Research of influence of pile-fermentation on the qualities of Fu-zhuan Dark Tea

The effect of tea raw materials moisture content, piling time, and piling temperature on the water extracts, tea polyphenols, free amino acid, caffeine, flavone content of Fuzhuan Dark Tea were studied.The result showed that:with the pile-fermentation moisture content, piling temperature and piling time increasing, the water extract content increased, but the high moisture content and high piling temperature leaded to reduction of the water extract of Fu-zhuan dark tea.With the increasing of water content, the pile temperature and piling time, content of tea polyphenols and flavonoids decreased.With the increasing of water content, the piling temperature and piling time, the content of caffeine slightly increased.The content of free amino acid increased with the increasing of water content, after 24h, it increased slowly with the increasing of piling time.The comprehensive comparison, the optimal processing technology of pile-fermentation was that:the moisture content of tea raw materials 23%～28%, piling temperature 35～40℃, piling time 24～30h.