Kinetic models for colour changes in kiwifruit slices during hot air drying.

摘要

The colour changes that occur in kiwifruit during the drying process were experimentally studied in order to determine the magnitudes of the parameters for a corresponding colour change model. The drying experiments were carried out with air temp. of 40, 50, 60, 70 and 80 degrees C, air velocity of 1.0 m/s and kiwifruit slice thickness of 4 mm. The colour change was quantified using the Hunter L, a and b system. These values were also used for calculation of the total colour change ( DeltaE), chroma, hue angle and browning index. The values of L and b decreased, while values of a and DeltaE increased during hot air drying. The mathematical modelling study of colour change kinetics showed that changes in L, b values, chroma and browning index fitted well to the first-order kinetic model while DeltaE, a value and hue angle followed zero-order kinetics.