Antioxidant activity, phenol and flavonoid contents of eleven Iranian barley grain varieties (Hordeum vulgare L.)

Cultivated barley, Hordeum vulgare L., belongs to the grass family Poaceae. Barley is a widely consumed cereal, because of its dietary and technological properties. There have been some studies on the antioxidant activity and phenolic content of barley. Total phenolic and flavonoid contents of the extracts were determined using the Folin–Ciocalteu and Aluminium chloride methods, respectively. The objectives of the present study were to investigate the antioxidant activities of methanolic extract of eleven Iranian barley varieties and to establish the relationships between antioxidant activity and total phenolic and flavonoid contents. The total phenolic content of extracts was in the range of 56.6 and 142.7 mg gallic acid equivalent (GAE) /g of extract. UH-12 and Kavir showed the highest amount with 142.7 and 106.8 GAE /g of extract, respectively. The total flavonoid contents were in the range of 26.6 and 65.6 mg quercetin equivalent (QE)/g of extract, respectively, by reference to standard curve. UH-12 and Kavir showed the highest amount with 65.6 and 62.0 QE /g of extract, respectively. Nimrooz and Valfajr with 78.9 and 74.6 percent inhibition at 400 ?g ml-1 were the most active antioxidant in this series. No correlation found between phenol contents and antioxidant activity and flavonoid contents and antioxidant activity in barley grain varieties (r2 < 0.1).