In recent years, interest has increased in using mathematical models to describe the growth of microorganisms as a function of specific environmental conditions (e.g. temperature, water activity, pH, oxygen availability, product composition). Predictive modeling provides a fast and yet relatively inexpensive way to get reliable estimates on microbial growth and survival (Mc Meekin et al., 1993). Mathematical models can be used to describe the fate of micro-organisms in the manufacturing process design and optimization for production and distribution of food products (Alavi et al., 1999).