この論文を読む／探す
抄録
ノリ葉体の色落ちの程度を色彩色差計で,LAB表色糸を別して評価した。色落ちの程度が中程度から重度のノリのa^*値はマイナスの値を示し正常ノリのa^*値が示す赤色方向から緑色方向に色彩が変化した。色落ちノリの色調を回復させるため硫酸アンモニウム添加海水で浸漬処理を行ったところ,液胞は大きいが細胞内の各器官の形態が明瞭で,細胞質が顆粒状になっていない中程度から重度の色落ちノリを,NH-N濃度25mg/Lに調整した海水に24時間浸漬したときの色調回復効果が最も高かった。
To quantify the degree of discoloration in faded laver Porphyra yezoensis the levels of tristimulus (L^*, a^*, b^*) were determined using a color difference meter. When the degree of discoloration of the thalli was moderate to severe, a^*-values were negative. A negative of a^*-value meant that the color of thalli changed from red to green. With increasing decolorization, the a^* levels decreased while levels of L^* and b^* increased beyond normal tristimulus values. When the ^*-, a^*-, and b^*-values were compared with the levels of chlorophyll a, phycoerythrin, and phycocyanin, the a^*-values correlated best with these pigments. To restore color in faded laver, thalli were treated with four concentrations of NH_4-N (1, 10, 25 and 50mg/L seawater). It was found that seawater enriched with 25mg/L NH_4-N promoted the best recovery of moderately or seriously faded laver within 24h. After this treatment, the levels of chlorophyll a, phycoerythrin and phycocyanin increased to 140-186%, 116-153% and 116-157%, respectively (relative to levels in untreated thalli). It is important to note that this treatment was only effective when the laver had a minus a^*-value and when cells in the tissue were without granulated cytoplasmic contents. This study demonstrates a rapid method for evaluating the degree of discoloration of harvested Porphyra and offers a simple treatment method to restore thalli color.
