A selective extraction of hydroxytyrosol rich olive oil from alperujo
Loading...
Official URL
Full text at PDC
Publication date
2019
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Citations
Exportar
Citation
Abstract
Alperujo, the solid-liquid waste generated by the current two-phase method of olive oil extraction, was dried,
milled and treated with supercritical carbon dioxide (sc-CO2) to obtain a hydroxytyrosol (HT)-rich oil. At first,
extraction rates were analysed as a function of operating variables and the pre-condition of the raw material.
Samples with particle size diameter<0.80mm and in equilibrium moisture (1%) with the atmosphere, improved
oil extraction yield almost 40% compared with samples with the whole range of particle sizes. Extraction
yield improved with solvent flow rate, but a minimum residence time was required. The optimum was
0.18 kg h−1 (7.5 kg CO2 h−1 kg biomass−1). Higher pressures and lower temperatures resulted in higher extraction
yields; at 30 MPa and 323 K the extraction curve slope was close to the theoretical oil solubility and the
yield was 13%, like that obtained with n-hexane by Soxhlet (14%). However, the HPLC-DAD analysis identified
higher HT concentration (1900 ppm) in the supercritical extracts at the highest temperature. Consequently, at
373 K, the total phenol content and the antioxidant capacity of the extracts was uppermost. No HT was found in
the n-hexane extracts.