Ochratoxin A in dried grapes and grape-derived products in Turkey

Abstract

Ochratoxin A (OTA) is a naturally occurring mycotoxin and widespread food contaminant which results in a probable human exposure. A total of 85 samples (50 dried grapes, 10 grape juices and 25 pekmez (boiled and concentrated grape juices) were collected from different supermarkets and traditional bazaars in Istanbul during 2008-2009. An analytical method based on immuno-affinity column for clean-up and high-performance liquid chromatography equipped with fluorescence detection was used to determine the OTA. Contamination frequencies were 8%, 20% and 88% with mean concentrations of positive samples of 1.15, 1.40 and 2.04 µg/kg for dried grapes, grape juices and pekmez samples, respectively. These levels were lower than the maximum levels as set by the European Commission (EC). However, 12 of 25 pekmez samples had higher levels than permitted by the European Union (EU) for safe consumption.

Keywords: HPLC-FLD; Ochratoxin A; dried grapes; grape juice; immuno-affinity columns; pekmez.