Perfil lipídico e composição química de tilápias nilóticas em diferentes condições de cultivo

Abstract

This study aimed to evaluate the lipid profile and the chemical composition of the fillets of Nile tilapia (Oreochromis niloticus) maintained under three raising conditions, for a period of 120 days. A total of 2075 sexed males of tilapia were utilized, allotted into two ponds and one alvenaria pond. The applied treatments were: feeding with a basal diet in the alvenaria pond; feeding with the basal diet in the earthen pond and natural feeding through chemical and organic fertilization. The experimental design was in a completely randomized design, with three treatments and ten replicates. The evaluated parameters were: identification of plankton, profile of fatty acids and contents of moisture, crude protein, etereo extract and ashes of the fillets. The data were subjected to analysis of variance and the means of the treatments were evaluated by Tukey´s test (5% of significance). A total of five predominant distinct genera of zooplankton and four genera of phytoplankton were found. The results shown any statistical differences for the moisture and ashes contents of the fillets over all treatments tested. Therefore only the animals raised under the fertilization system shown increased crude protein content and decreased lipid content. The fatty acid profile of the fillets shown better omega-3/omega-6 ratio, with higher amounts of docosahexaenoic fatty acid in fertilization system.