Dynamic mechanical analysis (DMA) was applied to potato cortex tissue of two cultivars (more waxy 'Nicola' and more mealy 'Saturna') in temperature scans in range the 30-90 degrees C and constant air humidity of 90%. The obtained scans indicate peaks in both storage and loss module of elasticity (SM and LM, respectively) at temperatures higher than 70 degrees C as was observed previously. The peak temperature as well as the peak value increase with increasing potato density. Higher peaks and higher peak temperatures was observed in the industrial cultivar 'Saturna' in comparison to more waxy salad cultivar 'Nicola'. The source of the observed module peaks in the potato cooking process is discussed from the point of view of starch swelling. (C) 2010 Elsevier Ltd. All rights reserved.