Comparing nonsynergistic gamma models with interaction models to predict growth of emetic Bacillus cereus when using combinations of pH and individual undissociated acids as growth-limiting factors

The quantification of hurdle technology has identified synergistic or multiplicative effects and the validity of the gamma hypothesis is tested with respect to the use of pH and various concentrations of undissociated acids to control growth of Bacillus cereus in brain heart infusion broth. The studies have shown that the introduction of synergy factors into the models have not improved the quality of the prediction, but have led to the overestimation of the growth boundary.