Optimization of ultrasonic extraction of Lycium barbarum polysaccharides using response surface methodology

Ultrasonic extraction was a new development method to achieve high-efficiency extraction of polysaccharides instead of hot water extraction. In this paper, the single factor method combined with the box Behnken design of response surface method was used to study the influence of extraction time, extraction temperature, material liquid ratio and ultrasonic power on the extraction rate of polysaccharide. The results indicated that the best extraction rate of polysaccharide was 12.54 ± 0.12% under the conditions of 80 min for extraction time, 73 °C for extraction temperature, 1 g:38 mL for material to liquid ratio, and 185 W for ultrasonic power. Under the same operating conditions, the yield of polysaccharide using ultrasonic extraction was 83.3%, which was higher than that hot water extraction. Moreover, the extraction time of ultrasonic extraction was only 47% of that using hot water extraction. This suggested that there was great potentials of using ultrasonic extraction in the realization of high-efficiency extraction of polysaccharide. The results of this study could also provide a theoretical basis for the coupling of ultrasonic extraction and ultrasonic concentration process to develop the integrated equipment of both ultrasonic extraction and ultrasonic concentration.