Free Fatty Acids from Orange Juice Absorption into Laminated Cartons and their Effects on Adhesion

Orange juice was stored in polyethylene/aluminum foil laminated cartons at 8°C room temperature (RT), 35°C, and 55°C for up to 1 yr. Studies were carried out on the formation of 6 major free fatty acids (FFAs) in orange juice and their absorption into packaging materials during storage. Simultaneously adhesion tests on packaging materials were performed. Depending on storage temperature FFA concentrations increased steadily during storage and they were absorbed (in parallel) into the food contact layer of the packaging materials. Delamination between the plastic layer and aluminum foil occurred when a critical absorption level of 4–5 mg/dm² packaging material (corresponding to a level of 10.5–13.2 mg/cm³ or 1.1–1.4% in the inside polymer layer) was exceeded.