ANTIOXIDANT CAPACITIES FROM DIFFERENT POLARITIES EXTRACTSOF THREE KINDS GINGERUSINGDPPH, FRAPASSAYS ANDCORRELATION WITH PHENOLIC, FLAVONOID, CAROTENOID CONTENT

Objectives: The objectives of this research were to study antioxidant capacityfrom different polarities extracts of three kinds ginger using two methods of antioxidant testing which were DPPH (2.2-diphenyl-1-picrylhydrazyl) and FRAP (Ferric Reducing Antioxidant Power) and correlation of total phenolic, flavonoid and carotenoid content in different polarities extracts of three kinds gingerwith DPPH and FRAP antioxidant capacities. Methods: Extraction was performed by reflux using different polarities solvents. The extracts were vaporated using rota vapor. Then antioxidant capacities were tested using DPPH and FRAP assays. Determination of total phenolic, flavonoid and carotenoid content were performed by spectrophotometry UV-Vis and its correlation with FRAP and DPPH antioxidant capacities were analyzed by Pearson method. Results: EG3(ethanol extract of elephant ginger rhizomes) had the highest DPPH scavenging capacity with IC 50 0.26 ppmandEG3had the highest FRAP capacity also with EC 50 91.90 ppm.SG1(n-hexane extract of small ginger) contained the highest total phenolic (14.56 g GAE/100 g), EG2(ethyl acetate extract of elephant ginger rhizomes) had highest flavonoid content (7.5 gQE/100 g) andEG3 had the highest carotenoid 0.95 g BET/100 g. Conclusions: There were positively high correlation between total phenolic content in small ginger rhizomes extracts with their antioxidant activity using DPPH and FRAP assays. DPPH scavenging capacities in small ginger rhizomes extracts had positively high correlation with their FRAP capacities. Keywords: Antioxidants,FRAP, DPPH, Three kinds ginger,flavonoid, Phenolic, Carotenoid.