Soy dietary fiber/soy protein isolates nanoparticles to stabilize Pickering emulsion for astaxanthin delivery

Astaxanthin (AST), a powerful antioxidant, faces challenges due to its susceptibility to decomposition, poor solubility and low bioavailability. In this study, green edible plant-Pickering emulsion was prepared by soy dietary fiber (SDF) and soy protein isolate (SPI) complex nanoparticles (SSPs) and used for AST delivery. The SSPs characterized by their negatively charged fibrous rod-like structures, are primarily held together by hydrogen bonding. When the SDF/SPI mass ratio of SSPs is closed to 1:1, it exhibit good dispersibility and water-oil amphiphilicity. The storage stability test and rheological measurement showed that Pickering emulsions stabilized by SSPs have high viscosity and fluid stability, with a higher creaming index than the emulsions by separate SDF/SPI material. DPPH and ABTS free radical scavenging of AST in the 1:1 ratio of SDF and SPI stabilized Pickering emulsion, were higher( 65.5 ± 5.7% and 97.6 ± 0.5% respectively). In vitro digestion indicated that the bioaccessibility and chemical stability of AST in Pickering emulsion was 20.56% and 22.34% higher than free astaxanthin in oil (AST-O) group. Thus, Pickering emulsion stabilized by SDF/SPI complex particles is a potential delivery system for AST in the food industry.