Design principles of oil-in-water emulsions with functionalized interfaces: Mixed, multilayer, and covalent complex structures.

Proteins and polysaccharides are widely used as ingredients in food emulsions due to their high biocompatibility, good biodegradability, and a broad range of techno-functionalities. In particular, they are used as emulsifiers, texture modifiers, and stabilizers in many emulsion-based foods. Moreover, the functionality of these biopolymers can be extended by forming protein-polysaccharide complexes that can be used to modulate the characteristics of the oil-water interface, thereby altering the stability and performance of food emulsions. This review highlights a number of approaches to modulate the interfacial properties of oil-in-water emulsions based on the utilization of protein-polysaccharide complexes: direct mixing, layer-by-layer assembly, and conjugation. Besides, the impact of altering the interfacial properties on emulsion performance is highlighted, including their formation, stability, and functional attributes. Interfacial engineering approaches can be used to tailor the properties of food emulsions to particular applications. For instance, they can be used to create emulsion-based delivery systems for bioactive agents, such as vitamins, nutraceuticals, antimicrobials, colors, flavors, and antioxidants. Moreover, they can be used to create emulsion-based foods with lower calorie contents and enhanced satiety responses. Nevertheless, it is important to account for various factors when developing successful interfacial engineering technologies, including safety concerns, production costs, environmental impact, sustainability, government regulations, and labeling issues.