Hansen-guided green recovery of non-extractable hesperidin from lemon by-products with antioxidant and cholinesterase inhibitory potential.

Abstract

Non-extractable phenolics (NEPs), including high-value flavonoids such as hesperidin, remain trapped in residues after conventional and advanced extraction processes, despite their recognized antioxidant and neuroprotective potential. Their sustainable recovery is key to fully valorizing citrus by-products. For the first time, a Box-Behnken experimental design was applied to optimize the recovery of extractable phenolics (EPPs) from lemon by-products using aqueous-organic pressurized liquid extraction (PLE), followed by the recovery of non-extractable hesperidin from the residual matrix using Hansen Solubility Parameter-guided green solvents and a mixture design optimization. Optimal PLE conditions (11.9 min, 100 °C, EtOH:H₂O 40:60 v/v) maximized EPP yield and bioactivity. Residual NEPs were efficiently recovered by PLE using benzyl alcohol:1,3-butanediol (67.6:32.4 v/v), enhancing non-extractable hesperidin content. HPLC-MS/MS analysis confirmed hesperidin as the main compound, while methyl naringenin rutinoside showed predictive bioavailability and blood-brain barrier permeability. Molecular docking highlighted their strong cholinesterase inhibitory potential, supporting their relevance as neuroprotective agents.