Mapping of physical-chemical, microbiological, and chemical component characteristics of water samples from Nile tilapia slaughterhouses
The aim of this study was to analyze the physicochemical and microbiological characteristics of the water used in fish processing and tilapia fillets in slaughterhouses. The study analyzed the processing water from nine slaughterhouses. The water samples for analysis were collected at three points: process water (PW), it is the water used inside the slaughterhouses in direct contact with the fish; clean water entering the purification tank (EPT) and water leaving the purification tank (LPT). The processing waters of the nine tilapia slaughterhouses were analyzed and characterized according to their microbiological and physical-chemical characteristics. The results of microbiological analyzes meet the values indicated by legislation, in most cases. Regarding microbiological data, we can highlight that there was an increase in the total coliforms of the water entering the purification tank to the water leaving the purification tank in five slaughterhouses. Still, there was an increase in the aerobic mesophilic bacteria content observed in the outgoing water in relation to the inlet water of the purification tank in seven slaughterhouses. In relation to the physical chemical analyzes for the process water samples, the results show that the evaluated indices are in accordance with the values indicated by the legislation. The levels of Cd, Mg, Sc and Cd were below that detectable by the analysis in all slaughterhouses. The levels of Al, Sc, As, Rb, Ba, Pb, Mn, As, Se, Rb, Ag, Sb, Ba and Pb were detected only in one or two slaughterhouses. It is concluded that although some abattoirs have water characteristics outside the limits indicated by the legislation, the observed changes were not significant and small adjustments are necessary for the adequacy.