Rendimento de carcaça e aspectos sanitários de tilápia do nilo (Oreochromis niloticus) e catfish (Ictalurus punctatus)

Abstract

The Nile Tilapia (Oreochromisniloticus) and Catfish (Ictaluruspunctatus) are two of the most consumed fish in Brazil. Due to this fact, fish farms or companies linked directly to fishery products, strive to achieve steak and carcass yield values to be profitable. However this commitment does not help anything, if the product did not comply with standards and rules for processing proper sanitary manner. Therefore, the aim of this study was to investigate the relationship between carcass and steak yield of Tilapia and Catfish compared to debugging time also analyzing their chemical and microbiological composition of the steak. 60 fish of each species were used, collected randomly (mean 0.536 ± 0.066 Kg for Tilapia and 0.88 ± 0.13 Kg for Catfish), belonging to the Instituto Federal do Espírito Santo - Campus Alegre. These animals were placed in a tank by species and kept for purification 0, 24, 48 and 72 hours before slaughter. It conducted initial biometrics, checking mass, body width, eviscerated body mass, housing clean mass, steak mass, viscus mass, fin mass, adipose fin mass (for the Catfish), liver mass, fat mass, visceral mass, mass of the head and skin mass. Patterns were observed related to carcass yield, viscerosomatic index, yield fins, income adipose fin (for the Catfish), hepatosomatic index, viscerosomatic fat index, headless carcass yield, skin yield, clean carcass yield and fillet yield. Samples of the fillet of each species, after collected were forwarded to bromatological and microbiological analysis at laboratories in the same intitution. The microbiological analysis was conducted in two environments, one considered proper and others improper for slaughter. There was a significant difference in viscus mass and fillet yields, carcass with and without head and viscerosomatic index on Tilapia. Regarding the Catfish, debugging time significantly interfered in its steak mass, body width and carcass and adipose fin yield. Nevertheless the percentage of fillet yield and carcass remained high in both species. In bromatological analysis, there was no reduction in non-nitrogen extract levels in tilapia and ether extract in both species. In the microbiological analysis, it was noticed among treatments for fish processing with respect to presence or absence of Salmonella and Staphylococcus aureus, ie, the environment in which not had care of the hygiene of the place of slaughter and handlers were most contaminated of mentioned microorganisms, which did not occur when it was increased the health care for processing the product. Concludes that debugging time influence on physical and chemical characteristics of the steak and carcass yield in both species. It is also realize that the environmental conditions of slaughter and fish handling influence on the microbial load present in the final product.