Comparative analysis of aroma characteristics of three kinds of Taiwan oolong tea from different fermentation degree

The aroma components of three kinds of Taiwan oolong tea from different fermentation degree were extracted by fully automated headspace solid- phase microextraction( HS- SPME) and identified by gas chromatography- mass spectrometry( GC- MS). Comparison of the analytical results obtained was carried out on the composition and content of aroma compounds. Results showed that in total 72 aroma constituents were identified,among Pouchong tea and Dongding oolong tea had smaller difference,but there were many differences with oriental- beauty tea. The major aromatic components in Pouchong tea were nerolidol,α- farnesene,indole,jasmine lactone,cis- 3- hexenyl benzoate,caffeine,methyl jasmonate,and β- ionone; the major aromatic components in Dongding oolong tea were α- farnesene,nerolidol,indole,jasmine lactone,geraniol,2,6,10,14-tetramethyl- pentadecane,cis- 3- hexenyl benzoate,caffeine,β- ionone,methyl hexadecanoate and geranyl acetone; while the major aromatic components in Oriental- beauty tea were linalool oxides,nerolidol,hexadecylic acid,β- ionone,linalool,dihydroactinidiolide,caffeine,geraniol,hexanoic acid- 3- hexene ester,geranylacetone,phytone,cis- 3- hexenyl benzoate,etc. In comparison,the similarities and differences in aroma composition and content of three kinds of Taiwan oolong tea may be related to the different processing technologies and fermentation degree.