Chemical composition of Cymbopogon citratus essential oil and its effect on mycotoxigenic Aspergillus species

Abstract

This study evaluated the antifungal activity of essential oil of Cymbopogon citratus (Poaceae) against five mycotoxigenic species of the genus Aspergillus (Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Aspergillus niger and Aspergillus fumigatus) isolated from maize samples. The oil of C. citratus was obtained by hydro-distillation and analysed by Gas Chromatography – Mass Spectrometry (GC-MS). The oil was dominated by monoterpene hydrocarbons which accounted for 94.25% of the total oil and characterised by a high percentage of geranial (39.53%), neral (33.31%), and myrecene (11.41%). The antifungal activity tests showed that the oil was active against all the five Aspergillus species. The extent of inhibition of fungal growth was dependent on the concentration of the oil. The activity of the oil against the mycotoxigenic fungi had Minimun Inhibitory Concentration (MIC) values ranging from 15 to 118 mg/ml. These results show that the essential oil of C. citratus has antifungal activities against fungi that are the producers of poisonous mycotoxins found in foods. This oil can be used in food preservation systems to inhibit the growth of moulds and retard subsequent mycotoxin production. Key words: A. flavus, A. fumigatus, A. niger, A. ochraceus, A. parasiticus, antifungal.