Kinetic studies of internal boiling extraction and other two extraction techniques for polysaccharides from Cortex periplocae

•A time-saving, efficient and simple polysaccharide extraction method was introduced.•Medium infiltrated into material greatly promoted liquid exchange due to gasification.•Three extraction methods were compared by the second Fick’s law.•The extraction rate of internal boiling extraction was the best above 75 °C. A method based on the boiling of immersion agent inside the material to improve polysaccharide extraction efficiency called internal boiling method (IBE), is reported herein. It was compared with hot water extraction (HWE) and ultrasonic-assisted extraction (UAE) using an extracted mathematical model. The mathematical model was based on Fick’s second law, and the employed variables were the temperature, ultrasonic power, and extraction time. The rate constant (κ), diffusion coefficient (Ds), relative raffinate ratio, and extraction t0.8 were analyzed. In the case of IBE, the extraction process reached its equilibrium concentration after approximately 20–30 min, thereby indicating a more rapid extraction compared with UAE (30–50 min) and HWE (120–180 min). In addition, the equilibrium concentration of IBE (0.484 mg/mL, 358.15 K) was significantly higher than those of the UAE (0.451 mg/mL, 300 W) and HWE (0.256 mg/mL, 358.15 K) processes. Furthermore, the ranges of κ and Ds were in the order of IBE > UAE > HWE at temperatures ≥348.15 K. These results indicated that IBE is a fast, efficient, and simple method for polysaccharide extraction.