Modelling Migration from Paper into Food Simulants

Considerable amount of work has been devoted to the identification and quantification of contaminants in paper and paperboard for food packaging applications, particularly in papers containing recycled fibre. However, much less effort has been dedicated to the development of predictive migration models for such materials when used in contact with food. The work presented here has as main objectives: (i) to identify the most important factors affecting the migration rate and migration level of paper contaminants into food simulants, and (ii) to contribute for the development of a mathematical model to describe the migration from paper into simulants. An experimental design using the Taguchi method was applied, considering the following factors at two levels: paper grammage (80-160 g/m), percentage of recycled pulp (20-80%), initial concentration of the migrant in the paper (50-150 ppm), temperature (8-40oC), food simulant (Tenax® and Poropak®) and the migrant (DBP and DEHP). The Weibull kinetic model was applied to describe the migration. The influence of molecular weight on the model parameters, employing 5 phthalates of similar structure and increasing molecular weight, was performed. Results show that the model describes very well the transfer of migrants from paper into the simulant. The model parameter τ increased linearly with the phthalates molecular weight.