Method and application for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke, and cigarette

Abstract

The present invention discloses a method and application for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke, as well as a cigarette, which relates to the technical field of harm reduction in tobacco processing. The method includes: preparing a lipase solution; uniformly spraying the lipase solution on both the front and back sides of the tobacco leaves to be treated; subjecting the tobacco leaves sprayed with the lipase solution to constant temperature and humidity treatment, and the content of polycyclic aromatic hydrocarbons in the tobacco leaves after lipase treatment is reduced; cutting the tobacco leaves treated with lipase into shreds, and inactivating the lipase in the shredded tobacco leaves treated with lipase; rolling the inactivated shredded tobacco into cigarette sticks, and the content of polycyclic aromatic hydrocarbons in the smoke after combustion is reduced. The method is applicable to low-grade flue-cured tobacco or cut tobacco after threshing and redrying. The cigarette includes shredded tobacco obtained by lipase treatment. The method of the present invention is simple and easy to operate. After treatment with lipase preparation, it can specifically reduce the content of PAHs in tobacco leaves and cigarette smoke, especially the content of fluoranthene, and can significantly improve the safety of tobacco with a high fluoranthene content.

Description

Technical Field

[0001] The present invention relates to the technical field of tobacco processing and harm reduction, and particularly relates to a method and application for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke, as well as a cigarette. Background Art

[0002] Polycyclic aromatic hydrocarbons (PAHs) are aromatic compounds containing at least two benzene rings, and have attracted much attention due to their "carcinogenic, teratogenic and mutagenic" effects. Incomplete combustion of carbon-containing fuels such as wood and coal and petroleum refining are important processes for PAHs release. The released PAHs can enter the soil directly or indirectly through atmospheric deposition, sewage irrigation, etc., and the soil is their main reservoir. Tobacco is widely grown in more than 100 countries, and PAHs in the soil can be directly or indirectly absorbed and accumulated by tobacco plants. From fresh tobacco leaves to cigarette products, multiple processing steps are required, and the safety of tobacco leaves directly affects the safety of tobacco products.

[0003] Ohnishi et al. in Japan detected the fluoranthene content in burley tobacco to be 1.4 μg / kg. Ma Jun et al. analyzed the pollution situation of 16 PAHs in fresh tobacco leaves at the mature stage in 6 tobacco-growing areas of Songtao County, Guizhou Province, and found that the total amount of 16 PAHs in the tobacco leaf samples was 502.79 μg / kg - 2217.15 μg / kg, with an average value of 1011.23 μg / kg. The average contents of benzo[a]pyrene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]anthracene were 404.07 μg / kg, 47.34 μg / kg, 103.05 μg / kg, 78.64 μg / kg, and 23.83 μg / kg respectively. The factors affecting the pollution level and distribution of PAHs, in addition to the properties of PAHs themselves, also depend on the characteristics of the soil itself, the type of plants, and the planting location. CN 109222202 A discloses a method for preparing low-polycyclic aromatic hydrocarbon tobacco sheets by a biological method, using Bacillus thuringiensis in the processes of tobacco product extraction, extraction liquid fermentation, and tobacco sheet base material fermentation in the preparation process of tobacco sheets, to reduce the contents of naphthalene, fluorene, and phenanthrene in the smoke of tobacco sheets. CN 109222202 A only targets tobacco sheet products and is added in multiple technological processes, which is relatively cumbersome. In other studies, there are few methods for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method that is simple and easy to operate, applicable to most tobacco products, and can simultaneously reduce the content of PAHs in tobacco leaves and cigarette smoke, so as to improve the safety of tobacco products.

[0005] To this end, in the first aspect of the present invention, a method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke is provided, including:

[0006] Prepare a lipase solution;

[0007] Spray the lipase solution evenly on both the front and back sides of the tobacco leaves to be treated;

[0008] Subject the tobacco leaves sprayed with the lipase solution to a constant temperature and humidity treatment to obtain lipase-treated tobacco leaves, and the content of polycyclic aromatic hydrocarbons in the lipase-treated tobacco leaves is reduced;

[0009] Cut the lipase-treated tobacco leaves into shreds to obtain lipase-treated tobacco shreds;

[0010] Inactivate the lipase in the lipase-treated tobacco shreds to obtain inactivated tobacco shreds;

[0011] Roll the inactivated tobacco shreds into cigarettes, and the content of polycyclic aromatic hydrocarbons in the smoke after combustion is reduced.

[0012] In a feasible implementation manner, for the lipase solution, the volume concentration of the lipase stock solution is 3‰ - 8‰, and the enzyme activity of the lipase stock solution is not less than 6000 U / mL.

[0013] In a feasible implementation manner, for the lipase solution, the volume concentration of the lipase stock solution is 5‰.

[0014] In a feasible implementation manner, the step of spraying the lipase solution evenly on both the front and back sides of the tobacco leaves to be treated includes: the dosage of the lipase solution accounts for 0.05% - 0.25% of the mass of the tobacco leaves to be treated.

[0015] In a feasible implementation manner, the step of spraying the lipase solution evenly on both the front and back sides of the tobacco leaves to be treated includes: the dosage of the lipase solution accounts for 0.15% of the mass of the tobacco leaves.

[0016] In a feasible implementation manner, for the constant temperature and humidity treatment, the temperature is 45 ± 2°C, the humidity is 70% - 80%, and the treatment time is 45 h - 50 h.

[0017] In a feasible implementation manner, for the lipase inactivation, the temperature is 125 ± 2°C, and stir-fry for 10 s - 15 s.

[0018] After being treated with lipase, the content of fluoranthene in the lipase-treated tobacco leaves is reduced by more than 90%, and the total amount of 5 polycyclic aromatic hydrocarbons including anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene and benzo[a]pyrene in the lipase-treated tobacco leaves is reduced by more than 30%; the content of fluoranthene in the smoke after combustion of the cigarette is reduced by more than 35%, and the total amount of 5 PAHs including anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene and benzo[a]pyrene in the smoke after combustion of the cigarette is reduced by more than 15%.

[0019] In a second aspect of the present invention, there is provided an application of the above method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke, wherein the method is applicable to low-grade flue-cured tobacco, and is used to reduce polycyclic aromatic hydrocarbons in low-grade flue-cured tobacco and cigarette smoke. It is particularly applicable to cut tobacco after threshing and redrying, and is used to reduce polycyclic aromatic hydrocarbons in cut tobacco and cigarette smoke after threshing and redrying.

[0020] In a third aspect of the present invention, there is provided a cigarette, comprising tobacco shreds and cigarette paper; wherein, the tobacco shreds comprise the inactivated tobacco shreds obtained by the above method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] The method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke provided by the present invention is simple and easy to operate. After treatment with lipase preparation, the substances in tobacco leaves change, affecting the combustion characteristics of tobacco leaves and the composition and content of PAHs in cigarette smoke. It can specifically reduce the content of PAHs in tobacco leaves and cigarette smoke, especially the content of fluoranthene, and can significantly improve the safety of tobacco with high fluoranthene content. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a result diagram of the addition ratio of the best sensory evaluation effect after different enzyme dilutions.

[0024] Figure 2 It is a heat map of the content change of 5 PAHs in tobacco leaves after different enzyme treatments.

[0025] Figure 3 It is a heat map of the content change of 5 PAHs in cigarette smoke after different enzyme treatments.

[0026] Figure 4 It is a box plot of the total amount change of 5 PAHs in tobacco leaves after different enzyme treatments.

[0027] Figure 5 It is a box plot of the total amount change of 5 PAHs in cigarette smoke after different enzyme treatments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to better understand the above technical solutions, the technical solutions of the present invention will be described in detail below through specific embodiments.

[0029] In a first aspect of the embodiments of the present invention, there is provided a method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke, comprising:

[0030] (1) Prepare a lipase solution;

[0031] (2) Uniformly spray the lipase solution on both the front and back sides of the tobacco leaves to be treated;

[0032] (3) Subject the tobacco leaves sprayed with the lipase solution to constant temperature and humidity treatment to obtain the tobacco leaves after lipase treatment, and the content of polycyclic aromatic hydrocarbons in the tobacco leaves after lipase treatment is reduced;

[0033] (4) Cut the tobacco leaves after lipase treatment into shreds to obtain the shredded tobacco after lipase treatment;

[0034] (5) Inactivate the lipase in the shredded tobacco after lipase treatment to obtain the inactivated shredded tobacco;

[0035] (6) Roll the inactivated shredded tobacco into cigarettes, and the content of polycyclic aromatic hydrocarbons in the smoke after burning is reduced.

[0036] It can be understood that PAHs have characteristics such as lipophilicity and hydrophobicity, are stable in nature, highly toxic and difficult to degrade, are widely present in tobacco and smoke, and are harmful to human health. Differences in tobacco plant varieties and planting locations will lead to differences in the content of PAHs in tobacco plants.

[0037] The embodiment of the present invention provides a method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and smoke. After treatment with lipase preparations, the substances in the tobacco leaves change, affecting the combustion characteristics of the tobacco leaves and the composition and content of PAHs in the smoke. It is a highly targeted enzyme preparation harm reduction method, simple and easy to operate, can specifically reduce the content of PAHs in tobacco leaves and smoke, especially the content of fluoranthene, can significantly improve the safety of tobacco with high fluoranthene content, and has good application prospects in the field of tobacco harm reduction.

[0038] In some embodiments, the lipase solution is prepared by diluting the lipase stock solution with distilled water. The volume concentration of the lipase stock solution is 3‰ - 8‰, and the enzyme activity of the lipase stock solution is not less than 6000 U / mL; further preferably, the volume concentration of the lipase stock solution is 5‰, and the enzyme activity of the lipase stock solution is not less than 6000 U / mL.

[0039] In some embodiments, the lipase solution is evenly sprayed on both the front and back sides of the tobacco leaves to be treated, and the proportion of the amount of the lipase solution used to the mass of the tobacco leaves to be treated is controlled at 0.05% - 0.25%; preferably, the proportion of the amount of the lipase solution used to the mass of the tobacco leaves to be treated is 0.15%.

[0040] Specifically, in order to ensure the sensory evaluation effect of the tobacco leaves after lipase treatment, experiments investigated different addition ratios of lipase (0.05% - 0.25%), and it was found that when the proportion of the amount of the lipase solution used to the mass of the tobacco leaves to be treated was 0.15%, the best sensory evaluation effect was obtained.

[0041] In some embodiments, the constant temperature and humidity treatment is carried out at a temperature of 45 ± 2 °C, a humidity of 70% - 80%, and a time of 45 h - 50 h. Preferably, the temperature is 45 °C, the humidity is 75%, and the time is 48 h.

[0042] Specifically, the tobacco leaves sprayed with lipase solution are placed in a thermostatic and humidostatic chamber, with the temperature controlled at 45 ± 2°C, the humidity at 70% - 80%, and the reaction time at 45 h - 50 h, so that the lipase can fully act on the tobacco leaves.

[0043] In some embodiments, the lipase is inactivated at a temperature of 125 ± 2°C and stir-fried for 10 s - 15 s.

[0044] In some embodiments, the inactivated cut tobacco is rolled into cigarettes, and the weight of the cigarettes is between 0.850 g and 0.900 g, preferably 0.875 g.

[0045] In summary, after treatment with lipase, the content of fluoranthene in the tobacco leaves treated with lipase is reduced by more than 90%, and the total amount of 5 polycyclic aromatic hydrocarbons, namely anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene, in the tobacco leaves treated with lipase is reduced by more than 30%; the inactivated cut tobacco is rolled into cigarettes, and the content of fluoranthene in the mainstream smoke of the cigarettes after burning is reduced by more than 35%, and the total amount of 5 PAHs, namely anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene, in the mainstream smoke of the cigarettes after burning is reduced by more than 15%.

[0046] In the second aspect of the embodiments of the present invention, there is provided an application of the method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke. The method is applicable to low-grade flue-cured tobacco, and is used to reduce polycyclic aromatic hydrocarbons in low-grade flue-cured tobacco and the mainstream smoke of low-grade flue-cured tobacco cigarettes after burning, especially to reduce the content of fluoranthene in low-grade flue-cured tobacco and the mainstream smoke of low-grade flue-cured tobacco cigarettes after burning; it is particularly applicable to threshed and redried tobacco leaves, and is used to reduce polycyclic aromatic hydrocarbons in threshed and redried tobacco leaves and the mainstream smoke of threshed and redried tobacco leaf cigarettes after burning, especially to reduce the content of fluoranthene in threshed and redried tobacco leaves and the mainstream smoke of threshed and redried tobacco leaf cigarettes after burning.

[0047] In the third aspect of the embodiments of the present invention, there is provided a cigarette, which includes cut tobacco and cigarette paper; wherein, the cut tobacco includes the inactivated cut tobacco obtained by using the method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke as described above.

[0048] The method for collecting the cigarette smoke used in the following examples and comparative examples is as follows:

[0049] Twenty cigarettes (each type) that meet the requirements of weight and draw resistance and Cambridge filter pads are placed in an environment with a relative humidity of 60 ± 2% and a temperature of 22 ± 1°C and equilibrated for 48 h, and then suction is carried out with a rotary smoking machine according to the method of national standard GB / T19609 - 2004. The suction parameters are the parameters in ISO mode: the suction volume is 35 mL, the duration is 2 s, the suction interval is 60 s, and the mainstream smoke particulate matter of 20 cigarettes is trapped with 92 mm Cambridge filter pads.

[0050] The determination method of PAHs used in the following examples and comparative examples is as follows:

[0051] Take tobacco leaf or cigarette filter sample, add n-hexane, and ultrasonically extract for 30 min. After centrifugation (2280 g, 15 min), aspirate the n-hexane layer, add 10 mL of n-hexane and repeat the extraction once. Mix the n-hexane extracts from the two extractions, add them to a rotary evaporation flask and evaporate to dryness. Add 5 mL of n-hexane to redissolve. Activate a Florisil solid-phase extraction column with 5 mL of dichloromethane and 10 mL of n-hexane in sequence. Transfer all the 5 mL of n-hexane-redissolved extraction sample solution into the Florisil solid-phase extraction column, then wash the rotary evaporation flask with 5 mL of n-hexane, and incorporate the washing solution into the column. Elute with 8 mL of a n-hexane-dichloromethane mixed solvent (1:1), collect all the effluents in a 20 mL glass centrifuge tube, and blow dry with nitrogen. Dilute to 1 mL with acetonitrile, mix well, and pass through a 0.22 μm organic phase microporous filter membrane to prepare the test solution. Take the test solution in an injection vial and determine the contents of anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene.

[0052] Detect and analyze PAHs in tobacco leaf samples by an Agilent 1260 Infinity-FLD liquid chromatograph. Use a Waters PAH C18 column (4.6 mm × 250 mm, 5 µm). Mobile phase A is water, and mobile phase B is acetonitrile. The elution gradient is as follows: 0 - 9 min, 60% B; 9 - 12 min, 60% - 100% B; 12 - 28 min, 100% B; 28 - 32 min, 100% - 60% B; 32 - 35 min, 60% B. The column temperature is 35 °C, the flow rate is 1.2 mL / min. The injection volume is 10 µL. 0.0 - 12.5 min, excitation wavelength 279 nm, emission wavelength 340 nm; 12.5 - 13.65 min, excitation wavelength 248 nm, emission wavelength 375 nm; 13.65 - 15.50 min, excitation wavelength 280 nm, emission wavelength 462 nm; 15.50 - 17.50 min, excitation wavelength 270 nm, emission wavelength 385 nm; 17.50 - 18.50 min, excitation wavelength 270 nm, emission wavelength 446 nm; 18.50 - 25.70 min, excitation wavelength 292 nm, emission wavelength 410 nm; 25.70 - 35.00 min, excitation wavelength 305 nm, emission wavelength 480 nm.

[0053] Example 1 Determine the addition ratio of lipase-treated tobacco leaves using the sensory evaluation effect and the contents of polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke after treatment with the optimal sensory addition ratio of lipase

[0054] (I) Treatment method

[0055] Method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke by lipase treatment, comprising the following steps:

[0056] (1) Preparation of lipase solution: Using distilled water, prepare a lipase solution with a volume concentration of 0.5‰ from the lipase stock solution, and the nominal activity of the lipase stock solution is 6000 U / mL;

[0057] (2) Spraying tobacco leaves: Select Chongqing B4F tobacco leaves in 2020, and use an electronic sprayer to evenly spray the prepared lipase solution on both the front and back sides of the tobacco leaves. Set 5 enzyme addition gradients (the proportion of the amount of lipase solution to the mass of tobacco leaves), which are 0.1000%, 0.1500%, 0.2000%, 0.2500% and 0.3000% respectively;

[0058] (3) Treatment of tobacco leaves: Place the tobacco leaves sprayed with lipase in a constant temperature and humidity box at a temperature of 45°C and a humidity of 75% for 48 h;

[0059] (4) Cutting tobacco leaves into shreds: After the treatment reaction of the tobacco leaves is completed, use a laboratory small-scale tobacco leaf cutter to cut the lipase-treated tobacco leaves into cigarette shreds;

[0060] (5) Inactivation of lipase: The cigarette shreds are instantaneously stir-fried at 125°C for 15 s at high temperature to inactivate the enzyme for production use;

[0061] (6) Hand-rolling cigarettes: Use a hand-held cigarette rolling machine to roll the inactivated cigarette shreds into cigarettes with a weight of 0.875 g per stick.

[0062] Preparation of control sample cigarettes: The prepared lipase solution with a volume concentration of 0.5‰ is inactivated by heating in a water bath at 100°C for 8 min, and then the same tobacco leaf spraying, tobacco leaf treatment, tobacco leaf cutting and hand-rolling cigarettes as the lipase-treated cigarettes are carried out.

[0063] (II) Testing

[0064] Place the cigarettes meeting the requirements of weight and draw resistance in an environment with a relative humidity of 60±2% and a temperature of 22±1°C for 48 h of equilibration, and then conduct two rounds of sensory evaluations by professional cigarette graders, with 7 professional cigarette graders in each round. Conduct a comprehensive evaluation of indicators such as aftertaste, irritation, concentration, aroma, and off-flavors to screen the addition amount of lipase with obvious quality improvement. Sensory evaluation is the basis for ensuring the quality of tobacco leaves. As can be seen from Figure 1 it, for lipase-treated tobacco leaves, the optimal sensory addition ratio of lipase is 0.1500% (the proportion of the amount of lipase solution to the mass of tobacco leaves).

[0065] Select cigarettes with a lipase addition ratio of 0.1500%, aspirate them using a smoking machine, and collect the mainstream smoke particulate matter of 20 cigarettes. Determine the contents of 5 PAHs, namely anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene, in the tobacco leaves and the smoke after combustion. The results of the PAH contents and the total amounts in the tobacco leaves are as Figure 2 , Figure 4 , and the results of the PAH contents and the total amounts in the smoke are as Figure 3 , Figure 5 . After treatment with lipase, the fluoranthene content in the tobacco leaves decreased by 94.90%, and the total amount of 5 PAHs decreased by 34.51%; the fluoranthene content in the smoke decreased by 38.82%, and the total amount of 5 PAHs decreased by 16.33%.

[0066] Control Example 1 Use the sensory evaluation effect to determine the addition ratio of pectinase-treated tobacco leaves and the contents of polycyclic aromatic hydrocarbons in the tobacco leaves and smoke after treatment with the optimal sensory addition ratio of pectinase

[0067] (I) Treatment method

[0068] A method for reducing polycyclic aromatic hydrocarbons in both tobacco leaves and smoke by treating with pectinase includes the following steps:

[0069] (1) Preparation of enzyme solution: Prepare a pectinase solution with a volume concentration of 0.5‰ using distilled water, and the nominal activity of the pectinase stock solution is 6000 U / mL;

[0070] (2) Spraying on tobacco leaves: Uniformly spray the above pectinase solution on both sides of the tobacco leaves (Chongqing B4F tobacco leaves in 2020), and set 5 enzyme addition gradients (the dosage of the pectinase solution accounts for the mass ratio of the tobacco leaves), which are 0.1000%, 0.1500%, 0.2000%, 0.2500%, and 0.3000% respectively;

[0071] (3) Treatment of tobacco leaves: Place the tobacco leaves sprayed with pectinase in a constant temperature and humidity box at a temperature of 45°C and a humidity of 75% for 48 h;

[0072] (4) Cutting the tobacco leaves; Cut the tobacco leaves after the treatment reaction;

[0073] (5) Inactivation of pectinase: Instantaneously inactivate the enzyme activity of the cut tobacco leaves by continuously stir-frying at 125°C for 15 s for production use;

[0074] (6) Hand-rolling cigarettes: Use a hand cigarette rolling machine to roll the inactivated cut tobacco leaves into cigarettes with a weight of 0.875 g per stick.

[0075] Production of control sample cigarettes: Carry out inactivation treatment on the prepared pectinase solution with a volume concentration of 0.5‰ by heating in a water bath at 100°C for 8 min, and then carry out the same tobacco leaf spraying, tobacco leaf treatment, tobacco leaf cutting, and hand-rolling of cigarettes as the pectinase-treated cigarettes.

[0076] (2) Testing

[0077] Place the cigarettes that meet the weight and draw resistance requirements in an environment with a relative humidity of 60±2% and a temperature of 22±1°C for 48 hours of equilibration. Then, conduct two rounds of sensory evaluations by professional smokers, with 7 professional smokers in each round. Conduct a comprehensive evaluation of indicators such as aftertaste, irritation, concentration, aroma, and off-flavors to screen for the addition amount of pectinase that significantly improves the quality. Sensory evaluation is the basis for ensuring the quality of tobacco leaves. As can be seen from Figure 1 it can be seen that when treating tobacco leaves with pectinase, the optimal sensory addition ratio of pectinase is 0.2000% (the ratio of the amount of pectinase solution to the mass of tobacco leaves).

[0078] Select cigarettes with a pectinase addition ratio of 0.2000%, use a smoking machine to draw, and capture the mainstream smoke particulate matter of 20 cigarettes. Determine the contents of 5 PAHs, namely anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene, in the tobacco leaves and the smoke after combustion. The results of the PAH contents and total amounts in the tobacco leaves are as shown in Figure 2 and Figure 4 , and the results of the PAH contents and total amounts in the smoke are as shown in Figure 3 and Figure 5 . After treatment with pectinase, the fluoranthene in the tobacco leaves decreases, the total amount of PAHs in the tobacco leaves decreases, the fluoranthene in the smoke has no significant change, and the total amount of PAHs in the smoke increases.

[0079] Comparative Example 2: Determine the addition ratio of amylase for treating tobacco leaves using the sensory evaluation effect and the contents of polycyclic aromatic hydrocarbons in the tobacco leaves and smoke after treatment with the optimal sensory addition ratio of amylase

[0080] (1) Treatment method

[0081] A method for reducing polycyclic aromatic hydrocarbons in both tobacco leaves and smoke by treating with amylase includes the following steps:

[0082] (1) Preparation of enzyme solution: Prepare an amylase solution with a volume concentration of 0.5‰ using distilled water, where the nominal activity value of the amylase stock solution is 4500 U / mL;

[0083] (2) Spraying on tobacco leaves: Spray the above amylase solution evenly on both sides of the tobacco leaves (Chongqing B4F tobacco leaves in 2020), and set 5 enzyme addition gradients (the ratio of the amount of amylase solution to the mass of tobacco leaves), which are 0.1000%, 0.1500%, 0.2000%, 0.2500%, and 0.3000% respectively;

[0084] (3) Treatment of tobacco leaves: Place the tobacco leaves sprayed with amylase in a constant temperature and humidity box at a temperature of 45°C and a humidity of 75% for 48 hours of reaction;

[0085] (4) Tobacco leaf cutting: Cut the tobacco leaves after the treatment reaction.

[0086] (5) Amylase inactivation: The cut tobacco is stir-fried continuously at 125 °C for 15 s for high-temperature instantaneous frying to inactivate the enzyme for production use.

[0087] (6) Hand-rolling cigarettes: Use a hand-rolling cigarette machine to roll the inactivated cut tobacco into cigarette sticks with a weight of 0.875 g per stick.

[0088] Preparation of control cigarette sticks: Perform inactivation treatment on the prepared amylase solution with a volume concentration of 0.5‰ by heating in a water bath at 100 °C for 8 min, and then perform the same tobacco leaf spraying, tobacco leaf treatment, tobacco leaf cutting and hand-rolling cigarettes as the amylase-treated cigarette sticks.

[0089] (2) Testing

[0090] Place the cigarette sticks that meet the weight and draw resistance requirements in an environment with a relative humidity of 60 ± 2% and a temperature of 22 ± 1 °C for 48 h of equilibration, and then conduct two rounds of sensory evaluations by professional smokers, with 7 professional smokers in each round. Conduct a comprehensive evaluation of indicators such as aftertaste, irritation, concentration, aroma, and off-flavors to screen the addition amount of amylase with obvious quality improvement. Sensory evaluation is the basis for ensuring the quality of tobacco leaves. As can be seen from Figure 1 It can be seen that after the amylase treatment, the optimal sensory addition ratio of amylase is 0.2500%.

[0091] Select the cigarette sticks with an amylase addition ratio of 0.2500%, use a smoking machine to draw, and collect the mainstream smoke particulate matter of 20 cigarettes. Determine the contents of 5 PAHs, namely anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene, in the tobacco leaves and the smoke after combustion. The results of the PAH contents and total amounts in the tobacco leaves are as shown in Figure 2 、 Figure 4 and the results of the PAH contents and total amounts in the smoke are as shown in Figure 3 、 Figure 5 . After the amylase treatment, the content of fluoranthene in the tobacco leaves increases, and the total amounts of PAHs in the tobacco leaves and the smoke increase.

[0092] In summary, after treating tobacco leaves with lipase, while meeting the sensory evaluation quality, it has a good harm reduction effect.

[0093] It is easily understandable to those skilled in the art that, on the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed. The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application. The above is only the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art of this technology, several improvements and variations can be made without departing from the technical principle of the present application, and these improvements and variations should also be regarded as within the protection scope of the present application.

Claims

1. A method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke, characterized in that, Comprising: Preparing a lipase solution, wherein the volume concentration of the lipase stock solution in the lipase solution is 3‰ - 8‰, and the enzyme activity of the lipase stock solution is not less than 6000 U / mL; Spraying the lipase solution evenly on both the front and back sides of the tobacco leaves to be treated, and the dosage of the lipase solution accounts for 0.05% - 0.25% of the mass of the tobacco leaves to be treated; Performing constant temperature and humidity treatment on the tobacco leaves sprayed with the lipase solution to obtain tobacco leaves treated with lipase, and the content of polycyclic aromatic hydrocarbons in the tobacco leaves treated with lipase is reduced; Cutting the tobacco leaves treated with lipase into shreds to obtain shredded tobacco treated with lipase; Inactivating the lipase in the shredded tobacco treated with lipase to obtain inactivated shredded tobacco; Rolling the inactivated shredded tobacco into cigarette sticks, and the content of polycyclic aromatic hydrocarbons in the smoke after combustion is reduced.

2. The method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke according to claim 1, characterized in that, In the lipase solution, the volume concentration of the lipase stock solution is 5‰.

3. The method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke according to claim 1, characterized in that, The step of spraying the lipase solution evenly on both the front and back sides of the tobacco leaves to be treated includes: the dosage of the lipase solution accounts for 0.15% of the mass of the tobacco leaves.

4. The method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke according to claim 1, characterized in that, For the constant temperature and humidity treatment, the temperature is 45 ± 2°C, the humidity is 70% - 80%, and the treatment time is 45 h - 50 h.

5. The method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke according to claim 1, characterized in that, For the lipase inactivation, the temperature is 125 ± 2°C, and it is stir-fried for 10 s - 15 s.

6. The method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke according to any one of claims 1-5, characterized in that, The content of fluoranthene in the tobacco leaves treated with lipase is reduced by more than 90%, and the total amount of 5 polycyclic aromatic hydrocarbons including anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene in the tobacco leaves treated with lipase is reduced by more than 30%; the content of fluoranthene in the smoke after combustion of the cigarette sticks is reduced by more than 35%, and the total amount of 5 PAHs including anthracene, fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene in the smoke after combustion of the cigarette sticks is reduced by more than 15%.

7. Use of a method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke, characterized in that, The method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and smoke according to any one of claims 1 - 6 is used to reduce polycyclic aromatic hydrocarbons in low - grade flue - cured tobacco and its smoke, or to reduce polycyclic aromatic hydrocarbons in cut - tobacco and its smoke after threshing and redrying.

8. A cigarette, characterized in that, Comprising shredded tobacco and cigarette paper; wherein, the shredded tobacco includes the inactivated shredded tobacco obtained by using the method for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and smoke according to any one of claims 1 - 6.

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