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

TL;DR

Researchers developed a new food packaging material that slowly releases an antimicrobial agent to preserve strawberries and extend their shelf life.

Contribution

A coaxial electrospun nanofiber system was designed to encapsulate and sustainably release glycerol monolaurate for active food packaging.

Findings

The core–shell nanofibers showed a uniform structure and successfully encapsulated glycerol monolaurate within hydroxypropyl-γ-cyclodextrin.

The nanofibers exhibited prolonged antibacterial and antifungal activity, reducing spoilage in strawberries over 8 days of storage.

The material demonstrated sustained radical scavenging activity and improved thermal stability compared to non-encapsulated forms.

Abstract

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-γ-cyclodextrin (HPγCD), 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 HPγCD. 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-HPγCD NF exhibited sustained radical scavenging activity (p < 0.05, ANOVA). Compared to GML-HPγCD NF, PLA/GML-HPγCD NF exhibited prolonged antibacterial activity against Escherichia coli and superior antifungal efficacy in strawberry preservation. Meanwhile, PLA/GML-HPγCD 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-HPγCD NF as a promising active packaging material for extending the shelf life of perishable fruits.

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