Purple-fleshed potato varieties Blaue Elise, Blaue St. Galler, Blue
Congo, Valfi, Vitelotte and red-fleshed varieties Highland Burgundy
Red, Herbie 26, Rosalinde and Rote Emma from the 2009 harvest
were used. Varieties were grown at the testing station of The
Central Institute for Supervising and Testing in Agriculture at
Prerov nad Labem (The Czech Republic). The tubers after harvesting
at physiological maturity were stored in a cooling facility at a
temperature range of 3e5 C for nine months and reconditioned for
3 weeks at 15 C. Mechanically and physiologically undamaged
tubers (Ø 4e7 cm) were used for analysis. A laboratory sample of
each potato variety weighed 5 kg.