The free and bound phenolic compounds in 10 common Chinese edible flowers were investigated using reversed phase high-performance liquid chromatography. Their antioxidant capacities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging activity, oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), and cellular antioxidant activity (CAA).
Of the flowers Paeonia suffruticosa and Flos lonicerae showed the highest total phenolic content (TPC) 235.5 mg chlorogenic acid equivalents/g of dry weight and total flavonoid content 89.38 mg rutin equivalents/g of dry weight. The major phenolic compounds identified were gallic acid, chlorogenic acid, and rutin. P. suffruticosa had the highest antioxidant capacity in the DPPH, ABTS, and ORAC assays, whereas Rosa chinensis had the highest FRAP value.
Edible flowers have been used in China for centuries, where they constitute an essential ingredient in a recipe, act as seasoning or garnish. Phenolics have been linked with anti-inflammatory activity, reduced risk of cardiovascular disease and cancer. The specific nature of the anti-oxidant mechanism still needs to be established.
Lina Xiong, Jiajia Yang, Yirong Jiang, Baiyi Lu, Yinzhou Hu, Fei Zhou, Shuqin Mao, Canxi Shen. Phenolic Compounds and Antioxidant Capacities of 10 Common Edible Flowers from China. Journal of Food Science, 2014; 79 (4): C517 DOI: 10.1111/1750-3841.12404