Abstract
Apple pomace represents a major agro-industrial byproduct rich in bioactive polyphenols, yet conventional extraction methods often suffer from high solvent consumption, prolonged processing times, and thermal degradation. In this study, pulsed electric fields (PEF) were investigated as an innovative, non-thermal cell disintegration technique to enhance the recovery of phenolic compounds from industrial apple pomace. A Box-Behnken design and response surface methodology were employed to optimize electric field strength (1.0–3.0 kV/cm), specific energy input (5–25 kJ/kg), and ethanol concentration (20–60% v/v). Under optimized conditions (2.35 kV/cm, 18.2 kJ/kg, and 48% aqueous ethanol), PEF treatment achieved a total phenolic content of 14.82 ± 0.35 mg gallic acid equivalents per gram of dry matter, representing a 43.6% enhancement over untreated controls. High-performance liquid chromatography analysis revealed substantial recovery improvements for major polyphenols, notably phloridzin, chlorogenic acid, and quercetin-3-galactoside. Furthermore, PEF extracts exhibited significantly elevated radical scavenging activities (DPPH and FRAP assays) and demonstrated notable thermal and oxidative stability when incorporated into an oil-in-water model emulsion. These findings demonstrate that PEF is an efficient, sustainable processing intervention for transforming apple processing residues into high-value functional food ingredients.
