Abstract
ABSTRACT. Battaglini A.P.P., Beloti V., Fagnani R., Tamanini R. & Dunga K.S. [Microbiology and physical chemical characterization of unstable non-acid milk according to the seasons.] Caracterização físico-química e microbiológica do leite bovino instável não ácido em função das estações do ano. Revista Brasileira de Medicina Veterinária 35(1):26-32, 2013. Laboratório de Inspeção de Produtos de Origem Animal, Departamento de Medicina Veterinária Preventiva, Centro de Ciências Agrá- rias, Universidade Estadual de Londrina, Rodovia PR 445 Km 380, Cx. Postal 6001, Londrina, PR 86051-980, Brasil. E-mail: apaulabattaglini@hotmail.com The objective was to characterize the components of unstable non-acid bovine milk (UNAM) and normal bovine milk, as well to determine the occurrence of UNAM in the north region of the State of Paraná, Brazil, according to the seasons. Were collected 353 raw milk samples and analyzed for percentage of fat, protein, lactose, total solids (TS) and solids nonfat (SNF), somatic cell count (SCC), total bacterial count (TBC), alcohol test 72o (v/v), titrated acidity Dornic, clot-on-boiling test and pH. There was variation of the components analyzed according to the seasons, with exception of pH, fat and lactose. The occurrence of LINA was highest in the fall and lowest in the winter. The seasons influenced the percentage of protein, TS, SNF, SCC and TBC. The behavior of the milk (normal or UNAM) had effect on lactose, SNF and TBC. About the clot-on-boiling test, there was highest frequency of precipitation in acid milk samples and lowest in normal milk samples. The pH range of normal milk and UNAM was similar, regardless of its stability in clot-on-boiling test. In this study, seasonality and the behavior of milk had influence on its components, also, acidity is not the only factor related to thermal stability.