不同烘烤工艺对初烤烟叶多酚及有机酸含量的影响

[目的]探索改善烤烟品种K326中部叶质量的最佳烘烤调制工艺,实现K326中部叶在烘烤过程中的提质增香。[方法]采用4种不同的烘烤工艺对重庆市烟区K326品种中部烟叶进行烘烤调制,并对各烘烤工艺下的初烤烟叶多酚和有机酸的含量进行了比较研究。[结果]研究表明,中部初烤烟叶总绿原酸含量和多酚类物质总含量均表现为:重庆市三段六步式烘烤工艺初烤烟叶最高,外动力排湿烘烤工艺次之,三段式烘烤工艺最低;4个处理的中部初烤烟叶高级脂肪酸含量差异不明显,但外动力排湿烘烤工艺能明显降低中部初烤烟叶中柠檬酸和草酸的含量,其他非挥发性有机酸的含量与其他3个处理相比差异不明显。[结论]重庆市三段六步式烘烤工艺和外动力排湿烘烤工艺的中部初烤烟叶香气质和香气量优于其他2个处理,且外动力排湿烘烤工艺处理的中部烟叶原料有利于其卷烟制品燃吸时烟气的酸碱平衡。

装烟密度对烤烟中性致香物质含量的影响

以烤烟中部叶为材料,研究密集烘烤装烟密度对烤烟中性致香物质含量的影响。结果表明,中性致香物质含量、新植二烯和苯丙氨酸类降解产物含量随装烟密度的增加而提高,高密度处理中性致香物质含量、新植二烯和苯丙氨酸类降解产物含量分别较低密度处理高12.48%、18.46%、24.27%;高装烟密度处理能促进棕色化反应产物的积累,但会明显降低类西柏烷类降解产物总含量;低装烟密度有利于类胡萝卜素降解产物的充分转化形成;中密度装烟(T2)条件下类西柏烷类降解产物含量较其他处理高。

Judgment of Aroma Types of Middle and Upper Flue-cured Tobacco Leaves Based on Stepwise Discriminant Analysis

[Objective] The aim of this study was to establish mathematical models for judging the aroma types of middle and upper flue-cured tobacco leaves according to the contents and proportions of aroma compositions. [Method] The aroma types of tobacco leaves were judged based on stepwise discriminant analysis, using 63 C3F and 65 B2F tobacco leaf samples from 13 tobacco producing regions in 11 provinces of China （Huili in Sichuan, Baokang in Hubei, Wulong in Chongqing, Lu- oyang in Henan, Zhucheng in Shandong, Wuyi Mountain in Fujian, Malong in Yun- nan, Chuxiong in Yunnan, Bijie in Guizhou, Liuyang in Hunan, Suiyang in Guizhou, Kaiyuan in Liaoning, Nanxiong in Guangdong） as calibration samples, and 67 aroma components as indices. And the Fisher discriminant functions were verified using 21 C3F and 19 B2F tobacco leaf samples. [Result] Variation coefficients of the propor- tions were lower than that of contents of most aroma components in middle and upper leaves of the samples, indicating that the proportions were more stable than contents of aroma components. The proportions of benzyl alcohol, solanone, β-dam- ascone, neophytadiene, farnesylacetone A, palmitic acid, thunbergol, methyl linole- nate and cembratriene-diol were all over 1% in both middle and upper leaves, al- though the dominant aroma components of the same aroma type varied between middle and upper leaves. Moreover, 11, 18, 7 and 11 aroma components were re- spectively introduced into the Fisher discriminant functions established based on the contents and proportions of middle and upper flue-cured tobacco leaves, which ex- hibited accuracy rates of 91.7%, 100%, 91.7% and 91.7% in the judgments of other tobacco leaf samples. The results revealed that the components those determined aroma types in middle leaves were obviously more than in upper leaves. In middle leaves, the accuracy rates of aroma type judgment could be improved by using the proportions rather than the contents of aroma components as indices. However, the functions based on the proportions and the contents of aroma components in upper leaves gave close accuracy rates. [Conclusion] The results of the study will provide references for identifying aroma types of flue-cured tobacco leaves in future work.

Judgment of Aroma Types of Middle and Upper Flue-cured Tobacco Leaves Based on Proportions of Aroma Components

[Objective] This study aimed to establish mathematical models for judging the aroma types of flue-cured tobacco leaves from the upper and middle parts of plants. [Method] A total of 128 samples （63 C3F and 65 B2F） from 11 main tobac- co production provinces of China were selected as materials. Stepwise discriminant analysis was applied to samples with different aroma types and discriminant function was expressed with the proportions of 67 aroma components in total aroma con- stituents as the index. [Result] The ratio of most aroma components in clear and full aroma tobacco leaves was higher than that in middle aroma leaves. The ratios of 51, 43 and 40 aroma components of clear, middle and full aroma tobaccos were higher in upper leaves than that in middle leaves. Aroma components dominated certain aroma types differed between middle and upper leaves. The proportions of 18 and 11 aroma components in upper and middle leaves were led in the stepwise discriminant function respectively. Self-validation and cross-validation methods were applied to evaluate the original samples, and the accuracy rates reached 100% and 98.6% on middle leaves, 96.37% and 94.4% on upper leaves. The accuracy rates on some other samples reached 100% on middle leaves and 91.7% on upper leaves predicted with the model. [Conclusion] The ratio of aroma components as discriminant index could improve discriminant accuracy significantly in the middle and upper leaves. It could be used to analyze aroma types objectively, accurately and quickly.