Test methods for the characterization of gas and vapor permeability in polymers for food packaging application: A review

The assessment of the transport properties of different substances in polymeric materials is of crucial importance for the evaluation of packaging performances, aiming to protect packed food products and ensure a prolonged shelf-life. The most relevant substances for such application can be identified in O2, CO2 and C2H4 (together with N2 as control) as permanent gases, and water vapor as condensable species. All these penetrants are able to alter significantly food properties, in term of sensory characteristics, textures, and quality in general. All relevant techniques for the experimental characterization of mass transport properties in polymeric films or packages are critically reviewed, focusing in detail on standard methods. Each technique is briefly presented in terms of apparatus requirements and general procedures, followed by a discussion on its main features.