Impact of natural pigments (Betanin, β-Carotene) with reference to colour enhancement in ornamental fishes

Abstract

The present study investigates the impact of natural pigments—Betanin from Beta vulgaris (beetroot) and β-carotene from Citrus sinensis (orange peel)—on colour enhancement in ornamental fishes. Colour intensity is a primary factor influencing the aesthetic and commercial value of ornamental species, making pigmentation a crucial area of focus in ornamental aquaculture. Since fish cannot synthesize carotenoids de novo, dietary supplementation becomes essential for achieving optimal skin coloration. In this experiment, multiple ornamental fish species such as Koi, Molly, Gourami, Black Moor Goldfish, Crucian Carp, and Shubunkin were fed diets enriched with beetroot powder and orange peel powder over a 15-week period. Weekly visual assessments were conducted to evaluate pigmentation changes. The findings revealed that beetroot powder significantly enhanced pigmentation in most species, particularly Koi fish, producing brighter and more intense hues compared to the control. Orange peel powder showed limited effectiveness, with noticeable improvement only in Crucian Carp and Shubunkin. These results align with earlier studies indicating that carotenoid-rich natural pigments improve colour intensity, antioxidant activity, immunity, and overall fish health. The study concludes that beetroot powder is a more potent natural pigment source than orange peel powder for colour enhancement. The use of natural carotenoids offers an eco-friendly alternative to synthetic colourants, reducing environmental impact while enhancing commercial value. Incorporating 10 grams of beetroot or orange peel powder per day demonstrated the most effective results, supporting its potential application in ornamental fish feed formulations within the aquaculture industry.