This study was undertaken to model and predict growth of Salmonella and the dominating natural
microbiota, and their interaction in ground pork. Growth of Salmonella in sterile ground pork at constant
temperatures between 4 C and 38 C was quantified and used for developing predictive models for lag
time, max. specific growth rate and max. population density. Data from literature were used to develop
growth models for the natural pork microbiota. Challenge tests at temperatures from 9.4 to 24.1 C and
with Salmonella inoculated in ground pork were used for evaluation of interaction models. The existing
Jameson-effect and LotkaeVolterra species interaction models and a new expanded Jameson-effect
model were evaluated. F-test indicated lack-of-fit for the classical Jameson-effect model at all of the
tested temperatures and at 14.1e20.2 C this was caused by continued growth of Salmonella after the
natural microbiota had reached their max. population density. The new expanded Jameson-effect
model and the LotkaeVolterra model performed better and appropriately described the continued but
reduced growth of Salmonella after the natural microbiota had reached their max. population density.
The expanded Jameson-effect model is a new and simple species interaction model, which performed as
well as the more complex LotkaeVolterra model