Pressurized Liquid Extraction Optimization from Supercritical Defatted Olive Pomace: A Green and Selective Phenolic Extraction Process

Olive pomace (OP) is the main by-product of olive oil industry produced in large quantities. Its valorization as a source phenolic bioactive compounds paramount for sustainable growth related industries. This work proposes an intensified process to maximize recovery dry extracts using hydroalcoholic mixtures. Supercritical carbon dioxide defatting pre-treatment was performed. Following this, pressurized liquid extraction optimized through circumscribed central composite design. The factors consisted temperature (65.0–185.0 °C), ethanol percentage (8.0–92.0%), and solid/liquid ratio (0.2–0.8 gOP/mLSOLVENT). Besides total content (TPC) flavonoid (TFC), major OP [hydroxytyrosol (HT), tyrosol (TY), oleuropein (OL)] were evaluated. Further, decarboxymethyl OL aglycone dialdehyde (3,4-DHPEA-DEDA) identified by HPLC-DAD-MS/MS most abundant polyphenol studied first time OP. Different conditions found optimize each key compound. In 67% shorter 38% less solvent consumption compared conventional extraction, increase 475% OL, 428% HT, 194% TY, 373% 3,4-DHPEA-DEDA, 89% TPC, 158% TFC observed. antioxidant activity oxygen radical absorbance capacity (ORAC) assay increased (optimal conditions) correlated with TFC. Thus, efficient, selective, scalable, green established.