Abstract: The microwave-assisted alkali extraction of polysaccharides from Mesona Blumes was optimized in this paper. To do this, the effects of four factors including water-bath boiling time, alkaline concentration, material/liquid ratio and microwave treatment time on the extraction rate of polysaccharides were explored by single-factor and orthogonal design methods. Results indicated that alkaline concentration was the most critical factor affecting the extraction rate of polysaccharides, followed by material/liquid ratio. Microwave treatment time and water-bath boiling time exhibited less effect on the extraction rate of polysaccharides. The optimal extraction conditions were microwave treatment time of 90 s, extraction power of 400 W, water-bath boiling time of 1 h, alkaline concentration of 0.125 mol/L, and material/liquid ratio of 1:35. Under these optimal conditions, the extraction rate of polysaccharides from Mesona Blumes was up to 43.84%.

Key words: Mesona Blumes polysaccharides, microwave-assisted extraction, alkali extraction