A comparative evaluation: phytochemical composition and antioxidant capacity of three roselle (Hibiscus sabdariffa L.) accessions
An increased consumption and demand in international trade suggests a need for quality assurance of roselle (Hibiscus sabdariffa) products. A liquid chromatography-mass spectrometry method was developed for the determination of anthocyanin profiles of the calyces, phenolic acids and flavonoids of the leaves of Jamaica, Senegal and Malaysia accessions. Delphinidin-sambubioside, delphinidin-glucoside, cyanidin-sambubioside, cyanidin-glucoside and delphinidin were identified from the calyces of these accessions. Chlorogenic acid and its isomers, glycosylated derivatives of quercetin and kaempferol, and 5-(hydroxymethyl) furfural were identified from the leaves of these accessions. No significant differences in anthocyanins among accessions were found, except the accession from Malaysia, which contained significantly (P<0.05) higher amounts of delphinidin-glucoside and delphinidin. The total phenols determined by Folin-Ciocalteu's assay were 15.92+1.12, 17.63+0.7, and 19.25+1.10 mg g-1 for the calyces of Jamaica, Malaysia and Senegal, respectively, and 23.76+2.16, 22.28+1.77 and 20.62+1.61 mg g-1 for the leaves of Malaysia, Senegal and Jamaica, respectively, calculated as gallic acid equivalents. The Senegal accession contained a higher (P<0.05) amount of total phenols in calyces than the Jamaica accession. The antioxidant activities determined by the ABTS radical cation decolorization assay were 64.38+1.56, 60.36+3.34 and 62.49+2.69 mg g-1 for the calyces and 111.43+7.17, 121.84+12.55 and 110.68+10.27 mg g-1 for the leaves of Malaysia, Senegal and Jamaica, respectively, as Trolox equivalents. Macro- and micro-nutrient elements varied significantly (P<0.05) among accessions. This study reveals variability in phenolic, antioxidant and elemental nutrient contents and suggests that the selection of roselle accessions can influence the quality of developed products.
Chin, K.L., Zhen, J., Qi, Y., Chin, S.L., Breithaupt, M., Wu, Q.L., Simon, J., Henson, J. and Ferchaud, V. (2016). A comparative evaluation: phytochemical composition and antioxidant capacity of three roselle (Hibiscus sabdariffa L.) accessions. Acta Hortic. 1125, 99-108
anthocyanin, polyphenol, antioxidant, calyces, leaves, nutrient elements