Study on Optimal Extraction of Oolong Tea Polysaccharides
Ni Dejiang et al.
The effects of extracting temperature, heating time, ratio between tea and water and pH on extraction rate and activity of tea polysaccharides(TPS) were studied. The results showed that extraction rate of TPS was affected obviously in the successive order of pH, temperature, heating time and ratio between tea and water . The model of extraction rate(Y)showed no significant lack of fit at 5%(FF0.05(10,11)),but it was statistically significant at 1%(FF0.01(14,21)). The model was appropriate to express response variables. It aslo revealed that pH was the main factor affecting the activity of TPS because contents of sugar and protein of TPS extracted during acidity or basicity were very low, which resulted in lowest activity of TPS. Considering high extracted rate and activity of TPS, the extracting conditions were optimized by using desirability function approach for simultaneous optimization of several variables levels that were 0.85 temperature,0.60 heating time, 0.40 ratio between tea and water and -0.95 pH.