Prediction of Optimum Cooking Time of Potato Basing on Softening Rate

Abstract

The softening of potatoes during cooking was evaluated in terms of hardness by texturometer. The rate of softening followed first-order kinetics and the rate constant, k was given (80-99.5°C) by k=7.49×10¹⁹ exp (-1.74×10⁴/T) where, T: temperature (°K). Internal temperature of potatoes during cooking was calculated from an equation of three-dimensional heat conduction and the internal temperature at arbitrary cooking time was expresed as rate constant. Thus, it was possible to calculate the softening ratio of cooked potatoes from the rate constant. The optimum cooking time for 1-4.6cm cube-shaped potatoes at 99.5°C was represented by the following equation approximately by Θ=0.98LL²+0.67L+6.15 where, Θ: optimum cooking time (min), and L: length of edge (cm).