Color, Antioxidant Capacity and Flavonoid Composition in <i>Hibiscus rosa</i>-<i>sinensis</i> Cultivars

Abstract

Hibiscus rosa-sinensis plants are mainly cultivated as ornamental plants, but they also have food and medicinal uses. In this work, 16 H. rosa-sinensis cultivars were studied to measure their colorimetric parameters and the chemical composition of hydroethanolic extracts obtained from their petals. These extracts were characterized using UHPLC-ESI+-Obitrap-MS, and their antioxidant activity was evaluated using the ORAC assay. The identified flavonoids included anthocyanins derived from cyanidin, glycosylated flavonols derived from quercetin and kaempferol, and flavan-3-ols such as catechin and epicatechin. Cyanidin-sophoroside was the anthocyanin present in extracts of lilac, pink, orange, and red flowers, but was not detected in extracts of white or yellow flowers. The total flavonol concentration in the flower extracts was inversely proportional to the total anthocyanin content. The flavonol concentration varied according to the cultivar in the following order: red ®/g sample (white cultivar) to 3840 µmol Trolox®/g sample (red cultivar).

Keywords

• <i>Hibiscus rosa-sinensis</i>
• color
• flavonoids
• antioxidant capacity