Mechanistic and comparative perspectives on ultrasonication-driven interfacial engineering in plant-based dairy emulsions.

Plant-based dairy alternatives (PBDAs) often struggle to achieve the colloidal stability, interfacial functionality, and sensory characteristics of bovine milk because of differences in protein structure, interfacial behavior, and matrix composition. Ultrasonication (US) has attracted increasing attention as a non-thermal processing technology capable of modifying protein conformation, droplet size, and interfacial organization through acoustic cavitation. This review critically examines the mechanistic basis of ultrasonication in PBDA emulsions, with particular emphasis on its influence on protein adsorption, interfacial film formation, droplet disruption, rheological behavior, and colloidal stability across different plant matrices. Compared with conventional thermal and pressure-based technologies, ultrasonication transfers energy through localized cavitation phenomena that may induce distinct structural responses; however, these responses are highly dependent on protein source, formulation composition, processing conditions, and reactor configuration. Evidence indicates that appropriately optimized ultrasonication can improve emulsion stability and functional performance, whereas excessive treatment may promote protein aggregation, lipid oxidation, localized heating, and deterioration of interfacial functionality. Furthermore, inconsistencies in cavitation quantification, treatment reproducibility, and industrial scale-up remain important challenges that limit direct comparison among studies. This review therefore provides a balanced mechanistic perspective on the opportunities and limitations of ultrasonication, identifies key knowledge gaps, and discusses future research priorities for improving process standardization, hybrid processing strategies, and industrial translation in plant-based dairy emulsions.