Preparation, characterization, and antimicrobial activity of cinnamon essential oil and cinnamaldehyde nanoemulsions

ABSTRACT Cinnamomum verum essential oil and its main component, cinnamaldehyde, were incorporated into nanoemulsions to improve their stability and activity. Oil-in-water (O/W) nanoemulsions were prepared using the high-energy ultra-sonication method. Cinnamon oil nanoemulsion exhibited a more vigorous DPPH radical scavenging activity (IC50 = 1.81 mg/L) than the standard α-tocopherol (IC50 = 9.16 mg/L). Cinnamaldehyde nanoemulsion exhibited the highest antibacterial action against Salmonella typhimurium and Staphylococcus aureus (MIC = 175 and 150 mg/L, respectively). It was also displayed the highest inhibition against Candida albicans (EC50 = 19.92 mg/L). Cinnamaldehyde nanoemulsion was the most active against mycelial growth of Aspergillus flavus and A. niger (EC50 = 38.20 and 134.80 mg/L, respectively). It also presented the highest activity against spore germination. This study describes antimicrobials and antioxidants based on nanoemulsions made from natural products that can be used to treat microbial infections.