Microencapsulation of anthocyanins from roselle (Hibiscus sabdariffa) and its application on a pigment supplied diet to fantail goldfish (Carassius auratus)

Abstract

Hibiscus sabdariffa has gained an important position in the food industry because of its high anthocyanins content, related to the persistent red calyx of its flowers as the major component. Moreover, it has been used as a food colorant and active ingredient to develop food with some health benefits. The effect of addition of microencapsulated anthocyanins from Hibiscus sabdariffa in a fish feed was evaluated using Carassius auratus as a study model. Anthocyanins were microencapsulated with maltodextrins (10 DE) and microcapsules structure was analyzed by scanning electron microscopy. Microcapsules were added to fish diet (D) at 150, 300, and 450 mg anthocyanin/kg of diet. Fantail goldfish were feeding for 8 weeks and the feed intake (FI), feed conversion ratio (FCR), growth rate (GR), specific growth rate (SGR), survival, and weight gain (WG) were evaluated. Skin chromatophores from the head, dorsal, and caudal fin of each treatment were observed by light microscopy. Microencapsulation efficiency was 90 ± 0.2%. The microcapsules showed a spherical shape, the mean size was 4.0 μm, and the powder showed a pink-red color. Feed intake and survival were similar to all diets (p > 0.05). D150 and D300 showed a significant variation in GR, SGR, and WG (p < 0.05) compared with other diets. Fish fed with D450 showed the highest increase in color compared with control diet; however, fish size is lower than D300. Size and color are important parameters in the marketing of Carassius, and these results suggest that microencapsulation can be used as anthocyanins carrier during fish diet manufacture being an alternative to provide natural pigments that enhance growth and pigmentation of fantail goldfish.