacco leaves, conventional extraction techniques are insufficient to obtain tobacco aroma compounds with a fixed style, thus limiting the large-scale utilization of aroma components in low-grade tobacco leaves. Furthermore, the components that impart flavor characteristics to tobacco are mainly volatile aroma components, characterized by low boiling points and low aroma thresholds. If these characteristic aroma components are directly added to cigarette products, they are easily lost during processing, transportation, and storage, making it difficult to realize their potential value. Therefore, obtaining a flavoring agent with stable flavor and excellent aroma retention properties from low-grade tobacco leaves of different styles is of great significance for the resource utilization of low-grade tobacco leaves. Based on this, this application was developed. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method and application for preparing flavorings based on low-grade tobacco leaves. This method uses waste low-grade tobacco leaves as raw materials, turning waste into treasure. The flavorings obtained can significantly enhance the tobacco aroma and smoke volume of cigarettes, and retain a good sensory flavor even after the product has been stored for more than one year.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for preparing flavorings based on low-grade tobacco leaves, comprising the following steps:

[0007] (1) Leaf threshing: Low-grade tobacco leaves are processed into tobacco dust with a size of 2-8mm using a tobacco leaf shredder. The purpose is to improve the uniformity of the raw materials and the stability of the subsequent puffing reaction.

[0008] (2) Increasing temperature and humidity: The tobacco dust is humidified at 80-100℃ to a moisture content of about 14-20%;

[0009] (3) Expansion: The humidified tobacco powder is subjected to expansion treatment;

[0010] (4) Drying: Dry the expanded tobacco powder until the moisture content is less than 12%;

[0011] (5) Crushing: The tobacco powder dried in step (4) is made into tobacco powder of 200-400 mesh. The preferred equipment is a supersonic airflow pulverizer.

[0012] (6) Preparation of tobacco flavor compounds: under high temperature or microwave conditions, tobacco powder is reacted with sugars; here, the main reactions are caramelization and Maillard reaction to obtain tobacco flavor compounds;

[0013] (7) Preparation of flavor matrix: Add an aqueous ethanol solution with a volume fraction of more than 95% uniformly to the tobacco powder after the reaction in step (6), then extract the tobacco flavor compounds, and obtain the flavor matrix by concentration and purification;

[0014] (8) Preparation of gel matrix: The extracted tobacco powder is dried, and soluble substances are removed by hot water extraction. Insoluble substances are removed by alkali dissolution to remove lignin, hemicellulose and other compounds, and acidification is used to obtain microcrystalline cellulose. Then, it is successively treated with near-critical water, high pressure homogenization and gelation to obtain gel matrix.

[0015] (9) Preparation of fragrance: Mix the fragrance matrix and the gel matrix at a mass ratio of 1:10-100 to obtain a stable fragrance with a sustained-release effect.

[0016] Specifically, in step (3), an expansion device is used to expand the humidified tobacco dust. This mainly removes the low-boiling-point tobacco aroma substances from low-grade tobacco leaves of different styles, degrades some macromolecular substances such as pectin, starch, protein, and a small amount of cellulose, and generates some tobacco aroma precursors while changing the microstructure of the tobacco dust. The expansion device used during expansion is one or more of the following: microwave reactor, steam explosion device, CO2 expander, etc. The expansion device can be prepared using conventional technology in this field or can be purchased directly from ordinary commercial products. Since this is not the innovation of this application, it will not be described in detail here. When using a microwave reactor, the reaction parameters are: power 30-80kW, steam pressure 0.2-1.0Mpa, and the proportion of material in the cranial cavity is 2-10%; when using a steam explosion device, the reaction parameters are: steam explosion pressure 0.1-3.0Mpa, pressure retention time 10-60s; when using a CO2 expander, the reaction parameters are: reaction temperature 200-350℃.

[0017] Specifically, in step (6), the sugar is one or more combinations of glucose, fructose, maltose, lactose, sucrose, etc., and the mass ratio of tobacco powder to sugar is 100:(0.2-2).

[0018] Furthermore, in step (6), the reaction temperature during high-temperature reaction is 160-250℃ and the reaction time is 20-60min; during microwave reaction, the microwave frequency is 2-3MHz, the microwave power is 600-1200W, the heating time is 3-10min, and the proportion of material in the cranial cavity is 0.1-2%.

[0019] Specifically, in step (7), high-pressure micro-mist technology is used to uniformly add an ethanol aqueous solution with a volume fraction of more than 95% to the tobacco powder after the reaction. The amount of ethanol aqueous solution added is 5-15% of the mass of the tobacco powder. Then, one of the following techniques is used to extract tobacco aroma compounds: supercritical extraction, molecular distillation, organic solvent extraction, etc.; organic solvent extraction is preferred. Further, in step (7), the aroma components are extracted with an organic solvent to obtain an extract. An appropriate amount of anhydrous sodium sulfate is added to the extract to remove water. Solid-liquid separation is performed by filtration, centrifugation, etc., to obtain an anhydrous extract, which is then concentrated and purified to obtain the fragrance matrix. The organic solvent is one or more combinations of dichloromethane, ethyl acetate, petroleum ether, etc., and the solid-liquid ratio during organic solvent extraction is 1:3-20. For dichloromethane extraction, the extraction temperature is 15-45℃, preferably 35℃, and the extraction time is 10-180 min, preferably 10-30 min. For ethyl acetate extraction, the extraction temperature is 20-70℃, preferably 40-50℃, and the extraction time is 10-200 min, preferably 10-15 min. Ultrasonic or microwave extraction can be used to enhance the extraction process.

[0020] The concentration and purification steps can be referenced as follows: The extract is concentrated by distillation or low-temperature vacuum to remove 90-98% of the organic solvent. Silica gel packing is added and mixed thoroughly, then the remaining organic solvent is removed under reduced pressure. The amount of silica gel added is 5-25% of the tobacco powder mass. The silica gel packing, now free of organic solvent, is packed into a column. Anhydrous ethanol is used as the eluent. Collection begins when the effluent has a distinct aroma and continues until the effluent loses its aroma. The collected aroma solution is concentrated 50-500 times to obtain the fragrance matrix.

[0021] Specifically, in step (8), the conditions for hot water extraction are: hot water temperature of 40-70℃, solid-liquid ratio of 1:3-10; extraction times of 2-5 times; after extraction, high-speed centrifugation to obtain precipitate, centrifugation speed of 5000-15000 r / min, centrifugation time of 5-30 min;

[0022] Alkali dissolution: First, use a 5-20% sodium hydroxide solution to dissolve the insoluble substances at room temperature to remove compounds such as lignin and hemicellulose. The solid-liquid ratio is 1:10-30, and the reaction time is 30-60 minutes. After the reaction, the solid and liquid are separated and washed with water until the pH of the washing solution is 7-8.

[0023] Acidification: The acid used is an inorganic acid, such as one or more of phosphotungstic acid, hydrochloric acid, sulfuric acid and phosphoric acid, with an acid concentration of 10-60%; the reaction temperature is 70-95℃, the solid-liquid ratio is 1:10-30, and the reaction time is 1-3h; after the reaction, the solid and liquid are separated and washed with water until the pH of the washing solution is 7-8, and powder 1 is obtained by freeze drying or spray drying;

[0024] Near-critical water treatment: the solid-liquid ratio of powder 1 to water is 1:5-20, the temperature is 150-300℃, and the time is 10-90 min; after the reaction, the solid and liquid are separated, and powder 2 is obtained by freeze drying or spray drying;

[0025] High-pressure homogenization: Powder 2 is mixed with water at a solid-liquid ratio of 1:5-50 and a working pressure of 400-1000 bar. Powder 3 is obtained by freeze drying or spray drying.

[0026] Gelation: Gelation techniques include freeze-thaw cycles, ionic crosslinking, polymerization, and 3D printing. Freeze-thaw technology is preferred. The reaction conditions for freeze-thaw are as follows: Powder 3 is mixed evenly with a mixed solution of water, glycerol, and polyethylene glycol, wherein the mass ratio of water, glycerol, and polyethylene glycol in the mixed solution is 100:1-10:3-20; the solid-liquid ratio of powder 3 to liquid is 1:20-100; a gel matrix is ​​obtained through freeze-thaw. The freezing temperature is within the range of -10 to -100℃, and the number of freeze-thaw cycles is 2-10.

[0027] This invention provides a fragrance prepared using the above method.

[0028] This invention provides the application of the above-mentioned roasted spices in cigarettes. Specifically, it can be done by: coating the prepared spices onto the surface of reconstituted tobacco leaves used for heating cigarettes, with an addition amount of 0.1-10%; controlling the moisture content of the reconstituted tobacco leaves to 12-18% before coating, adjusting the moisture content of the sample to 10-12% after coating using a low-temperature slow drying process, and then using a roller pressing device to compact the coating into the reconstituted tobacco leaves after drying, with a roller pressing pressure of 0.5-2 MPa and a temperature of 60-80℃.

[0029] The present invention also provides a cigarette, wherein the cigarette is added with the aforementioned flavoring.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] This invention uses waste low-grade tobacco leaves as raw materials, turning waste into treasure. The resulting flavoring contains a large amount of tobacco aroma substances, has strong tobacco style characteristics, and is safer. When applied to cigarettes, it can significantly improve the sensory quality of the product, especially significantly improve the tobacco aroma and smoke volume. The product retains a good sensory style even after being stored for more than one year.

[0032] This invention utilizes low-grade tobacco leaves of different styles to obtain a flavoring agent with stable flavor and excellent aroma retention, which is of great significance for the resource utilization of low-grade tobacco leaves. Attached Figure Description

[0033] Figure 1 shows the GC diagrams of flavorings prepared from light and strong aroma low-grade tobacco leaves. Detailed Implementation

[0034] The technical solution of the present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited thereto.

[0035] In this invention, unless otherwise specified, the unit of the solid-liquid ratio is g:ml, such as a solid-liquid ratio of 1:10-30, which means 1g:10-30ml. Room temperature refers to 25±5℃. Processes or operations not mentioned in detail, such as freeze drying and spray drying, can be performed using conventional techniques in the field.

[0036] Example 1

[0037] A method for preparing flavorings based on low-grade tobacco leaves, comprising the following steps:

[0038] (1) Leaf threshing: Low-grade tobacco leaves are processed into tobacco dust with a size of 2-8mm using a tobacco leaf shredder.

[0039] (2) Increasing temperature and humidity: The tobacco dust is humidified at 80-100℃ to a moisture content of about 16%.

[0040] (3) Expansion: The humidified tobacco powder was expanded using an expansion device. The expansion device used was a microwave reactor. When using a microwave reactor, the reaction parameters were: power 50kW, steam pressure 0.6MPa, and the proportion of material in the cranial cavity 6%.

[0041] (4) Drying: Dry the expanded tobacco powder until the moisture content is less than 12%.

[0042] (5) Crushing: The expanded tobacco powder is made into tobacco powder of 200-400 mesh.

[0043] (6) Preparation of tobacco aroma compounds: under high temperature conditions, tobacco powder and sugar were subjected to caramelization reaction and Maillard reaction to obtain tobacco aroma compounds. The sugar was composed of glucose and fructose in a mass ratio of 1:1. The mass ratio of tobacco powder to sugar was 100:1. The reaction temperature was 180℃ and the reaction time was 50min.

[0044] (7) Preparation of fragrance base:

[0045] High-pressure micro-mist technology was used to uniformly add a 95% (v / v) ethanol aqueous solution to the tobacco powder after the reaction in step (6), with the addition amount being 10% of the tobacco powder mass. Then, the tobacco aroma compounds were extracted using an organic solvent. The aroma components were extracted with the organic solvent to obtain an extract. An appropriate amount of anhydrous sodium sulfate was added to the extract to remove water, and solid-liquid separation was performed by filtration to obtain an anhydrous extract. The extract was then concentrated and purified to obtain the flavor matrix.

[0046] The organic solvent used was dichloromethane, and the solid-liquid ratio during organic solvent extraction was 1:20. The extraction temperature was room temperature (25℃), and the extraction time was 60 minutes.

[0047] The concentration and purification steps are as follows: 90-98% of the organic solvent in the extract is removed by distillation, and silica gel packing is added and mixed well. The remaining organic solvent is removed under reduced pressure. The amount of silica gel added is 15% of the relative mass of the tobacco powder. The silica gel packing with the organic solvent removed is packed into a column, and anhydrous ethanol is used as the eluent. Collection begins when the effluent has a fragrance (i.e., collection begins when a fragrance is detected by a fragrance test strip, the same applies below) until the effluent has no fragrance. The collected fragrance solution is concentrated 200 times to obtain the fragrance matrix.

[0048] (8) Preparation of gel matrix:

[0049] After the tobacco powder is extracted with organic solvents and dried, it is then extracted with hot water to remove soluble substances. The insoluble substances are removed by alkali dissolution to remove lignin, hemicellulose and other compounds. After acidification, microcrystalline cellulose is obtained. Then, it is successively treated with near-critical water, homogenized under high pressure and gelled to obtain a gel matrix.

[0050] The conditions for hot water extraction were: hot water temperature of 55℃, solid-liquid ratio of 1:7, and extraction times of 3 times. After extraction, the precipitate was obtained by high-speed centrifugation at a speed of 10000 r / min for 20 min.

[0051] Alkali dissolution: First, use an 18% sodium hydroxide solution to dissolve the solid at room temperature with a solid-liquid ratio of 1:20 and a reaction time of 45 minutes. After the reaction, the solid and liquid are separated and washed with water until the pH of the washing solution is close to 7.

[0052] Acidification: The acid used was phosphotungstic acid with a concentration of 30%, the reaction temperature was 80℃, the solid-liquid ratio was 1:20, and the reaction time was 2h. After the reaction, the solid and liquid were separated and washed with water until the pH of the washing solution was close to 7. Powder 1 was obtained by spray drying.

[0053] Near-critical water treatment: the solid-liquid ratio of powder 1 to water is 1:15, the temperature is 230℃, and the time is 60min; after the reaction, the solid and liquid are separated, and powder 2 is obtained by spray drying.

[0054] High-pressure homogenization: Powder 2 is mixed with water at a solid-liquid ratio of 1:25 and a working pressure of 800 bar, and then spray-dried to obtain powder 3.

[0055] Gelation: The preferred gelation technique is freeze-thaw mixing. The reaction conditions for freeze-thaw mixing are as follows: powder 3 is ultrasonically mixed with a mixture of water, glycerol, and polyethylene glycol, wherein the mass ratio of water, glycerol, and polyethylene glycol in the mixture is 100:8:12; the solid-liquid ratio of powder 3 to liquid is 1:60; and then subjected to freeze-thaw mixing. The freezing temperature is below -40°C, and the number of freeze-thaw cycles is 5.

[0056] (9) Preparation of spices:

[0057] Mixing the fragrance matrix and the gel matrix at a mass ratio of 1:50 yields a stable fragrance with a sustained-release effect.

[0058] Example 2

[0059] A method for preparing flavorings based on low-grade tobacco leaves, comprising the following steps:

[0060] (1) Leaf threshing: Low-grade tobacco leaves are processed into tobacco dust with a size of 2-8mm using a tobacco leaf shredder.

[0061] (2) Increasing temperature and humidity: The tobacco dust is humidified at 80-100℃ to a moisture content of about 14-16%.

[0062] (3) Expansion: The humidified tobacco powder is expanded using an expansion device. The expansion device used is a steam explosion device. When using a steam explosion device, the reaction parameters are: steam explosion pressure 1.5 MPa, pressure retention time 30 s.

[0063] (4) Drying: Dry the expanded tobacco powder until the moisture content is less than 12%.

[0064] (5) Crushing: The expanded tobacco powder is made into tobacco powder of 200-400 mesh.

[0065] (6) Preparation of tobacco aroma compounds: tobacco aroma compounds were obtained by caramelizing tobacco powder and sugar under high temperature conditions. The sugar was composed of maltose and lactose in a mass ratio of 1:1. The mass ratio of tobacco powder to sugar was 100:0.3. The reaction temperature was 240℃ and the reaction time was 30 min.

[0066] (7) Preparation of fragrance base:

[0067] High-pressure micro-mist technology was used to uniformly add a 95% (v / v) ethanol aqueous solution to the tobacco powder after the reaction in step (6), with the addition amount being 10% of the tobacco powder mass. Then, the tobacco aroma compounds were extracted using an organic solvent. The aroma components were extracted with the organic solvent to obtain an extract. An appropriate amount of anhydrous sodium sulfate was added to the extract to remove water, and solid-liquid separation was performed by filtration to obtain an anhydrous extract. The extract was then concentrated and purified to obtain the flavor matrix.

[0068] The organic solvent used was dichloromethane, and the solid-liquid ratio during organic solvent extraction was 1:4. The extraction temperature was 20℃, and the extraction time was 60 min.

[0069] The concentration and purification steps are as follows: The extract is concentrated by distillation or low-temperature vacuum to remove 90-98% of the organic solvent, and silica gel packing is added and mixed well. The remaining organic solvent is then removed by vacuum. The amount of silica gel added is 10% of the relative mass of the tobacco powder. The silica gel packing with the organic solvent removed is packed into a column, and anhydrous ethanol is used as the eluent. Collection begins when the effluent has a fragrance and continues until the effluent has no fragrance. The collected fragrance solution is concentrated 200 times to obtain the fragrance matrix.

[0070] (8) Preparation of gel matrix:

[0071] After the tobacco powder is extracted with organic solvents and dried, it is then extracted with hot water to remove soluble substances. The insoluble substances are removed by alkali dissolution to remove lignin, hemicellulose and other compounds. After acidification, microcrystalline cellulose is obtained. Then, it is successively treated with near-critical water, homogenized under high pressure and gelled to obtain a gel matrix.

[0072] The conditions for hot water extraction were: hot water temperature of 40℃, solid-liquid ratio of 1:9, and extraction times of 5. After extraction, the precipitate was obtained by high-speed centrifugation at a speed of 8000 r / min for 30 min.

[0073] Alkali dissolution: First, use an 8% sodium hydroxide solution to dissolve the solid at room temperature with a solid-liquid ratio of 1:10 and a reaction time of 60 minutes. After the reaction, the solid and liquid are separated and washed with water until the pH of the washing solution is close to 7.

[0074] Acidification: The acid used is hydrochloric acid with a concentration of 36-38%, the reaction temperature is 75℃, the solid-liquid ratio is 1:15, and the reaction time is 3h. After the reaction, the solid and liquid are separated and washed with water until the pH of the washing solution is close to 7. Powder 1 is obtained by spray drying.

[0075] Near-critical water treatment: the solid-liquid ratio of powder 1 to water is 1:20, the temperature is 150℃, and the time is 90min; after the reaction, the solid and liquid are separated, and powder 2 is obtained by spray drying.

[0076] High-pressure homogenization: Powder 2 is mixed with water at a solid-liquid ratio of 1:40 and a working pressure of 800 bar, and then spray-dried to obtain powder 3.

[0077] Gelation: The preferred gelation technique is freeze-thaw mixing. The reaction conditions for freeze-thaw mixing are as follows: powder 3 is ultrasonically mixed with a mixture of water, glycerol, and polyethylene glycol, wherein the mass ratio of water, glycerol, and polyethylene glycol in the mixture is 100:5:15; the solid-liquid ratio of powder 3 to liquid is 1:40; and then subjected to freeze-thaw mixing. The freezing temperature is below -30°C, and the number of freeze-thaw cycles is 4.

[0078] (9) Preparation of spices:

[0079] Mixing the fragrance matrix and the gel matrix at a mass ratio of 1:30 yields a stable fragrance with a sustained-release effect.

[0080] Example 3

[0081] A method for preparing flavorings based on low-grade tobacco leaves, comprising the following steps:

[0082] (1) Leaf threshing: Low-grade tobacco leaves are processed into tobacco dust with a size of 2-8mm using a tobacco leaf shredder.

[0083] (2) Increasing temperature and humidity: The tobacco dust is humidified at 80-100℃ to a moisture content of about 18-20%.

[0084] (3) Expansion: The humidified tobacco powder is expanded using an expansion device. The expansion device used is a CO2 expander. When using a CO2 expander, the reaction parameters are a reaction temperature of 280℃.

[0085] (4) Drying: Dry the expanded tobacco powder until the moisture content is less than 12%.

[0086] (5) Crushing: The expanded tobacco powder is made into tobacco powder of 200-400 mesh.

[0087] (6) Preparation of tobacco flavor compounds: tobacco flavor compounds were obtained by caramelization and Maillard reaction of tobacco powder and sugar under microwave conditions. The sugar was sucrose and the mass ratio of tobacco powder to sugar was 100:2. During the microwave reaction, a household microwave oven was used with a microwave frequency of 2.45MHz, a microwave power of 700W, a heating time of 10min, and the proportion of the material in the cranial cavity was 1%.

[0088] (7) Preparation of fragrance base:

[0089] High-pressure micro-mist technology was used to uniformly add a 95% (v / v) ethanol aqueous solution to the tobacco powder after the reaction in step (6), with the addition amount being 10% of the tobacco powder mass. Then, the tobacco aroma compounds were extracted using an organic solvent. The aroma components were extracted with the organic solvent to obtain an extract. An appropriate amount of anhydrous sodium sulfate was added to the extract to remove water, and the solid-liquid separation was carried out by centrifugation to obtain an anhydrous extract. The extract was then concentrated and purified to obtain the flavor matrix.

[0090] The organic solvent used was ethyl acetate, and the solid-liquid ratio during organic solvent extraction was 1:10. The extraction temperature was 50℃, and the extraction time was 15 min.

[0091] The concentration and purification steps are as follows: the extract is concentrated by distillation or low-temperature vacuum to remove 90-98% of the organic solvent, and silica gel packing is added and mixed well. The remaining organic solvent is then removed by vacuum. The amount of silica gel added is 25% of the relative mass of the tobacco powder. The silica gel packing with the organic solvent removed is packed into a column, and anhydrous ethanol is used as the eluent. Collection begins when the effluent has a fragrance and continues until the effluent has no fragrance. The collected fragrance solution is concentrated 150 times to obtain the fragrance matrix.

[0092] (8) Preparation of gel matrix:

[0093] After the tobacco powder is extracted with organic solvents and dried, it is then extracted with hot water to remove soluble substances. The insoluble substances are removed by alkali dissolution to remove lignin, hemicellulose and other compounds. After acidification, microcrystalline cellulose is obtained. Then, it is successively treated with near-critical water, homogenized under high pressure and gelled to obtain a gel matrix.

[0094] The conditions for hot water extraction were: hot water temperature of 70℃, solid-liquid ratio of 1:4, and extraction times of 3 times. After extraction, the precipitate was obtained by high-speed centrifugation at a speed of 12000 r / min for 10 min.

[0095] Alkali dissolution: First, use a 20% sodium hydroxide solution to dissolve the solid at room temperature. The solid-liquid ratio is 1:25, and the reaction time is 50 minutes. After the reaction, the solid and liquid are separated and washed with water until the pH of the washing solution is close to 7.

[0096] Acidification: The acid used is phosphoric acid with a concentration of 40%, the reaction temperature is 90℃, the solid-liquid ratio is 1:25, and the reaction time is 1h. After the reaction, the solid and liquid are separated and washed with water until the pH of the washing solution is close to 7. Powder 1 is obtained by freeze drying.

[0097] Near-critical water treatment: the solid-liquid ratio of powder 1 to water is 1:10, the temperature is 300℃, and the time is 20min; after the reaction, the solid and liquid are separated, and powder 2 is obtained by freeze drying.

[0098] High-pressure homogenization: Powder 2 is mixed with water at a solid-liquid ratio of 1:25 and a working pressure of 800 bar, and then freeze-dried to obtain powder 3.

[0099] Gelation: The preferred gelation technique is freeze-thaw mixing. The reaction conditions for freeze-thaw mixing are as follows: powder 3 is ultrasonically mixed with a mixture of water, glycerol, and polyethylene glycol, wherein the mass ratio of water, glycerol, and polyethylene glycol in the mixture is 100:6:10; the solid-liquid ratio of powder 3 to liquid is 1:50; and then subjected to freeze-thaw mixing. The freezing temperature is below -45°C, and the number of freeze-thaw cycles is 6.

[0100] (9) Preparation of spices:

[0101] Mixing the fragrance matrix and the gel matrix at a mass ratio of 1:70 yields a stable fragrance with a sustained-release effect.

[0102] GC-MS detection test

[0103] The aromatic low-grade tobacco leaves and the light-aroma low-grade tobacco leaves were processed using the process described in Example 1 of this invention. The process involved leaf threshing, heating and humidification, puffing, drying, and pulverizing to prepare tobacco aroma compounds. Then, a 95% (v / v) ethanol aqueous solution was uniformly added to the prepared tobacco powder at 10% of the powder's mass. The aroma components were extracted using the organic solvent dichloromethane (extraction temperature: room temperature, time: 60 min, solid-liquid ratio: 1 g: 20 ml). The obtained extract was analyzed by GC-MS, and its total ion chromatogram is shown in Figure 1. The main aroma components are shown in Table 1. Simultaneously, the aromatic low-grade tobacco leaves and the light-aroma low-grade tobacco leaves were directly extracted using the organic solvent dichloromethane and analyzed by GC-MS for comparison.

[0104] The results in Figure 1 and Table 1 show that the main chemical components of the extracts obtained from the two styles of low-grade tobacco leaves, namely strong aroma and light aroma, are similar.

[0105] Table 1. Main aroma components of the extract obtained from dichloromethane extraction.

[0106]

[0107]

[0108] Cigarette application test

[0109] The flavoring prepared in Example 1 was coated onto the surface of reconstituted tobacco leaves for heated cigarettes. The addition amounts were 0% (control sample), 0.5%, and 1% of the mass of the reconstituted tobacco leaves for heated cigarettes, respectively. Before coating, the moisture content of the reconstituted tobacco leaves was controlled at approximately 14%. After coating, a low-temperature slow drying process was used to adjust the moisture content of the samples to approximately 10%. After drying, the samples were pressed into the interior of the reconstituted tobacco leaves using a roller press at a pressure of 0.8 MPa and a temperature of 60°C. Then, cigarettes were prepared using conventional techniques in the art. The sensory evaluation results of the cigarette products after application are shown in Table 2 below.

[0110] Table 2 Sensory evaluation results of the products

[0111]

[0112] The results in Table 2 show that, compared with the control sample without the flavoring of the present invention, adding the flavoring of the present invention can significantly improve the aroma and smoke volume of the cigarette product, maintain the stable style of each puff of smoke, and retain a good sensory style even after the cigarette product has been stored for more than one year.

[0113] In summary, the flavorings prepared by the method of this invention contain a large amount of tobacco aroma substances, have strong tobacco flavor characteristics, and are safer. Applying them to heated cigarettes can significantly improve the sensory quality of the product.

Claims

1. A method for preparing flavorings based on low-grade tobacco leaves, characterized in that, The process includes the following steps: (1) Leaf threshing: processing low-grade tobacco leaves into tobacco dust; (2) Heating and humidifying: humidifying the tobacco dust at 80-100℃ to a moisture content of 14-20%; (3) Puffing: puffing the humidified tobacco dust; (4) Drying: drying the puffed tobacco dust to a moisture content of less than 12%; (5) Pulverizing: making the tobacco dust dried in step (4) into tobacco powder of 200-400 mesh; (6) Preparing tobacco flavor compounds: reacting the tobacco powder with sugars under high temperature or microwave conditions; (7) Preparing flavor matrix: uniformly adding an ethanol aqueous solution with a volume fraction of more than 95% onto the tobacco powder after the reaction in step (6), and then... Extract tobacco aroma compounds and obtain a flavor matrix by concentration and purification; (8) Prepare gel matrix: dry the extracted tobacco powder, remove soluble substances by hot water extraction, and obtain microcrystalline cellulose by alkali dissolution and acidification of insoluble substances, and then obtain a gel matrix by near-critical water treatment, high pressure homogenization and gelation; (9) Prepare flavor: mix flavor matrix and gel matrix at a mass ratio of 1:10-100; in step (7), tobacco aroma compounds are extracted by one of supercritical extraction, molecular distillation and organic solvent extraction; in step (8), the conditions for hot water extraction are: hot water temperature of 40-70℃ and solid-liquid ratio of 1:3-10; Alkali dissolution: First, dissolve the insoluble substance in a 5-20% sodium hydroxide solution at room temperature, with a solid-liquid ratio of 1:10-30 and a reaction time of 30-60 min. After the reaction, separate the solid and liquid, and wash with water until the pH of the washing solution reaches 7-8. Acidification: Use one or more of phosphotungstic acid, hydrochloric acid, sulfuric acid, and phosphoric acid, with an acid concentration of 10-60%. The reaction temperature is 70-95℃, the solid-liquid ratio is 1:10-30, and the reaction time is 1-3 h. After the reaction, separate the solid and liquid, and wash with water until the pH of the washing solution reaches 7-8. Obtain powder 1 by freeze drying or spray drying. Near-critical water treatment: The solid-liquid ratio of powder 1 to water is 1:5-20, and the temperature is 150-30℃. 0℃, time 10-90min; after reaction, solid and liquid are separated, and powder 2 is obtained by freeze drying or spray drying; high pressure homogenization: powder 2 is mixed with water, the solid-liquid ratio is 1:5-50, the working pressure is 400-1000 bar, and powder 3 is obtained by freeze drying or spray drying; gelation: freeze-thaw technology is used, and the reaction conditions of freeze-thaw technology are: powder 3 is mixed evenly with a mixed solution of water, glycerol and polyethylene glycol, wherein the mass ratio of water, glycerol and polyethylene glycol in the mixed solution is 100:1-10:3-20; the solid-liquid ratio of powder 3 to liquid is 1:20-100; the freezing temperature is in the range of -10-100℃, and the number of freeze-thaw cycles is 2-10.

2. The method for preparing flavorings based on low-grade tobacco leaves as described in claim 1, characterized in that, In step (3), the expansion device used during expansion is one or more of the following: microwave reactor, steam explosion device, and CO2 expander; when using a microwave reactor, the reaction parameters are: power 30-80kW, steam pressure 0.2-1.0Mpa, and the proportion of material in the cranial cavity is 2-10%; when using a steam explosion device, the reaction parameters are: steam explosion pressure 0.1-3.0Mpa, and pressure retention time 10-60s; when using a CO2 expander, the reaction parameters are: reaction temperature 200-350℃.

3. The method for preparing flavorings based on low-grade tobacco leaves as described in claim 1, characterized in that, In step (6), the sugar is one or more combinations of glucose, fructose, maltose, lactose and sucrose, and the mass ratio of tobacco powder to sugar is 100:(0.2-2).

4. The method for preparing flavorings based on low-grade tobacco leaves as described in claim 1, characterized in that, In step (6), the reaction temperature during high-temperature reaction is 160-250℃ and the reaction time is 20-60min; during microwave reaction, the microwave frequency is 2-3 MHz, the microwave power is 600-1200W, the heating time is 3-10min, and the proportion of material in the cranial cavity is 0.1-2%.

5. The method for preparing flavorings based on low-grade tobacco leaves as described in claim 1, characterized in that, In step (7), after organic solvent extraction, an appropriate amount of anhydrous sodium sulfate is added to the extract to remove water, and solid-liquid separation is performed to obtain anhydrous extract, which is then concentrated and purified to obtain fragrance matrix; the organic solvent is one or more combinations of dichloromethane, ethyl acetate, and petroleum ether, and the solid-liquid ratio during organic solvent extraction is 1:3-20; during dichloromethane extraction, the extraction temperature is 15-45℃ and the extraction time is 10-180min; during ethyl acetate extraction, the extraction temperature is 20-70℃ and the extraction time is 10-200min.

6. The fragrance prepared by any one of the methods described in claims 1 to 5.

7. The use of the flavoring agent of claim 6 in cigarettes.

8. A cigarette, characterized in that, The flavoring as described in claim 6 is added.

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