Instrumental Texture Profile Analysis can be used in studying thermal degradation of apple texture. Heating time and temperature significantly reduced fracturability, hardness, energy required during first compression and gumminess in both Red and Golden Delicious apples. Heating time did not significantly affect changes of springiness, cohesiveness and chewiness in both varieties. The changes in energy required during second compression were significant for Red but not for Golden Delicious apples. Two first-order kinetic mechanisms (1 & 2) are required to describe changes of apple texture during thermal processing. The rate constant for 1 was at least 16 times that for 2; activation energy was 27.7-92.6 kJM-1 for both. The z values were 25-99°C and QIO coefficients 1.26-2.50 for both mechanisms. Such results can be used to improve thermal processes for apples. Kinetics of texture degradation in apples during thermal processing.