Antimicrobial Efficacy of GS-2 on Reusable Food Packaging Materials for Specialty Crops

The European Union (EU) regulations mandate 10% of all food packaging to be reusable by 2030. United States (U.S.) exporters of specialty crops face new challenges in ensuring microbiological food safety using reusable packaging. A novel antimicrobial formulation consisting of ammonium carboxylate salt of capric acid and L-arginine (GS-2) was recently developed as a spray coating chemical for food packaging materials. In this study, we evaluated the antimicrobial efficacy of GS-2 against microbial strains representing three foodborne bacterial pathogens (<i>Escherichia coli</i> O157:H7, <i>Listeria monocytogenes</i>, <i>Salmonella enterica</i>), one fungal spoilage organism (<i>Aspergillus niger</i>), and one surrogate viral pathogen (murine norovirus) on three reusable plastic materials (acrylonitrile butadiene styrene, high-density polyethylene, and polypropylene) and one cardboard packaging material, respectively. Different chemical concentrations, exposure times, and storage conditions were individually evaluated for the relative antimicrobial efficacies of GS-2 against these microorganisms. Our results showed that GS-2 was highly effective for inactivating bacterial pathogens on both plastic and cardboard surfaces. For instance, 3% GS-2 achieved a >5 log CFU/in² reduction in <i>E</i>. <i>coli</i> O157:H7, <i>L. monocytogenes</i>, and <i>S. enterica</i> on tested plastic surfaces at an exposure time of 60 min. However, its efficacy against <i>A. niger</i> and murine norovirus was less optimal, resulting in a ≤1 log CFU/in² reduction on all tested surfaces. Based on our study, GS-2 demonstrated a strong potential as an antibacterial coating reagent for reusable food packaging materials to minimize pathogen contamination and ensure the safety of the specialty crops.