Ochratoxin A production during ambient-air drying

OTA was found in the wettest treatments and not in the treatments with lower initial moisture content. Neither the presence nor the amount of OTA, or the counts of fungal colonies of P. verrucosum, showed any significant relationship to level of inoculum. This means that drying rate to avoid OTA does not need to depend on the amount of inoculum present. When drying by continuous ventilation, the risk of OTA appeared to be no greater than the risk of visible mould or significant loss of viability, and hence the time for the drying front to pass through the bed to achieve drying with low risk of OTA does not need to be reduced. Current recommendations given in the UK Grain Storage Guide for bed depth and airflow rate in drying by continuous ventilation remain appropriate.