| Tobacco is a very complicated organic system,according to reports,tobacco and smoke contain more than six thousand of chemical components,and it’s smoke consist of two parts,one is the tobacco itself,another is the new constituents from combustion process.It is not only including some important tobacco aroma components,but also there are small amount of harmful ingredients to human health.Pyrolysis combined with gas chromatography and mass spectrometry has been applied usefully to study the behavior of combustion of cigarette,and analysis of bobacco pyrolysis products.In this paper,pyrolysis gas chromatography/massspectrometry(Py-GC/MS)was used for analyzing the compounds in cut tobacco,tobacco flavours and casings.The main achievements obtained in this research were as follows.1)Compared with the pyrolysis products of three types of cut tobacco,it was found the main components between them were same,but the content was significantly different.In addition to 1,2-Propylene glycol,it didn,t contain in the cut tobacco that without any additives.The main pyrolysis products belonged to numerous kinds of compounds such as aliphatic hydrocarbons,aromatic hydrocarbons,alcohols,phenols,terpenes,heterocyclics,aldehydes,ketones,sterols,etc.The results indicated that the kinds of pyrolysis products were related to the pyrolysis temperature.Trough the different temperatures studied,we found the kinds of pyrolysis products from low temperature is less than that from the high pyrolysis temperature,with the increase of pyrolytic temperature,the yields of aromatic hydrocarbons increased more rapidly from 600℃ to 800℃.There were many kinds of aroma components in the cut tobacco,including limonene,neophytadiene,2,5-dimethylfuran,pyridine,pyrrole,furfural,furfuryl alcohol,methyl cyclopentenol,solanone and megastigmatrienone,etc.The yields of individual aroma components varied with the pyrolysis temperature,and its origin and special flavor type were not same with each other.On the other hand,the harmful lingredients were including indene,2-methyl indene,naphthalene,phenol and nicotine,etc.Nicotine as the characteristics of tobacco pyrolysis products was primarily released by distilling,when the temperature was higher than 600℃,the pyrolysis of nicotine occurred,its pyrolysis products including pyridine,myosmine and other compounds.Phenol has an adverse effect on the smoke.Indene,2-methyl indene and naphthalene were mainly released under the high pyrolysis temperature(over 600℃).2)The pyrolysis products of tobacco flavours and casings were investigated by pyrolysis gas chromatography mass spectrometry(Py-GC/MS)at three typical temperature levels of 300℃,500℃,and 800℃,respectively.The result showed that a variety of aroma compounds of benzaldehyde,5-hydroxymethylfurfural,dihydrogen coumarin,ethyl maltol,vanillin,methyl cyclopentenol were generated,they play an important role on cigarette with better aroma and taste.The results showed that the classes of pyrolysis products at 300℃ were less than 500℃,at the same time,the type and amount of aldehydes,ketones and heterocyclics were significantly increased at 500℃.Most of aromatic hydrocarbons were detected at 800℃,such as benzene,toluene,styrene,indene,etc.3)A systematic comparative study on pyrolysis products of cut tobacco,flavours and casings was carried out,the results showed that some pyrolysis products were same,such as hydroxyacetone,furfural,5-methyl furfural,5-hydroxymethylfurfural,2,5-dimethylfuran and methyl cyclopentenol,they were the main products of maillard reaction,and have an important role on tobacco aroma.In addition,it was found that some of pyrolysis products in flavored and feeding cut tobacco were higher than the other tobacco,the reason probably was the flavoring and casing process increased their content in cut tobacco. |
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