The objective of the study was to determine the qualitative changes in black current nectars stored at 20 °C during a period of 1, 2, and 4 months with no access to light. Three variants of nectars were analysed: nectars without the additives, nectars enriched in an echinacea purpurea extract, and nectars enriched in a green tea extract. In the nectars analysed, the following contents were determined: total polyphenols, anthocyanins, L-ascorbic acid, and, also the antioxidant activity was determined. Immediately after the production, the nectars without the additives, as well as those enriched in the echinacea extract and in the green tea extract were characterized by the following antioxidant activity levels: 9.3 µmol Troloxu/ml, 11.8 µmol Troloxu/ml, and 16.3 µmol Troloxu/ml, respectively. In the same nectars, the content of anthocyanins was 89.7, 100.2, and 105.2 mg/100 ml, respectively, whereas the content of polyphenols was 96.3, 110.1, and 124.2 mg/100 ml, respectively. It was found that during the 4 months of storage the content of total polyphenols, anthocyanins, and vitamin C decreased in all nectars, and this decrease caused the antioxidant activity to fall. After the 4 month storage, the content of anthocyanins in the nectars was 70% lower compared to the initial samples.
nectars, black currant, polyphenols, anthocyanins, antioxidant activity