STUDIES ON FUNCTIONAL BARRIERS TO MIGRATION - USE OF MODEL SUBSTANCESTO INVESTIGATE TRANSFER FROM PAPER AND BOARD PACKAGING TO FOOD

Model substances were incorporated into cartonboard packaging by air-b rush spraying and foods heated in the packaging in order to study the possible routes by which migrants may transfer. Enclosure in a paper b ag for heating was shown to reduce migration to burgers by at least 3- fold compared to direct heating in a cartonboard box. Migration was re duced by 24-92% where the burger was heated in a paper bag placed on t op of a box. There was greater transfer of the more volatile substance s. ''Set-off'' of model substances was shown to occur. Transfer of mod el substances to cartonboard stored in a stack for 3 months was rapid over the first two weeks but then slowed. Substances of boiling point 223-305 degrees C reached equilibrium within the stack over 3 months. Higher boiling point substances did not reach equilibrium over this ti me. There was 17-96% overall loss of model substances from microwave p otato chip packaging with 3-14% transfer to the food, indicating that volatiles can be carried out in steam. The more volatile substances we re lost most readily from the packaging. Substances of boiling point g reater than or equal to 370 degrees C transferred less readily to food s. Transfer to foods was increased by 20-50% where the venting of stea m was impeded. Migration into foods heated in trays with cartonboard s plashguards was shown to be some 10-fold higher where there was direct contact between the food and the lid compared to the situation where there was no direct contact.