Active-antimicrobial coatings based on silver nano-particles and natural polymers for paper packaging functionalization

According to the new promising technology called antimicrobial packaging, which was developed in the last time, the packaging materials are coated with antimicrobial agents leading to the death or inhibition of microbial growth on food surfaces. In this context, it is a high practical interest to develop an efficient process for imparting antibacterial properties to conventional cellulose paper aiming to obtain the sustainable package with high protection of foods. The aim of present study is a preliminary investigation on the combination of natural polymers (starch and chitosan) with silver nanoparticles (AgNPs) as bio-based coatings and their application onto paper surface with the aim to develop a material with specific properties for food packaging applications. For the coated paper samples that were obtained the antimicrobial activity, water and air barrier properties as well as mechanical strength have been assessed. The results demonstrated that the coatings based on starch/chitosan: AgNPs exhibit improved barrier and mechanical properties. Better properties were obtained for chitosan: AgNPs coatings. The silver nanoparticles embedded in the coating structure had as effect on the inhibition of S. enteritidis and E. coli growth also, especially for the chitosan based coatings.