不同成熟度对鲜烟素质和烤后烟叶质量的影响

为进一步探讨贵阳烟区不同成熟度鲜烟叶素质特点和适宜成熟度特征指标，以云烟87为试验材料，研究了下中上3个部位由低到高3个成熟度鲜烟叶的含水量、色素、主要化学成分，以及烤后烟叶等级结构、化学成分和感官质量的差异。结果表明，不同部位随着成熟度的提高，鲜烟叶片、叶脉和整叶含水量，叶绿素a、叶绿素b、叶绿素、类胡萝卜素含量均呈逐渐降低趋势，类胡萝卜素/叶绿素逐渐增高，且达到显著差异；总糖、还原糖含量逐渐增加，总氮、烟碱、蛋白质含量逐渐降低。从不同成熟度的烤后烟叶等级结构、均价、外观质量、化学成分含量和感官质量综合分析表明，下中上3个部位适宜成熟度为XM2、CM2、BM2，即下部烟适宜成熟度外观指标为叶面60%黄绿色，主脉变白1/3以上；中部烟为叶面70%黄绿色，主脉变白1/2以上；上部烟为叶面80%黄绿色，主脉变白2/3以上。

Effect of Different Maturity on the Quality Features of Fresh and Cured Tobacco

In order to explore the quality characteristics of fresh tobacco with different maturity in Guiyang and to reveal indicators for their optimal maturity,using Yunyan 87 as the experimental material,the quality features(water content,pigment and major chemical components)of lower,middle and upper fresh tobaccos with three levels of maturity were investigated.Furthermore,the effects of position and maturity on the quality of cured tobacco were studied.The results showed that with the increase of maturity,the water content of fresh tobacco leaves,veins and whole leaves,as well as the content of chlorophyll a,chlorophyll b,chlorophyll and carotenoid gradually reduced,while the ratio of carotenoid to chlorophyll significantly increased;the content of total sugar,reducing sugar and the total nitrogen gradually increased while the content of nicotine and protein decreased steadily.The comprehensive analysis of the leaf grade structure,average price,appearance quality,content and coordination of chemical components,as well as the sensory evaluation of the cured tobacco turned out that the appropriate maturity of the lower,middle and upper leaves are XM2,CM2 and BM2,respectively.Specifically,the appearance index for the lower leaves with optimal maturity is 60%yellowish green leaf area and 1/3 white main vein at least;the middle leaves can be harvested with 70%yellowish green leaf area and 1/2 white main vein;the upper leaves with appropriate maturity are those with 80%yellowish green leaf area and 2/3 white main vein at least.