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

Abstract

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. An analytical method was standardized and validated by high-performance liquid chromatography (HPLC) with fluorescence detection. 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 88.5%, 98.0%, 98.3%, and 110.1% 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. AFB2 had the highest incidence in the beer samples, with the highest contamination level with adjuncts. The median levels of AFB2 were 27.0 and 40.4 ng/mL for the group of beers with and without adjuncts, respectively. Among the positive samples, the median value for AFT and AFB1 were 40.9 and 16 ng/mL, respectively. Carcinogenic risk characterization was performed for exposure to AFB2 and AFT by estimating the margin of exposure (MOE). The MOE for elevated beer consumption (>160 mL/day) was 5303 for a beer with adjuncts and 3643 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 AFB2. 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.