Faculty of Agriculture, Kochi University, B200 Monobe, Nankoku, Kochi 783-8502, Japan
To improve the commercial value of cultured yellowtail, the following two experiments were conducted. In the first experiment, the anti-oxidant effects of yuzu Citrus junos juice on prevention of dark muscle discoloration during storage in yellowtail Seriola quinqueradiata were investigated. Yellowtails were fed one of four diets supplemented with yuzu juice (0, 12.5, 25 and 50 mL/kg diets) for 40 days. Growth performance was not significantly different among the dietary groups. Dark muscle discoloration was reduced in fish fed yuzu juice-supplemented diets during storage at 4°C. These results indicate that yuzu juice-supplemented diets prevent dark muscle discoloration without affecting the growth of young yellowtail after 40 days of feeding. In the second experiment, the accumulation of yuzu flavor components in fish meat was confirmed; the fish meat had a delicate yuzu flavor after the first experiment. The five yuzu flavor components were detected and identified in the meat from fish fed a yuzu juice-supplemented diet for a month. This indicates that some yuzu flavor components were transferred from the yuzu juice-supplemented diet to fish meat.