A research into aroma formation in Chinese oolong tea has revealed the role of continuous wounding of tea leaves and low temperature during processing.

Oolong is a semi-oxidized tea known for its elegant fruity and floral aroma. It is produced through a process including withering, rolling and firing.

Researchers from the South China Botanical Garden of the Chinese Academy of Sciences found that under multiple stresses such as continuous wounding and the combination of wounding and low temperature, changes in phytohormones in response to these stresses activate regulators and structural genes that affect the aroma of oolong tea.

They also identified potential indicators for the selection of suitable tea cultivars and materials for processing into oolong tea.

Fertilization, shading and insect attack treatments are among the agronomic measures used to improve the quality of tea leaves plucked at the preharvest stage in summer and autumn, according to the research article published in the journal Trends in Food Science and Technology.

Meanwhile, the quality of aroma may be enriched at the expense of tea yield when such measures are applied at the preharvest stage, said the researchers. (Xinhua)