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|Category Catégorie||Publication Date Date de Publication||WP|
Recent crises involving packaging materials (e.g. bisphenol A, 4 methyl-benzophenone, isopropyl thioxanthone,etc.) contribute to undermine consumer confidence in industrial food products. The food industry faces in particular two important technical requirements: developing a packaging material that keeps or improves the shelf-life of food and complying with a highly demanding European legal framework to prevent the contamination of food by packaging constituents. In most cases, the packaging filler (usually a small or medium industry) has indeed very low knowledge on technical specifications of materials from different suppliers and he has no means to control a posteriori or during the production time line their complete design and compliance. Since 2005, the Codex Alimentarius Commission (FAO and WHO) and ISO organization are developing a new harmonized safety framework (ISO 2200x standards) for all classes of hazards (biological, chemical and physical) while covering packaging materials.
The principles are summarized as follows:
- safety is controlled adequately at each step with auditable requirements;
- communications upstream and downstream are supported by a systematic hazard analysis;
- control systems and intervention strategies for reducing risk are defined.
As the new world-wide standard promotes the delivery of packaged food products safe-by-design instead of safe-as-stated, it may be thought superior to or at least more robust than the current European Legislation of plastic materials intended to be in contact with food (Regulations 1935/2004/EC and 10/2011/EC).
The research aims at:
integrating last research results (e.g. European database transport properties hosted by INRA, mathematical methods…) into primary risk mitigation tools and optimization approaches for packaging design and compliance testing;
contributing to expand predictive approaches to different polymers and thermodynamic conditions (in particular the largest database of activity coefficients will be created from molecular simulations);
tailoring current deterministic and probabilistic approaches to handle seamlessly missing data or large sources of uncertainties (e.g. in case of multi-layer materials, non-isothermal migration conditions);
providing a formal “Failure Modes, Effects, and Criticality Analysis” (FMECA) and its quantitative assessment according to the best knowledge available on physico-chemistry as well as according to four major driven applications (by class of materials, by class of substances, by class of food contact, by class of process and use conditions);
collecting a large rulebase of formulations of food packaging materials on the French market (in addition to additives and monomers, colorants, inks, adhesives, and some nano-filled polymers will be partly covered) and devising a combination of techniques to extract and compare the formulation fingerprints of packaging materials.
The objective is twofold: firstly generating reference formulation finger prints (i.e. major components) of about 100 typical food packaging materials currently on the French market and secondly developing fast deformulation methods to be used routinely by technical laboratories and food companies. Reference deformulation data will be subsequently used to derive realistic formulation rules and to increase a currently missing expertise.
As an example, it is currently unclear whether materials in contact with fatty substances are formulated with different adjuvants and/or with different concentration ranges.
- Reference deformulation of “100 typical materials”
- Rapid deformulation methods
Tough the proposed methodology to replace food packaging “safe by control” or “safe as stated”’ by food packaging “safe by design” relies on very simple principles, it is a new one and is supported by a generalization of the paradigm laid down in the plastics regulation 2011/10/EC. In particular, it tends to be more severe than the current regulation but more robust and flexible in presence of large sources of uncertainty, as required in an engineering approach. Ground rules are sketched hereafter.
Two simple principles can draw the design of materials safe-by-design: preventing the occurrence in the material of substances with a toxicity concern and reducing their migrations in the food.
- Generation of guidelines as risk priorities numbers and knowledge base examples
- Computer-aided criticality analysis
RESULTS: Master's Thesis (Mémoire) and presentation of Audrey Goujon (CV)
The food engineer or the risk assessor will not be the ideal decision maker as he will not be perfectly informed. Moreover, the migration calculations will not be performed with perfect accuracy due to possible large sources of uncertainties. In addition, a methodology that would increase the number of choices could lead to poor decisions. Current expertise on materials, substances, conditions of process/use needs to be “coded” in software and decision rules in an efficient way such that current rational ignorance is identified and clarified.
- Identification of expert rules for design
- Implementation of rules in the engine autoscenario
- Connection with FMECA and ISO 22000 standards
Tracer diffusion coefficients, D, of additive-type molecules in thermoplastics have been addressed in several EU projects and in some academic works, in particular from INRA. A very important result has been highlighted: the scaling relationship of D values with molecular mass, M, written as D∝M-α, does not obey to any already described molecular mechanism.
- Scaling relationships of D values in glassy polymers
- Determination of activation energies close to polymer critical temperatures
Although a much smaller number of partition coefficients (ratio of activity coefficients), K, than D values have been measured, the current situation is more favorable for prediction. Indeed, a tailored generalized Flory-Huggins approach has been devised by INRA and validated to predict ab-initio activity coefficients on polyolefins (with arbitrary crystallinity) and a wide number food simulants. The current method suffers however three main limitations:
- the generalization to other glassy polymers and copolymers is pending,
- handling aqueous simulants still requires a detailed calculation of the radial distribution by classical isobaric molecular dynamics,
- detailed validation on activity coefficients instead of partition coefficients is missing.
By improving current methods while reducing their overall computational costs, 10-50 activity coefficients can be expected to be calculated each day on Massy INRA cluster.
- Collecting experimental activity coefficients in water for additives type molecules
- Collecting partitioning between glassy polymers and common food simulants
- Collecting activation energies for typical partitioning systems
- Extension and optimization of current calculation methods for complex cases (mixtures, copolymers)
- Prediction of partitioning for all non-ionic, positively-listed substances
The reverse migration of gas or volatiles from the food (e.g. aroma, small free fatty acids, CO2, H2O) or from the environment (H2O, peracetic acid used for packaging ddecontamination) can affect in return dramatically the leeching of packaging constituents. When plasticization occurs, the sorption/desorption kinetic may deviate from rules commonly applied without interactions: significant deviation to Henry law, diffusion coefficient varying significantly with local concentration, significant swelling.
The goal of this task is to provide enough scientific evidences on the need of sophistication of the transport equations involved in the general migration model (e.g. is it acceptable for carbonated drinks?, for polar polymer subjected to water swelling?, for polymers in contact with organic substances such as aroma or decontamination substances?).
- Development of Permconnect (an automatic tool to retrieve permeation values from suppliers)
- Creation of database of diffusion coefficients, solubilities and their related activation energies
- Extending current migration engines to tackle uncertainty in transport properties and transport coupling
- Plasticizing effects and its consequences on migration
The “SAFE FOOD PACKAGING DESIGN” framework will inherit the modular and server oriented architecture, developed in SFPP3 by INRA while extending significantly its range of application and its ability to create seamlessly a new enterprise-class application.
- Consolidating available computational sever engines and adding new engines
- EasyInstaller and EasyUpdater: a unified installer and updater for Windows and Linux
- Security requirements and EasyAccountManager
- Consolidation of EasyReport
The current project will enable risk attributes (likelihood, rank, impact) for many migration pathways and for regulated and non-regulated substances. The conventional mitigation of such risks through brainstorming sessions or conceptual scenarios is considered insufficient as it is, at best, a matter of consensus and is not concerted with other governance activities. It follows that the developed approach may be envisioned as an add-on to additional constraints of product design, quality/safety management instead of core-tools that benefit product safety, industry practices and finally consumer. The same criticism may hold for suggesting recommendations towards enforcement and regulatory authorities. In this perspective, a holistic approach is preferred. An appropriate risk management system can therefore be seen as a set of complex relations among several stakeholders including consumers, which involve the sources of risks, the available technologies, industrial practices and tools and finally the regulatory or recommendation measures.
The following principles will be focused:
- Learn the risk. The primary burden is to teach participants what the risk and vulnerabilities are. A performance-based approach will be encouraged to propose cost-efficient and individualized viable solutions.
- Facilitating the communication within the food-packaging sector. The identification of best practices will be identified. Businesses that share sensitive or critical information will be considered via the concept of “safe harbor”.
- Do not lump the issues. Needs between stakeholders (compliance, audit, supplier selection, certification, and standardization/harmonization) will not be confused.
- Move innovation and engineering practices forward.
- Estimating knowledge about outcomes to prioritize resources and programs
- Direct impact and opinion assessment
- Technical documentation and guidance
- Training sessions
- Integration and communication with existing tools