Impact of food processing and detoxification treatments on mycotoxin contamination

Abstract

Mycotoxins are fungal metabolites commonly occurring in food, which pose a health risk to the consumer. Maximum levels for major mycotoxins allowed in food have been established worldwide. Good agricultural practices, plant disease management, and adequate storage conditions limit mycotoxin levels in the food chain yet do not eliminate mycotoxins completely. Food processing can further reduce mycotoxin levels by physical removal and decontamination by chemical or enzymatic transformation of mycotoxins into less toxic products. Physical removal of mycotoxins is very efficient: manual sorting of grains, nuts, and fruits by farmers as well as automatic sorting by the industry significantly lowers the mean mycotoxin content. Further processing such as milling, steeping, and extrusion can also reduce mycotoxin content. Mycotoxins can be detoxified chemically by reacting with food components and technical aids; these reactions are facilitated by high temperature and alkaline or acidic conditions. Detoxification of mycotoxins can also be achieved enzymatically. Some enzymes able to transform mycotoxins naturally occur in food commodities or are produced during fermentation but more efficient detoxification can be achieved by deliberate introduction of purified enzymes. We recommend integrating evaluation of processing technologies for their impact on mycotoxins into risk management. Processing steps proven to mitigate mycotoxin contamination should be used whenever necessary. Development of detoxification technologies for high-risk commodities should be a priority for research. While physical techniques currently offer the most efficient post-harvest reduction of mycotoxin content in food, biotechnology possesses the largest potential for future developments.

Keywords: Biological detoxification; Chemical treatment; Decontamination; Mitigation; Natural toxins; Physical methods.

Fig. 1

Chemical structures of major mycotoxins and modification due to food processing. 1 de-epoxidation, 2 acetylation, 3 oxidation, 4 epimerization, 5 deamination, 6 glucosylation, 7 hydrolysis, 8 lactone cleavage (hydrolysis), 9 hydroxylation, 10 peptide cleavage, 11 sulfonation, 12 reduction, 13 ether cleavage

Fig. 2

Summary of physical and chemical processes applicable to food commodities in order to mitigate targeted mycotoxins. *Conversion to a more estrogenic cis-form. **Experimentally demonstrated on apple juice