Study On The Changing Rule Of The Main Curing Characteristics Of Two Varieties Of Flue-cured Tobacco

In order to explore the change rule of the main curing characteristics of Yunyan87 and Yunyan 85 during flue-curing,this study sampling every 6 hours to studied the change rule of yellowing,water dispersion,dry matter and main chemical components of two varieties,and compared with K326 to explore the generality and difference of the changing rules of the main curing characteristics of the two varieties,it provides a theoretical basis for the formulation and improvement of Yunyan 87 and Yunyan 85 curing technology.The results showed: 1.The change rule of yellowing:The change rule of yellowing in all position of tobacco leaves of Yunyan 87 and Yunyan 85 represent as the leaves turned yellow slowly in the first stage of yellowing,yellowing mainly for leaf tip and leaf edge of tobacco leaves,and the speed of yellowing is quicker until the tobacco leaves all yellow in the last stage of yellowing.The yellowing speed of Yunyan 87 and Yunyan 85 was almost the same in the whole process of yellowing stage.Compared with K326,the yellowing speed of two varieties is higher than K326,Yunyan 87 and Yunyan 85 were more easily turned yellow during flue-curing.2.The change rule of water:The change rule of water is showed a "slow,fast,slow" trend as a "S" curve,the water loss rate is slow and the water loss is less in the yellowing stage,the speed of water loss is quicker and the water loss is more in the color-fixing stage,the speed of water loss is slow and the amount of water loss is less in the stem drying stage.In the yellowing stage,the speed of water loss of Yunyan 87 and Yunyan 85 is faster than K326,and the rate of water loss is similar of Yunyan 87 and Yunyan 85 during flue-curing.3.The change rule of dry matter:The change rule of dry matter quality in all position of Yunyan 87 and Yunyan 85 are gradually decreasing,the dry matter loss rapidly in yellowing stage,the loss amount accounts for more than 70% of the total,the loss of dry matter become slowly in the color-fixing stage,the quality of dry matter basically the same in the stem drying stage.In the yellowing stage,the loss of dry matter quality of Yunyan 87 and Yunyan 85 is more than K326,and the change rate of dry matter quality is similar of Yunyan87 and Yunyan 85 during flue-curing.4.The change rule of main chemical components:(1)The tobacco leaves all showed a trend of overall decline in the content of total nitrogen and nicotine of Yunyan 87 and Yunyan 85 during flue-curing,and the decline rate were similar of the two varieties.During the whole process,the absolute value of total nitrogen and nicotine content of Yunyan 85 and Yunyan 87 was less than K326,and the difference between the total nitrogen and nicotine content was relatively small of Yunyan 87 and Yunyan 85.(2)The content of reducing sugar and total sugar in the tobacco leaves all showed a trend of increasing and then decreasing,and the content of starch showed a trend of gradual decline of Yunyan 87 and Yunyan 85.During the whole process,the rising speed of reducing sugar,total sugar and starch content were similar of Yunyan87 and Yunyan 85.The absolute value of reducing sugar,total sugar and starch content in Yunyan 87 was always higher than Yunyan 85,and two varieties all were higher than K326.(3)The tobacco leaves of the content of protein were gradually decreasing of Yunyan 87 and Yunyan 85,and the decrease rate of protein content was similar in the two varieties.In the yellowing stage,the protein content decreased most rapidly,and decreased slowly in color-fixing and stem drying stage.In the whole process,the absolute value of protein content Yunyan 85 was always higher than Yunyan 87,and the absolute value of protein content of two varieties was lower than K326.(4)The tobacco leaves of the content of petroleum ether extract was showed an overall trend of growth of Yunyan 87 and Yunyan 85 during flue-curing,which showed a double wave peak curve.The content of petroleum ether extract was in the trend of growth in the initial stage of yellowing stage and color-fixing stage.During the whole process,the change rate of the content of petroleum ether extract is similar of Yunyan 87 and Yunyan 85.The absolute value of petroleum ether extract contentof Yunyan 87 is always higher than Yunyan 85 and K326,and the absolute value of petroleum ether extract content of Yunyan85 is always higher than K326,and the content of petroleum ether extract of Yunyan 87 is highest after curing.