Theoretical Consideration by the Authors

In this paper [6], a physico-mathematical model describing the migration across functional barrier layers into foodstuffs is described. 

The system appears as follows a polymer barrier B of thickness b initially free from contaminant is surrounded by a semi-infinite matrix 1, with a concentration Cj of diffusing substance, considered as a contaminant and by another semi-infinite matrix 2, whose potential pollutant concentration is C2, while the diffusivity of the diffusing substance is called in these three media Dj, D2, Dg, respectively. 

The diffusion being mono-directional, and perpendicular to the planes separating the media, the equation of diffusion is  

By following, these assumptions, the initial condition may be written as  

The solution of the problem of diffusion from a semi-infinite medium into another semiinfinite medium, is generally expressed in terms of the error-function complement [7]  

---