The changes of aroma compounds during black tea manufacture.

ere are four major process stages in black tea manufacture, namely, withering, rolling, fermentation and drying. Formation of tea aroma during manufacturing is a complex process depending on the variety of tea plant, geographical location, climatic and manufacturing conditions. Particularly withering and fermentation stages influence the formation of the aroma compounds during black tea manufacture. Tea aroma is recently demonstrated to be an important quality parameter determining the price of made tea.