Pigmentos antociânicos de amora-preta e batata-doce-roxa: caracterização e viabilidade de utilização em dietas para peixes ornamentais

Abstract

The commercialization of ornamental fish depends on their phenotypic characteristics. It has been reported that the expression of skin coloration in fish decreases when they are kept in breeding systems and aquariums. As an alternative to mitigate these effects, nutritional additives can be used. This study investigated whether microencapsulated anthocyanin pigments from blackberry and purple sweet potato are effective in modulating responses related to skin coloration parameters and biochemical responses when added to the diet of ornamental fish. This study was conducted in two distinct experiments: the first used microencapsulated anthocyanins extracted from blackberry (MAP) as a dietary supplement for black tetra (Gymnocorymbus ternetzi); and the second used microencapsulated anthocyanins from purple sweet potato (MABDR) for the Mato Grosso fish (Hyphessobrycon eques), evaluating the acceptability and biochemical responses of the fish to the provided diets. For the MAP experiment, 90 juvenile black tetras were used, distributed into nine aquariums (60 L) in an individual recirculation system, with a density of 1 fish/6 L. The fish were divided into three groups and subjected to experimental diets: Control group (commercial diet), M15 group (diet supplemented with 800 mg.kg⁻¹ of dye and microcapsules with 15% wall material composed of maltodextrin), and M20 group (diet supplemented with 800 mg.kg⁻¹ of dye and microcapsules with 20% wall material composed of maltodextrin). The fish were fed twice daily to apparent satiation for 21 days. The results suggest that the use of natural blackberry dyes in the diet of black tetra has antioxidant capacity, potentially reducing the rate of reactions, protecting cells against the effects of free radicals produced by the organism, and possibly prolonging their lifespan in aquariums. For the MABDR experiment, 135 fish were randomly distributed into 9 experimental units of 20 L, in a recirculation system with a biological filter, with a stocking density of 15 fish per experimental unit. The fish were subjected to a 30-day feeding experiment, during which they were fed three times daily to apparent satiation. The experimental diets consisted of the following treatments: Control, ME (maltodextrin + 7% extract), and MEC (maltodextrin + 7% extract + controller). The ME and MEC diets were enriched with 800 mg.kg⁻¹ of anthocyanin. The results suggest that the use of microencapsulated anthocyanins from purple sweet potato has the potential to be used in the diet due to its acceptability and modulation of digestive and absorption responses for the Mato Grosso fish (Hyphessobrycon eques). When the controller was added, the microencapsulated anthocyanins from purple sweet potato improved the fish's coloration indices.