Interactions between the major bioactive polyphenols of berries: effects on antioxidant properties

Berries possess structurally diverse polyphenols that may have different effects on their antioxidant properties; a combination of various berries may exhibit additive, synergistic, or antagonistic interactions between their different bioactive compounds. Even if this kind of interactions between the antioxidant properties of green tea polyphenols and other plant-derived foods has already been studied, in what concerns berries and their major polyphenols, such study has not yet been undertaken. Therefore, the goal of this work was to study the individual antioxidant activity of 19 selected major polyphenols from the most consumed berries as well as the activity of the mixtures resulting from the 171 possible combinations between them using 2 in vitro model systems. It was observed that 2.92% of the mixtures presenting synergistic effects in scavenging DPPH free radicals were composed by cyanidin, and 2.34% composed by cyanidin-3-O-glucoside. These results indicate that cyanidin, a common anthocyanin present in berries, is responsible for the enhancement of the radical scavenging properties of other berries’ polyphenols.