Incidence of aflatoxins in commercial nuts in the holy city of Mekkah

The incidence of aflatoxins contamination in different nuts has been studied. Two hundred and sixty four samples of nuts were collected randomly from the main outlets across seven municipalities of the holy city of Mekkah. The samples were first screened for total aflatoxins using Aflatest immunoaffinity column (IAC) technique. The IAC results showed that 70 samples (26.5%) were contaminated with AFT in levels ranged between 1.0 and 110 μg/kg. The percentages of contamination of AFT in groundnuts were (18.4%), Pistachio (34%), walnuts (50%), cashew (15%), hazelnut (43%) and almond (17%). Only 23 samples (8.7%) had levels equal or exceeded the maximum tolerable limit for AFT in EU (4 μg/kg), and only 7 samples (2.65%) had exceeded the MTL in Saudi Arabia (20 μg/kg). The samples that exceeded MTL of Saudi Arabia were five pistachio sample (110, 45, 43, 34 and 30 μg/kg) and two peanut samples (100 and 28 μg/kg). Quantitative testing of total and individual AFs was conducted in selected samples from the IAC results with contamination levels exceeded the MTL of EU (23 samples) by using HPLC and fluorescence detection. AFB1 was detected in 22 out of 23 samples with contamination level in most of the positive samples exceeded the MTL set by EU regulations (2 μg/kg). The highest levels of AFB1 were detected in two sample of pistachio (411 and 126 μg/kg) and one sample of peanut (73.9 μg/kg). Aflatoxin G2 is detected in 5 out of 23 samples, pistachio (2), walnut (2) and hazelnut (1). While, B2 and G1 were detected in 17 samples in levels ranged between ND–10.7 μg/kg and ND–12.9 μg/kg, respectively.