Co-occurrence of aflatoxins and ochratoxin A in nuts, dry fruits, and nuty products

A total of 320 samples of edible nuts (poppy seed, peanut, pistachio, cashew, almonds) and dry fruits (plum, raisins, figs, dates, apricot, watermelon seed, melon seeds, pomegranate seeds) collected from major cities of Punjab, and Khyber Pakhtunkhwa, Pakistan, were analyzed for the presence of aflatoxins (AFs) and ochratoxin A (OTA). Sample extracts were purified using immunoaffinity columns and analyzed by reversed phase HPLC with fluorescence detection. Aflatoxin B-1 (AFB(1)) and total AFs (AFB(1), AFB(2), AFG(1), AFG(2)) were found in 128 (40%) samples, and total AFs exceeded levels of 4 mu g/kg and 10 mu g/kg in 34 and 25% of samples. The highest mean levels of total AFs (7.301.80 mu g/kg) were found in peanuts without shell, the lowest mean levels (2.90 +/- 1.50 mu g/kg) were found in watermelon seeds with shell samples. OTA was found in 18 (5%) samples, the highest levels (5.60 +/- 1.34 mu g/kg) were found in raisins (maximum 18.5 mu g/kg). Only four samples of edible nuts and dry fruits were contaminated with OTA at levels above the recommended limit of 10 mu g/kg. The results have revealed the co-occurrence of OTA and total AFs in 25% total samples of dry fruits and nuts with a mean level of OTA 3.58 +/- 1.30 mu g/kg and total AFs mean level of 4.13 +/- 0.48 mu g/kg, respectively. The high frequency especially of AFs in dry fruits and edible nuts is regarded as a health issue for consumers. Practical applicationsThe manuscript has provided the current status on the levels of AFs and OTA in dry fruits and nuts in Pakistan. The results of current finding revealed that the levels of AFs and OTA in those samples which have stored in shells are significantly less as compared to those samples of nuts and dry fruits which have been stored without shells. Therefore, to use good storage practices, farmers, venders, and traders can eliminate or minimize the levels of these toxins in their products. Furthermore, the study will provide the awareness and levels of AFs and OTA in nuts and dry fruits and help to implement strict regulations for these toxins by law enforcement agencies.