Researchers from the U.S. Department of Agriculture’s Agricultural Research Service (USDA-ARS) and Bradley University have developed a device that helps prevent mycotoxin contamination during barley malting.

The Food Safety Issue of Mycotoxins

The novel solution addresses mycotoxins produced by Fusarium graminearum, which can infect cereal crops during flowering. Even low levels of fungal contamination in grains used in brewing and malting pose a significant food safety risk, as mycotoxins continue to accumulate during the malting process.

Exposure to mycotoxins is associated with serious harms to human health, affecting the endocrine and immune systems, damaging the liver and kidneys, causing miscarriages and developmental damage, and contributing to cancer. Additionally, mycotoxin contamination of food crops is expected to worsen due to the effects of climate change.

A New ‘Bio-Fumigation’ Method Based on a Natural Compound

Led by USDA-ARS Plant Physiologist William Hay, Ph.D., a team of researchers at the National Center for Agricultural Utilization Research (NCAUR) in Peoria, Illinois discovered that a natural gaseous compound called allyl isothiocyanate, which is produced by mustard plants, can limit fungal growth and prevent mycotoxin contamination during malting. Importantly, this compound is already approved by U.S. regulatory agencies and is used by industry as a food additive and flavoring.

Using this compound, the researchers developed a bio-fumigation method in the laboratory that completely prevented mycotoxin accumulation without damaging barley seeds or leaving unsafe residues post-processing. These findings were published in ACS Agricultural Science & Technology.

Engineering a Micro-Malting Prototype that Improves Food Safety

Building upon this discovery, Dr. Hay received a USDA Innovation Grant to help the malting and brewing industry adopt the new bio-fumigation treatment. He collaborated with Bradley University Mechanical Engineering Professor Ahmad Fakheri, Ph.D. and fellow USDA-ARS scientist Jason Walling, Ph.D., Director of the Cereal Quality Lab in Madison, Wisconsin.

Guided by Drs. Hay, Fakheri, and Walling, Bradley University mechanical engineering students participated in a multi-year capstone project to create a self-contained micro-malting machine that is not only capable of malting, steeping, germinating, and kilning cereal grains, but also incorporates the mycotoxin bio-fumigation process while preserving grain viability and malt quality.

The resulting micro-malting prototype is both effective and scalable.

Working Toward Industry Adoption

Now, ARS researchers are collaborating with the American Malting Barley Association (AMBA) and the Distiller's Technology Council to ensure the new technology is accessible to both micro-breweries and large-scale operations, with the goal of enhancing food safety industry-wide.

“Although malting barley is selected to minimize fungal contamination, it is not feasible to eliminate all microbes from the barley supply chain,” said Scott Heisel, President, AMBA. “We are excited to see a fumigation method using natural compounds to inhibit fungal growth during processing. It represents a viable strategy for preserving barley quality and delivering added value to both producers and consumers.