Abstract

REYES-LUENGAS, Alberto et al. Analysis of phenolic acids and antioxidant activity of aqueous extracts of jamaica (Hibiscus sabdariffa L.) varieties with calyxes of different colors. Agrociencia [online]. 2015, vol.49, n.3, pp.277-290. ISSN 2521-9766.

The growing market of functional beverages requires characterize specifically the sources of bio-actives to select those with the highest quantity of the compound needed in the formulation. The composition of phenolic acids and the content of anthocyanins and proanthocyanidins, from aqueous extracts of the calyxes of three varieties of jamaica (Hibiscus sabdariffa L.) were assessed using HPLC-DAD: dark red (Sudan), light red (Criolla Nayarit) and white (Alma Blanca). Antioxidant activity was also determined. The experimental design was completely randomized with three replications. The highest contents of total phenolic acids were detected in Sudan and Alma Blanca (10.71±0.29 and 8.22±0.30 mg GAE g^-1 DM). The fraction of free phenolic acids (FPA) was abundant and was highly complex in the calyxes of the three colors. Chlorogenic acid and its two isomers were predominant in the FPA, and the glycosylated phenolic acids (GPA) accounted for 77.4 to 81.5 % of the total phenolic acids in the three varieties. The white Alma Blanca calyxes contained more caffeic and protocatechuic acid derivatives than the red calyxes of the other varieties. The highest antioxidant activity (p≤0.05) was found in the Sudan extract (CI₅₀=113.3 μg mL^-1). The color of the calyxes can indicate the predominant type of phenols in H. sabdariffa L. and aid in the selection of varieties for formulations with particular nutraceutical properties.

Keywords : Hibiscus sabdariffa L.; phenols; calyx; color; antioxidant activity.

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