Ultrasonic-associated extraction of water soluble polysaccharides from defatted Korean pine kernel

Experiments of ultrasonic-associated extraction and hot water extraction of water soluble polysaccharides from defatted Korean pine (Pinus koraiensis) were conducted in Northeast Forestry University, Harbin, China. The factors affecting extraction yield and content, such as extracting temperature, extracting time, the ratio of water to defatted kernel and concentration of ethanol were analyzed under specific condition. The optimal extracting parameters for ultrasound-associated extraction were determined as the ultrasonic temperature 70°C, the ratio of defatted kernel to water 1:20, the extracting time 40 min, and ethanol concentration 80%. Under such extraction conditions, the yield of water soluble polysaccharide was 3.65% and the average content of polysaccharide was 45.38% in the raw polysaccharides which gained in the experiment. Both extraction yield and content of polysaccharides extracted with ultrasound-associated extraction were higher than that with hot water extraction. The study demonstrates that ultrasound is a reliable and extremely effective tool for the fast extraction of water soluble polysaccharide of Korean pine kernel. © Northeast Forestry University and Ecological Society of China 2007.