Chapter 1. Introduction to Masked Mycotoxins

Abstract

Mycotoxins are toxic, secondary metabolites of moulds. They are produced by filamentous fungi on almost every agricultural commodity worldwide. After the infection of crop plants, mycotoxins are modified by plant enzymes and often conjugated to more polar substances, like sugars. The formed—often less toxic—metabolites are stored in the vacuole in soluble form or bound to macromolecules. As these substances are usually not detected during routine analysis, nor any maximum limits are in force, they are called masked mycotoxins. While having a low intrinsic toxicity, masked mycotoxins might be reactivated during mammalian metabolism. In particular, the polar group might be cleaved off (e.g. by intestinal bacteria), liberating the native mycotoxin. The aim of this chapter is to provide a brief overview of the various aspects of masked mycotoxins that are discussed in more detail in the following chapters. Further, we clarify the terminology used, which unfortunately is rather inconsistent in the scientific literature, and also discuss the historical perspective of these food contaminants.