Combining plasma-induced surface activation and salt-assisted stabilization to coat polyethylene terephthalate with Ethyl Lauroyl Arginate as a novel approach to impart antimicrobial properties

While Ethyl Lauroyl Arginate (LAE) has traditionally been incorporated into polymers intended for antimicrobial packaging, its application onto polymers remains limited and its incorporation into/application onto polymers using large-scale manufacturing procedures is even more scarce. This study aimed to develop a combined plasma-induced surface activation and salt-assisted stabilization method to create an antimicrobial coating made of LAE for polyethylene terephthalate (PET) and likely other polymers. After determining the minimum inhibitory and bactericidal concentrations of LAE for Escherichia coli and Listeria innocua, active PET sheets with LAE were produced by first evaluating plasma parameters able to increase surface energy (pressure, air flow, and time) and then various aqueous salts as a top layer for the LAE coated on the plasma-treated PET. The active sheets were characterized for coating chemical structure, morphology, adhesion, LAE release, and validated for antimicrobial activity. The results showed that the LAE coating was attached to plasma-treated PET with a high cohesive force (a breaking strength σ > 234.4 kPa) when disodium phosphate (DSP) in aqueous solution was layered on top of the LAE coating. As demonstrated by the changes in the FTIR absorption bars, this is due to a combination of hydrogen bounding, ionic bounding, and van der Waals forces between DSP, LAE and PET. The coating reduced 5–8 logs of E. coli and L. innocua, and fully detached from the PET in aqueous food simulants (∼20–40 ppm of LAE). Our research shows promising results for the scalable development of antimicrobial LAE-coated PET sheets, which could reduce food deterioration, thereby promoting increased food safety.