On the use of vibrational spectroscopy to characterize the structure and aroma barrier of food packaging polymers

High barrier polymers are of increasing interest and use in nowadays food packaging applications. The reason for that is packaging being more often regarded as a very efficient and convenient means of preserving foodstuffs from deterioration during products handling, transport and shelf-life. This study reports on some novel morphological characterization aspects by means of vibrational spectroscopy of one of the most widely used families of high gas and aroma barrier materials in commercial food packaging, i.e. the ethylene-vinyl alcohol copolymers (EVOH). Nevertheless, and as a result of the highly hydrophobic character of the EVOH resins, it is usually low density polyethylene (LDPE) the high water barrier material that is put in direct contact with foods. A description of a simple methodology, yet effective, based on FT-IR to determine diffusion coefficients of aroma components in LDPE is also presented.