Growth rate and growth probability of Listeria monocytogenes in dairy, meat and seafood products in suboptimal conditions.

AIMS

To evaluate the performances of models predicting the growth rate or the growth probability of Listeria monocytogenes in food.

METHODS AND RESULTS

Cardinal and square root type models including or not interactions between environmental factors and probability models were evaluated for their ability to describe the behaviour of L. monocytogenes in liquid dairy products, cheese, meat and seafood products. Models excluding interactions seemed sufficient to predict the growth rate of L. monocytogenes. However, the accurate prediction of growth/no-growth limits needed to take interactions into account. A complete and a simplified form (preservatives deducted) of a new cardinal model including interactions and parameter values were suggested to predict confidence limits for the growth rate of L. monocytogenes in food. This model could also be used for the growth probability prediction.

CONCLUSIONS

The new cardinal model including interactions was efficient to predict confidence limits for the growth rate of L. monocytogenes and its growth probability in liquid dairy products, meat and seafood products. In cheese, the model was efficient to predict the absence of growth of the pathogen.

SIGNIFICANCE AND IMPACT OF THE STUDY

The suggested model can be used for risk assessment and risk management concerning L. monocytogenes in dairy, meat and seafood products.