Comprehensive Evaluation Of Flue-Cured Tobacco Quality In Hubei Tobacco-Growing Areas And Difference Analysis With The Domestic And International Tobacco

On the basis of 137 tobacco samples (B2F, B2L, C3F, C3L, C2F, C2L, X2F, X3F) of 2006 in Hubei tobacco-growing areas, the appearance quality, physical properties, chemical components, sensory quality and neutral aroma matters of flue-cured tobacco were analyzed, and differences of flue-cured tobacco quality in four tobacco-growing areas (Enshi, Yichang, Xiangfan and Shiyan) were compared. Then the tobacco quality were comprehensively evaluated. The relationship between the total smoking score and the rest quality indexes (appearance quality, physical properties, chemical components) were studied. Hubei and domestic (Yunnan, Sichuan and Guizhou) and foreign (Zimbabwe) high quality flue-cured tobacco were comparatively analyzed. At the same time, 186 flue-cured tobacco (B2F, C3F, X2F) from 2003 to 2006 were selected for the study and variation of chemical components of Hubei flue-cured tobacco were analyzed. Main results were as follows:1. The tobacco leaves in Hubei tobacco-growing areas had distinguishing features of high appearance quality with orange or lemmon color, good maturity and good sensory quality with high quality of aroma, ample quantity of aroma, good combustibility. The upper part had thicker leaves and higher stem ratio; the middle and lower leaves had smaller pulling force and higher stem ratio; the remaining indexes were suitable. The nicotine content of the upper and middle leaves was higher; the total sugar, reducing sugar content of the middle and lower leaves were higher too. The total neutral aroma matters content was middle leaves> lower leaves> upper leaves.2. On the basis of middle leaves, tobacco quality status of Enshi, Yichang, Xiangfan and Shiyan were compared. Structure of appearance quality of Yichang tobacco was loosest and the body of Enshi tobacco was the best. Pulling force of physical property of Yichang tobacco was largest, stem ratio of Yichang tobacco was lowest, and weight per leaf of Yichang tobacco was weightiest. Aroma quality of sensory quality of Enshi and Yichang tobacco were better; biting taste of Enshi tobacco was smallest, and aftertaste of Enshi tobacco was most comfortable. The total smoking score of Enshi tobacco was highest and was significantly higher than that of Xiangfan tobacco. Five types of neutral aroma matters and the total neutral aroma matters content had significant differences at the 0.05 level among different areas in Enshi. For the total neutral aroma matters content, Xianfeng and Xuan'en were better.3. Characteristics of variation for tobacco chemical components from 2003 to 2006 in Hubei tobacco-growing areas was analyzed. The results indicated that: (1) Eight chemical components indexes (reducing sugar, total alkaloids, total nitrogen, potassium, chlorine, the ratio of total nitrogen to nicotine, the ratio of total sugar to nicotine and K2O/Cl) had significant differences among different grades. (2) Differences of reducing sugar, total alkaloids, potassium, the ratio of total nitrogen to nicotine and the ratio of total sugar to nicotine among three tobacco cultivars (K326, Yunyan 85, Yunyan 87) didn't reach significant levels. (3) Reducing sugar, total nitrogen, the ratio of total nitrogen to nicotine and K2O/Cl had significant differences at 5% level among different years. (4) Total nitrogen, potassium, chlorine and K2O/Cl had significant differences among four areas, but other indexes had no significant differences.4. Hubei tobacco quality was comprehensively evaluated by using quantitative method. The results indicated that: (1) The score of apperance quality index was highest for the middle leaves, and was lowest for the lower ones. In addtion, all the samples were better appearance quality. The score of physical property index was highest for the middle leaves, and was lowest for the upper ones. More than 86 percent of the tobacco samples of physical property index scored over the middle grade. Chemical components usability index, sensory quality index and tobacco quality comprehension index of middle leaves scored highest; the upper part scored secondly and the lower part scored lowest. More than 74 percent of the tobacco samples of chemical components usability index scored over the middle grade. All the samples were better sensory quality and had better tobacco quality comprehension index. (2) Apperance quality index was Enshi> Yichang> Xiangfan> Shiyan; physical property index was Yichang> Enshi> Xiangfan; chemical components usability index was Xiangfan> Enshi> Yichang> Shiyan; sensory quality index was Enshi> Yichang> Shiyan> Xiangfan and tobacco quality comprehension index was Yichang> Enshi> Xiangfan. Specific to 11 different areas, tobacco quality comprehension index showed the trend of Xianfeng> Xuan'en> Xingshan> Hefeng> Zigui> Enshi city> Badong> Lichuan> Baokang> Laifeng> Nanzhang. 5. The relationship between the total smoking score and the rest quality indexes were studied by correlation analysis. The results indicated that there were positive correlations between the total smoking score and all appearance quality indexes. Thickness and pulling force of physical property indexes were positively correlated with the total smoking score and the other indexes were negatively correlated. Total sugar, reducing sugar, nicotine, total nitrogen, chlorine and volatile base were positively correlated with the total smoking score; the ratio of total sugar to nicotine and the ratio of total nitrogen to nicotine were negatively correlated. At the same time, sensory quality was classified into 3 groups by cluster analysis, then the relationship among 3 groups sensory quality with the rest quality indexes were studied. The tobacco with better sensory quality, had better appearance quality, smaller thickness and pulling force, suitable leaf density, heavier weight per leaf, and had higher sugar, total nitrogen and nicotine content.6. The results of ANOVA method indicated that: In addition to oil of Hubei tobacco significantly less than Yunnan tobacco, the other indexes of appearance quality and total score had no significant difference with three southwest areas. Nicotine content of Hubei tobacco was significantly higher than that of flue-cured tobacco in Yunnan and Sichuan. Aroma quality was poor than Yunnan and Sichuan, and the differences reached 5% significant level. Generally speaking, Hubei tobacco quality was similar to Guizhou tobacco and had differences between Sichuan and Yunnan tobacco.7. Hubei tobacco and Zimbabwe tobacco quality were compared. The results indicated that: The upper leaves of Hubei tobacco had thicker leaves and larger leaf density; middle leaves had larger leaf density and stem ratio; all the indexes of lower leaves were lower. Reducing sugar, nicotine, total nitrogen and volatile base content of the upper and middle leaves were higher; reducing sugar and volatile base content of the lower leaves were higher too. All the indexes scores of appearance quality and sensory quality of Hubei tobacco were lower than Zimbabwe tobacco.