Method for increasing proline content in planted tobacco leaves and baked tobacco leaves

Abstract

The invention discloses a method for increasing the content of proline in planted tobacco leaves and baked tobacco leaves, and belongs to the technical field of tobaccos. According to the method, the eugenol solution is sprayed to the tobacco plants in the planting process, so that the proline content in the harvested fresh tobacco leaves is increased; the eugenol solution is used for spraying the picked tobacco leaves and then the tobacco leaves are baked, so that the proline content in the baked tobacco leaves is increased. The method provided by the invention has great significance in improving the quality of tobacco leaf raw materials and improving the flavor style characteristics of the tobacco leaves.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco, and particularly relates to a method for increasing the proline content in planted tobacco leaves and flue-cured tobacco leaves. Background Art

[0002] Amino acids not only promote the growth of tobacco, but also have a great influence on the color and aroma of tobacco leaves during the baking process. Appropriate amino acid content can make tobacco leaves have a better color, and the melanoidins produced by the reaction between amino acids and reducing sugars can darken the color of tobacco leaves, affecting the appearance and quality of tobacco leaves. In addition, amino acids can also promote the improvement of the internal chemical composition of flue-cured tobacco, increase the content of aroma substances in flue-cured tobacco, and thus improve the overall quality of tobacco.

[0003] The aroma of the flue-cured tobacco variety Honghua Dajinyuan is good, and one of the main reasons is that it has a high content of free amino acids such as proline. The content of amino acids is affected by a combination of factors. Most of them are to change the content of free amino acids in tobacco leaves by adjusting the nitrogen application level, thereby improving the quality of tobacco leaves. However, long-term application of chemical fertilizers will cause soil compaction, which will affect the absorption of nitrogen fertilizers by tobacco. Therefore, a new scientific and effective method is needed to increase the proline content in tobacco leaves.

[0004] Since proline is the main amino acid that affects the flavor and style characteristics of flue-cured tobacco, increasing the proline content in the flue-cured tobacco leaves, thereby increasing the aroma of the flue-cured tobacco leaves and improving the quality of tobacco raw materials, is of great significance to improving the flavor and style characteristics of tobacco leaves. Summary of the invention

[0005] The object of the present invention is to provide a method for increasing the proline content in planted tobacco leaves and flue-cured tobacco leaves. The proline content in the harvested fresh tobacco leaves is increased by spraying the tobacco plants with eugenol solution during the planting process; the proline content in the flue-cured tobacco leaves is increased by spraying the harvested tobacco leaves with eugenol solution before flue-curing. The provided method is of great significance in improving the quality of tobacco raw materials and improving the flavor and style characteristics of tobacco leaves.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a method for increasing the proline content in cultivated tobacco leaves, comprising the following steps: spraying eugenol solution on the leaves during the seedling stage and the vigorous growth stage of tobacco leaves; topping and removing branches of tobacco plants during the budding stage, and spraying eugenol solution on the topping wounds and lateral bud wounds of the tobacco plants.

[0008] Preferably, the concentration of the eugenol solution sprayed during the seedling stage is 1-3 mmol / L; the concentration of the eugenol solution sprayed during the vigorous growth stage is 5-10 mmol / L; the concentration of the eugenol solution sprayed during the budding stage is 6-8 mmol / L.

[0009] More preferably, the method for increasing the proline content in planted tobacco leaves comprises the following specific steps:

[0010] A. Seedling cultivation: rinse the seeds of safflower Dajinyuan with distilled water, and then disinfect them with 0.2% potassium permanganate for 8-10 minutes; then rinse the seeds twice with distilled water; place the seeds on a three-layer filter paper soaked in a culture dish for germination and growth; all seedlings are cultured in a plant growth cabinet with a light intensity of 5000Lx, a photoperiod of 12h, a relative air humidity of 45-55%, and a temperature of 25-26°C; after the seeds germinate, move the seeds into a seedling tray filled with a substrate for floating seedling cultivation;

[0011] B. Land preparation measures: Soil plowing depth 20-25cm, exposure time 10-15 days, ridge height 0.4m, row spacing 1.1m, plant spacing 0.6m, fixed-distance pond digging, pond diameter 25-30cm, depth 18-20cm;

[0012] C. Transplanting tobacco seedlings: After 40-45 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them to the tobacco pond in a standardized manner, and apply 750kg / hm2 of biological organic fertilizer in the pond at one time. 2 and commercial organic fertilizer 1500kg / hm 2 ;

[0013] D. Seedling stage: 10-15 days after transplanting, spray the leaves of tobacco plants with 1-3 mmol / L eugenol solution for the first time;

[0014] E. Clustering stage: 20-25 days after transplanting, add water and apply liquid organic fertilizer 750kg / hm 2 ;

[0015] F. Vigorous growth period: 50-55 days after transplanting, spray the leaves of tobacco plants with 5-10mmol / L eugenol solution for the second time;

[0016] G. Bud stage: 80-85 days after transplanting, the tobacco plants are topped and branches are removed, and then 6-8mmol / L eugenol solution is sprayed on the top wound and side bud wound of the tobacco plants. Then the removed tops and side buds are crushed and finally applied back to the tobacco plants as organic fertilizer;

[0017] H. Tobacco leaf harvesting: When the tobacco leaf surface turns light yellow, the maturity is about 70% to 80% yellow, and the main vein turns more than 2 / 3 white, it can be harvested.

[0018] The biological organic fertilizer in the present invention contains potassium feldspar, phosphate rock powder, nitrogen-fixing, phosphorus-dissolving, potassium-dissolving and growth-promoting microbial flora, with an effective live bacteria count of ≥ 20 million / g, N ≥ 4.5%, P2O5 ≥ 3%, and K2O ≥ 6%; the commercial organic fertilizer has N ≥ 2%, P2O5 ≥ 4%, and K2O ≥ 4%; the liquid organic fertilizer has N ≥ 6%, P2O5 ≥ 2%, and K2O ≥ 12%.

[0019] The second technical solution of the present invention is to provide a method for increasing the proline content in flue-cured tobacco leaves, comprising the following steps: spraying eugenol solution on the harvested tobacco leaves, drying them and then baking them.

[0020] Preferably, the concentration of the eugenol solution is 4-6 mmol / L.

[0021] More preferably, the spraying amount of the eugenol solution is 100-150 mg / kg.

[0022] The beneficial technical effects of the present invention are as follows:

[0023] The present invention uses eugenol solution to spray tobacco plants in the cultivation process and tobacco leaves after picking, so as to increase the proline content in the harvested fresh tobacco leaves and the proline content in the flue-cured tobacco leaves. The method for increasing the proline content in the cultivated tobacco leaves and the flue-cured tobacco leaves provided by the present invention is of great significance for improving the quality of tobacco raw materials and improving the flavor and style characteristics of tobacco leaves. DETAILED DESCRIPTION

[0024] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0025] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0026] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0027] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0028] The tobacco variety planted in the embodiments of the present invention and the comparative examples is Honghua Dajinyuan from Midu, Yunnan.

[0029] The biological organic fertilizer and commercial organic fertilizer used in the examples and comparative examples of the present invention are provided by Yunnan Shunfeng Erhai Environmental Protection Technology Co., Ltd., and the liquid organic fertilizer used is provided by Yunnan Microbial Fermentation Engineering Research Center Co., Ltd.

[0030] Example 1

[0031] Spraying eugenol increases the proline content in Honghua Dajinyuan tobacco leaves:

[0032] A. Seedling cultivation: Rinse the seeds of safflower Dajinyuan with distilled water, and then disinfect them with 0.2% potassium permanganate for 8 minutes. Then rinse the seeds twice with distilled water. Place the seeds on a three-layer filter paper soaked in a culture dish for germination and growth. All seedlings are cultured in a plant growth cabinet with a light intensity of 5000Lx, a photoperiod of 12h, a relative air humidity of 45%, and a temperature of 25°C. After the seeds germinate, move the seeds into a seedling tray filled with a substrate for floating seedling cultivation;

[0033] B. Land preparation measures: Soil plowing depth 20cm, exposure time 10 days, ridge height 0.4m, row spacing 1.1m, plant spacing 0.6m, fixed-distance pond digging, pond diameter 25cm, depth 18cm;

[0034] C. Transplanting tobacco seedlings: After 40 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them into tobacco ponds in a standardized manner. Apply 750kg / hm2 of biological organic fertilizer (containing potassium feldspar, phosphate rock powder, nitrogen-fixing, phosphorus-dissolving, potassium-dissolving and growth-promoting microbial flora, with effective live bacteria count ≥ 20 million / g, N ≥ 4.5%, P2O5 ≥ 3%, K2O ≥ 6%) to the ponds at one time. 2 and commercial organic fertilizer (N≥2%, P2O5≥4%, K2O≥4%) 1500kg / hm 2 ;

[0035] D. Seedling stage: 10 days after transplanting, spray the leaves of tobacco plants with 1mmol / L eugenol solution for the first time at 240L / hm2. 2 (about 40g / hm 2 ) amount for spraying;

[0036] E. Planting stage: 20 days after transplanting, add water and apply liquid organic fertilizer (N≥6%, P2O5≥2%,

[0037] K2O≥12%)750kg / hm2 ;

[0038] F. Vigorous growth period: 50 days after transplanting, spray the leaves of tobacco plants with 5mmol / L eugenol solution for the second time at 55L / hm 2 (about 45g / hm 2 ) amount for spraying;

[0039] G. Bud stage: 80 days after transplanting, the tobacco plants are topped and branches are removed. Then, 6mmol / L eugenol solution is sprayed on the top wound and lateral bud wound of the tobacco plants. Use a spray pot to spray twice on each wound, and the amount of liquid discharged each time is about 0.6mL. Then, the removed top and lateral buds are crushed and finally applied back to the tobacco plants as organic fertilizer.

[0040] H. Tobacco leaf harvesting: When the tobacco leaf surface is light yellow, the maturity is about 70% yellow, and the main vein turns more than 2 / 3 white, it can be harvested;

[0041] I. Curing tobacco leaves: Fix the harvested tobacco leaves with tobacco clips, control the weight of each clip to 8kg, and evenly spray 4mmol / L eugenol solution at a rate of 100mg / kg (about 150mL / kg), place in a cool place to dry for 6h, and then put into the curing room for baking for 192h.

[0042] Example 2

[0043] Spraying eugenol increases the proline content in Honghua Dajinyuan tobacco leaves:

[0044] A. Seedling cultivation: Rinse the seeds of safflower Dajinyuan with distilled water, and then disinfect them with 0.2% potassium permanganate for 9 minutes. Then rinse the seeds twice with distilled water. Place the seeds on a three-layer filter paper soaked in a culture dish for germination and growth. All seedlings are cultured in a plant growth cabinet with a light intensity of 5000Lx, a photoperiod of 12h, a relative air humidity of 50%, and a temperature of 25°C. After the seeds germinate, move the seeds into a seedling tray filled with a substrate for floating seedling cultivation;

[0045] B. Land preparation measures: soil plowing depth 22cm, exposure time 12 days, ridge height 0.4m, row spacing 1.1m, plant spacing 0.6m, fixed-distance pond digging, pond diameter 27cm, depth 19cm;

[0046] C. Transplanting tobacco seedlings: After 42 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them into tobacco ponds in a standardized manner. Apply 750kg / hm2 of biological organic fertilizer (containing potassium feldspar, phosphate rock powder, nitrogen-fixing, phosphorus-dissolving, potassium-dissolving and growth-promoting microbial flora, with effective live bacteria count ≥ 20 million / g, N ≥ 4.5%, P2O5 ≥ 3%, K2O ≥ 6%) to the ponds at one time. 2and commercial organic fertilizer (N≥2%, P2O5≥4%, K2O≥4%) 1500kg / hm 2 ;

[0047] D. Seedling stage: 12 days after transplanting, spray the leaves of tobacco plants with 2mmol / L eugenol solution for the first time at 140L / hm2. 2 (about 45g / hm 2 ) amount for spraying;

[0048] E. Clustering stage: 21 days after transplanting, add water and apply liquid organic fertilizer (N≥6%, P2O5≥2%,

[0049] K2O≥12%)750kg / hm 2 ;

[0050] F. Vigorous growth period: 52 days after transplanting, spray the leaves of tobacco plants with 6mmol / L eugenol solution for the second time at 50L / hm 2 (about 50g / hm 2 ) amount for spraying;

[0051] G. Bud stage: 82 days after transplanting, the tobacco plants are topped and branches are removed. Then, 7mmol / L eugenol solution is sprayed on the top wound and lateral bud wound of the tobacco plants. Use a spray pot to spray twice on each wound. The amount of liquid discharged each time is about 0.6mL. Then, the removed top and lateral buds are crushed and finally applied back to the tobacco plants as organic fertilizer.

[0052] H. Tobacco leaf harvesting: When the tobacco leaf surface is light yellow, the maturity is about 70% yellow, and the main vein turns more than 2 / 3 white, it can be harvested;

[0053] I. Curing tobacco leaves: Fix the harvested tobacco leaves with tobacco clips, control the weight of each clip to 9kg, and evenly spray 5mmol / L eugenol solution at a rate of 110mg / kg (about 135mL / kg), place in a cool place to dry for 6h, and then put into the curing room for baking for 192h.

[0054] Example 3

[0055] Spraying eugenol increases the proline content in Honghua Dajinyuan tobacco leaves:

[0056] A. Seedling cultivation: Rinse the seeds of safflower Dajinyuan with distilled water, and then disinfect them with 0.2% potassium permanganate for 10 minutes. Then rinse the seeds twice with distilled water. Place the seeds on a three-layer filter paper soaked in a culture dish for germination and growth. All seedlings are cultured in a plant growth cabinet with a light intensity of 5000Lx, a photoperiod of 12h, a relative air humidity of 55%, and a temperature of 25°C. After the seeds germinate, move the seeds into a seedling tray filled with a substrate for floating seedling cultivation;

[0057] B. Land preparation measures: soil plowing depth 25cm, exposure time 15 days, ridge height 0.4m, row spacing 1.1m, plant spacing 0.6m, fixed-distance pond digging, pond diameter 30cm, depth 19cm;

[0058] C. Transplanting tobacco seedlings: After 45 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them into tobacco ponds in a standardized manner. Apply 750kg / hm2 of biological organic fertilizer (containing potassium feldspar, phosphate rock powder, nitrogen-fixing, phosphorus-dissolving, potassium-dissolving and growth-promoting microbial flora, with effective live bacteria count ≥ 20 million / g, N ≥ 4.5%, P2O5 ≥ 3%, K2O ≥ 6%) to the ponds at one time. 2 and commercial organic fertilizer (N≥2%, P2O5≥4%, K2O≥4%) 1500kg / hm 2 ;

[0059] D. Seedling stage: 15 days after transplanting, spray the leaves of tobacco plants with 3mmol / L eugenol solution for the first time at 100L / hm2. 2 (about 50g / hm 2 ) amount for spraying;

[0060] E. Clustering stage: 25 days after transplanting, add water and apply liquid organic fertilizer (N≥6%, P2O5≥2%,

[0061] K2O≥12%)750kg / hm 2 ;

[0062] F. Vigorous growth period: 55 days after transplanting, spray the leaves of tobacco plants with 10mmol / L eugenol solution for the second time at 35L / hm 2 (about 40g / hm 2 ) amount for spraying;

[0063] G. Bud stage: 85 days after transplanting, the tobacco plants are topped and branched, and then 8mmol / L eugenol solution is sprayed on the top wound and lateral bud wound of the tobacco plants. Use a spray pot to spray twice on each wound, and the amount of liquid discharged each time is about 0.6mL. Then, the removed tops and lateral buds are crushed and finally applied back to the tobacco plants as organic fertilizer;

[0064] H. Tobacco leaf harvesting: When the tobacco leaf surface is light yellow, the maturity is about 80% yellow, and the main vein turns more than 2 / 3 white, it can be harvested;

[0065] I. Curing tobacco leaves: Fix the harvested tobacco leaves with tobacco clips, control the weight of each clip to 10kg, and evenly spray 6mmol / L eugenol solution at a rate of 120mg / kg (about 120mL / kg), place in a cool place to dry for 6h, and then put into the curing room for baking for 192h.

[0066] Comparative Example 1

[0067] Conventional safflower Dajinyuan tobacco leaf planting and harvesting:

[0068] A. Seedling cultivation: Rinse the seeds of safflower Dajinyuan with distilled water, and then disinfect them with 0.2% potassium permanganate for 8 minutes. Then rinse the seeds twice with distilled water. Place the seeds on a three-layer filter paper soaked in a culture dish for germination and growth. All seedlings are cultured in a plant growth cabinet with a light intensity of 5000Lx, a photoperiod of 12h, a relative air humidity of 45%, and a temperature of 25°C. After the seeds germinate, move the seeds into a seedling tray filled with a substrate for floating seedling cultivation;

[0069] B. Land preparation measures: Soil plowing depth 20cm, exposure time 10 days, ridge height 0.4m, row spacing 1.1m, plant spacing 0.6m, fixed-distance pond digging, pond diameter 25cm, depth 18cm;

[0070] C. Transplanting tobacco seedlings: After 40 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them into tobacco ponds in a standardized manner. Apply 750kg / hm2 of biological organic fertilizer (containing potassium feldspar, phosphate rock powder, nitrogen-fixing, phosphorus-dissolving, potassium-dissolving and growth-promoting microbial flora, with effective live bacteria count ≥ 20 million / g, N ≥ 4.5%, P2O5 ≥ 3%, K2O ≥ 6%) to the ponds at one time. 2 and commercial organic fertilizer (N≥2%, P2O5≥4%, K2O≥4%) 1500kg / hm 2 ;

[0071] D. Clustering stage: 20 days after transplanting, add water and apply liquid organic fertilizer (N≥6%, P2O5≥2%,

[0072] K2O≥12%)750kg / hm 2 ;

[0073] E. Bud stage: 80 days after transplanting, take management measures such as topping and removing branches of tobacco plants;

[0074] F. Tobacco leaf harvesting: When the tobacco leaf surface is light yellow, the maturity is about 70% yellow, and the main vein turns white for more than 2 / 3, it can be harvested;

[0075] G. Curing tobacco leaves: Fix the harvested tobacco leaves with tobacco clips, and control the weight of each clip to 14kg. Then put them into the curing room and bake them for 192 hours.

[0076] The proline content in the fresh tobacco leaves and the first-cured tobacco leaves after picking in Examples 1-3 and Comparative Example 1 was measured. The measurement results are shown in Table 1.

[0077] Table 1 Proline content (mg / g)

[0078] deal with Fresh tobacco leaves First-cured tobacco leaves Example 1 4.246 5.539 Example 2 4.332 5.624 Example 3 4.427 5.753 Comparative Example 1 4.012 5.231

[0079] As can be seen from Table 1, after multiple spraying of eugenol in Examples 1, 2 and 3 of the present invention, the proline content of the fresh tobacco leaves and the first-cured tobacco leaves increased. The proline content of the fresh tobacco leaves and the first-cured tobacco leaves in Example 1 was increased by 0.234 mg / g and 0.308 mg / g respectively compared with the control group, the proline content of the fresh tobacco leaves and the first-cured tobacco leaves in Example 2 was increased by 0.32 mg / g and 0.393 mg / g respectively compared with the control group, and the proline content of the fresh tobacco leaves and the first-cured tobacco leaves in Example 3 was increased by 0.415 mg / g and 0.522 mg / g respectively compared with the control group.

[0080] The sensory evaluation of the first-cured tobacco leaves of Examples 1-3 and Comparative Example 1 was conducted according to the industry standard YC / T 138-1998. The sensory evaluation results are shown in Table 2.

[0081] Table 2 Sensory evaluation results

[0082]

[0083]

[0084] As shown in Table 2, after multiple spraying of eugenol in Examples 1, 2, and 3 of the present invention, the sensory evaluation grade of the flue-cured tobacco leaves is relatively high, especially the aroma quantity, aroma quality, and miscellaneous odors are significantly improved. The aroma quantity, aroma quality, and miscellaneous odors of Examples 1, 2, and 3 are all higher than those of Comparative Example 1.

[0085] The economic properties of the first-cured tobacco leaves of Examples 1-3 and Comparative Example 1 were evaluated, and the evaluation results are shown in Table 3.

[0086] Table 3 Evaluation results of economic traits

[0087] High-quality tobacco (%) Medium smoke (%) Low-quality cigarettes (%) Average price (yuan / kg) Example 1 51.6 31.7 16.7 28.9 Example 2 56.8 28.3 14.9 29.4 Example 3 60.4 31.3 8.3 30.6 Comparative Example 1 46.2 34.9 18.9 28.2

[0088] It can be seen from Table 3 that the proportion of high-quality cigarettes in Example 1 is 5.4% higher than that of the high-quality cigarettes in Comparative Example 1, and the average price of Example 1 is 0.7 yuan / kg higher than that of Comparative Example 1; the proportion of high-quality cigarettes in Example 2 is 10.6% higher than that of the high-quality cigarettes in Comparative Example 1, and the average price of Example 2 is 1.2 yuan / kg higher than that of Comparative Example 1; the proportion of high-quality cigarettes in Example 3 is 14.2% higher than that of the high-quality cigarettes in Comparative Example 1, and the average price of Example 3 is 2.4 yuan / kg higher than the average price of Comparative Example 1.

[0089] Example 4

[0090] Spraying eugenol increases the proline content in Honghua Dajinyuan tobacco leaves:

[0091] A. Seedling cultivation: Rinse the seeds of safflower Dajinyuan with distilled water, and then disinfect them with 0.2% potassium permanganate for 10 minutes. Then rinse the seeds twice with distilled water. Place the seeds on a three-layer filter paper soaked in a culture dish for germination and growth. All seedlings are cultured in a plant growth cabinet with a light intensity of 5000Lx, a photoperiod of 12h, a relative air humidity of 55%, and a temperature of 26°C. After the seeds germinate, move the seeds into a seedling tray filled with a substrate for floating seedling cultivation;

[0092] B. Land preparation measures: Soil plowing depth 20cm, exposure time 10 days, ridge height 0.4m, row spacing 1.1m, plant spacing 0.6m, fixed-distance pond digging, pond diameter 25cm, depth 18cm;

[0093] C. Transplanting tobacco seedlings: After 40 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them into tobacco ponds in a standardized manner. Apply 750kg / hm2 of biological organic fertilizer (containing potassium feldspar, phosphate rock powder, nitrogen-fixing, phosphorus-dissolving, potassium-dissolving and growth-promoting microbial flora, with effective live bacteria count ≥ 20 million / g, N ≥ 4.5%, P2O5 ≥ 3%, K2O ≥ 6%) to the ponds at one time. 2 and commercial organic fertilizer (N≥2%, P2O5≥4%, K2O≥4%) 1500kg / hm 2 ;

[0094] D. Seedling stage: 10 days after transplanting, spray the leaves of tobacco plants with 3mmol / L eugenol solution for the first time at 110L / hm2. 2 (about 55g / hm 2 ) amount for spraying;

[0095] E. Planting stage: 20 days after transplanting, add water and apply liquid organic fertilizer (N≥6%, P2O5≥2%,

[0096] K2O≥12%)750kg / hm 2 ;

[0097] F. Vigorous growth period: 50 days after transplanting, spray the leaves of tobacco plants with 10mmol / L eugenol solution for the second time at 40L / hm 2 (about 65g / hm 2 ) amount for spraying;

[0098] G. Bud stage: 80 days after transplanting, the tobacco plants are topped and branched, and then 8mmol / L eugenol solution is sprayed on the top wound and lateral bud wound of the tobacco plants. Use a spray pot to spray each wound twice, and the amount of liquid discharged each time is about 0.6mL. Then, the removed tops and lateral buds are crushed and finally applied back to the tobacco plants as organic fertilizer;

[0099] H. Tobacco leaf harvesting: When the tobacco leaf surface is light yellow, the maturity is about 80% yellow, and the main vein turns more than 2 / 3 white, it can be harvested;

[0100] I. Curing tobacco leaves: Fix the harvested tobacco leaves with tobacco clips, control the weight of each clip to 8kg, and evenly spray 6mmol / L eugenol solution at a rate of 130mg / kg (about 130mL / kg), place in a cool place to dry for 6h, and then put into the curing room for baking for 192h.

[0101] Example 5

[0102] Spraying eugenol increases the proline content in Honghua Dajinyuan tobacco leaves:

[0103] A. Seedling cultivation: Rinse the seeds of safflower Dajinyuan with distilled water, and then disinfect them with 0.2% potassium permanganate for 10 minutes. Then rinse the seeds twice with distilled water. Place the seeds on a three-layer filter paper soaked in a culture dish for germination and growth. All seedlings are cultured in a plant growth cabinet with a light intensity of 5000Lx, a photoperiod of 12h, a relative air humidity of 55%, and a temperature of 26°C. After the seeds germinate, move the seeds into a seedling tray filled with a substrate for floating seedling cultivation;

[0104] B. Land preparation measures: soil plowing depth 23cm, exposure time 13 days, ridge height 0.4m, row spacing 1.1m, plant spacing 0.6m, fixed-distance pond digging, pond diameter 27cm, depth 19cm;

[0105] C. Transplanting tobacco seedlings: After 44 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them into tobacco ponds in a standardized manner. Apply 750kg / hm2 of biological organic fertilizer (containing potassium feldspar, phosphate rock powder, nitrogen-fixing, phosphorus-dissolving, potassium-dissolving and growth-promoting microbial flora, with effective live bacteria count ≥ 20 million / g, N ≥ 4.5%, P2O5 ≥ 3%, K2O ≥ 6%) to the ponds at one time. 2 and commercial organic fertilizer (N≥2%, P2O5≥4%, K2O≥4%) 1500kg / hm2 ;

[0106] D. Seedling stage: 13 days after transplanting, spray the leaves of tobacco plants with 2mmol / L eugenol solution for the first time at 180L / hm2. 2 (about 60g / hm 2 ) amount for spraying;

[0107] E. Planting stage: 23 days after transplanting, add water and apply liquid organic fertilizer (N≥6%, P2O5≥2%,

[0108] K2O≥12%)750kg / hm 2 ;

[0109] F. Vigorous growth period: 53 days after transplanting, spray the leaves of tobacco plants with 8mmol / L eugenol solution for the second time at 55L / hm 2 (about 70g / hm 2 ) amount for spraying;

[0110] G. Bud stage: 83 days after transplanting, the tobacco plants were topped and branches were removed, and then 7mmol / L eugenol solution was sprayed on the top wound and lateral bud wound of the tobacco plants. Each wound was sprayed twice with a spray pot, and the amount of liquid discharged each time was about 0.6mL. Then the removed top and lateral buds were crushed and finally applied back to the tobacco plants as organic fertilizer;

[0111] H. Tobacco leaf harvesting: When the tobacco leaf surface is light yellow, the maturity is about 80% yellow, and the main vein turns more than 2 / 3 white, it can be harvested;

[0112] I. Curing tobacco leaves: Fix the harvested tobacco leaves with tobacco clips, control the weight of each clip to 9kg, and evenly spray 5mmol / L eugenol solution at a rate of 140mg / kg (about 170mL / kg), place in a cool place to dry for 6h, and then put into the curing room for baking for 192h.

[0113] Example 6

[0114] Spraying eugenol increases the proline content in Honghua Dajinyuan tobacco leaves:

[0115] A. Seedling cultivation: Rinse the seeds of safflower dajinyuan with distilled water, and then disinfect them with 0.2% potassium permanganate for 9 minutes. Then rinse the seeds twice with distilled water. Place the seeds on a three-layer filter paper soaked in a culture dish for germination and growth. All seedlings are cultured in a plant growth cabinet with a light intensity of 5000Lx, a photoperiod of 12h, a relative air humidity of 50%, and a temperature of 26°C. After the seeds germinate, move the seeds into a seedling tray filled with a substrate for floating seedling cultivation;

[0116] B. Land preparation measures: soil plowing depth 25cm, exposure time 15 days, ridge height 0.4m, row spacing 1.1m, plant spacing 0.6m, fixed-distance pond digging, pond diameter 30cm, depth 20cm;

[0117] C. Transplanting tobacco seedlings: After 45 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them into tobacco ponds in a standardized manner. Apply 750kg / hm2 of biological organic fertilizer (containing potassium feldspar, phosphate rock powder, nitrogen-fixing, phosphorus-dissolving, potassium-dissolving and growth-promoting microbial flora, with effective live bacteria count ≥ 20 million / g, N ≥ 4.5%, P2O5 ≥ 3%, K2O ≥ 6%) to the ponds at one time. 2 and commercial organic fertilizer (N≥2%, P2O5≥4%, K2O≥4%) 1500kg / hm 2 ;

[0118] D. Seedling stage: 15 days after transplanting, spray the leaves of tobacco plants with 1mmol / L eugenol solution for the first time at 400L / hm2. 2 (about 65g / hm 2 ) amount for spraying;

[0119] E. Clustering stage: 25 days after transplanting, add water and apply liquid organic fertilizer (N≥6%, P2O5≥2%,

[0120] K2O≥12%)750kg / hm 2 ;

[0121] F. Vigorous growth period: 55 days after transplanting, spray the leaves of tobacco plants with 6mmol / L eugenol solution for the second time at 75L / hm 2 (about 75g / hm 2 ) amount for spraying;

[0122] G. Bud stage: 85 days after transplanting, the tobacco plants are topped and branches are removed. Then, 6mmol / L eugenol solution is sprayed on the top wound and lateral bud wound of the tobacco plants. Use a spray pot to spray twice on each wound, and the amount of liquid discharged each time is about 0.6mL. Then, the removed top and lateral buds are crushed and finally applied back to the tobacco plants as organic fertilizer.

[0123] H. Tobacco leaf harvesting: When the tobacco leaf surface is light yellow, the maturity is about 80% yellow, and the main vein turns more than 2 / 3 white, it can be harvested;

[0124] I. Curing tobacco leaves: Fix the harvested tobacco leaves with tobacco clips, control the weight of each clip to 10kg, and evenly spray 4mmol / L eugenol solution at a rate of 150mg / kg (about 180mL / kg), place in a cool place to dry for 6h, and then put into the curing room for baking for 192h.

[0125] Comparative Example 2

[0126] Spray eugenol during planting and do not spray eugenol during baking:

[0127] Curing tobacco leaves: Take the fresh tobacco leaves harvested in Example 6 and fix them with tobacco clips. The weight of each clip of tobacco leaves is controlled at 10 kg. Place them in a cool place to dry for 6 hours, and then put them into a curing room for curing for 192 hours.

[0128] The proline content in the fresh tobacco leaves and the first-cured tobacco leaves after picking in Examples 4-6 and Comparative Example 2 was measured. The measurement results are shown in Table 4.

[0129] Table 4 Proline content (mg / g)

[0130] deal with Fresh tobacco leaves First-cured tobacco leaves Example 4 4.468 5.823 Example 5 4.325 5.734 Example 6 4.301 5.578 Comparative Example 2 4.301 5.352

[0131] As shown in Table 4, after the picked fresh tobacco leaves were sprayed with eugenol and then baked, the proline content of the obtained freshly baked tobacco leaves increased significantly. Compared with Comparative Example 2, the proline content in the freshly baked tobacco leaves of Example 6 increased by 0.226 mg / g.

[0132] The sensory evaluation of the first-cured tobacco leaves of Examples 4-6 and Comparative Example 2 was conducted according to the industry standard YC / T 138-1998. The sensory evaluation results are shown in Table 5.

[0133] Table 5 Sensory evaluation results

[0134]

[0135] It can be seen from Table 5 that spraying eugenol on the picked fresh tobacco leaves before baking is beneficial to the sensory evaluation grade of the newly baked tobacco leaves. Spraying eugenol before baking can improve the aroma amount, aroma quality and miscellaneous smell of the newly baked tobacco leaves (see data comparison between Example 6 and Comparative Example 2).

[0136] The economic properties of the first-cured tobacco leaves of Examples 4-6 and Comparative Example 2 were evaluated, and the evaluation results are shown in Table 6.

[0137] Table 6 Evaluation results of economic traits

[0138]

[0139]

[0140] It can be seen from Table 6 that the proportion of high-quality tobacco in Example 6 is 4.5% higher than that in Comparative Example 2, and the average price of Example 6 is 0.7 yuan / kg higher than that of Comparative Example 2.

[0141] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for increasing the proline content in tobacco leaves, characterized in that: The following steps are involved: During the seedling stage and vigorous growth stage of tobacco planting, spray eugenol solution on the leaves; during the budding stage, top the tobacco plants and remove the branches, and spray eugenol solution on the topping wound and side bud wound of the tobacco plants.

2. The method for increasing the proline content in tobacco leaves according to claim 1, characterized in that: The concentration of the eugenol solution sprayed during the seedling stage is 1-3 mmol / L; the concentration of the eugenol solution sprayed during the vigorous growth stage is 5-10 mmol / L; the concentration of the eugenol solution sprayed during the budding stage is 6-8 mmol / L.

3. A method for increasing the proline content in flue-cured tobacco leaves, characterized in that: The following steps are involved: The harvested tobacco leaves are sprayed with eugenol solution, dried and then baked for 192 hours.

4. The method for increasing the proline content in flue-cured tobacco leaves according to claim 3, characterized in that: The concentration of the eugenol solution is 4-6 mmol / L.

5. The method for increasing the proline content in flue-cured tobacco leaves according to claim 4, characterized in that: The spraying amount of the eugenol solution is 100-150 mg / kg.

Images