The influence of alpha-tocopherol concentration on the stability of linoleic acid and the properties of low-density polyethylene

In food packaging applications where low-density polyethylene (LDPE) film c ontaining alpha-tocopherol is used the antioxidant may have a dual function , i.e. to protect the polymer from oxidative degradation during processing, and to delay the onset of oxidation of the packaged foodstuff during stora ge. Incorporation of high levels of alpha-tocopherol into LDPE film was fou nd to inhibit oxidation of a linoleic acid emulsion stored in contact with the film at 6 degrees C. However, the presence of 360 ppm caused changes in mechanical properties and an increase in oxygen transmission. Levels as hi gh as 3400 ppm alpha-tocopherol also caused yellowing and reduction in crys tallinity of the material. Thus, the use of high amounts of alpha-tocophero l in LDPE, which might be needed in active packaging applications, requires careful consideration of the protective requirements for each specific foo d and the maintenance of the desired properties of the packaging material. Copyright (C) 2000 John Wiley & Sons, Ltd.