Chemical composition and effectiveness of Bay leaf and Cinnamon essential oils against Aflatoxigenic fungi

Spoilage of agricultural produce due to the action of Aspergillus spp. pose significant challenges to farmers and importer/exporter of agricultural produce. Aflatoxins are toxin produced by fungi and they contaminate food threatening food safety. Studies have shown that essential oils are capable of inhibiting the growth of Aspergillus spp. This study determined the chemical composition of the essential oils of Bay leaf and Cinnamon using Gas Chromatography-Mass Spectroscopy (GC-MS) techniques and evaluated the in vitro effect of the oils against Aflatoxigenic fungi (Aspergillus flavus, Aspergillus niger and Aspergillus parasiticus). Food poisoning technique was used to determine the inhibitory effect of the oils with radial mycelia growth of each observed and measured 24 hourly. The result of GC-MS analyses revealed cinnamaldehyde (5.83%), 3-Methyl- Benzofuran (14.49%), 2,6,6,9-tetramethyl-Tricycloundec-9-ene (10.59%) and other bioactive constituents as abundant in the essential oil of Cinnamon. Additionally, Bay leaf essential oil recorded Eucalyptol (12.30%), Eugenol (4.15%), and 2-octyl-Cyclopropaneoctanal (9.16%) among other bioactive compounds. Antifungal result revealed that both oils were active against the studied microorganisms as they were able to completely inhibit the growth of A. niger. Cinnamon oil had 92.69 and 91.27% inhibition against A. flavus and A. parasiticus respectively at 72 hr of observation, while essential oil from Bay leaf recorded 23.50% and 76.50% inhibition for A. flavus and A. parasiticus after 72 hr. Results from this study have further confirmed the antimicrobial potentials of essential oils against the tested Aspergillus spp. and their potential use in the development of natural antifungal products.