Enhancement of emulsion pH stability by Ca2+ modulation: A novel approach for preparing egg white protein fibril cold emulsion gels

Egg white, a crucial ingredient in bulk food production with limited emulsifying properties, can be significantly improved by fibrillation modification. However, resulting emulsions may exhibit instability at critical food processing pH values. In this study, the egg white protein fibril (EWPF) emulsion gel was constructed by Ca2+, and the stability enhancement mechanism under different EWPF and Ca2+ concentrations was investigated. The results showed that higher EWPF concentrations led to improved stabilization of the oil-water interface. At 60 mg/mL EWPF concentration, water loss decreased by 13.86% and oil loss by 35.79%, while the firmness and viscosity of the emulsion gel system were enhanced. The ζ-potential was reduced by 67.98% and the ionic bond content was increased by 22 times with the addition of Ca2+, the droplets showed a uniform cross-linked structure, and the stability and plasticity of the system were improved. By adjusting EWPF concentration to 40 mg/mL and Ca2+ concentration to 30 mM, pH stability of the system was also enhanced. This study provided a reference for the high-value utilization of egg white and a possibility for the application of EWPF in food processing, such as low-fat foods.