烤前晾置时间对烟叶淀粉和总糖含量及烤后烟叶化学成分的影响

Influence of different rest time before curing on starch content and total sugar content and chemical compounds of the cured tobacco leaves

采用小型密集电烤房,研究了烤前晾置时间(0、24、48、72 h)对粤北烟区烤烟中、上部烟叶淀粉和总糖含量及烤后烟叶化学成分的影响。结果表明:与常规烘烤相比,烟叶淀粉含量随晾置时间延长呈减少趋势,而总糖则呈上升趋势;各晾置处理进入烘烤阶段后,中部烟叶的淀粉降解和总糖积累速度加快,上部烟叶淀粉降解和总糖积累呈减少趋势;初烤烟,中部烟叶淀粉含量有随晾置时间延长分解增多的趋势,但各处理间差异不显著,烟叶晾置时间超过48 h,总糖含量明显增加,烟碱含量下降,糖碱比增高,上部烟叶晾置超过48 h,碳化物的变化呈相反趋势。综合上述结果,在粤北烟区气候条件下,中上部烟叶最好收获当天上烤,烤前晾置时间超过48 h不利于糖类转化分解。

Using small bulk curing barns, the effects of rest time（0, 24, 48, 72 h） before curing on starch content, total sugar content, and chemical compounds in middle and upper leaves of cured tobacco from North Guangdong were studied. The results showed that compared with normal curing, tobacco starch content was reduced with the rest time before curing, while total sugar content increased with the rest time. During dry-processing stage, degradation of tobacco starch and accumulation of total sugar were accelerated in middle leaves, while degradation of tobacco starch and accumulation of total sugar reduced in upper leaves. At the beginning of the curing, starch degradation in middle leaves increased with the rest time with no significant difference concerning different rest times, but when the leaves rested over 48 h, total sugar content was obviously increased, nicotine content declined, and the ratio of sugar to alkali increased; for upper leaves, when rested more than 48 h, the change of carbon compounds showed a contrast tendency compared to the middle leaves. Therefore, under North Guangdong climate conditions, its better to cure the middle and upper leaves on the day when the leaves were collected and resting over 48 h is disadvantageous for conversion and degradation of carbondyrate.