Ochratoxin A in human blood in Abidjan, Côte d'Ivoire.

Ochratoxin A (OTA) produced by Aspergillus and Penicillium genera contaminates a diversity of foods including cereals; cereals-derived foods; dry fruits; beans; cocoa; coffee; beer; wine; and foodstuffs of animal origin mainly poultry, eggs, pork and milk, including human breast milk. OTA is nephrotoxic to all animal species studied so far and most likely to humans, who show the longest half-life for elimination of this toxin among all species examined. Among other toxic effects, OTA is teratogenic, immunotoxic, genotoxic, mutagenic and carcinogenic, all of which lead to life-threatening pathologies through several molecular pathways. In Côte d'Ivoire, preliminary surveys conducted by us have proven from 1998 to 2004 the reality of ochratoxin A-contamination of foodstuffs. To assess OTA in human blood, the immunoaffinity columns were used along with HPLC for separation and fluorimetric quantification of blood samples collected in Abidjan from two categories of people: apparently healthy donors (n=63) and nephropathy patients undergoing dialysis (n=39). Among healthy donors, 34.9% show OTA concentrations ranging from 0.01 - 5.81 microg/l with a mean value of 0.83 microg/l, whereas, among nephropathy patients undergoing dialysis 20.5% are OTA positive in a range of 0.167-2.42 microg/l and a mean value of 1.05. Although the sex ratio is 0.82 (46 females for 56 males) ochratoxin A contamination is equally distributed in both sexes. Nephropathy patients undergoing dialysis appear, however, less frequently contaminated than healthy donors (20.5 versus 34.9%) and show higher OTA concentrations (higher mean value, p=0.01). Ochratoxin A concentrations found in human blood reflect concentrations previously detected in cereals and peanuts according to the eating habits and diets of people in Côte d'Ivoire. But, the prevalence of ochratoxin A in blood of nephropathy people undergoing dialysis appears lower than expected from the frequency of OTA contamination in cereals and peanuts. Pearson chi(2)-test indicates that among OTA-positive individuals renal dialysis and age are important modalities for consideration.

Impact of industrial treatments on ochratoxin A content in artificially contaminated cocoa beans.

Ochratoxin A (OTA) is a mycotoxin mainly produced by mould species of the genera Aspergillus and Penicillium, which grow on a variety of agricultural products. OTA-contaminated foodstuffs pose a major health hazard to consumers, including human and animal. In Cote d'Ivoire, numerous studies are being carried out to find the best way of preventing OTA contamination of cocoa raw material. The objectives of this investigation were to assess the impact of industrial treatment on OTA content in cocoa-derived products. Samples of cocoa pods were prepared under specific conditions promoting fungal proliferation on cocoa beans before processing. The beans underwent the usual industrial treatments - roasting, shelling, crushing, pressing and additive addition - and samples were taken at each stage. OTA was extracted with a methanol/3% sodium hydrogen carbonate solution and purified using an immunoaffinity column prior to HPLC analysis with fluorescence detection. OTA was detected in artificially contaminated cocoa beans at levels ranging from 3.4 to 44.7 microg kg(-1) with a mean value of 22.9 +/- 3.6 microg kg(-1). OTA was mainly concentrated in the shell (93%). Roasting, shelling and additive addition significantly decreased levels of OTA by 24-40, 76 and 52%, respectively, with an overall reduction of approximately 91%. These results indicate that industrial processing of cocoa has a real impact on the reduction of OTA in final cocoa products.

Co-occurrence of aflatoxin B1, fumonisin B1, ochratoxin A and zearalenone in cereals and peanuts from Côte d'Ivoire.

This survey examined 30 samples of rice (n = 10), maize (n = 10) and peanuts (n = 10) from Côte d'Ivoire for aflatoxin B1, fumonisin B1 and zearalenone using immunoassays, and ochratoxin A using a validated HPLC method with fluorescence detection. In Côte d'Ivoire, as in other countries, several mycotoxins are present in the same commodities. These mycotoxins are from different structural families: aflatoxin B1, fumonisin B1, zearalenone and ochratoxin A, normally produced by fungal species from Aspergillus, Penicillium and Fusarium genera. Some samples contained four mycotoxins (86%). Four peanuts samples did not show ochratoxin A (14%), whereas they contained aflatoxin B1 concentrations above the EU regulatory limits. Concentrations of ochratoxin A, zearalenone and fumonisin B1 were low and may not cause problems per se; however, fears remain that the tolerable daily intake may be exceeded due to eating habits and synergistic effects could be important with the combination of several mycotoxins. Investigations in this direction are underway, together with isolation and characterization of the fungal species involved.