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Ronald L. Prior - One of the best experts on this subject based on the ideXlab platform.
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determination of total antioxidant capacity by Oxygen Radical absorbance capacity orac using fluorescein as the fluorescence probe first action 2012 23
Journal of AOAC International, 2013Co-Authors: Tony Chang, Dejian Huang, Ronald L. PriorAbstract:An improved method for the measurement of Oxygen Radical absorbance capacity (ORAC) was developed and validated using fluorescein (3',6'-dihydroxyspiro[isobenzofuran-1[3H], 9'[9H]-xanthen]-3-one) as a new fluorescence probe (ORAC(FL)). Randomly methylated beta-cyclodextrin (RMCD) was introduced as the water-solubility enhancer for lipophilic antioxidants. 7% RMCD (w/v) in 50% acetone-H2O mixture sufficiently solubilized vitamin E compounds and other lipophilic phenolic antioxidants in 75 mM phosphate buffer (pH 7.4). Results indicated that fluorescein shows excellent photostability under the plate reader conditions. This ORAC(FL) was validated through linearity, precision, accuracy, and ruggedness. The validation results demonstrated that the ORACFL assay is reliable and robust. The mean of intraday and interday CVs were <15%; for hydrophilic ORAC, LOD and LOQ are 5 and 6.25 microM, respectively; for lipophilic ORAC, LOD and LOQ are 6.25 and 12.5 microM, respectively. It is concluded that unlike other popular methods, the ORAC(FL) assay provides a direct measure of total antioxidant capacity against the peroxyl Radicals.
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anthocyanin and proanthocyanidin content in selected white and red wines Oxygen Radical absorbance capacity comparison with nontraditional wines obtained from highbush blueberry
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Concepcion Sanchezmoreno, Guohua Cao, Ronald L. PriorAbstract:Antioxidant capacity, as measured by Oxygen Radical absorbance capacity (ORACPE), total phenolic, total and individual anthocyanins, and proanthocyanidin fraction contents were evaluated in red and white wines from grapes. A comparison in terms of antioxidant capacity is made with nontraditional wines made from highbush blueberry. Blueberries are among fruits that are best recognized for their potential health benefits. In red wines, total oligomeric proanthocyanidin content, including catechins, was substantially higher (177.18 ± 96.06 mg/L) than that in white wines (8.75 ± 4.53 mg/L). A relative high correlation in red wines was found between ORACPE values and malvidin compounds (r = 0.75, P < 0.10), and proanthocyanidins (r = 0.87, P < 0.05). In white wines, a significant correlation was found between the trimeric proanthocyanidin fraction and peroxyl Radical scavenging values (r = 0.86, P < 0.10). A moderate drink (1 drink per day, about 140 mL) of red wine, or white wine, or wine made from highbush b...
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anthocyanin and proanthocyanidin content in selected white and red wines Oxygen Radical absorbance capacity comparison with nontraditional wines obtained from highbush blueberry
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Concepcion Sanchezmoreno, Guohua Cao, Ronald L. PriorAbstract:Antioxidant capacity, as measured by Oxygen Radical absorbance capacity (ORAC(PE)), total phenolic, total and individual anthocyanins, and proanthocyanidin fraction contents were evaluated in red and white wines from grapes. A comparison in terms of antioxidant capacity is made with nontraditional wines made from highbush blueberry. Blueberries are among fruits that are best recognized for their potential health benefits. In red wines, total oligomeric proanthocyanidin content, including catechins, was substantially higher (177.18 +/- 96.06 mg/L) than that in white wines (8.75 +/- 4.53 mg/L). A relative high correlation in red wines was found between ORAC(PE) values and malvidin compounds (r = 0.75, P < 0.10), and proanthocyanidins (r = 0.87, P < 0.05). In white wines, a significant correlation was found between the trimeric proanthocyanidin fraction and peroxyl Radical scavenging values (r = 0.86, P < 0.10). A moderate drink (1 drink per day, about 140 mL) of red wine, or white wine, or wine made from highbush blueberry corresponds to an intake of 2.04 +/- 0.81 mmol of TE, 0.47 +/- 0.15 mmol of TE, and 2.42 +/- 0.88 mmol of TE of ORAC(PE)/day, respectively.
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high throughput assay of Oxygen Radical absorbance capacity orac using a multichannel liquid handling system coupled with a microplate fluorescence reader in 96 well format
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Dejian Huang, Maureen Hampschwoodill, Judith A Flanagan, Ronald L. PriorAbstract:The Oxygen Radical absorbance capacity (ORAC) assay has been widely accepted as a standard tool to measure the antioxidant activity in the nutraceutical, pharmaceutical, and food industries. However, the ORAC assay has been criticized for a lack of accessibility due to the unavailability of the COBAS FARA II analyzer, an instrument discontinued by the manufacturer. In addition, the manual sample preparation is time-consuming and labor-intensive. The objective of this study was to develop a high-throughput instrument platform that can fully automate the ORAC assay procedure. The new instrument platform consists of a robotic eight-channel liquid handling system and a microplate fluorescence reader. By using the high-throughput platform, the efficiency of the assay is improved with at least a 10-fold increase in sample throughput over the current procedure. The mean of intra- and interday CVs was ≤15%, and the limit of detection and limit of quantitation were 5 and 6.25 μM, respectively. Keywords: ORAC; anti...
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development and validation of an improved Oxygen Radical absorbance capacity assay using fluorescein as the fluorescent probe
Journal of Agricultural and Food Chemistry, 2001Co-Authors: Maureen Hampschwoodill, Ronald L. PriorAbstract:An improved method of Oxygen Radical absorbance capacity (ORAC) assay has been developed and validated using fluorescein (3‘,6‘-dihydroxyspiro[isobenzofuran-1[3H],9‘[9H]-xanthen]-3-one) as the fluorescent probe. Our results demonstrate that fluorescein (FL) is superior to B-phycoerythrin. The oxidized FL products induced by peroxyl Radical were identified by LC/MS, and the reaction mechanism was determined to follow a classic hydrogen atom transfer mechanism. In addition, methodological and mechanistic comparison of ORACFL with other widely used methods was discussed. It is concluded that, unlike other popular methods, the improved ORACFL assay provides a direct measure of hydrophilic chain-breaking antioxidant capacity against peroxyl Radical. Keywords: Fluorescein; ORAC; TEAC; FRAP; chain-breaking antioxidant; free Radical; hydrogen atom transfer; single electron transfer
Guohua Cao - One of the best experts on this subject based on the ideXlab platform.
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anthocyanin and proanthocyanidin content in selected white and red wines Oxygen Radical absorbance capacity comparison with nontraditional wines obtained from highbush blueberry
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Concepcion Sanchezmoreno, Guohua Cao, Ronald L. PriorAbstract:Antioxidant capacity, as measured by Oxygen Radical absorbance capacity (ORAC(PE)), total phenolic, total and individual anthocyanins, and proanthocyanidin fraction contents were evaluated in red and white wines from grapes. A comparison in terms of antioxidant capacity is made with nontraditional wines made from highbush blueberry. Blueberries are among fruits that are best recognized for their potential health benefits. In red wines, total oligomeric proanthocyanidin content, including catechins, was substantially higher (177.18 +/- 96.06 mg/L) than that in white wines (8.75 +/- 4.53 mg/L). A relative high correlation in red wines was found between ORAC(PE) values and malvidin compounds (r = 0.75, P < 0.10), and proanthocyanidins (r = 0.87, P < 0.05). In white wines, a significant correlation was found between the trimeric proanthocyanidin fraction and peroxyl Radical scavenging values (r = 0.86, P < 0.10). A moderate drink (1 drink per day, about 140 mL) of red wine, or white wine, or wine made from highbush blueberry corresponds to an intake of 2.04 +/- 0.81 mmol of TE, 0.47 +/- 0.15 mmol of TE, and 2.42 +/- 0.88 mmol of TE of ORAC(PE)/day, respectively.
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anthocyanin and proanthocyanidin content in selected white and red wines Oxygen Radical absorbance capacity comparison with nontraditional wines obtained from highbush blueberry
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Concepcion Sanchezmoreno, Guohua Cao, Ronald L. PriorAbstract:Antioxidant capacity, as measured by Oxygen Radical absorbance capacity (ORACPE), total phenolic, total and individual anthocyanins, and proanthocyanidin fraction contents were evaluated in red and white wines from grapes. A comparison in terms of antioxidant capacity is made with nontraditional wines made from highbush blueberry. Blueberries are among fruits that are best recognized for their potential health benefits. In red wines, total oligomeric proanthocyanidin content, including catechins, was substantially higher (177.18 ± 96.06 mg/L) than that in white wines (8.75 ± 4.53 mg/L). A relative high correlation in red wines was found between ORACPE values and malvidin compounds (r = 0.75, P < 0.10), and proanthocyanidins (r = 0.87, P < 0.05). In white wines, a significant correlation was found between the trimeric proanthocyanidin fraction and peroxyl Radical scavenging values (r = 0.86, P < 0.10). A moderate drink (1 drink per day, about 140 mL) of red wine, or white wine, or wine made from highbush b...
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measurement of Oxygen Radical absorbance capacity in biological samples
Methods in Enzymology, 1999Co-Authors: Guohua Cao, Ronald L. PriorAbstract:Publisher Summary Several methods have been developed to assess the total antioxidant capacities of various biological samples, particularly complex matrices such as plasma, serum, wine, fruits, vegetables, and animal tissues. This chapter presents a method called “Oxygen Radical absorbance capacity” (ORAC) assay based largely on the work reported by Glazer's laboratory, which depends on the unique properties of phycoerythrin (PE). The ORAC assay is the only method that takes reactive species (RS) reaction to completion and uses an “area under the curve” (AUC) technique for quantitation, thus combining both inhibition time and inhibition percentage of the RS action by antioxidants into a single quantity. The chapter discusses the general principles of ORAC assay for assessing antioxidant capacity against peroxyl Radicals. By integrating inhibition percentages over the whole inhibition time period, the ORAC assay successfully overcomes all related problems in quantitation of the antioxidant capacity of a biological sample. Either B- or R-phycoerythrin (B-PE or R-PE) can be used in the ORAC assay. The sensitivity of B- or R-PE to hydroxyl Radical damage may be different even for the same PE with different lot numbers. The concentrations of Cu 2+ and standard (Tro lox) can be adjusted, when it is necessary. The aforementioned procedures are based on using B- or R-PE that loses more than 90% of its fluorescence within 30 rains. The chapter concludes with a discussion of ORAC assay for assessing antioxidant capacity against transition metals.
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high performance liquid chromatography coupled with coulometric array detection of electroactive components in fruits and vegetables relationship to Oxygen Radical absorbance capacity
Journal of Agricultural and Food Chemistry, 1997Co-Authors: Changjiang Guo, Guohua Cao, E Sofic, Ronald L. PriorAbstract:An HPLC procedure utilizing reversed-phase chromatography coupled with a coulometric array detection system was developed for the characterization of overall antioxidant status in fruits and vegetables. The method was reliable and sensitive (20 pg to 1 ng detection limit) and can also be used to identify and simultaneously quantify multi-antioxidants including vitamin C, glutathione, phenolic acids, and flavonoids in fruits and vegetables. Each fruit and vegetable aqueous extract showed an unique distribution of chromatographic peaks that could serve as a “fingerprint” for the fruit or vegetable. A significant positive linear correlation was demonstrated in fruit and vegetable aqueous extracts between the total antioxidant activities determined by using Oxygen Radical absorbance capacity (ORACROO•) assay and the electrochemical data generated from the coulometric array detectors. From these data, the ORACROO• assay appears to be a valid and useful procedure for measuring total antioxidant activity in extr...
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Oxygen Radical Absorbing Capacity of Anthocyanins
Journal of Agricultural and Food Chemistry, 1997Co-Authors: Hong Wang, Guohua Cao, Ronald L. PriorAbstract:Anthocyanins are natural colorants belonging to the flavonoid family. They are widely distributed among flowers, fruits, and vegetables. Using the automated Oxygen Radical absorbance capacity (ORAC) assay developed in our laboratory, we determined the antioxidant capacity of 14 anthocyanins including the aglycons delphinidin, cyanindin, pelargonidin, malvidin, peonidin, and their derivatives with different sugar linkages. Among these anthocyanins, kuromanin (cyanidin-3-glucoside) had the highest ORAC activity, which was 3.5 times stronger than Trolox (vitamin E analogue), while pelargonin had the lowest antioxidant activity but was still as potent as Trolox. Different patterns of hydroxylation and glycosylation in anthocyanins appear to modulate their antioxidant properties. Therefore, in addition to their colorful characteristics, anthocyanins possess potent antioxidant properties.
Concepcion Sanchezmoreno - One of the best experts on this subject based on the ideXlab platform.
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anthocyanin and proanthocyanidin content in selected white and red wines Oxygen Radical absorbance capacity comparison with nontraditional wines obtained from highbush blueberry
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Concepcion Sanchezmoreno, Guohua Cao, Ronald L. PriorAbstract:Antioxidant capacity, as measured by Oxygen Radical absorbance capacity (ORACPE), total phenolic, total and individual anthocyanins, and proanthocyanidin fraction contents were evaluated in red and white wines from grapes. A comparison in terms of antioxidant capacity is made with nontraditional wines made from highbush blueberry. Blueberries are among fruits that are best recognized for their potential health benefits. In red wines, total oligomeric proanthocyanidin content, including catechins, was substantially higher (177.18 ± 96.06 mg/L) than that in white wines (8.75 ± 4.53 mg/L). A relative high correlation in red wines was found between ORACPE values and malvidin compounds (r = 0.75, P < 0.10), and proanthocyanidins (r = 0.87, P < 0.05). In white wines, a significant correlation was found between the trimeric proanthocyanidin fraction and peroxyl Radical scavenging values (r = 0.86, P < 0.10). A moderate drink (1 drink per day, about 140 mL) of red wine, or white wine, or wine made from highbush b...
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anthocyanin and proanthocyanidin content in selected white and red wines Oxygen Radical absorbance capacity comparison with nontraditional wines obtained from highbush blueberry
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Concepcion Sanchezmoreno, Guohua Cao, Ronald L. PriorAbstract:Antioxidant capacity, as measured by Oxygen Radical absorbance capacity (ORAC(PE)), total phenolic, total and individual anthocyanins, and proanthocyanidin fraction contents were evaluated in red and white wines from grapes. A comparison in terms of antioxidant capacity is made with nontraditional wines made from highbush blueberry. Blueberries are among fruits that are best recognized for their potential health benefits. In red wines, total oligomeric proanthocyanidin content, including catechins, was substantially higher (177.18 +/- 96.06 mg/L) than that in white wines (8.75 +/- 4.53 mg/L). A relative high correlation in red wines was found between ORAC(PE) values and malvidin compounds (r = 0.75, P < 0.10), and proanthocyanidins (r = 0.87, P < 0.05). In white wines, a significant correlation was found between the trimeric proanthocyanidin fraction and peroxyl Radical scavenging values (r = 0.86, P < 0.10). A moderate drink (1 drink per day, about 140 mL) of red wine, or white wine, or wine made from highbush blueberry corresponds to an intake of 2.04 +/- 0.81 mmol of TE, 0.47 +/- 0.15 mmol of TE, and 2.42 +/- 0.88 mmol of TE of ORAC(PE)/day, respectively.
Nicki J Engeseth - One of the best experts on this subject based on the ideXlab platform.
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antioxidant capacity of honeys from various floral sources based on the determination of Oxygen Radical absorbance capacity and inhibition of in vitro lipoprotein oxidation in human serum samples
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Nele Gheldof, Nicki J EngesethAbstract:Honeys from seven different floral sources were analyzed for in vitro antioxidant capacity and total phenolic content. Antioxidant capacity was measured by the Oxygen Radical absorbance capacity (ORAC) assay and by monitoring the formation of conjugated dienes as an index of the inhibition of copper-catalyzed serum lipoprotein oxidation. ORAC values ranged from 3.1 to 16.3 micromol Trolox equivalent/g honey. The darkest colored honeys, such as buckwheat honey, had the highest ORAC values. A linear correlation was observed between phenolic content and ORAC activity of the investigated honeys (p < 0.0001, R (2) = 0.9497). The relationship between the ORAC activity and inhibition of lipoprotein oxidation by the honeys yielded a correlation coefficient of 0.6653 (p = 0.0136). This work shows that honey may be used as a healthy alternative to sugar in many products and thereby serve as a source of dietary antioxidants.
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antioxidant capacity of honeys from various floral sources based on the determination of Oxygen Radical absorbance capacity and inhibition of in vitro lipoprotein oxidation in human serum samples
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Nele Gheldof, Nicki J EngesethAbstract:Honeys from seven different floral sources were analyzed for in vitro antioxidant capacity and total phenolic content. Antioxidant capacity was measured by the Oxygen Radical absorbance capacity (ORAC) assay and by monitoring the formation of conjugated dienes as an index of the inhibition of copper-catalyzed serum lipoprotein oxidation. ORAC values ranged from 3.1 to 16.3 μmol Trolox equivalent/g honey. The darkest colored honeys, such as buckwheat honey, had the highest ORAC values. A linear correlation was observed between phenolic content and ORAC activity of the investigated honeys (p < 0.0001, R 2 = 0.9497). The relationship between the ORAC activity and inhibition of lipoprotein oxidation by the honeys yielded a correlation coefficient of 0.6653 (p = 0.0136). This work shows that honey may be used as a healthy alternative to sugar in many products and thereby serve as a source of dietary antioxidants. Keywords: Honey; antioxidants; lipoprotein oxidation; phenolics
Elizabeth K. Deemer - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Antioxidant Activities of Common Vegetables Employing Oxygen Radical Absorbance Capacity (ORAC) and Ferric Reducing Antioxidant Power (FRAP) Assays: A Comparative Study
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Boxin Ou, Maureen Hampsch-woodill, And Judith A. Flanagan, Dejian Huang, Elizabeth K. DeemerAbstract:A total of 927 freeze-dried vegetable samples, including 111 white cabbages, 59 carrots, 51 snap beans, 57 cauliflower, 33 white onions, 48 purple onions, 130 broccoli, 169 tomatoes, 25 beets, 88 peas, 88 spinach, 18 red peppers, and 50 green peppers, were analyzed using the Oxygen Radical absorption capacity (ORAC) and ferric reducing antioxidant capacity (FRAP) methods. The data show that the ORAC and FRAP values of vegetable are not only dependent on species, but also highly dependent on geographical origin and harvest time. The two antioxidant assay methods, ORAC and FRAP, also give different antioxidant activity trends. The discrepancy is extensively discussed based on the chemistry principles upon which these methods are built, and it is concluded that the ORAC method is chemically more relevant to chain-breaking antioxidants activity, while the FRAP has some drawbacks such as interference, reaction kinetics, and quantitation methods. On the basis of the ORAC results, green pepper, spinach, purple o...
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development and validation of Oxygen Radical absorbance capacity assay for lipophilic antioxidants using randomly methylated beta cyclodextrin as the solubility enhancer
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Dejian Huang, Maureen Hampschwoodill, Judith A Flanagan, Elizabeth K. DeemerAbstract:We recently reported the improved Oxygen Radical absorbance capacity (ORAC) assay using fluorescein (FL) as the fluorescent probe. The current ORAC(FL) assay is limited in hydrophilic antioxidant due to the aqueous environment of the assay. Lipophilic antioxidants mainly include the vitamin E family and carotenoids, which play a critical role in biological defense systems. In this paper, we expanded the current ORAC(FL) assay to lipophilic antioxidants. Randomly methylated beta-cyclodextrin (RMCD) was introduced as the water solubility enhancer for lipophilic antioxidants. Seven percent RMCD (w/v) in a 50% acetone-H(2)O mixture was found to sufficiently solubilize vitamin E compounds and other lipophilic phenolic antioxidants in 75 mM phosphate buffer (pH 7.4). This newly developed ORAC assay (abbbreviated ORAC(FL-LIPO)) was validated through linearity, precision, accuracy, and ruggedness. The validation results demonstrate that the ORAC(FL-LIPO) assay is reliable and robust. For the first time, by using 6-hydroxy-2,5,7,8-tetramethyl-2-carboxylic acid as a standard (1.0), the ORAC values of alpha-tocopherol, (+)-gamma-tocopherol, (+)-delta-tocopherol, alpha-tocopherol acetate, tocotrienols, 2,6-di-tert-butyl-4-methylphenol, and gamma-oryzanol were determined to be 0.5 +/- 0.02, 0.74 +/- 0.03, 1.36 +/- 0.14, 0.00, 0.91 +/- 0.04, 0.16 +/- 0.01, and 3.00 +/- 0.26, respectively. The structural information of oxidized alpha-tocopherol obtained by liquid chromatography/mass spectrometry reveals that the mechanism for the reaction between the vitamin E and the peroxyl Radical follows the hydrogen atom transfer mechanism, which is in agreement with the notion that vitamin E is the chain-breaking antioxidant.
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development and validation of Oxygen Radical absorbance capacity assay for lipophilic antioxidants using randomly methylated β cyclodextrin as the solubility enhancer
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Dejian Huang, Boxin Ou, Maureen Hampschwoodill, Judith A Flanagan, Elizabeth K. DeemerAbstract:We recently reported the improved Oxygen Radical absorbance capacity (ORAC) assay using fluorescein (FL) as the fluorescent probe. The current ORACFL assay is limited in hydrophilic antioxidant due to the aqueous environment of the assay. Lipophilic antioxidants mainly include the vitamin E family and carotenoids, which play a critical role in biological defense systems. In this paper, we expanded the current ORACFL assay to lipophilic antioxidants. Randomly methylated β-cyclodextrin (RMCD) was introduced as the water solubility enhancer for lipophilic antioxidants. Seven percent RMCD (w/v) in a 50% acetone−H2O mixture was found to sufficiently solubilize vitamin E compounds and other lipophilic phenolic antioxidants in 75 mM phosphate buffer (pH 7.4). This newly developed ORAC assay (abbbreviated ORACFL-LIPO) was validated through linearity, precision, accuracy, and ruggedness. The validation results demonstrate that the ORACFL-LIPO assay is reliable and robust. For the first time, by using 6-hydroxy-2,5...
