Effect of heat treatment on the stability of ultrasound-assisted cross-linked myofibrillar protein-stabilized emulsion filler phases via rheology and tribology

This work aimed to reveal the effect of heat treatment on the stability of ultrasound-assisted cross-linked myofibrillar protein-stabilized emulsion and its potential application as a filler phase. The interfacial dilatational rheology, emulsion droplets, linear and nonlinear shear rheological properties, microrheological properties, and tribological properties of emulsion fabricated by the original myofibrillar protein (MP) (NA), crosslinked MP (NAG), and sonication after crosslinked MP (MPGU) were determined at the heat temperature of 40 °C, 60 °C, and 80 °C. Results indicated that heat treatment would affect the stability and processing adaptability of the emulsion. The elasticity and strength of the interfacial film were enhanced with the treated temperature increased from 40 °C to 80 °C, and the MPGU group showed a more linear shape of interfacial Lissajous plot than the other groups even at large amplitudes. Based on the good interfacial properties, the MPGU group had the smaller emulsion droplets with more protein-coated, and the network structure was formed only at 80 °C. For the rheological properties, the lower apparent viscosity, elastic index (EI), and macroscopic viscosity index (MVI) in the MPGU group indicated the formation of a more stable emulsion. Furthermore, the lower closed area of Lissajous curves and friction coefficient for the MPGU group also proved the highest stability and lubrication of the emulsion after heat treatment. Therefore, this study indicated that ultrasound-assisted cross-linked myofibrillar protein-stabilized emulsions had good thermal stability and processing adaptability, which contributed to the fabrication of stable emulsion-filled foods.