First survey on the natural occurrence of Fusarium mycotoxins in Bulgarian wheat.

Wheat for human consumption (140 samples) was collected after harvest from all regions of Bulgaria. The 1995 crop year was characterized by heavy rainfall in the spring and summer months. The internal mycoflora of wheat samples was dominated by Fusarium spp. and Alternaria spp., and storage fungi were rarely present. The samples were analysed for contamination with Fusarium mycotoxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), T-2 Toxin (T-2), diacetoxyscirpenol (DAS), and zearalenone (ZEA), using enzyme immunoassay methods. DON and ZEA were the predominant toxins, with a contamination frequency of 67% and 69%, respectively. The average levels of these toxins in positive samples were 180 micrograms/kg (DON) and 17 micrograms/kg (ZEA), maximum concentrations were 1800 micrograms kg-1 and 120 micrograms kg-1, respectively. Acetyl derivatives of DON, namely 3-AcDON and 15-AcDON, were found in 2.1% and 0.7% of the samples, at at maximum level of about 100 micrograms kg-1. Only one sample was positive for T-2 (55 micrograms/kg), DAS was not detected. This is the first report about the natural occurrence of a range of Fusarium mycotoxins in wheat for human consumption in Bulgaria.