Regulating the thermal properties of egg white by adding surfactants

The essential pasteurization process in liquid egg white (EW) production often leads to denaturation and solidification, causing pipe blockage and economic losses due to EW's sensitivity to heat. Therefore, some substances and methods to improve the thermal stability of EW during pasteurization were explored in this study to achieve better commercial operation and circulation of liquid EW. Combining surfactants induced changes in the thermal properties of the EW after different heating conditions (55 C-degrees/3.5 min, 65 C-degrees/2.5 min, 67 C-degrees/1.5 min, and 70 C-degrees/0.5 min) were analyzed by differential scanning calorimetry, particle size analyzer, rheometer, and Fourier transform infrared spectroscopy analysis. Results indicated that after heating, the smaller particle size (decreased by 56.02%-86.68%, p < 0.05), the higher denaturation temperature (increased by 1.5-10.5 C-degrees), and the lower viscosity (ranged from 0 to 0.5 Pa s) were achieved in EW treated by adding soybean lecithin and rhamnolipid. These showed that the combination of rhamnolipid and soybean lecithin effectively alleviates the aggregation behavior induced by heat treatment. This was also confirmed by the results of molecular docking that revealed the mechanism of thermodynamic behavior. Overall, the synergistic effect of rhamnolipid and soybean lecithin displayed great application potential in stabilizing the liquid EW during pasteurization, which could provide a theoretical basis for the non-destructive processing of egg white.