Estabelecimento de uma curva de calibração para o equipamento bactcount para monitoramento da qualidade do leite cru refrigerado

Abstract

The experiment was conducted at PROGENE laboratory in the Rural Federal University of Pernambuco. The aim of this paper was to develop a calibration curve for the Bactocount IBC equipment. This equipment perform the individual counting of bacteria in milk, but it is necessary to express the results of this counting in colonies formed per unit (CFU). The CFU is one of the most important parameters indicating the quality of the raw milk because milk may carry a variety of microrganisms that can infect humans. 169 samples were collected from bulk milk from four states of Northeast region of Brazil and stored in a sterile device at 4ºC and brought to the laboratory. After the analysis in Bactocount equipment, the analysis by the CFU method was performed by using the standard count in Petri dish. A calibration curve was constructed with data from Bactocount equipment compared to the CFU method. It was applied a correlation analysis and a linear regression. The correlation between Bactocoun and CFU was 0,98 and equation generated was log(CFU) = - 0,6324 + 1,102 * log(IBC).