Aflatoxin B 1 production by Aspergillus parasiticus and strains of Aspergillus section Nigri in currants of Greek origin Paraskevi Kostarelou a , Alexandros Kanapitsas a , Ioanna Pyrri b , Evangelia Kapsanaki-Gotsi b , Panagiota Markaki a, * a Department of Food Chemistry, Faculty of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, GR-15784 Athens, Greece b Department of Ecology and Systematics, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece article info Article history: Received 4 November 2013 Received in revised form 28 January 2014 Accepted 8 February 2014 Keywords: Aflatoxin B 1 Aspergillus parasiticus Aspergillus section Nigri Currants Yeast extract sucrose HPLC abstract Aflatoxin B 1 (AFB 1 ) mostly produced by Aspergillus flavus and Aspergillus parasiticus, is an extremely toxic and carcinogenic metabolite. Currants are used in the Mediterranean diet as a food with antioxidant properties. Four strains of Aspergillus section Nigri have been isolated from currants originated from Crete and Corinth. In this study AFB 1 production by A. parasiticus and the four strains of Aspergillus section Nigri in Cretan and Corinthian currants (Vitis vinifera L.) is investigated. AFB 1 determination was performed by HPLCeFID. Results revealed that the four strains Aspergillus section Nigri, as well as the aflatoxigenic strain A. parasiticus produced AFB 1 (0.0052e1.31 mg AFB 1 15 g 1 , corresponding to 0.0003e0.087 mg AFB 1 g 1 ) in both type of currants (Cretan and Corinthian) on the 12th day of observation. Moreover, AFB 1 production, by A. parasiticus in the synthetic Yeast Extract Sucrose (YES) medium was also studied. The ability of AFB 1 production has been affected by the special characteristics of each isolate and the currants substrate. Ó 2014 Published by Elsevier Ltd. 1. Introduction Raisins constitute an important component of the Mediterra- nean diet. They are considered to be a rich source of ascorbic acid, citric acid, malic and tartaric acids with plenty minerals, such as potassium, calcium and magnesium (Nour, Trandafir, & Ionica, 2011). Moreover, currants contain polyphenolic compounds such as anthocyanins (Nour et al., 2011), vanillic acid, caffeic, gallic and p-coumaric acids and quercetin. The consumption of currants contributes to the intake of antioxidants (Chiou et al., 2007) and moreover they have potent anticarcinogenic properties against several cancers like hepatocellular carcinogenesis in rats (Bishayee et al., 2011). Aflatoxins (AFs) are highly toxic secondary metabolites pro- duced by the species of Aspergillus (A.), especially Aspergillus flavus and Aspergillus parasiticus (Wejdan et al., 2010). AFs are of great concern because of their harmful effects on the health of humans and animals, including carcinogenic, mutagenic, teratogenic and immunosuppressive effects (Zinedine & Mañes, 2009). Aflatoxin B 1 (AFB 1 ) is the most potent hepatocarcinogen in mammals and it is classified by the International Agency of Research on Cancer as Group 1 carcinogen (IARC, 1993a). These mycotoxin-producing mold species can grow on a wide range of agricultural commodities in the field, but also during post- harvest operations and storage conditions (Zinedine & Mañes, 2009). Major food commodities affected are nuts, figs and other dried fruits, spices, crude vegetable oils, cocoa beans and maize ac- cording to many authors (Iamanaka, Castle de Menezes, Vicente, Leite, & Taniwaki, 2007; Imperato, Campone, Piccinelli, Veneziano, & Rastrelli, 2011; Luttfullah & Hussain, 2011). The European Commis- sion has established the maximum level for AFB 1 in dried fruits for direct human consumption to 2 ng g 1 (European Commission, 2006). The Aspergillus section Nigri (also known as black-spored As- pergilli) are an important group of fungi because of their impact on food safety, medical mycology and industrial biotechnology (Palencia, Klich, Glenn, & Bacon, 2009). The black Aspergilli are Abbreviations: AFB 1 ,Aflatoxin B 1 ; AFB 2a ,Aflatoxin B 1 hemiacetal derivative; A., Aspergillus; AFPA, Aspergillus flavus parasiticus agar; CFU, Colony forming units; CZA, Czapek Dox agar; HPLC, High performance liquid chromatography; ATHUM, ATHens University Mycology; NOAEL, No Observed e Adverse Effect Level; PMTDI, Provi- sional Maximum Tolerable Daily Intake; RSD, Relative Standard Deviation; TDI, Tolerable Daily Intake; YES, Yeast Extract Sucrose. * Corresponding author. Tel.: þ30 210 7274489; fax: þ30 210 7274476. E-mail address: markaki@chem.uoa.gr (P. Markaki). Contents lists available at ScienceDirect Food Control journal homepage: www.elsevier.com/locate/foodcont http://dx.doi.org/10.1016/j.foodcont.2014.02.011 0956-7135/Ó 2014 Published by Elsevier Ltd. Food Control 43 (2014) 121e128