Irish project shows the mycotoxin situation in the grain industry

Scientists have been looking at mycotoxin problems in Ireland’s grain sector to better protect consumers.

Ireland is a major producer of oats and barley. Although part of the production is used as animal feed, a significant part is used in the food and beverage industry.

Chris Elliott, a former professor of food security at the Institute for Global Food Security at Queen’s University Belfast, and a team of researchers took on the work. The prevalence of certain mycotoxins and approaches to their measurement and control were examined. Safe food published the findings.

Typical foods derived from oats include breakfast cereals, breads, cookies, infant food, muesli, granola bars and oat dairy alternatives. Barley is used in the production of breakfast cereals, malt vinegar and in various cooked foods.

Analysis of oats has shown that mycotoxins T-2, HT-2 and ochratoxin A pose an ongoing challenge to the industry. Processing, such as peeling, is sufficient to reduce the concentrations of T-2 and HT-2 in oats. The observed contamination of oats with ochratoxin A has reinforced the importance of adequate drying, storage, monitoring and control.

Data analysis highlighted higher contamination levels in conventionally produced oats compared to organic systems. The use of fungicides and the storage of oats in farm stores led to increased mycotoxin contamination. Preharvest application of fungicides and postharvest storage conditions of oat crops are critical control points for mycotoxin management.

Prevalence of mycotoxins and updated rules
A study of oats and barley from Ireland and Great Britain found that T-2 and HT-2 were found in 94 percent of samples. The number of samples analyzed was 281: 229 oat and 52 barley samples.

In total, 35 percent of the oat samples were contaminated with more than one mycotoxin. In 16 percent of unprocessed oat samples, T-2 and HT-2 levels combined exceeded EU legal limits.

No exceedances were observed for processed oat samples. Ochratoxin A limits were exceeded in 3 and 6 percent of raw and processed oat samples, respectively, indicating storage problems or inadequate grain drying.

The report was prepared before the EU introduced revised maximum limits for T-2, HT-2 and DON (deoxynivalenol) in grains and grain products. Scientists said the changes would have serious consequences for the grain industry, as increased oversight and mitigation strategies would place an additional burden on farmers and producers. A higher rate of non-conformities could lead to greater economic losses for the sector and more food waste.

Another study involved 310 oat samples collected from farmers and oat processors across Ireland between July 2021 and September 2022. The results show that contamination with Fusarium mycotoxins, specifically T-2 and HT-2, affects oat producers. T-2 and HT-2 toxins were detected in more than 90 percent of the oat samples. Zearalenone and deoxynivalenol were detected in 20 and 13 samples, respectively.

The testing regimes used by industry to prevent mycotoxins from entering the food chain vary. Based on the information received, researchers said that sampling and sample preparation procedures could be significantly improved.

Two of the four primary oat producers and processors tested for the Fusarium mycotoxins, T-2 and HT-2, deoxynivalenol and zearalenone. The third tested only for T-2 and HT-2, and the fourth had no testing regimen established. One company involved in barley processing says it relies on the certificate of analysis as proof of compliance and does not conduct testing.

“The knowledge gained from this project will facilitate improved practical mitigation approaches to protect public health, meet regulatory requirements and ultimately increase the resilience of the grain industry,” researchers said.

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