Quality of Coloured Varieties of Potatoes

Coloured potatoes ( Solanum tuberosum L.) were evaluated as important source of natural antioxidants. Eight varieties of these potatoes (Salad Blue, Shetland Black, Blue Congo, Blaue St. Galler, Highland Burgundy Red, Violette, Valfi, Vitelotte) grown in four different locations in the Czech Republic (Přerov nad Labem, Suchdol, Valecov and Stachy) were analysed. Content of majority antioxidants (anthocyanins, chlorogenic acid and ascorbic acid) was determined and the obtained results were correlated with antioxidant activity. Total anthocyanin content and antioxi - dant activity were determined spectrophotometrically and phenolic acids by HPLC-DAD. The best positive correlation was observed between total anthocyanin content and antioxidant activity ( r 2 = 0.64). Good correlation was found between chlorogenic acid content and antioxidant activity ( r 2 = 0.55); however, no correlation between ascorbic acid content and antioxidant activity ( r 2 = 0.08) was found.