Pickering stabilizers with additional antioxidant, photostabilizing, and metal-chelating properties are suitable for structuring multifunctional Pickering emulsion systems. Tannic acid (TA) is a potential material which when adsorbed onto the interface may impart antioxidant, UV-light-shielding, and chelating properties to Pickering stabilizers. Herein, we report a type of TA polyelectrolyte nanoparticles (NPs) fabricated following a complexation between TA and aminated sugar beet pectin (SBP-NH2). This study is geared toward investigating the performance of TA/SBP-NH2 NPs in stabilizing Pickering emulsions and protecting β-carotene from degradation. TA/SBP-NH2 NPs formed under optimum conditions had a mean diameter of 82 nm with a sphere-like shape. Because of their favorable surface wettability (91.2°), TA/SBP-NH2 NPs promoted formation of the low-, medium-, and high-internal-phase Pickering emulsions (HIPEs) in an oil volume fraction (φ)-dependent manner; the TA/SBP-NH2 NP-stabilized HIPE demonstrated viscoelastic properties increasing with the increasing concentration (c) of nanoparticles. Due to the excellent storage stability and UV light-absorbing capacity, the photostability of β-carotene was significantly improved by a TA/SBP-NH2 NP-stabilized HIPE (φ = 0.75; c = 3 mg/mL). Altogether, this study highlights that TA/SBP-NH2 NPs have potential applications in structuring Pickering emulsions with improved protective effects on loaded lipophilic compounds.
Keywords: Pickering emulsion; aminated sugar beet pectin; nanoparticles; tannic acid.