Chitosan polymer as biloactive coating and film against Aspergillus niger contamination

The inhibitory activity of chitosan-based edible coatings and films was assessed against the Aspergillus niger food pathogen and deterioration microorganism. Spore-counting assays showed an almost total inhibition of A niger growth when either film-forming solution or film were used at a low concentration of chitosan (0.1% w/v). Epifluorescence microscopic results showed the action of chitosan on the relative proportion of RNA compared with DNA. The water vapor permeability (WVP) of chitosan film was relatively low compared with the poor moisture barrier of some polysaccharide films. Moreover, a coating with chitosan film on an agar gel, used as a food model, induced a 30% reduction in water loss. These results showed potential applications of chitosan-based films as bioactive packaging with properties to limit the food dehydration phenomenon.