Efficacy of Kleinia odora Essential Oil on Aspergillus flavus Link Ex Fries Growth and Aflatoxin B1 Production

Aflatoxin contamination in food products continues to be one of the most important food safety concerns worldwide. Aspergillus flavus and A. parasiticus are the primary producers of aflatoxins. Among the different aflatoxin types aflatoxin B1 (AFB1) is the most harmful foodborne mycotoxin. In this study, essential oil (EO) was extracted from Kleinia odora and its effect on A. flavus growth and AFB1 production was evaluated under in vitro condition. K. odora EO (KOEO) effectively suppressed A. flavus growth which resulted in a 43.1% reduction in mycelial weight over the control at a dose of 100 μL/50 mL of medium. The KOEO suppressed the toxin production by A. flavus in a dose-dependent manner and suppressed AFB1 production up to 93.7% at the concentration of 100 μL/50 mL as determined by liquid chromatography-mass spectrometry analysis. The chemical analysis of KOEO by gas chromatography-mass spectrometry showed the presence of ledol (21.0%), caryophyllene (12.0%), gamma-curcumene (10.2%), 4(10)-thujene (9.9%) and D-limonene (7.6) as major constituents. These compounds have been demonstrated to have a wide range of biological properties including antimicrobial activity. These results suggest that KOEO has huge potential to be used as a bio-preservative to suppress A. flavus growth and to minimize aflatoxin contamination in food products.