DON is a mycotoxin primarily produced by Fusarium fungi, occurring predominantly in cereal grains.
The CONTAM Panel of the European Food Safety Authority (EFSA) published a risk assessment related to four forms of DON in food and feed earlier this week.
“A key finding in the EFSA opinion was that masked DON-3-Glucoside and the acetylated forms of DON (3-Ac-DON and 15-Ac-DON) pose an equivalent risk to DON because they are readily transformed back to DON in the intestine. The acetylated forms have their own toxicity. In fact, 15-Ac-DON demonstrates greater cytotoxicity than DON itself,” Dr Timothy Jenkins, mycotoxin risk management product manager, Biomin, told us.
The EFSA panel said, for pigs, the estimated dietary concentrations indicated the risk of acute adverse health effects is low, but the experts identified a possible risk of chronic adverse health effects for that species from feed containing DON, 3-Ac-DON, 15-Ac-DON and DON-3-glucoside at the 95th percentile dietary concentrations.
They also said the estimated dietary exposures indicated a possible risk of chronic adverse health effects from feed containing DON, 3-Ac-DON, 15-Ac-DON and DON-3-glucoside for carp. However, the CONTAM Panel noted that the diet composition of different fish species may majorly differ and some fish species might be more tolerant.
Testing challenge
Jenkins said modified forms of DON pose a particular challenge for the agriculture sector, since they are not readily detected by conventional or rapid tests.
“We have analyzed 2,502 feed samples for these forms of deoxynivalenol using advanced LC-MS/MS technology. Those results show that these three DON metabolites often account for half of the total DON present. In one-third of those samples, the three other forms of DON make up at least 10% of total DON.
“These findings imply that the real on-farm threat to animals posed by deoxynivalenol could be routinely underestimated. DON metabolites are notoriously resistant to binding,” continued Jenkins.
He said Biomin’s mycotoxin survey database, which contains analysis results of thousands of feed samples taken globally since 2004, indicates that DON is the most frequent mycotoxin of concern in feed samples. The main risk comes from corn and cereals, but other commodities also commonly contain DON at levels that pose a risk for animals, he added.
Further research needed
The EFSA experts called for the research community to undertake well-designed studies that take into account practical feeding conditions for farm and companion animals to study toxicokinetics and toxicity of the four forms of DON.
The CONTAM panel also said modified forms of DON, other than those covered in the opinion, which could be potentially relevant concerning their (co-)occurrence and toxicological properties, should be investigated to further refine the human and animal risk assessment.
The full EFSA opinion can be read here.