Optimized complex coacervation and tailored cross-linking of faba protein-xanthan gum complexes for enhanced...

This study examined the complex coacervation between faba protein isolate (FPI) and xanthan gum (XG), focusing on the effects of pH and FPI/XG mixing ratios. Turbidity, zeta potential, and coacervation yield analyses identified pH 4 and a 10:1 mixing ratio as the optimal conditions. The impacts of cross-linking through the Maillard reaction (MR, 3-5 h) and tannic acid (TA, 0.1-0.5 %) were also evaluated. TA treatments produced coacervates with higher surface charge and yield, as well as smaller and more uniform particles compared with MR-treated samples. Structural analyses (FTIR, XRD, and CD) showed a reduction in α-helix content and an increase in amorphous character, while TGA indicated improved thermal stability, particularly in TA-treated samples. Both MR and TA modifications enhanced solubility, surface hydrophobicity, and emulsifying activity; however, TA provided superior emulsifying stability. Molecular docking further confirmed stronger TA-mediated interactions. Overall, both cross-linking strategies improved the structural and functional properties of FPI-XG coacervates, with TA demonstrating greater efficiency in producing stable, high-performance emulsifiers suitable for clean-label food formulations.