A method for baking upper leaves of GZ36 flue-cured tobacco

Abstract

The present invention discloses a baking method for the upper leaves of GZ36 flue-cured tobacco, comprising the following steps: S1, judging the baking characteristics of the upper leaves of GZ36 flue-cured tobacco; S2, harvesting fresh tobacco leaves when ripe: harvesting fresh tobacco leaves when ripe according to the ripe characteristics of fresh tobacco leaves in low-altitude areas and high-altitude areas; S3, classifying and stringing fresh tobacco leaves and loading them into the baking barn; S4, baking fresh tobacco leaves: scientifically baking according to the baking characteristics and ripe characteristics of tobacco leaves in different regions, wherein during the yellowing stage, the dry-bulb temperature cyclic rise and fall method is adopted to promote the tobacco leaves to fully soften and wither. By judging the baking characteristics of the upper leaves of GZ36 flue-cured tobacco, formulating key baking strategies, harvesting fresh tobacco leaves when ripe according to the ripe characteristics of fresh tobacco leaves in different regions, classifying and stringing them and loading them into the baking barn, and scientifically baking according to the baking characteristics and ripe characteristics of tobacco leaves under different ecological conditions in different regions, and adopting the dry-bulb temperature cyclic rise and fall method during the yellowing stage to promote the tobacco leaves to fully soften and wither, the internal quality of the upper tobacco leaves after baking of GZ36 can be effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of flue-cured tobacco modulation, and particularly relates to a baking method for upper leaves of GZ36 flue-cured tobacco. Background Art

[0002] GZ36 is an F1 hybrid of 9011×Anyan No. 3, and is a flue-cured tobacco strain selected after hybridization with K730. 65% of its genetic traits are derived from K326. This flue-cured tobacco strain is resistant to bacterial wilt and black shank, susceptible to brown spot and virus disease, not prone to early flowering, with a cylindrical plant type, long oval leaf shape, about 55 days from transplanting to budding, about 130 days of field growth period, natural plant height of 159.9 cm, topped plant height of 111.9 cm, 26.0 natural leaves, and 21-22 leaves available for baking. The cured tobacco leaves are mainly orange-yellow, with oiliness, loose structure, moderate body, suitable main internal chemical components, good overall coordination, good overall sensory quality, and strong industrial usability. Taking Guizhou as an example, in recent years, GZ36 has been demonstrated and promoted in Guizhou Province at an average of more than 30,000 mu per year, with an average yield of about 125 kg per mu, and relatively high income for tobacco farmers.

[0003] As a flue-cured tobacco strain selected after hybridization, the baking characteristics and maturity characteristics of the upper leaves of GZ36 are somewhat different from those of conventional flue-cured tobacco varieties such as K326 and Yunyan 87. This results in the fact that the tobacco leaf baking standards formulated based on K326, Yunyan 87, etc. cannot well adapt to GZ36 flue-cured tobacco, especially the upper leaves of GZ36 flue-cured tobacco. Through experiments, when using the conventional three-stage baking process for baking, problems such as relatively high proportions of ash hanging and stiffness of the cured tobacco leaves, poor appearance quality, and insufficient aroma are more prominent, and the quality of the cured tobacco leaves is not satisfactory.

[0004] At the same time, during the promotion process in Guizhou, due to the obvious three-dimensional mountain climate in Guizhou, the temperature is relatively high during the mature baking period of the upper leaves in the central and eastern tobacco-growing areas at low altitudes, while the temperature is relatively low in the western region at low altitudes, and there are also certain differences in other ecological conditions. The unique ecological climate conditions also result in differences in the baking characteristics and maturity of the upper leaves of GZ36 flue-cured tobacco.

[0005] Therefore, it is necessary to formulate a baking method for the upper leaves of GZ36 flue-cured tobacco by region, combining the baking characteristics and maturity characteristics of the fresh upper leaves of GZ36 flue-cured tobacco. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a baking method that can improve the internal quality of the cured tobacco leaves of the upper part of GZ36 flue-cured tobacco.

[0007] The technical solution of the present invention is as follows:

[0008] A baking method for the upper leaves of GZ36 flue-cured tobacco, which comprises the following steps:

[0009] S1. Fresh tobacco leaves are harvested at maturity: Distinguish GZ36 flue-cured tobacco according to low-altitude areas and high-altitude areas, and harvest at maturity when the upper leaves meet the maturity characteristics.

[0010] S2. Classification, stringing and loading of fresh tobacco leaves: Screen and classify the harvested fresh tobacco leaves, remove immature and overripe leaves without baking value, and the remaining leaves are divided into three categories: physiological maturity, technological maturity and full maturity, and then string and load them into the barn by category.

[0011] S3. Baking of fresh tobacco leaves: According to the different baking characteristics and maturity characteristics of tobacco leaves in low-altitude areas and high-altitude areas, distinguish the baking steps of tobacco leaves in low-altitude areas and high-altitude areas. The baking of tobacco leaves in low-altitude areas includes the following steps:

[0012] S3 Low-1. After ignition, start the circulation fan to run at low speed, raise the dry-bulb temperature to 33-35°C at a heating rate of 1°C / h, the wet-bulb temperature is 32-34°C, and keep the temperature stable for baking for 3-5h until the upper-layer tobacco leaves turn yellow by 1-2 tenths.

[0013] S3 Low-2. Start the circulation fan to run at high speed, raise the dry-bulb temperature to 41-42°C at a heating rate of 1°C / h, the wet-bulb temperature is 38-39°C, and keep the temperature stable for baking for 2-3h until the upper-layer tobacco leaves turn yellow by 2-3 tenths and are slightly soft.

[0014] S3 Low-3. Lower the dry-bulb temperature to 37-38°C at a cooling rate of 1°C / h, keep the wet-bulb temperature stable at 36-37°C, start the circulation fan to run at low speed, and keep the temperature stable for baking for 10-20h until the upper-layer tobacco leaves turn yellow by 7-8 tenths and the leaves are soft.

[0015] S3 Low-4. Start the circulation fan to run at high speed, raise the dry-bulb temperature to 41-42°C at a heating rate of 1°C / h, the wet-bulb temperature is 37-38°C, and keep the temperature stable for baking for 2-3h until the upper-layer tobacco leaves turn yellow by 8-9 tenths and the main vein is slightly soft.

[0016] S3 Low-5. Lower the dry-bulb temperature to 39-40°C at a cooling rate of 1°C / h, keep the wet-bulb temperature stable at 38°C, start the circulation fan to run at medium speed, and keep the temperature stable for baking for 6-8h; then lower the wet-bulb temperature to 37°C and keep the temperature stable for baking for 2-3h until the upper-layer tobacco leaves turn yellow by 9 tenths or more and the leaves are fully soft and withered.

[0017] S3 Low-6. Start the circulation fan to run at high speed, raise the dry-bulb temperature to 42°C at a heating rate of 1°C / 2h, keep the wet-bulb temperature stable at 37°C, and keep the temperature stable for baking for 6-8h; then lower the wet-bulb temperature to 36°C and keep the temperature stable for baking for 3-5h until the upper-layer tobacco leaves are basically yellow, the leaves start to curl at the tip, the base of the middle-layer tobacco leaves is slightly green, and the main veins of all the tobacco leaves in the barn are soft.

[0018] S3 Low-7. Keep the circulation fan running at high speed, raise the dry bulb temperature to 44°C at a heating rate of 1°C every 3 hours, keep the wet bulb temperature stable at 35 - 36°C, and bake at a constant temperature for 10 - 12 hours until the upper-layer tobacco leaves are fully yellowed, with the tips and edges curled, and more than 1 / 3 of the leaves are dried;

[0019] S3 Low-8. Keep the circulation fan running at high speed, raise the dry bulb temperature to 47°C at a heating rate of 1°C every 2 - 3 hours, keep the wet bulb temperature at 36 - 37°C, and bake at a constant temperature for 8 - 12 hours until the main veins of the upper-layer tobacco leaves turn yellow and more than 1 / 2 of the leaves are dried, showing a small scroll state;

[0020] S3 Low-9. Start the circulation fan running at medium speed, raise the dry bulb temperature to 50°C at a heating rate of 1°C every 2 hours, keep the wet bulb temperature at 38°C, and bake at a constant temperature for 6 - 8 hours until more than 2 / 3 of the upper-layer tobacco leaves are dried, and the main veins of the whole-batch tobacco leaves turn yellow and shrink significantly;

[0021] S3 Low-10. Keep the circulation fan running at medium speed, raise the dry bulb temperature to 53°C at a heating rate of 1°C every 2 hours, keep the wet bulb temperature at 39°C, and bake at a constant temperature for 15 - 18 hours until the whole-batch tobacco leaves are dried and in a large scroll state, and more than 1 / 3 of the main veins of the upper-layer tobacco leaves are dried;

[0022] S3 Low-11. Keep the circulation fan running at medium speed, raise the dry bulb temperature to 60°C at a heating rate of 1°C per hour, keep the wet bulb temperature at 39 - 40°C, and bake at a constant temperature for 6 - 8 hours until more than 1 / 2 of the main veins of the upper-layer tobacco leaves are dried;

[0023] S3 Low-12. Start the circulation fan running at low speed, raise the dry bulb temperature to 65°C at a heating rate of 1°C per hour, keep the wet bulb temperature at 40°C, and bake at a constant temperature for 20 - 30 hours until the whole-batch tobacco leaves are completely dried;

[0024] The tobacco leaf baking in the high-altitude area includes the following steps:

[0025] S3 High-1. Start the circulation fan running at low speed, raise the dry bulb temperature to 31 - 32°C at a heating rate of 1°C per hour, keep the wet bulb temperature at 30.5 - 31.5°C, with the temperature difference between the dry bulb and wet bulb being 0 - 0.5°C, and bake while maintaining temperature and humidity for 3 - 5 hours until the tips and edges of the upper-layer tobacco leaves turn yellow;

[0026] S3 High-2. Start the circulation fan running at high speed, raise the dry bulb temperature to 41 - 42°C at a heating rate of 1°C per hour, keep the wet bulb temperature at 38 - 39°C, and bake at a constant temperature for 2 - 3 hours until the upper-layer tobacco leaves turn 1 - 2 grades yellow and become slightly soft;

[0027] S3 High - 3: Lower the dry - bulb temperature at a rate of 1°C / h to 35 - 36°C, keep the wet - bulb temperature stable at 34 - 35°C, start the circulation fan running at low speed, and bake at a constant temperature for 3 - 5 h until the upper - layer tobacco leaves turn yellow by 2 - 3 tenths and the leaves become soft by more than 1 / 3;

[0028] S3 High - 4: Start the circulation fan running at high speed, raise the dry - bulb temperature at a rate of 1°C / h to 41 - 42°C, keep the wet - bulb temperature at 37 - 38°C, bake at a constant temperature for 2 - 3 h until the upper - layer tobacco leaves turn yellow by 3 - 4 tenths and the leaves become soft by more than 1 / 2;

[0029] S3 High - 5: Lower the dry - bulb temperature at a rate of 1°C / h to 38°C, keep the wet - bulb temperature stable at 36 - 37°C, start the circulation fan running at low speed, and bake at a constant temperature for 15 - 25 h until the upper - layer tobacco leaves turn yellow by 7 - 8 tenths and the leaves become soft;

[0030] S3 High - 6: Start the circulation fan running at high speed, raise the dry - bulb temperature at a rate of 1°C / h to 41 - 42°C, keep the wet - bulb temperature at 37 - 38°C, bake at a constant temperature for 2 - 3 h until the upper - layer tobacco leaves turn yellow by 8 - 9 tenths and the main veins become slightly soft;

[0031] S3 High - 7: Lower the dry - bulb temperature at a rate of 1°C / h to 40°C, keep the wet - bulb temperature stable at 38°C, start the circulation fan running at medium speed, bake at a constant temperature for 8 - 10 h; then lower the wet - bulb temperature to 37°C and bake at a constant temperature for 2 - 3 h until the upper - layer tobacco leaves turn yellow by 9 tenths or more and the leaves become fully soft and withered;

[0032] S3 High - 8: Start the circulation fan running at high speed, raise the dry - bulb temperature at a rate of 1°C / 2h to 42°C, keep the wet - bulb temperature stable at 37°C, bake at a constant temperature for 6 - 8 h; then lower the wet - bulb temperature to 36°C and bake at a constant temperature for 3 - 5 h until the upper - layer tobacco leaves have yellow leaves with green veins, hooked tips and curled edges, the middle - layer tobacco leaves have slightly green bases at the bottom, and the main veins of all the tobacco leaves in the pit become soft;

[0033] S3 High - 9: Keep the circulation fan running at high speed, raise the dry - bulb temperature at a rate of 1°C / 3h to 45°C, keep the wet - bulb temperature stable at 35 - 36°C, bake at a constant temperature for 10 - 15 h until more than 1 / 3 of the upper - layer tobacco leaves are dry, and the middle - layer tobacco leaves have yellow leaves with green veins, hooked tips and curled edges;

[0034] S3 High - 10: Keep the circulation fan running at high speed, raise the dry - bulb temperature at a rate of 1°C / 2h to 49°C, keep the wet - bulb temperature at 37 - 38°C, bake at a constant temperature for 10 - 15 h until the main veins of the upper - layer tobacco leaves turn yellow, more than 1 / 2 of the leaves are dry, and the leaves are in a small - roll state;

[0035] S3 High-11, start the circulating fan at medium gear, raise the dry bulb temperature to 54℃ at a heating rate of 1℃ / 2h, and the wet bulb temperature to 38-39℃, and bake at a steady temperature for 12-18h, until the whole kang tobacco leaves are dry, the large rolls are dry, and the main tendons of the high-temperature layer tobacco are dry by more than 1 / 3;

[0036] S3 High-12, keep the circulating fan running at medium gear, raise the dry bulb temperature to 60℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 39-40℃, and bake at a steady temperature for 6-8h, until the main tendons of the high-temperature layer tobacco leaves are more than 1 / 2 dry;

[0037] S3 High-13, start the circulating fan at low speed, raise the dry-bulb temperature to 68℃ at a heating rate of 1℃ / h, and the wet-bulb temperature to 40-41℃, and bake at a steady temperature for 20-30h until the tobacco leaves on the kang are completely dry.

[0038] The above-mentioned method for baking the upper leaves of GZ36 flue-cured tobacco is as follows: in step S2, the fresh tobacco leaves are classified and sorted, and then placed on a tobacco drying rack in the tobacco sorting area for 4 to 6 hours to promote the physiological aging of the tobacco leaves.

[0039] The aforementioned method for baking the upper leaves of GZ36 flue-cured tobacco is that, when loading tobacco, according to the airflow movement mode and type of the flue-curing room, physiologically mature tobacco leaves are loaded in a low-temperature area, fully mature tobacco leaves are loaded in a high-temperature area, and technologically mature fresh tobacco leaves are loaded in other areas; the loading amount is 5% to 10% more than the conventional loading amount.

[0040] The aforementioned GZ36 flue-cured tobacco upper leaf baking method is to start the circulating fan at high speed for 2 to 3 hours before ignition in step S3 to promote physiological aging of tobacco leaves in the baking room.

[0041] The above-mentioned GZ36 flue-cured tobacco upper leaf baking method is that the circulating fan adopts frequency conversion technology, and the frequency is divided into three gears, the high-end circulating fan frequency is 44-50Hz, the medium-end circulating fan frequency is 37-43Hz, and the low-end circulating fan frequency is 30-36Hz.

[0042] The above-mentioned GZ36 flue-cured tobacco upper leaf baking method is that the GZ36 upper leaves in the low altitude area are easy to bake and have a poor baking resistance; the GZ36 upper leaves in the high altitude area are relatively easy to bake and have a medium baking resistance.

[0043] The above-mentioned GZ36 flue-cured tobacco upper leaf baking method is that the difference between the GZ36 flue-cured tobacco in the low altitude area and the GZ36 flue-cured tobacco in the high altitude area is as follows: the basic color of the leaf surface of the upper mature tobacco leaves in the low altitude area is light yellow or pale yellow, the yellow area is 80% to 90%, the main vein is whitish, more than 80% of the branch veins are completely white, the leaf surface is wrinkled, the leaf tips and edges are whitish and curled, the fuzz is basically fallen off, the yellow-white mature spots are obvious, and the stem-leaf angle is significantly increased; the basic color of the leaf surface of the upper mature tobacco leaves in the high altitude area is light yellow or pale yellow, the yellow area is 70% to 80%, the main vein is whitish, the branch veins are 70% to 80% whitish, the leaf surface has a strong sense of shrinkage, the leaf tips and edges are light yellow or whitish and curled, most of the fuzz has fallen off, the yellow mature spots are obvious, and the stem-leaf angle is increased.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] 1. The present invention proposes a standardized picking and baking method for the newly cultivated GZ36 flue-cured tobacco upper leaves, preliminarily formulates a baking strategy for the GZ36 upper leaves according to the characteristics of the GZ36 flue-cured tobacco upper leaves, and puts the formulated baking strategy into practice. After multiple comparative tests, the test data of the baked GZ36 tobacco leaves are analyzed and compared, and the baking method and key parameters of the GZ36 flue-cured tobacco upper leaves are gradually adjusted and improved. A new baking method is proposed to use a dry-bulb temperature cycle rising and falling method to promote the full softening and withering of tobacco leaves and material conversion, and to improve the coordination of the chemical components of the baked tobacco leaves and the content of aroma substances. The new baking method has the following advantages in terms of the appearance quality and detection data of the tobacco leaves after baking:

[0046] (1) It is conducive to the full softening and withering of tobacco leaves and the full degradation and transformation of macromolecular substances during the baking process, thereby improving the coordination of the chemical composition of the tobacco leaves after baking;

[0047] (2) It is beneficial to improve the appearance quality of the tobacco leaves after curing, such as maturity, color, oil content, chroma, and organizational structure;

[0048] (3) It is helpful to reduce the loss of tobacco leaf aroma, reduce the proportion of stiff and gray tobacco leaves, and improve the aroma substance content and sensory quality of tobacco leaves after curing.

[0049] 2. This paper analyzes the data of flue-cured tobacco leaves and clarifies the cultivation cycle and picking time of the upper leaves of GZ36 flue-cured tobacco. The cultivation cycle and picking time are 125 to 135 days in the field growth period and 85 to 95 days in leaf age, which is 5 to 10 days later than the conventional flue-cured tobacco varieties Yunyan 87 and K326. The tobacco leaves in the upper second position are fully mature and are harvested at one time.

[0050] 3. In the analysis of multiple baking tests in Guizhou, differences in tobacco leaves between low-altitude and high-altitude areas were discovered. The quality, maturity characteristics, and ecological climate characteristics of tobacco leaves in the central and eastern regions with lower altitudes and the western regions with higher altitudes in Guizhou were analyzed by region, further refining and improving the baking processes for high-altitude and low-altitude areas. The baking of tobacco leaves in the low-altitude area is divided into 12 steps, with the dry-bulb temperature cycling up and down 2 times during the yellowing period; the baking of tobacco leaves in the high-altitude area is divided into 13 steps, with the dry-bulb temperature cycling up and down 3 times during the yellowing period. At the same time, data were summarized to refine the dry-bulb temperature, corresponding wet-bulb temperature, heating time, temperature stabilization time, and corresponding circulating fan gears for each step, enabling smokers to quickly master them, improving the quality of tobacco leaves, and increasing the income of tobacco farmers.

[0051] 4. A tobacco leaf withering treatment was further set up, clarifying the classification of loading tobacco and the differences from the conventional loading amount, which can promote the full conversion of substances during the baking process of harvested and baked tobacco leaves and improve the quality of the baked tobacco leaves.

[0052] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be learned from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. Detailed implementation manners

[0053] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the tables in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0054] Example 1: A method for baking the upper leaves of GZ36 flue-cured tobacco. First, the baking characteristics of the upper leaves of GZ36 flue-cured tobacco were judged according to the tobacco industry standard YC / T 311-2009 "Evaluation of Baking Characteristics of Flue-cured Tobacco Varieties": The conclusion is that the upper leaves of GZ36 in the low-altitude area have good ease of baking and poor heat resistance; the upper leaves of GZ36 in the high-altitude area have relatively poor ease of baking and medium heat resistance.

[0055] Taking Guizhou as an example, the low-altitude areas below 1500 m in Guizhou include some tobacco-growing areas in Southeast Guizhou, Tongren, Zunyi, Guiyang, South Guizhou, Anshun, Southwest Guizhou, and parts of Bijie and Liupanshui. The high-altitude areas above 1500 m in Guizhou include the tobacco-growing areas in the western parts of Bijie, Liupanshui, and Southwest Guizhou. There are certain differences in the upper mature tobacco leaves between the two. The main manifestations are as follows: for the upper mature tobacco leaves in the low-altitude areas, the basic color of the leaf surface is light yellow or pale yellow, the yellow area is 80% - 90%, the main vein is white, more than 80% of the secondary veins are completely white, the leaf surface is wrinkled, the leaf tip and leaf margin are white and curled downwards, the pubescence has basically fallen off, the yellowish-white mature spots are obvious, and the stem-leaf angle has increased significantly; for the upper mature tobacco leaves in the high-altitude areas, the basic color of the leaf surface is light yellow or pale yellow, the yellow area is 70% - 80%, the main vein is white, 70% - 80% of the secondary veins are white, the leaf surface has a strong sense of shrinkage, the leaf tip and leaf margin are light yellow or white and curled downwards, most of the pubescence has fallen off, the yellow mature spots are obvious, and the stem-leaf angle has increased. Due to the certain differences in the upper leaves of GZ36 flue-cured tobacco in different altitude areas, the baking methods for the upper leaves of GZ36 flue-cured tobacco in the low-altitude area and the high-altitude area are formulated separately.

[0056] The baking method for the upper leaves of GZ36 flue-cured tobacco in the low-altitude area includes the following steps:

[0057] S1. Fresh tobacco leaves are harvested when mature: Regarding the characteristics of fresh tobacco leaves with a basic leaf surface color of light yellow or pale yellow, a yellow area of 80% - 90%, a white main vein, more than 80% of the secondary veins completely white, a wrinkled leaf surface, a white and curled-down leaf tip and leaf margin, basically fallen-off pubescence, obvious yellowish-white mature spots, and a significantly increased stem-leaf angle as the fully mature characteristics, a one-time harvest is carried out based on the full maturity of the second-to-last leaf position in the upper part.

[0058] S2. Classification, stringing, and loading of fresh tobacco leaves into the barn: Immature and overripe tobacco leaves without baking value are removed. The remaining tobacco leaves are classified into three categories: physiological maturity, technological maturity, and full maturity, and then strung separately. Then, they are placed on the tobacco drying racks in the stringing area and left to dry for 4 - 6 h to further promote the physiological senescence and after-ripening of the tobacco leaves. Then, according to the air flow movement mode and the type of the barn, the physiologically mature tobacco leaves are first loaded in the low-temperature area, the fully mature tobacco leaves are loaded in the high-temperature area, and then the fresh tobacco leaves with technological maturity are loaded in other areas for loading into the barn; the loading amount is 5% - 10% more than the conventional loading amount. After loading the tobacco, before ignition, the circulation fan is started at high speed and runs for 2 - 3 h.

[0059] S3 Low-1. After ignition, start the circulation fan to run at low speed, and raise the dry-bulb temperature to 33 - 35 °C at a heating rate of 1 °C / h, with a wet-bulb temperature of 32 - 34 °C, and bake at a constant temperature for 3 - 5 h until the upper-layer tobacco leaves turn yellow by 1 - 2 tenths.

[0060] S3 Low-2. Start the circulation fan to run at high speed, and raise the dry-bulb temperature to 41 - 42 °C at a heating rate of 1 °C / h, with a wet-bulb temperature of 38 - 39 °C, and bake at a constant temperature for 2 - 3 h until the upper-layer tobacco leaves turn yellow by 2 - 3 tenths and become slightly soft.

[0061] S3 Low-3: Lower the dry-bulb temperature to 37 - 38°C at a cooling rate of 1°C / h, keep the wet-bulb temperature stable at 36 - 37°C, start the circulation fan running at low speed, and bake at a constant temperature for 10 - 20 h until the upper-layer tobacco leaves turn yellow by 7 - 8 tenths and the leaves become soft.

[0062] S3 Low-4: Start the circulation fan running at high speed, raise the dry-bulb temperature to 41 - 42°C at a heating rate of 1°C / h, keep the wet-bulb temperature at 37 - 38°C, bake at a constant temperature for 2 - 3 h until the tobacco leaves turn yellow by 8 - 9 tenths and the main veins become slightly soft.

[0063] S3 Low-5: Lower the dry-bulb temperature to 39 - 40°C at a cooling rate of 1°C / h, keep the wet-bulb temperature stable at 38°C, start the circulation fan running at medium speed, bake at a constant temperature for 6 - 8 h; then lower the wet-bulb temperature to 37°C and bake at a constant temperature for 2 - 3 h until the upper-layer tobacco leaves turn yellow by 9 tenths or more and the leaves become fully soft and withered.

[0064] S3 Low-6: Start the circulation fan running at high speed, raise the dry-bulb temperature to 42°C at a heating rate of 1°C / 2h, keep the wet-bulb temperature stable at 37°C, bake at a constant temperature for 6 - 8 h; then lower the wet-bulb temperature to 36°C and bake at a constant temperature for 3 - 5 h until the upper-layer tobacco leaves are basically yellow, the leaves start to hook at the tip, the base of the middle-layer tobacco leaves is slightly green, and the main veins of all the tobacco leaves in the pit become soft.

[0065] S3 Low-7: Keep the circulation fan running at high speed, raise the dry-bulb temperature to 44°C at a heating rate of 1°C / 3h, keep the wet-bulb temperature stable at 35 - 36°C, bake at a constant temperature for 10 - 12 h until the upper-layer tobacco leaves are fully yellow, hooked at the tip and curled at the edge, and more than 1 / 3 of the leaves are dry.

[0066] S3 Low-8: Keep the circulation fan running at high speed, raise the dry-bulb temperature to 47°C at a heating rate of 1°C / 2 - 3h, keep the wet-bulb temperature at 36 - 37°C, bake at a constant temperature for 8 - 12 h until the main veins of the upper-layer tobacco leaves turn yellow, more than 1 / 2 of the leaves are dry, and the leaves are in a small roll state.

[0067] S3 Low-9: Start the circulation fan running at medium speed, raise the dry-bulb temperature to 50°C at a heating rate of 1°C / 2h, keep the wet-bulb temperature at 38°C, bake at a constant temperature for 6 - 8 h until more than 2 / 3 of the upper-layer tobacco leaves are dry, and the main veins of all the tobacco leaves in the whole pit turn yellow and shrink significantly.

[0068] S3 Low-10: Keep the circulation fan running at medium speed, raise the dry-bulb temperature to 53°C at a heating rate of 1°C / 2h, keep the wet-bulb temperature at 39°C, bake at a constant temperature for 15 - 18 h until all the tobacco leaves in the whole pit are dry and in a large roll state, and more than 1 / 3 of the main veins of the upper-layer tobacco leaves are dry.

[0069] S3 low-11, keep the circulating fan running at medium gear, raise the dry bulb temperature to 60℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 39-40℃, and bake at a steady temperature for 6-8h, until the main tendons of the high-temperature layer tobacco leaves are more than 1 / 2 dry;

[0070] S3 low-12, start the circulating fan at low speed, raise the dry bulb temperature to 65℃ and the wet bulb temperature to 40℃ at a heating rate of 1℃ / h, and bake at a steady temperature for 20 to 30 hours until the tobacco leaves on the kang are completely dry.

[0071] The method for baking the upper leaves of GZ36 flue-cured tobacco in high altitude areas comprises the following steps

[0072] S1. Mature harvesting of fresh tobacco leaves: The basic color of the tobacco leaves is light yellow or pale yellow, the yellow area is 70% to 80%, the main veins are whitish, the side veins are 70% to 80% whitish, the leaves have a strong sense of shrinkage, the tips and edges of the leaves are light yellow or whitish and curled downward, the hairs are mostly shed, the yellow mature spots are obvious, and the angle between the stems and leaves is increased. The fresh tobacco leaves are considered fully mature, and the leaves in the upper second leaf position are fully mature and harvested at one time;

[0073] S2. Classification, arrangement and loading of fresh tobacco leaves: Unripe and overripe tobacco leaves with no baking value are removed, and the tobacco leaves are kept and arranged into three categories: physiological maturity, technological maturity and complete maturity, and then placed on the tobacco drying racks in the arrangement area for 4 to 6 hours to further promote the physiological aging and after-ripening of the tobacco leaves; then, according to the air flow movement mode and type of the curing room, the physiologically mature tobacco leaves are first loaded in the low-temperature area and the complete-ripe tobacco leaves are loaded in the high-temperature area, and then the technologically mature fresh tobacco leaves are loaded in other areas for loading; the loading amount is 5% to 10% more than the conventional loading amount; after the loading is completed, before ignition, the circulating fan is started to run at high speed for 2 to 3 hours;

[0074] S3 High-1. Start the circulating fan at low speed, raise the dry-bulb temperature to 31-32℃ at a heating rate of 1℃ / h, and the wet-bulb temperature to 30.5-31.5℃. The difference between the dry-bulb temperature and the wet-bulb temperature is 0-0.5℃. Bake for 3-5 hours at a stable temperature and moisture retention until the tips and edges of the tobacco leaves in the high-temperature layer turn yellow.

[0075] S3 High-2, start the circulating fan to run at high speed, raise the dry bulb temperature to 41-42℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 38-39℃, and bake at a steady temperature for 2-3h, until the tobacco leaves in the high temperature layer turn 10% to 20% yellow and slightly soften;

[0076] S3 High -3, reduce the dry bulb temperature to 35-36℃ at a cooling rate of 1℃ / h, stabilize the wet bulb temperature at 34-35℃, start the circulating fan at low speed, and bake at a steady temperature for 3-5h, until the high temperature layer tobacco leaves turn 20% to 30% yellow and more than 1 / 3 of the leaves become soft;

[0077] S3 high-4, start the circulating fan to run at high speed, raise the dry bulb temperature to 41-42℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 37-38℃, and bake at a steady temperature for 2-3h, until the high temperature layer tobacco leaves turn 30%-40% yellow and the leaves become more than 1 / 2 soft;

[0078] S3 high-5, reduce the dry bulb temperature to 38℃ at a cooling rate of 1℃ / h, stabilize the wet bulb temperature at 36-37℃, start the circulating fan at low speed, and bake at a steady temperature for 15-25h, until the high-temperature layer tobacco leaves turn 70% to 80% yellow and the leaves become soft;

[0079] S3 high-6, start the circulating fan to run at high speed, raise the dry bulb temperature to 41-42℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 37-38℃, and bake at a steady temperature for 2-3h, until the high temperature layer tobacco leaves turn 80%-90% yellow and the main veins become slightly soft;

[0080] S3 high-7, reduce the dry bulb temperature to 40℃ at a cooling rate of 1℃ / h, stabilize the wet bulb temperature at 38℃, start the circulating fan at medium gear, and bake at a steady temperature for 8-10h; then reduce the wet bulb temperature to 37℃, bake at a steady temperature for 2-3h, until the high temperature layer tobacco leaves turn 90% or more yellow and the leaves are fully soft and withered;

[0081] S3 high-8, start the circulating fan to run at high speed, raise the dry bulb temperature to 42℃ at a heating rate of 1℃ / 2h, stabilize the wet bulb temperature at 37℃, and bake at a steady temperature for 6-8h; then lower the wet bulb temperature to 36℃, bake at a steady temperature for 3-5h, until the high-temperature layer of tobacco leaves have yellow leaves with blue veins, hooked tips and curled edges, the base of the middle layer of tobacco leaves is slightly green, and the main veins of the whole pit tobacco leaves are soft;

[0082] S3 High-9, keep the circulating fan running at high speed, raise the dry bulb temperature to 45℃ at a heating rate of 1℃ / 3h, stabilize the wet bulb temperature at 35-36℃, and bake at a steady temperature for 10-15h, until the high-temperature layer tobacco leaves are more than 1 / 3 dry, and the middle layer tobacco leaves are yellow with blue veins, hook tips and curled edges;

[0083] S3 high-10, keep the circulating fan running at high speed, raise the dry bulb temperature to 49℃ at a heating rate of 1℃ / 2h, and the wet bulb temperature to 37-38℃, and bake at a steady temperature for 10-15h, until the main tendons of the high-temperature layer tobacco turn yellow, the leaves are more than 1 / 2 dry, and are in a small roll state;

[0084] S3 High-11, start the circulating fan at medium gear, raise the dry bulb temperature to 54℃ at a heating rate of 1℃ / 2h, and the wet bulb temperature to 38-39℃, and bake at a steady temperature for 12-18h, until the whole kang tobacco leaves are dry, the large rolls are dry, and the main tendons of the high-temperature layer tobacco are dry by more than 1 / 3;

[0085] S3 High - 12. Keep the circulation fan running at medium speed, raise the dry - bulb temperature to 60°C at a heating rate of 1°C / h, with the wet - bulb temperature at 39 - 40°C, and keep the temperature stable for baking for 6 - 8h until more than half of the main veins of the upper - layer tobacco leaves are dried;

[0086] S3 High - 13. Start the circulation fan running at low speed, raise the dry - bulb temperature to 68°C at a heating rate of 1°C / h, with the wet - bulb temperature at 40 - 41°C, and keep the temperature stable for baking for 20 - 30h until all the tobacco leaves in the whole barn are completely dried.

[0087] The above - mentioned baking method for the upper leaves of GZ36 flue - cured tobacco is as follows: In step S2, classify and string the fresh tobacco leaves, and then place them on the curing rack in the stringing area for 4 - 6h to promote the physiological senescence of the tobacco leaves.

[0088] The above - mentioned baking method for the upper leaves of GZ36 flue - cured tobacco is as follows: According to the air - flow movement mode and the type of the curing barn, load the physiologically mature tobacco leaves in the low - temperature area, the fully ripe tobacco leaves in the high - temperature area, and the fresh tobacco leaves at the technological maturity stage in other areas; the loading amount is 5% - 10% more than the conventional loading amount.

[0089] The above - mentioned baking method for the upper leaves of GZ36 flue - cured tobacco is as follows: Before ignition in step S3, start the circulation fan running at high speed for 2 - 3h to promote the physiological senescence of the tobacco leaves in the curing barn.

[0090] For the upper leaves of GZ36 in the low - altitude area, the ease of baking is relatively good, but the heat - tolerance is relatively poor; for the upper leaves of GZ36 in the high - altitude area, the ease of baking is relatively poor, and the heat - tolerance is medium.

[0091] The circulation fan adopts variable - frequency technology, and the frequency is divided into three gears. The frequency of the high - gear circulation fan is 44 - 50Hz, the frequency of the medium - gear circulation fan is 37 - 43Hz, and the frequency of the low - gear circulation fan is 30 - 36Hz.

[0092] After improving the baking method for the upper leaves of GZ36 flue - cured tobacco, the applicant compared the two baking processes of the initial conventional baking (traditional three - stage baking) and the new - technology baking (the method described in the present invention) for baking the upper leaves of GZ36 flue - cured tobacco in the central - eastern region of Guizhou: compared the average values of the appearance quality, grade structure, chemical - component content, aroma - component content, and sensory quality of the baked tobacco leaves under different treatments, and the results are shown in Tables 1 - 5.

[0093] Table 1. Effects of different treatments on the appearance quality of baked tobacco leaves

[0094]

[0095]

[0096] Table 2. Effects of different treatments on the grade structure of baked tobacco leaves (%)

[0097]

[0098] Note: Different lowercase letters indicate significant differences among different treatments at the 5% level. The same below.

[0099] Table 3 Effects of Different Treatments on the Contents of Aroma Components in Flue-cured Tobacco Leaves after Baking (μg / g)

[0100]

[0101] Table 4 Effects of Different Treatments on the Contents of Chemical Components in Flue-cured Tobacco Leaves after Baking

[0102]

[0103] Table 5 Effects of Different Treatments on the Sensory Quality of Flue-cured Tobacco Leaves after Baking

[0104]

[0105] Note: The sensory quality evaluation is the sum of the scores of 6 items including aroma quality, aroma quantity, taste, off-odor, irritation, and body, and each item is scored out of 10.

[0106] Two baking processes, conventional baking (traditional three-stage baking) and new technology baking (the method described in the present invention), were used to bake the upper leaves of GZ36 flue-cured tobacco in the western region of Guizhou. The average values of the appearance quality, grade structure, chemical component content, aroma component content, and sensory quality of flue-cured tobacco leaves after different treatments were compared, and the results are shown in Tables 6 - 10.

[0107] Table 6 Effects of Different Treatments on the Appearance Quality of Flue-cured Tobacco Leaves after Baking

[0108]

[0109]

[0110] Table 7 Effects of Different Treatments on the Grade Structure of Flue-cured Tobacco Leaves after Baking (%)

[0111]

[0112] Note: Different lowercase letters indicate significant differences among different treatments at the 5% level. The same below.

[0113] Table 8 Effects of Different Treatments on the Contents of Aroma Components in Flue-cured Tobacco Leaves after Baking (μg / g)

[0114]

[0115] Table 9 Effects of Different Treatments on the Contents of Chemical Components in Flue-cured Tobacco Leaves after Baking

[0116]

[0117] Table 10 Effects of Different Treatments on the Sensory Quality of Flue-cured Tobacco Leaves after Baking

[0118]

[0119] Note: The sensory quality evaluation is the sum of the scores of 6 items, namely aroma quality, aroma quantity, taste, off-flavors, irritation, and body, with each item having a full score of 10 points.

[0120] It can be easily seen from Tables 1 to 10 that when the upper leaves of GZ36 flue-cured tobacco are baked by using the new baking method (the method described in the present invention) in the central-eastern and western tobacco-growing areas of Guizhou, the appearance quality, grade structure, chemical composition content, aroma component content, and sensory quality of the baked tobacco leaves are all superior to those of conventional baking (traditional three-stage baking), and the quality and quality of the baked tobacco leaves are significantly improved.

[0121] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. This specification selects and specifically describes the embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the relevant technical fields can understand and utilize the present invention well.

Claims

1. A method for baking upper leaves of GZ36 flue-cured tobacco, characterized in that, It includes the following steps: S1. Mature harvesting of fresh tobacco leaves: GZ36 flue-cured tobacco is divided into low-altitude areas and high-altitude areas, and the upper leaves are harvested when they meet the maturity characteristics; the high-altitude area is an area above 1500m, and the low-altitude area is an area below 1500m; S2. Classification, weaving and packing of fresh tobacco leaves: The harvested fresh tobacco leaves are screened and classified, and unripe and overripe tobacco leaves with no baking value are removed. The remaining tobacco leaves are divided into three categories: physiologically mature, technologically mature and fully mature, and the tobacco leaves are classified, weaved and packed into the heatable bed; S3, fresh tobacco leaf baking: according to the difference in tobacco leaf baking characteristics and tobacco leaf maturation characteristics in low altitude areas and high altitude areas, the tobacco leaf baking steps in low altitude areas and high altitude areas are distinguished, and the tobacco leaf baking in the low altitude area includes the following steps: S3 low-1. After ignition, start the circulating fan at low speed, raise the dry bulb temperature to 33~35℃ and the wet bulb temperature to 32~34℃ at a heating rate of 1℃ / h, and bake at a steady temperature for 3~5h until the tobacco leaves in the high temperature layer turn 10% to 20% yellow; S3 low-2, start the circulating fan to run at high speed, raise the dry bulb temperature to 41~42℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 38~39℃, and bake at a steady temperature for 2~3h, until the tobacco leaves in the high temperature layer turn 20%~30% yellow and slightly soften; S3 low-3, reduce the dry bulb temperature to 37~38℃ at a cooling rate of 1℃ / h, stabilize the wet bulb temperature at 36~37℃, start the circulating fan at low speed, and bake at a steady temperature for 10~20h until the high temperature layer tobacco leaves turn 70% to 80% yellow and the leaves become soft; S3 low-4, start the circulating fan at high speed, raise the dry bulb temperature to 41~42℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 37~38℃, and bake at a steady temperature for 2~3h, until the tobacco leaves turn 80% to 90% yellow and the main veins become slightly soft; S3 low-5, reduce the dry bulb temperature to 39~40℃ at a cooling rate of 1℃ / h, stabilize the wet bulb temperature at 38℃, start the circulating fan at medium gear, and bake at a steady temperature for 6~8h; then reduce the wet bulb temperature to 37℃, bake at a steady temperature for 2~3h, until the high temperature layer tobacco leaves turn yellow by 90% or more, and the leaves are fully soft and withered; S3 low-6, start the circulating fan to run at high speed, raise the dry bulb temperature to 42℃ at a heating rate of 1℃ / 2h, stabilize the wet bulb temperature at 37℃, and bake at a steady temperature for 6~8h; then lower the wet bulb temperature to 36℃, bake at a steady temperature for 3~5h, until the leaves of the high-temperature layer basically turn yellow and begin to hook, the base of the middle layer of tobacco leaves is slightly green, and the main veins of the whole pit tobacco leaves are soft; S3 low-7, keep the circulating fan running at high speed, raise the dry bulb temperature to 44℃ at a heating rate of 1℃ / 3h, stabilize the wet bulb temperature at 35~36℃, and bake at a stable temperature for 10~12h, until the high temperature layer tobacco leaves are fully yellow, the tips are curled, and the leaves are more than 1 / 3 dry; S3 low-8, keep the circulating fan running at high speed, raise the dry bulb temperature to 47℃ at a heating rate of 1℃ / 2~3h, and the wet bulb temperature to 36~37℃, and bake at a steady temperature for 8~12h, until the main tendons of the high-temperature layer tobacco turn yellow, the leaves are more than 1 / 2 dry, and are in a small roll state; S3 low-9, start the circulating fan at medium speed, raise the dry bulb temperature to 50℃ and the wet bulb temperature to 38℃ at a heating rate of 1℃ / 2h, and bake at a steady temperature for 6~8h until the high temperature layer of tobacco leaves is more than 2 / 3 dry, and the main tendons of the tobacco leaves on the whole kang turn yellow and shrink significantly; S3 low -10, keep the circulating fan running at medium gear, raise the dry bulb temperature to 53℃ and the wet bulb temperature to 39℃ at a heating rate of 1℃ / 2h, and bake at a steady temperature for 15~18h until the whole kang tobacco leaves are dry, the large rolls are dry, and the main tendons of the high-temperature layer tobacco are dry by more than 1 / 3; S3 low-11, keep the circulating fan running at medium gear, raise the dry bulb temperature to 60℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 39~40℃, and bake at a steady temperature for 6~8h until the main tendons of the high-temperature layer tobacco leaves are more than 1 / 2 dry; S3 low-12, start the circulating fan at low speed, raise the dry bulb temperature to 65℃ and the wet bulb temperature to 40℃ at a heating rate of 1℃ / h, and bake at a steady temperature for 20-30h until the tobacco leaves are completely dry; The high-altitude tobacco leaf baking comprises the following steps: S3 High-1. Start the circulating fan at low speed, raise the dry-bulb temperature to 31~32℃ at a heating rate of 1℃ / h, and the wet-bulb temperature to 30.5~31.5℃. The difference between the dry-bulb temperature and the wet-bulb temperature is 0~0.5℃. Bake at a stable temperature and moisture retention for 3~5h until the tips and edges of the tobacco leaves in the high-temperature layer turn yellow; S3 High-2, start the circulating fan at high speed, raise the dry bulb temperature to 41~42℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 38~39℃, and bake at a steady temperature for 2~3h, until the tobacco leaves in the high temperature layer turn 10% to 20% yellow and slightly soften; S3 High -3, reduce the dry bulb temperature to 35~36℃ at a cooling rate of 1℃ / h, stabilize the wet bulb temperature at 34~35℃, start the circulating fan at low speed, and bake at a steady temperature for 3~5h, until the high temperature layer tobacco leaves turn 20% to 30% yellow and more than 1 / 3 of the leaves become soft; S3 high-4, start the circulating fan to run at high speed, raise the dry bulb temperature to 41~42℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 37~38℃, and bake at a steady temperature for 2~3h, until the high temperature layer tobacco leaves turn 30% to 40% yellow and the leaves become more than 1 / 2 soft; S3 high-5, reduce the dry bulb temperature to 38℃ at a cooling rate of 1℃ / h, stabilize the wet bulb temperature at 36~37℃, start the circulating fan at low speed, and bake at a steady temperature for 15~25h until the high temperature layer tobacco leaves turn 70% to 80% yellow and the leaves become soft; S3 high-6, start the circulating fan to run at high speed, raise the dry bulb temperature to 41~42℃ at a heating rate of 1℃ / h, and the wet bulb temperature to 37~38℃, and bake at a steady temperature for 2~3h, until the high temperature layer tobacco leaves turn 80% to 90% yellow and the main veins become slightly soft; S3 high-7, reduce the dry bulb temperature to 40℃ at a cooling rate of 1℃ / h, stabilize the wet bulb temperature at 38℃, start the circulating fan at medium gear, and bake at a steady temperature for 8~10h; then reduce the wet bulb temperature to 37℃, bake at a steady temperature for 2~3h, until the high temperature layer tobacco leaves turn yellow by 90% or more, and the leaves are fully soft and withered; S3 High-8. Start the circulation fan to operate at high speed, raise the dry-bulb temperature to 42°C at a heating rate of 1°C every 2 hours, keep the wet-bulb temperature stable at 37°C, and bake at a constant temperature for 6 - 8 hours; then lower the wet-bulb temperature to 36°C and bake at a constant temperature for 3 - 5 hours until the upper-layer tobacco leaves show yellow leaves with green veins, hooked tips and curled edges, the base of the middle-layer tobacco leaves is slightly green, and the main veins of all the tobacco leaves in the pit are soft. S3 High-9. Keep the circulation fan operating at high speed, raise the dry-bulb temperature to 45°C at a heating rate of 1°C every 3 hours, keep the wet-bulb temperature stable at 35 - 36°C, and bake at a constant temperature for 10 - 15 hours until more than 1 / 3 of the upper-layer tobacco leaves are dry, and the middle-layer tobacco leaves show yellow leaves with green veins, hooked tips and curled edges. S3 High-10. Keep the circulation fan operating at high speed, raise the dry-bulb temperature to 49°C at a heating rate of 1°C every 2 hours, with the wet-bulb temperature at 37 - 38°C, and bake at a constant temperature for 10 - 15 hours until the main veins of the upper-layer tobacco leaves turn yellow and more than 1 / 2 of the leaves are dry, showing a small roll state. S3 High-11. Start the circulation fan to operate at medium speed, raise the dry-bulb temperature to 54°C at a heating rate of 1°C every 2 hours, with the wet-bulb temperature at 38 - 39°C, and bake at a constant temperature for 12 - 18 hours until all the tobacco leaves in the whole pit are dry and in a large roll state, and more than 1 / 3 of the main veins of the upper-layer tobacco leaves are dry. S3 High-12. Keep the circulation fan operating at medium speed, raise the dry-bulb temperature to 60°C at a heating rate of 1°C per hour, with the wet-bulb temperature at 39 - 40°C, and bake at a constant temperature for 6 - 8 hours until more than 1 / 2 of the main veins of the upper-layer tobacco leaves are dry. S3 High-13. Start the circulation fan to operate at low speed, raise the dry-bulb temperature to 68°C at a heating rate of 1°C per hour, with the wet-bulb temperature at 40 - 41°C, and bake at a constant temperature for 20 - 30 hours until all the tobacco leaves in the whole pit are completely dry.

2. The baking method for the upper leaves of GZ36 flue-cured tobacco according to claim 1, wherein: In step S2, the fresh tobacco leaves are classified and strung, and then placed on the tobacco-stringing area drying rack for 4 - 6 hours to promote the physiological senescence of the tobacco leaves.

3. The baking method for the upper leaves of GZ36 flue-cured tobacco according to claim 2, characterized in that: When loading the tobacco, according to the air flow movement mode and the type of the curing barn, the physiologically mature tobacco leaves are loaded in the low-temperature area, the fully mature tobacco leaves are loaded in the high-temperature area, and the fresh tobacco leaves at the technological maturity stage are loaded in other areas; the loading amount is 5% - 10% more than the conventional loading amount.

4. The baking method for upper leaves of GZ36 flue-cured tobacco according to any one of claims 1-3, characterized in that: Before igniting in step S3, start the circulation fan to operate at high speed for 2 - 3 hours to promote the physiological senescence of the tobacco leaves in the curing barn.

5. The baking method for upper leaves of GZ36 flue-cured tobacco according to claim 4, characterized in that: The circulation fan adopts frequency conversion technology, and the frequency is divided into three gears. The frequency of the high-speed circulation fan is 44 - 50Hz, the frequency of the medium-speed circulation fan is 37 - 43Hz, and the frequency of the low-speed circulation fan is 30 - 36Hz.

6. The baking method for the upper leaves of GZ36 flue-cured tobacco according to claim 1, characterized in that: For the upper leaves of GZ36 in the low-altitude area, the ease of baking is relatively good, but the resistance to baking is relatively poor; for the upper leaves of GZ36 in the high-altitude area, the ease of baking is relatively poor, and the resistance to baking is medium.

7. The baking method for upper leaves of GZ36 flue-cured tobacco according to claim 1, characterized in that: The differences between the GZ36 flue-cured tobacco in the low-altitude area and the high-altitude area are as follows: For the upper mature leaves in the low-altitude area, the basic color of the leaf surface is light yellow or pale yellow, the yellow area is 80% - 90%, the main vein is white, more than 80% of the secondary veins are completely white, the leaf surface is wrinkled, the leaf tip and leaf margin are white and curled downwards, the pubescence has basically fallen off, the yellowish-white mature spots are obvious, and the angle between the stem and leaves increases significantly; For the upper mature leaves in the high-altitude area, the basic color of the leaf surface is light yellow or pale yellow, the yellow area is 70% - 80%, the main vein is white, 70% - 80% of the secondary veins are white, the sense of leaf surface shrinkage is stronger, the leaf tip and leaf margin are light yellow or white and curled downwards, most of the pubescence has fallen off, the yellow mature spots are obvious, and the angle between the stem and leaves increases.

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