Oxygen Radical Absorbing Capacity of Anthocyanins

TLDR

Anthocyanins are flavonoid colorants widely found in flowers, fruits, and vegetables, and their hydroxylation and glycosylation patterns modulate antioxidant activity. We measured the antioxidant capacity of 14 anthocyanins, including aglycons and sugar‑linked derivatives, using a laboratory‑developed automated ORAC assay. Kuromanin exhibited the highest ORAC activity, 3.5× stronger than Trolox, while pelargonin, though lowest, remained as potent as Trolox, confirming anthocyanins’ strong antioxidant properties. Keywords: Anthocyanins; flavonoids; colorants; ORAC; antioxidant; peroxyl radical.

Abstract

Anthocyanins are natural colorants belonging to the flavonoid family. They are widely distributed among flowers, fruits, and vegetables. Using the automated oxygen radical absorbance capacity (ORAC) assay developed in our laboratory, we determined the antioxidant capacity of 14 anthocyanins including the aglycons delphinidin, cyanindin, pelargonidin, malvidin, peonidin, and their derivatives with different sugar linkages. Among these anthocyanins, kuromanin (cyanidin-3-glucoside) had the highest ORAC activity, which was 3.5 times stronger than Trolox (vitamin E analogue), while pelargonin had the lowest antioxidant activity but was still as potent as Trolox. Different patterns of hydroxylation and glycosylation in anthocyanins appear to modulate their antioxidant properties. Therefore, in addition to their colorful characteristics, anthocyanins possess potent antioxidant properties. Keywords: Anthocyanins; flavonoids; colorants; ORAC; antioxidant; peroxyl radical