Studies on the Effect of Low Winter Temperatures and Harvest Times on the Volatile Aroma Compounds in Green Teas

Kyung-Heon Ryu, Hye-Jin Lee, and Seung-Kook Park*Department of Food Science and Biotechnology, Kyung Hee UniversityAbstract Green tea leaves grown in Jeju island were harvested at different times in 2010 and 2011. Green teas harvestedin 2010 experienced higher effective accumulative temperature than green teas harvested in 2011. The free and boundvolatile compounds in green tea were analyzed using headspace-solid phase microextraction gas chromatography (GC) andGC-mass spectrometry. All green teas contained the 6 major volatile compounds α-methylbutanal, pentanal, (E)-2-hexen-1-ol, β-linalool, geraniol and α-farnesene. After enzyme treatment, (Z)-3-hexen-1-ol, benzaldehyde, (Z)-3-hexenyl acetate,β-linalool and geraniol were increased in all green teas. (Z)-3-hexen-1-ol increased significantly in green tea harvested in2010, and benzaldehyde increased widely in green tea harvested in 2011. However, the total volatile compounds in greenteas harvested in 2011 were remarkably decreased in comparison to harvested in 2010. It was confirmed that free andbound volatile compounds in green tea are affected by low winter temperatures.Keywords: green tea, low temperature, harvest time, volatile compound, HS-SPME