Bioactive compounds of blackberry fruits (Rubus spp.) grown in Brazil

Abstract

The blackberry (Rubus spp.), a small fruit that grows in temperate climate, shows an attractive color ranging from purple red to blue, due to the high content of anthocyanins. The anthocyanins, along with carotenoids, are the major natural pigments found in several fruits. Many studies have reported the importance of these natural pigments as protectors and, or, inhibitors of degenerative disorders; however, data regarding the bioactive compounds in blackberry cultivated in Brazil are rare. Thus, the objectives of the present study were to identify the anthocyanins and carotenoids in blackberry (Rubus spp.), to determine the total contents of phenolic compounds, flavonoids, carotenoids, and total, monomeric, polymeric and co-pigmented anthocyanins, and the antioxidant capacity against the free radicals ABTS and DPPH. The total carotenoids level was low (86.5 ± 0.2 μg/100 g), with all-trans-b-carotene (39.6 %) and all-trans-lutein (28.2 %) as the major ones. The blackberries showed high antioxidant status mainly due to the high level of monomeric anthocyanins (104.1 ± 1.8 mg/100 g of fruit), presence of polymeric anthocyanins (22.9 ± 0.4 %), low percentage of co-pigmented anthocyanins (1.6 ± 0.1 %) and high contents of phenolic compounds (241.7 ± 0.8 mg Gallic acid equivalent/100 g) and total flavonoids (173.7 ± 0.7 mg catechin equivalent/100 g). Cyanidin 3-glucoside was the major anthocyanin (92.9 %). These results indicate that the blackberry cultivated in Brazil can be considered a rich natural source of antioxidants and pigments.