A method for preparing low-tar reconstituted tobacco leaf and application thereof

Abstract

The application discloses a low-tar reconstituted tobacco preparation method and application thereof, and the catalyst in the low-tar reconstituted tobacco preparation method is CA@MOF@PEG-citric acid, the catalyst preparation method comprises the following steps: synthesizing MOF-Al, preparing a combustion catalyst and forming CA@MOF@PEG-citric acid. The low-tar reconstituted tobacco preparation method comprises the following steps: mixing and extracting tobacco leaves and stems, pulping, adding an additive, papermaking a base sheet, coating, drying and adding flavoring, and the like. The flavoring step is added after drying, so as to improve the sensory quality. Physical performance detection and smoke index detection results show that the prepared reconstituted tobacco has good physical performance and a significantly reduced tar release amount, and the tar release amount is reduced by more than 39.69%, thereby providing a new way for low-tar cigarette research and development.

Description

Technical Field

[0001] This invention relates to the field of tobacco processing technology, and in particular to a method for preparing low-tar reconstituted tobacco leaves and its application. Background Technology

[0002] Reconstituted tobacco, as an important component of cigarette formulation, plays a role in saving production costs, reducing tar release, regulating combustion performance, and improving smoking quality. With the development of industry technology and the increasing health demands of consumers, the demand for low-tar cigarette products is growing. Correspondingly, the proportion of reconstituted tobacco, a key raw material for reducing tar, in cigarette formulation is gradually increasing. The requirement is that reconstituted tobacco, while maintaining low tar release, should not negatively impact the sensory quality of cigarettes and should ensure stable quality.

[0003] Therefore, how to reduce the tar release of reconstituted tobacco leaves without changing their flavor has become a critical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for preparing low-tar reconstituted tobacco and its application. Based on the basic principle of catalytic combustion, a water-soluble combustion catalyst, CA@MOF@PEG-citric acid, was designed and prepared. A low-tar sheet was developed by adding the combustion catalyst, modifying cellulose, and reducing the coating rate. Without significantly altering the flavor, the tar release per gram of reconstituted tobacco is reduced by more than 39.69%.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solution:

[0006] A method for preparing a regenerated tobacco combustion catalyst includes the following steps:

[0007] (1) Synthesis of MOF-Al:

[0008] MOF-Al can be obtained by dissolving aluminum nitrate nonahydrate (Al(NO3)3·9H2O) and aminoterephthalic acid (NH2-BDC) in a mixed solution of water and DMF and heating at 150℃ for 24 hours.

[0009] (2) Preparation of combustion catalyst (CA@MOF):

[0010] Prepare a ferric sulfate solution of a certain concentration, add a certain weight of MOF-Al in a certain proportion, impregnate and stir for 2 hours, then add potassium hydroxide solution as a precipitant dropwise to adjust the pH of the mixture to 12, continue stirring and reacting for 1 hour, wash the obtained precipitate repeatedly with water until no new precipitate is produced when 0.1 MBaCl2 solution is added to the filtrate, and dry the precipitate at 120℃ to obtain CA@MOF;

[0011] (3) Preparation of CA@MOF@PEG-citric acid:

[0012] Weigh a certain amount of CA@MOF and add it in batches to citric acid-functionalized polyethylene glycol (PEG) under stirring to form a homogeneous CA@MOF@PEG-citric acid solution.

[0013] Preferably, in the above technical solution, in step (1), the molar ratio of Al(NO3)3·9H2O and NH2-BDC / BDC / NO2-BDC is 1:1.5; and the volume ratio of water and DMF in the mixed solution is (0~1):3.

[0014] Preferably, in the above technical solution, in step (2), the concentration of ferric sulfate / ferric chloride / ferric nitrate is 1.0-1.5 mol / L; the mass ratio of ferric sulfate / ferric chloride / ferric nitrate to MOF-Al is (2-4):1.

[0015] Preferably, in the above technical solution, in step (3), the mass ratio of CA@MOF and PEG-citric acid is 1:(2-5).

[0016] A regenerated tobacco combustion catalyst is prepared according to the above-described preparation method.

[0017] A method for preparing low-tar reconstituted tobacco leaves includes the following steps:

[0018] (1) Papermaking process for reconstituted tobacco production:

[0019] Tobacco leaves and tobacco stems are mixed to prepare a mixed raw material. Water is added to the mixed raw material for extraction, and solid-liquid separation is performed to obtain residue and extract.

[0020] Repeat the above steps, combine the residues, and control the freeness of the pulp to (20±2°)SR through pulping;

[0021] The extracts were combined and concentrated to a density of (1.180±0.005) g / cm³. 3 Tobacco concentrate;

[0022] (2) Weigh 4% wood pulp fiber and 3% cationic nanocellulose by mass, and control the freeness of the pulp to (50±2°)SR by pulping.

[0023] After mixing with tobacco pulp, adjust the pulp concentration to 0.5%;

[0024] Adding 10-15% by mass of spindle-shaped calcium carbonate (D50 1.5-2.5μm) and 0.5% of functional additives (cationic guar gum: nonionic guar gum = 1:1), the basis weight of the paper produced using a standard sheet forming machine is 60±2g / m³. 2 Reconstituted tobacco substrate;

[0025] (3) The CA@MOF@PEG-citric acid prepared by any of the preparation methods described in claims 1-4 is added to the tobacco concentrate at a mass ratio of 3%. The reconstituted tobacco substrate is coated by dip coating, and the tobacco concentrate is coated onto the substrate. The coating rate is controlled to be 15%-25%. Then, the reconstituted tobacco is dried, and the moisture content is adjusted to 11.7%. The substrate is then sent to a shredder for shredding.

[0026] (4) After drying, the flavoring dissolved in ethanol is applied to the filamentous reconstituted tobacco leaves in the form of spray, which is low tar reconstituted tobacco leaves.

[0027] Preferably, in the above technical solution, in step (1), the mass ratio of tobacco leaves and tobacco stems is 7:3, and the mass ratio of mixed raw materials to water is 1:7; the extraction conditions are: extraction at 60℃ for 40 minutes.

[0028] Preferably, in the above technical solution, in step (2), the D50 of the spindle-shaped calcium carbonate is 1.5-2.5μm; the functional additives include cationic guar gum and nonionic guar gum, with a mass ratio of 1:1.

[0029] Preferably, in the above technical solution, in step (3), the width of the shredded tobacco is controlled to be 0.9±0.1mm; in step (4), the flavoring is menthol, and the total amount added is 1.0 to 2.0% of the total amount of tobacco.

[0030] Application of a low-tar reconstituted tobacco leaf in cigarettes.

[0031] The above-described technical solution of the present invention has the following beneficial effects:

[0032] (1) The process is simple to operate and easy to achieve large-scale production and application.

[0033] (2) The present invention adds a combustion catalyst to the reconstituted tobacco leaves. During the cigarette burning process, the catalytic effect of the combustion catalyst makes the tobacco burn more completely. While reducing the amount of tar and harmful components generated, it also makes the compounds in the tobacco undergo more oxidation reactions, increases the content of aroma substances, and makes the smoke more delicate and mellow.

[0034] (3) On the one hand, it avoids the loss of fragrance caused by high temperature drying after the fragrance coating is applied, reduces the amount of fragrance used, and lowers the production cost; on the other hand, the fragrance formula design can be flexibly adjusted as needed, so as to produce characteristic reconstituted tobacco products that can meet different functional needs and different taste requirements, which can effectively broaden the functionality and applicability of reconstituted tobacco and shorten the development cycle of reconstituted tobacco. Detailed Implementation

[0035] Various exemplary embodiments of the present invention will now be described in detail. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0036] Unless otherwise specified, all reagents used in this application are commercially available or obtained through commercial channels, or may be prepared by referring to existing chemical methods.

[0037] Example 1

[0038] (1) Synthesis of MOF-Al:

[0039] MOF-Al is obtained by dissolving aluminum nitrate nonahydrate (Al(NO3)3·9H2O) and aminoterephthalic acid (NH2-BDC) in a mixed solution of water and DMF, and heating at 150℃ for 24 h. The molar ratio of Al(NO3)3·9H2O to NH2-BDC / BDC / NO2-BDC is 1:1.5; the volume ratio of water and DMF in the mixed solution is (0~1):3.

[0040] The obtained MOF-Al crystals are mostly octahedral in shape, uniformly dispersed, and do not aggregate.

[0041] (2) Preparation of combustion catalyst (CA@MOF):

[0042] A ferric sulfate solution of a certain concentration was prepared, and a predetermined weight of MOF-Al was added in a certain proportion. After soaking and stirring for 2 hours, potassium hydroxide solution was added dropwise as a precipitant to adjust the pH of the mixture to approximately 12. The reaction was continued with stirring for 1 hour. The resulting precipitate was repeatedly washed with water until no new precipitate was formed when 0.1 M BaCl2 solution was added to the filtrate. The precipitate was dried at 120℃ to obtain the regenerated tobacco combustion catalyst (CA@MOF). The concentration of ferric sulfate was 1.0–1.5 mol / L, and the mass ratio of ferric sulfate to MOF-Al was (2–4):1.

[0043] (3) Preparation of CA@MOF@PEG-citric acid:

[0044] A certain amount of combustion catalyst (CA@MOF) was weighed and added in batches to citric acid-functionalized polyethylene glycol (PEG) under stirring. The citric acid groups have a high affinity for metal oxide surfaces, allowing them to form self-assembled monolayers on these surfaces, resulting in CA@MOF@PEG-citric acid. This composite can be uniformly dispersed in water. The mass ratio of CA@MOF to PEG-citric acid was 1:(2-5).

[0045] Reconstituted tobacco preparation

[0046] (1) Papermaking process for reconstituted tobacco production:

[0047] Tobacco leaves and tobacco stems were mixed at a mass ratio of 7:3 to prepare a mixed raw material (1000 kg of oven-dry weight). Water was added at a mass ratio of 7 times the mixture. The mixture was extracted at a temperature of 60℃ for 40 min, and then solid-liquid separation was performed to obtain residue and extract.

[0048] Repeat the above steps, combine the residues, and pulp, controlling the freeness of the pulp to (20±2°)SR. Combine the extracts and concentrate them to a density of (1.180±0.005) g / cm³. 3 Tobacco concentrate.

[0049] (2) Weigh 40 kg of wood pulp fiber (4% by weight) and 30 kg of cationic nanocellulose (3% by weight). Pulping is performed, controlling the freeness of the pulp to (50±2°)SR. After mixing with tobacco pulp, the pulp concentration is adjusted to 0.5%. Add 15% by weight of spindle-shaped calcium carbonate (particle size 2-4 μm) and 0.5% by weight of functional additives (cationic guar gum: nonionic guar gum = 1:1). Using a standard paper forming machine, the basis weight is 60±2 g / m³. 2 Reconstituted tobacco substrate.

[0050] (3) Add CA@MOF@PEG-citric acid to the tobacco concentrate at a mass ratio of 3%. The reconstituted tobacco substrate is coated by dip coating. The tobacco concentrate is coated onto the substrate, and the coating rate is controlled at 15%. Then, after drying and adjusting the moisture content of the reconstituted tobacco to 11.7%, it is sent to the shredder for shredding. The shredding width is controlled at 0.9±0.1mm.

[0051] (4) Due to the high temperature during the drying process, a large amount of volatile aroma components are lost, resulting in a decline in the sensory quality of reconstituted tobacco leaves. To compensate for this defect, an aromatization step is added after the drying process for filamentous reconstituted tobacco leaves. 1.5g of menthol is dissolved in ethanol and applied to the filamentous reconstituted tobacco leaves in the form of a spray, which is sample A.

[0052] The types of spices can be flexibly adjusted according to the needs of the spice formula design, thereby producing distinctive reconstituted tobacco products that can meet different functional needs and different taste requirements. This can not only effectively broaden the functionality and applicability of reconstituted tobacco, but also shorten the development cycle of reconstituted tobacco.

[0053] Example 2

[0054] The difference from Example 1 is that the coating rate is controlled at 20%, and the amount of menthol used is reduced to 1.0 g / kg of tobacco.

[0055] Example 3

[0056] The difference from Example 1 is that the coating rate is controlled at 25%, and menthol is replaced with clove oil.

[0057] Comparative Example 1

[0058] Unlike Example 1, the percentage of wood pulp fiber is 7%, no cationic nanofibers are added, no combustion catalyst CA@MOF@PEG-citric acid is added, the coating rate is 40% (normal product), and there is no subsequent flavoring process for filamentous reconstituted tobacco leaves.

[0059] Physical property testing of reconstituted tobacco leaves:

[0060] Table 1. Test results of physicochemical properties of reconstituted tobacco leaves produced by papermaking.

[0061]

[0062] As shown in Table 1, replacing wood fibers with cationic nanocellulose significantly improves the tensile index, bulk, and filling value of the reconstituted tobacco. This is because cationic nanocellulose carries a positive charge, while the entire pulping system is a negatively charged system. Cationic nanocellulose easily adsorbs with pulp fibers, increasing the number of hydrogen bonds between fibers while maintaining a certain porosity between fibers, which also has a positive impact on the bulk of the tobacco substrate.

[0063] Routine flue gas index testing for reconstituted tobacco:

[0064] Using the obtained shredded reconstituted tobacco leaves as tobacco, and employing auxiliary materials (cigarette paper, tipping paper, and filter rod) from a certain brand of slim cigarettes, the samples were rolled and packaged on a pilot cigarette production line to obtain experimental verification samples. The conventional smoke components of the cigarettes (cigarette length 97mm, combustion termination line 40mm, burning tobacco length 57mm, unburned tobacco length 10mm, cigarette weight approximately 0.54g, material weight approximately 0.16g) were tested according to GB / T 19609—2004 and GB / T23355—2009.

[0065] Table 2 Results of routine flue gas analysis for reconstituted tobacco produced by papermaking

[0066]

[0067] As shown in Table 2, compared with the comparative example, the tar release of Examples 1-3 was significantly reduced, with a decrease of more than 39.69% in tar release per gram of reconstituted tobacco. This is partly due to the use of CA@MOF@PEG-citric acid combustion catalyst, which changed the combustion state of the reconstituted tobacco; and partly due to the reduction in coating rate, which reduced the amount of large organic molecules such as polysaccharides in the reconstituted tobacco, both of which led to a reduction in tar generation during combustion of the reconstituted tobacco.

[0068] Sensory evaluation of filamentous reconstituted tobacco leaves:

[0069] The filamentous reconstituted tobacco leaves obtained above were rolled into cigarettes. The sensory evaluation of the prepared cigarette samples was carried out in accordance with the industry standard YC / T 498 "Sensory Evaluation Method of Reconstituted Tobacco (Papermaking Method)" and the "Sensory Quality Evaluation Method of Reconstituted Tobacco Leaves of Henan Tobacco". The results are shown in Table 3.

[0070] Table 3 Sensory Quality Evaluation of Reconstituted Tobacco Leaves

[0071]

[0072]

[0073] As can be seen from Table 3, the filamentous reconstituted tobacco leaves prepared by this invention, when used in cigarettes, improve the aroma quality and aroma quantity of the cigarettes, and improve the fineness of the smoke, impurities, irritation, aftertaste, and oral comfort. This makes up for the aroma loss caused by the reduction of coating rate and has good application prospects.

[0074] Verification of the effect of finished cigarettes:

[0075] To further verify the tar-reducing effect of low-tar flakes, they were added to the tobacco of a certain brand of slim cigarettes at a ratio of 16%. Using the same brand of auxiliary materials (cigarette paper, tipping paper, and filter rod), the samples were rolled and packaged on a pilot cigarette production line to obtain the test verification samples. The conventional smoke components of the cigarettes were tested in accordance with GB / T 19609—2004 and GB / T 23355—2009 (see Table 4).

[0076] Table 4 Results of routine cigarette smoke analysis

[0077]

[0078] As shown in Table 4, compared with cigarette 1, the tar release of cigarettes 2-4 is significantly reduced, with a reduction of more than 55.07% in tar release per cigarette. This indicates that the low-tar reconstituted tobacco developed in this invention can reduce the release of tar and nicotine from cigarettes, which is beneficial to the development of low-tar cigarettes.

[0079] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various different choices and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a reconstituted tobacco combustion catalyst, characterized in that, Includes the following steps: (1) Synthesis of MOF-Al: Aluminum nitrate nonahydrate (Al(NO3)3·9H2O) and aminoterephthalic acid (NH2-BDC) or terephthalic acid (BDC) or 2-nitroterephthalic acid (NO2-BDC) were dissolved in a mixed solution of water and DMF. After stirring for 30 min, the mixture was transferred to a polytetrafluoroethylene reactor and heated at 150 °C for 24 h. The mixture was then filtered, and the precipitate was washed four times alternately with methanol and DMF. After drying under vacuum at 100 °C, MOF-Al was obtained. (2) Preparation of combustion catalyst (CA@MOF): Prepare a solution of ferric sulfate, ferric chloride, or ferric nitrate of a certain concentration, add a certain weight of MOF-Al in a certain proportion, impregnate and stir for 2 h, add potassium bicarbonate solution as a precipitant dropwise, adjust the pH of the mixture to 12, continue stirring and react for 1 h, transfer to a polytetrafluoroethylene reactor, heat and react at 150 ℃ for 4 h, wash the obtained precipitate repeatedly with water, and dry the precipitate at 120 ℃ to obtain CA@MOF; (3) Preparation of CA@MOF@PEG-citric acid: Weigh a certain amount of CA@MOF and add it in batches to citric acid-functionalized polyethylene glycol (PEG) under stirring to form a homogeneous CA@MOF@PEG-citric acid solution.

2. The method for preparing the reconstituted tobacco combustion catalyst according to claim 1, characterized in that, In step (1), the molar ratio of Al(NO3)3·9H2O to NH2-BDC or BDC or NO2-BDC is 1:1.5; in the mixed solution of water and DMF, the volume ratio of the two is less than 1:

3.

3. The method for preparing the reconstituted tobacco combustion catalyst according to claim 1, characterized in that, In step (2), the concentration of ferric sulfate, ferric chloride, or ferric nitrate is 1.0~1.5 mol / L; the mass ratio of ferric sulfate, ferric chloride, or ferric nitrate to MOF-Al is (2~4):

1.

4. The method for preparing the reconstituted tobacco combustion catalyst according to claim 1, characterized in that, In step (3), the mass ratio of CA@MOF to PEG-citric acid is 1:(2~5).

5. A catalyst for the combustion of reconstituted tobacco, characterized in that, It is prepared by the preparation method according to any one of claims 1-4.

6. A method for preparing low-tar reconstituted tobacco, characterized in that, Includes the following steps: (1) Papermaking method for reconstituted tobacco production: Tobacco leaves and tobacco stems are mixed to prepare a mixed raw material. Water is added to the mixed raw material for extraction, and solid-liquid separation is performed to obtain residue and extract. Repeat the above steps, combine the residues, and control the freeness of the pulp to 20±2°SR through pulping; The extracts were combined and concentrated to a density of 1.180 ± 0.005 g / cm³. 3 Tobacco concentrate; (2) Weigh 4% wood pulp fiber and 3% cationic nanocellulose by mass, and control the freeness of the pulp to 50±2°SR by pulping. After mixing with tobacco pulp, adjust the pulp concentration to 0.5%; Adding 10-15% (by weight) of spindle-shaped calcium carbonate and 0.5% of functional additives, the basis weight of the paper produced using a standard paper forming machine is 60±2 g / m³. 2 Reconstituted tobacco substrate; (3) The CA@MOF@PEG-citric acid prepared by any of the preparation methods described in claims 1-4 is added to the tobacco concentrate at a mass ratio of 3%. The reconstituted tobacco substrate is coated by dip coating, and the tobacco concentrate is coated onto the substrate. The coating rate is controlled to be 15%-25%. Then, the reconstituted tobacco is dried, and the moisture content is adjusted to 11.7%. The substrate is then sent to a shredder for shredding. (4) After drying, the flavoring dissolved in ethanol is applied to the filamentous reconstituted tobacco leaves in the form of spray, that is, low tar reconstituted tobacco leaves.

7. The method for preparing low-tar reconstituted tobacco according to claim 6, characterized in that, In step (1), the mass ratio of tobacco leaves to tobacco stems is 7:3, and the mass ratio of mixed raw materials to water is 1:7; the extraction conditions are: extraction at 60℃ for 40 min.

8. The method for preparing low-tar reconstituted tobacco leaves according to claim 6, characterized in that, In step (2), the D50 of the spindle-shaped calcium carbonate is 1.5-2.5µm; the functional additives include cationic guar gum and nonionic guar gum, with a mass ratio of 1:

1.

9. The method for preparing low-tar reconstituted tobacco according to claim 6, characterized in that, In step (3), the width of the shredded tobacco is controlled to be 0.9±0.1mm; in step (4), the flavoring is menthol, and the total amount added is 1.0~2.0% of the total amount of tobacco.

10. The application of low-tar reconstituted tobacco leaves prepared by any one of claims 6-9 in cigarettes.

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