The phenolic compounds and antioxidant capacities of orange juices obtained from cvs. Moro and Sanguinello (Citrus sinensis (L.) Osbeck) were determined. A high-performance liquid chromatographic method coupled with diode-array detection was used to identify and quantify phenolic compounds of the orange juices. A total of 18 phenolic compounds were identified and quantified in Moro and Sanguinello orange juices, including hydroxybenzoic acids (2), hydroxycinnamic acids (5), flavanones (5), and anthocyanins (6). It was observed that total phenolic content of Moro juice was higher than that of Sanguinello juice. Ferulic acid was the most dominant hydroxycinnamic acid and cyanidin 3-(6 ''-malonyl glucoside) and cyanidin 3-glucoside were the most dominant anthocyanins in both cultivars. Antioxidant activities of orange juices were measured using the DPPH. (2,2-diphenyl-1-picrylhydrazyl) method. According to DPPH assays, the antioxidant capacity of Moro juice was found to be higher than that of Sanguinello juice. (C) 2007 Elsevier Ltd. All rights reserved.