梨の表面色と熟度の相関について

概要

論文の詳細を見る
The Japanese pear called 'Kosui' does not increase in ripeness after being harvested. Therefore, a harvester must estimate the ripeness of pears on the tree. To estimate the ripeness of a pear, the harvester examines its surface color. However, the surface color estimation of pears is influenced by the harvester's sensory ability. Recently, the sugar content of fruit has been measured by portable noncontact equipment using rays in the infrared region. This equipment has some problems in that it is heavy, bulky and expensive. In this study, the ripeness of pears was estimated from their surface color by a method in which only reflectance in the visible-light region is used. Therefore, the resulting equipment is small, portable and inexpensive. Currently, the surface color of a pear is determined by spectroscopy using an Lab color system. However, this method entails a long measurement time and expensive equipment. The feature of our proposed method is to use only two wavelengths in the visible-light region. In this method, pear ripeness was determined using the reflectance ratio of these two wavelengths. Band-pass filters and LEDs were used for detecting the two characteristic wavelengths. As a result, the degree of pear ripeness was successfully estimated. Miniaturization and a low cost were realized using LEDs. We propose that this method can be applied to many other types of fruit.