The moisture-releasing effect of lysozyme and its differential regulation of the thermal gelation properties of egg white in combination with arginine/lysine

Egg white gel has adverse effects due to the heat induced aggregation of egg white solution, while the specific role of lysozyme during the heat-induced aggregation and subsequent gelation stages is still unclear. In this paper, the role of lysozyme in the process of thermal induced aggregation and thermal gel formation of egg white and the mechanism of its interaction with Arg/Lys were studied. The results showed that the absence of lysozyme had higher turbidity and average particle size of heat induced egg white, water holding capacity of gel and the proportion of bound water than that of lysozyme in the presence of lysozyme, which was due to the weakening of hydrophobic interaction and disulfide bond, as well as the formation of pore structure. Lysozyme and arginine tend to form a uniform and dense gel network, showing higher hardness, chewiness and water retention. On the contrary, lysine and lysozyme tend to form a fibrous porous gel network intertwined with each other, which has relatively low water holding capacity but high hardness. This study provides multi-dimensional insights into the formation process and cross-linking mode of lysozyme in gel network, reveals the mechanism of Arg/Lys differential regulation of gel structure and performance through different paths, and provides a theoretical basis for improving the quality of egg white gel after heat treatment.