Abstract
The impact of pressure-assisted thermal processing (PATP) on selected polymeric food packaging materials was studied. Two commercially available packaging materials called APP (combination of biaxially oriented and PVdC coated polyester with a sealing layer against polypropylene) and BPE (combination of biaxially oriented polyester with coextruded barrier film of the structure polyethylene/EVOH/m-polyethylene) were pressurized at 600 MPa for 10 min, at 70°C. The impact of combined pressure-heat treatment on the change of packaging materials was assessed by SEM (Scanning Electron Microscopy). In addition, visual examination was performed for the treated APP and BPE materials. The results showed that the combined extreme pressure-heat treatments can compromise the integrity of both packaging materials. Opaque areas, delaminations and dark spots were a general consequence of the pressure-assisted thermal processing of tested packaging materials.
Keywords: food packaging materials; pressure-assisted thermal processing; opaque areas; delaminations