Abstract: Composite-enzymolysis assisted ethanol extraction of tea polyphenols from Danzong-tea was optimized in this investigation. The effects of factors including enzymolysis temperature, enzyme content, enzymolysis pH, enzymolysis time, ethanol concentration, solid-to-liquid ratio,extraction temperature, extraction time on the extraction rates of tea polyphenols were explored by single-factor and orthogonal test. The results showed that the optimal extraction conditions were after enzyming pretreatment in the conditions of enzymatic content 3.5%, enzymolysis temperature 60℃, enzymolysis pH 4.8, enzymolysis time 3 h, then 60% ethanol to extract for 1.5 h with extraction temperature70℃ and solid-to-liquid ratio 1︰50, tea polyphenols extraction in Danzong-tea was up to 25.82% and ncreased 69.87% compared with the traditional water extraction.

Key words: tea polyphenols, composite- enzymolysis, ethanol extraction