Optimization of the ultrasonically assisted extraction of polysaccharides from Zizyphus jujuba cv. jinsixiaozao

Recently, the use of ultrasound has attracted considerable interest as an alternative approach to the traditional extraction methods. In the present study, in order to maximize the yield and purity of polysaccharides from Zizyphus jujuba cv. jinsixiaozao, response surface methodology (RSM) was employed to optimize the ultrasound-assisted extraction conditions. The results indicated optimum extraction conditions were temperature of 45–53 °C, actual sonic power of 31.7 W, time of 20 min and water/solid ratio of 20:1, respectively. The chemical analysis of crude polysaccharides revealed the polysaccharides extracted were most contaminated by co-extracted proteins. Using a short application of ultrasound, the yield of polysaccharides was 20.2% above that of classical extraction and the purity increased by a factor of 1.2, which confirmed the importance and great potential of ultrasound-assisted extraction of the polysaccharides from different tissues of plant materials.