effect of chitosan-polyvinyl alcohol coatings with nisin on antibacterial properties of packaging paper

it is possible to develop new biodegradable active packaging by coating biopolymers on paper-based packaging material and also incorporating proper antimicrobial agents into coating structure. in this study bacterial contamination of two commercial cardboard were evaluated.in order to manufacture an appropriate antibacterial packaging material, coating of chitosan-poly vinyl alcohol blends with different ratios and of nisin were applied on cardboard made from recycled fibers. the antibacterial activity was investigated separately by preparing corresponding films. the results indicated that the chitosan-poly vinyl alcohol films activity against gram-negative escherichia coli bacteria are significant. the more chitosan was blended the more antibacterial activity was observed. although with incorporating nisin into film structure, the activity against gram-positive staphylococcus aureus bacteria and bacillus bacteria extracted from the board also developed. the most antibacterial activity was observed at films with 15% nisin. the results indicated the synergistic effect of antimicrobial agents with different mechanisms in fabricating active packaging materials.