Original scientific paper
DPPH radical inhibition kinetic and antiradical activity of polyphenols from chokeberry and elderberry fruits
Lidija Jakobek
; Faculty of Food Technology, Department of Applied Chemistry and Ecology, Osijek, Croatia
Marijan Šeruga
; Faculty of Food Technology, Department of Applied Chemistry and Ecology, Osijek, Croatia
Ivana Novak
; Faculty of Food Technology, Department of Applied Chemistry and Ecology, Osijek, Croatia
Martina Medvidović-Kosanović
; Faculty of Food Technology, Department of Applied Chemistry and Ecology, Osijek, Croatia
Bernarda Šeruga
; Faculty of Food Technology, Department of Applied Chemistry and Ecology, Osijek, Croatia
Abstract
Chokeberry and elderberry fruits are rich sources of polyphenols, the compounds with significant antiradical and chelating properties. They are studied intensively because of beneficial effects on human health. In this study, three fractions enriched with different classes of polyphenols were isolated from chokeberry and elderberry to study their antiradical activity by DPPH test. The first fraction contained flavonols and phenolic acids, the second anthocyanins, and third proanthocyanidins. The polyphenol content was determined by reversed-phase high performance liquid chromatography. Anthocyanins were found to be the main polyphenolic components of these berries with the highest portion in total antiradical activity, followed by proanthocyanidins and phenolic acids and flavonols. Furthermore, proanthocyanidins were found to be more effective in free DPPH• radical scavenging than flavonols, phenolic acids and anthocyanins. A biphasic reaction was observed in reaction between DPPH• radicals and polyphenols, at “fast” and “slow” scavenging rate. All classes of polyphenols showed strong antiradical activity in the first fast period, while in the slow period antiradical activity of polyphenols decreased. This kind of biphasic reaction could be important in biological activity of chokeberry and elderberry. This study is a contribution to a better understanding of antiradical activity of polyphenols from chokeberry and elderberry.
Keywords
chokeberry; elderberry; antiradical activity; anthocyanins; proanthocyanidins; flavonols; phenolic acids
Hrčak ID:
32659
URI
Publication date:
22.1.2009.
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