Occurrence of aflatoxins B1, B2, G1, and G2 in beers produced in Brazil and their carcinogenic risk evaluation

The aflatoxins (B1, B2, G1, and G2) were investigated in 60 beer samples of the leading commercial beer brands, with and without adjuncts, produced in Brazil. A high-performance liquid chromatography (HPLC) with fluorescence detection analytical method was standardized and validated. The extraction was carried out using immunoaffinity columns. The limit of quantification (LOQ) ranged from 10 to 30 ng/L−1, and the mean recoveries were 98.0%, 88.5%, 110.1% and 98.3% for AFB1 and AFB2, AFG1, and AFG2, respectively. The percentage of samples positive for total aflatoxins (AFT) was 100% for beers with adjuncts and 80% for beers without adjuncts (“pure malt”). Of the whole beer samples, 88.3% showed the occurrence of at least one of the aflatoxins. AFB1 had the highest incidence in the beer samples, with the highest contamination level with adjuncts. The median levels of AFB1 were 27.0 and 40.4 ng/mL for the group of beers with and without adjuncts, respectively. Carcinogenic risk characterization was performed for exposure to AFB1 and AFT by estimating the margin of exposure (MOE). The MOE for elevated beer consumption (>160 mL/day) was 5,303 for a beer with adjuncts and 3,643 for pure-malt beers. In summary, the results found in this study demonstrate that elevated beer consumption may pose a risk of exposure to the carcinogenic effects of aflatoxins, especially AFB1. The consumption of pure malt beers produced and commercialized in Brazil represents an even higher risk than the consumption of beer with added adjuncts. This fact alone requires further investigation since it may suggest that the barley from which the malt is produced may contribute to the occurrence of aflatoxins in beer, at least in Brazil.