Toxicological significance of modified fumonisins

Fumonisins are produced by various Fusarium (and Aspergillus) spp. and are often occurring on maize and maize products. They are potent renal toxins, cancer promoters and cause birth defects. Maximum (or guidance) levels in food (and feed) have been set by authorities worldwide, but unaltered mycotoxins are not the only source of exposure for consumers. Fumonisins are prone to be non-covalently bound with proteins and complex carbohydrates. In addition, next to nothing is known about covalently bound fumonisins or about the natural occurrence of (potential) fumonisin metabolites other than their hydrolysed forms. Currently there is a lack of knowledge in the understanding how fumonisins interact with plants in in which form they are incorporated and carried over in food. In their recent report from 2018, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) specifically recommends that “studies should be conducted to better understand the occurrence of bound fumonisins … and their bioavailability after consumption”. To the best of our knowledge this is the first study worldwide that systematically aims to answer the questions raised above and therefore to significantly contribute to the risk assessment of these food contaminants.