Advanced Bacteriophage-Loaded Nanofiber Coatings for Active Food Packaging

Abstract The food industry faces significant challenges from microbial contamination, particularly by Salmonella , a leading cause of foodborne illnesses. Bacteriophages offer a promising biocontrol strategy due to their host specificity, safety, and environmental sustainability, but their practical application is limited by stability issues. This study presents a scalable approach to develop phage-functionalized antimicrobial packaging by electrospinning Felix O1 phage-loaded nanofibers composed of a dual hydrophilic polymer blend of sodium alginate and hydroxypropyl methylcellulose (HPMC) directly onto food-grade substrates (parchment paper and polystyrene). Parchment paper coatings achieved higher phage loading (≈10 9 PFU/mL) compared to polystyrene (≈10 8 PFU/mL), with thicknesses of 46.5 ± 0.24 µm and 59.7 ± 0.94 µm, respectively. Contact angles decreased from 107.6 to 45.7° on parchment and from 91.4 to 70.1° on polystyrene, indicating increased hydrophilicity, while water vapor transmission remained largely unchanged. Phage release exhibited a burst pattern, reaching ~ 100% release from parchment and films within 20 min, and 93.5% from polystyrene in 40 min. Antibacterial testing against Salmonella enteritidis demonstrated substrate-dependent efficacy. The electrospun films achieved the highest antimicrobial performance, with a 2.95 log reduction in bacterial counts, followed by coated parchment paper (2.05 log reduction), whereas polystyrene coatings exhibited a comparatively lower reduction of 0.76 log. These results were consistent with inhibition halo diameters of 24–25 mm for films, 16–17 mm for coated parchment, and slightly lower activity for polystyrene coatings. FTIR and mechanical analyses confirmed polymer deposition and improved tensile strength, particularly on parchment. These findings demonstrate that substrate surface properties strongly influence nanofiber deposition, phage incorporation, release kinetics, and antimicrobial efficacy. This work is the first to integrate bacteriophages into a dual-polymer electrospun nanofiber matrix directly applied to real-world food packaging, providing a practical and scalable strategy for active antimicrobial packaging.