Validation of an overall model describing the effect of three environmental factors on the apparent D-value of Bacillus cereus spores.

Several factorial models extending the famous Bigelow model to describe the influence of the heating and recovery pH and a(w) conditions on bacterial heat resistance have been developed. These models can be associated in an overall multifactorial model describing the influences of heating and recovery conditions on D values. For Bacillus cereus strain ADQP 407 the model parameters characterising the environmental factor influences (pH, Temperature, a(w)) were evaluated. Determination of bacterial heat resistance in cream chocolate have been realised to validate these parameter values and to evaluate the level of the influence of food texture or different compounds not taken account of in the model.