Detection of <i>Aspergillus spp</i<>. and determination of the levels of aflatoxin B1 in rice imported to Bushehr, Iran

Abstract

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.