ORIGINAL PAPER Mycotoxin production by different ochratoxigenic Aspergillus and Penicillium species on coffee- and wheat-based media Katherine Muñoz & Mario Vega & Gisela Rios & Rolf Geisen & Gisela H. Degen Received: 25 February 2011 /Revised: 28 April 2011 /Accepted: 29 April 2011 /Published online: 17 May 2011 # Society for Mycotoxin Research and Springer 2011 Abstract Ochratoxin A (OTA) is one of the most widespread mycotoxins, and is produced by several Aspergillus or Penicillium species. Human exposure to OTA is mainly by intake of contaminated food, with cereal products, followed by coffee and red wine as the main sources of OTA. In this study, the OTA production of four ochratoxigenic fungi (two Aspergillus and two Penicillium species) was investigated in four different media, i.e. wheat and coffee model media as food-based media and two standard laboratory media (malt extract glucose agar, MEA and yeast extract sucrose agar, YES). Colony growth was documented and OTA concen- trations in cultures were determined at day 2, 4 and 8 of incubation at 25°C by high-performance thin-layer chroma- tography (HPTLC) and high-performance liquid chromatog- raphy (HPLC). OTA production clearly depended upon time of incubation, fungal species, and medium composition. On coffee based medium, moderate OTA levels were produced by A. ochraceus BFE635 (9.8 μg/g) and by A. niger BFE632 (10.6 μg/g) on day 8 of incubation. In wheat-based medium, these strains produced much more OTA than in coffee. The highest OTA concentration (83.8 μg/g on day 8) was formed by A. ochraceus BFE635 followed by the other Aspergillus niger BFE632 (49 μg/g). Lower OTA levels were produced by P. verrucosum BFE550 and P. nordicum BFE487, in both wheat and in YES medium, whilst OTA was hardly detectable in coffee and in MEA in case of P. nordicum. Colony growth of the tested strains on different media was not indicative of OTA production. Guttation droplets developed on wheat-based medium with the Aspergillus strains within a week, and this phenomenon coincided with the high OTA amounts formed by these species. Results from this study add to our knowledge on the behaviour of ochratoxigenic fungal species when cultured on food based media. Keywords Ochratoxin A . Aspergillus . Penicillium . Guttation droplets . HPTLC Introduction Mycotoxins are toxic secondary metabolites of fungi belonging mainly to the genera Aspergillus, Penicillium and Fusarium. Their occurrence in plant-derived foods and feeds can have a serious negative impact on human health and animal productivity. Since it is estimated that 25% of the world’s food crops, including many basic foods, are affected by mycotoxin-producing fungi, this is also associated with significant economic losses (FAO 2001). Ochratoxin A (OTA) is a mycotoxin produced by several species of the genus Aspergillus or Penicillium. OTA is a potent nephrotoxin in pigs and rats, and it is suggested to be Electronic supplementary material The online version of this article (doi:10.1007/s12550-011-0100-0) contains supplementary material, which is available to authorized users. K. Muñoz (*) : G. H. Degen Leibniz Research Centre for Working Environment and Human Factors -IfADo, Ardeystr. 67, 44139 Dortmund, Germany e-mail: munoz@ifado.de M. Vega : G. Rios Department of Food Science, Faculty of Pharmacy, University of Concepción, Concepción, Chile R. Geisen Max Rubner Institut—Bundesforschungsinstitut für Ernährung und Lebensmittel, Karlsruhe, Germany Mycotox Res (2011) 27:239–247 DOI 10.1007/s12550-011-0100-0