Due to its full and balanced composition, milk comprises an ideal raw material for the development of a variety of groups of microorganisms. Bacteria, fungus, viruses and others can provoke significant alterations in milk and derivatives. Despite the UHT process, in which long-life milk is submitted, the presence of a new type, highly thermal-resistant bacterium, called Bacillus sporothermodurans, was verified in the last years, due possibly to its capacity of spores formation. This work is aimed at investigating the presence of this bacterium in both integral and skimmed UHT milk, commercialized in the north and neighbor region of Rio Grande do Sul state and to quantify the resistance capacity to high temperatures processing. Results revealed the presence of this bacterium in 54.5% of the products analyzed with 36.5% of the analyzed batches contaminated. The thermal resistance of this bacterium with regard to lipids content was demonstrated to be greater in integral milk. We can conclude that even though this bacterium is described as not being pathogenic, it might be relevant to conduct new investigations towards assessing its characteristics, once its presence has been noticed to be very common.
Bacillus sporothermodurans; UHT; endoesporos
