Effect of oil/water phase modifications on the structural and sensory properties of emulsions stabilized with pea proteins

The development of plant protein-based emulsions is essential for meeting the growing demand for healthy and sustainable food systems. While the physicochemical properties of the oil and aqueous phases are known to determine the texture and sensory quality of emulsions, how the oil/water phase modifications tune the structure and lubrication behavior of emulsions and then further their sensory perception remains poorly understood. In this study, the effects of oil and water phase modifications on the rheological, tribological, and sensory properties of plant protein-stabilized emulsions are systematically investigated using beeswax and soy lecithin as oil phase modifiers and inulin and guar gum as water phase modifying agents. In addition, emulsions stabilized by a low-denatured functional pea protein isolate extracted by self-coacervation method (F-PPI) and a conventional pea protein isolate produced via alkaline extraction-isoelectric precipitation (PPI) are compared. The results show that the oil/water phase modifications improve both lubrication performance and sensory perception, primarily through reducing droplet size and modulating the rheological properties of the oil and water phases. Oil phase modification mainly improves slipperiness by improving lubrication, whereas the water phase modification increases the perception of thickness. However, their effects on other sensory attributes, including creaminess and stickiness, were relatively limited. Additionally, F-PPI stabilized emulsions exhibit superior sensory perception than PPI emulsions due to the better lubrication performance and reduced beany flavor caused by mild extraction method. These findings provide mechanistic insights into the relationships among emulsion structure, rheological properties, tribological behavior, and sensory perception, and demonstrate that the combination of oil/water phase modifications with the low-denatured plant proteins obtained through mild extraction represents an effective strategy for developing stable, palatable, and sustainable plant protein-based emulsion foods.