Comparison Of Pyrolysis Behaviors And Chromatography-Mass Spectrometry Analysis Between Two Different Flavors Flue-Cured Tobacco Leaves

Tobacco usually belongs to chemical complex system and consists of thousands ofconstituents, about half of which have influence on tobacco aroma. The flavor andaroma of tobacco is the most important factor to quality. Three types of fen-flavor,middle flavor and enriched flavor of flue-cured tobacco are classified according tosensory evaluation, which has the disadvantage of subjective. In order to classify theflavor types and evaluated the quality of tobacco, researchers begin to explore theformation mechanism of the tobacco flavor and establish the physical-chemicalindexes to evaluate the quality and the flavor classification of tobacco. Studying thechanges of aroma constituents of the pre-and post tobacco combustion can providereference for the evaluation of tobacco quality and the flavor classification.Py-GC/MS is applied to analyze pyrolysis products on-line and the non-volatilearoma constituents can be qualitative and quantitative quickly by HPLC-MS/MS.The objectives of the present study included three aspects as following:（1）through the comparison of the separation efficiency of three types of quartz capillary columns （DB-1701, HP-5, Ultra2）, the best quartz capillary columns Ultra2（50m×0.32mm×0.52μm） was selected to analyze the pyrolysis products of cigarettesby Py-GC/MS.（2） The thermogravimetry behavior both under N2and Air atmosphere,（H₂O、CH₄、CO₂、CO、NH₃） gas releasing and the changes of aroma constituentsduring the tobacco pyrolysized of the clear flavor and enriched flavor flue-curedtobaccos were investigated by TG-FTIR and Py-GC/MS. The results showed thatthere were some differences in DTG curves and ash content, little difference in gasreleasing. Tobaccos have been pyrolysed more fully under air atmosphere. Thecontent of alkali aroma components, some important acid aroma components andneutral aroma components of neophytadiene and the carotenoid degradation productswere higher in enriched flavor tobacco. The non enzymatic browning reacton productscontent was higher in the clear flavor tobacco. Regularity of the differences existed indifferent parts of tobacco leaves.（3） the components extracted from the clear flavortobacco leaves were analyzed by HPLC-MS/MS, according to publications and MS2fragmentations deduction,56components were detected in–ESI mode, including3oligosaccharides,9caffeoylquinic acids,4coumarins,13phenolic acids andglucuronides derivatives,9flavonoids,9glucosides of carotenoid derivatives and9other glucosides;50components were detected in+ESI mode, excepting20compounds detected before,5neonicotinoids,9amadoris,3sesquiterpene glucosides,2glucosides of carotenoid derivatives,4other glucosides,4cembranoids and6unknown compounds were also detected.