Antioxidant activity in fruits and leaves of blackberry, raspberry, and strawberry varies with cultivar and developmental stage

Fruits and leaves from different cultivars of thornless blackberry (Rubus s p.), red raspberry (Rubus idaeus L.), black raspberry (Rubus occidentalis L .), and strawberry (Fragaria x ananassa D.) plants were analyzed for total antioxidant capacity (oxygen radical absorbance capacity, ORAC) and total p henolic content. In addition, fruits were analyzed for total anthocyanin co ntent. Blackberries and strawberries had the highest ORAC values during the green stages, whereas red raspberries had the highest ORAC activity at the ripe stage. Total anthocyanin content increased with maturity for all thre e species of fruits. Compared with fruits, leaves were found to have higher ORAC values. In fruits, ORAC values ranged from 7.8 to 33.7 mu mol of Trol ox equivalents (TE)/g of fresh berries (35.0 - 162.1 mu mol of TE/g of dry matter), whereas in leaves, ORAC values ranged From 69.7 to 182.2 mu mol of TE/g of fresh leaves (205.0-728.8 mu mol of TE/g of dry matter). As the le aves become older, the ORAC values and total phenolic contents decreased. T he results showed a linear correlation between total phenolic content and O RAC activity for fruits and leaves. For ripe berries, a linear relationship existed between ORAC values and anthocyanin content. Of the ripe fruits te sted, on the basis of wet weight of fruit, cv. Jewel black raspberry and bl ackberries may be the richest source for antioxidants. On the basis of the dry weight of fruit, strawberries had the highest ORAC activity followed by black raspberries (cv. Jewel), blackberries; and red raspberries.