Kinetic Modeling and Mechanism of the Gas Bubble-Assisted Extraction of Paclitaxel from Biomass of Taxus chinensis

In this study, the extraction efficiency, extraction kinetics, and extraction mechanism according to bubble size in gas bubble-assisted extraction were investigated to recover paclitaxel efficiently from Taxus chinensis. When the bubble diameters were 2.3, 2.7, 3.0, 3.3, 3.7, 4.1, 4.5, 4.8, and 5.3 mm, the maximum extracted paclitaxel concentrations were 0.812, 0.830, 0.845, 0.850, 0.868, 0.876, 0.900, 0.916, and 0.933 mg/mL, respectively. The results indicated that the paclitaxel yield increased as the bubble diameter increased during extraction. Most of the paclitaxel (> 93.3%) could be recovered by a one-time extraction when the bubble diameters were greater than 5.3 mm. The extraction mechanism demonstrated that the bubbles collapsed at the surface of the extraction solution and created shockwaves that strongly impacted the biomass, which disrupted the cells. When the extracted data were applied to various empirical models (second-order model, parabolic diffusion model, power law model, and logarithmic model), the second-order model was found to be the most suitable. In addition, a model that can predict the concentration of extracted paclitaxel was proposed using regression analysis of the equilibrium concentration and initial extraction rate according to the bubble diameter. The experimental data and the predicted data were found to be in agreement.