Polyphenolic compounds with anthocyanins characteristic for coloured flesh potatoes are known for their antioxidant properties which could improve the quality of ready products as potato chips. Five purple potato varieties (Blaue Elise, Blaue St. Galler, Blue Congo, Valfi and Vitelotte) and four red flesh potato varieties (Highland Burgundy Red, Herbie 26, Rosalinde, Rote Emma) were stored for nine months and analysed for the polyphenols, anthocyanins, reducing sugars and antioxidant activity with two different methods viz. ABTS and DPPH.