关键词: 乌龙茶, 加工工艺, 儿茶素

Abstract: This study was conducted to investigate the impact of lightly fermented Oolong tea processing on catechins as bioactive compounds. Freshly harvested tea shoots were immediately processed under strict control. Tea infusions from each processing stage were analyzed for total catechin profiles and various individual compounds including (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (+)-catechin (C), (-)-epicatechin (EC), (-)-epigallocatechin gallate (EGCG), (-)-gallocatechin gallate (GCG), (-)-epicatechin gallate (ECG) and (-)-catechin gallate (CG). During processing, the content of total catechins was slightly decreased by approximately 10% while the contents of individual catechins varied differently. Among the processing operations, indoor withering, pan-firing and drying steps had potent impacts on catechin concentrations. This result should be considered for tea manufacturing in order to maximize the potential health benefits of catechins in Oolong tea. We expect that this study will pave a chemical foundation for Oolong tea processing.

Key words: Oolong tea, processing, catechins