COMPARISON OF THE COOKING BEHAVIOR OF THE POTATO CULTIVARS NICOLA ANDIRENE WITH RESPECT TO PECTIN BREAKDOWN AND THE TRANSFER OF IONS

The potato cultivars Nicola and Irene were investigated with respect t o cell sloughing, specific cell surface area, release of pectic materi al and transfer of ions using a model cooking study. Both cell sloughi ng and the release of pectic material were higher for the mealy-cookin g cultivar Irene. As the respective cell size distributions measured w ere the same for both cultivars, the difference in release of pectic m aterial could not be explained by a difference in the specific cell su rface areas between the cultivars. Additionally, it was recorded that during cooking only 20% of the calcium present in non-cooked tissue wa s transferred into the cooking medium, whereas more than 70% of potass ium and citrate were transferred. The ratios D-a,D-citr2/D-a,D-K+ and D-a,D-Ca2+/D-a,D-K+ for water and cooked potato tissue revealed that i n water, potassium ions diffused faster than citrate and calcium ions. However, in cooked potato tissue both citrate and calcium ions diffus ed faster than potassium ions.