Supercritical CO2 extraction and selective adsorption of aroma materials of selected spice plants in functionalized silica aerogels

Static supercritical fluid extraction has been used to concentrate the aroma materials of common herbs and spices. The technique has provided a higher number of components and cleaner extract than the one-step ethanol maceration. The one-step supercritical fluid extraction of the aroma compounds has been combined with their in situ adsorption in hydrophilic and hydrophobic silica aerogels. The extracts have been analyzed by a GC-MS technique and 55 aroma compounds have been identified. Most of the compounds have been adsorbed in both polar and apolar silica aerogels with no direct connection with the surface polarity. However, previously undetected compounds enriched to an analytically significant level, while others competed with each other for the active sites on the surface. Functionalized silica aerogels can be used as a new type of aroma storage materials and as selective and tuneable adsorbents for the extraction and enrichment of potentially active components from a complex matrix.