Tannic acid enhanced the oxidation stability of vitamin A-vitamin D3 coencapsulated in emulsion based on OSA starch/chitosan: Interfacial absorption, antioxidation and viscoelasticity

In this work, vitamin A (VA) and vitamin D (VD3) were co-encapsulated in the emulsion stabilized by sodium octenyl succinate starch/chitosan/tannic acid (OSA-S/CS/TA) complex. The influence of TA concentration on emulsion stability was estimated, and the underlying mechanism was revealed from the perspective of interface characteristic. The TA incorporation improved the long-term and thermal stability of the emulsion. Compared with the emulsion without TA, the retention rate of VA and VD3 increased by 15.2%–24.5% after storage, and the oxidative product decreased by 23.9%–43.3% after heating. TA was anchored at the oil-water interface to reduce the interfacial tension and form the interfacial film with antioxidation and viscoelasticity. TA and OSA-S/CS were combined by hydrogen bonds at sequential two sites (ΔH1 = −36.42 kJ mol−1, ΔS1 = −0.04 kJ mol−1·K−1, ΔH2 = −2.77 × 103 kJ mol−1, ΔS2 = −9.25 kJ mol−1·K−1). The research expanded the application of TA, VA, and VD3 in food systems.