Carotenoid degradation and colour loss in dehydrated blanched and unblanched carrot slices during storage at 27, 37, 47 and 57 degrees C were investigated. The degradation of beta-carotene and colour loss followed a first-order reaction. A significant relationship was found between the colour loss and P-carotene degradation in blanched (r = 0.878-0.97 1, p < 0.05) and unblanched samples (r = 0.9030.998, p < 0.05). Degradation of beta-carotene had an activation energy of 15.8 +/- 0.81 kcal mol(-1) and 9.3 +/- 2.07 kcal mol(-1) for blanched and unblanched carrots, respectively. For blanched samples, the activation energies of colour loss determined on the basis of a and b values were 15.7 +/- 2.81 kcal mol(-1) and 21.7 +/- 4.13 kcal mol(-1), while those for unblaDched samples determined as 10.5 +/- 0.62 kcal mol(-1) and 14.7 +/- 1.30 kcal mol(-1), respectively. Nonenzymatic browning of dehydrated carrots was also investigated and this reaction fitted to zero-order kinetic model. Activation energies of nonenzymatic browning occurred in blanched (25.3 +/- 12.30 kcal mol(-1)) and unblanched (25.9 +/- 2.61 kcal mol(-1)) dehydrated carrots was found similar. (c) 2005 Elsevier Ltd. All rights reserved.