CN115969070A - Method for picking and baking tobacco leaves on upper part of autumn - Google Patents

Abstract

The invention discloses a method for picking and baking tobacco leaves at the upper part after autumn, which firstly improves the mature aging degree of the tobacco leaves at the upper part after autumn and the softness of the baked tobacco leaves through stem breaking treatment. Secondly, the baking characteristics of the upper tobacco leaves are improved by spraying the nutrient solution of ethephon and monopotassium phosphate on the leaf surfaces, and the proportion of ash hanging smoke and green smoke after baking is reduced. And thirdly, the fresh tobacco leaves are ripe, harvested, reasonably classified, woven and loaded into a kang, and softened, withered and yellow in the tobacco loading of the curing barn, so that the flexibility of the cured tobacco leaves can be improved, and the proportion of green tobacco is reduced. Finally, in the aspect of the baking process, a low-temperature moisture-preserving slow yellowing baking technology is adopted in the early yellowing stage, a low-temperature low-humidity slow yellowing baking technology is adopted in the later yellowing stage to promote the tobacco leaves to be fully softened, withered and yellow, a low-temperature low-humidity slow heating and color fixing baking technology is adopted in the color fixing stage to promote the yellow color of the tobacco leaves to be fixed, a low-temperature low-humidity dry rib baking technology is adopted in the dry rib stage to promote the tobacco ribs to be dried, and the appearance quality and the internal quality of the cured tobacco leaves are improved.

Description

A method for harvesting and roasting upper tobacco leaves after autumn

technical field

The invention relates to a method for harvesting and roasting upper tobacco leaves after autumn, and belongs to the technical field of tobacco leaf roasting.

Background technique

Tobacco leaves after autumn are mostly upper tobacco leaves developed under dry and cool autumn climate conditions. The leaves contain less water, the leaves are thick, the leaf tissue cells are tightly arranged, and the inner substances are substantial. Guizhou is a large flue-cured tobacco planting province in the country, and flue-cured tobacco is one of the important economic crops and sources of fiscal revenue in Guizhou. Guizhou is located on the Yunnan-Guizhou Plateau, with an obvious three-dimensional mountain climate and an average altitude of about 1 000m. In the middle and late September and early October, climate factors such as low temperature and frost after autumn, increasing temperature difference between day and night, autumn wind and autumn rain in the western Guizhou tobacco area were particularly harmful to the upper tobacco leaves. Due to the unique geographical location and altitude characteristics of Guizhou, ecological environment factors have a significant impact on tobacco leaf maturation, senescence and quality formation, which can easily lead to tight tissue structure in the upper tobacco leaves, tobacco leaves that cannot mature and turn yellow normally, and tobacco leaves that are not easy to roast, and have average or poor roasting resistance. Deviation, easy to bake green and hang ash, even roast black, roasting loss even reaches more than 30%, which is not conducive to improving the quality and usability of the upper tobacco leaves. Therefore, improving the maturity and aging degree of fresh tobacco leaves and improving the curing process are important guarantees for improving the quality of upper tobacco leaves.

Judging from the current situation, the quality and nutritional conditions of the upper tobacco leaves under the condition of chilling damage are mainly obtained by spraying potassium dihydrogen phosphate and sucrose solution on the leaves (the invention patent has been published: flue-cured tobacco cultivation management and curing based on potassium dihydrogen phosphate and sucrose to alleviate chilling damage) Roasting method; the method of reducing the loss of low-temperature chilling damage of Honghua Dajinyuan tobacco leaves in high-altitude areas) is improved, but the single increase of spraying potassium dihydrogen phosphate and sucrose solution for tobacco leaf ripening treatment still cannot effectively solve the problem of curing the upper tobacco leaves. Therefore, more complete and systematic upper tobacco leaf processing supporting technical measures are needed.

Contents of the invention

The technical problem to be solved by the present invention is to provide a tobacco leaf harvesting and roasting method that can improve the maturity, quality and consistency of roasting characteristics of fresh tobacco leaves, as well as the appearance quality and internal quality of roasted tobacco leaves, and reduce the proportion of gray smoke and green tobacco. , can overcome the deficiencies of the prior art.

The technical scheme of the present invention is: the method for collecting and roasting the upper tobacco leaves after autumn comprises:

S1, broken stems: 1 to 2 days after the central tobacco leaves are harvested, the stems of the tobacco plants are cut at a place 10 to 20 cm below the 4 to 6 upper tobacco leaves. /3～1/2, to promote the maturity and aging of the upper tobacco leaves;

S2, Spraying foliar maturation promoting nutrient solution: dilute 40% ethephon solution with 300 to 500 times of water, dilute potassium dihydrogen phosphate solution with 200 to 300 times of water, and mix the above two diluted solutions in a ratio of 1:1 Carry out foliage spraying, the spraying rate per mu is 15-20kg, further coordinate the nutritional balance of the upper tobacco leaves, improve the quality of the tobacco leaves, and promote the maturity and aging of the tobacco leaves;

S3, harvesting of mature fresh tobacco leaves: more than 90% of fresh tobacco leaves harvested are physiologically mature and technically mature tobacco leaves, the leaves are mainly green-yellow and light yellow, the tips of the leaves turn yellow and wither, the edges of the leaves turn yellow, and most of the hairs fall off. The main vein is basically completely white, and most of the branch veins are white;

S4. Classification and weaving of fresh tobacco leaves: according to the degree of maturity, the fresh tobacco leaves are roughly divided into three categories: underripe, mature and fully ripe tobacco leaves, and classified into stalks, with 120 to 130 pieces of tobacco per stalk;

S5, Pack fresh tobacco leaves into kang: sort and layer, pack tobacco in the same layer with the same quality, unripe tobacco leaves are packed in the low-temperature layer, fully-ripe tobacco leaves are packed in the high-temperature layer, and mature tobacco leaves are packed in other layers. ;

S6, fresh tobacco leaves become soft and withered and turn yellow: after the fresh tobacco leaves are loaded into the barn, close the cold air inlet and the moisture removal window, start the circulation fan for 2-3 hours, then turn off the circulation fan to keep warm and moisturize for 15-25 hours, until the fresh tobacco leaves are slightly Soft and withered, 10% to 20% of tobacco leaves turn yellow;

S7, Baking: In the early stage of yellowing, the low-temperature and low-humidity slow-yellowing baking technology is used, and in the later stage of yellowing, the low-temperature, low-humidity slow-yellowing baking technology is used to make the tobacco leaves fully soft and withered and turn yellow. The baking technology promotes the yellow color of the tobacco leaves, and the low-temperature and low-humidity drying technology is used in the dry tendon period to promote the drying of the tobacco tendons.

The above-mentioned method for collecting and roasting the upper tobacco leaves after autumn is that in step S1, a relatively good weather is selected for stem-cutting treatment. During the stem-cutting treatment, there is no dewdrop or rain on the surface of the stem bark of the tobacco plants, so as to prevent the tobacco plants from being infected with diseases, and the stems are broken. More than 1/2 of the cross-section is easy to break the stem.

The above-mentioned method for picking and roasting the upper tobacco leaves after autumn is that in step S2, after 1-2 days of stem-cutting treatment, the better weather is selected to spray the foliar maturation-promoting nutrient solution at 9-10 am or 4-5 pm .

The aforementioned method for collecting and roasting the upper tobacco leaves after autumn is that, in step S4, underripe tobacco leaves are tobacco leaves that are still ripe and have a degree of maturity lower than that of still ripe tobacco leaves, mature tobacco leaves are physiologically mature and technologically mature tobacco leaves, and fully mature tobacco leaves are tobacco leaves with a maturity degree higher than Mature fresh tobacco leaves with roasting value.

The aforementioned method of harvesting and roasting the upper tobacco leaves after autumn is that in step S7, the low-temperature moisturizing and slow-yellowing baking technology is used in the early stage of yellowing to reduce the dry bulb temperature and heating rate, slow down the moisture removal rate and the drying rate of tobacco leaves, and prolong the drying time before 38°C. The low-temperature yellowing time can impel the tobacco leaves to fully soften and wither and turn yellow. The specific operations are as follows:

After ignition, raise the dry bulb temperature to 32°C and wet bulb temperature to 31-32°C at a heating rate of 1°C/h, and bake at a steady temperature for 15-20 hours, and the tobacco leaves will turn yellow by 30-50%. At a heating rate of /2h, the dry bulb temperature is raised to 35-36°C, the wet bulb temperature is 34-35°C, and the temperature is stabilized for 35-45h. The tobacco leaves turn yellow by 60-70%, and the leaves become soft by more than 1/2.

The aforementioned method of harvesting and roasting the upper tobacco leaves after autumn is that in step S7, the low-temperature, low-humidity slow-yellowing baking technology is adopted in the later stage of yellowing to reduce the dry bulb temperature and wet bulb temperature, prolong the time for the tobacco leaves to turn yellow at 38°C, and promote the tobacco leaves to fully develop. Soft wither and turn yellow, the specific operation is as follows:

With a heating rate of 1°C/3h, the dry bulb temperature is raised to 38°C, the wet bulb temperature is 34-36°C, and the temperature is stable for 30-40 hours. The tobacco leaves turn yellow by 90%, and wither and become soft; /3h heating rate, the dry bulb temperature is raised to 40°C, the wet bulb temperature is 34-35°C, and the temperature is stabilized for 8-10 hours. The yellow slices of the tobacco leaves are fully softened and withered and turned yellow, preventing the tobacco leaves from turning green after baking.

The aforementioned method of harvesting and roasting the upper tobacco leaves after autumn is that in step S7, the low-temperature, low-humidity and slow-rising temperature-fixing baking technology is used in the color-fixing period to reduce the dry bulb temperature, wet bulb temperature and heating rate, so as to promote the yellow color of the tobacco leaves to be fixed. The specific operations are as follows :

With a heating rate of 1°C/3h, the dry bulb temperature is raised to 42°C, the wet bulb temperature is 34-35°C, and the temperature is stabilized for 10-15 hours. ℃/3h heating rate, the dry bulb temperature is raised to 44℃, the wet bulb temperature is 34-35℃, and the temperature is stable for 10-15h. The main veins of the high-temperature layer tobacco leaves basically turn yellow, and the tobacco leaves dry 1/2-2/ 3; Afterwards, with a heating rate of 1°C/2h, the dry bulb temperature is raised to 48°C, the wet bulb temperature is 35-36°C, and the temperature is stabilized for 10-15 hours. The main tendons of the whole kang tobacco leaves are all yellow and the leaves are all dry.

The above-mentioned method for harvesting and roasting the upper tobacco leaves after autumn is that in step S7, low-temperature and low-humidity dry tendon baking technology is used in the dry gluten period to reduce the dry bulb temperature and wet bulb temperature in the dry gluten period, so as to promote the drying of the tobacco tendons. The specific operations are as follows:

At a heating rate of 1°C/h, raise the temperature of the dry bulb to 53-54°C, and the temperature of the wet bulb to 35-36°C, bake at a steady temperature for 3-5 hours, and dry 1/3-1/2 of the stem; after that, use At a heating rate of 1°C/h, the dry bulb temperature is raised to 60-65°C, the wet bulb temperature is 37-38°C, and the temperature is stabilized for 15-25 hours until the whole kang tobacco leaves are completely dry.

The aforementioned method for picking and roasting the upper tobacco leaves after autumn is that, in steps S6 and S7, the speed of the circulating fan can be operated according to the conventional operation.

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

The present invention firstly promotes the ripening and senescence of the upper tobacco leaves after autumn, improves the maturity consistency of the upper tobacco leaves, and improves the softness of the tobacco leaves after roasting through the treatment of stem cutting. Secondly, spraying the mixed solution of ethephon and potassium dihydrogen phosphate on the leaves coordinates the nutritional balance of the upper tobacco leaves, and promotes the maturity and aging process of the tobacco leaves, further improves the maturity consistency of the tobacco leaves, the quality and curing characteristics of the fresh tobacco leaves, and reduces the risk of curing. The proportion of gray smoke and blue smoke hanging behind. Thirdly, through the mature harvesting of fresh tobacco leaves, reasonable classification, weaving and packing on kang, and the softening, withering and yellowing of fresh tobacco leaves in the curing room, it can ensure that the tobacco leaves are fully softened and withered and turn yellow during baking, and improve the quality of tobacco after roasting. The softness of tobacco leaves reduces the proportion of green smoke after roasting. Finally, in terms of the baking process, the low-temperature and low-humidity slow-yellow baking technology is used in the early stage of yellowing, and the low-temperature, low-humidity slow-yellow baking technology is used in the later stage of yellowing to make the tobacco leaves fully soft and withered and yellow. The temperature-setting and color-fixing baking technology promotes the yellow color of the tobacco leaves, and the low-temperature and low-humidity drying technology is used to promote the drying of the tobacco tendons during the dry tendon period, which improves the appearance and internal quality of the tobacco leaves after roasting. This method has the following benefits:

1. It is beneficial to the nutritional balance of the upper tobacco leaves after autumn, and improves the maturity consistency, quality and curing characteristics of fresh tobacco leaves;

2. It is conducive to the full degradation and transformation of the internal substances of tobacco leaves, and improves the internal quality of tobacco leaves after roasting;

3. It is beneficial to improve the appearance quality of the cured tobacco leaves and reduce the proportion of hanging gray smoke and blue smoke;

4. It is beneficial to reduce the proportion of stiff tobacco leaves and improve the softness of cured tobacco leaves.

Other advantages, objects and features of the present invention will be set forth in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the investigation and research below, or can be obtained from It is taught in the practice of the present invention. The objects and other advantages of the invention may be realized and attained by the following specification.

Instructions attached

Fig. 1 is the first group of tobacco plants and contrast pictures after steps S1 and S2 of the present invention are used;

Fig. 2 is second group adopting the tobacco plant after step S1 of the present invention and S2 process and control picture;

Fig. 3 is a picture of a single tobacco plant treated with steps S1 and S2 of the present invention and a control.

Detailed ways

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 some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Embodiment 1. A method for picking and curing the upper tobacco leaves after autumn, which includes pre-picking treatment, pre-picking and roasting treatment, and curing.

Pre-harvest treatments include:

S1, broken stems: the time of broken stems is 1 day after the central tobacco leaves are harvested, and the stems are broken under good weather conditions. When the stems are broken, there is no dewdrop or rain on the surface of the stem bark of the tobacco plants, so as to prevent the tobacco plants from being infected with diseases. 10 cm below the 6 upper tobacco leaves, the stems of the cut tobacco plants are processed, and the cross-section of the stems of the cut tobacco leaves is 1/3 of the cross section of the stem, so as to promote the maturity and aging of the upper tobacco leaves; A gap is cut on the stem of the tobacco plant, and the cross section of the gap cannot exceed 1/2 of the stem of the tobacco plant to avoid breaking.

S2, after 1 day of broken stem treatment, select the 4 to 5 o'clock in the afternoon when the weather is better to spray the leaf surface ripening nutrient solution. Dilute the potassium dihydrogen phosphate solution twice with water, and mix the above two diluted solutions according to the ratio of 1:1 to spray on the leaves. The amount of spraying per mu is 15-20kg, so as to further coordinate the nutritional balance of the upper tobacco leaves, improve the quality of the tobacco leaves, and promote the quality of the tobacco leaves. Maturity and aging.

Picking and pre-roasting processing steps include:

S3, harvesting of mature fresh tobacco leaves: more than 90% of fresh tobacco leaves harvested are physiologically mature and technically mature tobacco leaves, the leaves are mainly green-yellow and light yellow, the tips of the leaves turn yellow and wither, the edges of the leaves turn yellow, and most of the hairs fall off. The main vein is basically completely white, and most of the branch veins are white;

S4, Classification and compilation of fresh tobacco leaves: According to the degree of maturity, the fresh tobacco leaves are roughly divided into three categories: underripe, mature and fully mature tobacco leaves, and classified into stalks, with 120 pieces of tobacco per stalk; the underripe tobacco leaves are still mature and mature The degree is lower than that of still mature tobacco leaves, mature tobacco leaves are physiologically mature and technologically mature tobacco leaves, and fully mature tobacco leaves are fresh tobacco leaves with a higher degree of maturity than technologically mature tobacco leaves with curing value;

S5, Fresh tobacco leaves are loaded into kang: sorted and layered, homogeneous tobacco is packed in the same layer, underripe tobacco leaves are packed in the low-temperature layer, fully-ripe tobacco leaves are packed in the high-temperature layer, and mature tobacco leaves are packed in other layers, and the smoke density is increased by 5% compared with the conventional one;

S6, the fresh tobacco leaves become soft and withered and turn yellow: after the fresh tobacco leaves are put into the barn, close the cold air inlet and the dehumidification window, start the circulation fan for 2 hours, then turn off the circulation fan to keep warm and moisturize for 15-25 hours, until the fresh tobacco leaves are slightly soft Withering, 1-20% of the tobacco leaves turn yellow.

The baking process steps include:

S7, Baking: Compared with the national standard GB/T 23219-2008, the technical regulations for flue-cured tobacco baking, the speed of the circulating fan can be operated according to the standard, and it is changed to low-temperature moisturizing and slow yellowing baking technology in the early stage of yellowing to reduce the dry bulb temperature and heating rate, slow down the rate of dehumidification and drying of tobacco leaves, prolong the low-temperature yellowing time before 38°C, and promote the tobacco leaves to fully soften and wither and turn yellow. The specific operation is as follows: The dry bulb temperature is raised to 32°C, the wet bulb temperature is 32°C, and the tobacco leaves turn yellow by 30% after being baked at a steady temperature for 15 hours; after that, the dry bulb temperature is raised to 35°C at a heating rate of 1°C/2h, and the wet bulb temperature is 34°C. ℃, baked at a steady temperature for 35 hours, the tobacco leaves turn yellow by 60%, and the leaves become soft by more than 1/2.

In the later stage of yellowing, low-temperature, low-humidity slow yellowing baking technology is adopted to reduce the dry bulb temperature and wet bulb temperature, prolong the yellowing time of tobacco leaves at 38°C, and promote the tobacco leaves to fully soften and wither and turn yellow. The specific operation is as follows: 1°C/3h Heating speed: raise the dry bulb temperature to 38°C, wet bulb temperature to 34°C, and bake at a steady temperature for 15 hours, then raise the wet bulb temperature to 35°C, and bake at a steady temperature for 20 hours until the tobacco leaves turn yellow 90%, wither and become soft Afterwards, at a heating rate of 1°C/3h, raise the temperature of the dry bulb to 40°C, and the temperature of the wet bulb to 35°C, and bake at a steady temperature for 8 hours. green.

In the color-fixing period, the low-temperature, low-humidity, slow-rising and color-fixing baking technology is used to reduce the dry bulb temperature, wet bulb temperature and heating rate, so as to promote the yellow color of the tobacco leaves. The specific operation is as follows: the dry bulb temperature is raised to 42°C, wet bulb temperature 34°C, steady temperature baking for 10 hours, the tobacco leaves are hooked and curled, and the water loss is more than 45%; after that, the dry bulb temperature is raised to 44°C at a heating rate of 1°C/3h, and the wet bulb 35°C, baked at a steady temperature for 10 hours, the main veins of the tobacco leaves in the high-temperature layer basically turned yellow, and 1/2 to 2/3 of the tobacco leaves were dried; after that, the dry bulb temperature was raised to 48°C at a heating rate of 1°C/2h, and the wet The bulb temperature is 35°C, and the temperature is stable for 10 hours. The main ribs of the whole kang tobacco leaves are all yellow and the leaves are all dry.

During the dry gluten period, the low-temperature and low-humidity dry gluten baking technology is adopted to reduce the dry bulb temperature and wet bulb temperature during the dry gluten period, so as to promote the drying of the tobacco tendon. The specific operation is as follows: the temperature of the dry bulb is raised to 53°C at a heating rate of 1°C/h , the wet bulb temperature is 36°C, the temperature is stable and baked for 3 hours, and the tobacco stem is dried by 1/3~1/2; after that, the dry bulb temperature is raised to 65°C at a heating rate of 1°C/h, and the wet bulb temperature is 37°C. Bake at a steady temperature for 15 hours until the whole kang tobacco leaves are completely dry.

Embodiment 2. A method for picking and curing the upper tobacco leaves after autumn, which includes pre-picking treatment, pre-picking and roasting treatment, and curing.

Pre-harvest treatments include:

S1, broken stems: the time of broken stems is 1 to 2 days after the central tobacco leaves are harvested, and the stems are cut off in relatively good weather. When the stems are broken, there is no dewdrop or rain on the stem skin of the tobacco plants, so as to prevent the tobacco plants from being infected with diseases. 15 cm below the 4-6 upper tobacco leaves, the stems of the cut tobacco plants are processed, and the section of the stems of the cut tobacco plants is 5/12 of the cross section of the stem, so as to promote the maturity and aging of the upper tobacco leaves; pruning scissors can be used for warp cutting Cut a gap on the stem of the tobacco plant, and the cross section of the gap cannot exceed 1/2 of the stem of the tobacco plant to avoid breaking.

S2, after 1 to 2 days of broken stem treatment, choose better weather to spray the leaf surface ripening promoting nutrient solution at 9 to 10 in the morning. The used leaf surface ripening promoting nutrient solution is 40% ethephon diluted with 400 times of water. solution, dilute the potassium dihydrogen phosphate solution with 250 times of water, and mix the above two diluted solutions according to the ratio of 1:1 to spray the leaves. , to promote the maturity and senescence of tobacco leaves.

Picking and pre-roasting processing steps include:

S3, harvesting of mature fresh tobacco leaves: more than 90% of fresh tobacco leaves harvested are physiologically mature and technically mature tobacco leaves, the leaves are mainly green-yellow and light yellow, the tips of the leaves turn yellow and wither, the edges of the leaves turn yellow, and most of the hairs fall off. The main vein is basically completely white, and most of the branch veins are white;

S4, Classification and compilation of fresh tobacco leaves: According to the degree of maturity, the fresh tobacco leaves are roughly divided into three categories: underripe, mature and fully mature tobacco leaves, and classified into stalks, with 125 pieces of tobacco per stalk; the underripe tobacco leaves are still mature and mature The degree is lower than that of still mature tobacco leaves, mature tobacco leaves are physiologically mature and technologically mature tobacco leaves, and fully mature tobacco leaves are fresh tobacco leaves with a higher degree of maturity than technologically mature tobacco leaves with curing value;

S5, Pack fresh tobacco leaves into kang: sort and layer, pack tobacco in the same layer with the same quality, unripe tobacco leaves are packed in the low-temperature layer, fully-ripe tobacco leaves are packed in the high-temperature layer, other layers are packed with mature tobacco leaves, and the density of tobacco packing is 10% higher than conventional;

S6, the fresh tobacco leaves become soft and withered and turn yellow: after the fresh tobacco leaves are loaded into the barn, close the cold air inlet and the moisture removal window, start the circulation fan for 2.5 hours, then turn off the circulation fan to keep warm and moisturize for 20 hours, until the fresh tobacco leaves are slightly soft and withered wilting, tobacco leaves turn yellow 1 to 20%.

The baking process steps include:

S7, Baking: Compared with the national standard GB/T 23219-2008, the technical regulations for flue-cured tobacco baking, the speed of the circulating fan can be operated according to the standard, and it is changed to low-temperature moisturizing and slow yellowing baking technology in the early stage of yellowing to reduce the dry bulb temperature and heating rate, slow down the rate of dehumidification and drying of tobacco leaves, prolong the low-temperature yellowing time before 38°C, and promote the tobacco leaves to fully soften and wither and turn yellow. The specific operation is as follows: The dry bulb temperature is raised to 32°C, the wet bulb temperature is 32°C, and the temperature is stable for 18 hours. The tobacco leaves turn yellow by 30% to 50%. After that, the dry bulb temperature is raised to 35°C at a heating rate of 1°C/2h. Bake at a temperature of 34°C for 40 hours at a steady temperature, the tobacco leaves will turn yellow by 60% to 70%, and more than 1/2 of the leaves will become soft.

In the later stage of yellowing, low-temperature, low-humidity slow yellowing baking technology is adopted to reduce the dry bulb temperature and wet bulb temperature, prolong the yellowing time of tobacco leaves at 38°C, and promote the tobacco leaves to fully soften and wither and turn yellow. The specific operation is as follows: 1°C/3h Heating rate: raise the dry bulb temperature to 38°C, wet bulb temperature to 35°C, and bake at a steady temperature for 38 hours. Raise the temperature to 40°C, the wet bulb temperature is 35°C, and bake at a steady temperature for 9 hours. The tobacco leaves are yellow and veined, fully softened and withered and turned yellow, so as to prevent the tobacco leaves from turning green after baking.

In the color-fixing period, the low-temperature, low-humidity, slow-rising and color-fixing baking technology is used to reduce the dry bulb temperature, wet bulb temperature and heating rate, so as to promote the yellow color of the tobacco leaves. The specific operation is as follows: the dry bulb temperature is raised to 42 ℃, wet bulb temperature 34 ℃, steady temperature baking for 13 hours, tobacco leaf tip curling, water loss of more than 45%; after that, the dry bulb temperature is raised to 44 ℃ at a heating rate of 1 ℃/3h, and the wet bulb temperature 35°C, baked at a steady temperature for 13 hours, the main veins of the tobacco leaves in the high-temperature layer basically turned yellow, and the leaves of the tobacco leaves were dried by 1/2 to 2/3; after that, the dry bulb temperature was raised to 48°C at a heating rate of 1°C/2h, and the wet The bulb temperature is 35-36°C, and the temperature is stable for 13 hours. The main ribs of the whole kang tobacco leaves are all yellow and the leaves are all dry.

During the dry gluten period, the low-temperature and low-humidity dry gluten baking technology is used to reduce the dry bulb temperature and wet bulb temperature during the dry gluten period, so as to promote the drying of the tobacco tendon. 54°C, wet bulb temperature 35-36°C, steady temperature baking for 4 hours, drying 1/3-1/2 of the stem; after that, raise the dry bulb temperature to 63°C at a heating rate of 1°C/h, wet bulb The temperature is 37-38°C, and it is baked at a steady temperature for 20 hours until the whole kang tobacco leaves are completely dry.

Embodiment 3. A method for picking and curing the upper tobacco leaves after autumn, which includes pre-picking treatment, pre-picking and roasting treatment, and curing.

Pre-harvest treatments include:

S1, the stem cutting time is 1 to 2 days after the central tobacco leaves are harvested, and the stem cutting treatment is carried out in relatively good weather. During the stem cutting treatment, there is no dew or rain on the stem skin of the tobacco plants to prevent the tobacco plants from being infected with diseases. 20cm below the upper tobacco leaves, the stems of the tobacco plants are broken, and the section of the stems of the broken tobacco plants is 1/3 to 1/2 of the cross-section of the stems, so as to promote the maturity and aging of the upper tobacco leaves; The scissors cut a gap on the tobacco stem, and the section of the gap should not exceed 1/2 of the tobacco stem to avoid breaking;

S2, after 1-2 days of broken stem treatment, select better weather at 9-10 o'clock in the morning to promote the ripening nutrient solution on the leaf surface, and the used leaf surface ripening-promoting nutrient solution is to utilize 500 times of water to dilute 40% ethephon solution, Dilute the potassium dihydrogen phosphate solution with 300 times of water, and mix the above two diluted solutions according to the ratio of 1:1 to spray on the leaves. mature tobacco leaves;

Picking and pre-roasting processing steps include:

S3, harvesting of mature fresh tobacco leaves: more than 90% of fresh tobacco leaves harvested are physiologically mature and technically mature tobacco leaves, the leaves are mainly green-yellow and light yellow, the tips of the leaves turn yellow and wither, the edges of the leaves turn yellow, and most of the hairs fall off. The main vein is basically completely white, and most of the branch veins are white;

S4, Classification and compilation of fresh tobacco leaves: According to the degree of maturity, the fresh tobacco leaves are roughly divided into three categories: underripe, mature and fully mature tobacco leaves, and classified into stalks, with 130 pieces of tobacco per stalk; the underripe tobacco leaves are still mature and mature The degree is lower than that of still mature tobacco leaves, mature tobacco leaves are physiologically mature and technologically mature tobacco leaves, and fully mature tobacco leaves are fresh tobacco leaves with a higher degree of maturity than technologically mature tobacco leaves with curing value;

S5, Pack fresh tobacco leaves into kang: sort and layer, pack tobacco in the same layer with the same quality, unripe tobacco leaves are packed in the low-temperature layer, fully-ripe tobacco leaves are packed in the high-temperature layer, and mature tobacco leaves are packed in other layers.

S6, the fresh tobacco leaves become soft and withered and turn yellow: after the fresh tobacco leaves are loaded into the barn, close the cold air inlet and the dehumidification window, start the circulation fan for 3 hours, then turn off the circulation fan to keep warm and moisturize for 25 hours, until the fresh tobacco leaves are slightly soft and withered , Tobacco leaves turn yellow by 1 to 20%.

The baking process steps include:

S7, Baking: Compared with the national standard GB/T 23219-2008, the technical regulations for flue-cured tobacco baking, the speed of the circulating fan can be operated according to the standard, and it is changed to low-temperature moisturizing and slow yellowing baking technology in the early stage of yellowing to reduce the dry bulb temperature and heating rate, slow down the rate of dehumidification and drying of tobacco leaves, prolong the low-temperature yellowing time before 38°C, and promote the tobacco leaves to fully soften and wither and turn yellow. The specific operation is as follows: The dry bulb temperature is raised to 32°C, the wet bulb temperature is 31°C, and the tobacco leaves turn yellow by 40% after being baked at a steady temperature for 20 hours; after that, the dry bulb temperature is raised to 36°C at a heating rate of 1°C/2h, and the wet bulb temperature is 35°C. ℃, baked at a steady temperature for 45 hours, the tobacco leaves turn yellow by 70%, and the leaves become soft by more than 1/2.

In the later stage of yellowing, low-temperature, low-humidity slow yellowing baking technology is adopted to reduce the dry bulb temperature and wet bulb temperature, prolong the yellowing time of tobacco leaves at 38°C, and promote the tobacco leaves to fully soften and wither and turn yellow. The specific operation is as follows: 1°C/3h Heating rate: raise the dry bulb temperature to 38°C, wet bulb temperature to 36°C, and bake at a steady temperature for 40 hours, the tobacco leaves will turn yellow by 90%, and wither and become soft; after that, increase the dry bulb temperature to 1°C/3h Raise the temperature to 40°C, wet bulb temperature 35°C, and bake at a steady temperature for 10 hours. The tobacco leaves will turn yellow with blue tendons, fully soften and wither and turn yellow, so as to prevent the tobacco leaves from turning green after baking.

In the color-fixing period, the low-temperature, low-humidity, slow-rising and color-fixing baking technology is used to reduce the dry bulb temperature, wet bulb temperature and heating rate, so as to promote the yellow color of the tobacco leaves. The specific operation is as follows: the dry bulb temperature is raised to 42 ℃, wet bulb temperature 35 ℃, steady temperature baking for 15 hours, tobacco leaves curled, and the water loss is more than 45%; after that, the dry bulb temperature is raised to 44 ℃ at a heating rate of 1 ℃/3h, and the wet bulb temperature 34°C, baked at a steady temperature for 15 hours, the main veins of the tobacco leaves in the high-temperature layer basically turned yellow, and 1/2 to 2/3 of the tobacco leaves were dried; after that, the dry bulb temperature was raised to 48°C at a heating rate of 1°C/2h, and the wet The bulb temperature is 36°C, and the temperature is stable for 15 hours. The main ribs of the whole kang tobacco leaves are all yellow and the leaves are all dry.

During the dry gluten period, the low-temperature and low-humidity dry gluten baking technology is adopted to reduce the dry bulb temperature and wet bulb temperature during the dry gluten period, so as to promote the drying of the tobacco tendon. The specific operation is as follows: the temperature of the dry bulb is raised to 53°C at a heating rate of 1°C/h , with a wet bulb temperature of 36°C, bake at a steady temperature for 5 hours, and dry 1/2 of the stem; then, at a heating rate of 1°C/h, raise the temperature of the dry bulb to 65°C, and the wet bulb temperature at 37°C, and bake at a steady temperature 25h, until the whole kang tobacco leaves are completely dry.

At the same time, the method of the present invention is adopted to adopt a method of picking and roasting the upper tobacco leaves after autumn for the tobacco leaves of Yunyan 87. The test is carried out in Weining County, Guizhou Province and other tobacco areas in 2021-2022. The flue-cured tobacco variety for testing is Yunyan 87, and the upper tobacco leaves are used as test materials. .

As shown in Figures 1-3, it is a comparison photo of the applicant after the actual operation in the tobacco field using the pre-picking treatment steps. The degree is more consistent and the time is earlier, which can greatly reduce the impact of the later rainy season on tobacco leaf picking and curing. At the same time, the data in Table 1 are obtained through statistics on the multi-regional tobacco leaf data;

Table 1 Effects of spraying ripening-promoting nutrient solution on leaves and cutting off stems on the maturity and curing characteristics of upper fresh tobacco leaves

Note: Different lowercase letters indicate significant differences between treatments at the 5% level. Same below

Table 2-Table 6 are the analytical data of the upper tobacco leaves after autumn harvesting and roasting of the upper tobacco leaves after autumn

Table 2 Effects of different treatments on the appearance quality of the upper tobacco leaves after roasting

Table 3 Effects of different treatments on the content of chemical components in cured tobacco leaves

Table 4 Effects of different treatments on the sensory quality of cured tobacco leaves

Note: The evaluation of sensory quality is the sum of the scores of aroma quality, aroma quantity, taste, miscellaneous smell, irritation, and energy, each of which is 10 points.

Table 5 Effects of different treatments on the grade structure of cured tobacco leaves (%)

Table 6 Effects of different treatments on the softness of cured tobacco leaves

Through the experimental data in the above table, it can be proved that the method of harvesting and roasting the upper tobacco leaves after autumn can: 1. It is beneficial to the nutritional balance of the upper tobacco leaves after autumn, and improves the maturity consistency, quality and curing characteristics of fresh tobacco leaves; 2. It is beneficial to the internal substances of tobacco leaves 3. It is beneficial to improve the appearance quality of cured tobacco leaves and reduce the proportion of gray and green smoke; 4. It is beneficial to reduce the proportion of stiff tobacco leaves and improve the softness of cured tobacco leaves. It has good practical value and generalizability.

Claims (9)

1. A method for harvesting and baking tobacco leaves at the upper part of the autumn is characterized by comprising the following steps:

s1, stem breaking: 1 to 2 days after the middle tobacco leaves are picked, carrying out tobacco stem breaking treatment at a position of 4 to 6 sheets and 10 to 20cm below the upper tobacco leaves, wherein the section of the tobacco stem breaking treatment is 1/3 to 1/2 of the cross section of a stem, so as to promote the upper tobacco leaves to mature and age;

s2, spraying a leaf surface ripening nutrient solution: diluting 40% ethylene solution with water of 300-500 times, diluting potassium dihydrogen phosphate solution with water of 200-300 times, mixing the two diluted solutions according to a ratio of 1;

s3, ripening and harvesting fresh tobacco leaves: more than 90% of the fresh tobacco leaves are physiologically mature and technologically mature tobacco leaves, the leaves mainly take green yellow and light yellow, the leaf tips become yellow and withered, the leaf edges become yellow, most of the antler hair falls off, the main vein is basically white, and most of the branch veins become white;

s4, classifying fresh tobacco leaves and weaving the tobacco leaves: roughly dividing the fresh tobacco leaves into three categories of under-cured tobacco leaves, mature tobacco leaves and fully cured tobacco leaves according to the maturity, and performing classified rod weaving, wherein each rod is used for weaving 120-130 tobacco leaves;

s5, fresh tobacco leaves are filled into a kang: the tobacco is loaded in a same layer and in a layered mode, under-cured tobacco leaves are loaded in a low-temperature layer, fully-cured tobacco leaves are loaded in a high-temperature layer, other layers of the under-cured tobacco leaves are loaded with the cured tobacco leaves, and the tobacco loading density is increased by 5% -15% compared with the conventional tobacco loading density;

s6, softening, withering and yellowing fresh tobacco leaves: after fresh tobacco leaves are filled into a baking room, closing a cold air inlet and a moisture exhaust window, starting a circulating fan for 2 to 3 hours, then closing the circulating fan, preserving heat and moisture for 15 to 25hours until the fresh tobacco leaves are slightly softened and withered and the tobacco leaves turn yellow for 1 to 2 percent;

s7, baking: the low-temperature moisture-retention slow yellowing baking technology is adopted in the early yellowing stage, the low-temperature low-humidity slow yellowing baking technology is adopted in the later yellowing stage to promote the tobacco leaves to be fully softened, withered and yellow, the low-temperature low-humidity slow heating color fixing baking technology is adopted in the color fixing stage to promote the yellow color of the tobacco leaves to be fixed, and the low-temperature low-humidity dry rib baking technology is adopted in the dry rib stage to promote the tobacco ribs to be dried.

2. The method for picking and baking tobacco leaves at the upper part after autumn according to claim 1, wherein in step S1, a relatively good weather is selected for stem breaking treatment, no dew or rain is left on the surface of the stem skin of the tobacco plant during stem breaking treatment, the tobacco plant is prevented from being infected with diseases, and the cross section of the broken stem exceeds 1/2 of the stem easy to break.

3. The method for baking tobacco leaves at the upper part after autumn according to claim 2, is characterized in that in step S2, after stem breaking treatment is carried out for 1 to 2 days, the foliar ripening nutrient solution is sprayed at 9 to 10 am or 4 to 5 pm in a better weather.

4. The method for harvesting and curing the tobacco leaves at the upper part after autumn according to claim 3, wherein in step S4, the tobacco leaves which are under-cured are the tobacco leaves which are under-cured and have a lower degree of maturity than the tobacco leaves which are under-cured, the cured tobacco leaves are the tobacco leaves which are physiologically and technically cured, and the fully cured tobacco leaves are the fresh tobacco leaves which have a higher degree of maturity than the technically cured and have a curing value.

5. The method for picking and baking tobacco leaves at the upper part after autumn according to claim 4, characterized in that in step S7, a low-temperature moisture-retention slow yellowing baking technology is adopted in the early stage of yellowing, the temperature of dry balls and the heating rate are reduced, the moisture-removal rate and the tobacco leaf drying rate are slowed down, the low-temperature yellowing time before 38 ℃ is prolonged, and the tobacco leaves are promoted to be fully softened, withered and yellow, and the specific operation is as follows: after ignition, heating the dry bulb to 32 ℃ at the heating rate of 1 ℃/h, and heating the wet bulb to 31-32 ℃, and stably baking for 15-20h to turn the tobacco leaves yellow for 3-5 hours; and then, heating the dry bulb to 35-36 ℃ at a heating rate of 1 ℃/2h, heating the wet bulb to 34-35 ℃, baking at a stable temperature for 35-45h, yellowing the tobacco leaves for 6-7, and softening the leaves for more than 1/2.

6. The method for picking and baking the tobacco leaves at the upper part after autumn according to the claim 5, characterized in that in the step S7, the low-temperature low-humidity slow yellowing baking technology is adopted at the later yellowing stage, the dry bulb temperature and the wet bulb temperature are reduced, the tobacco leaf yellowing time at 38 ℃ is prolonged, and the tobacco leaves are promoted to be fully softened, withered and yellow, and the specific operation is as follows: heating the dry bulb to 38 ℃ at the heating speed of 1 ℃/3h, heating the wet bulb to 34-36 ℃, and stably baking for 30-40h to ensure that the tobacco leaves become yellow 9 and wither and soften; and then, heating the dry-bulb temperature to 40 ℃ at a heating speed of 1 ℃/3h, heating the wet-bulb temperature to 34-35 ℃, baking at a stable temperature for 8-10 h, wherein the tobacco leaves are greenish, fully soften, wither and turn yellow, and are prevented from being baked and turned green.

7. The method for picking and baking tobacco leaves at the upper part after autumn according to claim 6, characterized in that in step S7, a low-temperature low-humidity slow-temperature-rise color-setting baking technology is adopted in a color setting period, and the dry bulb temperature, the wet bulb temperature and the temperature rise rate are reduced to promote the tobacco leaves to be yellow and fixed, and the specific operations are as follows: heating the dry-bulb temperature to 42 ℃ at the heating rate of 1 ℃/3h, heating the wet-bulb temperature to 34-35 ℃, baking at a stable temperature for 10-15h, and curling the tip of the tobacco leaf with the water loss of more than 45%; then, heating the dry bulb to 44 ℃ at a heating speed of 1 ℃/3h, heating the wet bulb to 34-35 ℃, baking at a stable temperature for 10-15h, wherein the main vein of the tobacco leaves in the high-temperature layer basically turns yellow, and drying the tobacco leaves for 1/2-2/3; and then, heating the dry bulb temperature to 48 ℃ at the heating rate of 1 ℃/2h, heating the wet bulb temperature to 35-36 ℃, baking the tobacco leaves in a stable temperature range for 10-15h, wherein the main ribs of the tobacco leaves in the complete kang are all yellow, and the leaves are all dry.

8. The method for picking and baking tobacco leaves at the upper part after autumn according to claim 7, wherein in step S7, a low-temperature low-humidity dry-rib baking technology is adopted in a dry rib period, the dry bulb temperature and the wet bulb temperature in the dry rib period are reduced, and the tobacco ribs are promoted to be dried, and the specific operations are as follows: heating the dry bulb to 53 to 54 ℃ at a heating speed of 1 ℃/h, heating the wet bulb to 35 to 36 ℃, baking for 3 to 5h at a stable temperature, and drying the tobacco ribs for 1/3 to 1/2; and then, heating the dry-bulb temperature to 60-65 ℃ at a heating speed of 1 ℃/h, heating the wet-bulb temperature to 37-38 ℃, and baking for 15-25h at a stable temperature until the tobacco leaves in the whole kang are completely dry.

9. The method for plucking and roasting autumn upper tobacco leaves according to claims 5 to 8, characterized in that in the steps S6 and S7, the rotating speed of the circulating fan is controlled according to the conventional operation.

Images