Ochratoxin A in corn and wheat: Geographical association with endemic nephropathy

Aim. To determine the presence and concentration of ochratoxin A in wheat and corn from Slavonski Brod surroundings, the area of endemic nephropathy allegedly caused by ochratotoxin. Methods. Thin-layer chromatography was used to determine ochratoxin A concentrations in 92 wheat and 51 corn samples from the surroundings of Slavonski Bred, Osijek, Hrvatsko Zagoje, Istria, and Celje (Slovenia). Results. Ochratoxin A was present in 74 of 92 (75.8%) wheat samples and 17 of 51 (33.3%) corn samples, in a concentration range of 0.02-160.00 mug/kg in wheat and 0.02-40.00 mug/kg in corn. Wheat samples from the Slavonski Bred surroundings contained the highest level of ochratoxin A (38.8+/-27.2 mug/kg), followed by Osijek (8.7+/-8.3 mug/kg). Ochratoxin A levels in the wheat from Hrvatsko Zagorje, Istria, and Celje were considerably lower (2.1+/-1.5, 1.3+/-2.6 and 0.2+/-0.5 mug/kg, respectively). Wheat samples from Slavonski Bred significantly differed from all other sample groups (p<0.001), and wheat samples from Osijek differed from those from Hrvatsko Zagoje, Istria, and Celje (p<0.001, p=0.003, p<0.001, respectively). Ochratoxin A level was the highest in the corn samples from the Slavonski Brod surroundings (20.0+/-14.8 <mu>g/kg) and considerably lower in samples from Osijek, Celje, Hrvatsko Zagoje, and Istria (0.8+/-1.4, 0.7+/-1.9, 0.41+/-0.4, and 0.4+/-0.8 mug/kg, respectively). A statistically significant difference was also observed between the Slavonski Brod samples and all other corn samples (p<0.001). Conclusion. Irrespective of the real association between ochratoxin A and endemic nephropathy, our data clearly demonstrate their geographical overlap.