稻作烟区不同素质上部鲜烟叶烘烤特性研究

Curing characteristics of different quality fresh upper leaves from paddy–tobacco growing area

为明确南方稻作烟区上部烟叶烘烤特性,采用暗箱和电烤箱方法研究了云烟87不同素质(正常烟叶、落黄快、落黄慢、早衰发白)上部鲜烟叶的变黄变褐特性、失水特性、叶绿素降解特性和多酚氧化酶活性。结果表明,正常烟叶、落黄慢烟叶、落黄快烟叶和早衰发白烟叶的变黄指数分别为1.58、1.53、1.60、1.58,变褐指数分别为0.18、0.13、0.17、0.33,失水均衡性分别为0.45、0.61、0.43、0.43,叶绿素降解量分别为90.73%、85.33%、92.48%、95.42%,叶绿素降解速率分别为每小时降解1.26%、1.19%、1.30%、1.33%,多酚氧化酶活性平均值分别为0.21、0.15、0.23、0.45 U。正常烟叶、落黄快烟叶和早衰发白烟叶变黄快、易失水,易烤性好,落黄慢烟叶变黄慢、失水难,易烤性中等。正常烟叶、落黄慢烟叶和落黄快烟叶变褐慢、多酚氧化酶活性低,耐烤性好,早衰发白烟叶易变褐,多酚氧化酶活性高,耐烤性中等。

In order to clarify the curing characteristics of upper tobacco leaves from paddy–tobacco growing area in southern China,the characteristics of yellowing,browning,water loss,chlorophyll degradation and polyphenol oxidase(PPO)activity of different quality fresh upper leaves were studied by using dark chamber and electric–heated flue–curing barn.The results showed that:The yellowing index of4quality leaves,namely,normal tobacco leaves,“slow–yellowing”tobacco leaves,“fast–yellowing”tobacco leaves and“premature senescence and pale”tobacco leaves were1.58,1.53,1.60,1.58,separately;the browning index of4qualities were0.18,0.13,0.17,0.33,separately;the proportionality of water loss rate of4qualities were0.45,0.61,0.43,0.43,separately;the degradation amount of chlorophyll of4qualities were90.73%,85.33%,92.48%,95.42%,separately;the degradation rate of chlorophyll of4qualities were1.26%/h,1.19%/h,1.30%/h,1.33%/h,separately;the average value of PPO activity of4qualities were0.21,0.15,0.23,0.45U,separately;yellowing and water loss of normal tobacco leaves,“fast–yellowing”tobacco leaves and“premature senescence and pale”tobacco leaves were quickly and curing of these leaves was easy,“slow–yellowing”tobacco leaves yellowed slowly and water loss was hard to obtain,the easy curing potential for“slow–yellowing”was medium;browning of normal tobacco leaves,“slow–yellowing”tobacco leaves and“fast–yellowing”tobacco leaves were slowly,their PPO activity were low and the endurable curing potential were good;browning of“premature senescence and pale”tobacco leaves was easily,its PPO activity was high and the endurable curing potential was medium.