Optimization of Ultrasonic-assisted Extraction Conditions of Polysaccharides from Radix Pseudostellariae by Response Surface Methodology

To obtain the optimal conditions of ultrasonic-assisted extraction of polysaccharides from Radix Pseudostellariae,on the basis of the single factor test,the response surface methodology was applied to optimize the main extraction conditions.The results showed that extraction temperature,extraction time and liquid-solid ratio had significant effects on extraction yield of polysaccharides.The optimum conditions for the ultrasonic assisted extraction technique of polysaccharide from Radix Pseudostellariae were:extraction temperature of 74 ℃,extraction time of 65 min,ultrasonic power of 100 W,ratio of liquid to solid of 26 mL/g.Under these optimized conditions,the extraction yield of polysaccharides was 2.48%,exhibiting a good agreement with the predicted values.