Droplet Evaporation and Deposition Patterns of Jinsha Jiangxiangxing Baijiu

This study systematically investigated the droplet evaporation behavior and deposition pattern characteristics of Jinsha Jiangxiangxing Baijiu, and analyzed the correlation between the deposition patterns and sensory quality. The results showed that during evaporation, all Baijiu samples of different quality grades exhibited particle self-assembly, with particles moving and depositing under the influence of the internal fluid flow within the droplet. The deposition patterns left at the interface after droplet evaporation significantly varied with the degree of self-assembly and fluid flow effects. High-quality samples (Grades Ⅰ-Ⅲ) showed a greater number of self-assembled particles at the three-phase contact line, while low-quality samples (Grade Ⅳ and Ⅴ) had fewer particles. The observation of evaporation modes revealed that Grades Ⅰ-Ⅲ primarily exhibited a mixed evaporation mode of constant contact angle (CCA) and constant contact radius (CCR), accompanied by pronounced “pinning-slipping” phenomena, resulting in irregular multi-ring deposition patterns with more abundant particle distribution within the rings. In contrast, Grades Ⅳ and Ⅴ mainly followed the CCR evaporation mode, forming typical coffee-ring structures with sparse particle distribution within the rings. Image analysis indicated a significantly positive correlation between the integrated optical density of deposition patterns and sensory scores, validated using various commercially available Baijiu products. Gas chromatography-mass spectrometry (GC-MS) analysis suggested that this correlation was closely associated with the content of long-chain fatty acid ethyl esters in Baijiu. This study provides a visualization-based method for evaluating the quality of Jiangxiangxing Baijiu through deposition patterns, offering a new strategy for the rapid quality evaluation of Jiangxiangxing base and finished Baijiu.