Gum Arabic Modification Routes for Food Colloids and Encapsulation: Structure–Property–Process Relationships and Engineering Trade-Offs

Gum arabic (GA) is a widely used natural hydrocolloid in food processing because its protein–polysaccharide architecture combines high water solubility, low bulk viscosity, and useful interfacial activity. These attributes make GA valuable as an emulsifier, encapsulating agent, and film-forming material, but native GA is constrained by source-dependent heterogeneity, limited antioxidant functionality, relatively high dosage requirements in some emulsions, and modest barrier and mechanical performance in dried matrices. This review synthesizes recent advances in chemical functionalization, enzymatic and oxidative grafting, physical fractionation and complexation, and Maillard-type bioconjugation as routes to tailor GA for food engineering applications. Emphasis is placed on process-relevant structure–property relationships, including dynamic adsorption, interfacial rheology, emulsifying and encapsulation efficiency, bulk rheology, powder glass transition and hygroscopicity, film barrier behavior, and release kinetics. Across beverage emulsions, spray-dried powders, coacervates, coatings, and delivery systems, the evidence shows that modification must be selected according to the dominant process bottleneck, such as adsorption kinetics, oxidative stability, drying behavior, or humidity-sensitive matrix mobility. This review also identifies priorities for translation, including model-ready measurements, the management of raw-material variability, scale-up-aware processing, and sustainability and regulatory practicality. Overall, modified GA emerges as a versatile platform for designing more robust, application-specific food colloids, encapsulates, and functional coatings.