上部烟叶带茎烘烤过程中呼吸强度及水分、色素含量的变化

Dynamic Changes of Respiration Intensity,Water and Pigment Contents in Flue-curing of Upper Tobacco Leaves with Stalk

为确定烤烟上部叶的最佳采烤方式,提高上部叶烘烤质量,以烤烟品种云烟87上部叶为材料,以不带茎烘烤为对照,研究了2片叶带茎、4片叶带茎烘烤过程中烟叶呼吸强度及水分、色素含量的变化规律,并比较了烤后烟叶的化学成分和经济性状。结果表明,4片叶带茎烘烤烟叶主变黄期(烘烤24~48 h)呼吸强度高于对照烟叶,变黄后期和定色前期呼吸强度低于对照;带茎烘烤上部烟叶在变黄期失水慢,定色期失水快,4片叶带茎烘烤的茎秆失水速率快于2片叶带茎烘烤;带茎烘烤烟叶变黄快,色素降解充分;4片叶带茎烘烤的烤后烟叶总氮和烟碱含量低,糖含量高,糖碱比适宜,且中上等烟比例和均价最高,经济性状最好。综上所述,烤烟上部叶采烤时,4片叶带茎烘烤在变黄期叶片含水率高,细胞生理代谢旺盛,内在化学成分降解转化充分;烟叶变黄快,色素降解迅速;叶片失水速度在变黄期慢、定色期快,烟叶失水与变黄、定色协调性好;烤后烟叶化学成分协调,经济性状较好,可作为提高上部叶产质量的最佳采烤模式。

Using upper leaves of Yunyan 87 as materials with the flue-curing of upper leaves as the control,the changes of respiration intensity,water content and pigment content in 2 leaves with stalk,4 leaves with stalk of flue-cured tobacco leaves were studied,and the chemical composition and economic characteristics of flue-cured tobacco leaves were compared. The results showed that the respiration intensity of 4 leaves with stalk in the main yellowing stage（ 24—48 h） was higher than that of the control leaves,and was lower than that of the control at the late yellowing stage and the early color fixing stage. The flue-curing of tobacco leaves with stalk dehydrated slowly during the yellowing stage while faster at the color fixing stage,and the dehydration rate of the 4 leaves with stalk was faster than that of the 2 leaves. The fluecuring of tobacco leaves with stalk turned yellow fast,and the pigment was degraded sufficiently. The chemical composition and economic characteristics of 4 leaves with stalk were shown as follows： low con-tent of total nitrogen and nicotine,high content of sugar,suitable ratio of sugar to alkali,and the highest proportion and best economic characteristics of middle and upper tobacco. In summary,the flue-curing of4 leaves with stalk can be used as the best model for improving the quality of upper leaves.