Longan is one the most economically important fruits in the northern part of Thailand. There are several preservation methods for reducing spoilage, increasing shelf life and adding value to product, such as canning, freezing and drying. The export value of dried longan in 2010 was $68 million. The quality of dried product is a specific characteristic that is acceptable by the consumer. The color is one of the most important quality factors of dried longan flesh. Browning reaction occurs during the drying of the fruit and this has a significant impact on the color of the final dried product. The rate of the browning reaction increases with increasing product temperature and the increase is faster when the product contains high sugar content. Browning reactions can occur during drying of longan flesh because
longan flesh is rich in sugar. The kinetic models of color change are essential to design a new process for achieving the best quality of dried product. Several researchers studied on the kinetics of color changes of vegetables and fruits such as banana, apple, carrot and potato, kiwifruit, spinach pineapple puree, whole longan and longan without stone but no kinetics studied related with the color change during drying of longan flesh were found. Therefore, the aim of this research is to study the kinetics of color change of longan flesh during drying in order to predict color changes with time and drying air temperature.