Development and structural characterization of chitosan films containing Eucalyptus globulus essential oil: Potential as an antimicrobial carrier for packaging of sliced sausage

Novel antimicrobial biopolymer films based on the incorporation Eucalyptus globulus essential oil (EGO) in chitosan were successfully developed and characterized as an active film for packaging of sliced sausage. Characterization of the films revealed that incorporation of EGO (0.5, 1.5, and 1.5%) in the biopolymer led to change in morphology, mechanical and barrier properties. Antibacterial activity of EGO was assayed against Salmonella entertidis and Escherichia coli as Gram-negative bacteria; furthermore, Bacillus cereus and Staphylococcus aureus as Gram-positive bacteria. Results showed that the EGO was able to generatean excellent antibacterial effect in liquid and vapour phases. Chitosan films with 1.5% EGO in liquid medium produced 4.22, 3.98, 4.55, and 4.71 log reduction against S. aureus, E. coli, B. cereus and S. entertidis, respectively. However, only minor population reduction of bacteria was observed in the vapour phase. The highest antibacterial activity in sliced sausage was obtained by chitosan films containing 1.5% EGO (1.01 log reduction). This work highlighted that EGO incorporation in chitosan is a promising approach in order to control risk of foodborne contamination in a real food system.