Sophorolipid-mediated green synthesis of silver nanoparticles for antimicrobial starch nanocomposite films

This study aimed to synthesize silver nanoparticles with sophorolipids (AgNP-SL) and develop starch nanocomposite films with improved properties to be explored in food packaging applications. AgNP-SL were spherical and highly stable, with an average size of 61.46 nm. They also demonstrated potent antibacterial action against Escherichia coli and Staphylococcus aureus, revealing its promising application for antimicrobial packaging. The addition of AgNP-SL into films resulted in color changes, which could contribute to a better UV-barrier capacity. Nanoparticles and tartaric acid incorporation resulted in a heterogeneous matrix, suggesting chemical interactions between the compounds and the biopolymer. The nanocomposite films presented thermal stability, enhanced flexibility, and antimicrobial action against E. coli, Salmonella enterica serovar Enteritidis, and S. aureus. The combination of AgNP-SL and tartaric acid resulted in pronounced bactericidal properties. The results demonstrate the great potential of these nanocomposite films as an effective packaging material against foodborne pathogens. AgNP biosynthesis by sophorolipids and nanocomposite films development. image