ANALYSIS OF COLOR ENHANCEMENT OF GOLDFISH, Carassius auratus FED DIETS SUPPLIMENTED WITH NATURAL ANNATTO DYE FROM Bixa orellana

Dananjaya S.H.S*, Manjula U. D. P, Rathnapala J. M. S. N., Mahanama De Zoysa

College of Veterinary Medicine (BK21 Plus Program) and Research Institute of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon, 305-764, Republic of Korea.
E-mail: shsdananjaya@gmail.com

Annatto dye is natural carotenoid which can be extracted from the seed or achiote tree Bixa orellana. This study was conducted to evaluate the growth performance and color enhancement of goldfish, Carassius auratus, fed with diets supplemented with natural annatto dye containing five levels (0, 50, 100, 150, 200, and 250 mg kg^-1) for 60 days. Feed conversion ratio was significantly (p> 0.05) lower in fish fed with 200 mg/kg (1.43) and 250 mg/kg (1.42) diets compared to that of control (1.72).

Pigmentation was significantly (p<0.05) enhanced in dose dependent manner (R² = 0.995-skin, 0.997-fin) by annatto based diets in skin and caudal fin. The diets containing 200-250 mg/kg of annatto dye has resulted a higher amount of total carotenoid deposition on both the skin and fin. Level of highest redness (a*) 43.21 was observed in fish fed with 250 mg/kg annatto dye compared to that of in control (10.33).

The present results show that annatto dye can be successfully used as an alternative natural carotenoid source to the goldfish diets. It is also evident that 250 mg/kg is the optimum dietary level of annatto dye to ensure higher pigmentation, acceptable growth and feed utilization in goldfish.