晾制期间白肋烟烟叶含氮化合物的变化

通过人工调控晾房湿度,对白肋烟晾制期间高、中、低3种湿度条件下烟叶含氮化合物(蛋白质、烟碱和叶绿素)的变化进行了研究。结果表明①烟叶中蛋白质含量的变化主要发生在晾制前期,中湿处理的烟叶蛋白质含量下降趋势较为明显,在变黄期仍有下降趋势。而高湿和低湿处理的烟叶蛋白质含量下降趋势相对平缓,仅在凋萎期内表现明显。高湿和低湿的环境条件均不利于烟叶中蛋白质的降解,晾制结束后蛋白质含量偏高;②在凋萎期高湿和低湿处理的上部和中部烟叶烟碱含量呈上升的趋势,中湿处理的白肋烟进入变黄期时烟碱含量还继续呈现上升趋势。与上部和中部烟叶相比,下部烟叶烟碱含量较低,晾制过程中烟碱变化较缓慢,在晾制后期各部位均稍有下降;③在凋萎期高湿和低湿处理的白肋烟上部和中部烟叶叶绿素含量呈明显下降的趋势,在凋萎期和变黄期中湿处理的上部和中部烟叶的叶绿素含量均有明显下降趋势。下部烟叶的叶绿素含量较低,在晾制期间变化不大。

Changes of Nitrogenous Compounds in Burley Tobacco Leaves during Air-curing

The changes of nitrogenous compounds (protein, nicotine and chlorophyll) in burley tobacco leaves during air-curing under 3 different barn humidities controlled artificially were studied. The results showed that: 1) the change of protein content mostly occurred during the early stages (wilting and yellowing stages) of air-curing particularly apparent in upper and middle leaves; the protein content tended to decrease during wilting stage under high or low barn humidities, the descending of protein content under middle barn humidity was more obvious and the tendency extended from wilting to yellowing stages; 2) the nicotine content in upper and middle leaves tended to increase during wilting stage under high or low barn humidities, the tendency continued during the yellowing stage under middle barn humidity; the change of nicotine content in lower leaf was slower than that in upper and middle leaves, and the nicotine contents in all leaves decreased slightly at later stage of air-curing; 3) the contents of chlorophyll in upper and middle leaves reduced obviously during wilting stage in the barns with high or low humidities, while the changes of chlorophyll content in upper and middle leaves had an obvious descending tendency both in wilting and yellowing stages under middle barn humidity; the chlorophyll content in lower leaf was less and changed little during air-curing.