A method for predicting total nitrogen content and sugar-alkali ratio of tobacco leaves after curing

Abstract

This invention discloses a method for predicting the total nitrogen content and sugar-alkali ratio of tobacco leaves after curing. The prediction method includes: predicting the total nitrogen content of tobacco leaves after curing: establishing a prediction model of the chemical component content of fresh tobacco leaves and the total nitrogen content of cured tobacco leaves, detecting the total nitrogen content of fresh tobacco leaves at the harvest period, substituting it into the prediction model, and outputting the total nitrogen content of cured tobacco leaves; predicting the sugar-alkali ratio of tobacco leaves after curing: establishing a prediction model of the chemical component content of fresh tobacco leaves and the sugar-alkali ratio of cured tobacco leaves, detecting the starch and total nitrogen content of fresh tobacco leaves at the harvest period, substituting it into the prediction model, and outputting the sugar-alkali ratio of cured tobacco leaves. The method for predicting the total nitrogen content and sugar-alkali ratio of tobacco leaves after curing provided by this invention, through the detection and analysis of specific indicators of fresh tobacco leaves, achieves accurate prediction of the total nitrogen content and sugar-alkali ratio of cured tobacco leaves, and can provide a methodological basis for tobacco quality monitoring and prediction.

Description

Technical Field

[0001] This invention relates to the field of tobacco production technology, and in particular to a method for predicting the total nitrogen content and sugar-alkali ratio of tobacco leaves after curing. Background Technology

[0002] Fresh tobacco leaves are the foundation of flue-cured tobacco, and the quality of fresh tobacco leaves harvested in the field is a crucial factor affecting their curing characteristics and post-curing quality. The quality of fresh tobacco leaves is generally reflected in their physicochemical characteristics, dry matter accumulation, and enzyme activity, and is influenced by factors such as ecology, variety, cultivation management, part of the plant, and maturity. Total nitrogen content and the sugar-alkali ratio are important indicators of the coordination of chemical components in tobacco leaves. Total nitrogen content reflects the nutritional level of fresh tobacco leaves and has a significant impact on the sensory quality of flue-cured tobacco leaves. The sugar-alkali ratio reflects the acid-base balance of the smoke and has a high weight in the evaluation of chemical component coordination. Therefore, effective monitoring of the total nitrogen content and sugar-alkali ratio of tobacco leaves is an important aspect of tobacco quality monitoring and prediction. Currently, there are few research reports on the prediction of chemical component content in tobacco leaves. Chinese patent CN202011429022.1 discloses a method for predicting the chemical component content of field-grown tobacco leaves using hyperspectral imaging, but it does not involve flue-cured tobacco leaves. Predicting the quality of flue-cured tobacco leaves through the physicochemical indicators of fresh tobacco leaves is the main means of achieving post-cured tobacco quality prediction, but there are currently no relevant reports. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for predicting the total nitrogen content and sugar-alkali ratio of tobacco leaves after curing, thereby solving the problem that existing methods cannot predict the chemical composition of cured tobacco leaves during the field stage.

[0004] The technical problem to be solved by the present invention is achieved through the following technical solution:

[0005] A method for predicting the total nitrogen content and sugar-to-alkali ratio of tobacco leaves after curing, the prediction method comprising:

[0006] Prediction of total nitrogen content in tobacco leaves after curing: A predictive model for the chemical composition content of fresh tobacco leaves and the total nitrogen content of cured tobacco leaves was established. The total nitrogen content of fresh tobacco leaves at the harvest period was detected, substituted into the prediction model, and the total nitrogen content of cured tobacco leaves was output.

[0007] Prediction of sugar-alkali ratio of tobacco leaves after curing: A predictive model for the chemical composition content of fresh tobacco leaves and the sugar-alkali ratio of cured tobacco leaves was established. The starch and total nitrogen content of fresh tobacco leaves at the harvest period were detected, substituted into the prediction model, and the sugar-alkali ratio of cured tobacco leaves was output.

[0008] Preferably, the method for predicting the total nitrogen content of tobacco leaves after curing includes the following steps:

[0009] A1) Establish a predictive model for the chemical composition content of fresh tobacco leaves and the total nitrogen content of cured tobacco leaves:

[0010] The prediction model for total nitrogen content is as follows:

[0011] Total nitrogen content of tobacco leaves after curing: Y = 1.161 + 0.459X1 (1);

[0012] In formula (1), X1 is the total nitrogen content of fresh tobacco leaves;

[0013] A2) Detect the total nitrogen content of fresh tobacco leaves during the harvest period, substitute it into the prediction model determined in step A1), and output the total nitrogen content of tobacco leaves after curing.

[0014] Preferably, in step A1), the unit of the total nitrogen content of the fresh tobacco leaves is %.

[0015] Preferably, the method for predicting the sugar-to-alkali ratio of tobacco leaves after curing includes the following steps:

[0016] B1) Establish a predictive model for the chemical composition content of fresh tobacco leaves and the sugar-alkali ratio of cured tobacco leaves;

[0017] The prediction model for the sugar-to-alkali ratio is as follows:

[0018] Sugar-alkali ratio of tobacco leaves after curing: Y = 5.657 + 0.146X1 - 1.881X2 (2);

[0019] In formula (2), X1 is the starch content of fresh tobacco leaves; X2 is the total nitrogen content of fresh tobacco leaves;

[0020] B2) Detect the starch and total nitrogen content of fresh tobacco leaves during the harvest period, substitute them into the prediction model determined in step B1), and output the sugar-alkali ratio of the tobacco leaves after curing.

[0021] Preferably, in step B1), the unit of the total nitrogen content of the fresh tobacco leaves is %.

[0022] Preferably, in step B1), the unit of the starch content of the fresh tobacco leaves is %.

[0023] The above-described technical solution of the present invention has the following beneficial effects:

[0024] The method for predicting the total nitrogen content and sugar-alkali ratio of tobacco leaves after curing provided by this invention achieves accurate prediction of the total nitrogen content and sugar-alkali ratio of cured tobacco leaves through the detection and analysis of specific indicators of fresh tobacco leaves, and can provide a methodological basis for tobacco leaf quality monitoring and prediction. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0026] Figure 1 This is a schematic diagram showing the model-predicted total nitrogen content and the measured total nitrogen content of Example 1.

[0027] Figure 2 The model predicted values ​​and measured values ​​of total nitrogen content of tobacco leaves after curing in different tobacco-producing counties of Pingdingshan City are shown in Example 1, where a is Baofeng County of Pingdingshan, b is Ruzhou City of Pingdingshan, and c is Ye County of Pingdingshan.

[0028] Figure 3 This is a schematic diagram showing the measured and predicted sugar-alkali ratio values ​​of the sugar-alkali ratio model in Example 1.

[0029] Figure 4 The model predicted and measured values ​​of the sugar-alkali ratio of tobacco leaves after curing in different tobacco-producing counties of Pingdingshan City are shown in Example 1, where a is Baofeng County of Pingdingshan, b is Ruzhou City of Pingdingshan, and c is Ye County of Pingdingshan. Detailed Implementation

[0030] Various exemplary embodiments of the present invention will now be described in detail. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0031] A method for predicting the total nitrogen content and sugar-to-alkali ratio of tobacco leaves after curing:

[0032] The prediction of total nitrogen content includes the following steps:

[0033] A1) Establish a predictive model for the total nitrogen content of fresh tobacco leaves and the total nitrogen content of cured tobacco leaves;

[0034] A2) Detect the total nitrogen content of fresh tobacco leaves during the harvest period, substitute it into the prediction model determined in step A1), and output the total nitrogen content of the cured tobacco leaves.

[0035] The present invention provides a method for predicting the total nitrogen content of tobacco leaves after curing. There is a strong correlation between the total nitrogen content of fresh tobacco leaves at harvest and the total nitrogen content after curing. Through modeling, the method can effectively reflect the differences in total nitrogen content among different types of cured tobacco leaves, thus enabling accurate prediction of the total nitrogen content of cured tobacco leaves using the established prediction model. These indicators of fresh tobacco leaves at harvest can be objectively and non-destructively detected using methods such as drones and hyperspectral imaging, showing great promise for predicting the quality of cured tobacco leaves.

[0036] In step A1), the prediction model for total nitrogen content is: Total nitrogen content of tobacco leaves after curing: Y =

[0037] 1.161 + 0.459X1;

[0038] In step A2), when testing the fresh tobacco leaves to be predicted, the total nitrogen content can be measured in units of a single leaf or a contiguous tobacco field.

[0039] Predicting the sugar-to-alkali ratio involves the following steps:

[0040] B1) Establish a predictive model for the total nitrogen and starch content of fresh tobacco leaves and the sugar-alkali ratio of cured tobacco leaves;

[0041] B2) Detect the total nitrogen and starch of fresh tobacco leaves during the harvest period, substitute them into the prediction model determined in step B1), and output the sugar-alkali ratio of the cured tobacco leaves.

[0042] The present invention provides a method for predicting the sugar-to-alkali ratio of tobacco leaves after curing. The total nitrogen and starch content of fresh tobacco leaves at the harvest time are strongly correlated with the sugar-to-alkali ratio after curing. Through modeling, the method can effectively reflect the differences in the sugar-to-alkali ratio of different cured tobacco leaves, thus enabling accurate prediction of the sugar-to-alkali ratio using the established prediction model. These indicators of fresh tobacco leaves at the harvest time can be objectively and non-destructively detected using methods such as drones and hyperspectral imaging, showing great promise for predicting the quality of cured tobacco leaves.

[0043] In step B1), the prediction model for the sugar-alkali ratio is: sugar-alkali ratio after tobacco curing: Y = 5.657 + 0.146X1 - 1.881X2; In step B2), when testing the fresh tobacco leaves to be predicted, it can be a single leaf or a contiguous tobacco field, and the units for total nitrogen and starch are %.

[0044] Example 1

[0045] In 2021, this patent was implemented in three major tobacco-producing counties in Pingdingshan City, Henan Province: Baofeng, Ruzhou, and Jiaxian.

[0046] Specific procedures:

[0047] (1) Select 667m representative tobacco fields from each tobacco-producing county. 2 ;

[0048] (2) After the tobacco leaves in the middle and upper parts of the field mature and are harvested, 20 fresh tobacco leaves are randomly selected. The total nitrogen and starch content of the fresh tobacco leaves are measured using a continuous flow analyzer to obtain the index information of the fresh tobacco leaves.

[0049] (3) The total nitrogen content and sugar-alkali ratio of the flue-cured tobacco leaves were calculated using the method provided in this invention;

[0050] (4) After normal curing, 20 curing tobacco leaves were randomly selected, and the total nitrogen content and sugar-alkali ratio of the curing tobacco leaves were determined using a continuous flow analyzer.

[0051] (5) Compare the model calculation results in step (3) with the actual detection results in step (4).

[0052] Result comparison:

[0053] (1) Prediction of total nitrogen content:

[0054] Depend on Figure 1 and Figure 2It can be seen that, using the prediction method provided by this invention, the coefficient of determination between the model-predicted values ​​and the actual measured values ​​of total nitrogen content in flue-cured tobacco leaves from the three tobacco-producing counties in Pingdingshan City is 0.54. Looking at the specific tobacco-producing counties, the average absolute error of the predicted total nitrogen content in flue-cured tobacco leaves in Baofeng County, Pingdingshan City, is 0.08 percentage points, and the average relative error is 4.2%; the average absolute error in Ruzhou City, Pingdingshan City, is 0.10 percentage points, and the average relative error is 4.9%; and the average absolute error in Ye County, Pingdingshan City, is 0.14 percentage points, and the average relative error is 6.6%.

[0055] (2) Prediction of sugar-alkali ratio:

[0056] Depend on Figure 3 and Figure 4 As can be seen, using the prediction method provided by this invention, the coefficient of determination between the predicted value and the actual measured value of the sugar-alkali ratio of flue-cured tobacco leaves in the three tobacco-producing counties of Pingdingshan City is 0.72. Looking at the different tobacco-producing counties, the average absolute error of the predicted sugar-alkali ratio of flue-cured tobacco leaves in Ye County, Pingdingshan City is 0.90, and the average relative error is 17.8%; the average absolute error of the predicted sugar-alkali ratio of flue-cured tobacco leaves in Baofeng County, Pingdingshan City is 0.83, and the average relative error is 16.5%; the average absolute error of the predicted sugar-alkali ratio of flue-cured tobacco leaves in Ruzhou City, Pingdingshan City is 0.77 percentage points, and the average relative error is 12.4%.

[0057] In summary, the method for predicting the total nitrogen content and sugar-alkali ratio of tobacco leaves after curing, based on the detection of starch and total nitrogen in fresh tobacco leaves at the harvest period, can accurately predict the total nitrogen and sugar-alkali ratio of cured tobacco leaves and can be effectively applied to the process of tobacco leaf quality monitoring and prediction. Multi-origin validation results show that the average absolute error of the total nitrogen content prediction is 0.08-0.14 percentage points, and the average relative error is 4.2%-6.6%; the average absolute error of the sugar-alkali ratio prediction is 0.77-0.90, and the average relative error is 12.4%-17.8%.

[0058] The present invention has been disclosed above with reference to embodiments, but it is not intended to limit the present invention. Any person skilled in the art can make various different choices and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. A method of predicting total nitrogen content and sugar-alkaloid ratio of cured tobacco leaves, characterized by, The prediction method comprises: Total nitrogen content prediction after tobacco leaf curing: a prediction model of fresh tobacco leaf chemical component content and total nitrogen content of cured tobacco leaf is established, total nitrogen content of fresh tobacco leaf at harvest period is detected, and the total nitrogen content of cured tobacco leaf is output by substituting into the prediction model; Tobacco leaf curing sugar base ratio prediction: a prediction model of fresh tobacco leaf chemical component content and cured tobacco leaf sugar base ratio is established, starch and total nitrogen content of fresh tobacco leaf at harvest period is detected, and the sugar base ratio of cured tobacco leaf is output by substituting into the prediction model; The total nitrogen content prediction method after tobacco leaf curing comprises the following steps: A1) Establish a prediction model of fresh tobacco leaf chemical component content and total nitrogen content of cured tobacco leaf: The prediction model of total nitrogen content is: Total nitrogen content of cured tobacco leaf: Y=1.161+0.459X1(1); In formula (1), X1 is the total nitrogen content of fresh tobacco leaf; A2) The total nitrogen content of fresh tobacco leaf at harvest period is detected, and the total nitrogen content of cured tobacco leaf is output by substituting into the prediction model determined in step A1); The total nitrogen content prediction method after tobacco leaf curing comprises the following steps: B1) Establish a prediction model of fresh tobacco leaf chemical component content and total nitrogen content of cured tobacco leaf: The prediction model of total nitrogen content is: Total nitrogen content of cured tobacco leaf: Y=1.161+0.459X1(1); In formula (1), X1 is the total nitrogen content of fresh tobacco leaf; B2) The total nitrogen content of fresh tobacco leaf at harvest period is detected, and the total nitrogen content of cured tobacco leaf is output by substituting into the prediction model determined in step A1); 2. The method for predicting the total nitrogen content and sugar / alkaloid ratio of cured tobacco leaves according to claim 1, characterized by, In step A1), the unit of total nitrogen content of fresh tobacco leaf is %.

3. The method for predicting the total nitrogen content and sugar-to-alkali ratio of tobacco leaves after curing according to claim 1, characterized in that, In step B1), the unit of total nitrogen content of fresh tobacco leaf is %.

4. The method of predicting total post-cure nitrogen content and sugar-alkaloid ratio of tobacco leaves according to claim 1, characterized by, In step B1), the unit of total nitrogen content of fresh tobacco leaf is %. In step B1), the unit of total nitrogen content of fresh tobacco leaf is %.

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