MIGRATION AND SORPTION PHENOMENA IN PACKAGED FOODS

Rapidly developing analytical capabilities and continuously evolving s tringent regulations have made food/package interactions a subject of intense research. This article focusses on: (1) the migration of packa ge components such as oligomers and monomers, processing aids, additiv es, and residual reactants in to packaged foods, and (2) sorption of f ood components such as flavors, lipids, and moisture into packages. Pr inciples of diffusion and thermodynamics are utilized to describe the mathematics of migration and sorption. Mathematical models are develop ed from first principles, and their applicability is illustrated using numerical simulations and published data. Simulations indicate that a vailable models are system (polymer-penetrant) specific. Furthermore, some models best describe the early stages of migration/sorption, wher eas others should be used for the late stages of these phenomena. Migr ation- and/or sorption-related problems with respect to glass, metal, paper-based and polymeric packaging materials are discussed, and their importance is illustrated using published examples. The effects of mi grating and absorbed components on food safety, quality, and the envir onment are presented for various foods and packaging materials. The im pact of currently popular packaging techniques such as microwavable, o venable, and retortable packaging on migration and sorption are discus sed with examples. Analytical techniques for investigating migration a nd sorption phenomena in food packaging are critically reviewed, with special emphasis on the use and characteristics of food-simulating liq uids (FSLs). Finally, domestic and international regulations concernin g migration in packaged foods, and their impact on food packaging is b riefly presented.