Abstract:

In order to understand the differences in aroma components between steamed green tea and roasted green tea, the
aroma components of Jade Dew steamed green tea and roasted Xinyang Maojian tea both with one bud and one leaf, or two
leaves from a sexual tea cultivar in Xinyang, Henan province were extracted by simultaneous distillation extraction (SDE)
technique and analyzed by gas chromatography-mass spectrometry (GC-MS). Results showed that 32 aroma constituents
were identified, 19 of which were found in roasted Xinyang Maojian tea and 25 of which in steamed green tea, and 12
aroma compounds were common to both, suggesting differences in aroma composition between the two kinds of green tea.
The relative content of aroma components in the Maojian tea was 4.041%, significantly higher than that (2.312%) of the
steamed green tea. Both kinds of tea were mainly composed of alcohols which accounted for more than half of the total
aroma compounds, but the kinds and proportions of these dominant aroma components were somewhat different. Xinyang
Maojian tea mainly contained geraniol, caproicacidhexneylester, nerolidol, linalool, n-caproaldehyde, benzyl alcohol, translinalool
oxide, phenethyl alcohol, cis-3-hexen-1-ol, menthyl salicylate and cis-linalool oxide, whereas steamed green tea
mainly contained nerolidol, β-ionone, α-cubebene, copaene, trans-3-hexen-1-ol, ethyl acetate, benzil alcohol, phenethyl
alcohol, D-limonene, caproicacidhexneylester and α-farnesene. The low-boiling-point aroma compounds in steamed green
tea accounted for 25.43% of the total ones, higher than in Xinyang Maojian tea, 20.66%. The relative content of terpenic
alcohols, responsible for the floral and fruity aroma, representing 45.83% of the total aroma compounds was 1.852% in Xinyang Maojian tea. In contrast, streamed green tea had a relative content of terpenic alcohols of 0.644%, accounting for
27.85%, and also contained exclusively terpenic compounds such as α-farnesene, α-cubebene, copaene, D-limonene with a
total relative content of 0.491%, accounting for 21.24% of the total aroma compounds.

Key words: steamed green tea, Xinyang Maojian tea, aroma components, gas chromatography-mass spectrometry (GC-MS)