Tailoring egg white protein and pea protein isolate complexes by ultrasound-assisted pH-shifting for stabilizing high internal phase Pickering emulsions as structured fat replacers in ice cream: Oral tribology and structural transfer

This study aimed to reduce fat and saturated fatty acid contents in ice cream while maintaining the frozen aerated structure and sensory quality that are often compromised by fat reduction. Ultrasound-assisted pH-shifting treatment was used to regulate the interfacial behavior of an egg white protein (EWP)-pea protein isolate (PPI) binary protein system and construct high internal phase Pickering emulsions (HIPPEs). They were then used to replace 30% of the coconut oil in a cream formulation designed for ice cream. The resulting cream was subsequently used to prepare low-fat ice cream. The results indicated that moderate pH-shifting treatment enhanced the interfacial adsorption and film-forming capabilities of the EWP-PPI system. In particular, the pH 10 group exhibited an emulsion stability index (ESI) of 96.8% and a relatively uniform droplet size distribution. In ice cream applications, the pH 10 group formed a finer and more continuous porous network, with the lowest porosity of 38% and the highest total sensory score of 45.6. Overall, HIPPEs stabilized by ultrasound-assisted pH-shifting modified EWP-PPI complexes could be used as structured fat replacers in low-fat ice cream, offering a feasible approach for improving the quality of low-fat frozen aerated foods.