Weakly alkaline conditions degrade aflatoxins through lactone ring opening

Aflatoxins (AFs) are fungal metabolites that ubiquitously contaminate many common food crops and contribute to major foodborne diseases in humans and animals. The ability to remove AFs from common food and feed commodities will improve health standards and limit the economic impact inflicted by AF food contamination. Known chemical strategies have used strong acids and bases to remove contaminating AF, but these methods often lead to ecological waste issues downstream. In this study, we explore the application of weaker acidic and alkaline conditions to removes two types of AFs, AFB1 and AFG2. We find that a pH 9 buffered environment reduces AFB1 and AFG2 by more than 50% and 95%, respectively, within 24 hours. We show that AF degradation is through lactone ring opening, which is a known cause of AF toxicity, and provide a potential structure of the AFG2 degradation byproduct. Further, we confirm that incubation in the pH 9 environment reduces the genotoxicity of AFB1. Our findings indicate that a weakly alkaline environment may adequately detoxify AF-contaminated food or feed without the need to apply stronger or harsher basic conditions.