Improving Antibacterial Activity of Edible Films Based on Chitosan by Incorporating Thyme and Clove Essential Oils and EDTA

The objectives of this study were to study the antibacterial effect of thyme and clove essential oils as well as their synergistic effect with chelating agent (EDTA) from chitosan-based edible films against gram-positive and gram-negative bacteria. Thyme and clove essential oils were incorporated into chitosan-based edible films at 0.5, 1 and 1.5% v/v both alone and in combination with EDTA at 5 mmol. Films containing thyme essential oil revealed larger inhibitory zones than those of containing clove essential oil. EDTA enhanced antimicrobial effects of essential oils against both gram-positive and gram-negative bacteria. The results of this study showed that thyme and clove essential oils in combination with EDTA have a good potential for using with chitosan to make antimicrobial edible films and coatings for various food applications.