Abstract:

The aroma components of 5 kinds of Oolong tea from three main producing regions (Fujian, Guangdong,
and Taiwan) were extracted by fully automated headspace solid-phase microextraction (HS-SPME) and identified by
gas chromatography-mass spectrometry (GC-MS). Comparison of the analytical results obtained was carried out on the
composition and content of aroma compounds. Results showed that in total 127 aroma constituents were identified and 53
of them were common to all the tested samples with the dominant ones being alcohols, esters, ketones and hydrocarbon
compounds, although ketones were less abundant in Tieguanyin tea than other Oolong teas. Among the common aroma
components, the average contents of 16 compounds was relatively higher, including nerolidol, α-farnesene, β-ionone,
caffeine, jasmine lactone, indole, phytol, phytone, linalool and its oxidized form, dihydroactinidiolide, geranylacetone,
hexanoic acid-3-hexene ester, geraniol, γ-decalactone, jasmine and methyl jasmonate. In comparison, there were remarkable
differences in flavor and aroma composition among the five types of Oolong tea, which may be related to the growing
regions and processing technologies.

Key words: Oolong tea, headspace solid-phase microextraction (HS-SPME), aroma components, gas chromatography-mass spectrometry (GC-MS)