Aflatoxin B1 Degradation by Ery4 Laccase: From In Vitro to Contaminated Corn

Aflatoxins (AFs) are toxic secondary metabolites produced by Aspergillus spp. and are found in food and feed as contaminants worldwide. Due to climate change, AFs occurrence is expected to increase also in western Europe. Therefore, to ensure food and feed safety, it is mandatory to develop green technologies for AFs reduction in contaminated matrices. With this regard, enzymatic degradation is an effective and environmentally friendly approach under mild operational conditions and with minor impact on the food and feed matrix. In this work, Ery4 laccase, acetosyringone, ascorbic acid, and dehydroascorbic acid were investigated in vitro, then applied in artificially contaminated corn for AFB(1) reduction. AFB(1) (0.1 mu g/mL) was completely removed in vitro and reduced by 26% in corn. Several degradation products were detected in vitro by UHPLC-HRMS and likely corresponded to AFQ(1), epi-AFQ(1), AFB(1)-diol, or AFB(1)dialehyde, AFB(2a), and AFM(1). Protein content was not altered by the enzymatic treatment, while slightly higher levels of lipid peroxidation and H2O2 were detected. Although further studies are needed to improve AFB1 reduction and reduce the impact of this treatment in corn, the results of this study are promising and suggest that Ery4 laccase can be effectively applied for the reduction in AFB(1) in corn.

Automated summary

Aflatoxins (AFs), toxic secondary metabolites produced by Aspergillus spp., are globally present as contaminants in food and feed. Climate change is expected to increase AFs occurrence in western Europe. Enzymatic degradation, specifically using Ery4 laccase, acetosyringone, ascorbic acid, and dehydroascorbic acid, has been investigated for AFs reduction in corn. The study showed promising results, with complete AFs removal in vitro and a 26% reduction in corn, although further research is required to improve the efficacy and minimize potential impacts on corn.