Evaluating and managing the migration of contaminants from cellulosic materials – FoodSafeBioPack

The consortium involves four complementary partners. Two academic laboratories specialized in the study of material transfer and materials in contact with food (INRAe Massy, coordination), and the characterization and modeling of microstructures (University of Grenoble Alpes). The French national reference laboratory on materials in contact with food (LNE, Trappes) and the technical center for paper and board (Grenoble) will combine their experience and expertise to provide practical solutions to the food, paper & board, and retail sectors.

[intermediate results - not final]

The project teams have learned to adapt to the different time scales and concentration ranges involved in the mass transfer of substances from the paper and board to the food. They range from a few seconds to several months, depending on whether volatile substances are studied or not. This adaptation phase is now over. With the thermodynamic model, robust strategies will be set up to study the two extreme transfer mechanisms: transfers via the gas phase without recondensation and recondensation. The first mechanism is confirmed in commercial samples where the already advanced contamination does not evolve significantly over time and remains uniformly distributed. The second mechanism can be activated by temperature and by causing air circulation in the fibrous network. This mechanism will be demonstrated in a dedicated migration cell and in desorption microbalance. The possible role of a slow mass transfer mechanism will be investigated on dry foods with the long-term ongoing tests on commercial products. Microscopic sorption/desorption, surface diffusion, and transport through the gas phase work are integrated currently integrated into a structure-property model that will allow the prediction of the apparent diffusivities from the spatial organization and compaction of the fibers. Apparent diffusivities are measured on reference materials and substances for model validation. The publication of the project's first results will be drafted soon and discussed with the professionals participating in the steering committee.

The results and deliverables (28) will support the harmonization of regulations for paper and board for food contact in Europe and future testing standards. The development of new types of eco-designed and safe packaging is within reach, especially as one of the partners already patented the wet deposition technology for MFCs. The cost is 2 to 4 times cheaper than a solution with a plastic layer. The structure-property relationships and computer-aided evaluation will optimize the MFCs for packaging, overpackaging, and dry or fatty foods.

Publications are to come.

Our societies are at a crossroads between several alternatives. The end of single plastic packaging is scheduled in France (~2030) and Europe (~2040). Cellulosic materials such as paper and cardboard are today the only viable bio-sourced alternative, biodegradable and already 70% recycled, which can reach a mass market. The contamination of recycled cellulosic fibers with a fraction of carcinogenic substances from printing inks and solvents has, however, become a major concern for consumer health. The German (2017, 2019) and French (2019) authorities have activated the precautionary principle to reduce our exposure to these substances. The situation can be described as critical because the transfer to food can occur without contact, through the plastic layers. Both primary and secondary packaging (American crate) and transport packaging are sources of contaminants. Current analytical techniques can hardly assess the level of contamination of food products on the market because of their lack of sensitivity and the presence of food constituents hindering their detection.

The FOODSAFEBIOPACK project offers THREE significant contributions. (1) The transfer conditions will be exhaustively qualified by food type and modality for packaged foods sampled from the market by using a new design of migration cells enabling humidity control, freezing, and oven heating. (2) The relationships between the structure of fibrous assemblages, the structure and composition of foods, and the transfer mechanisms of complex mixtures of substances from printing inks will be investigated from the nanoscale (20 nm) to the macroscopic scale using novel nano/micro-tomographic techniques, multispectral imaging and multi-scale numerical simulations. (3) A preventive and comprehensive approach to the risk of contamination will be proposed thanks to a water-based deposition of microfibrillated cellulose (MFC). This technological solution not only preserves the recyclability and initial biodegradability of the materials but also greatly improves the barrier properties of the fibrous materials to liquids and gases to compete directly with plastic materials. The MFC layer sizing and risk assessment rules will be integrated into predictive tools compatible with the approaches already used to demonstrate compliance of plastic packaging (10/2011/EC) or to design food packaging.

The results and deliverables (28) will support the harmonization of regulations for paper and board for food contact in Europe, as well as future testing standards. The development of new types of eco-designed and safe packaging is within reach, especially as the wet deposition technology for MFCs is already patented by one of the partners. The cost is 2 to 4 times cheaper than a solution with a plastic layer. The structure-property relationships and computer-aided evaluation will allow the MFCs to be optimized for packaging, overpackaging, and dry or fatty foods.

The consortium involves four complementary partners. Two academic laboratories specialized in the study of material transfer and materials in contact with food (INRAe Massy, coordination), and the characterization and modeling of microstructures (University of Grenoble Alpes). The French national reference laboratory on materials in contact with food (LNE, Trappes) and the technical center for paper and board (Grenoble) will combine their experience and expertise to provide practical solutions to the food, paper & board, and retail sectors.