Antioxidant activity and phenolic content of oat as affected by cultivar and location

Phenolic compounds in oat (Avena sativa L.) may have health-promoting effects on humans due to their antioxidant or other properties. The objective of this study was to determine the effects of cultivar and location on phenolic contents and antioxidant activities of alcohol-soluble extracts from oat groats. Antioxidant activities (AOA) and concentrations of eight phenolic compounds having AOA were measured in three cultivars grown at seven locations in Wisconsin during 1998. There were significant differences among cultivars for AOA, concentrations of all of the phenolic compounds measured except p-coumaric and ferulic acids, and for total free phenolic contents (FPC). Location significantly affected the concentrations of five of the phenolics and total FPC, but did not affect AOA. There were significant cultivar X location interactions for the concentrations of avenanthramides and for total FPC. The unexpectedly high concentrations of avenanthramides from the Sturgeon Bay location were confirmed by analysis of groats from 1999 and 2000. It should be possible to improve the AOA and phenolic concentrations of oat as quantitative traits in a cultivar development program, but significant location effects may attenuate rapid progress.