Electrospun core-shell nanofibers based on interfacial modification by sodium caseinate of zein/pullulan bilayer emulsion

In this study, electrospun core-shell nanofibers composed of zein and pullulan were fabricated by using bilayer emulsions, with sodium caseinate added as the emulsifier. The findings demonstrated that emulsions gained notable robustness after sodium caseinate was introduced. As the proportion of sodium caseinate rose, both the apparent viscosity and the elastic modulus of zein/pullulan emulsions registered a concurrent uptick, which resulted in the average diameter of electrospun fibers gradually increasing from 405.6 nm (Z1SC0P1) to 704.8 nm (Z1SC40%P1). Furthermore, the electrospun nanofibers added sodium caseinate showed higher water stability, thermal stability, and mechanical properties. The encapsulation efficiency of flaxseed oil in the electrospun nanofiber film reached 86.21% and had good storage stability. Besides, the coated flaxseed oil could be slowly released from the emulsion electrospinning core-shell fiber and maintain its antioxidant activity. This work yields critical guidance for entrapping hydrophobic actives in core–shell zein-based nanofibers fabricated via emulsion electrospinning.