The Changes Of Main Enzyme Activities And The Influence Of Chemical Components Under Different Yellowing Condition To Flue-curing

The activities of amylase and protease and the variable laws of chemical composition to different yellowing extent were studied for which the flue-cured tobacco was roasted by 3 stages process conditions. The results showed that the laws in activities of amylase and protease were varied in "higher-lower-higher" under different yellowing extent, among which the activities of amylase and protease of lower leaves with 80% yellowing and upper leaves with full yellowing were the highest of all, the amylase activity of middle leaves with full yellowing and the protease activity of middle leaves with 90% yellowing were the highest of all. With the time of roasting, the contents of starch and protein were decreased and the contents of total sugar and reducing sugar increased, among which the lower leaves with 80% yellowing, the middle leaves with 90% yellowing and the upper leaves with full yellowing were the most obvious performance. There were negative correlation between the contents of starch and reducing sugar significantly.Under the condition of70%-80% yellowing and high-speed color-fixing, the contents and ratio of chemical composition were more appropriate for the flue-cured tobacco lower leaves; Under the condition of 80%-90% yellowing and high-speed color-fixing, the contents and ratio of chemical composition were more appropriate for the flue-cured tobacco middle leaves; Under the condition of full yellowing and high-speed color-fixing, the contents and ratio of chemical composition were more appropriate for the flue-cured tobacco upper leaves as well.