Formation mechanism and stability of egg white fluid gels under ultrahigh-pressure homogenization pretreatment and synergistic heating effect.

The thermal sterilization process of protein beverages inevitably leads to the formation of insoluble thermal aggregates, greatly reducing the texture and taste of protein beverages. In this study, homogenized egg white (HEW) was obtained by ultrahigh-high-pressure (UHP) homogenization pretreatment of egg white (EW), and then a special egg white fluid gel (EWFG) was prepared by water bath heating. The results showed that the optimal conditions for preparing EWFG were three cycles at 20 MPa homogenizing pressure and heating in a water bath at 72℃ for 10 min. Under these conditions, the EWFG was a milky-white homogeneous liquid with an average particle size of about 560 nm. Measurements of the physicochemical properties of HEW and EWFG showed that the UHP homogenization treatment reduced the viscosity of HEW, decreased the particle size of protein aggregates, and increased the zeta potential, which altered the interactions of proteins during the subsequent heating process and facilitated the formation of homogeneous and dispersed EWFG. EWFG showed good stability at pH 6-10 and in low-concentration saline and medium-concentration sucrose solutions. The EWFG obtained by the present treatment is more suitable for factory-scale production and has great potential for protein beverage applications.