In order to evaluate the sensory quality and style characteristics of flue-cured tobacco leaves,a method consisting of evaluation items,scoring rubrics,sample preparation,evaluation requirement,evaluation procedure and result expression was developed by referring to known tobacco sensory evaluation methods at home and abroad.The samples of flue-cured tobacco leaves collected from some typical ecological zones at home and abroad were evaluated with the developed method.The results showed that the developed method could comprehensively and exactly describe the sensory quality and style of leaves from different ecological zones.The evaluation results provide a technical basis for the development of characteristic and quality tobacco leaves,the design and maintenance of cigarette products among others.

An improved and simple method using capillary gas chromatography coupled with a flame ionization detection system (GC–FID) has been developed for quantitative analysis of free and conjugated phytosterols in tobacco. Direct acid and alkaline hydrolysis were first introduced into tobacco analysis to liberate free phytosterols from conjugates, followed by extraction with hexane, derivatization to trimethylsilyl ether derivatives and finally GC quantitative determination. The generality and applicability of this improved method for analyzing free and conjugated phytosterols in tobacco were validated after a series of optimization and comparison were done. Compared with traditional methods, this improved method not only simplified procedures, but also saved time and solvent. The limits of detection (LODs) of phytosterols varied from 0.35 to 0.10 μg mL−1, the relative standard deviations (RSD) were from 2.3% to 3.3% and recovery ranged from 87% to 99%. The analysis results showed that total phytosterols' content in tobacco ranged from 1.0 to 2.5 mg g−1, and most phytosterols existed as conjugates, only approximately 15–25% phytosterols existed in free-form. Ergosterol was only found in mildewy flued-cured tobacco and the level was approximately 0.2–0.25 mg g−1.

Relation between addition levels of cholesterol,ergosterol,stigmasterol,and β-sitosterol into cigarettes and delivery of 14 types of PAHs was studied by GC-MS with standard method.Results showed that there were significant positive correlations between quantity of free phytosterols and the delivery of PAHs and benzo[a]pyrene,and diverse phytosterols' effects on the delivery of various types of PAHs were different when the addition level changed.The delivery of three-ring PAHs and four-ring PAHs were significantly influenced by cholesterol and β-sitosterol,respectively.The delivery of four,five,six ring PAHs were significantly influenced by stigmasterol,and delivery of all ring PAHs were significantly influenced by ergosterol.

In order to improve the grouping processing technology of Chinese style cigarette,the formulation of tobacco groups in a cigarette blend was studied. The groups or sub-blends were formulated on the basis of the chemical components analysis and sensory evaluation of single grade tobacco in a tobacco blend.Different grades in a blend were grouped according to their chemical constituents then modified by the sensory evaluation of cigarettes made of each single grade tobacco.It was indicated that the tobacco sub-blend groups formulated with this method were more reasonable and scientific,and convenient for production management and process control.