DEVELOPMENT OF METHODS FOR TESTING BARRIERS IN FOOD-PACKAGING MATERIALS

In some countries recycled materials are not allowed to come into cont act with food without a protective layer such as plastic or virgin fib er. The purpose of this kind of barrier is to reduce migration of subs tances from beyond the barrier to the food. Two methods for studying a functional barrier are described. Both utilize migration cells in whi ch one surface of the test specimen (for example a paper plate) is exp osed to the food simulant. The first method involves the addition of i ndicator substances to the non-food contact layer. The second method i s to measure the migration of substances originally present in the lay ers beyond the functional barrier layer. Several kinds of barrier used in commercial paper plates were studied and differences between them were found.