Determination of antioxidant capacity in some foods by oxygen radical absorbance capacity (ORAC)

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.

Teneurs en phénols totaux, activités antioxydantes des macérés et décocté des feuilles de Uvaria chamae P. Beauv. (Annonaceae)

Uvaria chamae est une plante de la biodiversité Ivoirienne utilisée en médecine traditionnelle. Malgré les vertus biologiques et thérapeutiques de cette plante, peu d’informations sur la teneur en phénols totaux et l’activité antioxydante existent. L’objectif de cette étude était d’évaluer la teneur en phénols totaux, l’activité antioxydante de macéré aqueux, de macéré éthanolique et de décocté aqueux des feuilles de Uvaria chamae. La teneur en phénols totaux a été effectuée par la méthode de Folin-Ciocalteu. L’activité antioxydante a été évaluée par la méthode de piégeage du DPPH (2,2-diphenyl-1-picrylhydrazyle) et d’ORAC (Oxygen Radical Absorbance Capacity). La teneur en phénols totaux était respectivement de 110,51 ± 7,18 µg GAE/mg d’extraits, de 86,34 ± 1,38 µg GAE/mg d’extrait et de 65,80 ± 0,13 µg GAE/mg d’extrait pour le macéré éthanolique, le décocté aqueux et le macéré aqueux de Uvaria chamae. Les différents macérés et décocté ont présenté une activité de piégeage des deux radicaux libres. S’agissant du radical DPPH, le macéré éthanolique de U. chamae exerce une forte activité antiradicalaire significative avec un CI50 de l’ordre de 0,08 ± 0,02 mg/ml. Avec la méthode ORAC, le macéré éthanolique de U. chamae (3,51 ± 0,15 µmol TE/µg d’extrait) et le décocté aqueux de U. chamae (3,36± 0,18 µmol TE/µg d’extrait) présentent des valeurs d’activités antioxydantes significatives. Par contre, les valeurs de l’activité antioxydante du macéré aqueux de U. chamae (3,04 ± 0,20 µmol TE/µg d’extrait) et du témoin positif : extrait éthanolique de R. officinalis (2,54 ± 0,06 µmol TE/µg d’extrait) ne sont pas significativement différentes (P ˃ 0,05). Ces résultats montrent l’existence d’une bonne corrélation linéaire entre la teneur en phénols totaux et le pouvoir antioxydant des différents macérés et décocté de cette plante. Cette plante Ivoirienne pourrait donc être considérée comme une source d’antioxydant naturel à des fins médicinales.Mots clés : Uvaria chamae, teneur en phénols totaux, antioxydant, Côte d’Ivoire

Structure-antioxidant Activity (Oxygen Radical Absorbance Capacity) Relationships of Phenolic Compounds

Antioxidant capacity is the extent to which a compound can eliminate reactive oxygen species, and in vitro methods for its chemical evaluation have been proposed. Among these methods, the oxygen radical absorbance capacity (ORAC) assay comes close to the oxidation reaction in the living body because it generates radical species that mimic the lipid peroxyl radical involved in the peroxidation reaction of biological components and react in a phosphate buffer. In this study, PM7, a semi-empirical molecular orbital method, was used to calculate the thermodynamic properties (bond dissociation enthalpy, ionisation potential, and proton affinity) associated with ORAC. We also applied the clusterwise linear regression analysis as a statistical method for grouping the antioxidants by structure. By analysing the data for antioxidants, the trend in the hydrophilic ORAC values was determined using the calculated structures and bond dissociation enthalpies of the groups classified according to the presence or absence of oxygen functional groups in the ortho position of phenol. Further studies of indicators other than bond dissociation enthalpy are needed to predict the ORAC of other antioxidants such as flavonoids and indoles.

Relationship Between Oxygen Radical Absorbance Capacity (ORAC) Index, Body Composition and Blood Biochemical Markers in Overweight /Obese Compared to Normal Weight Subjects: A Cross-Sectional Study

Background: Obesity is an important preventable disease, which promotes the development of chronic disorders by altering several factors including oxidative stress. Dietary antioxidants protect the body against oxidative stress. The purpose of this study was to evaluate the potential association of oxygen radical absorbance capacity (ORAC) index with obesity and its associated features in adults.Methods: participants were divided in two groups of normal weight and overweight /obesity. General characteristics were registered and a 147-item food frequency questionnaire was completed. Thereafter, anthropometric measurements were conducted. Biochemical indices were obtained from science and Research branch of Islamic Azad University of Tehran, Iran. The amount of the dietary ORAC index was estimated using the data provided by the USDA Foods Table.Results: The results showed that there was a significant difference between the normal and overweight/obese groups in terms of body mass index (BMI) and waist-to-hip ratio (WHR) (P=0.0001). Participants with normal weight consumed more fruits and vegetables than another group. Also, the dietary ORAC index in normal individuals was higher than the case group, but there was not significant difference (P=0.352). There was also a significant inverse correlation between dietary ORAC and BMI and WHR, whereas a significant positive correlation between dietary ORAC and plasma HDL was observed (P<0.05).Conclusion: Our findings suggest that dietary antioxidants is inversely associated with BMI, fasting blood glucose, triglyceride, total Cholesterol and LDL in both groups. It seems that following a diet rich in antioxidants can counteract obesity and its associated comorbidities.

Relationship between oxygen radical absorbance capacity (ORAC) index, body composition and blood biochemical markers in overweight /obese compared to normal weight subjects: a cross-sectional study

Background: Obesity is an important preventable disease, which promotes the development of chronic disorders by altering several factors including oxidative stress. Dietary antioxidants protect the body against oxidative stress. The purpose of this study was to evaluate the potential association of oxygen radical absorbance capacity (ORAC) index with obesity and its associated features in adults.Methods: participants were divided in two groups of normal weight and overweight /obesity. General characteristics were registered and a 147-item food frequency questionnaire was completed. Thereafter, anthropometric measurements were conducted. Biochemical indices were obtained from science and Research branch of Islamic Azad University of Tehran, Iran. The amount of the dietary ORAC index was estimated using the data provided by the USDA Foods Table.Results: The results showed that there was a significant difference between the normal and overweight/obese groups in terms of body mass index (BMI) and waist-to-hip ratio (WHR) (P=0.0001). Participants with normal weight consumed more fruits and vegetables than another group. Also, the dietary ORAC index in normal individuals was higher than the case group, but there was not significant difference (P=0.352). There was also a significant inverse correlation between dietary ORAC and BMI and WHR, whereas a significant positive correlation between dietary ORAC and plasma HDL was observed (P<0.05).Conclusion: Our findings suggest that dietary antioxidants is inversely associated with BMI, fasting blood glucose, triglyceride, total Cholesterol and LDL in both groups. It seems that following a diet rich in antioxidants can counteract obesity and its associated comorbidities.

Relationship between oxygen radical absorbance capacity (ORAC) index, body composition and blood biochemical markers in overweight /obese compared to normal weight subjects: a cross-sectional study

Background: Obesity is an important preventable disease, which promotes the development of chronic disorders by altering several factors including oxidative stress. Dietary antioxidants protect the body against oxidative stress. The purpose of this study was to evaluate the potential association of oxygen radical absorbance capacity (ORAC) index with obesity and its associated features in adults.Methods: participants were divided in two groups of normal weight and overweight /obesity. General characteristics were registered and a 147-item food frequency questionnaire was completed. Thereafter, anthropometric measurements were conducted. Biochemical indices were obtained from science and Research branch of Islamic Azad University of Tehran, Iran. The amount of the dietary ORAC index was estimated using the data provided by the USDA Foods Table.Results: The results showed that there was a significant difference between the normal and overweight/obese groups in terms of body mass index (BMI) and waist-to-hip ratio (WHR) (P=0.0001). Participants with normal weight consumed more fruits and vegetables than another group. Also, the dietary ORAC index in normal individuals was higher than the case group, but there was not significant difference (P=0.352). There was also a significant inverse correlation between dietary ORAC and BMI and WHR, whereas a significant positive correlation between dietary ORAC and plasma HDL was observed (P<0.05).Conclusion: Our findings suggest that dietary antioxidants is inversely associated with BMI, fasting blood glucose, triglyceride, total Cholesterol and LDL in both groups. It seems that following a diet rich in antioxidants can counteract obesity and its associated comorbidities.

Relationship between oxygen radical absorbance capacity (ORAC) index, body composition and blood biochemical markers in overweight /obese compared to normal weight subjects: a cross-sectional study

Backgroumd: Obesity is an important preventable disease, which promotes the development of chronic disorders by altering several factors including oxidative stress. Dietary antioxidants protect the body against oxidative stress. The purpose of this study was to evaluate the potential association of oxygen radical absorbance capacity (ORAC) index with obesity and its associated features in adults.Methods: participants were divided in two groups of normal weight and overweight /obesity. General characteristics were registered and a 147-item food frequency questionnaire was completed. Thereafter, anthropometric measurements were conducted. Biochemical indices were obtained from science and Research branch of Islamic Azad University of Tehran, Iran. The amount of the dietary ORAC index was estimated using the data provided by the USDA Foods Table.Results: The results showed that there was a significant difference between the normal and overweight/obese groups in terms of body mass index (BMI) and waist-to-hip ratio (WHR) (P=0.0001). Participants with normal weight consumed more fruits and vegetables than another group. Also, the dietary ORAC index in normal individuals was higher than the case group, but there was not significant difference (P=0.352). There was also a significant inverse correlation between dietary ORAC and BMI and WHR, whereas a significant positive correlation between dietary ORAC and plasma HDL was observed (P<0.05).Conclusion: Our findings suggest that dietary antioxidants is inversely associated with BMI, fasting blood glucose, triglyceride, total Cholesterol and LDL in both groups. It seems that following a diet rich in antioxidants can counteract obesity and its associated comorbidities.

Relationship Between Oxygen Radical Absorbance Capacity (ORAC) Index, Body Composition and Blood Biochemical Markers in Overweight /Obese Compared to Normal Weight Subjects

Background and aim: Obesity is an important preventable disease, which promotes the development of multiple chronic disorders by altering several factors including oxidative stress. Dietary antioxidants protect the body against oxidative stress. The purpose of this study was to evaluate the potential association of oxygen radical absorbance capacity (ORAC) index with obesity and its associated biochemical factors in adults. Methods: The present study was a cross-sectional study of 157 adult females and males in two groups of normal weight and overweight /obesity. General characteristics were registered and a 147-item food frequency questionnaire was completed for every participant. Thereafter, anthropometric measurements were conducted. Biochemical indices were obtained from the Electronic Health Clinic Database of science and Research branch of Islamic Azad University (SRBIAU) of Tehran, Iran. The amount of the dietary ORAC index was estimated using the data provided by the USDA Foods Table. Results: The results showed that there was a significant difference between the normal and overweight/obese groups in terms of weight, body mass index (BMI), waist to hip ratio (WHR), visceral fat level, body fat mass and body fat percentage (P=0.0001). Participants with normal weight consumed more fruits and vegetables than individuals in another group. Also, the dietary ORAC index in normal individuals was higher than the case group, but there was not significant difference (P=0.222). There was also a significant inverse correlation between dietary ORAC and BMI and WHR, whereas a significant positive correlation between dietary ORAC and plasma levels of HDL was observed (P<0.05). Conclusion: Our findings suggest that consumption of antioxidants from dietary sources is inversely associated with BMI and other measurements of adiposity, fasting blood glucose (FBG), triglyceride (TG), total Cholesterol (TC) and LDL in both groups. It seems that following a diet rich in antioxidants can counteract obesity and its associated comorbidities.