Comparison of Supercritical Fluid Extraction (SFE) and Pressurized Solvent Extraction (PSE) for the Recovery of gamma-Tocopherols in Walnut Oil

Gamma-Tocopherol is the dominant form of Vitamin E in many commonly ingested foods in the human diet (i.e. plant seeds, nuts). In the past, supplement companies have focused on the health benefits of alpha-tocopherol. Researchers are now realizing that gamma-tocopherol may have medicinal properties that have not been previously considered. Supercritical fluid extraction (SFE) offers many distinct advantages over other hydrocarbon base extraction techniques including: faster extraction time, more selective extractions, decreased solvent usage (90–100%) and thus solvent disposal cost. In addition, SFE requires very little to no dry down time, post extraction prior to the analysis. SFE is ideal for extraction of oils from natural products due to the compatibility of supercritical CO₂ and oil. Pressurized Solvent Extraction (PSE) is similar in theory to the SFE technique with one major differentiation, the solvent used in the PSE technique is typically hexane or other hydrocarbon based solvents. Similar to SFE a sample is placed in a pressure vessel and is processed at given temperatures, pressures and flow rates in order to extract analytes of interest. In this poster we will illustrate the use of SFE and its competing technique, PSE, in the same instrument for the removal of gamma-tocopherol from walnuts. We will compare the two techniques focusing on the total processing time, total hydrocarbon based solvents required and total gamma-tocopherols extracted.