Multi-stage ethanol-water biorefining of pomegranate pomace by-product enables time-resolved fractionation of fatty acids, phenolics and protein-rich residual biomass.

Efficient recovery of oils and phenolics from fruit pomace using food-grade solvents is challenged by composition shifts and extraction kinetics. Here, a multi-stage ethanol-water biorefining of pomegranate pomace was benchmarked under stirred liquid (SLE), ultrasound-assisted (UAE), and pressurized liquid extraction (PLE) regimes. Early alcoholic fractions preserved punicic acid (C18:3n-5 ≈ 78 %), while later ones shifted toward higher saturation. PLE maximized phenolic yield (11.96 mg GAE g-1) and concentration per solvent unit, whereas UAE achieved faster concentration ratios (CR = 0.8 in 7.5 min). Hydroalcoholic extracts were dominated by punicalagin and ellagic acid, showing time-dependent hydrolysis. Representative extracts maintained antioxidant capacity during 28 days at 25 °C. Residual biomass exhibited higher protein retention after PLE and lignin-enriched signatures. Path2Green screening identified solvent recycling and energy efficiency as key sustainability levers. This kinetic mapping defines actionable operating windows for targeting oil quality, phenolic enrichment, and greener bioprocessing.