Preparation method and application of low-tar reconstituted tobacco

Abstract

The invention discloses a preparation method and application of low-tar reconstituted tobacco, a catalyst in the preparation method of the low-tar reconstituted tobacco is CA (at) MOF (at) PEG-citric acid, and the preparation method of the catalyst comprises synthesis of MOF-Al, preparation of a combustion catalyst and formation of the CA (at) MOF (at) PEG-citric acid. The preparation method of the low-tar reconstituted tobacco comprises the steps of mixed extraction of tobacco leaves and tobacco stems, pulping, addition of auxiliaries, paper making of substrates, coating, drying, perfuming and the like. And a flavoring link is added after drying, so that the sensory quality is improved. Physical performance detection and smoke index detection results show that the prepared reconstituted tobacco has good physical performance and remarkably reduced tar release amount, the tar release amount reduction amplitude exceeds 39.69%, and a new way is provided for research and development of low-tar cigarettes.

Description

Technical Field

[0001] The invention relates to the technical field of tobacco processing, and in particular to a method for preparing low-tar reconstituted tobacco leaves and applications thereof. Background Art

[0002] As an important component of cigarette formula, reconstituted tobacco can save production costs, reduce tar release, adjust combustion performance and improve smoking quality. With the development of industry technology and the increasing health needs of consumers, the demand for low-tar cigarette products is growing. Correspondingly, the proportion of reconstituted tobacco, the main raw material for reducing tar, in cigarette formulas is gradually increasing. It is required that reconstituted tobacco should not have a negative impact on the sensory quality of cigarettes and have stable quality under the premise of low tar release.

[0003] Therefore, how to ensure that the tar release of reconstituted tobacco leaves is reduced without changing the taste of the reconstituted tobacco leaves has become an important problem that needs to be solved urgently in this field. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing low-tar reconstituted tobacco leaves and its application. Based on the basic principle of catalytic combustion, a water-soluble combustion catalyst CA@MOF@PEG-citric acid is designed and prepared, and a low-tar sheet is developed by adding a combustion catalyst, modifying cellulose, reducing the coating rate, etc. Under the premise of basically not changing the smoking taste, the tar release of a single gram of reconstituted tobacco leaves is reduced by more than 39.69%.

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

[0006] A method for preparing a reconstituted tobacco combustion catalyst comprises the following steps:

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

[0008] MOF-Al was 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°C for 24h;

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

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

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

[0012] A certain amount of CA@MOF was weighed and added into citric acid functionalized polyethylene glycol (PEG) in batches under stirring to form a CA@MOF@PEG-citric acid homogeneous 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; in the mixed solution of water and DMF, the volume ratio of the two 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 reconstituted tobacco leaf combustion catalyst is prepared according to the above preparation method.

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

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

[0019] The 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 a residue and an extract;

[0020] Repeat the above steps, combine the residues, and make pulp to control the beating degree of the pulp to (20±2°)SR;

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

[0022] (2) Weighing 4% by weight of wood pulp fiber and 3% by weight of cationic nanocellulose, and pulping the pulp to control the beating degree of the pulp to (50±2°)SR;

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

[0024] Add 10-15% spindle-shaped calcium carbonate (D50 is 1.5-2.5μm) and 0.5% functional additives (cationic guar gum: non-ionic guar gum = 1:1) in a mass ratio, and use a standard paper former to make a paper with a basis weight of 60±2g / m 2 of reconstituted tobacco leaf 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%, and the tobacco concentrate is coated on the reconstituted tobacco leaf substrate by dipping, and the coating rate is controlled to be 15%-25%, and then the reconstituted tobacco leaf is dried and the moisture content is adjusted to 11.7%, and then sent to a shredder for shredding;

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

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

[0028] Preferably, in the above technical solution, in step (2), the D50 of the spindle-shaped calcium carbonate is 1.5-2.5 μm; and the functional additive comprises cationic guar gum and non-ionic guar gum, and the mass ratio of the two is 1:1.

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

[0030] The invention discloses an application of low-tar reconstituted tobacco in cigarettes.

[0031] The above 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, reduces the amount of tar and harmful components generated, and causes more oxidation reactions of the compounds in the tobacco, thereby increasing the content of aroma substances and making the smoke more delicate and soft.

[0034] (3) On the one hand, it avoids the loss of spices caused by high-temperature drying after the spices are applied, reduces the amount of spices used, and reduces production costs; on the other hand, the spice formula design can be flexibly adjusted according to needs, thereby producing special 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 DESCRIPTION

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

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

[0037] Example 1

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

[0039] MOF-Al was 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°C for 24 hours. The molar ratio of Al(NO3)3·9H2O and NH2-BDC / BDC / NO2-BDC was 1:1.5; the volume ratio of the two in the mixed solution of water and DMF was (0-1):3.

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

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

[0042] Prepare a certain concentration of ferric sulfate solution, add a certain weight of MOF-Al in a certain proportion, soak and stir for 2 hours, add a precipitant potassium hydroxide solution dropwise, adjust the pH of the mixed solution to about 12, continue stirring and reacting for 1 hour, wash the resulting precipitate repeatedly with water until no new precipitate is produced when 0.1M BaCl2 solution is added to the filtrate, and dry the precipitate at 120°C to obtain a recycled tobacco leaf combustion catalyst (CA@MOF). Among them, the concentration of ferric sulfate is: 1.0~1.5mol / L; the mass ratio of ferric sulfate and MOF-Al is (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 to citric acid functionalized polyethylene glycol (PEG) in batches under stirring. The citric acid group has a high binding affinity to the metal oxide surface and can form a self-assembled monolayer on these surfaces to form CA@MOF@PEG-citric acid, which can be evenly dispersed in water. Among them, the mass ratio of CA@MOF and PEG-citric acid is: 1: (2-5).

[0045] Reconstituted tobacco preparation

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

[0047] Tobacco leaves and tobacco stems were mixed in a mass ratio of 7:3 to prepare a mixed raw material (absolute dry mass 1000 kg), 7 times the mass of water of the mixture was added, and extraction was performed at a temperature of 60°C for 40 minutes, and solid-liquid separation was performed to obtain a residue and an extract.

[0048] Repeat the above steps, combine the residues, and control the pulping degree of the pulp to (20±2°)SR by pulping. Combine the extracts and concentrate to a density of (1.180±0.005)g / cm 3 Tobacco concentrate.

[0049] (2) Weigh 4% wood pulp fiber (40 kg) and 3% cationic nanocellulose (30 kg) by weight, and control the pulping degree of the pulp to (50±2°)SR by pulping. After mixing with tobacco pulp, adjust the pulp concentration to 0.5%, add 15% spindle-shaped calcium carbonate (particle size of 2-4 μm) by weight, and 0.5% functional additives (cationic guar gum: non-ionic guar gum = 1:1), and use a standard paper former to make a paper with a basis weight of 60±2 g / m 2 of reconstituted tobacco leaf substrate.

[0050] (3) CA@MOF@PEG-citric acid was added to the tobacco concentrate at a mass ratio of 3%. The tobacco concentrate was coated on the reconstituted tobacco leaf substrate by dipping, and the coating rate was controlled to be 15%. The reconstituted tobacco leaf was then dried and the moisture content was adjusted to 11.7%, and then sent to a shredder for shredding, and the shredding width was controlled to be 0.9±0.1 mm.

[0051] (4) Due to the high temperature during the drying process, a large amount of volatile aroma components are lost, resulting in a decrease in the sensory quality of reconstituted tobacco leaves. To compensate for this defect, a flavoring step is added after the drying process for filamentary reconstituted tobacco leaves. 1.5 g of menthol is weighed and dissolved in ethanol, and then applied to the filamentary 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, so as to produce special 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 between the embodiment 1 and the embodiment 1 is that the coating rate is controlled to 20%, and the usage amount of menthol is reduced to 1.0 g / kg of tobacco.

[0055] Example 3

[0056] The difference between the embodiment 1 and the embodiment 1 is that the coating rate is controlled to be 25%, and menthol is replaced by clove oil.

[0057] Comparative Example 1

[0058] The difference from Example 1 is that 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 filamentary reconstituted tobacco leaf flavoring step.

[0059] Physical properties test of reconstituted tobacco leaves:

[0060] Table 1 Test results of physical and chemical indexes of papermaking reconstituted tobacco

[0061]

[0062] As can be seen from Table 1, after replacing wood fiber with cationic nanocellulose, the tensile index, bulk and filling value of the reconstituted tobacco leaves are significantly improved. This is because the cationic nanofibers are positively charged, while the entire pulping system is a negatively charged system. The cationic nanofibers are easily adsorbed with the pulp fibers, increasing the number of hydrogen bonds between the fibers while maintaining a certain porosity between the fibers, which also has a certain positive effect on the bulk of the tobacco substrate.

[0063] Routine smoke index testing of reconstituted tobacco leaves:

[0064] The obtained filamentous reconstituted tobacco leaves were used as tobacco shreds, and the auxiliary materials for a certain brand of slim cigarettes (cigarette paper, tipping paper, mouthpiece) were used to roll and package on the pilot production line of cigarettes to obtain the test verification samples. According to GB / T 19609-2004 and GB / T23355-2009, the conventional smoke components of the cigarettes were tested (cigarette length 97mm, burning end line 40mm, burning tobacco length 57mm, unburned tobacco length 10mm, cigarette weight about 0.54g, material weight about 0.16g).

[0065] Table 2 Results of conventional smoke testing of papermaking reconstituted tobacco leaves

[0066]

[0067] As can be seen from Table 2, compared with the comparative example, the tar release of Examples 1-3 is significantly reduced, and the tar release of a single gram of reconstituted tobacco leaf is reduced by more than 39.69%. On the one hand, this is because the use of CA@MOF@PEG-citric acid combustion catalyst has changed the combustion state of the reconstituted tobacco leaves; on the other hand, the reduction in coating rate has reduced the organic macromolecular weight such as polysaccharides in the reconstituted tobacco leaves, which has led to a reduction in the amount of tar generated when the reconstituted tobacco is burned.

[0068] Sensory evaluation of filamentous reconstituted tobacco leaves:

[0069] The filamentous reconstituted tobacco leaves prepared above were rolled into cigarettes. The sample cigarettes were subjected to sensory evaluation according to the industry standard YC / T 498 "Sensory Evaluation Method for Reconstituted Tobacco Leaves (Papermaking Method)" and "Sensory Quality Evaluation Method for Henan China Tobacco Reconstituted Tobacco Leaves". 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, when the filamentous reconstituted tobacco leaves prepared by the present invention are used in cigarettes, the aroma quality and aroma quantity of the cigarettes are improved, and the smoke fineness, impurities, stimulation, aftertaste and comfort in the oral cavity are all improved, which makes up for the aroma loss caused by reducing the coating rate, and has good application prospects.

[0074] Finished cigarette effect verification:

[0075] To further verify the tar-reducing effect of low-tar flakes, 16% of the flakes were added to a certain brand of slim cigarette shreds. The auxiliary materials (cigarette paper, tipping paper, and mouthpiece) of this brand were used to roll and package the cigarettes on a pilot production line to obtain test 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 conventional cigarette smoke test

[0077]

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

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

Claims

1. A method for preparing a reconstituted tobacco combustion catalyst, characterized in that: The following steps are involved: (1) Synthesis of MOF-Al: Aluminum nitrate nonahydrate (Al(NO3)3·9H2O) and aminoterephthalic acid (NH2-BDC) / terephthalic acid (BDC) / 2-nitroterephthalic acid (NO2-BDC) were dissolved in a mixed solution of water and DMF, stirred for reaction for 30 minutes, transferred into a polytetrafluoroethylene reactor, heated at 150°C for 24 hours, filtered, and the precipitate was washed alternately with methanol and DMF for 4 times, and dried in vacuum at 100°C to obtain MOF-Al; (2) Preparation of combustion catalyst (CA@MOF): A certain concentration of ferric sulfate / ferric chloride / ferric nitrate solution was prepared, and a certain weight of MOF-Al was added in a certain proportion. After immersion and stirring for 2 hours, a precipitant potassium bicarbonate solution was added dropwise, and the pH of the mixed solution was adjusted to 12. The mixture was stirred for 1 hour, and then transferred to a polytetrafluoroethylene reactor, heated at 150°C for 4 hours, and the obtained precipitate was repeatedly washed with water, and the precipitate was dried at 120°C to obtain CA@MOF. (3) Preparation of CA@MOF@PEG-citric acid: A certain amount of CA@MOF was weighed and added into citric acid functionalized polyethylene glycol (PEG) in batches under stirring to form a CA@MOF@PEG-citric acid homogeneous solution.

2. The method for preparing a reconstituted tobacco combustion catalyst according to claim 1, characterized in that: In step (1), the molar ratio of Al(NO3)3·9H2O and NH2-BDC / BDC / NO2-BDC is 1:1.5; in the mixed solution of water and DMF, the volume ratio of the two is (0-1):

3.

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

1.

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

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

6. A method for preparing low-tar reconstituted tobacco, characterized in that: The following steps are involved: (1) Papermaking process for reconstituted tobacco production: The 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 a residue and an extract; Repeat the above steps, combine the residues, and control the beating degree of the slurry to 20±2°SR by slurrying; The extracts were combined and concentrated to a density of 1.180 ± 0.005 g / cm 3 Tobacco concentrate; (2) weighing 4% by weight of wood pulp fiber and 3% by weight of cationic nanocellulose, and controlling the beating degree of the pulp to 50±2°SR by pulping; After mixing with tobacco slurry, adjust the slurry concentration to 0.5%; Add 10-15% spindle-shaped calcium carbonate and 0.5% functional additives by mass ratio, and use a standard paper former to make a paper with a basis weight of 60±2g / m 2 of reconstituted tobacco leaf 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%, and the tobacco concentrate is coated on the reconstituted tobacco leaf substrate by dipping, and the coating rate is controlled to be 15%-25%, and then the reconstituted tobacco leaf is dried and the moisture content is adjusted to 11.7%, and then sent to a shredder for shredding; (4) After drying, the flavoring agent dissolved in ethanol is applied to the filamentous reconstituted tobacco leaves, i.e., low-tar reconstituted tobacco leaves, in the form of a spray.

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 the mixed raw material to water is 1:7; and the extraction conditions are: extraction at 60° C. for 40 minutes.

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

1.

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

10. Use of the low-tar reconstituted tobacco prepared by the preparation method according to any one of claims 6 to 9 in cigarettes.

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