Gum arabic crosslinked by 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholine chloride: Interfacial behavior and emulsification enhancement

Gum arabic (GA), as a natural emulsifier, has been broadly applied in the food industry. However, it suffers from issues such as high dosage requirements and poor emulsion stability. This study aims to prepare amide-modified GA (M-GA) by inducing endogenous amidation crosslinking in GA using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholine chloride (MMTM). Subsequently, the emulsification mechanism of M-GA was thoroughly investigated from structural and interfacial perspectives. The results indicate that crosslinking treatment extended the molecular chains of M-GA, forming larger ellipsoidal aggregates with higher molecular weight (1.27×10 6 g/mol) and surface hydrophobicity compared to control GA (C-GA). In terms of interfacial properties, although high molecular weight M-GA adsorbed more slowly at the oil-water interface, it can form a film with higher interfacial concentration, effectively inhibiting droplet coalescence. Furthermore, the emulsions stabilized by M-GA exhibited superior emulsification stability and pH stability. These findings confirm that endogenous amidation crosslinking can enhance the emulsifying stability of GA and decrease the emulsifier dosage, offering a novel approach for developing high-performance emulsifiers.