Quaternized Lignin-Loaded Electrospun Fish Gelatin Nanofibers for Active Food Packaging

This study proposes quaternized lignin (QL) as a sustainable and multifunctional additive for active food packaging applications and presents the development of fish gelatin (FG)-based nanofiber packaging materials. Cationic QL was synthesized via glycidyltrimethylammonium chloride (GTMAC) modification of kraft lignin to enhance its water dispersibility and antimicrobial properties. The resulting QL derivatives were incorporated into FG-based nanofibers via electrospinning, which were stabilized through Maillard reaction-induced cross-linking. The quaternization degree and incorporation of QL into FG nanofibers considerably affected the nanofiber morphology, mechanical properties, hydrophilicity, and structural stability. Antioxidant and antibacterial assays revealed that FG-based QL (FG/QL) nanofibers, especially those containing highly quaternized lignin (QL3), exhibited enhanced radical scavenging and bactericidal activities againstStaphylococcus aureus and Escherichia coli, which were attributed to the synergistic effect of QL and Maillard reaction products. The blueberry preservation test confirmed the practical efficacy of Maillard reaction-cross-linked FG/QL3 nanofibers in extending shelf life by inhibiting microbial spoilage. These results indicated that QL-functionalized FG nanofibers have potential applicability as biodegradable natural materials for active food packaging systems.