Polymeric-Based Food Packaging for High-Pressure Processing

Abstract

High-pressure processing (HPP) of foods mainly utilizes flexible packaging materials for commercial products. Many materials have been evaluated for their adequacy in the process. There are a number of integrity requirements for these packaging materials that must be complied with for acceptance and use in different product applications. These include visual integrity, gas permeability, seal and physical strength properties, and global migration of packaging components into the food, some of which are specific to either refrigerated or shelf-stable products. Different laminate options reported in the literature were reviewed in this article with the aim of classifying suitable packaging materials for HPP at both lowand high-temperature conditions according to these requirements. Packaging materials currently utilized in industry are also listed. The suitability of standards to assess requirement deviations after HPP is also discussed. Current scientific literature has shown to lack information on one or more of these requirements to provide a complete picture for their suitability. Studies have shown that EVOH-based and other high-pressure-high-temperaturetreated materials do not follow the barrier requirements established by the US Army for shelf-stable products. However, they still show potential for their utilization in the development of commercial products. The importance of package headspace on package integrity is also highlighted. Studies on transport phenomena such as material sorption and diffusion of components from the food and the pressurization fluid are described. Methods such as SEM, C-SAM, DSC, FT-IR, and X-Ray diffraction provide complementary information to assess the structural and barrier changes observed during HPP. The article concludes by providing preliminary recommendations according to specific requirements that are met after the process. Other types of materials not yet evaluated for HPP are presented as potential alternatives to be explored for this technology.

The Influence of High Pressure Treatment and Thermal Pasteurization on the Surface of Polymeric Packaging Films

“…Because it appears that the influence of HPP on the tensile strength of polymer films is material related we tested the influence of thermal and high pressure induced pasteurization on the tensile strength of the used multi‐layer films, too. In congruence with most other published results the tensile strength was not influenced by any kind of treatment as shown in Table . Because of the dimensions of the tray and a required free clamping length of 50 mm, testing merely could be performed in CD.…”

“…Likewise the tensile strength has not been influenced by any treatment. This is in congruence with most of the other published results . Regarding the enthalpy of melting and the melting temperature of the polymers, no change could be detected for the PP‐BO and the PET‐BO part of the tested multilayer for both treatments.…”

“…The effects of high pressure treatment of packed food on the ‘must‐haves’ of their properties like visual integrity, gas and water vapour barrier and seal strength have been investigated in depth, see the reviews . Also the influence of new combinations such as high pressure, modified atmosphere and packaging design was investigated recently .…”

Influence of selected packaging materials on some quality aspects of pressure-assisted thermally processed carrots during storage

“…Accordingly, packages made using metal, glass, or paper may not be good packaging candidates for use during pressure treatment. Single and combinations of PET, PE, PP, and EVOH films are some of the commonly used as packaging materials for high-pressure pasteurization (Juliano, Koutchma, Sui, Barbosa-Canovas, & Sadler, 2010). Co-extruded films with polymeric barrier layers, adhesive laminated films on a polymer base or inorganic layers such as aluminum foil (a few micrometers thick) or vacuum deposited coating (nanometer levels thick) are also used (Richter, Sterr, Jost, & Langowski, 2010).…”

“…Very limited information is available on impact of combined pressure-heat treatment on packaging material during PATP treatment (Caner, Hernandez, & Pascall, 2000;Galotto et al, 2009;Juliano et al, 2010;Schauwecker, Balasubramaniam, Sadler, Pascall, & Adhikari, 2002). Similarly, the changes in barrier properties of PATP treated packaging materials during extended storage have not been investigated.…”