Increasing Antioxidant Levels in Oats

MADISON, Wis.Researchers at the Cereal Crops Research Unit are exploring the biological function of avenanthramides (Avns) in oats and how increased Avn levels could lead to higher antioxidant levels in the foods we eat. Avns is a metabolite with potent antioxidant properties found exclusively in oats. Previous studies found an increased production of Avns in oat leaves when the plant is attacked by a fungus, leading researchers to believe it plays an antimicrobial role.

Researchers examined the correlation between crown rust pressure and Avn concentration in the oats, testing 16 oat cultivars and two breeding lines at three locations over two years. Genotypes with the strongest crown rust resistance typically had the highest Avn concentrations in environments where crown rust occurred. They also found Avn production is likely influenced by additional environmental factors, as not all cultivars with strong crown rust resistance produced high Avn concentrations. Their results suggest that oat breeders can select certain cultivars for enhanced production of Avns.

Though there are at least 25 structural varieties of Avns found in oats, three formsavnA, avnB, and avnCare most abundant in the grain. Researchers also were able to create pure synthetic compounds of each type. They also developed a suspension culture system from oat shoot tissue in which Avns are produced in response to a chemical that mimics fungal infection. The suspension cultures produce large amounts of avnA and avnG and, under certain culture conditions, avnB and avnC.