Antioxidant capacity of phenolic extracts from wild blueberry leaves and fruits

Leaves are by-products from mechanical harvesting of wild blueberries. To explore their use as a natural source of antioxidants, blueberry leaves were extracted with ethanol (95%, v/v) and acetone (70%, v/v). The dried crude extracts were then fractionated on a Sephadex LH-20 column. The extracts contained 181-213mg catechin equivalents/g of tannins and their antioxidant activity was similar to that of BHA is a beta-carotene linoleate model system. Over 99% of DPPH was also scavenged by 100 mu g of extract in each assay. The antioxidant activity of polyphenolic extracts was evaluated by the beta-carotene-linoleate and DPPH radical assays.