Occurrence and exposure assessment of aflatoxin B1 in Iranian breads and wheat-based products considering effects of traditional processing

Aflatoxin B1 (AFB1) is a mycotoxin made by various fungal strains, which could be contaminated cereal-based products, such as bread and sweets widely consumed worldwide. The objective of this research was to survey the fate of AFB1 from wheat flour samples to various kinds of Iranian traditional breads and bakery products. The study evaluates the contamination levels of AFB1 during the bread-making process by high-performance liquid chromatography with fluorescence detection (HPLC-FLD); in addition, calculation of exposure assessment of AFB1 through the consumption of these products. All flour samples were contaminated with AFB1 in the range of 0.47–3.38 ng/g, which the lowest and highest contamination was regarding null flour and dark flour used in the preparation of cake and Sangak bread (a sourdough type of bread that is made from wholemeal flour). AFB1 levels in the mixed dough were the same and insignificantly lower than initial flour samples (P > 0.05), and were significantly decreased in the fermented dough and baked samples compared to the initial flour (P < 0.05). During the fermentation process, the lowest AFB1 reduction was observed, in cake and biscuit samples (8.5% and 6.5%), and the highest reduction percentage of AFB1 was attributed to Sangak dough (24.2%). The highest and lowest AFB1 levels of the various traditional baked products were observed in biscuits (1.15 ± 0.04 μg/kg), and cake (0.21 ± 0.01 μg/kg). Overall, These results highlight that although the mean levels of AFB1 in Iranian traditional bread and bakery products are not worried with regard to the current EU legislation and the national Iran standards, however, due to the high consumption amount of bread in Iran (286 g/day), the estimated average exposure of AFB1 in adults and children through different Iranian bread types was higher than the guidance value. Therefore it is recommended that regular monitoring be done to assess the rates of these toxins in cereals and the related product to the confidence that human exposure levels be held as low as possible.