Evaluation of Free Radical Scavenging Activity and Antioxidant Potential of a Few Popular Green Leafy Vegetables of Malaysia

In this study, phenolic contents and antioxidant activity of five popular green leafy vegetables of Malaysia—Kangkung, Kucai, Di Huang Miao, Ubi Keledek, and Yaw Mak Choy—were evaluated. Methanol, acetone, and distilled water were the solvent systems used for extraction. The antioxidant capacity of the extracts was evaluated using ferric reducing antioxidant potential assay and the free radical scavenging capacity was evaluated using the DPPH· radical-scavenging assay. The total flavonoids, flavonols, and tannins were also quantified. The efficacy of the three solvents used for extraction differed significantly for both the levels of antioxidants and free radical scavenging activity. In general, methanol was the best of the three solvents for extraction of antioxidants. The results of this study will be useful for health conscious consumers, and they will provide a basis for future exploration of these green leafy vegetables as potential sources of natural antioxidants for food and nutraceutical applications.