A research team from the University of Illinois Urbana-Champaign suggests that far-ultraviolet C (far-UVC) light holds potential for reducing fungal contamination in maize and wheat.

The team sought to reduce fungal contamination in both maize and wheat because it can reportedly impact cereal market prices and result in revenue loss for farmers. Further, in the event that contaminated grain is downgraded to animal feed, the health problems associated with mycotoxins — for example, immune deficiency, cancer, kidney damage and fetal development effects — are transferred to livestock.

“Light-based technology is easy to use, and the cost is minimal compared to many other methods. However, conventional UVC lamps emit light at a wavelength of 254 nm, which can cause skin or eye damage to humans, so it’s not safe to use when workers or consumers are around. So instead, we are using a technology called microplasma-based far-UVC light. It emits light at 222 nm, a wavelength other studies have found to be safe for humans, even at prolonged exposure. We wanted to see if it can also be used to mitigate fungal contamination,” the researchers explained.

The team examined the efficacy of far-UVC light against two fungi that affect grains in the field: Aspergillus flavus and Fusarium graminearum. These fungi can potentially lead to losses in grain quality and also produce mycotoxins.

Far-UVC light was tested by suspending fungal spores in a liquid buffer and exposing them to varying doses. At the highest doses, 99.999% of Aspergillus and Fusarium spores were inactivated due to alterations in the spores’ cell membranes and mitochondria.

The second step involved testing the far-UVC light treatment against the two fungi’s mycelia — which is a network of strands that penetrate host plants’ tissues after spores germinate. The team reported that on agar plates, the growth of mycelia for both types of fungi was inhibited.

The researchers believe that the system could one day be used in food processing facilities.

The team’s findings are detailed in the article, “Mitigating fungal contamination of cereals: The efficacy of microplasma-based far-UVC lamps against Aspergillus flavus and Fusarium graminearum,” which appears in the journal Food Research International.

To contact the author of this article, email mdonlon@globalspec.com