Abstract: To investigate the low⁃temperature pyrolysis characteristics and aroma release differences of eight aroma types of flue⁃cured tobacco during heating，eight aroma types of flue⁃cured tobacco from typical ecological regions（fresh⁃sweet aroma type，honey⁃sweet aroma type，alcohol⁃sweet aroma type，burnt⁃sweet and burnt aroma type，burnt⁃sweet and alcohol⁃sweet aroma type，fresh and honey⁃sweet aroma type，honey⁃sweet and burnt aroma type，woody and honey⁃sweet aroma type，numbered QT，MT，CT，JJ，JC，QM，MJ and MM，respectively）were selected as the research materials. Thermogravimetric analysis was adopted，combined with the self⁃built program temperature control heating platform，the flue gas capture device and the GC⁃MS instrument，to analyze the thermogravimetric characteristic parameters and the differences in species and contents of heat⁃released aroma components of the eight flavor types of flue⁃cured tobacco. The results showed that the thermogravimetric loss process of all eight aroma types of flue⁃cured tobacco was divided into three stages. In stage Ⅱ，the maximum weight loss temperature（T_max）was 199.1—210.9 ℃，the maximum weight loss rate（DTG_max）was 6.9—10.1%/min，and the weight loss rate was 19.7%—26.3%.The weight loss rate and DTG_max of JC tobacco leaves were the lowest，and the weight loss rate and DTG_max of CT，JJ，QM and QT tobacco leaves were relatively higher.A total of 118 aroma components were identified in the heat⁃released aroma traps of the eight aroma types of flue⁃cured tobacco，with the total content of 10 223.92—15 338.56 μg/g. Nitrogen heterocyclic compounds accounted for the largest proportion（44.70%—56.70%），while oxygen heterocyclic compounds accounted for 9.86%—16.73%.The release order of oxygen heterocyclic components was aroma MJ>JJ>QM>JC>CT>MT>QT>MM.Based on the distribution of heat release products combined with principal component analysis，a comprehensive evaluation function of aroma quality was established.The comprehensive score was ranked as MJ>QT>JC>QM>MT>CT>JJ>MM. In summary，there are significant differences in the characteristic parameters of the thermal weight loss stage Ⅱ of the eight flavor types of flue⁃cured tobacco. The weight loss rate and DTG_max of the fresh⁃sweet aroma type，alcohol⁃sweet type，burnt⁃sweet and burnt aroma type，and fresh and honey⁃sweet aroma type tobacco leaves are relatively higher，which can be preferentially selected in the screening of heated cigarette raw materials.It provides a reference for clarifying the heat release characteristics of the eight flavor types of flue⁃cured tobacco and optimizing of heated cigarette raw materials.

Key words: Flue?cured tobacco, Eight aroma type, Thermogravimetric analysis, Low temperature pyrolysis, Aroma components, Principal component analysis

摘要： 为考察八大香型烤烟的低温热解特征及加热状态下香味物质释放的差异，选取典型生态区的八大香型烤烟（清甜香型、蜜甜香型、醇甜香型、焦甜焦香型、焦甜醇甜香型、清甜蜜甜香型、蜜甜焦香型和木香蜜甜香型，分别编号为QT、MT、CT、JJ、JC、QM、MJ和MM）为研究材料，采用热重分析技术，结合自行搭建的程序控温加热平台耦连烟气捕集装置与气质联用仪，分析八大香型烤烟的热失重特征参数以及热释放香味成分的种类与含量差异。结果表明，八大香型烤烟热失重过程均分为3个阶段，其中阶段Ⅱ的最大失重温度（T_max）为199.1~210.9 ℃，最大失重速率（DTG_max）为6.9~10.1%/min，失重率为19.7%~26.3%，JC烟叶失重率和DTG_max最低，CT、JJ、QM和QT烟叶失重率与DTG_max相对较高。八大香型烤烟热释放香味捕集物中共鉴定出118种香味成分，总量为10 223.92~15 338.56 μg/g，氮杂环化合物占比最高（44.70%~56.70%），氧杂环化合物占比为9.86%~16.73%，其香味成分释放量排序为MJ>JJ>QM>JC>CT>MT>QT>MM；基于热释放产物分布结合主成分分析，建立香气品质综合评价函数，综合得分排序为MJ>QT>JC>QM>MT>CT>JJ>MM。综上，八大香型烤烟热失重阶段Ⅱ的特征参数存在明显差异，清甜香型、醇甜香型、焦甜焦香型、清甜蜜甜香型烟叶的失重率和DTG_max相对较高，在加热卷烟原料筛选时可优先选用，为明晰八大香型烤烟热释放特性，以及加热卷烟原料优选提供参考。

关键词: 烤烟, 八大香型, 热重分析, 低温热解, 香味成分, 主成分分析