A method for regulating the formation of aroma components and nicotine in tobacco through pretreatment

Abstract

This invention relates to a method for regulating the formation of aroma components and nicotine in tobacco through pretreatment. It clarifies the effect of organic acid washing pretreatment on the enrichment of aroma compounds during tobacco pyrolysis. The organic acid washing pretreatment method generally promotes the decomposition of proteins in tobacco, promotes the formation of aromatic compounds, and inhibits the formation of nitrogenous products. The organic acid washing pretreatment method greatly promotes the formation of carbohydrate-derived dehydrated sugars and ketones, which is crucial for enriching aroma compounds. Furthermore, organic acid washing significantly improves the conversion rate of tobacco and reduces char content. This method can enrich substances such as nicotine, ketones, and sugars in tobacco pyrolysis products. These chemical substances can be directly formulated and used as e-liquids for electronic cigarettes or as smoking agents in heated tobacco products, or added to traditional cigarettes to improve flavor.

Description

Technical Field

[0001] This invention belongs to the field of tobacco pretreatment technology, specifically relating to a method for regulating the generation of aroma components and nicotine in tobacco through pretreatment. Background Technology

[0002] Tobacco leaves, due to their aroma, flavor, and odor, are widely used in the production of cigarettes and cigars. Tobacco pyrolysis, a key step in the smoking process, has been extensively studied for the production of flavoring ingredients such as sugars, alkaloids, and acids. To improve the sensory quality of cigarettes, it is essential to control the formation of aroma components during tobacco pyrolysis.

[0003] Tobacco leaves are mainly composed of carbohydrates, lipids, proteins, and inorganic components. Acid washing is widely used in tobacco leaf processing. Its purpose is to maximize the production of aroma compounds and minimize the formation of byproducts such as charcoal and permanent gases. Injecting small amounts of inorganic acids into lignocellulosic biomass can significantly mitigate the effects of alkali metals and alkaline earth metals. Acids react with alkali metals and alkaline earth metals in biomass to form thermally stable salts. The catalytic activity of these salts is negligible during pyrolysis. Acid washing of biomass can also lead to higher yields of bio-oil and L-glucan. However, inorganic acid washing can pollute the environment. Therefore, some scholars have proposed using environmentally friendly organic acids to treat tobacco samples. The addition of acetic acid can promote the formation of dehydrated sugars in the pyrolysis products of poplar sawdust. Acetic acid pretreatment can also increase the yield of bio-oil from peanut shell pyrolysis. However, no strategy for enriching aroma compounds in tobacco pyrolysis products using organic acid pretreatment has yet been clearly proposed.

[0004] Current research on the enrichment of aroma components during tobacco pyrolysis mostly focuses on pyrolysis temperature, heating rate, additives, and tobacco type. There are few reports on organic acid pretreatment methods for aroma enrichment strategies during tobacco pyrolysis and the control of nicotine formation. Summary of the Invention

[0005] The purpose of this invention is to provide a method for regulating the generation of aroma components and nicotine in tobacco through pretreatment, so as to solve the above-mentioned problems of acid treatment.

[0006] To achieve the above objectives, this application employs the following technical solution:

[0007] A method for regulating the formation of aroma components and nicotine in tobacco through pretreatment includes the following steps:

[0008] Step 1) After the tobacco leaves are crushed into granules, they are then sieved to separate 40-60 mesh particles to obtain tobacco leaf sample particles.

[0009] Step 2) Select three tobacco leaf samples according to the set weight obtained in Step 1), and use three 0.1M organic acid solutions to acid wash the three tobacco leaf samples one by one to obtain three pretreated tobacco leaf samples.

[0010] Step 3) The three pretreated tobacco leaf samples obtained in Step 2) are subjected to high-temperature pyrolysis reactions respectively. The obtained pyrolysis reaction products are directly detected by the online analysis module to obtain the type and content of pyrolysis products of each pretreated tobacco leaf sample.

[0011] Furthermore, in step 1), the tobacco leaves are crushed using a crusher and sieved using a vibrating screen.

[0012] Further, the specific steps for acid washing in step 2) are as follows: Take any tobacco leaf sample and place it in a beaker, then add a set volume of 0.1M dilute organic acid solution, and stir at 600r / min for 5min in a water bath magnetic stirrer at room temperature. Then filter the stirred solution through filter paper, and wash the obtained solid with room temperature deionized water six times. Dry the washed tobacco leaf sample in a 60℃ forced-air oven for 12h.

[0013] Furthermore, organic acids include at least lactic acid, acetic acid, or citric acid.

[0014] Furthermore, the reaction apparatus for the high-temperature pyrolysis reaction in step 3) includes a micro pyrolysis instrument coupled with a gas chromatograph and a mass spectrometer system.

[0015] Furthermore, the high-temperature pyrolysis reaction in step 3) is carried out at a temperature of 500°C and atmospheric pressure, with helium as the carrier gas.

[0016] Furthermore, the specific steps of the high-temperature pyrolysis reaction in step 3) are as follows:

[0017] Select the pretreated tobacco leaf sample of the set mass in step 2) and place it in the sample cup. Suspend the sample cup above the first reaction zone of the micro pyrolysis instrument. Then heat the first reaction zone to 500°C and keep the second reaction zone at 300°C. Use helium as the reaction carrier gas.

[0018] The column oven temperature program for the gas chromatograph is as follows: hold at 40℃ for 3 minutes, then increase to 250℃ at a heating rate of 3℃ / min, and then stop. The injection port temperature of the gas chromatograph is set to 250℃. The HP-5 membrane gas chromatograph and mass spectrometer are used, and the area normalization method is used to quantify the pyrolysis volatiles.

[0019] Furthermore, it also includes weighing the sample cups before and after the reaction, and determining the yield of coke formed in the pyrolysis experiment by the mass difference method.

[0020] The beneficial effects of this invention are:

[0021] This invention utilizes organic acid washing and pyrolysis processes to treat tobacco leaves, reducing the yield of permanent gaseous and solid residues while enriching the content of aroma raw materials in the pyrolysis products. These products can be used to heat tobacco leaf products and traditional cigarettes, generating economic benefits and forming an environmentally friendly and sustainable scheme for enriching aroma raw materials in tobacco leaves. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the high-temperature pyrolysis reaction system of the present invention.

[0023] Figure 2 Bar chart showing the effect of different alkali metals and alkaline earth metals on the content of aromatic raw materials in tobacco pyrolysis products.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. First reaction zone; 2. Second reaction zone; 3. Sample cup; 4. Gas chromatograph; 5. Mass spectrometer. Detailed Implementation

[0026] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, and should not be construed as limiting the technical solution of the present invention.

[0027] Figure 1 This is a schematic diagram of the high-temperature pyrolysis reaction system of the present invention, including a first reaction zone 1, which is electrically heated, a second reaction zone 2, which is also electrically heated, and also includes a gas chromatograph 4, a mass spectrometer 5, and a sample cup 3.

[0028] This technical solution provides a method for regulating the generation of aroma components and nicotine in tobacco through pretreatment, including the following steps:

[0029] Step 1) After crushing the tobacco leaves into granules, sieve out 40-60 mesh particles to obtain tobacco leaf sample particles.

[0030] Step 2): Select three tobacco leaf samples obtained in Step 1) according to a set weight, and perform acid washing treatment with 0.1M organic acid solution (lactic acid, acetic acid, citric acid) on each sample to obtain pretreated tobacco leaf samples. Specific steps for acid washing with 0.1M organic acid solution: Weigh 5g of tobacco leaf sample sieved to 40-60 mesh into a 250mL beaker, then add 100mL of 0.1M dilute acid solution. Stir the solution vigorously in a water bath magnetic stirrer at 600r / min for 5min at room temperature. Then filter the stirred solution through circular filter paper, and wash the obtained solid six times with room temperature deionized water. Dry the obtained 0.1M dilute acid-washed tobacco leaf samples in a 60℃ forced-air oven for 12h.

[0031] Step 3) The three pretreated tobacco samples obtained in Step 2) were subjected to pyrolysis experiments. The pyrolysis experiments were conducted on a micropyrolysis instrument coupled with a gas chromatography-mass spectrometry (GC-MS) system. The micropyrolysis instrument was responsible for converting the samples into pyrolysis products. The GC-MS and GC-MS were responsible for qualitative analysis of the volatile pyrolysis products. In a typical experimental procedure, 0.5 mg of tobacco leaves was weighed into a stainless steel sample cup, which was suspended above the first reaction zone of the micropyrolysis instrument via the injector. This zone was close to room temperature to prevent sample volatilization and decomposition. Before the experiment, the first reaction zone of the micropyrolysis instrument was heated to 500 °C. The second reaction zone was maintained at 300 °C as a heat preservation zone. Helium was used as the carrier gas to propel the pyrolysis products into the subsequent GC-MS and GC-MS. The GC-MS column oven temperature program was as follows: hold at 40 °C for 3 minutes, then increase to 250 °C at a heating rate of 3 °C / min, and then stop. The injection port temperature of the gas chromatograph was set to 250℃. An HP-5 (60m × 0.320mm, 1μm film thickness) gas chromatograph and mass spectrometer were used in series. The pyrolysis volatiles were quantified using the area normalization method. The yield of coke formed in the pyrolysis experiment was determined by weighing the stainless steel sample cups before and after the reaction and using the mass difference method. Thus, the content of aromatic raw materials in the pyrolysis products of tobacco samples pretreated with different 0.1M organic acid solutions was determined.

[0032] Example

[0033] Effects of 0.1M citric acid pickling, 0.1M acetic acid pickling and 0.1M lactic acid pickling pretreatment on the content of aroma ingredients in tobacco pyrolysis products.

[0034] Tobacco leaf samples pickled with 0.1M citric acid, 0.1M acetic acid, and 0.1M lactic acid were respectively placed in stainless steel sample cups. The temperature of the first reaction zone of the micro pyrolysis instrument was set to 500℃, and the temperature of the second reaction zone was set to 300℃, with helium as the carrier gas.

[0035] Gas chromatography-coupled mass spectrometry (GC-MS / MS) was used to analyze the components of tobacco pyrolysis, thereby revealing the effects of different alkali metals and alkaline earth metals on the content of flavoring ingredients in tobacco pyrolysis products. Figure 2 As shown.

[0036] In the above experiments, the increasing order of relative nitrogen-containing compounds was: citric acid-washed tobacco sample (9.4%) < acetic acid-washed tobacco sample (10.6%) < lactic acid-washed tobacco sample (14.5%) < original tobacco sample (52.1%). All organic acid washing pretreatment methods inhibited the formation of nitrogen-containing compounds. Organic acid pretreatment slightly increased the relative content of aromatics in the tobacco pyrolysis products. The increasing order of relative phenolic content was: original tobacco sample (1.6%) < citric acid-washed tobacco sample (5.5%) < lactic acid-washed tobacco sample (6.0%) < acetic acid-washed tobacco sample (7.6%). The acetic acid-washed tobacco sample produced the highest relative phenolic content during pyrolysis, possibly due to the promotion of aromatic amino acid decomposition. Overall, organic acid washing pretreatment significantly inhibited protein decomposition in tobacco but promoted the formation of aromatic compounds.

[0037] For various compounds derived from carbohydrates, different organic acid pretreatment methods significantly affect their relative content. Organic acid washing greatly promotes the production of anhydrous sugars. The increasing order of relative content of dehydrated sugar products is: original tobacco sample (1.6%) < lactic acid-washed tobacco sample (22.2%) < acetic acid-washed tobacco sample (22.9%) < citric acid-washed tobacco sample (46.2%). The increasing order of relative furan content is: original tobacco sample (7.0%) ≈ acetic acid-washed tobacco sample (7.0%) < citric acid-washed tobacco sample (8.9%) < lactic acid-washed tobacco sample (9.8%). Organic acid washing pretreatment also promotes furan formation. Organic acid washing pretreatment has little effect on the relative content of acid products. The increasing order of relative acid content is: citric acid-washed tobacco (2.3%) < acetic acid-washed tobacco sample (4.0%) < original tobacco sample (5.6%) < lactic acid-washed tobacco sample (5.7%). The relative ketone content increased in the following order: original tobacco sample (20.4%) < citric acid-washed tobacco sample (20.9%) < lactic acid-washed tobacco sample (30.8%) < acetic acid-washed tobacco sample (34.9%). Organic acid washing pretreatment had a positive impact on ketone formation. The aldehyde production increased in the following order: acetic acid-washed tobacco sample (0%) ≈ lactic acid-washed tobacco sample (0%) < citric acid-washed tobacco sample (1.9%) < original tobacco sample (4.6%). Organic acid washing pretreatment inhibited aldehyde formation, possibly because it promoted the conversion of aldehydes to ketones.

[0038] The relative content of lipid-derived esters increased in the following order: lactic acid-washed tobacco samples (4.4%) < citric acid-washed tobacco samples (4.9%) < virgin tobacco samples (5.7%) < acetic acid-washed tobacco samples (7.5%). The effect of organic acid washing pretreatment on lipid decomposition in tobacco samples was uneven. Acetic acid promoted lipid decomposition in tobacco. The yield of solid residues increased in the following order: citric acid-washed tobacco samples (14.3%) < lactic acid-washed tobacco samples (14.5%) < acetic acid-washed tobacco samples (15.9%) < virgin tobacco samples (23.8 wt.%). Organic acid washing improved tobacco conversion and reduced char formation.

[0039] The effects of organic acid washing pretreatment on the enrichment of aroma compounds during tobacco pyrolysis were clarified through the aforementioned pretreatment techniques. Organic acid washing pretreatment generally promoted the decomposition of proteins in tobacco, fostered the formation of aromatic compounds, and inhibited the formation of nitrogenous products. It significantly promoted the formation of carbohydrate-derived dehydrated sugars and ketones, which is crucial for the enrichment of aroma compounds. Furthermore, organic acid washing greatly improved the conversion rate of tobacco and reduced char content. This method can enrich substances such as nicotine, ketones, and sugars in tobacco pyrolysis products. These chemicals can be directly formulated and used as e-liquids for e-cigarettes or as smoking agents in heated tobacco products, or added to traditional cigarettes to improve flavor.

[0040] The terminology and expressions used above are for descriptive purposes only, and the present invention should not be limited to these terms and expressions. The use of these terms and expressions does not imply the exclusion of any illustrative and descriptive equivalent features (or parts thereof), and it should be recognized that various modifications that may exist should also be included within the scope of the claims. Other modifications, variations, and substitutions may also exist, and accordingly, the claims should be considered to cover all such equivalents.

[0041] Similarly, it should be noted that although the present invention has been described with reference to the specific embodiments described above, those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and various equivalent changes or substitutions can be made without departing from the spirit of the present invention. Therefore, any changes or modifications to the above embodiments within the scope of the essential spirit of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A method for regulating the generation of aroma components and nicotine in tobacco through pretreatment, characterized in that, Includes the following steps: Step 1) After the tobacco leaves are crushed into granules, they are then sieved to separate 40-60 mesh particles to obtain tobacco leaf sample particles. Step 2) Select three tobacco leaf samples according to the set weight obtained in Step 1), and use three 0.1M organic acid solutions to acid wash the three tobacco leaf samples one by one to obtain three pretreated tobacco leaf samples. Step 3) The three pretreated tobacco leaf samples obtained in Step 2) are subjected to high-temperature pyrolysis reactions respectively. The obtained pyrolysis reaction products are directly detected by the online analysis module to obtain the type and content of pyrolysis products of each pretreated tobacco leaf sample. The specific steps of the high-temperature pyrolysis reaction in step 3) are as follows: Select the pretreated tobacco leaf sample of the set mass in step 2) and place it in the sample cup. Suspend the sample cup above the first reaction zone of the micro pyrolysis instrument. Then heat the first reaction zone to 500°C and keep the second reaction zone at 300°C. Use helium as the reaction carrier gas. The column oven temperature program for the gas chromatograph is as follows: hold at 40℃ for 3 minutes, then increase to 250℃ at a heating rate of 3℃ / min, and then stop. The injection port temperature of the gas chromatograph is set to 250℃. The HP-5 membrane gas chromatograph and mass spectrometer are used, and the area normalization method is used to quantify the pyrolysis volatiles.

2. The method for regulating the generation of aroma components and nicotine in tobacco through pretreatment according to claim 1, characterized in that, In step 1), the tobacco leaves are crushed using a crusher and sieved using a vibrating screen.

3. The method for regulating the generation of aroma components and nicotine in tobacco through pretreatment according to claim 1, characterized in that, Step 2) The specific steps for acid washing are as follows: Take any tobacco leaf sample and place it in a beaker, then add a set volume of 0.1M dilute organic acid solution, and stir at 600r / min for 5min in a water bath magnetic stirrer at room temperature. Then filter the stirred solution through filter paper, and wash the obtained solid with room temperature deionized water six times. Dry the washed tobacco leaf sample in a 60℃ forced-air oven for 12h.

4. The method for regulating the generation of aroma components and nicotine in tobacco through pretreatment according to claim 1, characterized in that, The three organic acids are lactic acid, acetic acid, and citric acid.

5. The method for regulating the generation of aroma components and nicotine in tobacco through pretreatment according to claim 1, characterized in that, The reaction apparatus for the high-temperature pyrolysis reaction in step 3) includes a micro pyrolysis instrument coupled with a gas chromatograph and a mass spectrometer system.

6. The method for regulating the generation of aroma components and nicotine in tobacco through pretreatment according to claim 5, characterized in that, The high-temperature pyrolysis reaction in step 3) is carried out at a temperature of 500°C and atmospheric pressure, with helium as the carrier gas.

7. The method for regulating the generation of aroma components and nicotine in tobacco through pretreatment according to claim 1, characterized in that, It also includes weighing the sample cups before and after the reaction, and determining the yield of coke formed in the pyrolysis experiment by the mass difference method.

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