Pulsed Electric Field-Induced Ethanol Cluster Assembly: A Molecular Mechanism Accelerating Baijiu Aging

Abstract

Pulsed electric fields (PEF) accelerate Baijiu aging, yet the molecular mechanism remains unclear. A simplified ethanol–water-ester-acid model system combined with multiscale characterization and molecular dynamics (MD) simulations revealed PEF triggers cascaded hydrogen-bond network reorganization, proceeding from aqueous network dissociation to ethanol cluster assembly and subsequent hydrophobic microdomain expansion. The resulting ethanol clusters serve as binding sites that preferentially solubilize hydrophobic flavor compounds through strengthened directional hydrogen bonds, weakening solute–solute interactions. This pathway facilitates transformation from metastable supersaturation to thermodynamically stable homogeneous colloid. Time-resolved 2D-COS spectroscopy established the kinetic sequence as 370 nm (water-dominated) to 330 nm (transitional) and finally to 308 nm (ethanol-rich), confirming that water network disruption precedes cluster formation. This finding fills the molecular gap underlying PEF-promoted Baijiu aging and provides a theoretical foundation for flavor stability regulation in complex food colloidal systems.