We investigated the phenolic compounds and antioxidant capacities of free and bound
phenolics from 12 available Thai edible flowers which have long been consumed as vegetable and used as ingredients in cooking. Cassia siamea showed the highest value of total
phenolic content (TPC) (88 mg gallic acid equivalents (GAE)/g dry weight). Tagetes erecta
had the highest total flavonoid content (TFC) (68.9 mg RE/g dry weight). Antigonon leptopus
and T. erecta had the highest ferric reducing antioxidant power (FRAP) value (62.0 and
60 mmolFeSO4/g 100 dry weight). Major phenolic acids identified in these analyses were
gallic acid, ferulic acid and sinapic acid, while predominant flavonoids were quercetin
and rutin. The results of this study showed that soluble as well as bound fractions of edible
flowers are rich sources of phenolic compounds with antioxidant, DPPH radical-scavenging
activity and reducing power. This study has provided useful information for screening edible flowers as potential sources of bioactive components with high antioxidant properties
that may be of interest to consumers and public health workers.