Interventional effect of compound sugar and salt on the thermal instability behavior of liquid egg yolk

Abstract

In this study, the influence of compound sugar (glucose, sucrose, trehalose, and arabinose) and compound sugar and salt (glucose, sucrose, trehalose, arabinose, and NaCl) on the thermal stability of heat‐treated liquid egg yolk was explored. The results showed that the addition of 4% compound sugar or 4% compound sugar salt could significantly enhance the heat resistance of liquid egg yolk and increase the denaturation temperature of liquid egg yolk to above 77°C. Moreover, the addition of sugar and salt could improve the functional properties of liquid egg yolk to varying degrees, allowing it to maintain excellent emulsification and soluble protein content after heat treatment. Further analysis using Fourier transform infrared spectroscopy showed that the increase in α‐helix content in liquid egg yolk treated with sugar salt also contributes to improving the thermal stability of egg yolk. The method of inhibiting egg yolk aggregation caused by heat treatment provided in this study provides a selective method and theoretical basis for the commercial production of heat‐resistant liquid egg yolk.

Potassium Chloride as an Effective Alternative to Sodium Chloride in Delaying the Thermal Aggregation of Liquid Whole Egg

“…This finding implies that the addition of KCl to LWEs can effectively impede the conformational change from α-helix to β-sheet and random coil structures. These findings confirm that increased ionic strength reduces the prevalence of ordered secondary structures (β-sheets), reduces protein collisions and contacts, and hinders protein aggregation by decreasing hydrogen bonding interactions between proteins [45,51]. Additionally, studies have indicated that an increase in electrostatic repulsion between protein molecules may contribute to a decrease in random coil content and an increase in α-helix content.…”

“…Moreover, salt shields repulsive forces among protein molecules, enhancing randomness in the aggregation and embedding of nonpolar groups and inhibiting aggregation. Consequently, salt induces disordered aggregation and elevates the temperature threshold for network formation throughout the entire system [45]. The salt concentration also affects the delay in the thermal transition temperature.…”

“…Differential scanning calorimetry (DSC) is widely used to analyze the thermal denaturation characteristics of food proteins, providing valuable insights into protein stability under heating. Protein denaturation typically involves a conformational change from ordered to disordered or from folded to unfolded [45]. To further understand the impact of KCl on thermal stability, the thermal solidification behaviors of both KCl and NaCl were analyzed.…”

“…The intensity of tryptophan fluorescence is a quantitative indicator of the exposure level of tryptophan residues, with a higher intensity indicating enhanced exposure. [45,51]. Additionally, studies have indicated that an increase in electrostatic repulsion between protein molecules may contribute to a decrease in random coil content and an increase in α-helix content.…”