Facile fabrication of green synthesized silver-decorated magnetic particles for coating of bioactive packaging

To avoid bacterial and viral infections on food products, the use of antibacterial and antiviral packaging offers great benefit to the food industry. In this study, the coating of paper packaging with silver-decorated magnetic particles (Ag@Fe₃O₄) was developed. The Ag@Fe₃O₄ was prepared by a facile and environmentally friendly method using extracted spent coffee grounds (ex-SCG). The effects of Ag@Fe₃O₄ content on properties of coated paper were investigated. The overall properties of coated paper improved when the Ag@Fe₃O₄ content increased up to 0.15%w/v. An increase in tensile strength of 154.01% and a decrease in water vapor permeability of 48.50% were found in coated paper with 0.15%w/v Ag@Fe₃O₄. Furthermore, the coated paper also exhibited the synergistic effect on antibacterial activities against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The release of metal ions in food simulants and kinetic release parameters were also studied. The release of silver ions and ferrous ions in food simulants met the requirement of overall migration limit of the European Standard. The paper coated with 0.15%w/v Ag@Fe₃O₄ had better capabilities to maintain quality and extend shelf-life of tomatoes. The obtained Ag@Fe₃O₄ coated paper is promising for bioactive food packaging to retain food freshness.

The online version contains supplementary material available at 10.1007/s10570-022-04636-0.