Optimization of polysaccharides extraction from Gynostemma pentaphyllum Makino using Uniform Design

Uniform Design was used to optimize the effects of processing parameters of extraction from Gynostemma pentaphyllum Makino on the yield of polysaccharides. Four independent variables such as extraction time (min), solid:liquid ratio (g/ml), immersing time (min), and extraction temperature (°C) were study. The optimal conditions were determined and Three-dimensional response surfaces were plotted from the mathematical models. The t-value and p-value indicated that both immersing time and water extraction time (X2X4) had interaction effects on the response value, followed by the linear terms of water extraction time (X4), and the interaction effects of immersing time and water extraction temperature(X2X3). Considering the efficiency, the optimum conditions of polysaccharides extraction were liquid:solid ratio of 1:67, immersing time of 10 min, water extraction temperature of 95 °C, and water extraction time of 15 min. Under optimized conditions, the experimental yield 11.29% agreed closely with the predicted yield. Therefore, application of Uniform Design in the extraction of polysaccharides from Gynostemma pentaphyllum Makino dramatically reduced extraction time.