Effects of Different Drying Techniques on the Pore Structure and Ginsenoside Solubilization of American Ginseng Slices

This study examines the microstructural properties of Radix et Rhizoma Ginseng slices obtained through different drying methods and investigates how pore structure affects ginsenoside dissolution. Freeze drying was used as the control group to compare the dissolution of ginsenosides under hot air, vacuum, and hot air vacuum combined drying methods. Microscopic examinations were performed using mercuric intrusion porosimetry (MIP) and scanning electron microscopy (SEM). The results revealed that, compared to single drying methods, the saponin residue rate was lowest (42.19%) with the hot air-vacuum combination method. Although porosity was highest (10.4%) with the hot air method, the total pore area was greater with the hot air-vacuum combination. This indicates that while both porosity and pore area affect ginsenoside residue rates, pore area has a more significant impact. Therefore, in addition to freeze drying, hot air-vacuum combined drying is more effective for American ginseng, significantly enhancing ginsenoside dissolution rates.