Encapsulation of cyclodextrin nanosponges containing quercetin in electrospun gelatin/kappa carrageenan nanofiber with antibacterial and antioxidant properties and their potential use for food packaging

The development of bioactive and biodegradable materials has gained significant attention for applications in food packaging, aiming to extend shelf life while providing functional benefits. In this study, quercetin—a natural flavonoid with potent antioxidant and antibacterial properties—was encapsulated at 5, 10, and 15 g/100 g within cyclodextrin nanosponges (NSP) and incorporated into gelatin/kappa-carrageenan (Ge-Kar) electrospun nanofibers. Morphological analysis via scanning electron microscopy revealed a substantial reduction in fiber diameter from 182.2 ± 53.5 nm for pristine Ge-Kar (80:20) to 95.4 ± 26.4 nm for Ge-Kar/NSP 15 g/100 g, attributed to modified solution properties including decreased electrical conductivity and increased surface tension. Mechanical testing showed enhanced tensile strength (6.32 ± 0.25 MPa → 8.12 ± 0.22 MPa) and modulus (202 ± 22.4 MPa → 279 ± 33.2 MPa), while thermogravimetric analysis indicated improved thermal stability with higher NSP content. Optical characterization demonstrated effective UV-blocking and quercetin-driven color modulation. Hydrophilicity and water vapor transmission analyses suggested superior barrier performance. Importantly, the controlled release of quercetin significantly increased antioxidant activity, and in vitro biocompatibility assays confirmed high cell viability over 72 h. Collectively, these findings indicate that Ge-Kar/NSP nanofibers are promising candidates for active food packaging, combining structural robustness, functional bioactivity, and biocompatibility.