CN107637855B

CN107637855B - Flue-cured tobacco primary curing method for effectively improving processability of tobacco industrial re-curing link

Info

Publication number: CN107637855B
Application number: CN201710922839.4A
Authority: CN
Inventors: 邹聪明; 李军营; 赵高坤; 黄维; 熊开胜; 任汝周; 徐安传; 杨雪彪; 晋艳; 苏家恩; 胡小东; 晏飞; 徐鸿飞; 陈颐; 王涛; 冀新威; 高福宏; 郑志云; 何军; 郑红艳
Original assignee: Yunnan Academy of Tobacco Agricultural Sciences
Current assignee: Yunnan Academy of Tobacco Agricultural Sciences
Priority date: 2017-09-30
Filing date: 2017-09-30
Publication date: 2020-02-07
Anticipated expiration: 2037-09-30
Also published as: CN107637855A

Abstract

The invention discloses a flue-cured tobacco primary curing method for effectively improving the processability of a re-curing link in the tobacco industry, which comprises the steps of tobacco loading, yellowing, withering, leaf drying and tendon drying. The invention can effectively improve the physical processing resistance of flue-cured tobacco after primary curing and enhance the crushing resistance; by optimizing the temperature, the humidity and the baking time, the tobacco smoke has the advantages of fullness, thickness, enough quantity, slightly large stimulation and slightly concentrated strength while ensuring the yellow property stability of the tobacco, and meanwhile, the subsequent redrying can be facilitated to continuously improve the sensory quality of the tobacco according to the industrial requirement, and the problem of poor industrial redrying processability caused by the fact that the quality of the tobacco after being baked is close to the quality after being redried by the traditional primary baking method is effectively avoided; the invention can accelerate the moisture absorption rate of the tobacco leaves, thereby being beneficial to absorbing moisture quickly to a state suitable for threshing in the redrying process; meanwhile, the flue-cured tobacco primary curing method can accelerate the moisture dissipating rate of the tobacco leaves, and is beneficial to rapid water loss in the re-curing stage, so that the required moisture content requirement is met.

Description

Flue-cured tobacco primary curing method for effectively improving processability of tobacco industrial re-curing link

Technical Field

The invention belongs to the technical field of flue-cured tobacco curing processes, and particularly relates to a flue-cured tobacco primary curing method for effectively improving the processability of a tobacco industrial redrying link.

Background

In recent years, with the progress of threshing and redrying process technology in the cigarette industry, under the guidance of a cigarette 'big process' processing concept that a former process is to serve a later process, part of process tasks (such as formula and tobacco leaf quality improvement) of the original shred making processing are moved forward to the threshing and redrying process. The primary tobacco curing process, which is a previous process of threshing and redrying, is also gradually developing in a direction of satisfying the requirements of threshing and redrying processes. Therefore, in order to improve the usability of tobacco raw materials in cigarette formulations, adjusting the parameters of the threshing and redrying process, especially the parameters of equipment which affect the intrinsic sensory quality of tobacco leaves, is a key point for research and attention of each cigarette industry.

Compared with primary baking, the secondary baking regulation and control is finer, and the method has more effective effects on the aspects of tobacco leaf physics, physiology, biochemistry, quality, safety, individuation, specialization and the like. However, the existing primary curing methods basically or mostly do not take the industrial re-curing processability into consideration, for example, the important indexes of the industrial re-curing such as the processing resistance, the moisture absorption and moisture dispersion characteristics, the crushing resistance and the sensory quality improvement condition of the re-cured tobacco leaves are important, the tobacco leaves after the primary curing have the problems of poor processing resistance, easy crushing and quality shaping, thereby causing the problem of poor processing performance in the re-curing stage, and the cured tobacco cannot smoothly show the characteristics of the tobacco leaves in the re-curing stage, even generates some unpleasant scorched flavor. Moreover, the tobacco leaves of different varieties and different parts of the existing primary flue-curing process appear on the re-curing line in the same mode, so that the problems that the upper leaves are not enough in curing maturity, the leaves are stiff, the middle leaves are usually good in maturity but not enough in fragrance, and the lower leaves are too mature and easy to break often appear. Therefore, it is necessary to develop a flue-cured tobacco primary curing method capable of solving the above-mentioned re-curing problem.

Disclosure of Invention

The invention aims to provide a flue-cured tobacco primary curing method for effectively improving the processability of a tobacco industrial re-curing link.

The purpose of the invention is realized by the following steps:

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weaving tobacco weight is 7-9 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 12-15 cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise;

B. yellowing: including the early yellowing stage and the later yellowing stage; in the early yellowing stage, the temperature of dry balls is increased to 30-34 ℃, the temperature of wet balls is increased to 29-33 ℃, the heating time is 5.5-6.5 hours, the dry-wet difference of tobacco leaves collected under the dry and sunny conditions is controlled to be 1 ℃, the dry-wet difference of tobacco leaves collected under the continuous rainy condition and the dry-wet difference of tobacco leaves collected after-emergence or light yellow tobacco leaves are controlled to be 2-3 ℃, the temperature of the dry balls and the wet balls is stabilized, the tobacco leaves are baked for 12-18 hours until the tobacco leaves obviously sprout and begin to yellow; then, in the later yellowing stage, the dry bulb temperature is increased to 36-38 ℃ at the heating rate of 0.5-1 ℃/h, the wet bulb temperature is adjusted to 33-35 ℃, the dry-wet difference of tobacco leaves harvested under the drought and sunny conditions is controlled to be 3 ℃, the dry-wet difference of tobacco leaves harvested under the continuous rainy condition and the dry-wet difference of later-developed or bright yellow tobacco leaves are controlled to be 4 ℃, the dry and wet bulb temperatures are stabilized, and the tobacco leaves are baked for 36-48 h until the leaves are all yellow;

C. withering: heating tobacco leaves collected under the conditions of drought and sunny days at a heating rate of 1 ℃/1-2 h, heating tobacco leaves collected under the conditions of continuous rainy days and later-developed or bright yellow tobacco leaves at a heating rate of 1 ℃/2-3 h, raising the dry bulb temperature to 39-44 ℃, adjusting the wet bulb temperature to 35-36 ℃, stabilizing the dry bulb temperature and the wet bulb temperature, baking for 18-20 h until the tobacco leaves are soft and withered, the large tobacco stems are more than half soft, the leaf tips and leaf margins begin to dry, and the small tobacco stems turn yellow;

D. drying leaves: including the early stage of dry leaves and the later stage of dry leaves; in the early stage of dry leaf, the temperature of a dry bulb is increased to 45-48 ℃ according to the heating rate of 1 ℃/2h, the temperature of a wet bulb is adjusted to 36-37 ℃, the temperature of the dry bulb and the temperature of the wet bulb are stabilized, the tobacco leaves are baked for 18-24 h to form small drums, large tobacco stems are all yellow and all soft, and leaves are dried by more than half; then, in the later stage of dry leaves, the temperature of dry balls is increased to 52-54 ℃ according to the heating rate of 1 ℃/2h, the temperature of wet balls is adjusted to 37-38 ℃, the temperature of dry balls and wet balls is stabilized, the dry balls and the wet balls are baked for 32-38 h until large tobacco leaves are wound on a reel, the leaves are completely dry, and the main vein is dried by more than half;

E. and (3) drying tendons: the method comprises the steps of drying the tobacco leaves in the early stage of stem drying and the later stage of stem drying, wherein in the early stage of stem drying, the temperature of dry balls is increased to 56-63 ℃ according to the heating rate of 1 ℃/h, the temperature of wet balls is adjusted to 38-39 ℃, the temperature of dry balls and wet balls is stabilized, the tobacco leaves are baked for 6-8 h, and the tobacco leaves are baked to the bottom completely dry; and then, in the later stage of dry rib, according to the heating rate of 1 ℃/h, the temperature of the dry balls is increased to 64-68 ℃, the temperature of the wet balls is adjusted to 39-41 ℃, the temperature of the dry balls and the temperature of the wet balls are stabilized, and the baking is carried out for 14-22 h.

Compared with the prior art, the invention has the following technical effects:

1. the method can effectively improve the physical processing resistance of the flue-cured tobacco after primary curing and enhance the crushing resistance; by optimizing the temperature, the humidity and the baking time, the tobacco smoke has the advantages of fullness, thickness, enough quantity, slightly large stimulation and slightly concentrated strength while ensuring the yellow property stability of the tobacco, and meanwhile, the subsequent redrying can be facilitated to continuously improve the sensory quality of the tobacco according to the industrial requirement, so that the problem of poor industrial redrying processability caused by the fact that the quality of the tobacco after being baked is close to the quality after being redried by the traditional primary baking method is effectively solved;

2. the baking method can accelerate the moisture absorption rate of the tobacco leaves, thereby being beneficial to absorbing moisture quickly to a state suitable for threshing in the redrying processing process; meanwhile, the flue-cured tobacco primary curing method can accelerate the moisture dissipating rate of the tobacco leaves, and is beneficial to rapid water loss in the re-curing stage, so that the required moisture content requirement is met.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to be limiting in any way, and any modifications or alterations based on the teachings of the present invention are intended to fall within the scope of the present invention.

The invention specifically comprises the following steps:

In the step A, the fresh tobacco leaves are the lower leaves of the tobacco plants, the tobacco loading of the curing barn is 390-410 rods, or the fresh tobacco leaves are the middle leaves of the tobacco plants, the tobacco loading of the curing barn is 400-440 rods, or the fresh tobacco leaves are the upper leaves of the tobacco plants, and the tobacco loading of the curing barn is 430-450 rods.

And E, when the tobacco leaves at the later stage of the dried ribs are lower tobacco leaves, tobacco leaves harvested under the rainy condition or tender yellow tobacco leaves, the dry bulb temperature is increased to 65 ℃, and the wet bulb temperature is increased to 39 ℃.

And in the step B, the temperature of the dry bulb is increased to 32 ℃ in the early yellowing stage, and the temperature of the dry bulb is increased to 37 ℃ in the later yellowing stage.

In the step C, the temperature of the dry bulb is increased to 42 ℃, and the temperature of the wet bulb is adjusted to 35 ℃.

In the step D, the dry bulb temperature is increased to 47 ℃ in the early stage of dry leaves, the wet bulb temperature is adjusted to 36 ℃, and the dry bulb temperature is increased to 54 ℃ in the later stage of dry leaves, and the wet bulb temperature is adjusted to 37 ℃.

And E, the dry bulb temperature is increased to 62 ℃ in the early dry rib stage, and the wet bulb temperature is adjusted to 39 ℃.

And in the later stage of the dry tendon, the temperature of the dry bulb is raised to 68 ℃ and stabilized, and the temperature of the wet bulb is stabilized at 40 ℃.

The tobacco variety is Honghuadajinyuan or K326, and the tobacco planting ecological area is a southwest plateau ecological area.

The curing barn is a bulk curing barn.

The present invention will be further described with reference to examples 1 to 18.

Example 1

The flue-cured tobacco primary curing method for effectively improving the processability of the re-curing link of the tobacco industry comprises the following steps:

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 7 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod pitch of 12cm, filling the moderately-cured tobacco leaves into a middle layer of the curing barn, and filling the under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise;

B. yellowing: including the early yellowing stage and the later yellowing stage; in the early yellowing stage, the dry bulb temperature is increased to 30 ℃, the wet bulb temperature is increased to 29 ℃, the heating time is 5.5 hours, the dry-wet difference of tobacco leaves collected under the drought and sunny conditions is controlled to be 1 ℃, the dry-wet difference of the tobacco leaves collected under the continuous rainy condition and the after-emergence or bright yellow tobacco leaves is controlled to be 2 ℃, the dry bulb temperature and the wet bulb temperature are stabilized, the tobacco leaves are baked for 12 hours, and the tobacco leaves are obviously germinated and begin to yellow; then, in the later yellowing stage, the dry bulb temperature is increased to 36 ℃ at the heating rate of 0.5 ℃/h, the wet bulb temperature is adjusted to 33 ℃, the dry-wet difference of tobacco leaves collected under the drought and sunny conditions is controlled to be 3 ℃, the dry-wet difference of tobacco leaves collected under the continuous rainy condition and the dry-wet difference of tobacco leaves collected under the continuous rainy condition are controlled to be 4 ℃, the dry bulb temperature and the wet bulb temperature are stabilized, and the tobacco leaves are baked for 36h until the leaves are all yellow;

C. withering: the method comprises the following steps of (1) heating tobacco leaves collected under the dry and sunny conditions to 39 ℃ according to a heating rate of 1 ℃/2h, and heating tobacco leaves collected under the continuous rainy conditions to 1 ℃/3h, adjusting the dry bulb temperature to 35 ℃, stabilizing the dry bulb temperature and the wet bulb temperature, baking for 18h until the tobacco leaves are soft and withered, the large tobacco ribs are over half soft, the leaf edges of the leaf tips begin to dry, and the small tobacco ribs turn yellow;

D. drying leaves: including the early stage of dry leaves and the later stage of dry leaves; in the early stage of drying the tobacco leaves, the temperature of the dry bulb is increased to 45 ℃ and the temperature of the wet bulb is adjusted to 36 ℃ according to the heating rate of 1 ℃/2h, the temperature of the dry bulb and the temperature of the wet bulb are stabilized, the tobacco leaves are baked for 18h until the tobacco leaves are wound into small rolls, the large tobacco stems are all yellow and soft, and the leaves are dried by more than half; then, in the later stage of dry leaves, the temperature of the dry balls is increased to 52 ℃ and the temperature of the wet balls is adjusted to 37 ℃ according to the heating rate of 1 ℃/2h, the dry and wet ball temperatures are stabilized, the tobacco leaves are baked for 32h until the tobacco leaves are wound into large rolls, the leaves are completely dry, and the main vein is dried by more than half;

E. and (3) drying tendons: the method comprises the steps of a dry-rib initial stage and a dry-rib later stage, wherein in the dry-rib initial stage, the dry-bulb temperature is increased to 56 ℃ according to the heating rate of 1 ℃/h, the wet-bulb temperature is adjusted to 38 ℃, the dry-bulb temperature and the wet-bulb temperature are stabilized, the tobacco leaves are baked for 6h, and the tobacco leaves are baked to a bottom station to be completely dry; and then, in the later stage of dry ribs, the temperature of the dry balls is increased to 64 ℃ according to the temperature rise rate of 1 ℃/h, the temperature of the wet balls is adjusted to 39 ℃, the temperature of the dry balls and the temperature of the wet balls are stabilized, and the baking is carried out for 14 h.

Example 2

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 9 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 15cm, filling the moderately-cured tobacco leaves into a middle layer of the curing barn, and filling the under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise;

B. yellowing: including the early yellowing stage and the later yellowing stage; in the early yellowing stage, the dry bulb temperature is increased to 34 ℃, the wet bulb temperature is increased to 33 ℃, the heating time is 6.5 hours, the dry-wet difference of tobacco leaves collected under the drought and sunny conditions is controlled to be 1 ℃, the dry-wet difference of the tobacco leaves collected under the continuous rainy condition and the after-emergence or bright yellow tobacco leaves is controlled to be 3 ℃, the dry bulb temperature and the wet bulb temperature are stabilized, the tobacco leaves are baked for 18 hours, and the tobacco leaves are obviously germinated and begin to yellow; then, in the later yellowing stage, the dry bulb temperature is increased to 38 ℃ according to the heating rate of 1 ℃/h, the wet bulb temperature is adjusted to 35 ℃, the dry-wet difference of tobacco leaves collected under the drought and sunny conditions is controlled to be 3 ℃, the dry-wet difference of the tobacco leaves collected under the continuous rainy condition, the after-yellowing or bright yellow tobacco leaves is controlled to be 4 ℃, the dry bulb temperature and the wet bulb temperature are stabilized, and the tobacco leaves are baked for 48h until the leaves are completely yellow;

C. withering: the method comprises the following steps of (1) heating tobacco leaves collected under the dry and sunny conditions to 44 ℃ according to a heating rate of 1 ℃/h, and heating tobacco leaves collected under the continuous rainy conditions, later-growing or bright yellow tobacco leaves to 1 ℃/2h, adjusting the dry bulb temperature to 36 ℃, stabilizing the dry bulb temperature and the wet bulb temperature, baking for 20h until the tobacco leaves are soft and withered, the large tobacco ribs are over half soft, the leaf edges of the leaf tips begin to dry, and the small tobacco ribs turn yellow;

D. drying leaves: including the early stage of dry leaves and the later stage of dry leaves; in the early stage of drying the tobacco leaves, the temperature of the dry bulb is increased to 48 ℃ and the temperature of the wet bulb is adjusted to 37 ℃ according to the heating rate of 1 ℃/2h, the temperature of the dry bulb and the temperature of the wet bulb are stabilized, the tobacco leaves are baked for 24h until the tobacco leaves are wound into small rolls, the large tobacco stems are all yellow and soft, and the leaves are dried by more than half; then, in the later stage of dry leaves, the temperature of the dry balls is increased to 54 ℃ and the temperature of the wet balls is adjusted to 38 ℃ according to the heating rate of 1 ℃/2h, the temperature of the dry balls and the temperature of the wet balls are stabilized, the dry balls and the wet balls are baked for 38h, the tobacco leaves are completely dry, and the main vein is dried by more than half;

E. and (3) drying tendons: the method comprises the steps of a dry-rib initial stage and a dry-rib later stage, wherein in the dry-rib initial stage, the dry-bulb temperature is increased to 63 ℃ according to the heating rate of 1 ℃/h, the wet-bulb temperature is adjusted to 39 ℃, the dry-bulb temperature and the wet-bulb temperature are stabilized, the tobacco leaves are baked for 8h, and the tobacco leaves are baked to be completely dry; and then, in the later stage of dry ribs, the temperature of the dry balls is increased to 68 ℃ according to the temperature rise rate of 1 ℃/h, the temperature of the wet balls is adjusted to 41 ℃, the temperature of the dry balls and the temperature of the wet balls are stabilized, and the dry balls and the wet balls are baked for 22 h.

Example 3

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise;

B. yellowing: including the early yellowing stage and the later yellowing stage; when the tobacco leaves are yellow, the temperature of the dry bulb is increased to 32 ℃, the temperature of the wet bulb is increased to 31 ℃, the temperature rise time is 6 hours, the dry-wet difference of the tobacco leaves collected under the dry and sunny conditions is controlled to be 1 ℃, the dry-wet difference of the tobacco leaves collected under the continuous rainy condition and the after-emergence or bright yellow tobacco leaves is controlled to be 2.5 ℃, the temperature of the dry bulb and the wet bulb is stabilized, the tobacco leaves are baked for 15 hours, and the tobacco leaves are baked to obviously sprout and begin to yellow; then, in the later yellowing stage, the dry bulb temperature is increased to 37 ℃ according to the heating rate of 0.75 ℃/h, the wet bulb temperature is adjusted to 34 ℃, the dry-wet difference of tobacco leaves collected under the drought and sunny conditions is controlled to be 3 ℃, the dry-wet difference of the tobacco leaves collected under the continuous rainy condition and the dry-wet difference of the tobacco leaves collected under the continuous rainy condition are controlled to be 4 ℃, the dry bulb temperature and the wet bulb temperature are stabilized, and the tobacco leaves are baked for 42h until the leaves are all yellow;

C. withering: the method comprises the following steps of (1) heating tobacco leaves collected under the dry and sunny conditions at a heating rate of 1 ℃/1.5h, heating tobacco leaves collected under the continuous rainy conditions and later-cured or bright yellow tobacco leaves at a heating rate of 1 ℃/2.5h, raising the dry bulb temperature to 41.5 ℃, adjusting the wet bulb temperature to 35.5 ℃, stabilizing the dry bulb temperature and the wet bulb temperature, baking for 19h until the tobacco leaves are soft and withered, the large tobacco stems are more than half soft, the leaf edges of the leaf tips begin to dry, and the small tobacco stems turn yellow;

D. drying leaves: including the early stage of dry leaves and the later stage of dry leaves; at the early stage of drying the tobacco leaves, the temperature of the dry bulb is increased to 46.5 ℃ according to the heating rate of 1 ℃/2h, the temperature of the wet bulb is adjusted to 36.5 ℃, the temperature of the dry bulb and the temperature of the wet bulb are stabilized, the tobacco leaves are baked for 21h to form small tobacco leaves rolls, the large tobacco stems are all yellow and all soft, and the leaves are more than half dry; then, in the later stage of dry leaves, the temperature of dry balls is increased to 53 ℃ and the temperature of wet balls is adjusted to 37.5 ℃ according to the heating rate of 1 ℃/2h, the temperature of the dry balls and the temperature of the wet balls are stabilized, the dry balls and the wet balls are baked for 35h until the tobacco leaves are baked into large drums, the leaves are completely dry, and the main vein is dried by more than half;

E. and (3) drying tendons: the method comprises the steps of a dry-rib initial stage and a dry-rib later stage, wherein in the dry-rib initial stage, the dry-bulb temperature is increased to 59.5 ℃ according to the heating rate of 1 ℃/h, the wet-bulb temperature is adjusted to 38.5 ℃, the dry-bulb temperature and the wet-bulb temperature are stabilized, the tobacco leaves are baked for 7h, and the tobacco leaves are baked to the bottom completely dry; and then, in the later stage of dry tendon, the temperature of the dry balls is increased to 66 ℃ according to the temperature rise rate of 1 ℃/h, the temperature of the wet balls is adjusted to 40 ℃, the temperature of the dry balls and the temperature of the wet balls are stabilized, and the baking is carried out for 18 h.

Example 4

E. and (3) drying tendons: the method comprises the steps of a dry-rib initial stage and a dry-rib later stage, wherein in the dry-rib initial stage, the dry-bulb temperature is increased to 59.5 ℃ according to the heating rate of 1 ℃/h, the wet-bulb temperature is adjusted to 38.5 ℃, the dry-bulb temperature and the wet-bulb temperature are stabilized, the tobacco leaves are baked for 7h, and the tobacco leaves are baked to the bottom completely dry; and then, in the later stage of dry stem, when the tobacco leaves in the later stage of dry stem are lower tobacco leaves, tobacco leaves harvested under the condition of overcast and rainy or tender yellow tobacco leaves, the dry bulb temperature is increased to 65 ℃, the wet bulb temperature is adjusted to 39 ℃, the dry bulb temperature and the wet bulb temperature are stabilized, and the tobacco leaves are baked for 18 hours.

Example 5

C. withering: the method comprises the following steps of (1) heating tobacco leaves collected under the dry and sunny conditions at a heating rate of 1 ℃/1.5h, heating tobacco leaves collected under the continuous rainy conditions and later-cured or bright yellow tobacco leaves at a heating rate of 1 ℃/2.5h, raising the dry bulb temperature to 42 ℃, adjusting the wet bulb temperature to 35 ℃, stabilizing the dry bulb temperature and the wet bulb temperature, baking for 19h until the tobacco leaves are soft and withered, the large tobacco stems are over half soft, the leaf edges of the leaf tips begin to dry, and the small tobacco stems turn yellow;

Example 6

D. drying leaves: including the early stage of dry leaves and the later stage of dry leaves; at the early stage of drying the tobacco leaves, the temperature of the dry bulb is increased to 47 ℃ and the temperature of the wet bulb is adjusted to 36 ℃ according to the heating rate of 1 ℃/2h, the temperature of the dry bulb and the temperature of the wet bulb are stabilized, the tobacco leaves are baked for 21h until the tobacco leaves are wound into small rolls, the large tobacco stems are all yellow and soft, and the leaves are more than half dry; then, in the later stage of dry leaves, the temperature of the dry balls is increased to 54 ℃ and the temperature of the wet balls is adjusted to 37 ℃ according to the heating rate of 1 ℃/2h, the temperature of the dry balls and the temperature of the wet balls are stabilized, the dry balls and the wet balls are baked for 35h until the tobacco leaves are completely dry, and the main vein is dried by more than half;

Example 7

E. and (3) drying tendons: the method comprises the steps of a dry-rib initial stage and a dry-rib later stage, wherein in the dry-rib initial stage, the dry-bulb temperature is increased to 62 ℃ according to the heating rate of 1 ℃/h, the wet-bulb temperature is adjusted to 39 ℃, the dry-bulb temperature and the wet-bulb temperature are stabilized, the tobacco leaves are baked for 7h, and the tobacco leaves are baked to be completely dry; and then, in the later stage of dry tendon, the temperature of the dry balls is increased to 66 ℃ according to the temperature rise rate of 1 ℃/h, the temperature of the wet balls is adjusted to 40 ℃, the temperature of the dry balls and the temperature of the wet balls are stabilized, and the baking is carried out for 18 h.

Example 8

E. and (3) drying tendons: the method comprises the steps of a dry-rib initial stage and a dry-rib later stage, wherein in the dry-rib initial stage, the dry-bulb temperature is increased to 59.5 ℃ according to the heating rate of 1 ℃/h, the wet-bulb temperature is adjusted to 38.5 ℃, the dry-bulb temperature and the wet-bulb temperature are stabilized, the tobacco leaves are baked for 7h, and the tobacco leaves are baked to the bottom completely dry; and then, in the later stage of dry tendon, the temperature of the dry balls is increased to 68 ℃ according to the temperature rise rate of 1 ℃/h, the temperature of the wet balls is adjusted to 40 ℃, the temperature of the dry balls and the temperature of the wet balls are stabilized, and the baking is carried out for 18 h.

Example 9

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are lower leaves of tobacco plants, and the tobacco loading of a curing barn is 390 rods;

Example 10

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are the middle leaves of the tobacco plant, and the tobacco loading of the curing barn is 400 rods;

Example 11

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are upper leaves of tobacco plants, and the tobacco loading of a curing barn is 430 rods;

Example 12

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are lower leaves of tobacco plants, and the tobacco loading of a curing barn is 410 rods;

Example 13

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are the middle leaves of the tobacco plant, and the tobacco loading of the curing barn is 440 rods;

Example 14

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are upper leaves of tobacco plants, and the tobacco loading of a curing barn is 450 rods;

Example 15

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are the lower leaves of the tobacco plants, and the tobacco loading of the curing barn is 400 rods;

Example 16

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are the middle leaves of the tobacco plant, and the tobacco loading of the curing barn is 420 rods;

Example 17

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weight of the woven tobacco is 8 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 13.5cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are upper leaves of tobacco plants, and the tobacco loading of a curing barn is 440 rods;

Example 18: comparative test

The test sites are Yunnan Dali, Yuxi and Chuxiong, which are respectively represented by D, Y and C; adopting Honghuadajinyuan and K326 flue-cured tobacco varieties, which are respectively represented by H, K; 2 treatments were set up in the experiment, treatment M being the method of the invention, treatment R being the current conventional mode of flue-cured tobacco growers, the numbering being shown in Table 1.

TABLE 1 test number cases

Processing number	Year of experiment	Test site	Variety of test	Test siteTheory of things
					DHM	2015	Theory of the major organization	Hongda (Red big)	M
DHR	2015	Theory of the major organization	Hongda (Red big)	R
					YKM	2015	Yuxi tea	K326	M
YKR	2015	Yuxi tea	K326	R
					CKM	2016	Chuxiong medicine	K326	M
CKR	2016	Chuxiong medicine	K326	R

The evaluation method of the industrial processing-resistant characteristic of the tobacco leaves comprises the following steps: after green and miscellaneous tobacco in the flue-cured tobacco leaves is removed, 10kg of samples C3F and C2F are selected and delivered to the Yunan tobacco technology center for industrial processing-resistant characteristic analysis; after the sample is balanced for 72 hours in a constant temperature and humidity environment with the temperature of 22 ℃ and the humidity of 60%, the detection is carried out according to a tobacco leaf anti-crushing index monitoring method provided by Chenhongli et al, and the detection result is shown in Table 2.

The tobacco leaf moisture absorption and dispersion characteristic analysis method comprises the following steps: and (3) detecting the moisture absorption and dispersion characteristics of the sample by using an SPSx type tobacco moisture retention performance instrument. Setting detection conditions: the initial environment temperature and humidity is 25 ℃, and the relative humidity is 60%; after the balance is achieved, adjusting the temperature and the humidity of the environment to be 25 ℃ and the relative humidity to be 75%, and observing the moisture absorption characteristics of the sample; after the balance is achieved, the temperature and the humidity of the environment are adjusted to be 25 ℃ and the relative humidity is 60%, the moisture dispersion characteristics of the sample are observed, and the detection results are shown in table 3.

The method for evaluating the sensory quality of the flue-cured tobacco leaves comprises the following steps: after green and miscellaneous tobacco in the flue-cured tobacco leaves is removed, 5kg of samples C3F and C2F are selected respectively and delivered to the technical center of Yunan Zhongyan tobacco for sensory quality evaluation; the quality report of the tobacco leaf smoking after passing through the redrying link is provided by redrying enterprises (technical center of tobacco industry, llc, yunnan), and the detection results are shown in tables 4 and 5.

Statistical analysis: data were processed using SAS9.3 software and data analysis was based on the General Linear Model (GLM). Statistical analysis was performed after averaging the data from duplicate measurements, with P values <0.05 to distinguish significant differences between treatments. The mean was calculated by Tukey's HSD test at 95% confidence interval.

TABLE 2 Effect of different treatments on the physical resistance of tobacco leaves to processing

Treatment of	Ratio (%) > 4mm or more	Ratio (%) > 2mm	Ratio of not less than 1mm (%)	Proportion of < 1mm (%)
					DHM	94.04a	1.48b	0.94a	3.05b
DHR	93.53b	1.82a	0.82a	3.55a
					YKM	94.08a	1.57b	0.95a	2.76a
YKR	93.72b	1.74a	1.02a	2.88a
					CKM	96.24a	1.31b	0.89a	0.42b
CKR	95.92b	2.73a	1.37a	0.79a

Note: evaluation criteria: the higher the proportion of < 1mm, the worse the sample shatter resistance, and the higher the proportion of > 4mm, the better the sample shatter resistance.

After the pretreatment of the samples, the detection is carried out according to a tobacco leaf anti-crushing index monitoring method proposed by Chenhongli et al, and the detection data of different samples are shown in Table 2; the combination of the ratio of less than 1mm and the ratio of more than 4mm shows that the samples treated with M all have the best resistance to crushing for the tobacco leaves tested at the three test points; the varieties have no obvious difference, and the physical processing resistance of the tobacco leaves subjected to the three test points is the best.

TABLE 3 Effect of different treatments on the moisture absorption and diffusion characteristics of tobacco leaves

Treatment of	60% -75% RH equilibration time (h)	Balance weight change (%) -60% to 75% RH	75% -60% RH equilibration time (h)	Balance weight change (%) -75% to 60% RH
					DHM	10.85b	17.32a	16.5b	15.26a
DHR	15.47a	15.39a	29.3a	11.87b
					YKM	7.98b	16.88a	20.59b	13.4a
YKR	10.47a	20.18a	25.45a	10.97b
					CKM	6.81b	20.18a	16.45b	8.21a
CKR	8.84a	22.88a	18.59a	4.61b

Note: evaluation criteria: 60% -75% RH equilibration time (h) represents the moisture absorption characteristics; the 75% -60% RH equilibration time (h) represents the moisture dissipating characteristics.

As can be seen from table 3, the three test point test samples all absorbed the fastest in moisture absorption characteristics as the sample treated with M; in terms of the dewetting characteristics, the test samples all gave the fastest rate of dewetting for the samples treated with M. The absorption rate and the diffusion rate of the red are both slower than those of K326; from the region, the moisture absorption rate of the Chuxiong tobacco leaves is higher than that of the Dali and Yuxi, and the moisture dispersion rate of the Chuxiong tobacco leaves is lower than that of the Dali and Yuxi; the tobacco leaves with high moisture absorption rate can easily absorb moisture in the storage and transportation processes, so that the crushing resistance of the tobacco leaves is improved, and the crushing loss is reduced; the tobacco leaves have high moisture dissipating rate and can rapidly lose moisture in the redrying stage, so that the required dry moisture state is rapidly achieved; thus, treatments M are all superior to treatments R.

TABLE 4 Effect of different treatments on the sensory quality of flue-cured tobacco leaves

Treatment of	Fragrant note	Amount of fragrance	Quality of fragrance	Concentration of	Irritation property	Stiff head	Miscellaneous qi	Degree of cleanliness	Moistening	Aftertaste	Total up to
												DHM	7.50	12.50	12.50	7.50	13.00	5.00	7.50	7.50	4.00	3.50	80.50
DHR	8.50	13.00	13.00	8.50	13.00	5.00	8.50	8.50	4.00	3.50	85.50
												YKM	7.50	12.50	12.50	7.50	13.00	5.00	7.50	7.50	4.00	3.50	80.50
YKR	8.00	13.00	13.00	8.00	13.00	5.00	8.00	8.00	4.00	3.50	83.50
												CKM	7.50	12.50	12.44	7.31	7.50	4.88	7.13	7.25	4.00	3.88	74.38
CKR	8.00	13.00	13.50	7.50	7.50	5.00	7.50	7.50	4.00	4.00	77.50

Note: the tobacco sensory evaluation quality analysis is performed by the certified evaluation expert, is relatively objective and is not repeated.

As can be seen from Table 4, the quality of the smoke panel test of the treatment R of the three test points is superior to that of the treatment M, and is mainly reflected on several indexes such as aroma note, aroma amount, aroma quality and cleanliness; from the situation among varieties, the red smoking quality is higher than K326 in terms of aroma, concentration and cleanliness, and the total score is also higher than K326; from the test area, the tobacco leaf smoking quality of Dali and Yuxi is superior to Chuxiong, which is mainly reflected in three indexes of irritation, miscellaneous gas and cleanliness, but the aftertaste of Chuxiong tobacco leaf is superior to other two test points; according to industrial requirements, the industrial link needs redrying processing and other processes; according to the feedback of industrial product smoking, the processing R has high score, but has loose smoke, light impurity gas and slightly residual taste, is close to the quality of the redried tobacco leaves, and has little space for adjusting the quality of the tobacco leaves for the industry; the concentration of the treated M is higher, the smoke is full, thick, sufficient, slightly stimulated and slightly concentrated, and the quality of the tobacco leaves can be continuously improved according to the industrial requirements through the subsequent redrying processing.

TABLE 5 Effect of different treatments on the sensory quality of redried tobacco leaves

Treatment of	Sample name	Pleasure property （10）	Fineness of fineness （5）	Round moisture property （5）	Feeling of lingering （5）	Amount of fragrance （10）	Sweetness level （10）	Concentration of （10）	Irritation property （10）	Stiff head （5)	Miscellaneous gas (10)	Degree of cleanliness （10）	Feeling of moistening the body fluid （5）	Aftertaste (5)	Total up to
																YKM	Before redrying	7.5	3.9	3.4	3.6	7.1	7.0	7.3	7.5	5.0	7.1	7.3	4.0	3.9	74.6
YKM	Redrying 1	7.6	3.9	3.5	3.8	7.2	7.0	7.5	7.3	5.0	7.0	7.2	3.8	3.9	74.7
																YKM	Redrying 2	7.8	3.9	3.5	4.0	7.5	7.2	7.6	7.5	5.0	7.3	7.3	4.0	4.0	76.6
YKM	Redrying 3	8.1	4.0	3.5	4.1	7.7	7.5	7.8	7.6	5.0	7.5	7.5	4.0	4.2	78.5
																YKR	Before redrying	8.0	4.0	3.5	4.0	7.5	7.5	7.5	7.5	5.0	7.5	7.5	4.0	4.0	77.5
YKR	Redrying 1	8.0	4.0	3.5	4.2	7.7	7.6	7.5	7.5	5.0	7.5	7.6	4.0	4.0	78.1
																YKR	Redrying 2	7.9	4.0	3.5	4.0	7.5	7.5	7.5	7.5	5.0	7.3	7.5	4.0	4.0	77.2
YKR	Redrying 3	7.6	4.0	3.3	3.9	7.3	7.3	7.3	7.4	5.0	7.3	7.5	3.8	4.0	75.7
																DHM	Before redrying	7.6	3.9	3.4	3.6	7.0	7.0	7.3	7.3	5.0	7.1	7.3	4.0	3.9	74.4
DHM	Redrying 1	7.6	3.9	3.5	3.8	7.2	7.2	7.5	7.3	5.0	7.0	7.2	3.8	3.9	74.9
																DHM	Redrying 2	7.8	3.9	3.5	4.0	7.5	7.4	7.6	7.5	5.0	7.3	7.3	4.0	4.0	76.8
DHM	Redrying 3	8.1	4.0	3.5	4.1	7.5	7.7	7.7	7.5	5.0	7.5	7.5	4.0	4.2	78.3
																DHR	Before redrying	8.0	4.0	3.5	4.0	7.5	7.7	7.5	7.5	5.0	7.5	7.5	4.0	4.0	77.7
DHR	Redrying 1	8.0	4.0	3.5	4.2	7.6	7.8	7.6	7.5	5.0	7.5	7.5	4.0	4.0	78.2
																DHR	Redrying 2	7.9	4.0	3.5	4.0	7.5	7.7	7.5	7.5	5.0	7.3	7.5	4.0	4.0	77.4
DHR	Redrying 3	7.6	4.0	3.3	3.9	7.3	7.5	7.3	7.4	5.0	7.3	7.5	3.8	4.0	75.9
																CKM	Before redrying	7.6	4.0	3.4	3.4	6.9	7.1	7.2	7.5	5.0	7.1	7.5	3.9	3.7	74.3
CKM	Redrying 1	7.6	4.0	3.5	3.5	7.2	7.2	7.3	7.5	5.0	7.2	7.5	4.0	3.8	75.3
																CKM	Redrying 2	7.9	4.0	3.7	4.0	7.5	7.3	7.5	7.5	5.0	7.5	7.5	3.6	3.5	76.5
CKM	Redrying 3	8.2	4.0	4.0	4.0	8.0	7.7	7.9	7.5	5.0	7.5	7.5	4.0	4.0	79.3
																CKR	Before redrying	8.0	4.0	3.9	3.9	7.9	7.5	7.5	7.6	5.0	7.5	7.5	4.0	4.0	78.3
CKR	Redrying 1	8.0	4.0	4.0	4.0	8.0	7.5	7.8	7.5	5.0	7.5	7.5	4.0	4.0	78.8
																CKR	Redrying 2	7.8	4.0	3.5	3.8	7.5	7.2	7.5	7.6	5.0	7.5	7.5	4.0	3.7	76.6
CKR	Redrying 3	7.3	4.0	3.5	3.5	7.2	7.0	7.0	7.2	5.0	7.2	7.5	3.5	3.0	72.9

Note: the redrying 1 is mild redrying; the redrying 2 is moderate redrying; redrying 3 is a heavy redrying.

As can be seen from table 5, the sensory quality of the treatment M was improved with the increase of the redrying strength, while the sensory quality of the treatment R was improved by mild redrying, and the overall sensory quality tended to be worse with moderate and severe redrying processes. Among them, the sample treated with the redrying process No. 3 in treatment M had the best sensory quality, and the sample treated with the redrying process No. 1 in treatment R had the better sensory quality. The difference between varieties is not obvious. Therefore, the processing M is most suitable for industrial requirements according to the requirements of the industrial redrying link.

Claims

1. A flue-cured tobacco primary curing method for effectively improving the processability of a tobacco industrial redrying link is characterized in that the tobacco variety is Honghuadajinyuan or K326, and a tobacco planting ecological area is a southwest plateau ecological area, and specifically comprises the following steps:

A. loading cigarettes: dividing fresh tobacco leaves into moderate-mature, over-mature and under-mature tobacco leaves according to the mature degree, and classifying and weaving rods, wherein the weaving tobacco weight is 7-9 kg/rod; then, filling the woven over-cured tobacco leaves into a high-temperature area of a curing barn at a rod distance of 12-15 cm, filling moderate-cured tobacco leaves into a middle layer of the curing barn, and filling under-cured tobacco leaves into a low-temperature area of the curing barn; after the tobacco leaves are installed, closing doors and windows of the curing barn, and starting ignition and temperature rise; fresh tobacco leaves are lower leaves of the tobacco plant, the tobacco loading of the curing barn is 390-410 rods, or fresh tobacco leaves are middle leaves of the tobacco plant, the tobacco loading of the curing barn is 400-440 rods, or fresh tobacco leaves are upper leaves of the tobacco plant, and the tobacco loading of the curing barn is 430-450 rods;

2. The flue-cured tobacco primary curing method for effectively improving the processability of the redrying link of the tobacco industry according to claim 1, wherein when the tobacco leaves at the later stage of the stem drying in the step E are lower tobacco leaves, tobacco leaves harvested under the rainy condition or bright yellow tobacco leaves, the dry bulb temperature is increased to 65 ℃, and the wet bulb temperature is increased to 39 ℃.

3. The method of claim 1, wherein the dry bulb temperature is raised to 32 ℃ in the early yellowing stage and the dry bulb temperature is raised to 37 ℃ in the later yellowing stage in step B.

4. The method of claim 1, wherein the dry-bulb temperature of step C is increased to 42 ℃ and the wet-bulb temperature is adjusted to 35 ℃.

5. The method according to claim 1, wherein the dry-bulb temperature is raised to 47 ℃ and the wet-bulb temperature is adjusted to 36 ℃ in the early stage of the dry leaf, and the dry-bulb temperature is raised to 54 ℃ and the wet-bulb temperature is adjusted to 37 ℃ in the later stage of the dry leaf.

6. The method of claim 1, wherein the dry-bulb temperature of the dry-cured tobacco in step E is raised to 62 ℃ and the wet-bulb temperature is adjusted to 39 ℃ during the initial stage of the dry-curing process.

7. The flue-cured tobacco primary curing method for effectively improving the processability of the redrying link of the tobacco industry according to claim 1, characterized in that the curing barn is a bulk curing barn.