The ORAC (oxygen radical absorbance capacity) index does not reflect the capacity of antioxidants to trap peroxyl radicals

Dorta, Eva; Fuentes‐Lemus, Eduardo; Aspée, Alexis; Atala, Elías; Speisky, Hernán; Bridi, Raquel; Lissi, E. A.

doi:10.1039/c5ra01645b

Cited by 36 publications

(27 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The use of the pyrogallol red (PGR) as probe is related to the amount and reactivity of a given phenolic compound towards the free radicals generated in the AAPH (2,2'-azo-bis(2-amidinopropane) dihydrochloride) thermolysis. The ORAC-PGR index can be considered as a measure of the capacity of the sample to remove peroxyl and alkoxyl radicals [44]. In complex mixtures, concentration, chemical nature, and possibly the interaction between the antioxidants present in the sample determine this index.…”

Section: Antioxidant Activitymentioning

confidence: 99%

The Value of Chilean Honey: Floral Origin Related to their Antioxidant and Antibacterial activities

Bridi¹,

Montenegro²

2017

Honey Analysis

View full text Add to dashboard Cite

Honey chemical composition is related to the plant species where nectar is collected by honeybees. Chilean beekeeping is characterized by a variety of honey types, some unique, due to a high participation of endemic and native species. In Chile, the most emblematic lower honey, both for its abundance and sensory characteristics, is ulmo honey (Eucriphya cordifolia) and quillay honey (Quillaja saponaria). Melissopalynological analyses are used to establish whether a honey is uniloral, where at least 45% or more pollen grains found in it belong to the same species. The antioxidant and antimicrobial activities of Chilean honey have been studied in the last years with excellent results. Quillaja saponaria, Eucriphya cordifolia, Azara petiolaris, and Retanilla trinervia are within the Chilean endemic species that produce uniloral honeys that show antioxidant potential and antibacterial activity against pathogenic gram positive and gram -negative bacteria and also multiresistant strains. These activities are mainly atributed to the phenolic compounds such as lavonoids. Among these atractive characteristics of honey, it is important to note that this product has low toxicity and the medicinal properties of honey will help to protect honeybees by adding value not only to the signiicantly important process of pollinating crops and native plants, but also for the medicinal importance of their products.

show abstract

Section: Antioxidant Activitymentioning

confidence: 99%

The Value of Chilean Honey: Floral Origin Related to their Antioxidant and Antibacterial activities

Bridi¹,

Montenegro²

2017

Honey Analysis

View full text Add to dashboard Cite

show abstract

“…ORAC utiliza una sonda de referencia para evaluar la capacidad de eliminar los radicales libres que se producen, no evalúa las características de los antioxidantes y no necesariamente muestra la capacidad de suprimir la oxidación; i.e. anti-oxidación (Dorta et al, 2015). En la PCL, un fotosensibilizador (luminol) se excita ópticamente para producir el radical del anión superóxido (O 2 .-), entonces la muestra que contiene compuestos antioxidantes neutraliza una parte de O 2 .y, por último, los radicales restantes se cuantifican por comparación con un estándar de ácido ascórbico o Trolox (Gramza-Michalowska, Sidor, Regula & Kulczynski, 2015).…”

Section: Resultados Y Discusiónunclassified

Determinación de la capacidad antioxidante total de alimentos y plasma humano por fotoquimioluminiscencia: Correlación con ensayos fluorométricos (ORAC) y espectrofotométricos (FRAP)

et al. 2020

View full text Add to dashboard Cite

La determinación de la capacidad antioxidante es útil para valorar la calidad de un alimento, la cantidad de antioxidantes presentes en un sistema, o la biodisponibilidad de compuestos antioxidantes en el cuerpo humano. Los métodos disponibles realizan la determinación del efecto potencial de las sustancias antioxidantes, presentes en los alimentos y en el organismo humano, contra las reacciones de oxidación. El objetivo fue comparar los resultados de la detección de la capacidad antioxidante total (CAT) en muestras de alimentos y plasma humano, mediante la quimioluminiscencia por fotosensibilización (PCL), en contraste con métodos que cuantifican la capacidad de absorbancia del radical de oxígeno (ORAC) y el poder antioxidante reductor del hierro (FRAP). Se obtuvieron extractos hidrosolubles y liposolubles de salvado de arroz estabilizado (SAE) y de harina de Ulva clathrata (HUC). El plasma se obtuvo de muestras de sangre humana (PHU). Se procesaron tres muestras en cada caso. Los resultados se analizaron mediante análisis de varianza de una vía y correlación de Pearson, p < 0.05. La CAT determinada mediante PCL fue: SAE 246.37 ± 5.37, HUC 21.05 ± 0.41 y PHU 90.59 ± 1.17 equivalentes Trolox (ET) μmol /100 g ó 100 mL, p < 0.05; ORAC: SAE 5015.62 ± 12.83, HUC 852.37 ± 3.45 y PHU 2563.31 ± 39.47 ET μmol /100 g ó 100 mL, p < 0.05. FRAP: SAE 519.37 ± 0.04, HUC 52.78 ± 0.01 y PHU 90.26 ± 0.01 equivalentes Fe2+ (EFe2+) µmol /100 g ó 100 mL. Se observaron correlaciones entre PCL y ORAC, r = 0.99; y la PCL y FRAP, r = 0.94, ambas estadísticamente significativas (p < 0.05). La PCL mostró ser un método confiable y alternativo para cuantificar la CAT, que se puede aplicar en estudios de alimentos y de intervenciones en salud.

show abstract

“…The concentration range of changing order for 7-ACs was lower than 5 mM establishing these compounds as excellent free radical scavengers similar to phenolic compounds such as cinnamic acids. [34][35][36] Based on these results, we estimated at high coumarin concentration (zero order) that 2 peroxyl radicals were trapped per C 314 and C 334 ( Table 1). These results indicate that the stoichiometric peroxyl radical consumption (n) is similar to that of reactive phenols or even polyphenols like quercetin.…”

Section: Evaluation Of the Free Radical Reaction Of 7acs With Peroxylmentioning

confidence: 99%

“…Thus, in the absence of reactive substrates, self-reaction of peroxyl radicals renders alkoxyl radicals; hence a larger n value calculated only reects a reduced fraction of alkoxyl radical formation rather than peroxyl radicals. 35,38 It is important to note that an increase in the stoichiometry could also be related to a secondary reaction of peroxyl radicals toward unsaturated Fig. 1 (A) Differential on the absorbance spectra DA after 15 mM C 314 incubation with 10 mM AAPH at 37 C, pH 7.0.…”

Section: Evaluation Of the Free Radical Reaction Of 7acs With Peroxylmentioning

confidence: 99%

Atypical antioxidant activity of non-phenolic amino-coumarins

et al. 2018

View full text Add to dashboard Cite

show abstract

The ORAC (oxygen radical absorbance capacity) index does not reflect the capacity of antioxidants to trap peroxyl radicals

Abstract: We demonstrate from kinetic studies that under the experimental conditions proposed for the ORAC protocol, ORAC values do not correlate with the capacity of antioxidants to trap peroxyl radicals (ROO˙), suggesting a dominant role of alkoxyl radicals (RO˙) in the assay.

Cited by 36 publications

References 20 publications

The Value of Chilean Honey: Floral Origin Related to their Antioxidant and Antibacterial activities

The Value of Chilean Honey: Floral Origin Related to their Antioxidant and Antibacterial activities

Determinación de la capacidad antioxidante total de alimentos y plasma humano por fotoquimioluminiscencia: Correlación con ensayos fluorométricos (ORAC) y espectrofotométricos (FRAP)

Atypical antioxidant activity of non-phenolic amino-coumarins

Contact Info

Product

Resources

About