Food safety is a major issue in Europe and all over the world. In this respect much attention needs to be paid to the possible contamination of food and feed by fungi and the risk of mycotoxin production. Mycotoxins are very common contaminants of cereals. Global surveys estimated that 25% of the world crop production is contaminated with such toxins (European Commission 2003; CAST 2003). Moreover, most mycotoxins are heat-resistant and could remain after the disappearance of the producing fungi. Mycotoxins thus raise a significant problem throughout the food chain. This problem might be amplified by the global warming and by the increased consumption of organic products, which are potentially more contaminated because of the ban of antifungal treatments in this type of production.

Mycotoxins are secondary metabolites produced by fungi, especially by those included in the genus Aspergillus, Fusarium and Penicillium. In Europe, Fusarium spp are the most worrying species due to their ecology, their physiology and the frequency of their occurrence and to the wide range of mycotoxins produced (also called fusariotoxins). For example, the incidence of Fusarium head blight on wheat is lower or absent in the southern regions of Italy than that in more temperate central regions of the country. Among fusariotoxins, three families are considered as particularly important due to their high toxicity and their incidence in European agricultural products: trichothecenes, in particular deoxynivalenol and T2/HT2 toxins, fumonisins and zearalenone. In addition to the “major” mycotoxins, Fusarium species also produce “emerging” mycotoxins that are much less characterized. Despite intensive research, efforts to control Fusarium infections and to prevent or eliminate the presence of mycotoxins in foods and feed have not been successful.

Fusarium species are able to produce simultaneously different mycotoxins; moreover food and feed can be contaminated by several fungal species at the same time. Thus humans and animals are generally not exposed to one mycotoxin but to several toxins at the same time. Co-occurrence of mycotoxins in cereals is a common situation, not an exceptional one. For example, 95% of the maize kernels harvested in France during 2004-2006, were multicontaminated: 3% were contaminated by trichothecenes and zearalenone, 30% by trichothecenes and fumonisins and 65 % by all three families of fusariotoxins (Arvalis-Institut du végétal, unpublished data). In the United Kingdom, a report dealing with trichothecenes and zearalenone in retail cereal products indicated that 15 % of the analyzed samples contained zearalenone and all these positive samples also contained significant levels of trichothecenes (Patel, 2003). The occurrence of these mycotoxin multi-contaminations raises a problem in terms of both, food safety and regulation. In terms of food safety, it is important to understand the interaction between the different mycotoxins and to determine if these toxins act additionally, antagonistically or synergistically. In terms of regulation, so far mycotoxin contamination has always been established for single mycotoxins (or a family of related mycotoxins). This is still the case in the recent EU regulation (Regulation UE 1881/2006). The lack of consideration of multicontamination in regulations is mainly due to the paucity of toxicological data on multi-contamination. However, we can anticipate that if multicontamination increases the toxicity of mycotoxins, the tolerable daily intake should be modified and regulation might be revised accordingly.