Study on Kinetics of Color Changes in Thompson Seedless Grapes during Drying Process

The aim of this study was to investigate the characteristic of color changes in Thompson seedless grape during drying at 30°C, 35°C and 40°C air temperatures. The CIE LAB color system was used to measure the surface color of the grapes. It was found that browning began at middle period of drying, where parameters L* and b* decreased and parameter a* increased during drying. Color changes during browning process were described as a first-order kinetic model, where the activation energies for the parameters L*, a*, b*, and total color difference were respectively 40.19, 24.29, 35.43, and 39.46 kJ·mol1.