Growth performance and color enhancement of goldfish, Carassius auratus, fed diets containing natural dyes extracted from annatto (Bixa orellana) seeds

Abstract

The present study was conducted to evaluate growth performance and color enhancement of goldfish, Carassius auratus, fed diets containing 0, 50, 100, 200, and 250 mg kg−1 diet of annatto dye (AD) for 60 days. The survival rate was significantly higher in fish fed 100, 200, and 250 mg AD kg−1 diet over than these fed control and 50 mg AD kg−1 diet (p < 0.05). AD significantly (p <0 .05) increased the pigmentation in the skin and caudal fin of goldfish in a concentration dependent manner (R2 = 0.995, 0.997). The highest amount of total carotenoid deposition in fish skin and fins were given by diets containing 200–250 mg AD kg−1 diet. The highest redness (a*) of 43.21 and yellowness (b*) of 12.53 were obtained by 250 and 50 mg AD kg−1, respectively. The present results show that AD can be successfully used as an alternative natural carotenoid source in goldfish diets at levels of 200–250 mg AD kg−1 diet.