Curcumin-loaded Pickering emulsion stabilized by insoluble complexes involving ovotransferrin-gallic acid conjugates and carboxymethyldextran

The present work aimed to fabricate antioxidant particle-stabilized Pickering emulsions with outstanding protection of encapsulated nutraceuticals. Antioxidant ovotransferrin-gallic acid conjugates (OTGCONJ) were prepared using the alkaline method, and the electrostatic assembly technique was utilized to construct OTGCONJ-CMD particles with OTGCONJ and carboxymethyldextran (CMD) as the building blocks. After the investigation of the particle size, insoluble nature and intermediate wettability of the OTGCONJ-CMD particles, the OTGCONJ-CMD particles were verified as eligible Pickering stabilizers. Visual observation showed that the stable OTGCONJ-CMD particle-stabilized Pickering emulsion consisted of the emulsified phase alone. Rheological analysis revealed that the Pickering emulsion had a high viscosity and a gel-like structure. In terms of the protective effect, the OTGCONJ-CMD particle-stabilized Pickering emulsion could significantly retard curcumin degradation under UV light. An in vitro digestion study revealed that the OTGCONJ-CMD particle-stabilized Pickering emulsion improved both the extent of lipolysis and curcumin bioaccessibility remarkably, suggesting that the OTGCONJ-CMD particle-stabilized Pickering emulsion was an excellent nutraceutical delivery vehicle. The novel findings in this work could have important implications for the design of nutraceutical-loaded Pickering emulsions with an excellent protective effect and nutraceutical delivery efficiency.