Methodological developments in evaluation of antioxidant activity of complex mixtures : towards miniaturization and coupling of analytical methods

Abstract

Antioxidant compounds in food play an important role as a health-protecting factor. Highly reactive free radicals and oxygen species are present in biological systems. Antioxidant compounds like phenolic acids, polyphenols and flavonoids scavenge free radicals such as peroxide, hydroperoxide or lipid peroxyl and thus inhibit the oxidative mechanisms that lead to degenerative diseases. There is a number of the free radical scavenging assays for evaluation of plant extracts. The main task of this work was to create rapid, simple and less material and time consuming method to separate analytes and evaluate antioxidant activity within a single analytical run. The on-line capillary electrophoresis-reaction (antioxidant activity) detection method can be used for a rapid evaluation of individual antioxidants in complex mixtures, particularly plant extracts. Combined UV (positive signals of all UV absorbing separated compounds) and DPPH (2,2-diphenyl-1-picrylhydrazyl) reaction detector (negative signals for colored DPPH radical bleaching) signal profiles are registered. Electropherograms of the methanolic extracts of wild hops forms cones as well as antioxidant activity detection profiles will be presentedBiochemijos katedraVytauto Didžiojo universiteta