Hot Water Extraction of Crude Polysaccharide from Codonopsis pilosula and Determination of the Rheological Properties

The extraction condition of crude polysaccharides from Codonopsis pilosula by hot water reflux method was studied and the results analyzed by kinetic model. Then, the extraction rate and maximum extraction temperature were determined. furthermore, the thermal and pH stability and the rheological properties of the crude polysaccharide were also studied. crude Codonopsis pilosula polysaccharide (CCPP) under different conditions was extracted by hot water reflux method, the content was determined by phenol-sulfuric acid and DNS method, and the kinetic model of the extraction process was established. The viscosity was determined under different solute concentration, salt concentration, rotation speed, pH, and temperature. The thermal stability and pH stability were determined; the protein content and sulfate ion content were determined by the coomassie brilliant blue method and barium sulfate turbidimetry method, respectively. The yield of CCPP by the hot water reflux method was 25.72%. At 50 oC, the maximum extraction concentration, the rate constant and the linear relationship between the rate constant and the time were obtained at different ratios of material to liquid. The extraction process of this experiment coincided with Fick`s second law, R2 was greater than 0.88 and with the increase of extraction time, the dissolution rate increased, but with the increase of the ratio of material to liquid, the dissolution rate was decreased. CCPP showed a loss of polysaccharide fluidity as temperature increased and was affected by pH change. The apparent viscosity was affected by a change in solute concentration, temperature, pH, rotation speed and salt and sucrose concentrations.