Enhancing stability of fermented egg white gels: Influence of guar and xanthan gum addition order during yogurt-like fermentation

Egg white gels prepared through fermentation, similar to yogurt production, offer a high-protein, zero-fat alternative to traditional dairy products. This study investigated the impact of guar gum (GG) and xanthan gum (XG) as rheological modifiers on the stability of fermented egg white gels. Rheological analysis revealed that the addition of both gums significantly influenced gel properties, with XG demonstrating superior performance. Specifically, XG-containing gels exhibited increased viscosity and enhanced viscoelasticity compared to GG-containing and control gels. Low-field nuclear magnetic resonance (LF-NMR) analysis showed reduced water mobility in XG-added gels, indicating improved water retention. Furthermore, syneresis rates were notably lower in XG-modified gels, especially when the concentration exceeded 0.3 %, indicating an improved system stability. Fourier transform infrared (FTIR) spectroscopy analysis indicated structural changes in the protein secondary structure, with an increase in β-sheet content in XG-added gels. Notably, the addition of GG and XG prior to fermentation facilitated protein co-aggregation, aiding in the reduction of syneresis rates. However, incorporating GG and XG after fermentation offered superior stability to the gel, achieved through a surface modification process that minimized water loss compared to pre-fermentation addition. These findings reveal how optimizing protein-gum interactions enhances gel stability and functional properties, advancing the design of stable, high-protein, non-dairy gel systems.