A kind of baking process for improving the baking quality of upper leaves of high-quality tobacco 36

Abstract

This invention discloses a baking process for improving the baking quality of the upper tobacco leaves of Guiyan 36, comprising the following steps: After loading the tobacco, close the loading door, turn on the automatic temperature and humidity control equipment, close the air inlet, and turn on the circulating fan for 1-2 hours; ignite the fire, raising the dry bulb temperature to 34.0℃-35.0℃ and the wet bulb temperature to 34.0℃-35.0℃, and bake at a stable temperature for 4-6 hours; then, raise the dry bulb temperature to 38.0℃ and the wet bulb temperature to 37.0℃, and bake at a stable temperature until the high-temperature layer tobacco leaves are 40-50% yellow; then, raise the dry bulb temperature to 42.0℃ and the wet bulb temperature to 37.0℃-38.0℃, and bake at a stable temperature until the high-temperature layer tobacco leaves are 70-80% yellow; then... Keep the dry-bulb temperature constant, and decrease the wet-bulb temperature from 37.0℃~38.0℃ to 36.0℃, 35.0℃, 34.0℃, and 33.5~33.0℃ in sequence. Then, control the wet-bulb temperature to remain constant at 33.5~33.0℃ and bake at a stable temperature and humidity until more than half of the leaf veins in the high-temperature layer turn white and shiny, the main veins soften and wilt, and the leaf tips dry for 5~10cm. After that, proceed to the color fixing stage and the rib drying stage in sequence.

Description

Technical Field

[0001] This invention relates to the field of flue-cured tobacco, and in particular to a curing process for improving the curing quality of the upper tobacco leaves of Guiyan 36. Background Technology

[0002] Guiyan 36 is a flue-cured tobacco cultivar bred from the F1 generation of 9011 × Anyan 3 and K730, with 65% of its genetic traits derived from K326. This cultivar is resistant to bacterial wilt and black shank, but susceptible to red spot disease and viral diseases. It is not prone to early flowering, has a cylindrical plant type, and oblong leaves. It takes about 55 days from transplanting to budding, and its field growth period is about 130 days. The natural plant height is 159.9 cm, and the height after topping is 111.9 cm. The natural number of leaves is 26.0, with 21-22 leaves available for curing. After curing, the leaves are predominantly orange-yellow, contain oil, have a loose structure, moderate color, suitable main internal chemical components, good overall coordination, good overall sensory quality, and strong industrial applicability. Taking Guizhou as an example, in recent years, Guiyan 36 has been demonstrated and promoted on an average of over 30,000 mu (approximately 2,000 hectares) annually in Guizhou Province, with a yield of about 125 kg per mu (approximately 8,333 kg per hectare), resulting in high income for tobacco farmers. However, experiments showed that using conventional curing techniques on the upper leaves of Guiyan 36 tobacco leaves easily resulted in excessive ash buildup and stiffness after curing, making these leaves unsuitable for purchase. This was especially true for the upper leaves, which were less mature due to abnormal weather conditions during their ripening period; the conventional curing process was even more prone to producing ash-covered and stiff leaves. Therefore, improvements were made to the conventional curing process to mitigate these issues, thereby increasing the amount of tobacco leaves available for purchase and improving farmers' income. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a baking process for improving the baking quality of the upper tobacco leaves of Guiyan 36.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A baking process for improving the baking quality of the upper tobacco leaves of Guiyan 36 includes the following steps:

[0006] Step 1: Baking during the yellowing stage, which includes the following steps:

[0007] After loading the tobacco into the tobacco curing barn, close the loading door, turn on the automatic temperature and humidity control equipment, close the air inlet, and turn on the circulating fan for 1-2 hours. Then, ignite the fire, raising the dry-bulb temperature to 34.0-35.0℃ at a rate of 1℃ per hour, and the wet-bulb temperature to 34.0-35.0℃, maintaining this temperature for 4-6 hours. Afterward, raise the dry-bulb temperature to 38.0℃ at a rate of 1℃ per hour, and the wet-bulb temperature to 37.0℃, maintaining this temperature for 4-5 minutes. Finally, raise the dry-bulb temperature to 38.0℃ at a rate of 1℃ per hour, maintaining this temperature until the high-temperature layer tobacco leaves are 40-50% yellow. The temperature is raised to 42.0℃, and the wet-bulb temperature is 37.0℃~38.0℃. The leaves are baked at a stable temperature until the high-temperature layer is 70-80% yellow. Then, while keeping the dry-bulb temperature constant, the wet-bulb temperature is decreased from 37.0℃~38.0℃ to 36.0℃, 35.0℃, 34.0℃, and 33.5~33.0℃ at a rate of 1℃ every 2-3 hours. After that, the wet-bulb temperature is kept constant at 33.0~33.5℃, and the leaves are baked at a stable temperature and humidity until more than half of the veins of the high-temperature layer leaves turn white and shiny, the main veins soften and wilt, and the leaf tips dry for 5-10cm. After that, the color-fixing stage begins.

[0008] Step 2: Color setting stage baking, which includes the following steps:

[0009] The dry-bulb temperature is increased to 45℃ at a rate of 1℃ every 3 hours, while the wet-bulb temperature is 33.0–34.0℃. The leaves are then baked at a stable temperature until the tobacco leaves in the high-temperature layer are completely yellow, the midribs are fully softened, and about one-third of the leaves are dry. After that, the dry-bulb temperature is increased to 48℃ at a rate of 1℃ every 3 hours, while the wet-bulb temperature is 37.0℃. The leaves are then baked at a stable temperature until the small tobacco rolls are dry and the leaves are more than half dry. Finally, the dry-bulb temperature is increased to 54.0℃ at a rate of 1℃ every 2 hours, while the wet-bulb temperature is 38–39℃. The leaves are then baked at a stable temperature until the large tobacco rolls are completely dry.

[0010] Step 3: Baking during the gluten drying stage, which includes the following steps:

[0011] The dry bulb temperature was increased from 54.0℃ to 60.0℃ at a rate of 1℃ per hour, and then maintained at a constant temperature for 6 hours. Then, the temperature was increased to 68.0℃ at a rate of 1℃ per hour, and the wet bulb temperature was maintained at 40.0~41.0℃ for more than 20 hours until the tobacco fibers were completely dry.

[0012] The beneficial effects of this invention are:

[0013] This invention discloses a curing process for improving the quality of the upper leaves of Guiyan 36 tobacco. Compared with conventional curing processes, this process raises the main yellowing temperature to 42℃. High-temperature yellowing accelerates the yellowing process, increases the degree of yellowing, and reduces the duration of disease on leaves with minor lesions in the curing barn. At the main yellowing temperature of 42℃, when the leaves reach 70% or 80% yellowness, the wet-bulb temperature is lowered four times to coordinate water loss and yellowing. This process results in better appearance quality of the cured leaves, a 20.1% reduction in ash residue, softer leaves, an 18.5% increase in orange-yellow color, and a 20.3% increase in the amount of tobacco sold to farmers. This process is particularly suitable for curing the upper leaves of Guiyan 36 tobacco, which have slightly lower maturity due to abnormal weather conditions during the ripening period. The amount of ash residue and stiff leaves after curing is almost the same as that after curing when the weather conditions are not significantly different during the ripening period.

[0014] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained from the following description and claims. Detailed Implementation

[0015] The preferred embodiments of the present invention will now be described in detail. It should be understood that the preferred embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0016] A baking process for improving the baking quality of the upper tobacco leaves of Guiyan 36 includes the following steps:

[0017] Step 1: Baking during the yellowing stage:

[0018] After loading the tobacco into the tobacco curing barn, close the loading door, turn on the automatic temperature and humidity control equipment, close the air inlet, and turn on the circulating fan for 1-2 hours. Then, ignite the fire, raising the dry-bulb temperature to 34.0-35.0℃ at a rate of 1℃ per hour, and the wet-bulb temperature to 34.0-35.0℃, maintaining this temperature for 4-6 hours. Afterward, raise the dry-bulb temperature to 38.0℃ at a rate of 1℃ per hour, and the wet-bulb temperature to 37.0℃, maintaining this temperature for 4-5 minutes. Finally, raise the dry-bulb temperature to 38.0℃ at a rate of 1℃ per hour, maintaining this temperature until the high-temperature layer tobacco leaves are 40-50% yellow. The temperature is raised to 42.0℃, and the wet-bulb temperature is 37.0℃~38.0℃. The leaves are baked at a stable temperature until the high-temperature layer is 70-80% yellow. Then, while keeping the dry-bulb temperature constant, the wet-bulb temperature is decreased from 37.0℃~38.0℃ to 36.0℃, 35.0℃, 34.0℃, and 33.5~33.0℃ at a rate of 1℃ every 2-3 hours. After that, the wet-bulb temperature is kept constant at 33.0~33.5℃, and the leaves are baked at a stable temperature and humidity until more than half of the veins of the high-temperature layer leaves turn white and shiny, the main veins soften and wilt, and the leaf tips dry for 5-10cm. After that, the color-fixing stage begins.

[0019] Step 2: Baking for color setting:

[0020] The dry-bulb temperature is increased to 45℃ at a rate of 1℃ every 3 hours, while the wet-bulb temperature is 33.0–34.0℃. The leaves are then baked at a stable temperature until the tobacco leaves in the high-temperature layer are completely yellow, the midribs are fully softened, and about one-third of the leaves are dry. After that, the dry-bulb temperature is increased to 48℃ at a rate of 1℃ every 3 hours, while the wet-bulb temperature is 37.0℃. The leaves are then baked at a stable temperature until the small tobacco rolls are dry and the leaves are more than half dry. Finally, the dry-bulb temperature is increased to 54.0℃ at a rate of 1℃ every 2 hours, while the wet-bulb temperature is 38–39℃. The leaves are then baked at a stable temperature until the large tobacco rolls are completely dry.

[0021] Step 3: Baking during the drying stage:

[0022] The dry bulb temperature was increased from 54.0℃ to 60.0℃ at a rate of 1℃ per hour, and then maintained at a constant temperature for 6 hours. Then, the temperature was increased to 68.0℃ at a rate of 1℃ per hour, and the wet bulb temperature was maintained at 40.0~41.0℃ for more than 20 hours until the tobacco fibers were completely dry.

[0023] A comparative experiment was conducted in Bozhou, Zunyi. The upper leaves of Guiyan 36 tobacco, harvested when the climate remained largely unchanged during the ripening stage, were cured using both the new curing process of this invention and the conventional curing process. The curing quality is shown in Table 1.

[0024] Table 1

[0025]

[0026] The upper leaves of Guiyan 36 tobacco, which were harvested during an abnormal climate period and had slightly lower maturity, were cured using both the new curing process of this invention and the conventional curing process. The curing quality is shown in Table 2.

[0027] Table 2

[0028]

[0029] A comparative experiment was conducted in Tongzi, Zunyi. The upper leaves of Guiyan 36 tobacco, harvested when the climate remained largely unchanged during the ripening stage, were cured using both the new curing process of this invention and the conventional curing process. The curing quality is shown in Table 3.

[0030] Table 3

[0031]

[0032] The upper leaves of Guiyan 36 tobacco, which were harvested during an abnormal climate period and had slightly lower maturity, were cured using both the new curing process of this invention and the conventional curing process. The curing quality is shown in Table 4.

[0033] Table 4

[0034]

[0035]

[0036] As shown in Tables 1 to 4, the new baking process of this invention achieves better appearance quality of the baked tobacco leaves by raising the main yellowing temperature to 42℃, reducing the wet-bulb temperature four times when the tobacco leaves turn 70% and 80% yellow at the main yellowing temperature of 42℃, and manually opening the air inlet door 8-10cm to remove moisture and maintaining it at 54℃ in the later stage of the main yellowing temperature. This results in a 20.1% reduction in ash and smoke, softer baked tobacco leaves, an 18.5% increase in orange-yellow tobacco, and a 20.3% increase in tobacco sold to warehouses by tobacco farmers. Tables 1 to 4 also show that this process is particularly suitable for baking the upper tobacco leaves of Guiyan 36, which have slightly lower maturity due to abnormal climate during the ripening period of the upper tobacco leaves. The amount of ash and stiff tobacco leaves after baking is almost the same as that of tobacco leaves after baking when the climate does not change significantly during the ripening period of the upper tobacco leaves.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A baking process for improving the baking quality of upper tobacco leaves of Guiyan 36, characterized in that: Includes the following steps: Step 1: Baking during the yellowing stage: After the tobacco is loaded into the tobacco curing barn, close the loading door, turn on the automatic temperature and humidity control equipment, close the air inlet, and turn on the circulating fan for 1-2 hours. Then, ignite the fire, raising the dry-bulb temperature to 34.0-35.0°C at a rate of 1°C per hour, and the wet-bulb temperature to 34.0-35.0°C, maintaining this temperature for 4-6 hours. Afterward, raise the dry-bulb temperature to 38.0°C at a rate of 1°C per hour, and the wet-bulb temperature to 37.0°C, maintaining this temperature for 4-5 minutes until the high-temperature layer tobacco leaves are 40-50% yellow. Finally, raise the dry-bulb temperature to 42.0°C at a rate of 1°C per hour. At a constant temperature of 37.0℃~38.0℃, the tobacco leaves in the high-temperature layer are baked until they turn 70-80% yellow. Then, while keeping the dry-bulb temperature constant, the wet-bulb temperature is decreased from 37.0℃~38.0℃ to 36.0℃, 35.0℃, 34.0℃, and 33.5~33.0℃ at a rate of 1℃ every 2~3 hours. After that, the wet-bulb temperature is kept constant at 33.0~33.5℃, and the leaves are baked at a constant temperature and humidity until more than half of the veins of the tobacco leaves in the high-temperature layer turn white and shiny, the main veins soften and wilt, and the leaf tips dry for 5~10cm. After that, the leaves enter the color-fixing stage. Step 2: Baking for color setting: The dry-bulb temperature was increased to 45°C at a rate of 1°C every 3 hours, while the wet-bulb temperature remained at 33.0–33.5°C. The leaves were then baked at a stable temperature until the high-temperature layer was completely yellow, the midrib was fully softened, and about one-third of the leaves were dry. Next, the dry-bulb temperature was increased to 48°C at a rate of 1°C every 3 hours, while the wet-bulb temperature remained at 37.0°C. The leaves were then baked at a stable temperature until the small tobacco rolls were more than half dry. Finally, the dry-bulb temperature was increased to 54.0°C at a rate of 1°C every 2 hours, while the wet-bulb temperature remained at 38–39°C. The leaves were then baked at a stable temperature until the large tobacco rolls were completely dry. Step 3: Baking during the drying stage: The dry bulb temperature was increased from 54.0℃ to 60.0℃ at a rate of 1℃ per hour, and then maintained at a constant temperature for 6 hours. Then, the temperature was increased to 68.0℃ at a rate of 1℃ per hour, and the wet bulb temperature was maintained at 40.0~41.0℃ for more than 20 hours until the tobacco fibers were completely dry. At the later stage of yellowing at 42℃, manually open the air inlet door by 8-10cm to remove moisture and continue until 54℃.

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