Determination of phenolic compounds, flavonoids, and antioxidant activities in water extracts of Thai red and white rice cultivars.

Background: Free radical-induced oxidative stress damages cellular components leading to many human diseases. Plant-derived antioxidant compounds have become a profitable alternative to prevent oxidative stress in cells.

Objective: To determine and compare total phenolic and flavonoid contents as well as antioxidant activity using both chemical and cell assays in the water extracts of brown rice and rice bran from two Thai rice cultivars: Sangyod, a red pigmented rice typically grown in Southern Thailand and Dawk Mali 105, a commercial white-colored rice.