Abstract
Walnut protein (WP)-based emulsions are notable for their sustainability and biocompatibility. However, their emulsifying capability is often hindered by a densely packed structure. This study investigates the impact of physical modifications, specifically high-speed shearing, heat treatment, and ultrasonic treatment, on the structure of WP and examines the subsequent effects on the physicochemical properties and stability of the resulting high internal phase emulsions (HIPEs). The three modification methods reduced the average WP particle diameter by 55.38 %, 48.31 %, and 73.66 %, respectively, the corresponding D(4,3) values of HIPEs decreased by 41.31 %, 36.77 %, and 50.43 %. Additionally, the gel-like properties and stability of the HIPEs from modified WP significantly improved. Notably, ultrasonic treatment exhibited the most substantial influence, as cavitation effectively unfolded the WP structure, enhancing its adsorption at the interface of HIPEs droplets and with altered rheological properties. These findings would offer valuable insights for WP modification and its potential applications in HIPEs.