Different PET bottles for beer were tested regarding oxygen ingress, loss of carbon dioxide, sensory evaluation and some other analytical parameters like turbidity. The range of bottles consisted of various multilayer techniques with ethylene vinyl alcohol (EVOH), polyamide and scavenger layer, internally and externally coated bottles as well as pure PEN containers. The results show the improved gas barrier properties of all kinds compared with monolyaer PET. The oxygen ingress was reduced to different values, with scavenger multilayer going down to zero ingress during 12 weeks. Carbon dioxide loss of most bottles exceeded 10% of the initial content during the specified shelf life of 6 months. Coated bottles showed significantly better gas barrier properties than multilayer bottles. The scavenger multilayer performed better than the other multilayer techniques. Similar results were obtained with analytical parameters like ITT and turbidity. The sensory analysis results of internally coated bottles were the best of all tested PET bottles. Parallel tests with different screw caps showed a significant improvement of all parameters using a scavenger/barrier liner. This led to a similar shelf life of an internal coated PET bottle with scavenger/barrier screw cap compared with a glass bottle with crown cork.
