Emerging mycotoxin issues

Food or feed are not necessarily safe due to the absence or low concentrations of well-known mycotoxins, as these toxic compounds can be present in disguise as a result of plant, mammal or fungal metabolism or even food processing (Berthiller, Schuhmacher, Adam, Krska, 2009 Berthiller et al., 2013). Modified mycotoxins 

Several Fusarium toxins such as DON, fumonisins, fusarenon-x, fusaric acid, nivalenol, T-2, HT-2 and ZEA are prone to masking biofransformations or binding by plants (Berthiller et al., 2013). In addition, other mycotoxins such as OTA and patulin have been found in conjugated forms. The major form of modified DON is deoxynivalenol-3-p-D-glucopyranoside (D3G), which is perhaps the most widely studied cereal-associated modified mycotoxin so far. 

Food and beverage processing can alter mycotoxins chanically. For example, microbes used in fermentations may transform mycotoxins to less toxic compounds. So far, only a few studies have been carried out concerning the modified mycotoxins in the barley-to-beer chain. The studies have indicated that bound DON appears to be fairly common in barley (Lancova et al., 2008 Zhou, He, Schwarz, 2008). Zhou et al. (2008) reported that bound DON in naturally infected barley was detected in almost 40% of samples and represented an additional 6-21% of DON determined by the standard gas chromatography method. 

The extractable conjugated or bound mycotoxins are not currently regulated by legislation (Berthiller et al., 2013). Further studies are required on determination of modified mycotoxins and on their stability, transformation, toxic properties and bioavailability. With respect to regulation, a possible approach in the future could be the definition of the sum of all relevant forms of each mycotoxin, including its relevant derivatives. 

Barley-associated fungi are also responsible for the production of bioactive compounds called emerging or minor mycotoxins. This group includes toxins such as enniatins (ENNs) and beauvericin (BEA). Recently, the occurrence and fate of these toxins in the barley-to-beer chain have gained attention (Hu, Gastl, Linkmeyer, Hess, Rychlik, 2014 Vaclavikova et al., 2013). 

---