Zein/hyaluronic acid nanoparticle stabilized Pickering emulsion for astaxanthin encapsulation

Pickering emulsions have attracted considerable attention owing to the stability and functionality. In this study, zein/hyaluronic acid (ZH) nanoparticles were prepared and applied for stabilizing astaxanthin encapsulated Pickering emulsions. By non-covalent interaction between Zein and hyaluronic acid (HA), the conformation of zein changed and therefore improved the wettability of ZH nanoparticles. Unlike the spherical zein nanoparticles, ZH nanoparticles possessed a cross-linked structure with rough surface. Confocal laser scanning microscopy indicated that the nanoparticles accumulated at the oil-water interface. The Pickering emulsion stabilized by ZH nanoparticles exhibited high viscoelasticity and a solid-like behavior, as well as excellent stability during the storage. In vitro digestion results revealed that the presence of HA coating prevented the emulsion from pepsin hydrolysis and achieved efficient delivery of astaxanthin. This work confirmed that Pickering emulsion stabilized by ZH nanoparticles could be used as an effective deliver system for bioactive substances.