Modelling Bacillus cereus adhesion on stainless steel surface as affected by temperature, pH and time

The adhesion of Bacillus cereus to stainless steel was modelled as a function of pH (4.0–8.0), time (2–24 h) and temperature (4.0–36.0 °C) using response surface methodology. Based on the initial inoculum (3 or 6 log cfu mL−1), two equations describing B. cereus adhesion to stainless steel were obtained. The results indicated that B. cereus was able to reach up to 5.5 cfu cm−2 and 6.4 cfu cm−2 when the initial inocula were 3 log cfu mL−1 and 6 log cfu mL−1, respectively. The significance of the factors varied with the model; i.e., inoculum of 3 or 6 log cfu mL−1. Bias and accuracy factors showed that the models are adequate to predict B. cereus adhesion to stainless steel surface under conditions assessed and to assess the adhesion of B. cereus under a range of conditions to which this microorganism can be exposed during either milk processing or cleaning procedures.