Optimization of polysaccharides from Panax japonicus C.A. Meyer by RSM and its anti-oxidant activity

Response surface method (RSM) was used to optimize the extraction conditions of polysaccharides from the rhizomes of Panax japonicus C.A. Meyer. A three-level, three-variable Box-Behnken design (BBD) was applied for experimental design and analyzed of the results to obtain the optimal processing parameters. RSM analysis indicated good correspondence between experimental and predicted values. The optimal condition for the yield of polysaccharide was extraction time 3.74 h, extraction temperature 93.90 °C and ratio of water to raw material 40.22. Polysaccharide was analyzed by chemical methods and Fourier transform infrared (FT-IR). IR spectra indicated the presence of uronic acids and α-pyranose of the glucose residue. The antioxidant activities of Panax japonicus polysaccharides (PJP) were investigated including scavenging activity of hydrogen peroxide, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and free radicals of superoxide anion in vitro. The results of antioxidant activity exhibited PJP had a good potential for antioxidant.