Optimization of Microwave-assisted Extraction of Flavonoids from Cryptotaenia japonica Hassk using Response Surface Methodology

The objective of the study was to optimize the processing of Microwave-Assisted Extraction (MAE) of flavonoids from Cryptotaenia japonica Hassk. The effects of processing parameters include ethanol proportion, extraction time, extraction temperature and ratio of liquid to solid on the flavonoids yield were determined and the optimal conditions for flavonoids were evaluated by means of Response Surface Methodology (RSM). The optimal conditions were detected and tri-dimensional response surfaces were plotted from the mathematical models. The Ftest and p-value showed that all parameters had highly significant effects on the response value. The optimum extraction conditions were ethanol of 70% (v/v), extraction time of 15 min, extraction temperature of 75°C and liquid to solid ratio of 20 mL/g. Under these conditions, 27.01 mg/g total flavonoids were obtained by MicrowaveAssisted Extraction (MAE), which are close to the predicted value (27.48 mg/g). MAE method was applied successfully to extract total flavonoids from Cryptotaenia japonica Hassk.