Changes of phenolic compounds of tea leaves during Oolong tea process

Abstract

It was believed that provided photographs of changes of total polyphenols (TPP), tannin, theaflavins (TF), thearubigins (TR) contents and total colour liquids. Green tea leaves were going through the stages: fresh tea → withering → incubated 1 → aromatic spin 1 → incubated 2 → aromatic spin 2 →fried inactivated enzymes. Tea samples in the stages were provided by Cau Tre tea factory. Tea samples were divided into two groups: the activated and inactivated enzyme groups – microwave was applied to treated the activated enzyme one. Tea samples after the inactivation were conducted. The results showed that TPP and tannin contents generally decreased. Changes of theaflavin contents were contrast to tannin contents. On the other hand, theaflavin and thearubigin are the major polyphenols that determine on the quality of Oolong tea.