Gel-like pea protein Pickering emulsions at pH 3.0 as a potential intestine-targeted and sustained-release delivery system for β-carotene

In recent years, there is increasing interest in the development of food-grade Pickering emulsions as promising delivery systems for bioactive compounds . Our previous work reported that most of the proteins in pea protein isolate (PPI) at pH   3.0, present in the nanoparticle form, can effectively perform as a kind of food-grade Pickering stabilizers for oil-in-water emulsions (LWT, 2014). The purpose of this study was to further report that PPI-stabilized emulsions at pH   3.0 exhibited great potential to act as intestine-targeted and sustained-release delivery systems for β -carotene. The emulsions were produced by microfluidization at a specific protein concentration of 6.0% (w/v) and varying oil fractions ( ϕ ) of 0.2–0.6. The results indicated that increasing ϕ was favorable for the gel-like network strengthening of these emulsions. The gel formation was largely related to the droplet flocculation as well as inter-floc attractive interactions. The in vitro simulated digestion results showed that the release of β -carotene during the intestinal digestion of these emulsions could be well modulated by altering ϕ . The gel-like emulsion at ϕ   =   0.6 exhibited much lower release of β -carotene, but higher stability towards degradation during the digestion, than that at ϕ   =   0.3. The findings provide important information not only for the design of novel delivery systems for lipophilic bioactive components, but also for the development of plant protein-based formulations.