Engineering methods to reduce aflatoxin contamination of corn in on-farm bin drying and storage systems

ABSTRACT

On-farm, in-bin drying of corn is weather dependent process that requires a careful selection of drying strategy in a locality to prevent reduction in the grain quality. This study simulated drying and storage of corn using different fan control methods and assessed the impact of infrared heat treatments to decontaminate corn of harmful molds spores. Fan operation considered included running the fan continuously, only at night (NANO), only during the day (NADO), at a set window of equilibrium moisture content of natural air, and when supplemented with heating of ambient air. The drying was investigated at various initial moisture contents (16 to 22%, wet basis), air flow rates (1.11 to 4.46 m³ min⁻¹[air] t⁻¹ [corn]) and corn harvesting start dates (August 15–November 15). To prevent aflatoxin contamination, freshly-harvested corn should be dried within 10 days to MC below 15% if prevailing relative humidity exceeds 86%.

KEYWORDS:

• Corn
• fan control
• in-bin drying and storage
• infrared
• quality

Acknowledgments

The author acknowledges the following for supporting this research: National Corn Growers Association courtesy of the Aflatoxin Mitigation Center of Excellence; Samuel McNeill of University of Kentucky, Carol Jones of Oklahoma State University and Sammy Sadaka.