Electrospinning of emulsions stabilized by octenylsuccinylated starch and pullulan

Emulsion electrospinning emerges as a promising technique for producing core-shell nanofibers used in delivering bioactive compounds. This work aims to investigate the feasibility of employing octenylsuccinylated (OS) starch-based emulsions in electrospinning for the fabrication of these nanofibers. The influence of sunflower seed oil concentration, ranging from 5% to 50%, on the emulsions was systematically examined. Increasing the oil concentration affects several key characteristics of the emulsions. These changes include a rise in apparent viscosity (from 0.78 to 7.72 Pa·s at 100 s⁻¹) and average droplet size (from 1.21 to 1.79 μm), as well as a decrease in conductivity (from 727 to 193 μs/cm), leading to a larger average diameter of electrospun fibers, which increased from 294 to 533 nm. Confocal laser scanning microscopy and transmission electron microscopy confirmed the core–shell structure of the fibers. Furthermore, the correlation between fiber size and emulsion properties was discussed, and it was noted that the average fiber diameter, loading capacity, and encapsulation efficiency were significantly affected by emulsion composition and properties. These insights contribute to our understanding of the emulsion electrospinning process and offer a valuable guidance for the development of OS starch-based core–shell electrospun fibers.