Tobacco leaf modulation process dynamic regulation and control method based on multi-source information fusion

Abstract

The invention discloses a multi-source information fusion-based tobacco leaf curing process dynamic regulation and control method, which is characterized by comprising the following steps of: extracting a plurality of tobacco leaf samples from a curing barn at the yellowing last stage or the color fixing early stage of tobacco leaf curing, and respectively carrying out appearance state evaluation, chemical component determination and sensory smoking; the indexes of total sugar, reducing sugar, nicotine and starch are obtained through chemical component determination; the sensory quality of the tobacco leaves is evaluated through sensory smoking, and sensory quality scores are obtained; according to a starch content target value and sensory quality threshold values of tobacco leaves at different parts, on the basis of a conventional modulation scheme, the modulation precision is improved, the tobacco leaf quality is optimized, the flexibility is enhanced, and different tobacco leaf differences are adapted by prolonging or shortening the time of a color fixing stage and finely adjusting temperature and humidity parameters of the color fixing stage; and the defects of the traditional modulation process are effectively overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of tobacco modulation, and particularly relates to a method for dynamically adjusting process parameters through multi-dimensional detection and analysis at the end of the yellowing stage or the color-fixing stage of tobacco leaf modulation, and is particularly applicable to intelligent temperature and humidity control during the flue-curing process of flue-cured tobacco. Background Art

[0002] During the tobacco leaf modulation process, traditional process parameter adjustments often lack accuracy and timeliness. Most rely on empirical judgment and it is difficult to dynamically adjust according to the actual quality changes of tobacco leaves, resulting in uneven quality of the modulated tobacco leaves and being unable to fully meet the market demand for high-quality tobacco leaves. The existing technologies mainly have the following defects: First, strong dependence on experience, the traditional modulation process parameters are fixed, and mostly use fixed three-stage or five-stage temperature and humidity curves, which cannot adapt to the characteristics of tobacco leaves in different production areas and with different qualities; Second, feedback lag, the existing methods mostly detect chemical components or conduct sensory evaluation after the modulation is completed, and cannot guide the process adjustment in real time; Third, single detection dimension, the existing technologies mostly judge the tobacco leaf modulation process through color and the state of tobacco leaves, lacking the collaborative analysis of sensory quality and chemical components. Summary of the Invention

[0003] The present invention aims to avoid the deficiencies of the above-mentioned existing technologies, and provides a dynamic control method for tobacco leaf modulation process based on multi-source information fusion, which adjusts the modulation process parameters according to the real-time tobacco leaf quality status data, improves the quality and stability of the flue-cured tobacco leaves, and better meets the industrial requirements.

[0004] The present invention adopts the following technical solutions to achieve the above object:

[0005] The dynamic control method for tobacco leaf modulation process based on multi-source information fusion of the present invention is characterized in that at the end of the yellowing stage or the early stage of color-fixing of tobacco leaf modulation, multiple tobacco leaf samples are extracted from the curing barn, and the appearance state evaluation, chemical component determination and sensory evaluation are carried out respectively; the indexes of total sugar, reducing sugar, nicotine and starch are obtained through chemical component determination; the sensory quality of tobacco leaves is evaluated through sensory evaluation, and the sensory quality score is obtained; according to the starch content target value and the sensory quality threshold of tobacco leaves in different parts, on the basis of the conventional modulation scheme, by extending or shortening the time of the color-fixing stage, and slightly adjusting the temperature and humidity parameters of the color-fixing stage to improve the modulation accuracy and optimize the quality of tobacco leaves.

[0006] The dynamic control method for tobacco leaf modulation process based on multi-source information fusion of the present invention is also characterized by including the following steps:

[0007] Step 1, sampling and detection: At the end of the yellowing stage or the early stage of color-fixing of tobacco leaf modulation, multiple tobacco leaf samples are extracted from the middle layer of the curing barn, and the appearance state evaluation, chemical component determination and sensory evaluation are carried out respectively;

[0008] Step 2: Data processing and analysis: Based on the indexes of total sugar, reducing sugar, nicotine, and starch of the tobacco leaf samples obtained through chemical composition determination, calculate the average values of total sugar, reducing sugar, and nicotine of the tobacco leaves, as well as the average starch content S1. Quantify the sensory evaluation results into a sensory quality score Q1; Set the target starch content value S0 to 5% according to the starch content and sensory quality requirements of high-quality tobacco leaves, and set the sensory quality thresholds Q0 to 65 points for upper tobacco leaves, 68 points for middle tobacco leaves, and 56 points for lower tobacco leaves respectively;

[0009] Step 3: Process parameter adjustment: Calculate the adjustment duration T according to formula (1) adj :

[0010] T adj =α(S1 - S0)+β(Q0 - Q1)

[0011] where α and β are both weighting coefficients, and: α = 0.6 and β = 0.4;

[0012] Set the time of the color-fixing stage according to the adjustment duration Tadj to enable the tobacco leaves to achieve the best modulation effect.

[0013] Another feature of the dynamic regulation method for tobacco leaf modulation based on multi-source information fusion in the present invention is that the multiple tobacco leaf samples are extracted from the middle layer of the curing barn, and the number of tobacco leaves is 10 - 20 pieces.

[0014] Another feature of the dynamic regulation method for tobacco leaf modulation based on multi-source information fusion in the present invention is that the evaluation content of the sensory evaluation includes: aroma quality, aroma quantity, foreign odor, irritation, dryness, aftertaste, and sweetness, all of which are on a 9-point scale and are all positive scores. The better the quality, the higher the score; Then the calculation formula for the sensory quality score Q1 is:

[0015] Q1=(0.25×aroma quality + 0.15×aroma quantity + 0.2×foreign odor + 0.1×irritation + 0.05×dryness + 0.1×aftertaste + 0.15×sweetness)×100 / 9.

[0016] Another feature of the dynamic regulation method for tobacco leaf modulation based on multi-source information fusion in the present invention is that the suitable index range for the tobacco leaf samples is set as: total sugar 18% - 42%, reducing sugar 16% - 36%, nicotine 1.0% - 3.8%; Tobacco leaves that exceed the suitable index range and have a sensory quality score Q1 less than 45 points are determined as abnormal tobacco leaves and are discarded for baking.

[0017] Another feature of the dynamic regulation method for tobacco leaf modulation based on multi-source information fusion in the present invention is that the appearance state of the tobacco leaves at the end of the yellowing stage or the early stage of color-fixing is set as the tobacco leaves being 80% yellow or more, the main vein being soft, and fully collapsed.

[0018] The characteristics of the dynamic regulation method for the tobacco leaf curing process based on multi-source information fusion of the present invention also lie in that in step 3, if Tadj > 0, the curing time is extended; if Tadj ≤ 0 and all indicators show that the tobacco leaves have reached a good state, the temperature is increased at a rate of 1 °C / h to 54 °C to enter the dry leaf stem period, avoiding over-curing.

[0019] The characteristics of the dynamic regulation method for the tobacco leaf curing process based on multi-source information fusion of the present invention also lie in that in step 3, while setting the fixing stage time according to the adjustment duration Tadj, the temperature and humidity parameters in the fixing stage are finely adjusted to enable the tobacco leaves to achieve the best curing effect.

[0020] The characteristics of the dynamic regulation method for the tobacco leaf curing process based on multi-source information fusion of the present invention also lie in that the fine adjustment of the temperature and humidity parameters in the fixing stage is carried out on the basis of the set temperature and humidity parameters, and the set temperature and humidity parameters are as follows: the starting temperature is 38 °C - 40 °C, the temperature is increased at a rate of 0.5 °C - 1 °C per hour to 54 °C - 55 °C, the relative humidity is controlled at 70% - 80% in the early stage and gradually decreases to 35% - 45% as the temperature increases, and the fixing duration is 36 - 48 hours.

[0021] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0022] 1. The method of the present invention improves the curing accuracy and realizes the precise regulation of the tobacco leaf curing process through multi-dimensional information fusion;

[0023] 2. The method of the present invention optimizes the quality of tobacco leaves and ensures that the tobacco leaves achieve the best sensory quality and chemical components during the curing process;

[0024] 3. The method of the present invention has wide applicability and can dynamically adjust the process parameters according to the actual state of the tobacco leaves to adapt to the differences in tobacco leaves in different regions, different varieties and different batches.

[0025] Specific embodiments

[0026] The following details the embodiments of the present invention. The embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0027] The dynamic regulation method for tobacco leaf curing process based on multi-source information fusion in this embodiment is to extract multiple tobacco leaf samples from the curing barn at the end of the yellowing stage or the early stage of color fixing, and conduct appearance state evaluation, chemical composition determination, and sensory evaluation respectively; obtain the indexes of total sugar, reducing sugar, nicotine, and starch through chemical composition determination; evaluate the sensory quality of tobacco leaves through sensory evaluation and obtain the sensory quality score; based on the target value of starch content and the sensory quality threshold of tobacco leaves in different parts, on the basis of the conventional curing scheme, improve the curing accuracy and optimize the quality of tobacco leaves by extending or shortening the time of the color fixing stage and slightly adjusting the temperature and humidity parameters of the color fixing stage.

[0028] The dynamic regulation method for tobacco leaf curing process based on multi-source information fusion in this embodiment includes the following steps:

[0029] Step 1, Sampling and detection: At the end of the yellowing stage or the early stage of color fixing of tobacco leaf curing, extract multiple tobacco leaf samples from the middle layer of the curing barn, and conduct appearance state evaluation, chemical composition determination, and sensory evaluation respectively; for efficient and simple detection and analysis to ensure the timely and effective adjustment of the process, a handheld near-infrared spectrometer can be used for chemical composition determination to meet the requirements of on-site use.

[0030] Step 2, Data processing and analysis: Based on the indexes of total sugar, reducing sugar, nicotine, and starch of the tobacco leaf samples obtained through chemical composition determination, calculate the average value of total sugar, reducing sugar, nicotine of the tobacco leaves, and the average starch content S1, and quantify the sensory evaluation results into the sensory quality score Q1; set the target value of starch content S0 as 5% according to the starch content and sensory quality requirements of high-quality tobacco leaves, and set the sensory quality thresholds Q0 as 65 points for upper tobacco leaves, 68 points for middle tobacco leaves, and 56 points for lower tobacco leaves respectively.

[0031] Step 3, Process parameter adjustment: Calculate the adjustment duration T according to formula (1) adj :

[0032] T adj =α(S1 - S0)+β(Q0 - Q1)

[0033] where α and β are both weight coefficients, and there are: α = 0.6 and β = 0.4;

[0034] Set the time of the color fixing stage according to the adjustment duration Tadj to make the tobacco leaves achieve the best curing effect.

[0035] The specific measures of the dynamic regulation method for tobacco leaf curing process based on multi-source information fusion in this embodiment also include:

[0036] Extracting multiple tobacco leaf samples from the curing barn is to extract tobacco leaves from the middle layer of the curing barn, and the number of tobacco leaves is 10 - 20 pieces.

[0037] The evaluation content of sensory smoking includes: aroma quality, aroma quantity, foreign odor, irritation, dryness, aftertaste and sweetness, all of which are on a 9-point scale and are all positive scores. The better the quality, the higher the score. The calculation formula for the sensory quality score Q1 is:

[0038] Q1 = (0.25×aroma quality + 0.15×aroma quantity + 0.2×foreign odor + 0.1×irritation + 0.05×dryness + 0.1×aftertaste + 0.15×sweetness) × 100 / 9.

[0039] The foreign odor among them is mainly green foreign odor.

[0040] The suitable index range for the tobacco leaf samples is set as: total sugar 18% - 42%, reducing sugar 16% - 36%, nicotine 1.0% - 3.8%. The tobacco leaves that exceed the suitable index range and have a sensory quality score Q1 less than 45 points are determined as abnormal tobacco leaves and are discarded for baking.

[0041] The appearance state of the tobacco leaves at the end of the yellowing stage or in the early fixing stage is set as the tobacco leaves being 80% yellow or more, the main vein being soft, and fully collapsing.

[0042] In step 3, if Tadj > 0, the curing time is extended; if Tadj ≤ 0 and all indicators show that the tobacco leaves have reached a good state, the temperature is increased to 54°C at a rate of 1°C / h to enter the dry - ribbing stage to avoid over - curing. In step 3, while setting the fixing stage time according to the adjusted duration Tadj, the temperature and humidity parameters in the fixing stage are finely adjusted to make the tobacco leaves achieve the best curing effect.

[0043] In specific implementation, the fine - tuning of the temperature and humidity parameters in the fixing stage is carried out on the basis of the set temperature and humidity parameters. The set temperature and humidity parameters are: the starting temperature is 38°C - 40°C, the temperature is increased to 54°C - 55°C at a heating rate of 0.5°C - 1°C per hour, the relative humidity is controlled at 70% - 80% in the early stage, and gradually decreases to 35% - 45% as the temperature rises, and the fixing duration is 36 - 48 hours.

[0044] Example 1 Curing of Upper - part Tobacco Leaves of Yunyan 87 Variety in a Certain Area of Sichuan

[0045] 1. Sampling and Detection:

[0046] In a certain tobacco barn in Sichuan, at the end of the yellowing stage of tobacco leaf curing, 15 upper - part tobacco leaf samples of Yunyan 87 variety are randomly selected from the middle layer of the tobacco barn. At this time, the appearance characteristics of the tobacco leaves are 80% yellow, the leaf meat is basically all yellow, the main and secondary veins contain green, the main vein is soft, and fully collapses. The climate in this area is relatively mild and the soil fertility is medium.

[0047] A handheld near - infrared spectrometer is used to measure the conventional chemical components of the samples, and the results are shown in Table 1:

[0048] Table 1 Mean values of conventional chemical components of sampled tobacco leaves

[0049] Total sugar % Reducing sugar % Nicotine % <![CDATA[S1 (starch%)]]> 20 18 2.2 6.5

[0050] Then, the main veins of the tobacco leaves were removed, shredded, dried to the specified moisture content (10.5% - 13.5%), made into cigarette sticks, and sensory evaluation was carried out by 3 professional sensory evaluation personnel with the qualification of sensory evaluation. The sensory evaluation indexes and scores are shown in Table 2. The aroma of the tobacco leaves is revealed, and the aroma is relatively pure. There is room for improvement in the layering and elegance of the aroma; there is a certain amount and concentration of aroma, but it is not full and thick enough; the green and miscellaneous odors have been reduced to some extent, but they are still relatively prominent, affecting the purity and texture of the tobacco leaf aroma; the irritation of the tobacco leaves is at a medium level. Although it will not bring strong discomfort to smokers, there is still room for reduction, which may be related to the incomplete conversion of irritating components such as alkaloids in the tobacco leaves; there is a sense of dryness, and it will not bring excessive dryness to the mouth during smoking. It is necessary to further optimize the humidity control to improve the smoking comfort. The aftertaste is average, there is an obvious residue on the tongue surface, and the tobacco leaves have a certain amount of sweetness but not much.

[0051] Table 2 Mean values of sensory evaluation scores

[0052] Quality of aroma Quantity of aroma Off-odor Irritation Dry feeling Aftertaste Sweetness 5.5 5 4 4 4 4 4

[0053] 2. Data processing and analysis:

[0054] According to the starch content and sensory quality requirements of high-quality tobacco leaves, the target starch content S0 was set at 5%, and the sensory quality threshold Q0 was set at 65 points.

[0055] The total sugar, reducing sugar and nicotine of the tobacco leaf samples were all within the appropriate ranges (total sugar 18% - 42%; reducing sugar 16% - 36%; nicotine 1.0% - 3.8%). According to the formula, the quality score Q1 was calculated to be about 50 points. However, the starch content of this variety of tobacco leaves in this area is relatively high, and the sensory quality needs to be improved.

[0056] 3. Process parameter adjustment:

[0057] According to the formula Tadj = α(S1 - S0) + β(Q0 - Q1), where α = 0.6, β = 0.4, it was calculated that Tadj = 0.6×(6.5 - 5) + 0.4×(65 - 50) = 0.6×0.015 + 0.4×15 = 0.9 + 6 = 6.9 (hours).

[0058] Since Tadj > 0, it is necessary to extend the modulation time. On the basis of the designed color-fixing process, the starting temperature is set at 38°C and the temperature is gradually increased at a rate of 0.5°C per hour. In the initial stage of heating, the relative humidity is maintained at 70% and the temperature is kept stable for 5 hours to allow the tobacco leaves to adapt to the temperature change and promote the initial transformation of internal chemical components. Subsequently, the temperature is increased to 42°C at a rate of 0.5°C per hour, and during this process, the relative humidity gradually decreases to 68% over 8 hours. Then, the temperature is continued to be increased to 46°C at a rate of 0.5°C per hour, and the relative humidity synchronously decreases to 65% over 8 hours. When the temperature reaches 46°C, the temperature is kept stable for 6 hours, and at this time, the relative humidity is maintained at 65% to allow the tobacco leaves to be fully color-fixed. After that, the temperature is increased to 50°C at a rate of 0.5°C per hour, and the relative humidity decreases to 60% over 8 hours. Finally, the temperature is increased to 54°C, and the relative humidity gradually decreases to 35% during the heating process. The total color-fixing duration is extended by 6.9 hours on the basis of the original 36 hours, that is, the total color-fixing duration is about 42.9 hours. During the extended color-fixing time, the relative humidity in the early stage (from the start of extension to the first 3.9 hours of the extended time) is controlled at about 72% to promote the uniform evaporation of internal moisture of the tobacco leaves and the formation of aroma substances; in the later stage (the last 3 hours of the extended time), it is gradually reduced to about 37% to ensure that the tobacco leaves have an appropriate degree of dryness and avoid over-drying from affecting the quality.

[0059] The effects of the tobacco leaves after modulation were evaluated, and the results are as follows:

[0060] Appearance: The color uniformity of the tobacco leaves after modulation is further improved, and the color is more saturated. Compared with before modulation, the degree of leaf unfolding is better and the tissue structure is looser, further proving the sustainability of the modulation process in optimizing the internal structure of the tobacco leaves. When comparing the upper tobacco leaves of conventional modulation, the incidence of ash hanging and green roasting phenomena in the tobacco leaves modulated by this method is significantly reduced, from about 10% in conventional modulation to less than 2%, greatly improving the appearance quality.

[0061] Chemical components: The starch content of the tobacco leaves after modulation was measured again, and the average value decreased to 5.1%, closer to the target value of 5%. The total sugar content increased from 21.4% before modulation to 22.5%, the reducing sugar increased from 19.2% to 20.5%, and the nicotine content remained stable at about 2.1%. These chemical components are further optimized within an appropriate range. The increase in total sugar and reducing sugar helps to increase the sweetness and aroma of the tobacco leaves, and the decrease in starch content makes the tobacco leaves burn more fully, improving the quality. Compared with conventional modulation, the chemical components of the tobacco leaves modulated by this method are closer to the standard range of high-quality tobacco leaves. For example, the average starch content of the upper tobacco leaves of conventional modulation is about 5.5%, and the increase in total sugar and reducing sugar is not as obvious as this method.

[0062] Sensory quality: The score of aroma quality was increased to 6.0 points, the amount of aroma reached 6.0 points, the score of foreign odor rose to 5.8 points, the irritation score was 5.8 points, the dryness improved to 6 points, the aftertaste was more comfortable reaching 5.8 points, the sweetness was increased to 6 points, and the comprehensive quality score Q2 was increased to 65.8 points, showing a significant improvement compared with that before modulation, slightly exceeding the sensory quality threshold of 65 points for high-quality upper tobacco leaves. Compared with conventional modulation, the tobacco leaves modulated by this method have obvious advantages in terms of aroma, taste and other sensory aspects. The comprehensive quality score of the upper tobacco leaves modulated conventionally is about 63 points.

[0063] Example 2: Modulation of middle-leaf tobacco leaves of K326 variety in a certain area of Yunnan

[0064] 1. Sampling and detection

[0065] In a tobacco barn in a certain area of Yunnan, during the early color-fixing stage, 20 middle-leaf tobacco leaf samples of K326 variety were taken from the middle layer of the tobacco barn. The tobacco leaves showed 100% yellowing, yellow leaves with green veins, dehydration at the leaf margins, and naturally curling inwards. This area has sufficient sunlight and acidic soil.

[0066] The conventional chemical components were measured using a handheld near-infrared spectrometer, and the results are shown in Table 3:

[0067] Table 3 Mean values of conventional chemical components of sampled tobacco leaves

[0068] Total sugar % Reducing sugar % Nicotine % <![CDATA[S1 (starch%)]]> 26 23 2.6 4.5

[0069] Then the samples were made into cigarettes, and 5 professional smokers carried out sensory evaluation. The scores of each index are shown in Table 4. The aroma of the tobacco leaves is relatively permeable, the aroma quality is good, the amount of aroma is sufficient, and the fullness and persistence of the aroma need to be further improved; the foreign odor is relatively light, and the green foreign odor is slightly noticeable and needs to be further reduced; there is irritation and dryness, and further improvement is needed in terms of comfort and moist feeling; the aftertaste is relatively clean and the sweet feeling is somewhat apparent.

[0070] Table 4 Mean values of sensory evaluation scores

[0071] Quality of aroma Quantity of aroma Off-odor Irritation Dry feeling Aftertaste Sweetness 6 5.5 5.5 5 5 5.5 5.5

[0072] 2. Data processing and analysis

[0073] The target starch content S0 was set at 5%, and the sensory quality threshold Q0 was 68 points.

[0074] The contents of total sugar, reducing sugar and nicotine are all within the appropriate range. According to the formula, the quality score Q1 was calculated to be about 62 points. The starch content of the middle-leaf tobacco leaves of K326 variety in this area is slightly lower than the target value, and the sensory quality is slightly lower than the threshold.

[0075] 3. Process parameter adjustment

[0076] Calculate Tadj = 0.6×(4.5 - 5) + 0.4×(68 - 62) = 0.6×(-0.5) + 0.4×6 = -0.3 + 2.4 = 2.1 hours.

[0077] Since Tadj > 0, the modulation time needs to be extended. Set the color fixation process to start at a temperature of 40°C and increase the temperature at a rate of 1°C per hour. In the initial stage, the relative humidity is maintained at 80% and the temperature is stabilized for 3 hours to preliminarily fix the color of the tobacco leaves in a relatively high humidity environment. Subsequently, the temperature is increased to 45°C at a rate of 1°C per hour, and the relative humidity is reduced to 75%, which takes 5 hours. Then, continue to increase the temperature to 50°C, and the relative humidity is reduced to 70%, which takes 5 hours. When the temperature reaches 50°C, the temperature is stabilized for 4 hours, and the relative humidity is maintained at 70% to ensure sufficient color fixation of the tobacco leaves. After that, the temperature is increased to 55°C, and the relative humidity gradually decreases to 45% during the heating process. The total color fixation duration is extended by 2.1 hours on the basis of the original 48 hours, that is, the total color fixation duration is about 50.1 hours. During the extended color fixation time, the relative humidity in the early stage (from the start of the extension to the first 0.8 hours of the extended time) is adjusted to 78% to provide a suitable humidity environment for the tobacco leaves and promote the further generation of aroma substances; in the later stage (the last 1.3 hours of the extended time), it is reduced to 43% to improve the quality of the tobacco leaves.

[0078] Evaluate the effect of the tobacco leaves after modulation, and the results are as follows:

[0079] Appearance: The color of the tobacco leaves after modulation is more saturated and uniform, and the looseness of the leaf structure is better. Compared with conventional modulation, the advantage of the appearance quality of the middle tobacco leaves modulated by this method is that the color uniformity of the middle tobacco leaves modulated conventionally is slightly worse, and the tissue structure is not loose enough.

[0080] Chemical composition: The starch content of the tobacco leaves after modulation is stable at 4.2%, the total sugar content is maintained at 30%, the reducing sugar is 25%, and the nicotine content is about 2.5%. These chemical compositions are not only within the appropriate range, but also the coordination between the components is better. Compared with before modulation, the total sugar and reducing sugar contents are stable, the starch content is further transformed, and the nicotine content decreases slightly, making the overall quality of the tobacco leaves more stable. Compared with conventional modulation, the stability of the chemical composition of the middle tobacco leaves modulated by this method is higher, and the fluctuation range of each chemical composition of the middle tobacco leaves modulated conventionally is relatively large.

[0081] Sensory quality: After modulation, the score of the aroma quality of the tobacco leaves reaches 6.5 points, the aroma quantity is 6.5 points, the score of foreign odors is 6.5 points, the irritation score is 6.5 points, the dryness is improved to 6.0 points, the aftertaste is longer and reaches 6.2 points, the sweetness is increased to 6.5 points, and the comprehensive quality score Q2 is increased to 71 points, which has exceeded the sensory quality threshold of 68 points for high-quality middle tobacco leaves, significantly improving the sensory quality of middle tobacco leaves. Compared with conventional modulation, the middle tobacco leaves modulated by this method are significantly better in terms of aroma quality and aroma quantity. The comprehensive quality score of the middle tobacco leaves modulated conventionally is usually around 68 points.

[0082] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A dynamic regulation method for tobacco leaf curing process based on multi-source information fusion, characterized in that At the end of the yellowing stage or the early stage of color fixation during tobacco leaf curing, multiple tobacco leaf samples are taken from the curing barn and subjected to appearance state evaluation, chemical composition determination, and sensory evaluation respectively; the indexes of total sugar, reducing sugar, nicotine, and starch are obtained through chemical composition determination; the sensory quality of the tobacco leaves is evaluated through sensory evaluation, and the sensory quality score is obtained; based on the target value of starch content and the sensory quality threshold of tobacco leaves in different parts, on the basis of the conventional curing scheme, the curing precision is improved and the tobacco leaf quality is optimized by extending or shortening the time of the color fixation stage and slightly adjusting the temperature and humidity parameters of the color fixation stage.

2. The dynamic regulation method for tobacco leaf curing process based on multi-source information fusion according to claim 1, characterized in that It includes the following steps: Step 1, Sampling and detection: At the end of the yellowing stage or the early stage of color fixation during tobacco leaf curing, multiple tobacco leaf samples are taken from the middle layer of the curing barn and subjected to appearance state evaluation, chemical composition determination, and sensory evaluation respectively; Step 2, Data processing and analysis: The indexes of total sugar, reducing sugar, nicotine, and starch of the tobacco leaf samples obtained through chemical composition determination are used to calculate the average value of total sugar, the average value of reducing sugar, the average value of nicotine, and the average value of starch content S1 of the tobacco leaves, and the sensory evaluation results are quantified into the sensory quality score Q1; according to the starch content and sensory quality requirements of high-quality tobacco leaves, the target value of starch content S0 is set to 5%, and the sensory quality thresholds Q0 are set to 65 points for upper tobacco leaves, 68 points for middle tobacco leaves, and 56 points for lower tobacco leaves respectively; Step 3, Process parameter adjustment: Calculate the adjustment duration T according to Equation (1). adj : T adj = α(S1 - S0) + β(Q0 - Q1) Among them, both α and β are weight coefficients, and there are: α = 0.6 and β = 0.4; Set the time of the color fixation stage according to the adjusted duration Tadj to make the tobacco leaves achieve the best curing effect.

3. The dynamic regulation method of tobacco leaf curing process based on multi-source information fusion according to claim 1 or 2, characterized in that, The extraction of multiple tobacco leaf samples from the curing barn is to extract the tobacco leaves in the middle layer of the curing barn, and the number of tobacco leaves is 10 - 20 pieces.

4. The dynamic regulation method for tobacco leaf curing process based on multi-source information fusion according to claim 1 or 2, characterized in that, The evaluation content of the sensory evaluation includes: aroma quality, aroma quantity, off-flavor, irritation, dryness, aftertaste, and sweetness, all of which are on a 9-point scale and are all positive scores. The better the quality, the higher the score; then the calculation formula for the sensory quality score Q1 is: Q1 = (0.25×aroma quality + 0.15×aroma quantity + 0.2×off-flavor + 0.1×irritation + 0.05×dryness + 0.1×aftertaste + 0.15×sweetness)×100 / 9.

5. The dynamic regulation method for tobacco leaf curing process based on multi-source information fusion according to claim 1 or 2, characterized in that Set the appropriate index range for the tobacco leaf samples as: total sugar 18% - 42%, reducing sugar 16% - 36%, nicotine 1.0% - 3.8%; the tobacco leaves that exceed the appropriate index range and have a sensory quality score Q1 less than 45 points are determined as abnormal tobacco leaves and are discarded for curing.

6. The dynamic regulation method for tobacco leaf curing process based on multi-source information fusion according to claim 1 or 2, characterized in that Set the appearance state of the tobacco leaves at the end of the yellowing stage or the early stage of color fixation as the tobacco leaves are 80% yellow or more, the main vein is soft, and it has fully collapsed.

7. The dynamic regulation method of tobacco leaf curing process based on multi-source information fusion according to claim 2, wherein In Step 3, if Tadj > 0, extend the curing time; if Tadj ≤ 0, and all indicators show that the tobacco leaves have reached a good state, then raise the temperature at a rate of 1°C / h to 54°C and enter the dry leaf stage to avoid over-curing.

8. The dynamic regulation method for tobacco leaf curing process based on multi-source information fusion according to claim 2, characterized in that, In Step 3, while setting the time of the color fixation stage according to the adjusted duration Tadj, slightly adjust the temperature and humidity parameters of the color fixation stage to make the tobacco leaves achieve the best curing effect.

9. The dynamic regulation method for tobacco leaf curing process based on multi-source information fusion according to claim 8, wherein, The temperature and humidity parameters in the fine-tuning color-fixing stage are based on the set temperature and humidity parameters, and the set temperature and humidity parameters are as follows: the starting temperature is 38°C to 40°C, with a heating rate of 0.5°C to 1°C per hour, heating up to 54°C to 55°C, the relative humidity is controlled at 70% to 80% in the early stage, and gradually decreases to 35% to 45% as the temperature rises, and the color-fixing duration is 36 to 48 hours.