Katsinas, NikolaosBento Da Silva, AndreiaEnríquez-De-Salamanca, AmaliaFernández, NaiaraBronze, Maria RosárioRodríguez-Rojo, Soraya2022-03-292022-03-292021-04-262168-0485PURE: 42313508PURE UUID: 9f205986-330a-4221-bb32-51871a62f2c0Scopus: 85105105729WOS: 000644738000012http://hdl.handle.net/10362/135408H2020-MSCA-ITN-2017 01 0145 FEDER 402 022125Olive pomace (OP) is the main by-product of the olive oil industry produced in large quantities. Its valorization as a source of phenolic bioactive compounds is paramount for the sustainable growth of related industries. This work proposes an intensified process to maximize the recovery of phenolic compounds in dry extracts using hydroalcoholic mixtures. Supercritical carbon dioxide defatting pre-treatment was performed. Following this, pressurized liquid extraction was optimized through a circumscribed central composite design. The factors consisted of temperature (65.0-185.0 °C), ethanol percentage (8.0-92.0%), and solid/liquid ratio (0.2-0.8 gOP/mLSOLVENT). Besides the total phenolic content (TPC) and the total flavonoid content (TFC), the major phenolic compounds of OP [hydroxytyrosol (HT), tyrosol (TY), and oleuropein (OL)] were evaluated. Further, decarboxymethyl OL aglycone dialdehyde (3,4-DHPEA-DEDA) was identified by HPLC-DAD-MS/MS as the most abundant polyphenol and was studied for the first time for OP. Different conditions were found to optimize each key compound. In 67% shorter extraction time and 38% less solvent consumption compared to conventional extraction, an increase of 475% for OL, 428% for HT, 194% for TY, 373% for 3,4-DHPEA-DEDA, 89% for TPC, and 158% for TFC was observed. The antioxidant activity by oxygen radical absorbance capacity (ORAC) assay increased 89% (optimal conditions) and correlated with TPC, 3,4-DHPEA-DEDA, and TFC. Thus, an efficient, selective, scalable, and green extraction process was established.131954376engantioxidant capacitydecarboxymethyl oleuropein aglycone dialdehyde (oleacein)hydroxytyrosololeuropeinolive pomace phenolic compoundspressurized fluid extractionGeneral ChemistryEnvironmental ChemistryGeneral Chemical EngineeringRenewable Energy, Sustainability and the EnvironmentSDG 7 - Affordable and Clean EnergySDG 8 - Decent Work and Economic Growthjournal article10.1021/acssuschemeng.0c09426https://www.scopus.com/pages/publications/85105105729