Phytochemical screening and antioxidant capacity of two berry cultivars, ‘Ruben’ and ‘Duke’, depending on their harvesting time

Commercial berry production is an attractive industry worldwide, including in Romania because berries are a rich source of bioactive compounds with antioxidant capacity, thus becoming the most important functional and nutraceutical foods in our diet. The aim of our work was to characterize two different species, Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae), from the point of view of total phenols and anthocyanin as well as of antioxidant capacity depending on their harvesting time. The analyzed cultivars ‘Ruben’ and ‘Duke’ were cultivated in the North-West of Romania, the first cultivar has been officially introduced in Romania in 2018.  The results show that ‘Ruben’ cultivar is richer in bioactive compounds compared with ‘Duke’ cultivars. The level of total phenols of ‘Ruben’ cultivar was 297.937 ± 4.30 and 347.412 ± 14.13 mg GAE/100 g fw (fresh weight) at early and full ripening time, respectively. The highest anthocyanins content was found in ‘Ruben’ cultivar (410.659 ± 52.88 mg/100 g fw) at full ripening time. Also, the high values of antioxidant capacity determined by four different methods (DPPH, FRAP, ABTS, CUPRAC) was recorded in the case of cultivar ‘Ruben’. Both blueberry cultivars ‘Duke’ and ‘Ruben’ are rich sources in bioactive compounds such as phenolics, especially anthocyanins. The blueberries harvested at full ripening period provided the highest level of total phenols and anthocyanins compounds. These compounds act as powerful antioxidants and thus they could improve the health status of the human body, or can be used by food and nutraceutical manufacturers.