Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrie r materials. In such tests it would be convenient for both foodstuffs and m aterials below the functional barrier (sub-barrier materials) to be represe nted by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential si mulant of sub-barrier materials based on polypropylene (PP) or similar poly olefins. Experiments were performed to characterize the kinetics of the per meation of low molecular weight model permeants (octene, toluene and isopro panol) from liquid paraffin, through a surrogate potential functional barri er (25 mu m-thick oriented PP) into the food simulants olive oil and 3% (w/ v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model p ermeant in the post-barrier medium (i.e. the food simulant). The results ob tained justify the development and evaluation of liquid sub-barrier simulan ts that would allow flexible yet rigorous testing of new laminated multilay er packaging materials.