Antioxidant properties of domesticated and wild Rubus species

The antioxidative capacities of a number of Rubus species of varied pigmentation have been investigated. In addition, total phenol, anthocyanin and ascorbic acid contents have been determined. Two methods to assess the antioxidant potential of fruit juices have been used. The antioxidant capacities of the fruit ranged from 0 to 25.3 μmol Trolox equivalents g^-1 (TEAC) or from 190 to 66 000 μmol^-1 ferric reducing antioxidant power (FRAP). Ascorbic acid contributes only minimally to the antioxidant potential of Rubus juices (< 10%, TEAC). There are apparent linear relationships between antioxidant capacity (assessed as both TEAC and FRAP) and total phenols (r(xy) = 0.6713 and 0.9646 respectively). Also, anthocyanin content has a minor influence on antioxidant capacity (r(xy) = 0.3774, TEAC; r(xy) = 0.5883, FRAP). The sample with the highest antioxidant capacity (Rubus caucasicus) had the highest phenol content, but only a low percentage was represented by anthocyanins. The present study demonstrates the potential of certain wild Rubus species, notably R caucasicus, for improvement of nutritional value through germplasm enhancement programmes. (C) 2000 Society of Chemical Industry.