Cross-scale study of aging-driven colloidal transformations in Qingxiangxing baijiu via EEM-guided multi-technique integration

A cross-scale study of QXB aging covered macro-to microscopic colloidal changes. • Aged QXB was characterized employing EEM, Tyndall, AFM, and DLS. • Cross-brand test confirmed EEM's potential for rapid, noninvasive QXB detection. Qingxiangxing baijiu (QXB) aging involves dynamic colloidal evolution, yet its underlying mechanisms remain underexplored. This study integrated excitation–emission matrix spectroscopy (EEM), Tyndall imaging, atomic force microscopy (AFM), and dynamic light scattering (DLS) to investigate aging-induced colloidal dynamics in QXB. EEM identified characteristic peaks (excitation/emission wavelengths of 250/310 and 310/340 nm) and effectively distinguished aroma types and aging years. Tyndall intensity fluctuated periodically (129.5–193.3) with aging. AFM visualized colloidal self-assembly and ripening, while DLS showed predominant particles sized 0.3–5.0 nm alongside growing larger particles exceeding 1 μm. These results reveal a periodic “dispersion–assembly–ripening” cycle driven by colloidal self-assembly and Ostwald ripening. The multi-scale approach elucidates QXB aging mechanisms and supports EEM's potential for rapid vintage authentication.