Abstract: In this study, solid phase microextraction followed by gas chromatography-mass spectrometry (SPME-GC-MS), aroma activity value (OAV), sensory evaluation and chemometrics were used in combination for analysis of characteristic aroma components in different grades of yellow tea samples. The results showed that the characteristic aroma attributes of bud-type, bud-leaf-type, and multi-leaf-type yellow tea were described by sensory evaluation as ‘refreshing’, ‘refreshing and sweet’, and ‘crispy rice crust-like’, respectively; totally 100 volatile components were detected in the three degrades of yellow tea, with hydrocarbons being dominant in bud-type yellow tea, alcohols being dominant in bud-leaf-type yellow tea, and pyrrole and its derivatives being dominant in multi-leaf-type yellow tea. Based on OAV value and orthogonal partial least squares-discriminant analysis (OPLS-DA), 35 characteristic aroma components were identified in the three grades of yellow tea. Phenylacetaldehyde with a refreshing aroma was the major characteristic aroma component of bud-type yellow tea, ethyl hexanoate, benzyl alcohol, geraniol, phenethyl alcohol, citral, neral and myrcene with flowery, fruity and sweet aromas were the major characteristic aroma components of bud-leaf yellow tea, and 2-pyrrole formaldehyde, 3-ethyl-2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine and 2,3-diethyl-5-methylpyrazine with a roasted aroma were the major characteristic aroma ingredients of multi-leaf yellow tea.

Key words: yellow tea; aroma properties; characteristic aroma components