Enhancing mechanical and thermal properties of zein films via shellac incorporation using coaxial electrospinning

This study aims to investigate the fabrication of composite films using coaxial electrospinning, and the interactions between zein and shellac was investigated through multi-spectroscopic methods. Spectroscopic analysis revealed that shellac quenches the intrinsic fluorescence of zein through both dynamic and static quenching mechanisms, with hydrophobic interactions and hydrogen bonding serving as the primary forces driving this interaction. The zein/shellac composite films exhibited a smooth, bead-free morphology. The addition of shellac significantly enhanced the mechanical properties of the composite films by integrating uniformly into the zein matrix, achieving a maximum tensile strength of 1.15 MPa in the Z-S6 film and an elongation at a break of 55.24%. Additionally, the thermal stability of the zein/shellac composite films improved while their barrier properties were slightly reduced. These findings suggest that incorporating shellac into the zein films enhances their physical properties for food packaging applications.