Evolutionary Pattern of Liquid-Liquid Phase Separation in Amphiphilic Molecular Self-Assembly during the Natural Aging Process of Strong-Aroma Baijiu

Abstract

This study reveals liquid-liquid phase separation (LLPS) as the evolutionary driver in amphiphilic self-assembly during strong-aroma Baijiu aging. Fresh Baijiu is a heterogeneous colloidal system dominated by supersaturated ethyl hexanoate/hexanoic acid, forming $∼$38~$μ$m LLPS droplets. Over 10~years, droplet size decreases by 73.68~%, evolving into hydrophobic-core/hydrophilic-shell structures. Raman mapping shows ethanol densification within droplets via hydrophobic interactions and H-bond reorganization, correlating with a 13.3~% free ethanol reduction and sensory mellowing. Crucially, electric field-assisted aging achieves structural/flavor equivalence to 5–6~years of natural aging in 40~days. This establishes LLPS as fundamental to Baijiu maturation, providing a physicochemical framework to optimize colloidal stability, sensory quality, and sustainable production in distilled spirits.

Zhaoyong Zou

Professor

My research interests include bioprocess inspired fabrication, crystallization and ceramics.