Revitalizing Unfermented Cabernet Sauvignon Pomace Using an Eco-Friendly, Two-Stage Countercurrent Process: Role of pH on the Extractability of Bioactive Phenolics

As the major byproduct of winemaking industry, grape pomace remains an untapped source valuable bioactive phenolic compounds. This study elucidated optimal aqueous extraction parameters for maximizing extractability, while avoiding use harsh conventional solvents and limiting water usage, from Cabernet Sauvignon in which red was processed white wine. In single-stage process (AEP), concurrent impact pH (2.64–9.36), solids-to-liquid ratio (SLR, g pomace/mL water) (1:50–1:5), temperature (41.6–58.4 °C) on total content (TPC) evaluated alongside a kinetic (15–90 min). Optimal conditions (pH 9.36, 1:50 SLR, 50 °C, 75 min) guided development two-stage countercurrent 1:10 to further reduce consumption without compromising overall extractability. The reduced fresh usage by 80%, increased TPC extracts 18%, improved vitro antioxidant activities (ABTS ORAC) extracts. Untargeted metabolomics enabled identification diverse pool phenolics, especially flavonol glycosides, associated with pomace, quantitation detected improvements release commonly bound phenolics such as ferulic acid, p-coumaric syringic protocatechuic acid alkaline compared ethanolic extract. investigation provides efficient, eco-friendly strategy suitable applications functional food, beverage, nutraceutical, cosmetic industries.