High internal phase emulsions stabilized by pea protein isolate modified by ultrasound and pH-shifting: Effect of chitosan self-assembled particles

This study unveils an effective and simple approach to formulate solid-sate high internal phase emulsions (HIPEs) with strong viscoelasticity and high stability, using modified pea protein isolate (MPPI) as emulsifier and self-assembled chitosan (CS) particles as cofactor to stabilize the system. The results demonstrated that native pea protein isolate (PPI) has poor emulsification, whereas PPI modified by ultrasound and pH-shifting can successfully stabilize HIPEs. Incorporation of CS particles further increases the viscoelasticity and self-supporting properties of HIPEs. Micromorphological and microrheological analyses indicated that CS particles could enhance the interfacial adsorption of proteins and fill in the interdroplet network structure. Decreased droplet size, improved interfacial film strength, and improved viscoelasticity endow HIPEs with better properties, such as higher self-supporting capacity, improved plasticity, and superior stability, which are regulated by the CS particle level. These improvements provide the opportunity for HIPEs as 3D printing inks to print high-resolution, self-supporting products. In addition, the constructed HIPEs showed better tolerance to various processing environments such as centrifugation, storage, and heating and, remain stable at 0-400 mM NaCl and pH settings of 6.5-7.5. These findings promote the constructed HIPEs as potential solid fat substitutes for meat products.