The incidence of fungi and mycotoxins in South African barley and barley products

Barley is grown as a crop in South Africa, mainly for use in the barley beer (lager) industry, particularly in the production of barley malt. This investigation was done to find out what fungal infection and mycotoxin contamination this barley and the malt contained. The survey, done in 2005, not only covered barley and malt but also the final product in the form of several brands of beer purchased from retail outlets. Analysis was done using a range of methodologies including chromatography, immunoaffinity/fluorimetry and cytotoxicity testing. The results show that barley, which also includes barley sold directly to the public, and malt, contain various fungi, sometimes at high incidence and also a range of mycotoxins which persisted through, although at low levels, to beer. The malt showed a different pattern of micro flora, as compared to the barley, which indicates infection during the malting process, which is not uncommon. Interestingly, fumonisin B-1 was found in some of the samples, as well as the beer, although in the latter case these were at very low levels. Recent studies have shown that the immunoaffinity/fluorimetry method can give false positives for the fumonisins, so these results were confirmed by high performance liquid chromatography. As is the case with other cereals grown in South Africa, there is the concern that the public is exposed to mycotoxins on a regular basis through the consumption of products made from them.