Studies of mass transport of model chemicals from packaging into and within cheeses Original Research Article

The aim of this work was to study the processes of migration and transport of diphenylbutadiene, triclosan and BHT, as model migrants, from LDPE film into and within cheeses containing different amounts of fat and water (Gouda cheese, soft cheese and cottage cheese) and stored at two temperatures (5 °C and 25 °C) for different storage periods under different conditions. A mathematical model based on the Fick’s second law was validated to predict migration from the packaging material into cheese, and another model based on the Moisan equation was validated to estimate the rate of diffusion of chemicals within cheeses. The results obtained contribute to a better understanding of the mass transport processes of migrants from packaging to cheeses. The effective diffusion coefficient of DPBD in the whole system, LDPE film–Gouda cheese, was 6.3 × 10−11 cm2 s−1 and the diffusion coefficient within Gouda cheese was 6.4 × 10−8 cm2 s−1 at 5 °C. Effective diffusion coefficient in soft cheese under the same conditions was 3.2 × 10−11 cm2 s−1 and the diffusion coefficient within soft cheese was 2.4 × 10−8 cm2 s−1. It can be concluded that the transport rate limiting step does not occur in the cheese itself but rather involves diffusion in the packaging material and transfer from the packaging surface to the cheese. In addition, the diffusion coefficients in the cheese were very similar at the temperatures used (5 °C and 25 °C), thus indicating small activation energies for diffusion processes in cheeses.