Volatile components and key odorants of Chinese yellow tea (Camellia sinensis)

In the present study, volatile compounds from 15 yellow tea samples were extracted and examined using stir bar sorptive extraction (SBSE) combined with gas chromatography-mass spectrometry (GC-MS), and the key odorants were identified by gas chromatography-olfactometry (GC-O) analysis. Results revealed 74 volatile compounds in these yellow teas, geraniol (3.89 μg/g) being the most abundant aroma compound. Alcohols and esters were the dominant volatiles, accounting for approximately 52.44% of the total volatiles in content. Moreover, 25 key odorants were identified by GC-O method, and were considered to be responsible for the unique aroma quality of yellow tea. Major key odorants included (E, E)-3,5-octadien-2-one, (Z)-linalool oxide (furanoid), (E)-2-heptenal, naphthalene, geraniol, (E)-linalool oxide (furanoid), styrene, linalool, α-ionone, 1-octen-3-ol, trans-β-ionone, and (E, Z)-3,5-octadien-2-one. In addition, huge differences were observed among the content levels of key odorants in three types of yellow tea samples, namely MengDingHuangYa (MDHY), WeiShanHuangCha (WSHC), and PingYangHuangTang (PYHT). This is an important study describing the characterization of aroma and key odorants in yellow tea. The results obtained from this study advance our understanding of the aroma quality of yellow tea, thereby providing a theoretical basis for the processing and quality control of yellow tea aroma quality.