Occurrence of ochratoxin A in black pepper, coriander, ginger and turmericin India

Ochratoxin A (OA) contamination of black pepper, coriander seeds, powdered ginger and turmeric powder was estimated using indirect competitive ELISA. Samples (1 g) were extracted with 0.5% potassium chloride (KCl) in 70% meth anol (5 ml) and diluted subsequently to give two-fold to ten-fold step-wise dilutions in phosphate-buffered saline containing 0.05% Tween 20 and 0.2% bovine serum albumin (PBS-T BSA). For extracts from the spices analysed, EL ISA estimates of OA concentrations were compared with those made by HPLC. A ll estimates were within 1-2 standard deviation of the ELISA values. More t han 90% of OA added to spice samples was recovered from samples containing between 5 and 100 mu /kg OA. Extracts of OA-free spice samples contained su bstances that interfered with ELISA, presumably because of non-specific rea ctions. This effect was avoided by preparing all the test solutions in extr acts of OA-free spice samples. In 126 samples obtained from retail shops, O A was found to exceed 10 mug/kg in 14 (in the range of 15-69 mug/kg) of 26 black pepper samples, 20 (in the range of 10-51 mug/kg) of 50 coriander sam ples, two (23 mug/kg and 80 mug/kg) of 25 ginger samples and nine (in the r ange of 11-102 mug/kg) of 25 turmeric samples. This is the first record in India of the occurrence of OA in what are some of the most widely used spic es in Indian cooking.