Formation and Stability of Core-Shell Nanofibers by Electrospinning of Gel-Like Corn Oil-in-Water Emulsions Stabilized by Gelatin.

Core-shell nanofibers were fabricated by electrospinning of gel-like corn oil emulsions stabilized by gelatin. The oil-in-water (O/W) emulsions satisfied the Herschel-Bulkley rheological model and showed shear-thinning and predominantly elastic gel behaviors. The increasing oil fractions (φ) ranging from 0 to 0.6 remarkably increased the apparent viscosity and then led to an increase in the average diameter and encapsulation efficiency of electrospun fibers. Core-shell structured fibers by emulsion electrospinning were observed in transmission electron microscopy (TEM) images. The encapsulated oil was found to randomly distribute as core, especially inside the beads. The binding of corn oil to gelatin was mainly driven by noncovalent forces. These core-shell fibers at various φ values (φ = 0.2, 0.4, 0.6, and 0.8) showed a high thermal decomposition stability upon heating to 250 °C, and the denaturation temperatures were 85.32 °C, 77.97 °C, 82.99 °C, and 87.25 °C, respectively. The corn oil encapsulated in emulsion-based fiber mats had good storage stability during 5 days. These results contributed to a good understanding of emulsion electrospinning of food materials for potential applications in bioactive encapsulation, enzyme immobilization, and active food packaging.