Alginate Biocomposite Films Incorporated with Cinnamon Essential Oil Nanoemulsions: Physical, Mechanical, and Antibacterial Properties

摘要

Alginate-based antibacterial biocomposite films were prepared by incorporating with cinnamon essential oil nanoemulsions (CEO-NE). CEO-NE was first prepared by mixing and homogenizing the oil phase and aqueous phase containing polysorbate 80 (Tween 80), using a probe-type ultrasonication equipment. The biocomposite films were then prepared by incorporating the CEO-NE to an aqueous solution of alginate and glycerol, homogenizing, casting, and drying. The mean droplet size, zeta potential, and polydispersity index of the CEO-NE were 92.2nm, -15.58mV, and 0.25, respectively. Young's modulus of the CEO-NE/alginate biocomposite films was significantly increased with an increasing concentration of CEO-NE, while their elongation at break was significantly decreased. However, the tensile strength of the CEO-NE/alginate biocomposite films was not significantly changed. The maximum tensile strength and elongation at break of the biocomposite films were 15.63MPa and 23.67%, respectively, corresponding to the biocomposite films containing 20% CEO-NE. The biocomposite films containing 20% CEO-NE also showed strong antibacterial effects against Salmonella typhimurium, Bacillus cereus, Escherichia coli, and Staphylococcus aureus, achieving inhibition zones from 29.7 to 53.0mm. These results show the potential of the CEO-NE/alginate biocomposite films as antibacterial packaging for extending the shelf life of fresh foods.