Extraction Optimization of Saffron Nutraceuticals Through Response Surface Methodology

In this study, response surface methodology (RSM) was applied to optimize the extraction of picrocrocin, safranal, and crocin, three major ingredients of saffron. The process parameters included ethanol concentration (0–100 %), extraction time (2–7 h), and temperature (5–85 °C). The extracted compounds were measured spectrophotometrically at 257, 330, and 440 nm at which picrocrocin, safranal, and crocin had the maximum absorbance values, respectively. Four models including linear, linear squares, linear interactions, and full quadratic were fitted to the final data. As expected, the best model was the full quadratic with R2 values of 83.91, 86.60, and 92.42 % for the picrocrocin, safranal, and crocin contents, respectively. Our results indicated that high temperatures, short times, and moderate concentrations of ethanol had the superlative impact on the extraction efficiencies of the compounds. According to the response surface analysis, ethanol concentration of 33.33 %, extraction time of 2.0 h, and temperature of 85.0 °C were found to be as the optimum conditions of the process under which the empirical amounts of E1cm% 1λmax were 1,190.47 ± 154.45, 474.02 ± 95.00, and 2,311.68 ± 57.37 for the picrocrocin, safranal, and crocin contents, respectively. While the theoretical values for the same responses were 1,237.27, 652.08, and 2,821.23.