Stabilization Mechanism of a High-protein Fresh Walnut Emulsion: The Role of Mono- and Diglycerides

To overcome the insufficient nutritional density of plant-based protein emulsions owing to their low protein content, this study utilized fresh walnuts as raw material to develop a high-protein fresh walnut emulsion (FWE). The effects of monoglycerides and diglycerides (MG/DG) on emulsion stability and structural properties were systematically investigated. Multidimensional analyses, including rheological properties, interfacial tension, and microstructural characterization revealed that MG/DG formed a dense interfacial film at the oil-water interface through hydrogen bonding and hydrophobic interactions, thereby significantly enhancing FWE stability. After adding 0.5% MG/DG, the emulsion exhibited the smallest particle size and lowest interfacial tension, while rheological data indicated optimal network structure strength and stability. However, excessive MG/DG addition (0.6%) induced over-aggregation of MG/DG molecules, which competed for interfacial adsorption and consequently compromised the integrity of the interfacial film. This study elucidates the stabilization mechanism of MG/DG in high-protein plant-based milk bases from interfacial and rheological perspectives, providing a theoretical basis for developing FWE bases.