Response surface optimization of Safranal and Crocin extraction from Crocus sativus L. via supercritical fluid technology

Safranal (2,3-Dihydro-2,2,6-trimethylbenzaldehyde) and Crocin (Crocetin digentoboisyl ester) were experimentally extracted from saffron (Crocus sativus L.) via supercritical carbon dioxide (SC-CO2) and modified SC-CO2 with methanol as entrainer, respectively. The extracted samples were analyzed by high performance liquid chromatography (HPLC). The response surface methodology (RSM) was applied to evaluate the effects of four independent variables (temperature, pressure, SC-CO2 flow rate, and dynamic extraction time) on the recovery of Safranal and Crocin. The recovery results indicated that the data adequately fitted into a second-order polynomial model. The optimal values of variables for Safranal extraction were determined by RSM to be 92 degrees C, 21.3 MPa, 0.9 cm(3) min(-1) and 122.0 min for the optimum predicted recovery of 91.76 w/w%. Optimum Recovery of Crocin (32.67 w/w%) was obtained at 44 degrees C, 19.3 MPa, 1.0 cm(3) min(-1) and 110.0 min. The accuracy of the modeling optimal Safranal and Crocin recovery was validated with triplicate experiments giving the average extraction recovery of 90.03 and 33.05 respectively. (C) 2015 Elsevier B.V. All rights reserved.