Arginine-carboxylated pullulan, a potential antibacterial material for food packaging

Pullulan possesses excellent film-forming properties and oxygen isolation capabilities. However, it exhibits limited antibacterial properties and poor water resistance, thereby hindering its application in the field of food preservation. In this study, we synthesized D-arginine-succinic anhydride-pullulan (Arg-SA-Pul) by carboxylating pullulan and subsequently grafting it with D-arginine. The antimicrobial test demonstrated that Arg-SA-Pul exhibited comparable antibacterial activity against Escherichia coli and Staphylococcus aureus. Using Arg-SA-Pul as the primary material and glycerol as the plasticizer, we fabricated an antibacterial film via the tape casting method. The film's light transmittance, water solubility, and water vapor permeability were evaluated. Compared to the natural pullulan film, the Arg-SA-Pul film exhibited lower vapor permeability. Additionally, we conducted preservation tests on cherries by coating them with the Arg-SA-Pul film. The results demonstrated that the Arg-SA-Pul film exhibited a significant preservation effect on cherries and effectively delayed their ripening and senescence. In the future, the Arg-SA-Pul film could be employed as a bacteriostatic preservation material to extend the shelf life of fruits.