Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2010
Publication Date: 4/1/2011
Citation: Inglett, G.E., Chen, D., Berhow, M., Lee, S. 2011. Antioxidant activity of commercial buckwheat flours and their free and bound phenolic compositions. Food Chemistry. 125:923-929. Interpretive Summary: In this research, we found that buckwheat flours contained high levels of phenolic compounds, antioxidant activities, and flavonoid contents. With the current interests on healthy foods, buckwheat flours are of considerable interest for their health related properties related to people who are celiac sensitive to wheat gluten. Also, many of the health benefits of buckwheat flours are attributed to their high levels of phenolic compounds and antioxidant activities. Whole buckwheat flour contained 2-5 times more phenolic compounds than oats or barley, while buckwheat bran and hulls had 2-7 times higher antioxidant activity than barley, triticale, and oats. These results should result in the increased use of buckwheat flours for increasing the health benefits of some foods.
Technical Abstract: Buckwheat flours (Whole, Farinetta, Supreme, and Fancy) were investigated for their compositions, free and bound phenolic contents, antioxidant activities, and flavonoid contents using spectrophotometer and LC-ESI-IT- MS (LC-MS). Farinetta flour contained the highest oil, protein, and free and bound phenolic contents, followed by Supreme flour, whole buckwheat flour, and Fancy flour, respectively. Overall, the 50% ethanol extraction achieved significantly higher free phenolic content compared to water and absolute alcohol. However, the absolute ethanol extraction contained considerable more bound phenolic and flavonoid compounds. A high extraction temperature enhanced the phenolic and flavonoid contents under certain conditions. The results of antioxidant activities were not conclusive as obtained for the phenolic contents. The optimal solvent to solids ratio was 50:1, and the optimal extraction time was 5 h for flavonoid contents. The spectral method was reproducible for analyzing the total flavonoid contents. The LC-MS analysis was suitable for indentifying the specific flavonoid compounds.