Effects of multiple freeze-thaw cycles on the foaming and structural properties of egg whites subjected to different thawing methods

This study systematically investigated the effects of multiple freeze-thaw(F-T)cycles using four thawing methods on the foaming characteristics of egg white proteins and their regulatory mechanisms. The results indicated that the foaming capacity of air and water bath thawed samples increased with the number of F-T cycles. In contrast, vacuum thawing significantly reduced the foaming capacity, while ultrasonic thawing exhibited the optimal foaming capacity. Structural analysis showed that the protein was fractured after F-T cycles. Simultaneously, the viscosity and particle size of the proteins decreased, and the internal hydrophobic groups were exposed. The enhanced surface hydrophobicity and the low-aggregated protein state facilitated the adsorption of proteins at the interface, thereby enhancing the foaming capacity. This study contributes to a profound theoretical understanding of the mechanisms governing the foaming properties of egg white proteins F-T cycles, and provides crucial mechanistic insights for optimizing the processing of frozen eggs.