Factors determining the transport coefficients of aroma compounds through polyethylene films

Aroma sensitivity of two PE films having different composition was evaluated with four aroma compounds by measuring (i) aroma permeation (ii) aroma uptake by immersing films in pure aroma compounds, (iii) aroma vapour sorption by exposing films to saturated vapour phase and finally (iv) aroma sorption under realistic conditions by immersing films in water solution containing low concentration of aroma compounds. From permeation and sorption kinetics, diffusion coefficients were determined by modelling the curve over time.Results were clearly related to the conditions of measurement, to the aroma compounds characteristics such as hydrophobicity and size. Regardless of the method used, the crystallinity of PE films was found to be the most critical factor.