Physical properties of mucilage polysaccharides from Dioscorea opposita Thunb

The physical properties of the mucilage polysaccharides of Dioscorea opposita (DOMP) were investigated in this study. The monosaccharide and amino acid contents, and molecular weight were determined, and morphology was observed. The rheological and emulsifying properties of different concentrations of DOMP were determined at acidic and basic pH (pH 5.0 and 9.0). The glucose and protein contents were 11.05% and 13.39%, respectively, and the average molecular weight was 9062 Da. The DOMP particles were spheres of 0.18 mu m diameter, which aggregated in solution. The viscosity of DOMP decreased gradually with increase in shear rate, which was indicative of pseudoplastic characteristics. DOMP showed relatively better emulsification properties than Konjac glucomannan (KGM). The particle size of DOMP decreased and its emulsifying properties improved under both acidic and basic conditions. These results suggested that DOMP can be used as a natural processing agent for improving the mouth-feel of food.