Total antioxidant activity

The total antioxidant activity of teas and tea polyphenols in aqueous phase oxidation reactions has been deterrnined using an assay based on oxidation of 2,2 -azinobis-(3-ethylbenzothiazoline-sulfonate) (ABTS) by peroxyl radicals (114—117). Black and green tea extracts (2500 ppm) were found to be 8—12 times more effective antioxidants than a 1-mAf solution of the water-soluble form of vitamin E, Trolox. The most potent antioxidants of the tea flavonoids were found to be epicatechin gallate and epigallocatechin gallate. A 1-mAf solution of these flavanols were found respectively to be 4.9 and 4.8 times more potent than a 1-mAf solution of Trolox in scavenging an ABT radical cation. 

SOLID-PHASE REDOX REAGENTS FOR THE DETERMINATION OF BIO ANTIOXIDANTS AND TOTAL ANTIOXIDANT ACTIVITY... 

Consequently, the antioxidant activity of GA in biological systems is still an unresolved issue, and therefore it requires a more direct knowledge of the antioxidant capacity of GA that can be obtained by in vitro experiments against different types of oxidant species. The total antioxidant activity of a compound or substance is associated with several processes that include the scavenging of free radical species (eg. HO, ROO ), ability to quench reactive excited states (triplet excited states and/ or oxygen singlet molecular 1O2), and/or sequester of metal ions (Fe2+, Cu2+) to avoid the formation of HO by Fenton type reactions. In the following sections, we will discuss the in vitro antioxidant capacity of GA for some of these processes. 

The on-line measurement of reducing capacity can be performed with either a single or a series of electrochemical detectors, and linear correlations have been demonstrated between total antioxidative activities determined by the electrochemical detection and those determined by DPPH- reduction or by the ORAC assay (Guo et al, 1997 Peyrat-Maillard et al, 2000). The reducing capacity must also be quantified by post-column reactions, either with DPPH- or by the reduction of phosphomolybdenum complexes followed by UV-VIS-detection (Bandoniene and Murkovic, 2002 Cardenosa et al, 2002). A combination of HPLC and semi-automatic ORAC analysis has also been described (Caldwell, 2001). 

BENZIE i FFand STRAIN J J (1999) Ferric reducing/antioxidant power assay Direct measure of total antioxidant activity of biological fluids and modified version for simultaneous measurement of total antioxidant power and ascorbic acid concentration, Meth Enzymol, 299, 15-27. 

Mahattanatawe K, Manthey JA, Luzio G, Talcott ST, Goodner K and Baldwin EA. 2006. Total antioxidant activity and fiber content of select Florida-grown tropical fruits. J Agric Food Chem 54 7355—7363. 

Miller NJ and Rice-Evans CA. 1997. The relative contributions of ascorbic acid and phenolic antioxidants to tiie total antioxidant activity of orange and apple fruit juices and blackcurrant drinks. Food Chem... 

Amao MB, Cano A and Acosta, M. 2001a. The hydrophilic and lipophilic contribution to total antioxidant activity. Food Chem 73(2) 239—244. 

Cano A, Hemandez-Ruiz J, Garcia-Canovas F, Acosta M and Arnao MB. 1998. An end-point method for estimation of the total antioxidant activity in plant material. Phytochem Anal 9(4) 196-202. 

Ismail A, Marjan ZM and Foong CW. 2004. Total antioxidant activity and phenolic content in selected vegetables. Food Chem 87(4) 581-586. 

Kusznierewicz B, Bartoszek A, Wolska L, Drzewiecki J, Gorinstein S and Namiesnik J. 2008. Partial characterization of white cabbages (Brassica oleracea var. capitata f. alba) from different regions by glucosinolates, bioactive compounds, total antioxidant activities and proteins. LWT Food Sci Technol 41 (1) 1 —9. 

Patras A, Brunton NP, DaPieve S and Butler F. 2009. Impact of high pressure processing on total antioxidant activity, phenolic, ascorbic acid, anthocyanin content and colour of strawberry and blackberry puree. Innov Food Sci Emerg Technol doi 10.1016/j.ifset.2008.12.004. 

The Outcome of 37 Studies in Which Volunteers Were Given Foods, Beverages, or Supplements Rich in PPT and Plasma was Analyzed for Total Antioxidant Activity... 

NJ Miller, AT Diplock, CA Rice-Evans. Evaluation of the total antioxidant activity as a marker of the deterioration of apple juice on storage. J Agric Food Chem 43 1794 -1801, 1995. 

Bramati L, Aquilano F, Pietta P. 2003. Unfermented roooibos tea Quantitative characteriztion of flavonoids by HPLC-UV and determination of total antioxidant activity. J Agric Food Chem 51 7472-7474. 

Effect of Nutrition on Total Antioxidant Activity of Body Fluids. 254... 

The sum of antioxidant activities of this nonspecific pool of antioxidants is often called total antioxidant capacity (TAC). A number of synonyms of this term have been used in the literature, one of the most frequent being total antioxidant activity. It has been suggested that the term antioxidant activity should be restricted to characterize the rate constant of a single antioxidant against a given oxidant... 

Fig. 9. Total antioxidant activity of commonly consumed fruits and vegetables estimated with three different methods. Data of Proteggente et al. (P24). TAC was estimated by TEAC (R3), FRAP (B8), and ORAC (Cl5).

A9. Alho, H., and Leinonen, J., Total antioxidant activity measured by chemiluminescence methods. Meth. Enzyntol. 299, 3-14 (1999). 

G16. Grodzinska, L., Jachym, R., Slawinski, M., and Robak, J., Influence of bezafibrate on total antioxidant activity of serum and deformability of blood cells in hypercholesterolaemic patients. Pol. J. Pharmacol. 50, 361-364 (1998). 

K3. Kar Man Choy, C., Benzie, I. F. F., and Cho, P., Ascorbic acid concentration and total antioxidant activity of human tear fluid measured using the FRASC assay. Invest. Ophthalmol. 41, 3293— 3298 (2000). 

P12. Pizzichini, M., Fonzi, M., Gasparoni, A., Mencarelli, M., Rocchi, G., Kaitsas, V., andFonzi, L., Influence of amalgam fillings on Hg levels and total antioxidant activity in plasma of healthy donors. Bull. Group Int. Rech. Sci. Stomatol. Odontol. 43, 62-67 (2001). 

R16. Rice-Evans, C. A., Measurement of total antioxidant activity as a marker of antioxidant status in vivo Procedures and limitations. Free Radic. Res. 33, S59—S66 (2000). 

Surai, P. F., Blesbois, E., Grasseau, I., Chalah, T., Brillard, J. P., Wishart, G. J., Cerolini, S., and Sparks, N. H., Fatty acid composition, glutathione peroxidase and superoxide dismutase activity and total antioxidant activity of avian semen. Comp. Biochem. Physiol. B 120, 527—533... 

V13. Vento, G., Mele, M. C., Mordente, A., Romagnoli, C., Matassa, P. G., Zecca, E., Zappacosta, B., and Persichilli, S., High total antioxidant activity and uric acid in tracheobronchial aspirate fluid of preterm infants during oxidative stress An adaptive response to hyperoxia . Acta Paediatr. 89, 336-342 (2000). 

The comparison in terms of preservation of the total antioxidant activity and of the bioactive antioxidant components of the juice (ascorbic acid, anthocyanins, hydroxycinnamic acids, flavanones) demonstrates that this integrated membrane... 

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