Vitamin C content and antioxidant activity of red currant (Ribes rubrum L.) juices

Red currants (Ribes rubrum L.) belong to Grossulariaceae family and the Ribes genus. They are sweet and sour, nutrient rich berries that have shown antioxidant, antibacterial, antiseptic, cardioprotective, and anti-inflammatory effects. The aim of this study was to determine the vitamin C content and antioxidant potential of fruit juices from six varieties of red currants - Redpoll, Makosta, Stanza, Jonkheer van Tets, Rolan, and Rondom. Fresh, undamaged fruits were pressed into juice and stored at -18 °C. Ascorbic and dehydroascorbic acid were determined by high-pressure liquid chromatography. Antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) system as well as β-carotene bleaching assay. The results showed that the juice of the Redpoll variety had the highest vitamin C content(66.52±2.9 mg/100 g juice), while the juice of the Stanza variety had the lowest content (6.23±0.28 mg/100g). The Redpoll variety juice also showed the strongest antioxidant activity (IC 50 = 1.76±0.25 mg/mL), while the juice of the Rolan variety showed the weakest antioxidant activity (IC 50 = 6.65±0.84 mg/mL). Thanks to its favorable cultivation properties and numerous potential and proven positive health effects, red currant is becoming the subject of increasing research. The results of this study can serve as an incentive for the use of red currants and their products in nutrition, as well as for the selection of nutritionally high-quality varieties.