Stability and Transfer of Fusarium Mycotoxins During Oat Processing: A Review

Fusarium mycotoxins are frequent natural contaminants of oats, posing significant challenges for food safety and processing. This review critically evaluates the behaviour of major Fusarium mycotoxins, including deoxynivalenol (DON), T-2 and HT-2 toxins, zearalenone (ZEN), fumonisins (FUMs), emerging toxins and selected modified forms, throughout oat processing and in derived products. Evidence consistently shows that the most effective mitigation occurs during early physical processing. Cleaning, sorting, and particularly dehulling can substantially reduce mycotoxin levels, with reductions exceeding 80–90% reported for some mycotoxins and processing conditions, mainly through the removal of outer grain layers and defective grains in which mycotoxins are preferentially concentrated, although this results in the concentration of toxins in by-products such as hulls and bran. Subsequent operations—including milling, flaking, and fractionation—primarily redistribute mycotoxins within product streams rather than eliminate them. Conventional thermal processes, such as steaming, kilning, baking, and porridge preparation, generally lead to limited reductions due to the high thermal stability of these compounds, whereas extrusion of oat flour can achieve high reductions under specific conditions. However, mycotoxins can persist and be transferred into final products, indicating that processing alone cannot ensure complete detoxification. By integrating technological, chemical, and regulatory perspectives, this review proposes a value-chain framework to support risk assessment, industrial decision-making, and future research directions for oats.