A method for splitting and layering baking of thick-stemmed and burst-stemmed tobacco leaves

Abstract

The invention relates to a rib-splitting and layered baking method for thick-ribbed and stem-bursting tobacco leaves. The root and stem parts of tobacco plants are girdled 5 days before harvesting to reduce root nutrition, especially nitrogen supply, regulate tobacco leaf carbon and nitrogen metabolism, and improve the maturity and baking characteristics of fresh tobacco leaves. The maturity standard of the second leaf that can be harvested from the top is used as a reference. When the second leaf from the top is yellow in color, the leaf tip is obviously yellowed, yellow spots appear on the leaf surface, the main vein is completely white, the branch veins are basically white, the villi fall off, and the leaf tip is bent downward, the upper tobacco leaves are harvested at one time. The temperature is raised to 68°C / 40 to 42°C at a rate of 1°C / h, the temperature is stabilized until the tobacco ribs are completely dried, and the rotation speed of a fan is controlled throughout the whole process. The special baking method for thick-ribbed and stem-bursting tobacco leaves provides an accurate and easy-to-master baking process.

Description

Technical Field

[0001] The invention relates to the technical field of tobacco leaf production and raw tobacco processing, and in particular to a method for splitting and layering baking of thick-stemmed and burst-stemmed tobacco leaves. Background Art

[0002] Henan tobacco area is a production area of ​​strong-flavor flue-cured tobacco. The strong-flavor tobacco leaves produced in Henan tobacco area are favored by domestic tobacco industry enterprises and are the core raw materials for the development of Chinese cigarettes. At present, the overall tobacco planting level in Henan tobacco area has been close to the planting level of high-quality tobacco abroad. However, due to the pursuit of economic benefits by tobacco farmers and the lack of technical implementation, the growth and development of tobacco plants in some tobacco fields are not ideal, the growth of tobacco plants in the field is unbalanced, the main tendons are too thick, the leaves are large and thick, the color is dark green, and the maturity and baking characteristics are not ideal.

[0003] The thick-ribbed and bursting tobacco leaves are mostly upper leaves formed under the conditions of high water and fertilizer and excessive helium application. The main veins are thick, the leaves are large and thick, the dark green and old green are difficult to turn yellow, the tissue is tight and the water retention is strong, the water content is not too high, the contents are still full, but the proportion of nitrogen compounds is high, and the polyphenol oxidase activity is strong. It is slow to turn yellow during baking and difficult to dehydrate. It is easy to turn yellow insufficiently and bake green, and it is easy to hang ash or bake black due to excessive delay and dry matter consumption. It is also easy to hang ash or burn the leaves due to the sudden increase in temperature when there is still a lot of water, which makes it difficult to bake. It is easy to cause dark yellow, reddish yellow, darker color, and poor oil content, resulting in poor quality of tobacco leaves after baking, reduced economic benefits of tobacco areas and tobacco farmers, and affecting the enthusiasm of tobacco farmers to grow tobacco and the high-quality development of strong-flavor tobacco areas. In response to the above problems, targeted technical research is carried out to improve the baking quality of thick-ribbed and bursting tobacco leaves and enhance the economic benefits of the production areas. Summary of the invention

[0004] In view of the above problems, the present invention provides a method for splitting and layered baking of thick-ribbed and burst-stem tobacco leaves, which achieves improvement in baking quality and enhanced economic benefits of thick-ribbed and burst-stem tobacco leaves through comprehensive nitrogen reduction regulation in tobacco field production, mature harvesting, reasonable loading of split ribs and tobacco, natural ventilation pre-yellowing, and coordination of leaf yellowing, water loss rate and baking time during baking.

[0005] The technical solution of the present invention is achieved as follows: a method for splitting and layering baking of thick-ribbed and burst-stem tobacco leaves, characterized in that the method comprises the following steps:

[0006] 1) Nitrogen reduction regulation: 5 days before harvest, the rhizomes of tobacco plants are ring-cut to reduce the supply of root nutrients, especially nitrogen, to regulate the carbon and nitrogen metabolism of tobacco leaves, and to improve the maturity and baking characteristics of fresh tobacco leaves;

[0007] 2) One-time harvesting: Taking the maturity standard of the second leaf from the top as a reference, when the second leaf from the top is yellow, the tip of the leaf is obviously yellow, the leaf surface has yellow spots, the main vein is completely white, the side veins are basically white, the hairs fall off and the tip of the leaf is bent downward, the upper tobacco leaves are harvested at one time;

[0008] 3) Split the ribs and clamp the tobacco, and load the tobacco in layers: Split the harvested tobacco leaves into two parts from the base to the middle of the leaves along the main ribs, and clamp the tobacco leaves with comb-type tobacco clamps. When clamping the tobacco, separate the main ribs of the cut tobacco leaves by 2 cm, and each clamp weighs 11 to 12 kg. When loading the tobacco, divide the upper 6 leaves into three parts according to the leaf position and baking characteristics. The top 1 to 2 leaves are loaded in the low-temperature layer, the middle 3 to 4 leaves are loaded in the medium-temperature layer, and the lower 5 to 6 leaves are loaded in the high-temperature layer. The density of the high-temperature greenhouse is 5% higher than that of the medium-temperature greenhouse, and the density of the low-temperature greenhouse is 5% lower than that of the medium-temperature greenhouse. The spacing between the clamps in the same layer is required to be equal, without gaps, and uniform;

[0009] 4) Natural ventilation pre-yellowing stage: After loading tobacco, close the door of the curing room, fully open the air inlet and moisture outlet, and let the tobacco leaves in the room slowly change under natural environmental conditions for 24 hours until the leaf tips become slightly soft;

[0010] 5) High temperature humidity adjustment and yellowing stage: close the cold air door and dehumidification port, raise the temperature to 36℃ / 36℃ at 1℃ / 1h, control the fan speed to 960 r / min, stabilize the temperature for 20h, until the leaf tip turns slightly yellow; raise the temperature to 40℃ / 36℃ at 1℃ / 2h, maintain for 30h, until the tobacco leaves turn 80% to 90% yellow, and the fine veins turn basically yellow; raise the temperature to 43℃ / 37℃ at 1℃ / 3h, stabilize for 24h, control the fan speed to 1440r / min, until the tobacco leaves turn 90% to 100% yellow, the leaves fully collapse and soften, with obvious hook tips and curled edges, and the branch veins turn yellow;

[0011] 6) Low humidity and slow color fixing stage: Raise the temperature to 47 to 48℃ / 38℃ at 1℃ / 3h, and keep the temperature steady for 20h until the leaves are completely yellow, the branch veins are completely yellow, and the small curls are formed; Raise the temperature to 50 to 52℃ / 39℃ at 1℃ / 2h, and keep the temperature steady for 20h until the leaves are yellow, the veins are completely yellow, and the small curls are formed, and the branch veins are more than 1 / 2 dry; Raise the temperature to 54 to 55℃ / 40℃ at 1℃ / h, and keep the temperature steady for 20h until the leaves are completely dry, the branch veins are completely dry, and more than 1 / 2 of the main veins are dry, and the fan speed is controlled at 1440 r / min throughout the process;

[0012] 7) Drying stage: Raise the temperature to 68℃ / 40 to 42℃ at 1℃ / h, maintain steady temperature until the smoke ribs are completely dry, and control the fan speed throughout the process.

[0013] In the step 7), the fan speed is 960 r / min.

[0014] The present invention has the following positive effects: the present invention systematically clarifies the accurate parameters of thick rib and stem tobacco leaves from field production nitrogen reduction regulation, mature harvesting, rib splitting and tobacco sandwiching, natural ventilation pre-yellowing to baking, innovatively proposes the impact of nitrogen reduction regulation, rib splitting and tobacco sandwiching and other production operations on the tobacco leaf baking process and the corresponding measures, and provides an accurate and easy-to-master baking process for the special baking method of thick rib and stem tobacco leaves. At the same time, it solves the prominent problems of Henan thick rib and stem tobacco leaves, such as insufficient maturity, irregular color, thick identity, poor oil content and green content after baking, due to the thick main veins, thick and large leaves, tight structure and high nitrogen compounds. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention, but not to limit the present invention.

[0016] Embodiment 1:

[0017] 5 days before harvesting, the rhizomes of tobacco plants are girdled to reduce the supply of root nutrients, especially nitrogen, regulate the carbon and nitrogen metabolism of tobacco leaves, and improve the maturity and baking characteristics of fresh tobacco leaves. The second leaf from the top can be harvested at maturity. When the second leaf from the top is yellow, the tip of the leaf is obviously yellow, the leaf surface has yellow spots, the main vein is completely white, the side veins are basically white, the hairs fall off, and the tip of the leaf is bent downward, the upper tobacco leaves can be harvested at one time.

[0018] Divide the harvested tobacco leaves into two parts along the main ribs from the base to the middle of the leaves, and clamp the tobacco leaves with the main ribs cut with comb-type tobacco clips. When clamping tobacco, separate the main ribs of the cut tobacco leaves by 2cm, and each clip weighs 12kg. When loading tobacco, divide the upper 6 leaves into three parts according to the leaf position and baking characteristics. The top 1-2 leaves are placed in the low-temperature layer, the middle 3-4 leaves are placed in the medium-temperature layer, and the lower 5-6 leaves are placed in the high-temperature layer. The high-temperature greenhouse is slightly denser than the medium-temperature greenhouse, increasing by 5%, and the low-temperature greenhouse is slightly sparser than the medium-temperature greenhouse, reducing by 5%. The same layer is required to have equal spacing, no gaps, and uniformity. After loading tobacco, close the door of the curing room, fully open the air inlet and moisture outlet, and allow the tobacco leaves in the whole room to slowly change under natural environmental conditions for about 24 hours until the leaf tips are slightly soft.

[0019] Close the cold air door and dehumidification port, raise the temperature to 36℃ / 36℃ at 1℃ / 1h, control the fan speed to 960r / min, and keep the temperature steady for 20h until the tip of the tobacco leaves turns slightly yellow; raise the temperature to 40℃ / 36℃ at 1℃ / 2h, and keep it for 30h until the tobacco leaves turn 80% yellow and the fine veins turn basically yellow. Raise the temperature to 43℃ / 37℃ at 1℃ / 3h, keep it steady for 24h, control the fan speed to 1440 r / min, and make the tobacco leaves turn 90% yellow, the leaves fully collapse and soften, the tips of the leaves curl obviously, and the side veins turn yellow.

[0020] Raise the temperature to 48℃ / 38℃ at 1℃ / 3h, and keep it steady for 20h until the leaves are completely yellow, the branch veins are completely yellow, and the small rolls are dry; raise the temperature to 52℃ / 39℃ at 1℃ / 2h, and keep it steady for 20h until the leaves are yellow, the veins are completely yellow, the large rolls are dry, and more than 1 / 2 of the branch veins are dry; raise the temperature to 55℃ / 40℃ at 1℃ / h, and keep it steady for 20h until the leaves are completely dry, the branch veins are completely dry, and more than 1 / 2 of the main veins are dry. The fan speed is controlled at 1440 r / min throughout the process. Raise the temperature to 68℃ / 42℃ at 1℃ / h, and keep it steady until the tobacco veins are completely dry. The fan speed is controlled at 960 r / min throughout the process.

[0021] In 2022, a comparative test of the above-mentioned flue-cured tobacco method with the local conventional method was designed in Wangluo Town, Xiangcheng County, Xuchang City, and a comprehensive evaluation of the appearance quality of the flue-cured tobacco was conducted. The results are shown in Table 1.

[0022] Table 1 Evaluation of the appearance quality of the upper leaf flue-cured tobacco in Xiangcheng County in 2022 / points

[0023]

[0024] Table 1 shows that the special processing and baking method of the present invention can improve the maturity of the flue-cured tobacco, increase the identity, leaf structure, oil content and chromaticity score of the flue-cured tobacco, reduce the degree of green and gray color in the flue-cured tobacco, and significantly improve the overall evaluation of the appearance quality of the flue-cured tobacco.

[0025] Embodiment 2:

[0026] The present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention, but not to limit the present invention.

[0027] 5 days before harvesting, the rhizomes of tobacco plants are girdled to reduce the supply of root nutrients, especially nitrogen, regulate the carbon and nitrogen metabolism of tobacco leaves, and improve the maturity and baking characteristics of fresh tobacco leaves. The second leaf from the top can be harvested at maturity. When the second leaf from the top is yellow, the tip of the leaf is obviously yellow, the leaf surface has yellow spots, the main vein is completely white, the side veins are basically white, the hairs fall off, and the tip of the leaf is bent downward, the upper tobacco leaves can be harvested at one time.

[0028] Divide the harvested tobacco leaves into two parts along the main ribs from the base to the middle of the leaves, and clamp the tobacco leaves with the main ribs cut with comb-type tobacco clips. When clamping tobacco, separate the main ribs of the cut tobacco leaves by 2cm, and each clip weighs 12kg. When loading tobacco, divide the upper 6 leaves into three parts according to the leaf position and baking characteristics. The top 1-2 leaves are placed in the low-temperature layer, the middle 3-4 leaves are placed in the medium-temperature layer, and the lower 5-6 leaves are placed in the high-temperature layer. The high-temperature greenhouse is slightly denser than the medium-temperature greenhouse, increasing by 5%, and the low-temperature greenhouse is slightly sparser than the medium-temperature greenhouse, reducing by 5%. The same layer is required to have equal spacing, no gaps, and uniformity. After loading tobacco, close the door of the curing room, fully open the air inlet and moisture outlet, and allow the tobacco leaves in the whole room to slowly change under natural environmental conditions for about 24 hours until the leaf tips are slightly soft.

[0029] Close the cold air door and dehumidification port, raise the temperature to 36℃ / 36℃ at 1℃ / 1h, control the fan speed to 960 r / min, and keep the temperature steady for 20h until the tip of the tobacco leaves turns slightly yellow; raise the temperature to 40℃ / 36℃ at 1℃ / 2h, and keep it for 30h until the tobacco leaves turn 80% yellow and the fine veins turn basically yellow. Raise the temperature to 43℃ / 37℃ at 1℃ / 3h, keep it steady for 24h, control the fan speed to 1440 r / min, and make the tobacco leaves turn 90% yellow, the leaves fully collapse and soften, the tips of the leaves curl obviously, and the side veins turn yellow.

[0030] Raise the temperature to 48℃ / 38℃ at 1℃ / 3h, and keep it steady for 20h until the leaves are completely yellow, the branch veins are completely yellow, and the small rolls are dry; raise the temperature to 52℃ / 39℃ at 1℃ / 2h, and keep it steady for 20h until the leaves are yellow, the veins are completely yellow, the large rolls are dry, and more than 1 / 2 of the branch veins are dry; raise the temperature to 55℃ / 40℃ at 1℃ / h, and keep it steady for 20h until the leaves are completely dry, the branch veins are completely dry, and more than 1 / 2 of the main veins are dry. The fan speed is controlled at 1440 r / min throughout the process. Raise the temperature to 68℃ / 42℃ at 1℃ / h, and keep it steady until the tobacco veins are completely dry. The fan speed is controlled at 960 r / min throughout the process.

[0031] In 2022, a comparative test was designed for the above-mentioned flue-cured tobacco leaves with thick ribs and bursting stems in Jiangliji Township, Jian'an District, Xuchang City, and a comprehensive evaluation of the appearance quality of the flue-cured tobacco was conducted. The results are shown in Table 2.

[0032] Table 2 Appearance quality evaluation of upper leaf flue-cured tobacco in Jian'an District in 2022 / points

[0033] deal with Maturity color identity Blade structure Chroma Oil content Contains blue Gray mottled color Smell Overall rating conventional 7 6.5 6 6.5 6 6 6 6.5 6 6.46 Example 2 7.5 7.5 6.5 7 6.5 7 6.5 7 6.5 7.11

[0034] Table 2 shows that the special processing and baking method of the present invention can improve the maturity of the smoked tobacco, improve the identity and leaf structure of the smoked tobacco, increase the oil content, enhance the chroma, reduce the degree of green and gray color in the smoked tobacco, and provide a distinct olfactory aroma, thereby greatly improving the overall appearance quality of the smoked tobacco.

Claims

1. A method for splitting and layering baking of thick-stemmed and burst-stemmed tobacco leaves, It is characterized in that The method comprises the following steps: 1) Nitrogen reduction regulation: 5 days before harvest, the rhizomes of tobacco plants are ring-cut to reduce nitrogen supply to the roots, regulate the carbon and nitrogen metabolism of tobacco leaves, and improve the maturity and baking characteristics of fresh tobacco leaves; 2) One-time harvesting: Taking the maturity standard of the second leaf from the top as a reference, when the second leaf from the top is yellow, the tip of the leaf is obviously yellow, the leaf surface has yellow spots, the main vein is completely white, the side veins are basically white, the hairs fall off and the tip of the leaf is bent downward, the upper tobacco leaves are harvested at one time; 3) Split the ribs and clamp the tobacco, and load the tobacco in layers: Split the harvested tobacco leaves into two parts from the base to the middle of the leaves along the main ribs, and clamp the tobacco leaves with comb-type tobacco clamps. When clamping the tobacco, separate the main ribs of the cut tobacco leaves by 2 cm, and each clamp weighs 11 to 12 kg. When loading the tobacco, divide the upper 6 leaves into three parts according to the leaf position and baking characteristics. The top 1 to 2 leaves are loaded in the low-temperature layer, the middle 3 to 4 leaves are loaded in the medium-temperature layer, and the lower 5 to 6 leaves are loaded in the high-temperature layer. The density of the high-temperature greenhouse is 5% higher than that of the medium-temperature greenhouse, and the density of the low-temperature greenhouse is 5% lower than that of the medium-temperature greenhouse. The spacing between the clamps in the same layer is required to be equal, without gaps, and uniform; 4) Natural ventilation pre-yellowing stage: After loading tobacco, close the door of the curing room, fully open the air inlet and moisture outlet, and let the tobacco leaves in the room slowly change under natural environmental conditions for 24 hours until the leaf tips become slightly soft; 5) High temperature humidity adjustment and yellowing stage: close the cold air door and dehumidification port, raise the temperature to 36℃ / 36℃ at 1℃ / 1h, control the fan speed to 960 r / min, and keep the temperature steady for 20h until the leaf tip turns slightly yellow; raise the temperature to 40℃ / 36℃ at 1℃ / 2h, and keep it for 30h until the tobacco leaves turn 80% to 90% yellow, and the fine veins basically turn yellow; raise the temperature to 43℃ / 37℃ at 1℃ / 3h, and keep it steady for 24h, control the fan speed to 1440 r / min, and make the tobacco leaves turn 90% to 100% yellow, the leaves fully collapse and soften, with obvious hook tips and curled edges, and the branch veins turn yellow; 6) Low humidity and slow color fixing stage: Raise the temperature to 47 to 48℃ / 38℃ at 1℃ / 3h, and keep the temperature steady for 20h until the leaves are completely yellow, the branch veins are completely yellow, and the small curls are formed; Raise the temperature to 50 to 52℃ / 39℃ at 1℃ / 2h, and keep the temperature steady for 20h until the leaves are yellow, the veins are completely yellow, and the small curls are formed, and the branch veins are more than 1 / 2 dry; Raise the temperature to 54 to 55℃ / 40℃ at 1℃ / h, and keep the temperature steady for 20h until the leaves are completely dry, the branch veins are completely dry, and more than 1 / 2 of the main veins are dry, and the fan speed is controlled at 1440 r / min throughout the process; 7) Drying stage: Raise the temperature to 68℃ / 40 to 42℃ at 1℃ / h, maintain steady temperature until the smoke ribs are completely dry, and control the fan speed throughout the process.

2. The method for baking thick-stemmed and burst-stemmed tobacco leaves in layers according to claim 1, It is characterized in that In the step 7), the fan speed is 960 r / min.

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