Properties of treated papers and plastic film influencing ethyl ester transfer

The objective of this work was to compare and understand the aroma compound barrier property of two impregnated–supercalendered papers, with or without surface coating, and one plastic film (BOPP) in standard conditions of temperature (25 °C) and relative humidity gradient (50%) for foodstuff storage. For that purpose, solubility, diffusivity and permeability coefficients were determined for a homologous series of ethyl esters with a range of physico-chemical properties and vapor concentrations. Whatever the aroma compound and its vapor concentration, the non-coated paper was the more permeable; the coated paper and BOPP presenting close and lower permeability values. The transfer behavior was mainly controlled by aroma compound diffusivity related to packaging microstructure. Mutual affinity between aroma compound and packaging surface, determined experimentally or estimated, was related to their respective hydrophobicity. Conversely to papers which were treated to become more hydrophobic, BOPP was surface-treated to become more hydrophilic. In the conditions of the study, ethyl hexanoate sorption slightly increased BOPP crystallinity.