Preparation and 3D printing of high internal-phase Pickering emulsions stabilized by chicken egg white microgel

In this study, the effects of heating temperature (70 °C, 80 °C, 90 °C) and egg white dosage (5%, 7.5%, 10%) on the physicochemical properties of chicken egg white microgels (EWMGs) were investigated. The results showed that both temperature and EW dosage would affect the EWMG in terms of its particle size, surface hydrophobicity, contact angle and zeta potential. At a given temperature, the content of α-helix in the EWMG was positively correlated to the protein concentration; while at a fixed EW dosage, the content of α-helix in the EWMG was negatively correlated to the temperature. High inter-phase Pickering emulsions (HIPEs) with EWMGs prepared at high temperature-low protein as stabilizer were shown to have smaller droplet size and better thermal and centrifugal stability. Rheological analysis of these HIPEs showed slight upward trends for both storage modulus (G′) and loss modulus (G″) and relatively weak frequency dependency. The HIPEs showing both shear thinning and recovery rate can be used as good food ink for 3D printing, and the HIPEs stabilized by the EWMG obtained at 90°C-5% performed the best.