Analysis of chemical and aroma components of three types of Guangdong Fenghuangdancong oolong tea

To investigate the discrepancies of Fenghuangdancong oolong tea of different flavor types which were plucked in three different seasons, chemical and aroma components of Milanxiang, Xingrenxiang and Wuye were analyzed by high performance liquid chromatography ( HPLC) and solid phase micro- extraction / gas chromatography- mass spectrometry ( HS- SPME / GC- MS) , respectively. The contents of total soluble solids, EGCG, GCG and ECG of spring tea were significantly lower than those of summer and autumn tea; in addition, a notable downtrend of the caffeine content was observed in these tea leaves with their plucking seasons from spring to autumn.Furthermore, alcohols and olefins with their highest relative content were found to be the predominant aromatic components in these oolong tea leaves.Among these tea leaves plucked in different seasons, the spring tea contained more 3, 7- dimethyl- 1, 5, 7- octatrien- 3- ol, geraniol and myrcene, whereas a higher content of linalool and ( E) -4, 8- dimethyl-1, 3, 7- nontriene were found in autumn tea.Via principal component analysis ( PCA) and cluster analysis in the aromatic composition, spring tea of three types of Fenghuangdancong oolong tea was successfully distinguished from summer and autumn tea.