Development of a predictive model to describe the effects of temperature and water activity on the growth of spoilage pseudomonads

A combined temperature and water activity model for the growth of psychrotrophic pseudomonads was developed using turbidimetic data. Psychrotrophic pseudomonads were isolated from various modified and whole milks. The fastest growing strain was identified and used to develop the model. Generation time estimates calculated by turbidimetric and viable count data differed but this difference was constant with respect to temperature and was incorporated into the modelling process so that all models are constructed to predict generation times equivalent to those calculated by viable counts, the standard method for enumerating microorganisms in food products.