Study on characteristics and formation of aroma components in green tea based on HS-SPME/GC-MS method

Fixation and drying are the key process of the green tea aroma formation.1 bud 2, 3 fresh tea leaves of Camellia sinensis cv.Huang shn zhong were taken as experimental material, dried at 80, 110, 130 ℃, respectively, faint scent, chestnut flavor scent and high fire scent of green tea were got. Using headspace solid phase micro extraction ( HS-SPME) and gas chromatography/mass spectrometry ( GC-MS) , the aroma components and proportions were analyzed. And then aroma composition variability of fresh tea, enzym-denatured leaf and dry tea was learned.Experiment showed that fixation removed lots of ocimene, leaf acetate and some other ingredients which smell gramineous. High boiling aromatic substances in tea were increased during drying process.Tea dried at 80 ℃ contained relatively little aromatic components, showing faint scent.Tea dried at 110 ℃ produced phenylacetaldehyde and ethyl laurate and some more original aroma component, showing chestnut flavor scent.Tea dried at 130 ℃ produced high fire components, like pyrrole and pyrazine, showing high fire scent.So the temperature of drying affects the types and contents of aroma components, resulting in a variety of flavor types.