CONCENTRAÇÃO HIDROGENIÔNICA DO LEITE DE OVELHAS: INFLUÊNCIA DA MASTITE E DO CONGELAMENTO DA AMOSTRA

The measurement of pH in milk is one of the most important and frequent procedures performed in biochemistry practices. This variable is applied to the diagnosis of mammary gland disease, assessment of industrial yields, and identification of metabolic diseases. The objective of this study was to evaluate de effect of freezing the milk from healthy and infected mammary glands of Santa Ines ewes on the pH. The bacteriological culture of 183 milk samples was analyzed resulting in 146 negative and 37 positive samples. From these, the hydrogen ion concentration was determined on sampling day and after freezing at -20°C for 30 months. A reduction on pH was observed after freezing, and the bacteriological positive samples showed the highest pH values. A higher decrease of the pH after freezing was seen in positive samples. Thus, the kind of conservation of milk samples should be considered, as well as the results of parameters that could be influenced by such variation