Migration modelling as a tool for quality assurance of food packaging

The current potential for the use of migration modelling for studying polyolefin packaging materials (low- and high-density polyethylene and polypropylene) is summarized and demonstrated with practical examples. For these polymers, an upper limit of migration into foodstuffs can be predicted with a high degree of statistical confidence. The only analytical information needed for modelling in such cases is the initial concentration of the migrant in the polymer matrix. For polyolefins of unknown origin or newly dei,eloped materials with new properties, a quick experimental method is described for obtaining the characteristic matrix parameter needed for migration modelling. For easy handling of both the experimental results and the diffusion model, user-friendly software has been developed. An additional aim of the described method is the determination of the migrant partition between polymer and food or food simulant and the specific contribution of the migrant molecular structure on the diffusion coefficient. For migration modelling of packaging materials with multilayer structures, a numerical solution of the diffusion equation is described. This procedure has been also applied for modelling the migration into solid or high viscous foodstuffs.