Evaluation of the antioxidant capacity of food samples: a chemical examination of the oxygen radical absorbance capacity assay

Author(s):  
Eva Dorta ◽  
Eduardo Fuentes-Lemus ◽  
Hernán Speisky ◽  
Eduardo Lissi ◽  
Camilo López-Alarcón
1995 ◽  
Vol 41 (12) ◽  
pp. 1738-1744 ◽  
Author(s):  
G Cao ◽  
C P Verdon ◽  
A H Wu ◽  
H Wang ◽  
R L Prior

Abstract Reactive oxygen species are of interest in biology and medicine because of evidence relating them to aging and disease processes. A relatively simple but sensitive and reliable method for quantifying the oxygen radical absorbance capacity (ORAC) of antioxidants in biological tissues has been automated for use with the COBAS FARA II centrifugal analyzer with a fluorescence-measuring attachment. In this assay, beta-phycoerythrin (beta-PE) is used as an indicator protein, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) as a peroxyl radical generator, and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) as a calibrator for antioxidant activity. This assay is unique because the reaction goes to completion so that both inhibition time and inhibition degree are considered in quantifying ORAC (micromoles of Trolox equivalent per liter or per gram of tissue). This method can be used not only for serum but also other tissue and food samples and is suitable for application to a range of nutritional and clinical conditions.


2002 ◽  
Vol 50 (18) ◽  
pp. 5053-5057 ◽  
Author(s):  
Anne C. Kurilich ◽  
Elizabeth H. Jeffery ◽  
John A. Juvik ◽  
Matthew A. Wallig ◽  
Barbara P. Klein

2010 ◽  
Vol 57 (12) ◽  
pp. 525-531 ◽  
Author(s):  
Jun Watanabe ◽  
Tomoyuki Oki ◽  
Jun Takebayashi ◽  
Koji Yamasaki ◽  
Tojiro Tsushida

2006 ◽  
Vol 61 (1-2) ◽  
pp. 19-25 ◽  
Author(s):  
Marcos J. Salvador ◽  
Eliane O. Ferreira ◽  
Susanne U. Mertens-Talcott ◽  
Whocely Victor De Castro ◽  
Veronika Butterweck ◽  
...  

Abstract Phytochemical analysis of the antioxidant ethanolic extract of Alternanthera tenella Colla led to the isolation of six flavonoids, acacetin 8-C-[α-ʟ-rhamnopyranosyl-(1→2)-β-ᴅ-glucopyranoside] (1), 2″-O-α-ʟ-rhamnopyranosyl-vitexin (2), 2″-O-β-d-glucopyranosyl-vitexin (3), vitexin (4), quercetin (5) and kaempferol (6). All the structures were established by ESIMS and NMR spectroscopic methods. Antioxidant capacity of extract, fractions and isolated compounds was determined using the oxygen radical absorbance capacity (ORAC) assay and extract, fractions and flavonoids isolated showed antioxidant activity in vitro. Moreover, the total soluble phenolic contents of the extract and fractions were measured using the Folin- Ciocalteau reagent and the quantitative analysis of flavone C-glycosides major constituents was performed by HPLC


Author(s):  
Thuy Le Thi ◽  
Thuong Nguyen Nhu ◽  
Bang Nguyen Thi ◽  
Truc Quynh Do ◽  
Trang Vu Thi ◽  
...  

Oxygen radical absorbance capacity (ORAC) assay has been applied to determine the Hydrophilic – ORAC index in food. The method measures antioxidant scavenging activity against peroxyl radical induced by 2,2′-azobis(2-amidino-propane) dihydrochloride (AAPH) at 37ºC, used fluororescein as the fluorescent probe. The antioxidant capacity is measured by assemssing the fluorescence decay curve (AUC) of the sample as compared to that of the blank in which no antioxidant is present. Results expressed in ORAC units, equivalent to micromole Trolox per 100 grams sample (Trolox equivalent). The method was shown with high selectivity, a wide linear range, from 5 to 50µM Trolox with linear coefficient R2 = 0.9987. The recovery from 93.2% to 104.4% and repeatability (RSD) was less than 6.60%. The limits of detection and quantitation were 5 and 10µM Trolox, respectively. The method has been applied to determine of H-ORAC index in 65 samples including vegetables, fruits, vegetable products and health supplements with content ranging from 720 µM TE/100g to 310878 µM TE/100g.


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