Complex enzyme preparation for baking and upgrading upper tobacco leaves and spraying method of complex enzyme preparation

Abstract

The invention discloses a compound enzyme preparation for improving the baking quality of upper tobacco leaves and a spraying method of the compound enzyme preparation, and mainly aims to solve the smoking quality problems of high starch content, strong irritation and the like and the smoking safety problems of high tar content, low potassium-chlorine ratio and the like after the upper tobacco leaves of flue-cured tobaccos are baked. High-temperature-resistant alpha-amylase, cellulase and pectinase are selected in proportion to prepare a compound enzyme preparation, the compound enzyme preparation is sprayed before tobacco leaves are baked, and the formula proportion and the spraying method of the final compound enzyme preparation are determined. According to the method, the baking process directly acts on the substrate, the tobacco leaf yellowing degree is promoted in the baking yellowing period, macromolecular substance conversion is accelerated in the yellowing period and the color fixing period, the content of neutral aroma components is increased, the appearance quality is improved, the aroma amount and the aroma quality are improved, green offensive odor and irritation are effectively reduced, and the usability of upper leaves is improved; not only can tobacco growers be helped to increase income, but also tobacco leaf raw materials with higher quality are provided for industrial enterprises.

Description

Technical Field

[0001] The present invention relates to the technical field of primary processing of raw tobacco, and particularly relates to a composite enzyme preparation for improving the baking quality of upper tobacco leaves and a spraying method thereof. Background Art

[0002] Tobacco is a special cash crop, and the quality of tobacco leaves is a key factor restricting the development of cigarette technology, mainly including aspects such as appearance quality, internal chemical composition, the content of neutral aroma components, and sensory evaluation quality.

[0003] The upper leaves of flue-cured tobacco account for 30%-40% of the whole plant's tobacco leaves. However, due to problems such as insufficient maturity, relatively thick leaves, tight tissue structure, high starch and nicotine content, low sugar-alkali ratio, uncoordinated internal chemical composition, and relatively large irritation, the industrial usability of the upper leaves of flue-cured tobacco is reduced. In particular, substances such as cellulose, pectin, protein, and starch contained in tobacco all have an adverse impact on the aroma and taste of cigarettes. Starch affects the combustibility of cigarettes on the one hand, and on the other hand, starch will produce a burnt smell during combustion, which has an adverse impact on the smoke. Pectin affects the physical properties of tobacco leaves. Methanol is also contained in the pectin molecular structure. Methanol is further converted into formaldehyde and formic acid during combustion, which will bring irritation and insecurity to tobacco. Moreover, pectin is a hygroscopic substance, which affects the combustibility of tobacco leaves and can also lead to an increase in tar content, affecting the taste of cigarettes. As the basic substance constituting the plant cell tissue and skeleton, cellulose is not conducive to the combustibility of tobacco leaves. Reducing the content of these substances in tobacco plays an important role in improving the quality of cigarette products. Summary of the Invention

[0004] In view of the above problems, the present invention provides a composite enzyme preparation for improving the baking quality of upper tobacco leaves and a spraying method thereof. By spraying a composite enzyme preparation composed of a specific ratio of thermostable α-amylase, cellulase, pectinase, etc. before the baking and modulation of tobacco leaves, the chemical composition of the tobacco leaves after baking is coordinated, the aroma quantity and quality of the tobacco leaves after baking are improved, the appearance quality and sensory evaluation quality are improved, and the green and miscellaneous odors of the tobacco leaves after baking are reduced. Application and promotion in the tobacco leaf baking link can further improve the usability of upper tobacco leaves and provide high-quality cigarette raw materials for tobacco industrial enterprises.

[0005] In one aspect, the present invention provides a composite enzyme preparation, which comprises thermostable α-amylase, pectinase, and cellulase, and the mass ratio m(thermostable α-amylase):m(cellulase):m(pectinase) = 1:3:4.

[0006] In another aspect, the present invention provides the use of the above composite enzyme preparation in improving the baking quality of upper tobacco leaves.

[0007] In some embodiments, the dosage of the complex enzyme is 90 U / g, and this dosage refers to the enzyme activity corresponding to each gram of enzyme preparation during the implementation process.

[0008] In some embodiments, the variety of tobacco leaves is Zhongyan 100, selected from mature tobacco leaves or abnormal tobacco leaves that have reached the picking stage, such as black violent tobacco leaves, etc.

[0009] In some embodiments, after the upper tobacco leaves are baked, improvements are obtained in at least one of the following aspects: appearance quality, sensory quality, coordination of chemical components, and the number of aroma components.

[0010] In some embodiments, the improvement in appearance quality includes increased maturity of tobacco leaves, loose structure, enhanced chroma, and reduced ash and mottling; the improvement in sensory quality includes increased aroma quantity, improved aroma quality, fuller aftertaste and strength, and reduced foreign odors and irritation; the improvement in the coordination of chemical components includes increased reducing sugar content, decreased nicotine content, significantly reduced starch, pectin, and cellulose content, and increased sugar-alkali ratio and potassium-chlorine ratio; the improvement in the number of aroma components includes increased content of carotenoids, phenylalanines, cembranoids, and neophytadiene.

[0011] In another aspect, the present invention provides a method for applying the complex enzyme preparation, including: diluting the complex enzyme preparation, spraying it on the surface of the upper tobacco leaves with a sprayer, with the principle that the leaf surface is wet but does not drip water, and then, drying for about 4 h under natural ventilation conditions before loading into the baking kiln for baking.

[0012] In some embodiments, the dosage of the complex enzyme is 90 U / g, and this dosage refers to the amount of enzyme preparation sprayed per gram of upper tobacco leaves after picking.

[0013] The beneficial effects of the present invention include but are not limited to the following aspects:

[0014] 1. Spraying a complex enzyme preparation for improving the baking quality of upper tobacco leaves before baking according to the present invention. After being treated with the complex enzyme preparation, the appearance quality of the baked tobacco leaves is improved to a certain extent, mainly manifested in increased maturity of tobacco leaves, loose structure, enhanced chroma, and reduced ash and mottling.

[0015] 2. Spraying a complex enzyme preparation for improving the baking quality of upper tobacco leaves before baking according to the present invention. After being treated with the complex enzyme preparation, the sensory evaluation quality of the rolled baked tobacco leaves is improved, mainly manifested in increased aroma quantity of flue-cured tobacco, improved aroma quality, fuller aftertaste and strength, and reduced foreign odors and irritation.

[0016] 3. Before baking modulation, a compound enzyme preparation for improving the baking quality of upper tobacco leaves is sprayed according to the present invention. After being treated with the compound enzyme preparation, the chemical components of the baked tobacco leaves are more coordinated. The main manifestations are that the content of reducing sugar increases, the content of nicotine decreases, and the contents of starch, pectin and cellulose decrease significantly. The sugar-alkali ratio and potassium-chlorine ratio both increase.

[0017] 4. Before baking modulation, a compound enzyme preparation for improving the baking quality of upper tobacco leaves is sprayed according to the present invention. After being treated with the compound enzyme preparation, the neutral aroma components of the baked tobacco leaves increase. The main manifestations are that the contents of carotenoids, phenylalanines, cembranoids and neophytadiene all increase.

[0018] The compound enzyme preparation for improving the baking quality of upper tobacco leaves is sprayed before baking modulation according to the present invention, avoiding the interference of other factors during the field period of tobacco leaves. It is also different from traditional nutritional regulation and regulation means after reconstitution and processing of tobacco leaves. Instead, it directly acts on the baking stage which plays the most direct and irreplaceable role in manifesting, fixing and improving the quality of flue-cured tobacco. The operation is simple and controllable, which has important significance for the popularization of improving the baking quality of flue-cured tobacco.

[0019] Detailed Embodiment

[0020] Research shows that various means can be adopted, such as selecting excellent flue-cured tobacco varieties, improving cultivation techniques, regulating field nutrition, improving baking technology, etc. to improve the quality of upper flue-cured tobacco leaves. Among them, the baking technology plays the most direct and irreplaceable role in manifesting, fixing and improving the quality formed by flue-cured tobacco in the field. The baking process is a process of transformation of the internal substances of tobacco leaves, and enzymes are crucial in this process. During the baking process, the starch content in tobacco leaves decreases significantly under the action of endogenous enzymes, and the content of aroma substances increases significantly. Pectinase can reduce the cell wall substances and pectin content of tobacco leaves, reduce miscellaneous odors and relieve irritation. Under the action of cellulase, the aroma quality and aroma quantity of flue-cured tobacco leaves increase, the miscellaneous odors decrease, the irritation decreases, and the aroma is coordinated.

[0021] The content of endogenous enzymes in tobacco leaves themselves is relatively small. Simply relying on the action of the enzymes in tobacco leaves during the baking process is not enough to fully transform the uncoordinated components in tobacco leaves in a short time, so as to improve the quality and meet the requirements of industrial production for the quality of tobacco leaves. Therefore, appropriate application of some exogenous enzyme preparations can better improve the coordination of chemical components, make the internal component ratio of tobacco leaves more coordinated and reasonable, so as to improve the quality reduction problem caused by some nutrient deficiencies during the growth and development process of tobacco leaves in the field, and essentially improve the grade and quality of tobacco leaves. Regulating the quality with a single type of enzyme preparation is one-sided, while adding two or more enzymes at the same time has greater advantages than adding only one enzyme in improving the chemical components of tobacco and enhancing its smoking quality.

[0022] In view of this, the present invention selects high-temperature α-amylase, cellulase, and pectinase suitable for the high-temperature and high-humidity environment during the baking process as the formula raw materials of the complex enzyme preparation.

[0023] The following further details the present invention in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and not for limiting the present invention. Unless otherwise specified, the enzyme preparation raw materials in the embodiments of the present invention are all purchased through commercial channels.

[0024] The high-temperature-resistant α-amylase, cellulase, pectinase and other enzyme preparations used in the present invention are all purchased from Jiaxing Sicheng Chemical Co., Ltd. The definition of the enzyme activity of the enzyme preparations used in the present invention is as follows:

[0025] High-temperature-resistant α-amylase: 1 g of solid enzyme powder (or 1 mL of liquid enzyme) liquefies 1 mg of soluble starch in 1 min at 70 °C and pH 6.0, which is defined as 1 enzyme activity unit, expressed as U / g (U / mL);

[0026] Cellulase: 1 g of solid enzyme powder (or 1 mL of liquid enzyme) hydrolyzes 1 mg of reducing sugar from sodium carboxymethylcellulose substrate in 1 h at 50 °C and pH 5.0, which is defined as 1 enzyme activity unit, expressed as U / g (U / mL);

[0027] Pectinase: 1 g of solid enzyme powder (or 1 mL of liquid enzyme) decomposes 1 mg of galacturonic acid from pectin in 1 h under the reaction conditions of 50 °C and pH 3.5, which is defined as 1 enzyme activity unit, expressed as U / g or U / mL.

[0028] In the implementation process of the present invention, the flue-cured tobacco variety Zhongyan 100 is selected.

[0029] Example 1

[0030] In this example, by studying the influence of different ratios of raw materials in the complex enzyme preparation on the baking quality of upper tobacco leaves, the optimal ratio of enzyme raw materials is determined.

[0031] (1) Preparation of complex enzyme preparation, the concentrations of high-temperature-resistant α-amylase, cellulase, and pectinase are proportioned between 30 and 120 U / g. The compounding ratios of the enzyme preparations in each treatment group are shown in the following table. Among them, the CK0 group is sprayed with clear water as a control.

[0032] Table 1 Setting of compounding ratios of enzyme preparations

[0033] Treatment group Compound enzyme ratio CK0 0 A1 m(Thermostable α-amylase):m(Cellulase):m(Pectinase)=1:3:4 A2 m(Thermostable α-amylase):m(Cellulase):m(Pectinase)=2:3:4 A3 m(Thermostable α-amylase):m(Cellulase):m(Pectinase)=1:2:3 A4 m(Thermostable α-amylase):m(Cellulase):m(Pectinase)=1:1:1

[0034] (2) Spraying the complex enzyme preparation

[0035] For the upper - maturity tobacco leaves with consistent maturity, after one - time harvesting, they are strung on poles. A certain volume of enzyme solution is measured, appropriately diluted according to the required concentration and ratio, and then the compound enzyme preparation is evenly sprayed on the surface of the tobacco leaves with a small and extremely fine - mist sprayer. Taking the principle that the leaf surface is wet but does not drip water, it is air - dried for about 4 hours under natural ventilation conditions and then baked to ensure the consistency of the baking process.

[0036] The experiment was carried out in Lishifang Village, Jianglijizhen, Jian'an District, Xuchang City in 2024, using the upper leaves (black - storm tobacco) of Zhongyan 100 as experimental materials. For each treatment sample after baking, 2 kg was taken for the determination of conventional chemical components, the evaluation of appearance quality and sensory quality. The results are shown in Table 2 - 4.

[0037] Table 2 Effects of compound enzyme preparation on the sensory evaluation quality of upper - leaf tobacco leaves after baking

[0038]

[0039] Table 2 shows that spraying compound enzyme preparations with different ratios can improve the sensory evaluation quality of tobacco leaves after baking. For the tobacco leaves treated with enzyme preparations of each ratio, the quality of the aroma is improved, the softness is enhanced, the irritation is reduced, and the comprehensive score is increased. Among them, for the A1 - group treatment, the aroma quantity is significantly increased, the miscellaneous gas is significantly reduced, the color of the ash is the best, and the sensory evaluation score is the highest.

[0040] Table 3 Effects of compound enzyme preparation on the chemical components and coordination of upper - leaf tobacco leaves after baking

[0041]

[0042]

[0043] Table 3 shows that spraying compound enzyme preparations with different ratios can effectively reduce the starch content, increase the total sugar and reducing sugar, increase the potassium ion content, increase the sugar - alkali ratio and potassium - chloride ratio, improve the coordination of tobacco leaf chemical components, and reduce harmful macromolecular substances - starch, cellulose, and pectin. Among them, the A1 treatment group has the most obvious effect on improving the coordination of chemical components of tobacco leaves after baking, and the most significant effect on reducing macromolecular substances such as starch, cellulose, and pectin, reducing them by 31.76%, 26.67%, and 19.46% respectively, which is consistent with the reduction of tobacco leaf irritation, the reduction of miscellaneous gas, and the purity of the ash color in sensory evaluation.

[0044] Table 4 Effects of compound enzyme preparation on the appearance quality of upper - leaf tobacco leaves after baking

[0045]

[0046] Table 4 shows that spraying compound enzyme preparations with different ratios can improve the appearance quality of flue-cured tobacco leaves to varying degrees. The A1 treatment group can maximize the improvement of the color, chroma, increase the oil content, reduce the green and ash mottles, improve the aroma, and has the highest appearance quality score, which is consistent with the results of sensory evaluation quality and chemical composition coordination, achieving the comprehensive improvement of the quality of flue-cured tobacco leaves.

[0047] In summary, among the compound enzyme preparations, the best ratio is m(thermostable α-amylase):m(cellulase):m(pectase) = 1:3:4, which is superior to other ratios in optimizing the appearance quality, sensory quality, and chemical composition of upper tobacco leaves.

[0048] Example 2

[0049] In this example, the best concentration or dosage of the compound enzyme preparation for spraying is determined by studying the effect of the concentration of the compound enzyme preparation on improving the baking quality of upper tobacco leaves.

[0050] (1) The best ratio of the compound enzyme preparation is adopted, that is, m(thermostable α-amylase):m(cellulase):m(pectase) = 1:3:4. Among them, when the dosage of the compound enzyme preparation is 90 U / g, the application concentration of the relatively single enzyme preparation thermostable α-amylase is controlled at about 30 U / g, the application concentration of cellulase is controlled at about 90 U / g, and the application concentration of pectase is controlled at about 120 U / g.

[0051] In this example, different experimental groups are set up, and each experimental group adopts the above best ratio:

[0052] Group B1: The dosage of the compound enzyme preparation is 90 U / g;

[0053] Group B2: The dosage of the compound enzyme preparation is 60 U / g;

[0054] Group B3: The dosage of the compound enzyme preparation is 30 U / g;

[0055] Group CK1: Sprayed with clear water.

[0056] (2) Spraying the enzyme preparation

[0057] For the upper tobacco leaves with consistent maturity at the upper mature stage, after being harvested and strung on poles at one time, a certain volume of the enzyme solution is measured, appropriately diluted according to the required concentration and dosage ratio, and the enzyme preparation is evenly sprayed on the surface of the tobacco leaves with a small and extremely fine mist sprayer. Based on the principle that the leaf surface is wet with dew but does not drip, it is air-dried for about 4 h under natural ventilation conditions and then baked to ensure that the baking process is the same.

[0058] The experiment was carried out in Lishifang Village, Jiangli Town, Jian'an District, Xuchang City in 2024. 2 kg of each treated sample after baking was taken for the determination of conventional chemical components, aroma components, appearance quality, and sensory evaluation quality. The results are shown in Tables 5 - 8.

[0059] Table 5 Appearance Quality Evaluation of Upper-leaf Flue-cured Tobacco in Jian'an District in 2024 / points

[0060]

[0061] Table 5 shows that all compound enzyme preparations with different dosages can effectively improve the appearance quality of flue-cured tobacco after curing. The present invention (Group B1) can effectively improve the color and leaf structure of flue-cured tobacco after curing, increase the chroma and oil content, reduce the degree of green and ash-colored mottling in flue-cured tobacco after curing, increase the olfactory aroma, and the overall evaluation of the appearance quality of flue-cured tobacco after curing is the highest.

[0062] Table 6 Conventional Chemical Components and Coordination of Upper-leaf Flue-cured Tobacco in Jian'an District in 2024

[0063]

[0064] Table 6 shows that all compound enzyme preparations with different dosages can effectively reduce the content of macromolecular substances such as starch, cellulose, and pectin in flue-cured tobacco after curing and improve the coordination of chemical components. The present invention (Group B1) can reduce the nicotine in upper-leaf flue-cured tobacco after curing to achieve the maximum degradation amount of starch. Compared with CK1, the starch degradation is 65.79%, making the total sugar and reducing sugar increase significantly, the sugar-alkali ratio and nitrogen-alkali ratio increase, the degradation amounts of cellulose and pectin are increased, which are 23.89% and 4.76% lower than CK1 respectively, the potassium ion concentration increases, the chloride ion concentration decreases, and the potassium-chloride ratio increases. The overall chemical components and their coordination perform the best.

[0065] Table 7 Neutral Aroma Components of Upper-leaf Flue-cured Tobacco in Jian'an District in 2024 μg / kg

[0066]

[0067] Table 7 shows that all compound enzyme preparations with different dosages can effectively increase the neutral aroma components. The present invention (Group B1) can effectively increase the overall content of neutral aroma components in upper-leaf flue-cured tobacco after curing. Among them, the content of plastid pigment and phenylalanine neutral aroma components increases significantly, and the total amount of neutral aroma components increases the most.

[0068] Table 8 Sensory Evaluation Quality of Upper-leaf Flue-cured Tobacco in Jian'an District in 2024

[0069]

[0070] Table 8 shows that all compound enzyme preparations with different dosages can effectively improve the sensory evaluation quality of flue-cured tobacco after curing. The present invention (Group B1) can improve the aroma quality of upper-leaf flue-cured tobacco after curing, increase the aroma amount and smoke concentration, reduce the irritation, and make the aftertaste more comfortable. The overall sensory evaluation quality is significantly improved.

[0071] In summary, when the dosage of the complex enzyme preparation is 90 U / g, it is superior to other dosages in optimizing the appearance quality, sensory quality, and chemical composition of the upper tobacco leaves. Both too high and too low dosages will slightly damage the improvement of baking quality.

[0072] Example 3

[0073] In this example, upper tobacco leaves were selected in different regions for verification experiments, and the preparation of the enzyme preparation was the same as in Example 2.

[0074] (1) Different experimental groups were set up in this example, and each experimental group adopted the above optimal ratio:

[0075] Group C1: Dosage of complex enzyme preparation 90 U / g;

[0076] Group C2: Dosage of complex enzyme preparation 60 U / g;

[0077] Group C3: Dosage of complex enzyme preparation 30 U / g;

[0078] Group CK2: Sprayed with clear water.

[0079] (2) Spraying the enzyme preparation

[0080] For tobacco leaves with consistent maturity at the upper mature stage, after being harvested once and strung on poles, a certain volume of enzyme solution was measured, appropriately diluted according to the required concentration, and the enzyme preparation was evenly sprayed on the surface of the tobacco leaves with a small and extremely fine mist sprayer. Taking the principle that the leaf surface was wet with dew but did not drip water, it was air-dried for about 4 h under natural ventilation conditions and then baked to ensure consistent baking processes.

[0081] The experiment was carried out in Maoshixian Village, Shundian Town, Yuzhou City in 2024. For each treated sample after baking, 2 kg was taken for the determination of conventional chemical components, aroma components, appearance quality, and sensory evaluation quality. The results are shown in Table 9-12.

[0082] Table 9 Evaluation of the appearance quality of upper tobacco leaves after baking in Yuzhou City in 2024 / score

[0083]

[0084] Table 9 shows that all complex enzyme preparations with different dosages can effectively improve the appearance quality of upper tobacco leaves after baking. In the present invention (Group C1), the identity is thinner, the leaf structure is more loose, the chroma is enhanced, the oil content is increased, the green and ash-colored mottling degree of the tobacco leaves after baking is reduced, the olfactory aroma is obvious, and the overall evaluation of the appearance quality of the tobacco leaves after baking is the highest.

[0085] Table 10 Conventional chemical components and coordination of upper tobacco leaves after baking in Yuzhou City in 2024

[0086]

[0087] Table 10 shows that all compound enzyme preparations with different dosages can effectively promote the degradation of macromolecular substances such as starch, cellulose, and pectin. In the present invention (Group C1), the degradation degrees of substances such as starch, cellulose, and pectin are the largest, with a degradation of 62.59%, 11.51%, and 13.18% respectively compared to CK2. The total sugar and reducing sugar contents are the highest, the sugar-alkali ratio and nitrogen-alkali ratio are improved, the potassium ion content is the largest, the chloride ion content is the lowest, and the potassium-chloride ratio is significantly increased, maximizing the coordination of the chemical components of the flue-cured tobacco leaves after baking.

[0088] Table 11 Neutral aroma components of upper-leaf flue-cured tobacco leaves in Yuzhou City in 2024

[0089]

[0090]

[0091] Table 11 shows that all compound enzyme preparations with different dosages can greatly increase the total amount of neutral aroma components in upper-leaf flue-cured tobacco leaves after baking. In the present invention (Group C1), the contents of plastid pigments, phenylalanine, browning reaction, and other neutral aroma components increase the most, and the total amount of neutral aroma substances is the highest.

[0092] Table 12 Sensory evaluation quality of upper-leaf flue-cured tobacco leaves in Yuzhou City in 2024

[0093] Treatment Aroma quality Aroma quantity Concentration Off-flavor Body Irritation Aftertaste Combustibility Ash color Score CK2 6.30 6.30 6.40 6.20 6.50 6.28 6.20 7.00 7.00 6.34 C1 6.50 6.50 6.42 6.50 6.40 6.50 6.50 7.00 7.20 6.51 C2 6.30 6.32 6.25 6.40 6.42 6.40 6.34 7.00 7.00 6.37 C3 6.35 6.38 6.40 6.30 6.42 6.38 6.30 7.00 7.00 6.39

[0094] Table 12 shows that all compound enzyme preparations with different dosages can effectively improve the sensory evaluation quality of flue-cured tobacco leaves after baking. For the upper-leaf flue-cured tobacco leaves in the present invention (Group C1), the quality of the aroma is the best, the amount of aroma is the largest, effectively increasing the smoke concentration, reducing the miscellaneous gas and irritation, with a clean and long aftertaste, and the overall sensory evaluation quality score is the highest.

[0095] In summary, when evaluating the baking quality of upper-leaf tobacco in different regions, when the dosage of the compound enzyme preparation is 90 U / g, it is still the best dosage concentration, and it is superior to other dosages in optimizing the appearance quality, sensory quality, and chemical components of upper-leaf tobacco.

Claims

1. A composite enzyme preparation, which comprises a heat-resistant α-amylase, pectinase, and cellulase, and the mass ratio of m(heat-resistant α-amylase):m(cellulase):m(pectinase) = 1:3:

4.

2. Use of the composite enzyme preparation according to claim 1 in improving the baking quality of upper tobacco leaves.

3. Use according to claim 2, wherein, The dosage of the composite enzyme is 90 U / g.

4. The use according to claim 2, wherein, The variety of the tobacco leaves is Zhongyan 100, and the upper tobacco leaves are from mature tobacco leaves or abnormal tobacco leaves that have reached the picking period.

5. The use according to claim 2, wherein, After the upper tobacco leaves are baked, improvement is achieved in at least one of the following aspects: appearance quality, sensory quality, coordination of chemical components, and quantity of aroma components.

6. The use according to claim 5, wherein The improvement in the appearance quality includes increased maturity of the tobacco leaves, loose structure, enhanced chroma, and reduced ash hanging and variegation.

7. The use according to claim 5, wherein, The improvement in the sensory quality includes increased aroma quantity, improved aroma quality, stronger aftertaste and strength, and reduced off-flavors and irritation.

8. The use according to claim 5, wherein, The improvement in the coordination of chemical components includes increased reducing sugar content, decreased nicotine content, significantly reduced starch, pectin, and cellulose contents, and increased sugar-alkali ratio and potassium-chlorine ratio.

9. The use according to claim 5, wherein, The improvement in the quantity of aroma components includes increased contents of carotenoids, phenylalanines, cembranoids, and neophytadiene.

10. The application method of the complex enzyme preparation according to claim 1, comprising: Dilute the composite enzyme preparation and spray it on the surface of the upper tobacco leaves with a sprayer, with the principle that the leaf surface is wet with dew but does not drip. Subsequently, air-dry for about 4 h under natural ventilation conditions and then load into the baking chamber for baking.

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