关键词: 青砖茶, 香气, 顶空固相微萃取, 主成分分析

Abstract: The volatile components of 16 typical samples of Qingzhuan dark tea were analyzed using sensory evaluation and headspace solid-phase micro-extraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The result showed that pure stale flavor as well as arohid or woody flavor was good for the aroma characteristics of Qingzhuan dark tea. A total of 72 aroma compounds were identified, and among them, hexanal, linalool, nonanal and toluene were the major components. Aldehydes and ketones were the principal aroma types. The aroma score obtained by sensory evaluation was correlated highly significantly with the levels of (E,E)-2,4-heptadienal, (Z)-linalool oxide, camphor, 1-methylnaphthalene and longicyclene (P < 0.01), and significantly with (E)-2-hexenal, 1-methoxy-4-methyl-benzene, (E)-2-nonenal, 2,2,6-trimethylcyclohexanone and the proportion of olefine aldehyde as an aliphatic aldehydes in total aldehydes (P < 0.05). Principal component analysis showed that the sixth principal components contributed 82.250% to the aroma quality of Qingzhuan dark tea, and the main representative components were β-cyclocitral, β-ionone, dihydro-β-ionone, hexanal, (E)-2-pentenal, (E)-2-hexenal, heptanal, nonanal, decanal, naphthalene, 1-methylnaphthalene, limonene and 6-methyl-5- heptene-2-one, suggesting that they are the key aroma constituents influencing the aroma quality of Qingzhuan dark tea, which can basically reflect the flavor characteristics of Qingzhuan dark tea.

Key words: Qingzhuan dark tea, aroma, headspace-solid phase microextraction, principle component analysis