Evaluating the Degree of Ripeness in 'Masui Dauphine' Figs (Ficus carica L.) using an Improved Color Chart

Abstract

　The aim of this study was to update the color chart that is currently used (NCC) to identify the optimal harvest stage for figs. 'Masui Dauphine' figs were harvested from August to October in 2014 and classified by experts into five levels of ripeness, from slightly immature to overripe. Their appearance was assessed using the NCC, and their ingredients such as total soluble solids, and characteristics such as breaking stress were also analyzed. During the harvesting period, as the coloration of the pericarp progressed, the fruit continued to ripen, the total soluble solids increased, the titratable acidity decreased, and the fruit softened. Fruits with progressed ripeness and high total soluble solids content received high-evaluations in the sensory, however, as the ripening progressed further the freshness retention period decreased. The quality and freshness retention period of the fruit could be evaluated using the pericarp coloration, consequently, the new improved color chart (improved CC) that was developed incorporated photographs of the equatorial sections of the fruit as color chips to evaluate the complex color patterns on the pericarp. This improved CC system was further validated by testing fruits from production plots. We have demonstrated that the improved CC is a practical and effective tool for the classification of high-quality fruits throughout the entire harvest season.