Precise Study of Cooked Potato Texture

Cylindrical specimens from potato tubers were cooked at constant temperatures (75, 80, 85, 90, 95C) in a special heating cell located on the table of an Universal Testing Machine and arranged in such a manner that a cooked specimen could be tested repeatedly in nondestructive compression test during the whole cooking process. The decrease of Young's modulus during cooking form the basis for the calculation of the Cooking Depression Coefficients and activation energies of the process. The whole cooking time could be divided into two parts for varieties ‘Nicola’ and ‘Panda'. The first part represents a modulus decrease of at least 50% and can be well described by a first order kinetic equation. The second part is kinetically very complicated and represents only a 10–15% further decrease of the original modulus value. Temperature dependence of mean Cooking Depression Coefficients (CDC) for both parts of the cooking curve, as well as Cooking Time Limits (CTL—time limit between both parts) fit the Arrhenius model. Cooking differences between both tested varieties are briefly discussed.