Studies On The Effects Of Maturity And Flue-curing Process To Flue-cured Tobacco Aroma Precursors

The random block experiment of two factors was designed to study the dynamic changes rule of the polyphenols compounds and petroleum ether extract of the leaves,and to analyse of inherent chemical composition of the leaves by determining the contents of the polyphenol compounds,petroleum ether extract and inherent chemical composition in the flue-curing stages. The purpose was to find out a optimum combination to efficiently use the resources and to improve the quality of flue-cured tobacco by discussing the effects to the aroma precursors of the tobacco with different maturity and different flue-curing process. The main results obtained from this experiment were as follows:Firstly,the changes trends of the polyphenol compounds and the petroleum ether extract contents of the flue-cured tobacco in the flue-curing stages were similar. Both of them were gradually growing from the yellowing phase with 38℃to the color fixing phase with 53℃. At the end of the set-color phase with 53℃,the polyphenol compounds reached the highest content.Both of them had the largest growth range during the end of the yellowing phase with 38℃to color fixing phase with 53℃,and then gradually decreased from the period of stem drying to the end of the flue-curing.Secondly, the factor of baking process had no significant effect on the polyphenol compounds and the petroleum ether extract contents, but the maturity of the leaves had significant effect on both of them. There were extreme differences in the polyphenol compounds and the petroleum ether extract contents between the mature leaves and the immature and over-mature leaves, which was also performed between the immature leaves and over-mature leaves. The inherent chemical composition of the cured tobacco with the mature leaves was more coordinated than the cured tobacco with the immature and over-mature leaves.Thirdly, there were extreme differences in the polyphenol compounds and the petroleum ether extract contents in different positions of the leaves. There were also significant differences in the coordination of the inherent chemical composition of the cured tobacco in different positions of the leaves. The middle leaves had the best coordination. From the maturity and flue-curing process on the terms of the combined effect of tobacco, the mature leaves had the best quality in the flue-curing process of growing 70% to 80% as yellowing at the yellow phase with 38℃and holding the temperature at set-color phase with 53℃for 11 hours.