Antioxidant power quantification of decoction and cold infusions of Hibiscus sabdariffa flowers

Abstract

In this paper the overall antioxidant power, expressed as Briggs-Rauscher antioxidant index, of decoction or cold infusions of dried Hibiscus sabdariffa flowers was determined at 25 and 37°C, to compare the scavenger ability of the beverages at either room or physiological temperature. Total polyphenol contents and the absorbance of anthocyanin pigments were also determined, and the trend with the overall antioxidant capability is considered. Combined photometric and pH-metric titrations were acquired to obtain information on the colour-total acidity relationship of the product. The results show that the decoction preparation protocol provides karkadè with the highest nutritional value and that the polyphenol content can account for the antioxidant capability of H. sabdariffa-based beverages. Moreover, a quantitative relationship between acid-base and redox chemistry was found. The H. sabdariffa-based drinks can be considered as protective beverages and a regular consumption of karkadè might be proposed to ensure protection against free radicals.

Effect of Colorant on Cytogenetic, Biochemical and Histochemical Parameters and Quality Changes during Storage of some Commercial Fruit Drinks

“…Degradation rate increases as corresponding with food properties and anthocyanins compositions. Many researchers [9,10] reported anthocyanin losses in different foods during storage. The importance of the assessment of the effect of colorants (anthocyanine drinks) on metabolism and upon the genetic make up of mankind is obviously a critical issue in the use of these chemicals.…”

Characterization of Superoxide Anion Scavenging Compounds in Roselle (Hibiscus sabdariffa L.) Extract by Electron Spin Resonance and LC/MS

“…Compared with those studies providing only the overall antioxidative information of Roselle (Hibiscus sabdariffa L.) extract (Degenhardt et al, 2000;Duh and Yen, 1997;Prenesti et al, 2007;Tsai and Huang, 2004;Tseng et al, 1997;Wang et al, 2000), the present approach investigated the superoxide anion scavenging capacities of the individual Roselle chemical species, in particular the contribution from ascorbic acid which has never been mentioned in the literature. As revealed by our study, the major superoxide anion scavenging chemicals in Roselle extract are ascorbic acid (ca.…”

“…Some recent reports showed that the anthocyanins extracted from Roselle exhibited high free radical scavenging capacity against several typical free radicals such as 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS + ), superoxide radical anion (O 2 -) and peroxyl radical (ROO) (Degenhardt et al, 2000;Duh and Yen, 1997;Prenesti et al, 2007;Tsai et al, 2002;Tsai and Huang, 2004;Tseng et al, 1997;Wang et al, 2000). In addition to anthocyanins, the large amount of ascorbic acid in Roselle may also help in preventing autooxidation (Wong et al, 2002;Wong et al, 2003).…”

An Electron Microscopic Study of the Antifertility Potential of Rosemary (Rosmarinus officinalis L.) in Male Albino Rats

“…The anti-oxidant activity of RO could be attributed to its phenolic contents, namely protocatechuic acid (Wang et al, 2000) and anthocyanins Tsai & Huang, 2004). RO has also been reported to prevent or attenuate decrease in tissue anti-oxidant enzymes in different animal models and to provide cellular protection against oxidative stress (Prenesti et al, 2007;Amin & Hamza, 2006). The essential action of RO essential oil is in stimulation of the nervous system under sympathetic control resulting in improved memorizing and concentrating abilities (Amin & Hamza, 2005).…”