Title
Antimicrobial coatings based on chitosan derivatives and quaternary ammonium salts for packaging paper applications
Authors
PETRONELA NECHITA ELENA BOBU GEORGIANA PARFENE RODICA MIHAELA DINICA and TUDOR BALAN

Published Volume 49 Issue 7-8 July-August
Keywords food packaging paper, antimicrobial activity, paper coating, quaternary ammonium salts, chitosan

Abstract
Conventional food packaging systems are designed to act as passive barriers, protecting food against the surrounding environment, while active food packaging systems are designed to interact with surrounding medium in order to prevent harmful effects, like microbial contamination. In this paper, two (bio)active compounds – quaternary ammonium salts (QAS) and quaternary chitosan (QCh), were evaluated as potential materials to be used in formulations of antimicrobial coating for packaging paper applications. Composite particulates of QAS: ZnO at different ratios were applied on paper surface as water dispersions in a single layer, while QCh water solution of constant concentration was applied by multi-layer coating (1-3 layers). The antimicrobial activity of paper samples was evaluated against the gram-positive bacteria and against fungi, respectively. The QAS immobilized on ZnO particulates showed good antimicrobial activity against both gram-positive bacteria and fungi, which increased with QAS:ZnO ratio. The QCh films proved to be very effective for bacterial inhibition and paper strength improvement, but less effective against fungi.