Modeling the Combined Effect of pH and Temperature on the Heat Resistance of Bacillus stearothermophilus Spores Heated in a Multicomponent Food Extract
The combined effect of pH and temperature on the heat resistance of Bacillus stearothermophilus spores heated in an extract of complex food was studied. The results showed that, in general, reducing
the pH reduced the heat resistance of the spores. Similarly, the value for the D parameter in the nonacidified extract was between 30 and 70% lower than the one obtained with double-distilled water.
This result once again shows the importance of the substrate in inactivation studies of microorganisms. The experimental data were used to carry out a comparison of two predictive mathematical models of
inactivation, one based on a multiparametric regression obtained in this study and the other obtained from the bibliography and based on a linear-Bigelow equation. Both models predict reasonably well, although
the multiparametric model presented a slightly better accuracy factor (1.11) than the one obtained with the linear-Bigelow equation (1.13).
Document Type: Research Article
Instituto de Agroquímica y Tecnología de Alimentos, Apartado de Correos 73, 46100 Burjassot, Valencia, Spain