Evaluation and mitigation of mycotoxin contamination across the Scottish cereal supply chain to assess human exposure and inform risk analysis

Challenges

Chemical food contaminants are a persistent problem when assuring the provision of safe and healthy foods for consumers. Cereals are frequently contaminated with mycotoxins produced by a fungal infection of grains in the field or storage. Guidance on good agricultural practices to minimize risks of Fusarium fungi and mycotoxins in UK wheat is available. As demand for high-quality UK food oats increases, guidance for growers to improve agronomy practices has also been developed. Prevention of Fusarium fungi and mycotoxins is, to date, not included in such advice. 

Once a cereal is contaminated, mycotoxins are subject to further plant metabolism, resulting in conjugated metabolites, so-called masked mycotoxins, which co-occur in cereal grains. Masked mycotoxins are not toxic per se, but the human gut microbiota releases free mycotoxins in the colon, which will contribute to exposure. 

The fate of some Fusarium mycotoxins, such as deoxynivalenol and its masked form deoxynivalenol-glucoside, has been well described in humans and validated urinary biomarkers are available to assess exposure. However, accurate assessments of dietary exposure to potent mycotoxins T-2 and HT-2 toxins in humans are very limited. Our preliminary work has shown that increased oat consumption resulted in increased urinary excretion of T2 and HT2, and there is an urgent need to better understand the absorption of T2 and HT2 and their masked forms from food and their metabolism in humans to fully validate urinary biomarkers to be used in human biomonitoring studies. 

Overall, the production of T2 and HT2 and their masked forms in oat cereals, their fate through processing and their contribution to overall exposure in humans are not well understood.

Questions

Solutions

This project aims to minimize the risk to consumers from mycotoxin contamination in cereal foods by improving our understanding of the sources of contamination in primary cereal production and processing and by assessing human exposure and risk through biomarker analysis.

Understanding contamination within the cereal industry and supporting testing 

We are improving our understanding of contamination within the cereal industry and testing common, commercially available tests for a range of type A trichothecenes and their masked forms in cereals. Several commercial tests are available for the determination of regulated mycotoxins in cereals. However, these methods are validated for specific free mycotoxins and their ability to detect masked forms is less well described especially for type A trichothecenes.

Identifying key intervention points to prevent and minimise mycotoxin contamination in the cereal supply chain

Much research has been conducted to identify the main drivers of fungal growth and mycotoxin production in agricultural systems with the main focus on Aspergillus fungi in maize and Fusarium fungi in wheat. These studies have identified a range of drivers from climate parameters to varietal differences and agronomy practices that are increasing the risk for fungal infection and mycotoxin contamination. However, less attention has been given to the oat supply chain and the production of mycotoxins and masked mycotoxins in oat cereals. The oat crops have already been identified to be at risk of mycotoxin contamination. This project focuses on identifying key intervention points in oat production and processing to minimise contamination. 

Inform risk assessment of human mycotoxin exposure through oat foods

Urinary biomonitoring is an important tool to assess dietary exposure to mycotoxins in consumers. Validated biomarkers exist for some mycotoxins, but the fate of type A trichothecenes and their masked forms in the human body is not well understood. We are predicting the bioaccessibility of mycotoxins from oat foods and confirming the findings in a human diet intervention to fully validate urinary biomarkers.

Project Partners

Progress