Supercritical CO2 extraction and response surface optimization of ginkgolic acids from ginkgo biloba exopleura

Supercritical (Sc)-CO 2 extraction was adopted to extract ginkgolic (G.) acids from ginkgo biloba exopleura. Response surface optimization was employed to maximize extraction recovery of G. acids from ginkgo biloba exopleura. The effects of pressure, temperature, CO 2 mass flow rate, dosage of entrainer and extraction static-dynamic time on the yield of G. acids were investigated in detail, and the central composite design was used to maximize the extraction recovery of G. acids. The amounts of G. acids were analyzed by HPLC with the mixture of methanol and acetic acid solution as the mobile phase. The optimal process parameters for sc-CO 2 extraction were determined to be: 31.3MPa extraction pressure, 46.1 °C extraction temperature and 11.1 g min -1 CO 2 flow rate, 30mL ethanol entrainer, 1 h extraction static time and 2 h dynamic time. Under the conditions of optical extraction process, the average G. acids extraction rate was 74mg g -1 .