Deoxynivalenol (DON) Testing in Food and Feed

Deoxynivalenol (DON), commonly referred to as vomitoxin, is a trichothecene mycotoxin produced primarily by Fusarium species, including Fusarium graminearum and Fusarium culmorum. These fungi infect cereal crops in the field, particularly under cool and wet conditions.
DON is most frequently associated with maize, wheat, barley and other cereal grains. Because infection occurs predominantly pre-harvest, contamination may be present even in grain that appears visually acceptable.

DON contamination is closely linked to climatic conditions during flowering and grain development. Prolonged rainfall and high humidity significantly increase the risk of Fusarium infection and subsequent toxin production.
High-risk commodities include:
‣ Maize and maize-based products
‣ Wheat and wheat-based products
‣ Barley
‣ Oats
‣ Animal feed and cereal-based premixes
DON is relatively stable and may persist through milling and certain processing steps, allowing it to enter finished food and feed products.
Co-contamination with other Fusarium toxins, such as ZEA, NIV, T-2 and HT-2 toxins, is common.

DON primarily affects the gastrointestinal tract and immune system.
In animals, exposure may result in:
‣ Reduced feed intake
‣ Vomiting (particularly in pigs and dogs)
‣ Reduced weight gain
‣ Impaired immune function
‣ Decreased production performance
Swine and dogs are particularly sensitive to DON, whereas ruminants generally show greater tolerance due to ruminal metabolism.
In humans, dietary exposure to DON has been associated with gastrointestinal symptoms and immunological effects. Although DON is not classified as a human carcinogen, regulatory limits are established to minimise chronic exposure.

DON contamination may be unevenly distributed within a grain lot, making representative sampling essential.
Analytical testing provides quantitative measurement of DON levels and supports:
‣ Verification of compliance with regulatory or guidance limits
‣ Risk-based formulation of feed rations
‣ Raw material acceptance decisions
‣ Identification of high-risk harvest seasons or origins
‣ Management of co-occurring Fusarium toxins
Multi-mycotoxin LC-MS/MS methods enable simultaneous detection of DON alongside related trichothecenes, providing a broader assessment of contamination risk.

Effective management of DON relies on:
‣ Good agricultural practices
‣ Selection of resistant crop varieties
‣ Appropriate harvesting and drying
‣ Monitoring of high-risk seasons
‣ Representative sampling and validated analytical testing
Given the strong influence of climatic conditions on Fusarium development, routine monitoring is essential in cereal-based food and feed supply chains.