Gastrointestinal pH-sensitive Pickering emulsions stabilized by glycosylated zein conjugates ferulic acid nanoparticles: Improving oral bioaccessibility of Coenzyme Q10

Abstract

Pickering emulsion stabilized by food grade nanoparticles with stimulus response as a targeted delivery system for lipophilic bioactive compounds has attracted people's attention. In this study, ferulic acid was used to modify saccharified zein to prepare pH-sensitive nanoparticles for stabilizing Pickering emulsion. The structure, interface behavior, stability of Pickering emulsion and gastrointestinal digestion characteristics of nanoparticles in vitro were studied. The results showed that covalent embedding of ferulic acid (ZGF-con) effectively improved the surface properties of zein nanoparticles based on glycosylation modification of zein, further regulating their behavior at the oil-water interface. In addition, the particle size of ZGF-con was small (92.93 nm), the wettability was moderate (89.85 °), and it was spherical, with orderly transition of secondary structure, which was conducive to the formation of stable emulsion at the oil-water interface. The stable Pickering emulsion formed by ZGF-con showed ideal emulsification performance, and the electrostatic repulsion between droplets and the formation of a robust spatial network structure promoted the stability of the emulsion. In addition, the encapsulation efficiency of CoQ10 in ZGF-con stabilized Pickering emulsion reached 96.11 %. In vitro simulated digestion, ZGF-con stabilized Pickering emulsion was relatively stable in the gastric acid environment, and slowly released in the small intestine, realizing the small intestine targeted release of CoQ10, which increased its bioaccessibility from 10.57 % to 56.42 %. This study provides an effective strategy for the preparation of pH-sensitive Pickering emulsion to improve the bioaccessibility of hydrophobic active ingredients.