Related Experiment Video
Updated: Oct 1, 2026
Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology
Published on: August 23, 2024
On-line HPLC-DPPH screening method for evaluation of radical scavenging phenols extracted from apples (Malus
Donata Bandoniene1, Michael Murkovic
1Institute of Food Chemistry and Technology, Graz University of Technology, Petersgasse 12, A-8010 Graz, Austria.
Abstract:
An on-line HPLC-DPPH screening method for phenolic antioxidants in apple methanol/water (80:20, v/v) extracts was applied. The determination of antioxidants was based on a decrease in absorbance at 515 nm after postcolumn reaction of HPLC-separated antioxidants with the 2,2'-diphenyl-1-picrylhydrazyl radicals (DPPH*). Each of the antioxidants separated by the HPLC column was observed as a negative peak corresponding to its antioxidative activity. The on-line method was applied for quantitative analysis of the antioxidants. A linear dependence of negative peak area on concentration of the reference antioxidants was observed. For validation of the on-line method the limit of detection, LOD (microg/mL), and the limit of quantification, LOQ (microg/mL), of the phenolic compounds were determined. Comparison of the UV and DPPH radical quenching chromatograms with authentic compounds identified catechin, chlorogenic acid, caffeic acid, epicatechin, and phloridzin in the apple cultivars (Lobo, Golden Delicious, and Boskoop), and the distribution of total antioxidant activity was calculated.
