No abstract

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.

Leonurus japonicus is rich in bioactive compounds especially polysaccharide. Single factors test and response surface methodology were used to study the optimum conditions for ultrasonic - assisted extraction of polysaccharide from L. japonicus, and its physiochemical and DPPH scavenging activities also were evaluated. The optimal conditions as underpinned by this paper is as follow: extraction temperature of 70 �C, extraction time of 50 min and extraction power of 210W. The polysaccharide of L. japonicus was shown to be a non-reducing sugar and to exhibit DPPH scavenging activity to an extent. The polysaccharide structures were studied using SEM, AFM, and FT-IR. It showed L. japonicus polysaccharide had been having more than one chains which were branched and entangled with each other. and existed a broad band wavelength of 2925.64, 1635.06, 1539.7, 1046.73, and 477.86 cm-1. The study indicated that L. japonicus may have a beneficial use to the medical and food industries.