Increasing the pasteurization temperature of liquid egg white by phosphorylation modification: Exploring the mechanism and application

Pasteurization is an effective sterilization technique for the treatment of liquid egg white (LEW), but the pasteurization temperature is generally limited because increased temperature can lead to aggregation of the proteins and affect their processing properties. In this study, phosphorylation modification was used to increase the thermal stability and pasteurization temperature of LEW, aiming to enhance the pasteurization sterilizing effect. The FT-IR results showed that the phosphate groups were successfully grafted into protein molecules, improving the order degree of protein molecules. In this case, the pasteurization temperature of LEW increased from 58 °C to 61 °C, without accompanying thermal aggregation. The molecular structural results suggested that the enhanced thermal stability was attributed to the decreased average particle size and the increased electrostatic repulsion between protein molecules, which largely reduced the turbidity of LEW during pasteurization treatment. Meanwhile, this process was dominated by noncovalent interactions (hydrophobic interactions and hydrogen bonding). Furthermore, the phosphorylation modification can synchronously improve emulsifying and foaming properties of LEW. Therefore, this work suggested that phosphorylation has great potential to improve thermal stability and pasteurization temperature of LEW, which can be utilized to extend its sterilizing effect and shelf life.