Antioxidant activity and quality of red and purple flesh potato chips

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. After additionally in prepared potato chips oil content, texture and colour parameters were evaluated. Both, red and purple fleshed potato varieties contained higher content of total polyphenols (250-526 mg 100 g(-1) DW) and anthocyanins (16-57 mg 100 g(-1) DW). The higher content of polyphenols are directly related to higher antioxidant activity of tested potatoes. The process of frying caused almost total degradation of anthocyanin compounds, while polyphenols exhibited quite good stability (especially in chips obtained from red fleshed potatoes). The antioxidant activity decreased significantly in chips obtained from purple fleshed potatoes. Better stability after long term storage exhibited red fleshed varieties and also obtained chips exhibited better properties. (C) 2014 Published by Elsevier Ltd.