Abstract
The effect of mint (Mentha viridis) essential oil (EO) on Aspergillus flavus growth and aflatoxin production was investigated in stored corn and evaluated. A. flavus was isolated from stored corn and identified as an aflatoxigenic strain. Conical flasks of 250 mL each containing 100 g of corn were sterilized by autoclave (121C, 15 lbs/in(2) for 15 min) and artificially inoculated with A. flavus approximately 10(6) cfu/mL (control sample). Other samples were inoculated in the same manner as the control, but with the addition of different values of mint EO (50, 100, 200, 300, 500 and 700 mu L/100 g corn). Mint EO was fungistatic at all concentrations, fungicidal and antiaflatoxigenic at 300, 500 and 700 mu L/100 g corn from 7 days storage up to the end of storage at 21 days. Minimum inhibitory concentration for A. flavus was found to be 200 mu L/100 g corn, and also limited the aflatoxin production to be under the safety level of 20 ppb determined by the Food and Agricultural Organization and World Health Organization. Mint EO could be used as fungicidal and antiaflatoxigenic agents for A. flavus in stored corn especially in granaries. Mint EO is safe, acceptable and extends the storage period of corn.