Essential Oil Extracted from Cymbopogon citronella Leaves by Supercritical Carbon Dioxide: Antioxidant and Antimicrobial Activities

Hong Wu; Jilie Li; Yuan Jia; Zhihong Xiao; Peiwang Li; Yixian Xie; Aihua Zhang; Rukuan Liu; Zewen Ren; Mengrui Zhao; Chaozhen Zeng; Changzhu Li

doi:10.1155/2019/8192439

Essential Oil Extracted from Cymbopogon citronella Leaves by Supercritical Carbon Dioxide: Antioxidant and Antimicrobial Activities

J Anal Methods Chem. 2019 Jan 2:2019:8192439. doi: 10.1155/2019/8192439. eCollection 2019.

Authors

Hong Wu^{1

2

3}, Jilie Li¹, Yuan Jia¹, Zhihong Xiao^{2

3}, Peiwang Li^{2

3}, Yixian Xie¹, Aihua Zhang^{1

2

3}, Rukuan Liu^{2

3}, Zewen Ren¹, Mengrui Zhao¹, Chaozhen Zeng¹, Changzhu Li^{2

3}

Affiliations

¹ Key Laboratory of Cultivation and Protection Co-constructed for Non-wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China.
² Key Laboratory of State Forestry Administration on Utilization Science for Southern Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, China.
³ Hunan Engineering and Technology Research Center of Lipids, Changsha 410004, China.

Abstract

To improve essential oil quality, especially to reserve the thermal instability of compounds, supercritical CO₂ extraction (SFE) was applied to recover essential oil from Cymbopogon citronella leaves. A response surface methodology was applied to optimize the extraction process. The highest essential oil yield was predicted at extraction time 120 min, extraction pressure 25 MPa, extraction temperature 35°C, and CO₂ flow 18 L/h for the SFE processing. Under these experimental conditions, the mean essential oil yield is 4.40%. In addition, the chemical compositions of SFE were compared with those obtained by hydrodistillation extraction (HD). There were 41 compounds obtained of SFE, while 35 compounds of HD. Alcohols and aldehydes were the main compositions in the essential oils. Furthermore, the antioxidant activities and antimicrobial of essential oils obtained by HD and the evaluated condition of SFE were compared. Results showed that the antioxidant activities of SFE oil are better than those of HD. Minimum inhibitory concentrations (MICs) were determined by the microdilution method. Essential oil obtained from SFE and HD exhibited a significant antimicrobial activity against all tested microorganisms. It is confirmed that the SFE method can be an alternative processing method to extract essential oils from Cymbopogon citronella leaves.