Aflatoxins are toxins produced by certain Aspergillus moulds that grow on crops that were dried too slowly, dried incompletely or stored damp. Commission Regulation (EU) 2023/915 sets maximum levels for the relevant spice lines, and no decontamination treatment removes them once formed.
Why it works this way
The organism needs available water. If a crop reaches a low water activity quickly and stays there, the mould does not establish. Where drying is delayed by wet harvest weather, or where a lot is packed before moisture has equalised through the batch, the wet fraction supports growth even though the composite sample looks compliant.
The critical point is that the toxin outlasts the mould. Killing the organism – by steam, by irradiation, by any process – leaves the aflatoxin behind, because these are chemically stable molecules. A treated lot with a mycotoxin problem still has one. This is the most consequential misunderstanding in the category.
Distribution is also extremely uneven. Contamination concentrates in a small number of particles, so a single grab sample is close to meaningless. Sampling plans for mycotoxins are built around large composite samples for that reason, and the sampling error usually exceeds the analytical error.
What follows in practice
Control it upstream: fast drying, conditioning before packing, dry storage, and colour sorting where the commodity allows it. Then verify with testing to a defined sampling plan, and require the plan in the contract rather than only the limit.
Read the maximum level in the consolidated text for the specific commodity line, not from a number quoted on a specification sheet. Irradiated against non-irradiated spices explains why the treatment decision is separate from this one.