Radical scavenging capacity

Besides all the sensory and texturizing properties, GA has interesting antioxidant properties such as an efficient capacity for deactivation of excited electronic states and moderated radical scavenging capacity. There is increasing experimental evidence that associate the antioxidant function with its protein fraction, mainly by amino acid residues such as histidine, tyrosine and lysine, which are generally considered as antioxidants molecules (Marcuse, 1960,1962 Park et al., 2005). 

Mercadante, A.Z. Alvarez, R.M.S. Borsarelli, G.D. (2009). Singlet oxygen quenching and radical scavenging capacities of structurally related flavonoids present in Zuccagnia punctata Gav. Free Radical Research, Vol.43, No.6, (January 2009), pp. 553-564, ISSN 1071-5762... 

ANCos B DE, GONZALES E M and CANO M p (2000) Ellagic acid, vitamin C, and total phenolic contents and radical scavenging capacity affected by freezing and frozen storage in raspberry fruit , J Agric Food Chem, 48 (10) 4565-70. 

ESPIN J c, soLER-RivAS c and WICKERS H J (2000) Characterization of total free radical scavenger capacity of vegetable oils and oil fractions using 2,2-diphenyl-1 -picryUiydrazyl radical, JAgric Food Chem, 48, 648-56. 

LARRAURi J A, SANCHEZ-MORENO c, RUPEREZ p and SAURA-CALIXTO F (1999) Free radical scavenging capacity in the aging of selected red Spanish wines, JAgric Food Chem, 47, 1603-6. 

Chanjirakul K, Wang SY, Wang CY and Siriphanich J. 2007. Natural volatile treatments increase free-radical scavenging capacity of strawberries and blackberries. J Sci Food Agric 87(8) 1463-1472. 

Choi CW, Kim SC, Hwang SS, Choi BK, Ahn HJ, Lee MY, Park SH and Kim SK. 2002. Antioxidant activity and free radical scavenging capacity between Korean medicinal plants and flavonoids by assay-guided comparison. Plant Sci 163(6) 1161-1168. 

Sanchez-Moreno C, Larrauri JA and Saura-Calixto F. 1999b. Free radical scavenging capacity and inhibition of lipid oxidation of wines, grape juices and related polyphenolic constituents. Food Res Int 32(6) 407—412. 

Sanchez-Moreno C, Larrauri, JA and Saura-Calixto L. 1999a. Lree radical scavenging capacity of selected red, rose and white wines. J Sci Food Agric 79(10) 1301—1304. 

Solerrivias C, Espin JC and Wickers HJ. 2000. An easy and fast test to compare total free-radical scavenger capacity of foodstuffs. Phytochem Anal 11 330—338. 

Wang SY and Ballington JR. 2007. Free radical scavenging capacity and antioxidant enzyme activity in deerberry (Vaccinium stamineum L.). LWT Food Sci Technol 40(8) 1352—1361. 

Ricardo DS, Darmon N, Eemandez Y et al (1991) Oxygen free radical scavenger capacity in aqueous models of different procyanidins from grape seeds. 1 Agric Pood Chem 39 1549-1552... 

Table 5.6 shows the total phenolic content (determined using the Folin-Ciocalteu assay) and antioxidant activity (ABTS radical scavenging capacity) of extracts from morama bean seed coat and cotyledon prepared with acidified mefhanol. If is clear fhaf morama bean seed coat and cotyledon have appreciable levels of fofal phenolics and antioxidant activity. These phenolics are concentrated in the seed coat. It has been reported that the morama bean cotyledon contains high levels of the amino acid tyrosine (Maruatona et ah, 2010) which is phenolic in nature and can therefore confribufe fo fhe fofal phenolic content of the cotyledon as determined with the Folin-Ciocalteu assay. 

Many EOs also exhibit antioxidant activity and therefore several studies have been carried out in order to elucidate the activity of the components [139,153]. For instance, y-terpinene retarded the peroxidation of linoleic acid [139, 154-156], sabinene showed strong radical-scavenging capacity [139, 157], a-pinene [158] and limonene [146] showed low antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test, while terpinene and terpinolene showed high hydrogen-donating capacity against the DPPH radical [146, 150, 155, 158],... 

FIGURE S.8 Changes in the molecular mass distribution of peptides and the radical-scavenging capacity of miso extracts prepared from unrinsed squid meat at different points in the fermentation period measured with an online HPLC-DPPH system. Source Giri et at. (2011a). Permission has been obtained for the use of copyrighted material from Elsevier B.V. 

There is room for ambiguity in the data, however. Because one Trolox molecule reacts with two free radicals, TAC, meant as free radical scavenging capacity, is usually expressed as the amount (concentration) of free radicals that can be scavenged by antioxidants present in the sample. Therefore, the Trolox concentration of TAC equal to that of the sample is multiplied by two. Sometimes it is not clear whether the published values follow this convention. 

Antioxidant activities of caffeine (1,3,7-trimethylxanthine) and its main metabolites was compared. Caffeine, 1,7-dimethylxanthine, and 3,7-dimethylxanthine did not show any peroxyl radical-scavenging capacity at concentration up to 100 fxM. Flowever, the relative antioxidant activities (with respect to Trolox) of 1-methyl-xanthine and 1-methyluric acid were 0.82 and 0.58, respectively (L9). 

Oziol, L., Faure, P., Vergely, C., Rochette, L., Artur, Y., and Chomard, P., In vitro free radical scavenging capacity of thyroid hormones and structural analogues. J. Endocrinol. 170,197-206 (2001). 

PI 1. Pieri, C., Testa, R., Marra, M., Bonfigli, A. R., Manfrini, S., and Testa, I., Age-dependent changes of serum oxygen radical scavenger capacity and haemoglobin glycosylation in non-insulin-dependent diabetic patients. Gerontology 47, 88-92 (2001). 

Tl. Tarkka, M. R., Kaukinen, S., Holm, P., Kaukinen, U., Sisto, T., Kataja, J., and Huang, W. Q., Allopurinol does not increase free radical scavenging capacity during reperfusion in coronary artery bypass graft patients. Scand. Cardiovasc. J. 34, 409—414 (2000). 

T4. Tsai, K., Hsu, T., Kong, C., Lin, K., and Lu, F., Is the endogenous peroxyl-radical scavenging capacity of plasma protective in systemic inflammatory disorders in humans Free Radic. Biol. Med. 28, 926-933 (2000). 

I 13 Aejmelaeus RT, Holm P Kaukine U, etal, Age-related changes in the peroxyl radical scavenging capacity of human plasma. Free Radic Biol Med 1997 23 69-75,... 

Recent reports show unexpected information on the role of free radicals in the health effects of nanotubes currently employed in many industries.31 Unlike asbestos and most toxic particles, nanotubes do not release but blunt free radicals, which are considered one of the features imparting toxicity to particulates. Multi-wall carbon nanotubes (MWCN) in aqueous suspension do not generate oxygen or carbon centered free radicals detectable with the spintrapping technique. Conversely, when in contact with an external source of hydroxyl (HO) or superoxide radicals (CL h MWCN exhibit a remarkable radical scavenging capacity (Figure 3). It is therefore possible that the inflammatory reaction reported in vivo should be ascribed to MWCN features other than particle derived free radical generation. 

Adorn, K.K. Liu, R.H. 2005. Rapid peroxyl radical scavenging capacity (PSC) assay for assessing both hydrophilic and lipophilic antioxidants. J. Agric. Food Chem. 53 6572-6580. 

The development of free radical scavenging capacity as determined by the DPPH method was studied during aging of selected red Spanish wines (Larrauri et al.,... 

Molybdenum dialkyldithiocarbamates Molybdenum dialkyldithiocarbamates are multifunctional lubricant additives as anti-wear, anti-friction and antioxidants. Molybdenum dialkyldithiocarbamates are also multifunctional antioxidants due to the hydroperoxide decomposing ability of dialkyldithiocarbamates, see Section 4.4.2, and the radical scavenging capacity of molybdenum. The best established structure for molybdenum dialkyldithiocarbamates is a six-coordinate complex of a dinuclear molybdenum centre with each molybdenum bonded to terminal oxygen or sulphur atoms, two bridging oxygen or sulphur atoms and one dialkyldithiocar-bamate ligand. Fig. 4.6 [44] ... 

The free radical-scavenging capacity of oleuropein and hydroxy-tyrosol was tested, using some radical generators. As a radical initiator, AAPH 2,2 -azobis (2-amidinopropane)-hydrochloride) was used for peroxyl radicals generation, because it is a common free radical found in the body [59] and has often been used in several antioxidant activity assays [60]. It appears to be slightly less reactive than OH-radical [61]. 

---