Characterization of transparent silver loaded poly(l-lactide) films produced by melt-compounding for the sustained release of antimicrobial silver ions in food applications

•15 thermally stable silver formulations were incorporated into PLA by melt-compounding.•Color and mechanical properties of some PLA samples were unaffected.•Sustained release of silver ions was monitored over a week exposure.•Excellent antimicrobial performance of most films on the surface and in liquid and solid foods.

In the present study, thermally stable silver complexes were produced and incorporated into a poly-(l-lactide) (PLA) matrix by melt-compounding. The effect of the different formulations on the mechanical and color properties was first evaluated. Additionally, the release of silver ions to an aqueous environment was also monitored over time by anodic stripping voltammetry and correlated with the antimicrobial performance against Salmonella enterica. The incorporation of some silver compounds with contents of 1 wt% did not affect the mechanical or optical properties of the films. The films showed a good potential for application in surface treatment and demonstrated a sustainable, antibacterial effectiveness in liquid and solid food environments. These results give new unreported insight into the production of transparent thermally stable and antimicrobial polymers based on the release of ionic silver and about their potential application in antimicrobial food packaging.