Comprehensive Evaluation Of Flue-cured Tobacco Quality In Qingjiang Tobacco Growing Areas Of Hubei Province And Similarity Analysis With Zimbabwei Tobacco

132 Flue-Cured tobacco samples in 2007 and 2008 of QingJiang tobacco growing areas were analyzed (including B2F, C3F and X2F, 3 grades), the analysis items including appearance quality, chemical composition, smoking quality and neutral aroma constituents; the tobacco quality differences of QingJiang tobacco area were also analyzed (EnShi, XuanEn, XianFeng, LaiFeng,LiChuan and BaDong) , then a comprehensive evaluation was also made of the overall quality of QingJiang area; The relationship between smoking quality and other quality factors was analyzed ,the similarity analysis was made between QingJiang tobacco and Zimbabwe tobacco. Results were as followed:1.Appearance quality of QingJiang tobacco was fine and most of the leaf color was orange and lemon; the maturity of most tobacco was high and thickness was suitable, open structure leaves account for 80% of samples. The appearance quality was close to Zimbabwe tobacco except for oil. The physical characteristic of QingJiang tobacco was suitable for blending. The filling quality and moisture content was close to Zimbabwe tobacco. The tensile strength was lower than Zimbabwe tobacco and lamina to stem ratio was higher than Zimbabwe.The chemical composition amount was suitable for blending and the ratio between chemical composition was harmony. The overall amount of total nitrogen and nicotine was at the range of fine tobacco chemical amount index, but the amount of reducing sugar and total sugar was high. The chlorine amount was at 0.3%, and the amount of potassium, starch was higher than Zimbabwe. Reducing sugar to alkaloid ratio and nitrogen to alkaloid ratio was higher than Zimbabwe. The compatibility of QingJiang tobacco was high, but still not as fine as Zimbabwe tobacco.The amount of neophytadiene and degradation products of carotenoid was higher than Zimbabwe tobacco, and Maillard reaction products was lower than Zimbabwe tobacco. The average smoking score was 85 plus. The score of aroma quality, aroma quantity, offensive aroma, combustibility and ash were more close to Zimbabwe. The score of aftertaste and irritation were lower than Zimbabwe. The tobacco quality of cutters was most close to Zimbabwe tobacco.2. Quantify the appearance quality of QingJiang tobacco, then a partial correlation was made between quantification score and smoking quality score. Color and maturity was positively correlated to aroma quality and total smoking score. Oil and thickness was positively correlated to aroma quality, and the positive correlation was significant. The correlation between leaf structure and chroma was small. Partial correlation analysis showed significantly negative correlation between thickness and irritation and a significantly negative correlation between tensile strength and irritation. Fill value was significant correlated to aroma quantity. The correlation between other physical characteristic and smoking quality was very small.A principal component analysis was made from chemical components and C/N factor, combustibility factor and starch factor were extracted, the sequence of impact on smoking quality was C/N factor, combustibility factor and starch factor.A grey relativity analysis was made between neutral aroma constituents and smoking quality. The sequence neutral aroma constituents impact on smoking quality was: carotenoids degradation products, Maillard reaction products, neophytadiene and degradation products of phenylalanine.Through the stepwise regression analysis, path analysis and partial correlation analysis to find the relation between neutral aroma constituents and aroma type that can extract the contribution material to QingJiang aroma type. The material sequence that had a positive effect on aroma type was: Furfural,Benzyl Alcohol,dihydroactinidiolide,megastigmatrienone,geranylacetone and neophytadiene;the negative effect material sequence wasβ-damascenone,solanone,3-Oxo-α-ionol,2-acetopyrrole,2-Acetyl furan and furfuryl alcohol.3. The similarity analysis by leaf position was made from chemical components and derivative index between Zimbabwe and QingJiang tobacco, the results showed: the upper-stalk leaf chemical components of XuanEn and LaiFeng was more close to Zimbabwe tobacco; the cutters of XuanEn, LaiFeng and XianFeng was more close to Zimbabwe cutters; the lower-stalk leaf of XianFeng, XuanEn and Enshi was more close to Zimbabwe lower-stalk leaf.The comprehensive evaluation of QingJiang tobacco quality was made through quantification way. The cutters had the highest appearance quality index, the upper-stalk leaf was followed and the last was lower-stalk leaf; physical characteristic index was cutters had the highest score, then was the upper-stalk leaf and the lower-stalk leaf had the lowest.; the chemical components index was cutters > lower-stalk leaf > upper-stalk leaf; smoking quality index was cutters had the highest and lower-stalk leaf had the lowest. The cutters had the highest comprehensive quality score, then was upper-stalk leaf and lower-stalk leaf had the lowest score, the average score of this three stalk position leaves was 0.85, which was belong to the range of fine tobacco quality index.The sequence of comprehensive quality index of upper-stalk leaf was XianFeng, XuanEn, EnShi, LaiFeng, LiChuan and BaDong. The sequence of comprehensive quality index of cutters was XuanEn, XianFeng, EnShi, LaiFeng, LiChuan and BaDong. The sequence of comprehensive quality index of lower-stalk leaf was XuanEn, XianFeng, LiChuan, EnShi, LaiFeng and BaDong. In addition, the overall comprehensive quality index of XuanEn and XianFeng was better.