Extraction of natural products using supercritical fluid

Original spent coffee grounds, which supplied from Illycaffè S.P.A (I) and bar of Faculty of Economics in University of Trieste (II), were used in this study. Firstly, it was observed that they, which were dried at 60°C, contain moisture of 60 and 55 wt%, respectively. The oil from spent coffee grounds was also extracted with n-hexane and dichloromethane in a Soxhlet apparatus, and by supercritical CO2 extraction depending on experimental design. In the experiments using Sc-CO2, which were performed using a tubular type extractor (Autoclave A21, Separex), the effects of temperature, pressure, and dynamic extraction time on the amount of oil extracted from spent coffee grounds have been investigated. According to the results, which were optimized by using Response Surface Methodology, the highest oil content was obtained at a temperature of 33.2 ? C, pressure of 284.1 bar and extraction time of 220.9 min. However, the main compounds in the profile of resulting oils were palmitic acid and linoleic acid (totally about 75%); some significant differences were found in the compositions of fatty acids between the spent coffee grounds? oils. Furthermore, the contents of sterols and tocopherols of spent coffee grounds? oils were also analyzed.