Studies of Bacillus cereus Resistance to Fermentation and Drying of Four Milk Based Cereals Dough

The resistance of Bacillus cereus (B. cereus) cells to fermentation and drying in 4 different dough based on cereal flours (malted and unmalted sorghum, malted and unmalted maize) was studied. B. cereus vegetative cells in order of 107 cfu g 1 inoculated in the dough before the onset of fermentation increased to 108 cfu g 1 after fermentation for 48 h at 30 C inspite of the low pH recorded at the end of fermentation (pH< 4,7). Similarly, the cells present in the fermented dough at the start of drying reduced to only 4 104-4,71 104 cfu g 1 after drying in an oven at either of the three different temperatures (50, 65 and 80 C) to a final moisture content of less than 7%. These results reveal that once the cells of B. cereus have established themselves in dough based on cereal flours and milk, they can withstand fermentation and drying at temperatures between 50 and 80 C.