Response Surface Methodology for Ultrasonic and Microwave Synergistic Extraction Optimization of Ginger Polysaccharides

Fresh gingers were dried in a far infrared drying oven and powder to provide a starting material for extraction ginger polysaccharides on an ultrasonic and microwave synergistic instrument.The effects of liquid/solid ratio,microwave power,extraction duration,material particle size and added ultrasonic treatment on polysaccharide yield were explored through single factor experiments.Three main affecting factors,namely microwave power,extraction duration and liquid/solid ratio were selected to carry out response surface optimization based on Box-Behnken experimental design.The optimal extraction conditions were determined as follows:drying temperature for fresh gingers,60℃;sieve mesh size for powdered gingers,40;extraction solvent;pure water;microwave power,258 W;and extraction duration,85 s.The polysaccharide yield obtained under these optimal conditions was 23.65%,higher than that obtained after three-time hot water reflux extraction for 2 hour each time(19.53%).Ultrasonic and microwave synergistic extraction has the benefits of simplicity and high efficiency.