Chemical mixture in the crop production chain: a focus on mycotoxins

Abstract

Several crops can be infested by filamentous fungi, both in the field and during storage. Some of these fungi, under appropriate conditions, are capable of producing a wide range of secondary metabolites mycotoxins, which may be produced in crops in the field, be accumulated during storage, and be resilient during food processing and persist in the final food product. Contamination of food products with fungi is frequent, and will impact food security and food safety. Cereals are the main contributors to mycotoxins exposure and maize is the principal staple food/feed crop exposed to mycotoxins, where the co-occurrence of multiple mycotoxins and their metabolites has been well documented. In this presentation maize will be used as a case study to illustrate the occurrence of chemical hazard mixtures in the crop production chain (with a focus on mycotoxins). The infection cycle, ecology, and plant-pathogen interactions of Aspergillus and Fusarium species in maize, determines a succession of species in maize, yielding a potential contaminated crop with fumonisins by some Fusarium species (e.g., F. verticillillioides, F. proliferatum), deoxynivalenol by other Fusarium species (e.g., F. graminearum), and aflatoxins by Aspergillus species (e.g., Aspergillus flavus), just to mention the most frequent ones. In addition, the plant pathogen interaction, as well as food processing after storage, may transform (or modify) these mycotoxins into to compounds that remain toxic but may escape official control. This presentation will give insights on the maize chain to illustrate the possible occurrence of multiple chemical hazards in a single crop.