Aproveitamento dos resíduos oriundos do processamento da carpa prateada cultivada ecologicamente no Lago Paranoá por métodos de silagem

Abstract

Urban aquatic ecosystems, as the Paranoá Lake, meet amongst that more suffer with the generation of decurrent residues of contamination processes, especially the eutrophication. The biomanipulation is an important strategy of ecotechnology that it aims at to intervene with the alimentary chain of lakes and dams for the reduction of the main symptoms of the eutrophication. Amongst the ecotechnologies alternatives of handling of Paranoá Lake ictiofauna, the culture of fish is distinguished filter-reeding as the silver carp for biological control of the buddings of cianobacteria and exportation of the match arrived in port to the ecosystem. Aiming at the creation of a aquaculture park in the arm of the Deep Stream for the production of fish filtering(silver carp) in wide scale and the additional generation of income for the local inhabitants, the processing of the silver carp if becomes basic, since this fish possesss great amount of spines and dull flavor, not being consumed in natura. In the processing of the fresh fished, 22% of the cool weight of the fish for the manufacture of nourishing products are only used to advantage as nugget, to hamburger, sausage, cookie and surimi, being been that 78% remainders, represented for the carcass, viscera, skin, etc, are generally discarded. The present project objective to use to advantage the residues generated for the processing of the silver carp for ensilage methods. After one has attacked acid preliminary with the addition of the hydrochloric acid, specifically in the samples destines to the acid and biological ensilage, had been tested and compared 3 distinct methods, to know: (a) the acid ensilage, with this exactly acid; (b) the biological ensilage, with Lactobacillus plantarum, and (c) the enzymatic ensilage, with the alcalase enzyme. After each one of these processes, they had been made, microbiological analyses and protein determination to evaluate the sanitary and nutricional quality of the products. The acid ensilage was the method more cheap, getting good sanitary quality, as well as nutricional (average of 29% of proteins), however its texture did not reach the results told for other authors. The biological ensilage got external contamination, probably happened of the sugar cane molasses, being also the one that presented minor protein text, approximately 17%. The enzymatic ensilage more quickly suffered the process from hydrolysis (60 minutes), getting a product with good nutricional value (average of 30% of proteins), with good organoleptics characteristic, however, had great contamination, having until presence of fecal coliforms, needing an acid daily pay-treatment. The ensilage, in the generality, is an efficient method in the exploitation of silver carp ix residues, serving with one viable and efficient ecotechnology technique, for being simple and of low cost, and for propitiating the generation of a new product of good quality.