Avaliação do efeito da pasteurização nas características microbiológicas e físico-químicas do leite cru em um laticínio do município de Montes Claros - Minas Gerais

Abstract

Milk is a food with important nutrients and necessary for the maintenance of a healthy life. However, the high water activity and the amount of nutrients available in this food makes it susceptible to microbiological contaminations ranging from animal health to the use of contaminated equipment during processing. Hence, it needs be subjected to a heat treatment that ensures its safety. On the other hand, it is known that heat treatments can cause changes in the components of milk. Therefore, the aim of this study was to evaluate the effect of pasteurization on the physical-chemical and microbiological characteristics of raw milk. Thus, it was verified that pasteurization reduced coliforms at 45 °C and Staphylococcus aureus present in raw milk. Regarding to the physical-chemical analyses, the pH values found are in accordance with the current legislation, while the values of acidity and cryoscopy were in accordance with others reported in the literature. The alcohol test revealed that the samples were heat sensitive and the total dry extract value also decreased after pasteurization. Along this lines, it was concluded that pasteurization did not cause physical-chemical changes in the milk, however, it reduced the amount of coliforms at 45 °C and lead to the absence of Staphylococcus aureus, making the milk suitable for human consumption.