The Influence of Microfiltration on Raw Milk Quality

Although the milk’s predominant microflora consists of lactic acid bacteria, it is probable that pathogenic bacteria such as Listeria, Brucella, Mycobacterium, Staphylococcus, Escherichia coli O157: H7 and Salmonella are also present. Due to the fact that milk contains components with high nutritional value and therefore suitable for the growth of microorganisms, the microorganism populations in the milk can reach to the numbers that can threat human health in a short time. Therefore, it is very important to ensure the microbial safety of the milk before it is consumed. Microfiltration, one of the techniques that can be used for this purpose, physically separates the microorganisms from the milk by passing the milk through the membranes having pores with certain diameters by the effect of pressure. Studies on the microorganism load of milk that microfiltration is used showed that the number of microorganisms in milk generally decreases depending on the working conditions such as pore diameters of the membranes, the initial microorganism load of milk, temperature and pressure. The membranes used in microfiltration technique are chosen according to the purpose. It is known that membranes with a pore diameter of 1,4 µm cause a pasteurization effect and membranes with a pore diameter of 0,2 µm cause a sterilization effect. Therefore, the choice of suitable membrane is very important for microfiltration application. Several studies have been done on the effect of microfiltration on extension of shelf life in drinking milk, the removal of bacterial spores which can withstand high temperatures and can cause milk deterioration of milk, the production of dairy products like cheese without damaging the natural components of milk. These researches are important in terms of providing information on a technique that allows the removal of pathogen microorganisms which cause a risk for public health and can cause food poisoning in case of consumption of raw milk and raw milk cheeses, without any change in the natural structure of milk.