抄録
In order to determine which is effective to intensify the color of red Tilapia, test diets containing lutein, rhodoxanthin, and spirulina (zeaxanthin is dominant) were fed to red Tilapia for 84 days. After feeding experiment, the color of the integuments of red Tilapia in the control group, the lutein group, the rhodoxanthin group, and the spirulina group became pale pink, orange, pink, and orange red in appearance, respectively.
The four groups were similar to one another in the carotenoid patterns, but were different in the percentage compositions and the amounts of carotenoids.
The orange color of the integuments in the lutein group was mainly due to the presence of lutein which increased by ten times to that of the control group. Rhodoxanthin accumulated a little in the rhodoxanthin group, but in the spirulina group rhodoxanthin accumulated much more easily and amounted to eight times to that of the control.
The authors suggest that zeaxanthin might to metabolized to rhodoxanthin in vivo.
