Thermal-assisted high hydrostatic pressure extraction of nutraceuticals from saffron (Crocus sativus): Process optimization and cytotoxicity evaluation against cancer cells

Abstract

The extraction of nutraceuticals (crocin, picrocrocin, and safranal) from saffron was conducted using high hydrostatic pressure. A pressure range of 100–600 MPa in combination with elevated temperatures (30–70 °C) was studied. Extract quality was determined by an ISO (the international organization for standardization) method, and also compared with HPLC analysis. The results showed a significantly (P < 0.05) positive effect of pressure on the extract quality with an increase of 52–63%, 54–85%, and 55–62% in crocin, picrocrocin, and safranal content, respectively, as the pressure increased. However, a highly significant decrease (25–36%) in crocin content was observed with the increase in temperature. Moreover, the effect of pressure on saffron components varied with the change in temperature which was observed from the response surfaces. A third-order model showed a good fit (R2 > 0.9) of these data including pressure effect on crocin, picrocrocin, and safranal content. An optimum pressure-temperature combination of 580 MPa and 50 °C with an extraction time of 5 min (dwell time) was obtained, predicting 100, 50, and 92 units of crocin, safranal, and picrocrocin content, respectively. A <5% error was found between the predicted and experimental values. Anti-cancer activity of the optimized extract obtained under high hydrostatic pressure was evaluated using MTT (3,(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) based assay, which showed a 28% higher anti-cancer activity as compared to the conventionally extracted sample. High hydrostatic pressure proved to be a better technology than conventional process for extraction of bioactive components from saffron, the highest valued spice in the world. Pressure-extracted components of saffron can be used to formulate functional foods or directly applied for clinical trials.