title: Comparative evaluation of post-column free radical scavenging and ferric reducing antioxidant power assays for screening of antioxidants in strawberries.
abstract: ABTS and FRAP post-column techniques evaluate the antioxidant characteristics of HPLC separated compounds with specific reagents. ABTS characterize their ability to scavenge free radicals by electron-donating antioxidants, resulting in the absorbance decrease of the chromophoric radical. FRAP - is based on the reduction of Fe(III)-tripyridyltriazine complex to Fe(II)-tripyridyltriazine at low pH by electron-donating antioxidants, resulting in an absorbance increase. Both post-column assays were evaluated and compared according to the following validation parameters: specificity, precision, limit of detection (LoD), limit of quantitation (LoQ) and linearity. ABTS and FRAP post-column assays were specific, repeatable and sensitive and thus can be used for the evaluation of antioxidant active compounds. Antioxidant active compounds were quantified according to TEAC for each assay and ABTS/FRAP ratio was derived. No previous records of antioxidative activity of leaves and fruits of strawberries (Fragaria viridis, Fragaria moschata) research have been found. The research results confirm the reliability of ABTS and FRAP post-column assays for screening of antioxidants in complex mixtures and the determination of radical scavenging and ferric reducing ability by their TEAC values.
authors.affiliation: Department of Pharmacognosy, Lithuanian University of Health Sciences, Mickeviciaus Str. 9, LT-44307, Lithuania. raimondas.raudonis@gmail.com
authors.forename: Raimondas
authors.initials: R
authors.lastname: Raudonis
authors.forename: Lina
authors.initials: L
authors.lastname: Raudone
authors.forename: Valdas
authors.initials: V
authors.lastname: Jakstas
authors.forename: Valdimaras
authors.initials: V
authors.lastname: Janulis
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D031985:Fragaria / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D057230:Limit of Detection; D015203:Reproducibility of Results
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers