Basic Study on Color Sorting of Fresh Market Tomatoes

The surface colors of tomatoes are one of decision factor for the ripeness rate of fruits, and that is mainly graded by the human sense in fact. The color sorting based on the surface colors of tomatoes was attemped by using an opto-electronic system consisting of the color sensors. The sample tomatoes of each ripeness rate were prepared and tested by the color sorting system. As the ripeness rate of tomatoes develops from unripe to ripe, the surface colors change from green to pink or red. We were considered the coloring index for the surface colors to judge the ripeness rate. The coloring index was calculated by the output of color sensors. The possibility of color sorting on the fresh market tomatoes was found by this experiment