Evaluation of phytochemicals content, antioxidant activity and mineral composition of selected edible flowers

Fourteen edible flowers used in cooking were investigated in order to obtain quantitative information on the phytochemicals content and mineral composition. Additionally, the antioxidant capacity was also evaluated by employing 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. These analyses were performed in extracts prepared from flowers and vegetative parts and the results showed that contents of total phenolics, ortho-diphenols and flavonoids were high in flower extracts. Results also revealed considerable variation among the fourteen edible flowers extracts in total phenols (9.89-79.78 mg gallic acid equivalent/g of dry weight), orthodiphenols (14.90-238.61 mg gallic acid equivalent/g of dry weight) and flavonoids (2.62-56.86 mg catechin equivalents/g of dry weight). Correlation analysis indicated a moderately positive correlation between antioxidant activity and the contents of phenolic and ortho-diphenol compounds. In addition, the results of this study also showed that all edible flowers are major sources of mineral elements, especially potassium, magnesium, calcium, and sodium with an average concentration of 5,861, 542.0, 274.2 and 218.0 mg/100 g of dry weigh, respectively. Flowers also contain appreciable amounts of essential trace metals, such as zinc, selenium and manganese. Data obtained confirmed that edible flowers are good sources of minerals and phytochemicals, namely antioxidants, therefore their inclusion in cooking can provide health benefits.