Total phenolic contents and antioxidant capacities of 51 edible and wild flowers

Antioxidant capacities of 51 edible and wild flowers from China were systemically evaluated using ferric-reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays, and their total phenolic contents were measured by Folin-Ciocalteu method. The lipophilic components of flowers 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. The results showed that different flowers had diverse antioxidant capacities and phenolic compounds were a major contributor to their antioxidant activities. Rosa rugosa, Limonium sinuatum, Pelargonium hortorum, Jatropha integerrima and Osmanthus fragrans were found to have the highest antioxidant capacities. Homogentisic acid, cyanidin-3-glucoside, protocatechuic acid, catechin, gallic acid and epicatechin were quantified in these flowers using HPLC analysis. These flowers should save as potential rich resources of natural antioxidants for use as functional food ingredients or pharmaceuticals for control of diseases caused by oxidative stress.