Modeling the Rate of Attachment of Listeria monocytogenes , Pantoea agglomerans , and Pseudomonas fluorescens to, and the Probability of Their Detachment from, Potato Tissue at 10°C

The rate of attachment of bacteria to, and their subsequent detachment from, the cut surface of raw potato tissue was measured and modeled by using mathematical approaches that allowed detailed objective comparisons of adhesion processes under different conditions. Attachment was rapid and reached equilibrium after contact for 60 min. A new method to measure the probability of detachment was developed and modeled, revealing that the probability of detachment for Pseudomonas fluorescens remained unchanged for contact times between less than 5 s and 60 min. Listeria monocytogenes, however, was more easily removed initially, with the probability of detachment decreasing over the first 2 min of contact but remaining constant and equivalent to that for Pseudomonas fluorescens thereafter. For all of the bacteria tested, the number of bacteria attached after 2 min of contact was proportional to the inoculum concentration raised to the power of 0.79.