An Emulsion Gel Made by Waxy Maize Starch Hydrogel Incorporated With Tea Polyphenols/Exopolysaccharides: Structure and Stability Properties, Antioxidant and Delivery Function

To explore the structure and stability properties of emulsion gel made by waxy maize starch (WMS) hydrogel incorporated with tea polyphenols (TPs) and exopolysaccharides (EPS). The structural properties (including microstructure), rheological properties, emulsifying properties, antioxidant properties and delivery function of emulsion gel were studied. The results demonstrated that the addition of TPs and EPS resulted in an increased pore size within the WMS hydrogel network, thereby enhancing its viscoelastic characteristics. Confocal laser scanning microscopy images revealed that varying concentrations of TPs led to distinct coating structures around oil droplets. Notably, the hydrogel containing 20% TPs exhibited an optimal encapsulation to oil droplets, contributing to a stable state for storage up to 30 days because of forming a uniform layer that effectively inhibited droplet aggregation. Moreover, WMS-TPs hydrogels supplemented with EPS showed significantly higher scavenging efficiency compared to those without EPS. Specifically, the WMS-20% TPs-EPS achieved a radical scavenging rate of 97.87±2.42%, surpassing other experimental groups. These findings indicate that WMS-TPs-EPS hydrogels can serve as effective food-grade matrix materials for stabilizing emulsion gel while enhancing their antioxidant properties, offering significant potential for the development of novel starch-based emulsion delivery systems in the food and pharmaceutical industries.