Strategically Designed Coaxial Electrospun Nanofibers of Polylactic Acid/Glycerol Monolaurate Hydroxypropyl-γ-Cyclodextrin Inclusion Compound with Sustained Release for Active Food Packaging

Post-harvest deterioration in strawberries is an urgent and critical issue that requires significant attention. Glycerol monolaurate (GML), a broad-spectrum food-grade antimicrobial agent, faces limited applicability due to its poor water solubility. In this study, a confined encapsulation strategy was employed to encapsulate GML within hydroxypropyl-<i>γ</i>-cyclodextrin (HP<i>γ</i>CD), which improved the physicochemical properties of GML and enhanced its stability in the environment. The fiber morphology was observed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirming the presence of a uniform, non-nodular core-shell structure. The Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) validated the successful encapsulation of GML within the cavity of HP<i>γ</i>CD. Thermogravimetric analysis (TGA) demonstrated that the thermal stability of the core-shell system was significantly improved. In vitro release followed first-order kinetics (R² = 0.9842), with 79.5% of GML released over 68 h. The DPPH and ABTS assays demonstrated that PLA/GML-HP<i>γ</i>CD NF exhibited sustained radical scavenging activity (<i>p</i> < 0.05, ANOVA). Compared to GML-HP<i>γ</i>CD NF, PLA/GML-HP<i>γ</i>CD NF exhibited prolonged antibacterial activity against Escherichia coli and superior antifungal efficacy in strawberry preservation. Meanwhile, PLA/GML-HP<i>γ</i>CD NF significantly reduced lesion diameter and weight loss while maintaining hardness, total soluble solids, and vitamin C content over 8 days of storage. In conclusion, these characteristics highlighted the potential of P/G-HP<i>γ</i>CD NF as a promising active packaging material for extending the shelf life of perishable fruits.