CN115399498A - Tobacco extract, preparation method thereof and tobacco product - Google Patents

Abstract

The invention relates to a tobacco extract, a preparation method thereof and tobacco products. The preparation method of the tobacco extract comprises: drying and pulverizing tobacco raw materials to obtain tobacco powder; ultrasonically washing the tobacco powder with deionized water for 1 to 3 times, and successively performing filtration and centrifugal dehydration after each ultrasonic washing to obtain a washing residue ;Dry the washing residue to obtain low-nicotine tobacco powder; perform a carbon dioxide supercritical extraction on the low-nicotine tobacco powder to obtain an extract; continue to perform a second carbon dioxide supercritical extraction on the residue after a carbon dioxide supercritical extraction , to obtain a secondary extract; combine the primary extract and the secondary extract to obtain a tobacco extract. The preparation method of the tobacco extract enables the separation of tobacco endogenous aroma components and nicotine, the tobacco aroma components are not damaged, the nicotine content in the extract is extremely low, and the content of aroma and taste components is greatly increased, and the preparation cost is low , Spice quality is good, no solvent residue.

Description

Tobacco extract and its preparation method and tobacco products

technical field

The invention relates to the technical field of tobacco extracts, in particular to a tobacco extract, a preparation method thereof and tobacco products.

Background technique

Tobacco extracts are derived from tobacco. According to homology and homogeneity, different styles of tobacco fragrances can be obtained through the selection of tobacco leaf raw materials of different categories and flavor styles. Tobacco extract is the most important part of tobacco flavor and fragrance, which mainly includes: tobacco essential oil, tobacco absolute, tobacco extract, tobacco tincture, super (sub) critical fluid tobacco extract, tobacco non-enzymatic browning products, tobacco heat Processed products, unconcentrated tobacco extracts, etc. GB 41700-2022 "Electronic Cigarettes" mandatory national standard clearly stipulates that the characteristic flavor of the product should not show flavors other than tobacco, and clearly requires that the atomizer should contain nicotine, and electronic cigarette products that do not contain nicotine are not allowed to enter the market Sales, but the nicotine extracted from tobacco must be used, and the concentration of nicotine in the atomized product should not be higher than 20mg/g, and the total amount should not be higher than 200mg.

Nicotine (Nicotine, nicotine) is the main alkaloid in tobacco, accounting for more than 90% of the total plant alkaloids in tobacco. .Appropriate nicotine content in cigarettes can increase energy, alcohol and taste, reduce irritation, moderate intake can boost spirits and eliminate fatigue, but excessive inhalation can induce addiction and damage human health. Therefore, reducing the nicotine content in tobacco products Alkaline content without weakening tobacco flavor is the pursuit goal of the tobacco industry, which requires the separation of tobacco aroma substances from nicotine, and then add them separately according to needs, so as to maximize the utilization of tobacco resources. The current extraction and separation technology is mainly for extraction The method or the acquisition of a single component, on the one hand, the quality of the extract is not good, and further separation is required, and the high nicotine content increases the difficulty of flavoring, on the other hand, it is easy to cause environmental pollution and waste of tobacco resources.

Contents of the invention

In order to solve or partly solve the problems in the related technologies, the present invention provides a tobacco extract, its preparation method and tobacco products.

The present invention provides a kind of preparation method of tobacco extract, it comprises:

Step a), drying and pulverizing the tobacco raw material to obtain tobacco powder;

Step b), the tobacco powder is ultrasonically washed with deionized water for 1 to 3 times, and then filtered and centrifugally dehydrated after each ultrasonic washing to obtain a washing residue;

Step c), drying the water-washed residue to obtain low-nicotine tobacco powder;

Step d), performing a carbon dioxide supercritical extraction on the low-nicotine tobacco powder to obtain an extract;

Step e), continue to perform a second carbon dioxide supercritical extraction on the residue after the first carbon dioxide supercritical extraction, to obtain a second extract; the temperature of the second supercritical extraction is 80-100° C., and the pressure is 20-30 MPa;

Step f), combining the primary extract and the secondary extract to obtain tobacco extract.

Further, the step a) specifically includes drying the raw tobacco at 40-60° C. for 1-2 hours, and pulverizing it to 20-40 meshes to obtain tobacco powder.

Further, in the step b), in each ultrasonic washing, the mass ratio of deionized water to tobacco powder is (10-50):1, the ultrasonic time is 20-40 min, and the ultrasonic frequency is 30KHz-60KHz.

Further, in the step c), the water content of the low-nicotine tobacco powder is 10%-15%.

Further, the carbon dioxide supercritical extraction condition once in the step d) is as follows:

The extraction temperature is 40°C-60°C, the extraction pressure is 10MPa-30MPa, the extraction is cyclic, and the extraction time is 1h-3h.

Further, in the step d), absolute ethanol is used as an entrainer during the extraction process; the weight-to-volume ratio of the low-nicotine tobacco powder to absolute ethanol is 1 g: (0.1 mL-0.25 mL).

Further, the conditions of secondary carbon dioxide supercritical extraction in the step e) are as follows:

The extraction temperature is 80°C-100°C, the extraction pressure is 20MPa-30MPa, the extraction is cyclic, and the extraction time is 1h-2h.

Further, in the step e), absolute ethanol is used as an entrainer during the extraction process; the weight-to-volume ratio of the low-nicotine tobacco powder to absolute ethanol is 1 g: (0.05 mL-0.125 mL).

The present invention also provides a tobacco extract prepared according to any one of the methods described above.

Correspondingly, the present invention also provides a tobacco product, which contains the above-mentioned tobacco extract.

The preparation method of the tobacco extract provided by the invention may include the following beneficial effects:

1. The method provided by the present invention uses deionized water to wash the tobacco raw materials in advance for 1 to 3 times, which can dissolve the nicotine and some macromolecular impurities in the tobacco powder without losing the non-polar flavor components; the experiment proves that The nicotine content of the tobacco extract prepared by the method provided by the present invention is extremely low, the nicotine content in the extract is lower than 0.5% after one ultrasonic washing, less than 0.1% after twice ultrasonic washing, and less than 0.1% after three ultrasonic washing. 0.05%.

2. The method provided by the present invention pre-washes the tobacco raw material with ultrasonic water, which can also make the tissue structure of the treated tobacco powder loose, and is more conducive to improving the extraction yield of the endogenous aroma components by the supercritical _CO2 fluid.

3. In the method provided by the present invention, after performing a carbon dioxide supercritical extraction, the residue is subjected to a second supercritical extraction at a higher temperature. Raising the temperature can accelerate the degradation rate of the fragrance precursor and generate some small molecular aldehydes Ketone and ester fragrance substances, the temperature continues to rise, the Maillard reaction speeds up, and the content of Maillard reactants such as furanone, pyrone and pyrrole substances increases rapidly, which can not only make up for the water solubility caused by ultrasonic washing. The loss of sexual aldehydes and ketones also produces more flavor components and enriches the flavor, making the prepared spices more prominent in the taste "sweetness", improving the sweetness of cigarette smoke and highlighting the "sweetness" of cigarettes And "run" taste characteristics;

To sum up, the preparation method of the tobacco extract provided by the present invention enables the separation of the endogenous tobacco aroma components and nicotine, the tobacco aroma components are not damaged, the nicotine content in the extract is extremely low, and the aroma and flavor components The content is greatly increased, the preparation cost is low, the spice quality is good, and there is no solvent residue.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.

Description of drawings

The above and other objects, features and advantages of the present invention will become more apparent by describing the exemplary embodiments of the present invention in more detail with reference to the accompanying drawings, wherein, in the exemplary embodiments of the present invention, the same reference numerals generally represent same parts.

Fig. 1 is the GC/MS figure of extract 0, extract 1 and extract 2 in the embodiment 1 of the present invention;

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The terminology used in the present invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein and in the appended claims, the singular forms "a", "the", and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the term "and/or" as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

It should be understood that although the terms "first", "second", "third" and so on may be used in the present invention to describe various information, the information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of the present invention, first information may also be called second information, and similarly, second information may also be called first information. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

The present invention provides a kind of preparation method of tobacco extract, it comprises the steps:

Step a), drying and pulverizing the tobacco raw material to obtain tobacco powder;

Step b), the tobacco powder is ultrasonically washed with deionized water for 1 to 3 times, and after each ultrasonic washing, it is successively filtered and centrifugally dehydrated to obtain a washing residue;

Step c), drying the water-washed residue to obtain low-nicotine tobacco powder;

Step d), performing a carbon dioxide supercritical extraction on the low-nicotine tobacco powder to obtain an extract;

Step e), continue to perform a second carbon dioxide supercritical extraction on the residue after the first carbon dioxide supercritical extraction, to obtain a second extract; the temperature of the second supercritical extraction is 80-100° C., and the pressure is 20-30 MPa;

Step f), combining the primary extract and the secondary extract to obtain tobacco extract.

The above-mentioned step a) is a step of pretreating the tobacco raw material, and processing it into a powder state, so as to facilitate the subsequent processes of washing with water and supercritical extraction. This step may specifically be as follows: drying the tobacco raw material at 40-60° C. for 1-2 hours, and crushing to 20-40 mesh to obtain tobacco powder. The tobacco raw materials described in this application can be tobacco leaves, tobacco dust, tobacco stems and other tobacco and tobacco products produced in the process of tobacco leaf cultivation, transportation, threshing and redrying and rolling.

Step b) is a step of ultrasonically washing the pretreated tobacco powder. Nicotine is a water-soluble component. The main purpose of ultrasonic washing in this step is to remove the nicotine in the tobacco powder, thereby reducing the content of nicotine in the tobacco extract obtained by subsequent extraction. In addition, the cavitation effect generated by ultrasound can also make the tissue of tobacco powder more loose, which is beneficial to improve the extraction yield of endogenous aroma components by subsequent supercritical CO ₂ fluid.

In this step, the reason for choosing deionized water as the ultrasonic medium is that: on the one hand, deionized water is a polar solvent, which can dissolve nicotine and some macromolecular impurities in tobacco powder, without losing non-polar flavor components; on the other hand, The tobacco powder treated with deionized water still contains a certain amount of moisture after drying, and the tissue cells of the tobacco powder collapse and become loose after removing some macromolecules such as sugars, proteins, and starches, and the yield of aroma components extracted by supercritical carbon dioxide higher. In this step, a total of 1 to 3 times of ultrasonic washing is carried out. With the increase of the number of ultrasonic washing, the nicotine content in the washing residue shows a downward trend, but when the number of washing exceeds 3 times, the nicotine content in the washing residue is already extremely low. , generally less than 0.05%; in addition, while ultrasonic washing removes nicotine, it also loses flavor substances such as water-soluble aldehydes and ketone compounds; The content of aroma compounds becomes lower. To sum up, the present invention sets the total times of ultrasonic water washing to 1-3 times. As a preferred solution of this embodiment, in each ultrasonic washing, the mass ratio of deionized water to tobacco powder is (10-50):1, the ultrasonic time is 20min-40min, and the ultrasonic frequency is 30KHz-60KHz; more preferably, The mass ratio of deionized water to tobacco powder is (25-40):1, the ultrasonic time is 30min, and the ultrasonic frequency is 40KHz. For the specific times of ultrasonic water washing, those skilled in the art can select according to specific requirements.

Step c) is a process of further drying the washing residue after ultrasonic washing and dehydration treatment. The effect of drying is that the washed tobacco powder still contains relatively high water. When the water content is too high, it is easy to form a water film on the surface of the material. It affects the mass transfer of supercritical carbon dioxide and materials, and it is easy to make materials agglomerate, prolong the extraction time, and reduce the extraction yield. The inventors of the present application have found through research that the moisture content of the tobacco powder after ultrasonic washing has an impact on supercritical extraction. When the moisture content of the material is higher than 15%, the extraction yield drops significantly, and the extract has a water layer, and some The number of aroma components is reduced. Further, the present invention controls the water content of the low-nicotine tobacco powder obtained after drying to be 10% to 15%, and the supercritical extraction effect of the above-mentioned low-nicotine tobacco powder with this water content is the best. Therefore, in this step, the low-nicotine tobacco powder has the best effect. The water content of the nicotine powder is preferably 10% to 15%. This step is preferably as follows: drying the washing residue at 40-60° C. until the water content is 10%-15%, to obtain low-nicotine tobacco powder.

Step d) is to perform the first carbon dioxide supercritical extraction on the dried low-nicotine smoke powder. The carbon dioxide supercritical extraction does not use or uses a small amount of organic solvent, and the extraction agent carbon dioxide can be recycled, which is safe and environmentally friendly; and, It can be extracted at low temperature, and the heat-sensitive aroma components can also be extracted. In this embodiment, substances such as alcohols, acids, esters, aldehydes, ketones, and alkanes in the low-nicotine tobacco powder can be extracted by performing a supercritical extraction. After a supercritical extraction, the material in the separation tank is desolvated to obtain a primary extract. Preferably, the conditions for a carbon dioxide supercritical extraction in this step are as follows: the extraction temperature is 40°C-60°C, the extraction pressure is 10MPa-30MPa, the extraction is cyclic, and the extraction time is 1h-3h. More preferably, the extraction temperature is 45° C., the extraction pressure is 30 MPa, the extraction is cyclic, and the extraction time is 1.5 h to 2 h. As a preferred solution of this embodiment, during the extraction process, absolute ethanol is preferably used as an entraining agent. Ethanol is an excellent solvent and has a good solubility for strong and weak polar flavor components. It has a boiling point of 78.3°C and is non-toxic. Addition of permitted solvents. Further, the weight-to-volume ratio of the low-nicotine tobacco powder to absolute ethanol is 1g:(0.1mL-0.25mL). Absolute ethanol can be pre-added to the extract and mixed with low-nicotine tobacco powder before the carbon dioxide fluid is introduced, or it can be introduced into the extraction kettle together with the carbon dioxide fluid.

The above step e) is a step of continuing to carry out secondary carbon dioxide supercritical extraction on the residue after the primary extraction. Although the supercritical water washing carried out in the above step a) is beneficial to the removal of nicotine, part of the water-soluble aldehyde and ketone compounds in the tobacco powder are also lost together during the ultrasonic water washing. In order to make up for the loss of such compounds, this step is performed. Compared with the first supercritical extraction, the second supercritical extraction has a higher extraction temperature, the temperature is 80°C-100°C, and the pressure is 20MPa-30MPa. There are many types of aroma substances and their precursors in tobacco. Elevating the temperature can accelerate the degradation rate of aroma precursors and generate some small molecule aldehydes, ketones, and ester aroma substances. If the temperature continues to rise, the Maillard reaction will be accelerated, and the Maillard reaction will be accelerated. The content of German reactants such as furanone, pyrone and pyrrole increases rapidly, which can not only make up for the loss of water-soluble aldehydes and ketones caused by ultrasonic washing, but also generate more fragrance components and enrich the fragrance. In this step, the conditions for the secondary carbon dioxide supercritical extraction are as follows: the extraction temperature is 80° C. to 100° C., the extraction pressure is 20 MPa to 30 MPa, the extraction is cyclic, and the extraction time is 1 h to 2 h. In this step, the extraction temperature has an influence on the composition of the aroma components. If the temperature is too low, the content of the aroma components will be small, and if the temperature is too high, a burnt bitter component will be generated. The extraction temperature is more preferably 95°C to 100°C, most preferably 95°C ; The extraction pressure is most preferably 30MPa. Similar to a supercritical extraction, absolute ethanol is preferably used as an entrainer in this step. Further, the weight-to-volume ratio of the low-nicotine tobacco powder to absolute ethanol is 1 g:(0.05mL-0.125mL).

After secondary supercritical extraction, the feed liquid in the separation tank can be desolventized to obtain the secondary extract, and then the above-mentioned primary extract and secondary extract are combined according to step f) to obtain a tobacco extract, which is The content of nicotine is low, and the content of endogenous aroma components is high.

As can be seen from the foregoing, the preparation method of the tobacco extract provided by the invention has the following advantages:

1. The method provided by the present invention uses deionized water to wash the tobacco raw materials in advance for 1 to 3 times, which can dissolve the nicotine and some macromolecular impurities in the tobacco powder without losing the non-polar flavor components; the experiment proves that The nicotine content of the tobacco extract prepared by the method provided by the present invention is extremely low, the nicotine content in the extract is lower than 0.5% after one ultrasonic washing, less than 0.1% after twice ultrasonic washing, and less than 0.1% after three ultrasonic washing. 0.05%.

2. The method provided by the present invention pre-washes the tobacco raw material with ultrasonic water, which can also make the tissue structure of the treated tobacco powder loose, and is more conducive to improving the extraction yield of the endogenous aroma components by the supercritical _CO2 fluid.

3. In the method provided by the present invention, after performing a carbon dioxide supercritical extraction, the residue is subjected to a second supercritical extraction at a higher temperature. Raising the temperature can accelerate the degradation rate of the fragrance precursor and generate some small molecular aldehydes Ketone and ester fragrance substances, the temperature continues to rise, the Maillard reaction speeds up, and the content of Maillard reactants such as furanone, pyrone and pyrrole substances increases rapidly, which can not only make up for the water solubility caused by ultrasonic washing. The loss of sexual aldehydes and ketones also produces more flavor components and enriches the flavor, making the prepared spices more prominent in the taste "sweetness", improving the sweetness of cigarette smoke and highlighting the "sweetness" of cigarettes And "run" taste characteristics;

To sum up, the preparation method of the tobacco extract provided by the present invention enables the separation of the endogenous tobacco aroma components and nicotine, the tobacco aroma components are not damaged, the nicotine content in the extract is extremely low, and the aroma and flavor components The content is greatly increased, the preparation cost is low, the spice quality is good, and there is no solvent residue.

The technical solution of the present invention will be further described below in conjunction with specific embodiments:

The impact of the number of times of embodiment 1-ultrasonic water washing on low temperature supercritical extraction

1. Collect the tobacco powder produced during the rolling process, dry the tobacco powder at 40°C for 1 hour, and crush it through a 20-mesh sieve for later use;

2. Weigh 1kg of tobacco powder into a flask, add 25 times the mass of deionized water, filter at room temperature with a frequency of 40KHz for 30 minutes, and collect the first filtrate. The tobacco powder is centrifuged to obtain the first residue; weigh 600g of the first residue One residue, add 25 times the amount of deionized water by mass, filter after ultrasonication for 30min, collect the second filtrate, and then carry out centrifugation and dehydration of the smoke powder to obtain the second residue; add 25 times the amount of deionized water to 300g of the second residue, After ultrasonication for 30 minutes, filter, collect the third filtrate, and centrifuge and dehydrate the tobacco powder to obtain the third residue.

3. The first residue, the second residue and the third residue were further dried at 60°C to obtain the first low-nicotine tobacco powder, the second low-nicotine tobacco powder and the third low-nicotine tobacco powder with a moisture content of about 12%. end;

4. Weigh 200g of the dried first low-nicotine tobacco powder and put it into the extraction kettle, add 50mL of absolute ethanol, set the extraction pressure to 30MPa, the temperature is 45°C, and introduce CO ₂ ; pressurize to the set pressure, and cycle the extraction After 1.5h, the tobacco supercritical CO ₂ extract was collected. Since this embodiment only analyzes the influence of the number of times of ultrasonic water washing on the effect of low-temperature carbon dioxide supercritical extraction, the second step of carbon dioxide supercritical extraction is not performed in this embodiment.

Carry out _CO2 supercritical fluid extraction to the original tobacco powder, the first low-nicotine tobacco powder, the second low-nicotine tobacco powder and the third low-nicotine tobacco powder that have not been washed by ultrasonic water successively according to the above method, and obtain corresponding Supercritical CO ₂ Tobacco Extract. The above-mentioned supercritical _CO2 tobacco extracts of raw tobacco powder, first reduced nicotine tobacco powder, second reduced nicotine tobacco powder and third reduced nicotine tobacco powder were labeled as extract 0, extract 1, extract 2 and extract 3.

Take an equal amount of the above-mentioned tobacco extract, add 100 μL of 10 mg/mL ethyl salicylate as an internal standard, adjust the volume to 5 mL, take an appropriate amount of the solution and filter it for GC/MS analysis, the results are shown in Figure 1 (because Figure 1 mainly It shows the change of nicotine content in each extract, and the nicotine content of the extract after two times of ultrasonic washing is already very low, so the GC/MS diagram of the extract after three times of ultrasonic washing is not shown in Figure 1)

Taking the relative content of each aroma component in extract 0 as reference 1, analyze and compare the variation rate of each aroma component in extract 0, extract 1, extract 2 and extract 3, and the results are listed in Table 1.

Table 1 Comparison of aroma components in tobacco extracts (times)

It can be seen from Table 1 that:

1) Part of the water-soluble aroma components (because the raw materials are crushed during the cigarette production process, propylene glycol, glycerol, and some aldehydes and ketones and other aroma components should be introduced during flavoring and feeding) are lost after one wash, and basically cannot be detected ;

2) A small number of ingredients such as small molecule benzoic acid, phenylacetic acid, solanone, scopoletin, etc. are basically not affected by washing treatment;

3) The content of most tobacco endogenous aroma components increased to varying degrees after one, two, and three times of ultrasonic washing;

4), the content of some endogenous aroma components in tobacco is significantly increased after one wash; for example: β-Damascenone, geranylacetone, 4,7,9-macrostigmatrien-3-one, Xinzhidi Alkenes, palmitic acid, methyl palmitate, benzyl benzoate, methyl linolenate, phytoalcohol, pentadecanoic acid, stearic acid, higher alkanes, squalene and vitamin E increased by more than 2 times, especially giant Stigmatrienone, also known as tobacco leaf ketone, presents a long-lasting sweet tobacco aroma. It is an important component of the natural aroma of flue-cured tobacco. Adding a small amount in cigarettes can play a role in flavoring and seasoning. After a washing treatment, its content increases by 3 times β-Damascenone is also an extremely important aroma component in tobacco, which can sweeten and mellow smoke, improve rough gas, increase natural and thick feeling, and its content will increase by about 3 times after one washing treatment; methyl palmitate, palm The total amount of long-chain fatty acid esters such as ethyl linolenate, methyl linolenate, methyl myristate, and methyl stearate has increased several times. These fatty acid esters can give cigarettes a delicate fragrance, soft smoke, and increase the fragrance of cigarettes. ; Higher alkanes are the main components of tobacco leaf wax, which can inhibit the loss of water and play a role in moisturizing, and its content also increases significantly after washing; the content of squalene, which has a harm-reducing effect, increases by about 5 times after a washing; Vitamin E can reduce the damage to DNA caused by harmful components in smoke, and the extraction amount also increases significantly after washing with water;

5) The nicotine content is reduced by about 90%, 97%, and 99% after one, two, and three times of ultrasonic water washing, respectively.

This example is used to illustrate the impact of water washing and the number of times of water washing on the aroma components of carbon dioxide supercritical extraction of smoke powder. The extract has been separated, and the second supercritical extraction step is carried out on the basis of this step. After the temperature rises, the tobacco powder continues to be extracted, and the obtained extracts are combined to obtain the tobacco extract of the present invention. Therefore, although this embodiment does not include the second supercritical step, it does not affect the description of the washing effect.

The influence of the temperature of embodiment 2-high temperature supercritical extraction on extraction effect

1. Take the tobacco leaf raw material and place it in an oven at 60°C for 2 hours to dry, with a moisture content of about 10%, and then crush it to 20-mesh tobacco powder for later use;

2. Weigh 200g of dry smoke residue and put it into the extraction kettle, add 50mL of absolute ethanol, set the extraction pressure to 30MPa, the temperature is 45°C, pass in CO ₂ , pressurize to the set pressure, and circulate the extraction for 2 hours, then extract The residue in the kettle was desolvated under reduced pressure, and CO ₂ and 20 mL of absolute ethanol were continuously introduced, and the second supercritical extraction was continued at 100°C and 30 MPa for 1 hour, and the supercritical CO ₂ tobacco extract was collected, which was labeled as extract g.

3. Repeat the above steps, the only difference is that the temperature of the secondary supercritical extraction is 35°C, 45°C, 55°C, 65°C, 75°C, 85°C respectively, and the collected supercritical _CO2 tobacco extracts are marked as Extract A, Extract B, Extract C, Extract D, Extract E, Extract F.

Take an equal amount of the above extracts, add 100 μL of 10 mg/mL ethyl salicylate as an internal standard, adjust the volume to 5 mL with absolute ethanol, and conduct GC/MS analysis after micromembrane filtration. The contents are listed in Table 2.

Taking the relative content of each aroma component in extract A as reference 1, analyze and compare the change rate of each aroma component content in extract B to extract G, and the results are listed in Table 3.

Table 2 Contents of various aroma substances in the extract (mg)

The content comparison (times) of aroma components in the extract of table 3

It can be seen from Table 2 and Table 3 that the total amount of furan and pyran cyclic aldehydes and ketones in the extract increases significantly at 85°C, and increases by 260% at 100°C, of which 3,5-dihydroxy-2 -Methyl-4H-pyran-4-one increased by 230%, 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP), which The extraction amount increases about 7 times from 80 to 100°C. These ketones have good water solubility and show a prominent sweetness in taste, which can enhance the sweetness of cigarette smoke and highlight the "sweet" and "moist" taste characteristics. Solanone, Geranylacetone, Farnesylacetone, Macrostigmatrienone, 4-Hydroxy-β-Damascone, 1-Hydroxy-4-keto-2-Ionone are the main aroma-inducing substances in tobacco The extraction rate at 80-100°C is also increased by 30%-100%.

It should be noted that this example is used to verify the influence of the secondary supercritical extraction temperature on the extraction effect. In order to simplify the experimental process, the step of ultrasonic washing is omitted, but it does not affect the effect of the secondary supercritical extraction temperature on the extraction effect. influence trends.

The impact of the moisture content of the material before the embodiment 3-extraction on the supercritical extraction

1. Collect the tobacco powder produced during the rolling process, add 35 times the mass of deionized water, filter it at room temperature with a frequency of 40KHz for 30 minutes, and collect the first filtrate, and the tobacco powder is centrifuged and dehydrated to obtain the tobacco powder residue;

2. Dry the washed tobacco residues in an oven at 60°C until the moisture content is about 5%, 10%, 15% and 20% for later use;

3. Weigh 200g of smoke powder residue with a moisture content of about 5% and put it into the extraction kettle, set the extraction pressure to 30MPa, and the temperature to 45°C, inject CO ₂ , pressurize to the set pressure, and circulate the extraction for 2 hours to obtain super Tobacco extract with critical CO ₂ is recorded as extract I, and the tobacco dust residue with water content of about 10%, 15%, and 20% is sequentially extracted by the same method, which are respectively marked as extract II, extract III, and extract IV.

The above extracts were treated according to the method of Example 2 and analyzed by GC/MS, and the relative contents of various aroma substances in the extracts are listed in Table 4.

Table 4 The amount of various aroma substances in the extract (mg)

Extract I Extract II Extract III Extract IV moisture content 5% 10% 15% 20% Alcohols 3.53 3.46 4.15 3.55 Organic acids 0.84 1.32 1.94 0.43 Esters 0.65 0.66 0.85 0.84 Aldehydes and Ketones 0.27 0.38 0.59 0.57 Heterocycle 1.03 3.32 3.66 5.47 Alkanes 4.44 2.72 2.78 2.71 Terpenes 3.46 4.10 4.00 3.02 Total 14.22 15.96 17.97 16.59 Extraction yield/% 1.45 2.05 2.17 1.86 Amount of aroma compounds 87 108 108 105

It can be seen from Table 4 that after the tobacco powder is dried, the total amount of aroma substances extracted is low, and the content of some low-boiling point alcohols, small molecular acids, aldehydes and ketones is significantly reduced. As the water content increases, the extraction rate of flavors and the number of aroma compounds also increase, and the extraction amount increases most for esters, especially dihydroactinolactone, DL-pantothenolactone and scopoletin; 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DMPP), methylcyclopentenolone (MCP), 5- Hydroxymethylfurfural, etc. increased with the increase of moisture content in tobacco powder; terpenoids such as neophytadiene and squalene decreased gradually with the increase of moisture content. Therefore, an appropriate amount of water in the material can improve the performance of the supercritical fluid and help improve the solubility of polar hydrophilic fragrance substances. However, when the water content is too high, the material in the extraction kettle is relatively wet, and it is easy to cluster under high pressure, resulting in some fragrance components. The extraction yield was reduced.

It should be noted that this example is used to verify the influence of the water content of the material before extraction on the effect of supercritical extraction. Therefore, although the steps of ultrasonic washing and high-temperature supercritical extraction are omitted, it does not affect the effect of the water content of the material before extraction on the effect of supercritical extraction. Trends in the effects of critical extraction.

Example 4

1. Collect the tobacco powder produced during the rolling process, dry the tobacco powder at 40°C for 1 hour, and crush it through a 20-mesh sieve for later use;

2. Weigh 1 kg of tobacco powder and put it into a flask, add 40 times the amount of deionized water, filter it at room temperature with a frequency of 40KHz for 30 minutes, and collect the filtrate. ℃ and further dried to obtain tobacco powder with a moisture content of about 15% for subsequent use;

3. Weigh 200g of the above-mentioned processed tobacco powder into the extraction kettle, add 50mL of absolute ethanol, set the extraction pressure to 30MPa, the temperature is 45°C, inject CO ₂ , pressurize to the set pressure, and circulate the extraction for 1.5h. The residue in the extraction kettle was desolvated under reduced pressure. After the temperature was raised to 95°C, 20mL of absolute ethanol and CO ₂ were introduced, and the second supercritical extraction was carried out under the condition of 30MPa for 1.5h, and the collected smoke dust was extracted by supercritical CO ₂ things.

4. Carry out CO ₂ supercritical extraction on the raw tobacco powder that has not been washed by ultrasonic water according to the above method, and obtain the corresponding supercritical CO ₂ tobacco extract. The above-mentioned supercritical _CO2 tobacco extracts of raw tobacco powder and tobacco powder after washing with water were successively marked as extract X and extract Y.

Take 0.1g of the above-mentioned extract X and extract Y, add 100μL of 10mg/mL ethyl salicylate as the internal standard, adjust the volume to 5mL with absolute ethanol, take an appropriate amount of the solution and pass it through a 0.45μm organic phase filter membrane and perform GC/ MS analysis. The relative content of each aroma component in extract X and extract Y is shown in Table 5.

Content of some aroma components in the extract of Table 5 (mg)

Table 5 shows that: the tobacco powder is firstly subjected to a supercritical extraction at a low temperature after being washed with water once, and the temperature of the extracted material is raised, and the second supercritical extraction is continued. Compared with the original control tobacco powder extract, the tobacco powder can be significantly improved. The content of endogenous aroma substances, the number of aldehydes and ketones aroma components increased.

Observing the appearance, the color of the extract X is uniform and orange-yellow; through the evaluation of the smell of spices, the aroma of flue-cured tobacco, the sweetness and the roasted aroma of the extract X are prominent, and the smoke aroma is more pure and natural.

The organic combination of different aroma components constitutes the aroma characteristics of the spice. Therefore, according to the nicotine content of the tobacco powder, the present invention can adjust the number of times of washing and extraction conditions within a certain range, and combine the results of the aromatization test to prepare the applicability Strong tobacco-derived flavors help improve the self-protection ability of cigarette flavoring and flavors and fragrances.

Having described various embodiments of the present invention, the foregoing description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and alterations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principle of each embodiment, practical application or improvement of technology in the market, or to enable other ordinary skilled in the art to understand each embodiment disclosed herein.

Claims (10)

1. A preparation method of tobacco extract, characterized in that, comprising: Step a), drying and pulverizing the tobacco raw material to obtain tobacco powder; Step b), the tobacco powder is ultrasonically washed with deionized water for 1 to 3 times, and then filtered and centrifugally dehydrated after each ultrasonic washing to obtain a washing residue; Step c), drying the water-washed residue to obtain low-nicotine tobacco powder; Step d), performing a carbon dioxide supercritical extraction on the low-nicotine tobacco powder to obtain an extract; Step e), continue to perform a second carbon dioxide supercritical extraction on the residue after the first carbon dioxide supercritical extraction, to obtain a second extract; the temperature of the second supercritical extraction is 80-100° C., and the pressure is 20-30 MPa; Step f), combining the primary extract and the secondary extract to obtain tobacco extract. 2 . The preparation method according to claim 1 , wherein the step a) specifically comprises: drying the tobacco raw material at 40-60° C. for 1-2 hours, and pulverizing it to 20-40 meshes to obtain tobacco powder. 3 . 3. The preparation method according to claim 1, characterized in that, in the step b), in each ultrasonic washing, the mass ratio of deionized water to tobacco powder is (10-50): 1, and the ultrasonic time is 20~40min, the ultrasonic frequency is 30KHz~60KHz. 4. The preparation method according to claim 1, characterized in that, in the step c), the water content of the low-nicotine tobacco powder is 10%-15%. 5. preparation method according to claim 1, is characterized in that, in described step d), carbon dioxide supercritical extraction condition is as follows: The extraction temperature is 40°C-60°C, the extraction pressure is 10MPa-30MPa, the extraction is cyclic, and the extraction time is 1h-3h. 6. the preparation method according to claim 5, is characterized in that, in described step d), with dehydrated alcohol as entrainer in extraction process; The weight volume ratio of described low nicotine tobacco powder and dehydrated alcohol is 1g: (0.1mL～0.25mL). 7. preparation method according to claim 1, is characterized in that, the condition of secondary carbon dioxide supercritical extraction in described step e) is as follows: The extraction temperature is 80°C-100°C, the extraction pressure is 20MPa-30MPa, the extraction is cyclic, and the extraction time is 1h-2h. 8. The preparation method according to claim 7, characterized in that, in the step e), dehydrated alcohol is used as entrainer in the extraction process; the weight-to-volume ratio of the low-nicotine tobacco powder and dehydrated alcohol is 1g: (0.05mL～0.125mL). 9. A tobacco extract, characterized in that it is prepared according to the method described in any one of claims 1-8. 10. A tobacco product, characterized in that it contains the tobacco extract according to claim 9.

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