Edible films were prepared by combining high molecular weight chitosan with sunflower oil. Films were obtained by casting and were applied to the surface of pork meat hamburgers. Chitosan-based films increased the metmyoglobin (MtMb) content of coated hamburgers during cold storage, especially when using lactic acid as a solvent. The incorporation of sunflower oil to the chitosan matrix led to a reduction in MtMb content of hamburgers as compared to samples coated with pure chitosan films. Chitosan films led to a reduction in the microbial counts of samples during storage. However, it is important to modulate the oxygen permeability of films in order to avoid undesirable effects (MtMb formation)