Color Index Development of Nagoya Cochin Eggshell

Abstract

Nagoya Cochin is one of Japan’s famous chicken breeds and was also the first domestic commercial chicken. The eggshell is a pink cherry-blossom color, with white speckles on its surface. The purpose of this study is to develop an eggshell color index for quality control to improve the commercial value. This study consists of two experiments. In the first experiment, the eggshell color of sixty eggs was measured by a colorimeter TC-8600A, and a visual evaluation using photo images of each egg was conducted by fourteen visual inspection experts. They scored on a Likert scale of five steps on four criteria: attractiveness of color, attractiveness of white speckles distribution, overall attractiveness, and preference. The relationship between the eggshell color and the visual impression was analyzed on a Hunter Lab color space. In the second experiment, a range of color variations of eggshells were generated on a screen using Adobe Photoshop, and a visual evaluation of three hundred and fifteen egg images was conducted by seven experts. It is hoped the results from both experiments will be useful for agricultural producers to develop more attractive products and increase the commercial value of Nagoya Cochin chickens.