Inapplicable tobacco leaf extract for heating cigarettes and preparation method of inapplicable tobacco leaf extract

Abstract

The invention provides an inapplicable tobacco leaf extract for heating cigarettes. A preparation method of the inapplicable tobacco leaf extract comprises the following steps: 1) picking and collecting inapplicable tobacco leaves in a field; 2) pretreatment of inapplicable tobacco leaves: filling the inapplicable tobacco leaves in the field into drying equipment, reducing the moisture content of the inapplicable tobacco leaves in the field to 8%-16% through variable-temperature drying, and performing tendon removal and shredding on the dried tobacco leaves to obtain tobacco shreds for later use; 3) preparation of inapplicable tobacco leaf extract: 3.1, ethanol extraction and primary concentration; 3.2, alcohol precipitation and adsorption impurity removal; and 3.3, preparing the fluid extract. The invention belongs to the technical field of tobaccos, and provides a technology for drying tobacco leaves not suitable for heating cigarettes in the field and a preparation method of extracts, which do not need extraction of organic solvents except for enzymolysis or ethanol, have low requirements on equipment and reaction conditions, realize resource utilization of the tobacco leaves not suitable for the field, and are easy to popularize and apply on a large scale.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco, and in particular relates to an unsuitable tobacco leaf extract for heating cigarettes and a preparation method thereof. Background Art

[0002] During the growth and maturation of tobacco leaves, the lower or top leaves of the tobacco plants have low industrial availability after baking due to insufficient light and poor development, and are called unsuitable tobacco leaves in the field. In tobacco field production, removing the lower 3-5 unsuitable tobacco leaves after topping has become an effective means to save baking costs and increase the effective supply of high-quality tobacco leaves. If 1,100 tobacco plants are planted per acre, 4 unsuitable tobacco leaves are removed from each plant, and the dry weight of each tobacco leaf is 5g, the dry weight of unsuitable tobacco leaves removed per acre reaches 22kg, which shows the huge number of unsuitable tobacco leaves in the field.

[0003] Unsuitable tobacco leaves in the field often carry pathogens and contain tobacco alkaloids and other components that are not conducive to the growth of microorganisms, making it difficult to carry out harmless treatment by burying. CN 115844048A discloses a harmless treatment method for unsuitable tobacco leaves, comprising the following steps: dry distilling the unsuitable tobacco leaves, dispersing the obtained dry distillation tobacco dust in an organic solvent to form a dry distillation tobacco dust infusion, reacting the dry distillation tobacco dust infusion under high temperature and high pressure conditions to obtain a plant-based tobacco flavoring agent and unsuitable tobacco leaves with low harm. However, the harmless treatment method requires multiple steps of dry distillation and other reactions, and has strict requirements on equipment and reaction conditions, which is not conducive to large-scale promotion and application. The moisture content of unsuitable tobacco leaves in the field is high and difficult to store, but there is currently a lack of effective and easy-to-implement resource utilization methods.

[0004] Heat-not-burn cigarettes (HNB), also known as heated cigarettes for short, are a smoking method that heats tobacco substances through electronic devices instead of burning them. There is no open flame and less harmful substances are produced. As a harm-reducing alternative to traditional cigarettes, it has shown strong growth momentum in the international market in recent years. Due to the low heating temperature of heated cigarettes (300-350°C), the aroma and physiological satisfaction obtained during the smoking process are still far behind those of traditional cigarettes. In order to improve the aroma and taste quality of heated cigarettes, adding tobacco extracts has become an important measure to improve the aroma and taste quality of heated cigarettes. CN 105661625 A discloses a method for preparing a tobacco extract for a new type of cigarette, including enzymatic hydrolysis with α-amylase, ethanol extraction with a mass fraction of 75%-95%, and reduced pressure distillation. CN 112011405 A discloses a method for preparing a high-nicotine tobacco extract, including enzymatic hydrolysis with pectinase and cellulase, ethanol extraction with a mass fraction of 90%-95%, addition of alkali solution and organic solvent extraction. CN 111528517A discloses a method for preparing an extract for heat-not-burn cigarettes, comprising the steps of 80%-95% v / v ethanol extraction, reduced pressure concentration, addition of alkali solution and organic solvent extraction. The tobacco raw materials used in the above method are all conventionally conditioned tobacco raw materials, which require enzymatic hydrolysis and / or organic solvent extraction, and the operation is relatively complicated. In addition, high concentration (greater than 70%) ethanol is used for extraction, which easily leads to solvent waste and pollution.

[0005] Therefore, there is no report on the technology of using unsuitable tobacco leaf extracts from the field for heating cigarettes, and it is of great significance to provide a method for preparing unsuitable tobacco leaf extracts for heating cigarettes. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a field unsuitable tobacco leaf drying technology and an extract preparation method suitable for heating cigarettes, which does not require enzymatic hydrolysis or organic solvent extraction other than ethanol, has low requirements on equipment and reaction conditions, realizes the resource utilization of field unsuitable tobacco leaves, and is easy to promote and apply on a large scale.

[0007] The present invention provides an unsuitable tobacco leaf extract for heating cigarettes, and the preparation method thereof comprises the following steps:

[0008] 1) Pick and collect unsuitable tobacco leaves in the field;

[0009] 2) Pretreatment of unsuitable tobacco leaves: the unsuitable tobacco leaves are loaded into a drying device, and the moisture content of the unsuitable tobacco leaves is reduced to 8%-16% by variable temperature drying. The dried tobacco leaves are deveined and shredded to obtain shredded tobacco for later use; the variable temperature drying step comprises: firstly heating for 0.8-1.2h to a dry bulb temperature of 34-36°C and a wet bulb temperature of 30-32°C, and maintaining the temperature for 1-3h; then heating for 1.8-2.2h to a dry bulb temperature of 34-36°C and a wet bulb temperature of 30-32°C; Temperature: 41-43℃ and wet-bulb temperature: 34-36℃, keep temperature steady for 4-6h; then heat up for 1.8-2.2h to dry-bulb temperature 46-48℃ and wet-bulb temperature 34-36℃, keep temperature steady for 4-6h; then heat up for 0.8-1.2h to dry-bulb temperature 51-53℃ and wet-bulb temperature 36-38℃, keep temperature steady for 4-6h; then heat up for 0.8-1.2h to dry-bulb temperature 56-58℃ and wet-bulb temperature 37-39℃, keep temperature steady for 2-8h;

[0010] 3) Preparation of unsuitable tobacco leaf extract: 3.1 Ethanol extraction and preliminary concentration: The shredded tobacco is stirred and extracted with a 38%-42% v / v ethanol solution at a solid-liquid ratio of 1g:10-14g, filtered, and extracted continuously for 2-4 times. The extracts are combined, concentrated under reduced pressure to 28%-38% of the original mass, cooled, and a preliminary concentrated solution is obtained; 3.2 Alcohol precipitation and adsorption removal: 1.8-2.2 times the mass of the preliminary concentrated solution is added to the preliminary concentrated solution while stirring, after standing, activated carbon is added for stirring and adsorption, filtered, and the impurity-free extract is obtained; 3.3 Preparation of fluid extract: The impurity-free extract is concentrated under reduced pressure to remove the solvent, and the obtained extract extract is dissolved with an equal mass of 28%-32% v / v ethanol solution to prepare a fluid extract and incubate, cool, stand, and centrifuge to remove the precipitate to obtain an unsuitable tobacco leaf extract for heating cigarettes.

[0011] By adopting the above technical scheme, the drying time can be shortened through specific variable temperature drying, which is significantly shorter than the 5-7 days required for conventional constant temperature baking, and the content of volatile aroma components in tobacco leaves can be significantly increased, and the content of aroma component precursors such as reducing sugars, higher fatty acids, and polyphenols can be increased, thereby reducing the loss during the drying process. No enzymatic hydrolysis or organic solvent extraction other than ethanol is required, and the extract yield obtained by extraction with a lower concentration of 38%-42% v / v ethanol solution is high, which is beneficial to improving the aroma and taste quality of heated cigarettes. The requirements for equipment and reaction conditions are not high, and the resource utilization of tobacco leaves that are not suitable for use in the field is realized, which is easy to promote and apply on a large scale.

[0012] Preferably, in the drying equipment, the packing density of tobacco leaves not suitable for field use is 70-80 kg / m 3 .

[0013] Preferably, in step 3), the shredded tobacco is extracted by stirring with a 40% v / v ethanol solution at a solid-liquid ratio of 1 g:12 g.

[0014] Preferably, the stirring extraction is carried out at a temperature of 55-65°C and for a time of 40-60 minutes.

[0015] Preferably, the temperature of the reduced pressure concentration is 50-55° C., and the vacuum degree is 0.08-0.1 MPa.

[0016] Preferably, the incubation temperature is 65-75°C and the time is 4-6h.

[0017] Preferably, the amount of activated carbon added is 0.6%-0.8% of the mass of the tobacco.

[0018] Preferably, the centrifugal speed is 800-1200 r / min and the time is 6-12 min.

[0019] In addition, the present invention also provides a method for preparing an unsuitable tobacco leaf extract for heating cigarettes, comprising the following steps: 1) picking and collecting unsuitable tobacco leaves in the field;

[0020] 2) Pretreatment of unsuitable tobacco leaves: the unsuitable tobacco leaves are loaded into a drying device, and the moisture content of the unsuitable tobacco leaves is reduced to 8%-16% by variable temperature drying. The dried tobacco leaves are deveined and shredded to obtain shredded tobacco for later use; the variable temperature drying step comprises: firstly heating for 0.8-1.2h to a dry bulb temperature of 34-36°C and a wet bulb temperature of 30-32°C, and maintaining the temperature for 1-3h; then heating for 1.8-2.2h to a dry bulb temperature of 34-36°C and a wet bulb temperature of 30-32°C, and then maintaining the temperature for 1-3h; Bulb temperature 41-43℃ and wet bulb temperature 34-36℃, keep temperature steady for 4-6h; then heat up for 1.8-2.2h to dry bulb temperature 46-48℃ and wet bulb temperature 34-36℃, keep temperature steady for 4-6h; then heat up for 0.8-1.2h to dry bulb temperature 51-53℃ and wet bulb temperature 36-38℃, keep temperature steady for 4-6h; then heat up for 0.8-1.2h to dry bulb temperature 56-58℃ and wet bulb temperature 37-39℃, keep temperature steady 2-8h; 3) Preparation of unsuitable tobacco leaf extract: 3.1 Ethanol extraction and preliminary concentration: The shredded tobacco is stirred and extracted with 38%-42% v / v ethanol solution at a solid-liquid ratio of 1g:10-14g, filtered, and extracted continuously for 2-4 times. The extracts are combined, concentrated under reduced pressure to 28%-38% of the original mass, cooled, and a preliminary concentrated solution is obtained; 3.2 Alcohol precipitation and adsorption removal: 1.8-2.2 times the mass of the preliminary concentrated solution is added to the preliminary concentrated solution while stirring, after standing, activated carbon is added for stirring and adsorption, filtered, and the impurity-free extract is obtained; 3.3 Preparation of fluid extract: The impurity-free extract is concentrated under reduced pressure to remove the solvent, and the obtained extract extract is dissolved with an equal mass of 28%-32% v / v ethanol solution to prepare a fluid extract and incubate, cool, stand, and centrifuge to remove the precipitate to obtain an unsuitable tobacco leaf extract for heating cigarettes.

[0021] In addition, the present invention also provides a heating cigarette, comprising the unsuitable tobacco leaf extract for heating cigarettes. The unsuitable tobacco leaf extract for heating cigarettes (fluid extract with centrifugal removal of precipitation) and water are mixed evenly in a mass ratio of 1:1 to obtain a coating liquid; the mass of a tobacco substrate is weighed as m, placed in a tray, and the coating liquid of 3 times the mass of the substrate (3m) is brushed on the substrate; the coated substrate is placed in a 120°C oven for 6 minutes until the moisture is dried to obtain a thin slice; the thin slice is placed in a constant temperature and humidity chamber (25°C, 60% RH) overnight, cut into shreds and evaluated, and the addition of the unsuitable tobacco leaf extract for heating cigarettes provided by the present invention can significantly improve the aroma and taste quality of the heated cigarette.

[0022] Compared with the prior art, the beneficial effects of the present invention include:

[0023] (1) The present invention provides a drying technology for field tobacco leaves that are not suitable for heating cigarettes and a method for preparing an extract, which does not require enzymatic hydrolysis or extraction with organic solvents other than ethanol, has low requirements for equipment and reaction conditions, realizes the resource utilization of field tobacco leaves that are not suitable for heating cigarettes, and is easy to promote and apply on a large scale.

[0024] (2) The present invention can shorten the drying time through specific variable temperature drying, which is significantly shorter than the 5-7 days required for conventional constant temperature baking, and significantly increase the content of volatile aroma components in tobacco leaves, and increase the content of aroma component precursors such as reducing sugars, higher fatty acids, and polyphenols, thereby reducing losses during the drying process; the use of a lower concentration of 38%-42% v / v ethanol solution for extraction reduces the use and pollution of solvents, and the yield of the obtained extract is high, which is beneficial to improving the aroma and taste quality of heated cigarettes; the different components of the tobacco extract are separated by chromatography, and the application effects of the different components of the extract in heated cigarettes are clarified. Based on the above research, a method for preparing tobacco leaf extracts that are not suitable for heated cigarettes is established. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below through specific embodiments.

[0026] In the present invention, the raw materials involved are conventional commercial products, or can be obtained by conventional technical means in the art. The percentage content, if not clearly stated, refers to the volume percentage content.

[0027] Example 1 A method for preparing an unsuitable tobacco leaf extract for heating cigarettes

[0028] A method for preparing an extract of tobacco leaves not suitable for heating cigarettes comprises the following steps:

[0029] 1) Pick and collect unsuitable tobacco leaves in the tobacco fields of Zunyi, Guizhou; take Yunyan 87 as the representative variety, and remove 3 to 5 unsuitable tobacco leaves from the bottom 1 day after topping in the field and collect them;

[0030] 2) Pretreatment of unsuitable tobacco leaves: The unsuitable tobacco leaves are loaded into a drying device, and the moisture content of the unsuitable tobacco leaves is reduced to 11%-13% by variable temperature drying. The dried tobacco leaves are deveined and shredded to obtain shredded tobacco for later use. The control conditions such as the temperature and time of the variable temperature drying are shown in Table 1. The drying device is a small electric heating temperature and humidity automatic controlled dense curing room (3.5m×1.35m×1.40m), and each curing room is loaded with 2 layers of tobacco, with an average density of 75kg / m 3 ;

[0031] Table 1 Control conditions such as temperature and time of variable temperature drying

[0032] Dry bulb temperature / ℃ Wet bulb temperature / ℃ Heating time / h Temperature stabilization time / h 35 31 1 2 42 35 2 5 47 35 2 5 52 37 1 5 60 38 1 5

[0033] 3) Preparation of unsuitable tobacco leaf extract: 3.1 Ethanol extraction and preliminary concentration: The tobacco shreds are stirred and extracted with 40% v / v ethanol solution at a solid-liquid ratio of 1g:12g, filtered, and extracted three times continuously. The extracts are combined, concentrated under reduced pressure to 33% of the original mass, cooled, and a preliminary concentrated solution is obtained; 3.2 Alcohol precipitation and adsorption and impurity removal: Anhydrous ethanol twice the mass of the preliminary concentrated solution is added to the preliminary concentrated solution while stirring, and after standing, activated carbon is added for stirring and adsorption, filtered, and the impurity-free extract is obtained; 3.3 Preparation of fluid extract: The impurity-free extract is concentrated under reduced pressure to remove the solvent, and the obtained extract is dissolved with an equal mass of 30% v / v ethanol solution to prepare a fluid extract and incubate, cool, stand, and centrifuge to remove the precipitate to obtain an unsuitable tobacco leaf extract for heating cigarettes. The mass concentration of the fluid extract is 35%. The stirring extraction temperature is 60°C and the time is 40 minutes; the reduced pressure concentration temperature is 52°C and the vacuum degree is 0.08MPa; the amount of activated carbon added is 0.7% of the mass of the tobacco; the incubation temperature is 70°C and the time is 5 hours; the centrifugal speed is 1000r / min and the time is 8 minutes.

[0034] Example 2 Effect of different drying methods on aroma components of unsuitable tobacco leaves

[0035] 1. Detection method

[0036] 100g of tobacco shreds (water content 12%) dried by different drying methods (variable temperature drying, low temperature 40°C constant temperature drying, ventilation drying) were taken respectively, crushed and the chemical composition of tobacco shreds was determined. The detection indicators include volatile aroma components, nicotine, reducing sugar, organic acid, and polyphenol compounds. Volatile aroma components were determined by organic solvent extraction and GC-MS; reducing sugar was determined by continuous flow method; tobacco organic acid was determined by GC-MS after methyl sulfate esterification; nicotine was determined by gas chromatography; polyphenol compounds were determined by high performance liquid chromatography.

[0037] 2. Test results

[0038] 2.1 Differences in the content of volatile aroma components in tobacco leaves with different drying methods

[0039] Solanone, geranylacetone, norsolanadione, ionone, dihydroactinol, damascenone and neophytadiene are volatile aroma components with relatively high content in tobacco and contribute greatly to the aroma quality of cigarettes. As shown in Table 2, under ventilation and air-drying conditions, the content of the main volatile aroma components of tobacco leaves is significantly lower, and the content of the components (except solanone) under variable temperature drying and low-temperature constant temperature drying conditions is not significantly different, but the content and total amount of most volatile aroma components of tobacco leaves dried at variable temperature are generally higher than those dried at low temperature constant temperature. Under variable temperature drying conditions, the content of solanone is significantly higher than that of low-temperature constant temperature drying and ventilation drying. Therefore, the use of the variable temperature drying of the present invention is conducive to improving the content of volatile aroma components of tobacco leaves that are not suitable.

[0040] Table 2 Differences in mass fractions of main volatile aroma components in tobacco leaves dried by different methods (μg·g -1 )

[0041]

[0042] Note: Different lowercase letters after the same row of data indicate significant differences among treatments (P<0.05), the same below.

[0043] 2.2 Differences in reducing sugar, nicotine and organic acid contents in tobacco leaves with different drying methods

[0044] Nicotine, reducing sugars, and organic acids are the key chemical components that determine the quality of tobacco leaves. Nicotine is a characteristic chemical component that determines the physiological satisfaction of smoke. Reducing sugars and organic acids can not only regulate the acid-base balance of smoke, but are also important precursors of aroma components. Reducing sugars can react with amino acids under heating conditions to produce Maillard reactions. The reaction products are an important source of characteristic aromas such as tobacco sweetness, roasted aroma, and popcorn aroma, and can effectively improve the fullness, softness, and coordination of smoke. Organic acids can make smoke mellow and reduce smoke irritation. As shown in Table 3, there is no significant difference in the content of nicotine and non-volatile organic acids in tobacco leaves with different drying methods. Under variable temperature drying conditions, the content of reducing sugars and higher fatty acids is the highest. Therefore, considering the effects of different drying methods on the content of reducing sugars, nicotine, and organic acids, variable temperature drying is the best choice from the perspective of the utilization of tobacco aroma component precursors.

[0045] Table 3 Analysis of differences in reducing sugar, nicotine and organic acid contents in tobacco leaves with different drying methods

[0046]

[0047] 2.3 Differences in polyphenol content in tobacco leaves with different drying methods

[0048] Chlorogenic acid, rutin, and scopoletin are the main polyphenolic compounds in tobacco. The above compounds can produce simple phenolic compounds with fragrance by thermal decomposition, which has a good effect on the aroma and taste of tobacco. As shown in Table 4, under the variable temperature drying condition, the main phenolic compounds and the total amount of tobacco leaves are the highest. Therefore, from the perspective of extraction and utilization of tobacco leaf phenolic compounds, variable temperature drying is the best choice.

[0049] Table 4 Analysis of the difference in polyphenol content of tobacco leaves with different drying methods

[0050]

[0051] Based on the above analysis, variable temperature drying can significantly increase the content of volatile aroma components in tobacco leaves, and increase the content of aroma component precursors such as reducing sugars, higher fatty acids, and polyphenols. Therefore, from the perspective of being unsuitable for extracting and utilizing aroma components from tobacco leaves, the present invention selects variable temperature drying.

[0052] Example 3: Chromatographic separation of tobacco leaf extract and evaluation of representative components in new cigarettes

[0053] Referring to the method of Example 1, the unsuitable tobacco leaves were pretreated to obtain shredded tobacco, and the unsuitable tobacco leaf extract was extracted and separated by chromatography. Representative components obtained by separation were selected and added to special sheets for new cigarettes. Through sensory evaluation, the application effects of different components of the tobacco leaf extract in the flavoring of new cigarettes (heated cigarettes) were clarified.

[0054] 1. Extraction

[0055] Take 1kg of tobacco shreds and use 40% ethanol solution as the extraction solvent. The solid-liquid ratio of tobacco shreds to ethanol solution is 1g:12g. Extract for 3 times, each time for 40 minutes. Combine the extracts, filter, and concentrate under reduced pressure at 52°C to obtain 269g of unsuitable tobacco leaf extract.

[0056] 2. Chromatographic separation

[0057] Take 100 g of the above unsuitable tobacco leaf extract, mix it with 100-200 mesh silica gel at a ratio of 1:1, and evenly load it into the upper layer of a chromatography column with a diameter of 10 cm pre-loaded with 300 g silica gel (100-200 mesh). Use petroleum ether, ethyl acetate, and ethanol as eluents. According to the composition of the eluent in Table 5, use 1.2 L of eluent in sequence to elute the tobacco leaf extract, and collect the eluates of each component (Fr1~Fr9) respectively.

[0058] 3. Identification of chromatographic separation components

[0059] For each component of the eluate, two portions of 1 mL each were taken, one of which was blown dry with nitrogen, dissolved with 1 mL of ethyl acetate, filtered through a 0.22 μm filter, and volatile aroma components were determined by GC-MS. The other portion was blown dry with nitrogen, and 500 μL of trimethylsilylating agent (DMF: BSTFA = 1: 1) was added to derivatize at 75 ° C for 1 h, and filtered through a 0.22 μm filter to determine the composition of reducing sugars, organic acids, and chlorogenic acid. As shown in Table 5, Fr1 is neophytadiene, Fr2 is a component with a waxy smell such as higher alkanols, and the main volatile aroma components and organic acids are eluted from Fr3 to Fr6. Fr6 begins to have fructose, lactose, and polyphenols such as scopoletin eluted. The Fr7 component is mainly reducing sugars and chlorogenic acid, and Fr8 and Fr9 are mainly sugars.

[0060] Table 5 Chromatographic separation of tobacco extract

[0061]

[0062] 4. Evaluation of the application of representative components separated by chromatography in new cigarettes

[0063] The eluates of each component obtained above were concentrated under reduced pressure to remove the solvent, and the mass of each eluate component (Fr1 to Fr9) was weighed respectively. As shown in Table 5, the mass of the eluates of Fr1 to Fr5 is relatively small, and the mass of the eluate begins to increase from Fr6 due to the presence of reducing sugars. The mass of the different eluate components obtained is consistent with the content trend of the relevant chemical components in the components in tobacco leaves.

[0064] Since the mass of Fr1 component is small, it is not convenient for application evaluation; Fr2 is a component with a waxy smell such as a higher alkanol, which is generally believed to have a negative impact on the quality of smoke; now Fr3 and Fr4 are combined (mainly containing volatile aroma components), and Fr5 and Fr6 are combined (mainly containing volatile aroma components, organic acids, scopolamine, and reducing sugars). The above samples are dissolved in 95% organic solvent (40% ethanol + 55% propylene glycol) to prepare a solution with a mass concentration of 50% of the content. The Fr7 component (mainly containing reducing sugars and chlorogenic acid) is dissolved in 70% organic solvent (20% ethanol + 50% propylene glycol) to prepare a solution with a mass concentration of 50% of the content. The Fr3+Fr4, Fr5+Fr6 and Fr7 mixed solutions are mixed with water at a mass ratio of 1:1 to obtain a coating solution. Weigh the mass of three substrates as m1, m2 and m3, place them in a tray, and brush the three coating liquids obtained on the corresponding substrates according to 3m1, 3m2 and 3m3 of coating liquid respectively. Place the coated substrate in a 120℃ oven for 6min until the moisture is dried to obtain a thin slice. Put the thin slice into a constant temperature and humidity chamber (25℃, 60%RH) overnight, cut into shreds and evaluate. The results are shown in Table 6. Sensory evaluation Based on GB 5606.4-2005, 10 smoking experts with national cigarette sensory evaluation qualifications evaluate and score the quality characteristics of the samples after adding flavors, including aroma quality, aroma quantity, miscellaneous smell, irritation, taste, and strength. The score increases with the increase of sensory quality. The scoring scale is 0 to 10 points, and the total score is recorded as the average value.

[0065] Table 6 represents the evaluation of the application of elution components in new cigarettes

[0066] Components Fragrance Aroma volume Taste Miscellaneous gas Irritant Momentum Comprehensive evaluation Fr3+Fr4 9 8.5 9 8.5 8.5 8 The effect is good Fr5+Fr6 9.5 9 9.5 9 8.5 8 Good effect Fr7 10 9.5 10 9.5 9 9 Outstanding effect

[0067] As shown in Table 6, according to the evaluation results, the effect of adding Fr7 component to the special thin sheet of new cigarettes is outstanding, followed by Fr5+Fr6. Fr3+Fr4 also has a certain effect on improving the aroma and taste quality of heated cigarettes, but the effect is less prominent than Fr7 and Fr5+Fr6. The components of Fr7 are mainly reducing sugars and chlorogenic acid, the components of Fr5 and Fr6 are mainly glandular hair secretion components, degradation products of carotenoids, reducing sugars, organic acids, scopolamine, etc., and Fr3 and Fr4 are mainly glandular hair secretion components and carotenoid degradation products. Therefore, from the analysis of component composition and flavor enhancement effect, reducing sugar and chlorogenic acid components have the best effect of flavor enhancement and quality improvement, and organic acids and volatile aroma components also contribute to the aroma and taste of new cigarettes. Reducing sugar is a water-soluble compound, and chlorogenic acid has good solubility in water and low-concentration ethanol. From this perspective, tobacco extracts obtained by extraction with lower concentration ethanol may be more conducive to improving the aroma and taste quality of heated cigarettes.

[0068] Example 4 Effect of different process conditions on unsuitable tobacco extract

[0069] 1. Ethanol concentration selection

[0070] The unsuitable tobacco leaf extract was prepared according to the method of Example 1, 80 g of temperature-variable dried tobacco was weighed, and different concentrations of ethanol solutions were used as extraction solvents in step 3.1. The six different ethanol concentration groups were 40%, 50%, 60%, 70%, 80%, and 90%, respectively, and the other operating conditions were the same.

[0071] The unsuitable tobacco leaf extracts prepared from 6 different ethanol concentration groups were mixed with water at a mass ratio of 1:1 to obtain a coating liquid. Weigh the mass of a substrate as m, place it in a tray, and brush 3m of the coating liquid on the substrate. Place the coated substrate in a 120°C oven for 6 minutes until the moisture is dried to obtain a thin sheet. Put the thin sheet into a constant temperature and humidity chamber (25°C, 60% RH) overnight, cut into shreds and evaluate according to the method in Example 3. The results are shown in Table 7.

[0072] Table 7 Evaluation of the application of tobacco extracts prepared with different ethanol concentration groups in new cigarettes

[0073]

[0074] According to the application evaluation results in Table 7, the unsuitable tobacco leaf extract prepared by the 40% ethanol group is added to the new cigarette, and the effect is outstanding, which can make the aroma texture good, the aroma volume sufficient, the aroma harmonious, elegant, the smoke fine and soft, the smoke is more natural and comfortable; the stimulation is light, the aftertaste is comfortable and clean; the smoke volume is good. The second is the unsuitable leaf extract prepared by the 50%, 80%, and 90% ethanol groups, and the unsuitable tobacco leaf extract prepared by the 60% ethanol group has a relatively poor effect. According to the evaluation results of the flavoring effect of different components of tobacco leaf extract chromatographic separation in new cigarettes, the reducing sugar and chlorogenic acid components have the best effect of flavoring and quality improvement, and organic acids and volatile aroma components also contribute to the aroma and taste of new cigarettes. The yield of tobacco leaf reducing sugar in low concentration ethanol solution is high, and 40% ethanol has good solubility for chlorogenic acid. Therefore, the application effect of unsuitable tobacco leaf extracts prepared by different ethanol concentration groups in new cigarettes further verifies the flavoring effect of different components of tobacco leaf extract chromatographic separation in new cigarettes.

[0075] 2. Extraction temperature selection

[0076] The unsuitable tobacco extract was prepared according to the method of Example 1, 80 g of temperature-variable dried tobacco was weighed, and the stirring extraction temperatures in step 3.1 were 40° C., 50° C., 60° C., and 70° C., respectively. The other operating conditions were the same.

[0077] The unsuitable tobacco leaf extracts prepared from 4 different extraction temperature groups were mixed with water at a mass ratio of 1:1 to obtain a coating liquid. Weigh the mass of a substrate as m, place it in a tray, and brush 3m of the coating liquid on the substrate. Place the coated substrate in a 120°C oven for 6 minutes until the moisture is dried to obtain a thin slice. Put the thin slice into a constant temperature and humidity chamber (25°C, 60% RH) overnight, cut into shreds and evaluate according to the method in Example 3. The results are shown in Table 8.

[0078] Table 8 Evaluation of the application of tobacco extracts at different temperatures in new cigarettes

[0079]

[0080] According to the application evaluation results in Table 8, the best extraction effect was achieved with 40% ethanol as the extraction solvent and 60°C.

[0081] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A tobacco leaf extract not suitable for heating cigarettes, characterized in that: The preparation method thereof comprises the following steps: 1) Pick and collect unsuitable tobacco leaves in the field; 2) Pretreatment of unsuitable tobacco leaves: the unsuitable tobacco leaves are loaded into a drying device, and the moisture content of the unsuitable tobacco leaves is reduced to 8%-16% by variable temperature drying. The dried tobacco leaves are deveined and shredded to obtain shredded tobacco for later use; the variable temperature drying step comprises: firstly heating for 0.8-1.2h to a dry bulb temperature of 34-36°C and a wet bulb temperature of 30-32°C, and maintaining the temperature for 1-3h; then heating for 1.8-2.2h to a dry bulb temperature of 34-36°C and a wet bulb temperature of 30-32°C; Temperature: 41-43℃ and wet-bulb temperature: 34-36℃, keep temperature steady for 4-6h; then heat up for 1.8-2.2h to dry-bulb temperature 46-48℃ and wet-bulb temperature 34-36℃, keep temperature steady for 4-6h; then heat up for 0.8-1.2h to dry-bulb temperature 51-53℃ and wet-bulb temperature 36-38℃, keep temperature steady for 4-6h; then heat up for 0.8-1.2h to dry-bulb temperature 56-58℃ and wet-bulb temperature 37-39℃, keep temperature steady for 2-8h; 3) Preparation of unsuitable tobacco leaf extract: 3.1 Ethanol extraction and preliminary concentration: The shredded tobacco is stirred and extracted with a 38%-42% v / v ethanol solution at a solid-liquid ratio of 1g:10-14g, filtered, and extracted continuously for 2-4 times. The extracts are combined, concentrated under reduced pressure to 28%-38% of the original mass, cooled, and a preliminary concentrated solution is obtained; 3.2 Alcohol precipitation and adsorption removal: 1.8-2.2 times the mass of the preliminary concentrated solution is added to the preliminary concentrated solution while stirring, after standing, activated carbon is added for stirring and adsorption, filtered, and the impurity-free extract is obtained; 3.3 Preparation of fluid extract: The impurity-free extract is concentrated under reduced pressure to remove the solvent, and the obtained extract extract is dissolved with an equal mass of 28%-32% v / v ethanol solution to prepare a fluid extract and incubate, cool, stand, and centrifuge to remove the precipitate to obtain an unsuitable tobacco leaf extract for heating cigarettes.

2. The unsuitable tobacco leaf extract for heating cigarettes according to claim 1, characterized in that: In the drying equipment, the packing density of tobacco leaves not suitable for field use is 70-80kg / m 3 .

3. The unsuitable tobacco leaf extract for heating cigarettes according to claim 1, characterized in that: In the step 3), the shredded tobacco is extracted by stirring with a 40% v / v ethanol solution at a solid-liquid ratio of 1 g:12 g.

4. The unsuitable tobacco leaf extract for heating cigarettes according to claim 1, characterized in that: The stirring extraction is carried out at a temperature of 55-65°C and for a time of 40-60 minutes.

5. The unsuitable tobacco leaf extract for heating cigarettes according to claim 1, characterized in that: The temperature of the reduced pressure concentration is 50-55° C., and the vacuum degree is 0.08-0.1 MPa.

6. The unsuitable tobacco leaf extract for heating cigarettes according to claim 1, characterized in that: The incubation temperature is 65-75°C and the time is 4-6 hours.

7. The unsuitable tobacco leaf extract for heating cigarettes according to claim 1, characterized in that: The amount of activated carbon added is 0.6%-0.8% of the mass of the tobacco.

8. The unsuitable tobacco leaf extract for heating cigarettes according to claim 1, characterized in that: The centrifugal speed is 800-1200 r / min, and the time is 6-12 min.

9. A method for preparing an extract of tobacco leaves not suitable for heating cigarettes, characterized in that: The steps include: 1) Pick and collect unsuitable tobacco leaves in the field; 2) Pretreatment of unsuitable tobacco leaves: the unsuitable tobacco leaves are loaded into a drying device, and the moisture content of the unsuitable tobacco leaves is reduced to 8%-16% by variable temperature drying. The dried tobacco leaves are deveined and shredded to obtain shredded tobacco for later use; the variable temperature drying step comprises: firstly heating for 0.8-1.2h to a dry bulb temperature of 34-36°C and a wet bulb temperature of 30-32°C, and maintaining the temperature for 1-3h; then heating for 1.8-2.2h to a dry bulb temperature of 34-36°C and a wet bulb temperature of 30-32°C; Temperature: 41-43℃ and wet-bulb temperature: 34-36℃, keep temperature steady for 4-6h; then heat up for 1.8-2.2h to dry-bulb temperature 46-48℃ and wet-bulb temperature 34-36℃, keep temperature steady for 4-6h; then heat up for 0.8-1.2h to dry-bulb temperature 51-53℃ and wet-bulb temperature 36-38℃, keep temperature steady for 4-6h; then heat up for 0.8-1.2h to dry-bulb temperature 56-58℃ and wet-bulb temperature 37-39℃, keep temperature steady for 2-8h; 3) Preparation of unsuitable tobacco leaf extract: 3.1 Ethanol extraction and preliminary concentration: The shredded tobacco is stirred and extracted with a 38%-42% v / v ethanol solution at a solid-liquid ratio of 1g:10-14g, filtered, and extracted continuously for 2-4 times. The extracts are combined, concentrated under reduced pressure to 28%-38% of the original mass, cooled, and a preliminary concentrated solution is obtained; 3.2 Alcohol precipitation and adsorption removal: 1.8-2.2 times the mass of the preliminary concentrated solution is added to the preliminary concentrated solution while stirring, after standing, activated carbon is added for stirring and adsorption, filtered, and the impurity-free extract is obtained; 3.3 Preparation of fluid extract: The impurity-free extract is concentrated under reduced pressure to remove the solvent, and the obtained extract extract is dissolved with an equal mass of 28%-32% v / v ethanol solution to prepare a fluid extract and incubate, cool, stand, and centrifuge to remove the precipitate to obtain an unsuitable tobacco leaf extract for heating cigarettes.

10. A heated cigarette, characterized in that: The unsuitable tobacco leaf extract for heating cigarettes comprising any one of claims 1 to 8.

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