Zein/Shellac Composite Films with Limonin and Resveratrol: Characterization and Application for Strawberry Preservation

This study aimed to fabricate an active film incorporating limonin (LM) and resveratrol (RES) within a zein/shellac (ZS) matrix for use in strawberry preservation. Zein/shellac composite films embedded with varying concentrations of LM (0-4% <i>w</i>/<i>w</i>) and RES were successfully fabricated using coaxial electrospinning. The prepared films were comprehensively characterized for their mechanical properties, water vapor permeability (WVP), antioxidant capacity (DPPH, ABTS, FRAP), and antibacterial efficacy against <i>E. coli</i> and <i>S. aureus</i>. Mechanical properties and WVP results revealed that the ZSLM4R film exhibited an elongation at break (EBA) of 28.91%, tensile strength (TS) of 0.93 MPa, elastic modulus (EM) of 40.76 MPa, and a WVP of 1.55 g mm/m². h. kPa. Furthermore, LM and RES increased the antioxidant properties of the composite film. ZSLM4R's free radical scavenging activities against DPPH and ABTS were 68.14% and 89.69%, respectively. The composite film also demonstrated strong antibacterial efficacy against <i>E. coli</i> and <i>S. aureus</i>. When applied to strawberries, ZSLM4R packaging effectively extended the fruit's shelf life compared to the unwrapped and commercial polyethylene (PE) controls. These obtained results indicate that LM/RES-incorporated zein/shellac composites are a promising eco-friendly packaging alternative for preserving perishable fresh produce and extending its shelf life.