デジタルカメラと画像解析を用いた生ノリの簡便な色調評価法の開発

抄録

We developed a method for evaluating the color tone of raw nori (Pyropia yezoensis) by using a digital camera and image analysis. The RGB values of raw nori were derived from images taken using a digital camera, and then image analysis was performed using the freeware Lia32 (http://www.agr.nagoya-u.ac.jp/~shinkan/LIA32/index.html). As a result, the RGB values obtained using 2 different digital cameras were highly correlated. The G value derived using this method was highly correlated with the L* value, which is the measured colorimeter value, and nitrogen content of nori (L*: r=-0.865, nitrogen content: r=0.528). We converted the L* values into G values, and the G values into nitrogen contents using regression equations. As a result, G values below 20 and nitrogen contents below 47 μg・mg DW-1 were determined to indicate discoloration of nori.