不同变黄条件对烤烟上部叶中性致香成分和感官质量的影响

　　摘 要：采用热风循环标准烤房对烟叶进行烘烤，设置不同变黄时间和定色时间，研究烘烤过程中不同变黄条件对中性致香成分含量和感官质量的影响。结果表明：烘烤过程中，在对照基础上只延长变黄时间24 h，各类中性致香成分含量都有明显增加，其中茄酮含量增加近2.20倍；只延长定色时间24 h不利于香气成分的降解和积累；延长变黄和定色时间各24 h，主要促进叶绿素降解产物新植二烯的积累，增加百分比为33.24%，但是抑制了某些致香成分的降解和积累。说明烘烤过程中，只延长变黄时间24 h，能促进各类中性致香成分含量的积累及感官质量的提高。并建立第一主成分和第二主成分各致香物质对香气总量的回归模型，分别为y=x+0.05347（R2=0.9197）和y=x+0.1475（R2=0.6984），经验证，该模型可行。
　　关键词：烤烟；变黄条件；中性致香成分；感官质量；PCA和PLS
　　中图分类号：S572.01文献标识号：A文章编号：1001-4942（2016）12-0057-07
　　Abstract Using heated air circulation standard curing barn to bake tobacco leaves， the effects of different yellowing conditions during the baking process on contents of neutral aroma components and smoking quality of upper leaves were studied by setting different yellowing time and leaf drying time. The results showed that during the baking process， only extending the yellowing time for 24 hours on the basis of control， the contents of every kind of neutral aroma components increased obviously and the content of solanone increased by nearly 2.20 times. It was unfavorable for the degradation and accumulation of aroma components when only prolonging leaf drying stage time for 24 hours. It mainly promoted the accumulation of the chlorophyll degradation product neophytadiene with the increasing percentage of 33.24%， but inhibited the degradation and accumulation of some aroma components when simultaneously prolonging yellowing time and leaf drying time for 24 hours. In conclusion， only extending the yellowing time for 24 hours could promote the accumulation of every kind of neutral aroma components and improve the quality of tobacco leaves. The regression models were established of the neutral aroma constituents in the first and second principal components to the total aroma contents， which were y=x+0.05347（R2=0.9197） and y=x+0.1475（R2=0.6984）respectively. And they were verified to be feasible.
　　Keywords Flue-cured tobacco； Yellowing conditions； Neutral aroma constituents； Smoking quality； PCA and PLS
　　致香物质成分对烟叶的品质有着至关重要的作用，其组成和含量会直接影响烟叶的感官质量[1]。致香物质按照其提取方法的不同，可以分为酸性致香物质、中性致香物质和碱性致香物质3大类，其他的分类方法还有很多[2]。致香物质的形成与很多因素有关，大量研究表明不同的生态环境、品种和栽培措施均会影响烟叶致香物质的种类、含量和最终香气物质的协调性[3-11]。中性致香物质种类繁多，对感官香味贡献率最大，它们的前体物与转化物种类繁多，其含量变化对烟草香味有很大影响[12-14]。烘烤是烟叶致香物质形成的关键技术，对烟叶的内在品质影响重大[15，16]。烟叶成熟度、装烟密度、装烟方式、施肥方式、温湿度等因素对烟叶中性致香成分含量、化学成分及感官质量都有不同程度的影响： 散叶和插签装烟方式、低温中湿、适熟、施氮量适度增加等可以增加烤后烟叶的中性致香成分含量、协调化学成分及提高感官质量[17-21]。不同变黄条件对烟叶主要化学成分影响的研究较多[8，22，23]，但是有关不同变黄条件对中性致香成分及感官质量影响的研究较少，本研究从这个角度设置不同的变黄条件，探究最有利于中性致香成分降解和积累的条件，以及对感官质量的影响，旨在找到当下最优的烘烤时间，提高上部叶质量。

相关热词搜索：烤烟 感官 成分 变黄 条件