Multifunctional antibacterial films with silver nanoparticles reduced in situ by lemon juice

Microorganisms contribute to deterioration of garden stuff after picking. Antibacterial films consisting of polyvinyl alcohol (PVA), soluble starch (SS), and silver nanoparticles (AgNPs) with AgNPs in situ reduced from AgNO₃ by lemon juice (LJ) were developed to combat microbial corruption. PVA/SS/LJ/AgNPs films have better tensile strength and elongation at break, but lower water vapor permeability, moisture absorption, and transmittance compared to PVA/SS and PVA/SS/LJ films. Silver released from PVA/SS/LJ/AgNPs films were 13.55, 18.97, 19.55, 20.19, 20.47, and 20.82 mg/g after submerging samples in water for three seconds and soaking for 1, 2, 3, 4, and 5 days, respectively. PVA/SS/LJ/AgNPs films had good bacteriostatic effects on Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Salmonella, as the average diameter of the inhibition circle was 12.12 ± 0.01, 13.04 ± 0.02, 14.79 ± 0.01, 14.20 ± 0.01, and 12.68 ± 0.01 mm, respectively. Therefore, PVA/SS/LJ/AgNPs film has a wide application prospect.