Detection of Aspergillus spp. and determination of the levels of aflatoxin B1 in rice imported to Bushehr, Iran
Aflatoxins (B1, B2, G1 and G2) are hepatotoxic metabolites produced by Aspergillus flavus on a number of agricultural commodities. Their levels were studied in rice samples imported to Iran through a southern port in Bushehr. Aflatoxins analysis was performed by solvent extraction, immunoaffinity clean-up and determination using high performance liquid chromatography (HPLC) equipped with post-column photochemical reactor and fluorescence detector. Among 152 samples analyzed, 75% showed levels of aflatoxin B1 (AFB1) contamination. However, there was no sample with AFB1 above maximum tolerated level (MTL) of 5 ng/g assigned by Institute of Standard and Industrial Research of Iran (ISIRI). AFB1 concentrations in the samples was 0.09 to 3.3 ng/g. Out of the 152 samples analyzed, about 76.97% were contaminated with total aflatoxin (AFT) with the mean of 0.671 ng/g which is lower than MTL of AFT in rice (30 ng/g) assigned by (ISIRI). AFT concentration ranged from 0.15 to 4.27 ng/g. Contamination of aflatoxin in imported rice was dissimilar between different months. The highest levels of AFB1 and AFT were detected in rice samples imported in September, while the lowest levels were in rice imported during November.
Key words: Iran, aflatoxins, food safety, rice.