Phenolics content and antioxidant activity of three Sorbus species

Abstract

The phenolic content and antioxidant activity of Sorbus aucuparia L., Sorbus aria (L.) Crantz and Sorbus austriaca (Beck) Hedlund leaves and fruit were investigated. The quantification of total phenolics, flavonoids and phenolic acids was performed using the Folin–Ciocalteu, Dowd and Arnow methods, respectively. The antioxidant activity of the extracts was evaluated using DPPH, TEAC and FRAP methods with Trolox as a standard. Leaves had a higher content of phenolic compounds and antioxidant activity than the fruits for all species. The highest content of phenolics (76.11 mg gallic acid equivalents (GAE)/g plant), flavonoids (15.86 mg rutin equivalents (RE)/g plant) and phenolic acids (44.54 mg caffeic acid equivalents (CAE)/g plant) was determined for S. austriaca leaves. Sorbus austriaca fruit had the highest content of phenolics (13.21 mg GAE/g plant), flavonoids (1.82 mg RE/g plant) and S. aucuparia fruit had the highest content of phenolic acids (9.05 mg CAE/g plant). The antioxidant activity was in the range: DPPH=38.42–274.52 μmol Trolox equivalents (TE)/g plant; TEAC=43.23–403.02 μmol TE/g plant; FRAP=47.13–706.96 μmol TE/g plant. The highest values of antioxidant activity were found for S. austriaca leaf and fruit extracts while the lowest values were determined for S. aucuparia leaves and S. aria fruit. The antioxidant activity was highly correlated with total phenolics and phenolic acids.