不同生态区影响烤烟上部烟叶感官品质的关键外观指标

为明确不同产区影响上部烟叶内在品质的关键外观指标，制备我国5个生态二级区上部烟叶品质梯度样品，对不同生态区上部烟叶外观特征与感官品质、外观特征与化学成分间的相互关系进行分析。结果表明:①不同生态区上部烟叶的多数外观特征指标分值差异显著。②在一定范围内，上部烟叶随颜色加深，香气饱满程度提升，总氮含量（质量分数）增加，糖碱比值、糖含量和淀粉含量下降；随柔软度改善、油润感增强或身份趋于中等，香气质感和口感舒适程度改善，糖含量和糖碱比值升高。③随机森林特征贡献率分析发现，豫中和豫西生态区影响上部烟叶感官品质的关键外观特征指标为身份、油润感和成熟度，湘南生态区为叶片结构、身份和颜色深浅，滇东生态区为柔软度、叶片结构和颜色深浅，渝东南生态区为油润感、叶片结构和成熟度。影响上部烟叶感官品质的关键外观指标在不同生态区间存在差异。 

Key appearance indexes affecting sensory quality of upper flue-cured tobacco leaves from different ecological regions

In order to identify the key appearance indexes affecting the intrinsic quality of upper flue-cured tobacco leaves from different producing areas, upper leaf samples with quality gradients from 5 ecological secondary regions in China were prepared, and the relationships of appearance characteristics with chemical components and sensory quality of upper leaves in different ecological regions were analyzed. The results showed that: 1) There were significant differences in the scores of most appearance characteristic indexes of upper leaves from different ecological regions. 2) Within a certain range, the fullness of aroma and the content (mass fraction) of total N increased, while the sugar/nicotine ratio and the contents (mass fractions) of sugar and starch decreased with the deepening of leaf color. With the improvement of softness and oily level or when the body was moderate, the aroma quality and sensory pleasurableness were improved and the sugar content and sugar/nicotine ratio increased. 3) Random forest characteristic analysis revealed that the key appearance characteristic indexes affecting the sensory quality of upper tobacco leaves from the ecological regions in central and western Henan Province were body, oily level and maturity; those for leaves from the ecological regions in southern Hunan were leaf structure, body and color; those for leaves from the eastern Yunnan were softness, leaf structure and color; those for leaves from the southeastern Chongqing were oily level, leaf structure and maturity. The key appearance indexes affecting the sensory quality of upper tobacco leaves were different in different ecological regions.