The influence of interactions among phenolic compounds from chokeberry on the antiradical activity of chokeberry.

Phenolic compounds are widely distributed in fruits and vegetables, and have been shown to have good antiradical properties. The antiradical activity of these compounds can be affected by interactions that can occur among phenols itself and among phenols and different compounds from fruits. Moreover, these complex interactions can promote changes in the total antiradical activity of fruits. In this study, the antiradical activity of various phenolic classes from chokeberry fruits (Aronia melanocarpa) and the interactions that can occur among phenolic classes were investigated. Phenolic fractions were isolated from chokeberry fruits. First phenol fraction was enriched with phenolic acids and flavonols, the second with anthocyanins, and the third with insoluble phenols and proanthocyanidins. The main phenolic compounds in fractions were identified by using the high performance liquid chromatography (HPLC). The antiradical activity of fractions was studied by using the DPPH test, over a period of 300 minutes. Furthermore, phenolic fractions were mixed in different concentration ranges and the antiradical activity of mixtures was studied. The antiradical activity of phenolic mixtures was lower in comparison to the individual phenolic fractions. This suggests the existence of complex interactions among phenolic compounds which promoted the decrease of the antiradical activity.