Evaluation of microwave-assisted extraction technology for separation of bioactive components of saffron (Crocus sativus L.)

Saffron is the most expensive spice in the world and it is necessary to develop efficient extraction methods for separation of its bioactive compounds. The aim of this study was to evaluate the microwave-assisted extraction (MAE) of saffron major compounds - picrocrocin, safranal and crocin- through response surface methodology (RSM). A central composite design was utilized to optimize the process variables such as extraction temperature (45-125 degrees C), time (10 -30 min) and ethanol concentration (0-100 v\v%). The contents of the components were spectrophotometrically determined at 257, 330 and 440 nm (the peak absorbance values of picrocrocin, safranal and crocin). According to the optimization algorithm of RSM, the temperature of 95.91 degrees C, time of 30 min and ethanol concentration of 59.59 % were determined to be the optimum circumstances of the process. Four crocetin esters were recognized in the optimum saffron extract by HPLC analysis. GC-MS merely quantified safranal with a retention time of 6.719 min and a molecular weight of 150.