Determination of antioxidant property and their lipophilic and hydrophilic phenolic contents in cereal grains

In order to supply new information on the antioxidant function of cereal foods, the antioxidant activity and total phenolic contents of both lipophilic and hydrophilic components of 24 cereal grains from China were systematically evaluated using spectrophotometric methods. The lipophilic components of cereals were extracted with tetrahydrofuran, and the hydrophilic ones were extracted with a methanol-acetic acid-water (50:3.7:46.3, v/v/v) mixture. Main phenolic compounds and their contents were also quantified using high-performance liquid chromatography equipped with a photodiode array detector. The results showed that different cereals had diverse antioxidant capacities and the variation was very large. Phenolic compounds gallic acid, kaempferol, quercetin, galangin and cyanidin 3-glucoside were widely found in those cereals. The pigmented cereals, such as black rice, red rice and purple rice, possessed the highest antioxidant capacities and total phenolic contents among tested cereals, and could be important sources of natural antioxidants for health promotion and disease risk reduction. (C) 2012 Elsevier Ltd. All rights reserved.