Why it’s critical to avoid relying on colour sorting to fix the ergot problem

Ergots contain large amounts of mycotoxins (ergot alkaloids), therefore highly contaminated grain can pose a risk to both animal and human health. Furthermore, as of 1 January 2022, the EU reduced ergot sclerotia limits from 0.05% to 0.02% in unprocessed grain, highlights UK Flour Millers’ Joe Brennan.

“It also established maximum levels for ergot alkaloids in processed cereal products such as flour. Although this applies to the EU and NI, many GB customers sell flour or flour-based products into this marketplace, so it affects a significant proportion of food cereal demand.”

He says it’s very difficult to control ergot alkaloids in grain relative to the very low legal limits in processed cereal products. “So there’s a mis-match between the ergot sclerotia limit in wheat and the ergot alkaloid limit in processed cereal products.

“A study found if milling wheat containing ergot sclerotia at the EU/ NI legal limit of 0.02% results in white flour with ergot alkaloids of around 350parts/Bn, this is well above the legal limit of 100parts/Bn. The EU regulations don’t actually make sense.

“This is why many mills have stricter limits for ergot sclerotia in grain with some having a zero tolerance, which reaffirms the importance of vigilance.”

Perhaps concerningly, although removing sclerotia from grain reduces the ergot alkaloid content, this isn’t always to zero, as demonstrated through AHDB-funded research by Niab.

The work suggests this is due to various reasons, for one, through the transfer of dust or residue to the grain. “Equally, when you disturb infected grain, this can cause the sclerotia to fragment, making it more difficult to clean. Plus, the efficacy of colour sorting for small ergot pieces and grassweed ergot isn’t currently clear,” continues Joe.

Secondly, ergot infections have also been proven to lead to ergot alkaloids in ‘healthy’ grain above and below the infection site, as indicated by Niab’s research.

“Both of these forms are effectively invisible to a mill intake and rapid testing for alkaloids isn’t currently available. This should prove a strong incentive to tackle ergot at the point of infection to avoid background levels of alkaloids,” concludes Joe.

This article was taken from the latest issue of CPM. For more articles like this, subscribe here.

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