)2  
[PERSON]  
2 Han Key Laboratory of Tea Plant Comprehensive Utilization in South Henan, Henan Engineering Research Center of Tea Processing and Testing, College of Tea Science, Xinyang Agriculture and Forestry University, Xinyang 464000, China; [EMAIL_ADDRESS] (Y.-S.K. ); [EMAIL_ADDRESS] (C.-L.J. ); [EMAIL_ADDRESS] (M.-F.S. )2  
[PERSON]  
2 Han Key Laboratory of Tea Plant Comprehensive Utilization in South Henan, Henan Engineering Research Center of Tea Processing and Testing, College of Tea Science, Xinyang Agriculture and Forestry University, Xinyang 464000, China; [EMAIL_ADDRESS] (Y.-S.K. ); [EMAIL_ADDRESS] (C.-L.J. ); [EMAIL_ADDRESS] (M.-F.S. )2  
[PERSON]  
2 Han Key Laboratory of Tea Plant Comprehensive Utilization in South Henan, Henan Engineering Research Center of Tea Processing and Testing, College of Tea Science, Xinhigher contents of umami-tasting free amino acids but lower levels of astringent-tasting flavonoids, whereas this phenomenon is converse for the summer and autumn tea [5,6]. Within the spring season, the quality of green tea changes greatly due to the fluctuation of metabolites in tender shoots [7]. Tea consumers always choose the harvest season as an important concern for purchasing green tea. Moreover, the spring green teas have a much higher price than the summer and autumn green teas [8]. The organoleptic quality and character of tea is determined by its taste, aroma, infusion color and appearance. Although aroma compounds account for less than 0.03% in tea dry weight, the score evaluating coefficient of aroma is 25% for the green tea sensory evaluation, which is just only below the taste (30%). There are more than 260 volatile compounds that have been identified in green tea, and about 30 of these identified volatile compounds contribute to the characteristic green tea aroma [9,10]. Parts of the volatile compounds come from the fresh tea leaves, while the other parts appear during the tea processing [9]. There are many factors that have effects on the tea aroma quality, such as cultivars, natural environment, elevation, processing technology and storage methods [1,11,12,13,14]. Among these factors, the harvest season is one of the important factors for tea aroma quality. However, the temporal variation of aroma compounds in spring and autumn green tea has been scarcely reported so far. Grown and produced primarily in Henan province, Xinyang Maojian (XYMJ) green tea is one of the top ten teas in China, and it is distinguished for its umami taste and refreshing aroma [15]. Our previous studies showed that the quality and chemical constituents of XYMJ green teas were greatly affected by cultivars, elevation and production region, whereas the identified metabolites between manual and mechanical XYMJ teas were not significantly different [16,17]. However, the previous reports of XYMJ green teas mainly focused on the non-volatile chemical constituents [16,17]. The understanding on the temporal variation of the volatile compounds in XYMJ green teas is very limited. Headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) has been widely applied to determine volatile compounds in teas [4,11,18,19,20]. In the present work, HS-SPME/GC-MS combined with odor activity value (OAV) method was adopted to identify the key odorants responsible for XYMJ green teas during the spring and autumn seasons.