Aflatoxins Fifty Years Later: Still Unsolved Challenge

Aflatoxins were discovered after the massive death of turkeys in the UK more than 50 years ago. These toxins, secondary metabolites of moulds classified in Aspergillus section Flavi, present a high health hazard due to their cytotoxic, genotoxic immunosuppressive and teratogenic effects on humans and animals. Therefore, the concentration of aflatoxins in food and feed commodities is limited by law in almost all countries. The contamination with aflatoxins can occur on different plant and animal derived substrates (seeds, dried fruit, cheese, dried meat), but seeds, especially the oily ones, are considered the major vehicle of aflatoxins in the food chain. After the ingestion, aflatoxins can be transmitted along the food chain either unchanged or metabolised in other more or less toxic forms, like aflatoxins M-1 in milk The aflatoxigenic moulds require relatively low water activity for their growth (a(w) >= 0.7) and consequently contamination of seeds with aflatoxins can occur in the field or during any phase of postharvest processing and storage. In the last decade, probably due to climate changes, the contamination in the fields also occurs more frequently in European countries where, in the past, the presence of aflatoxins in food and feed was related to imported raw materials or inadequate storage. Different strategies, either prevention or detoxification, have been applied to control the presence of aflatoxins in food and feed but none of them has completely solved the problem. The research of new, more environmentally friendly strategies and tools in aflatoxin control is still ongoing.