Ação do ácido cítrico na redução do off-flavor e na qualidade microbiológica e físico-química de filé de Pacamã ("Lophiosilurus a lexandri" Steindachner, 1876)

The off-flavor is a problem reported worldwide in aquaculture and its caused by the microalgae and cyanobacteria accumulation in the water. These lead to the change of flavor and smell of the fish meat, bringing many damages to the productive chain. This work aimed to evaluate if the addition of citric acid reduces the off-flavor in the pacamã fillet. The experimental design for the microbiological and physicochemical analyzes was entirely random, with seven replicates per treatment, totaling a sample number of 21. For the sensorial analysis, a randomized block design with six replications was used, having then, a sample number of 18. The three treatments were the control (0% citric acid), 2% citric acid and 5% citric acid. Then, the pacamã fillets were submitted to sensorial analysis, with eight trained judges; studies of mesophilic aerobic, psychrotrophic, proteolytic psychrotrophic and lipolytic psychrotrophic microorganisms, more probable numbers of total and thermotolerant coliforms; and determinations of pH and of percentage contents of lipids, protein, fixed mineral residue, and moisture. In data analysis, for sensorial analysis was used the Friedman's test, then for microbiological analysis was used the T-test and for the physicochemical analysis was used Tukey, all the tests with p<0.05. It was observed that the action of citric acid was effective in reducing the sensorial perception of the off-flavor in the pacamã fillet, due to the statistical difference regarding the standard. The citric acid decreased the microbial load of the fillets and did not cause interference in the physicochemical composition of them. Therefore, 2% or 5% citric acid may be used for the conservation of pacamã meat, without interfering with its taste and with the quality and physicochemical, besides modulating in a beneficial way the undesirable microbiota.