Optimization of Extraction Process for Polysaccharide from Old Stem of Asparagus

[Objective] To optimize the extraction conditions of microwave extraction and microwave-soxhlet extraction for polysaccharide from old stems of Asparagus.[Method] By employing yield of polysaccharide as investigation index,the extraction processes of the two methods were optimized by orthogonal test.[Result] The optimal extraction conditions of microwave extraction were determined to be solid to liquid ratio of 1∶ 30,extraction duration of 20 min,extraction temperature of 60 ℃ and extraction power of 600 W,under which,the yield of polysaccharide reached as high as 4.35%.The optimum extraction process of microwave-soxhlet extraction were as follows:solid to liquid ratio of 1∶ 30,extraction duration of 10 min,extraction power of 600 W and extraction temperature of 70℃,and the yield of polysaccharide reached 2.29% under the optimal extraction conditions.[Conclusion] High in extraction efficiency,low in extraction temperature and save in consumption,the microwave extraction is favorable for the extraction of polysaccharide from old stem of Asparagus in practical production.