Practice Safe Storage to Prevent OTA in Cereals

Moisture and temperature are the two biggest factors in grain spoilage. Making sure the grain that goes into the bin has been dried to an optimum moisture level and checking the bins frequently to monitor temperature and identify any issues early will reduce the chances of spoilage. 

When it comes time to store cereals, one of the best things a grower can do for their grain is to ensure that it’s dry and kept cool – well below 10°C.

Ochratoxin A (OTA), is a potent, naturally occurring mycotoxin that can form on stored cereal grains in high moisture conditions. OTA is produced by Penicillium verrucosum a naturally occurring soil fungus; but, unlike deoxynivalenol (also known as DON or vomitoxin) which is formed by fusarium infections in the field, OTA forms exclusively in storage. 

OTA can be a risk to market access as countries can have different maximum allowable limits of OTA in grain. Make sure to monitor this regularly throughout the storage season, and to remove a minimum of one-third of bins if there’s a detectable temperature rise. Not doing so risks the development of OTA.

Preventing even the smallest pockets of OTA-contaminated cereals during storage is the only way to manage OTA and help reduce the risk of toxins being produced and avoiding product recall. OTA is not destroyed with heat or processing, so it can persist in grain/grain products. By taking steps to prevent the formation of OTA in stored grain, farmers can protect their investments and help keep markets open for all. 

The most common cause of OTA is from contaminated soil particles, last year’s stored grain, grain handling equipment, and/or residues remaining in the bin. OTA can develop 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.

Cooling the grain as quickly as possible and keeping it cool can help reduce the production of condensation in storage. 

No matter the crop that’s in the bin, Keep it Clean recommends checking them frequently and following these best management practices for safe storage: 

• Keep bins and grain handling equipment clean.  
• Thoroughly clean dust and debris between grain lots. 
• Ensure crops are harvested or dried to a safe level for storage. 
• Do not blend tough/damp grain with dry grain on-farm – it’s too risky. 
• Cool the grain quickly to well below 10°C to achieve uniform, cold temperatures throughout the bulk, ideally well below zero. 
• Monitor bins regularly. Move at least one-third of the grain out of the bin with any detectable temperature rise.  
• Condition grain as soon as possible in the spring, as soon as ambient temperatures allow for drying. 

By keeping an eye on your bins and taking these steps to maintain the quality of your stored cereals grains you can protect both its marketability and your investment. 

See 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. Managing storage is one of our 5 Tips to keep your crops ready for market. By properly storing your cereals, you can protect your investment and help keep markets open for all.