Determination of total antioxidant activity of fruit juices widely consumed in Syria Al Asaad Nour1,*, Al Diab Dima2 1MSc in Food Control, Department of Analytical and Food Chemistry, Faculty of Pharmacy, Al-Andalus University for Medical Sciences, Tartus, Syria 2Ph. D. in Food Control, Assistant Professor at the Department of Analytical and Food Chemistry, Faculty of Pharmacy, Tishreen University, Latakia, Syria *Corresponding Author E-mail: nour-alasaad@outlook.com
Online published on 17 July, 2017. Abstract Fruits are considered essential constituents of a healthy diet. They possess antioxidant properties which can be attributed mainly to their phenolic compounds. Two samples of the following fruit juices (orange, grapefruit, blackberry, black mulberry, black sweet cherry, strawberry, pomegranate, organic tomato, greenhouse tomato, black plum, black grape and red grape) were investigated for their phenolic content and total antioxidant activity. Total phenolic content was determined according to Folin-Ciocalteu method. Black mulberry juice showed the highest results with amounts from 8.6gGAE/Ljuice to 11.2gGAE/Ljuice, while the lowest was red grape juice with amounts from 0.3 gGAE/Ljuice to 0.7gGAE/Ljuice. Total Antioxidant activity was subsequently determined using Ferric Reducing Antioxidant Power (FRAP) assay and reducing power assay. The results were in accordance with Folin-Ciocalteu method since black mulberry juice had the highest antioxidant power, while red grape juice had the lowest. The study indicates that black mulberry juice is the richest source of phenolic compounds and provides the highest antioxidant potential compared with other fruit juices in this study. Reducing power assay gave a similar order compared to FRAP assay. Both assays depend on reducing the ferric complex to its ferrous form which could explain the similarity in juice order considering their antioxidant activity. Top Keywords Phenolic compounds, antioxidant activity, FRAP, total phenolic content, reducing power. Top |