Liquid Carbon Dioxide Use in the Extraction of Extra Virgin Olive Oil From Olive Paste

摘要

were examined and extracted oil was compared with oils obtained by centrifugation, pressure and use ofchemical solvent.It is well known that the use of CO2 has many advantages: miscibility with a wide range of molecules, foodsafety, non-flammability, absence of residues in the extract, possibility of total solvent recovery and noproduction of olive mill waste water that are highly polluting for the environment and require expansivedisposal.Samples were subjected to the following analyses: determination of Free Fatty Acids (FFA), Peroxides Value(PV), Spectrophotometric Indices, Fatty Acids Composition (FA), determination of biophenols content anddetermination of Volatile Organic Compounds (VOCs). All samples showed FFA, PV and ΔK values within thelimits established by law for extra-virgin olive oil. The use of CO2 did not catalyze hydrolysis, oxidation andcondensation of double bonds. Centrifuged oils and oils extracted with carbon dioxide presented the lowest PVand FFA values. Extraction with liquid carbon dioxide contributed to an increasing of phenolic content with avalue of 270.5 mg/kg, a value twice that of the oils extracted with centrifugation (135.3 mg/kg) or pressuremethods (173.2 mg/kg). Oil extracted with liquid carbon dioxide showed the greatest amount of t-2-octenal andt-2-heptenal, giving herbaceous and pungent notes. Moreover the presence of aromatic compounds such aslimonene, generally absent in olive oils, was only detected in the sample extracted with liquid carbon dioxide.