Evolução da proteólise do leite inoculado in vitro com Pseudomonas fluorescens

Abstract

The present study was carried in the Laboratório de Microbiologia of the Centro de Pesquisa em Alimentos from the Escola de Veterinária of the Universidade Federal de Goiás with the objective of detecting proteolysis in milk caused by the Pseudomonas fluorescens. Were acquired strain lyophilized of P. fluorescens ATCC 13525 from the Instituto Adolfo Lutz. After the growth of strain of P. fluorescens, were determined amounts that corresponded to 100.000, 500.000 and 1.000.000 of UFC/mL, to be carried the inoculation in vitro in samples of reconstituted skimmed milk 12% (RSM 12%) and sterilized. The experiments of P. fluorescens strain growth were lead in aliquot of 40 mL of RSM 12%. The samples were incubated at 4ºC, 7ºC and 10ºC in refrigerator. During the incubation period the samples were evaluated at each 24 hours, for a 120 hours period. The samples were also analyzed to verify the presence of caseinmacropeptide through highperformance liquid cromatography (HPLC) technique. The growth of P. fluorescens in RSM 12% was not significant at the storage temperatures of 4 ºC, 7 ºC and 10ºC interfering only on the storage time. It was not verified the presence of caseinmacropeptide in the evaluated samples.