Bioactive Compounds and Antioxidant Capacity of Several Blackberry (Rubus spp.) Fruits Cultivars Grown in Romania

Blackberry fruit (Rubus spp.) has a powerful antioxidant capacity due to the high levels of anthocyanins and other phenols it contains. In this work, we investigated the physico-chemical characteristics, the bioactive compounds (total phenols, flavonoids, and monomeric anthocyanins), and the antioxidant capacity of seven blackberry cultivars belonging to the Rubus fruticosus L. and Rubus laciniatus L. genera growing in the NW region of Romania. In addition, the wild blackberry cultivar from the same area was also evaluated. Anthocyanins from the blackberry fruit were extracted using SPE (Solid Phase Extraction), and the anthocyanin profile was identified and quantified using HPLC-PDA analysis. In terms of polyphenol content and antioxidant capacity, two of the cultivars examined stood out. The majority of anthocyanin found in blackberries was cyanidin-3-glucoside, with the highest amount recorded in the ‘Thorn Free’ cultivar at 329.26 ± 9.36 mg/g dw. Comparatively, ‘Loch Ness’ and ‘Thorn Free’ fruits exhibited total phenol contents of 1830.98 ± 13.55 and 1687.14 ± 62.41 mg GAE/100 g dw, respectively. Antioxidant capacities varied significantly among the eight blackberry cultivars, with cultivars ‘Loch Ness’ and ‘Thorn Free’ achieving high values in comparison to the others. The findings of the multivariate analysis also supported the experimental results. Knowing the phytochemical composition and antioxidant potential of different blueberry cultivars, one can use them as fresh, functional foods or for commercial purposes to produce products derived from fruits with a high concentration of bioactive components.