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Chokeberries () are rarely used in diet in Croatia but they have high content of polyphenolic compounds and one of the highest antioxidant activities among fruits. The aim of this study is to compare the quality, phenolic content and antioxidant capacity of different chokeberry products (juices, powders, fruit tea, capsules and dried berries). It can be expected that processing influences antioxidant activity and phenolic content of final products reaching consumers. Characterisation of phenolic compounds was carried out by using spectroscopic methods (Folin-Ciocalteu and pH differential methods). Antioxidant activity of chokeberry products was determined using 2,2-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. The results show that the investigated products contain high amount of phenols (3002 to 6639 mg per L and 1494 to 5292 mg per 100 g of dry matter) and lower amount of total anthocyanins (150 to 1228 mg per L and 141 to 2468 mg per 100 g of dry matter). The examined juices and other chokeberry products possess high antioxidant capacity (12.09 to 40.19 mmol per L or 58.49 to 191.31 mmol per 100 g of dry matter, respectively) and reducing power (38.71 to 79.86 mmol per L or 13.50 to 68.60 mmol per 100 g of dry matter, respectively). On the basis of phenolic content and antioxidant activity, capsules and powders stand out among other products. The study indicates that there are significant differences (p<0.05) in the quality, phenolic content and antioxidant capacity among examined products.

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Chokeberries are a subject of numerous studies due to a high phenolic compound content, antioxidant properties and potential positive infl uence on the health. Effects of weather conditions on fruit quality attributes, phenolic compounds and antioxidant capacity of chokeberry (Aronia melanocarpa) juice over three consecutive years were investigated. Total phenolic content and total fl avonoids range were from 8834 to 11093 mg/L and from 6993 to 9710 mg/L, respectively. High variations and discrepancy during different growing seasons are due to the different air temperature, sunlight and rainfall rate. The highest concentrations of anthocyanins and phenolics were observed in fruits harvested in 2012, which is most likely due to the favorable weather conditions (temperature and bright sunshine hours). All chokeberry juices possess high antioxidant activity (12.9-14.6 mmol/L; 128-167 mmol/L). Strong correlation implies that fl avonoids and non-fl avonoids were the major contributors to the antioxidant capacity. This study indicates that although the examined properties vary considerably through the growing seasons (p0.05), chokeberry juices can serve as a good source of bioactive phytochemicals in a human diet.