Ascorbic acid, anthocyanins, organic acids and mineral content of some black and red currant cultivars

Introduction. Red and black currants are a valuable component of a healthy diet because they are an excellent source of ascorbic acid, anthocyanins and minerals. Materials and methods. Three red currant cultivars and eight black currant cultivars were evaluated in terms of fruit quality. Some selected physicochemical characteristics such as berry weight, dry matter, soluble solids, total sugars, titratable acidity and total anthocyanins were investigated. Total anthocyanin content was measured with the pH differential absorbance method while citric, malic, tartaric and ascorbic acid were quantified by a reversed-phase HPLC method. Sodium, calcium, magnesium, iron, manganese, chromium and zinc were determined by ICP-MS following a microwave digestion, while potassium content was determined by FAAS. Results. Significant differences in the physicochemical and mineral content were detected among the cultivars. The range of total anthocyanins of the tested samples was 12.14–22.06 mg·100 g-1 (red currants) and 116.17–287.78 mg·100 g-1 (black currants). Ascorbic acid content varied between 23.23–44.62 mg·100 g-1 (red currants) and 161.58–284.46 mg·100 g-1 (black currants). Citric acid was predominant in all studied black and red currant cultivars, followed by malic and tartaric acids. Black and red currants have rich mineral composition, especially potassium, calcium and magnesium. Black currant fruits were superior to red currants with regard to calcium and magnesium content.