The biphasic model was applied for determining the time domains in which the two reaction rate constant operate. The point of changeover was determined at which the slopes of the two reaction rate constants intersect These changeover points were at 6, 8 and 10 min of cooking at 98 +/- 2 C, for green peas, carrot and knol-khol respectively. It was interesting to note that radish did not have any changeover point. These observations also confirmed the findings of earlier work, that there are two substrates S-1 and S-2 which provide skeletal rigidity to the vegetables. These findings are important to decide the operating parameters in the blanching of vegetables as preprocessing.