Ciencia e investigación agraria
versão On-line ISSN 0718-1620
SALAZAR-GONZALEZ, Claudia; VERGARA-BALDERAS, Fidel T; ORTEGA-REGULES, Ana E e GUERRERO-BELTRAN, José Á. Antioxidant properties and color of Hibiscus sabdariffa extracts. Cienc. Inv. Agr. [online]. 2012, vol.39, n.1, pp.79-90. ISSN 0718-1620. http://dx.doi.org/10.4067/S0718-16202012000100006.
Liquid extracts of dried Roselle (Hibiscus sabdariffa) calyces obtained using ethanol:water (50:50 and 70:30%, v/v), water, ethanol:1.5 N HCl (85:25%, v/v), and ethanol (96%) to evaluate selected antioxidant characteristics (phenolic compounds and antioxidant capacity), color parameters (L, a, and b), and anthocyanins (delphinidin-3-O-sambubioside, delphinidin-3-O-glucoside (myrtillin), and cyanidin-3-O-sambubioside) by high performance liquid chromatography (HPLC). The total monomeric anthocyanin content was also assessed using the differential pH technique. The phenolic compound content ranged from 1,067±22 (in ethanol) to 2,649±96 (in ethanol:water 70:30%) mg of gallic acid100 g-1 of dehydrated calyces, and the antioxidant capacity ranged from 3.11±0.50 (in ethanol) to 8.0±0.2 mmoles of trolox100 g-1 of calyces. The total monomeric anthocyanin content (209±21 mg100 g-1) was similar to that obtained using the HPLC technique (215±31 mg100 g-1) when extracting the calyces with the 50:50% (v/v) ethanol:water solution. The deepest red-purple (Hue = 62.50±0.34) colored solution was observed when extracting the calyces with ethanol. The antioxidant and color properties of Roselle calyces make the extracts ideal for use in foods as a natural extract, concentrate, or powder.
Palavras-chave : Anthocyanins; antioxidant capacity; cyanidin-3-O-sambubioside; delphinidin-3-O-sambubioside; delphinidin-3-O-glucoside; myrtillin; Hibiscus sabdariffa; Roselle calyces.