Ultrasound-Driven Arginine/Lysine to Delay Thermal Induced Aggregation Behavior of Egg White: Temporal Coordination and Improvement of Gel Behavior

This study focused on understanding the synergistic effects of ultrasound and amino acids (arginine and lysine) in delaying the heat-induced protein aggregation process of liquid egg whites (EW) and enhancing gel characteristics, as well as the impact of the sequence of these treatments. The results indicate that the amino acid-only group had a limited effect in preventing thermal aggregation, but it could enhance the gumminess and chewiness of egg white gels. Compared to the control group CH, the group that first received lysine followed by ultrasound treatment (LU) exhibited superior gel properties, with improvements of approximately 14.35% in hardness, 36.96% in chewiness, 31.77% in gumminess, 15.76% in cohesiveness, and 36.87% in resilience. EW treated with arginine followed by ultrasound (AU) demonstrated greater potential in enhancing gel water-holding capacity, cohesiveness, and elasticity. In contrast, the LU exhibited lower turbidity, particle size, and gel color difference while showing higher gel hardness. The ultrasound treatment applied after amino acids accelerated the unfolding of protein structures, leading to enhanced hydrophobic interactions and disulfide bonds, as well as an increased β-sheet content, resulting in a more regular and ordered gel structure with tighter packing and uniform dispersion. These findings suggest that the combination of arginine and lysine with ultrasound is an effective strategy to delay thermal aggregation during the thermal sterilization process, while also enhancing the textural properties of the gel.