Control of Mycotoxin Contamination in Cereals by Breeding

Abstract

The mycotoxin contamination of cereal commodities is a much older problem than its detection and characterization. Molded grains often caused different animal and human health problems long before the causal agents were known. The first mycotoxin detected is the aflatoxin B1 in the 1960s and since then hundreds of toxins have been described (D'Mello and McDonald 1997; Bartok et al. 2006). They represent chemically very different groups, very far from each other in physiological actions; some, such as aflatoxins or fumonisins, are highly carcinogenic. The most numerous group of toxins is at present the trichothecenes with about 100 toxins and toxic degradation products. At least 90 fumonisin toxins are known (Bartok et al. 2008), most of them without physiological and toxic characterization. For now, we have a rather comprehensive view on the occurrence of the different mycotoxins in cereal grains; most of the synthesis and decomposition mechanisms of the major mycotoxins are known. It is very probable that new toxins, maybe toxic groups, will be characterized in the future. Most of the synergism between toxins is not known. It could be high, as the same severity of swine toxicoses from natural deoxynivalenol (DON) could be reached by the addition of 5–10 times more chemically clean DON (Miller and Trenholm 1994). Increasing knowledge of the toxins has verified the food and feed safety risks. Now many countries, such as EU member states (Anonymous 2005), have binding toxin regulations or suggested toxin levels, as in the USA, Canada, etc. As the EU is a significant market, EU regulations generate stricter toxin regulations in the source countries. Many accept the view that the bioethanol industry can utilize toxin-contaminated commodities. However, the industry has shown (Stepanik et al. 2007) that the ethanol yield from toxin-contaminated grain is lower, and the toxin-containing remains (dried distillery grain with solubles) provides large problems in economic utilization, because a costly detoxification is needed. This means also that non-food uses might need healthy grains.