Abstract: By means of orthogonally rotational combination design, a four-factor (temperature, time, ratio between tea and water, pH) substrate cultivation experiment was conducted by using of brick tea. The regression equations of the relationship between temperature, time, ratio between tea and water, pH and extraction rate of tea polysaccharides (TPS) were established. The results indicated that extraction rate of TPS was affected obviously in successive order by pH, temperature, ratio between tea and water and time. In range of experiment, extraction rate of TPS was increased obviously when pH and temperature were in higher levels, and the interaction of pH and temperature to the ratio between tea and water was significant, but the change of time and ratio between tea and water had less influence effects on extraction rate of TPS. Considering the high extraction rate and activity of TPS, the extraction conditions were optimized by frequency analysis that were 74.06~80.74℃temperature, 69.56~79.58βmin time, 38.49~42.59 ratio between tea and water, 7.411~8.284 pH.

Key words: Brick tea, Tea polysaccharides, Extraction, Optimum