Índice de rigor mortis de Tilápias do Nilo abatidas de diferentes formas após cultivo em esgoto doméstico tratado

Abstract

It is conducted a comparative analysis of Rigor Mortis Index (IRM) on the flesh of the Nile tilapias cultivated in treated domestic sewage and submitted, or not, to depuration before slaughter by eugenol solution immersion and by hypothermia, aiming to evaluate if there is influence of the treatments in the quality of the fish produced. The experiment lasted 170 hours and four different kinds of treatments were tested: “DE”, depuration in raw water for five days and slaughter by eugenol solution; “DH”, the same depuration process and slaughter by hypothermia; “EE”, no depuration and slaughter by eugenol solution; and “EH”, no depuration and slaughter by hypothermia. The different kinds of treatments caused differences on rigor mortis start time. Both sacrifice techniques worked, however the use of eugenol presented a better result, providing higher values of the index on full rigor. In the end of the experiment, we observe that, although the four treatments do not present a statistically significant difference, the “EE” has higher IRM value, followed by “EH”, “DH” and “DE”. We do not observe differences in the rigor mortis evolution between the tilapias which go through the depuration process and the ones which do not. The fish sacrificed with eugenol reach higher IRM value on full rigor compared to the fish sacrificed by hypothermia.