In vitro Antimicrobial and Antioxidant Properties of Edible Coating Enriched with Cinnamomum verum Essential Oil

Food coatings are a promising strategy to improve the safety and shelf life of food products by inhibiting or retarding the growth of harmful microorganisms. The current study assessed the in vitro antibacterial and antioxidant characteristics of a coating based on natural ingredients, including whey protein isolate (WPI), nanochitosan (NCH), bacterial nanocellulose (BNC), and cinnamon essential oil (CEO). The in vitro antibacterial assay of the edible coating solution was performed against four food-born pathogens, consisting Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella Typhimurium. The antioxidant potency of the edible coating solution was evaluated by measuring its capability to scavenge free radicals. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of the coating decreased as the CEO concentration increased. The most significant difference in MIC and MBC was observed between the pure coating and the essential oil enriched coating group, which had the maximum essential oil concentration (1.5%). For Salmonella Typhimurium bacteria, this difference was 20% for MIC and 15% for MBC. For Escherichia coli, it was 15% for MIC and 20% for MBC. For Staphylococcus aureus, it was 20% for MIC and 20% for MBC. For Listeria monocytogenes, it was 15% for MIC and 20% for MBC. The antibacterial charachtristics of the coating were evaluated using the disc diffusion technique. The results showed that the coating exhibited considerable antibacterial efficacy against all tested pathogens. The coating also exhibited significant antioxidant activity (up to 5.7% more than the control group). These findings suggest that the coating based on WPI, NCH, BNC, and CEO has potential applications to improve the food safety.