Distribution Of The Contents Of Pectin And Cellulose And Their Effect On Smoking Quality In Flue-cured Tobacco Of China

The 317 flue-cured tobacco samples were from 13 regions of primary tobacco-growing areas of China, Brazil, Zimbabwe, including 25 grades and 10 varieties. The difference of pectin and cellulose content in flue-cured tobacco leaves among different regions, different years, different positions, different grades and different aroma types were analyzed. The characteristic which chemical indices, polyphenols, polyprotic organic acid, senior fatty acid, neutral aroma substance and smoke quality which changed in different pectin and cellulose content was studied. Regressive mathematical model was applied to analyze relations of smoke quality with the content of pectin and cellulose in different aroma types. Effects of pectin, cellulose in different aroma types to aroma quality, smoke quality also were studied. The main conclusions were followed.1. Descriptive statistics analysis was completely done for the content of pectin and cellulose. The results showed that pectin content of flue-cured tobacco ranged from 11.2% to 14.8%, with the average of 12.96% and the percentage of 84.86%. Cellulose content ranged from 12.0% to 17.0%, with the average of 14.66% and the percentage of 82.65%.2. The difference of pectin and cellulose content in flue-cured tobacco leaves among different areas, different years, different positions, different grades and different aroma types was analyzed. The content of pectin in tobacco-growing areas domestic was higher than abroad, but the content of cellulose showed no significant difference with domestic and abroad. The content of pectin and cellulose were lowest in the Middle and Upper Reaches of the Yangtze River. The trend of pectin content was upward since the minimum in 2001, and the cellulose content was no significant difference in different years with the biggest coefficient variation. No significant difference of pectin and cellulose content were found in different positions, appearing the highest content in middle part respectively. The variation degree was bigger in different grades. The pectin content was higher in middle and superior grade tobacco leaves and lowest in low grade tobacco leaves, but it showed significant difference with superior grade tobacco leaves and no difference with middle tobacco leaves. The cellulose content was highest in fen-flavor and lowest in enriched flavor, and it showed significant difference between with fen-flavor and middle flavor, the same as cellulose content.3. Pectin and cellulose content could be classified into three groups with high, medium, and low contents by applying cluster analysis. On the basis of 3 groups, the characteristic of each group which chemical composition, polyphenols, polyprotic organic acid, senior fatty acid, neutral aroma substance and smoke quality which changed in different pectin and cellulose content was studied, and the results indicated that: for chemical indices, pectin content had great influence on total nitrogen, but no significant influence on chlorine, potassium and total content of ether extract. There were lower total plant nicotine, protein and higher reducing sugar, total sugar when the content of pectin was high. There was no significant influence between cellulose content and potassium, pH value, total content of ether extract. There were lower total plant nicotine, chlorine and higher reducing sugar, total sugar when the content of cellulose was high. As far as aroma matter was contained, pectin content had no significant influence on polyphenols, polyprotic organic acid and senior fatty acid. The group with the highest pectin content was significantly lower than the group with the medium, lowest pectin content except products degraded by cembrane. Cellulose content had no significant influence on the content of products of maillard reaction, products degraded by cembrane, neoplytadiene, rest aroma matters and total content of neutral aroma components. If the cellulose content was high, the content of chlorogenic acid, polyprotic organic were lower, with higher acidscopoletin content. The content of products of aromatic amino, products degraded by carotene were relatively higher when cellulose content was low. Pectin content had no significant influence on volume of aroma, physiological strength, smoke concentration, ash color, combustibility and total smoke score. Aroma quality, after-taste and biting taste in the group with the highest pectin content were significantly higher than the other two groups. Cellulose content had significant influence on after-taste, undesirable taste, combustibility and total smoke score. After-taste and undesirable taste in the group with lowest cellulose content were lower than the medium group, and the score of combustibility in the group with highest cellulose content was significantly higher than the lowest group. Overall, the medium group had highest total smoke score.4. The relationship between the pectin, cellulose content and sensory quality was analyzed. The results showed that: pectin content in flue-cured tobacco had significantly negative correlation with degraded by cembrane, total content of aroma component, and extremely negative correlation with products degraded by carotene, total content of neutral aroma substance. There was significantly negative correlation between cellulose content and products degraded by carotene. Pectin content in middle flavor had extremely significantly negative correlation with products of maillard reaction, products of aromatic amino, and negative correlation with products degraded by carotene, total content of neutral aroma substance, total content of aroma component. There were no significant differences between the all kinds of aroma matter and cellulose content. Pectin content in fen-flavor emerged extremely significantly negative correlation with other types of aroma substance(such as farnsylacetone and linalool),but showed extremely significantly positive correlation with products degraded by carotene. There was significantly negative correlation between cellulose content and polyphenol, products of aromatic amino, total content of neutral aroma substance and total content of aroma component.5. The regression relation between smoke indexes and pectin, cellulose content in enriched flavor, middle flavor and fen-flavor flue-cured tobacco was analyzed. For enriched flavor, at some extent, pectin content had significantly positive correlation with aroma quality, after-taste, ash color, and cellulose content had significantly positive correlation with after-taste, ash color, combustibility, smoking quality. For middle flavor, there were significantly regression relations between pectin content and aroma quality, after-taste and combustibility followed quadratic function model. The relations of cellulose content and aroma quality, after-taste, combustibility were described with quadratic function y(?) = 33.792(?)4.039x+0.144x~2, liner function y(?) = 2.938+0.166x, and cubic function y(?) = 19.244(?)0.198x~2 +0.009x3respectively. For middle flavor, pectin content showed significantly positive correlation with after-taste and combustibility, also cellulose content had significantly positive correlation with offensive odor.