Tannic acid-mediated reconfiguration of oat globulin fibril-based hydrogels for quercetin encapsulation: construction, mechanism and performance.

In this study, tannic acid (TA) was applied to remodel the structure of quercetin-loaded oat globulin fibrils (UF-Que), to form novel fibril-based composite hydrogels (UF-Que-TA) to encapsulate Que. The hydrogels were prepared by varying the [TA]/[UF] ratio to investigate the impact of TA on gelation behavior, microstructure, molecular interactions, and stability of Que. Physicochemical results indicated that the incorporation of TA significantly enhanced the gel strength and promoted non-covalent interactions including hydrogen bonding, hydrophobic interactions, and ionic interactions. Morphological findings proved that TA promoted the interconnection and densification of the gel network, and induced aggregation and entanglement among fibrils. Moreover, UF-Que-TA hydrogels significantly improved the thermal and UV stability of Que., had good biocompatibility, and could protect cells from oxidative stress damage by scavenging ROS free radicals. In conclusion, protein fibrils with structural plasticity, high flexibility, and encapsulation ability are expected to become advantageous carriers of hydrophobic functional active substances.