Fabrication and characterization of methylcellulose/chitosan active films incorporated with l-arginine and their potential in the green packaging of grapes

Active biodegradable films are in great demand as green packaging materials for extending the shelf life of food. In this study, methylcellulose (MC)/chitosan (CS) active films (AMC) were fabricated by incorporating different weight percentages of L-arginine. The fabricated active films were investigated for their physicochemical, mechanical and functional properties. FTIR, SEM and XRD results confirmed the intermolecular hydrogen bonding interaction and compatibility of L-arginine with the MC/CS film matrix, improving the mechanical properties, UV light blocking ability, water vapor barrier and oxygen barrier properties of the AMC active films. The inclusion of L-arginine improved the antimicrobial, antioxidant and packaging efficiency of the films. Compared with the L-arginine-free MC/CS film (control), the AMC active film containing 7.5% of L-arginine exhibited strong DPPH radical scavenging activity (72.28% ± 0.28) and displayed potent antimicrobial activity against E. coli, S. aureus, B. subtilis and C. albicans. Grapes packed with the AMC active film containing 7.5% L-arginine showed a limited weight loss percentage of 13.35% ± 1.07 and a restricted browning degree of 0.87 ± 0.01 over 17 days of storage. These findings suggest that the fabricated active films meet the essential prerequisites of green food packaging materials.