Optimization of Ultrahigh Pressure Extraction of Momordicosides from Bitter Melon

Response surface methodology was used to optimize the conditions of ultrahigh pressure extraction of momordicosides from fresh fruits of bitter melon. The effect of extraction pressure, extraction time, ethanol concentration and solvent to sample ratio, and their interactions on yield of total momordicosides was investigated. Results showed that data could be well fitted to a second-order polynomial model. The independent parameters of extraction pressure, extraction time, solvent to sample ratio, all quadratics as well as the interactions between extraction pressure and solvent to sample ratio affected the yield significantly (p < 0.05). The model predicted that the optimal conditions were 423.1 MPa, extraction time 7.0 min, ethanol concentration 70.0 percent (V/V) and solvent to sample ratio 45.3 : 1 mL/g, and under such conditions, the maximum yield of 3.270 g Rg1 equivalents /100 g bitter melon dry weight could be achieved. In comparison with conventional heat reflux extraction, ultrahigh pressure extraction is more efficient and rapid to extract momordicosides from bitter melon. Additionally, the momordicosides compositions in extracts by both the methods were similar, which were investigated by using HPLC profile.