Regulation of goat whey protein complex interfacial structures by gum Arabic to improve emulsion performance for curcumin delivery and application.

Hydrophobic bioactive ingredients are often encapsulated within emulsion-based delivery systems to enhance their dispersibility, stability, and nutritional impact. Designing appropriate interfacial structures around the oil droplets in these systems is crucial for achieving these objectives. In this study, the effects of the interfacial structures regulated by gum Arabic on the properties of oil-in-water emulsions were investigated, including their physicochemical properties, physical stability, delivery properties, and potential practical applications. Oil-in-water emulsions were prepared that contained oil droplets coated using goat whey protein (GWP) and/or gum Arabic (GA). These emulsions were designed to contain different interfacial structures: GWP-only; GA-only; GWP-GA physical mixtures; GWP/GA bilayers; and GWP-GA conjugates. The presence of GA significantly increased protein adsorption, as well as the thickness of the interfaces formed around the oil droplets. Emulsions with GWP and GA interfaces had better resistance to heating, salt addition, and lipid oxidation than the other emulsions. Droplets containing both GWP and GA in their interfacial layers also had enhanced light stability and increased curcumin bioaccessibility, with the GWP-GA conjugates being the most effective at improving emulsion performance. The potential of using GWP-GA conjugate emulsions as additives in goat milk beverages was assessed through colorimetric, electronic nose, and sensory evaluation tests. These emulsions masked unpleasant flavors and enhanced the color of goat milk. This study underscores the importance of optimizing interfacial structures based on adding anionic polysaccharides when designing emulsions for functional foods and beverages with enhanced performance.