Dextran chain length dictates the interfacial properties of Maillard-conjugated 11S globulin: a molecular mechanism...

As 11S limits SPI emulsifying properties, this study investigated how dextran molecular weight regulates 11S interfacial adsorption. Maillard conjugation with 5000 Da dextran enhanced 11S flexibility and emulsifying properties, yielding a 35.0% increase in EAI (65 m²/g) and improved ESI (92%). The resulting emulsions exhibited markedly smaller and more uniform droplets (approximately 10-20 μm) compared to aggregated native 11S. Adsorption kinetics revealed a critical molecular weight dependency: 5000 Da dextran induced optimal structural transformation and interfacial reorganization, strengthening stability. In contrast, larger dextrans likely induced steric hindrance and provided limited flexibility enhancement, which may have contributed to suppressing interfacial rearrangement and limiting emulsification improvement. Based on these findings, we propose a chain-length balance model, and the results strongly suggest that Maillard glycation is an effective strategy to enhance non-glycosylated 11S functionality, elucidating a molecular weight-dependent modulation mechanism and providing new insights for improving protein emulsifying properties.