Powdered milk containing Lactobacillus acidophilus isolated in Brazil

In order to determine the feasibility of producing powdered milk supplemented with viable cells of Lactobacillus acidophilus UFV H2b20, an experiment was conducted in which the microbial cells were added to milk at the time of drying to produce powdered milk with viable probiotic microorganisms. This bacterium has good thermal resistance in MRS, as evidenced by a Z value of 14.49 °C, in the studied range (60 to 73 °C). Two methods for producing powdered milk with viable cells of L . acidophilus UFV H2b20 were tested. In the first method, 100 l of “minas-padrão” cheese whey were inoculated and fermented at 37 °C for 10 h. The cells were concentrated (15 l), added to 21 l of milk (concentrated from 50 l) and spray dried with an inlet air temperature and outlet of 215 and 81 °C respectively. In the second method, 200 l of whey were inoculated, the cells were concentrated to 15 L, added to 21 l of milk (concentrated from 50 l) and spray dried with an inlet air temperature and outlet of 230 and 95 °C respectively. During the drying of the milk, a large portion of the cells died, and another portion were probably injured, mostly likely due to the moist heat generated at the beginning of the drying process. After spray drying the inoculated milk at temperatures of 215 and 230 °C, there was a reduction of approximately 92 and 97 %, respectively, in the population of viable cells. Based on the results obtained it is concluded that it is feasible the production of milk powders containing viable cells in the L . acidophilus