Occurrence of ochratoxin A in cocoa products and chocolate

In this work, the occurrence of ochratoxin A (OTA) in 170 samples of cocoa products of different geographical origins was studied. An immunoaffinity column with HPLC separation was developed to quantify low levels of OTA in cocoa bean, cocoa cake, cocoa mass, cocoa nib, cocoa powder, cocoa shell, cocoa butter, chocolate, and chocolate cream with >80% recoveries. The method was validated by performing replicate analyses of uncontaminated cocoa material spiked at three different levels of OTA (1, 2, and 5 mug/kg). The data obtained were related on the acceptable safe daily exposure for OTA. The highest levels of OTA were detected in roasted cocoa shell and cocoa cake (0.1 - 23.1 mug/kg) and only at minor levels in the other cocoa products. Twenty-six cocoa and chocolate samples were free from detectable OTA (<0.1 mug/kg). In roasted cocoa powder 38.7% of the samples analyzed contained OTA at levels ranging from 0.1 to 2 mug/kg, and 54.8% was contaminated at >2 mug/kg (and 12 samples at >3 mug/kg). Ochratoxin A was detected in cocoa bean at levels from 0.1 to 3.5 mug/kg, the mean concentration being 0.45 mug/kg; only one sample exceeded 2 mug/kg (4.7%). In contrast, 51.2% of cocoa cake samples contained OTA at levels greater than or equal to2 mug/kg, among which 16 exceeded 5 mug/ kg (range of 5-9 mug/kg). These results indicate that roasted cocoa powder is not a major source of OTA in the diet.