Toxins of Aspergillus and Penicillium in beer production
Aflatoxins are produced by a group of 14 different species in three sections of the fungal genus Aspergillus, i.e. sections Flavi, Nidulantes, and Ochraceorosei (Varga et al., 2009). Aflatoxins are known as the most potent carcinogens among natural products. They act as acute liver toxicants and trigger liver carcinomas in addition to impairing respiration, renal and gastrointestinal function, and the nervous and immune systems in humans and animals (Coulombe, 1994). Owing to its high toxicological potential, the compound and its derivatives are regulated in most countries worldwide
(van Egmond and Jonker, 2005; van Egmond et al., 2007). Aspergillus flavus and A. parasiticus are the species that occur on brewing cereals and brewing adjuncts and aflatoxins have been isolated from barley and malt in different parts of the world (Park et al., 2002; Mateo et al., 2011). However, contamination of beer in most cases resulted from the use of contaminated maize grits rather than from cereal malt (Pietri et al., 2010). Due to its low water solubility, only a small proportion of the initial aflatoxin concentration is transmitted into the final beer so that its occurrence in the product is rather an exception, at least in Europe and in Northern America (Mably et al., 2005; Bertuzzi et al., 2011; Burdaspal and Legarda, 2013).