Phytochemical Examination of Oils Obtained from the Fruit of Mille Thistle (Silybum marianum L. Gaertner) by Supercritical Fluid Extraction

Abstract

Supercritical fluid extraction (solvent: CO2 and propane) was used for mild recovery of fatty oil of mille thistle fruit (Silybum marianum L. Gaertner). Fatty acid compounds (palmic acid, oleic acid, linolic acid, linolenic acid, behenic acid), coloring content (expressed in pheophytin and carotene), tocopherol content and concentrations of some metals (Al, As, B, Ba, Ca, Cd,Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, Pb, S, Ti, V, Zn), boron and sulfur were determined from oils and compared with oil obtained by Soxhlet extraction. There is significant difference between supercritical oil and traditional oil in the quantity of bioactive compounds and elements. The ratio of bioactive components and elements of oils changed during the extraction. Supercritical oils have higher concentration of C18:1 oleic acid, C18:3 linolenic acid, C20:0 and C22:0 behenic acid than the oil gained by Soxhlet extraction. The oil obtained by supercritical fluid extraction at 80 bar and 25 °C with propane has the highest coloring content. Our paper is the first report to be published on element concentrations of mille thistle oils. Accumulation of some heavy metals can be observed in almost each oil sample.