title: Countercurrent supercritical fluid extraction and fractionation of high-added-value compounds from a hexane extract of olive leaves.
abstract: Countercurrent supercritical fluid extraction (CC-SFE) at a pilot scale plant was used for fractionation of high-added-value products from a raw extract of olive leaves in hexane. Compounds found in the raw extract were waxes, hydrocarbons, squalene, beta-carotene, triglycerides, alpha-tocopherol, beta-sitosterol, and alcohols. The CC-SFE extraction process was investigated according to a 2(3) full factorial experimental design using the following variables and ranges: extraction pressure, 75-200 bar; extraction temperature, 35-50 degrees C; and ethanol as modifier, 0-10%. Data were analyzed in terms of extraction yield, enrichment, recovery, and selectivity. Higher extraction yields were attained at 200 bar. For most of the compounds analyzed enrichment was attained at the same conditions, that is, 75 bar, 35 degrees C, and 10% ethanol. Hydrocarbons were usually recovered in the separators, whereas waxes and alpha-tocopherol remain in the raffinate. Selectivity data reveal that alpha-tocopherol is the most easily separable compound. The influence of the experimental factors on the recovery of all the compounds was studied by means of regression models. The best fitted model was attained for beta-sitosterol, with R2 = 99.25%.
authors.affiliation: Area de Tecnología de Alimentos, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Cantoblanco, Madrid, Spain. javier.tabera@uam.es
authors.forename: Javier
authors.initials: J
authors.lastname: Tabera
authors.forename: Angeles
authors.initials: A
authors.lastname: Guinda
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ruiz-Rodríguez
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Señoráns
authors.forename: Elena
authors.initials: E
authors.lastname: Ibáñez
authors.forename: Tomás
authors.initials: T
authors.lastname: Albi
authors.forename: Guillermo
authors.initials: G
authors.lastname: Reglero
mesh_terms: D005591:Chemical Fractionation; D025924:Chromatography, Supercritical Fluid; D003377:Countercurrent Distribution; D006586:Hexanes; D031658:Olea / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*
chemical_list: D006586:Hexanes; D010936:Plant Extracts