Nanostructuring and Microstructuring of Materials from a Single Agropolymer for Sustainable MAP Preservation of Fresh Food

The main objective of the present work was to determine whether a single agropolymer [wheat gluten (WG)] could fit the modified atmosphere packaging (MAP) requirements of a range of six different fresh produce in key terms of oxygen permeation (PeO2) and CO2/O2 permselectivity (S) values. The required properties for optimal packaging of fresh fruits and vegetables were first evaluated using the Tailorpack MAP modelling software (UMR IATE, Montpellier, France) with packaging dimensions and respiratory and optimal atmosphere data as input parameters. Then, the modelled values obtained were compared with the properties of a range of WG composite films: monolayer self-supported or multilayer at microscale or nanoscale, cast or thermoplasticised, with different formulations (percentage of plasticisers or nanofillers). The experimental gas transfer properties that could be covered by these materials ranged from 0.05x1010 to 2.00x1010mol/m2sPa for PeO2 and up to 18.0 for S. These ranges are much larger than conventional plastics that exhibit PeO2 from 0.10x1010 to 0.20x1010mol/m2sPa and S up to 4.5. It was demonstrated from a food-requirements-driven (Tailorpack modelling) and a multiscale film structuring (WG-based composites) approaches, that transfer properties of WG-based films would fit the requirements of the six selected fruits and vegetables better than conventional plastics. Copyright (c) 2012 John Wiley & Sons, Ltd.