Ovalbumin fibril-stabilized oleogel-based Pickering emulsions improve astaxanthin bioaccessibility

The present study aimed to enhance the bioaccessibility of hydrophobic astaxanthin (AST) by developing food-grade emulsion systems. Ovalbumin (OVA) fibrils and candelilla wax-based oleogels were prepared for the next fabrication of AST-loaded oleogel-based Pickering emulsions. The food-grade oleogel was obtained by mixing 0.7% (w/w) candelilla wax and soybean oil. The nano-scale OVA fibrils were observed by transmission electron microscope. SDS-PAGE analysis of OVA fibrils displayed the appearance of peptides with molecular weight around 10 kDa. Contact angle measurement indicated that excellent amphiphilicity endowed OVA fibrils with satisfactory Pickering emulsifier performance. The obtained oleogel-based Pickering emulsions displayed ultrastability during 90-day storage and outstanding freeze-thaw stability. Furthermore, the superiority of AST-loaded oleogel-based Pickering emulsion was further reflected in the apparently ameliorative lipolysis extent and AST bioaccessibility compared with oleogel. This work would facilitate the utilization of OVA and the development of oleogel-based Pickering emulsions with desirable nutraceutical bioaccessibility.