A nanoparticle/oil double epigallocatechin gallate-loaded Pickering emulsion: Stable and delivery characteristics

Abstract

A nanoparticle/oil double epigallocatechin gallate (EGCG)-loaded Pickering emulsion was prepared, and its stability (pH 3–9, 0–100 mmol/LNaCl, heat treatment) and delivery (bioaccessibility, controlled release) characteristics were investigated. The EGCG-loaded zein nanoparticles (ZPs) had a relatively small particle size of 69.4 nm, an encapsulation efficiency of 52.1% and an oil-water three-phase contact angle of 85.5°. The emulsion prepared with EGCG-loaded ZPs showed highly stable properties when stored at pH 3–9, in 0–100 mmol/L NaCl, with droplet size ranging from 15.4 (fresh) to 58.3 μm (100 mmol/L NaCl, 8 weeks) and creaming index increasing from 3.2 (0 mmol/L NaCl, 1 week) to 37.6% (100 mmol/L NaCl, 8 weeks). The double EGCG-loaded emulsion released less EGCG (20.1%, 2 h gastric) and exhibited increased bioaccessibility (65.2%) than that of free EGCG. Highly stable properties, less EGCG released and increased bioaccessibility of prepared emulsion demonstrate potential applications of EGCG-loaded ZPs as efficient emulsifiers in the preparation of Pickering emulsions for use in food delivery systems.