Effect of High-Pressure Food Processing on the Mass Transfer Properties of Selected Packaging Materials

The effect of high-pressure processing (HPP) on the total migration into distilled water and olive oil and on the barrier properties of four complex packaging materials were evaluated. The films were polyethylene/ethylene-vinyl-alcohol/polyethylene (PE/EVOH/PE), metallized polyester/polyethylene, polyester/polyethylene (PET/PE), and polypropylene-SiOx (PPSiOx). Pouches made from these films were filled with food simulants, sealed and then processed at a pressure of 400 MPa for 30 min, at 20 or 60 degrees C. Pouches kept at atmospheric pressure were used as controls. Prior to and after treatment, all films were evaluated for their barrier properties (oxygen transmission rate and water vapour transmission rate) and 'Total' migration into the two food simulants. In the case of water as the food stimulant, a low 'Total' migration was observed and even a lower one after the HPP treatment. In the case of oil as the food simulant, a higher 'Total' migration was found compared to the control as a result of damage to the structures during the HPP treatment. The gas permeability of the films increased after the HPP, compared to the control, due to damages in the structure caused during the treatment. The PET/PE film presented minimum changes in properties after HPP. Copyright (C) 2010 John Wiley & Sons, Ltd.