Study on Ultrasonic-Assisted Extraction of Essential Oil from Cinnamon Bark and Preliminary Investigation of Its Antibacterial Activity

Abstract

Ultrasonic-assisted extraction of essential oil from cinnamon bark was explored in this study. Effects of different parameters such as solvent, extraction time, powder granularity, ultrasonic power, solid–liquid ratio, and extraction temperature on the yield of essential oil were also investigated through single factor and orthogonal tests. The antibacterial activity of cinnamon oil obtained by ultrasonic-assisted extraction was preliminary determined. Results show that ultrasonic power has the largest effect on the oily yield, followed by powder granularity, time, and solid–liquid ratio. The optimized extraction conditions are as follows: petroleum ether (b.p. 60–90 °C) as extraction solvent, 165 W, 80–100 mesh cinnamon power, 40 min, and 6:60 (W/V) solid–liquid ratio, respectively. And under this condition, cinnamon oil yield can reach 14.8034 %, in which the content of trans-cinnamaldehyde is 82.62 % by HPLC analysis. Ultrasonic-assisted extraction of essential oil from cinnamon bark is feasible, and it can be used as a good alternative compared with other traditional methods. In addition, antibacterial activity assay demonstrates that cinnamon oil shows a strong inhibitory effect against Escherichia coli and Bacillus subtilis, and it can be applied as a natural antibacterial agent in many areas.