Methods For Tobacco Quality Evaluation And Their Application Based On Chemical Components

Tobacco is important economic crop and has great influence on national economy.Tobacco quality evaluation is the base of grades of tobacco leaf substitution, grouping process and little formulation module.The test got such as follows results of tobacco chemical components,the relationship between chemical components and shape character and sensory quality by integrating grey theory,neural network theory and fuzzy theory.1.It was difficult for fiue-cured tobacco leaves to analyze and evaluate quality because of numerous chemical compositions index.To solve the problem,the test analyzed ten routine chemical compositions index of 247 samples from main tobacco-growing areas of China by grey statistic analysis.The results indicated that the great influence index were ratio of total nitrogen to nicotine(RNN) which had the biggest influence on quality of flue-cured tobacco leaves,on the opposite,it was inferior to the great influence index that the influence of total nitrogen(TN),ratio of total sugar to nicotine(RSN),chlorine,reducing sugar,nicotine,total sugar,total alkaloid and ratio of potassium to chlorine(RPC) on quality of flue-cured tobacco leaves,and protein was little influence index.If the chemical compositions were beyond optimum range when blending leaf groups selected flue-cured tobacco leaves,it was rational to select less than optimum range for the great influence index such as RNN.On the opposite,it was rational to select more than optimum range for the chemical compositions index such as reducing sugar,nicotine,total sugar,total alkaloid,RPC,TN,RSN and chlorine.2.There existed close and complicated relationship among chemical component indexes in flue-cured tobacco leaves.To simplify chemical component indexes,272 samples from main tobacco-growing areas of China were selected as materials,and 14 common chemical component indexes were analyzed by grey relational degree cluster.The results indicated that the 14 common chemical component indexes could be classified into five groups when cluster critical value was fixed at the level of 0.8.Meantime,total nitrogen,ratio of total sugar to nicotine,ratio of total nitrogen to nicotine,chlorine and total volatile acids were determined the representative indexes for each group.When cluster critical value was fixed at the level of 0.7, the chemical component indexes could be classified into two groups,named acids group and alkaloid group with representative indexes of the ratio of total sugar to nicotine and ratio of total nitrogen to nicotine,respectively.Grey relational degree cluster analysis was more rational than hierarchical cluster analysis.3.It is difficult to obtain mensurable comprehensive evaluation results because descriptive language for different single index was mostly used to evaluating unblended cigarette sensory quality.In order to solve the problem,the hierarchical fuzzy systems were introduced to comprehensive evaluation for unblended cigarette sensory quality.The results indicated that the weight determined by analytic hierarchy process was in accord with actual needs;fuzzy evaluation could easily make mensurable comprehensive results;ffunction values estimated on the basis of analytic hierarchy process and fuzzy transformation were convenient for giving the quality order of different unblended cigarette samples.4.In order to explore the theory basis of flue-cured tobacco grade substitute and grouping process,the test clustered 68 chemical component samples of 18 flue-cured tobacco-growing areas by grey equal weight cluster method.The results indicated that the chemical components of Jiangle county of Fujian province should be clustered A class which belonged to better region of chemical components,and other 17 flue-cured tobacco-growing areas should be clustered B class which belonged to good region of chemical components.The result of comprehensive cluster coefficient and common cluster coefficient was consistent when some cluster coefficient was distinguished difference with other cluster coefficients and it was the biggest.The cluster result was similar by applying 5 indexes including total nitrogen,the ratio of total nitrogen to nicotine,total sugar to nicotine,chlorine and volatile acid and 14 indexes.It could be avoided of influence on cluster results of factitious factor by applying mean-standard deviation method to confirm the values of albino function.5.In order to discuss the chemical components comparability of different main tobacco-growing areas and explore the theory basis of flue-cured tobacco grade substitute and grouping process,the test analyzed the chemical components of different main tobacco-growing areas upper leaves by combining factor analysis and absolute degree of grey incidence.The results indicated the most similar area was Yiliang of Yunnan province with chemical components of upper leaf of Shaowu of Fujian province,the next was Nanxiong of Guangdong province,and the most difference of chemical components was Huaning of Yunnan province.The factor analysis method could solve the problem of multiple mutual linear of chemical components evaluation indexes.On the basis of absolute degree of grey incidence,the chemical components comparability of different main tobacco-growing areas was evaluated combining sensory evaluation.The relation between positive correlation, negative correlation and degree of grey incidence had no effect on evaluation of the chemical components comparability of different main tobacco-growing areas;however,the minus original data were converted.6.The test systems analyzed the chemical components difference of different position tobacco leaves among main tobacco-growing areas,different variety in the same tobacco-growing area and different variety in the different tobacco-growing area,respectively. The results indicated that the comprehensive effect difference was significant at 1%level among main tobacco-growing areas;the comprehensive effect difference was significant at 1% level among different variety at Yunnan province;the comprehensive effect difference was significant at 1%level among different variety,different main tobacco-growing areas and interaction of tobacco-growing areas and variety for B₂F;the comprehensive effect difference was not significant at 5%level among different variety and interaction of tobacco-growing areas and variety,but the comprehensive effect difference was significant at 1%level among different tobacco-growing areas for C₂F;the comprehensive effect difference was not significant at 5%level among different variety,different main tobacco-growing areas and interaction of tobacco-growing areas and variety for C₃F;the comprehensive effect difference was significant at 1%level among different variety and tobacco-growing areas,but the comprehensive effect difference was not significant at 5%level among interaction of tobacco-growing areas and variety for X₂F.The multianalysis of variance could be used the comprehensive effect analysis for more indexes of samples,and the evaluation results had factual significance for grades of tobacco leaf substitution,grouping process and little formulation module.7.The test analyzed tobacco leaves of four grades among four years of ten tobacco-growing areas by multifactor variance method.The results indicated that the influence orders was grades＞tobacco-growing areas＞years on the ratio of total sugar to nicotine of different grades,different tobacco-growing areas and different years,and the influence of different grades and different tobacco-growing areas were the significant at 1%level,but it was not significant at 5%level of different years.The mutual influence of years and tobacco-growing areas,years and grades was not significant at 5%level on the ratio of total sugar to nicotine,but the mutual influence of grades and tobacco-growing areas was significant at 5%level on the ratio of total sugar to nicotine.The influence orders was grades＞tobacco-growing areas＞years on the ratio of total nitrogen to nicotine of different grades, different tobacco-growing areas and different years,and the influence of different grades, different years and different tobacco-growing areas were the significant at 1%level.The mutual influence of years and grades was not significant at 5%level on the ratio of total nitrogen to nicotine,but the mutual influence of grades and tobacco-growing areas,grades and tobacco-growing areas was significant at 5%level on the ratio of total s nitrogen to nicotine. The multifactor variance method could be used the comprehensive evaluation on the influence of tobacco-growing areas,grades and years on the ratio of total sugar to nicotine and the ratio of total nitrogen to nicotine,and the evaluation results had factual significance for grades of tobacco leaf substitution.8.K326,a flue-cured tobacco cultivar widely used in main tobacco-growing areas of China,was selected as materials to determine the nicotine content and physical properties;total 391 samples including three grades(C₃F,B₂F and X₂F) were employed to studying the relationship between the nicotine content and physical properties.The results indicated that there existed extensive variation among samples for physical properties and the nicotine content.In the given range,the nicotine content had significant positive correlation with the single leaf weight of upper leaf,high positive correlation and negative correlation with leaf length of upper leaf and lower leaf respectively,negative correlation and high negative correlation with leaf width of cutters and lower leaf respectively,and no correlation with other physical properties.The relationship could be described by S equation(?)=e^{(1.484-2.041/x)} between nicotine content and single leaf weight of upper leaf,by inverse equation (?)=8.225-265.750/x and(?)=0.427 + 105.053/x between nicotine content and leaf length of upper leaf and lower leaf respectively,by quadratic equation(?)=0.533+0.316x-0.010x² and (?)=-0.157 + 0.307x-0.009x² between nicotine content and leaf width of cutters and lower leaf respectively.All above equations were significant at 5%level.However,the curve regression equation between nicotine content and other physical properties was not significant at 5%level, and were more efficient than simple linear regression.The relationship between nicotine and physical properties could be described by using the methods of linear correlation,curve regression and degree distribution.9.Total 124 samples of X₂F grades of K326,a flue-cured tobacco cultivar widely planted in main tobacco-growing areas of China,were selected as materials to determine total nitrogen content,nicotine content and physical properties;relationships of total nitrogen content and ratio of total nitrogen to nicotine with physical properties were analyzed.The results indicated that there existed largely variation for total nitrogen content,ratio of total nitrogen to nicotine and physical properties among samples.The total nitrogen content decreased gradually along with the increase of single leaf weight,leaf length and leaf density;the ratio of total nitrogen to nicotine increased along with the increase of leaf length and leaf width,and decreased along with the increase of leaf density.Relationships of total nitrogen content could be described by inverse equation of(?)=0.827+38.047/x with leaf length,and compound equation of (?)=1.880 x 0.99^x with leaf density,respectively;relationships of ratio of total nitrogen to nicotine could be described by compound equation of(?)= 0.413×1.023^x with leaf width,and power equation of(?)= 2.791×x^-0.354 with leaf density,respectively.10.By using statistical analysis methods,124 samples of cutters in flue-cured tobacco leaves from main tobacco-growing areas of China were used as materials to analyze the relationship between the reducing sugar content(RS),ratio of reducing sugar to nicotine (RS/Nic) and shape characters.The results indicated that there existed extensive variation among samples for shape characters and RS.The variation tendency was similar between RS, RS/Nic and single leaf weight that was generally decrease along with increase of single leaf weight,however it was increase after single leaf weight was beyond 12.3g.Similarly,the variation tendency was similar between RS,RS/Nic and leaf length that was increase along with increase of leaf length,especially,both rapidly increased after leaf length was beyond 64.9cm.The variation tendency was also similar between RS,RS/Nic and leaf thickness that was generally decrease along with increase of leaf thickness,and RS/Nic rapidly decreased after leaf thickness was beyond 0.126mm.Moreover,RS/Nic gradually increased along with increase of leaf width.The curve regression equations between RS,RS/Nic and each shape characters were built respectively.The relationship of RS could be respectively described by quadratic equation(?)=45.243-3.667x+0.139x²,(?)=11.217+316.779x-2026.595x² with single leaf weight,leaf thickness.Meantime,the relationship of RS/Nic could be respectively described by logarithmic equation(?)=16.278-3.375In x,compound equation (?)=14.075×0.002^x with single leaf weight,leaf thickness.All above equations were significant at the 5%level,and more efficient than simple linear regression analysis.The forecast effect was better after data validation.11.122 samples of cutters in flue-cured tobacco leaves from main tobacco-growing areas of China were used as materials to analyze the relationship between potassium content, chlorine content,ratio of potassium to chlorine and physical property.The results indicated that there existed extensive variation among samples of flue-cured tobacco leaves studied.The potassium content had respectively high significant positive correlation with leaf length, negative correlation with leaf density.The chlorine content had significant positive correlation with leaf density.The ratio of potassium to chlorine had respectively high significant positive correlation with leaf length,significant negative correlation with leaf thickness.The relationship of potassium content could be respectively described by inverse equation (?)=7.803-343.262/x with leaf length,by compound equation(?)=4.612×0.991^x with leaf density of cutters in flue cured-tobacco leaves from south tobacco-growing areas of China. Meantime,the relationship of chlorine content could be described by quadratic equation (?)=1.268-0.034x + 0.0003x² with leaf density.The relationship of ratio of potassium to chlorine could be respectively described by compound cquation(?)=0.023×1.105^x with leaf length,by quadratic equation(?)=94.408-1355.208x + 5897.907x² with leaf thickness.All above equations were significant at the 5%level,and more efficient than simple linear regression analysis.The potassium content and chlorine content decreased along with increase of single leaf weight, significantly increased along with increase of leaf length of cutters in flue-cured tobacco.The chlorine content increased along with increase of single leaf weight,rapidly decreased along with leaf length,increased along with increase of leaf thickness.These were two sensitive values of leaf width as 23.5cm,leaf density as 85.31 g/m² of cutters in flue cured-tobacco leaves from south tobacco-growing areas of China.12.In order to find the correlation between appearance quality and inner quality in flue-cured tobacco,the experiment studied the correlation between main chemical compositions and leaf length of different stalk positions in flue-cured tobacco by applying descriptive statistics,ANOVA,nonparametric tests,multiple comparisons and degree distribution.The results indicatcd that there existed extensive variation among chemical compositions and leaf length.The difference of chlorine,ratio of potassium versus chlorine among stalk positions was not significant in flue-cured tobacco.However,it is opposite of leaf length,nicotine,ratio of total nitrogen versus nicotine and ratio of rcductivc sugar versus nicotine.For total nitrogen and rcductivc sugar,the diffcrcncc between cutters and lower leaf was not significant,but it was significant between cutters,lower leaf and upper leaf.Similarly, for potassium,the difference between cutters and upper leaf was not significant,but it was significant between cutters,upper leaf and lower leaf.When leaf length was over 55.3cm,there was biggish change for nicotine,total nitrogen and ratio of total nitrogen versus nicotine of upper leave and lower leaf and for rcductive sugar of cutters and lower leaf.For ratio of rcductivc sugar versus nicotine of upper leaf and potassium,chlorine and ratio of potassium versus chlorine of cutters and lower leaf,there was also biggish change.13.K326,a flue-cured tobacco variety,was selected as materials and employed to study the correlation between main chemical components and physical properties of different leaf positions by using the method of canonical correlation analysis.The results indicated that the significant indexes of chemical components and physical properties were different with different leaf positions.The common significant indexes of different leaf positions including upper leaf,cutters and lower leaf were leaf length,leaf thickness and leaf density for physical properties,and chlorine content,potassium content and the ratio of potassium to chlorine for chemical components.The effects of common significant indexes of chemical components showed the same order of potassium＞ratio of potassium to chlorine＞chlorine among different leaf positions.The correlations of leaf length,leaf thickness and leaf density with potassium,chlorine and ratio of potassium to chlorine were significant for different leaf positions.The canonical loading coefficients could be as a reference for determining the significant indexes of physical properties and chemical components in flue-cured tobacco leaves.14.In order to advise the little blending leaf groups design of blending strips,the test founded GM(1,1) grey model and metabolic GM(1,1) grey model of ratio of total sugar to nicotine,and GM(1,1) grey mode,exponent smoothness GM(1,1) grey mode and logarithm GM(1,1) grey mode of ratio of total nitrogen to nicotine in aged flue-cured tobacco.The model test indicated that all model founded were significative and were applied in medium and long-term forecast.The model accuracy of ratio of total sugar to nicotine was higher and attained 98.37%and 99.73%,respectively.The model accuracy of ratio of total nitrogen to nicotine attained 93.56%and 88.52%after the GM(1,1) grey model was modified by exponent smoothness and logarithm.15.The test founded GM(1,1) grey model of total aroma contents,aroma quality and aroma quantity of aged leaf by grey theory.The model accuracy of total aroma contents,aroma quality and aroma quantity of Henan B2F attained 98.63%,99.24%and 99.91%,respectively. The model accuracy of total aroma contents,aroma quality and aroma quantity of Henan C3F attained 97.82%,99.94%and 99.09%.16.The most important problem of modeling was to correctly select the variable of model. To solve the problem,the test analyzed the grey model variable between main chemical components and aroma quality of flue-cured tobacco by integrated evaluation method both absolute degree of grey incidence and grey incidence.The results indicated that the variables of aroma quality modeling were total nitrogen,reducing sugar,ph values,the ratio of total sugar to nicotine and the ratio of total nitrogen to nicotine.The variables of aroma quantity modeling were total nitrogen,reducing sugar,potassium,ph values and the ratio of total sugar to nicotine The problem of relation between independent variable and dependent variable was solved by integrated evaluation method both absolute degree of grey incidence and grey incidence,so was the problem of multiple mutual linear of independent variable.17.The test founded GM(1,N)-BP neural network forecast model of aroma quality and aroma quantity.The results indicated that the model simulation and forecast accuracy of aroma quality attained 95.29%and 98.56%,respectively,and the forecast accuracy increased 3.4% than that of GM(1,N).The model simulation and forecast accuracy of aroma quantity attained 95.13%and 98.20%,respectively,and the forecast accuracy increased 2.16%than that of GM (1,N).When network structure was 1-3-1,the forecast accuracy of aroma quality was the highest.So was when network structure of aroma quantity was 1-9-1.18.In order to provide the base for computer-aided design blending,the tar of cigarettes from different batches of the same trademark as materials,were analyzed by time series analysis and the forecast model of tar of cigarettes smoke was built.The results indicated that the forecast precision of ARMA(2,2) model reached 99.51%and the average relative error was 0.49%,so the ARMA(2,2) model belonged to the first grade model(excellent model) and was superior to cause and effect model.Modeling by time series could escape the difficulty of independent variable choice of model,however,time series usually was used as short-term forecast and not long-term forecast.