Functional barriers: properties and evaluation

• Published in: Food additives and contaminants 2005-10, Vol.22 (10), p.956-967
• Main Authors: Feigenbaum, A, Dole, P, Aucejo, S, Dainelli, D, Cruz Garcia, C. de la, Hankemeier, T, N'Gono, Y, Papaspyrides, C.D, Paseiro, P, Pastorelli, S
• Format: Article
• Language: English
• Subjects: Alkanes - analysis; Biological and medical sciences; Chemical and Process Engineering; Chlorobenzenes - analysis; Dibutyl Phthalate - analysis; diffusivity; Dimethyl Sulfoxide - analysis; Engineering Sciences; Environmental Exposure - adverse effects; Equipment Design; food contact surfaces; Food Contamination; Food engineering; Food industries; Food Packaging; Functional barrier; Fundamental and applied biological sciences. Psychology; Humans; Life Sciences; Molecular Weight; monolayers; multilayers; octanol-water partition coefficients; packaging materials; packaging materials migration; permeability; plastics; Polymers; Polypropylenes; Solubility; Temperature; Time Factors
• ISSN: 0265-203X; 1464-5122
• DOI: 10.1080/02652030500227776

Functional barriers are multilayer structures deemed to prevent migration of some chemicals released by food-contact materials into food. In the area of plastics packaging, different migration behaviours of mono- and multilayer structures are assessed in terms of lag time and of their influence of the solubility of the migrants in food simulants. Whereas barriers to oxygen or to aromas must prevent the diffusion of these compounds under conditions of use, a functional barrier must also be efficient under processing conditions, to prevent diffusion of substances when the polymer layers are in contact at high (processing) temperatures. Diffusion in melted polymers at high temperatures is much slower for glassy polymers, than in polymers that are rubbery at ambient temperature. To evaluate the behaviour of functional barriers under conditions of use, a set of reference diffusion coefficients in the 40-60 degrees C range were determined for 14 polymers. Conditions for accelerated migration tests are proposed based on worst-case activation energy in the 40-60 degrees C range. For simulation of migration, numerical models are available. The rules derived from the models can be used both by industry (to optimize a material in terms of migration) or by risk assessors. Differences in migration behaviour between mono- and multilayer materials are discussed.