Study on the Baking Characteristics of Drought-Affected Middle Tobacco Leaves in Tongren

为探明烘烤过程中伏旱烟叶的烘烤特性，通过动态取样研究烘烤过程烟叶生化指标的变化。研究结果表明：烟叶烘烤过程：含水量呈“慢–快–慢”的下降趋势，其中变黄期、定色期、干筋期水分分别散失为8.2%、51.5%、32.8%；烟叶收缩率呈“慢–快–慢”的收缩规律，整个烘烤过程烟叶叶长、叶宽、叶面积分别减少了18.7%、29.8%、42.9%；SPAD值呈“快速降低–缓慢降低–缓慢增加”的变化规律；淀粉和总糖、还原糖含量呈明显的消长关系，淀粉含量整体呈下降趋势，总糖、还原糖则相反；总氮、烟碱及蛋白质含量呈“快–慢–缓慢”变化规律，烘烤结束时，烟叶总氮及烟碱含量分别为1.74%、2.02%、8.70%；K含量呈“快–慢–缓慢”的变化规律，烘烤结束时，烟叶K含量为2.07%；石油醚提取物含量呈“快–慢–缓慢”的上升趋势。To explore the baking characteristics of drought-affected tobacco leaves during the baking process, the changes in biochemical indicators of tobacco leaves were studied through dynamic sampling. The research results show that during the baking process of tobacco leaves: the moisture content shows a “slow-fast-slow” decreasing trend, with 8.2%, 51.5%, and 32.8% of moisture lost during the yellowing period, color-fixing period, and drying period, respectively; the shrinkage rate of tobacco leaves shows a “slow-fast-slow” shrinking pattern, with the leaf length, leaf width, and leaf area of tobacco leaves reducing by 18.7%, 29.8%, and 42.9% throughout the baking process, respectively; the SPAD value shows a “rapid decrease-slow decrease-slow increase” change pattern; starch and total sugar and reducing sugar contents show a significant growth and decline relationship, with the starch content showing an overall downward trend, while total sugar and reducing sugar contents are the opposite; total nitrogen, nicotine, and protein contents show a “fast-slow-slower” change pattern, and at the end of baking, the total nitrogen, nicotine, and protein contents of tobacco leaves are 1.74%, 2.02%, and 8.70%, respectively; K content shows a “fast-slow-slower” change pattern, and at the end of baking, the K content of tobacco leaves is 2.07%; the content of petroleum ether extract shows a “fast-slow-slower” increasing trend.