Antioxidant properties and color of Hibiscus sabdariffa extracts

Abstract

100 g -1 of calyces. The total monomeric anthocyanin content (209±21 mg . 100 g -1 ) was similar to that obtained using the HPLC technique (215±31 mg . 100 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.

Optimization of heat- and ultrasound-assisted extraction of anthocyanins from Hibiscus sabdariffa calyces for natural food colorants

“…In general, these levels are higher than those found in the literature (Table 1). Salazar-González et al (2012) obtained up to 2.08 mg CT/g P (1.33 mg C1/g and 0.75 mg C2/g) when performing a 120-min extraction with ethanol:water mixtures (50:50, v/v) at a S/L of 100 g/L and room temperature. Up to 7.92 mg CT/g R (4.11 mg C1/g and 3.81 mg C2/g) were achieved by Sindi et al (2014) with aqueous extractions of 10 min at 100°C.…”

“…Most of the phytochemical studies on the H. sabdariffa constituents have been directed towards the characterization of pigments, namely anthocyanins (Ali et al, 2005;Beye, Hiligsmann, Tounkara, & Thonart, 2017;Jabeur et al, 2017). Delphinidin-3-glucoside, cyanidin-3-glucoside, and in particular delphinidin-3-sambubioside (hibiscin) and cyanidin-3-sambubioside (gossypicyanin) have been identified in calyx extracts (Alarcón-Alonso et al, 2012;Beye et al, 2017;Salazar-González, Vergara-Balderas, Ortega-Regules, & Guerrero-Beltrán, 2012). These anthocyanins are responsible for the characteristic red colour of the H. sabdariffa calyces and can be recovered for subsequent use as colorants in different industrial sectors.…”

Roselle calyces (Hibiscus sabdariffa), an alternative to the food and beverages industries: a review

“…Mungole (2011) reported an EC 50 of 0.13 mg/mL and 88.03 % inhibition in alcoholic Roselle extracts. Mohd-Esa et al (2010) conducted a study for determining phenolics content of different parts of Roselle plant (seed, calyces, leaf, and stem); they reported a content of total phenols (by Folin-Ciocalteu method) of 1.85±0.1 mg Gallic acid/g of calyces (30.8±1.4 % of inhibition) in aqueous extracts, and 2.91±0.07 mg Gallic acid/g of calyces (87.9± González et al (2012) reported 209±21 mg anthocyanins/ 100 g (differential pH method), 2,415 ± 96 mg Gallic acid/100 g (Folin-Ciocalteu method), and 8,035±220 μM Trolox/100 g (about 2,011.1 mg Trolox/100 g) (ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) method) of Roselle using a 50:50 ethanol:water ratio. Cid-Ortega and Guerrero-Beltrán (2014) reported a content of anthocyanins (differential pH method) and total phenols (Folin-Ciocalteu method) in Roselle calyces extracts from powder (average particle size of 0.55±0.016 mm) of 451.4±28.1 mg/100 g and 2,016.2±159.8 mg Gallic acid/100 g, respectively, carrying out the extraction with 50 % ethanol at 50°C for 30 min.…”

Roselle Calyces Particle Size Effect on the Physicochemical and Phytochemicals Characteristics

“…The extracts were obtained by stirring; they mixed one gram of Roselle in one L of solvent for 2 hours at room temperature. Salazar-González et al (2012), who used the same Roselle variety, as the one used in this study, reported an anthocyanins concentration of 209 ± 21 mg/100 g of Roselle and a total phenolics content of 2415 ± 96 mg/100 g of Roselle in 50:50 % (v/v) ethanol:water extracts. Differences in results from this work and other studies are mainly due to the variety of Roselle, as well as sample:solvent ratio, extracting method, and type of solvent.…”