Analysis of key aroma substances in Wuyi Rock Tea Shuixian of different tea gardens

【Objective】 This study aimed to analyze the key aroma substances of the Wuyi Rock Tea Shuixian of diffe-rent tea gardens， reveal the aroma differences of Wuyi Rock Tea of various production areas， so as to provide a reference basis for the quality improvement of Wuyi Rock Tea.【Method】 Volatile compounds of Shuixian Tea of six tea gardens in three production areas （Zhengyan District： Baihuayan and Shuilian， Banyan District： Meiziqiao and Yanzike， Zhoucha District： Shangmei and Huangtu） were isolated and identified by headspace solid-phase microextraction （HS-SPME） with gas chromatography-mass spectrometry （GC-MS）. Key aroma substances were screened via orthogonal partial least squares-discriminant analysis （OPLS-DA）， and the aroma differences of Shuixian Tea of tea gardens of different production areas were analyzed according to odor activity value （OAV）.【Result】 A total of 101 volatile compounds were detected in the Shuixian Tea samples from 6 tea gardens， including 12 alcohols， 14 aldehydes， 5 acids， 12 ketones， 3 alkanes， 9 alkenes， 10 heterocyclic compounds， 26 esters， and 10 other compounds； 56 common volatile compounds were shared by the Shuixian Tea samples from the 6 tea gardens； alcohols were the were the main components for the aroma. Based on OAV analysis， 15 key aroma substances were screened： β-ionone， 2,4-decadienal， coumarin， decanal， geranylacetone， α-ionone， trans-nerolidol， β-cyclocitral， nerol， phenethyl alcohol， safranal， jasmonone， methyl jasmonate， phenylacetaldehyde， and trans-isoeugenol. 11 and 12 key aroma compounds identified in the teas from Baihuayan and Shuiliandong， respectively， mainly demonstrated flowery and fruity notes， secondarily demonstrated sweet， green， and woody notes；15， 15， 15， and 14 key aroma compounds were found in Meiziqiao， Yanzike， Shangmei， and Huangtu numbered ， respectively， mainly demonstrated flowery notes， secondarily demonstrated waxy， herbaceous， and fruity notes.【Conclusion】 According to OPLS-DA with OAV， 15 key aroma compounds are screened from 6 tea gardens； aroma characteristics also differ among production areas： Zhengyan District mainly shows floral-fruity notes， and Banyan District and Zhoucha District mainly show flowery notes.