ACCURACY OF MICROBIAL-GROWTH PREDICTIONS WITH SQUARE-ROOT AND POLYNOMIAL-MODELS

The results of growth predictions using square root and polynomial mod els published in 14 papers were studied. Errors on quantities of pract ical interest such as lag time, generation time or the time required t o reach a given increase in number of cells, are analyzed. The distrib ution of these errors was examined with the perspective of the practic al use of predictive models in food industry. Highly unsafe prediction s and significant average errors were observed in some cases. A good k nowledge of predictive models accuracy seems essential for their effic ient and safe use, for example to predict the shelf life of a product. Yet, authors generally gave no pragmatic information on such things a s the average relative error or the range of errors on predicted varia bles. Problems of robustness of models when tested in different condit ions were noticed, which corroborates the necessity of a systematic va lidation of models on new data.