Effect of epigallocatechin-3-gallate modification on the Pickering emulsion oxidative stability of rice bran protein-polysaccharide-phenol natural complex and antioxidant properties of interfacial particle

To enhance the oxidative stability of natural complex-stabilized Pickering emulsions (PE), insoluble rice bran protein-polysaccharide-phenol natural complex particles (IRBPPP) were modified with epigallocatechin-3-gallate (EGCG; 0-100 mg/g) under alkaline conditions. Compared to untreated IRBPPP (size: 69.04 μm; interfacial tension: 24.34 mN/m), EGCG modification at an appropriate concentration (25 mg/g) increased IRBPPP size (69.97 μm), reduced IRBPPP interfacial tension (22.11 mN/m), and increased the antioxidant capacity of IRBPPP in PE, thereby enhancing the PE oxidative stability. Compared to EGCG modification at an appropriate concentration, EGCG modification at an excessive concentration (100 mg/g) further increased IRBPPP antioxidant capacity in PE, while reducing IRBPPP size (66.79 μm) and increasing IRBPPP interfacial tension (23.46 mN/m), consequently decreasing the PE oxidative stability. Overall, EGCG modification improved the oxidative stability of IRBPPP-stabilized PE by regulating the structure, the antioxidant capacity in PE, and the interfacial adsorption properties of IRBPPP. • EGCG modification enhanced antioxidant properties of natural complex. • Appropriate EGCG modification reduced the interfacial tension of natural complex. • Appropriate EGCG modification inhibited lipid oxidation in emulsion. • Appropriate EGCG modification inhibited protein oxidation in emulsion.