The present study evaluated the sensory, proximate and morphometric differences of pond and net-cage-reared Nile tilapia (Oreochromis niloticus). Thirty samples from ponds and 30 samples from net-cages were used. Morphometric measurements were performed in fish and the fillets; proximate composition of the fillets was determined; and sensory analysis of the meat was performed. The fish reared in ponds exhibited similar weights and larger measurements than those reared in net-cages. Fillet measurement and weight were similar for both rearing techniques. The proximate composition analysis of the fillets showed that there was less lipid deposition (12.6 g/kg) and higher moisture retention (792.6 g/kg) in fish reared in the ponds compared with those reared in net-cages (31.7 and 767.8 g/kg, respectively). Although the amount of lipid in the fillets from fish reared in net-cages was higher, the fillets do not contain excessive fat. There was no difference in fillet protein or ash. The flavor of the fillet was moderately good to good and was similar in both farming systems. Fillets produced with the 2 farming systems have similar morphometric, proximate and sensory characteristics.

O objetivo deste trabalho foi testar a eficiência do óleo de cravo como anestésico em adultos de tilápia-do-nilo (Oreochromis niloticus) e avaliar, sensorialmente, o aroma e o sabor do filé, após a anestesia. No primeiro experimento, os peixes foram expostos a banhos anestésicos em diferentes concentrações de óleo de cravo (0, 100, 150, 200, 250 e 350 mg L-1). No segundo experimento, avaliaram-se diferentes tempos (10, 20 e 30 minutos) de exposição à anestesia. Finalmente, o aroma e o sabor dos filés de tilápia foram testados, em diferentes tempos de exposição à concentração adequada de óleo de cravo. A concentração de 250 mg L-1 de óleo de cravo foi adequada para a indução de parada dos batimentos operculares em adultos de tilápia, e para a anestesia voltada para biometria e breve manejo, a concentração recomendada é 100 mg L-1. Os filés de tilápias previamente anestesiadas com óleo de cravo apresentaram diferença moderada no aroma e no sabor logo após a anestesia. O óleo de cravo é um anestésico eficaz no manejo de adultos de tilápia em procedimentos de rotina na piscicultura, porém o abate de tilápias deve ser realizado a partir de 12 horas após a exposição a este anestésico, para não induzir alteração nas características organolépticas dos filés de peixes anestesiados

The objective of this study was to test the efficiency of clove oil as an anesthetic for adult tilapia (Oreochromis niloticus) and to evaluate, sensorially, the aroma and taste of fillets after anesthesia. In the first experiment, fish were exposed to different clove oil concentrations (0, 100, 150, 200, 250 and 350 mg L-1) of anesthetic baths. In the second experiment, different times of exposure (10, 20 and 30 minutes) to anesthesia were evaluated. Finally, the aroma and taste of the tilapia fillets, when exposed to optimal concentration of clove oil, were tested. The concentration of 250 mg L-1 of clove oil was adequate to induce lower opercular movement in adult tilapia, and for anesthesia for biometrics and brief management, the recommended concentration is 100 mg L-1. Fillets from tilapia anesthetized with clove oil showed a moderate difference in aroma and taste just after anesthesia. Thus, clove oil is an effective anesthetic for the management of adult tilapia as a routine procedure in fish farming, however tilapias should be slaughtered 12 hours after exposure to the drug, so as not to change the organoleptic characteristics of anesthetized fishes