Aflatoxin contamination level in Iran's pistachio nut during years 2009-2011

An efficient monitoring system for sampling, analyzing and issuing the export certificates for pistachio consignments has been established in Iran in recent years. Accordingly, 3181 commercial raw pistachio nut lots were supplied for testing for European export certification since January 2009 till December 2011. Aflatoxin analysis was carried out by high-performance liquid chromatography with fluorescence detection after immunoaffinity column clean up with recoveries ranging from 77 to 99%. Amongst 8203 sub-samples analyzed, aflatoxin B₁ (AFB₁) was detected in 1921 cases (23.4%) with the mean and median values of 2.18 ± 13.1 ng/g and <LOD, respectively. Total aflatoxin (AFT) was detected in 1927 sub-samples (23.5%) with the mean and median values of 2.42 ± 14.7 ng/g and <LOD, respectively. AFB₁ level in 556 (6.78%) and 428 (5.22%) sub-samples was above the maximum tolerable levels set for AFB₁ in Iran (5 ng/g) and European Union (EU) (8 ng/g). The mean contamination levels of AFB₁ (2.18 ng/g) and AFT (2.42 ng/g) were lower than the maximum tolerable levels set in Iran and EU. The contamination levels of pistachio nut for export to EU were ∼50% of those found in 2002-2003 indicating a satisfying improvement in hygienic conditions of pistachio cultivation, harvesting and post-harvesting practices in Iran.