Studies on the physico-chemical properties of the gum polysaccharides from opuntia milpa alta

Aim To study the physico-chemical properties of the opuntia milpa alta gum polysaccharides.Methods The gum polysaccharides was isolated from Opuntia Milpa Alta by water and precipitated with ethanol.Monosaccharide composition was determined by gas chromatography.Sugar content,UV and IR spectrum were analyzed.Results Gas chromatography analysis showed that the gum polysaccharides was composed with Rha,Fuc,Ara,Xyl,Man,Glc,Gal,GlcA and GalA,their molar ratio was 13.49∶1∶61.83∶26.37∶3.49∶6.70∶66.76∶6.68∶29.81.The total sugar content is 91.10%,uronic acid content is 18.78%.The UV spectrum shows there may be glycoprotein in this polysaccharides,and the IR spectrum shows polysaccharides feature absorbs.Conclusion Opunita milpa alta gum polysaccharide is a sticky polysaccharide mainly composed of Ara and Gal,a slight amount of Rha,Xyl,and GalA,and a micro amount of Man,Glc,Fuc,and GlcA.Some glycoproteins possibly exist in the polysaccharides because the total sugar content of 91.10% is detected.