1.2. PROGRAM LIMITATION

The migration from a package to a food is a complicated phenomenon, which can be influenced by many different factors. This program does not take into account all the possible situations. The following assumptions have been considered in order to design a simple and practical model:

- the migration follows a diffusive process (Fick’s law) and is not controlled by other kinetic steps
- the solubility of the migrant in the food is either infinite or limited
- the food is in intimate contact with all the package surfaces (no void space)
- the transfer of migrant at the interface material/food is rapid and the migrant is homogeneously distributed in the food