Production of extracts from preserved olives using supercritical CO 2 and preliminary evaluation of its polyphenol content Obtenção de extractos de azeitona em conserva usando CO 2 supercrítico e avaliação preliminar do seu conteúdo em polifenóis

The supercritical fluid extraction (SFE) technique was used to obtain extracts from a sample simulating an olive pomace, obtained from preserved olives. The objective was to achieve the extraction of polyphenolic components from this matrix which is considered a hazardous waste from the production of olive oil. The supercritical fluid used was carbon dioxide and the SFE studies were conducted in two stages, the first at a pressure of 200 bar and 40 oC and the second stage at 300 bar, 45 oC and using ethanol as co-solvent. In both cases the SFE was performed for 3 hours. The first stage was carried out to obtain a cleaner matrix and the second step was aimed at the components of interest. The overall mass yield obtained was 5.5 %. Preliminary HPLC screening of the samples obtained and also of the water in which the olives were preserved showed that the polyphenol compounds were mostly in the latter.