October 9, 2019
By Top Crop Manager
The mycotoxin OTA forms exclusively in storage and is carefully monitored by end users such as food processors.
A recent spate of wet weather across the Prairies has increased the potential for the formation of ochratoxin A (OTA), a potent mycotoxin that forms in high moisture conditions in cereals storage.
“With the current conditions in Western Canada, it is important that growers are aware of OTA and the conditions under which it can form,” says Brenna Mahoney, director of communications and stakeholder relation for Cereals Canada. “By understanding what OTA is and how and when it forms during storage, growers can take proactive steps to safely store their grain and keep it free of OTA.”
OTA is produced by Penicillium verrucosum, a naturally occurring soil fungus. Unlike deoxynivalenol (also known as DON or vomitoxin) which is formed in the field, OTA forms exclusively in storage. OTA is strictly regulated in Europe but not yet in Canada or the USA. However, because of its potential risk to human health, OTA is carefully monitored by end users such as food processors, CFIA/Health Canada, and the US Food and Drug Administration.
The most common source of Penicillium verrucosum spores is from soil particles, last year’s stored grain, grain handling equipment, and residues remaining in the bin. Penicillium can grow in small pockets of wet grain, or when water comes in contact with grain – even in bins that are generally well managed and properly aerated.
The most common source of Penicillium verrucosum spores is from soil particles, last year’s stored grain, grain handling equipment, and residues remaining in the bin.
Growers are urged to adhere to the following protocols for safe storage to mitigate the risk of OTA forming in their grain:
- Keep bins and grain handling equipment clean, thoroughly cleaning dust and debris between grain lots.
- Ensure crops are harvested or dried to a safe level for storage.
- Cool the grain quickly to well below 10 C and keep it cool for as long as possible to minimize condensation in the bin. Even fine droplets of condensate can allow the fungus to grow.
Cereals producers are encouraged to visit keepingitclean.ca/cereals/storage for further information on OTA and how it forms, along with visual examples of OTA formation at critical points of handling and storage.
Prevention of even small pockets of OTA-contaminated grain during storage is the only way that it can be managed to protect health and prevent product recalls. By taking steps to prevent the formation of OTA in stored grain, growers can protect their investments and help keep markets open for all.
Keep it Clean! is an initiative by the Canola Council of Canada, Cereals Canada and Pulse Canada to provide growers with the information they need to ensure their crops are market ready.